Molecular cloning and immunohistochemical localization of rat dipeptidyl peptidase III

Dipeptidyl peptidase III (DPP III) was purified to homogeneity from rat liver cytosol. The calculated molecular weight of the purified enzyme was 82845.6 according to TOF-MS, and 82000 on non-denatured PAGE and 82000 on SDS-PAGE in the absence or presence of beta-ME. These findings suggest that the enzyme assumes a monomeric form in rat liver cytosol. The enzyme rapidly hydrolyzed the substrate Arg-Arg-MCA and moderately hydrolyzed Ala-Arg-MCA in a pH range of 7. 5 to 9.5. The K(in), K(cat) and K(cat)/K(m) values of DPP III at optimal pH (pH 8.5) were 290 microM, 18.0 s(-1) and 6.21x10(4) s(-1)M(-1) for Arg-Arg-MCA and 125 microM, 4.53 s(-1) and 3.62x10(4) s(-1)M(-1) for Ala-Arg-MCA, respectively. DPP III was potently inhibited by EDTA, 1,10-phenanthroline, DFP, PCMBS, NEM, beta-ME and iodoacetamide. Furthermore, we screened a rat liver cDNA library using affinity-purified anti-rat DPP III rabbit IgG, and we determined the cDNA structure and deduced the amino acid sequence. The cDNA designated as lambdaRDIII-11 is composed of 2640 bp of nucleotides in length and encodes 738 amino acids in the coding region. Although the enzyme has a novel zinc-binding motif, HEXXXH in structure, DPP III is thought to belong to family 1 in clan MA in the metalloprotease kingdom. These findings suggest that DPP III is a metalloprotease that is probably regulated by SH modification. The DPP III antigen was extensively detected in the cytosol of various rat tissues by the immunohistochemical examination of the protein.     

SMCY性别特异融合抗原的克隆表达及其抗体制备

目的利用蛋白检测的快速性优势,研究不同性别在SMCY抗原氨基酸序列的差异,筛选出特异性氨基酸序列,并克隆表达性别特异融合抗原,制备相应抗体,建立一种快速鉴别法医物证性别的方法。方法通过对人SMCY和SMCX进行序列分析,发现了三段差异片段,采用搭桥PCR方法获得差异片段全长基因,连接入p ET-28a载体进行原核表达,用Ni柱纯化后的性别特异融合抗原免疫制备多克隆抗体,用ELISA法和western blot检测SMCY多抗与抗原的反应特异性,制作胶体金试纸条检测样本。结果筛选出具有性别特异性的氨基酸序列,获得SMCY性别特异融合抗原,成功制备出多克隆抗体及胶体金试纸条。结论获得SMCY性别特异融合抗原具有很好的抗原活性,制备的多克隆抗体可以与抗原特异性地结合,用于性别鉴定。     

血中安定及其代谢物的酶水解研究

目的考察木瓜蛋白酶水解血中安定及其代谢物蛋白结合物的酶解条件,提高安定的提取率。方法采用正交试验确定酶解的最优条件,检材经蛋白酶水解,固相萃取后,应用LC-MS／MS方法进行检测,运用保留时间和MRM（多离子反应监测）方式来对血中安定及其代谢物进行定性定量分析。结果安定、去甲安定、去甲异安定、羟基安定和去甲羟基安定的最佳酶解条件分别为55℃,2．5h,pH7．0,8000U;50℃,1h,pH7．5,8000U;50℃,1h,pH7．5,8000U;50℃,1．5h,pH7．5,8000U;50℃,1．5h,pH7．5,8000U。结论酶水解后的血液中安定及其代谢物检出量明显增加。     

抗人转铁蛋白单链抗体的研制及部分性能研究

研制人转铁蛋白的单链抗体。以纯化人转铁蛋白免疫小鼠,制备小鼠脾脏 mRNA,RT-PCR 扩增重轻链可变区基因;Linker 连接及引入 Sfi Ⅰ和 NotⅠ酶切位点构建单链抗体基因;同载体 pCANTAB 5E 连接,转化 E.coliTG1细胞,以 M13K07挽救制备噬菌体抗体呈现文库,筛选抗原阳性重组噬菌体粒子(Panning);感染 E.coliHB2151菌株,制备可溶抗体并检测其性质;测定抗体基因序列并分析同源性及结构特征。制备出4株分泌抗人转铁蛋白可溶抗体的 E.coli HB2151菌株。抗体基因只由小鼠抗体的轻重链可变区基因构成,开放读码,无终止子,并紧接一末尾为一琥珀终止密码的 E 末端序列,其对应氨基酸序列 V_H 和 V_L 部分均遵从抗体可变区特征。实验证明,可把基因工程抗体技术应用于法医血清学,以制备新型抗体试剂。     

