生物检材中氰化物浓度与保存时间关系研究

通过动物试验，用荧光光度法测定生物检材中氰化物浓度，研究了氰化物浓度与保存时间关系。结果表明，染毒血液高体120h内，氰化物浓度呈平缓直线上升；120h至168h之间呈指数下降；染毒肝脏检材在168h内呈直线上升，建立了线性方程。     

生物检材采集与保存套管的应用

目的探讨生物检材采集与保存套管在法医学中的应用价值。方法在不同温、湿度环境下，观察悬空放置在生物检材采集与保存套管、有孔与外界相通的套管及密闭管内的湿润棉签的干燥时间30次；分别用生物检材采集与保存套管和医用棉签采集纸袋保存口腔细胞、血液、皮肤脱落细胞样本各20例，磁珠法提取DNA并进行DNA定量；用生物检材采集与保存套管采集口腔脱落细胞和血样进行DNA直接扩增。结果在温度4～30℃、相对湿度21％～90％的环境下，湿润棉签在套管内的平均干燥时间为7．89h，有孔管内的为23．30h，密闭管内观察15天仍不干燥，出现霉斑。生物检材用套管采集保存比医用棉签采集纸袋保存方式获得的DNA量显著提高，平均高达0．968倍；用套管采集口腔细胞和血样进行直接扩增，操作简单方便，成功率高。结论生物检材采集与保存套管具有快速干燥、对检材无损耗和浓缩等优点，可提高检材DNA的提取效率，且适合直接扩增。     

不同保存条件对血中CN-浓度的影响

目的研究在各种温度贮存条件下血液中CN-浓度与保存时间的关系。方法用氯胺T衍生GC/ECD分析。结果在室温下存放的阳性血,在30天～50天中,CN-浓度有所增加,以后浓度下降很快,80天后则检不出。在4℃及-20℃下贮存的血液CN-浓度,在一定的时间段中,有所增加,以后则逐渐下降,至8个月仍可检出CN-。结论不同条件下存放的血液CN-其浓度的变化是不同的。     

不同保存时间血清心肌损伤标志物的变化规律

目的 测定不同温度、不同储存时间下血清心肌损伤标志物心肌肌钙蛋白I、肌酸激酶同工酶、肌红蛋白含量，探究血清cTnI、CK-MB、Myo随储存时间延长的变化情况。方法 收集96例心血管疾病患者中心静脉血，分别在4℃和25±3℃条件下保存，分别测定抽血即刻（0 h）、24 h、72 h、168 h、240 h的血清cTnI、CK-MB、Myo含量，探究其变化规律并进行相关性分析。结果 冷藏组血清Myo变化趋势不明显，血清cTnI、 CK-MB随储存时间延长逐渐下降；常温组血清Myo随储存时间延长上升，血清cTnI、CK-MB随储存时间延长逐渐下降。结论冷藏保存0～240 h及常温保存0～168 h的血液样本能够一定程度上反映死亡时心肌损伤情况，有望作为法医学诊断早期心肌损伤的新方法。     

纸张经茚三酮显现指印后的变色现象

目的研究经茚三酮显现指印后纸质检材的变色规律、产生条件及解决方法。方法比较不同茚三酮显现条件，显现后不同保存条件下各种纸质检材的变色现象。结果经茚三酮显现指印后纸质检材的保存环境中，当温度、湿度达到一定条件时，大部分纸质检材会发生不同程度的变色现象。结论经茚三酮显现后的纸质检材要采取适当的方法保存。影响纸张变色的决定性因素为检材所保存的温度和湿度。环境温度在25℃以上并且湿度在60％以上，经茚三酮药液显现的白色纸张保存24h后都会有变色的可能，48h后绝大部分白色纸张会发生变色。     

GC—MS／MS法检验生物检材中的无机氰化物

目的建立一种检验生物检材中无机氰化物的GCMS／MS方法。方法首先将生物检材中的无机氰化物在酸性条件下蒸馏出,用碱性溶液吸收后,氰离子在相转移催化剂作用下被五氟苄基溴（PFB-Br）衍生化,最后用GC-MS／MS法分析衍生化产物。结果衍生化产物PFB-CN的MS／MS质谱图特征性强,定性准确;在20-1500ng／g浓度范围内呈良好的线性关系（r＝0．998）,最低检测限为5ng／g,回收率为82．3％－98．6％。结论本方法简单实用,灵敏度高,准确可靠,适用于生物检材中无机氰化物的检验。     

