Genetic analysis of 27 Y-chromosomal STR loci in a Zimbabwean Shona ethnic group

Buccal swabs from 200 unrelated Zimbabwean males were collected from voluntary participants located in Harare province. The 5-dye SureID® 27Y Human STR Identification Kit was used to perform multiplex polymerase chain reactions (PCR) and generate Y-chromosomal DNA profiles. This kit targets markers DYS456, DYS576, DYS570, DYS481, DYF387S1, DYS627, DYS393, DYS391, DYS390, DYS635, DYS449, DYS533, DYS438, DYS389I, DYS448, DYS389II, DYS19, GATA_H4, DYS518, DYS458, DYS460, DYS437, DYS439, DYS392, and DYS385, similar to the Yfiler® Plus Amplification Kit. A total of 161 haplotypes were generated with the PowerPlex® Y system, whereas 159 complete haplotypes were generated for the Yfiler® Plus system. Haplotype Discrimination Capacity (DC) with the Yfiler® Plus system was determined to be 0.9686, while the Genetic Diversity (GD) of the targeted loci ranged from 0.03748 at DYS392 to 0.867239 at DYS449. One haplotype contained the triallelic pattern 37, 38, and 39 at DYS387S1. In addition, marker DYS387S1 and marker DYS385 had 13 counts of microvariant alleles overall, while 9 null allele counts were noted at marker DYS448. Genetic distances between our population data and 22 other data sets from African countries and people of African descent were estimated and results showed significant genetic variation.     

Autosomal and Y-STR analysis of degraded DNA from the 120-year-old skeletal remains of Ezekiel Harper

The 120-year-old skeletal remains of Confederate Civil War soldier Captain Ezekiel “Zeke” Harper were exhumed by court order in January 2011 for DNA analysis. The goal of the DNA testing was to support or refute whether Captain Harper had fathered a son (Earl J. Maxwell) with his Native American maid prior to his murder in 1892. Bones with adequate structural integrity (left tibia, right tibia, right femur, mandible, four teeth) were retrieved from the burial site and sent to the Institute of Applied Genetics in Fort Worth, Texas for analysis. Given the age and condition of the remains, three different extraction methods were used to maximize the probability of DNA recovery. The majority of the DNA isolates from over fifty separate bone sections yielded partial autosomal STR genotypes and partial Y-STR haplotypes. After comparing the partial results for concordance, consensus profiles were generated for comparison to reference samples from alleged family members. Considering the genetic recombination that occurs in autosomal DNA over the generations within a family, Y-STR analysis was determined to be the most appropriate and informative approach for determining potential kinship. Two of Earl J. Maxwell's grandsons submitted buccal samples for comparison. The Y-STR haplotypes obtained from both of these reference samples were identical to each other and to the alleles in Ezekiel Harper's consensus profile at all 17 loci examined. This Y-STR haplotype was not found in either of two major Y-STR population databases (U.S. Y-STR database and YHRD). The fact that the Y-STR haplotype obtained from Ezekiel's skeletal remains and Earl's grandsons is not found in either population database demonstrates its rarity and further supports a paternal lineage relationship among them. Results of the genetic analyses are consistent with the hypothesis that Earl J. Maxwell is the son of Ezekiel Harper.     

时间-空间相关成像技术测量妊娠期糖尿病胎儿心脏结构

目的探讨时间-空间相关成像技术对妊娠期糖尿病胎儿心脏结构的测量价值。资料与方法选取血糖控制良好的妊娠期糖尿病孕妇胎儿33例,以正常妊娠孕妇胎儿119例作为对照组。运用时间-空间相关成像技术后处理获得M型图像,比较两组胎儿心室收缩末期和舒张末期内径、心室缩短分数、心室壁和室间隔收缩和舒张末期厚度。结果血糖控制良好的妊娠期糖尿病孕妇胎儿与正常妊娠胎儿左、右心室收缩末期和舒张末期内径差异无统计学意义(W=2392、2278、2344、2218,P>0.05);左、右心室壁收缩和舒张末期厚度差异无统计学意义(W=2103、2142.5、2041.5、2113.5,P>0.05);室间隔收缩末期和舒张末期厚度差异无统计学意义(W=2183、2336,P>0.05);左、右心室缩短分数差异亦无统计学意义(W=2218.5、2071,P>0.05)。结论妊娠期糖尿病孕妇的血糖控制良好,胎儿的心脏结构和收缩功能影响不明显。     

Effects of DNA degradation and genotype imputation on high-density SNP microarray in pairwise kinship analysis

High-density single nucleotide polymorphisms (SNPs) can detect distant relatives even in the context of pairwise kinship analysis. Although DNA microarrays conveniently generate genome-wide SNP data, they require large quantities of high-quality DNA. Genotyping data obtained from low-quantity and low-quality samples are likely unreliable owing to the incidence of no-called or mistyped SNPs. In this study, we examined the effects of insufficient sample densities and sample degradation on the efficacy of kinship analysis. While low DNA amounts had a minor effect, DNA degradation led to a significant increase in no-call rates and error rates. Posterior probabilities of kinship determination, calculated using the index of chromosomal sharing, were markedly lower in proportion to the no-call rates and error rates. We also investigated the effect of genotype imputation to complement the no-called genome data utilizing SNPs reference panels. We found that the posterior probability of the relative-assumed person increased with genotype complementation in case of mild degradation, even with mistyped genotypes. Therefore, DNA microarray with imputation is a promising method for analyzing forensic DNA samples taken from situations where DNA quantity and quality may be compromised, such as disaster victim identification using pairwise kinship analysis.     

