21 d-6°头低位卧床期间运动训练对动态姿态平衡的影响

目的探讨21 d-6°头低位卧床和卧床运动训练对动态姿态平衡和控制功能的影响. 方法 10名健康男性青年被试者分为卧床对照组和卧床训练组,每组5人,卧床期间训练组每天进行2次、每次30 min逐级增加负荷的头低位功率自行车训练;分别于卧床前和卧床后21 d进行了动态姿态平衡和双膝等速肌力的测试. 结果与卧床前相比,对照组动态本体感觉得分和运动控制适应能力明显降低,双膝相对峰力矩明显降低,同时伴有腘绳肌与股四头肌峰力矩屈/伸比值的明显增加;训练组动态本体感觉得分和运动控制适应能力明显高于对照组,而腘绳肌与股四头肌峰力矩屈/伸比值无明显改变. 结论 21 d-6°头低位卧床运动训练能够明显改善卧床后动态姿态平衡及其动态运动适应功能.     

头低位限制活动对家兔主要脏器微血管壁通透性的影响

本文报导了用40只白色短毛家兔所做的动物模拟失重实验,得出各脏器微血管通透性的动态反应曲线。并用微循环研究方法,分析了模拟失重时各脏器微血管功能状态与微血管通透性之间的关系;阐述了各脏器微循环功能变化特点;并对变化机理作了初步探讨。     

头低位模拟失重状态对前庭功能的影响

为研究头低位模拟失重对运动病症状、垂直视动眼震（ＶＯＫＮ）及体液重新分配的影响，在头低位－１０°的模拟失重状态下，采用大视野的垂直视动刺激，观察１８名正常人的运动病症状、ＶＯＫＮ、激素（ＡＶＰ、ＶＩＰ、ＣＯＲＴ、ＡＬＤＯ）的反应特点。结果表明，头低位－１０°状态下的大视野垂直视动刺激可以诱发出明显的运动病症状，头低位－１０°的垂直视动刺激比坐位更容易诱发运动病。坐位状态ＶＯＫＮ慢相速度有明显的方向性不对称，敏感组ＶＯＫＮ方向性不对称有显著差异（Ｐ＜０．０５）。头低位－１０°时ＶＯＫＮ的不对称现象不明显，向下方向运动的ＶＯＫＮ慢相速度显著增加。分析指出，头低位－１０°状态下垂直视动刺激比坐位和秋千刺激的贡献率大。尿中ＣＯＲＴ（皮质醇）在秋千和头低位的垂直视动刺激前后有显著性增加。提示：大视野的垂直视动刺激与头低位－１０°两种刺激的结合可能成为预测空间运动病的方法之一．     

Qualitative difference between the cytotoxic T lymphocyte responses to melanocyte antigens in melanoma and vitiligo

Vitiligo is a skin disorder characterized by depigmented macules secondary to melanocyte loss. An unusual facet is its relation to melanoma: cytotoxic T lymphocytes directed to melanocyte antigens are found in both conditions and imply a breakdown of tolerance, yet the resulting immune reaction is the opposite. The mechanisms at the basis of these opposite effects are not known. Here, we performed a direct comparison of whole melanocyte-specific T cell populations in the two diseases. We demonstrate that neither precursor frequencies of Melan-A/MART-1-specific T lymphocytes nor their status of activation differ significantly. However, by using a tetramer-based T cell receptor down-regulation assay, we documented a higher affinity of vitiligo T cells. We calculated that the peptide concentration required for 50% of maximal receptor down-regulation differed by 6.5-fold between the two diseases. Moreover, only vitiligo T cells were capable of efficient receptor down-regulation and IFN-gamma production in response to HLA-matched melanoma cells, suggesting that this difference in receptor affinity is physiologically relevant. The differences in receptor affinity and tumor reactivity were confirmed by analyzing Melan-A/MART-1-specific clones established from the two diseases. Our results suggest that the quality, and not the quantity, of the melanocyte-specific cytotoxic responses differs between the two pathologies.     

Interleukin-10 secreted by B-1 cells modulates the phagocytic activity of murine macrophages in vitro

As demonstrated previously in our laboratory, B-1 cells migrate from the peritoneal cavity of mice and home to a distant site of inflammation to become macrophage-like cells. However, the influence that these cells might have on the kinetics and fate of the inflammatory process is not known. Considering that macrophages are pivotal in the inflammatory reaction, we decided to investigate the possible influence B-1 cells could have on macrophage activities in vitro. Our results show that peritoneal macrophages from Xid mice, a mouse strain deprived of B-1 cells, have higher phagocytic indexes for zymozan particles when compared with macrophages from wild-type mice. Moreover, macrophages from wild-type mice have a lower ability to release nitric oxide and hydrogen peroxide when compared with macrophages from Xid mice. Experiments using cocultures of B-1 cells and macrophages from Xid mice in transwell plates demonstrated that B-1 cells down-regulate macrophage activities. These observations also indicate that this phenomenon is not due to a physical interaction between these two cell populations. As B-1 cells are one of the main sources of interleukin (IL)-10, we demonstrate in this study that adherent peritoneal cells from Xid mice produce significantly less amounts of this cytokine in culture when compared with IL-10 production by cells from wild-type mice. When B-1 cells from IL-10 knock-out mice and macrophages from wild-type mice were cocultured in transwell plates, the phagocytic index of macrophages was not altered demonstrating that B-1 cells can influence the effector functions of macrophages in vitro via IL-10 secretion.     

