New alginate-gelatine method for casting of staining inside firearm barrels.

Contact shots to the head often leave behind biological traces inside firearm barrels, a phenomenon of great forensic interest. Until now, the visualization and preservation of these traces presented a significant challenge, lacking a reliable method. This study addresses this gap by searching for a suitable method to extract the traces within a casting. Using alginate or gelatine as suitable materials, the results were hampered by serious adhesion issues and their extraction out of the firearm barrel was impeded. Finally, the combination of 11% gelatine with 1% alginate, introduced into the barrel around a 'central spine', succeeded to consistently produce replicable castings. Experimental contact shots displayed a distinct staining gradient from the muzzle to the rear of the barrel, as revealed through endoscopy and proved in the macroscopic casting. The technique proved effective for various common handgun barrels and successfully preserved blood and gunshot residue (GSR) patterns within the barrel. This method offers the dual benefits of visually mapping staining patterns and securing localized samples for targeted molecular genetic analysis in forensic investigations.

Lack of association of a 9 bp insertion/deletion polymorphism within the bradykinin 2 receptor gene with myocardial infarction.

The BK (bradykinin) B2 receptor is the major cellular mediator of the effects of BK. A 9 bp deletion in the promoter of the receptor gene represents an allelic variant that is associated with enhanced mRNA expression levels. We tested whether this polymorphism is associated with the prevalence of MI (myocardial infarction) or with echocardiographically determined left ventricular function in post-MI patients. Patients with documented MI (n=484), matched controls and controls without evidence of coronary heart disease (n=1363) constituted cases and controls. MI patients and controls were carefully matched for age, gender and cardiovascular risk factors. Genotype distributions of the 9 bp insertion/deletion polymorphism were similar across the groups: -9/-9, -9/+9 and +9/+9 were 22.1, 49.5 and 28.5% in MI patients, and 23.0, 44.6 and 32.5% in matched control subjects respectively. The lack of association was also observed in selected subgroups, stratified by age, gender and cardiovascular risk factors. Furthermore, there was no relation between this polymorphism and left ventricular systolic function in post-MI patients. These findings indicate that the 9 bp insertion/deletion polymorphism of the BK B2 receptor gene is neither related to the prevalence of MI nor to left ventricular function after MI.