A xeroderma pigmentosum complementation group A related gene: confirmation using monoclonal antibodies against the cyclobutane dimer and (6-4) photoproduct

Xeroderma pigmentosum complementation group A was partially complemented by a cosmid genomic clone containing a 42-kb human DNA insert selected with a cDNA clone that we obtained through cDNA competition between the repair-proficient and repair-deficient cell line. The relationship between these two clones was confirmed using PCR amplifications. The enhancement in DNA-repair capacity of the transformants was assessed with the monoclonal antibodies specific for cyclobutane dimers and (6−4) photoproducts and partially correct the xeroderma pigmentosum complementation group A defect. Furthermore, the level of the photoproduct-repair capacity is in agreement with the survival enhancement calculated from the D₃₇ values. This gene was mapped to chromosome 8, suggesting that this may represent one of the defective gene(s) in xeroderma pigmentosum complementation group A.     

Identification of volatile organic compounds in muscle tissues of different species based on Headspace-Gas-Chromatography Ion-Mobility spectrometry

Species identification of unknown biological samples is crucial for forensic applications, especially in cases of explosion, disaster accidents, and body mutilation after murdering, as well as poaching, illegal trade in endangered animals, and meat food fraud. In this study, we identified 60 volatile organic compounds (VOCs) in fresh skeletal muscle tissues of seven different animal species (cattle, sheep, pigs, rabbits, rats, chickens and carp) and a human dead body by headspace-gas-chromatography ion-mobility spectrometry (HS-GC-IMS), and compared their differences by retention time, drift time and molecular weight. The results showed that these VOCs formed different gallery plot fingerprints in the skeletal muscle tissues of the human dead body and seven animal species. Principal component analysis (PCA) showed significantly different fingerprints between these species, and these fingerprints maintained good stability between the species and within the same species. Some VOCs have high species specificity, while VOCs of human fresh muscle tissues from different individual sources have little difference, demonstrating that all tested muscle tissue samples could be distinguished based on different VOCs. HS-GC-IMS has proved to be a rapid, high-throughput, highly sensitive and specific species identification method, which can be used for forensic species identification in criminal cases and disaster accidents, as well as detection in the field of food safety, such as meat fraud and adulteration.     

高浓度富氢生理盐水对脂多糖诱导大鼠急性肺损伤的作用

［摘要］ 目的探讨高浓度富氢生理盐水对腹腔注射脂多糖诱导急性肺损伤的影响。 方法选取60只清洁级SD雄性大鼠,随机分为空白组、高浓度富氢生理盐水组、脂多糖组、脂多糖+高浓度富氢生理盐水组各15只。脂多糖组、脂多糖+富氢生理盐水组腹腔内注射脂多糖10 mg/kg制备大鼠脓毒症模型。富氢生理盐水组、脂多糖+富氢生理盐水组治疗组在术后即刻、3 h、6 h、12 h、18 h,以5 mL/kg高浓度富氢生理盐水腹腔注射。空白组、脂多糖组给予等量生理盐水腹腔注射。取支气管肺泡灌洗液检测中性粒细胞计数,取肺组织检测丙二醛(malondialdehyde,MDA)含量及超氧化物歧化酶（superoxide dismutase,SOD）、过氧化氢酶（catalase,CAT）、谷胱甘肽过氧化物酶（glutathione peroxidase,GSH-Px）活性,Western blot检测肺组织中核因子E-2-相关因子2（nuclear factor erythroid-2-related factor-2,Nrf2）和血红素加氧酶1（hemeoxygenase-1,HO-1）的表达,比较组间差异。 结果与脂多糖组比较,脂多糖+富氢生理盐水组大鼠7 d平均生存时间延长（P＜0.05）;与空白组比较,脂多糖组中性粒细胞计数、MDA含量均明显升高,SOD、CAT、GSH-Px活性均下降（P＜0.05）,肺组织中Nrf2和HO-1的蛋白表达上升（P＜0.05）;与脂多糖组比较,脂多糖+富氢生理盐水组中性粒细胞计数、MDA含量均减少,SOD、CAT、GSH-Px活性以及Nrf2和HO-1的蛋白表达均明显增加（P＜0.05）。 结论高浓度富氢生理盐水可延长脂多糖所致脓毒症大鼠平均生存时间,减少肺部炎症细胞、氧化应激,可能通过Nrf2/HO-1通路控制急性肺损伤。     

Identification of organ tissue types and skin from forensic samples by microRNA expression analysis

