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51.
选择某电子对抗团战士和某坦克旅战士共64人,分别在高温、高湿等因素作用下连续作业1h(摩托小时),观察战士体内激素及电解质的变化情况。结果表明:两部队战士的心钠素、皮质醇、醛固酮水平作业前后有非常显著性以上的差异;血清K~+、Ca~(2+)浓度降低,Na~+浓度升高。以上结果表明:高温环境对战士体内激素水平影响显著,机体出现应激性改变。 相似文献
52.
53.
胃癌c-erbB-2过度表达与预后的关系 总被引:1,自引:0,他引:1
探讨c-erbB-2过度表达与胃癌预后的关系。方法:用免疫组化ABC法对103例胃癌手术标本及151个转移淋巴结进行c-erbB-2表达检测。结果:21.4%胃癌手术标本出现阳性表达.其中进展期胃癌、乳头状腺癌、高中分化胃癌及伴淋巴与肝转移的胃癌阳性率显著增高(P<0.05与<0.01);转移淋巴结表达阳性率高于胃癌原发灶(X2=3.7.P>0.05)。高中分化胃癌伴c-erbB-2过度表达者5年生存率显著低于阴性者(P<0.01)。结论:c-erbB-2过度表达可作为胃癌预后估计指标之一。 相似文献
54.
Zhenlin Li Emma Colucci Charles Babinet Denise Paulin 《Neuromuscular disorders : NMD》1993,3(5-6):423-427
Desmin synthesis is restricted to cardiac, skeletal and smooth muscles. In several familial myopathies involving fibre disorganization, filamentous aggregation of desmin has been characterized. During the development of the mouse embryo, desmin is one of the first muscle proteins detected in both the heart and the somites. To identify the DNA sequences involved in the regulation of desmin gene expression a 4.5 kb 5′-flanking region of the human desmin gene has been isolated. Different mutants were used to characterize specific enhancers in vitro and in vivo. The results obtained with transgenic mice provide evidence that the 1 kb cis-regulatory sequences, functional in skeletal muscle cells in vitro, confer specific developmental control for skeletal muscles. Furthermore, distinct programmes for cardiac and skeletal muscle-specific expression of the desmin gene are revealed. 相似文献
55.
Ion channel expression by white matter glia: I. Type 2 astrocytes and oligodendrocytes 总被引:12,自引:0,他引:12
White matter is a compact structure consisting primarily of neuronal axons and glial cells. As in other parts of the nervous system, the function of glial cells in white matter is poorly understood. We have explored the electrophysiological properties of two types of glial cells found predominantly in white matter: type 2 astrocytes and oligodendrocytes. Whole-cells and single-channel patch-clamp techniques were used to study these cell types in postnatal rat optic nerve cultures prepared according to the procedures of Raff et al. (Nature, 303:390-396, 1983b). Type 2 astrocytes in culture exhibit a "neuronal" channel phenotype, expressing at least six distinct ion channel types. With whole-cell recording we observed three inward currents: a voltage-sensitive sodium current qualitatively similar to that found in neurons and both transient and sustained calcium currents. In addition, type 2 astrocytes had two components of outward current: a delayed potassium current which activated at 0 mV and an inactivating calcium-dependent potassium current which activated at -30 mV. Type 2 astrocytes in culture could be induced to fire single regenerative potentials in response to injections of depolarizing current. Single-channel recording demonstrated the presence of an outwardly rectifying chloride channel in both type 2 astrocytes and oligodendrocytes, but this channel could only be observed in excised patches. Oligodendrocytes expressed only one other current: an inwardly rectifying potassium current that is mediated by 30- and 120-pS channels. Because these channels preferentially conduct potassium from outside to inside the cell, and because they are open at the resting potential of the cell, they would be appropriate for removing potassium from the extracellular space; thus it is proposed that oligodendrocytes, besides myelinating axons, play an important role in potassium regulation in white matter. The conductances present in oligodendrocytes suggest a "modulated Boyle and Conway mechanism" of potassium accumulation. 相似文献
56.
