Detection of cotinine in neonate meconium as a marker for nicotine exposure in utero

Neonate meconium cotinine level was evaluated as a marker of prenatal exposure to nicotine from tobacco smoking by mothers. Mothers admitted to a maternity hospital in Alexandria, Egypt, were divided into 3 groups: 10 active smokers, 10 passive smokers and 10 with no tobacco exposure during pregnancy. Urine and saliva samples were collected from mothers and first-day meconium samples from their neonates. Mean maternal urinary cotinine levels, measured using radioimmunoassay, differed significantly between the 3 groups, as did mean salivary cotinine and mean cotinine levels in meconium.There was a significant positive correlation between cotinine levels in meconium and both maternal urinary and salivary cotinine levels. Meconium is an ideal biological marker for testing direct fetal exposure to tobacco smoke in the neonatal period

DNA extraction and amplification from formalin fixed paraffin embedded tissues

Tissue preservation is very important in clinical settings for subsequent histological studies or genetic diagnosis. It is also critical in forensic investigations where human remains are collected for positive identification following plane crashes, terrorist bombings, homicides, and mass murders. Historically, formalin fixed [FF] tissues could not be used as a source of DNA in forensic science due to the fact that the DNA was too degraded for DNA analysis. With the introduction of the polymerase chain reaction [PCR] technique to forensic science, the usefulness of DNA from this biological material has been re-evaluated. This study attempts to evaluate the applicability of formalin fixed paraffin embedded [FFPE] tissue fit into the field of forensic science by examining these tissues as a source of DNA and applying current methodology. The study was conducted on 35 formalin fixed paraffin embedded [FFPE] different tissue samples [liver, kidney, lymphoid tissue, colon] prepared by and received from the Pathology Department at the Alexandria Faculty of Medicine. These tissues were removed at autopsy and put in 10% buffered neutral formalin [BNF] for a period of 24 to 48 hours. The tissues were then processed in an automated tissue processor. The samples were stored at room temperature for 24 months before processing. After getting rid of paraffin by using ParaClear reagent, the DNA was extracted by the organic phenol-chloroform method. The quantity and quality of the extracted DNA was evaluated by running a yield gel. The exact concentration of the extracted DNA was determined using the QuantiBlot[R] Human DNA Quantitation Kit. The extracted DNA was amplified for 3 forensic PCR systems: the AmpliType PM+DQA1, AmpliFLP D1S80, and The AmpFlSTR Profiler Plus, the three systems include 16 PCR loci; HLA DQA1, LDLR, GYPA, HBGG, D7S8, GC, D1S80, D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820 and amelogenin. The first six, HLA DQA1, LDLR, GYPA, HBGG, D7S8, and GC are typed by reverse dot blot, D1S80 is an amplified fragment length polymorphism [AmpFLP] system and the others are short tandem repeats [STRs]. This study showed that the DNA extracted from formalin-fixed, paraffin-embedded tissues is usually of adequate quality for PCR amplification using well characterized forensic PCR systems

Fatal Organophosphate insecticide poisoning. Clinical, light and electron microscopic study

Six victims who were admitted to Alexandria Poison Center and died due tosevere poisoning by organophosphate insecticides were investigated. Victimswere clinically examined and antidotes were given [atropine and toxogonin]before death. Antemortem serum cholinesterase activity was also determined ineach case. After death, samples were taken from liver and different areas ofbrain [cerebral cortex, midbrain and cerebellum]. All samples were processedfor light and scanning electron microscopy by the controlled manual fracturingtechnique. Six cases who died from car accidents were taken ascontrols for both cholinesterase determination and microscopic study. Thestudy recommended the necessity of examining the different areas of brainmicroscopically, particularly midbrain and cerebellum in cases of suspecteddeath from organic phosphate poisoning. The study also recommended theimportance of taking liver samples not only in autopsy cases but also frompersons exposed repeatedly to organic phosphate insecticides to indicate theextent of toxic effect of the insecticide itself as well as the organic solvent in which the insecticide is dissolved