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51.
Although the amino acid glutamate is used as an intercellular signaling molecule for normal bone homeostasis, little is known regarding its possible role in the metabolic disruption characteristic of bone metastasis. We have previously shown in vitro that cancer cell lines relevant to bone metastasis release glutamate into the extracellular environment. This study demonstrates the expression of multiple glutamate transporters in cancer cell lines of non-central nervous system origin. Furthermore, we identify the molecular mechanism responsible for glutamate export and show that this system can be inhibited pharmacologically. By highlighting that glutamate secretion is a common biological feature of cancer cells, this study suggests that tumor-derived glutamate could interfere with glutamate-dependent intercellular signaling in normal bone. Pharmacological interference with cancer cell glutamate release may be a viable option for limiting host bone response to invading tumor cells in bone metastasis.  相似文献   
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A new approach to the analysis of the neuroendocrine system (NES) is suggested. It is based on the fact of structural and metabolic determination of any effect on cell and cell aggregates. The principle of a common communication channel in the NES is formulated and a possible method of its formalization is proposed.  相似文献   
54.
We estimated the outcrossing rate in a population of 14 individuals of Dolichandra cynanchoides (Bignoniaceae), a species with late-acting self-incompatibility (LSI), at a site in Chaco woodland in Santa Fe province, Argentina. A subsample of five arbitrarily chosen loci from a total of 16 allozyme loci gave mating system parameters of tm=0.881 (SD 0.039) and ts=0.749 (SD 0.048), thus indicating that although predominantly outcrossing, D. cynanchoides has a mixed mating system. We draw attention to the fact that mixed mating in species with LSI is a very likely scenario, given that previous studies with diverse LSI taxa have shown that mixed cross-self pollen loads on the stigma, which is probably a common occurrence with natural pollinators, result in fruits with a proportion of selfed seeds.  相似文献   
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The linkage of the Phi, Pgd, Po2, S, H and halothane sensitivity loci was followed in a Belgian Landrace family, heterozygous for these systems over 6 generations. Recombination next to the S locus occurred mainly in pigs belonging to this particular family. From this investigation the position of the S locus is proved to be outwith the Phi-Pgd region, next to Phi . Therefore the gene sequence S - Phi - Hal -H- Po2 -Pgd is proposed. Higher recombination rates were observed in the female parental line of the multiheterozygous family when compared to the male parental line. Additional data from animals, unrelated to this strain, confirm the evidence of close linkage of the S system to the nearest marker loci.  相似文献   
56.
One of the family of voltage-gated calcium channels (VGCC), the N-type Ca2+ channel, is located predominantly in neurons and is associated with a variety of neuronal responses, including neurodegeneration. A precise mechanism for how the N-type Ca2+ channel plays a role in neurodegenerative disease, however, is unknown. In this study, we immunized N-type Ca2+ channel α1B-deficient (α1B−/−) mice and their wild type (WT) littermates with myelin oligodendrocyte glycoprotein 35–55 and analyzed the progression of experimental autoimmune encephalomyelitis (EAE). The neurological symptoms of EAE in the α1B−/− mice were less severe than in the WT mice. In conjunction with these results, sections of the spinal cord (SC) from α1B−/− mice revealed a reduction in both leukocytic infiltration and demyelination compared with WT mice. No differences were observed in the delayed-type hypersensitivity response, spleen cell proliferation, or cytokine production from splenocytes between the two genotypes. On the other hand, Western blot array analysis and RT-PCR revealed that a typical increase in the expression of MCP-1 in the SC showed a good correlation with the infiltration of leukocytes into the SC. Likewise, immunohistochemical analysis showed that the predominant source of MCP-1 was activated microglia. The cytokine-induced production of MCP-1 in primary cultured microglia from WT mice was significantly higher than that from α1B−/− mice and was significantly inhibited by a selective N-type Ca2+ channel antagonist, ω-conotoxin GVIA or a withdrawal of extracellular Ca2+. These results suggest that the N-type Ca2+ channel is involved in the pathogenesis of EAE at least in part by regulating MCP-1 production by microglia.  相似文献   
57.
