过敏性休克死亡尸体咽喉及肺组织中P物质免疫组化染色观察

目的探讨过敏性休克死亡法医学鉴定的形态学依据。方法15例明确诊断为过敏性休克死亡的尸体(设为实验组),取其咽喉部及肺组织,石蜡切片,分别进行HE染色及免疫组化超敏SP法染色,观察P物质染色变化,并通过图像分析系统对其阳性结果进行分析;20例因交通事故致颅脑损伤死亡的尸体相同组织作为对照。两组所得数据采用SPSS10.0统计软件进行t检验分析。结果实验组咽喉组织充血、水肿,复层扁平上皮和假复层纤毛柱状上皮P物质免疫组化染色均呈棕黄色染色,固有层内腺体上皮细胞及肌层染色变浅;对照组咽喉复层扁平上皮和假复层纤毛柱状上皮几乎不着色,固有层内腺体上皮细胞及肌层仅有少量棕黄色染色(实验组平均灰度值113.78,阳性信号面积均值17795.75;对照组平均灰度值104.63,阳性信号面积均值8953.50)。实验组支气管粘膜上皮呈深棕黄色染色,粘膜肌层染色变浅;对照组支气管粘膜上皮几乎不着色。(实验组平均灰度值136.32,阳性信号面积均值17194.84;对照组平均灰度值96.52,阳性信号面积均值8416.75)。计算各组的阳性指数PI,咽喉分别为50.62±10.04和23.42±6.84;支气管分别为58.60±12.3和20.31±5.68。两组数据差异具有显著性意义(P<0.01)。结论P物质免疫组化染色可能为过敏性休克致猝死的法医学鉴定提供形态学依据。     

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。     

肥大细胞类胰蛋白酶的免疫组化染色观察

目的　观察过敏性休克死亡者咽喉、肺、小肠组织肥大细胞类胰蛋白酶 (MCT) ,探讨过敏性休克死亡法医鉴定的形态学依据。方法　交通事故致严重颅脑损伤死亡者 10例 (对照组 )、明确诊断为过敏性休克死亡者 15例(实验A组 )和羊水栓塞死亡者 8例 (实验B组 )的尸体 ,分别取其咽喉部、肺及小肠组织 ,石蜡切片 ,HE染色及用免疫组化超敏SP法进行MCT染色。结果　实验A组的咽喉部组织充血、水肿 ,咽喉部粘膜下层MCT增多 (MCT颗粒计数为 48 2 3 ) ;实验B组的咽喉部粘膜下层MCT增多 (MCT颗粒计数为 42 72 )。肺间质尤其是小支气管壁及小血管壁上MCT增多 (MCT颗粒计数分别为 46 98和 43 5 0 ) ,小肠粘膜层MCT增多 (MCT颗粒计数分别为 48 2 3和 42 72 )。对照组的咽喉部、肺和小肠MCT颗粒计数较少 ,分别为 7 79、 12 94和 2 0 2 5。实验A组与对照组相比 ,两组具有显著性差异 (P <0 0 1) ;实验A、B组相比 ,两组无显著性差异 (P >0 0 1)。结论　过敏性休克及羊水栓塞死亡的尸体 ,其咽喉部组织、肺组织及胃肠道组织MCT增多。     

人体死后肝细胞DNA含量与死亡时间关系的研究

目的研究人体死后肝脏细胞DNA含量变化与死亡时间的关系及影响因素。方法选取46例已知死亡时间的人体肝脏,根据离体肝脏所处的环境温度分为12—19％（A组）和20—27％（B组）两组,每组23例。在死后24～72h内每隔4h穿刺取肝组织1次,制成细胞悬液,经RNA酶消化,PI染色后,用流式细胞仪测定被检测细胞中含不完整DNA的细胞数所占百分比,所得数据经Exp032V1．2软件计算N值。结果死后24～72h肝细胞N平均值,A组从10．91％增至49．72％,B组从16．22％增至69．63％。两组N平均值随死亡时间的延长均逐渐增高,与死亡时间有相关性,A组r值为：0．598,B组r值为0．77357。并且建立了不同环境温度对应的回归方程。结论在不同环境温度下,死后24～72h内人体肝脏细胞DNA降解均随死亡时间的延长和环境温度的升高而逐渐加快,相关数据可望为死亡时间推断提供一定参考依据。     

