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1.
The morphological changes of the alveolar wall of adult rats in the hypoxic state were studied by light and electron microscopy. The remarkable findings were the appearance of a large amount of lamellar, lattice- and thread-like structures together with a massive homogeneous substance on the surface of the alveoli which seemed to be closely connected with each other and with the surface of the cells lining the alveolus, especially in the 5%-group. The appearance of the above-mentioned structures with the homogeneous substance is considered to be the reaction of lung tissue to the decreased content of oxygen in the inhaled gas.  相似文献   

2.
Biochemical characterization in alveolar lavage fluids of rats which had inhaled 5% oxygen, carbon dioxide and carbon monoxide was studied in comparison with control rats. The protein content, consisting mainly of serum albumin, markedly increased in the hypoxic states. The phospholipid content also increased one and a half to two times as much as in the control rats. The phospholipids which increased in the alveoli were mainly pulmonary surfactant phospholipids, i.e. phosphatidylcholine and phosphatidylglycerol. The phospholipid profiles did not appear to be affected by the leakage of plasma lipids. These findings indicate that pulmonary surfactant phospholipids accumulate in the alveoli of rats in the hypoxic states examined here.  相似文献   

3.
To investigate the effects of very high concentrations of carbon dioxide (CO2) upon the course of respiration and circulation, dogs were allowed to breathe high concentrations of CO2 while intrathoracic pressure, blood pressure (BP) in the femoral artery, electrocardiogram and electroencephalogram readings were registered. The respiratory movements either increased just after inhalation of high concentrations of CO2 and then ceased in 1 min, or decreased and continued for a while according to the concentrations of CO2. The BP showed an initial depression, then returned to the original level, then fell again rapidly or maintained an appreciable level for a while until circulatory breakdown. In the dogs allowed to breathe the gas mixture of 80% CO2 with 20% O2, the respiratory movement ceased in 1 min, and the terminal respirations were seen with the circulatory breakdown after apnoea of several minutes. These findings showed that the cause of death in breathing high concentrations of CO2 is not hypoxia, but the CO2 poisoning.  相似文献   

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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。  相似文献   

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A combination absorption-elution, two-dimensional absorption-inhibition procedure was used to determine the ABH antigen composition of a series of human bone specimens of known ABO type that had been aged up to nine months under dry and humid conditions at ambient temperature, 37 degrees C, and 56 degrees C; at ambient temperature in dry and wet soil; and buried in soil outdoors. Grouping data for the separate elution and inhibition testing, as well as for the combination procedure, are given. The combination method was found to be a highly reliable procedure for bone tissue ABH typing. Some data on microbial contaminants of human bone specimens aging in soil, and their effects on ABH typing results, are presented. No direct correlation between the properties of microbial contaminants and specific changes in the ABH antigenic composition of aging bone tissue specimens could be ascertained. Data on IGH antigen determination and on the quantitation of immunoglobulin G (IgG) in human bone tissue extracts indicated that immunoglobulin levels were typically too low to expect routinely successful Gm antigen testing results. However, these factors can sometimes be determined in fresh bone tissue extracts, particularly if the extracts are concentrated.  相似文献   

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This article is the second part of a review of the event studymethodology, which has proved to be one of the most successfuluses of econometrics in policy analysis. In this part we focuson the methodology's application to corporate law and corporategovernance issues. Event studies have played an important rolein the making of corporate law and in corporate law scholarship.The reason for this input is twofold. First, there is a matchbetween the methodology and subject matter: the goal of corporatelaw is to increase shareholder wealth, and event studies providea metric for measurement of the impact upon stock prices ofpolicy decisions. Second, because the participants in corporatelaw debates share the objective of corporate law, to adopt policiesthat enhance shareholder wealth, their disagreements are overthe means to achieve that end. Hence, the discourse can be empiricallyinformed. The article concludes by sketching the methodology'suse in evaluating the economic effects of regulation. Whileevent studies' usefulness for policy analysis is by now familiarin the corporate law setting, we hope that our two-part reviewwill suggest appropriate applications to other fields of law.  相似文献   