Decomposition chemistry of human remains: a new methodology for determining the postmortem interval

This study was conducted to characterize the chemistry associated with the decomposition of human remains with the objective of identifying time-dependent biomarkers of decomposition. The purpose of this work was to develop an accurate and precise method for measuring the postmortem interval (PMI) of human remains. Eighteen subjects were placed within a decay research facility throughout a four-year time period and allowed to decompose naturally. Field autopsies were performed and tissue samples were regularly collected until the tissues decomposed to the point where they were no longer recognizable (encompassing a cumulative degree hour (CDH) range of approximately 1000 (approximately 3 weeks)). Analysis of the biomarkers (amino acids, neurotransmitters, and decompositional by-products) in various organs (liver, kidney, heart, brain, muscle) revealed distinct patterns useful for determining the PMI when based on CDHs. Proper use of the methods described herein allow for PMIs so accurate that the estimate is limited by the ability to obtain correct temperature data at a crime scene rather than sample variability.     

The chemical interconversion of GHB and GBL: forensic issues and implications.

In this work, the interconversion of GHB and GBL in a variety of aqueous media was studied. The effects of solution pH and time were determined by spiking GHB or GBL into pure water and buffered aqueous solutions, and determining the GHB and GBL contents at various time intervals. The degree of GBL hydrolysis to GHB was determined for several commercial aqueous-based GBL products, and further studied as a function of time. The effects of temperature and time were also determined for five commercial beverages spiked with GHB or GBL. GHB and GBL contents were determined using high performance liquid chromatography (HPLC). GHB and/or GBL confirmations were made using gas chromatography-mass spectrometry (GC-MS) and/or infrared spectroscopy (IR). Solution pH, time, and storage temperature were determined to be important factors affecting the rate and extent of GBL hydrolysis to GHB. Under strongly alkaline conditions (pH 12.0), GBL was completely converted to GHB within minutes. In pure water, GBL reacted to form an equilibrium mixture comprising ca. 2:1 GBL:GHB over a period of months. This same equilibrium mixture was established from either GHB or GBL in strongly acidic solution (pH 2.0) within days. A substantial portion of GBL (ca. 1/3) was hydrolyzed to GHB in aqueous-based GBL products, and in spiked commercial beverages, after ambient storage for a period ranging from several weeks to several months. Heat increased and refrigeration decreased the rate of GBL hydrolysis relative to ambient conditions. These studies show that hydrolysis of GBL to GHB does occur in aqueous-based solutions, with samples and time frames that are relevant to forensic testing. Implications for forensic testing and recommendations are discussed.     

Determination of dimethoate in blood and hemoperfusion cartridge following ingestion of formothion: a case study

A 57-year-old male who had ingested not more than 22 g of formothion was semicomatose on admission to hospital, approximately 1.5 h after ingestion. Dimethoate, a hydrolyzed formothion, was found in blood samples collected from the patient and in the charcoal column in the direct hemoperfusion cartridge which was used 6 to 7.5 h after ingestion. It was extracted and purified by Extrelut column extraction. A gas chromatograph, equipped with a flame photometric detector and a gas chromatograph-mass spectrometer, were used to detect and confirm the presence of dimethoate. The blood dimethoate concentrations which were taken approximately 1.5 and 6 h after ingestion were 21.4 and 12.7 micrograms/g, respectively. A blood dimethoate concentration of 21.4 micrograms/g would appear to indicate a high level of formothion intoxication. The total amount of dimethoate found in the charcoal column used was 15 mg.     

H-抗原缺乏分泌型个体FUT1及FUT2等位基因的分子基础

一例H-缺乏分泌型个体被发现。其血清学表现为：红细胞上无A、B、H抗原；唾液中有B、H抗原分泌；血清中检出了抗A抗体。推测其为类孟买OHmB型。在该个体FUT1等位基因编码区上发现两处单碱基突变（T460C、G1042A）。这两个点变异，将导致两个氨基酸的置换（Y154H、E348K）。同时也破坏了限制性内切酶RsaⅠ和AvaⅠ的作用部位。用PCR－RFLP法可检出此两种变异。用PCR－RFLP法证实，该个体为T460C、G1042A变异的纯合子。在136例随机个体中未能查出上述变异。将该FUT1基因转染COS－7细胞未能检出α2－FUT活性及证实H抗原的表达。该个体的FUT2基因与野生型一致。     

Liver damage in rats during acute carbon monoxide poisoning

Plasma leucine aminopeptidase (LAP) levels and respiration rates of isolated liver mitochondria were studied in carbon monoxide (CO)-poisoned rats sampled at respiratory arrest. An increase in LAP levels paralleled a decrease in the respiratory control ratio and the $\text{ADP}\text{O}$ ratio. The results suggest that the damage to mitochondria closely correlates with the liver damage in rats during acute CO poisoning.     

