Effect of acute exposure of triazophos on oxidative stress and histopathological alterations in liver, kidney and brain of Wistar rats.

Acute dose of organophosphorus pesticide Triazophos (O,O-diethyl O-1-phenyl-1H-1,2,4-triazol-3-yl phosphorothioate; Tz) administered orally affects oxidative stress parameters and the histo-architecture of liver, kidney and brain tissues. The results indicate a dose dependent induction of oxidative stress as evident by increased malondialdehyde level and decreased antioxidant defense including glutathione and superoxide dismutase activity in rat liver, kidney and brain. AChE activity was found significantly decreased in the Tz treated groups as compared to the vehicle control (DMSO) group. Histopathological examination of liver, kidney and brain in Tz treated rats revealed medullary congestion and hydropic degeneration of hepatocytes in liver and medullary congestion in kidney. However, no significant histopathological changes were observed in brain tissues.

Validation of qualitative test for phosphine gas in human tissues.

Phosphine has been known to science since the birth of modern chemistry. WHO reports that the technical product usually has a foul odour, like "fishy" or "garlicky" because of the presence of substituted phosphines and diphosphine (P2H4). Many medico-legal autopsy cases have been reported positive for aluminium phosphide even though there was neither any suspicion of consuming aluminium phosphide nor any clinical findings, postmortem findings or circumstantial evidences. The present study was carried out to validate the qualitative test, presently applied in many laboratories for testing phosphine. It was observed that 65% of human tissues in saturated solution of common salt show positivity for phosphine gas on the first day of autopsy.

Application of DNA fingerprinting in medicolegal practice.

Fingerprinting is thought to establish the identify of an individual in forensic cases. The technique is extensively used for forensic purposes. Deoxyribonucleic acid (DNA) is the vehicle of generational transference of heritable unit. While arching markers for genetic disease professor Alec Jeffreys discovered that certain regions of DNA showed variations in the number of tandem repeats known as variable number of tandem repeats (VNTRs). Thus DNA fingerprint was named by observing the number of repeated sequences which differ from individual to individual. The structure of DNA is quite flexible, within the nucleus of each cell resides an identical copy of the individual's genetic material, DNA. The coding regions of the genomic DNA are known as genes. The DNA fingerprinting in forensic science has generated considerable excitement in the criminal justice community. DNA fingerprinting can be applied to identify an individual in criminal and civil cases. Polymerase chain reaction has revolutionised molecular biology it has an ability to amplify (usually fewer than 3000 bp) a particular sequence of DNA into million of copies in a very short period. Consequently only a very tiny amount of an organism's DNA needs to be available originally. This property of polymerase chain reaction has enabled to analyse many forensic samples particularly which are degraded. Microsatellite DNA or commonly as short tandem repeats are scattered throughout the human genome and occur on an average of every 10,000 nucleotides. Microsatellite markers are considered to be the most powerful genetic markers. Collection, preservation and handling are the integral part of DNA fingerprinting analysis. There are various methods to isolate DNA from different biological materials but presently most of the laboratories prefer using FTA paper. The age of humans can be estimated by using DNA based on telomere shortening.