军事应激对机体免疫功能影响的研究进展

应激是生命活动所必需的,但强烈的心理应激或长期的慢性心理应激会严重影响人们的心身健康,导致情感行为异常、免疫功能低下、应激性溃疡和神经内分泌功能异常等[1]。军事应激是指军人在完成军事任务过程中,对包括极端恶劣生存环境、精神超负荷紧张及超强度作业等在内的多种军事行动反应的过程,包括心理、生理上发生的变化。适度的军事应激反应往往能活跃思维,提高军人的警觉性和作业效率,更好地适应环境;但当应激反应导致军人的认知、情绪和行为     

内质网应激和Ca2+超载在热打击诱导的肺微血管内皮细胞损伤中的作用与机制

目的 研究内质网应激和Ca2+超载在热打击诱导的肺微血管内皮细胞(PMVECs)损伤中的作用及其可能的机制.方法 建立PMVECs温度梯度热打击模型.对照组细胞始终置于标准37℃、5%CO2细胞培养箱孵育,热打击组细胞分别置于39、41、43℃细胞培养箱中热打击2h,热打击后继续在37℃、5%CO2细胞培养箱孵育6h;另取细胞在43℃热打击前分别以20μmol/L钙离子抑制剂BAPTA-AM和50μmol/L环孢霉素A(CsA)预处理,后续处理同43℃热打击组细胞.Western blotting检测磷酸化的蛋白激酶样内质网激酶(p-PERK)、磷酸化的真核生物翻译起始因子2α(p-eIF2α)、活性转录因子4(ATF4)以及葡萄糖调节蛋白78(GRP78)蛋白表达;流式检测细胞内Ca2+、线粒体膜电位以及线粒体通透性转换孔的变化;Caspase活性试剂盒检测caspase-3变化以反映细胞凋亡情况;Millicell-ERS细胞电阻仪测定细胞的跨上皮细胞电阻(TER)以了解细胞通透性的改变.结果 随着热打击温度的增高(41~43℃),PMVECs内p-PERK、p-eIF2α以及ATF4、GRP78蛋白表达增强,细胞内Ca2+水平增高,线粒体通透性转换孔开放,线粒体膜电位下降,细胞通透性增加,凋亡增多,且在43℃热打击组最为明显,与对照组比较差异有统计学意义(P<0.05).使用Ca2+抑制剂预处理细胞可以促使PMVECs线粒体通透性转换孔、膜电位以及细胞通透性恢复,减少凋亡的发生;使用线粒体保护剂预处理细胞并不能减轻PMVECs的Ca2+释放,但可促进细胞通透性恢复以及减少凋亡发生.结论 热打击可激活PMVECs的内质网应激反应,并诱导细胞内Ca2+超载介导的细胞和线粒体损伤,这可能是中暑导致内皮细胞损伤的重要机制之一.     

乌司他丁对中暑大鼠肾损伤及氧化应激的影响

目的 探讨乌司他丁对中暑(HS)大鼠肾脏损伤和氧化应激的影响.方法 SPF级Wistar雄性大鼠42只,随机分为正常对照组(n=6)、中暑组(HS组,n=18)和乌司他丁治疗组(UTI组,n=18).HS组及UTI组置于仿真高温气候舱内复制HS模型,以大鼠收缩压峰值开始下降为模型成功标志,对照组置于23.0±0.2℃室温下.UTI组于制模前腹腔注射UTI 10万U/kg,每12h重复给药,其余两组大鼠均注射等量生理盐水.分别于造模0,6,24h时点采血并处死大鼠,以自动生化分析仪检测大鼠血清肌酐(Cr)、尿素氮(BUN)水平,比色法检测肾脏组织丙二醛(MDA)及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GPx)活性等氧化应激指标.光镜及电镜观察造模24h后大鼠肾组织形态学变化.结果 与对照组比较,HS及UTI组大鼠肾组织MDA含量于模型复制成功后0h显著升高(P＜0.05),6h及24h有所下降,但仍显著高于对照组(P＜0.05).UTI组各时间点肾组织MDA含量均明显低于HS组(P＜0.05).HS组大鼠肾组织SOD和GPx活性于模型复制后6h显著低于对照组(P＜0.05),UTI组与对照组比较无明显下降(P＞0.05).与HS组比较,UTI组6h及24h血清Cr、BUN水平下降(P＜0.05),中暑后24h肾脏的病理损害明显减轻.结论 乌司他丁可减轻重症中暑大鼠肾脏氧化应激水平,从而保护肾功能.     

