共查询到20条相似文献,搜索用时 15 毫秒
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C A Favrod-Coune R C Gaillard H Langevin M C Jaquier W Dolci A F Muller 《Life sciences》1986,39(25):2475-2481
Corticotropin-releasing activity (CRa) and arginine-vasopressin (AVP) content were measured in seven human hypothalami. The hypothalami were obtained from routine autopsy of patients suffering from no obvious neuroendocrinological abnormality. Twelve distinct hypothalamic areas were dissected in the frozen state and extracted in aqueous solution. CRa was measured by a bioassay measuring the aCTH released by rat pituitary cells in vitro, and vasopressin by direct radioimmunoassay. CRa was detectable in almost every area with the highest values in the supraoptic, paraventricular and infundibular (arcuate) areas. Vasopressin concentrations were maximum in the supraoptic nucleus, followed by the paraventricular and infundibular nuclei. We conclude that: hypothalami obtained from routine autopsy at a general hospital can be used for consistent CRa and vasopressin assay. Vasopressin and CRa are similarly distributed in man and in the rat. In both species, high CRa, which is not explained by AVP, is found in the paraventricular nucleus. The infundibular (arcuate) nucleus seems to display non AVP-dependent CRa much greater in the human than in the rat. 相似文献
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Seymour S. Kety 《Neurochemical research》1991,16(9):1073-1078
Special issue dedicated to Dr. Louis Sokoloff. 相似文献
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Investigation of the functional effect of monoamine oxidase polymorphisms in human brain 总被引:14,自引:0,他引:14
Monoamine oxidase A and monoamine oxidase B ( MAOA and MAOB) have been suggested to play a role in psychiatric disorders and/or behavioral traits. We have investigated whether different polymorphisms can account for variations in enzyme activity and/or mRNA levels in human brain. Whereas several association studies have been reported previously, this is the first study of the functional effect of MAO DNA variants in human brain. Four polymorphic changes were analyzed: a VNTR located in the MAOA promoter, a VNTR located in the first intron of the MAOA gene, and two single nucleotide polymorphisms located in exon 8 of MAOA and in intron 13 of MAOB. We studied the association of the variants and the resulting haplotypes, with expression levels and enzyme activities of both monoamine oxidases in human cortical brain autopsies. We did not find a significant association of any single MAOA polymorphism with expression levels or enzyme activity in human brain. We did, however, find an association of a particular haplotype with MAOA enzyme levels ( P=0.03). Our results suggest that a novel functional polymorphism that affects enzyme activity in human brain may exist in MAOA. For MAOB, we found a significant association ( P=0.02) between the MAOB intron 13 alleles and different levels of MAOB enzyme activity in human brain. We postulate that there may be a cis-regulatory element in linkage disequilibrium with the B-SNP13 polymorphisms that alters MAOB enzyme activity in human brain. 相似文献
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I Siegle T Klein M H Zou P Fritz M K?mhoff 《The journal of histochemistry and cytochemistry》2000,48(5):631-641
Prostacyclin (PGI(2)) is a labile, lipid-derived metabolite of arachidonic acid synthesized through the sequential action of cyclo-oxygenase (COX) and prostacyclin synthase (PGIS). In addition to its well-characterized vasodilatory and thrombolytic effects, an increasing number of studies report an important role of PGI(2) in nociception in various animal species. In this study we investigated the regional distribution of PGIS in human brain by immunohistochemistry and in situ hybridization. PGIS-immunoreactive (ir) protein was localized to blood vessels throughout the brain. Neuronal cells and glial cells, such as microglia and oligodendrocytes, also showed intense labeling. The strongest expression of PGIS was seen in large principal neurons, such as pyramidal cells of the cortex, pyramidal cells of the hippocampus, and Purkinje cells of the cerebellum. Abundance of PGIS mRNA was observed in blood vessels and large neurons and correlated well with the immunohistochemical findings. The expression of PGIS in human brain was further demonstrated by immunoblotting and detection of 6-keto-PGF (1alpha), the stable degradation product of prostacyclin in human brain homogenate. These results demonstrate a widespread expression of PGIS in the central nervous system and suggest a potentially important role of prostacylin in modulating neuronal activity in human brain. 相似文献
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Oscillations in brain activity have long been known, but many fundamental aspects of such brain rhythms, particularly their functional importance, have been unclear. As we review here, new insights into these issues are emerging from the application of intervention approaches. In these approaches, the timing of brain oscillations is manipulated by non-invasive brain stimulation, either through sensory input or transcranially, and the behavioural consequence then monitored. Notably, such manipulations have led to rapid, periodic fluctuations in behavioural performance, which co-cycle with underlying brain oscillations. Such findings establish a causal relationship between brain oscillations and behaviour, and are allowing novel tests of longstanding models about the functions of brain oscillations. VIDEO ABSTRACT: 相似文献
