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See detailThe basic pattern of activation in motor and sensory temporal tasks: positron emission tomography data
Lejeune, Helga ULg; Maquet, Pierre ULg; Bonnet, Michel et al

in Neuroscience Letters (1997), 235(1-2), 21-24

Positron emission tomography (PET) data were obtained from subjects performing a synchronization task (target duration 2700 ms). A conjunction analysis was run to identify areas prominently activated both ... [more ▼]

Positron emission tomography (PET) data were obtained from subjects performing a synchronization task (target duration 2700 ms). A conjunction analysis was run to identify areas prominently activated both in this task and in a temporal generalization task (target duration 700 ms) used previously. The common pattern of activation included the right prefrontal, inferior parietal and anterior cingulate cortex, the left putamen and the left cerebellar hemisphere. These areas are assumed to play a major role in time processing, in relation to attention and memory mechanisms. [less ▲]

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See detailStereotactic radiation therapy for brain metastases: the Lausanne experience
Zouhair, Abderrahim; Tercier, Nicolas; Fankhauser, Heinz et al

in Bulletin du Cancer. Radiothérapie : Journal de la Société Française du Cancer : Organe de la Société Française de Radiothérapie Oncologique (1997)

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See detailEnhancement of MSH2-MSH3-mediated mismatch repair recognition by the yeast MLH1-PMS1 complex
Habraken, Yvette ULg; Sung, Patrick; Prakash, Louise et al

in Current Biology (1997), 7(10), 790-3

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See detailEIT Observations of the Extreme Ultraviolet Sun
Moses, D.; Clette, Frédéric; Delaboudinière, J.-P. et al

in Solar Physics (1997), 175

The Extreme Ultraviolet Imaging Telescope (EIT) on board the SOHO spacecraft has been operational since 2 January 1996. EIT observes the Sun over a 45 x 45 arc min field of view in four emission line ... [more ▼]

The Extreme Ultraviolet Imaging Telescope (EIT) on board the SOHO spacecraft has been operational since 2 January 1996. EIT observes the Sun over a 45 x 45 arc min field of view in four emission line groups: Feix, x, Fexii, Fexv, and Heii. A post-launch determination of the instrument flatfield, the instrument scattering function, and the instrument aging were necessary for the reduction and analysis of the data. The observed structures and their evolution in each of the four EUV bandpasses are characteristic of the peak emission temperature of the line(s) chosen for that bandpass. Reports on the initial results of a variety of analysis projects demonstrate the range of investigations now underway: EIT provides new observations of the corona in the temperature range of 1 to 2 MK. Temperature studies of the large-scale coronal features extend previous coronagraph work with low-noise temperature maps. Temperatures of radial, extended, plume-like structures in both the polar coronal hole and in a low latitude decaying active region were found to be cooler than the surrounding material. Active region loops were investigated in detail and found to be isothermal for the low loops but hottest at the loop tops for the large loops. [less ▲]

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See detailEIT and LASCO Observations of the Initiation of a Coronal Mass Ejection
Dere, K. P.; Brueckner, G. E.; Howard, R. A. et al

in Solar Physics (1997), 175

We present the first observations of the initiation of a coronal mass ejection (CME) seen on the disk of the Sun. Observations with the EIT experiment on SOHO show that the CME began in a small volume and ... [more ▼]

We present the first observations of the initiation of a coronal mass ejection (CME) seen on the disk of the Sun. Observations with the EIT experiment on SOHO show that the CME began in a small volume and was initially associated with slow motions of prominence material and a small brightening at one end of the prominence. Shortly afterward, the prominence was accelerated to about 100 km s[SUP]-1[/SUP] and was preceded by a bright loop-like structure, which surrounded an emission void, that traveled out into the corona at a velocity of 200 400 km s[SUP]-1[/SUP]. These three components, the prominence, the dark void, and the bright loops are typical of CMEs when seen at distance in the corona and here are shown to be present at the earliest stages of the CME. The event was later observed to traverse the LASCO coronagraphs fields of view from 1.1 to 30 Ro. Of particular interest is the fact that this large-scale event, spanning as much as 70 deg in latitude, originated in a volume with dimensions of roughly 35" (2.5 x 10[SUP]4[/SUP] km). Further, a disturbance that propagated across the disk and a chain of activity near the limb may also be associated with this event as well as a considerable degree of activity near the west limb. [less ▲]

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See detailThe LMC transition star R 84 and the core of the LH 39 OB association.
Heydari-Malayeri, M.; Courbin, F.; Rauw, Grégor ULg et al

in Astronomy and Astrophysics (1997), 326

On the basis of sub-arcsecond imaging obtained at the ESO NTT with SUSI and the ESO ADONIS adaptive optics system at the 3.6m telescope, we resolve and study the core components of the LMC OB association ... [more ▼]

On the basis of sub-arcsecond imaging obtained at the ESO NTT with SUSI and the ESO ADONIS adaptive optics system at the 3.6m telescope, we resolve and study the core components of the LMC OB association LH 39. The central star of the association, the rare transition object R 84, is also investigated using CASPEC echelle spectroscopy at the ESO 3.6m telescope. A new, powerful image restoration code that conserves the fluxes allows us to obtain the magnitudes and colors of the components. We bring out some 30 stars in a ~16"x16" area centered on R 84. At a resolution of 0.19"(FWHM), the closest components to R 84 are shown to be stars #21 and #7 lying at 1.1"NW and 1.7"NW respectively of the transition star. The former is possibly a blue star of V=16.7mag and the latter with its V=17.5mag is the reddest star of the field, after R 84. Star #7 turns out to be too faint to correspond to the red M2 supergiant previously reported to contaminate the spectrum of R 84. If the late-type spectrum is due to a line-of-sight supergiant with a luminosity comparable to R 84, it should lie closer than 0.12" to R 84. The transition star shows spectral variability between 1982 and 1991. We also note some slight radial velocity variations of the Of emission lines over timescales of several years. Furthermore, we derive the spectral types of two of the brightest stars of the cluster, using long slit spectra obtained at the NTT telescope equipped with EMMI, and discuss the apparent absence of O type stars in this association. [less ▲]

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See detailThe Bimodular G57-V577 Polypeptide Chain of the Class B Penicillin-Binding Protein 3 of Escherichia Coli Catalyzes Peptide Bond Formation from Thiolesters and Does Not Catalyze Glycan Chain Polymerization from the Lipid II Intermediate
Adam, Maggy; Fraipont, Claudine ULg; Rhazi, Noureddine ULg et al

in Journal of Bacteriology (1997), 179(19), 6005-6009

Because the specificity profile of the membrane anchor-free G57-V577 penicillin-binding protein 3 (PBP3) of Escherichia coli for a large series of beta-lactam antibiotics is similar to that of the full ... [more ▼]

Because the specificity profile of the membrane anchor-free G57-V577 penicillin-binding protein 3 (PBP3) of Escherichia coli for a large series of beta-lactam antibiotics is similar to that of the full-size membrane-bound PBP, the truncated PBP is expected to adopt the native folded conformation. The truncated PBP3 functions as a thiolesterase. In aqueous media and in the presence of millimolar concentrations of a properly structured amino compound, it catalyzes the aminolysis of the thiolester until completion, suggesting that the penicillin-binding module of PBP3 is designed to catalyze transpeptidation reactions. In contrast, the truncated PBP3 is devoid of glycan polymerization activity on the E. coli lipid II intermediate, suggesting that the non-penicillin-binding module of PBP3 is not a transglycosylase. [less ▲]

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See detailLes états précancéreux de l'endomètre: aspects hormonaux
Foidart, Jean-Michel ULg; Gilliquet, A.; Nondonfaz, N. et al

in Bulletin de l'Académie Nationale de Médecine (1997), 181(7), 1395-4041404-5

The two types of endometrial carcinomas are preceded by precancerous lesions. Type I endometrial carcinomas are most commonly encountered in perimenopausal women with the classical risk factors associated ... [more ▼]

The two types of endometrial carcinomas are preceded by precancerous lesions. Type I endometrial carcinomas are most commonly encountered in perimenopausal women with the classical risk factors associated with estrogen exposure: obesity, multiparity, diabetes, estrogen treatment, ... Hyperplasia (simple, followed by complex forms without cellular atypias and subsequently by complex hyperplasias with cellular transformation) precede such cancers. Estrogens exert a promoting effect on these lesions but do not initiate them. Progesterone and progestins exert a preventive and protective effect. However, the progressive loss of steroidal receptors is correlated to the progression of tissular anomalies and to the onset of cytogenetic anomalies and to mutations of p53 anti-oncogene. The preventive role of progestin is well established, but their curative beneficial effect on atypical precursors forms of endometrial cancers and on endometrial carcinomas remains controversial. The second type of endometrial cancer appears during the postmenopause and is characterized by an increased invasiveness and a poor prognosis, devoid of identifiable risks factors, these aggressive cancers are not preceded by hormone-sensitive precancerous lesions, but by an intra-epithelial endometrial carcinoma. This lesion appears most often in an atrophic endometrium. Finally, the two types of precancerous states are characterized by distinct gene anomalies suggesting two different pathogenic mechanisms of cancerisation. [less ▲]

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See detailPsychrophilic Enzymes: Molecular Basis of Cold Adaptation
Feller, Georges ULg; Gerday, Charles ULg

in Cellular and Molecular Life Sciences : CMLS (1997), 53(10), 830-41

Psychrophilic organisms have successfully colonized polar and alpine regions and are able to grow efficiently at sub-zero temperatures. At the enzymatic level, such organisms have to cope with the ... [more ▼]

Psychrophilic organisms have successfully colonized polar and alpine regions and are able to grow efficiently at sub-zero temperatures. At the enzymatic level, such organisms have to cope with the reduction of chemical reaction rates induced by low temperatures in order to maintain adequate metabolic fluxes. Thermal compensation in cold-adapted enzymes is reached through improved turnover number and catalytic efficiency. This optimization of the catalytic parameters can originate from a highly flexible structure which provides enhanced abilities to undergo conformational changes during catalysis. Thermal instability of cold-adapted enzymes is therefore regarded as a consequence of their conformational flexibility. A survey of the psychrophilic enzymes studied so far reveals only minor alterations of the primary structure when compared to mesophilic or thermophilic homologues. However, all known structural factors and weak interactions involved in protein stability are either reduced in number or modified in order to increase their flexibility. [less ▲]

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See detailThrombangiitis Obliterans (Buerger's Disease): Still a Limb Threatening Disease
VAN DAMME, Hendrik ULg; de Leval, Laurence ULg; CREEMERS, Etienne ULg et al

in Acta Chirurgica Belgica (1997), 97(5), 229-36

A series of 29 well-documented and properly analysed patients with thrombangiitis obliterans (Buerger's disease) is presented. The diagnosis of Buerger's disease was based on following criteria: smoking ... [more ▼]

A series of 29 well-documented and properly analysed patients with thrombangiitis obliterans (Buerger's disease) is presented. The diagnosis of Buerger's disease was based on following criteria: smoking history, onset before the age of 50 years, infrapopliteal arterial occlusive disease, either upper limb involvement or phlebitis migrans, absence of atherosclerotic risk factors other than smoking. In the last 10 years (1986-1996), we identified 29 patients who met these rigid criteria. There were 24 men and 5 women, aged 32.4 years at the moment of the disease first clinical symptom. The cumulative tobacco use averaged 16 pack-years for each patient. The initial symptom was limited gangrene of a toe (n = 9) or a finger (n = 2), foot claudication (n = 6), calf claudication (n = 3), rest pain (n = 3), migratory superficial phlebitis (n = 4), and Raynaud phenomenon (n = 2). Angiography and/or Doppler ultrasound revealed digital, pedal and calf artery involvement in all patients, with proximal extension in ten patients (femoropopliteal in ten, including three cases with external iliac artery involvement). Seven patients had also evidence of upper limb involvement. Histologic proof was available in only seven patients. Only nine patients completely stopped smoking. Treatment was exclusively medical in five cases. Twenty-four underwent sympathectomy (20 at lumbar, and four at thoracic level), with good immediate result in 16. In 11 patients a vascular reconstruction was done (eight femorocrural and three iliofemoral bypasses), with a patency rate of only 36% at two years. Amputation was required in 16 patients (a mean of 2.7 amputations per patient) at one or more levels: toe (n = 19), forefoot (n = 5), below knee (n = 8), above knee (n = 2), finger (n = 3). Two patients ended up with bilateral leg amputation. Overall, 23% (7/30) of the patients required major leg amputation during the course of the disease. Disease progression was moderately related to continued tobacco use. Buerger's disease still entails considerable risk of major amputation. Complete abstinence from tobacco use is crucial to expect stabilization of the process. However, in advanced stages of the disease and despite cessation of smoking recurrent episodes of ischaemia or tissue loss are not excluded. [less ▲]

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See detailComment je traite ... une infection par le VIH. I. Bases pathogéniques des choix thérapeutiques
Moutschen, Michel ULg; Nkoghe, D.; Leonard, Philippe ULg et al

in Revue Médicale de Liège (1997), 52(10), 622-4

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See detailCoil on the loop and selectively enhanced stiffness for improved control: feasibility study in the neonatal ovine model of the large patent ductus arteriosus.
Grabitz, R. G.; Freudenthal, F.; Sigler, M. et al

in Investigative Radiology (1997), 32(10), 636-43

RATIONALE AND OBJECTIVES: Several devices have been suggested and tested for interventional closure of the persistent ductus arteriosus. Coils were found effective only in small ducts due to their lack of ... [more ▼]

RATIONALE AND OBJECTIVES: Several devices have been suggested and tested for interventional closure of the persistent ductus arteriosus. Coils were found effective only in small ducts due to their lack of maneuverability and physical limitation of grip forces leading to risk of embolization. The authors evaluated the feasibility to place single coils with selectively enhanced stiffness into high shunting ductus arteriosus, the coils being deployed and controlled through a veno-arterial loop in a bovine model. METHODS: "Double-cone" shaped, stainless steel coils with enhanced stiffness of the outer rings were mounted on either end on a nitinol core wire. A snap-in mechanism attaches the coil to this delivery wire and is freed by a pusher system of coiled steel wire that is advanced over the core wire. Forming a veno-arterial loop across the patent ductus allows for repositioning into the pulmonary artery or aortic catheter. A chronic lamb model of large patent ductus arteriosus (PDAs) (> or = 9 mm) was used in which ductus patency was secured by a protocol of repetitive angioplasties. Different systems (n = 10) were placed having retrieved the previous coil by a snare after definitive release. RESULTS: Placement of coils was possible in all 10 attempts. The coils were pulled back into the catheters between five and eight times before definitive release. CONCLUSIONS: The device allows controlled placement of single coils in our model of large PDAs and may lead the way to overcome previous limitations of coils. Clinical trials are warranted. [less ▲]

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See detailFormation of nick instabilities due to particle clustering along crystal interfaces
Vandewalle, Nicolas ULg; Ausloos, Marcel ULg; Cloots, Rudi ULg

in Physical Review. E : Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics (1997), 56(4), 4042-4047

The kinetic growth of crystal grains is simulated on a square lattice in the presence of mobile particles. The model is based on the Eden and the dynamic epidemic models. Trapping of the particles by the ... [more ▼]

The kinetic growth of crystal grains is simulated on a square lattice in the presence of mobile particles. The model is based on the Eden and the dynamic epidemic models. Trapping of the particles by the advancing front and a short-range repulsion of the particles by the front are both allowed. The grain boundary morphology is studied through the kink density concept and the spatial distribution of particles is discussed. Indeed, the clustering of particles along the crystal edges is found to induce the formation of so-called nick instabilities at the liquid-solid interface. The particles, when trapped near such instabilities, occur as oblique filamentary structures in the crystal matrix, just like river networks. These findings agree with recent experimental observations. The numerical laws are also explained by theoretical arguments based on different characteristic lengths. [less ▲]

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See detailGenetic disorders and cerebellar structural abnormalities in childhood
RAMAEKERS, Vincent ULg; Heimann, G.; Reul, J. et al

in Brain : a journal of neurology (1997), 120 ( Pt 10)