热环境下运动中降温策略对有氧运动表现的影响研究进展

近些年来,许多备受瞩目的国际体育赛事往往在热环境下举行,热环境已成为许多运动员在训练和比赛中不得不面对的挑战之一。热环境下运动可能导致体温过高、加速运动性疲劳发生并损害身体机能和有氧运动表现。许多研究证实,在运动中实施降温策略能够缓解热应激并提高有氧运动表现。运动中降温（per-cooling）策略可分为内部降温、外部降温和混合降温。运动中实用的降温方法包括降温服、冰袋、降温项圈、喷雾风扇、冰毛巾、薄荷醇喷雾、冷液/冰浆/薄荷醇饮料摄入、薄荷醇漱口等。运动中降温策略提高有氧运动表现的可能机制包括缓解心血管系统压力、降低体温、增加蓄热能力、缓解中枢疲劳、改善热舒适度、热感觉和主观疲劳感觉等。目前,热环境下运动中最佳的降温策略未达成共识,不同的降温策略具有其自身的优点和局限性。建议运动员充分考虑运动环境、设备条件、专项特点和比赛规则等实际情况,选择最适的降温策略。     

内皮细胞热损伤机制及其对重要脏器功能的影响

血管内皮细胞(VECs)作为人体的重要器官,不但其完整性是维持血管通透的重要屏障,而且其结构及功能受损对热损伤早期具有重要影响.中暑时,高热刺激导致机体出现一系列急性、复杂的病理生理和微循环改变,引起VECs损伤,可诱发或加重多器官功能障碍综合征(MODS).同时,有研究显示VECs是热打击时重要的反应细胞,是中暑过程中发生形态和功能变化的最常见细胞之一,也是最早发生损伤的细胞.VECs损伤可能是机体由热应激的生理进程向中暑和重症中暑这一病理进程转变的重要中间环节,在重症中暑MODS的发病过程中起着关键性作用.     

急性热应激与夏季飞行对飞行员血浆热应激蛋白的影响

目的研究急性热应激和夏季飞行对飞行员血浆中主要热应激蛋白（ＨＳＰｓ）的影响。方法使用Ｄｏｔ－ｂｌｏｔ方法，分别检测飞行员在急性热应激前后和夏季飞行前后血浆ＨＳＰｓ水平。结果与应激前相比，急性热应激和飞行应激后，飞行员血浆中ＨＳＰ７０明显增加（Ｐ＜０．０５）；飞行应激后ＨＳＰ２７明显增加（Ｐ＜０．０５）。结论ＨＳＰｓ变化在评价飞行应激中可能具有某些生物学意义     

热应激对公牛精液品质的影响及机理的研究进展

本文在应激概念的理论基础上，阐明了热应激状态下种公牛的精液品质严重下降，并且从血液和精清生化指标的变化阐述了热应激影响种公牛精液品质的机理。     

锌对小鼠在高温环境下机体耐力的影响(论著)

目的：观察锌对热应激小鼠机体耐力的影响。方法：进行３种试验，即游泳试验、耐缺氧试验和高温致死试验。作各种试验的小鼠分别再分为高锌组、中锌组和低锌组，并喂以相应的高、中、低锌饲料２１天（高温致死试验为１４天）。每日光暗节律各１２小时，自由摄食与饮水，同时观察动物活动、皮毛、摄食及体重情况。游泳试验水温为４０．０±０．２℃，记录小鼠入水游泳至沉底死亡的时间。耐缺氧试验在高温室（干球３９℃、湿球３４℃）内进行，记录小鼠在腊封瓶内的存活时间。高温致死试验在ＤＬ－３０１Ａ型调温调湿箱（干球４６℃，湿球４１℃）内进行，观察３０分钟内的各组动物死亡数。结果：①高锌组小鼠游泳时间显著长于中、低锌组；②高锌组小鼠耐缺氧时间显著长于低锌组；③高锌组小鼠的３０分钟致死率显著低于低锌组。结论：适量补锌可以增强小鼠在高温环境下的热耐受能力     