异烟酸-吡唑啉酮色阶法分析生物检材样品中的氰化物

目的建立生物检材样品中氰化物定性半定量法——异烟酸一吡唑啉酮色阶法,以适应基层工作的需要。方法采用蒸馏法完成生物检材样品的净化、提取,吸收液中的氰化物在中性pH6．8～pH7．0溶液中,与氯胺T作用生成氯化氰。再与异烟酸-吡啉唑酮作用生成蓝色络合物。结果通过目视比较样品管与标准色阶管的颜色,可判断样品中氰化物的含量范围。结论本方法易操作、抗干扰性强、适合基层实验室参考使用。     

不同保存条件下呋喃丹及其代谢物在血液中的稳定性研究

目的研究呋喃丹及其代谢物呋喃酚在不同条件保存血液中的稳定性,为呋喃丹中毒案件的法医学鉴定提供实验依据。方法犬经口灌胃4LD50(13.5mg/kg)呋喃丹致死后,取血液分为五等份,分别为添加1%氟化钠(1%NaF)、添加2.5mg/m L枸橼酸钠(NC)、20℃、4℃和-20℃保存实验组。于保存当时(0d)、5d、7d、15d、40d、83d和150d取上述样品,多反应离子检测(MRM),气相色谱-质谱联用(GC-MS/MS)法检测其中呋喃丹及呋喃酚含量。结果血液中呋喃丹的含量随保存时间均呈下降趋势,7d显著下降(P0.05),之后下降缓慢。不同条件保存血液中呋喃酚的含量均呈先升高后下降趋势。枸橼酸钠和氟化钠可加快血液中呋喃丹的分解。结论呋喃丹及其代谢物呋喃酚在保存检材中均可发生分解,20℃保存分解较快,4℃和-20℃保存分解速度较慢,不适宜用枸橼酸钠或氟化钠作抗凝剂或防腐剂。在呋喃丹的相关案件的法医学鉴定中,生物检材应注意冷藏、冷冻保存,并尽快送检。     

顶空气质联用法测定腐败血、肝检材中CO

目的研究CO中毒腐败血、肝组织检材中CO的HS/GC/MS检测。方法用HS/GC/MS法分析碳氧血红蛋白(COHb)血的线性范围。配制10%、30%、50%、70%浓度COHb血样,分别在室温、冷藏、冷冻条件下保存,分别在当日、第4、14、45d进行测定,比较实验结果。腐败肝组织由雄性健康家兔通CO气体致死,当天解剖,家兔肝常温隔绝空气保存并放35d至腐败,期间进行不定期顶空测定分析。结果制备的COHb血在0-100%之间有良好的线性关系Y=2.4X+2.2(r=0.9995)。以此方法测定家兔CO中毒致死的COHb新鲜血的浓度和4℃下放置45dCOHb腐败血,结果表明温度对血样中COHb%的测定影响最大。采用HS/GC/MS法检测,每次只需0.25ml血样或1g肝脏,分析一次时间只需3min,均可检测出新鲜检材和常温放置45d的腐败肝组织检材CO的含量。结论HS/GC/MS法能检出CO中毒的腐败生物检材中CO。     

氰化物急性中毒大鼠的血浆代谢组学研究

目的 利用代谢组学技术研究急性氰化物中毒大鼠血浆中小分子代谢物的变化，寻找差异代谢物，分析与氰化物中毒相关的代谢途径，进而研究氰化物中毒的机制。方法 将健康SD大鼠随机分为空白对照组和实验组（雄性，每组5只），实验组灌胃3.2 mg/kg(1/2LD50)氰化钾溶液建立氰化物急性中毒模型，对照组灌胃等剂纯水，灌胃后分别于45 min,24 h,120 h眼眶静脉采血，通过高效液相色谱-飞行时间质谱采集大鼠血浆代谢谱，根据主成分分析（PCA）、正交偏最小二乘判别分析（OPLS-DA）以及t检验和变异倍数分析筛选差异代谢物，并通过KEGG(Kyoto Encyclopedia of Genes and Genomes)数据库进行代谢通路分析。结果 筛选出19个与氰化物中毒相关的差异代谢物，且随时间变化差异代谢物的种类存在差异，主要涉及胆汁分泌、氨基酸代谢等共11条代谢通路。结论 可将牛磺胆酸盐和牛磺鹅胆酸盐作为氰化物中毒潜在生物标志物，马尿酸可以作为两者的辅助指标，也可根据差异代谢物的不同进行服药时间的初步推断。氰化物会对机体酶的活性和能量代谢过程产生影响，且可能造成肝脏损伤。     

Cyanide distribution in five fatal cyanide poisonings and the effect of storage conditions on cyanide concentration in tissue