S. K. Goldsmith 《Oecologia》1987,73(2):317-320
Summary Adults of Perarthrus linsleyi feed on flowers of creosote bush, Larrea tridentata. Mating also occurs on the flowers and foliage of this plant. This food resource is widely and evenly distributed in space, and is usually abundant. The spatial distribution of the beetles bore no relationship to the spatial distribution of flowers among creosote bushes, nor were female beetles distributed predictably with respect to flower distribution. Males moved widely over the area under study, and moved much more frequently than females. Males actively searched for females, and mounted and began copulation attempts without preliminary courtship. Males did not engage in aggressive defense of females, creosote flowers, or creosote bushes. This species exhibits a scramble competition mating system. The spatial distribution of the food resource is a primary factor in the evolution of the mating system of Perarthrus linsleyi.  相似文献   
58.
Gentle handling seems to elicit positive states in sheep. The study investigated whether spatial distance alters sheep responses to brushing and whether spatial distance is influenced by reactivity. Twenty Romane ewes were assessed in three sessions: in Sessions 1 and 3, one grid separated the test animal from pen mates, with no distance between them, and in Session 2 two grids separated the test animal from pen mates by a distance of about 1.7 m. Ewes had been genetically selected for low (R−) or high (R+) behavioural reactivity to social isolation. Body postures, head orientation, ear postures, closed and half-closed eyes, tail wagging and feeding behaviour, in addition to heart rate (HR) and HR variability, as the root mean square of successive differences (RMSSD), standard deviation of all normal-to-normal (NN) intervals (SDNN), RMSSD/SDNN ratio and ratio between low-frequency (LF) and high-frequency (HF) powers (LF/HF) were assessed. Data were analysed using generalized linear models and linear mixed models. Session, genetic line and phase (pre-, brushing and post-brushing) were considered fixed effects. Increased distance in Session 2 might not have influenced ewes’ responses. Fewer changes in ear postures were noted in Session 3 than 1 (P<0.01), suggesting that ewes were more relaxed in Session 3. The RMSSD/SDNN ratio was higher mainly during brushing in Sessions 1 and 3 (P<0.05), indicating that ewes were more relaxed during brushing, and at no distance between pen mates. However, spatial distance influenced R− and R+ ewes’ responses; R+ ewes performed more asymmetric ear postures in Session 2 than 1 and 3 (P<0.01), and in Session 3 than 1 (P<0.01), indicating that spatial distance had a negative effect on R+ ewes. Low reactive ewes spent less time on horizontal ear postures in Session 2 than 1 and 3 (P<0.01), and R+ ewes spent more time on horizontal postures in Session 1 than 3 (P<0.01). Curiously, R− ewes spent more time eating and ruminating in Session 3 than 1 (P<0.01), and in Session 2 than 1 and 3 (P<0.01), whereas R+ ewes ate and ruminated more in Session 1 than 3 (P<0.05). Higher HR was found among R− ewes in Session 2 than 1 and 3, and in Session 3 than 1 (P<0.01). High reactive ewes showed higher HR in Session 1 than 3 (P<0.01). The findings suggest that the social context might influence sheep responses to gentle handling, and the effects depend on their reactivity traits.  相似文献   
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目的 旨在通过对我院岗前培训8年经验的总结,摸索出一套在医院文化背景下的岗前培训体系。方法 采用问卷方法对2007—2009年新员工岗前培训效果进行匿名调查,并使用Excel进行数据录入和统计。结果 调查对象中76.63%的员工对师资配置情况及课程设置情况表示满意,54.08%的员工对培训时间与进度表示很合适,69.47%的员工对培训保障措施表示满意,69.42%和80.08%的员工分别对授课形式和培训受益情况表示满意。结论 医院文化及人文医学培训是医院人力资源处岗前培训的核心内容,这对每个从医人员树立正确的职业价值观具有指导作用和现实意义。岗前培训中培训师的授课技巧、专业知识及能力有待进一步提高,今后应不断完善内部培训师的培养途径与方法。  相似文献   
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