热应激对血管内皮细胞增殖的影响及其机制初探

目的　探讨热应激条件下对血管内皮细胞增殖的影响 ,进一步从DNA损伤后P5 3mRNA、P2 1mRNA表达改变角度探讨增殖调控的机理。方法　以建立的血管内皮细胞热应激 (4 3℃ ,2小时 )为实验模型 ,应用流式细胞仪观察热应激后血管内皮细胞株ECV30 4的细胞周期变化 ,单细胞凝胶电泳方法观察热应激对血管内皮细胞DNA的损伤 ,RT PCR检测P5 3mRNA、P2 1mRNA表达改变情况。结果　热应激可使血管内皮细胞DNA产生显著损伤 (P <0 .0 5 ) ,继而P5 3mRNA表达增高 ,并促进P2 1mRNA的上调表达 ,最终使细胞产生G1期阻滞。结论　热应激可损伤血管内皮细胞DNA ,并通过P5 3、P2 1通路抑制细胞增殖     

The incidence of heat casualties in sprint triathlon: The tale of two Melbourne race events

Triathlon is a popular participation sport combining swimming, cycling and running into a single event. The Triathlon Australia medical policy advocates the use of wet bulb globe temperature as the criterion for altering race distance and an ambient temperature of 35 degrees C as a criterion for consideration of cancellation of an event, but there is little empirical evidence detailing the effectiveness of this policy. Nor has the impact of environmental thermal stress on triathletes in shorter duration events been determined. During an injury surveillance investigation of a triathlon race series over the 2006/2007 seasons, two events with similar environmental conditions were completed. One thousand eight hundred and eighty-four participants competed in event 1 (December 2006) and 2000 competed in event 2 (February 2007). Maximum dry bulb (DBT), minimum vapour pressure (VP) and minimum relative humidity (RH) for event 1 were 37 degrees C DBT, 0.56 kPa VP and 9% RH measured by the Bureau of Meteorology. Fifty-three participants presented for medical aid, 15 due to heat-related collapse. The conditions measured for event 2 were 33 degrees C DBT, 1.16 kPa VP and 24% RH and there were no heat illness presentations despite 38 individuals presenting for medical aid. These observations suggest that the risk of heat-related collapse is greatest when high-environmental temperatures occur early in the competitive season when participants may be inadequately prepared and have not yet acquired natural acclimatisation to heat. Any Triathlon Australia policy revision could place stronger emphasis on the use of ambient temperature as a limiting criterion for race organisers.     

氧化应激在中暑大鼠急性肝损伤中的作用及机制研究

目的 探讨氧化应激在中暑急性肝损伤发生中的作用及其可能机制.方法 32只大鼠按随机数字表法分为4组:假加热正常对照组(Sham组)、中暑组(HS组)、假加热N-乙酰半胱氨酸治疗组(Sham-NAC组)以及中暑NAC治疗组(HS-NAC组),每组8只.通过人工气候舱制备中暑大鼠模型,监测大鼠直肠温度(Tr)、脉率(HR)、收缩压(SBP).记录中暑发生的时间.于中暑开始后12h处死大鼠,测定大鼠血清丙氨酸氨基转移酶(ALT)和总胆红素(TBIL)水平,以及肝脏组织匀浆IL-6、IL-1β、TNF-α、丙二醛(MDA)、总超氧化物歧化酶(T-SOD)和谷胱甘肽(GSH)等指标的变化,组织学观察肝脏氧自由基(ROS)含量、中性粒细胞浸润以及病理损伤情况.结果 中暑发生时HS-NAC组与HS组Tr、HR、SBP、中暑发生时间等比较差异无统计学意义(P＞0.05),但HS-NAC组的生存时间与HS组相比明显延长,差异有统计学意义(P=0.039).中暑发生后12h,HS组肝组织匀浆中ROS和MDA含量及血清ALT和TBIL水平较其他3组明显升高(P=0.000),肝组织匀浆中T-SOD和GSH含量较其他3组明显下降(P=0.000).病理观察显示HS-NAC组肝损伤较HS组减轻(P=0.000).HS组肝脏中性粒细胞浸润水平及IL-6、IL-1β、TNF-α浓度均明显高于HS-NAC组(P=0.000).结论 氧化应激在中暑肝损伤中起重要作用,其机制可能与直接细胞毒和介导炎症反应有关.     

