Comparative Analysis of the HV1 and HV2 Regions of Human Mitochondrial DNA by Denaturing High-Performance Liquid Chromatography

Abstract:  Denaturing high-performance liquid chromatography (DHPLC) was evaluated as a sequencing-independent means of detecting the presence of sequence differences in pair-wise mixtures of nonconcordant amplicons of human mitochondrial DNA (mtDNA). A total of 920 pair-wise combinations of HV1 and HV2 mtDNA amplicons from 95 individuals were assayed by DHPLC for sequence concordance/nonconcordance. For the 72 combinations of amplicons from different individuals who shared identical DNA sequences, DHPLC assays consistently indicated sequence concordance between the samples. This was in 100% agreement with sequencing data. For the 849 combinations of amplicons which differed in sequence, DHPLC detected the presence of sequence nonconcordance in all but 13 assays to yield 98.5% concordance with sequencing. Thus, DHPLC can be used to detect a diversity of sequence differences (transitions, transversions, insertions, and deletions) in the mtDNA D-loop. Accordingly, DHPLC may have utility as a presumptive indicator of mtDNA sequence concordance samples, as a screen for heteroplasmy/situational mixtures, and as a means for the physical fractionation of the individual contributors to an mtDNA mixture prior to sequencing.     

儿童精神分析学的主要方法及其应用

儿童精神分析的出现被视为是精神分析"新范式的开始".儿童精神分析学的方法主要来自并运用于临床实践与临床发现,迥异于学院心理学的方法,有其自身的特色与优势.其方法主要包括两个方面,一是研究方法,二是治疗方法.儿童精神分析学最主要的方法包括重构法、观察法、实验法、测验法以及游戏疗法.纵观儿童精神分析学的主要方法,我们会发现它们与发展心理学的研究方法有某些共同之处,但发展心理学则更多地是进行标准化研究和对发展过程的详细描绘,而儿童精神分析学者更多研究心理发展动力与潜意识的影响.二者在研究结果与研究内容方面出现了逐渐融合的趋势,越来越多的儿童精神分析学的研究主题,如母婴关系、自我功能、自我发展、分离与剥夺、受挫与攻击性等逐渐纳入发展心理学的视野.     

A report of the 2002–2008 paternity testing workshops of the English speaking working group of the International Society for Forensic Genetics

The English Speaking Working Group (ESWG) of the International Society for Forensic Genetics (ISFG) offers an annual Paternity Testing Workshop open to all members of the group. Blood samples, a questionnaire and a paper challenge are sent to the participants. Here, we present the results of the 2002–2008 Paternity Testing Workshops with the objective to evaluate the uniformity of DNA-profiling and conclusions of the participating laboratories as well as to clarify tendencies in typing strategies and biostatistical evaluations of the laboratories. The numbers of participating laboratories increased from 46 in 2002 to 68 in 2008. The results showed an increasing degree of concordance concerning methods and DNA systems used and a high degree of uniformity in typing results with discrepancies in 0.1 and 0.3 % of all submitted PCR-based results. The paper challenges showed uniformity in the calculation of the weight of evidence for simple cases with straight-forward genetic constellations. However, a high degree of variation existed in complex scenarios with rare genetic constellations such as genetic inconsistencies/possible silent alleles, rare alleles and haplotypes.     

Mutation rates at 14 STR loci in the population from Pernambuco, Northeast Brazil

Definition about mutation rates of short tandem repeats (STRs) loci used in forensic analysis are useful for the correct interpretation of resulting genetic profiles and the definition of criterions for exclusion in paternity testing. Germline mutation of 14 STR loci was studied for 54,105 parent–child allelic transfers from 2575 paternity testing cases carried out during 2000–2007 from the Pernambuco State, Northeast Brazil. The parenthood in each of these cases was highly validated (probability > 99.99%). We identified 43 mutations at 12 loci. Locus-specific mutation rate estimates varied between 2 × 10⁻⁴ and 2 × 10⁻³, and the overall mutation rate estimate was 8 × 10⁻⁴. Mutation events in the male germline were more frequent than in the female germline. The majority of the mutations could be explained by losses or gains of one repeat unit and there was no evidence for selection between insertion or deletion changes. Our data were compared with those of Portuguese and North-American populations for CSF1PO, D18S51, D21S11, D7S820, TH01, TPOX and demonstrated, despite the great difference in the size of the sample, that mutation rates of STR loci in a mixed population do not differ from that encountered in different populations.     

ABO genotyping by duplex amplification and oligonucleotide arrays assay

Objective

Research on the application feasibility of ABO genotyping for forensic identification by oligonucleotide arrays assay.

Methods

Oligonucleotide microarrays which detect three different SNPs in exon 6 and exon 7 for ABO genotyping were used. After hybridization wash, the arrays were scanned and fluorescence intensities were analyzed using microarray population studies on ABO was carried out in a sample of 115 unrelated Chinese Han individuals oligonucleotide arrays for genotype detection. The method was also applied to cases.

Results

Technique could identify six genotypes of ABO system and the results of GeneChip analyses confirmed by PCR–RFLP. According to the results of population studies, no significant deviations Hardy–Weinberg equilibrium could be found. The observed heterozygosity (H-obs) was 0.591. Expected heterozygosity (H-exp) was 0.616. The polymorphic information content (PIC) was the average exclusion probability in paternity testing for duos (PE (1)) was 0.188. The average exclusion probability in paternity testing for trios (PE(2)) was 0.344. The discrimination power 0.777.

