拮抗细胞程序性坏死——机体应激损伤防护的新策略

应激是机体对内外环境变化做出的总体反应,过度应激导致机体的组织坏死和器官衰竭,从而诱发应激损伤。细胞程序性坏死是一种新鉴定的可调控的程序性细胞死亡,具有明确的调控靶点和信号转导通路,且在缺血再灌注、外源微生物感染和炎症反应等应激因素诱导的组织损伤过程中具有重要的调控作用。同时,细胞程序性坏死抑制剂在多种应激损伤动物模型中都表现出显著的预防和治疗效果,从而表明阻断细胞程序性坏死将成为应激损伤预防和治疗的新策略,而细胞程序性坏死的调控靶蛋白也为应激损伤的药物设计提供了新的靶点。     

光动力疗法与热损伤对正常大鼠胃损伤的研究

为了初步探讨ＰＤＴ与热损伤对正常胃损伤作用机制的差异，本实验以血卟啉衍生物及氩离子泵染料激光器为光敏剂及光源，观察了大鼠胃壁在单纯氩离子激光照射和ＰＤＴ时，照射部位的温度及组织学在照射后７２小时和二周的改变。结果：氩离子激光照射组和ＰＤＴ组胃壁温度均高于对照组（Ｐ＜０．０１），但ＰＤＴ组温度均低于３７℃。氩离子激光照射后的胃壁组织在７２小时各层组织均明显出血，炎细胞浸润，组织凝固坏死。电镜下见胶原纤维肿胀，排列紊乱，甚至溶解吸收。二周后损伤部位以纤维瘢痕组织修复。ＰＤＴ组在７２小时胃壁组织也有充血和炎细胞浸润，但仅有轻度组织坏死，损伤深度未超过粘膜下层。电镜下见胶原纤维结构基本正常。二周后损伤部位以组织再生修复，未留瘢痕。结论：ＰＤＴ与氩离子激光组织损伤及修复方式不同，ＰＤＴ不损伤胃粘膜下胶原纤维。     

烧伤治疗学的辩证观

烧伤治疗学的辩证观就是针对烧伤发病过程中不同阶段不同性质的矛盾，采用不同的治疗方法。既要抓住发病的根本原因，治病求本；又要权衡病情的轻重缓急，急则治标，缓则治本，或标本兼治。本文论证了烧伤发病过程中不同阶段的标本治疗原则。即：（1）在总体治疗原则中，局部治疗为本，全身治疗为标；（2）在局部治疗原则中，驱除坏死组织为本，修复缺损组织为标；（3）在驱除坏死组织治疗中，液化成脓为本，干燥结痂为标；（4）在修复创面治疗中，再生修复为本，植皮覆盖为标；（5）在防治感染中，坏死组织引流通畅为本，抗生素杀菌为标，（6）在营养支持治疗中，食补为本，药补为标。     

美军医学高新技术研究进展

1基础研究1.1再生医学 用于治疗因战伤所致的外伤性损伤，已经取得了初步成果，能够实现多个受损组织和器官再生，并可对其进行修复或更换。再生医学利用了许多新技术来治疗受损组织和器官，促进机体进行自主再生，并将伤员的自体细胞种植在可进行生物降解的支架上，创造出可用于治疗的生物工程器官。美军现时研究重点：     

胚胎无瘢痕修复机制的研究进展

最新的实验和临床研究表明，胚胎组织对损伤后的修复反应与成年机体存在较大的差异；成人伤口修复的结果一般以纤维化或瘢痕的形式替代损伤组织为特征，而胚胎组织损伤后却可以获得组织结构和功能上的完美修复，其突出表现为无瘢痕形成［１～３］。瘢痕形成或挛缩、组织纤...     