血浆中 BZ类失能剂的高效液相二极管矩阵检测分析方法的研究

目的：建立血浆中 Ｂ Ｚ类失能剂的高效液相二极管矩阵检测分析方法,为 Ｂ Ｚ类失能剂中毒病人的临床诊断提供分析手段。方法：采用 Ｓｅｐ Ｐａｋ Ｃ１８ 柱固相提取,乙酸乙酯洗脱, Ｒｅｓｏｌｖｅ Ｃ１８ 反相柱分离,０．１２％ 三氟乙酸（ Ｔ Ｆ Ａ）的 ５０％ 甲醇溶液梯度洗脱,二极管矩阵检测器（ Ｄ Ａ Ｄ） 三波长（２２０±４）ｎｍ ,（２５４±４）ｎｍ ,（３００±４）ｎｍ 检测。结果：血浆中 Ｈ Ｐ Ｌ Ｃ Ｄ Ａ Ｄ 法检测 ４ 种失能剂的线性范围为 ０．１～１．２ μｇ,回收率为６２．７６％ ～９２．２０％ ,标准偏差为 ３．４６％ ～１１．８４％ ,最低检出限为 １００～４００ ｎｇ。流动相中 Ｔ Ｆ Ａ 和甲醇浓度及梯度洗脱是影响分离效果和色谱峰形的主要因素。结论：本文为临床诊断提供简便、快速、灵敏的检测方法,血浆蛋白不干扰测定。４ 种失能剂在血浆中采用 Ｈ Ｐ Ｌ Ｃ Ｄ Ａ Ｄ 法同时分离测定目前未见报道。     

Sex determination and DNA competition in the analysis of forensic mixed stains by PCR

Sex determination of pure and mixed blood samples and stains was performed by amplification of the X-specific and Y-specific alphoid sequences by PCR (XY-PCR). From mixed blood samples with female DNA present in large excess of male DNA, the Y-specific sequence still amplified efficiently. In the analysis of vaginal secretions in a case of sexual assault, XYPCR was performed to test the efficiency of the selective lysis procedure in order to investigate whether alleles found with other PCR systems were of male or female origin. Our studies with mixed blood samples revealed pronounced DNA competition in the HLA-DQ and D1S80 PCR systems: the alleles from a minor DNA component could not be detected in the presence of a large excess of DNA from a second person.     

Rapid and highly sensitive analysis of benzodiazepines and tandospirone in human plasma by automated on-line column-switching UFLC-MS/MS

A high-throughput method was developed for the detection of 31 benzodiazepine drugs and tandospirone in human plasma by on-line column-switching ultra-fast liquid chromatography-tandem mass spectrometry. Plasma samples (100 μl) spiked with the 32 drugs and oxazepam-d₅ (internal standard) were diluted with 300 μl of 13.3 mM ammonium acetate/acetonitrile (33:67, v/v). After centrifugation and filtration, the clear supernatant was injected directly onto the extraction column (Oasis HLB cartridge column). The following procedure was fully automated. The analytes retained on the extraction column were eluted by backflushing of the extraction column and introduced into an analytical column (SUMIPAX ODS D-Swifter column, 30 mm × 3.0 mm i.d.; particle size 2 μm) by column switching. Quantification was performed by multiple reaction monitoring with positive-ion electrospray ionization. Distinct peaks appeared for each drug and the internal standard on each channel within 7 min, including the extraction time. All drugs spiked into plasma showed recoveries of 83–95%. The regression equations for the 32 drugs showed excellent linearities in the range of 50–2000 pg/ml of plasma and the limits of detection ranged from 20 to 50 pg/ml. The lower and upper limits of quantitation were 50–100 ng/ml and 2000 pg/ml, respectively. Intra- and interday coefficients of variation for none of the drugs were greater than 13.6%. The accuracies of quantitation were 87–112%. The multiple reaction monitoring information-dependent acquisition of enhanced product ions method enabled the quantification and confirmation of diazepam, triazolam, and lorazepam obtained from actual plasma.     

Evaluation of a solid-phase extraction procedure for the simultaneous determination of morphine, 6-monoacetylmorphine,codeine and dihydrocodeine in plasma and whole blood by GC/MS

Different procedures of solid-phase extraction were re-examined and a new solid-phase extraction procedure was developed using gas chromatography-mass spectrometry for the simultaneous detection and quantitation of morphine, 6-monoacetylmorphine, codeine and dihydrocodeine in plasma and whole blood. The effects of different types of sorbent and buffer solutions on the recoveries and purity of the extracts were also studied. Some preparation techniques on whole blood samples were also investigated. The method developed using Chromabond C18 (100) with spiked plasma samples had good recoveries for all opiates of interest: morphine 93.1% ± 7.4%, 6-monoacetylmorphine 68.0% ± 6.7%, codeine 77.0% ±8.3% and dihydrocodeine 67.9% ± 8.4%. The detection limit of all compounds was less than 5 g/L. The blank plasma showed no interfering peaks in the GC/MS-analysis.