Use of thin-layer chromatography for detection of 11-nor-9-carboxy-delta9-tetrahydrocannabinol in the urine

A simple method of thin-layer chromatography for detection of 11-nor-9-carboxy-delta9-tetrahydrocannabinol in biological material (urine) can be used in chemicotoxicological laboratories and chemical departments of forensic-medical expert examination without special facilities.     

Use of gold nanoparticles as molecular intermediates for the detection of fingermarks

Among the numerous methods dedicated to the detection of latent fingermarks, the MultiMetal Deposition (MMD) offers, as a main advantage, the ability to be applied on a great number of porous and non-porous surfaces, e.g., paper, plastic, glass, latex, and polystyrene, even if wetted. While considered as a powerful and sensitive technique, MMD is often neglected, mainly because of operational limitations (siliconized vessels, restrictive pH domain, numerous immersion baths, ...). In this contribution, we propose a modification of the standard MMD method so that the procedure is simplified with a number of baths reduced to a minimum. To reach this goal, it was necessary to obtain a fully operable solution which could detect fingermarks in a single step. We chose to take advantage of the molecular recognition mechanisms by functionalizing the gold nanoparticles with a molecular host able to bind itself to gold while keeping the ability to trap molecules in solution. Cyclodextrins were chosen as they can be easily chemically modified to offer gold-binding abilities. Moreover, they are widely used as hosts for various molecular guests (dyes, luminescent molecules, ...). This new formulation has been tested on three different surfaces to attest the feasibility of this strategy. Successful results were obtained with detailed fingermarks offering a good contrast to allow their identification without the need to enhance the results (such as with a physical developer). If the new formulation behaves very similarly to the old one, in terms of experimental conditions, it offers the additional advantage to develop fingermarks after immersing them in only one bath. The goal is thus reached.     

生物检材中有机磷农药的检验概述

从有机磷农药的性质、生物检材中有机磷农药的提取净化和分析检测等方面概述了生物检材中有机磷农药的检验研究现状。     

Use of a solid absorbent and an accelerant detection canine for the detection of ignitable liquids burned in a structure fire

ABSTRACT: Ignitable Liquid Absorbent^™ (ILA), a commercial solid absorbent intended to assist fire scene investigators in sample location and collection, has been field tested in three separate room fires. The ability of the ILA to detect and absorb different amounts of gasoline, odorless paint thinner, and camp fuel on two different substrates after a full-scale burn was assessed against results from an accelerant detection canine and laboratory analysis using gas chromatography-mass spectrometry (GC-MS). The canine correctly alerted on most of the panels that contained an ignitable liquid after the fire, while the ILA indicator dye failed to indicate in the presence of gasoline and camp fuel. GC-MS results for ignitable liquid residue from each panel and from the ILA showed that ILA absorbed odorless paint thinner and camp fuel from most of the test panels, but failed to absorb gasoline from the panels on which gasoline was confirmed to be present.     

Nails as useful materials for detection of methamphetamine or amphetamine abuse

Methamphetamine and amphetamine could be demonstrated in nail clippings obtained from methamphetamine users by sensitive gas chromatography/chemical ionization mass spectrometry with N-methylbenzylamine as an internal standard. The methamphetamine levels in fingernails were comparable to those in hair. Both stimulants were more concentrated in toenails than in fingernails. The detection of methamphetamine and amphetamine in nails provides an alternative informatian to that in hair on their past abuse.     

Optimization and initial evaluation of 1,2-indandione as a reagent for fingerprint detection

1,2-Indandione has been used to develop fluorescent fingerprints on porous materials such as paper. The compound reacts with amino acid residues to produce highly fluorescent fingerprint ridges. An optimized formulation and treatment protocol for using the reagent is presented here. The reagent is applied as a solution in HFE7100 containing acetic acid and ethyl acetate. Treated articles are heated at 100 degrees C for 10 min at ambient humidity and stored in the dark before recording the fingerprints using fluorescence photography or digital imaging. Photodecomposition of the fluorescent fingerprints has been observed. Storage in the dark reduces degradation, extending the lifetime of the fingerprints. Other chemical methods to stabilize the fingerprints proved unsuccessful. Comparisons of the performance of 1,2-indandione with DFO in CFC113 performed on a limited range of substrates indicated that the reagent might be an effective method for the development of latent fingerprints despite the new reagent producing less intense fluorescence.     