Neuroendocrine changes in colon of mice with a disrupted IL-2 gene

Neuroendocrine peptides have a variety of physiological functions in the gastrointestinal tract. This study was carried out to investigate the impact of IL-2 deficiency on the neuroendocrine system in normal colon, and the neuroendocrine changes during colonic inflammation. Mice with homozygous disrupted IL-2 gene (IL-2-/-) spontaneously developed a bowel disease with similarities to human ulcerative colitis. Different types of colonic endocrine cells and myenteric nerves were analysed in the IL-2-/- mice using immunomorphometry. The neuropeptide contents in the colonic tissues were determined by radioimmunoassay. Age-matched healthy IL-2+/- and IL-2+/+ mice served as controls and the colonic IL-2 levels were compared between these two groups of mice by ELISA. Our data showed that less than half the amount of IL-2 was synthesized in the colon of IL-2+/- mice compared with the IL-2+/+ wild-type mice. Two major differences in the neuroendocrine colon were found between the mice with an intact and disrupted IL-2 gene. One was age-related. The frequencies of various endocrine cells and myenteric nerves increased with age in the IL-2+/+ mice. However, no such increases were seen in the mice with a disrupted IL-2 gene. Instead, the volume densities of enteroglucagon, serotonin cells and substance P (SP), vasoactive intestinal polypeptide (VIP) and total myenteric nerves were lower in the older IL-2+/- and IL-2-/- mice compared with the wild type. The other was disease-related. Polypeptide YY (PYY) cells and tissue levels of PYY, SP and VIP were significantly decreased in the IL-2-/- mice during the course of bowel inflammation compared with the healthy IL-2+/- and IL-2+/+ controls. These findings indicate that colonic neuroendocrine alterations did occur in the mice with a disrupted IL-2 gene and diminished local IL-2 level, suggesting a role of IL-2 in the regulation of the neuroendocrine system and a prevalent interaction between the immune and neuroendocrine systems in normal colon. On the other hand, there were some changes that seemed to correlate with the bowel inflammatory process. They might be associated with the impaired function in inflamed gut and contribute to the development and/or prolongation of disease.     

Smad3基因剔除小鼠的繁殖与基因型鉴定

目的为进一步深入研究Smad3基因在脊椎动物发育中的重要作用,对Smad3基因剔除小鼠进行保种和繁育研究.方法采用基因剔除杂合子小鼠进行保种,通过PCR和Southern杂交对杂合子小鼠交配所产生的后代进行基因型鉴定,纯合子小鼠和野生型小鼠用于表型分析,杂合子小鼠用于留种和繁殖生产.结果采用PCR方法对278只子代小鼠进行了基因型鉴定,83只为野生型,133只为杂合子,62只为纯合子.结论Smad3基因剔除突变能稳定遗传.采用杂合子小鼠保种,子代小鼠三种基因型比例符合孟德尔遗传定律.     

Adverse childhood experiences and the development of Down syndrome regression disorder

Down syndrome regression disorder (DSRD) is a clinical symptom cluster of acute or subacute neurocognitive regression in otherwise health persons with Down syndrome. The objective of this study was to evaluate if adverse childhood experiences (ACEs) were more prevalent in children with DSRD than those with DS alone. A survey-based, cohort-based study was performed. Caregivers of individuals with DSRD with onset of symptoms between age 10 and 30 years and DS alone were administered the ACEs questionnaire via an online REDCap survey. A total of 159 responses were collected after excluding incomplete surveys and those not meeting criteria for DSRD. Individuals with DSRD were not more likely to experience ACEs (p = 0.18, 95% confidence interval [CI]: 0.43–1.17). In those with ACEs prior to the onset of symptoms, the median time prior was 7 months (interquartile range: 5–10). Individuals with DSRD were more likely to report three or more ACEs (52, 33%) compared to those with DS alone (39, 22%) (p = 0.02, 95% CI: 1.08–2.87). Exposure to ACEs were not predictive of response to particular therapeutic interventions although those with multiple ACEs 3 months prior to the onset of symptoms was associated with lower response rates to benzodiazepines and immunotherapy (p = 0.02, 95% CI: −3.64–−1.13). This study provides preliminary data that individuals with DSRD experience ACEs at a similar rate to individuals with only DS alone, although three or more ACEs, often preceding the onset of symptoms, was more prevalent in individuals with DSRD.     

大鼠三叉神经本体觉中枢传导通路的电生理学证明

近年来形态学上发现了三叉神经领域本体感觉中枢通路,在此基础上,本文用电生理学方法,通过电刺激咬肌神经和压下颌,观察了由四级神经元组成的此通路的二级（三叉神经脊束核吻侧亚核背内侧部及邻接的网状结构）、三级（沿三叉神经感觉主核内缘存在的“带状区”）中继核团以及作为最后驿站的丘脑腹后内侧核等处的单位放电反应;另外又分别刺激或损毁二、三级中继核团,观察了丘脑腹后内侧核的单位放电变化,结果证明电刺激咬肌神经和压下颌,在上述核团都出现对本体觉冲动反应的单位放电,包括兴奋性反应单位、抑制性反应单位和无关单位三种类型,以兴奋性单位为主,占神经元单位放电总数的５２．９％～６７．７％．分别刺激二和三级神经元的所在核团,在丘脑腹后内侧核处发生相应的单位放电效应;损毁二和三级核团,本体觉传入冲动被阻断。本研究结果从电生理学上确证了形态学上发现的三叉神经本体感觉中枢通路的客观存在,从定性研究方面支持了定位研究的结果,并填补了以往生理学上只证明初级传入核团与丘脑腹后内侧核之间存在着一条多突触联系的本体觉传递通路但未能判断其具体行径和中继部位的空白,本研究并对方法论以及一些有关问题进行了讨论．