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101.
Telomerase and cancer 总被引:35,自引:0,他引:35
102.
目的:研究黄体激素释放激素(Luteinizinghormone releasinghormone,LHRH)在大鼠体内的药动学规律。方法:用氯胺T法将125I标记到LHRH分子上(放化纯度96.2%),14只SD大鼠随机分为大剂量、小剂量组,每组7只,分别肌肉注射125I LHRH(小剂量组0.5mg.kg,大剂量组1.00mg.kg),给药后在21个不同时间点逐一取各鼠尾动脉血做放射性测定。结果:大鼠试验结果显示,大剂量组t1/2平均为67.83±20.84h;小剂量组半衰期平均为64.68±22.90h。LHRH的药—时曲线符合二室模型,大剂量LHRH和小剂量LHRH的主要药动学指标差别不大。结论:LHRH在大鼠体内的消除模式为二室模型,为一级动力学消除。 相似文献
103.
Vickers SM Johnson LL Zou LQ Yannas IV Gibson LJ Spector M 《Tissue engineering》2004,10(7-8):1214-1223
Cells derived from synovium have drawn interest as donor cells for articular cartilage tissue engineering because they have been implicated in certain cartilage repair processes in vivo and the chondrogenic potential of the cells has been demonstrated in vitro. Studies have demonstrated that several other types of musculoskeletal connective tissue cells--including chondrocytes, fibrochondrocytes, ligament fibroblasts and osteoblasts, and mesenchymal stem cells can express the gene for the contractile actin isoform, alpha-smooth muscle actin (SMA), and can contract analogs of extracellular matrix in vitro. Although the physiological roles of SMA-enabled contraction of these cells have yet to be established, cell-mediated contraction of scaffolds employed for tissue engineering can alter the pore diameter of the matrix and distort its overall shape, and thus needs to be addressed. Toward this goal, the objective of this study was to investigate the expression of SMA by synovial cells and to evaluate their contraction of collagen-glycosaminoglycan (GAG) scaffolds. Synovial membranes obtained from the knees (stifle joints) of six adult dogs were evaluated for the presence of SMA by immunohistochemistry. Cells isolated from the synovial tissue were expanded through seven passages in monolayer culture, with samples from each passage allocated for Western blot analysis of SMA. Cells from passage 4 were seeded into porous type I collagen-GAG matrices and cultured for 4 weeks. Synovial cell-mediated contraction of the scaffolds was determined by measuring the diameters of the cell-seeded scaffolds and nonseeded controls every other day. Synovium-derived cells cultured as micropellets or in collagen-GAG matrices were incubated in chondrogenic medium with and without fetal bovine serum and evaluated for chondrogenesis by type II collagen immunohistochemistry. Immunohistochemistry revealed the presence of SMA in some cells (less than 10% of the cells) in the intimal layer of synovium from four of the five animals analyzed. Western blot analysis demonstrated a regular increase in the amount of SMA in the synovium-derived cells with passage number. Synovial cell-mediated contraction of the collagen-GAG scaffolds reached a value of 43% of the original diameter after 4 weeks, comparable to that found with other musculoskeletal cell types. Incubation of micropellet cultures of synovium-derived cells with chondrogenic medium revealed trace amounts of type II collagen production by immunohistochemistry. The findings of this study indicate that control of SMA-enabled contraction may be important when employing synovial cells for cartilage repair procedures, and warrant further investigation into the physiological role of SMA expression in synovial cells. 相似文献
104.
Antidromic activity was recorded in anesthetized rats from single afferent fibers in the proximal ends of cut dorsal root filaments at the L(4-6) level and tested for responses to acute cutaneous inflammation produced by intradermal injection of capsaicin. This antidromic activity included low-frequency spontaneous firing and dorsal root reflex (DRR) discharges evoked by applying von Frey hairs to the skin of the foot. DRRs could be recorded from both small myelinated (Adelta) and unmyelinated (C) afferent fibers, as well as from large myelinated (Abeta) fibers. After capsaicin was injected intradermally into the plantar skin of the foot, a significant enhancement of DRR activity was seen in Adelta and C fibers but not in Abeta fibers, and this increase lasted for approximately 1 h. This study supports the hypothesis that centrally mediated antidromic activity in Adelta and C primary afferent fibers contributes to the development of neurogenic inflammation, presumably by release of inflammatory substances in the periphery. 相似文献
105.
邹盛铨 《生物医学工程学杂志》1991,8(2):117-122
作者研究了牦牛主动脉瓣叶的单向拉伸和应力松弛行为。发现在生理应变范围内,试件的应力应变曲线斜率在纤维方向比其垂直方向约大20倍,瓣叶对应变速率不很敏感。在分析瓣叶的松弛行为时应用了冯元桢[9](1972)提出的松弛模型,根据实验结果,得到了牦牛主动脉瓣叶的归一化松弛函数。 相似文献
106.