中医药治疗烧伤的研究进展

烧伤是指由热力所引起的组织损伤，如热液、火焰、热金属、热蒸汽等。由电、化学物质所致的损伤，也属烧伤范畴。烧伤火炽热甚。耗阴损气，主要侵犯中焦，热邪为病，多为阳明实热之症。烧伤后机体通过自身的再生能力为维持内环境稳定、恢复其表面的连续性和完整性，所进行的一系列修复活动为创面愈合。在这个复杂的生物学过程中，有多种组织和修复细胞、细胞外基质及各种调控因素参与。中医对烧伤的研究历史悠久，积累了丰富的经验。近年来，对中医药治疗烧伤的方法、剂型研究较多．取得了一定的进展，现综述如下。     

DNA同源重组修复的分子机制

电离辐射直接造成生物靶分子细胞DNA的损伤，DNA的损伤类型很多，其中以DNA双链断裂（double strand break，DSB）最为严重。DNA DSB的修复较其他类型的DNA损伤更加困难。不修复则可能导致染色体断裂和细胞死亡，而修复不当则可能导致染色体缺失、重排、转位和倒置等，从而易于形成肿瘤等疾病。DNA损伤的不完全修复可导致基因组不稳定，机体细胞为了对抗损伤，发展出多个修复系统来保证基因组的完整性，同源重组修复（homologous recombination repair，HRR）是DNA DSB损伤修复的主要方式，对于保持哺乳动物细胞的基因组完整性十分重要。重组即遗传物质的重排，同源重组是指发生在同源DNA序列间的重组，主要是利用DNA序列间的同源性来识别，而负责配对和重组的蛋白质因子并无碱基序列特异性。     

皮肤局部炎症反应与创面修复

本文主要关注机体皮肤损伤后在修复过程中所涉及的局部炎症反应。汇总迄今为止对该领域的研究结果和科学认识,主要涉及皮肤损伤后修复过程中局部无炎症反应、适度的炎症反应和异常的炎症反应三种情况。当一些特殊时期的胚胎皮肤组织（如人类仅限在胚胎22～24周胚胎皮肤,小鼠仅限在16天的胎鼠皮肤）损伤后的修复过程则无需涉及炎症反应,因为这类皮肤的毛囊和皮脂腺等附件有更新能力以及具有无瘢痕修复的正常真皮基质形成;当皮肤毛囊和皮脂腺等附件没有更新能力,但皮肤损伤后尚有完好的毛囊和皮脂腺等附件,适度的炎症反应则有利于创面修复;当局部皮肤炎症反应一旦出现失衡现象,则导致修复失衡——瘢痕形成或创面难愈。     

结肠组织热损伤后修复能力的实验研究

结肠组织热损伤后修复能力的实验研究５１０３１８广州解放军第４２１医院吴桂英，周益盛，陈国才，梁定章关键词结肠，损伤，热原，组织改变中国图书资料分类号Ｒ６４４正常结肠组织加热到一定温度时间会引起热损伤，这在我们［１］以前试验中已观察到。但对热损伤后能否...     

干细胞移植治疗缺血性心脏病:从基础到临床

心肌是终末化组织,坏死后不能再生。如何修复心肌细胞是缺血性心脏病治疗中的关键问题。目前,干细胞移植修复损伤坏死的心肌细胞在基础中展现了良好的前景,正在向临床应用转化。本文就干细胞应用于缺血性心脏病治疗的基础和临床研究进展、细胞种类、移植方法、优缺点和存在的问题等进行综述和讨论。     

Individual thermal profiles as a basis for comfort improvement in space and other environments

BACKGROUND: The development of individualized countermeasures to address problems in thermoregulation is of considerable importance for humans in space and other extreme environments. A methodology is presented for evaluating minimal/maximal heat flux from the total human body and specific body zones, and for assessing individual differences in the efficiency of heat exchange from these body areas. The goal is to apply this information to the design of individualized protective equipment. METHODS: A multi-compartment conductive plastic tubing liquid cooling/warming garment (LCWG) was developed. Inlet water temperatures of 8-45 degrees C were imposed sequentially to specific body areas while the remainder of the garment was maintained at 33 degrees C. RESULTS: There were significant differences in heat exchange level among body zones in both the 8 degrees and 45 degrees C temperature conditions (p < 0.001). The greatest amount of heat was absorbed/released by the following areas: thighs (8 degrees C: -2.12 +/- 0.14 kcal min(-1); 45 degrees C: +1.58 +/- 0.23); torso (8 degrees C: -2.12 +/- 0.13 kcal min(-1); 45 degrees C: +1.31 +/- 0.27); calves (8 degrees C: -1.59 +/- 0.26 kcal min(-1); 45 degrees C: +1.53 +/- 0.24); and forearms (8 degrees C: -1.67 +/- 0.29 kcal x min(-1); 45 degrees C: +1.45 +/- 0.20). These are primarily zones with relatively large muscle mass and adipose tissue. Calculation of absorption/release heat rates standardized per unit tube length and flow rate instead of zonal surface area covered showed that there was significantly greater heat transfer in the head, hands, and feet (p < 0.001). The areas in which there was considerable between-subject variability in rates of heat transfer and thus most informative for individual profile design were the torso, thighs, shoulders, and calves or forearms. CONCLUSIONS: The methodology developed is sensitive to individual differences in the process of heat exchange and variations in different body areas, depending on their size and tissue mass content. The design of individual thermal profiles is feasible for better comfort of astronauts on long-duration missions and personnel in other extreme environments.     