The cyanide distribution in five fatal cyanide poisonings was analyzed by the pyridine-pyrazolone method using a Conway diffusion cell. In order to study the effect of storage conditions on cyanide concentration in tissue samples, the cyanide concentrations were first measured immediately after collection of the samples at autopsy, then measured again after storage in a refrigerator (4 degrees C) or in a freezer (-20 degrees C) for periods ranging from 1 day to 3 weeks. Concentrations in all but three of the blood samples stored at 4 degrees C or -20 degrees C increased, with concentration ratios based on measurement made before and after storage ranging from 0.71 to 1.46. The concentrations in the liver, kidney, and brain samples either increased or decreased, with ratios of from 0.2 to 8.8. The concentrations in the stomach contents samples decreased rapidly at 4 degrees C, but hardly changed at all at -20 degrees C.     

Postmortem production of ethanol in different tissues under controlled experimental conditions

The aim of this study was to follow the postmortem ethanol production phenomenon under controlled experimental conditions (temperature, time interval) in different tissues. Specimens of blood, liver, skeletal muscle and kidney were taken from 30 corpses and no chemical preservatives were used in the specimens collected. Ethanol concentrations were detected by gas chromatography. All specimens stored at -20 degrees C and 4 degrees C did not show any change in ethanol concentration in an eight-day time interval. At 20 degrees C and 30 degrees C, all tissues, except blood, showed statistically significant ethanol production over the time interval tested. However, blood sample kept at 30 degrees C, showed statistically significant increase in ethanol production on the 2nd and 4th day comparing to the controls. Thus, we can state that postmortem ethanol production occurs in different tissues, and is increased at higher temperatures and, in general, it is in accordance with the course of time.     

红细胞和血痕酸性磷酸酶(EAP)表型及广东人群EAP基因频率的调查

本文采用薄层聚丙烯酰胺凝胶等电聚焦电泳检测红细胞及血痕酸性磷酸酶表型,并对不同条件下的血痕标本进行检测,发现室温下(15～33℃)保存的110例纱布血痕7周内可全部正确分型,21例磁板血痕9周内均可正确分型;含血量≥5λl 的血痕可被正确检出 EAP 表型;日晒、水洗、发霉等因素可影响血痕 EAP 型的正确检出。同时调查了广东人群的 EAP 表型分布,基因频率为 p~a=0. 2338,p~b=0. 7662,发现 EAP 基因频率分布存在着地区差异。     

Methamphetamine and amphetamine concentrations in postmortem rabbit tissues

The feasibility of detecting methamphetamine and its major metabolite, amphetamine, in postmortem tissues over a 2-year period was examined. It is important to determine if the abuse and toxic effects of drugs can be proved from evidence found in decayed, submerged, or stained tissue materials. The blood, urine, liver, skeletal muscle, skin and extremity bones from rabbits given methamphetamine intravenously were kept at room temperature, under 4 different conditions: sealed in a test tube, dried in the open air, submerged in tap water and stained on gauze. Methamphetamine was present in all the samples, with slight change in concentration in case of sealed and air dried tissues. Changes varied in bones kept in water. There were considerable decreases in methamphetamine in blood and urine stains. Despite long term storage, drug abuse and/or toxicity could be determined, in all tissues examined.     

探究尸体血样中乙醇、乙基葡萄糖醛酸苷和硫酸乙酯的产生

目的探索尸体血样保存过程中乙醇的产生情况及乙基葡萄糖醛酸苷(EtG)和硫酸乙酯(EtS)的产生可能。方法对照组为7例阳性静脉血,而实验组则为7例阴性尸体血。每例血样分成3份并保存在室温(18~22℃),4℃及-20℃等3种不同的条件下,在保存天数为0、2、3、5、7、9、11、13、15、17、19、21等时间点取样。使用顶空气相色谱法(HS-GC)检测乙醇,采用固相萃取提取EtG和EtS,使用高效液相色谱-三重四级杆质谱(LCMS/MS)法检测EtG和EtS。结果保存期间,对照组各血样中的乙醇、EtG和EtS浓度均呈下降趋势;实验组中1、2、4、5、6、7号血样的室温及4℃的样本在保存第2~3天时检出乙醇,而7号-20℃的样本在第6天检出乙醇。其中,6号室温血样的乙醇峰值浓度为64.27mg/100mL。各血样中均未检出EtG,EtS。结论室温及4℃保存的尸体血可产生乙醇且产生速度较快,反复冻融可导致-20℃保存的尸体血产生乙醇,乙醇峰值浓度可超过法定酒驾标准,但实验组血样中均无EtG和EtS产生。因此,尸体血中的EtG,EtS可以作为乙醇生前入体的特异性标志物,区分乙醇生前入体和腐败产生乙醇的依据。实际工作中,乙醇原体检测的酒精认定应注意血样保存和运输条件造成的影响。为了避免假阳性结果,涉及死亡的案件进行酒精认定时有必要辅以EtG和EtS的检测。     