The use of enzymatic hydrolysis for isolation of barbituric acid derivatives from blood (as exemplified by phenobarbital and barbamyl)

Modern isolation techniques by direct extraction with organic solvents or after protein precipitation by various sedimenting or salting-out agents are characterized by low efficiency and do not permit to liberate derivatives of barbituric acid from their complexes with blood proteins. The use of enzymatic hydrolysis makes it possible to break bonds between barbiturates and protein and thereby improve the efficiency of isolation. We performed enzymatic hydrolysis of the model phenobarbital-blood and barbamyl-blood complexes with the use of trypsin, pepsin, chymotrypsin, and papain. The degree of phenobarbital extraction with trypsin and barbamyl was estimated at 62.1 +/- 1.2% and 75.1 +/- 1.6% respectively; in other words, it was 32.7 +/- 1.0% and 51.1 +/- 1.0% higher than that achieved by traditional methods. Certain validation characteristics of the new method are presented.     

Heart fatty acid binding protein as a marker for postmortem detection of early myocardial damage

Depletion of heart fatty acid binding protein (H-FABP) from cardiomyocytes with varying post-ischemia intervals was studied in acute myocardial infarction (AMI) model of rat, and 22 human autopsy cases were studied with streptavidin-peroxidase conjugated method (S-P). It was observed that as early as 15 min after ischemia, the depletion of H-FABP could be detected in model rats. With the ischemic time prolonged, the depletion of H-FABP was more and more evident. In all human cases with myocardial infarction, absent H-FABP staining could be found in infarcted area. And in some suspected early myocardial infarction cases, depletion of H-FABP staining could be demonstrated in areas that showed normal hematoxylin-eosin (HE) staining. The blood samples from model rats before ligation, at varying post-ischemia intervals and various postmortem time were measured for plasma concentration of H-FABP with enzyme-linked immuno-sorbent assay (ELISA) method. At 15 min after myocardial ischemia, the concentration of H-FABP was 4 times higher (546.0+/-85.3 microg/l) than that of the baseline level (103.7+/-94.1 microg/l). With the continuation of ischemic time, the concentration of H-FABP increased and peaked at 4 h (1953.5+/-405.3 microg/l), then decreased. The plasma concentration of H-FABP decreased slightly with postmortem time, but was still significant higher at any postmortem intervals than that of baseline level within 48 h after death. The results suggest that H-FABP staining can detect very early ischemic damages in human myocardium and the elevated plasma concentration of H-FABP in rat was an indicator of AMI, which was not affected by autolysis.     

蛇毒检测方法的实验研究

目的建立系统的蛇毒检测方法。方法通过对3种常见蛇毒样品检测,确定用ELISA法检测蛇毒的最适条件。结果本研究所建立的ELISA蛇毒检测法灵敏度为3.9ng/ml;交叉实验结果显示,该方法特异性高,只有个别蛇毒存在交叉反应;样本从采集到检出时间在1h40min之内;动物实验显示,半致死量中毒家兔的血液蛇毒检测在中毒后48h内有效,中毒死亡家兔的血液蛇毒检测在死后72h内有效。结论所建立方法灵敏、准确、快速、简便,是一种可靠的蛇毒检测法。     

A review of postmortem alcohol detection as a diagnostic test for substance abuse disorders in suicides

To assess the role of toxicologic detection of alcohol to diagnose substance abuse disorders in suicides, the author reviewed suicide studies with both comprehensive toxicologic and diagnostic data. The sensitivity of alcohol detection to diagnose alcohol and substance abuse disorders in suicides was low in all studies (range, 39%-42%), and the specificity was 80%-95%. A higher cutoff level for alcohol did not increase diagnostic performance. The author concludes that toxicologic detection of alcohol is not a reliable indicator of alcohol and substance abuse disorders in suicides because of the high rate of false-negatives. Most of the suicides with positive alcohol detection seem to suffer from chronic substance abuse problems. The role of intoxication is difficult to assess because of methodologic problems.     

Identification of human semenogelin in membrane strip test as an alternative method for the detection of semen

Semenogelin (Sg), a protein originating in the seminal vesicles and a substrate for prostate specific antigen (PSA or p30), is a useful marker for the identification of semen. And detection of Sg has been available commercially in a membrane test recently. PSA is commonly used to detect semen in forensic significant samples taken from sexual assault cases. The strip PSA test has been available commercially from various manufacturers for many years. In this study, we evaluated two immunochromatographic membrane tests, one for Sg and the other for PSA by analyzing human semen, other human bodily fluids/materials including urine, blood, saliva, sweat, breast milk, vaginal secretion and fecal materials, semen from various animals and forensic casework samples. The data demonstrate that both Sg and PSA strip tests provide rapid and sensitive method for identification of seminal plasma. These results show that the immunochromatographic method for Sg detection is useful for the identification of seminal plasma in forensic samples, an alternative to the method for PSA detection.     

