Genetic variation in serotonin transporter alters resting brain function in healthy individuals.

BACKGROUND: Perfusion functional magnetic resonance imaging (fMRI) was used to investigate the effect of genetic variation of the human serotonin transporter (5-HTT) gene (5-HTTLPR, SLC6A4) on resting brain function of healthy individuals. METHODS: Twenty-six healthy subjects, half homozygous for the 5-HTTLPR short allele (s/s group) and half homozygous for the long allele (l/l group), underwent perfusion functional and structural magnetic resonance imaging during a resting state. The two genotype groups had no psychiatric illness and were similar in age, gender, and personality scores. RESULTS: Compared with the l/l group, the s/s group showed significantly increased resting cerebral blood flow (CBF) in the amygdala and decreased CBF in the ventromedial prefrontal cortex. The effect of functional modulation in these regions by 5-HTTLPR genotype cannot be accounted for by variations in brain anatomy, personality, or self-reported mood. CONCLUSIONS: The 5-HTTLPR genotype alters resting brain function in emotion-related regions in healthy individuals, including the amygdala and ventromedial prefrontal cortex. Such alterations suggest a broad role of the 5-HTT gene in brain function that may be associated with the genetic susceptibility for mood disorders such as depression.     

重组人白细胞介素-1β对小鼠骨髓粒系细胞和红系细胞的正负调节作用

为阐明IL-1对粒系细胞和红系细胞的作用,我们通过对小鼠骨髓及外周血的研究探讨了IL-1对粒系和红系造血细胞的调节作用.结果表明:IL-1单剂量腹腔注射后第7天红系造血细胞明显减少,外周血网织红细胞在第8天显著下降.在5～10万U/kg剂量范围内IL-1明显促进粒系细胞的增殖.应用流式细胞仪对DNA分析显示IL-1并不引起全骨髓细胞DNA的变化,但大体积细胞在注射IL-1后第3天S期细胞明显增多.我们的结果表明IL-1抑制红系造血细胞的分化增殖,在适当的剂量范围内促进粒系细胞的增殖和分化成熟.其作用的分子基础是诱导造血细胞的细胞周期变化.     

Modulation of carbohydrate metabolism in the selected tissues of marine prawn, Penaeus indicus (H. Milne Edwards), under phosphamidon-induced stress

Changes in carbohydrate metabolism were studied in midgut gland, muscle, and gill tissues of marine prawn Penaeus indicus exposed to a sublethal concentration (0.3 ppm) of phosphamidon. A significant decrease in glycogen and pyruvate and an increase in lactate content were observed in all phosphamidon-exposed prawn tissues after 96 hr. An increase in phosphorylase a and aldolase activity levels suggested the increased formation of triose sugars during phosphamidon toxicity. LDH activity was considerably decreased and an increment in lactate content was observed which indicates reduced mobilization of pyruvate into the citric acid cycle. Glucose-6-phosphate dehydrogenase activity was considerably increased, suggesting the enhanced oxidation of glucose in the hexose monophosphate shunt pathway. Krebs cycle enzymes such as NAD-isocitrate dehydrogenase, succinate dehydrogenase, and malate dehydrogenase were found to be decreased, suggesting the impairment in mitochondrial oxidative metabolism due to the acute toxic impact of phosphamidon. Cytochrome-c oxidase and Mg2+ ATPase activity levels were also decreased considerably, suggesting impaired energy synthesis and breakdown during phosphamidon toxicity, as a result of reduced oxidation of glucose aerobically. The increase in acid and alkaline phosphatase activities indicates the enhanced breakdown of phosphate to release energy in view of inhibiton or impairment in the ATPase system during phosphamidon-induced stress. These results suggest that phosphamidon has a profound effect on the oxidative metabolism of prawn which results in the triggering of compensatory metabolic pathways for survivability.     

Differentiation of pancreatic epithelial progenitor cells into hepatocytes following transplantation into rat liver

The ability to identify, isolate, and transplant progenitor cells from solid tissues would greatly facilitate the treatment of diseases currently requiring whole organ transplantation. In this study, cell fractions enriched in candidate epithelial progenitor cells from the rat pancreas were isolated and transplanted into the liver of an inbred strain of Fischer rats. Using a dipeptidyl dipeptidase IV genetic marker system to follow the fate of transplanted cells in conjunction with albumin gene expression, we provide conclusive evidence that, after transplantation to the liver, epithelial progenitor cells from the pancreas differentiate into hepatocytes, express liver-specific proteins, and become fully integrated into the liver parenchymal structure. These studies demonstrate the presence of multipotent progenitor cells in the adult pancreas and establish a role for the liver microenvironment in the terminal differentiation of epithelial cells of foregut origin. They further suggest that such progenitor cells might be useful in studies of organ repopulation following acute or chronic liver injury.