The identification of organ tissues in traces recovered from scenes and objects with regard to violent crimes involving serious injuries can be of considerable relevance in forensic investigations. Molecular genetic approaches are provably superior to histological and immunological assays in characterizing organ tissues, and micro-RNAs (miRNAs), due to their cell type specific expression patterns and stability against degradation, emerged as a promising molecular species for forensic analyses, with a range of tried and tested indicative markers.Thus, herein we present the first miRNA based approach for the forensic identification of organ tissues. Using quantitative PCR employing an empirically derived strategy for data normalization and unbiased statistical decision making, we assessed the differential expression of 15 preselected miRNAs in tissues of brain, kidney, lung, liver, heart muscle, skeletal muscle and skin. We show that not only can miRNA expression profiling be used to reliably differentiate between organ tissues but also that this method, which is compatible with and complementary to forensic DNA analysis, is applicable to realistic forensic samples e.g. mixtures, aged and degraded material as well as traces generated by mock stabbings and experimental shootings at ballistic models.     

Microhaplotype identified and performed in genetic investigation using PCR-SSCP

The recently introduced concept of microhaplotype loci has attracted attention in forensics. Previous studies estimated the allele frequencies generally through obtaining genotypic data on the individual SNPs from a larger set of unrelated individuals then phasing microhaplotypes by statistical and computational techniques. Determining phase for a single new individual requires the larger set of individuals to have been genotyped previously. Rare microhaplotypes possessed only by the target individual or microhaplotypes private to a specific population not previously studied are unlikely to be accurately phased using data sets of SNPs. Thus, there is a demand for an approach that could directly determine a gain single individual’s precise microhaplotype information. In the present study, we introduced potential approaches of single chain sequencing based Massively Parallel Sequencing Technology (MiSeq) and PCR based Single Strand Conformational Polymorphism (SSCP) technology which was simple, accurate, and cost-effective. The results indicated that microhaplotypes contain much more polymorphic information than divided SNPs per locus (average heterozygosity of microhaplotype 0.61 VS SNPs 0.41). When microhaplotype allele frequencies were compared among five Chinese ethnic populations, significantly different distributions were found between the Han and Uyghur populations. Further analysis of pairwise Fst values and analysis of molecular variance (AMOVA), showed significant population differentiation between the Uyghur and other populations.     

Haplotype diversity of 17 Y-STR loci in a Chinese Han population sample from Shanxi Province,Northern China

The distribution of 17 Y-chromosome STR loci DYS456, DYS389I, DYS390, DYS389II, DYS458, DYS19, DYS385a/b, DYS393, DYS391, DYS439, DYS635, DYS392, Y-GATA-H4, DYS437, DYS438, and DYS448 haplotypes was determined in a population sample of 222 unrelated Chinese Han from Shanxi Province, Northern China. A total of 219 haplotypes were observed, and of these, 216 were unique, while 3 were found two times. The overall haplotype diversity was 0.9999 and the discrimination capacity was 0.9865, indicating a high potential for differentiating between male individuals in this population. Comparison analysis via Analysis of Molecular Variance (AMOVA) and construction of MDS plot revealed that Shanxi Han sample clusters with Chinese origin populations and stands far apart of the non-Chinese populations, justifying the establishment of local databases in Shanxi Han population for any future forensic and genetic epidemiology efforts in this region.     

Magnetic bead-based separation of sperm from buccal epithelial cells using a monoclonal antibody against MOSPD3

Forensic DNA analysis of sexual assault evidence requires unambiguous differentiation of DNA profiles in mixed samples. To investigate the feasibility of magnetic bead-based separation of sperm from cell mixtures using a monoclonal antibody against MOSPD3 (motile sperm domain-containing protein 3), 30 cell samples were prepared by mixing 10⁴ female buccal epithelial cells with sperm cells of varying densities (10³, 10⁴, or 10⁵ cells/mL). Western blot and immunofluorescence assays showed that MOSPD3 was detectable on the membrane of sperm cells, but not in buccal epithelial cells. After biotinylated MOSPD3 antibody was incubated successively with the prepared cell mixtures and avidin-coated magnetic beads, microscopic observation revealed that each sperm cell was bound by two or more magnetic beads, in the head, neck, mid-piece, or flagellum. A full single-source short tandem repeat profile could be obtained in 80 % of mixed samples containing 10³ sperm cells/mL and in all samples containing ≥10⁴ sperm cells/mL. For dried vaginal swab specimens, the rate of successful detection was 100 % in both flocked and cotton swabs preserved for 1 day, 87.5 % in flocked swabs and 40 % in cotton swabs preserved for 3 days, and 40 % in flocked swabs and 16.67 % in cotton swabs preserved for 10 days. Our findings suggest that immunomagnetic bead-based separation is potentially a promising alternative to conventional methods for isolating sperm cells from mixed forensic samples.