Hypothyroidism provides resistance to kidney mitochondria against the injury induced by renal ischemia-reperfusion

Massive Ca(2+) accumulation in mitochondria, plus the stimulating effect of an inducing agent, i.e., oxidative stress, induces the so-called permeability transition, which is characterized by the opening of a nonspecific pore. This work was aimed at studying the influence of thyroid hormone on the opening of such a nonspecific pore in kidney mitochondria, as induced by an oxidative stress. To meet this objective, membrane permeability transition was examined in mitochondria isolated from kidney of euthyroid and hypothyroid rats, after a period of ischemia/reperfusion. It was found that mitochondria from hypothyroid rats were able to retain accumulated Ca(2+) to sustain a transmembrane potential after Ca(2+) addition, as well as to maintain matrix NAD(+) and membrane cytochrome c content. The protective effect of hypothyroidism was clearly opposed to that occurring in ischemic reperfused mitochondria from euthyroid rats. Our findings demonstrate that these mitochondria were unable to preserve selective membrane permeability, except when cyclosporin A was added. It is proposed that the protection is conferred by the low content of cardiolipin found in the inner membrane. This phospholipid is required to switch adenine nucleotide translocase from specific carrier to a non-specific pore.     

Cytokinins contribute to realization of nitric oxide growth-stimulating and protective effects on wheat plants

We investigated effects of sodium nitroprusside (SNP), the donor of nitric oxide (NO), on the growth and hormonal system of wheat plants (Triticum aestivum L.) in normal conditions and after salt stress (2% NaCl). During germination of seeds treated with SNP (50–500 μM), we obtained the SNP concentration (200 μM) optimal for stimulation of seedling growth estimated by increase in seed germination capacity and seedlings' linear sizes and their fresh and dry biomass. A comparative analysis of SNP (200 μM) effects, after seed germination in the medium with SNP or pretreatment of 3-day-old seedlings, showed SNP ability to increase the wheat plant resistance to subsequent effects of sodium chloride salinity at both treatment methods. Protective SNP effects appeared in the reduction of stress inhibitory action on seedling growth rates and significant reduction in the level of lipid peroxidation and exosmosis of electrolytes. An important contribution to realization of the growth-stimulating and protective effects of NO is associated with its ability to influence the state of the hormonal system of wheat plants due to an increase in the concentration of hormones of a cytokinin nature under normal conditions and the prevention of a decrease in their level under stress.     

Autoradiographies de Coupes d'os compact après marquage aux isotopes in vitro

Résumé Etude qualitative et quantitative du marquage in vitro de coupes d'os compact. Détermination du rôle joué par les processus de diffusion, d'adsorption et d'échange dans ces phénomènes.

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Zusammenfassung Qualitative und quantitative Studie der in vitro-Markierung von Schliffen aus Knochen-Compacta. Bestimmung der Rolle der Diffusions-, Adsorptions- und Austauschprozesse für diese Vorgänge.

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La partie expérimentale de ce travail a pu être réalisée grâce à des subsides fournis par l'European Office of the Air Research and Development Command [contrat n^o AF 61 (514) 1175], par l'Institut Interuniversitaire Belge des Sciences Nucléaires, et par la Commission pour la Science Atomique du Fonds National Suisse de la Recherche Scientifique.     

Role respectif des males et des femelles dans la formation des sexués néoténiques chezCalotermes flavicollis

Résumé ChezCalotermes flavicollis, la formation des sexués néoténiques est plus facile, ou plus rapide, dans le sexe femelle que dans le sexe mâle.Les sexués femelles montrent un pouvoir inhibiteur à l'égard des individus femelles; les sexués mâles inhibent les mâles de façon moins complète; la stabilisation complète peut être obtenue dans les élevages unisexués, formés uniquement de mâles ou de femelles.La régulation du nombre des néoténiques ne se fait pas de la même façon dans les élevages et dans les élevages . Dans les premiers, 2 néoténiques subsistent, quelquefois 3; dans les seconds ne persiste qu'un seul néoténique , rarement deux.Ces résultats mettent en lumière le rôle différent joué par les mâles et les femelles dans les sociétés de Termites.     

