悬挂双前肢致死兔的膈肌超微结构的研究

目的研究悬挂体位下窒息死亡动物的膈肌超微结构变化。方法取悬挂双前肢体位家兔的膈肌和腓肠肌组织,以勒颈致死家兔的膈肌和腓肠肌组织为对照,采用透射电镜方法观察其超微结构的变化。结果悬挂组膈肌的细胞核、细胞质、细胞膜均有缺氧损伤的征象,其中肌纤维内的肌原纤维、线粒体病变尤为严重;勒颈组膈肌的改变与悬挂组膈肌相类似,但程度上较轻微;悬挂组腓肠肌轻微病变,但肌原纤维无明显改变;勒颈组腓肠肌无明显改变。结论悬挂体位造成了膈肌纤维超微结构的损伤,形成了机体缺氧的病理基础,可导致死亡;本实验的结果可为限制性体位窒息死亡的法医学鉴定标准提供实验性的形态学依据。     

家兔双前肢悬挂致死过程中的电生理研究

目的探讨悬挂体位致窒息死亡的电生理方面的机制。方法成年家兔12只,雌雄不限。随机分为两组:一组监测膈肌肌电图,另一组监测肋间肌肌电图、心电图、脑电图。取仰卧位固定,手术暴露膈肌和肋间肌,引导肌电图;同时引导标准Ⅱ导联心电图和脑电图。然后将家兔固定双前肢悬挂,连续监测实验过程中家兔的心电、脑电、肌电图的变化情况,直至其死亡。结果悬挂末期和悬挂初期相比,膈肌肌电频率下降(P<0.05)、呼吸波持续时间、振幅和面积均有延长或增多(P<0.05)、最大传导速度无变化;肋间肌仅见肌电频率下降(P<0.05);脑电振幅降低(P<0.01)、δ波增多(P<0.01)、β波减少(P<0.05);心电仅见各波形振幅的降低(P<0.01)。膈肌肌电频率的下降最早,脑电频率的下降次之,肋间肌肌电的下降最晚(P<0.01)。结论悬挂体位致窒息死亡的机制的始动因素是呼吸运动受限,并最终形成外周性呼吸肌疲劳和呼吸中枢缺氧性衰竭而发生死亡。     

87例大脑及脑干挫伤HSP70变化的研究

目的探讨人大脑及脑干挫伤后神经细胞HSP70变化与损伤时间的关系及大脑与脑干HSP70变化的差异。方法对87例闭合性颅脑损伤死亡脑挫伤组织进行病理学及HSP70免疫组织化学染色,结果进行图像分析。结果脑挫伤24h后.HSP70阳性神经细胞最多见,且免疫反应性最强,随后逐渐下降,14d组及30d组HSP70表达与对照组类似。脑挫伤部位可见较多HSP70阳性的淀粉样小体。图像分析显示大脑与脑干HSP70阳性细胞3个参数(A、IOD及AOD)之间呈高度显著正相关或显著正相关,由高至低排列为:A>IOD>AOD。结论神经细胞HSP70免疫组化染色结合图像分析技术作为推断脑挫伤经过时间的参考,大脑与脑干挫伤后神经细胞HSP70变化规律基本一致,但脑挫伤灶周围淀粉样小体形成的意义有待于进一步研究。     

心肌早期缺血再灌流损伤HSP70表达研究

目的　探讨早期缺血再灌流损伤心肌组织热休克蛋白 70 (HSP70 )的变化 ,为心源性猝死的法医病理学鉴定寻找新的依据。　方法　建立家兔早期心肌缺血再灌流动物模型 ,用免疫组化SABC法观察HSP70的表达。　结果　心肌缺血 15min再灌流 30min后 ,再灌流区心内膜下可见HSP70阳性表达 ;缺血30min再灌流 30min后 ,HSP70阳性反应细胞数目较多 ,散布于心肌全层 ;缺血 6 0min再灌流 30min后 ,再灌流区阳性表达明显减少 ,而其边缘见阳性表达略有增强。各实验组正常区和对照组心肌组织均未见阳性反应。　结论　心肌组织HSP70的阳性表达是一项显示心肌早期缺血再灌流损伤的灵敏指标 ,HSP70的免疫组化检测对缺血再灌流损伤所致心源性猝死的死后诊断具有一定的应用价值。     