Amongst 78 patients with either unilateral or bilateral (ponto-) cerebellar hypoplasia, atrophy or lesions on neuro-imaging (CT and/or MRI), 16 showed unilateral hypoplasia or lesions, 15 vermis defects ... [more ▼]

Amongst 78 patients with either unilateral or bilateral (ponto-) cerebellar hypoplasia, atrophy or lesions on neuro-imaging (CT and/or MRI), 16 showed unilateral hypoplasia or lesions, 15 vermis defects, nine pontocerebellar hypoplasia, 10 non-progressive conditions with bilateral cerebellar hemisphere hypoplasia or lesions and 28 progressive cerebellar atrophy. Known genetic conditions did not occur with unilateral cerebellar involvement, whereas a high incidence of mostly autosomal recessively inherited diseases could be diagnosed in more than half of the patients with either pontocerebellar hypoplasia or progressive bilateral cerebellar atrophy. A minority of patients with vermis defects or non-progressive cerebellar hypoplasia suffered from genetic conditions. An overview of the literature is presented describing genetic and non-genetic syndromes, or metabolic disorders associated with cerebellar structural abnormalities. From these data, new proposals for improved diagnostic investigations will be presented. [less ▲]

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See detailTwo years of replacement therapy in adults with growth hormone deficiency.
Verhelst, J.; Abs, R.; Vandeweghe, M. et al

in Clinical Endocrinology (1997), 47(4), 485-494

OBJECTIVES: Although several studies have shown beneficial short-term effects of recombinant human growth hormone (rhGH) therapy in adult GH deficient (GHD) patients, few data are available on large ... [more ▼]

OBJECTIVES: Although several studies have shown beneficial short-term effects of recombinant human growth hormone (rhGH) therapy in adult GH deficient (GHD) patients, few data are available on large groups of patients treated for more than one year. In addition, the optimal dose of rhGH for each patient and the baseline parameters that predict which patients will benefit most from therapy or will have adverse events are not entirely elucidated. DESIGN: 148 adult GHD patients were enrolled in a multicentre 2-year rhGH replacement study which was placebo controlled for the first six months. rhGH (Genotropin/Genotonorm Pharmacia & Upjohn) was given in a dose of 0.25 IU/kg/week sc (1.5 IU/m2/day). MEASUREMENTS: Every 3-6 months body composition was measured using body impedance analysis and general well being was assessed using the Nottingham Health Profile (NHP) and social self-reporting questionnaire. At the same time patients had a full clinical examination and blood was sampled for glucose, HbA1c, IGF-1, creatinine, full blood count, thyroid hormones and liver function tests. RESULTS: With rhGH therapy IGF-1 levels increased from -2.00 +/- 2.60 SDS to 1.47 +/- 2.6 SDS after six months (P < 0.001), continued to rise despite no change in dose to 1.84 +/- 2.8 SDS after one year and remained constant thereafter (1.98 +/- 2.4 after 2 years). 56% of patients ultimately attained supranormal IGF-1 levels (+2 SD), 22% had levels below the mean, of which 9% were below -2 SD. Within 3 months lean body mass (LBM) increased by +5.09% (P < 0.001), total body water (TBW) by +5.40% (P < 0.001), while body fat (BF) dropped by -10.89% (P < 0.001) and waist circumference by -1.42% (P < 0.004). These effects were maintained during the first year of therapy, but the effect was attenuated after 24 months: LBM, +3.91% (P < 0.001); TBW, +3.28%, P < 0.001, BF, -6.42% (P < 0.001) and waist -2.22% (P < 0.009). Individual differences in response were large and could not be predicted by any of the baseline parameters, except for a better response in males. Treatment resulted in a large and progressive improvement on the NHP scale, especially energy, emotions and sleep, but a similar change was also found in patients during placebo treatment. With rhGH the number of full days of sick leave/6 months decreased from 12.17 +/- 3.90 days (SEM) to 7.15 +/- 3.50 days after six months (P = 0.009), 2.93 +/- 1.55 days after 12 months (P = 0.01), 0.39 +/- 0.17 days after 18 months (P < 0.001) and 3.3 +/- 2.51 days after 24 months (P = 0.026). Similarly, the hospitalization rate went down from 14.9 to 7% after 6 months and remained at this level thereafter (P = 0.12). About one third of patients on rhGH experienced fluid-related adverse events, most often within the first 3 months. They usually disappeared spontaneously or responded well to dose reduction. Cumulative dropout rates were 29% after 1 year and 38% after two years. Two thirds of these patients stopped treatment because of insufficient subjective improvement. Neither drop-outs nor fluid retention could not be predicted by any of the baseline parameters. CONCLUSIONS: We confirmed in a large group of patients the beneficial effects of rhGH therapy on body composition, metabolic parameters and general well-being and found a consistent drop in number of sick days and hospitalization rate. These effects were maintained during two years of therapy, except for an attenuation in body composition changes after 24 months. The high incidence of fluid-related adverse events suggests that it may be better to start with lower doses of rhGH and to increase the dose more slowly over a number of weeks. The finding of suboptimal high or low IGF-1 levels in many patients reinforces guidelines not to give rhGH in a weight-dependent dose but to titrate it individually for each patient. [less ▲]

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See detailZolmitriptan (Zomig, 311c90), a Novel Dual Central and Peripheral 5ht1b/1d Agonist: An Overview of Efficacy
Schoenen, Jean ULg; Sawyer, J.

in Cephalalgia : An International Journal of Headache (1997), 17(Suppl 18), 28-40

The efficacy of zolmitriptan (Zomig, 311C90), a 5-hydroxytryptamine (5HT)1B/1D receptor agonist, in the acute oral treatment of migraine was evaluated in an extensive clinical trial program. Four ... [more ▼]

The efficacy of zolmitriptan (Zomig, 311C90), a 5-hydroxytryptamine (5HT)1B/1D receptor agonist, in the acute oral treatment of migraine was evaluated in an extensive clinical trial program. Four randomized, placebo-controlled studies (total 2480 patients) were performed; data from two of these trials established that a 2.5 mg dose was on the shoulder of the dose-response curve (2-h headache response rate 64%), showing similar efficacy to the 5 mg dose (67%). In this program, the efficacy of zolmitriptan was not influenced by the pretreatment headache duration; the presence of aura preceding the headache, migraine associated with menses or migraine upon awakening; or by concomitant use of oral contraceptives or antidepressants. In addition, zolmitriptan 5 mg proved consistently effective in the treatment of multiple migraine attacks for up to 1 year. Zolmitriptan reduced the incidence of nausea, photophobia and phonophobia, reduced impairment of normal activity and demonstrated positive effects on patients' quality of life. Thus, zolmitriptan is a highly effective acute oral antimigraine therapy, with 2.5 mg providing the optimal balance between efficacy and tolerability. [less ▲]

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See detailDifferentiation between begnin and malignant breast lesions with MR imaging and scintimammography
Servais, Fabienne; Blocklet, Didier; Seret, Alain ULg et al

in Radiology (1997), 205(1), 283

No abstract for this letter.

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See detailEffects of Dopamine Agonists on Appetitive and Consummatory Male Sexual Behavior in Japanese Quail
Castagna, C.; Ball, G. F.; Balthazart, Jacques ULg

in Pharmacology, Biochemistry & Behavior (1997), 58(2), 403-14

The effects of pharmacological manipulations of dopaminergic transmission on appetitive and consummatory aspects of male sexual behavior were investigated in castrated male Japanese quail treated with ... [more ▼]

The effects of pharmacological manipulations of dopaminergic transmission on appetitive and consummatory aspects of male sexual behavior were investigated in castrated male Japanese quail treated with exogenous testosterone. Appetitive male sexual behavior was assessed by measuring a learned social proximity response and consummatory behavior was assessed by measuring copulatory behavior per se. The nonselective dopamine receptor agonist, apomorphine, inhibited in a dose-dependent manner both components of male sexual behavior. Two indirect dopamine agonists were also tested. Nomifensine, a dopamine re-uptake inhibitor, decreased appetitive sexual behavior but increased the frequency of mount attempts, a measure of consummatory sexual behavior. Amfonelic acid, a compound that enhances dopaminergic tone by a complex mechanism, increased aspects of both appetitive and consummatory behaviors. These data suggest that, in quail, as in rodents, increases in dopaminergic tone facilitate both appetitive and consummatory aspects of male sexual behavior. Apomorphine may be inhibitory in quail because it acts primarily on D2-like receptors, unlike in rats, where it stimulates sexual behavior and acts primarily on D1-like receptors at low doses but interacts with D2-like receptors at higher doses. This is supported by the observation that stereotyped pecking, a behavior stimulated selectively in quail by D2 agonists, was increased by apomorphine but not by the two indirect agonists. The observed partial dissociation between the effects of these dopaminergic agonists on appetitive and consummatory sexual behaviors suggests that these two components of male sexual behavior may be controlled by the action of dopamine through different neuronal systems. [less ▲]

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See detailCognitive and motor development in preschool and school-aged children after neonatal arterial switch operation
Hovels-Gurich, H. H.; SEGHAYE, Marie-Christine ULg; Dabritz, S. et al

in Journal of Thoracic and Cardiovascular Surgery (The) (1997), 114(4), 578-85

OBJECTIVE: The developmental status of children beyond 3 years of age after the neonatal arterial switch operation has not yet been systematically evaluated and is the topic of the present work. METHODS ... [more ▼]

OBJECTIVE: The developmental status of children beyond 3 years of age after the neonatal arterial switch operation has not yet been systematically evaluated and is the topic of the present work. METHODS: Seventy-seven unselected children operated on as neonates with combined deep hypothermic circulatory arrest and low-flow cardiopulmonary bypass were examined at an age of 3.2 to 9.4 years (5.4 +/- 1.6 years, mean +/- standard deviation). Clinical neurologic status, standard scores of intelligence, acquired abilities and vocabulary, and standardized tests on gross motor and fine motor functions were carried out, and the results were related to preoperative, perioperative, and postoperative status and management. RESULTS: Neurologic impairment was more frequent (9.1%) than in the normal population. Intelligence was not different in these patients compared with normal children (p = 0.11), but motor function, vocabulary, and acquired abilities were poorer. Reduced intelligence was found in 9.1%, fine motor dysfunction in 22.1%, and gross motor dysfunction in 23.4% of the children. Intelligence was weakly but significantly inversely related to the duration of bypass (Spearman correlation coefficient -0.25, p = 0.03) and tended to be inversely related to the duration of circulatory arrest (-0.21, p = 0.07), but not to core cooling time on bypass or degree of hypothermia. Gross motor function, vocabulary, and acquired abilities were not significantly related to any of the perioperative parameters considered. No correlation was found between the test results and the variables perinatal asphyxia, perioperative and postoperative cardiocirculatory insufficiency, resuscitation events, and plexal or intraventricular cerebral hemorrhage. CONCLUSIONS: The neonatal arterial switch operation with combined circulatory arrest and low-flow bypass in our experience is associated with neurologic as well as fine and gross motor impairment but appears to be well tolerated concerning cognitive functions as based on formal intelligence testing. [less ▲]

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See detailCardiological and general health status in preschool- and school-age children after neonatal arterial switch operation
Hovels-Gurich, H. H.; SEGHAYE, Marie-Christine ULg; Dabritz, S. et al

in European Journal of Cardio - Thoracic Surgery (1997), 12(4), 593-601

OBJECTIVE: Cardiological and general health status 3-9 years after neonatal arterial switch operation for transposition of the great arteries should be evaluated by non-invasive methods. METHODS: A total ... [more ▼]

OBJECTIVE: Cardiological and general health status 3-9 years after neonatal arterial switch operation for transposition of the great arteries should be evaluated by non-invasive methods. METHODS: A total of 77 unselected children with intact ventricular septum (75.3%) or ventricular septal defect (24.7%) without or with aortic isthmic stenosis (5.2%) were prospectively examined 3.2-9.4 years (5.4 +/- 1.6) after neonatal switch. Clinical pediatric and cardiological examination, standard and 24 h Holter electrocardiogram, M-mode, 2D-, Doppler and colour Doppler echocardiography were performed. Outcome data were compared to published normals. RESULTS: Reoperation rate was 2.6%, 96.1% were without limitation of physical activity and 98.7% without medication. Compared to normals, growth was adequate, weight and head circumference were slightly reduced. After median sternotomy, 23.4% had abnormal thoracic configuration (16.9% asymmetry, 6.5% funnel chest). ECG and Holter: 93.5% were in sinus, 6.5% in ectopic atrial or junctional rhythm. Incidence of complete right bundle branch block was 15.8% in patients with ventricular septal defect and 5.2% in those without. Ischemic ST-T changes during exercise due to coronary artery occlusion and evidence of old myocardial infarction were found in 1 patient (1.3%) each. Occasional atrial ectopy was found in 27.4%, ventricular ectopy in 15.3%: occasional in 12.5% and frequent (> 30/h) in 2.8% presenting bigemini, couplets and short runs of ventricular tachycardia at rest and during exercise. Echocardiography: Left ventricular function was normal in all. Endsystolic diameter of neoaortic valve annulus was beyond 90% confidence interval for controls in 79.2%, neoaortic root diameter in 100%. Mild aortic insufficiency was seen in 10.4%. No correlation was found between aortic insufficiency and aortic dilatation. Neoaortic stenosis was not seen, mild residual coarctation after end-to-end-anastomosis was found in 2.6%, native coarctation corrected later on in 1.3%. Supravalvular pulmonary stenosis was seen in 29.9% (19.5% trivial, 7.8% mild, 2.6% moderate), mild subvalvular pulmonary stenosis in 1.3%, pulmonary insufficiency in 2.6%. CONCLUSION: The study confirms good midterm results after neonatal arterial switch operation for transposition with or without ventricular septal defect. Long-term observation is necessary to assess rhythm, coronary artery and myocardial function as well as development of neo-aorta and pulmonary artery system. [less ▲]

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See detailLe cas clinique du mois. A propos d'un cas d'hypothermie accidentelle
Fraipont, V.; Finianos, Lucien ULg; Albert, Franz ULg et al

in Revue Médicale de Liège (1997), 52(10), 625-30

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See detailElectron Spin Resonance Evidence of the Generation of Superoxide Anion, Hydroxyl Radical and Singlet Oxygen During the Photohemolysis of Human Erythrocytes with Bacteriochlorin A
Hoebeke, Maryse ULg; Schuitmaker, H. J.; Jannink, L. E. et al

in Photochemistry & Photobiology (1997), 66(4), 502-8

Photodynamic therapy with bacteriochlorin a (BCA) as sensitizer induces damage to red blood cells in vivo. To assess the extent of the contributuion of reactive oxygen species (ROS) and to determine a ... [more ▼]

Photodynamic therapy with bacteriochlorin a (BCA) as sensitizer induces damage to red blood cells in vivo. To assess the extent of the contributuion of reactive oxygen species (ROS) and to determine a possible reaction mechanism, competition experiments with assorted ROS quenching or/and enhancing agents were performed in human erythrocytes as model system and in phosphate buffer. In the erythrocyte experiments, a 2% suspension was incubated with BCA for 1 h, washed with phosphate-buffered saline, resuspended and subsequently illuminated with a diode laser using a fluence rate of 2.65 mW/cm2. Potassium leakage and hemolysis were light and BCA dose dependent. Adding tryptophan (3.3 mM), azide (1 mM) or histidine (10 mM) to the erythrocyte suspension before illumination delayed the onset of K-leakage and hemolysis suggesting a type II mechanism. The D2O did not affect K-leakage nor photohemolysis. Adding mannitol (13.3 mM) or glycerol (300 nM) also caused a delay in the onset of K-leakage and hemolysis, suggesting the involvement of radicals. In phosphate buffer experiments, it was shown using electron spin resonance (ESR) associated with spin-trapping techniques that BCA is able to generate O2-. and OH. radicals without production of aqueous electron. Visible or UV irradiation of the dye in the presence of the spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) gave an ESR spectrum characteristic of the DMPO-hydroxyl radical spin adduct DMPO-OH. Addition of ethanol or sodium formate produced supplementary hyperfine splittings due to the respective CH3CHOH. and CO2-. radical adducts, indicating the presence of free OH.. Production of DMPO-OH was partly inhibited by superoxide dismutase (SOD), catalase and desferrioxamine, suggesting that the iron-catalyzed decomposition of H2O2 was partly involved in the formation of one part of the observed OH.. The complementary inhibition of DMPO-OH production by azide and 9,10-anthracenedipropionic acid (ADPA) was consistent with 1O2 production by BCA followed by reaction of 1O2 with DMPO and decay of the intermediate complex to form DMPO-OH and free OH.. All our results seem to indicate that BCA is a 50%/50% type 1/type 2 sensitizer in buffered aqueous solutions and confirmed that the dye-induced hemolysis of erythrocytes was cell caused by a mixed type 1/type 2 mechanism. [less ▲]

