E. Ponzano

Interleukin 12 gene polymorphisms enhance gastric cancer risk in H pylori infected individuals

Bacterial, environmental, population related, and individual host factors are major determinants of the outcome of H pylori infection.1,2 Many bacterial virulence genes—including the pathogenicity island cagA , the s1m1 vacA alleles, babA2 , sabA , and oipA —have been associated with a higher degree of gastric mucosal inflammation, intestinal metaplasia, gastric or duodenal ulcer, gastric adenocarcinoma, and MALToma.1,3–7 H pylori triggers and maintains gastric mucosal inflammation by different mechanisms, which are partly strain dependent and partly strain independent.1 T and B lymphocyte activation and infiltration of the gastric mucosa depend on H pylori antigen processing. The number of infiltrating polymorphonuclear cells varies depending on the virulence of the infecting strain, being much greater when infections are caused by cagA positive strains.3,5,7–9 The inflammatory cells infiltrating H pylori infected gastric mucosa produce a pattern of proinflammatory cytokines.10,11 High mucosal levels of mononuclear cytokines (IL8, IL6, IL1β, tumour necrosis factor α (TNFα), and interferon γ (IFNγ)) and lymphocytic derived cytokines (IL2, IL2R) have been described in H pylori infected patients.10–13 H pylori infection also induces the production of IL12,14–16 a heterodimeric proinflammatory protein that triggers the production of IFNγ and favours the differentiation of T helper 1 (Th1) cells,17,18 which, in H pylori infected mucosa, prevail over Th2 cells.15,16,19 The ability of IL12 to induce Th1 is one of the biological bases of the importance of this cytokine in resisting most bacteria, including H pylori , and also intracellular protozoa and fungal pathogens.18,20,21 Cellular sources of IL12 in response to infections are mainly dendritic cells and phagocytes.16–21 The two subunits of IL12—p35 and p40—are encoded by different genes, named IL12A and IL12B respectively, which are unrelated …

Allele sharing in first-degree and unrelated pairs of individuals in the Ge.F.I. AmpFlSTR® Profiler Plus™ database

Eleven Italian forensic laboratories participated in a population study based on the AB Profiler Plus loci with proficiency testing. The validated database, including 1340 individuals, is available on-line. Tests for Hardy-Weinberg equilibrium, gametic unbalance, and heterogeneity of gene frequency were generally not significant. Gene frequencies at each locus were consistent with those of two previously published Italian studies, but different from a third. Individuals of each subsample were paired, and the total number of alleles shared across the nine loci was determined in each pair. The analysis was replicated over the total sample. In addition, two samples of mother-child pairs (N=315) and full-sib pairs (N=91) were subjected to allele sharing analysis. The resulting distributions were sufficiently distinct from the sample of unrelated pairs as to be of practical usefulness.

Deletion of amelogenin Y-locus in forensics: literature revision and description of a novel method for sex confirmation.

Today, the molecular technique routinely for sex determination in forensics is based the detection of length variations in the X-Y homologous amelogenin gene (AMELX and AMELY). In humans, the amelogenin gene is a single-copy gene located on Xp22.1-Xp22.3 and Yp11.2; the simultaneous detection of the X and Y alleles using polymerase chain reaction (PCR) can lead to gender determination. Several studies have shown that normal males may be typed as females with this test: AMELY deletions may result in no product of amplification and normal males being typed as female as a result of the test (negative male). Considering the consequences of the result obtained using only the amelogenin marker, and the related potential difficulties in interpreting the results, the gender misinterpretation may be troublesome in clinical practice and in forensic casework. In this article, beginning with a review of the incidence of gender-testing failures among different populations, and with the different strategies proposed in the literature in case of doubt regarding the presence of deleted AMEL in the DNA profile, we propose a method for the identification of samples with deleted AMEL that can be applied, as an additional assay, in case of doubt regarding PCR results of sex determination.

