Fatty acid composition of brain hemispheres of spontaneously hypertensive rats suckled by female Wistar rats

Total lipid fatty acid composition was investigated in brain hemispheres of male Spontaneously Hypertensive Rats (SHR), compared with normotensive Wistar Kyoto rats (WKY) used as controls. Both strains were suckled by adoptive Wistar mothers, and then fed a standard diet after weaning. No difference was observed between the two hemispheres of WKY killed either at 10 or 30 days. In SHR killed at 10 days, the two hemispheres showed differences, SHR left hemispheres exhibiting greater fatty acid composition changes than those of WKY, phenomenon that toned down at 30 days. Hence, SHR pups showed a different total lipid fatty acid composition of their brain hemispheres when compared with their WKY controls, though the two strains received the same diet. Genetically programmed hypertension might be, directly or not, involved in these changes.     

BEPITOPE: predicting the location of continuous epitopes and patterns in proteins

In growing need of obtaining highly specific monoclonal antibodies against novel proteins, we developed new functions implemented in the program BEPITOPE to predict continuous protein epitopes. This program not only can compute, combine, display and print prediction profiles, but also provides a list of suggested linear peptides to be synthesized. Novel facilities incorporated in BEPITOPE include the treatment of a whole genome, the search for a user-defined pattern, and the combination of prediction to pattern profiles. This latter approach is useful to remove unwanted predictions such as those including glycosylation sites.     

Structure-activity relationship in the oxazolidinone-quinolone hybrid series: influence of the central spacer on the antibacterial activity and the mode of action

Oxazolidinone-quinolone hybrids, which combine the pharmacophores of a quinolone and an oxazolidinone, were synthesised and shown to be active against a variety of susceptible and resistant Gram-positive and Gram-negative bacteria. The nature of the spacer greatly influences the antibacterial activity by directing the mode of action, that is quinolone- and/or oxazolidinone-like activity. The best compounds in this series have a balanced dual mode of action and overcome all types of resistance, including resistance to quinolones and linezolid, in clinically relevant Gram-positive pathogens.     

Phylogenetic analysis of the tribe Bovini using microsatellites

The objective of the present study was to determine if the generally accepted phylogenetic relationships in the tribe Bovini correspond to a phylogenetic scheme derived from polymorphisms at 20 bovine microsatellite loci. This study comprises 17 representative populations: eight Bos taurus, two Bos indicus, one Poëphagus, one Bibos, one Bison, three Bubalus and one Syncerus. Phylogenetic analyses using (δμ)² and chord (D_C) distances revealed substantial divergence among species. Neighbor‐joining trees with both distance measures showed only minor differences. Bos taurus and Bos indicus grouped first, followed by Bos frontalis (Mithan) and Bos grunniens (Yak), Bison bison branched off next and Bubalus bubalis and Syncerus caffer emerged as the two most divergent species from the Bos clade. These findings would suggest that Bos, Poëphagus, and Bibos should be integrated into the Bos genus with each group classified as a subgenus. On the other hand, Bison, Bubalus and Syncerus should each be considered a separate genus. Direct estimates of the divergence times were calculated using the (δμ)² genetic distance. Bos taurus and Bos indicus were estimated to have diverged 0·31–0·82 MYA, Bos and Poëphagus: 0·57–1·53 MYA, Bos and Bibos: 0·57–1·52 MYA, Bos and Bison: 0·46–1·23 MYA, Bos and Bubalus: 1·85–4·93 MYA and Bos and Syncerus: 0·98–2·61 MYA.     

Growth rate influences reductive biodegradation of the organophosphorus pesticide demeton by Corynebacterium glutamicum

The organophosphorous pesticide, demeton-S-methyl was transformed byCorynebacterium glutamicum in co-metabolism with more readilydegradable substrates. Glucose, acetate and fructose were tested as growth substrates, and the highest demeton-S-methyl biotransformation average rate (0.78 mg l^-1 h^-1) and maximum instantaneous rate (1.4 mg l^-1 h^-1) were achieved on fructose. This higher efficiency seems to be linked to the atypical behavior of C. glutamicum grown on fructose, characterized by a prolonged period of accelerating growth instead of a constant growth rate observed on glucose or acetate. More precisely, for growth rates in the 0.1–0.4 h^-1 range, a direct coupling between the specific demeton-S-methyl consumption rate and the growth rate was demonstrated on fructose during batch –, steady state continuous – or continuous cultures with a controlled transient growth rate (accelerostat technology). The demeton-S-methyl biotransformation was more favoured during an acceleration phase of the growth rate.     

