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51.
Summary Microcirculation in the upper portion of the trapezius muscle was measured percutaneously by continuous laser-Doppler flowmetry (LDF) during two 10-min series of alternating 1-min periods of static contraction and rest determined electromyographically (EMG). Stepwise increased contraction was induced by keeping the arms straight and elevated at 30, 60, 90 and 135°, which was repeated with a 1-kg load carried in each hand. Thereafter, fatigue and recovery were recorded while the subject kept her arms straight and elevated at 45° carrying the 1-kg hand load as long as possible, followed by rest with arms hanging and no load. A group of 16 healthy women of different ages was studied. Signal processing was done on line using a 386 SX computer. The LDF- and root-mean-square (rms) EMG signals were normalized. Spectrum analyses of EMG mean power frequency (MPF) and median spectrum frequency were performed. The rms-EMG increased significantly with an increase in the calculated shoulder torque (r=0.75). Accumulated local fatigue was indicated by a decrease in MPF with increased shoulder angle and added load (r = –0.54). Blood flow increased with increased shoulder angle (r=0.82, with hand loadr=0.62) and with increased shoulder torque (r=0.72), and also showed a significant increase with increased EMG activity (r=0.74). The LDF showed a negative correlation to MPF (r= –0.67), with increased values when MPF was lowered. During the endurance test, a moderate increase of LDF occurred which reached its maximum during the 1st min of recovery. Then, a slow return to the base level was recorded. The ability to increase the flow in the microcirculation with increasing muscle load was not diminished with age.  相似文献   
52.
The detailed investigation of variation in functionally important regions of the human genome is expected to promote understanding of genetically complex diseases. We resequenced 65 candidate genes for CNS disorders in an average of 85 European individuals. The minor allele frequency (MAF), an indicator of weak purifying selection, was lowest in radical amino acid alterations, whereas similar MAF was observed for synonymous variants and conservative amino acid alterations. In noncoding sequences, variants located in CpG islands tended to have a lower MAF than those outside CpG islands. The transition/transversion ratio was increased among both synonymous and conservative variants compared with noncoding variants. Conversely, the transition/transversion ratio was lowest among radical amino acid alterations. Furthermore, among nonsynonymous variants, transversions displayed lower MAF than did transitions. This suggests that transversions are associated with functionally important amino acid alterations. By comparing our data with public SNP databases, we found that variants with lower allele frequency are underrepresented in these databases. Therefore, radical variants obtain distinctively lower database coverage. However, those variants appear to be under weak purifying selection and thus could play a role in the etiology of genetically complex diseases.  相似文献   
53.
Reperfusion after ischemia results in endothelial cell injury and Kupffer cell activation. Inflammatory cytokines thus released can induce major histocompatibility complex antigens and increase the immunogenecity of the graft. An orthotopic rat liver allotransplant model was used to test the hypothesis that prevention of reperfusion injury by infusion of polyethylene glycol superoxide dismutase (PEG-SOD) would result in long-term allograft survival in the presence of subthreshold immunosuppressive dosages. ACI rats were used as donors, and Lewis strain rats as recipients. Orthotopic liver transplantation was initially performed to identify a subthreshold dose of the immunosuppressant FK-506, which would be unable to extend survival longer than control untreated rats with this strain combination. After testing three intramuscular FK-506 doses of 0.04, 0.08, and 0.16 mg/kg, it was observed that an FK-506 dose of 0.04 mg/kg/day for 14 days was unable to extend survival longer than in untreated recipients. This dose of FK-506 was used in combination with PEG-SOD at doses of 1000, 3000, 10,000, or 30,000 units. Recipient animals were treated intravenously with PEG-SOD as a loading dose to facilitate tissue penetration on day 1, and beginning on the day of transplantation, every 2 days for the duration of the study. Results of histologic studies and mean survival time were compared in untreated recipients and in rats treated with PEG-SOD plus 0.04 mg/kg/day FK-506. Mean survival time was increased significantly in these animals (p < 0.007) to 40.6 ± 25.6 days as compared with either untreated rats (10.0 ± 2.7 days) or rats treated with 0.04 mg/kg FK-506 alone (13.7 ± 4.2 days). Histologic examination demonstrated a significant reduction in the cellular infiltrate in rats treated with PEG-SOD plus FK-506, as compared with recipients treated with either agent alone or left untreated. Our results therefore suggest a potential approach to reducing immunosuppression in transplantation. (J ALLERGY CLIN IMMUNOL 1995;95:1276-81.)  相似文献   
54.
