STR melting curve analysis as a genetic screening tool for crime scene samples

In this proof-of-concept study, high-resolution melt curve (HRMC) analysis was investigated as a postquantification screening tool to discriminate human CSF1PO and THO1 genotypes amplified with mini-STR primers in the presence of SYBR Green or LCGreen Plus dyes. A total of 12 CSF1PO and 11 HUMTHO1 genotypes were analyzed on the LightScanner HR96 and LS-32 systems and were correctly differentiated based upon their respective melt profiles. Short STR amplicon melt curves were affected by repeat number, and single-source and mixed DNA samples were additionally differentiated by the formation of heteroduplexes. Melting curves were shown to be unique and reproducible from DNA quantities ranging from 20 to 0.4 ng and distinguished identical from nonidentical genotypes from DNA derived from different biological fluids and compromised samples. Thus, a method is described which can assess both the quantity and the possible probative value of samples without full genotyping.     

Newborn screening in the genomics era

Newborn screening (NBS) exists in every state for the purpose of testing newborns for genetic medical conditions that can be severe, may be treatable, and are often not clinically evident at birth. While almost all of the diseases screened for in newborns have underlying genetic causes, NBS in its current form is performed not by testing for genetic mutations, but by testing for biochemical markers that indicate a disorder. The potential use of whole-genome newborn screening (WG-NBS) as an alternative to the current biochemical testing utilized for NBS would dramatically expand the quantity and types of information parents could learn from screening and is likely to have many implications, both positive and negative. As whole-genome sequencing (WGS) becomes more economical, it probably will be used for the purposes of NBS. However, such an expansion of NBS would contradict many of the principles that have historically guided public health screening programs and, if implemented without sufficient preparation, could result in insufficient infrastructure to accommodate the health care and data management needs that would arise. This article will first look at the past and present of NBS, then the rise of whole genome sequencing, before considering the challenges of WG-NBS, and will end with some thoughts on the path forward.     

Investigating the Refugee Health Disadvantage Among the U.S. Immigrant Population

Much health-disparities research focuses on race and ethnicity, but nativity has proved to be a crucial factor in explaining the immigrant health advantage. Foreign-born subgroups with certain immigration statuses, such as refugees, may have an initial disadvantage. Using nationally representative survey data, we explore differences in health outcomes by analyzing two visa category subgroups in the United States: refugees and nonrefugee immigrants. Our findings show that refugees have a significant disadvantage across multiple health outcomes. This suggests that current refugee health-screening practices should be changed to take into account broader issues, such as chronic disease and functional limitation.     

证据审查机制初探

近年来学界对于证据规则的研究已经相当深入，对于证据审查的相关机制却疏于关注。证据审查包括证据筛选和证据评价两个相对独立的环节。英美法系国家证据审查的“分离模式”与大陆法系国家证据审查的“融合模式”各有优劣。我国证据审查模式选择的基本思路是将证据筛选和证据评价适度分离、对证据筛选活动进行诉讼化改造以及完善证据评价机制。     

我国公务员激励机制人性假设之反思

中国历史上的封建官僚体制历来强调修身方能治国。新中国建立后,道德激励机制对政府官员的廉洁奉公行为曾产生过较大的影响,但随着计划经济向市场经济体制的转变,缺乏物质基础的道德激励渐显空乏无力。本文试图从传承已久的制度人性假设入手,对我国以道德人性假设为基石的公务员制度进行反思。     

Analysis of forensic SNPs in the canine mtDNA HV1 mutational hotspot region

A 60 bp sequence variation hotspot in the canine mitochondrial DNA hypervariable region 1 was evaluated for its use in forensic investigations. Nineteen haplotypes containing 18 single nucleotide polymorphisms were observed among laboratory-generated and GenBank-derived domestic dog sequences representing five regional localities in the U.S. Samples from the different localities were highly variable with the levels of intra-population variability being similar among the populations studied. AMOVA further confirmed that there was no significant genetic structuring of the populations. Assays using these haplotypes were robust, canid specific and portend a rapid method for correctly excluding individual dogs as noncontributors of forensic evidence. Species-specificity of the primers was confirmed by means of in-tube polymerase chain reaction of human and cat DNA and in-silico assessment of the genomes of several animal species. Breed-specific fragments were not detected among the common haplotypes but there is evidence that this assay may be capable of differentiating domestic dog, wolf, and coyote sequences.     

高效液相色谱法相对保留时间和峰高比在毒物筛选中的应用

本文用高效液相色谱法相对保留时间、２３０ｎｍ和２５０ｎｍ两个紫外检测的峰高比、荧光和２５０ｎｍ紫外检测的峰高比三个指标相结合对毒物进行筛选，３７种毒物区分率由单用保留时间区分的２４．３％提高到９４．６％，文中还考察了各种因素对相对保留时间和峰高比的影响。     

Screening Test for Shed Skin Cells by Measuring the Ratio of Human DNA to Staphylococcus epidermidis DNA

A novel screening method for shed skin cells by detecting Staphylococcus epidermidis (S. epidermidis), which is a resident bacterium on skin, was developed. Staphylococcus epidermidis was detected using real‐time PCR. Staphylococcus epidermidis was detected in all 20 human skin surface samples. Although not present in blood and urine samples, S. epidermidis was detected in 6 of 20 saliva samples, and 5 of 18 semen samples. The ratio of human DNA to S. epidermidisDNA was significantly smaller in human skin surface samples than in saliva and semen samples in which S. epidermidis was detected. Therefore, although skin cells could not be identified by detecting only S. epidermidis, they could be distinguished by measuring the S. epidermidis to human DNA ratio. This method could be applied to casework touch samples, which suggests that it is useful for screening whether skin cells and human DNA are present on potential evidentiary touch samples.     

Development of a Library Search‐Based Screening System for 3,4‐Methylenedioxymethamphetamine in Ecstasy Tablets Using a Portable Near‐Infrared Spectrometer

This is the first report on development of a library search‐based screening system for 3,4‐methylenedioxymethamphetamine (MDMA) in ecstasy tablets using a portable near‐infrared (NIR) spectrometer. The spectrum library consisted of spectra originating from standard substances as well as mixtures of MDMA hydrochloride (MDMA‐HCl) and diluents. The raw NIR spectra were mathematically pretreated, and then, a library search was performed using correlation coefficient. To enhance the discrimination ability, the wavelength used for the library search was limited. Mixtures of MDMA‐HCl and diluents were used to decide criteria to judge MDMA‐positive or MDMA‐negative. Confiscated MDMA tablets and medicinal tablets were used for performance check of the criteria. Twenty‐two of 27 MDMA tablets were truly judged as MDMA‐positive. Five false‐negative results may be caused by compounds not included in the library. No false‐positive results were obtained for medicinal tablets. This system will be a useful tool for on‐site screening of MDMA tablets.     

Screening for mental disorder using the UK national offender assessment system

Probation officers have large caseloads with high levels of psychiatric morbidity but receive minimal training in recognising/managing mental health problems. In the UK, there is no national screening procedure for mental illness among offenders that is considered effective. This study’s aim was to develop a screening system for mental/personality disorders using the Offender Assessment System. Seven screens for mental disorder were developed using items from assessments on 574 prisoners: alcohol misuse, drug dependence, antisocial personality disorder, psychopathy, learning difficulties, psychosis and severe mood disturbance. Internal validation showed that the screens performed well across accuracy estimates. Prevalence of mental disorders identified with the screens in test and validation samples was similar. However, the psychopathy and severe mood disturbance screens may be more effective in screening for true negatives. The screens are an economical method for prioritising mental health needs of the UK prison and probation population using routinely collected data.