Calcifications vasculaires et déficit en vitamine K: un facteur de risque modifiable dans l'insuffisance rénale chronique [Vascular calcifications and vitamin K deficiency: a modifiable risk factor in chronic kidney disease].

The mechanisms of vascular calcifications in chronic renal failure are complex. Apart for clotting factors, vitamin K-dependent proteins include matrix Gla protein. Glutamic acid residues in matrix Gla protein are carboxylated by vitamin K-dependent gamma-carboxylase, which enables it to inhibit calcification. The purpose of this review is to discuss available evidence implicating vitamin K as a modifiable risk factor in the pathogenesis of vascular calcification in renal diseases.

A link between FXYD3 (Mat-8)-mediated Na,K-ATPase regulation and differentiation of Caco-2 intestinal epithelial cells.

FXYD3 (Mat-8) proteins are regulators of Na,K-ATPase. In normal tissue, FXYD3 is mainly expressed in stomach and colon, but it is also overexpressed in cancer cells, suggesting a role in tumorogenesis. We show that FXYD3 silencing has no effect on cell proliferation but promotes cell apoptosis and prevents cell differentiation of human colon adenocarcinoma cells (Caco-2), which is reflected by a reduction in alkaline phosphatase and villin expression, a change in several other differentiation markers, and a decrease in transepithelial resistance. Inhibition of cell differentiation in FXYD3-deficient cells is accompanied by an increase in the apparent Na+ and K+ affinities of Na,K-ATPase, reflecting the absence of Na,K-pump regulation by FXYD3. In addition, we observe a decrease in the maximal Na,K-ATPase activity due to a decrease in its turnover number, which correlates with a change in Na,K-ATPase isozyme expression that is characteristic of cancer cells. Overall, our results suggest an important role of FXYD3 in cell differentiation of Caco-2 cells. One possibility is that FXYD3 silencing prevents proper regulation of Na,K-ATPase, which leads to perturbation of cellular Na+ and K+ homeostasis and changes in the expression of Na,K-ATPase isozymes, whose functional properties are incompatible with Caco-2 cell differentiation.

Myocardial impairment in chronic hypoxia is abolished by short aeration episodes: involvement of K+ATP channels.

In vivo exposure to chronic hypoxia is considered to be a cause of myocardial dysfunction, thereby representing a deleterious condition, but repeated aeration episodes may exert some cardioprotection. We investigated the possible role of ATP-sensitive potassium channels in these mechanisms. First, rats (n = 8/group) were exposed for 14 days to either chronic hypoxia (CH; 10% O(2)) or chronic hypoxia with one episode/day of 1-hr normoxic aeration (CH+A), with normoxia (N) as the control. Second, isolated hearts were Langendorff perfused under hypoxia (10% O(2), 30 min) and reoxygenated (94% O(2), 30 min) with or without 3 microM glibenclamide (nonselective K(+)(ATP) channel-blocker) or 100 microM diazoxide (selective mitochondrial K(+)(ATP) channel-opener). Blood gasses, hemoglobin concentration, and plasma malondialdehyde were similar in CH and CH+A and in both different from normoxic (P < 0.01), body weight gain and plasma nitrate/nitrite were higher in CH+A than CH (P < 0.01), whereas apoptosis (number of TUNEL-positive nuclei) was less in CH+A than CH (P < 0.05). During in vitro hypoxia, the efficiency (ratio of ATP production/pressure x rate product) was the same in all groups and diazoxide had no measurable effects on myocardial performance, whereas glibenclamide increased end-diastolic pressure more in N and CH than in CH+A hearts (P < 0.05). During reoxgenation, efficiency was markedly less in CH with respect to N and CH+A (P < 0.0001), and ratex pressure product remained lower in CH than N and CH+A hearts (P < 0.001), but glibenclamide or diazoxide abolished this difference. Glibenclamide, but not diazoxide, decreased vascular resistance in N and CH (P < 0.005 and < 0.001) without changes in CH+A. We hypothesize that cardioprotection in chronically hypoxic hearts derive from cell depolarization by sarcolemmal K(+)(ATP) blockade or from preservation of oxidative phosphorylation efficiency (ATP turnover/myocardial performance) by mitochondrial K(+)(ATP) opening. Therefore K(+)(ATP) channels are involved in the deleterious effects of chronic hypoxia and in the cardioprotection elicited when chronic hypoxia is interrupted with short normoxic aeration episodes.

L'utilisation de l'Evangile de Thomas dans la recherche actuelle sur les paroles de Jésus

(Résumé de l'ouvrage) Ce volume regroupe des travaux menés sur le Jésus de l'histoire par des spécialistes de cette question fondatrice. Celle-ci connait, en effet, de vigoureuses impulsions dues à l'application de nouvelles méthodologies aux effets inattendus: sociologie du judaisme ancien, anthropologie des sociétés agraires, utilisation des écrits apocryphes chrétiens. Pour la première fois, des savants mondialement réputés sont présentés en français tels John S. Kloppenborg (Toronto) ou Ed P. Sanders (Durham). L'ouvrage est construit en sept parties: l'état de la recherche, le judaisme au temps de Jésus, le coeur de la théologie de Jésus, la tradition extracanonique chrétienne et la question du Jésus historique, Jésus dans le Nouveau Testament, les lectures juives de Jésus, le Jésus historique et la théologie.

Validation of the Mini Nutritional Assessment short-form (MNA-SF): a practical tool for identification of nutritional status.

OBJECTIVE: To validate a revision of the Mini Nutritional Assessment short-form (MNA(R)-SF) against the full MNA, a standard tool for nutritional evaluation. METHODS: A literature search identified studies that used the MNA for nutritional screening in geriatric patients. The contacted authors submitted original datasets that were merged into a single database. Various combinations of the questions on the current MNA-SF were tested using this database through combination analysis and ROC based derivation of classification thresholds. RESULTS: Twenty-seven datasets (n=6257 participants) were initially processed from which twelve were used in the current analysis on a sample of 2032 study participants (mean age 82.3y) with complete information on all MNA items. The original MNA-SF was a combination of six questions from the full MNA. A revised MNA-SF included calf circumference (CC) substituted for BMI performed equally well. A revised three-category scoring classification for this revised MNA-SF, using BMI and/or CC, had good sensitivity compared to the full MNA. CONCLUSION: The newly revised MNA-SF is a valid nutritional screening tool applicable to geriatric health care professionals with the option of using CC when BMI cannot be calculated. This revised MNA-SF increases the applicability of this rapid screening tool in clinical practice through the inclusion of a "malnourished" category.

1st datings of ammonite-bearing Bajocian suites from Caucasus (Georgia) - K-Ar ages of volcanic hornblendes

Volcanic flows and tuffs interbedded with ammonite-bearing sediments directly correlatable with the stratotype section of the Bajocian stage have been dated for the first time within the Caucasus area. Three samples, each from a different section, allowed separation of well-preserved brown hornblende; these are considered reliable geochronometers in a region where subsequent volcanic activity occurred. The dated separates are V139: a volcanic layer probably near the base, V142 another layer near the top of the Lower Bajocian substage; V141 a boulder from a latest Bajocian volcanic conglomerate. From bottom to top, apparent ages at 173.5 +/- 2.6, 164.8 +/- 2.5 and 167.1 +/- 1.9 Ma (analytical uncertainty, 95% confidence level) respectively, can be calculated. The consistency of the results is obtained if the dated boulder is interpreted as derived from an underlying layer, The Bajocian-Bathonian boundary is much younger than commonly accepted and younger than 164 Ma.