Wet-bulb globe temperature (WBGT)—its history and its limitations

Wet-bulb globe temperature (WBGT) is nowadays the most widely used index of heat stress, yet many users appear to be unaware of its history and its limitations.History of WBGT: WBGT was invented and first used during the 1950s as one element in a successful campaign to control serious outbreaks of heat illness in training camps of the United States Army and Marine Corps. Control measures based on air temperature and humidity, and applied to all trainees alike, had proved effective but had entailed excessive compliance costs in the form of lost training time. New control measures introduced in 1956 further reduced heat illness and also lost fewer training hours. Crucial innovations were (1) replacing the temperature and humidity measurements with WBGT, which additionally responds to sun and wind, (2) using epidemiologic analyses of casualty records to identify hazardous levels of WBGT and vulnerable trainees, and (3) protecting the most vulnerable trainees by suspending drill at lower levels of WBGT, and by improving their heat tolerance in special conditioning platoons. This campaign has considerable relevance to the prevention of heat illness in sport.Limitations of WBGT: WBGT's most serious limitation is that environments at a given level of the index are more stressful when the evaporation of sweat is restricted (by high humidity or low air movement) than when evaporation is free. As with all indices that integrate elements of the thermal environment, interpretation of the observed levels of WBGT requires careful evaluation of people's activity, clothing, and many other factors, all of which can introduce large errors into any predictions of adverse effects. Moreover, the accuracy of WBGT is being eroded by measurement errors associated with the omission of the globe temperature, with non-standard instrumentation, and with unsatisfactory calibration procedures. Because of the above limitations WBGT can provide only a general guide to the likelihood of adverse effects of heat. A much clearer assessment can be obtained by measuring the individual elements of the thermal environment, and using those measurements to estimate the requirement for evaporative cooling, the likelihood of achieving it, and more accurate and comprehensive indices of heat stress.     

高温环境对女兵生理周期的影响及机制研究进展

在高温环境下开展军事作业的女兵不可避免受到高温的影响,其身体健康及生殖功能受到严重威胁,生理周期紊乱是女兵受高温危害的最突出表现.长期处于高温环境下,可能会出现神经内分泌紊乱,影响下丘脑?腺垂体?卵巢(HPO)轴,从而导致生理功能障碍,出现月经异常的现象.该文综述了高温环境对女兵生理周期的影响因素、神经内分泌机制、免疫...     

Research progress of heat stroke during 1989-2019:A bibliometric analysis

Background:Heat stroke (HS) is an acute physical disorder that is associated with a high risk of organ dysfunction and even death.HS patients are usually treated symptomatically and conservatively;however,there remains a lack of specific and effective drugs in clinical practice.An analysis of publication contributions from institutions,journals and authors in different countries/regions was used to study research progress and trends regarding HS.Methods:We extracted all relevant publications on HS between 1989 and 2019 from Web of Science.Using the Statistical Package for Social Science (SPSS,version 24) and the software GraphPad Prism 8,graphs were generated and statistical analyses were performed,while VOSviewer software was employed to visualize the research trends in HS from the perspectives of co-occurring keywords.Results:As of April 14,2020,we identified 1443 publications with a citation frequency of 5216.The United States accounted for the largest number of publications (36.2％) and the highest number of citations (14,410),as well as the highest H-index at 74.Although the sum of publications from China ranked second,there was a contradiction between the quantity and quality of publications.Furthermore,Medicine & Science in Sports & Exercise published the most papers related to HS,with Lin MT publishing the most papers in this field (112),while the review by Knochel JP received the highest citation frequency at 969.The keyword heat-stress appeared most recently,with an average appearing year of 2015.5.In the clinical research cluster,exertional heat-stroke was determined to be the hotspot,while ambient-temperature and heat waves were the new trends in the epidemiological research cluster.Conclusions:Corresponding to this important field,while the contributions of the publications from the United States were significant,the mismatch between the quantity and quality of publications from China must be examined.Moreover,it is hypothesized that clinical and epidemiological studies may become hotspots in the near future.     

