Mutation rates at Y chromosome specific microsatellites.

A collaborative work was carried out by the Spanish and Portuguese ISFG Working Group (GEP-ISFG) to estimate Y-STR mutation rates. Seventeen Y chromosome STR loci (DYS19, DYS385, DYS389I and II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS460, DYS461, DYS635 [GATA C4], GATA H4, and GATA A10) were analyzed in a sample of 3,026 father/son pairs. Among 27,029 allele transfers, 54 mutations were observed, with an overall mutation rate across the 17 loci of 1.998 x 10(-3) (95% CI, 1.501 x 10(-3) to 2.606 x 10(-3)). With just one exception, all of the mutations were single-step, and they were observed only once per gametogenesis. Repeat gains were more frequent than losses, longer alleles were found to be more mutable, and the mutation rate seemed to increase with the father's age. Hum Mutat 26(6), 520-528, 2005. (c) 2005 Wiley-Liss, Inc.

Thymine auxotrophy is associated with increased UV sensitivity in Escherichia coli and Bacillus subtilis.

Thymine auxotrophy was shown to be associated with an increase in UV sensitivity both in Bacillus subtilis and in Escherichia coli. This UV sensitization became clearly evident in polA5 mutants of Bacillus subtilis: at UV doses of 16 J/m2, a reduction of more than 10-fold in the survivor population is observed in thymine requiring spontaneous mutants (polA5 thyA thyB) compared to the parental strains (polA5). Reversion of either thyA or thyB mutation led to a partial recovery in the UV resistance. This result suggests that DNA repair polymerization might be improved by the biosynthesis of thymidylate or some effect associated with such activity.

Simultaneous measurement of toxicity and mutagenic activity.

The assay of mutagenic activity of toxic drugs is difficult to perform and analyze, because one needs to know the kinetics of both effects in order to draw reliable conclusions. This is the case with niflumic acid (NA), which reduced the viability of S. typhimurium TA1535 100 times in the Ames test, but the background microcolonies show no difference from controls and the number of revertants was not altered by the drug. A test which measures the kinetics of growth of viable bacteria and mutants in liquid medium has been developed and applied to NA. No mutagenic activity was detected and elimination of the toxicity from the medium is suggested.

DNA typing in a cattle stealing case.

DNA profiling was used as probative evidence in a cattle stealing case. The carcasses of the dead animals were found from a report and a farmer recognized the remains as those corresponding to the stolen animals by the farm mark on the coat. Those remains were collected as reference samples. Meat pieces were sequestered from a butchery and then sent to our Laboratory by the Justice Department of Buenos Aires (Argentine) to perform a DNA comparative analysis with the reference. Matches were found between the evidences and the references, supporting the hypothesis that the meat pieces had been obtained from the stolen animals. The butcher was suspected of stealing animals but no direct incrimination had been made yet.

Cytomegalovirus-associated Ménétrier's disease in adults. Demonstration by polymerase chain reaction (PCR).

Ménétrier's disease (MD) is a rare form of hypertrophic or hyperplastic gastropathy characterized by conspicuous thickening of the gastric mucosal folds and foveolar (crypt) hyperplasia. We examined the presence of cytomegalovirus (CMV) in 2 cases of MD in adults, one associated with gastric carcinoma, using the polymerase chain reaction (PCR). None of the cases showed intranuclear inclusions consistent with CMV infection. Both revealed, besides the features of MD, a peculiar pattern of "chronic active plasmacellular gastritis". Although the samples had been stored in formalin for more than 10 years CMV-DNA was recovered with good yield from both samples. The demonstration of CMV in MD in adults may helps to explain present knowledge of the complex relationships between this virus and gastric mucosa, and strongly suggests a pathogenetic role of the virus with variable phenotypic expression along the years.

Detection of human papillomavirus in juvenile laryngeal papillomatosis using polymerase chain reaction.

We examined the presence and subtypes of human papillomavirus (HPV) in 20 paraffin-embedded samples (from 12 patients) of juvenile laryngeal papillomatosis using the polymerase chain reaction (PCR). The biopsies had been stored for months to 12 years. Due to the great genetic variability of HPV, we selected a conservative sequence of the viral genome (L1 region) to identify the vast majority of the subtypes. Positive results were obtained by one-step PCR amplification with the MY09-11 consensus primers (L1 region) in only 10 of the cases. After a two-step amplification (nested-PCR) with GP5-6 primers the 20 samples proved to be positive demonstrating the higher sensitivity of this method. In order to amplify a highly variable region of the genome (E6), specific primers for HPV types 6 and 11 (H6/11 L1-R2) were used. 7/12 patients were positive for this subtype. Since more that one subtype has been reported in the same sample, the presence of HPV 6-11 sequences does not exclude that other subtypes might be involved. The results of this study show that: 1) HPV is present in JLP. 2) The most frequent HPV subtype involved was from the 6-11 group. 3) PCR can be successfully used in archived tissue routinely processed in a laboratory of pathology.