检测体液中氰含量的荧光光度法研究

本文报道了应用取代反应检测体液中氰含量的荧光光度法。探讨了检测的具体方法和有关条件对检测的影响。检测了正常人血、尿液和唾液中氰含量,并检测了小鼠氰化物染毒死亡后血中氰含量。研究表明,本法不但可检测体液中致死量的氰化物含量,亦可检测体液中正常氰含量。     

Acute effects of carbon monoxide and cyanide on hepatic mitochondrial function

The effects of carbon monoxide and cyanide on the hepatic redox state and energy charge were investigated. Rats were used for the experiment under pentobarbital anesthesia. Immediately after laparotomy, a rat was placed in an animal chamber made of a transparent plastic box and exposed to a test gas for 3 min. Every test gas was produced in a gas chamber connected to the animal chamber with a flexible tube. HCN was produced from NaCN and H2SO4. In the CO inhalation experiment, various amounts of CO were introduced into the gas chamber. Immediately after an exposure, about 2 g liver was frozen in situ with a precooled clamp. Oozed blood from the wound surface was sampled. Concentrations of ATP, ADP, AMP, acetoacetate, and beta-hydroxybutyrate in hepatic mitochondria were determined, and the redox state and the energy charge were calculated. For cyanide as well as CO, significant negative correlations were found between the concentration in the blood and the redox state. The same held true for the energy charge. The redox state showed a slight increase at low concentrations of both gases; however, thereafter it began to decrease sharply with increases in concentrations. When concentrations of the toxicant in the blood reached certain levels, a kind of turning point, beyond which the redox state does not decrease any more, was observed. It was about 40% for HbCO and about 2.0 micrograms/ml for cyanide, and the points seemed to be related to the concentrations, beyond which cells are irreversibly damaged. On the other hand, the energy charge did not change at low concentrations. With an increase in toxicant concentrations, the energy charge decreased drastically. The rate of decrease in the energy charge became higher when blood concentrations exceeded certain levels. It was about 40% for HbCO and 2.0 micrograms/ml for cyanide. The presence of low levels of blood cyanide did not affect the relationship between the energy charge and the HbCO concentration.     

家兔死后体内2-氨基噻唑啉-4-羧酸分布研究

目的建立家兔氰化钾灌胃给药致死动物模型,研究氰化物代谢物2-氨基噻唑啉-4-羧酸(ATCA)在家兔体内的死后分布规律。方法雄性家兔7只(体重约2.0kg~2.5kg)经口灌胃2LD50(10mg/kg)氰化钾水溶液,观察家兔反应,待家兔呼吸、心跳和反射全部消失后立即对家兔进行解剖取心、肝、脾、肺、肾、脑、睾丸、胃壁、肌肉等组织检材以及心血、玻璃体液、尿液等体液检材置于-80℃冷冻保存待检。液相色谱-串联质谱联用法测定生物检材中氰化物代谢物ATCA的含量,对其在各个组织的分布进行比较并寻找规律。结果氰化钾灌胃后家兔出现呼吸频率加快,走路乏力,癫痫大发作样抽搐,后瞳孔散大,肌肉松弛,各种反射消失,似"电击样"死亡。死亡后测得心血中氰基(CN-)平均浓度为11.81μg/ml。死后0h氰化物代谢物ATCA在家兔体内的分布如下:脾>肺>肾>肝、脑>睾丸>心血>心、胃壁>玻璃体液>右下肢肌肉>尿。结论大剂量氰化物中毒致死后其代谢物ATCA在家兔体内分布不均匀,在脾中最高,尿中最低。在疑似氰化物中毒致死案件的法医学鉴定中,除采取心血外,还应全面正确采集分布量较高的脾、肺、肾和肝组织进行氰化物代谢物ATCA的定性定量分析。     

血痕中PGM_1亚型的检出及酶谱的保存方法

本文报告用等电聚焦方法,采用拉丁方设计,对血痕保存的温度、布质及含量,以及血痕中 PGM_1亚型检出时间进行了研究。保存在0℃(6个月)、4℃(2个月)、18℃(1个月)及30℃(3周)的6μL 血痕,PGM_1亚型均可检出。血痕的总量对 PGM_1亚型的检出时间也有一定的影响。不同布质对血痕中 PGM_1亚型的检出时间,无明显差异。另外,利用聚脂膜具有亲水膜面的特点,将 PGM_1原始酶谱贴附在聚酯膜上,可长期保存酶谱。