冠状动脉粥样斑块中C-反应蛋白的免疫组化研究

目的探讨冠状动脉粥样硬化斑块中C-反应蛋白(CRP)对冠心病猝死(SCD)的诊断意义。方法从本教研室2001~2004年尸检案例中挑选68例案例资料和心脏标本,分为3组A组SCD(27例);B组冠心病非猝死者(21例);C组无明显动脉粥样硬化病变的死者(20例);应用免疫组化染色(SABC法)和图像分析技术,检测每例冠状动脉左前降支和右主支粥样硬化斑块内的CRP染色情况,并对所得数据进行统计分析。结果A组有20例CRP免疫组化染色强阳性,6例呈较强阳性,1例为弱阳性;B组中3例呈较弱阳性,11例微弱阳性,7例为阴性;C组均未见阳性反应。结论检测冠状动脉粥样硬化斑块中的CRP对SCD的死后诊断具有一定意义。     

心肌病猝死者心肌连接蛋白43的免疫组化染色观察

目的探讨心肌病猝死者心肌连接蛋白43(Cx43)染色变化及其与猝死的关系。方法运用免疫组化和图像分析技术,分2组(A和B组)检测20例心肌病猝死者心室肌的Cx43染色情况;并与14例非心肌病猝死者(C组)的检测结果对照。结果扩张型心肌病(DCM)猝死组(A组,11例)心肌Cx43染色明显减弱,阳性着色斑点大小不等、深浅不一、分布不均,有的呈散在颗粒状;其它类型的心肌病猝死组(B组,9例)亦见类似变化;非心肌病猝死的对照组(C组,14例)未见明显变化。定量检测并经统计分析发现,Cx43蛋白染色阳性的面积,A组与B组和C组的差异有非常显著性意义(P<0.01),B组与C组的差异无显著性意义(P>0.05);而平均光密度各组之间的差异无显著性意义(P>0.05)。结论心肌病猝死者心肌Cx43免疫组化染色明显减弱,尤以扩张型心肌病明显;心肌病猝死者心肌Cx43变化可能与其猝死有一定关系。     

DCM猝死与晚期DCM心肌Cx43表达的比较

目的观察和探讨扩张型心肌病(DCM)猝死与晚期DCM心肌中心肌连接蛋白(connexin,Cx)43表达差异及其意义。方法收集13例DCM猝死者心脏(A组)和5例晚期DCM患者行心脏移植手术切除的心脏(B组),运用免疫组化染色和图像分析技术,检测心肌Cx43阳性表达产物的平均光密度(OD)值和面积(S)值,比较两组间和左右心室间的差异。结果 Cx43阳性表达在A组明显减少,分布不均;在B组表达清晰,主要位于闰盘处。A组与B组心肌Cx43的S值之间的差异有统计学意义(P0.01),而各组左、右心室肌间相比,差异无统计学意义(P0.05);心肌Cx43的OD值,在A组与B组之间,以及各组左、右心室肌间差异均无统计学意义(P0.05)。结论 DCM猝死心肌Cx43表达较晚期DCM心肌明显减少,这种变化可能与DCM患者因心律失常发生猝死有关。     

大鼠脑损伤后COX-2表达变化的时间规律性研究

目的探讨大鼠脑损伤后环氧合酶2(COX-2)在神经元、神经胶质细胞中表达变化的时间规律性。方法以冲击应力σd为355.09kPa致大鼠脑损伤后,于不同时间段分别应用原位杂交、免疫组化、免疫组化双染色技术检测COX-2mRNA和蛋白的表达强度,用图像分析系统测定阳性反应物平均灰度,进行统计学处理。结果正常对照组COX-2mRNA和蛋白弱表达,伤后15min开始表达呈增强趋势,分别于伤后1,2d,表达达到峰值,平均灰度值分别为126.38±1.36、124.77±3.20,与对照组、邻近上组比较均具有显著性差异(P<0.05),于伤后3,4d,表达达到另一峰值,平均灰度值分别为127.18±1.96、120.14±3.52,并维持高水平表达分别至伤后7,15d,平均灰度值分别为110.03±2.61、111.27±2.83,与对照组比较具有显著性差异(P<0.05)。阳性细胞多为神经元。结论脑损伤后COX-2mRNA及蛋白的表达具有时间规律性,可作为法医学推断脑损伤形成时间的指标。     