A subset of midgut carcinoids (MCs) result in mesenteric angiopathy (MA) and bowel infarction as a consequence of vascular compression caused by extensive mesenteric sclerosis (MS). The goal of this study was to determine whether the level of expression of several fibrosing-related growth factors was related to the finding of MA and/or MS in MCs. Eighteen cases of MC, 6 with both extensive MS and MA (group I), 5 with extensive MS only (group II), and 7 with ordinary MS only (group III), were analyzed for immunoexpression of beta-catenin, transforming growth factor-beta 2 (TGF beta 2), nerve growth factor 2 (NGF2), fibroblast growth factor 2 (FGF2), insulin growth factor receptor (IGFR), and bone morphogenic protein 4 (BMP4) in formalin-fixed, paraffin-embedded sections. Standard immunohistochemical technique was used following antigen retrieval. Immunostaining was scored semiquantitively as the product of the percentage and intensity (0 to 2+) of the immunostaining, giving a possible range of 0 to 200. One-way analysis of variance and Mann-Whitney nonparametric analyses were used for statistical analysis. The mean scores of immunoreactivity of each factor in groups I, II, and III were as follows: 135, 174, and 147 for beta-catenin (cytoplasmic reactivity only); 106, 112, and 92 for TGF beta 3; 1.67, 32, and 36 for NGF-2; 2.5, 48, and 55 for FGF-2; 19, 112, and 66 for IGFR2; 140, 45, and 52 for BMP4. There were significant differences in NGF-2 immunoreactivity between groups I and III (P = 0.0023) and in BMP4 immunoreactivity between groups I and II (P = 0.017) and groups I and III (P = 0.022). All MCs expressed high levels of membranous beta-catenin, moderate levels of TGF beta 3 and IGFR2, and low levels of FGF-2, with no significant differences seen among the groups. MCs with prominent MS and MA (group I) expressed significantly higher BMP4 than those in groups II and III, suggesting a potential role of BMP4 in the pathogenesis of MA. The level of NGF-2 expression was significantly lower in group I than in group III, possibly indicating abnormal angiogenesis in the formation of angiopathy.  相似文献   
55.
重复电刺激前肢神经引起成年大鼠运动皮层的可塑性改变   总被引:2,自引:0,他引:2  
为了了解成年大鼠运动皮层的功能可塑性,利用皮层内微刺激方法测定MI代表区并观察重复电刺激前肢神经对MI代表区的影响。实验组大鼠(9例)持续1.2-2小时的前肢神经电刺激导致前肢运动区与面部触须运动区边界向VI方向,移动263.3±90.9μm并同时伴有运动阈值的改变;FL内MT降低5.0±13.3μA,而在VI内MT升高9.6±11.6μA对照组大鼠间隔1.5-2小时的两次测定结果,FL-VI边界  相似文献   
56.
Background: Despite years of research, the treatment of acute kidney injury (AKI) remains a significant challenge. Animal studies presented causal links between elevated regulatory T cell (Treg) response and better prognosis in AKI. Previous studies in mice and humans showed that TIM-3+ Treg cells were more potent than TIM-3- Treg cells. In this study, we investigated the role of TIM-3 in Treg in AKI patients.

Methods: Peripheral blood from AKI patients and healthy controls were gathered, and TIM-3+ Treg subset was examined.

Results: Compared to healthy controls, the AKI patients presented a significant upregulation in the frequency of circulating CD4+CD25+ T cells; however, the majority of this increase was from the CD4+CD25+TIM-3- subset, and the frequency of CD4+CD25+TIM-3+ T cells was downregulated in AKI patients. In both healthy controls and AKI patients, the CD4+CD25+TIM-3+ T cells expressed higher levels of Foxp3, and were more potent at expressing LFA-1, LAG-3, CTLA-4, IL-10 and TGF-β. In addition, the CD4+CD25+TIM-3+ T cells from both healthy controls and AKI patients presented higher capacity to suppress CD4+CD25- T cell proliferation than the CD4+CD25+TIM-3- T cells. Interestingly, the total CD4+CD25+ T cells from AKI patients presented significantly lower inhibitory capacity than those from healthy controls, indicating that the low frequency of CD4+CD25+TIM-3+ T cells was restricting the efficacy of the Treg responses in AKI patients.

Conclusions: We demonstrated that TIM-3 downregulation impaired the function of Treg cells in AKI. The therapeutic potential of CD4+CD25+TIM-3+ T cells in AKI should be investigated in future studies.  相似文献   

57.
