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991.
Schuld A Schmid DA Haack M Holsboer F Friess E Pollmächer T 《Journal of psychiatric research》2003,37(6):463-470
Dysfunction of the hyopthalamo-pituitary adrenal (HPA) system is frequently found in major depression. In addition, signs of non-specific inflammatory system activation have been reported. However, very little is known about interactions between the HPA and immune systems in depressive patients. To assess HPA system function, we performed a combined dexamethasone suppression and corticotropin-releasing hormone stimulation (DEX/CRH) test in 14 depressive patients. Moreover, baseline nocturnal plasma levels of the inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor (TNF)- were measured. In addition, the system was challenged with an intraveneous pulsatile injection of hydrocortisone (1 mg/kg body weight in total) and again cytokine levels were measured across one night. Baseline TNF- levels were negatively correlated with the amount of ACTH released upon CRH stimulation during the DEX/CRH test. Acute hydrocortisone administration suppressed TNF- and IL-6 levels independently of baseline HPA system activity. We conclude that chronic HPA system overactivity in depressed patients might compromise the production of inflammatory cytokines under baseline conditions. However, the responsivity of the cytokine production to acutely administered glucocorticoids does not seem to correlate with the state of the HPA system. 相似文献
992.
Tripathi M Goel V Padma MV Jain S Maheshwari MC Gaikwad S Gupta V Chandra PS Mehta VS 《Neurology India》2003,51(1):75-76
A 21-year-old male presented with sudden onset of right-sided third nerve paresis. Angiogram showed a fenestrated posterior communication artery on the right side and no other vascular anomalies. There was no other lesion that could suggest a cause for the third nerve weakness. Fenestration of the posterior communicating artery has not been reported till date. The case is discussed and the literature on the subject is reviewed. 相似文献
993.
994.
The association of internuclear ophthalmoplegia (INO) with torsional nystagmus is rare. We report a case of a 72-year-old male who developed brainstem stroke and was found to have left INO with torsional nystagmus. An MRI correlation in this case has been described. 相似文献
995.
The effects of visuomotor feedback training on the recovery of hemispatial neglect symptoms: assessment of a 2-week and follow-up intervention 总被引:2,自引:0,他引:2
In patients suffering from left unilateral neglect, their right-biased attention to the phenomenal world can be ameliorated, short-term, by making motor responses to left-right extended objects (rods) that immediately reveal to them that their phenomenal world is in fact skewed. In this study the extent to which more intensive experiences of this type produced enduring and useful improvements in neglect, was assessed by first examining the effect of a 3-day experimenter-administered practice of rod lifting, then by examining the effects of a self-administered practice for a further 2-week period and a further 1 month post-training. Despite the fact that by the time the patients were able to undergo the intervention they had progressed to the chronic neglect stage, significant improvements of the intervention over the control group were found for a third of the tests given after the 3-day practice. Additionally, at the 1-month follow-up the intervention group again showed significantly better results in 46% of the direct neglect tests. As far as we are aware this is the first time that significant long-term improvements have been shown in a rehabilitation approach with neglect patients with a mean time of more than 12 months post-stroke and visuomotor feedback training can thus be seen as a most encouraging paradigm for future attempts. 相似文献
996.
997.
998.
Stolz U Velez S Wood KV Wood M Feder JL 《Proceedings of the National Academy of Sciences of the United States of America》2003,100(25):14955-14959
The Jamaican click beetle Pyrophorus plagiophthalamus (Coleoptera: Elateridae) is unique among all bioluminescent organisms in displaying a striking light color polymorphism [Biggley, W. H., Lloyd, J. E. & Seliger, H. H. (1967) J. Gen. Physiol. 50, 1681-1692]. Beetles on the island vary in the color of their ventral light organs from yellow-green to orange and their dorsal organs from green to yellow-green. The genetic basis for the color variation involves specific amino acid substitutions in the enzyme luciferase. Here, we show that dorsal and ventral light color in P. plagiophthalamus are under separate genetic control, we resolve the allelic basis for color variation, and, through analyses of luciferase sequence variation, we demonstrate that natural selection has produced a long-term adaptive trend for longer wavelength (more orange) ventral light on Jamaica. Our results constitute a novel example connecting the selective fixation of specific nucleotides in nature to their precisely determined phenotypic effects. We also present evidence suggesting that a recently derived ventral orange luciferase allele on the island has deterministically increased in frequency. Thus, the current luciferase polymorphism for P. plagiophthalamus appears to be mirroring the long-term anagenic trend on Jamaica, revealing a possible ongoing adaptive color transition in progress. 相似文献
999.
