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.     

Evaluation of two DNA/RNA co-extraction methods for body fluid identification in forensics

Body fluid identification has become a field of interest in forensic casework as it can add value to particular investigative scenarios. Identifying the source of the biological material is not always an upfront task using conventional methods; therefore, profiling of specific mRNA markers can provide the answer. The implementation of RNA based analyses in forensic casework must focus on the quality and sensitivity of methods, starting with nucleic acid extraction, and without loss of DNA for STR profiling. In this work, two methods for DNA and RNA co-extraction were tested and compared: a commercial kit that uses a spin, mini column methodology, and a quick, simple nucleic acid isopropanol precipitation based protocol. Both methods simultaneously extract DNA and RNA, crucial for forensic casework and were tested in semen samples. Nucleic acid quantifications as well as purity assessment ratios (OD₂₆₀/OD₂₃₀ and OD₂₆₀/OD₂₈₀) were obtained by both methods to infer on the use of extracts in downstream applications such as PCR. The performance of the two tested protocols was further evaluated by analyzing two semen mRNA specific markers, PRM1 and SEMG1. When compared to the commercially developed kit, results suggest that the literature adapted protocol allowed more carryover of contaminants absorbing at 230 nm and 280 nm as the purity ratios were below the accepted standard ranges. Negative results for mRNA profiling supported the QC results obtained by spectrophotometry. On the hand, PRM1 and SEGM1 were positive in RNA samples extracted with the commercial kit.     

A Rapid,Confirmatory Test for Body Fluid Identification,

We have developed a technique that allows investigators to confirm the presence of blood, semen, and/or saliva in a crime scene sample. It is a confirmatory test where multiple samples can be processed in less than an hour, and it is potentially portable, permitting samples to be processed at the crime scene. Samples at a scene giving a positive result can be further processed while those failing to do so may be ignored. There is a large and growing backlog of DNA evidence in the USA, slowing down the criminal justice system. This backlog has continued to grow despite an increase in the ability to process evidence faster. This technique uses quantum dot molecular beacons to test for tissue‐specific RNA species, identifying particular body fluids. We have demonstrated the tissue specificity of molecular beacons for blood, semen, and saliva.     

应确立口供相对任意性的采证规则

口供作为法定证据中的一种,在诉讼中具有真伪两面性,真实的口供有利于查禁犯罪,而虚假的口供却极易诱发冤假错案。民主法制先进的国家在对待口供问题上都确立了一系列的可采性规则,其中主要是自白的任意性规则。在我国只应确立口供的相对任意性规则,这主要是基于我国的基本国情和刑事诉讼的任务,也是基于诉讼的价值平衡决定的。确立口供相对任意性的采信规则具有一定价值,有利于发现案件真实,提高办案质量,使诉讼更加人性化。但存在影响口供相对任意性采信规则的一些因素,所以要保障口供相对任意性规则的实施。     

生物检材中吗啡类生物碱的LC-MS／MS分析

目的针对滥用药物分析鉴定实践中亟待解决的问题,开展LC-MS/MS分析生物检材中吗啡类生物碱的应用研究。方法满足不同的鉴定需要,分别建立血液、尿液、唾液和头发等生物检材的样品前处理方法,确定同时分析海洛因、单乙酰吗啡、吗啡、可待因、乙酰可待因、二氢可待因酮和氢吗啡酮等吗啡类生物碱的LC-MS/MS方法。将方法应用于实际案例。结果所建立的方法对吗啡类生物碱分离良好。尿液稀释法、尿液提取法和头发中吗啡的最低检测限(LOD)分别为10ng/mL、0.01ng/mL和0.01ng/mg。结论所建立的方法简便、快速、特异性强、灵敏度高。目标物中加入二氢可待因酮和氢吗啡酮扩大了方法的实用范围。     

益肾蠲痛口服液治疗绝经后骨质疏松症临床观察

目的 观察益肾蠲痛口服液治疗肾阳虚型绝经后骨质疏松症（postmenopausal osteoporosis,PMOP）的临床疗效。方法 将120例肾阳虚型PMOP患者随机分为治疗组和对照组,每组60例。两组患者均口服钙尔奇,治疗组患者加服益肾蠲痛口服液,对照组患者加服骨康口服液,疗程均为12个月,随访24个月。治疗前后及随访时,分别采用视觉模拟评分法（visual analogue scale,VAS）评价腰背疼痛,采用双能X线检测骨密度（bone mineral density,BMD）;并观察两组中医证候疗效及脆性骨折发生情况。结果 治疗后,两组VAS评分均较治疗前显著降低（P<0.01）;腰椎、股骨颈、Ward三角BMD均较治疗前显著上升（P<0.01）;随访时,治疗组VAS下降值及腰椎（L2—4）、股骨颈、Ward三角BMD升高值均显著大于对照组（P<0.01）。两组中医证候疗效及脆性骨折复发率比较,差异均无统计学意义（P>0.05）。结论 益肾蠲痛口服液可减轻PMOP患者腰背疼痛,提高BMD,改善中医症状,防止脆性骨折复发,在减轻腰背疼痛和提高BMD方面较对照药具有明显优势。     