Gene frequencies of DRB3.2 locus of Argentine Creole cattle.

Gene and genotype frequencies of BoLA-DRB3 were studied in seven herds of Argentine Creole cattle. Twenty-one out of thirty previously identified alleles were detected in this breed. The F statistics showed high degree of variability among the studied subpopulations suggesting that subdivision and genetic drift, rather than inbreeding, have been the major factors acting on the observed interpopulation variability. The observed high degree of genetic variation in Argentine Creole cattle could be crucial for the long-term survival of this population. Maintenance of such polymorphism, as a genetic resource, could be an important issue that will demand attention in future breeding programmes in species under high selective pressures.

Presence of human papillomavirus in extrahepatic biliary atresia.

BACKGROUND: In a previous study the human papillomavirus DNA was detected in seven cases of so-called idiopathic neonatal giant cell hepatitis by using nested polymerase chain reaction. The purpose of the present study was to study the prevalence and possible common causes of human papillomavirus-associated idiopathic neonatal giant cell hepatitis and extrahepatic biliary atresia. METHODS: Formalin-fixed, paraffin-embedded archival tissues obtained in 18 cases of extrahepatic biliary atresia were studied for human papillomavirus DNA by nested polymerase chain reaction. In addition, in situ hybridization was performed on tissue obtained in 6 cases. RESULTS: Tissue in 16 of the 18 cases studied showed amplified human papillomavirus DNA, whereas no human papillomavirus was amplified in any of 30 control samples. Main human papillomaviruses detected were types 6 and 18. Punctate intranuclear positive signals were detected in the hepatocytes after in situ hybridization for human papillomavirus DNA. CONCLUSIONS: The high prevalence of human papillomavirus DNA in liver tissue in cases of extrahepatic biliary atresia suggests a strong correlation between this disorder and idiopathic neonatal giant cell hepatitis. It further suggests that this virus may be one of the causative agents in extrahepatic biliary atresia and may represent part of the spectrum of lesions associated with neonatal human papillomavirus-induced hepatic damage.

Human papillomavirus is present in some cases of childhood penile lichen sclerosus: an in situ hybridization and SP-PCR study.

Lichen sclerosus (LS) is a skin disease that may affect both sexes at all ages and at any site. Its etiology remains unknown. The observation of focal koilocytotic-like changes in the stratum malpighii in prepuce samples of LS in children prompted us to investigate the presence of HPV-DNA. Twenty-three paraffin-embedded samples of LS lesions from children aged 4 to 14 years were studied using nested-PCR and in situ hybridization (ISH). Twelve out of 23 cases amplified HPV-DNA (8 cases corresponded to HPV-DNA type 6; 2 cases each to HPV-DNA types 16 and 18). ISH detected HPV sequences in the nuclei of koilocytotic and some parakeratotic cells in 13 cases (9/13 also HPV-DNA positive by PCR). Our results demonstrated the presence of HPV-DNA in roughly 70% of cases of LS of the prepuce in children. We highlight the observation of koilocytotic-like changes in the prepuce and its association with HPV. The possible pathogenetic significance between the virus and the lesion is not settled.

Human papillomavirus (HPV)-associated neonatal giant cell hepatitis (NGCH).

Neonatal giant cell hepatitis (NGCH) is a clinicopathological syndrome that has been related to perinatal infections and metabolic disorders. In a great number of cases no apparent etiology has been found. To characterize the possible relationship between human papillomavirus (HPV) and idiopathic NGCH (INGCH) we analyzed paraffin-embedded hepatic biopsies from seven cases of INGCH for the presence of both HPV and cytomegalovirus (CMV) DNA. Clinically, jaundice, detected within the first 3 days of life (except in one case), and raised levels of serum transaminases and bilirubin, mainly the direct fraction, were recorded in all. Follow-up of six patients revealed complete recovery. In a "blind" experiment, samples were studied along with appropriate controls [2 cases of CMV hepatitis, one case of postinfantile GCH, 12 cases of juvenile laryngeal papillomatosis (JLP), and 5 normal neonatal liver samples] by polymerase chain reaction (PCR). All DNA samples from INGCH consistently showed positive HPV DNA amplification. This was also found in the samples from postinfantile GCH and JLP. In addition, a second biopsy performed 11 months later in one of the cases of INGCH revealed scattered multinucleated hepatocytes and was still positive for HPV DNA. CMV-DNA was detected only in the cases of CMV hepatitis. All five normal livers were negative for HPV and CMV-DNA. These data seem to indicate that HPV may be closely related to a subset of "idiopathic" NGCH with good outcome.

