Cloning and Sequencing of the Low-Affinity Penicillin-Binding Protein 3r-Encoding Gene of Enterococcus Hirae S185: Modular Design and Structural Organization of the Protein

in Journal of Bacteriology (1993), 175(10), 2844-2852

The clinical isolate Enterococcus hirae S185 has a peculiar mode of resistance to penicillin in that it possesses two low-affinity penicillin-binding proteins (PBPs): the 71-kDa PBP5, also found in other ... [more ▼]

The clinical isolate Enterococcus hirae S185 has a peculiar mode of resistance to penicillin in that it possesses two low-affinity penicillin-binding proteins (PBPs): the 71-kDa PBP5, also found in other enterococci, and the 77-kDa PBP3r. The two PBPs have the same low affinity for the drug and are immunochemically related to each other. The PBP3r-encoding gene has been cloned and sequenced, and the derived amino acid sequence has been compared by computer-assisted hydrophobic cluster analysis with that of the low-affinity PBP5 of E. hirae R40, the low-affinity PBP2' of Staphylococcus aureus, and the PBP2 of Escherichia coli used as the standard of reference of the high-M(r) PBPs of class B. On the basis of the shapes, sizes, and distributions of the hydrophobic and nonhydrophobic clusters along the sequences and the linear amino acid alignments derived from this analysis, the dyad PBP3r-PBP5 has an identity index of 78.5%, the triad PBP3r-PBP5-PBP2' has an identity index of 29%, and the tetrad PBP3r-PBP5-PBP2'-PBP2 (of E. coli) has an identity index of 13%. In spite of this divergence, the low-affinity PBPs are of identical modular design and possess the nine amino acid groupings (boxes) typical of the N-terminal and C-terminal domains of the high-M(r) PBPs of class B. At variance with the latter PBPs, however, the low-affinity PBPs have an additional approximately 110-amino-acid polypeptide stretch that is inserted between the amino end of the N-terminal domain and the carboxy end of the membrane anchor. While the enterococcal PBP5 gene is chromosome borne, the PBP3r gene appears to be physically linked to the erm gene, which confers resistance to erythromycin and is known to be plasmid borne in almost all the Streptococcus spp. examined. [less ▲]

Etude critique du rôle du sodium dans l'hypertension artérielle

Thèse d’agrégation de l’enseignement supérieur (1993)

Une partie de nos résultats expérimentaux et cliniques a fait l'objet d'un doctorat en Sciences Cliniques défendu en janvier 1986. La poursuite de ces travaux et le développement de nouvelles techniques ... [more ▼]

Une partie de nos résultats expérimentaux et cliniques a fait l'objet d'un doctorat en Sciences Cliniques défendu en janvier 1986. La poursuite de ces travaux et le développement de nouvelles techniques nous ont donné l'occasion de reprendre ce sujet et d'en approfondir la matière, avec un recul que nous espérons bénéfique. [less ▲]

Expression of the C-Erbb2 Gene in the Bt474 Human Mammary Tumor Cell Line: Measurement of C-Erbb2 Mrna Half-Life

in Oncogene (1993), 8(4), 849-54

BT474 and SK-BR-3 mammary adenocarcinoma cells contain eight copies of the c-erbB2 gene but overexpress the mRNA 80 times over the levels measured in normal breast or in the HBL-100 cell line. Using ... [more ▼]

BT474 and SK-BR-3 mammary adenocarcinoma cells contain eight copies of the c-erbB2 gene but overexpress the mRNA 80 times over the levels measured in normal breast or in the HBL-100 cell line. Using Northern blot analysis and molecular titration based on RNAase protection assay, the decrease in the c-erbB2 mRNA level was monitored in BT474 cells treated with actinomycin D from 1 up to 24 h. The c-erbB2 degradation rate during the first 12 h corresponds to a calculated c-erbB2 mRNA half-life of approximately 7 h. Forty percent of the mRNA present in the cells before treatment remains undegraded after transcription has been blocked for 24 h. Pretreatment with cycloheximide results in complete mRNA degradation in 24 h, suggesting that labile proteins stabilize part of the c-erbB2 mRNA population. Comparison with the c-erbB2 mRNA turnover in HBL-100 'normal' cells indicated that the accumulation of the c-erbB2 gene product in the tumor cells is not the result of stabilization of the messenger. Rather, it is correlated with an increased rate of c-erbB2 mRNA transcription as indicated by run-on transcription assays. Both BT474 and SK-BR-3 tumor cell lines were found to synthesize 20-40 times more c-erbB2 mRNA than HBL-100 cells. [less ▲]

Morphologie à seuillage: application au lissage des formes

Report (1993)