高温对大鼠热应激蛋白的影响

为了探讨高温环境对热应激蛋白（HSP70）的影响及HSP70在热应激中的作用，在模拟高温条件下，测定了大鼠HSP70的合成、HSP70mRNA基因的表达及肛温、心率、淋巴细胞形态学的改变。结果发现：机体心率加快、体温升高并伴有细胞损伤。三者与HSP70基因的表达呈负相关。提示：HSP70水平可成为判断机体热应激能力的敏感、特异指标。     

结肠途径治疗对中暑犬降温作用及血清酶、炎症因子的影响

目的 研究经结肠途径治疗对中暑犬的降温作用及对其血清酶、炎症因子的影响.方法 将14只犬随机分为两组,结肠途径治疗组(肠疗组)和常规治疗组(常疗组),每组7只.动物高温中暑(体温达43℃,10min)后均置于23℃、65%湿度的室温下行降温治疗.常疗组给予冰袋置于大动脉处降温;肠疗组应用结肠途径治疗机降温,调节肠疗液温度为37～38℃.犬体温下降至38℃时结束降温.比较两组犬的降温时间;用全自动生化分析仪测定中暑前(0h)和中暑后6h、24h、48h的血丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、乳酸脱氢酶(LDH)和肌酸激酶(CK)水平;用放射免疫法测定血清白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)、肿瘤坏死因子α(TNF-α)水平. 结果 肠疗组降温时间(92.9±9.5min)明显低于常疗组(123.4±11.6min,P＜0.01).中暑后两组血清ALT、AST、CK、LDH均明显升高;肠疗组中ALT、AST和CK在中暑后24h和48h较常疗组明显降低(P＜0.05),但两组中LDH在各时间点无显著性差异(P＞0.05).肠疗组中血清IL-1β在中暑后6h、24h和48h,均较常疗组明显降低(P＜0.05);IL-6在中暑后6h和24h明显低于常疗组(P＜0.01);TNF-α在中暑后24h和48h显著低于常疗组(P＜0.01).结论 采用结肠途径治疗机治疗可加快中暑犬的降温速度,促进其血清酶恢复,加速其血清炎症因子的清除.     

Epidemiology of exertional heat illnesses in organised sports: A systematic review

ObjectiveThis systematic review summarises reports of the incidence of exertional heat illnesses (EHI) in organised sports, to examine any trends in the EHI incidence over time, and to describe EHI incidence based on sporting activity, geographic location, and type of EHI.MethodThree electronic databases (CINAHL, PubMed, SportDiscuss) were searched from inception to January 2019. Original data in all epidemiological studies (any design except case-studies and case-series) that reported EHI incidence data in organised sports, across all age categories, and published in an English language peer-reviewed journal were included.ResultsThe primary search yielded 3556 results of which 62 studies were included in the final analysis, with 71% being from the USA. Reported EHI incidence rates ranged from 0.01 (cheerleading) to 4.19 (American football) per 1000 athletic-exposures (AEs), and 0.01 (mini-marathon) to 54.54 (desert ultra-marathon) per 100 participants. Endurance type events (running, cycling, adventure races) reported the highest EHI incidence rates per 100 participants. There was a considerable increase in EHI fatalities reported in the literature over the last three decades in American football and an increased reporting of EHI incidence in endurance type events during the last 5-years.ConclusionUse of different terminology and injury definitions in most studies have resulted in an inconsistency in reporting EHI incidence data, and also likely underreporting of less-severe forms of EHI conditions. Longitudinal studies focused on different sports and conducted in more countries (outside the USA), are needed for better understanding the global impact of EHI and the impact of prevention measures.