Genetic variability and population structure in loci related to milk production traits in native Argentine Creole and commercial Argentine Holstein cattle

Muitas raças de gado foram submetidas a alta pressäo de seleçäo para caracteres de produçäo. Conseqüentemente, a estrutura genética e a distribuiçäo alélica da populaçäo poderiam diferir em raças sob alta pressäo de seleçäo, quando comparadas a raças näo selecionadas. Foi feita a análise das freqüências dos genes de K-caseína, aS1-caseína e prolactina em rebanhos de gado Creole argentino (AC) e Holstein argentino (AH). Os valores de FST calculados mediram o grau de diferenciaçäo genética de subpopulaçöes, dependendo de variaçöes na freqüência dos genes. A raça AC apresentou variaçäo consideravelmente maior entre os rebanhos nos loci de aS1-caseína e K-caseína. Estratégias de conservaçäo devem considerar a populaçäo inteira de AC de forma a manter a variabilidade genética encontrada nesta raça nativa.

Detection of human papillomavirus in juvenile laryngeal papillomatosis using polymerase chain reaction.

We examined the presence and subtypes of human papillomavirus (HPV) in 20 paraffin-embedded samples (from 12 patients) of juvenile laryngeal papillomatosis using the polymerase chain reaction (PCR). The biopsies had been stored for months to 12 years. Due to the great genetic variability of HPV, we selected a conservative sequence of the viral genome (L1 region) to identify the vast majority of the subtypes. Positive results were obtained by one-step PCR amplification with the MY09-11 consensus primers (L1 region) in only 10 of the cases. After a two-step amplification (nested-PCR) with GP5-6 primers the 20 samples proved to be positive demonstrating the higher sensitivity of this method. In order to amplify a highly variable region of the genome (E6), specific primers for HPV types 6 and 11 (H6/11 L1-R2) were used. 7/12 patients were positive for this subtype. Since more that one subtype has been reported in the same sample, the presence of HPV 6-11 sequences does not exclude that other subtypes might be involved. The results of this study show that: 1) HPV is present in JLP. 2) The most frequent HPV subtype involved was from the 6-11 group. 3) PCR can be successfully used in archived tissue routinely processed in a laboratory of pathology.

Cytomegalovirus-associated Ménétriers disease in adults. Demonstration by polymerase chain reaction (PCR).

Ménétriers disease (MD) is a rare form of hypertrophic or hyperplastic gastropathy characterized by conspicuous thickening of the gastric mucosal folds and foveolar (crypt) hyperplasia. We examined the presence of cytomegalovirus (CMV) in 2 cases of MD in adults, one associated with gastric carcinoma, using the polymerase chain reaction (PCR). None of the cases showed intranuclear inclusions consistent with CMV infection. Both revealed, besides the features of MD, a peculiar pattern of [quot ]chronic active plasmacellular gastritis[quot ]. Although the samples had been stored in formalin for more than 10 years CMV-DNA was recovered with good yield from both samples. The demonstration of CMV in MD in adults may helps to explain present knowledge of the complex relationships between this virus and gastric mucosa, and strongly suggests a pathogenetic role of the virus with variable phenotypic expression along the years.

Delitos sexuales: relevamiento de las solicitudes de cotejo durante el 2001 / Sexual offenses: relevance of comparison requests for 2001

El Laboratorio de Inmunogenética es un organismo dependiente de la Suprema Corte de Justicia de la provincia de Buenos Aires. Durante el año 2001 ingresaron 295 pedidos de delitos sexuales, abarcando violaciones (41,4 por ciento), violaciones agravadas (18,7 por ciento), violaciones seguidas de muerte (2,2 por ciento), abuso sexual (28,4 por ciento), abuso deshonesto (7,2 por ciento) y estupro (2,1 por ciento). En un 22 por ciento las víctimas fueron menores. En un 34 por ciento el autor permanece desconocido. En el 45 por ciento del total de los casos analizados, se observó correspondencia entre el genotipo detectado en las evidencias y el imputado, mientras que un 20 por ciento resultaron exclusiones. Como conclusión del relevamiento surge la necesidad de implementar una base de datos (AU)