RESUMO
Bite mark evidence has been repeatedly found in criminal cases. Physical comparison of a bite mark to the teeth of available suspects may not always be possible. Experimental studies have shown that the analysis of DNA present in the saliva recovered from bite marks might help in the identification of individuals. However, the application of this approach to an actual criminal case has been reported only once before in forensic literature. Therefore, there is very limited scientific and technical information available on this subject. The current study focuses on a woman found dead in her home; the autopsy ruled the death to be a result of manual strangulation. A bite mark was found on each breast. The single swab technique was used to collect evidence from these bite marks, and an organic extraction method was employed for DNA isolation. Short tandem repeat (STR) sequence typing was performed using a commercially available kit, and the result was compared to the STR profile of a suspect. A full single-source STR profile was obtained from both bite marks, which matched the STR profile of the suspect. To the best of our knowledge, this is the second report on the analysis of DNA isolated from bite marks on the victim used to identify the crime perpetrator. Our results indicated that, contrary to most theoretical indications, a single swab technique for evidence collection and an organic method for DNA isolation could be very useful in solving this class of criminal cases.
Assuntos
Mordeduras e Picadas/diagnóstico , DNA/isolamento & purificação , Biologia Molecular/métodos , Saliva/metabolismo , Feminino , Humanos , Masculino , Repetições de Microssatélites/genética , Pessoa de Meia-IdadeRESUMO
Glutathione S-transferases (GSTs) are a family of phase II metabolizing enzymes involved in carcinogen detoxification and the metabolism of various bioactive compounds. Several genes that code for these enzymes are polymorphic in an ethnicity-dependent manner, with particular genotypes previously associated with an increased risk of breast cancer. The purpose of this study was to determine the frequencies of polymorphisms in the genes GSTM1, GSTT1, GSTP1, and GSTM3 and to investigate whether an association exists between these genes and breast cancer risk in subjects from northeastern Mexico. Genotypes were determined for 243 women with histologically confirmed breast cancer and 118 control subjects. Gene polymorphisms were analyzed using a DNA microarray. We found an increased breast cancer risk associated with the GSTM1 gene deletion polymorphism (OR = 2.19; 95%CI = 1.50-3.21; P = 0.001). No associations between the GSTT1, GSTP1, and GSTM3 genotypes and neoplasia risk were observed. In conclusion, we determined the genotype distribution of GST polymorphisms in control subjects and breast cancer patients from northeastern Mexico. The GSTM1 null genotype was associated with breast cancer risk. Our findings may be used to individualize breast cancer screening and therapeutic intervention in our population, which displays ethnic characteristics that differentiate it from other populations in Mexico.
Assuntos
Neoplasias da Mama/genética , Glutationa S-Transferase pi/genética , Glutationa Transferase/genética , Neoplasias da Mama/patologia , Detecção Precoce de Câncer , Etnicidade/genética , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , México , Polimorfismo de Nucleotídeo Único , Fatores de RiscoRESUMO
Ethyl methanesulphonate (EMS) is a mutagenic alkylating agent that induces marked elevations of sperm abnormalities in mice. In this paper, we report the ultrastructural findings on the morphology of the seminiferous epithelium of mice resulting from EMS administration. Eight- to twelve-weeks-old male mice were injected intraperitoneally with EMS at 200 mg kg(-1) body weight daily for five consecutive days. Analysis of smears of epididymis and semi-thin sections of testes revealed that the more suitable specimens for the ultrastructural analysis were tissues of mice killed at the third week, following EMS administration. At this time, the spermatid was the damaged cell type. Abnormalities were mainly observed in the morphology of the nucleus, the acrosome, chromatin distribution and in the arrangement of the cytoplasmic microtubules, and binucleated spermatids were also observed. EMS has the capacity to penetrate the blood-testis barrier, and thus it can damage post-meiotic spermatogenic cells. However, morphological abnormalities could be the consequence of damage exerted on the differentiated spermatogonia stage, the most sensitive spermatogenic cell to the action of chemical agents or drugs. Our findings contribute to elucidate the action mechanism of the damage exerted by EMS administration on the germinal male cells.
Assuntos
Metanossulfonato de Etila/toxicidade , Mutagênicos/toxicidade , Epitélio Seminífero/efeitos dos fármacos , Epitélio Seminífero/ultraestrutura , Animais , Masculino , Camundongos , Espermátides/efeitos dos fármacos , Espermátides/ultraestruturaRESUMO
Aedes albopictus was found in M. Muzquiz, Coahuila, Mexico, in the summer of 1993. Aedes albopictus larvae were collected in tires and bottles at low density. Aedes aegypti, Toxorhynchites theobaldi, Culex quinquefasciatus, and Culiseta incidens were collected in the same containers.