HPLC-MS法测定鲜鱼中河豚毒素

目的建立用液相色谱-质谱（HPLC-MS）法测定鲜鱼中河豚毒素含量的方法。方法样品经粉碎、酸性水溶液提取、蛋白酶解、石油醚脱脂、有机溶剂甲醇沉淀、固相萃取柱净化后,以液相色谱-质谱法测定,外标法定量。结果鱼肉和鱼肝中河豚毒素在0.10～10 mg/kg范围内呈良好线性关系,相关系数分别为0.9998和0.9991,平均回收率为94.6%~102%,相对标准偏差RSD小于6.6%,方法的最低检出限为0.03 mg/kg。结论该方法操作简便、快速,为饮用水及水产品中河豚毒素的检测、相关的司法鉴定等提供了准确有效的科学依据。     

New detection method for ribonuclease 2 (RNase 2) using immunoblotting with specific antibody

A ribonuclease (RNase) was isolated from the urine of a 35-year-old male and purified to electrophoretic homogeneity. The enzyme was tentatively designated RNase 2. A rabbit antibody produced by injection of the purified RNase 2 was able to distinguish RNase 2 from another type of RNase coexisting in body fluids. With this antibody it was possible to detect RNase 2 isozymes in human serum and urine without difficulty using isoelectric focusing or sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by immunoblotting. Both RNase 2 in serum and urine seemed to exist in multiple forms with regard to their molecular masses and pI values. This technique may prove to be useful in genetic and forensic studies of RNase polymorphism.     

Immunologic characterization of human seminal leucine aminopeptidase (LAP) and its medicolegal use

A new method for identification of seminal stains is described, based on the immunologic demonstration of leucine aminopeptidase (LAP), which is extremely abundant in human semen and specific for the prostate as well as semen. An antiserum against human seminal plasma was obtained by repeated immunization of rabbits with seminal plasma and Freund's adjuvant. Ouchterlony's double immunodiffusion test and Culliford's precipitin electrophoresis were performed to demonstrate specific proteins of seminal plasma. LAP activity was visualized with L-leucyl-beta-naphthylamide as substrate and with Fast Garnet GBC as coupler. The immunologic analysis of LAP produced two precipitin lines with enzyme activity. One was observed in kidney, jejunum, pancreas, prostate, as well as in semen, and was completely absorbed with kidney homogenates. The other was found only in semen and the prostate and was not absorbed with kidney homogenates. When the anti-seminal plasma serum absorbed with the kidney was used, the semen-specific LAP could be demonstrated by precipitin electrophoresis only in seminal stains stored for up to 2 months, whereas it was not demonstrated in stains from other human body fluids. By means of precipitin electrophoresis the detection of the semen-specific LAP was possible at semen dilutions of up to 1:32. The method described here greatly enhances the value of semen identification and is quite recommendable for the examination of stains in medico-legal practice.     

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.     

Simple and Sensitive Method for Identification of Human DNA by Allele-Specific Polymerase Chain Reaction of FOXP2

Abstract:  The forkhead box P2 ( FOXP2 ) gene is specifically involved in speech and language development in humans. The sequence is well conserved among many vertebrate species but has accumulated amino acid changes in the human lineage. The aim of this study was to develop a simple method to discriminate between human and nonhuman vertebrate DNA in forensic specimens by amplification of a human-specific genomic region. In the present study, we designed an allele-specific polymerase chain reaction (PCR) using primers to amplify smaller than 70-bp regions of FOXP2 to identify DNA as being of human or nonhuman, including ape, origin. PCR amplification was also successfully performed using fluorescence-labeled primers, and this method allows a single PCR reaction with a genomic DNA sample as small as 0.01 ng. This system also identified the presence of human DNA in two blood stains stored for 20 and 38 years. The results suggested the potential usefulness of FOXP2 as an identifier of human DNA in forensic samples.     

A sandwich enzyme immunoassay for human pancreatic elastase III

To develop a method for the determination of pancreas injuries using a pancreas-specific antigen as a marker, human elastase III was purified from the pancreas by chromatographic methods. A rabbit anti-human elastase III antibody was prepared, and this antibody was confirmed using immunoblotting to react only with elastase III among proteins from the pancreas. A sensitive sandwich enzyme immunoassay for human elastase III was developed. The detection limit for human elastase III was 0.3 pg (10 amol) per assay. Proteins extracted from the pancreas showed the strongest response, whereas reactions of the other organs were less than the detection limit. These results suggest that a sandwich enzyme immunoassay for human elastase III is useful for the determination of pancreas injury.     

