To study the effects of aging and gender, circadian profiles of heart rate variability were evaluated for 105 healthy volunteers by frequency domain analysis of a Holter electrocardiogram record. The low-frequency (LF) component representing cardiac beta-adrenergic function showed high values for the 0800-1200 period in male subjects and the 1200-2400 period in female subjects. The high-frequency (HF) component representing parasympathetic function showed a peak for the 0000-0600 period in both male and female subjects independent of age. Male subjects showed significantly higher %LF [LF/(LF + HF) x 100] than female subjects. LF showed consistently highly significant correlation with age. These basic findings can help elucidate the diurnal profile of cardiac nerve function and how it is affected by aging and sex difference.

The high-density-lipoprotein-associated enzyme paraoxonase, which has a role in the detoxification of organophosphorus compounds, is known to be polymorphic in humans. The Arg192 isoform of paraoxonase hydrolyzes paraoxon more rapidly than the Gln192 isoform. However, with respect to the hydrolysis of toxic nerve agents, such as diazoxon, soman, and sarin, the Arg192 isoform displays a lower activity than the other isoform. To evaluate the possibility that the genetic polymorphism was involved in the aggravated extent of human injury in the sarin gas poisoning incident in the Tokyo subway in March 1995, we investigated the prevalance of this polymorphism in the Japanese population. We found that the Arg192 allele is more common in the Japanese (allele frequency: 0.66) than in people of other races (ranging 0.24-0.31). In the Japanese, 135 out of the 326 subjects (41.4%) investigated were homozygous for the Arg192 allele, which shows a very low hydrolysis activity for sarin. Thus, there seems to be a racial difference in vulnerability to toxic nerve agents, such as sarin. The dominance of the Arg192 allele in the Japanese population probably worsened the tragedy of March 1995 in the Tokyo subway.

No abstract

Our findings suggest that impairment of myocardial FFA metabolism rather than small vessel abnormalities in the myocardium is responsible for modest left ventricular dysfunction in patients with diabetes.

A sensitive and specific radioimmunoassay system for rat plasma cholecystokinin (CCK) was employed to study the effect of trypsin inhibitor on plasma CCK levels. Feeding the trypsin inhibitor, FOY-305 200 mg/kg, to rats for 10 days stimulated the pancreatic growth. However, there was no significant difference in fasting plasma concentrations and duodenal contents of CCK and secretin. On the other hand, acute ingestion of same dosage of FOY-305 caused a marked (20-fold) and sustained elevation of plasma CCK levels. The principal form of circulating CCK was CCK-22 like on Sephadex G-50, in contrast to that of the cerebrum and duodenum where CCK-8 like form, or CCK-8 and CCK-22 like forms were main components, respectively. A significant rise in plasma levels of immunoreactive secretin was also found. These results suggest that the pancreatic growth observed by feeding the trypsin inhibitor to rats is caused by an excessive amount of CCK in conjunction with secretin.