心肌早期缺血再灌流损伤HSP70表达研究

目的探讨早期缺血再灌流损伤心肌组织热休克蛋白70(HSP70) 的变化,为心源性猝死的法医病理学鉴定寻找新的依据. 方法建立家兔早期心肌缺血再灌流动物模型,用免疫组化SABC法观察HSP70的表达. 结果心肌缺血15 min再灌流30 min后,再灌流区心内膜下可见HSP70阳性表达; 缺血30 min再灌流30 min后,HSP70阳性反应细胞数目较多,散布于心肌全层;缺血60 min 再灌流30 min后,再灌流区阳性表达明显减少,而其边缘见阳性表达略有增强.各实验组正常区和对照组心肌组织均未见阳性反应. 结论心肌组织HSP70的阳性表达是一项显示心肌早期缺血再灌流损伤的灵敏指标,HSP70的免疫组化检测对缺血再灌流损伤所致心源性猝死的死后诊断具有一定的应用价值.     

大鼠支气管哮喘模型的心肌HSP70表达研究

目的探讨支气管哮喘心肌组织的损害机制,为支气管哮喘诱发的猝死的法医学诊断提供形态学依据。方法应用HE和免疫组化技术,对大鼠支气管哮喘模型的心肌HSP70的表达规律进行研究。结果实验组的心肌HSP70阳性表达明显高于对照组(P<0.01),随着哮喘时间的延续,心肌HSP70的阳性表达逐渐增强(P<0.05),在第8周表达最强。结论实验组支气管哮喘早期心肌有损害,且随时间延续,损害增强。HSP70对支气管哮喘诱发的猝死的法医学诊断有一定的帮助。     

大鼠限制性体位窒息模型中膈肌Fn和HSP70的免疫荧光组化观察

目的观察Fn和HSP70在限制性体位窒息死亡的大鼠膈肌中的表达情况,进一步探讨限制性体位窒息死亡的机理。方法分组建立限制性体位窒息死亡大鼠模型,采用免疫荧光组织化学方法研究大鼠膈肌的Fn和HSP70的表达情况,并将荧光照片进行灰度值分析,比较抗原在不同组别间的表达差异。结果在Fn检测中,限制性体位窒息死亡组大鼠的膈肌肌内膜上有明亮荧光,肌纤维间隙的荧光强度明显大于对照组。在HSP70检测中,肌纤维内的荧光强度随着体位性限制程度的加重而明显增加。结论采用免疫荧光组织化学检测膈肌Fn和HSP70抗原的表达,对判断限制性体位窒息死亡者膈肌的损伤是一种有意义的手段。     

大鼠支气管哮喘模型的心肌HSP70表达研究

目的探讨支气管哮喘心肌组织的损害机制，为支气管哮喘诱发的猝死的法医学诊断提供形态学依据。方法应用HE和免疫组化技术，对大鼠支气管哮喘模型的心肌HSP70的表达规律进行研究。结果实验组的心肌HSP70阳性表达明显高于对照组（P〈0．01），随着哮喘时间的延续，心肌HSP70的阳性表达逐渐增强（P〈0．05），在第8周表达最强。结论实验组支气管哮喘早期心肌有损害，且随时间延续，损害增强。HSP70对支气管哮喘诱发的猝死的法医学诊断有一定的帮助。     