建立了丹酰氯柱前衍生HPLC法测定人尿中多胺含量的方法。以己二胺为内标 ,uBondapak -C18(2 5 0× 4.6mm ,10um)为固定相 ,甲醇和水为流动相 ,梯度洗脱 ,柱温 5 0℃ ,流速 1ml/min ,荧光检测器测得腐胺 (PUT)、精脒 (SPD)和精胺(SP)三者回收率为PUT 97%、SPD 98%、SP 10 3% ,回归方程线性良好 ( 均大于 0 99) ,分析时间约 9min。该法简洁 ,快速 ,灵敏度高 ,重现性好 ,可有效分析人尿及其他生物样品中的多胺含量 相似文献
107.
Characterization of a neurotoxigenic Clostridium butyricum strain isolated from the food implicated in an outbreak of food-borne type E botulism.
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X Meng T Karasawa K Zou X Kuang X Wang C Lu C Wang K Yamakawa S Nakamura 《Journal of clinical microbiology》1997,35(8):2160-2162
Neurotoxigenic Clostridium butyricum was isolated from the food implicated in an outbreak of clinically diagnosed type E botulism in China. PCR assay showed that the isolate (LCL 155) contained the type E botulinum toxin gene. This appears to be the first report of neurotoxigenic C. butyricum causing food-borne botulism. 相似文献
108.
通过梳理工伤康复服务项目规范与支付标准制定等相关政策,阐述“国家版”和“广东省版”工伤康复服务项目和支付标准制定情况,分析新增工伤康复服务项目管理现状。选择广东省40家协议医院为样本,基于专家咨询法,计算专家采纳率,建立新增工伤康复服务项目目录,并通过基准项目赋值定价,为新增工伤康复服务项目遴选及支付标准提出管理措施。文章建议进一步细化新增工伤康复服务价格项目立项审批流程,建立新增工伤康复服务项目管理办法,规范管理制度。探索新增工伤康复服务项目纳入工伤保险目录管理机制,同时,充分发挥行业学会或协会的作用,加强卫生技术评估准入评审与价格制定管理决策中的广泛应用。 相似文献
109.
Kaixuan Che Junqiang Qiu Longyan Yi Menghui Zou Zhihui Li Amelia Carr Rhiannon M.J. Snipe Dan Benardot 《Nutrients》2021,13(3)
Periodized carbohydrate availability can enhance exercise capacity, but the effects of short-term fat adaptation carbohydrate restoration (FACR) diets on metabolic responses and exercise performance in endurance athletes have not been conclusively determined. This study aimed to investigate the effect of a FACR diet on measures of resting metabolism, exercise metabolism, and exercise performance. Well-trained male runners (n = 8) completed a FACR dietary intervention (five days’ carbohydrate < 20% and fat > 60% energy, plus one-day carbohydrate ≥ 70% energy), and a control high-carbohydrate (HCHO) diet for six days (carbohydrate > 60% energy; fat < 20% energy) in a randomized crossover design. Pre- and post-intervention metabolic measures included resting metabolic rate (RMR), respiratory quotient (RQ), maximum fat oxidation rate during exercise (MFO), and maximum fat oxidation intensity (FATmax). Measures of exercise performance included maximal oxygen uptake (VO2max), running economy (RE), and 5 km running time trial (5 km-TT). In FACR compared with HCHO, there were significant improvements in FATmax (p = 0.006) and RE (p = 0.048). There were no significant differences (p > 0.05) between FACR and HCHO in RMR, RQ, VO2max, or 5 km-TT. Findings suggest that a short-term (six days) FACR diet may facilitate increased fat oxidation and submaximal exercise economy but does not improve 5 km-TT performance. 相似文献
110.
Shujuan Li Yacong Bo Hongyan Ren Chen Zhou Xiangqian Lao Liyun Zhao Dongmei Yu 《Nutrients》2021,13(4)
Infantile anaemia has been a severe public health problem in China for decades. However, it is unclear whether there are regional differences in the prevalence of anaemia. In this study, we used data from the China Nutrition and Health Surveillance (CNHS) to assess the prevalence of anaemia and the risk factors associated with its prevalence in different regions. We included 9596 infants aged 0–23 months from the CNHS 2013 database. An infant was diagnosed with anaemia if he/she had a haemoglobin concentration of <110 g/L. We used multivariate logistic regression to investigate the potential risk factors associated with the development of anaemia. We found that anaemia was present in 2126 (22.15%) of the infants assessed. Approximately 95% of these cases were classified as mild anaemia. Based on the guidelines laid out by the World Health Organization, 5.5% and 43.6% of the surveillance sites were categorized as having severe and moderate epidemic levels of anaemia, respectively. The prevalence of infantile anaemia in Eastern, Central and Western China was 16.67%, 22.25% and 27.44%, respectively. Premature birth, low birth weight, breastfeeding and residence in Western China were significantly associated with higher odds of developing anaemia. Female sex and having mothers with high levels of education and maternal birth age >25 years were associated with lower odds of developing anaemia. In conclusion, we observed significant regional disparities in the prevalence of infantile anaemia in China. Western China had the highest prevalence of infantile anaemia, and rural regions showed a higher prevalence of anaemia than urban regions. 相似文献