Acute Effect of Ammonia on Branched-Chain Amino Acid Oxidation and Incorporation into Proteins in Astrocytes and in Neurons in Primary Cultures

14CO2 production and incorporation of label into proteins from the labeled branched-chain amino acids, leucine, valine, and isoleucine, were determined in primary cultures of neurons and of undifferentiated and differentiated astrocytes from mouse cerebral cortex in the absence and presence of 3 mM ammonium chloride. Production of 14CO2 from [1-14C]leucine and [1-14C]valine was larger than 14CO2 production from [U-14C]leucine and [U-14C]valine in both astrocytes and neurons. In most cases more 14CO2 was produced in astrocytes than in neurons. Incorporation of labeled branched-chain amino acids into proteins varied with the cell type and with the amino acid. Addition of 3 mM ammonium chloride greatly suppressed 14CO2 production from [1-14C]-labeled branched chain amino acids but had little effect on 14CO2 production from [U-14C]-labeled branched-chain amino acids in astrocytes. Ammonium ion, at this concentration, suppressed the incorporation of label from all three branched-chain amino acids into proteins of astrocytes. In contrast, ammonium ion had very little effect on the metabolism (oxidation and incorporation into proteins) of these amino acids in neurons. The possible implications of these findings are discussed, especially regarding whether they signify variations in metabolic fluxes and/or in magnitudes of precursor pools.     

Identification and molecular cytogenetic characterization of a novel complex Y chromosome rearrangement in a boy with disorder of sexual development

Ambiguous genitalia or disorder of the sexual development is a birth defect where the external genitals do not have the typical appearance of either a male or female. Here we report a boy with ambiguous genitalia and short stature. The cytogenetic analysis by G-banding revealed a small Y chromosome and an additional material on the 15p arm. Further, molecular cytogenetic analysis by Fluorescence in situ hybridization (FISH) using whole chromosome paint probes showed the presence of Y sequences on the 15p arm, confirming that it is a Y;15 translocation. Subsequent, FISH with centromere probe Y showed two signals depicting the presence of two centromeres and differing with a balanced translocation. The dicentric nature of the derivative 15 chromosome was confirmed by FISH with both 15 and Y centromeric probes. Further, the delineation of the Y chromosomal DNA was also done by quantitative real time PCR. Additional Y-short tandem repeat typing was performed to find out the extent of deletion on small Y chromosome. Fine mapping was carried out with 8 Y specific BAC clones which helped in defining the breakpoint regions. MLPA was performed to check the presence or absence of subtelomeric regions and SHOX regions on Y. Finally array CGH helped us in confirming the breakpoint regions. In our study we identified and characterized a novel complex Y chromosomal rearrangement with a complete deletion of the Yq region and duplication of the Yp region with one copy being translocated onto the15p arm. This is the first report of novel and unique Y complex rearrangement showing a deletion, duplication and a translocation in the same patient. The possible mechanism of the rearrangement and the phenotype–genotype correlation are discussed.     

Somatic embryogenesis in Centella asiatica L. an important medicinal and neutraceutical plant of India

Leaf segments excised from Centella asiatica, a medicinal and neutraceutical plant, produced abundant somaticembryoswhen cultured onMS mediumwith 9.29 Mkinetin in combination with 2.26 M2,4-D. Granular, white,shiny clusters of callus developed after 1 week of culture, and then formed heart and cotyledonary stage embryoson the same medium after 4 weeks. Somatic embryos matured and germinated in the presence of MS mediumcontaining 2.32 M kinetin with (2.89M) GA3. Plantlets were successfully transferred to pots containing amixture of soil and vermiculite (1:1).     

A two-dimensional proteome map of maize endosperm

We have established a proteome reference map for maize (Zea mays L.) endosperm by means of two-dimensional gel electrophoresis and protein identification with LC-MS/MS analysis. This investigation focussed on proteins in major spots in a 4-7 pI range and 10-100 kDa M(r) range. Among the 632 protein spots processed, 496 were identified by matching against the NCBInr and ZMtuc-tus databases (using the SEQUEST software). Forty-two per cent of the proteins were identified against maize sequences, 23% against rice sequences and 21% against Arabidopsis sequences. Identified proteins were not only cytoplasmic but also nuclear, mitochondrial or amyloplastic. Metabolic processes, protein destination, protein synthesis, cell rescue, defense, cell death and ageing are the most abundant functional categories, comprising almost half of the 632 proteins analyzed in our study. This proteome map constitutes a powerful tool for physiological studies and is the first step for investigating the maize endosperm development.     

Phagocytosis in the developing CNS: more than clearing the corpses

Cell corpses generated during CNS development are eliminated through phagocytosis performed by a variety of cells, including mesenchyme-derived macrophages and microglia, or glial cells originating in the neurogenic ectoderm. Mounting evidence indicates that in different species, phagocytes not only clear cell corpses but also engulf still-living neural cells or axons, and thereby promote cell death or axon pruning. Knowledge of the mechanisms of corpse recognition by engulfing cells provides molecular signals to this new role for phagocytes. These observations support a conserved and instructive role for phagocytosis in the execution of regressive events during neurogenesis.