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See detailCarotid Chemodectomas. Experience with Nine Cases with Reference to Preoperative Embolization and Malignancy
Defraigne, Jean-Olivier ULg; Sakalihasan, Natzi ULg; Antoine, Paul ULg et al

in Acta Chirurgica Belgica (1997), 97(5), 220-8

The medical records of nine patients (five female and four male, mean age 58 +/- 5 years) presenting with a carotid chemodectoma between 1983 and 1995 were reviewed. In two cases (22%) the diagnostic was ... [more ▼]

The medical records of nine patients (five female and four male, mean age 58 +/- 5 years) presenting with a carotid chemodectoma between 1983 and 1995 were reviewed. In two cases (22%) the diagnostic was not suspected at the time of initial presentation. The most common complaint was a swelling in the anterolateral region of the neck. One patient (11%) presented with a preoperative peripheral nerves deficits (vagus and hypoglossal palsies and Horner's syndrome). Two tumours were embolized preoperatively with polyvinyl alcohol particles. Complete surgical excision was possible in each patient and the plane of resection was adventitial. In three cases, early ligation of the external carotid artery facilitated the resection. In two patients, the vagus nerve was sacrificed because of tumour involvement. No operative mortality was observed and no vascular complication occurred. In addition to the patient with preoperative neurologic symptoms, three patients developed peripheral nerve deficits (vagus and hypoglossal nerves) postoperatively. Two of these deficits were transient. These peripheral neurologic complications were observed with the largest tumour sizes. Two cases were malignant (lymph nodes and bony metastases). These two patients received postoperative radiotherapy. The mean follow-up period 63 +/- 19 months. No patient developed local recurrence during the follow-up. Two patients died during the follow-up, one for condition unrelated to their disease and the second from metastatic dissemination. In conclusion, carotid chemodectomas may be safely resected. The best way to minimize the rate of complications is to operate them at an early stage of evolution. [less ▲]

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See detailA High Serum Concentration of Interleukin-6 Is Predictive of Relapse in Quiescent Crohn's Disease
Louis, Edouard ULg; Belaiche, Jacques ULg; Van Kemseke, Catherine ULg et al

in European Journal of Gastroenterology & Hepatology (1997), 9(10), 939-44

BACKGROUND/AIMS: Relapses of Crohn's disease are difficult to predict. We assessed the value of serum level of interleukin-6, tumour necrosis factor alpha (TNF-alpha) and soluble TNF receptors as ... [more ▼]

BACKGROUND/AIMS: Relapses of Crohn's disease are difficult to predict. We assessed the value of serum level of interleukin-6, tumour necrosis factor alpha (TNF-alpha) and soluble TNF receptors as predictors of relapse in quiescent Crohn's disease. PATIENTS/METHODS: Thirty-six patients with inactive Crohn's disease, treated or not, were included. Various clinical and biological parameters, including interleukin-6, TNF-alpha and soluble TNF receptors serum levels were measured at inclusion in the study and the patients were followed clinically for 1 year. The relapse was defined as a Crohn's Disease Activity Index (CDAI) greater than 150 with an increase greater than 100 compared to the inclusion value. We analysed the ability of these parameters to predict relapse in parallel to clinical characteristics and other laboratory parameters. RESULTS: Among the 32 variables tested, interleukin-6 serum level had the greatest ability to predict the time-to-relapse, with 17-fold chance of relapse over a 1-year period for patients with an interleukin-6 serum level greater than 20 pg/ml than for patients with a lower level (P < 0.001). A high serum level of the soluble TNF receptors p55 and p75 also had significant predictive value, in contrast to TNF-alpha serum levels. An interleukin-6 serum level greater than 20 pg/ml and either an acid alpha-1-glycoprotein level greater than 1.1 g/l or a soluble interleukin-2 receptor serum level greater than 95 pM/l were risk factors selected by a stepwise multivariate analysis. In both models a good prognosis group was defined by the absence of the two risk factors, a bad prognostic group by the presence of the two risk factors and an intermediate in between. With both models, the good prognosis group included 17 patients who experienced no relapse over the 1-year follow-up, whereas all patients (seven with the first model and six with the second) in the bad prognosis group had a relapse during the follow-up. Looking specifically at two homogeneous subgroups including either naturally/5-aminosalicylic acid (5-ASA) quiescent or corticoid quiescent patients, a very good predictive value for interleukin-6 serum concentration was also found. CONCLUSION: Interleukin-6 serum level alone or in association with other biological parameters such as acid alpha-1-glycoprotein or the soluble interleukin-2 receptor serum level may be useful for predicting the course of the disease in patients with quiescent Crohn's disease. [less ▲]

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See detailAutomated Determination of Tramadol Enantiomers in Human Plasma Using Solid-Phase Extraction in Combination with Chiral Liquid Chromatography
Ceccato, Attilio ULg; Chiap, Patrice ULg; Hubert, Philippe ULg et al

in Journal of Chromatography. B : Biomedical Sciences and Applications (1997), 698(1-2), 161-70

A sensitive and automated method for the separation and individual determination of tramadol enantiomers in plasma has been developed using solid-phase extraction (SPE) on disposable extraction cartridges ... [more ▼]

A sensitive and automated method for the separation and individual determination of tramadol enantiomers in plasma has been developed using solid-phase extraction (SPE) on disposable extraction cartridges (DECs) in combination with chiral liquid chromatography (LC). The SPE operations were performed automatically by means of a sample processor equipped with a robotic arm (ASPEC system). The DEC filled with ethyl silica (50 mg) was first conditioned with methanol and phosphate buffer, pH 7.4. A 1.0-ml volume of plasma was then applied on the DEC. The washing step was performed with the same buffer. The analytes were eluted with 0.15 ml of methanol, and 0.35 ml of phosphate buffer, pH 6.0, containing sodium perchlorate (0.2 M) were added to the extract before injection into the LC system. The enantiomeric separation of tramadol was achieved using a Chiralcel OD-R column containing cellulose tris-(3,5-dimethylphenylcarbamate) as chiral stationary phase. The mobile phase was a mixture of phosphate buffer, pH 6.0, containing sodium perchlorate (0.2 M) and acetonitrile (75:25). The mobile-phase pH and the NaClO4 concentration were optimized with respect to enantiomeric resolution. The method developed was validated. Recoveries for both enantiomers of tramadol were about 100%. The method was found to be linear in the 2.5-150 ng/ml concentration range [r2=0.999 for (+)- and (-)-tramadol]. The repeatability and intermediate precision at a concentration of 50 ng/ml were 6.5 and 8.7% for (+)-tramadol and 6.1 and 7.6% for (-)-tramadol, respectively. [less ▲]

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See detailMacromolecular engineering of lactones and lactides. 24. Controlled synthesis of (R,S)-β-butyrolactone-b-ε-caprolactone block copolymers by anionic and coordination polymerization
Kurcok, Piotr; Dubois, Philippe ULg; Sikorska, Wanda et al

in Macromolecules (1997), 30(19), 5591-5595

Block copolymers of (R,S)-β-butyrolactone and ε-caprolactone have been synthesized by combining the anionic polymerization of the first monomer with the coordinative ring-opening polymerization of the ... [more ▼]

Block copolymers of (R,S)-β-butyrolactone and ε-caprolactone have been synthesized by combining the anionic polymerization of the first monomer with the coordinative ring-opening polymerization of the second one. The copolymerization yield is close to 100% and the final molecular weight of each sequence can be predicted from the initial monomer-to-initiator molar ratio. The molecular weight distribution of copolymers obtained is quite narrow (Mw/Mn ≤ 1.3). According to NMR and DSC analysis, the polybutyrolactone block is atactic and totally amorphous, in contrast to the polycaprolactone block which is semicrystalline. A partial miscibility of the two blocks in the amorphous phase has however been detected. Thermal and enzymatic degradations of the block copolymers have been investigated. The enzymatic degradation rate promoted by the lipase form Rhizopus arrhizus strongly depends on the copolyester composition and increases with the β-butyrolactone content. [less ▲]

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See detailIntramolecular excited-state processes of a halato-telechelic polymer, evaluated by global compartmental analysis of the fluorescence decay surface with the use of model coumpounds
van Stam, Jan; De Schryver, Frans C; Boens, Noël et al

in Macromolecules (1997), 30(19), 5582-5590

The excited-state processes of the halato-telechelic polymer bis[(N,N-dimethyl-N-[3-(1-pyrenyl)propyl]ammonio)trifluoromethanesulfonate]-end-capped poly(tetrahydrofuran) at low concentrations are ... [more ▼]

The excited-state processes of the halato-telechelic polymer bis[(N,N-dimethyl-N-[3-(1-pyrenyl)propyl]ammonio)trifluoromethanesulfonate]-end-capped poly(tetrahydrofuran) at low concentrations are investigated by time-resolved fluorescence. The photophysical processes can be described by an intramolecular three-state excited-state model. Such a system is not identifiable in the absence of a priori information. It is possible to perform a global compartmental analysis of the fluorescence decay surface using the scanning technique, based on model compound data previously obtained [Hermans et al., J. Phys. Chem. 1994, 98, 13583 and Hermans et al. Macromolecules 1995, 28, 3380]. The value boundaries on the rate constant for ring closure of the chain ends show that this process is close to diffusion-controlled. [less ▲]

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See detailAnionic block copolymerization of 4-vinylpyridine and tert-butyl methacrylate at "elevated" temperature : influence of various additives on the molecular parameters
Creutz, Serge; Teyssié, Philippe; Jérôme, Robert ULg

in Macromolecules (1997), 30(19), 5596-5601

The living anionic polymerization of 4-vinylpyridine (4VP) in 9/1 pyridine/THF at 0 °C has been reported lately (Creutz, S.; Teyssié, Ph.; Jérôme, R. Macromolecules 1997, 30, 1). The success of its block ... [more ▼]

The living anionic polymerization of 4-vinylpyridine (4VP) in 9/1 pyridine/THF at 0 °C has been reported lately (Creutz, S.; Teyssié, Ph.; Jérôme, R. Macromolecules 1997, 30, 1). The success of its block copolymerization with tert-butyl methacrylate (tBMA) has been shown to be dependent on the addition mode, highlighting the difference in reactivity between the two monomers. Moreover, the (co)solvent also strongly influences the fate of that copolymerization. Thus, the impact of various (co)solvents and additives has been investigated more thoroughly, revealing the interesting possibility of modifying the apparent relative reactivities of these two monomers. [less ▲]

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See detailBovine Attaching and Effacing Escherichia Coli Possess a Pathogenesis Island Related to the LEE of the Human Enteropathogenic Escherichia Coli Strain E2348/69
Goffaux, F.; Mainil, Jacques ULg; Pirson, V. et al

in FEMS Microbiology Letters (1997), 154(2), 415-421

Attaching and effacing Escherichia coli (AEEC) has been described as a cause of diarrhea in calves. The molecular pathogenesis of AEEC was mainly studied in human enteropathogenic E. coli strain E2348/69 ... [more ▼]

Attaching and effacing Escherichia coli (AEEC) has been described as a cause of diarrhea in calves. The molecular pathogenesis of AEEC was mainly studied in human enteropathogenic E. coli strain E2348/69 in which the virulence correlated with the presence of a 35.4 kb pathogenesis island called LEE. We showed that several strains isolated from calves with diarrhea were able to produce attaching and effacing lesions in a rabbit ileal loop model and that they possess a pathogenesis island related to the LEE. Moreover, we showed that the LEE from bovine strains was inserted mainly at a different position in the chromosome compared to the human enteropathogenic E. coli strain E2348/69. [less ▲]

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See detailJl 13, a Potential Successor to Clozapine, Is Less Sensitive to Oxidative Phenomena
Liégeois, Jean-François ULg; Mouithys-Mickalad, Ange ULg; Bruhwyler, J. et al

in Biochemical and Biophysical Research Communications (1997), 238(1), 252-5

The oxidation behaviour of JL 13, a promising antipsychotic, was investigated in comparison with clozapine and loxapine, by measuring their direct "radical scavenging" abilities and their efficacies in ... [more ▼]

The oxidation behaviour of JL 13, a promising antipsychotic, was investigated in comparison with clozapine and loxapine, by measuring their direct "radical scavenging" abilities and their efficacies in inhibiting the lipid peroxidation. In the lipid peroxidation system, the reactivity of these compounds with free radicals produced by gamma-irradiation of linoleic acid may be presented as follows: JL 13 = loxapine < clozapine. In two enzymatic systems (HRP/GSH and HRP/H2O2/ GSH) which generate the thiyl free radicals, clozapine produces a strong enhancement of the thiyl-radical EPR signal intensity while JL 13 and loxapine exhibit no or minimal effect on this signal. The redox potential values for the three derivatives confirm the spectro-photometric and EPR results. Following this study, we show that JL 13, although presenting a preclinical clozapine-like profile, appears less sensitive to oxidation than clozapine. [less ▲]

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See detailQuelles causes de justification devant le juge pénal ?
Delnoy, Michel ULg

in Immobilier (1997), 16

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See detailNoms propres d'étoiles.
Renson, Pierre ULg

in Ciel (Le) (1997), 59

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See detailLa restauration de la Grande Lunette Méridienne de l'Observatoire de Cointe.
Gosset, Eric ULg

in Ciel (Le) (1997), 59

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See detailMachine-learning approaches to power-system security assessment
Wehenkel, Louis ULg

in IEEE Expert (1997), 12(5), 60-72

The paper discusses a framework that uses machine learning and other automatic-learning methods to assess power-system security. The framework exploits simulation models in parallel to screen diverse ... [more ▼]

The paper discusses a framework that uses machine learning and other automatic-learning methods to assess power-system security. The framework exploits simulation models in parallel to screen diverse simulation scenarios of a system, yielding a large database. Using data mining techniques, the framework extracts synthetic information about the simulated system's main features from this database [less ▲]

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See detailDescription et commentaire de deux approches méthodologiques de la vidéo-évaluation des stages pratiques en didactique des langues germaniques à l'ULg (II)
Simons, Germain ULg

in Education-Formation (1997), (247), 1-8

Dans cette deuxième partie (voir commentaire ci-dessous), nous décrivons une approche particulière de l'HETEROscopie de la pratique enseignante. Outre le formateur, cet atelier d'évaluation assistée par ... [more ▼]

Dans cette deuxième partie (voir commentaire ci-dessous), nous décrivons une approche particulière de l'HETEROscopie de la pratique enseignante. Outre le formateur, cet atelier d'évaluation assistée par la vidéo regroupe seize personnes : deux enseignants-stagiaires (E-S) qui ont accepté d'être filmés dans le cadre de leurs stages, leurs deux maîtres de stages, et douze E-S. Ces derniers sont amenés à observer, à analyser, à évaluer, sous différents angles, les leçons données par leurs deux collègues. Les deux E-S qui ont été filmés contextualisent le montage-vidéo (max. 20') de leur leçon et précisent les objectifs qu'ils poursuivaient. Les douze E-S sont répartis en quatre groupes de trois. Chaque groupe reçoit la grille d'évaluation utilisée dans le cadre des stages et choisit un foyer d'évaluation spécifique. A l'intérieur des quatre groupes, chaque étudiant a la responsabilité d'un sous-foyer d'évaluation particulier. Une synthèse de l'évaluation est ensuite proposée par un rapporteur de chaque groupe. Pour la deuxième leçon, les trois groupes changent de foyer d'évaluation. Des suggestions prioritaires sont finalement formulées par le formateur, les maîtres de stages et, éventuellement, les collègues E-E. L'article se clôture en examinant l'intégration de ces deux ateliers de vidéo-évaluation (voir commentaire ci-dessous) dans la macro-structure méthodologique de la formation initiale en didactique des langues germaniques à l'ULg. [less ▲]