A cDNA for the estradiol-regulated 24K protein: Control of mRNA levels in MCF-7 cells 总被引:1,自引:0,他引:1
Ines Moretti-Rojas Suzanne A. W. Fuqua Robert A. Montgomery III William L. McGuire 《Breast cancer research and treatment》1988,11(2):155-163
We have previously demonstrated an estradiol-regulated 24 kDa (24K) protein in human breast cancer tissue culture cells and human tumor biopsies. The presence of 24K correlates well with the presence of steroid hormone receptors. In order to further study the hormonal regulation of the 24K protein and gene, we have isolated cDNA clones corresponding to the 24K mRNA.Poly(A)+ RNA isolated from the MCF-7 human breast cancer cell line was translated in a cell-free translation system containing [35S]-methionine. The translation products were immunoprecipitated with a 24K monoclonal antibody, and thein vitro synthesis of 24K protein was confirmed by sodium dodecylsulfate (SDS) polyacrylamide gel electrophoresis. The same poly(A)+ RNA was used to construct an oligo(dT)-primed cDNA library in thegt11 expression vector system. The library was screened with a highly specific polyclonal antibody raised against 24K protein purified by immunoaffinity chromatography. Four recombinant clones reacting with the antibody by virtue of antigen expression were isolated and three were used in hybridization-selected translation. Three clones were able to hybridize specifically to a messenger RNA (mRNA) that yielded a Mr 24,000 protein when translatedin vitro and analyzed by SDS/polyacrylamide gel electrophoresis. This protein was also immunoprecipitable by the 24K monoclonal antibody. MCF-7 mRNA size fractionated by formaldehyde-agarose gel electrophoresis was transferred to nitrocellulose paper and hybridized to a nick-translated 24K cDNA clone. A single band of hybridization corresponding to a mRNA size of approximately 0.9–1.0 kilobase (kb) was observed. Using this same technique, 24K cDNA was hybridized to mRNA extracted from MCF-7 cells that had been treated for varying periods with either estradiol, nafoxidine, or tamoxifen. The 24K mRNA was elevated by the addition of estradiol, and clearly diminished by nafoxidine and tamoxifen.These results demonstrate that we have isolated cDNA clones for the study of the hormonal regulation of the 24K gene in breast cancer cells, and have shown that the mRNA is regulated by estradiol. 相似文献
57.
胃黏膜上皮内瘤变是胃癌前病变,具有发展为胃癌的危险。阳主动,阴主静,文章基于阴阳理论,衷中参西,微观辨证与宏观辨证结合,以阴阳消长失调和基因调控紊乱的关系为出发点,认为胃黏膜上皮内瘤变发生时胃黏膜细胞凋亡周期紊乱和细胞异常增殖分化是阴阳消长失衡在细胞基因调控水平上的体现,进而探讨胃黏膜上皮内瘤变的病因病机以及辨证论治过程,为中医药治疗胃黏膜上皮内瘤变提供更多的理论依据,丰富治疗该病的临床手段。 相似文献
58.
目的 探讨糖尿病肾病(DN)患者血清瞬时受体电位通道7(TRPM7)、沉默调节蛋白-1(Sirtuin-1)与钙磷代谢、颈动脉钙化的相关性。方法 选取2020年12月—2022年11月成都大学附属医院收治的97例DN患者作为DN组,另取同期在该院就诊的120例2型糖尿病患者作为对照组。采用实时荧光定量聚合酶链反应检测血清TRPM7的表达,酶联免疫吸附试验检测血清Sirtuin-1水平。采用Pearson法分析DN患者血清TRPM7、Sirtuin-1水平与钙磷代谢的相关性,并通过多因素Logistic逐步回归模型分析DN患者颈动脉钙化的危险因素。结果 DN组血肌酐、尿素氮、血清TRPM7、血磷、颈动脉钙化率高于对照组(P <0.05)。DN组Sirtuin-1、血钙低于对照组(P <0.05)。Pearson相关性分析结果显示,DN患者血清TRPM7与血钙呈负相关(r=-0.247,P=0.000),与血磷呈正相关(r=0.415,P=0.000);DN患者血清Sirtuin-1与血钙呈正相关(r=0.367,P=0.000),与血磷呈负相关(r=-0.505,P=0.00... 相似文献
59.