体内痕量乌头碱的高相液相色谱测定

<正> 乌头碱是乌头属植物中所含的二萜双酯型生物碱类中的一种,成人口服纯品致死量仅约5mg,由乌头属植物引起的中毒与死亡屡见报导但一直缺乏较好的检测方法,使中毒后体内乌头碱分布与分解规律的研究难以进行,也给这类中毒案件的法医学鉴定带来一定困难。近年来应用HPLC分离检测生药中乌头碱类生物碱的方法已有报导。本文应用HPLC     

人精浆中A型血型物质的分离纯化及理化性质研究

应用凝胶过滤、阴离子高速液相色谱及免疫亲合层析方法成功地从A型分泌型人精浆中分离、纯化了具有A型活性的精浆血型物质（SPBGS－A）。理化分析结果表明：SPBGS－A为表现单一A型活性、分子量不均一的糖蛋白。其分子量约为100KD；等电点在pH2．7～3．5之间；糖含量占72．5％；蛋白质含量占24．2％。共检出了16种氨基酸成分，其中苏氨酸、丝氨酸及脯氨酸的含量约占50％。经与其它水溶性血型物质在化学组成上进行比较，提示其可能具有一定的器官特异性。     

Internal Validation of Human Mitochondrial DNA Quantification Using Real‐Time PCR

The quantity of mitochondrial DNA (mtDNA) template added for amplification and subsequent dye terminator reactions is critical for obtaining quality sequence data. Validation of a human mtDNA real‐time quantitative PCR (qPCR) assay demonstrated its high degree of reproducibility and precision as well as an extremely sensitive threshold of detection (0.0001 pg/μL or approximately six human mtDNA copies/μL). A study of 35 nonprobative bone and teeth evidence samples revealed that 20 pg of mtDNA template is recommended for successful HV1 and HV2 sequence analysis; however, as little as 0.013 pg can generate a full mtDNA profile when using enhanced amplification reactions. The assay can also detect PCR inhibition and is useful for identifying samples that may benefit from re‐purification. Overall, the assay is an excellent method to quantify mtDNA and is useful for determining the best analytical approach for successful sequencing.     

Detection of drugs using XAD-2 resin. II:Analysis of liver in medical examiner's cases

Liver tends to concentrate drugs in quantities generally higher than those found in blood or other body compartments. This fact as well as the general availability of liver in postmortem cases makes it an important specimen for comprehensive toxicologic investigation. A scheme for the analysis of liver for drugs with tissue hydrolysis, XAD-2 resin extraction, and TLC has been developed and the parameters affecting recovery have been studied. The hydrolysis of liver specimens at various pH conditions resulted in an improved recovery for morphine by using pH 2 (2N hydrochloric acid). Recoveries of barbiturates, codeine, and meperidine were essentially the same at pH 2 and pH 3. A considerable loss (22 to 55%) was observed for four drugs (pentobarbital, morphine, codeine, and meperidine) as a result of drug binding to the tissue pellets during the process of centrifuging the liver homogenates. This method is recommended as a comprehensive screening procedure for drugs in liver tissue. For quantitative purposes, however, it is necessary to determine a correction factor for all the losses occurring at the various steps of the procedure. This procedure compared favorably with other procedures for liver analysis reported in literature.     

A validation study for the extraction and analysis of DNA from human nail material and its application to forensic casework.

A validation study was conducted to demonstrate that deoxyribonucleic acid (DNA) could be successfully extracted from human nail material and analyzed using short tandem repeat (STR) profiling and/or mitochondrial DNA (mtDNA) sequencing. This study involved the development of a DNA extraction protocol that includes a cleaning procedure designed to remove external contaminants (e.g., biological, chemical). This protocol was used to test human nail material that had been soaked in whole blood from a second donor and coated with gold-palladium to simulate scanning electron microscopic analysis. The results showed no indication of a mixture and were consistent with that of the nail donor. Fresh human nail material usually yielded both STR profiles and mtDNA sequence information; however, aged human nail material (approximately eight years old) yielded only mtDNA sequence information. Upon completion of the validation study, the extraction protocol was used for the analysis of a torn fingernail fragment recovered from the scene of a violent homicide in 1983. A partial STR profile and mtDNA sequence information indicated that the fingernail fragment was excluded as originating from the suspect and was, in fact, consistent with originating from one of the victims.