10.
Food  Drug Administration  HHS 《Federal register》2002,67(240):76678-76681
The Food and Drug Administration (FDA) is reclassifying the cutaneous carbon dioxide (PcCO2) monitor from class II (performance standards) into class II (special controls). FDA is also reclassifying the cutaneous oxygen (PcO2) monitor for an infant patient who is not under gas anesthesia from class II (performance standards) into class II (special controls) and is reclassifying the cutaneous oxygen (PcO2) monitor for all other uses from class III (premarket approval) into class II (special controls). Elsewhere in this issue of the Federal Register, FDA is announcing the availability of the guidance document entitled "Class II [[Page 76679]] Special Controls Guidance Document: Cutaneous Carbon Dioxide (PcCO2) and Oxygen (PcO2) Monitors; Guidance for Industry and FDA" that will serve as the special control for the devices. These reclassifications are taken on the agency's own initiative based on new information. These actions are being taken under the Federal Food, Drug, and Cosmetic Act (the act), as amended by the Medical Device Amendments of 1976 (the 1976 amendments), the Safe Medical Devices Act of 1990 (the SMDA), the Food and Drug Administration Modernization Act of 1997 (FDAMA), and the Medical Device User Fee and Modernization Act.  相似文献   

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Liu XS  Chen YC  Li ZH 《法医学杂志》2004,20(3):129-32, 135
OBJECTIVE: To study the changes of electrocardiograms (ECG) and myocardial ultrastructure in heroin dependence in rats, in order to reveal the mechanisms of the myocardial injury by heroin. METHODS: Establish heroin addict model in SD mice, investigate the changes in electrocardiograms, HE staining and myocardial ultrastructure. RESULTS: The electrocardiograms of the addict group had prominently changes, main expressions: heart rate decreased, P wave and T wave amplitude reduced and duration increased, S-T reduced and duration increased, QT interval prolongation, these changes indicated that myocardium had been injured, myocardial ischemia, ventricle function declined. These difference was significant (P<0.05) between before inject heroin and after inject heroin. Transformations in the ultrastructure: nuclear concentrate, reduce, nuclear membrane shrink, chromatin agglutinate, mitochondria cristal had disorder formation, disappeared or hollowed, these indicated that heroin could cause pathological changes in myocardial ultrastructure. CONCLUSION: Above-mentioned changes indicated that heroin can injure myocardium, and the changes of myocardial ultrastructure suggested that myocardial apoptosis may be one of the mechanisms of the myocardial injury by heroin.  相似文献   

13.
大鼠死后心血中吗啡浓度变化的HPLC检测   总被引:1,自引:0,他引:1  
李利华  吴家文 《法医学杂志》1997,13(2):65-67,76
本文采用高效液相色谱(HPLC)分析技术检测了治疗量及中毒量吗啡肌注大鼠死后心血中吗啡浓度变化.结果表明.以治疗量吗啡肌注大鼠死后96h内,心血中吗啡浓度随死后时间增加而显著升高(P<0.01),吗啡浓度水平与死后时间呈显著正相关.以中毒量吗啡肌注大鼠死后12h内,心血中吗啡浓度无明显变化.死后24h、48h及96h.随死后时间延长,心血中吗啡浓度逐渐升高(P>0.01),其递增强度不如治疗量吗啡组大鼠的明显.本研究证实死后尸体心血吗啡浓度明显受生前剂量的影响,且死后96h内,随死后时间延长心血中吗啡浓度不断增高.本文初步探讨了死后心血吗啡浓度变化发生的可能机制.为海洛因或吗啡中毒死亡的血液检测结果评判及死因分析提供理论依据.  相似文献   

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海洛因成瘾大鼠心电图及心肌超微结构改变的研究   总被引:3,自引:1,他引:2  
目的探讨海洛因成瘾大鼠心电图及心肌超微结构的改变,为海洛因对心脏的损害机制提供研究基础。方法建立大鼠海洛因成瘾模型,观察心电图、HE染色及心肌超微结构改变。结果大鼠海洛因成瘾组心电图改变明显,主要表现在心率减慢、P波及T波压低、时间延长,S-T段压低、时间延长,QT间期延长,上述差异有统计学意义(P<0.05),提示心肌损伤、心肌缺血及心室功能下降。电镜改变主要表现在核浓缩,核变小,核膜皱缩,染色质凝集成块,线粒体嵴排列紊乱、消失及空泡变等,提示海洛因可造成心肌细胞超微结构的病理改变。结论海洛因对心肌可造成损害,并且心肌超微结构改变提示心肌凋亡可能是海洛因造成心肌损伤的机制之一。  相似文献   

