睡眠剥夺对HSP70表达及脑超微结构的影响

目的：观察睡眠剥夺（SD）后大鼠脑组织HSP70表达的变化及对超微结构的影响。方法：44只雄性SD大鼠随机分为11组，每组4只，免疫组织化学方法检测HSP70的表达，电镜观察海马超微结构的变化。结果：睡眠剥夺后12小时即可在大脑皮质及海马观察到HSP70阳性细胞，2—3天数量达到高峰，7天时明显下降。白天睡眠剥夺12小时（SDd12h）组HSP70阳性细胞数较夜晚睡眠剥夺12小时（SDn12h）组多（P〈0．05）。RS组大脑皮质HSP70阳性细胞数较白天睡眠剥夺1天（SDd1d）组减少（P〈0．05）。白天睡眠剥夺3天（SDd3d）海马出现超微结构改变，白天睡眠剥夺7天（SDd7d）后改变更加明显。结论：睡眠剥夺可影响大鼠脑组织HSP70表达及超微结构。     

热休克蛋白70对离体心脏心肌间质的保护作用

目的探讨热休克蛋白70（HSP70）对大鼠离体心脏心肌间质的影响。方法Wistar大鼠16只，分为2组：对照组（C，n=8），腹腔注射生理盐水0．4ml，24h后取离体心脏灌注HTK心脏保护液，4℃保存3h后建立Langendorff灌注模型，灌注KH液2h；实验组（E，n=8），腹腔注射重酒石酸去甲肾上腺素，24h后取离体心脏，方法同对照组。以心肌细胞中HSP70含量、血流动力学指标、心肌组织羟脯氨酸（HP）、内皮索（ET）含量和心肌超微结构等作为观察指标。结果HSP70含量E组与C组比较明显增高；E组心功能恢复方面优于C组（P〈0．05），HP含量优于C组（P〈0．01），ET含量低于C组（P〈0．01），心肌超微结构损伤较C组明显减轻。结论HSP 70对供心心肌间质具有保护作用。     

The effect of postural changes on body temperatures and heat balance

Early studies have demonstrated that rectal temperature (T _re) decreases and mean skin temperature (T _sk) increases in subjects changing their posture from standing to supine, and vice versa. Such changes have important implications insofar as thermal stress experiments are conducted and interpreted. However, the extent of these changes between steady-state conditions is not known. In addition, it is not known whether thermal balance is also affected by postural changes. To examine these questions, 11 healthy males were exposed to a thermoneutral air environment (28.2–28.5°C and 40% relative humidity) in various postures at rest. Body temperatures, heat losses, and metabolic rate were measured. Subjects wore shorts only and began in an upright posture (standing or sitting at an inclination of 7.5°) on a customized tilt-table. They were tilted twice, once into a supine position and then back to the original upright position. Each tilt occurred after steady state was satisfied based on the subject's circadian variation of T _re determined previously in a 4.25 h control supine trial. Times to supine steady state following the first tilt were [mean (SE)] 92.6 (6.4) and 116.6 (5.1) min for the standing and sitting trials, respectively. Times to upright steady state following the second tilt were 107.9 (11.4) and 124.1 (9.0) min. Mean steady-state T _re and T _sk were 36.87 (0.07) and 34.04 (0.14), 37.47 (0.09) and 33.48 (0.14), and 37.26 (0.05) and 33.49 (0.10) °C for supine, standing, and sitting, respectively. Thermal balance was attained in all steady-state conditions, and allowing for a decrease in the weighting factor of T _re for mean body temperature in the upright postures, it also appears that thermal balance was preserved between changes in posture. These results are consistent with no perceived changes by the subjects in their thermal comfort and skin wetness.     

Hyperthermia and maximal oxygen uptake in men and women

To compare the effect of hyperthermia on maximal oxygen uptake (O_2max) in men and women, O_2max was measured in 11 male and 11 female runners under seven conditions involving various ambient temperatures (T_a at 50% RH) and preheating designed to manipulate the esophageal (T_es) and mean skin temperatures at O_2max. The conditions were: 25°C, no preheating (control); 25, 35, 40, and 45°C, with exercise-induced preheating by a 20-min walk at ~33% of control O_2max; 45°C, no preheating; and 45°C, with passive preheating during which T_es and were increased to the same degree as at the end of the 20-min walk at 45°C. Compared to O_2max (l·min^–1) in the control condition (4.52±0.46 in men, 3.01±0.45 in women), O_2max in men and women was reduced with exercise-induced or passive preheating and increased T_a, ~4% at 35°C, ~9% at 40°C and ~18% at 45°C. Percentage reductions (7–36%) in physical performance (treadmill test time to exhaustion) were strongly related to reductions in O_2max (r=0.82–0.84). The effects of hyperthermia on O_2max and physical performance in men and women were almost identical. We conclude that men and women do not differ in their thermal responses to maximal exercise, or in the relationship of hyperthermia to reductions in O_2max and physical performance at high temperature. Data are reported as mean (SD) unless otherwise stated.     

Direct measurement of the thermal responses of nude resting men in dry environments

Summary Two nude resting men were exposed for two-hour periods to each of 25 dry environments, with air temperatures ranging between 12.8° C and 49.1° C and wind speeds between 0.67 m/sec and 4.94 m/sec. The mean radiant temperature of the surroundings was kept equal to the air temperature. Rates of radiant and convective heat exchange were measured directly, separately and continuously. The men had reached a thermal steady state after 105 min in the warm environments, but not in the cold environments. Graphs are presented to show the effect of ambient temperature and wind speed on the radiation and convection rates attained after 105 min, as well as on metabolic rate, sweat evaporation rate, rectal temperature and mean skin temperature. These graphs revealed some important aspects of the behaviour of man's thermal control system. In particular the physiological conductance increased with increasing ambient temperature and then saturated at an ambient temperature near 35° C. This saturation resulted in a constant difference between rectal temperature and mean skin temperature irrespective of the environmental conditions.Published with the permission of the Chamber of Mines of South Africa.     

