心肌氨基酸代谢与早期急性心肌缺血的关系

作者结扎家兔左冠状动脉前降支,对急性心肌缺血时蛋白质的降解和氨基酸代谢进行了研究。用离子交换色谱法测定缺血心肌组织游离氨基酸(酸性、中性、碱性)以及氨含量,发现缺血时大多数游离氨基酸含量上升,丙氨酸、缬氨酸、异亮氨酸和组氨酸含量在缺血15min即有明显增加,但苏氨酸、谷氨酸和游离氨基酸总量却随缺血时间的延长而逐渐下降。丝氨酸含量在缺血早期上升,缺血60～480min,含量无明显变化。缺血120min以后,甘氨酸和精氨酸含量逐渐下降。组织氨含量在缺血早期上升,晚期下降。游离氨基酸总量、苏氨酸、甘氨酸、精氨酸以及组织氨含量的降低是缺血心肌氨基酸代谢的特征性变化。作者认为:测定缺血心肌游离氨基酸及组织氨含量有助于急性心肌缺血的早期诊断。     

大鼠心脏型脂肪酸结合蛋白在早期心肌缺血时的含量变化

目的 观察心肌缺血后不同时间段心肌细胞胞浆内和血浆中的心脏型脂肪酸结合蛋白(H-FABP)含量变化。方法 按Selye法结扎大鼠左冠状动脉前降支复制心肌缺血模型,用免疫组织化学和酶联免疫吸附实验(ELISA)的方法,观察心肌缺血后不同时间H-FABP在心肌细胞和血浆中含量的变化规律。结果 心肌缺血15min时,缺血区心肌即可出现H-FABP缺失,随着缺血时间的延长,缺失的范围扩大,程度加重,与对照组相比差异有显著性;心肌缺血15min时,血浆H-FABP含量在心肌缺血15min时即明显升高,与对照组相比有显著性差异。随着缺血时间的延长,血浆含量逐渐上升,4h时达到高峰,以后逐渐下降。结论 心肌缺血后不同时间段心肌细胞胞浆内和血浆中的H-FABP含量变化呈现一定规律性,可望成为诊断早期心肌缺血所致的心源性猝死的敏感指标。     

苏木素—碱性复红—苦味酸染色法对诊断早期心肌缺血的意义

本文应用苏木素-碱性复红-苦味酸染色法(HBFP)对家兔实验性心肌缺血的早期改变及急死案例的尸检材料进行了研究,实验性心肌缺血材料均作电镜观察。结果表明,冠状动脉结扎后15min,缺血心肌显复红色,呈散在分布,与正常心肌对比明显。随缺血时间延长,显复红色之心肌纤维数目增多,缺血区扩大。HBFP 染色法不受常规组织处理及死后自溶的影响,可用于临床病理及法医病理诊断。     

心肌自溶与死后经过时间关系的研究进展

自溶是人体死亡以后,细胞自身固有的各种酶对自身组织、细胞的破坏,溶解。在实际工作中,发现尸体时,死亡发生多数已有一段时间,通过研究心肌自溶与死亡经过时间的关系,可以更准确的推断死亡时间,为案件的侦破提供线索,在实际工作中有一定实用价值。     

心肌自溶与死后经过时间关系的研究进展

自溶是人体死亡以后,细胞自身固有的各种酶对自身组织、细胞的破坏,溶解.在实际工作中,发现尸体时,死亡发生多数已有一段时间,通过研究心肌自溶与死亡经过时间的关系,可以更准确的推断死亡时间,为案件的侦破提供线索,在实际工作中有一定实用价值.     

用PCR技术鉴定自溶组织性别

本文用聚合酶链反应（PCR）检测已知男性各种不同程度自溶组织石蜡切片中的男性DNA序列。结果表明：自溶程度较低的组织可以用聚合酶链反应鉴定性别：但自溶程度达到核膜消失和细胞结构消失者，其性别鉴定阳性率明显降低，而且在自溶程度较高时，易出现假阴性结果。     

Cathepsin-L在缺血心肌中的表达

目的检测cathepsin-L(CTSL)在大鼠早期缺血心肌中的表达变化,并探讨其法医学意义。方法建立大鼠早期心肌缺血模型,设置早期缺血组(early ischemic myocardium,EIM)、非缺血组(non-ischemic myocardium,NIM)、假手术组以及空白对照组,采用real-time PCR方法检测大鼠缺血后15min,30min,1h和2h CTSL mRNA的表达量,并进行组内和组间比较。收集心源性猝死者缺血心肌和机械性损伤致死者正常心肌样本,采用免疫组化染色方法观察心肌组织中CTSL蛋白表达。结果 EIM组CTSL mRNA表达量与NIM组、假手术组及空白组相比,在15min时无统计学意义(P>0.05),在30min、1h和2h时分别升高1.4、3.1和4.5倍(P<0.05);其余3组间差异无统计学意义(P>0.05)。观察10例冠脉狭窄程度Ⅲ～Ⅳ级的心源性猝死(SCD)者缺血心肌,CTSL表达增强。结论大鼠心肌缺血后早期即可检测到CTSL mRNA的升高,并在SCD冠脉狭窄死者缺血心肌中高表达,提示CTSL可作为心肌缺血与SCD的参考指标。     

