Impaired semantic knowledge underlies the reduced verbal short-term storage capacity in Alzheimer's disease.

in Neuropsychologia (2009), 47(14), 3067-73

A decrease in verbal short-term memory (STM) capacity is consistently observed in patients with Alzheimer's disease (AD). Although this impairment has been mainly attributed to attentional deficits during ... [more ▼]

A decrease in verbal short-term memory (STM) capacity is consistently observed in patients with Alzheimer's disease (AD). Although this impairment has been mainly attributed to attentional deficits during encoding and maintenance, the progressive deterioration of semantic knowledge in early stages of AD may also be an important determinant of poor STM performance. The aim of this study was to examine the influence of semantic knowledge on verbal short-term memory storage capacity in normal aging and in AD by exploring the impact of word imageability on STM performance. Sixteen patients suffering from mild AD, 16 healthy elderly subjects and 16 young subjects performed an immediate serial recall task using word lists containing high or low imageability words. All participant groups recalled more high imageability words than low imageability words, but the effect of word imageability on verbal STM was greater in AD patients than in both the young and the elderly control groups. More precisely, AD patients showed a marked decrease in STM performance when presented with lists of low imageability words, whereas recall of high imageability words was relatively well preserved. Furthermore, AD patients displayed an abnormal proportion of phonological errors in the low imageability condition. Overall, these results indicate that the support of semantic knowledge on STM performance was impaired for lists of low imageability words in AD patients. More generally, these findings suggest that the deterioration of semantic knowledge is partly responsible for the poor verbal short-term storage capacity observed in AD. [less ▲]

Impaired verbal short-term memory for serial order information in dyslexic adults

Poster (2010, September 10)

This study used the distinction of item and order information in verbal short-term memory (STM) to further our understanding of verbal STM impairments in dyslexia. Item STM has been shown to depend on the ... [more ▼]

This study used the distinction of item and order information in verbal short-term memory (STM) to further our understanding of verbal STM impairments in dyslexia. Item STM has been shown to depend on the quality of underlying phonological representations and hence should be impaired in dyslexic participants given their poor phonological processing abilities. On the other hand, order STM represents a specific STM capacity predicting learning capacity for new phonological and orthographic sequences (Majerus et al., 2006; Nithart et al, 2010). If STM impairments contribute to dyslexia, then especially order STM should be impaired, in addition to item STM. [less ▲]

Impairment of neocortical metabolism predicts progression in Alzheimer's disease

in Dementia & Geriatric Cognitive Disorders (1999), 10(6), 494-504

Studied prediction of progression rates of Alzheimer's disease (AD) in a prospective multicenter cohort study of 186 patients (mean age 63.2 yrs) with possible or probable AD, mostly with presenile onset ... [more ▼]

Studied prediction of progression rates of Alzheimer's disease (AD) in a prospective multicenter cohort study of 186 patients (mean age 63.2 yrs) with possible or probable AD, mostly with presenile onset. In a cross-sectional analysis at entry, impairment of glucose metabolism in temporoparietal or frontal association areas measured with positron emission tomography was significantly associated with dementia severity, clinical classification as possible vs probable AD, presence of multiple cognitive deficits and history of progression. A prospective longitudinal analysis showed a significant association between initial metabolic impairment and subsequent clinical deterioration. In patients with mild cognitive deficits at entry, the risk of deterioration was up to 4.7 times higher if the metabolism was severely impaired than with mild or absent metabolic impairment. [less ▲]

Impairment of renal function with increasing blood lead concentrations in the general population

in New England Journal of Medicine [=NEJM] (1992), 327(3), 151-156

Cadmium and lead are toxic to the kidney. Both metals are known to induce nephropathy in subjects with heavy exposure. Environmental exposure to cadmium is associated with renal tubular dysfunction, but ... [more ▼]

Cadmium and lead are toxic to the kidney. Both metals are known to induce nephropathy in subjects with heavy exposure. Environmental exposure to cadmium is associated with renal tubular dysfunction, but few studies have attempted to evaluate the renal effects of environmental lead exposure. A weak positive correlation between serum creatinine and blood lead concentrations was found in men, but not women, in the British civil service. We investigated the relation between lead exposure and renal function in the general population, using data obtained during the Cadmibel (Cadmium in Belgium) Study. Lead exposure was estimated by measuring blood concentrations of lead and zinc protoporphyrin, which is increased in the presence of high lead levels. [less ▲]

Impairment of the mitochondrial electron chain transport prevents NF-kappa B activation by hydrogen peroxide.

in Free Radical Biology & Medicine (1998), 25(1), 104-112

A large body of work has been devoted to mechanisms leading to the activation of the transcription factor NF-kappa B in various cell types. Several studies have indicated that NF-kappa B activation by ... [more ▼]