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See detailLes cysteinyl-leucotrienes: des mediateurs importants dans l'asthme
Louis, Renaud ULg; Neven, I.; Quaedvlieg, Valérie ULg et al

in Revue Médicale de Liège (1997), 52(9), 598-602

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See detailAirway response of horses with COPD to dry powder inhalation of ipratropium bromide
Duvivier, Dominique Hannia; Votion, Dominique ULg; Vandenput, Sandrina ULg et al

in Veterinary Journal (1997), 154(2), 149-53

To determine the effects of the dry powder inhalation (DPI) of ipratropium bromide (ipratropium) on the airways of health horses and the dose-response curve in horses suffering from chronic obstructive ... [more ▼]

To determine the effects of the dry powder inhalation (DPI) of ipratropium bromide (ipratropium) on the airways of health horses and the dose-response curve in horses suffering from chronic obstructive pulmonary disease (COPD) by means of pulmonary function tests, five healthy horses were first studied. Ipratropium (2400 micrograms ipratropium horse-1) was contained in gelatine capsules and administered using a dry powder device connected to an adapted face mask. Pulmonary function tests were recorded before inhalation and 15 and 60 min after inhalation. No modification of pulmonary function was observed. The airway response to ipratropium DPI was then determined in six horses suffering from COPD. To induce airway obstruction, the horses were bedded on straw and fed hay. When the maximal change in pleural pressure during tidal breathing exceeded 1.96 kPa, pulmonary function tests were recorded before DPI, and 15 and 60 min post-inhalation. Placebo (six capsules horse-1) or ipratropium (600, 1200 and 2400 micrograms horse-1) was administered in a randomized order to each horse using the dry powder device and the adapted face mask. Neither ipratropium nor placebo DPI affected respiratory frequency (f) or tidal volume (VT). Inhalation of 600 micrograms ipratropium horse-1 resulted in a delayed decrease of total pulmonary resistance (RL) whereas dynamic compliance (Cdyn) was improved (although not significantly) at both times of measurement when compared with values following placebo inhalation. Simultaneous decreased RL and increased Cdyn, was observed within 15 min after DPI of 1200 micrograms ipratropium horse-1 and persisted for the 1 h duration of the experiment. Doubling the dose also improved pulmonary function but not significantly more than following inhalation of 1200 micrograms ipratropium. No systemic side effects were observed in either group of horses. [less ▲]

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See detailLa transposition corrigée des gros vaisseaux ou double discordance
RADERMECKER, Marc ULg; Limet, Raymond ULg

in Revue Médicale de Liège (1997), 52(9), 603-5

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See detailGenetic Risk in Natural and Medically Assisted Procreation
Koulischer, Lucien ULg; Verloes, Alain ULg; Lesenfants, S. et al

in Early Pregnancy (1997), 3(3), 164-71

Current in vitro fertilization techniques (IVF) including intracytoplasmic sperm injection (ICSI), microepididymal sperm aspiration (MESA) or testicular sperm extraction (TESE) clearly prevent any ... [more ▼]

Current in vitro fertilization techniques (IVF) including intracytoplasmic sperm injection (ICSI), microepididymal sperm aspiration (MESA) or testicular sperm extraction (TESE) clearly prevent any spontaneous choice of ova or spermatozoa. According to the widely admitted concept of gamete selection, pregnancies following IVF, when compared to natural fertilization, could therefore present a higher risk of genetic anomalies. However, no increased fetal or newborn abnormalities are noticed with IVF, except perhaps for sex chromosome aneuploidies. Data from the literature support the view that the uterus is, indeed, the organ where selection mechanisms occur (when they do so), as suggested by Carr in 1971. This selection concerns mainly autosome imbalances; unbalanced conceptuses are aborted. Sex chromosome aneuploidies, apparently, are less prone to natural abortion, but their higher rate of occurrence, as reported in a few series of studies, does not seem to be associated with the IVF procedures. [less ▲]

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See detailExpression of Bone Sialoprotein in Human Lung Cancer
Bellahcene, Akeila ULg; Maloujahmoum, Naïma ULg; Fisher, L. W. et al

in Calcified Tissue International (1997), 61(3), 183-8

Lung cancer belongs to the group of malignant lesions that specifically select bone as secondary implantation site. The molecular bases for this property, defined as osteotropism, is still largely unknown ... [more ▼]

Lung cancer belongs to the group of malignant lesions that specifically select bone as secondary implantation site. The molecular bases for this property, defined as osteotropism, is still largely unknown. The recent demonstration that human breast cancer cells express and attach to bone sialoprotein (BSP), a sulfated phosphoprotein rich in bone and other mineralized tissues, could provide a clue to elucidating bone metastases formation. BSP contains the integrin binding peptide Arg-Gly-Asp (RGD), as well as non-RGD cell attachment domain. Using an immunoperoxidase technique and a specific polyclonal antibody directed against a BSP synthetic peptide, we examined the expression of BSP in 48 lung lesions including 25 squamous carcinoma, 21 adenocarcinoma, and 2 bronchioloalveolar cancers, as well as 38 human ovarian carcinoma that constitute a group of generally nonosteotropic cancers. BSP was not specifically detected in normal lung tissue with the exception of cartilage associated with bronchi. Most of the adenocarcinoma (74%) and all squamous carcinoma of the lung examined exhibited detectable levels of BSP. Staining was mainly cytoplasmic and membrane associated. The two bronchioloalveolar lung cancers examined did not show detectable amounts of BSP. When microcalcifications were observed in pulmonary malignant lesions, they were usually associated with cancer cells expressing BSP. Only 21% of the ovarian cancers examined contained malignant cells with 2+ or 3+ positivity for BSP. We further demonstrated that in 8 of 10 additional lung cancers, BSP was detected at the mRNA level. Our observation is the first demonstration that BSP is expressed in non-small cell lung carcinoma. Lung cancer cells are now the second type of osteotropic malignant cells described to express BSP. Added to the observation that BSP expression is not frequent in ovarian carcinoma, a low osteotropic cancer, our study supports our hypothesis that BSP could play a role in determining the affinity of cancer cells to bone. [less ▲]

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See detailMelting and crystallization of poly(vinylidene fluoride) blended with polyamide 6
Liu, Zhehui; Maréchal, Philippe; Jérôme, Robert ULg

in Polymer (1997), 38(20), 5149-5153

Melting and crystallization of poly(vinylidene fluoride) (PVDF) blended with polyamide 6 (PA6) has been studied by differential scanning calorimetry. The melting of PVDF and PA6 is observed over a small ... [more ▼]

Melting and crystallization of poly(vinylidene fluoride) (PVDF) blended with polyamide 6 (PA6) has been studied by differential scanning calorimetry. The melting of PVDF and PA6 is observed over a small temperature range, i.e. 174 to 181 degrees C and 220 to 230 degrees C, respectively, over the whole blend composition. This observation indicates that PVDF and PA6 are immiscible and do not co-crystallize, although evidence for intermolecular interactions between PVDF and PA6 has been previously reported. Crystallinity of PVDF seems to decrease on addition of the first 30 wt% PA6, although this effect is not so different from the experimental errors. Kinetics of non-isothermal crystallization of pure PVDF and PVDF blends containing 20 and 40 wt% PA6 has been investigated. The crystallization rate of PVDF is not influenced by PA6 in the temperature range 138.5-145 degrees C. At lower temperatures, it is, however, adversely affected by addition of PA6. The non-isothermal crystallization data for PVDF are fitted by the Ozawa equation in the temperature range 131-141 degrees C. The Ozawa index, or Avrami exponent, for pure PVDF decreases from 3 to 1 on decreasing temperature. This observation agrees with the nucleation of PVDF crystals which is heterogeneous, and a decrease from 3 to 1 in the growth dimension. The main effect of PA6 is to restrict the decrease of the Avrami exponent from 3 to 2 on decreasing temperature, more likely due to a slower decrease in the growth dimension. PA6 does not contribute to nucleation although it is phase separated. [less ▲]

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See detailUso di immagini GAC NDVI per la previsione dei rendimenti agricoli in Aree Saheliane
Romanelli, Stefano; Lorenzo, Bottai; Andrea, Di Vecchia et al

in Rivista Italiana di Telerilevamento (1997), 11

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See detailAerosol Deposition in Equine Lungs Following Ultrasonic Nebulisation Versus Jet Aerosol Delivery System
Votion, Dominique ULg; Ghafir, Y.; Munsters, K. et al

in Equine Veterinary Journal (1997), 29(5), 388-393

Therapeutic aerosols pay an increasing role in the treatment of equine respiratory disorders. This route of delivery permits concentration of significant amounts of drugs at the site of action without ... [more ▼]

Therapeutic aerosols pay an increasing role in the treatment of equine respiratory disorders. This route of delivery permits concentration of significant amounts of drugs at the site of action without unwanted high systemic concentration and resultant side effects. The efficiency of such a topical therapy depends on the quantity of inhaled drugs deposited in the lungs and, for some drugs, on the proportion retained in specific parts of the lungs. The objective of this study was to define and to compare quantitative (dose deposited) and qualitative (regional distribution) deposition of an aerosol in the equine lungs, using either a ultrasonic nebuliser (UN) currently used in human medicine or a high pressure jet nebuliser (JN) especially developed for the equine species. This comparison was possible owing to gamma-scintigraphy, a noninvasive technique ideally suited to give information about both total and regional deposition of inhaled drugs in the respiratory tract. The quantitative study did not point out any difference between the 2 systems concerning the activity released from the nebuliser proportionally to the initial loaded dose (mean +/- s.d. 45.95 +/- 4.93% for the UN vs. 46.47 +/- 8.49% for the JN). By contrast, the percentage of the dose released reaching the lungs was significantly lower with the UN compared to the JN (5.09 +/- 0.66% vs. 7.35 +/- 1.96%). The qualitative analysis did not show any significant difference in size of aerosol deposition image between the 2 nebulisers. However peripheral deposition was significantly higher with JN compared to UN. In conclusion, both nebulisers may be used for aerosol therapy in the equine species. The ultrasonic and pneumatic nebulisation achieved drug deposition in the peripheral part of the lungs (i.e. small airways and lung parenchyma). [less ▲]

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See detailDifferential Effects of D1 and D2 Dopamine-Receptor Agonists and Antagonists on Appetitive and Consummatory Aspects of Male Sexual Behavior in Japanese Quail
Balthazart, Jacques ULg; Castagna, C.; Ball, G. F.

in Physiology & Behavior (1997), 62(3), 571-80

Pharmacological studies in Japanese quail based on behavioral tests with a variety of dopaminergic compounds suggest that the activation of D2 dopamine receptors inhibits, and the activation of D1 ... [more ▼]

Pharmacological studies in Japanese quail based on behavioral tests with a variety of dopaminergic compounds suggest that the activation of D2 dopamine receptors inhibits, and the activation of D1 dopamine receptors enhances, appetitive and consummatory components of male sexual behavior. This hypothesis was tested by studying the behavioral effects of specific D1 and D2 dopaminergic-receptor agonists and antagonists in castrated male Japanese quail chronically treated with exogenous testosterone (subcutaneous Silastic implants). The effects of 5 compounds were tested: 1 D1 (SKF38393) and 2 D2 (PPHT and quinpirole) agonists, and 1 D1 (SCH23390) and 1 D2 (Spiperone) antagonist. All compounds were tested at a low and a high dose (0.1 and 1 mg/kg, respectively, for all drugs, except spiperone where the doses were 2 and 10 mg/kg). A consistent effect of all drugs on consummatory sexual behavior was observed: it was stimulated by the D1 agonist and the D2 antagonist, but inhibited by the D1 antagonist and the D2 agonists. Far fewer effects of the treatments were detected on the measures of appetitive behavior. Measures of appetitive behavior were decreased by the 2 D2 agonists, but not affected by the other treatments. These data suggest that male copulatory behavior in quail is stimulated by dopamine acting on D1 receptors, but inhibited by activation of the D2 receptor subtype. The partial dissociation observed between the effects of the same treatments on appetitive and consummatory aspects of sexual behavior also suggests that these 2 behavioral systems may be controlled by the action of dopamine on different neuronal systems. [less ▲]

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See detailComment j'explore ... nouveaux critères pour le diagnostic du diabète sucré
Scheen, A. J.; Paquot, Nicolas ULg; Lefebvre, P. J.

in Revue Médicale de Liège (1997), 52(9), 606-9

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See detailExiste-t-il une relation entre les champs électromagnétiques 50-60 Hz et le risque de cancer?
Crasson, Marion ULg

in Tempo Médical (1997)

Cette publication permet de mieux comprendre à quoi correspond la notion de champs électromagnétiques et d'évaluer les résultats des études épidémiologiques en connaissant leurs principales difficultés ... [more ▼]

Cette publication permet de mieux comprendre à quoi correspond la notion de champs électromagnétiques et d'évaluer les résultats des études épidémiologiques en connaissant leurs principales difficultés méthodologiques et les principales hypothèses concernant l'interaction entre ces champs électromagnétiques et les organismes biologiques. [less ▲]

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See detailL'image du mois. Contraste spontané intracardiaque: facteur de risque d'accidents emboliques artériels
Hoffer, E.; Pierard, Luc ULg

in Revue Médicale de Liège (1997), 52(9), 561

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See detailBulk polymerization of lactides initiated by aluminum isopropoxide. 1. Mechanism and kinetics
Degée, Philippe; Dubois, Philippe ULg; Jérôme, Robert ULg

in Macromolecular Symposia (1997), 123

Commercially available Al isopiopoxide (Al(OiPr)3) has proved to be an efficient initiator for the bulk polymerization of lactide. The ring-opening polymerization proceeds through a "coordination ... [more ▼]

Commercially available Al isopiopoxide (Al(OiPr)3) has proved to be an efficient initiator for the bulk polymerization of lactide. The ring-opening polymerization proceeds through a "coordination-insertion" mechanism and the selective rupture of the acyl-oxygen bond of the monomer Polyester chains are selectively end-capped with an aluminum alkoxide and an isopropoxy group. Therefore, substitution of Al tris(4-penten-1-olate) for Al(OiPr)3 leads to the formation of macromonomers In the temperature range from 110 to 150°C, polymerization is "living", i.e. the molecular weight can be predicted by the initial monomer-to-Al molar ratio and the monomer conversion. The narrower polydispetsity of poly(L,L-lactide) compared to the amorphous poly(D,L-lactide) ( 1.3 compared to 1.9, respectively), both prepared in the bulk, is thought to result from the restricted mobility of the crystallized isotactic polyester chains. When the temperature is increased up to 180°C, inter- and intramolecular transesterification reactions interfere with chain propagation. [less ▲]

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See detailRetrievable patent ductus arteriosus plug for interventional, transvenous occlusion of the patent ductus arteriosus : Evaluation in lambs and preliminary clinical results.
Grabitz, R. G.; Schrader, R.; Sigler, M. et al

in Investigative Radiology (1997), 32(9), 523-8

RATIONALE AND OBJECTIVES: The clinically most widely used devices (Porstmann-plug, Rashkind-umbrella, Botallooccluder) have inherent specific limitations (eg, transarterial approach, residual shunts ... [more ▼]