VEGF在家兔缺血心肌中的表达及其死后稳定性研究

目的观察心肌中VEGF在死后一定时间的稳定性及表达的变化规律，评价其对死后诊断机体早期心肌缺血的作用。方法用冠状动脉结扎法建立家兔急性心肌缺血模型，应用SP法染色、图像分析和统计学处理系统，检测缺血心肌细胞内VEGF阳性表达面积和强度，并对VEGF在死后不同时间的稳定性进行比较。结果VEGF在缺血心肌组织中，见灶性或成片心肌细胞强阳性表达，部分细胞呈阴性或弱阳性表达，血管内皮及平滑肌细胞表达弱阳性，间质表达阴性；在4℃放置，随时间延长，缺血心肌组织VEGF阳性表达有减弱趋势，至10d时缺血心肌组织仍可见VEGF在少许心肌细胞胞浆内呈弱阳性表达。在4℃放置10d以内，缺血心肌和正常心肌标本之间VEGF阳性表达具有极显著性差异。结论VEGF能耐受一定程度自溶及腐败的影响，其免疫组化检测对于判断死后4℃放置10d以内的尸体是否出现过心肌缺血具有一定意义。     

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.     

Practical experiences with the determination of cadaver age by evaluation of bacterial metabolic products

In an experiment a corpse had been kept at room temperature (16 degrees-23 degrees C) for 1163 h. At regular intervals brain samples were taken and the content of free amino acids and related compounds was determined by column chromatography. It could be demonstrated that in a period of 4-20 days postmortem the age of the corpse could be calculated from the concentrations of alpha-aminobutyrate (ABU), gamma-aminobutyrate (GABA), and glutamic acid (GLU) in brain employing the previously [5] presented formula: (formula; see text) T is the postmortem time lapse (days). ABU, GABA, and GLU are the concentrations (mumol/g) wet tissue of the corresponding amino acids. During this postmortem interval there is nearly a linear correlation; from this interval a correct assignment between concentrations and time cannot be given. The determination method is in the range of about 15 degrees-25 degrees C (guarantees bacterial growth and metabolism) independent of ambient temperature. The brain samples (cortex or parts of the putrified brain mush) can be taken without any special precaution during normal autopsy. The results of the experiment (in Fig. 1) were supported by some practical cases where the time lapse since death was well (in Fig. 1) or reasonably (in Fig. 1) known. These results suggest that this method allows in many cases the determination of the age of a corpse found in a warm environment (approximately 15 degrees-25 degrees C) approximately 4-20 days after death.     

Free amino acid concentrations in vitreous humor and cerebrospinal fluid in relation to the cause of death and postmortem interval

We studied free amino acids in vitreous humor and cerebrospinal fluid from 58 cadavers in the course of routine medicolegal autopsies in the city of Granada. The main objective was to establish whether free amino acids contents in these fluids were related with the cause of death, postmortem interval, and severity of the classic signs of asphyxia. The amino acids (aspartic acid, glutamic acid, serine, glutamine, glycine/threonine/histidine, citruline, arginine, alanine, taurine, GABA, tirosine, valine, methionine, isoleucine, phenylalanine/tryptophan, leucine, and lysine) were quantified by high performance liquid chromatography. There were no statistically significant differences in amino acids concentrations in vitreous humor when the different causes of death were considered. Our results did not show any statistically significant relationship when asphyxial score was plotted against the vitreous content of each amino acid. A statistically significant increase with postmortem interval was observed in vitreous taurine (r = 0.3191, p = 0.01461), glutamate (r = 0.4323, p = 0.0007) and particularly in aspartate (r = 0.4508, p = 0.0003).     

Toward multidimensional information: A derivatization-free UHPLC-QqQ MS/MS method for amino acid components of fingerprint