Gi protein activation in intact cells involves subunit rearrangement rather than dissociation
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Bünemann M Frank M Lohse MJ 《Proceedings of the National Academy of Sciences of the United States of America》2003,100(26):16077-16082
G protein-coupled receptors transduce diverse extracellular signals, such as neurotransmitters, hormones, chemokines, and sensory stimuli, into intracellular responses through activation of heterotrimeric G proteins. G proteins play critical roles in determining specificity and kinetics of subsequent biological responses by modulation of effector proteins. We have developed a fluorescence resonance energy transfer (FRET)-based assay to directly measure mammalian G protein activation in intact cells and found that Gi proteins activate within 1-2 s, which is considerably slower than activation kinetics of the receptors themselves. More importantly, FRET measurements demonstrated that Galphai- and Gbetagamma-subunits do not dissociate during activation, as has been previously postulated. Based on FRET measurements between Galphai-yellow fluorescent protein and Gbetagamma-subunits that were fused to cyan fluorescent protein at various positions, we conclude that, instead, G protein subunits undergo a molecular rearrangement during activation. The detection of a persistent heterotrimeric composition during G protein activation will impact the understanding of how G proteins achieve subtype-selective coupling to effectors. This finding will be of particular interest for unraveling Gbetagamma-induced signaling pathways. 相似文献
1000.
Vogler R Sauer B Kim DS Schäfer-Korting M Kleuser B 《The Journal of investigative dermatology》2003,120(4):693-700
The sphingolipid metabolite sphingosine-1-phosphate has emerged as a new bioactive molecule involved in the regulation of cell growth, differentiation, survival, and chemotaxis as well as angiogenesis and embryogenesis. These effects are mediated either via G-protein-coupled receptors or through intracellular actions. The most prominent sources of sphingosine-1-phosphate are human platelets suggesting its potential role in wound healing. In agreement with a positive function on reconstruction of wounded skin, we identified sphingosine-1-phosphate as a potent chemoattractant for keratinocytes as well as an activator of extracellular matrix production by fibroblasts. An unexpected finding is a strong cell growth arrest of keratinocytes after exposure to sphingosine-1-phosphate, as keratinocyte proliferation is critical for re-epithelialization of the wound. Most interestingly, the anti-proliferative effect of sphingosine-1-phosphate is not a result of cytotoxicity or apoptosis as sphingosine-1-phosphate even protects these cells from programmed cell death. Moreover, sphingosine-1-phosphate enhances differentiation of keratinocytes. To investigate further by which signaling pathway cell growth inhibition is mediated expression of the mRNA of all sphingosine-1-phosphate receptors (S1P1-5) was identified. 1 (Edg 1), 2 (Edg 5), 3 (Edg 3), 4 (Edg 6), and 5 (Edg 8) mRNA in keratinocytes was identified. As demonstrated in guanosine 5-[gamma-35S] triphosphate-gammaS binding assays, these G-protein-coupled receptors are functional at nanomolar concentrations. As the anti-proliferative effect of sphingosine-1-phosphate is only partially inhibited in the presence of pertussis toxin, it was investigated if intracellular actions are also involved. Microinjections of sphingosine-1-phosphate in keratinocytes also reduce proliferation suggesting that both sphingosine-1-phosphate receptors as well as intracellular actions mediate sphingosine-1-phosphate- induced cell growth arrest. 相似文献