Ryoji Matoba

Cardiac muscle lesions associated with chronic administration of methamphetamine in rats.

Cardiovascular complications associated with methamphetamine abuse have increasingly been reported. However, chronic cardiotoxicity of methamphetamine is not experimentally well documented. In this study, methamphetamine (1 mg/kg/day) was subcutaneously injected into 5-week-old male Wistar Kyoto rats (n = 30). Age- and sex-matched Wistar Kyoto rats served as controls (n = 30). After 14 and 56 days, hearts were examined by light and electron microscopy. Foci of myocytic degeneration and necrosis appeared in the sub-endocardial areas on day 14 of methamphetamine exposure. Myocytic degeneration and necrosis became more extensive on day 56. At this stage, myocytolysis, contraction bands, atrophied myocytes, and spotty fibrosis were patchily distributed throughout the myocardium in most of rats treated with methamphetamine. The accompanying ultrastructural features included marked degeneration of cardiac mitochondria with fractured and disrupted cristae, hypercontraction of myofibrils, and loss of myofilament. In contrast, cardiac myocyte lesions were not observed in control rats. These myocardial lesions in rats treated with methamphetamine for 56 days resemble the cardiomyopathy associated with methamphetamine abuse in humans.

Event-related brain potentials as indicators of visual recognition and detection of criminals by their use

An event-related potential (ERP) was recorded, using photographs as stimuli, in 12 subjects for attended, 9 subjects for non-attended conditions and 14 subjects for a simulated criminal investigation. An ERP was detected only when a subject recognized a familiar image (target) mixed with other, unfamiliar images (non-target), regardless of whether he was asked to attend to or neglect the target image. ERPs in the subject who watched each picture but tried to ignore the relevant picture (non-attended) were more activated at the parietal region than at the central region, in contrast with ERPs in the subjects who paid attention to each picture without trying to ignore the relevant picture (attended). In the simulated criminal investigation, only a simulated thief, but not a simulated innocent subject elicited ERP only after the picture of a criminal site or thing was intermingled with pictures bearing no relationship to the crime. These findings indicate that the ERP using photographs as stimuli is useful as an objective indicator of crime-relevance.

A New Criterion of Classification on Sudden Infant Death (Sid) Cases of Japan Sids Research Society

A New Criterion of Classification on Sudden Infant Death (Sid) Cases of Japan Sids Research Society