Heat shock protein 60 from Chlamydia pneumoniae elicits an unusual set of inflammatory responses via Toll-like receptor 2 and 4 in vivo

Heat shock protein 60 (HSP60) from Chlamydia pneumoniae was described to trigger in vitro inflammatory and cytokine responses including TNF and IL-12p40. Although it can be found in atherosclerotic plaques of patients, the stimulatory potential of chlamydial and other HSP60 in vivo is unclear. We now report that chlamydial HSP60 fails to induce TNF expression in vivo, and significant serum levels of IL-12p40 are only found upon intraperitoneal injection of high doses of HSP60 or after intravenous application. Upon purification of chlamydial HSP60 with polymyxin B-agarose columns, its ability to induce TNF secretion in vitro is much reduced. However, purified chlamydial HSP60 causes increased serum levels of the CXC chemokines KC and MIP2 in vivo, as well as a strong accumulation of polymorphonuclear neutrophils (PMN) in the peritoneal cavity upon intraperitoneal challenge. With respect to PMN accumulation, chlamydial HSP60 is more potent than endotoxin or the CpG oligonucleotide 1668. The responses observed are completely abolished in Toll-like receptor (TLR)2/4-double-deficient mice, while single-deficient mice respond almost normally. Furthermore, KC induction and PMN accumulation are largely dependent on MyD88. In conclusion, HSP60 from C. pneumoniae triggers inflammatory responses in vivo that differ from responses induced by endotoxin or CpG oligonucleotides and are dependent on TLR2 and 4.     

应激相关的热休克信号转导通路的研究进展

随着社会的发展和医疗技术的不断进步与完善,人们的健康水平有了大幅度的提高。但急性梗塞(如脑梗、心梗)、感染性疾病(如败血症)等仍有较高的发病率和死亡率。特别是随着我国社会和经济的发展,老年人群的结构比例明显增高,心脑血管疾病和感染引起的疾病将进一步增加。而且随着     

Heat and water vapour transfer of protective clothing systems in a cold environment,measured with a newly developed sweating thermal manikin

A moveable sweating thermal manikin has recently been developed. Thermal and water-vapour resistances of three kinds of cold-protective clothing ensembles, laminated with polytetrafluoroethylene, polyurethane and without a laminate were measured, with the aid of the manikin in a cold environment of 5°C with a relative humidity of 70% and an air velocity of around 1.5 m s^–1. Two sweating rates of 65 and 130 g m^–2 h^–1 were employed. Supplied heat fluxes in both of the sweat rates ranged from 350 W m^–2 to 400 W m^–2. To maintain a comfortable condition, the skin wettedness (w) (mean weighted value) had to be kept at 0.6. The measurements obtained from the manikin when testing the three ensembles were w=0.3 (approximately) for the low sweat rate and w0.6 for the high sweat rate, irrespective of the property differences among the ensembles. In addition, the condensation in the ensembles in comparison with those calculated from an analytical equation is discussed. Condensation mass fluxes in the ensembles obtained byexperiment and those from the calculation agreed sufficiently well. Thus, distribution of the condensation in the ensembles was estimated using the equation.     

我国福建汉族人HSP70基因多态性分析

目的了解福建省汉族人HSP70基因多态性分布，进而为探讨HSP70基因多态性与疾病的相关性提供遗传背景资料。方法应用聚合酶链反应技术、限制性内切酶分析检测了127名福建汉族正常人的HSP70基因3个多态性位点，并比较了部分不同地区和人群之间的基因型与等位基因频率。结果福建汉族人HSP70-1基因型（GG，GC和CC）分布频率分别是55．1％、40．2％和4．7％；HSP70-2基因型（从，AG和GG）分布频率分别是44．1％、铝．8％和6．9％；HSP70-hom基因型（Tr，TC和CC）分布频率分别是59.8％、37．0％和3．2％；HSP70-1等位基因频率G和C分别是75．2％和24．8％；HSP70-2等位基因频率A和G分别是68．5％和31．5％；HSP70-hom等位基因频率T和C分别是78．3％和21．7％。福建汉族人HSP70-1的基因型分布和等位基因频率同日本、墨西哥人群比较差异无统计学意义，与美国和西班牙人比较，差异有统计学意义（P〈0．01）。福建汉族人HSP70-1的GG纯合型（55．1％）显著高于美国（42．6％）和西班牙（33．0％）人群；福建汉族人HSP70-2的基因型分布和等位基因频率与日本人比较差异无统计学意义，与墨西哥、美国和西班牙人群比较，差异有统计学意义（P〈0．05），福建汉族人HSP70-2的AA纯合型（44．1％）高于墨西哥（23．O％）、美国（38．8％）和西班牙（20．O％）人群；福建汉族人群的HSP70-hom基因型和等位基因频率分布同日本、墨西哥、美国和西班牙人群的基本一致，差异无统计学意义，福建汉族人群的HSP70基因型和等位基因频率分布同中国台湾汉族人基本一致，差异无统计学意义，与武汉地区汉族人某些位点存在差异。结论福建汉族人HSP70基因多态性分布不同于某些地区的人群，具有种族和地区差异。