1/3. Pathogenesis of unexplained drowning: new insights from a molecular autopsy.OBJECTIVE: To perform a molecular autopsy involving the RyR2-encoded cardiac ryanodine receptor/calcium release channel to determine whether mutations responsible for catecholaminergic polymorphic ventricular tachycardia (CPVT) represent a novel pathogenic basis for unexplained drownings. methods: A cardiac channel molecular autopsy was performed on 2 individuals who died of unexplained drowning and whose cases were referred to the Sudden death genomics Laboratory at the Mayo Clinic in Rochester, Minn. Comprehensive mutational analysis of all 60 protein-encoded exons of the 5 long qt syndrome-causing cardiac channel genes and a targeted analysis of 18 RyR2 exons known to host RyR2-mediated CPVT-causing mutations (CPVT1) was performed using polymerase chain reaction, denaturing high-performance liquid chromatography, and dna sequencing. RESULTS: Both individuals harbored novel mutations in RyR2. Postmortem mutational analysis revealed a familial missense mutation in exon 14, R414C, in a 16-year-old girl. A 9-year-old boy possessed a sporadic missense mutation in exon 49, V2475F. Both amino acid positions involve highly conserved residues that localize to critical functional domains in the calcium release channel. Neither substitution was present in 1000 reference alleles. CONCLUSIONS: This molecular autopsy study provides proof of principle that RyR2 mutations can underlie some unexplained drownings. A population-based genetic epidemiology study that involves molecular autopsies of individuals who die of unexplained drowning is needed to determine the prevalence and spectrum of KCNQ1 and now RyR2 mutations as potential pathogenic mechanisms for drowning.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
2/3. Studies on the composition of gases in the post-mortem body: animal experiments and two autopsy cases.The composition of gases was measured in a cadaver, particularly in the stomach, using gas chromatography. High concentrations of carbon dioxide (CO2) and hydrogen (H2) and a low concentration of methane (CH4) were found. At an environmental temperature of 25 degrees C, the concentrations of CO2 and H2 were approximately 80% and 10%, respectively, at an advanced stage of putrefaction, while at an environmental temperature of 15 degrees C the concentrations were approximately 60% and 35%, respectively. These gases were not produced until the fourth day at 15 degrees C, but after that the volume of gases was greater than that produced at 25 degrees C, the cadaver becoming greatly enlarged. oxygen (O2) in air injected into a body disappeared during putrefaction. This study revealed that H2 was the main component of inflammable gas in a dead body. The mechanisms of production of the gases are also discussed.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
3/3. Detection of bathsalts in the lungs of a baby drowned in a bathtub: a case report.This case is one in which a baby was found dead, apparently drowned in a bathtub. To confirm the inhalation of bathwater, an extract taken from the baby's lungs was analyzed with high-performance liquid chromatography. Bathsalts contained in the bathwater were detected in the extract. Bathsalts are usually used in home bathtubs and, as a dye material, they contain fluorescein which is highly sensitive to detection. The presence of fluorescein in the lung tissue and in the other tissues greatly helps to confirm the bathwater drowning.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |