中介素预处理对大鼠心肌细胞缺氧的保护作用

目的 通过对中介素（intermedin,IMD）预处理的大鼠心肌细胞缺氧后作用机制的研究,为法医病理学研究心脏性猝死机制提供思路. 方法 大鼠H9c2心肌培养细胞随机分为对照组、缺氧组和IMD预处理组.采用MTT比色法、透射电镜、激光共聚焦显微镜和流式细胞术检测各组心肌细胞存活率、细胞超微结构、细胞内游离钙离子浓度（[Ca2＋]i）及细胞凋亡率.结果 与对照组比较,缺氧组细胞存活率明显降低（P＜0.05）,内部超微结构存在损伤,而IMD预处理显著提高细胞存活率（P＜0.05）、减轻缺氧对心肌细胞结构的损伤.缺氧组细胞[Ca2＋]i（荧光强度）和细胞凋亡率较对照组升高（P＜0.05）,IMD预处理降低了缺氧对细胞[Ca2＋]i（荧光强度）和凋亡率的影响（P＜0.05）. 结论 IMD能提高缺氧心肌细胞存活率、减轻缺氧引起的细胞内钙超载从而抑制细胞凋亡,可以揭示心肌细胞缺氧保护作用的机制,为心脏性猝死鉴定提供依据.     

中介素（IMD）对大鼠心肌细胞缺氧-复氧损伤的作用

目的探讨中介素（IMD）对大鼠体外培养心肌细胞缺氧-复氧损伤的作用。方法用大鼠H9c2心肌细胞株制作实验模型,样本分为对照组、缺氧-复氧组（缺氧1h、复氧30min）、IMD组（缺氧-复氧前30min加入10-7mol/L IMD）。采用MTT比色法检测心肌细胞活力;透射电镜观察细胞超微结构;激光共聚焦显微镜观察并测定细胞内钙离子浓度;流式细胞术测定细胞凋亡率。结果与对照组比较,缺氧-复氧组和IMD组细胞存活率显著降低,而IMD处理组明显升高细胞存活率（P〈0.01）;在形态学上,IMD预处理可明显减轻缺氧-复氧对大鼠心肌细胞的损伤;缺氧-复氧组细胞[Ca2＋]i荧光强度和细胞凋亡率比对照组显著升高,IMD预处理可明显降低上述升高的比率（P〈0.01）。结论 IMD对大鼠心肌细胞缺氧-复氧损伤有一定保护作用,提高心肌细胞存活率、减轻心肌细胞钙超载和抑制凋亡是其作用途径。     

Intermedin在大鼠急性心肌缺血再灌注损伤中的作用

目的探讨Intermedin（IMD）对大鼠急性心肌缺血再灌注损伤的作用。方法72只健康雄性sD大鼠随机分为3组：对照组;缺血再灌注组（缺血1h再灌30min）;IMD预处理组（缺血再灌注前30min静脉注射10^-7mol／LIMD）。检测血清中LDH、心肌中MDA和SOD活性;半定量实时荧光PCR法检测心肌降钙素受体样受体（ealcitonin receptor like receptor,CRLR）、受体活性修饰蛋白（receptor activity modiying protein,RAMP）1／2／3的mRNA表达水平;酶联免疫吸附法（ELISA）测定心肌cAMP含量,SABC法检测Bcl-2／Bax蛋白表达及比值。结果与对照组比较,缺血再灌注组大鼠LDH、MDA分别升高87％和189％,SOD活性下降84％,IMD预处理组LDH、MDA均降低41％,SOD活性升高38％（均P〈0．01）;实验组心肌CRLR、RAMPl／2／3的mRNA水平均明显上调（P〈0．05或P〈0．01）,与对照组心肌cAMP相比,缺血再灌注组和IMD预处理组分别升高1．36、2．90倍（P〈0．05）。Bcl-2／Bax表达比值,缺血再灌注组较对照组降低,IMD预处理组亦低于对照组但高于缺血再灌注组2．225倍。结论IMD对大鼠急性缺血再灌注损伤的心肌有一定保护作用,减少缺血再灌所致的氧化应激,抑制心肌细胞凋亡可能是其作用机制之一。     