A large body of work has been devoted to mechanisms leading to the activation of the transcription factor NF-kappa B in various cell types. Several studies have indicated that NF-kappa B activation by numerous stimuli depends on the intracellular generation of reactive oxygen species (ROS). In this report, we first demonstrated that inhibition of the electron transport chain by either rotenone or antimycine A gave rise to dose-dependent inhibition of NF-kappa B translocation induced by 150 microM of hydrogen peroxide (H2O2). Conversely, the impairment of the mitochondrial respiratory chain did not affect T lymphocyte treatment by TNF-alpha (tumor necrosis factor alpha) or pre-B lymphocyte treatment with LPS (lipopolysaccharide). We also showed that oligomycine which inhibits ATP synthase and FCCP, which uncouples respiration also led to dose-dependent inhibition of NF-kappa B activation by H2O2. All these inhibitors were also shown to inhibit mitochondrial respiration in lymphocytes assessed by oxygen consumption. Although only a transient drop in ATP concentration was observed when lymphocytes were treated by H2O2, this effect was remarkably reinforced in the presence of oligomycine demonstrating the crucial role of ATP in the signal transduction pathway induced by H2O2. [less ▲]

Imparting antifouling properties of poly(2-hydroxyethyl methacrylate) hydrogels by grafting poly(oligoethylene glycol methyl ether acrylate)

in Langmuir (2008), 24(13), 6649-6658

The antifouling properties of poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) hydrogels were improved by the surface grafting of a brush of poly(oligoethylene glycol methyl ether acrylate) [poly ... [more ▼]

The antifouling properties of poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) hydrogels were improved by the surface grafting of a brush of poly(oligoethylene glycol methyl ether acrylate) [poly(OEGA)]. The atom-transfer radical polymerization (ATRP) of OEGA (degree of polymerization = 8) was initiated from the preactivated surface of the hydrogel under mild conditions, thus in water at 25 °C. The catalytic system was optimized on the basis of two ligands [1,1,4,7,10,10-hexamethyl-triethylenetetramine (HMTETA) or tris[2-(dimethylamino)ethyl]amine (Me6TREN)] and two copper salts (CuIBr or CuICl). Faster polymerization was observed for the Me6TREN/CuIBr combination. The chemical composition and morphology of the coated surface were analyzed by X-ray photoelectron spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy, contact angle measurements by the water droplet and captive bubble methods, scanning electron microscopy, and environmental scanning electron microscopy. The hydrophilicity of the surface increased with the molar mass of the grafted poly(OEGA) chains, and the surface modifications were reported in parallel. The antifouling properties of the coatings were tested by in vitro protein adsorption and cell adhesion tests, with green fluorescent protein, β-lactamase, and lens epithelial cells, as model proteins and model cells, respectively. The grafted poly(OEGA) brush decreased the nonspecific protein adsorption and imparted high cell repellency to the hydrogel surface. [less ▲]

L'impatto del Gaio veronese sull'insegnamento del diritto romano in Belgio

in Index : Quaderni Camerti di Studi Romanistici = International Survey of Roman Law (2013), 41

1817 is the year when the palimpsest of the Institutes of Gaius was discovered. It was also the year of the founding of the universities of Liège, Ghent and Louvain. But the teaching of Roman Law has not ... [more ▼]

1817 is the year when the palimpsest of the Institutes of Gaius was discovered. It was also the year of the founding of the universities of Liège, Ghent and Louvain. But the teaching of Roman Law has not equally profited of this discovery in all universities. The great Professor Leopold August Warnkönig has played a very important role in this respect: He was professor of roman law successively in Liège, Louvain and Ghent. [less ▲]

Impedance Spectroscopy of GeSn-based Heterostructures

in ECS Transactions (2013), 50(9), 481-490

In this work, we investigated the electrical characteristics of p-GeSn/p-Ge and p-GeSn/n-Ge structures obtained by simulation of the basic semiconductor equations. We developed a numerical formalism based ... [more ▼]

In this work, we investigated the electrical characteristics of p-GeSn/p-Ge and p-GeSn/n-Ge structures obtained by simulation of the basic semiconductor equations. We developed a numerical formalism based on a drift-diffusion model including a trap level and applied it to typical GeSn-based heterostructures by focusing on the electrical response under small-signal alternating current regime. The results demonstrate that our method provides an access to both microscopic and macroscopic properties, and thereon, to a physical interpretation of the electrical characteristics of GeSn-based structures by linking measurable quantities to micro-scale variations in the structures. [less ▲]

Imperial Power and Maritime Trade: Mecca and Cairo in the Later Middle Ages. By JOHN L. MELOY. Chicago: MIDDLE EAST DOCUMENTATION CENTER, UNIVERSITY OF CHICAGO, 2010

in Journal of the American Oriental Society (2013), 133(1), 53-55

L'impiété grecque entre loi humaine et loi divine : étude de l'asebeia dans les sources épigraphiques

Master's dissertation (2010)