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H Yoneda

Publications and source records attributed to H Yoneda.

At least 37 records · Page 2Linked to original sources
PubMed1998

Blunted natriuretic response to endogenous atrial natriuretic peptide during rapid cardiac pacing in anaesthetized dogs.

1. We investigated whether diuresis and natriuresis induced by endogenous atrial natriuretic peptide (ANP) were blunted during rapid cardiac pacing. 2. Changes in plasma ANP, renal function and haemodynamics during rapid cardiac pacing were studied in anaesthetized closed-chest dogs. Dogs were paced via the right ventricle at a rate of 200 b.p.m. (moderate pacing) or 250 b.p.m. (severe pacing) for 180 min. 3. The maximal increases in plasma ANP and urinary excretion of cGMP during severe pacing were four- and three-fold higher, respectively, than those during moderate pacing. Despite the higher concentration of plasma ANP, the maximal increases in urine volume, urinary excretion of sodium and fractional excretion of sodium during severe pacing were similar to those during moderate pacing. Mean arterial pressure and renal vascular resistance were decreased only by severe pacing. The increase in total peripheral resistance during severe pacing was significantly smaller than that during moderate pacing. However, the glomerular filtration rate was kept at basal levels by both moderate and severe pacing. 4. These results suggest that there are certain mechanisms that counteract renal tubular sodium reabsorption induced by endogenous ANP under conditions of severe pacing. The suppression occurs at tubular sites but at glomerular sites. One of the possibilities for the suppression is the decrease in renal perfusion pressure accompanied by decreases in peritubular capillary hydrostatic pressure.

Animals↗
PubMed1998

Relationships of disability, health management and psychosocial conditions to cause-specific mortality among a community-residing elderly people.

To examine the factors associated with cause-specific mortality, a cohort of 1,405 randomly selected elderly people aged 65 years and over living in Settsu, Osaka Prefecture, was followed up for 54 months. Multivariate analysis using Cox proportional hazards model identified male sex, age, disability, medical treatment, and no participation in social activities as independent factors for overall mortality. Use of health checks and daily health enhancing practices showed an independent negative association with overall mortality. As for cause-specific mortality, male sex was a constant factor for the three major causes of death: cancer, heart disease and stroke. Advanced age and no participation in social activities showed a close association with heart disease mortality, while disability and medical treatment were independent factors for death caused by stroke and cancer, respectively. Use of health checks and daily health enhancing practices exhibited a strong negative association with all three major causes of death. The same tendencies were seen after those who reported undergoing medical treatment for the index diseases of heart disease and stroke at entry were excluded. These results suggest that predictive factors for mortality vary for specific causes of death, but that health promoting measures contribute to a reduction in mortality related to three major causes of death, thus resulting in a decrease in overall mortality among the elderly.

Activities of Daily Living↗
PubMed1998

Mortality in relation to the type of household among elderly people living in a community.

The objective of this study was to determine whether there is an association of mortality with the type of household in elderly people. A cohort of 1,352 elderly people aged 65 years and over at baseline in October 1992 was followed for 42 months. Follow-up was completed for 1,266 (93.6%) (172 deceased and 1,094 alive). From the analysis using the Kaplan-Meier method and the log-rank test, male sex, older age group (75 years and over), no satisfaction with present dwelling, disability, no use of health checks, no practices of daily preventive health promotion, no participation in social activities, and no finding life worth living (no Ikigai) were univariately statistically significantly related to mortality. Furthermore, elderly people living with their spouse only or living alone had higher survival rates than those living with their spouse and children or living with their children, and the curves among the four subclasses of household were significantly different. From the Cox proportional hazards model, living with a spouse only remained as an independent predictor for survival, and living alone was not an increased risk factor for mortality, controlling for sex, age, housing conditions, disability, use of health management, and psychosocial conditions.

Aged↗
PubMed1997

T/G polymorphism at intron 9 of presenilin 1 gene is associated with, but not responsible for sporadic late-onset Alzheimer's disease in Japanese population.

To investigate whether presenilin 1 (PS1) gene, a major causative gene of familial early-onset Alzheimer's disease (AD), also contributes to the etiology of sporadic AD, we evaluated associations between Japanese AD and polymorphisms located at 14q24.3. While the D14S43 and FOS loci showed no association with either early- or late-onset AD, late-onset AD carrying no APOE-epsilon4 allele was associated with the G allele of the T/G polymorphism located at intron 9 of the PS1 gene (P = 0.016). Considering another study showing a positive association between AD and the T allele, this polymorphism is associated with, but not responsible for sporadic late-onset Alzheimer's disease.

Age of Onset↗
PubMed1997

Association between early-onset alcoholism and the dopamine D2 receptor gene.

We examined the allelic association between the dopamine D2 receptor (DRD2) gene and alcoholism in 100 biologically unrelated Japanese alcoholics and 93 unrelated controls. Genomic DNA was prepared from peripheral white blood cells using the phenol-chloroform method. A 310-bp region surrounding the TaqA site at the DRD2 locus was amplified by polymerase chain reaction (PCR), and the PCR product was incubated with TaqI. The A1 allele remained intact while the A2 allele was cut. The frequency of the A1/A1 genotype and the frequency of the A1 allele were higher in early-onset alcoholics than in controls, P < 0.05 and P < 0.01, respectively. Moreover, the frequency of the A1/A1 genotype and the frequency of the A1 allele were higher in early-onset alcoholics with family histories of alcohol dependence than in controls, P < 0.01 and P < 0.01, respectively. The results indicate that the DRD2 gene is associated with susceptibility to early-onset alcoholism, and that each additional A1 allele shifts onset of alcoholism to an earlier age.

Adult↗
PubMed1997

alpha 1-Antichymotrypsin as a risk modifier for late-onset Alzheimer's disease in Japanese apolipoprotein E epsilon 4 allele carriers.

In the Japanese population, sporadic late-onset Alzheimer's disease (LOAD) cases had significantly higher frequencies of the A allele of alpha 1-antichymotrypsin (ACT) gene as well as the epsilon 4 allele of apolipoprotein E (APOE) gene than controls. The odds ratio for LOAD in APOE4 carriers with the ACT-A allele was more than six times that in APOE4 carriers without the ACT-A allele (21.1 vs 3.2). These results indicate that the ACT-A allele is a risk modifier for LOAD in APOE4 carriers.

Age of Onset↗
PubMed1997

Effect of antipsychotic drugs on the gene expression of NMDA receptor subunits in rats.

It has been hypothesized that glutamatergic neurons play an important role in clinical manifestations of schizophrenia and that the therapeutic effect of antipsychotic drugs is related to glutamatergic neurotransmission. To elucidate the effect of antipsychotic drugs on glutamatergic transmission, we examined gene expressions of NMDA receptor subunits R1, R2A, R2B and R2C in the whole brains of rats after acute and chronic administrations of haloperidol and sulpiride, using the Northern blot technique. The levels of NMDAR2B mRNAs decreased after the acute administration of haloperidol, but showed no change after the chronic administration. The levels of NMDAR2A and R2B mRNAs decreased after the acute administration of sulpiride, whereas the levels of R2A and R2B increased following the chronic administration. Neither haloperidol nor sulpiride influenced NMDAR1 mRNA levels. These data support differential expression of NMDA receptor subunits in rats upon treatment with haloperidol and sulpiride. The results imply that NMDAR2 subunits may be crucial in the regulation and modification of antipsychotic drugs.

Animals↗
PubMed1997

Paracentric inversion of chromosome 9 with schizoaffective disorder.

A 36-year-old man with schizoaffective disorder was found to have a de novo 46 XY inv (9) (q31.2q34.3). Phenotypical abnormalities are short stature, depressed nasal bridge, hypertelorism and slender shoulders. Paracentric inversion of chromosome 9 is a rare chromosome aberration. This case suggests a new candidate region related to schizoaffective disorder.

Adult↗
PubMed1997

Location and action of angiotensin II type 1 receptor in the renal microcirculation.

To localize angiotensin II type 1a (AT-1a) receptor and to reveal the physiological roles of angiotensin II in the renal microcirculation, we investigated the AT-1a gene deficient mice, generated by a targeted replacement of the AT-1a receptor loci by the lacZ gene (Sugaya et al, J Biol Chem 270: 18719, 1995). Immunohistochemical localization of beta-galactosidase was performed in the heterozygous mutant mice to reveal the expression sites of AT-1a. The AT-1a receptor (that is, beta-galactosidase) was expressed both in the afferent and efferent arteriolar smooth muscles and also in the mesangial cells. The effect of angiotensin II on glomerular arterioles was directly observed using the hydronephrotic mice. Angiotensin II similarly constricted both the afferent and efferent arterioles in the wild-type and heterozygous mutant mice in a dose-dependent manner. This constriction was completely abolished by an AT-1 antagonist, CV-11974. In the homozygous null mutant mice, however, angiotensin II did not affect the arterioles at all. Electron microscopic studies revealed that the mesangial cells made contact with the glomerular basement membrane (GBM) at the capillary neck and also with each other in the wild-type mice. However, in the homozygous null mutant mice, the mesangial cells lost the contact either with GBM or with each other and thus the capillary neck became remarkably wider. The mesangial matrix area appeared loose and enlarged, suggesting impaired mesangial matrix formation. In conclusion, via the AT-1a receptor, angiotensin II equally constricts both the afferent and efferent arterioles and plays an essential role in maintaining the normal glomerular function and structure.

Angiotensin II↗
PubMed1997

[Correlates and prognosis in relation to intellectual dysfunction in a community-residing elderly population].

To estimate the risk factors for intellectual dysfunction and examine its prognosis in a community-residing (non-institutionalized) elderly population, a randomly selected sample of 1,473 elderly people aged 65 years and over living in S city, Osaka Prefecture, was studied in October 1992, and data were obtained from 1,383, a response rate of 93.9%. A cohort of 1,383 was followed for 42 months and follow-up was completed for 1,300 (94.0%). The main results were as follows: 1) The prevalence of intellectual dysfunction did not differ significantly between sexes, and there was an increasing prevalence of intellectual dysfunction with age in both sexes. The prevalence of severe intellectual dysfunction was found to increase highly at age 85 and over. 2) By univariate analysis, odds ratios for age older than 75 years, low Activities of Daily Living (ADL), urinary and fecal incontinence, and no participation in social activities were significantly higher than 1 in any level of mild, moderate, and severe intellectual dysfunction. In the multivariate analysis using logistic regression, age older than 75 years and urinary and fecal incontinence showed significant higher odds ratios than 1 for severe intellectual dysfunction, and low ADL and treatment for hypertension also showed significant higher odds ratios than 1 for moderate intellectual dysfunction. 3) From analysis using the Kaplan-Meier method, the cumulative survival rates decreased with a decline in intellectual functioning in both age groups of 65-74 and 75 years and older. 4) Application of the Cox proportional hazards model resulted in adjusted hazard ratio for severe intellectual dysfunction of 1.79 (95% confidence interval, 1.02-3.12), controlling for other factors such as sex, age, general health status, incontinence and social activities.

Activities of Daily Living↗
PubMed1996

Positive association between a DNA sequence variant in the serotonin 2A receptor gene and schizophrenia.

Sixty-two patients with schizophrenia and 96 normal controls were investigated for genetic association with restriction fragment length polymorphisms (RFLPs) in the serotonin receptor genes. A positive association between the serotonin 2A receptor gene (HTR2A) and schizophrenia was found, but not between schizophrenia and the serotonin 1A receptor gene. The positive association we report here would suggest that the DNA region with susceptibility to schizophrenia lies in the HTR2A on the long arm of chromosomes 13.

Adult↗
PubMed1996

Mutational screening of APP gene in patients with early-onset Alzheimer disease utilizing mismatched PCR-RFLP.

To elucidate the frequency of mutations of the beta/A4 amyloid protein precursor (APP) gene in early-onset Alzheimer disease, we designed a mismatched PCR-RFLP that can identify all kinds of missense mutations at codon 717 in addition to the seven kinds of known mutations at exon 17. When we screened mutations at exon 17 utilizing this method and the double missense mutations at exon 16 of the APP gene by PCR-RFLP, no cases revealed mutations of the APP gene among 13 familial and 54 sporadic cases, except one family (OS-1) that had previously been reported and used as a positive control of APP717(Val-->Ile). Our results support the hypothesis that mutations in the APP gene are not major causes in early-onset Alzheimer disease.

Adult↗
PubMed1996

Genetic association study between senile dementia of Alzheimer's type and APOE/C1/C2 gene cluster.

Senile dementia of Alzheimer's type (SDAT) is characterized by progressive deficits of multiple cognitive functions in elderly more than 65 years of age. The APOE-epsilon 4 allele has been shown to be a risk factor for SDAT. To investigate the genetic interactions between SDAT and the APOE/APOC1/APOC2 gene cluster located at 19q13.2, we genotyped these genes in patients with SDAT and nondemented controls. Although allelic associations were found between the APOC1 locus and SDAT (p = 0.0022) as well as between the APOE locus and SDAT (p < 0.0001), no associations were detected between the APOC2 locus and SDAT. And the association between the APOE and APOC1 locus in SDAT was statistically more significant than that in controls (p < 0.001). Estimation of the haplotype frequencies indicated that the association between the APOE/APOC1 haplotype and SDAT was more significant than linkage disequilibrium between the APOE and APOC1 locus (p < 0.01). These results suggest that genetic interaction between the APOE and APOC1 gene could modify a risk factor of APOE-epsilon 4 for SDAT. The APOE/APOC1 locus was estimated to be responsible for 54.8% of SDAT in the Japanese population.

Aged↗