大鼠死后肝脏磷酸果糖激酶-2含量的变化

目的 分析不同死亡时间和死亡原因大鼠肝脏组织内磷酸果糖激酶-2(PFK-2)含量的变化.方法 大鼠105只随机分为三组,以不同方式(失血、窒息、断颈)处死.分别于死后0、1、2、4、8、12和24h取大鼠肝脏组织,免疫组化和图像分析技术测定大鼠PFK-2变化.结果 三组不同死亡原因大鼠肝脏组织内PFK-2的含量随死亡时间延长呈规律性减弱趋势.结论 大鼠肝脏组织内PFK-2的变化可以反映死亡时间的变化趋势.     

MA与HIV-Tat协同作用致大鼠相关脑区ROS、GSH-PX和SOD的变化

目的 观察甲基苯丙胺(MA)与HIV-Tat蛋白协同作用致大鼠相关脑区活性氧(ROS)、谷胱甘肽过氧化物酶(GSH-PX)和超氧化物歧化酶(SOD)的变化,探讨协同作用对神经系统的影响.方法 50只健康雄性SD大鼠随机分为实验组:MA组(10mg/kg MA,每日两次腹腔注射,连续4d)、HIV-Tat组(10μg HIV-Tat注入大鼠脑纹状体)和MA+HIV-Tat组(按MA组注射MA 4d后按HIV-Tat组注入HIV-Tat);对照组:生理盐水腹腔注射或纹状体内注射.各组大鼠分别于注射结束后48h和7d处死,取各脑区脑组织制作匀浆;荧光分光光度计检测ROS含量,酶标仪检测GSH-PX和SOD吸光度,再根据蛋白质的浓度分别计算其活力.结果 各实验组与对照组比较,各脑区ROS含量有不同程度增高,GSH-PX和SOD活力则有不同程度下降,差异具有统计学意义(P＜0.05);其中MA+ HIV-Tat组与MA组和HIV-Tat组比较,ROS含量升高显著,GSH-PX和SOD活力下降明显(P＜0.01).结论 MA和HIV-Tat协同作用能够产生大量的ROS,并降低GSH-PX和SOD的活力,揭示ROS、GSH-PX和SOD参与了MA与HIV-Tat的协同神经毒性作用.     

急性酒精中毒对大鼠溺死后肺组织硅藻检出的影响

目的急性酒精中毒对大鼠溺死后肺组织硅藻检出的影响。方法将40只大鼠随机分为5组,进行酒精灌胃,灌注量分别为:正常组(0m L/kg)、低剂量组(7m L/kg)、中剂量组(15m L/kg)、高剂量组(22m L/kg)、死后抛尸组(0m L/kg)。观察各组大鼠行为变化、溺水时生存能力及死后肺组织中硅藻检出量。结果高剂量组呼吸出现浅慢,呼吸停止时间减少(P0.05)。酒精灌注各组大鼠攀附时间均减少(P0.05),肺组织硅藻检出量均减少(P0.05)。结论急性酒精中毒可以导致大鼠溺死后肺组织硅藻检出量减少。     

大鼠外伤性癫痫模型皮层SPP1蛋白的表达

目的检测分泌型焦磷酸蛋白1 (Secreted phosphoprotein 1,SPP1)在外伤性癫痫(post-traumaticepilepsy,PTE)大鼠皮层脑组织中的表达变化,探讨其与外伤性癫痫的关联。方法随机将18只大鼠分为正常对照组、生理盐水组和实验组。建立外伤性癫痫模型。采用免疫组化法检测GFAP蛋白,采用Western blot法检测SPP1蛋白。结果大鼠行为学平均评分为4分;EEG显示明显痫性放电;免疫组化结果显示,实验组大鼠脑组织GFAP阳性细胞与正常对照组和生理盐水组比较,显著增高(P <0.05);生理盐水组GFAP阳性细胞与正常对照组比较,差异不具有统计学意义(P> 0.05),以上结果综合表明成功建立了大鼠外伤性癫痫模型。Western blot结果显示,实验组SPP1蛋白表达量较正常对照组和生理盐水组显著增高(P <0.01);生理盐水组SPP1蛋白表达量较正常对照组不显著,差异无统计学意义(P> 0.05)。结论 SPP1在外伤性癫痫大鼠皮层脑组织中表达显著上调,外伤性癫痫的发生机制可能与SPP1的表达异常增高有关。     