HSP70在青壮年猝死综合征心肌组织中的变化

目的探讨热休克蛋白70（HSP70）在青壮年猝死综合征形成机制中的作用,及其早期诊断作用。方法取30例青壮年猝死、20例正常对照心脏标本的左右心室肌、窦房结、房室结组织,通过免疫组化学染色,应用图像分析软件对HSP70分布及强度变化进行定量检测分析,并进行统计学处理。结果青壮年猝死者心肌传导系统内HSP70表达高于正常对照组,且具有统计学意义（P〈0.05）。其中青壮年猝死者右心室肌HSP70的表达显著低于其他部位心肌组织（P〈0.05）。结论HSP70作为一种应激反应的介质参与青壮年猝死综合征的发生过程,并对心脏起到保护性作用。HSP70可作为青壮年猝死综合征诊断的参考指标。     

热休克蛋白70对大鼠脑干损伤诊断的免疫组织化学研究

为了解脑干在受到创伤后作为降解异常蛋白的分子伴侣（molecularchaperones）之一的热休克蛋白70（heatshockprotein70HSP70）在中枢神经系统的表达情况，用免疫组化法对Wistar大鼠脑干针刺损伤模型的HSP70在损伤前及损伤后1、3、6、12、24小时的中枢神经各区的表达数量、分布变化进行检测。在针刺后1小时脑组织HE染色尚无明显特异性改变的情况下，大脑及小脑内HSP7免疫活性阳性的血管内皮细胞、神经胶质细胞显著增加，在损伤灶局部周围出现HSP7I免疫活性阳性神经元细胞增多，伤后3小时该处HSP7阳性神经元数量显著多于伤前及同一时间点的其它处脑组织，伤后24小时HSP7阳性细胞依然广泛存在。脑干的外伤性损伤可导致脑组织的蛋白质结构发生改变，脑干局部HSP70阳性神经元数量增多可作为脑干损伤定位诊断的依据。     

无电流斑电击死兔骨骼肌il-6mRNA表达研究

目的探讨生前电击与死后电击的鉴别方法及电流通路的推断方法。方法15只新西兰兔，随机分为3组，每组5只，即电击死组、死后电击组、对照组。电击死组，用220V交流电的两极分别连接实验动物的左后肢与右前肢，通电致死。死后电击组，从耳缘静脉注射50ml空气致死，于死后即刻用220V交流电的两极分别连接实验动物的左后肢与右前肢通电3min。对照组直接从耳缘静脉注射50ml空气致死，不进行电击。用荧光RT—PCR技术检测骨骼肌白介素6信使核糖核酸（il-6mRNA）表达水平，所得结果进行统计学分析。结果电击死兔骨骼肌il-6mRNA水平远高于死后即刻电击者（P〈0．05）；电击死兔对称肢体中通电肢体骨骼肌il-6mRNA水平远高于非通电肢体（P〈0．05）。结论骨骼肌il-6mRNA表达变化可用于生前电击与死后电击的鉴别；机体对称部位骨骼肌il-6mRNA表达差异有助于推断电流通路。     

膈肌疲劳在家兔体位窒息死亡中的作用

目的探讨膈肌在固定双上肢悬挂致死中的作用。方法将家兔固定双上肢悬挂,并监测家兔膈肌肌电图(EMGdi)的变化。结果在连续记录的EMGdi中早期的EMGdi与晚期的EMGdi比较高频与低频(H/L)的比值显著降低,提示膈肌疲劳确实存在。结论膈肌疲劳在固定双上肢悬挂致死中起着重要的作用。     

家兔限制性体位窒息模型中的LDH/CHE活性变化

目的 探讨家兔体位性窒息模型中乳酸脱氢酶(LDH)和胆碱脂酶(CHE)活性变化与窒息死亡的关系。方法 建立动物模型，检测膈肌、腓肠肌，以及血清中LDH、CHE的活性变化。结果 实验组家兔膈肌与腓肠肌相比，LDH活性明显下降，且差异显著(P＜0.05)，CHE活性差异无显著性(P＞0.05)；2组膈肌比较，LDH活性明显下降，有显著性差异(P＜0.05)，CHE活性无显著性差异(P＞0.05)；实验组血清中LDH活性比对照组明显升高，有显著性差异(P＜0.05)，2组CHE活性无显著性差异(P＞0.05)。结论 膈肌中LDH活性的降低与固定双上肢悬挂体位具有相关性。     