Tumoural specimens for forensic purposes: comparison of genetic alterations in frozen and formalin-fixed paraffin-embedded tissues

In certain circumstances, tumour tissue specimens are the only DNA resource available for forensic DNA analysis. However, cancer tissues can show microsatellite instability and loss of heterozygosity which, if concerning the short tandem repeats (STRs) used in the forensic field, can cause misinterpretation of the results. Moreover, though formalin-fixed paraffin-embedded tissues (FFPET) represent a large resource for these analyses, the quality of the DNA obtained from this kind of specimen can be an important limit. In this study, we evaluated the use of tumoural tissue as biological material for the determination of genetic profiles in the forensic field, highlighting which STR polymorphisms are more susceptible to tumour genetic alterations and which of the analysed tumours show a higher genetic variability. The analyses were conducted on samples of the same tissues conserved in different storage conditions, to compare genetic profiles obtained by frozen tissues and formalin-fixed paraffin-embedded tissues. The importance of this study is due to the large number of specimens analysed (122), the large number of polymorphisms analysed for each specimen (39), and the possibility to compare, many years after storage, the same tissue frozen and formalin-fixed paraffin-embedded. In the comparison between the genetic profiles of frozen tumour tissues and FFPET, the same genetic alterations have been reported in both kinds of specimens. However, FFPET showed new alterations. We conclude that the use of FFPET requires greater attention than frozen tissues in the results interpretation and great care in both pre-extraction and extraction processes.

Development of a heptaplex PCR system to analyse X-chromosome STR loci from five Italian population samples. A collaborative study

Abstract A heptaplex PCR has been developed to amplify DXS6789, HUMARA, DXS10011, DXS7423, HPRTB, DXS6807 and DXS101 on Italian samples from Bologna, Modena, Padova, Ancona and Pisa. Statistical analyses were performed for all the loci.

Discrimination Between Human and Animal DNA Application of a Duplex Polymerase Chain Reaction to Forensic Identification

Identification of a reports species is one of the basic analyses in forensic laboratories. The authors report the case of 6 bone fragments recovered in a wooded area, which were not attributable to 1 animal species on the basis of morphologic examination. The aim of this study was to develop a duplex polymerase chain reaction (PCR) to discriminate human and animal origin of bone fragments. The method is based on the PCR amplification of cytochrome b and a 16S ribosomal mitochondrial DNA fragment, which has never been tested up to now. Our protocol combines a single-round PCR with direct visualization of amplicons in agarose gel, without sequencing analysis of the PCR products. The presence of a single band (359 bp) indicates a nonhuman origin of the sample, whereas 2 bands (157 and 359 bp) indicate a human biologic sample.This method revealed to be useful for forensic purposes because the 16S ribosomal mitochondrial DNA is a small human-specific fragment that is easily amplifiable even with degraded DNA from biologic materials such as old bones.

Application of Conventional and DNA Polymorphism to Paternity Cases

Multilocus and single locus minisatellite probes have been applied to the paternity expertise for sometime. DNA profiling has been routinely used in cases of disputed paternity at the Institute of Legal Medicine of Padua since 1991.

Collecting sexual assault history and forensic evidence from adult women in the emergency department: a retrospective study

BackgroundThe objective of this retrospective study was to examine the discrepancy between information derived from written medical reports and the results of forensic DNA analyses on swabs collected from the victims in 122 cases of alleged sexual assault treated at the Emergency Department of Padua Hospital. The examination of discrepant results has proved useful to support a broader application of sexual assault management, particularly during the taking of case history.MethodsThe Laboratory of Forensic Genetics of Padua University have processed samples from 122 sexual assault cases over a period of 5 years.ResultsOf the 103 cases in which the victim reported a penetration and ejaculation, only 67 (55% of all the samples) correlated with positive feedback match from the laboratory. In 36 cases in which the patient reported penetration with ejaculation, no male DNA was found in the samples collected. Therefore, there was a total of 41 cases in which the patient’s report were not supported by laboratory data. In the remaining ten cases, which had an ambiguous history, 3 tested positively for the presence of male DNA.ConclusionsTo avoid discrepancies between the medical reporting and reconstruction of sex crimes, it is crucial to deploy strategies which focus not only on the technical aspects of evidence collection, but also on how the victim’s story is recorded; such efforts could lead to better management of sexual assault victims, and to a strengthened legal impact of forensic evidence and of crime reconstruction.

A multicentric study of SE33 allele frequencies in the Italian population

Allele and genotype frequencies for STR SE33 were obtained for a sample of 419 Italians in view of application in personal identification and paternity. D 2003 Elsevier Science B.V. All rights reserved.

Mitochondrial DNA polymorphism in 50 unrelated individuals from North Italy

Abstract The hypervariable regions HVI and HVII of mitochondrial DNA (mtDNA) were sequenced in 50 unrelated individuals living in Veneto. A total of 48 different mtDNA haplotypes for HVI region (404 bp) and 49 for HVII region (313 bp) were observed. Nucleotide diversity was 0.0116 and 0.0097, respectively.