毒鼠强中毒大鼠脑GABA及GABAAR-α1的表达

目的探讨毒鼠强中毒大鼠脑GABA及GABAAR-α1表达的变化及可能机制。方法健康Sprague-Dawley(SD)大鼠60只,随机分为正常对照组、空白对照组、高剂量中毒组和低剂量中毒组,每组5只。高剂量中毒组每只以1.0mg/kg的剂量用毒鼠强悬浊液灌胃,低剂量中毒组每只以0.1mg/kg的剂量用毒鼠强溶液灌胃制作中毒模型。应用免疫组化技术和图像分析仪对GABA及GABAAR-α1的表达情况和变化规律进行研究。结果(1)正常大鼠脑组织内GABA及GABAAR-α1表达较为广泛,维持在中等水平;(2)高剂量中毒组脑内GABA及GABAAR-α1表达均下降;(3)低剂量中毒组脑内GABA表达先下降,于中毒后6h降至最低,后表达开始增加,3d时接近对照组水平,5～7d达高峰,10d时仍高于对照组;(4)低剂量中毒组脑内GABAAR-α1表达先下降,于中毒后6～12h降至最低,后表达开始增加,7～10d时接近对照组水平。结论(1)高剂量毒鼠强中毒情况下,GABA及GABAAR-α1表达均下降;(2)大鼠脑GABA及GABAAR-α1表达改变与毒鼠强中毒的发生机制密切相关。     

l-四氢巴马汀对氯胺酮依赖大鼠海马GFAP及伏隔核ERK磷酸化蛋白表达的影响

目的观察l-四氢巴马汀(l-THP)对氯胺酮依赖大鼠条件位置偏爱(CPP)、海马CA1区神经胶质纤维酸性蛋白(GFAP)以及伏隔核ERK磷酸化蛋白表达的影响。方法随机将40只大鼠分为空白对照组、氯胺酮模型组(10 mg/kg)、l-THP低剂量(10 mg/kg)干预组、l-THP高剂量干预(20 mg/kg)组,每天大鼠给药及训练,建立条件位置偏爱模型。采用免疫组化法检测海马CA1区GFAP蛋白,Western blot法检测大鼠伏隔核ERK磷酸化蛋白。结果与空白对照组比较,氯胺酮模型组大鼠在伴药箱时间明显增加(P0.05),成功建立氯胺酮依赖大鼠条件位置偏爱模型。与模型组比较,l-THP高剂量干预组可明显减少大鼠在伴药箱中的时间(P0.05)。免疫组化结果显示,与空白对照组比较,氯胺酮模型组GFAP阳性细胞数量明显增多(P0.05);与模型组比较,l-THP低剂量、高剂量干预组GFAP阳性细胞数量明显减少(P0.05)。Western blot结果显示,与空白对照组比较,模型组ERK磷酸化蛋白表达明显增加(P0.05);与模型组比较,l-THP低剂量、高剂量干预组ERK磷酸化蛋白明显降低(P0.05)。结论 l-THP拮抗氯胺酮依赖与伏隔核p-ERK蛋白表达有关,并且l-THP对氯胺酮依赖大鼠神经元损伤具有保护作用。l-THP对氯胺酮成瘾具有调制作用。     

甲卡西酮对大鼠血浆代谢谱变化研究

目的 应用代谢组学技术研究腹腔注射甲卡西酮大鼠血浆代谢谱的变化,筛选出可用于甲卡西酮吸毒法医学鉴定的入体生物标志物.方法 SD大鼠随机分成低剂量甲卡西酮组(腹腔注射甲卡西酮溶液3mg/kg)、中剂量甲卡西酮组(腹腔注射甲卡西酮溶液12mg/kg)和对照组(腹腔注射等量生理盐水),注射3min后收集大鼠眼眶血,应用超高效...     