不同环境条件下大鼠死后皮肤生物力学特性改变

目的死亡时间的推测是法医病理学研究的重点和难点。皮肤具有一定生物力学特性,是机体死后分解破坏发生较迟的部分。本研究观察不同环境条件下死后大鼠皮肤生物力学特性的改变,探索其与死亡时间的关系。方法系统测试雌性SD大鼠在不同环境条件下（A组较高环境温度,B组较低环境温度）的死后皮肤生物力学特性。结果 A组大鼠皮肤死后张应力、延伸率在死后1d内先降低后升高,1d～6d逐渐降低,6d～7d略呈上升趋势;B组大鼠皮肤死后张应力在死后2d内先降低后升高,2d～16d逐渐降低,16d～20d略上升。结论 A组的张应力、延伸率和B组的张应力、应变能密度均表现出与死亡时间较好的相关性,是较好的推测死亡时间的生物力学参数。     

硬脑膜厚度及生物力学参数时序性变化在死亡时间推断中的应用

目的研究人尸体硬脑膜厚度以及生物力学参数与死亡时间(postmortem interval,PMI)的关系,探讨其用于推断PMI的可行性。方法收集尸体检验的硬脑膜样本并按死后6h、12h、18h、24h、30h、36h、48h、60h、72h、84h、96h分组,统一制作成4.0cm×1.0cm的A、B两块试件。测量A试件厚度后检测极限载荷、最大力变形、抗拉强度、弹性模量、断裂力等生物力学参数,分别拟合厚度和生物力学参数值与PMI的回归方程,并通过验证组验证PMI预测值与实际值之间的差异。B试件经10%中性甲醛溶液固定后制备组织切片观察其形态学变化。结果死后6~96h,硬脑膜厚度逐渐减小,胶原纤维从排列清晰逐渐变为相互融合,细胞核数量逐渐变少;硬脑膜厚度、极限载荷、抗拉强度、弹性模量、断裂力呈时序性下降趋势,其中硬脑膜厚度、极限载荷、弹性模量、断裂力与PMI具有相关性(P<0.05)。回代检验中验证组PMI实际值和预测值之间差异无统计学意义(P>0.05)。结论人死后6~96 h的硬脑膜厚度、极限载荷、弹性模量、断裂力呈时序性变化,利用其与PMI的关系建立的回归方程可用于PMI推断。     

Ultrastructure of acute ammonia toxicity in the human lung

A tanker truck carrying anhydrous ammonia (NH3) fell off a freeway, releasing a dense cloud of NH3 gas, killing several people. The driver was dead upon impact. To our knowledge, pulmonary NH3 toxicity in humans has not been studied previously by electron microscopy (EM). Therefore, in two cases, the paraffin-embedded tissue blocks of lung were deparaffinized and reembedded in plastic for 1-mu sections and EM examination. The lung tissue of a third case, the truck driver, was similarly processed as a control. Light-microscopic pulmonary findings in the acute NH3 deaths included denudation of the tracheobronchial epithelium, edema of the lamina propria, and marked alveolar edema, congestion, and hemorrhage. In contrast, in the truck driver's lungs, the bronchial epithelium was intact, and there was no gross odor of NH3. Massive pulmonary hemorrhages in his lungs were attributed to trauma rather than NH3 inhalation. EM examination of the lungs of the truck driver showed no discernible toxic alterations in either the capillary endothelial cells or the Type I or II alveolar epithelial cells, and alveolar and capillary basement membranes were intact. In contrast, EM study of the lungs from two individuals dying acutely of NH3 inhalation showed marked swelling and imbitional edema of Type I alveolar epithelial cells; however, alveolar basement membranes and capillary endothelial cells appeared as usual. These electron-microscopic findings demonstrate the Type I epithelial cell to be the target cell of acute alveolar wall injury in NH3 inhalation.     