La morphologie mathématique englobe différentes techniques de filtrage aussi variées qu'originales. Parmi l'imposante panoplie des filtres se distinguent ceux qui sont nés de la morphologie à seuillage ... [more ▼]

La morphologie mathématique englobe différentes techniques de filtrage aussi variées qu'originales. Parmi l'imposante panoplie des filtres se distinguent ceux qui sont nés de la morphologie à seuillage, encore appelée morphologie floue, très en vogue à l'heure actuelle. Ce document s'inscrit dans ce courant. Nous y définissons le concept central d'érosion partielle, simple transcription d'une opération déjà connue, pour l'étendre ensuite aux notions de dilatation, d'ouverture et de fermeture partielles. À l'inverse des développements récents en ce domaine, c'est l'aspect géométrique qui y tient le haut du pavé; les opérations partielles se conçoivent comme des interactions entre objets et non en termes de lois de probabilité. Elles conduisent à une série de procédés de lissage des contours d'images binaires gérés par un seuil unique et une famille d'éléménts structurants adaptés à l'application. Des techniques similaires sont évoquées pour des images en niveaux de gris. Nous introduisons ensuite le nouveau concept de polymorphisme d'un point. Ce dernier indique pour chaque point le nombre d'éléments structurants qui contiennent ce point. C'est par son entremise que pourront s'appliquer des procédés d'optimisation de filtrage puisqu'il fournit une mesure analytique. [less ▲]

Morphological image sketch coding

in Workshop on Circuits, Systems and Signal Processing, Proceedings (1993, March)

Barium isotopes in the very metal-poor star HD 140283

in Astronomy and Astrophysics (1993), 268

The fractions of odd and even isotopes of barium in the metal-poor star HD140283 are determined from an analysis of the profile of the Ba II resonance line, taking advantage of the differences in ... [more ▼]

The fractions of odd and even isotopes of barium in the metal-poor star HD140283 are determined from an analysis of the profile of the Ba II resonance line, taking advantage of the differences in hyperfine structure splitting between the different isotopes. Although one would expect an increased contribution of the r-process in very metal-poor stars, it is found that the isotopic ratio is very close to solar. [less ▲]

Misdiagnosed Malignancy in Transplanted Organs

in Transplant International (1993), 6(1), 50-4

The case reports of three patients who received cancer-bearing organs at this institution are presented. A fourth recipient, who was to be transplanted with a cancerous kidney, was spared this disastrous ... [more ▼]

The case reports of three patients who received cancer-bearing organs at this institution are presented. A fourth recipient, who was to be transplanted with a cancerous kidney, was spared this disastrous complication. The relevant data regarding the donors is also alluded to, with special reference to the type and site of the primary malignancy. Following these case reports, the implications of these issues, their possible prevention, and further management are discussed. [less ▲]

Paget's Disease of Bone Treated with a Five Day Course of Oral Tiludronate

in Annals of the Rheumatic Diseases (1993), 52(1), 54-7

Chloro-4-phenyl thiomethylene bisphosphonate (tiludronate) is a new drug which can be used as an inhibitor of bone resorption. As it remains in bone for a long time, and as mineralisation defects have ... [more ▼]

Chloro-4-phenyl thiomethylene bisphosphonate (tiludronate) is a new drug which can be used as an inhibitor of bone resorption. As it remains in bone for a long time, and as mineralisation defects have only been seen at doses much higher than those required to decrease osteoclastic activity, it could be given at high doses over a short period of time. Eighteen patients with Paget's disease of bone were randomly allocated to three therapeutic groups receiving respectively 600, 800, and 1200 mg/day tiludronate for five days. Serum alkaline phosphatase activity and the urinary hydroxyproline/creatinine ratio were quickly and drastically reduced in all three groups. A significant reduction of serum alkaline phosphatases and the hydroxyproline/creatinine ratio was still present six months after the five day therapeutic course, reflecting a sustained activity of tiludronate even after stopping treatment. Dose dependent short and long term reductions of bone turnover rate were observed. Biochemical assessment of haematological, renal, or hepatic tolerance did not show any toxicity of tiludronate. Fifty per cent of patients treated by a dose of 1200 mg/day reported gastrointestinal disturbances, however, making this dosage unsuitable for clinical practice. [less ▲]

Chasse et conservation de la nature

Learning material (1993)

The Pomeron and odderon to order alpha-s**3

in Schechter, J. (Ed.) WALIFEST - MRST 15: NEW DIRECTIONS IN THE APPLICATION OF SYMMETRY PRINCIPLES TO ELEMENTARY PARTICLE PHYSICS (1993)