Ove Christensen Marek Simon Torben Randlev 《Pflügers Archiv : European journal of physiology》1990,415(1):37-46
We have used the patch-clamp technique to characterize three anion channels in the ventricular membrane of the choroid plexus epithelium from Necturus. The most frequently occurring channel had a nonlinear IV-curve. The conductance in excised patches with 112 mM chloride at both sides was 28 pS at 0 mV, increasing towards positive membrane potentials. The selectivity ratios were P
NaP
Cl 0.1 and
. SITS and furosemide (1 mM) on the inside reduces chloride flux to 0.15 and 0.37 times the control value. In attached patches, the most commonly observed channel had a conductance of 7.5 pS. The single-channel current for this channel reversed direction at 15 mV hyperpolarization, indicating accumulation of chloride to a factor of 1.8 above equilibrium. External stimulation of the tissue by theophylline, IBMX and dbcAMP, or by hypotonic shock did not increase the activity of this channel. In very few excised patches, we have observed a chloride channel with a conductance of 7 pS with 112 mM chloride at both sides. The 7 pS channel appears to be identical to a 2 pS channel found in attached patches. The 2 pS channel was not normally active in attached patches but was activated in 28% of the patches by external stimulation. Finally, in few excised patches we have found a 375 pS channel which inactivates within seconds when membrane potential is stepped from 0 mV to a value that differs more than 10–20 mV from zero. The channel did not conduct gluconate but
and P
NaP
Cl 0.1. Internal SITS and furosemide (1 mM) reduced chloride flux to 0.3 and 0.5 times the control value. The channel was never seen in attached patches. The current carried through these channels can not account for the transepithelial steady state Cl–-flux measured by microelectrodes. KCl exit from the cell is suggested to be carried by KCl-cotransport or by channels that are too small to be seen in patch-clamp experiments. 相似文献
60.
Dr. A. Härfstrand K. Fuxe L. Agnati B. Fredholm 《Journal of neural transmission (Vienna, Austria : 1996)》1989,75(2):83-99
Summary Interactions between a 2-adrenoreceptor agonist and neuropeptide Y (NPY) binding sites have been studied in the rat medulla oblongata (MO) using biochemical binding techniques as well as quantitative autoradiography. Tritiated para-amino clonidine (3H-PAC; 2-adrenoceptor agonist), idazoxan (3H-IDA; 2-adrenoceptor antagonist) and iodinated neuropeptide Y (125I-NPY) were used as radioligands. (1) Neuropeptide Y (NPY; 10–8M) but not bovine pancreatic polypeptide (BPP) nor peptide YY (PYY 10nM) increased the KD value of3H-PAC binding sites. However, intraventricular administration of a high dose of NPY (1.25nmol) did not change the3H-PAC binding characteristics in MO membrane preparations of these animals. (2) GTP 10–4 lowered the affinity of3H-PAC binding. NPY (10 nM) had no additional effect, nor did NPYinfluence the GTP induced shift in potency of clonidine to displace3H-IDA from its binding sites. (3) In the autoradiographical experiments NPY (10nM) significantly reduced3H-PAC binding (2nM) in the nucleus tractus solitarius (NTS) area by 35%. (4) When clonidine, either given centrally in vivo (3.75nmol) or in vitro (10 nM) the binding of125I-NPY was reduced (34 and 24%, respectively) in the NTS. When the monoamine receptors were irreversibly blocked in vivo by N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ, 10 g i.e. 24h)125I-NPY (0.5 nM) binding was increased by 137% in the NTS. This effect of EEDQ was prevented by pretreatment with the 2-adrenoreceptor antagonist idazoxan.These results provide support for a direct intramembrane interaction between the 2-receptor and the NPY receptor within the NTS and may be of importance in central cardiovascular regulation. 相似文献