Oral fluid collection: The neglected variable in oral fluid testing

The potential to use oral fluid as a drug-testing specimen has been the subject of considerable scientific interest. The ease with which specimens can be collected and the potential for oral fluid (OF) drug concentrations to reflect blood–drug concentrations make it a potentially valuable specimen in clinical as well as forensic settings. However, the possible effects of the OF collection process on drug detection and quantification has often been over looked. Several studies have documented that drug-contamination of the oral cavity may skew oral fluid/blood drug ratios and confound interpretation when drugs are smoked, insufflated or ingested orally. OF pH is predicted to have an effect on the concentration of drugs in OF. However, in a controlled clinical study, the effect of pH was less than that of collection technique. Mean codeine OF concentrations in specimens collected a non-stimulating control method were 3.6 times higher than those in OF collected after acidic stimulation. Mean codeine concentrations were 50% lower than control using mechanical stimulation and 77% of control using commercial collection devices.Several factors should be considered if a commercial OF collection device is used. In vitro collection experiments demonstrated that the mean collection volume varied between devices from 0.82 to 1.86 mL. The percentage of the collected volume that could be recovered from the device varied from 18% to 83%. In vitro experiments demonstrated considerable variation in the recovery of amphetamines (16–59%), opiates (33–50%), cocaine and benzoylecgonine (61–97%), carboxy-THC (0–53%) and PCP (9–56%). Less variation in collection volume, volume recovered and drug recovery was observed intra-device. The THC stability was evaluated in a common commercial collection protocol. Samples in the collection buffer were relatively stable for 6 weeks when stored frozen. However, stability was marginal under refrigerated conditions and poor at room temperature. Very little has been published on the efficacy of using IgG concentration, or any other endogenous marker, as a measure of OF specimen validity. Preliminary rinsing experiments with moderate (50 mL and 2 × 50 mL) volumes of water did not reduce the OF IgG concentration below proposed specimen validity criteria. In summary, obvious and more subtle variables in the OF collection may have pronounced effects on OF–drug concentrations. This has rarely been acknowledged in the literature, but should to be considered in OF drug testing, interpretation of OF–drug results and future research studies.     

公安英语口语语篇分析

公安英语口语主要是指公安人员在实施涉外管理中所用到的英语口语。按照公安人员接触外国人的类型把公安英语口语划分为两类,即公安人员接触非违法外国人时所用的口语和公安人员接触违法外国人时所用的口语。在衔接手段、主位推进模式和语域一致三个方面,这两类公安英语口语语篇有其特点和规律,公安院校提高英语口语教学质量和在职外事公安人员英语口语能力时必须注意这些特点和规律。     

GC/MS研究海洛因代谢物在吸毒者体内的分布

应用GC／MS－SIM测定了海洛因代谢物吗啡在两例海洛因延缓死亡者的体内分布,并分析了收集到的7例案子的毛发（头发、腋毛和阴毛）中6-单乙酰吗啡和吗啡含量。生物检材和毛发经酸水解、提取、醋酸酐或双（三甲基硅基）三氟乙酰胺（BSTFA）衍生化,然后进行GC／MS-SIM分析。结果表明尿、胆汁和肝脏是判定死者是否曾使用海洛因的最佳检材;毛发分析与生物检材相比有其独特的优点,可提供数月甚至数年的用药情况。为公安司法机关打击吸毒、惩治犯罪提供更可靠、有效的证据。     

Human semen stain analysis in casework sample by HRM-qPCR

Determining the biological origin of body fluid evidence from crime scenes is extremely important for criminal investigation, especially in sexual assault cases. In Brazil, sexual crimes still present low-resolution rates, where approximately 8% of cases are judged. The determination of the presence of semen in samples from crime scenes as a test prior to DNA analysis is a mandatory requirement in forensic analysis and can help to better understand the dynamics of the event. This report aims to present the methodological strategy used in a criminal case of a home invasion where a t-shirt containing visible stains similar to human semen was found at the site. Convencional tests to detect the presence of PSA and sperm cells were performed on the fabric cutouts which showed negative results. We then processed the fabric samples for genetic analysis after two-years-storage, where were performed automated method for the genetic material isolation (QIAcube, Qiagen). The Real-time PCR analysis were carried out using the SOLIScript 1-step SolisGreen (SolisBiodyne) kit, with specific primers to the TGM4 (Transglutaminase 4) gene, in the Rotor Gene Q-5Plex HRM equipment (Qiagen). The results obtained for the melt curve indicated the presence of human semen in the analyzed samples. After the HRM-qPCR assay we also analyzed the a-STR and Y-STR markers. All the results were useful for the criminal process, which led to the identification of the author of the crime.