Zinedin, SG2NA, and striatin are calmodulin-binding, WD repeat proteins principally expressed in the brain

Striatin is an intracellular protein characterized by four protein-protein interaction domains, a caveolin-binding motif, a coiled-coil structure, a calmodulin-binding domain, and a WD repeat domain, suggesting that it is a signaling or a scaffold protein. Down-regulation of striatin, which is expressed in a few subsets of neurons, impairs the growth of dendrites as well as rat locomotor activity (Bartoli, M., Ternaux, J. P., Forni, C., Portalier, P., Salin, P., Amalric, M., and Monneron, A. (1999) J. Neurobiol. 40, 234-243). Zinedin, a "novel" protein described here, and SG2NA share with striatin identical protein-protein interaction domains and the same overall domain structure. A phylogenetic analysis supports the hypothesis that they constitute a multigenic family deriving from an ancestral gene. DNA probes and antibodies raised against specific domains of each protein showed that zinedin is mainly expressed in the central nervous system, whereas SG2NA, of more widespread occurrence, is mainly expressed in the brain and muscle. All three proteins are both cytosolic and membrane-bound. All three bind calmodulin in the presence of Ca(2+). In rat brain, SG2NA and striatin are generally not found in the same neurons. Both localize to the soma and dendrites, suggesting that they share a similar type of addressing and closely related functions.     

Body mass and individual fitness in female ungulates: bigger is not always better

In female vertebrates, differences in fitness often correspond to differences in phenotypic quality, suggesting that larger females have greater fitness. Variation in individual fitness can result from variation in life span and/or variation in yearly reproductive success, but no study has yet assessed the relationships between the components of fitness and phenotypic quality while controlling for life span. We tried to fill this gap using data from long-term monitoring (23 years) of marked roe deer and bighorn sheep, two ungulates with very different life histories. In both species, we found a strong positive relationship between an adult female's mass and her probability of reaching old age: over the long term, bigger is indeed better for ungulate females. On the other hand, we found no evidence in either species that heavier females had higher fitness when differences in life span were accounted for: over the short term, bigger is not necessarily better. Our results indicate that, while broad differences in phenotypic quality affect individual fitness, when differences in life span are accounted for phenotypic quality has no residual effect on fitness. Therefore, within a given range of phenotypic quality, bigger is not always better, for reasons which may differ between species.     

Early expression of beta- and gamma-subunits of epithelial sodium channel during human airway development

The amiloride-sensitive epithelial Na(+) channel (ENaC) is an apical membrane protein complex involved in active Na(+) absorption and in control of fluid composition in airways. There are no data reporting the distribution of its pore-forming alpha-, beta-, and gamma-subunits in the developing human lung. With use of two different rabbit polyclonal antisera raised against beta- and gamma-ENaC, immunohistochemical localization of the channel was performed in fetal (10-35 wk) and in adult human airways. Both subunits were detected after 17 wk of gestation on the apical domain of bronchial ciliated cells, in glandular ducts, and in bronchiolar ciliated and Clara cells. After 30 wk, the distribution of beta- and gamma-subunits was similar in fetal and adult airways. In large airways, the two subunits were detected in ciliated cells, in cells lining glandular ducts, and in the serous gland cells. In the distal bronchioles, beta- and gamma-subunits were identified in ciliated and Clara cells. Ultrastructural immunogold labeling confirmed the identification of beta- and gamma-ENaC proteins in submucosal serous cells and bronchiolar Clara cells. Early expression of ENaC proteins in human fetal airways suggests that Na(+) absorption might begin significantly before birth, even if secretion is still dominant.