Colonization of diatoms in and on porcine bone substrate and considerations of diatom ecology for forensic science

The presence of diatom algae in bone marrow has been used as forensic evidence of drowning for several decades; however, these studies are based on known or suspected recent drowning events. This study addresses the potential for diatoms to enter the bone marrow of skeletal remains, that is, de-fleshed long bones post-mortem. In laboratory and field experiments, bones were either inflicted with two access points by a cut and acid pitting or left intact. The bones were submerged in water for at least 1 week and up to 3 months. Samples of the bone surface and marrow were inspected for diatoms. The analysis considered the time required for diatoms to enter marrow and whether genus characteristics like size or mobility affect entry. The presence of an access point influenced diatom entry in that bones without an introduced access point had zero to one diatom present in the marrow, whereas a bone with an access point had >150 diatoms present in the marrow. The results of both laboratory and field phases suggest that diatoms will reliably colonize bone in as quickly as 1 week, establishing and maintaining communities for at least 3 months. However, the bone surface assemblages differ from the source community. Bone marrow displayed even more restrictive access to diatom colonization, resulting in communities dominated by small raphid diatoms. Based on these findings, we suggest some caveats on the use of diatoms as trace evidence in forensic science with recommendations for future avenues of research.     

Analysis of carbohydrate-deficient transferrin (CDT) in vitreous humour as a forensic tool for detection of alcohol misuse

Analysis of carbohydrate-deficient transferrin concentration in vitreous humour (VH-CDT) has recently been demonstrated to be useful for diagnosis of pre-mortal alcohol misuse, but more knowledge considering possible methodological problems is warranted. In a forensic sample we examined the stability of VH-CDT during laboratory handling as well as the possible affection of time-dependent changes of total transferrin concentrations in vitreous humour (VH-Transferrin) in the dead body on VH-CDT as indicator of alcohol misuse. By use of a commercial assay designed for serum analysis (CDTect) it was possible to measure VH-CDT with high precision, and detectable amounts were found in 20 of 21 alcoholics and in two of seven controls. The compound was demonstrated to be stable in vitreous humour during laboratory handling, since the results of the first analysis were well reproducible after 4 months storage of the specimens (rs=0.86, P=0.0002). Transferrin concentrations in vitreous humour (VH-Transferrin) correlated to the estimated time since the individual last time had been alive before the forensic examination (rs=0.57, P<0.005). However, in this small sample the discriminating property of VH-CDT as indicator of alcohol misuse was not decisively affected, whether or not the variables "VH-Transferrin" and "estimated time since the individual last time had been alive" were considered in a multivariate logistic regression analysis (minor change in the beta-coefficient from 0.57 to 0.52, P=0.086). We conclude that CDT is stable in vitreous humour during proper laboratory handling and that detection of VH-CDT is primarily a marker of alcohol misuse before death. However, the results of this study do not exclude that time-dependent changes of VH-Transferrin, possibly affecting VH-CDT, may occur in the dead body. VH-CDT analysis should thus, at present, be restricted to cases with rather short post-mortal time interval.     

未上升为权利的法益——合理使用的性质界定及立法建议

目前学界对于合理使用的性质界定,大致有三种观点:"权利限制说"、"侵权阻却说"和"使用者权利说",这三种学说均有明显的不足之处.合理使用实际上是一种未上升为权利的法益,对其保护应采取一般条款加具体规则的立法模式.对此分析的基础上,对我国<著作权法>第22条关于合理使用的规定提出了修改建议.     

抗体芯片竞争抑制法检测尿液中吗啡含量

目的建立抗体芯片竞争抑制法检测尿液中吗啡含量的方法。方法将吗啡单克隆抗体固定在用琼脂糖包被的芯片上,与含有吗啡的尿液检材和Cy3荧光标记-吗啡-BSA复合物进行竞争抑制反应,共聚焦扫描仪采集反应图像并进行分析。结果吗啡单克隆抗体及Cy3-吗啡-BSA的最佳浓度是31.25μg/m l、12.50μg/m l,检测线性范围0.01~10ng/m。回收率在91.2%~109.2%之间,尿液检测限为0.02ng/m l。甲基苯丙胺、安非他明与吗啡抗体之间无交叉反应,与可待因有一定的交叉反应。结论抗体芯片竞争抑制法检测尿液中的吗啡含量具有灵敏度高,特异性好、操作简单、高通量等优点,可用于法医毒物检测、戒毒效果监测。