大鼠脑震荡后大脑多巴胺D_1受体的动态表达观察

目的探讨大鼠脑震荡后不同时间大脑多巴胺D1受体在不同部位的表达变化。方法用金属单摆打击装置复制大鼠脑震荡模型,将56只大鼠随机分为脑震荡后1、2、4、8、16和24d 6个损伤组和1个正常对照组,每组8只。于大鼠脑震荡后不同时间取内侧隔核(MSN)、左右Broca斜角带垂直支(VDB)、丘脑网状带(RT)脑组织,用免疫组化染色(SP法)观察脑组织不同区域多巴胺受体(D1)表达情况,用图像分析系统进行定量分析。结果各组大鼠脑组织D1受体免疫组化阳性表达变化情况:在MNS区,脑震荡后1d细胞阳性表达开始减弱,到16d细胞阳性表达最弱,16～24d细胞阳性表达开始增强,但在24d仍比对照组的表达弱。在VDB区,脑震荡后1d细胞阳性表达开始减弱,2d细胞阳性表达最弱,脑震荡后2～24d细胞阳性表达开始增强,但在24d仍比对照组的表达弱。在RT区,脑震荡后1d细胞阳性表达开始减弱,4d细胞阳性表达最弱,4～24d细胞阳性表达开始增强,到24d与对照组表达接近。结论大鼠脑震荡后不同时间,脑组织多巴胺D1受体在MSN、VDB、RT不同区域的表达轻微下调,但下调差异无显著性意义。     

青壮年猝死综合征心肌细胞内Cx43的表达

目的观察连接蛋白43（Cx43）在青壮年猝死综合征（SMDS）者心肌细胞的表达,并探讨其法医学意义。方法筛选法医尸检案例45例,其中SMDS组、冠心病猝死组及对照组各15例。采用免疫组织化学和图像分析技术对不同组别Cx43蛋白在心肌细胞内的表达进行阳性单位（PU）定量检测,分析Cx43蛋白在各组表达的差异。所得数据进行统计学分析。结果 SMDS组心肌Cx43染色明显减弱,阳性着色条带分布不均、深浅不一,有的呈散在颗粒状;冠心病猝死组亦见类似变化;对照组未见明显变化。经统计分析发现,3组心肌细胞内Cx43表达的PU值存在显著性差异（P〈0.05）。结论 SMDS死前存在心肌缺血及心电紊乱,应属心性猝死范畴。     

胆囊收缩素(CCK)在冠状动脉粥样硬化斑块中的表达

目的揭示胆囊收缩素(CCK)在冠状动脉粥样硬化斑块中的表达情况,以进一步探讨CCK在动脉粥样硬化形成过程中的作用。方法选用100例35～92岁男性尸检冠状动脉粥样硬化标本,分为粥样硬化Ⅰ～Ⅱ级组和Ⅲ～Ⅳ级组,同时设正常对照组,用免疫组化技术进行检测。结果对照组CCK呈阴性表达,而冠状动脉粥样硬化组呈阳性表达(P0.01),Ⅰ～Ⅱ级组与Ⅲ～Ⅳ级组之间CCK表达无显著差异(P0.05)。结论 CCK在冠状动脉粥样硬化斑块中的有表达,但不随粥样硬化斑块程度的变化而变化。     

Concentrations of Opiates and Psychotropic Agents in Polydrug Overdoses: A Surprising Correlation Between Morphine and Antidepressants

Abstract: The relationship between postmortem concentrations of morphine and co‐detected psychoactive drugs in fatal overdoses is examined. Morphine and other drugs were detected in 161 medicolegal autopsy cases. Subsets of these morphine‐positive cases based on drug class were established, including opioids, antidepressants, ethanol, benzodiazepines, and “other.” Each subset was split into high or low concentration groups based on median drug concentrations. Morphine concentrations of the [high] and [low] groups were compared, with no significant difference in morphine concentration identified in the opioid, ethanol, or benzodiazepine subsets. The “other” drug class was too heterogeneous for statistical assessment. Morphine concentrations did show a significant direct relationship (p = 0.01) with antidepressants, namely increased concentrations of antidepressant drugs are associated with an increased concentration of morphine. This trend probably remains even after excluding cocaine‐positive cases. The unsuspected finding that postmortem concentrations of antidepressants positively correlate with morphine levels may be important in the treatment of depression in drug addicts.     