心力衰竭心肌凋亡基因蛋白研究

心肌梗死致心力衰竭猝死者 ,心肌细胞存在凋亡现象。基因蛋白bcl-2和Bax对心肌凋亡具有调控作用。急性肌梗死灶周围有bcl-2 表达 ,陈旧性心肌梗死灶周围心肌细胞Bax表达明确     

急性心肌缺血早期血管内皮生长因子的免疫组织化学实验

对大鼠急性心肌缺血早期的不同时间、心脏不同部位的血管内皮生长因子（VEGF）的表达，运用免疫组织化学方法进行了研究。结果发现：缺血30min后在缺血心肌局部开始出现VEGF阳性表达，而缺血边缘区域和正常区域心肌在缺血1h后也开始出现VEGF阳性表达，并随着缺血时间的延长，VEGF的表达强度也越来越强。对照组未发现有阳性表达结果.表明运用免疫组化方法检测心肌缺血后心肌局部VEGF的表达，可望作为因心肌缺血导致心脏性猝死案例的诊断标准之一。     

缺血修饰白蛋白在急性缺血性心脏病中的法医学应用

目的探讨心包液中缺血修饰白蛋白(ischemia modified albumin,IMA)水平在心脏性猝死诊断中的应用价值及法医学意义。方法应用白蛋白-钴离子结合法检测急性缺血性心脏病组(36例)、急性心肌梗死组(6例)、心肌病组(4例)、对照组(15例)死者的心包液中IMA水平,比较各组之间IMA水平的差异。通过ROC曲线获得最佳IMA水平的截断值以及区分急性缺血性心脏病和对照组的敏感度和特异度。结果急性缺血性心脏病组心包液中IMA水平高于对照组(P0.05);而与急性心肌梗死组、心肌病组心包液中IMA水平比较,差异均无统计学意义(P0.05)。应用ROC曲线分析得出识别急性心肌缺血的IMA的截断值为40.65 U/m L,其诊断急性心肌缺血的敏感度为60.0%,特异度为80.5%。结论心包液中IMA有望作为诊断急性心肌缺血的参考指标,为心脏性猝死的法医学诊断提供客观依据。     

Detection of apoptosis in ischemic heart. Usefulness in the diagnosis of early myocardial injury

Myocardial samples of hearts with histologic findings of acute myocardial infarction (group A), sudden coronary deaths without histologic changes (group B), and chronic ischemic heart disease (group C) were analyzed to investigate the appearance of apoptosis in acute and chronic ischemic cardiac disorders. This analysis involved the morphologic detection of DNA strand breaks in myocyte nuclei by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay and the biochemical determination of DNA laddering in the myocardium using archival formalin-fixed, paraffin-embedded tissue sections of human myocardium. The authors demonstrated that apoptosis of myocardial cells could occur after ischemic myocardial cell injury. In all documented cases of acute myocardial infarction (group A), the infarcted area included extensive presence of both apoptosis and necrosis. In the tissue bordering on and away from the obviously infarcted areas, positive nuclei were intermingled with nonstained normal myocytes. The number of positive nuclei decreased with the distance from the infarction foci. In group B, myocardial samples showed focal or diffuse nuclear positivity of varying degrees for apoptosis, confirming the presence of myocardial ischemic cell death, whereas the histologic diagnosis remained inconclusive. This finding suggests that apoptosis could be used as a marker for acute ischemic injury. In group C, stained nuclei were dispersed with intermingled normal cardiomyocytes.     

大鼠急性早期心肌梗死细胞膜PNA受体表达

探测急性心肌缺血早期细胞膜PNA受体的表达特点。应用免疫组化法(S-P法)对32只SD大鼠急性心肌缺血早期不同时间心肌细胞膜凝集素受体的表达进行研究。结果发现:心肌缺血15min时,心肌局部可出现PNA染色阳性,且随着缺血时间的延长,其阳性表达面积明显增加;缺血2h;其表达水平达到高峰,呈弥漫性染色阳性,明显高于对照组;2h后,心肌缺血区域PNA受体的表达开始出现下降趋势。实验结果稳定,敏感性强,可为心肌缺血早期诊断提供客观的依据。     

Study on expression of the glycoprotein in myocardial cell membrane of the rat's early myocardial ischemic

OBJECTIVE: To explore expression of the glycoprotein in early myocardial ischemic. METHODS: The glycoprotein changes occurred at the early acute cardiac ischemic area induced experimentally by ligation of left coronary artery of 32 SD rats. 6 lectins were measured by means of immunohistochemical methods. RESULTS: Positive staining of PNA could be observed in ischemic area at 5 min after ischemia, and the positive area increased with the prolongation of ischemic period. It became the strongest for 2 h and then decreased. CONCLUSION: This experiment proved that myocardial cell membrane in ischemia expressed D-galactose. This may be of some value in forensic medicine practice.     

