Population genetics of nine short tandem repeat loci: allele frequency distribution in a Brazilian population sample

Gene and genotype frequencies in relation to the D3S1358, vWA, FGA, TH01, TPOX, CSF1PO, D5S818, D13S317, and D7S820 loci were determined in a sample of 290 unrelated individuals (204 Caucasians and 86 mulattoes) living in the city of S?o Paulo, Brazil. The sex test Amelogenin was also performed in all subjects from our sample, revealing the expected sex in all instances. Allele frequency data obtained from the analysis of these samples were in the usual range of other population groups with similar racial background. In the sample of Caucasian individuals, panmictic proportions were ruled out in relation to TPOX and CSF1PO loci, but only in the latter was the overall frequency of heterozygotes significantly less than expected. In the sample of mulattoes, Hardy-Weinberg proportions were rejected in relation to FGA and CSF1PO loci, but in no instance were the overall numbers of heterozygotes different from the corresponding expected ones under panmixia. Taking into account all this and also the number of tests performed, the degree of genetic heterogeneity of Brazilian populations, and the critical level reached by the significant results (1% < alpha<5%), the departures from panmixia here observed can be considered to be negligible in altering significantly biologic relationship odds calculated under the assumption of random matings.     

Basic education clusters in Cambodia: looking at the future while learning from the past

School clusters have been adopted as an education policy by most Asian countries since the 1960s. In Cambodia, primary schools have been organised in clusters since 1993. Clusters were considered a mechanism for quality improvements of education and a way to facilitate sharing and interaction between schools. Primary school clusters have been partially successful. Today there is a growing interest among Cambodian policymakers for integrating primary schools (Grades 1–6) and lower secondary schools (Grades 7–9). This article provides a policy suggestion by arguing for extending the cluster mechanism to these integrated basic education schools with all grades from 1 to 9.     

Community participation in local governance in Cambodia: learning from the village networks approach

Cambodia has embarked on a process of decentralisation and democratisation, including the establishment of elected Commune Councils in early 2002. Given the lack of a tradition of encouraging civic participation in public affairs, however, there was initially little general awareness of how to engage with these Councils. The authors describe a project supported by the Ministry of Rural Development and the German bilateral agency, GTZ, and undertaken with local non-government organisations, to identify and support active community groups and improve their capacity to interact with the Commune Councils, while at the same time seeking ways for the Commune Councils to support the different groups.     

A case of sudden infant death due to a primary cardiac sarcoma

The case reported herein concerns the unexpected death of a 3-month-old female newborn who suddenly collapsed in her mother's arms and was dead on arrival at the hospital. The clinical histories of the baby and her parents were negative for symptoms or signs of illness, even those of cardiovascular origin. Furthermore, no clinical appearance of a pathologic status was noted by pediatricians after the birth until the last emergency recovery. The autopsy excluded external and internal signs of violence but revealed a large primary cardiac tumor arising from the free wall of the left ventricle, which had totally invaded the heart causing mitral valve deformation. Histological examination showed a low-grade sarcoma that completely infiltrated the myocardial tissue. The pathogenesis of this sudden infant death was postulated as being owing to a fatal ventricular fibrillation combined with a tumor-related restrictive cardiomyopathy obstructing left ventricular filling.     

Y-STRs in forensic medicine: DNA analysis in semen samples of azoospermic individuals

ABSTRACT: The incidence of rape has increased, especially in metropolitan areas, such as the city of São Paulo. In Brazil, studies about it have shown that the majority of this type of crime is committed by the relatives and persons close to the victim. This has made the crime more difficult to be denounced, as only 10% of the cases are reported to competent police authorities. Usually, cytological exams are carried out in sex crime investigations. The difficulty in showing the presence of spermatozoa is frequent, but it does not exclude the presence of male DNA. The absence of spermatozoa in material collected from rape victims can be due to several factors, including the fact that the agressor suffers from azoospermia. This condition can be the result of a successful vasectomy. As the majority of DNA in the ejaculation sample is from spermatozoa, there is much less DNA to be analyzed. This study presents the application of Y‐STRs (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, and DYS393) in DNA analysis of sperm samples from 105 vasectomized men. The study demonstrated a great variation in DNA concentration. DNA extraction and amplification was possible in all sperm samples even in the absence of spermatozoa. The same profile was observed, for each individual, from DNA extracted from blood, pre‐ and postvasectomy semen samples. The use of markers specific for Y chromosome in sex crime cases, especially in the absence of spermatozoa, is very important, mainly because in most situations there is a small quantity of the agressor's DNA in the medium and a large quantity of the victim's DNA.     