The analysis of fingerprint chemical composition is a meaningful way to excavate the multidimensional information of fingerprint, including the donor profiling information and the age of a fingerprint, which broadens the evidential values of fingerprint, especially for the partial and distorted fingerprint. But the research remains still in the pilot phases or is ongoing. Amino acids are the dominant organic substances in latent sweat fingerprint and influenced by many donor factors. Hence, their content reflects personal information of donors. Forensic science will be revolutionized if suspects can be individualized by their amino acid content. The diverse nature, distinct physicochemical properties, and ultra-micro levels of amino acids present in fingerprints make it hard to detect. A high sensitivity method for detecting and quantifying multiple amino acid components is required. UHPLC-QqQ MS/MS offers high sensitivity, high separation, simultaneous multicomponents detection, and no derivatization, making it an ideal method for detecting and analyzing amino acids in fingerprints. Therefore, in this study, we propose and validate an efficient UHPLC-QqQ MS/MS method for the extraction and analysis of 13 amino acids from fingerprint. We compared the results of amino acids of 10 different substrates and found that the inherent amino acids in most porous substrates would have been extracted along with the fingerprint amino acids, making them unsuitable for quantitative amino acid analysis. Instead, plastic sheets are ideal substrates for laboratory studies. Then, extensive experiments were conducted among 30 donors for multidimensional information analysis. The type of samples analyzed were eccrine-rich fingerprints. A Binary Logistic Regression (BLR) model was developed, and the female and male donors were successfully differentiated by amino acids in fingerprints. Two other mathematical models were also developed to verify the accuracy, and all three different mathematical models were able to identify donors of different genders with over 90% accuracy. This demonstrates that amino acids have the potential to provide more information for donors as metabolic markers. In the future, we will conduct a series of experiments to analyze more multidimensional information for individual identification by amino acid content in the fingerprint.     

Quantitative investigation of the amino acid levels in putrefying liver (author's transl)]

To elucidate the post-mortem proteolysis we investigated the behaviour of the free amino acids in rotting liver homogenates by means of two-dimensional thin-layer chromatography and reflection densitometry. The post-mortem alterations of the amino acid levels are characterized mostly by a two-phase increase with maxima at the end of the first and after the third week. A few amino acids showed only little changes hardly above the physiological intra-cellular levels. Anaerobic rat experiments and experiences with antibiotic treatment give rise to the supposition that increasing amino acid concentrations indicate a predominance of proteolytic activities over aminoacid catabolism. In the beginning autoenzymes are prevalent, while afterwards bacterial proteases probably predominate. The transient regression about the second and thrid week is interpreted as the effect of a temporarily intensified amino acid degradation by foreign enzymes (maximal bacterial growth).     

损伤皮肤中白三烯B_4含量测定与损伤时间推断

本文作者利用高压液相色谱,快速检测大鼠皮肤切创创缘组织中白三烯B_4含量。结果发现,生前各损伤时间组创缘中白三烯B_4含量明显升高,且在1小时内与损伤时间有一定线性关系;死后损伤标本未见白三烯B_4含量升高。由此表明白三烯B_4含量测定,对推断生前1小时内的损伤时间有重要价值。高压液相色谱能快速、准确地检测损伤组织中的白三烯B_4。     

乌头碱在家兔体内的代谢动力学初步研究

本文应用甲醇-0.05mol/L碳酸铵水溶液-二氯甲烷(90:10:2)作流动相,在YWGC_(18)H_(37)反相键合相色谱柱上分离乌头碱和内标,用紫外分光检测器在235nm外定量,改进了动物组织内痕量乌头碱的HPLC检测法。运用该法检测家兔静脉注射乌头碱后的血毒物浓度,初步研究了乌头碱在家兔体内的代谢动力学过程,表明其体内过程符合开放二室模型,T_(1/2α)=1.4682min,T_(1/2β)=34.1379min。体内乌头碱可以原形由尿和胆汁中排出,但以前6h尿排泄为主。     

Brain amino acid abnormalities in liver disease--a postmortem study

In a postmortem exploratory study, we examined whether specific amino acid abnormalities associated with liver diseases in vivo may also be detected in human brain samples obtained at clinical autopsies. The branched-chain amino acids (BCAA: valine, leucine, isoleucine) were decreased in the group of patients with liver diseases compared with the control group, whereas the aromatic amino acids (AAA: phenylalanine, tyrosine) were increased. However, the ranges overlapped significantly and were not statistically different. The molar ratio BCAA/AAA was determined to be 1.92 in the collection of patients with liver diseases compared with 2.27 in the control group. In patients with liver disease, ornithine concentrations in the brain appeared significantly decreased whereas glutamine was significantly increased. No significant difference was found in the brain concentrations of proline. Amino acid analysis may contribute to the understanding of pathophysiological mechanisms of liver disease, which are discussed, and may supplement the postmortem diagnosis.     

死后组织DNA变化与死亡时间关系的研究

为调查死后组织DNA含量变化与死亡时间的关系,本文采用流式细胞仪对死后0～96小时(0～96hourpostmortem,hpm)大鼠的骨骼肌、脾、肾细胞DNA含量进行分析,结果表明,各组织显示了随死后间隔时间延长,含碎片DNA细胞增多,含完整DNA细胞减少的趋势;DNA降解系列组方图分析结果表明,脾组织降解速度明显快于肾和骨骼肌组织;骨骼肌在制成单细胞悬液过程中的人为损伤,可造成DNA提前降解.     

人体腹部皮肤切创纤维蛋白渗出量变化与时间相关性的研究

本文应用组织化学Ｍａｓｓｏｎ三色方法，对人体腹部２小时以内皮肤切创壁纤维蛋白渗出量变化规律进行了研究，发现切刨早期创壁纤维蛋白沙出量随着时间的延续而明显增多，为推断早期切创时间，提供了新的较为简便的方法。