Macroscopic,Microscopic, and Chemical Assessment of Gunshot Lesions on Decomposed Pig Skin

Abstract: Very little literature exists on gunshot wounds on decomposed material. In this study, seven pig heads underwent a shooting test. Entrance wounds from the first head underwent neutron activation analysis (NAA) and histological testing immediately after the firing test; the other six heads were exposed to two different environments (open air and soil) and analyzed by radiochemical and histological tests every 15 days. Gunshot wounds in air maintained their morphological characteristics, and those in soil showed severe alteration after 5 weeks. Microscopic testing verified positive results for lead in all gunshot wounds in open air, whereas in most of those in soil lead could not be detected. Radiochemical analysis performed by NAA yielded for all gunshot wounds but one antimony quantities in the range of 0.07–13.89 μg. In conclusion, it may be possible to detect residues of antimony even in degraded tissues.     

Fatal Drowning Accident and Undiagnosed Hydrocephalus

Abstract: Bodies found in water present several diagnostic challenges for the forensic examiner, such as the identification of the time and mechanism of death, the postmortem submersion time, and above all the circumstances of drowning. We report the case of a 33‐year‐old security guard found dead in Venice, in the water of the lagoon, who at autopsy presented a previously undiagnosed hydrocephalus with macrocephaly. The victim remained asymptomatic until 2 months before death and had never undergone a neurological or radiological examination. In the article, we emphasize the need to perform a thorough autopsy in all suspected drownings, discuss the etiopathogenesis of the neurological disease and hypothesize a possible relationship between the hydrocephalus and the drowning accident. Finally, we discuss the major clinical and forensic implications of macrocephaly and hydrocephalus in adults.     

Actin、Dm、Mb和Fn诊断急性心肌梗死的研究

目的探讨Actin、Dm、Fn和Mb在诊断急性心肌梗死中是否具有实际应用价值。方法选取已确诊的30例尸检心脏标本,分为急性心肌梗死组、冠状动脉粥样硬化组及正常心肌组。在心脏左前壁取材,连续切片,分别作HE染色,Actin、Dm、Fn和Mb免疫组化SP法染色,采用图像分析技术客观测量及比较各组标本染色强度。结果在急性心肌梗死组和冠状动脉粥样硬化组中,Actin、Dm和Mb在心肌细胞中表达均明显缺失,而Fn明显表达;而且在这两组间此4项指标表达效果无统计学差异。在正常心肌组中,Actin、Dm和Mb在心肌细胞中表达均无缺失,而Fn不表达。结论Actin、Dm、Fn和Mb对心肌细胞的缺血缺氧十分敏感,能反映明确的心肌坏死,但对坏死发生的机制缺乏特异性,因此用于诊断急性心肌梗死时需慎重。     

大鼠心肌傅里叶变换红外光谱变化与死亡时间的关系

目的应用傅里叶变换红外(Fourier transform infrared,FTIR)光谱技术分析大鼠死后心肌组织随死亡时间推移的化学降解过程,为死亡时间推断的研究提供新的途径与方法。方法大鼠断颈处死后置于(20±2)℃环境,在不同死亡时间点提取大鼠左心室心肌组织,并使用FTIR光谱仪测定不同化学基团的变化。结果随着死亡时间的推移,大鼠心肌组织FTIR光谱的主要吸收峰位没有明显变化,而其吸光度随着死亡时间增加呈现出增加、下降和稳定3种不同的变化方式,且不同峰的吸光度比显示了相似的时间变化趋势。结论心肌组织可以作为FTIR光谱技术分析死亡时间的适用检材。     

小鼠死后骨骼肌、心、肝、肾、脑细胞核中DNA的变化规律

目的 研究小鼠器官细胞核中DNA降解变化与死亡时间的关系,为法医学推断死亡时间提供一种新方法.方法 应用单细胞凝胶电泳技术结合荧光显微镜和计算机图像分析技术,测定小鼠在死后72h内不同时间点骨骼肌、心、肝、肾、脑细胞核头DNA含量、尾DNA含量、头半径、尾长度、尾矩、Olive矩、头面积、尾面积8项参数的变化值.结果 在小鼠死亡72h内,彗星尾DNA含量、尾长度、尾矩、Olive矩、尾面积都呈增加趋势,头DNA舍量、头半径、头面积均呈下降趋势.计算出体现DNA降解趋势的二项式回归方程(P<0.001)和多元回归方程(P<0.0001).结论 本研究提供的各组回归方程,可为法医学推断死后经过时间提供一种新的方法.