RATIONALE AND OBJECTIVES: The clinically most widely used devices (Porstmann-plug, Rashkind-umbrella, Botallooccluder) have inherent specific limitations (eg, transarterial approach, residual shunts, limited retrieval). The authors assess practicability, efficacy, and tissue reaction of the new retrievable transvenous plug device for the occlusion of the persistent patent ductus arteriosus (PDA). METHODS: A foam plug (polyvinyl alcohol) is mounted on a titanium core pin where, at both ends, small legs (titanium nickel alloy) with titanium heads are anchored, to ensure safe fixation in the ductus. The device is introduced transvenously through a long sheath (Mullins sheath) and held by a modified biopsy forceps allowing complete retrieval until final release. A common lamb model of large PDAs (n = 11) was used to test for practicability and the histomorphologic outcome. Clinical results were obtained from a consecutive series of 16 patients (aged 13 to 71 years). RESULTS: In all lambs, placement of the plug within the PDA was possible. Histopathology (follow-up 10 to 215 days; mean 112 days) revealed an adequate ingrowing of the device and no pathologic foreign body reaction. The diameter of the human PDAs ranged from 3 to 7 mm (mean 5 mm). The size of the sheath used for introducing the plug (diameter 8 to 16 mm) ranged from 8 to 16 French. Fourteen of 16 PDAs were closed immediately after or on day 1 after implantation, 1 was closed after the 12-month follow-up, and 1 needed an additional plug after 30 months for definitive closure. CONCLUSIONS: The device demonstrated practicability and biocompatibility in our experimental lamb model and effectively closed the PDA in a consecutive series of 16 patients. A greater number of patients and a longer follow-up period are necessary for the definitive clinical assessment of the new device. [less ▲]

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See detailD.m.a. and d.s.c. investigations of the β transition of poly(vinylidene fluoride)
Liu, Zhehui; Maréchal, Philippe; Jérôme, Robert ULg

in Polymer (1997), 38(19), 4925-4929

The origin of the beta transition in poly(vinylidene fluoride) (PVDF) is still a pending question. This transition has been studied by dynamic mechanical analysis (d.m.a.) and differential scanning ... [more ▼]

The origin of the beta transition in poly(vinylidene fluoride) (PVDF) is still a pending question. This transition has been studied by dynamic mechanical analysis (d.m.a.) and differential scanning calorimetry (d.s.c.) in dependence on sample annealing and dilution with epsilon-caprolactam (CPL). The beta transition temperature is increased upon annealing and thus influenced by the polymer crystallization. Upon addition of CPL, there is no systematic shift in the beta transition temperature, in contrast to the PVDF crystallinity that increases steadily. A shoulder on the low temperature side of the beta transition peak is also observed as a result of annealing. It is shifted to lower temperatures when CPL is added, consistently with a glass transition. It thus appears that the so-called beta-transition is sensitive to the amorphous material, but in a close relationship with the polymer crystallization. Comparison of the observations by d.s.c, and d.m.a. shows that the broad transition observed for the unannealed samples would result from the overlap of two transitions: the glass transition of the unconstrained amorphous phase and the glass transition of chains constrained by the crystalline phase. This situation can account for the complex dependence of the beta transition on the polymer history. [less ▲]

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See detailIncreased plasma malondialdehyde associated with cerebellar structural defects.
RAMAEKERS, Vincent ULg; Bosman, Bernard ULg; Jansen, G. A. et al

in Archives of disease in childhood (1997), 77(3), 231-4

BACKGROUND: Malondialdehyde (MDA) in plasma is regarded as an indicator for increased lipid peroxidation. METHOD: Measurements of MDA concentrations in plasma were compared among healthy children (n = 31 ... [more ▼]

BACKGROUND: Malondialdehyde (MDA) in plasma is regarded as an indicator for increased lipid peroxidation. METHOD: Measurements of MDA concentrations in plasma were compared among healthy children (n = 31), patients with neurological disorders or epileptic syndromes (n = 15), and children with pontocerebellar structural defects (n = 31), where the cause or genetic defect remained unknown. RESULTS: In healthy children the median MDA value was 5.86 nmol/ml (mean (SD) value: 6.25 (1.97), range: 3.76-11.19). For the group with various neurological disorders or epilepsy, the values were similar with the median value at 5.66 nmol/ml (range 0.22-10.86). Compared with healthy controls and the neurological/ epileptic group, the 31 children with pontocerebellar structural defects had significantly increased MDA values with a median value at 11.29 nmol/ml (mean (SD) value: 11.62 (3.27), range 3.65-19.22). IMPLICATION: These findings of increased plasma MDA in the majority of children with pontocerebellar structural defects of unknown origin raised the question whether increased lipid peroxidation leads to prenatal and postnatal pontocerebellar maldevelopment or degeneration. [less ▲]

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See detailVaricella-zoster virus open reading frame 4 encodes an immediate-early protein with posttranscriptional regulatory properties
Defechereux, Patricia; Debrus, Serge; Baudoux, Laurence et al

in Journal of Virology (1997), 71(9), 7073-7079

Varicella-zoster virus (VZV) encodes four putative immediate-early proteins based on sequence homology with herpes simplex virus type I: the products of ORF4, -61, -62, and -63. Until now, only two VZV ... [more ▼]

Varicella-zoster virus (VZV) encodes four putative immediate-early proteins based on sequence homology with herpes simplex virus type I: the products of ORF4, -61, -62, and -63. Until now, only two VZV proteins have been described as being truly expressed with immediate-early kinetics (IE62 and IE63). The ORF4-encoded protein can stimulate gene expression either alone or in synergy with the major regulatory protein IE62. Making use of a sequential combination of transcription and protein synthesis inhibitors (actinomycin D and cycloheximide, respectively), we demonstrated the immediate-early nature of the ORF4 gene product, which can thus be named IE4. The fact that IE4 is expressed with kinetics similar to that of IE62 further underlines the possible cooperation between these two VZV proteins in gene expression. Analysis of the IE4-mediated autologous or heterologous viral gene expression at the mRNA levels clearly indicated that IE4 may have several mechanisms of action. Activation of the two VZV genes tested could occur partly by a posttranscriptional mechanism, since increases in chloramphenicol acetyltransferase (CAT) mRNA levels do not account for the stimulation of CAT activity. On the other hand, stimulation of the human immunodeficiency virus type 1 long terminal repeat-or the cytomegalovirus promoter-associated CAT activity is correlated with an increase in the corresponding CAT mRNA. [less ▲]

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See detailPoly[methyl methacrylate (M)-b-styrene (S)-b-butadiene (B)-b-S-b-M] pentablock copolymers: synthesis, morphology, and properties.
Yu, Jian Ming; Dubois, Philippe ULg; Jérôme, Robert ULg

in Macromolecules (1997), 30(17), 4984-4994

A series of poly[methyl methacrylate (M)-b-styrene (S)-b-butadiene (B)-b-S-b-M], or MSBSM, pentablock copolymers have been successfully synthesized by sequential living anionic polymerization initiated ... [more ▼]

A series of poly[methyl methacrylate (M)-b-styrene (S)-b-butadiene (B)-b-S-b-M], or MSBSM, pentablock copolymers have been successfully synthesized by sequential living anionic polymerization initiated with the diadduct of tert-butyllithium (t-BuLi) onto m-diisopropenylbenzene (m-DIB) in a cyclohexane/diethyl ether mixture for the butadiene and styrene polymerization at room temperature and in a cyclohexane/THF mixture for the MMA polymerization at −78 °C. All the pentablock copolymers have a monomodal and narrow molecular weight distribution (Mw/Mn < 1.20), and their weight composition varies from 11 to 55% M, 18 to 55% S, and 15 to 64% B. Toluene-cast films of these copolymers have been analyzed by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and transmission electron microscopy (TEM). All these materials show a phase separation of the soft B component from the hard S and M blocks, which cannot, however, be distinguished one from each other by DSC or DMA. Indeed, a single transition is observed for the binary hard phase at a temperature intermediate between the glass transition temperature of polystyrene (PS) and poly(methyl methacrylate) (PMMA). In addition to classical phase morphologies, such as cylindrical and lamellar phase organization, two nonclassical morphologies, i.e., catenoid−lamellar and strut phase structures have been observed by TEM. The phase morphology strongly depends on the pentablock composition and any chemical modification of blocks. For instance, the cylindrical morphology, characteristic of an MSBSM copolymer containing equal amounts of hard and soft phases, is changed into a lamellar morphology upon hydrogenation of the B midblock. Copolymers of a relatively low hard phase content typically behave as thermoplastic elastomers of high ultimate tensile strength (ca. 30 MPa) and elongation at break (ca. 900%). These mechanical properties, however, depend on the casting solvent. [less ▲]

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See detailTriblock copolymer based thermoreversible gels. 4. Effect of the midblock and characterization of the sol-gel transition
Yu, Jian Ming; Blacher, Silvia ULg; Brouers, F. et al

in Macromolecules (1997), 30(16), 4619-4625

Thermoreversible gelation has been studied in o-xylene for poly(methyl methacrylate) containing 80% syndiotactic triads (sPMMA) and block copolymers of the MXM type, where M is sPMMA and X is either ... [more ▼]

Thermoreversible gelation has been studied in o-xylene for poly(methyl methacrylate) containing 80% syndiotactic triads (sPMMA) and block copolymers of the MXM type, where M is sPMMA and X is either polybutadiene (PBD), hydrogenated PBD (PEB), poly(styrene-b-butadiene-b-styrene) (SBS) triblock, or the hydrogenated version of this triblock (SEBS). In o-xylene, which is a selective solvent for the central X block, sPMMA forms thermoreversible gels provided that the molecular weight is high enough. When sPMMA is the outer block of MXM triblock copolymers, the midblock X appears to favor the gelation and it considerably improves the thermal stability of the matured gels. This thermal stability is, however, largely independent of the actual nature of the midblock. The dynamic properties of solutions and gels have been analyzed and discussed on the basis of scaling assumptions. At the gel point, where the loss angle tan δc = G‘‘/G‘ is independent of the probing frequency, the sample obeys the typical power law G‘(ω) G‘‘(ω) ωΔ. The scaling exponent Δ is found in the 0.65−0.75 range for both sPMMA and MXM block copolymers, independent of the nature of the midblock. Modulus−frequency master curves have been built by using appropriate reaction time dependent renormalization factors for the individual frequency and modulus data. The scaling of these factors with reaction time has allowed us to calculate the static scaling exponents for the increase observed in both modulus and viscosity. The accordingly calculated values agree with the scalar elasticity percolation model. [less ▲]

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See detailThe onset of photometric variability in red giant stars.
Jorissen, A.; Mowlavi, N.; Sterken, C. et al

in Astronomy and Astrophysics (1997), 324

The onset of variability in red giant stars is studied from the data collected by the `Long-Term Photometry of Variables' project which operates at ESO (La Silla) since 1982. The differential nature of ... [more ▼]

The onset of variability in red giant stars is studied from the data collected by the `Long-Term Photometry of Variables' project which operates at ESO (La Silla) since 1982. The differential nature of the observations combined with a multi-night reduction algorithm enables to study the variability of over 50 red giants with an accuracy of the order of 2 to 3 millimagnitudes on time scales ranging from days to years. All red giants with spectral types late G to early K (i.e. b-y~0.6-0.8) are stable at the level Ï _y_<6millimag (where Ï _y_ is the standard deviation of the Stroemgren y magnitude). Red giants with later spectral types are all variable, and it is found that the minimum variability level Ï _y, min_ increases with increasing b-y, thus defining a minimum-variability boundary. The new data obtained in this paper reveal that the time scale of the associated variability increases with increasing b-y (and thus amplitude), and that the stability of this time scale improves concomitantly. More precisely, irregular variations on time scales of 5 to 10-days (and Ï _y_~7millimag) characterize red giants with b-y~1.0, whereas the variations (with Ï _y_~100millimag) become more regular with periods of the order of 50d for red giants with b-y~1.3. A radial-velocity jitter (of the order of 1.5km/s r.m.s.) is associated with this photometric variability, and suggests that stellar oscillations may be responsible for the observed variations. [less ▲]

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See detailThe geometry of the quadruply imaged quasar PG 1115+080: implications for H_0_.
Courbin, F.; Magain, Pierre ULg; Keeton, C. R. et al

in Astronomy and Astrophysics (1997), 324

Time delay measurements have recently been reported for the lensed quasar PG 1115+080. These measurements can be used to derive H_0_, but only if we can constrain the lensing potential. We have applied a ... [more ▼]

Time delay measurements have recently been reported for the lensed quasar PG 1115+080. These measurements can be used to derive H_0_, but only if we can constrain the lensing potential. We have applied a recently developed deconvolution technique to analyze sub-arcsecond I band images of PG 1115+080, obtained at the Nordic Optical Telescope (NOT) and the Canada France Hawaii Telescope (CFHT). The high performance of the deconvolution code allows us to derive precise positions and magnitudes for the four lensed images of the quasar, as well as for the lensing galaxy. The new measurement of the galaxy position improves its precision by a factor of 3 and thus strengthens the constraints on the lensing potential. With the new data, a range of models incorporating some of the plausible systematic uncertainties yields H_0_=53^+10^_-7_km/s/Mpc. [less ▲]

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See detailLes constellations (IV).
Renson, Pierre ULg

in Ciel et Terre (1997), 113

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See detailLa néphropathie épidémique a Hantavirus
Weekers, Laurent ULg; Biessaux, Yves ULg; Lamproye, Anne ULg et al

in Revue Médicale de Liège (1997), 52(8), 515-519

L'Entre-Sambre-et-Meuse a été le siège d'une épidémie de néphropathie épidémique à Hantavirus (NE) en 199293. Cinq cas ont été rencontrés au CHU de Liège en moins d'un an. Le virus responsable de cette ... [more ▼]

L'Entre-Sambre-et-Meuse a été le siège d'une épidémie de néphropathie épidémique à Hantavirus (NE) en 199293. Cinq cas ont été rencontrés au CHU de Liège en moins d'un an. Le virus responsable de cette affection appartient à la famille dès Hantavirus dont il existe huit sérotypes aux caractéristiques propres en terme de vecteur (rongeurs), de distribution géographique et de pathogénicité. Les pathologies induites chez l'homme vont de la néphropathie épidémique à Hantavirus - d'évolution le plus souvent bénigne- au syndrome pulmonaire à Hantavirus (SPH) - fréquemment mortel - en passant par la fièvre hémorragique avec syndrome rénal (FHSR) de sévérité intermédiaire. Dans nos contrées, on rencontre le sérotype Puumala dont le vecteur est le campagnol roussâtre. L'homme s'infecte par inhalation de particules contaminées et développe dans un pourcentage non précisé des cas, après une période d'incubation de 1 à 3 semaines, un tableau clinique de néphropathie épidémique à Hantavirus. Celui-ci se caractérise par l'apparition brutale d'une fièvre, de myalgies diffuses, de douleurs abdominales et/ou lombaires et de céphalées. Apparaissent ensuite à des degrés divers: nausées et vomissements, oligurie, myopie aiguë, toux,diathèse hémorragique, diarrhée... Biologiquement, on observe l'association d'une insuffisance rénale aiguë et d'une thrombopénie. L'évolution est spontanément favorable dans les deux à trois semaines. Le diagnostic suggéré par la clinique sera confirmé par la sérologie. La physiopathologie de l'insuffisance rénale et de la thrombopénie fait intervenir des interactions complexes entre l'hôte et le virus. Il n'existe pas de thérapeutique spécifique pour la néphropathie épidémique à Hantavirus. Les formes plus sévères (SPH et FHSR) peuvent bénéficierd'un traitement par Ribavirineen iv. [less ▲]

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See detailEffect of platelet-activating factor on bovine pulmonary function
Van de Weerdt, ML; Desmecht, Daniel ULg; Lekeux, Pierre ULg

in Veterinary Record : Journal of the British Veterinary Association (1997), 141(7), 168-172

The objectives of this study were to determine whether the infusion of platelet-activating factor would modify bovine pulmonary function, heart rate and platelet count and whether any such modifications ... [more ▼]

The objectives of this study were to determine whether the infusion of platelet-activating factor would modify bovine pulmonary function, heart rate and platelet count and whether any such modifications could be antagonised by the prior intravenous injection of a specific antagonist (WEB 2086). In saline-pretreated calves, the respiratory rate, total lung resistance (RL) and maximal changes in transpulmonary pressure (delta Ptp) were significantly increased whereas lung dynamic compliance (CLdyn), tidal volume (VT), platelet count and heart rate were significantly decreased. The changes in RL, CLdyn, VT and delta Ptp were abolished by pretreatment with WEB 2086, whereas respiratory rate remained significantly increased to 125 per cent of the baseline value, but less than in the saline-pretreated calves in which it was 250 per cent of the baseline value. [less ▲]