Conclusion

The data and case application demonstrated that ABO typing by oligonucleotide probe arrays was a useful technique for paternity testing and individual identification.     

Optimization and validation studies of the Mentype Argus X-8 kit for paternity cases

The use of ChrX-STRs is enormous in forensic case as these have proven to be powerful tools, mainly in deficiency paternity cases when the disputed child is female, and also some special cases involving blood relatives, incest cases, fetal typing in abortion material. The Mentype^® Argus X-8 kit is a commercial multiplex system which contains Amelogenin for gender determination as well as gonosomal STR markers (DXS8378, HPRTB, DXS7423, DXS7132, DXS10134, DXS10074, DXS10101 and DXS10135). Validation studies were being performed on blood obtained from the volunteers in Turkish population. In this study, some parameters were taken under consideration for validation like DNA extraction using different protocols, quantitated by using commercially available Invitrogen Qubit Fluorometer, reaction volume validation of Master Mix and the analysis of female/male, female/female and male/male mixtures were performed. The conditions were optimized and validated using GenAmp 9700 and reducing reaction volume from 25 μl to 12.5 μl and 6.5 μl. After reducing the total volume of the reaction, the results were same and there was no effect on peak height and quality when analyzed on ABI 310 genetic analyzer. 2 paternity cases were also performed which gave the same power of discrimination as has been mentioned in Mentype^® Argus X-8 kit.     

Comparison of modern techniques for saliva screening

Saliva stains present a unique challenge in the forensic setting, often challenging the analyst to weigh the value of presumptive indication of the fluid versus the potential for DNA analysis to yield identification information. There are many situations in which determining the presence of a body fluid is probative and further corroborates DNA evidence. That said, even a minute portion of sample consumed by a screening test could mean the difference between a full, partial, or null profile obtained through DNA analysis. The basis of presumptive testing or screening of saliva has historically been based on the presence of amylase, a component found in relatively high concentrations in human saliva versus other body fluids and substances. Though the current available methods for the screening of saliva in a forensic application have grown in number, the popularity of these methods seemingly has not. This study attempts to identify a specific and sensitive saliva screening test by comparing three modern techniques--the recently released SALIgAE, Phadebas, and starch-iodine mini-centrifuge test--on the basis of sensitivity, specificity, mixtures, and simulated casework samples while also considering sample consumption. The Phadebas method for presumptive saliva testing detected dilutions of neat saliva down to 1:200 versus considerably less sensitive results with SALIgAE and the starch-iodine mini-centrifuge test. Utilizing a screening test with a high degree of sensitivity, such as Phadebas, allows an analyst to gain a maximum amount of information in the form of body fluid indication and DNA results because of the consumption of a small portion of sample.     

美国反垄断法中界定“相关市场”的临界损失分析法

美国早期用来界定"相关市场"的方法没有限定市场弹性幅度,这个缺陷直到"假定的垄断者测试"产生后才得到弥补。1986年,美国改进了"假定的垄断者测试"操作方法,提出了临界损失分析法。虽然人们对临界损失分析法还存在不少争议,但它在美国和欧盟得到了越来越广泛的应用,相关判例得到了极大的丰富。     

Blinking Subjects; Blinking Justice? – Law,Medicine and the PVS Patient

This paper argues that in medical discourse, there is insufficient unanimity of opinion with regards to the time at which an accurate diagnosis of PVS can be made and that clearly, there is an incomplete medical knowledge of the PVS condition. The judiciary chooses neither to question medical opinion that patients can be considered to be in PVS despite a failure to satisfy the diagnostic criteria, nor medical opinion that patients in `near PVS' will never recover. It is apparent from an examination of the judgements given in PVS cases that the law does not ascribe such individuals with full human status. Such a legal position is particularly problematic in ethical terms when applied in cases involving patients who are in a `near PVS' position, and in the light of evidence that some PVS diagnoses are inaccurate. The application of the best interests test in PVS cases results in the adoption of a paternalistic, objective approach that fails to respect the former competent individuals whom PVS patients once were. If, alternatively, the substituted judgement test were to be adopted, the principle of individual autonomy would become central to the question of whether PVS patients' treatment should be withdrawn. Furthermore, the application of this test would also ensure that PVS patients continue to be viewed as `persons'.     

抗人血红蛋白胶体金检测试剂条的研制

目的制备法医学检验所用的确定人血的免疫胶体金层析试剂条。方法选取抗人血红蛋白单克隆细胞株,制备其小鼠腹水,从腹水中纯化出单克隆抗体。制备胶体金并用一纯化的单克隆抗体包被,制成免疫胶体金。取玻璃纤维以免疫胶体金浸泡,烘干。在一硝酸纤维素膜上两个不同位置分别点加另一抗人血红蛋白抗体和羊抗鼠IgG。搭建试剂条并检测其灵敏度和特异性。结果制成的免疫胶体金试剂条可对稀释至20万倍的人血红蛋白溶液显示阳性,对法医学检验常见8种动物的血溶液显示阴性。结论所制备抗人血红蛋白胶体金试剂条可以应用于法医学检验。