Unusual presentation of purulent pericarditis: diagnostic contribution of MRI

Purulent bacterial pericarditis is an uncommon form of infectious pericarditis, occurring usually in immunocompromised patients. It may rarely present as a nodular or tumefactive lesion, and in such cases is liable to be confused with primary and metastatic tumors. We describe the imaging features and diagnostic contribution of CT and MRI in a 68-year-old woman with mass-like purulent pericarditis.     

Purulent pericarditis presenting as acute abdomen in children: abdominal imaging findings.

Purulent pericarditis is rapidly fatal if untreated [1,2]. With increased development of bacterial resistance to antibiotics, severe bacterial infections in children are becoming more frequent [3,4]. We report two children with purulent pericarditis who presented in a 1-month period for evaluation of acute abdominal distention and signs of sepsis. In both, one evaluated with computed tomography (CT) and one with ultrasound, abdominal findings included periportal edema, gallbladder wall thickening, and ascites secondary to right heart failure from cardiac tamponade. Radiologists should be aware that children with purulent pericarditis may have a normal heart size on radiographs, present with acute abdominal symptoms, and demonstrate findings of right sided heart failure on abdominal imaging.     

热盲管伤、热贯通伤的MEBO治疗

目的：探讨MEBO的自动液化，通畅引流，促进创伤愈合的作用。方法：对32例热育管伤及热贯通伤应用MEBO治疗。结果：32例病人应用MEBO后，坏死组织清创、引流完好，无一例感染，创口一期愈合。结论：MEBO具有很强的自动液化、引流坏死组织的作用，同时具有促进创伤愈合的作用，是治疗热育管伤及热贯通伤的理想用药。     

The thermophysiology of uncompensable heat stress. Physiological manipulations and individual characteristics

In many athletic and occupational settings, the wearing of protective clothing in warm or hot environments creates conditions of uncompensable heat stress where the body is unable to maintain a thermal steady state. Therefore, special precautions must be taken to minimise the threat of thermal injury. Assuming that manipulations known to reduce thermoregulatory strain during compensable heat stress would be equally effective in an uncompensable heat stress environment is not valid. In this review, we discuss the impact of hydration status, aerobic fitness, endurance training, heat acclimation, gender, menstrual cycle, oral contraceptive use, body composition and circadian rhythm on heat tolerance while wearing protective clothing in hot environments. The most effective countermeasure is ensuring that the individual is adequately hydrated both before and throughout the exercise or work session. In contrast, neither short term aerobic training or heat acclimation significantly improve exercise-heat tolerance during uncompensable heat stress. While short term aerobic training is relatively ineffective, long term improvements in physical fitness appear to provide some degree of protection. Individuals with higher proportions of body fat have a lower heat tolerance because of a reduced capacity to store heat. Women not using oral contraceptives are at a thermoregulatory disadvantage during the luteal phase of the menstrual cycle. The use of oral contraceptives eliminates any differences in heat tolerance throughout the menstrual cycle but tolerance is reduced during the quasi-follicular phase compared with non-users. Diurnal variations in resting core temperature do not appear to influence tolerance to uncompensable heat stress.     

