Biomedical subjects

R N Oliveira

Publications and source records attributed to R N Oliveira.

3 recordsLinked to original sources

PubMed2002

Population studies of the Y-chromosome of loci DYS390, DYS391 and DYS393 in Brazilian subjects and its use in human identification.

Human identification can be accomplished by several technical procedures, especially by the comparative analysis of dental documents. Recent advances in molecular biology have now widened the scope for human identification and defined the protocols for the collection of biological material. Allele patterns of a population are particularly useful and they should be verified since they vary in different populations. We have studied the frequency of the alleles in three STR loci of the Y chromosome (DYS390, DYS391 and DYS393) in a group of Brazilian caucasian subjects. Results presented alleles 21, 22, 23, 24, 25 and 26 in locus DYS390, alleles 8, 9, 10, 11 12 and 13 in STR DYS391 and alleles in STR DYS393 were 11, 12, 13 14 and 15. The highest frequencies were 24 (0.46), 11 (0.37) and 13 (0.45). Each of the three STR systems had a PE (power of exclusion) of 0.6764 (DYS390), 0.5988 (DYS391) and 0.6136 (DYS393), The combination of the three STR systems revealed a PE of 0.9498, suggesting that this data can help in human identification.

Alleles↗

PubMed2000

Postmortem tooth loss in human identification processes.

Teeth provide essential data for human identification. However, they are frequently lost during the process of skeletonization or under manipulation during exhumation. Because of the high frequency of postmortem tooth loss, this phenomenon was examined in three different samples, in an attempt to simulate the actual circumstances experienced in the forensic processes of identification of human remains. The method employed aimed to describe and quantify dental spaces, distinguishing between loss after death or before by extraction. The results showed a high prevalence of postmortem tooth loss: 41.37% in sample A, 56.83% in sample B and 3.96% in sample C. These losses were most frequent in the maxillary incisor group in all three samples analysed. These data underline the need for redoubled care in recovery, transportation and storage of crania, so that teeth are not lost, which could seriously compromise the identification process.

Forensic Dentistry↗

PubMedDate not supplied

[Evaluation of 3 methods of DNA extraction from paraffin-embedded material for the amplification of genomic DNA using PCR].

There are several protocols reported in the literature for the extraction of genomic DNA from formalin-fixed paraffin-embedded samples. Genomic DNA is utilized in molecular analyses, including PCR. This study compares three different methods for the extraction of genomic DNA from formalin-fixed paraffin-embedded (inflammatory fibrous hyperplasia) and non-formalin-fixed (normal oral mucosa) samples: phenol with enzymatic digestion, and silica with and without enzymatic digestion. The amplification of DNA by means of the PCR technique was carried out with primers for the exon 7 of human keratin type 14. Amplicons were analyzed by means of electrophoresis in an 8% polyacrylamide gel with 5% glycerol, followed by silver-staining visualization. The phenol/enzymatic digestion and the silica/enzymatic digestion methods provided amplicons from both tissue samples. The method described is a potential aid in the establishment of the histopathologic diagnosis and in retrospective studies with archival paraffin-embedded samples.

DNA↗