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See detailSuccessful Controlled Limb Reperfusion after Severe Prolonged Ischemia
Defraigne, Jean-Olivier ULg; Pincemail, Joël ULg; Laroche, C. et al

in Journal of Vascular Surgery : Official Publication, the Society for Vascular Surgery and International Society For Cardiovascular Surgery, North American Chapter (1997), 26(2), 346-50

Controlled limb reperfusion was performed in two patients who were admitted for lower limb-threatening ischemia as a result of embolism. After embolectomy, the inflow blood was drained with a cannula and ... [more ▼]

Controlled limb reperfusion was performed in two patients who were admitted for lower limb-threatening ischemia as a result of embolism. After embolectomy, the inflow blood was drained with a cannula and mixed with a crystalloid solution to obtain an hyperosmolar, hypocalcemic, alkalotic, and substrate-enriched (aspartate, glutamate) reperfusate. This reperfusate was reinjected with a roller pump for 30 minutes through two cannulas inserted in the profunda and superficial femoral arteries. Temperature, intraarterial pressures, and flow were closely controlled. No complications occurred, and complete recovery of motor and sensory functions were observed, with restoration of pedal pulses. [less ▲]

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See detailAnalysis of the Biochemical Properties of, and Complex Formation between, Glycoproteins H and L of the Gamma2 Herpesvirus Bovine Herpesvirus-4
Lomonte, P.; Filée, Patrice ULg; Lyaku, J. R. et al

in Journal of General Virology (The) (1997), 78((Pt 8)), 2015-23

Genes encoding glycoprotein gH and gL homologues were localized in the genome of the gamma-herpesvirus bovine herpesvirus-4 (BHV-4). Both genes were sequenced and glutathione S-transferase fusion proteins ... [more ▼]

Genes encoding glycoprotein gH and gL homologues were localized in the genome of the gamma-herpesvirus bovine herpesvirus-4 (BHV-4). Both genes were sequenced and glutathione S-transferase fusion proteins were produced and used to immunize rabbits against the translation products of the two genes. The anti-gH serum recognized a protein with an apparent molecular mass (MM) of 110 kDa both in infected cells and in virions. This protein was sensitive to endo-beta-N-acetylglucosaminase-H (endoH) and endoglycosidase F-N-glycosidase F (endoF-PNGaseF) digestion. A protein with the same relative mobility was immunoprecipitated from infected cells radiolabelled with [3H]glucosamine which confirmed that this product (gp110), now designated BHV-4 gH, was glycosylated. Western blotting with the anti-gL serum detected in infected cells a product with an apparent MM ranging from 31-35 kDa and diffusely migrating protein species ranging from 45-65 kDa. Tunicamycin, monensin, endoH or endoF-PNGaseF treatments showed that both the 31-35 kDa and the 45-65 kDa proteins were glycosylated, gp31-35 being a precursor of the 45-65 kDa glycoprotein species. In radioimmunoprecipitation assays, the anti-gL serum immunoprecipitated from infected cells two glycosylated proteins with apparent MMs of 31-35 kDa (gp31-35) and 45-55 kDa (gp45-55). However a third glycoprotein, gp110, was also immunoprecipitated together with gp31-35 and gp45-55. gp110 and gp45-55 were subsequently confirmed to be virion glycoproteins corresponding to mature forms of BHV-4 gH and gL respectively. In addition, the present study clearly demonstrated complex formation between BHV-4 gH and gL both in virions and in infected cells. [less ▲]

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See detailBiodegradable and biocompatible inorganic-organic hybrid materials. 1. Synthesis and characterization
Tian, Dong; Dubois, Philippe ULg; Jérôme, Robert ULg

in Journal of Polymer Science. Part A, Polymer Chemistry (1997), 35(11), 2295-2309

The hydroxyl or vinyl end-groups of linear or three-arm star-shaped poly(-caprolactone) (PCL) chains have been derivatized into triethoxysilane groups reactive in the sol-gel process. New transparent ... [more ▼]

The hydroxyl or vinyl end-groups of linear or three-arm star-shaped poly(-caprolactone) (PCL) chains have been derivatized into triethoxysilane groups reactive in the sol-gel process. New transparent hybrid materials that combine tetraethylorthosilicate (TEOS) and PCL known for biodegradability and biocompatibility have accordingly been prepared. The sol-gel process is, however, limited by the early vitrification of the reactive system. However, thermal posttreatment can overcome these diffusional and/or kinetic limitations as assessed by a set of analytical methods. The thermal stability of PCL is improved by incorporation into the silica network. Conversely, the thermal stability of the ceramer depends on the effective PCL content. The extent of PCL incorporation into the silica network depends on PCL molecular weight, number, and reactivity of the PCL functional groups. IR spectroscopy has shown that hydrogen bonding occurs between the ester groups of PCL and residual OH groups of the silicate component. © 1997 John Wiley [less ▲]

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See detailConsequences of Cold and Warm Ischemia on Pulmonary Mitochondrial Respiratory Function
Detry, Olivier ULg; Willet, K.; Lambermont, Bernard ULg et al

in Transplantation Proceedings (1997), 29(5), 2338-9

IN RECENT years, pulmonary transplantation has become the treatment of choice for several end-stage lung diseases, but remains limited by the scarcity of suitable donors and the lack of reliable prolonged ... [more ▼]

IN RECENT years, pulmonary transplantation has become the treatment of choice for several end-stage lung diseases, but remains limited by the scarcity of suitable donors and the lack of reliable prolonged method of lung preservation.1 Transplantation of lung 6 hours postharvest leads to an increased incidence of primary graft dysfunction, due in part to ischemic damage of pulmonary cell structure and metabolism, and to acute reperfusion injury. However, very little is known about the real mechanisms of pulmonary cell injuries before, during, and after lung transplantation. <br /> <br />During ischemia, the cytosolic and mitochondrial adenine nucleotide content falls,2,3 phospholipids are degraded, membrane permeabilities are increased, and the cytosolic levels of Na+, Ca2+ and phosphate are raised.4 Thus, cold and warm ischemia may induce cell dysfunctions and irreversible injuries responsible for necrosis. As mitochondia are believed to be the site of the determinants of irreversibility,5 the study of permanent oxidative phosphorylation damage after ischemia should be of great interest. <br /> <br />The aim of this present study was to investigate the consequences of warm and cold ischemia on the oxidative phosphorylation of isolated lung mitochondria [less ▲]

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See detailEsquisse d'un bilan provisoire
Beckers, Jacqueline ULg; Motte, André

in Puzzle (1997), 4

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See detailThrombolysis of Occluded Infrainguinal Bypass Grafts
VAN DAMME, Hendrik ULg; TROTTEUR, Geneviève ULg; Dongelinger, R.F. et al

in Acta Chirurgica Belgica (1997), 97(4), 177-83

From January 1993 to December 1995, intraarterial catheter guided urokinase infusion was used as an initial approach in the management of 29 episodes of infrainguinal graft thrombosis (12 venous and 17 ... [more ▼]

From January 1993 to December 1995, intraarterial catheter guided urokinase infusion was used as an initial approach in the management of 29 episodes of infrainguinal graft thrombosis (12 venous and 17 prosthetic grafts) in 27 patients. The infusion catheter was embedded inside the occluding clot which was infiltrated by 225.000 U urokinase from distal to proximal. Local low-dose urokinase (1.000 U/kg/hr) was continued for a mean of 39 hours. By this regimen, prompt relief of ischaemia was achieved in 69% (20/29) of cases. Complete recanalization was obtained in 79% of cases. In six cases, the graft remained totally (n = 3) or partially (n = 3) occluded. Two of these patients benefited from secondary surgery, two improved clinically by conservative treatment, and two required amputation. In the 23 successful cases, thrombolysis unmasked an underlying flow-limiting stenosis in 83% (19/23), that was subsequently corrected by percutaneous balloon angioplasty (n = 15), by surgery (n = 3), or by a combination of both (n = 4). One early rethrombosis resulted in an amputation. The immediate limb-salvage rate was 89% (26/29). Surgical intervention was avoided in 17 cases (58%). The main hospital stay was 13 days. The short-term follow-up (mean of 17 months) reveals a high early rethrombosis rate (8/23 or 35%) within one year. Four of these repeated graft failures evolved to amputation. At one year, the overall limb salvage rate dropped to 79%. Thrombolytic management of infrainguinal occluded bypass grafts gives excellent initial technical results (79%), minimizing the need for major surgical revision. It is however characterized by a high procedure-related morbidity (21%). These immediate favourable results are not longstanding. Diffuse graft disease, limited outflow and high recurrence rate of anastomotic stenoses after balloon angioplasty explain poor long-term results after thrombolysis of failed grafts. [less ▲]

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See detailDifferential expression of galectin-1 and galectin-3 during first trimester human embryogenesis.
van den Brûle, Frédéric; Fernandez, Pedro L.; Buicu, Crina et al

in Developmental Dynamics : An Official Publication of the American Association of Anatomists (1997), 209(4), 399-405

Development of complex organisms requires specific temporospatial differentiation and expression of the correct phenotype through activation of a variety of genes. Galectins are mammalian lectins able to ... [more ▼]

Development of complex organisms requires specific temporospatial differentiation and expression of the correct phenotype through activation of a variety of genes. Galectins are mammalian lectins able to interact with various extracellular matrix glycoconjugates and have been implicated in several biological events including cell attachment, differentiation, apoptosis, embryogenesis, and cancer invasion and metastasis. In this study, we have examined the expression of galectin-1 and galectin-3 during human first trimester embryogenesis using immunohistochemistry and Western blotting. Variable amounts of galectin-1 and galectin-3 were detected in all tissue protein extracts. Galectin-1 expression was demonstrated in the connective tissue and derived tissues such as smooth and striated muscle cells, and in some epithelia, such as in the basal layers of the skin after 14 weeks and in the epithelial cells of the gonads. Galectin-3 was detected mainly in epithelia, such as the skin, epithelial lining of the digestive and respiratory tract, and urothelium and excretory tubes of the kidney, but also in the myocardial cells, in the peripheral and preossifying hypertrophic chondrocytes, and in the notochord and in the liver. Our study constitutes the first demonstration of galectin-1 and galectin-3 during human embryogenesis. The differential expression of these two lectins suggests that they could participate in the complex processes of tissue differentiation. [less ▲]

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See detailSynthesis and characterization of hydrogenated poly[alkylmethacrylate(-b-styrene)-b-butadiene-b-(styrene-b-) alkylmethacrylate] triblock and pentablock copolymers
Yu, Jian Ming; Yu, Yisong; Dubois, Philippe ULg et al

in Polymer (1997), 38(12), 3091-3101

Triblock and pentablock copolymers of the X(Y)B(Y)X type have been synthesized by the sequential living anionic polymerization of butadiene (B), styrene (Y) and alkylmethacrylate (X), respectively. The ... [more ▼]

Triblock and pentablock copolymers of the X(Y)B(Y)X type have been synthesized by the sequential living anionic polymerization of butadiene (B), styrene (Y) and alkylmethacrylate (X), respectively. The diadduct of t-BuLi onto m-diisopropenylbenzene (m-DIB) has been used as a difunctional initiator. Methylmethacrylate (MMA), t-butylmethacrylate (tBMA) and isobornylmethacrylate (IBMA) have been used as precursors of the outerblocks X. The polybutadiene (PBD) midblock that contains ca 42-45% 1,2-units has been selectively hydrogenated into a saturated poly(ethylene-co-1-butene) (PEB) block. The homogeneous hydrogenation catalysis has no deleterious effect on the copolymer integrity. These completely soluble thermoplastic elastomers have been characterized by FT i.r., n.m.r., d.s.c. and d.m.a. The PEB midblock has a low Tg (-50°C) and a small propensity to crystallize. The effect of hydrogenation on the morphology and mechanical properties depends on the outer block. Upon hydrogenation of the PBD midblock in polymethylmethacrylate (PMMA) and polyisobornylmethacrylate (PIBMA) containing triblock copolymers, the ultimate tensile strength is increased (except for a hard block content > 50%) due to a sharper phase separation, whereas the elongation at break is decreased. The extent of phase separation is reduced in polyt-butylmethacrylate(PtBMA) containing triblock copolymers upon hydrogenation and the ultimate tensile strength is slightly decreased. Stereocomplexation of the syndiotactic PMMA outerblocks is observed to occur upon blending with isotactic PMMA [less ▲]

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See detailInsuffisance rénale, syndrome inflammatoire et anévrysme de l'aorte abdominale ... où est le lien?
Vazquez, C.; Bonnet, Pierre ULg; Fastre, M. et al

in Revue Médicale de Liège (1997), 52(8), 511-4

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See detailCoupling of α,ω-dichloropoly (methylphenylsilane) and living poly (styryllithium). Study of the coupling reaction
Demoustier-Champagne, Sophie; Canivet, I.; Devaux, Jacques et al

in Journal of Polymer Science. Part A, Polymer Chemistry (1997), 35(10), 1939-1948

Both di- and triblock copolymers consisting of polystyrene (PS) in conjunction with poly(methylphenylsilane) (PMPS) have been successfully prepared by coupling of ,-dichloro-PMPS with poly(styryllithium ... [more ▼]

Both di- and triblock copolymers consisting of polystyrene (PS) in conjunction with poly(methylphenylsilane) (PMPS) have been successfully prepared by coupling of ,-dichloro-PMPS with poly(styryllithium). The study of this reaction has shown a sudden limitation of the coupling yield, which however depends on the PS block length. Both the polymer concentration and the solvent have also an effect on the coupling reaction. Morphology of the PS-PMPS block copolymers has been observed by transmission electron microscopy. Very complex morphologies have been reported more likely as the result of the competition between the phase separation induced by PS and PMPS immiscibility and the tendency of PMPS to form ordered structures. [less ▲]

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See detailLiving anionic homo- and block copolymerization of 2-(tert-butylamino) ethyl methacrylate
Creutz, Serge; Teyssié, Philippe; Jérôme, Robert ULg

in Journal of Polymer Science. Part A, Polymer Chemistry (1997), 35(10), 2035-2040

Anionic polymerization of 2-(tert-butylamino)ethyl methacrylate (tBAEMA), which bears an unprotected secondary amine moiety, has been investigated in THF at -78°C. The presence of lithium chloride has ... [more ▼]

Anionic polymerization of 2-(tert-butylamino)ethyl methacrylate (tBAEMA), which bears an unprotected secondary amine moiety, has been investigated in THF at -78°C. The presence of lithium chloride has been shown to be desirable to afford narrow molecular weight distribution as well as a good agreement between theoretical and observed molecular weight. The living character of the polymerization has also been demonstrated, and the synthesis of block copolymers carried out successfully. They have been analyzed by SEC by adding a mixture of secondary and tertiary amines to the eluent (THF) so as to avoid any polymer adsorption during elution. © 1997 John Wiley [less ▲]

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See detailDifunctional initiator based on 1,3-diisopropenylbenzene. 6. Synthesis of methyl methacrylate-butadiene-methyl methacrylate triblock copolymers
Yu, Y. S.; Dubois, Philippe ULg; Teyssié, Philippe et al

in Macromolecules (1997), 30(15), 4254-4261

Synthesis of PMMA−PBD−PMMA (MBM) triblock copolymers with a 1,3-diisopropenylbenzene- (DIB-) based initiator is studied. Diethyl ether, tert-butyl methyl ether, N,N,N‘,N‘-tetramethylethylenediamine (TMEDA ... [more ▼]

Synthesis of PMMA−PBD−PMMA (MBM) triblock copolymers with a 1,3-diisopropenylbenzene- (DIB-) based initiator is studied. Diethyl ether, tert-butyl methyl ether, N,N,N‘,N‘-tetramethylethylenediamine (TMEDA) and THF were found to be efficient polar additives for obtaining PMMA−PBD−PMMA triblock copolymers, but these triblock copolymers displayed a high 1,2-microstructure of the PBD block. A combination of the initiator seeding technique and weakly polar additives has allowed MBM triblock copolymers with high 1,4-microstructure of PBD to be obtained. These copolymers exhibited a definitely higher upper service temperature than conventional thermoplastic elastomers, i.e. SBS or SIS Kratons. The influence of chain microstructure, copolymer composition and block length on the mechanical properties has been studied. Short polystyrene blocks of ca. Mn 2000 have been incorporated in between the PBD central block and the PMMA outer sequences. A higher tensile strength was observed for these MBM-like triblock coplymers. Contamination by a diblock structure expectedly had a very depressive effect on the bulk properties, and the stress−strain behavior mainly depended on the PMMA content and secondarily on molecular weight. [less ▲]