Thermoregulation during exercise in individuals with spinal cord injuries

The increased participation in wheelchair sports in conjunction with environmental challenges posed by the most recent Paralympic venues has stimulated interest into the study of thermoregulation of wheelchair users. This area is particularly pertinent for the spinal cord injured as there is a loss of vasomotor and sudomotor effectors below the level of spinal lesion. Studies within this area have examined a range of environmental conditions, exercise modes and subject populations. During exercise in cool conditions (15-25 degrees C), trained paraplegic individuals (thoracic or lumbar spinal lesions) appear to be at no greater risk of thermal injury than trained able-bodied individuals, although greater heat storage for a given metabolic rate is evident. In warm conditions (25-40 degrees C), trained subjects again demonstrate similar core temperature responses to the able-bodied for a given relative exercise load but elicit increased heat storage within the lower body and reduced whole-body sweat rates, increasing the risk of heat injury. The few studies examining a wide range of lesion levels have noted that, for paraplegic individuals where heat production is matched by available sweating capacity, excessive heat strain may be offset. Studies relating to tetraplegic subjects (cervical spinal lesions) are fewer in number but have consistently shown this population to elicit much faster rates of core and skin temperature increase and thermal imbalance in both cool and warm conditions than paraplegic individuals. These responses are due to the complete absence or severely reduced sweating capacity in tetraplegic subjects. During continuous exercise protocols, the main thermal stressor for tetraplegic subjects appears to be environmental heat gain, whereas during an intermittent-type exercise protocol it appears to be metabolic heat production. Fluid losses during exercise and heat retention during passive recovery from exercise are related to lesion level. Future research is recommended to focus on the specific role of absolute and relative metabolic rates, sweating responses, training status and more sport- and vocation-specific exercise protocols.     

热环境对机体功能影响的机制及防护研究进展

热环境增加高温作业人员发生热损伤的风险,充分认识热环境对高温作业人员机体的影响和危害,对提高高温作业人员防暑意识、减少作业时的职业性热损伤具有重要意义。笔者主要从热环境的定义、热环境对人体主要功能系统影响的机制、热应激的影响因素及防护研究进展进行综述,为高温作业人员对热致疾病的认识及防护提供参考。     

运动性和高血压性心肌肥大对再灌注损伤耐受性的研究

为探讨运动性心肌肥大和高血压心肌肥大对缺血再灌注损伤的差异，本文在大鼠游泳训练心肌肥大和主动脉缩窄性高血压心肌肥大离体心脏灌流模型上，观察它们对缺血再灌注损伤的差异。结果表明，反映组织损伤程度的指标如乳酸脱氢酶漏出，心肌脂质过氧化终产物丙二醛（ＭＤＡ）和心肌钙在高血压心肌肥大的心肌较对照组和运动心肌肥大组皆明显升高，而运动组和对照组则无差异，高血压心肌肥大的程度和运动性心肌肥大的程度基本一致。本研究提示运动性心肌肥大的心肌抗缺血再灌注损伤的能力较高血压心肌肥大者增强。     

Estimation of time since death by heat-flow Finite-Element model. Part I: method, model, calibration and validation

The determination of the time since death which often represents the presumed time of an offence plays an important role in medico-legal practice. In the early postmortem phase analyses of postmortem cooling provide the most accurate estimates. Empirical models of postmortem cooling are methodically restricted to standard conditions while heat flow models can in principle be applied to any complex cooling situations. The main problem having so far prevented heat flow models from being used in practice was the difficulty of solving the heat transfer equation for complex geometrical, initial and boundary conditions. This problem is now overcome by using the Finite-Element-Method as a numerical procedure. The study presents a three-dimensional Finite-Element-Model of the human body containing various tissue compartments with different thermal tissue properties. The initial temperature field is modelled inhomogeneously with a temperature gradient between body core and shell. Heat loss by conduction, convection and radiation as well as heat gain by supravital activity or irradiation from external sources can be simulated. One model parameter, the decrease rate of the supravital energy production, was calibrated and the model successfully validated using the experimentally verified empirical model by Marshall and Hoare.     

离体猪椎体多极射频消融范围及热场分布

目的 通过对离体猪椎体进行射频消融(RFA),观察其骨质凝固范围及热场分布,探讨RFA时电极针在椎体中的位置与脊髓的安全性关系,以及椎体周围有无软组织损伤.方法 取30节新鲜成年猪椎体,随机分成两组.电极针深度分别为10、20 mm.消融达稳态后按预先设计测温点测温.消融20 min后,沿电极针及垂直于电极针平面切开观察骨质凝同范围.结果 各测温点在3.5 min达稳态.靠电极越近温度上升越快.两组椎体周围软组织无损伤,当电极针深10、20 mm时均无脊髓损伤.结论 对椎体后壁保持完整的椎体转移性肿瘤RFA治疗安全、可靠.