15.
大鼠心肌缺血后SERCA和PLB基因表达变化的观察   总被引:1,自引:0,他引:1  
目的观察大鼠心肌缺血后,肌浆网钙调节蛋白SERCA和PLB基因表达水平变化,探讨其在早期心肌缺血诊断上的应用价值。方法25只大鼠随机分为正常对照组、缺血5、10、15min及缺血性猝死组,建立大鼠急性心肌缺血模型;利用荧光标记逆转录聚合酶链反应技术(RT—PCR)检测不同时间大鼠心肌缺血后,SERCA和PLB的基因表达变化,并与缺血性猝死组相比较。结果心肌缺血5min即可检测到SERCA和PLBmRNA表达相对下降,且随着缺血时间的延长,呈逐渐下降趋势,心肌缺血组与缺血性猝死组表达存在显著性差异。结论大鼠心肌缺血后SERCA和PLB基因表达变化呈一定规律性。对早期心肌缺血的诊断具有法医学意义。  相似文献   

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This paper presents the first referenced case on a death by traumatic asphyxia in a folding bunk bed. A middle-aged man was found dead in a hotel room trapped into a lower folding bunk bed where he had been sleeping after a party. The autopsy showed signs of asphyxia and excluded signs of struggle and sexual intercourse. Toxicological analyses revealed alcohol intoxication. A differential diagnosis of the manner of death including a technical study of the bed which contributed to understand the circumstances of death was made. The medico-legal investigation of the case strongly supported the hypothesis of an accidental death by traumatic asphyxia.  相似文献   

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利用尸体软组织生物力学性状时序性变化推断死亡时间   总被引:1,自引:1,他引:0  
目的探讨尸体软组织生物力学性状时序性变化规律及其推断死亡时间的可行性。方法将实验大鼠用颈椎脱臼法处死,放置25℃恒温培养箱内即刻、6、12、18、24、30、36、42、48、60、72、96、120、144、168、192h,定时、定位、定向、定形切取大鼠胸部正中皮肤、腹壁肌肉、胸主动脉、结肠和小肠的生物力学试件,用电子万能材料试验机检测各试件的极限载荷、应变、应力生物力学参数。结果除主动脉外,尸体皮肤、肌肉、小肠、结肠的各项软组织生物力学参数均呈明显的死后时序性下降趋势。各参数下降趋势具有显著性差异的"窗口期"分别为:极限载荷:死后18h内皮肤、小肠呈下降趋势;24h内肌肉、结肠呈下降趋势;96~168h肌肉呈下降趋势;72~192h结肠呈下降趋势。应变:各组织在24h内均呈下降趋势,其结肠72~192h缓慢下降趋势。应力:皮肤18h内呈下降趋势,肌肉、小肠24h内呈下降趋势,结肠36h内呈下降趋势。结论大鼠尸体软组织各生物力学性状在不同的"窗口期"存在时序性变化规律,综合各指标可用于推断相应"窗口期"内的死亡时间。  相似文献   

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目的探讨失血性休克大鼠肝肾脾细胞微管蛋白含量变化与死亡时间(PMI)的关系。方法大鼠经切断股动脉致失血性休克死亡后,分别于死亡即刻和死后1、2、3、5和7d剖取脾脏、肝脏及肾脏组织,应用western—blot技术检测微管蛋白含量,SPSS11.5软件对结果进行统计学分析。结果大鼠肝肾脾细胞内微管蛋白含量随PMI的延长而逐渐降低,至死后7d仅可见很淡的微管蛋白印记谱带,其中微管蛋白在肝脏内降解速率最快。3种组织内微管蛋白含量变化的同归方程及相关系数(r)分别为:肝脏Y=-2221.1X+14844,r=0.9823;脾脏Y=-1871.1X+11344,r=0.9749;肾脏Y=-1878.1X+13715,r=0.9629。结论大鼠死后肝肾脾细胞内微管蛋白降解规律与PMI之间具有相关性,并存在组织差异性。  相似文献   

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HELD: The Alaska Constitution's guarantees of privacy and liberty do not afford terminally ill persons the right to a physician's assistance in committing suicide and Alaska's statute prohibiting suicide assistance does not violate their right of equal protection.  相似文献   

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