Differential accumulation of pulmonary and cardiac mast cell-subsets and eosinophils between fatal anaphylaxis and asthma death: a postmortem comparative study

The distribution profile of infiltrated mast cell-subpopulations and eosinophils in the lung and heart sections of the patients who died of severe allergic hyperresponsiveness, was investigated. Four study groups were designed comprising 9 cases who died in systemic anaphylaxis (Group I), 10 asthmatic individuals whose death were assigned to acute and severe bronchial asthma (Group II), 10 asthmatic cases who died from non-immunological diseases (Group III). Twenty consecutive autopsies of non-allergic subjects who died of unnatural causes (Group IV) served as control group in this study. Utilizing antibodies against human tryptase and chymase and a double immunohistochemical staining method, we distinguished successfully all three subsets of mast cells (MC), MC-TC (containing both tryptase and chymase), MC-T (containing only tryptase) and MC-C (containing only chymase) types, subdivided on the basis of the protease compositions of their secretory granules. In order to immunostaining eosinophils, we used antibody to major basic protein as a marker. We also measured postmortem blood tryptase, specific and total serum IgE. The intriguing finding of this study was the marked differences of cellular composition in the lung between fatal anaphylaxis and asthma death. Significant augmentation of MCs infiltrated in lung and heart sections of anaphylaxis patients and drastic infiltration of bronchial eosinophils in asthmatic death and consequent release of their related inflammatory mediators might explain the differential expression of the associated symptoms in these two groups. The anaphylactic deaths did show neither emphysema nor significant mucous bronchial secretions whereas all asthmatic deaths did. The degree of pulmonary congestion and edema was also more severe in anaphylaxis. This corresponded with the histological findings and the location and number of mast cell-subsets and eosinophils in the different compartments of the lungs. We have demonstrated that the third type of mast cell MC-C is only found in the lungs in anaphylactic deaths. The practical consequence of our study will be that it is now possible to confirm a suspicion of anaphylaxis death not only by measurements of serum mast cell tryptase, but also by immunohistochemical methods.     

Homicidal asphyxia

Homicides due to asphyxia are relatively uncommon. To better understand the presentation of such cases, the files of the Bexar County Medical Examiner's Office were reviewed from January 1, 1985, through December 31, 1998, for all such homicides. A total of 133 cases were found. The largest category was ligature strangulation with 48 deaths (21 male, 27 female). Petechiae were present in the conjunctivae and/or sclerae in 86% of the cases; fractures of the hyoid and/or thyroid cartilage were present in 12.5%. There were a total of 41 deaths from manual strangulation (27 female, 14 male). Petechiae were present in 89% of the cases. In cases of manual strangulation, fractures of the hyoid, thyroid, or cricoid cartilage were found in all the male victims and slightly more than one half of the female victims. Twenty-six cases of suffocation were found; 20 of the victims were < or =2 years of age. Only 1 of these children had petechiae and/or scleral hemorrhage. Five deaths were due to choking. Three of the deaths involved adults who were gagged; 2 deaths involved infants with foreign material pushed into the mouth. Other categories of asphyxia were as follows: 9 deaths due to more than one form of asphyxia; 1 death due to hanging, and 3 deaths due to drowning. Rape was the motive in 66% of the female victims of ligature strangulation and 52% of those due to manual strangulation.     

Asthmatic deaths in the medical examiner's population

A study of people who die from asthma was performed. The case files of the Office of the Medical Examiner of Metropolitan Dade County in Miami, Florida, U.S.A., were examined during the 5-year period 1979-1983, and all autopsied cases in which bronchial asthma was the primary or contributory cause of death were collected. These 39 cases were then analyzed as to the age, race, sex, and cause of death of the victim. Additionally, the medication list of the victim, the location of the terminal incident, the scene circumstances, the presence of hospitalization at the terminal incident, and the histopathology of the lungs at autopsy were additionally observed. Essentially, the asthma victim the medical examiner sees at autopsy is an adult white male commonly dying in an acute asthmatic attack. Ninety percent (90%) of the deaths had medications noted with 20% having three or more medicines, one of which was a steroid. The terminal incident occurred at home most frequently with an acute attack or being found dead noted. Most victims received some form of terminal hospitalization. Histopathologically, classical "asthma findings" were noted approximately one half of the time.     