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See detailExchange of polymer molecules between block copolymer micelles studied by emission spectroscopy. A method for the quantification of unimer exchange rates
Creutz, Serge; van Stam, Jan; Antoun, Sayed et al

in Macromolecules (1997), 30(14), 4078-4083

Amphiphilic block copolymers, composed of poly(sodium methacrylate) (PMANa) as the water soluble sequence and poly((dimethylamino)ethyl methacrylate) (PDMAEMA) as the hydrophobic sequence, were ... [more ▼]

Amphiphilic block copolymers, composed of poly(sodium methacrylate) (PMANa) as the water soluble sequence and poly((dimethylamino)ethyl methacrylate) (PDMAEMA) as the hydrophobic sequence, were anionically synthesized. Due to their amphiphilic character, these polymers aggregate into micelles in aqueous solutions. Of particular interest is the possibility of exchange of free chains, called unimers, between micelles and the bulk and the quantification of the exchange rate. The exchange of unimers between the micellar aggregates was determined spectroscopically. A donor molecule, naphthalene, was covalently bound to the hydrophobic blocks of the copolymers, while the acceptor, pyrene, was dissolved in aggregates built up from an identical, but unlabeled, copolymer. The energy transfer from an excited donor to a ground-state acceptor, with subsequent emission from the acceptor, was used to follow the migration of donor-labeled chains into micelles containing the dissolved acceptor. These data were analyzed according to a kinetic model, and the respective kinetic parameters could be determined. The influence of the relative composition of the block copolymer on the exchange rate was investigated to illustrate the usability of the kinetic model. While keeping the relative amount of comonomers as well as the molecular weights constant, the molecular architecture was also studied: hence the diblock (PDMAEMA-b-PMANa) and the corresponding triblocks (PDMAEMA-b-PMANa-b-PDMAEMA) and (PMANa-b-PDMAEMA-b-PMANa) were investigated. [less ▲]

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See detailEfficiency of T Cell Triggering by Anti-Cd3 Monoclonal Antibodies (Mab) with Potential Usefulness in Bispecific Mab Generation
Jacobs, Nathalie ULg; Mazzoni, A.; Mezzanzanica, D. et al

in Cancer Immunology, Immunotherapy (1997), 44(5), 257-64

T cell triggering can be achieved by monoclonal antibodies (mAbs) specific for the CD3/TcR complex. In the presence of appropriate costimulation and/or progression factors, such triggering permits the ... [more ▼]

T cell triggering can be achieved by monoclonal antibodies (mAbs) specific for the CD3/TcR complex. In the presence of appropriate costimulation and/or progression factors, such triggering permits the generation of effector cells for immunotherapy protocols involving the redirection of T cell lysis against tumor cells by mAbs bispecific for anti-CD3/anti-tumor cells (bs-mAbs). Focusing our analysis on the clinically relevant bs-mAb OC/TR, we found that bs-mAbs generated with the same anti tumor specificity, but two other anti-CD3 mAbs, TR66 and OKT3, have the same and a significantly lower lytic potential, respectively, compared with that of OC/TR. To evaluate the relevance of the anti-CD3 component, we examined several anti-CD3 mAbs with respect to binding parameters and the ability to trigger T lymphocytes. Competitive binding assays suggested that all anti-CD3 mAbs recognized the same or overlapping epitopes, although mAbs BMA030 and OC/TR bound with lower avidity than did alpha CD3 (the bivalent anti-CD3 mAb produced by the hybrid hybridoma OC/TR). TR66 and OKT3, as determined by measurement of the affinity constants. In all lymphocyte populations examined, which included resting peripheral blood mononuclear cells (PBMC), activated PBMC and T cell clones, OKT3, BMA033 and OC/TR failed to mobilize Ca2+ without cross-linking, whereas alpha CD3, in both murine and murine-human chimeric versions, TR66 and BMA030, did not require cross-linking. The ability to induce CD3 modulation was associated in part with the induction of Ca2+ fluxes. Despite the differences in the behavior of these mAbs in triggering the events that precede proliferation, all of them ultimately led to expression of the IL-2 receptor and to proliferation in T cells in the presence of accessory cells. Our data suggest that anti-CD3 mAbs that bind more rapidly (strong Ca2+ mobilizers) and more tightly under physiological conditions are good candidates for retargeting T cells in the bs-mAb clinical application. [less ▲]

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See detailChronic varicella-zoster virus skin lesions in patients with human immunodeficiency virus are related to decreased expression of gE and gB
Nikkels, Arjen ULg; Rentier, Bernard ULg; Pierard, Gérald ULg

in Journal of Infectious Diseases (1997), 176(1), 261-264

The pathogenesis of chronic, verrucous varicella-zoster virus (VZV) cutaneous lesions in human immunodeficiency virus (HIV)-infected persons is unknown. It has been hypothesized that these lesions are due ... [more ▼]

The pathogenesis of chronic, verrucous varicella-zoster virus (VZV) cutaneous lesions in human immunodeficiency virus (HIV)-infected persons is unknown. It has been hypothesized that these lesions are due to an altered pattern of virus gene expression. Immediate early and late (L) gene expression in five chronic verrucous VZV lesions, four full-blown herpes zoster vesicular lesions in HIV-infected persons, and eight vesicular herpes zoster lesions in immunocompetent individuals was semiquantitatively assessed immunohistochemically using specific antibodies to the IE63, gE (L), and gB (L) proteins. All patients had evidence of IE63 expression in keratinocytes; however, gE expression was either weak or absent in keratinocytes of three verrucous lesions, and gB was either weak or absent in two. These results suggest that chronic VZV skin lesions are associated with diminished gE and gB expression. It is inferred that the VZV behavior in keratinocytes may vary from a latency-like state to a fully developed, productive infection. [less ▲]

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See detailVasotocinergic Innervation of Areas Containing Aromatase-Immunoreactive Cells in the Quail Forebrain
Balthazart, Jacques ULg; Absil, Philippe ULg; Viglietti-Panzica, C. et al

in Journal of Neurobiology (1997), 33(1), 45-60

In the male quail forebrain, aromatase-immunoreactive (ARO-ir) elements are clustered within the sexually dimorphic medial preoptic nucleus (POM), nucleus striae terminalis (nST), nucleus accumbens (nAc ... [more ▼]

In the male quail forebrain, aromatase-immunoreactive (ARO-ir) elements are clustered within the sexually dimorphic medial preoptic nucleus (POM), nucleus striae terminalis (nST), nucleus accumbens (nAc), and ventromedial and tuberal hypothalamus. These ARO-ir cells are sensitive to testosterone and its metabolites: Their number and size increase after exposure to these steroids. The POM and lateral septum are also characterized by a dense vasotocinergic innervation that is also sensitive to testosterone. We analyzed here the anatomical relationships between ARO-ir elements and VT-ir fibers in the quail prosencephalon. Sequential staining for vasotocin, aromatase, or vasotocin plus aromatase was performed on adjacent 30-microm-thick cryostat sections. High concentrations of thin VT-ir fibers were observed within the POM, nST, lateral septum, periventricular mesencephalic central gray, and ventromedial and tuberal hypothalamus. There was a close correspondence between the extension of the ARO-ir cells and of VT-ir fibers. In double-labeled sections, all clusters of ARO-ir cells with the exception of those located in the nAc were embedded in a dense network of VT-ir fibers. Many of the VT-ir terminals appeared to end in the neuropile surrounding ARO-ir elements rather than directly on their cell bodies. This study supports the idea that the testosterone-dependent aromatase system is directly innervated by a testosterone-dependent peptidergic system. Aromatase-containing cells could therefore be modulated by steroids both directly and indirectly through the vasotocin system. Alternatively, this neuroanatomical arrangement may mediate the control of vasotocin synthesis or release by steroids. Functional studies demonstrate that both aromatase and vasotocin affect reproductive behavior in quail, and the present data provide anatomical support for the integration of these effects. [less ▲]

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See detailArt, Mail-art, “Médiart”
Durand, Pascal ULg

in Cyber-Flux-News (1997)

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See detailDétection de la viabilité myocardique: rôle de l'échocardiographie de stress
Pierard, Luc ULg; Hoffer, E.

in Archives des Maladies du Coeur et des Vaisseaux (1997), 90(Spec No 4), 3-16

Identification of myocardial viability is of great clinical importance in patients with acute coronary events or chronic coronary artery disease. Stress echocardiography has emerged as a new accurate and ... [more ▼]

Identification of myocardial viability is of great clinical importance in patients with acute coronary events or chronic coronary artery disease. Stress echocardiography has emerged as a new accurate and cost-effective imaging modality to detect contractile reserve. Numerous studies have recently been published in this field. This article summarizes the main findings of these investigations and presents practical aspects of the method. [less ▲]

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See detailCHICK WILLIS
Sacré, Robert ULg

in Soul Bag (1997), (147), 26

Photo : CHICK WILLIS , Peer 20 juillet 1996

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See detailDesign of polymer blend rheology: 4. Effect of polymethacrylic ionomers on the melt viscosity of polyamide m x D,6
Degée, Philippe; Vankan, R.; Teyssié, Philippe et al

in Polymer (1997), 38(15), 3861-3867

Rheological properties of blends of polyamide m x D,6 (PA) with random copolymers of methyl methacrylate and methacrylic acid (P(MMA-co-MAA)) and the related ionomers (P(MMA-co-metal MA)), respectively ... [more ▼]

Rheological properties of blends of polyamide m x D,6 (PA) with random copolymers of methyl methacrylate and methacrylic acid (P(MMA-co-MAA)) and the related ionomers (P(MMA-co-metal MA)), respectively, have been investigated at 260°C. Addition of small amounts of suitable ionomers (up to 5 wt%) remarkably increases the melt viscosity of PA. At low shear rates and depending on the metal cation of the ionomer, the rheofluidity of PA is reduced by at least two orders of magnitude. The PA melt viscosity increases with the cation as follows: Ni2+ < Ba2+ < Mg2+ < Li+ < Na+ < K+ < Cs+. The major effect is believed to occur when the polymer compatibility is improved to the point where a finely dispersed two-phase system with a low interfacial tension is reached, as a result of strong ion-dipole interactions. Polyblends show a rheothinning behaviour which agrees with the reversibility of H-bonding and dipolar interactions. [less ▲]

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See detailDual Multimodular Class a Penicillin-Binding Proteins in Mycobacterium Leprae
Lepage, Sophie; Dubois, Philippe ULg; Ghosh, Thushar-Kanti et al

in Journal of Bacteriology (1997), 179(14), 4627-4630

The ponA gene of cosmid L222 of the Mycobacterium leprae genome library encodes a multimodular class A penicillin-binding protein (PBP), PBP1. The PBP, labelled with a polyhistidine sequence, has been ... [more ▼]

The ponA gene of cosmid L222 of the Mycobacterium leprae genome library encodes a multimodular class A penicillin-binding protein (PBP), PBP1. The PBP, labelled with a polyhistidine sequence, has been produced in Escherichia coli, extracted from the membranes with 3-[(3-cholamidopropyl)-dimethylammonio]-1-propane-sulfonate (CHAPS) and purified by Ni2(+)-nitrilotriacetic acid-agarose chromatography. In contrast to the pon1-encoded class A PBP1, PBP1 undergoes denaturation at temperatures higher than 25 degrees C, it catalyzes acyl transfer reactions on properly structured thiolesters, and it binds penicillin with high affinity. [less ▲]

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See detailLe contrôle des juridictions de fond sur la désignation par procureur général du magistrat compétent en application de l’article 155, alinéa 2, du Code judiciaire.
Michiels, Olivier ULg

in Journal des Tribunaux (1997), 5849

L’arrêt prononcé par la Cour de cassation le 8 octobre 1996 permet d’apprécier l’étendue du contrôle que peuvent exercer les juridictions de jugement sur la compétence de l’organe du ministère public ... [more ▼]

L’arrêt prononcé par la Cour de cassation le 8 octobre 1996 permet d’apprécier l’étendue du contrôle que peuvent exercer les juridictions de jugement sur la compétence de l’organe du ministère public amené à engager des poursuites pénales en cas de concours ou de connexité entre des infractions qui relèvent de la compétence des juridictions du travail et des infractions de droit commun. [less ▲]

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See detailApports et perspectives des dérivés de l'hémoglobine
Remy, Bernadette ULg; Deby, Ginette ULg; Lamy, Maurice ULg

in Schweizerische Medizinische Wochenschrift (1997), 127(25), 1088-96

Anoxia-reoxygenation leads to severe metabolic alterations, which result in a generalized inflammatory reaction and multiple organ dysfunction. Direct blood transfusion limits these alterations, but is ... [more ▼]

Anoxia-reoxygenation leads to severe metabolic alterations, which result in a generalized inflammatory reaction and multiple organ dysfunction. Direct blood transfusion limits these alterations, but is accompanied by risk of transmission of infections or viral diseases. To avoid these risks, "blood substitutes" have been designed. The modified hemoglobins are not true blood substitutes because they do not possess the complex functions of erythrocytes. They are only oxygen carriers, with a short intravascular life, adapted for temporary use. They are stable, devoid of toxicity and antigenicity, and are able to carry and deliver O2 without regulation of this oxygen transport and without chemical reaction with O2. They possess rheologic properties and an oncotic pressure like those of blood. The use of natural hemoglobin solutions, obtained after lysis of erythrocytes, remains "at risk" because these solutions easily form methemoglobin, increase the oncotic pressure, present renal toxicity, and possess a too high affinity for O2. For these reasons, 5 types of modified hemoglobin solutions have been designed, prepared from human or bovine hemoglobin or by genetic engineering. These hemoglobins are highly purified to eliminate trace amounts of stroma, lipids and endotoxins, which are responsible for acute toxicity. They are modified by internal cross-linking between the monomers, or by binding to macromolecules. Afterwards, they can be polymerized or encapsulated in liposomes. The purpose of these modifications is to modulate the affinity for O2 (by decreasing the binding of O2 and increasing its delivery to tissue), to reduce the dissociation into monomers and to guard against oxidation into methemoglobin. Encapsulation in liposomes allows co-encapsulation of effector molecules and protective substances. Genetic engineering allows the production of recombinant hemoglobin with selective modifications. The modified hemoglobin solutions are essentially used in hemorrhagic shock and perioperative hemodilution. Experimental work in animals has afforded good results: restoration of normal O2 pressure and no toxicity. These assays allow frequent observation of an unexpected rapid hypertensive effect, transient, reversible, and that could be controlled by antihypertensive drugs. The mechanisms of this hypertensive effect remain controverted (stimulation of endothelin production, inhibition of nitric oxide effects, etc.). In humans, studies with healthy volunteers have been completed, while phase II clinical studies are under way in hypovolemic shock, in major abdominal, orthopedic and cardiac surgery, in stroke and in intensive care patients after surgery. The detailed results are awaited, but the modified hemoglobin solutions already appear to be without toxicity and present the same hypertensive effect as observed in animals. However, until now only low doses have been used, and the catabolism of these solutions remains largely unknown. [less ▲]

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See detailPolarised light induced birefringence in azo dye doped polymer: a new model and polarised holographic experiments
Blanche, Pierre-Alexandre ULg; Lemaire, P. C.; Maertens, Christophe et al

in Optics Communications (1997), 139(1-3), 92-98

The photoinduced birefringence of azo dye DMNPAA (2,5-dimelthyl-4-(p-nitrophenylazo)anisole) in PVK (Poly(N-vinylcarbazole)) thin film is reported. A two-layer model of the film is proposed to take into ... [more ▼]