应用放射配体结合分析,测定40例正常晚期妊娠妇女及40例妊高征妇女外周血淋巴细胞β_2-肾上腺素能受体(β_2-AR)结合量,并测定两组妇女分娩的新生儿体重。结果为:1.正常晚期妊娠妇女外周淋巴细胞β_2-AR结合量明显降低,妊高征妇女β_2-AR结合量降低更显著;2.妊高征孕妇组的新生儿出生体重明显低于正常妊娠组的新生儿体重;3.孕妇β_2-AR结合量与新生儿出生体重呈明显正相关,提示好高征与机体β_2-AR结合量下降有关,β_2-AR改变影响胎儿生长发育。  相似文献   
58.
白云  朱锡华 《免疫学杂志》1994,10(4):214-217
用抗CD59单抗2A7与CNBr-Sepharose4B偶联制备亲和层析柱,从正常人红细胞膜蛋白抽提物中分离纯化出CD59分子。本法纯化的CD59分子量为18-20KDa对还原剂敏感,与McAbssMEM43和1F5有高亲和性,再掺入豚鼠红细胞后,能够抑制人体补体的反应性溶血,本文还对三株抗CD59单抗2A7,MEM43及1F5的抗原特异性进行了初步分析。  相似文献   
59.
The expression of human growth hormone (GH) in female transgenic mice (TM) is accompanied by sterility, whereas females expressing the bovine GH gene are fertile. A light and electron microscopic study was conducted to examine whether expression of these foreign GH genes in mice is associated with structural changes in the ovaries of young adult (3-month-old) or middle-aged (7-month-old) mice. One ovary was serially sectioned for light microscopy, and the contralateral ovary was used for electron microscopy. The numbers of preantral (PAF) and antral (AF) follicles, with and without signs of atresia, as well as the number of corpora lutea (CL), were determined. As expected, body weights of both young and middle-aged TM of either kind were significantly increased over those of their normal littermates. However, the ovarian weights of TM and control mice did not differ. In the 3-month-old TM, the ovaries were grossly normal at the light microscopic level. However, significantly more CL were counted in the ovaries of human GH-TM than in those of the other two groups. The percentage of PAF with signs of atresia was significantly reduced in ovaries of bovine GH-TM compared with the other groups, while the percentages of AF undergoing atresia were significantly different in all groups, with the highest values in normal animals, intermediate ones in human GH-TM, and the lowest in bovine GH-TM. In the ovaries of 7-month-old human GH-TM, conspicuous clusters of large, foamy light cells were present in the cortex and the medulla. Ultrastructurally, these cells appeared as interstitial cells in various stages of degeneration, accumulating cholesterol crystal-like inclusions. Although degeneration of interstitial cells was observed also in the other types of animals, it involved usually only single cells and no cytoplasmic crystal inclusions. Moreover, in the ovaries of 7-month-old human GH-TM the percentages of PAF were significantly reduced and the percentages of AF significantly increased compared with those in the two other groups, which did not differ from each other with respect to these parameters. No significant differences in the numbers of CL were found between the groups. Percentages of atretic PAF were significantly reduced in bovine GH-TM and comparable in the other two groups, while percentages of atretic AF were not different between normal and bovine GH-TM, but were significantly increased in human GH-TM.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   
60.
为获取有功能的IV型II类反式激活因子基因 (CIITA IV ) ,诱导肿瘤细胞表达MHCII类分子 ,从IFN γ刺激的THP 1细胞中以RT PCR获得CIITA IV ,将其连接到pGEMT easy载体。对所构建的pcDNA3 1 CIITA IV型表达载体进行反复测序后发现 ,所获得的CIITA IV基因存在结构变异 ,在 2 87位插入了 3个核苷酸TAG ,使 2 86 2 88位的AAG改变成为ATAGAG(2 86 2 90 ) ,并引起其他 8个座位核苷酸 (及推导的氨基酸残基 )发生改变。将表达载体转入原先不表达MHCII类分子的HeLa细胞中 ,检测到所获得的IV型CIITA变异体具有诱导人II类分子HLA DR表达的能力。空载体和CIITA IV基因导入的HeLa细胞中 ,DR阳性细胞百分率分别为 0 0 1 %和 37 6 4 %。该基因已从GenBank得到登录号 ,表明这是一个具有诱导HLA DR分子表达功能的IV型CIITA新基因。  相似文献   
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