Death as a result of asthma in Wayne County Medical Examiner cases, 1975-1987

All deaths ascribed to asthma in the 5-to-40-year age group at the Wayne County Medical Examiners' Office were reviewed from 1975 to 1987 inclusive. Fifty-eight deaths were attributed solely to asthma, and the annual number increased fivefold in the 1980s to a rate of approximately 0.5 per 100,000 per year when extrapolated to the Wayne County population. Blacks were overrepresented to double their proportion in the general population. Almost all cases were known asthmatics, and many had received previous emergency care. Most fatalities occurred at night and did not demonstrate any seasonal variation. The onset of the fatal attack was apparently very rapid in most cases, with many engaged in routine activities and few surviving any length of time in hospital or having sought treatment earlier. Our data reveal a significant increase in sudden death in previously well asthmatics in Wayne County in the 1980s. Similar increases in deaths as a result of asthma have been noted previously in other countries for reasons that remain unclear.     

Mechanism of formation of spinal injuries

It was stipulated that in medicolegal examination of deaths due to mechanical trauma accompanied by vertebral column separation it is necessary to investigate the surface of separation, which as a rule passes along the verge of the osseous and cartilagnous locking laminae. At the initial stage of avulsion a fragment of osseous lamina of the adjacent vertebral corpus remains fixed to cartilaginous lamina. Taking into account the localization of this fragment one may judge upon the direction of spine flexure.     

Acute deaths in nonpregnant adults due to invasive streptococcal infections

Streptococcal organisms, part of the normal human bacterial flora, occasionally become infectious pathogens responsible for a wide array of clinical syndromes, ranging from mild pharyngitis to death. Notably, infections due to group A and group B beta-hemolytic strains are well known for causing invasive disease leading to death. These deaths, while often suspected clinically, occasionally are not diagnosed until autopsy. We present 3 rapid deaths, with very different presentations, due to streptococcal infection. Two decedents experienced sudden deaths due to pneumonia and severe meningoencephalitis caused by group B beta-hemolytic streptococcal infection, a common cause of neonatal meningitis but only rarely reported in nonpregnant adults. The final case involves a 69-year-old male who presented to the emergency room with a complaint of shoulder pain but over the next several hours developed signs of necrotizing fasciitis, became septic, and died. While antemortem cultures were negative, owing to antibiotic administration, postmortem cultures of bone and deep soft tissue were positive for group A beta-hemolytic Streptococcus sp. Acute and sudden deaths due to infectious etiology represent an uncommon yet well-documented occurrence. The importance of appropriate postmortem cultures in these situations and a review of the literature will be discussed.     

Ochronosis Presenting as Methemoglobinemia

Ochronosis is the blue‐gray discoloration of collagen‐containing tissues due to homogentisic acid (HGA) deposition, secondary to endogenous alkaptonuria or exogenous enzyme inhibition. In renal disease, accumulation of HGA in serum can cause methemoglobinemia. A 60‐year‐old woman with renal disease and anemia presented with 3 days of weakness and months of gray skin discoloration. Her hemoglobin was 8.1g/dl with 24.5% methemoglobin. Despite treatment with methylene blue, exchange transfusion, and continuous renal replacement therapy, the patient died. Autopsy revealed gray discoloration and ochronotic pigment in the ribs and cartilage. Based on these findings, the patient was diagnosed with ochronosis, suggestive of alkaptonuria, complicated by methemoglobinemia. The differential diagnosis for blue‐gray skin discoloration includes argyria, methemoglobinemia, and ochronosis. This patient's clinical and autopsy findings suggested alkaptonuria complicated by methemoglobinemia due to progressive renal dysfunction. Development of methemoglobinemia in the setting of chronic skin discoloration and renal failure should prompt consideration of alkaptonuria.