Methamphetamine and amphetamine concentrations in postmortem rabbit tissues

The feasibility of detecting methamphetamine and its major metabolite, amphetamine, in postmortem tissues over a 2-year period was examined. It is important to determine if the abuse and toxic effects of drugs can be proved from evidence found in decayed, submerged, or stained tissue materials. The blood, urine, liver, skeletal muscle, skin and extremity bones from rabbits given methamphetamine intravenously were kept at room temperature, under 4 different conditions: sealed in a test tube, dried in the open air, submerged in tap water and stained on gauze. Methamphetamine was present in all the samples, with slight change in concentration in case of sealed and air dried tissues. Changes varied in bones kept in water. There were considerable decreases in methamphetamine in blood and urine stains. Despite long term storage, drug abuse and/or toxicity could be determined, in all tissues examined.     

Determination of Malathion levels and its effect on the development of Chrysomya megacephala (Fabricius) in South China

The present study determines the concentration of Malathion in rabbit tissues and Dipteral larvae feeding on those tissues. Malathion was found in all muscle and liver samples of the test rabbit, as well as larvae fed on it. Samples from the control rabbit and pupae from all colonies were negative for Malathion. Correlations were found between administered dosage, tissue concentrations and younger or prepuparial larvae. Effects of Malathion on the development rate of Chrysomya megacephala (Fabricius) were also reported. C. megacephala is the most common fly species found on corpses in South China during the early stages of decomposition. Significant differences in larval growth rate were both observed among the colonies fed on muscle and liver. The presence of Malathion in both muscle and liver appears to retard the normal growth rate of C. megacephala in larval stage. Larvae from all colonies fed on tissues from rabbits treated with Malathion were smaller and attained maximum length later than those from the control colony. Duration of the larval and pupal stages was both significantly prolonged for larvae on tissues from rabbit receiving Malathion than those from the control colony. The difference of the duration of the larval and pupal stages together from the muscle colonies would alter the postmortem interval estimation by up to 36 h. As for liver colonies, it would alter the postmortem interval estimation by up to 28 h. A significantly different duration of the larval and pupal stages from the muscle colonies would alter a postmortem estimate by up to 28 h relative to the liver colonies.     

Preliminary observations of the effect of methamphetamine in decomposing tissues on the development rate of Parasarcophaga ruficornis (Diptera: Sarcophagidae) and implications of this effect on the estimations of postmortem intervals.

Larvae of Parasarcophaga ruficornis (Fabricius) (Diptera: Sarcophagidae) were reared on tissues from rabbits administered different dosages of methamphetamine to study the effects of this drug on development of this species. The rabbits were given 37.5, 71.4, and 142.9 mg of methamphetamine via ear vein infusion. From Hours 30 to 60, larvae feeding on tissues from rabbits receiving 71.4 and 142.9 mg of methamphetamine developed more rapidly than larvae from the control colony and those feeding on tissues from the rabbit receiving 37.5 mg of methamphetamine. The time required for pupariation was significantly greater for colonies fed on tissues from methamphetamine-dosed rabbits than for the control. These differences were sufficient to alter postmortem interval estimates based on larval development by up to 18 h and estimates based on puparial development by up to 48 h. The presence of methamphetamine or amphetamine could not be detected in Diptera larvae in this experiment using radioimmunoassay techniques, as there was a nonspecific reaction, resulting in a false positive.     

Cardic death and apoptosis of myocardium

TdT-mediated Dutp nick end labeling (TUNEL) method was applied to detect apoptosis of myocardium of corpses dying from cardiac death. For arteriosclerotic coronary heart death, diffused apoptosis was observed around the border zones of histologically infarcted myocardium, and in the epithelial and smooth muscle of arteries. Few apoptosis cells were present for hypertensive heart death, and none for corpses dying from falling and hanging. Myocardium apoptosis may provide a new target for heart failure.