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M Iyo

Publications and source records attributed to M Iyo.

74 records · Page 5Linked to original sources

Linkage disequilibrium and association with methamphetamine dependence/psychosis of mu-opioid receptor gene polymorphisms.

Several studies indicate that the mu-opioid receptor plays a role in addiction not only to opiate drugs but also to alcohol and non-opiate addictive drugs. Our studies aim to reveal the associations between gene polymorphisms and methamphetamine (MAP) dependence/psychosis. We newly identified several polymorphisms and four substantial linkage disequilibrium (LD) blocks in the mu-opioid receptor (OPRM1) gene. We found significant differences in both genotype and allele frequencies of the single-nucleotide polymorphism (SNP) IVS2+G691C between control (n=232) and MAP-dependent/psychotic patients (n=128). There was also a significant association between IVS2+G691C and patients with transient psychosis. These results suggest that the OPRM1 gene variations may be a factor in development and prognosis of MAP psychosis.

Adult↗

Differential pattern of the circadian rhythm of serum melatonin in young and elderly healthy subjects.

The daily profile of serum level of melatonin was studied in 10 young and 13 elderly subjects. All of the subjects were physically and psychiatrically healthy and did not have any clinical symptoms related to rhythm disturbance. Blood samples were taken every 3 h for 1 day and serum melatonin levels were determined by RIA. All except for 1 of the elderly subjects exhibited a clear circadian rhythm of serum melatonin level with a nocturnal peak. In both subject groups, the melatonin rhythm showed significant diurnal variation. There was no significant difference in the total melatonin level per day between young and elderly groups, suggesting that there was no influence of aging on daily total melatonin secretion. However, there was a marked difference in the features of the melatonin rhythm between the two groups, i.e., a rapid decline of the melatonin level from the nocturnal peak in the elderly group, suggesting that the off-set time of melatonin secretion advances with aging. Our findings suggest that the pattern of melatonin rhythm alters significantly without clear clinical symptoms in the process of senescence.

Adult↗