A retrospective analysis of cardiovascular deaths: A 5-year autopsy study of 1045 cases in Antalya,Turkey

This study aims to identify the macroscopic and microscopic changes that occur in the heart in different causes of cardiovascular death and sudden cardiac death in autopsy cases and evaluate the difficulties that a forensic practitioner may encounter during autopsies. All forensic autopsy cases in the Morgue Department of the Council of Forensic Medicine, Antalya Group Administration between January 1, 2015, and December 31, 2019, were examined, retrospectively. The cases were chosen according to inclusion and exclusion criteria, and their autopsy reports were examined in detail. It was determined that 1045 cases met the study criteria, 735 of which were also met the sudden cardiac death criteria. The top three common causes of death were ischemic heart disease (n = 719, 68.8%), left ventricular hypertrophy (n = 105, 10%), and aortic dissection (n = 58, 5.5%). The frequency of myocardial interstitial fibrosis was significantly higher in deaths due to left ventricular hypertrophy than in deaths due to ischemic heart disease and other causes (χ²(2) = 33.365, p < 0.001). Despite detailed autopsy and histopathological examinations, some heart diseases that cause sudden death may still not be detected.     

HPLC-DAD determination of mepivacaine in cerebrospinal fluid from a fatal case

A fatal case involving mepivacaine-induced epidural anesthesia is described. The pathological findings were typical of cardiac shock from ischemic origin. Cerebrospinal fluid (CSF) was obtained several hours after death and mepivacaine was identified by gas chromatography-mass spectrometry (GC-MS). Its concentration was determined by high performance liquid chromatography with diode array detection (HPLC-DAD). Extraction from CSF was performed by deproteinization with acetonitrile. The mepivacaine concentration in the sample was 264 microg/mL. Concentrations of mepivacaine in CSF following epidural anesthesia are not reported in literature to our knowledge. This is the first reported case of death in which the mepivacaine concentration in CSF has been determined.     

Relationship of ischemic heart disease to sudden death

A clinicopathological synthesis is presented of the relationship of ischemic heart disease to sudden cardiac death. The immediate pathophysiological process responsible for sudden cardiac death is a lethal arrhythmia, usually ventricular fibrillation. Although significant coronary atherosclerosis is present in most cases of naturally occurring sudden death, available evidence indicates that several mechanisms can be operative in the pathogenesis of the fatal event. These are (1) acute myocardial infarction in a minority of cases; (2) myocardial ischemia, without infarction, which is initiated either by (a) an exertion-induced increase in myocardial oxygen demand or (b) an acute coronary event often involving plaque degeneration and platelet aggregation; and (3) a primary arrhythmia, usually resulting from altered electrical conduction in the setting of a previous myocardial infarction.     

Recognition of Early Myocardial Infarction by Immunohistochemical Staining with Cardiac Troponin‐I and Complement C9*

Abstract: The diagnosis of early myocardial infarction (MI) after death, especially in the first few hours (c. 6 h) after the onset of MI, poses a challenge to the forensic pathologists. During this time, the damaged myocardium does not show grossly identifiable morphological changes and may not be recognized even with routine histological microscopic examination. However, the infarcted cardiac tissue releases certain chemicals that can be detected microscopically, two of these being cardiac troponin‐I (CT‐I) and complement C9 (C9). This study utilizes the importance of these two biomarkers immunohistochemically in an attempt to identify this early phase of MI. This study reveals that the early phase of MI of <6 h duration may be detected through immunohistochemical staining with CT‐I and C9. The ischemic/infarcted cardiac myofibers in the <6 h group display reduced/absent CT‐I staining as well as positive C9 staining.