Gender identification of highly degraded DNA extracted from human compact bone samples

The present work revealed a sensitive and reliable method for sex typing of degraded DNA extracted from bones subjected to different environmental conditions, based on amplification of the single- copy X- Y homologous amelogenin gene using nested PCR technology. The success of retrieval of amplifiable amelogenin was related to the storage conditions, bones exposed to open air were found to provide sufficiently preserved DNA, followed by sand buried bones then sea water submerged samples. The success rate of the amelogenin amplification was 88.9%, 66.7% and 46.7%, respectively. Moreover, the method of DNA extraction with high salt, followed by phenol- chloroform gave the best results. This test enabled gender identification from as low as 3 ng DNA, suggesting that even a small fragment of a bone was sufficient to carry out the procedure of isolation of DNA for sex typing

Immunohistochemical labelling of prostate specific antigen in prostatic and some non-prostatic tissues

Prostate specific antigen [PSA] has traditionally been considered a marker unique to prostatic tissue. However, several recent reports on positive immunostaining for PSA in autopsy normal non-prostatic tissue samples have been documented. Hence the present study was carried out to investigate the expression of PSA in prostatic tissue at two postmortem intervals and to evaluate the prevalence of PSA immunoreactivity in some normal tissue samples of both sexes. Prostate, kidney, brain and pancreas tissue samples were collected from 16 healthy adult autopsied subjects [10 males, 6 females]. All of them were hospital deaths with a definite death time with the only cause death is trauma. The studied samples were taken at five and ten hours after death and all of them were stained with H and E and immunohistochemical PSA. The present study demonstrated that both the intensity and the distribution of PSA in prostate tissue appeared to be influenced by the time period between death and the collection of tissue during autopsy at five hours after death, prostate tissue showed strong positive PSA immunostaining in both glandular epithelium and fibromuscular stoma whereas moderate PSA positivity restricted to glandular epithelial cells together with heterogenity in the strength of PSA reactivity within the same specimen was noticed ten hours after death. Moreover, male tissue samples showed weak and focal PSA reaction principally in some collecting ducts and tubular cells of the kidney and in ductal cells of the pancreas, also weak and diffuse reaction was seen in brain tissue while female tissue samples showed absent PSA positive reaction. This finding raises certain issues regarding the value of using immunohistochemistly for tissue sexing