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A Somasekaram A Jarmuz A How J Scott N Navaratnam 《The Journal of biological chemistry》1999,274(40):28405-28412
The cytidine deaminases belong to the family of multisubunit enzymes that catalyze the hydrolytic deamination of their substrate to a corresponding uracil product. They play a major role in pyrimidine nucleoside and nucleotide salvage. The intracellular distribution of cytidine deaminase and related enzymes has previously been considered to be cytosolic. Here we show that human cytidine deaminase (HCDA) is present in the nucleus. A highly specific, affinity purified polyclonal antibody against HCDA was used to analyze the intracellular localization of native HCDA in a variety of mammalian cells by in situ immunochemistry. Native HCDA was found to be present in the nucleus as well as the cytoplasm in several cell types. Indirect immunofluorescence microscopy indicated a predominantly nuclear localization of FLAG-tagged HCDA overexpressed in these cells. We have identified an amino-terminal bipartite nuclear localization signal that is both necessary and sufficient to direct HCDA and a non-nuclear reporter protein to the nucleus. We also show HCDA binding to the nuclear import receptor, importin alpha. Similar putative bipartite nuclear localization sequences are found in other cytidine/deoxycytidylate deaminases. The results presented here suggest that the pyrimidine nucleotide salvage pathway may operate in the nucleus. This localization may have implications in the regulation of nucleoside and nucleotide metabolism and nucleic acid biosynthesis. 相似文献
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The evidence that samples of human brain tissue obtained at autopsy may be used as starting material for the isolation of cellular and subcellular preparations which exhibit metabolic and functional activity when incubated in vitro has been reviewed. Supporting evidence has been found in data from model experiments which used animal brain as the source material. Active preparations have been obtained after considerable (up to 24 h) post mortem delays. Such findings are less surprising when the post mortem stability of key tissue components (enzymes, receptors, nucleic acids) and the retention of cellular integrity are examined. The data from these fields have been reviewed and their relevance to functional studies assessed. Studies which use human autopsy material must consider many additional sources of variation not found in experiments with animal brain and the major problems are briefly discussed. It is argued that functional experiments present few, if any, difficulties not already inherent in static analyses of autopsy material and some procedures which help to minimise these difficulties are outlined. Experimentation in this area is greatly aided by the finding that metabolically and functionally active preparations may be obtained from frozen tissue pieces. Dynamic studies provide a new approach for testing hypotheses of the mechanisms underlying human brain disorders and for studying the actions of neuroactive drugs in man. 相似文献
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Since Darwin it is widely accepted that natural selection (NS) is the most important mechanism to explain how biological organisms—in their amazing variety—evolve and, therefore, also how the complexity of certain natural systems can increase over time, creating ever new functions or functional structures/relationships. Nevertheless, the way in which NS is conceived within Darwinian Theory already requires an open, wide enough, functional domain where selective forces may act. And, as the present paper will try to show, this becomes even more evident if one looks into the problem of origins. If there was a time when NS was not operating (as it is quite reasonable to assume), where did that initial functional diversity, necessary to trigger off the process, come from? Self-organization processes may be part of the answer, as many authors have claimed in recent years, but surely not the complete one. We will argue here that a special type of self-maintaining organization, arising from the interplay among a set of different endogenously produced constraints (pre-enzymatic catalysts and primitive compartments included), is required for the appearance of functional diversity in the first place. Starting from that point, NS can progressively lead to new (and, at times, also more complex) organizations that, in turn, provide wider functional variety to be selected for, enlarging in this way the range of action and consequences of the mechanism of NS, in a kind of mutually enhancing effect. 相似文献
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