The photoinduced birefringence of azo dye DMNPAA (2,5-dimelthyl-4-(p-nitrophenylazo)anisole) in PVK (Poly(N-vinylcarbazole)) thin film is reported. A two-layer model of the film is proposed to take into account the different results obtained in photoinduced birefringence experiments. According to this model, the sample exhibits intrinsic birefringence but the absorbed light can induce orientation of the optically active molecules contained in the first layer of the film, lending to photoinduced birefringence. Holographic experiments have been carried out in this media with recording at 514 nm and readout at 633 nm. Diffraction efficiency versus polarisation shows that these polymers can record polarisation states as well as intensity patterns. [less ▲]

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See detailNeonatal and Preweanling Rats Are Able to Express Short-Term Behavioral Sensitization to Cocaine
Tirelli, Ezio ULg; Ferrara, Marie-Antoinette ULg

in European Journal of Pharmacology (1997), 328(2-3), 103-14

The present study assessed the ability of suckling rats to express short-term behavioral sensitization to cocaine prior to weaning. Rat pups, aged either 3, 5, 10, 12, 17 or 19 days at the beginning of ... [more ▼]

The present study assessed the ability of suckling rats to express short-term behavioral sensitization to cocaine prior to weaning. Rat pups, aged either 3, 5, 10, 12, 17 or 19 days at the beginning of the experiment, were placed in a chamber after daily injection with cocaine (7.5 or 15 mg/kg. i.p.) for either 2 or 4 consecutive days, and were tested for behavioral responsiveness to cocaine in the same chamber 24 h later (at either 7, 14 or 21 days of age). Such a short post-treatment interval was adopted, along with a consistent pairing of the testing context with the drug effect and a sensitive technique of behavioral measurement (video recording), in order to maximize the possibility of detecting any cocaine sensitization. Locomotion was sensitized at all ages, after both regimens in 14-day-old pups, but solely after 2 injections in 21- and 4 injections in 7-day-old pups. Sensitization was also expressed via behaviors specific to each age. Four cocaine injections augmented cocaine-induced uncoordinated movements of head, paws and body (horizontal activity) in 7-day-old pups, and mouth movements in 14-day-old pups. In 21-day-old pups, sensitization was dose- and regimen-dependently expressed via adult-like stereotyped head movements. In neonatal 7-day-old pups, cocaine sensitization was also visible as reductions in immobility (both injection regimens). Contrary to previous studies, these results indicate that, given the use of an appropriate methodology, short-term sensitization to the motoric effects of cocaine can be expressed by suckling rats prior to weaning, even after relatively short regimens of daily injections. [less ▲]

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See detailIdentification of Catecholaminergic Inputs to and Outputs from Aromatase-Containing Brain Areas of the Japanese Quail by Tract Tracing Combined with Tyrosine Hydroxylase Immunocytochemistry
Balthazart, Jacques ULg; Absil, Philippe ULg

in Journal of Comparative Neurology (The) (1997), 382(3), 401-28

In the quail brain, aromatase-immunoreactive (ARO-ir) neurons located in the medial preoptic nucleus (POM) and caudal paleostriatum ventrale/nucleus accumbens/nucleus striae terminalis complex (PVT/nAc ... [more ▼]

In the quail brain, aromatase-immunoreactive (ARO-ir) neurons located in the medial preoptic nucleus (POM) and caudal paleostriatum ventrale/nucleus accumbens/nucleus striae terminalis complex (PVT/nAc/nST) receive catecholaminergic inputs identified by the presence of tyrosine hydroxylase-immunoreactive (TH-ir) fibers and punctate structures. The origin of these inputs was analyzed by retrograde tracing with cholera toxin B subunit (CTB) or red latex fluospheres (RLF) combined with TH immunocytochemistry. CTB and RLF injected in the POM or PVT/nAc/nST were found in cells located in anatomically discrete areas in the telencephalon (hippocampus, septum, archistriatum), hypothalamus (many areas in periventricular position), thalamus, mesencephalon, and pons. In these last two regions, many retrogradely labeled cells were located in dopaminergic areas such as the retroruberal field (RRF), substantia nigra (SN), and area ventralis of Tsai (AVT) but also in noradrenergic cell groups such as the locus ceruleus and subceruleus. CTB tracing showed that most of these connections are bidirectional. Many retrogradely labeled cells contained TH-ir material. As a mean, 10-20% and 40-60% of the RLF-containing cells in the dopaminergic areas were TH-ir when RLF had been injected in the POM or PVT/nAc/nST, respectively. TH-ir cells projecting to the POM appeared to be mostly located in the periventricular hypothalamus and in AVT, whereas projections to the PVT/nAc/nST originated mainly in the SN (with significant contributions from the RRF and AVT). These data support the existence of functional relationships between aromatase and catecholamines. [less ▲]

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See detailOptical Spectroscopy of EZ Canis Majoris: Indication for Large-Scale Structures in a Wolf-Rayet Wind
Morel, Thierry ULg; St-Louis, Nicole; Marchenko, Sergey V

in Astrophysical Journal (1997), 482

We have carried out optical spectroscopy of the Wolf-Rayet star EZ CMa during 20 consecutive nights in 1995 January in support of the IUE Mega-project. In parallel with this optical spectroscopy, we also ... [more ▼]

We have carried out optical spectroscopy of the Wolf-Rayet star EZ CMa during 20 consecutive nights in 1995 January in support of the IUE Mega-project. In parallel with this optical spectroscopy, we also monitored EZ CMa using narrowband photometry. The light curve was found to be remarkably stable when folded with the P=3.77 day period, and it had a peak-to-valley amplitude of 0.1 mag. The P Cygni absorption components of He I lambda 3889 and He I lambda 5876 display a similar global pattern of variability as was found for the simultaneously acquired UV profiles. The strengthening of the P Cygni absorption component of these transitions is associated with the maximum of the continuum flux. Conversely, the absorption trough of N V lambda 4604 gradually disappears as the star brightens. Although the emission parts of the lines are variable at different levels, they all show the same pattern of variability, which consists of phase-dependent shifts of extra emission components superposed on the profiles. A strong correlation is found between the continuum-light level and the equivalent width of most transitions. The line skewness and the full-width at half-maximum show a daily recurrence timescale, reflecting the light curve changes. We have addressed in a rigorous statistical way the significance of the variations by calculating the "temporal variance spectrum." For any given line, we found enhanced variability at some velocities, although the whole profile displays a statistically significant level of variability. Arguments against a compact companion as the cause of the observed periodic variability are presented. Instead, our observations strongly support the suggestion in the IUE Mega analysis that the atypical level of variability results from the rotation of a structured wind. We propose that the wind variability of EZ CMa is triggered by photospheric activity, or that the wind is controlled by a large-scale magnetic field. [less ▲]

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See detailComment on ``A model for meteoric magnesium in the ionosphere'' by W. J. McNeil, S. T. Lai, and E. Murad
Fesen, C. G.; Gérard, Jean-Claude ULg; Hays, P. B. et al

in Journal of Geophysical Research (1997), 102

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See detailLes constellation (III).
Renson, Pierre ULg

in Ciel et Terre (1997), 113

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See detailThe puzzling Luminous Blue Variable-like object HD 5980 in the Small Magellanic Cloud.
Heydari-Malayeri, M.; Rauw, Grégor ULg; Esslinger, O. et al

in Astronomy and Astrophysics (1997), 322

We have observed the exceptional SMC star HD 5980 during several runs from 1989 to 1995 at ESO La Silla. CASPEC at the 3.6m telescope and EMMI in echelle and long slit modes at NTT were used for ... [more ▼]

We have observed the exceptional SMC star HD 5980 during several runs from 1989 to 1995 at ESO La Silla. CASPEC at the 3.6m telescope and EMMI in echelle and long slit modes at NTT were used for spectroscopy. Sub-arcsecond images were obtained using SUSI at NTT and also an adaptive optics system at the 3.6m telescope. In all our spectra taken before 1994 September HD 5980 shows a spectral type of WN6. The 1994 September spectra were taken shortly after the maximum of the visual light-curve of the LBV-like phenomenon (Bateson & Jones, 1993PVSS...19...50B) and about one month before the observations of Barba et al. (1995ApJ...446L..23B). Near maximum visual brightness, HD 5980 displays a WN11-like spectrum with the HeI lines and the Balmer lines Hdelta and Hgamma showing well-developed PCyg profiles. The sub-arcsecond images (0.17" FWHM), through the near infrared bands J, H, and K, obtained in 1993 and 1996, show no stellar components down to 6.7 mag fainter than HD 5980 in K at a separation of 1.0" and the 3sigma level. For a separation of 0.3" this upper bound is 4.1mag fainter than HD 5980. The observed behavior of this object raises serious problems for our comprehension of the LBV phenomenon in the conventional scenarios of massive star evolution. The present observations cover a crucial period in the evolution of HD 5980 and will therefore be helpful for better understanding this peculiar object especially during its outburst as well as the evolution of W-R stars in general. [less ▲]

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See detailThe mean magnetic field modulus of AP stars
Mathys, G.; Hubrig, S.; Landstreet, J. D. et al

in Astronomy and Astrophysics. Supplement Series (1997), 123

We present new measurements of the mean magnetic field modulus of a sample of Ap stars with spectral lines resolved into magnetically split components. We report the discovery of 16 new stars having this ... [more ▼]

We present new measurements of the mean magnetic field modulus of a sample of Ap stars with spectral lines resolved into magnetically split components. We report the discovery of 16 new stars having this property. This brings the total number of such stars known to 42. We have performed more than 750 measurements of the mean field modulus of 40 of these 42 stars, between May 1988 and August 1995. The best of them have an estimated accuracy of 25 - 30 G. The availability of such a large number of measurements allows us to discuss for the first time the distribution of the field modulus intensities. A most intriguing result is the apparent existence of a sharp cutoff at the low end of this distribution, since no star with a field modulus (averaged over the rotation period) smaller than 2.8 kG has been found in this study. For more than one third of the studied stars, enough field determinations well distributed throughout the stellar rotation cycle have been achieved to allow us to characterize at least to some extent the variations of the field modulus. These variations are often significantly anharmonic, and it is not unusual for their extrema not to coincide in phase with the extrema of the longitudinal field (for the few stars for which enough data exist about the latter). This, together with considerations on the distribution of the relative amplitude of variation of the studied stars, supports the recently emerging evidence for markedly non-dipolar geometry and fine structure of the magnetic fields of most Ap stars. New or improved determinations of the rotation periods of 9 Ap stars have been achieved from the analysis of the variations of their mean magnetic field modulus. Tentative values of the period have been derived for 5 additional stars, and lower limits have been established for 10 stars. The shortest definite rotation period of an Ap star with magnetically resolved lines is 3.4 deg, while those stars that rotate slowest appear to have periods in excess of 70 or 75 years. As a result of this study, the number of known Ap stars with rotation periods longer than 30 days is almost doubled. We briefly rediscuss the slow-rotation tail of the period distribution of Ap stars. This study also yielded the discovery of radial velocity variations in 8 stars. There seems to be a deficiency of binaries with short orbital periods among Ap stars with magnetically resolved lines. Based on observations collected at the European Southern Observatory (La Silla, Chile; ESO programmes Nos. 43.7-004, 44.7-012, 49.7-030, 50.7-067, 51.7-041, 52.7-063, 53.7-028, 54.E-0416, and 55.E-0751), at the Observatoire de Haute-Provence (Saint-Michel-l'Observatoire, France), at Kitt Peak National Observatory, and at the Canada-France-Hawaii Telescope. Tables 2, 3, and 4 are also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html. [less ▲]

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See detailBlues à Lire: "Swamp Pop & Creole Rhythm & Blues" ( Shane K.Bernard)
Sacré, Robert ULg

in Jazz Hot (1997), (541), 37

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See detailLigated anionic block copolymerization of methyl methacrylate with n-butyl acrylate and n-nonyl acrylate as promoted by lithium 2-(2-methoxyethoxy) ethoxide/diphenylmethyllithium
Nugay, Nihan; Nugay, Turgut; Jérôme, Robert ULg et al

in Journal of Polymer Science. Part A, Polymer Chemistry (1997), 35(8), 1543-1548

Poly(methyl methacrylate-b-n-butyl acrylate) (PMMA-b-Pn-BuA) and poly(methyl methacrylate-b-n-nonyl acrylate) (PMMA-b-Pn-NonA) diblock copolymers have been successfully synthesized by the sequential ... [more ▼]

Poly(methyl methacrylate-b-n-butyl acrylate) (PMMA-b-Pn-BuA) and poly(methyl methacrylate-b-n-nonyl acrylate) (PMMA-b-Pn-NonA) diblock copolymers have been successfully synthesized by the sequential anionic polymerization of methyl methacrylate (MMA) and the n-alkyl acrylate (n-BuA or n-NonA), in a 90/10 toluene/ tetrahydrofuran (THF) mixture at -78°C. When diphenylmethyllithium (DPMLi) ligated with lithium 2-(2-methoxyethoxy) ethoxide (LiOEEM) is used as the initiator, the polymerization of each block appears to be living. Molecular weight and composition of block copolymers can be predicted from the monomer over initator molar ratio and the molecular weight distribution is narrow. Size exclusion chromatography (SEC) supports that no homo-PMMA contaminates the final copolymer. Although the reverse polymerization sequence Pn-NonA-b-PMMA always results in some contamination by homo-Pn-NonA, it has no really significant effect on the final product characteristics. [less ▲]

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See detailMyocardial Viability. Stress Echocardiography Vs Nuclear Medicine
Pierard, Luc ULg; Lancellotti, Patrizio ULg; Benoit, T.

in European Heart Journal (1997), 18(Suppl D), 117-23

Myocardial dyssynergy does not necessarily indicate myocardial necrosis in patients with coronary artery disease. The differentiation between viable and non-viable tissue is of great clinical importance ... [more ▼]

Myocardial dyssynergy does not necessarily indicate myocardial necrosis in patients with coronary artery disease. The differentiation between viable and non-viable tissue is of great clinical importance in order to make the most appropriate clinical decision in the individual patient. Several techniques are used to assess myocardial viability. Nuclear medicine gives reliable information on regional perfusion, metabolism and cell membrane integrity, while echocardiography provides real time visualization of myocardial thickening in basal conditions and continuously during pharmacological interventions. The presence or absence of contractile reserve in akinetic regions can be evaluated by pharmacological stress echocardiography. This article presents the semiology of myocardial viability as characterized by these different methods and reviews their relative value in different clinical settings. [less ▲]

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See detailLe rapport au capital, noyau dur de la coopération de production
Defourny, Jacques ULg

in Economie et Humanisme (1997), (341), 28-33

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See detailBulk polymerization of lactides initiated by aluminium isopropoxide, 2a). Beneficial effect of Lewis bases and transfer agents
Degée, Philippe; Dubois, Philippe ULg; Jérôme, Robert ULg

in Macromolecular Chemistry and Physics (1997), 198(6), 1973-1984

A high increase in the bulk polymerization rate of L,L-lactide and racemic D,L-lactide is observed when aluminium isopropoxide is added with an equimolar amount of a Lewis base, such as triphenylphosphine ... [more ▼]

A high increase in the bulk polymerization rate of L,L-lactide and racemic D,L-lactide is observed when aluminium isopropoxide is added with an equimolar amount of a Lewis base, such as triphenylphosphine (P(Φ)3) and better 4-picoline (C6H7N). Polylactide of high molecular weight and narrow molecular weight distribution is accordingly prepared in a controlled manner when the Al(OiPr)3 ; C6H7N combination is used as an initiator over a large temperature range from 110 to 180°C. A secondary alcohol, such as 2-propa-nol, has proved to be an efficient transfer agent, which allows the amount of Al per kg of polylactide to be advantageously reduced. All the alcohol molecules participate in the ring-opening polymerization even at an [iPrOH]0/[Al] ratio as high as 103. [less ▲]

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See detailRevascularisation coronaire multiple par pontages exclusivement artériels (mammaires internes et artère radiale gauche)
RADERMECKER, Marc ULg; Grenade, Thierry ULg; Cao-Thian, S.K. et al

in Revue Médicale de Liège (1997), 52(6), 377-8

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