Analysis of DNA profiles extracted from degraded samples from archival of formalin fixed tissue included in paraffin (FFTIP) and hairs

The possibility of studying DNA extracted from archival of formalin fixed tissue included in paraffin (FFTIP) enables valuable retrospective investigations. However, according to some authors it is difficult to obtain genomic DNA of good quality, since the process of fixation often results in fragmentation of DNA. In order to evaluate the quality and quantity of DNA extracted, necropsy samples of FFTIP (spleen/lung) and hairs, with or without bulbs, were analyzed using three methods of extraction (QIAamp DNA mini, QIAamp DNA micro-kit and phenol–chloroform followed by microcon YM-30). The amount of DNA recovered was quantified by spectrophotometer. The β-actin, amelogenin gene and the profiles of STR were analyzed. Based on experimental results, a general guideline concerning the appropriate extraction method according to the tissue and the quantity of the starting material for the analysis of DNA from FFTIP and hairs could be suggested.     

A qualitative study of compact bone microstructure and nuclear short tandem repeat obtained from femur of human remains found on the ground and exhumed 3 years after death

Forensic identification of human remains is composed of anthropological study of race, sex, age, etc. By using these traditional methods, inconclusive or nonidentified cases could be subjected to DNA analysis. However, in spite of advances in human identification techniques, especially by PCR-amplified DNA, some limitations that affect the ability of obtaining DNA from human remains still persist. Light microscope sections of postmortem compact bones from human remains are presented here for the purpose of increasing a forensic examiner's prediction of successful nuclear DNA typing. Femoral compact bones were obtained from 7 human remains found on the ground, in different degrees of decomposition, and were cleaned by boiling to remove soft tissues, 8 collections of bones having undergone natural decomposition, not boiled (as no soft tissue was adhered), and 5 cadavers 12 to 16 hours postmortem. The histologic sections were stained by hematoxylin and eosin, the loci CSF1PO, TPOX, TH01, F13A01, FESFPS, vWA, D16S539, D7S820, D13S317, and amelogenin were amplified by PCR, and the polyacrylamide gel was stained with silver. The results presented here clarify questions concerning the viability of DNA for identification analysis, and they also may help to establish better strategies for optimization of DNA extraction and analysis in compact bones of human remains.     

A standard procedure for accommodating forensic anthropological and genetic analysis of decomposing human remains from tropical climates

At the Medical Legal Center in Ribeirão Preto, Brazil (CEMEL/FMRP-USP), unidentified decomposing bodies routinely undergo soft tissue removal (by immersion in water at 80–90 °C for 24 h) prior to an anthropological analysis intended to yield a biological profile of age, sex, ancestry, height, pathology and so on. In the event that this analysis is unsuccessful, samples may be submitted for DNA profiling. The tropical climate and the defleshing process may confound preservation, recovery and analysis of DNA, however. In order to establish an optimal standardized protocol for identification of decomposing human remains from a tropical climatic region, the outcome of anthropological and genetic analyses was compared, along with the utility of bone (mainly femur and sternum) and teeth (mainly molar) specimens for DNA analysis. In a sample (n = 39) of partially skeletonized remains, anthropological analysis was sufficient for identification in eight cases. In further six cases, DNA profiling was successfully attempted. As a consequence of our study, we recommend collection of 1–2 well preserved teeth prior to defleshing and anthropological analysis in these circumstances.     

A Fatal Mediastinitis Due to a Neck Trauma from an Undeclared Assault

History of neck trauma should be promptly investigated in patients with severe infections of the chest as mediastinitis. We present a forensic case of a death due to a mediastinitis in a patient with an undetected fracture of the superior horn of the thyroid cartilage that was exclusively revealed at autopsy examination. Histological analyses of the neck tissues showed signs of pharyngeal mucosal microperforation caused by the fracture and surrounded by an inflammatory reaction. The fracture was caused by a not declared manual strangulation attempt, happened several days before medical evaluations. We share our experience to emphasize the importance of revealing the etiologies of fatal infections of the mediastinum both for clinical and forensic purposes.