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Biomedical subjects

H Suwaki

Publications and source records attributed to H Suwaki.

At least 37 records · Page 2Linked to original sources

[Acetaldehyde adducts in the cerebral cortex of ethanol-fed mice].

To investigate the neurotoxicity of acetaldehyde covalent adducts, immunohistochemical staining for acetaldehyde adducts using the antibody against acetaldehyde adducts, was performed in the cerebral cortex of ethanol-fed (withdrawal) mice. In the ethanol-fed mice, the degeneration in the cerebral cortex was found, while the protein epitope related to acetaldehyde was found in the cerebral cortex, liver and adrenal cortex. No histochemical and immunohistochemical changes in the tissues from the control mice were found. It is possible that acetaldehyde adducts may effect on the cerebral cortex as the neurotoxicity which cause psychosis such as delirium and hallucination after alcohol drinking.

Acetaldehyde↗

[Relationship between alcoholism and CYP2E1 genotypes].

The genotype of the CYP2E1 loci in 36 alcoholic and 42 non-alcoholic (healthy) Japanese were investigated to examine the relationship between the polymorphisms of CYP2E1 (C/D) and the susceptibility to alcohol dependence. There was a significant (df = 1, chi 2 = 4.39, p < 0.05) difference in CYP2E1 CD (heterozygote) genotype frequency between alcohol dependents (56%) and controls (33%), suggesting that the CD (heterozygote) genotype of CYP2E1 may have something to the risk of developing alcoholism in Japanese, whereas DD (homozygote) genotype was high among controls.

Adult↗

Tissue-specific alternative splicing of mouse brain type ryanodine receptor/calcium release channel mRNA.

We detected alternative splicing of the mouse brain type ryanodine receptor (RyR3) mRNA. The splicing variant was located in the transmembrane segment. The non-splicing type (RyR3-II) included a stretch of 341 bp, and that of the 13th codon was stop codon TAA. Reverse transcription-polymerase chain reaction (RT-PCR) analysis shows that RyR3-II mRNA was expressed in various peripheral tissues and brain at all developmental stages. However, interestingly, the splicing type (RyR3-I) mRNA was detected only in the cerebrum. These findings suggest that the splicing variants RyR3-I and RyR3-II may generate functional differences of RyR3 in a tissue-specific manner.

Aging↗

No association between the neuroleptic malignant syndrome and mutations in the RYR1 gene associated malignant hyperthermia.

The neuroleptic malignant syndrome (NMS) is a drug-induced disease caused by neuroleptics, but the pathogenesis of NMS is unknown. Since NMS is similar to malignant hyperthermia (MH) in clinical features and treatment, 6 mutations in the skeletal muscle ryanodine receptor (RYR1) gene, which were associated with MH, were investigated in unrelated NMS patients by single-strand conformation polymorphism analysis (SSCP). As a result, MH-susceptible RYR1 mutations were not detected in our NMS patients. A single base substitution, C7278T, was detected in one patient whose serum CPK level was repetitively elevated, but his other major symptoms did not fulfil the clinical criteria for NMS. Our results do not support the association between the neuroleptic malignant syndrome and mutations in the RYR1 gene associated with malignant hyperthermia.

Adult↗

Characteristics of Japanese alcoholics with the atypical aldehyde dehydrogenase 2*2. I. A comparison of the genotypes of ALDH2, ADH2, ADH3, and cytochrome P-4502E1 between alcoholics and nonalcoholics.

We examined the genotypes of the aldehyde dehydrogenase (ALDH)-2, alcohol dehydrogenase (ADH)-2, ADH3, and P-4502E1 loci of 53 alcoholics and 97 nonalcoholics. All of the subjects fulfilled the DSM-III-R criteria for alcohol dependence. The control group consisted of 97 subjects who were either hospital staff or students. We also compared the frequencies of homozygous ALDH2*1/1 and heterozygous ALDH2*1/2 genotypes in alcoholics. Our study revealed differences in the allelic frequencies of the ALDH2, ADH2, and ADH3 loci between alcoholics and nonalcoholics. For alcoholics with both homozygous ALDH2*1/1 and heterozygous ALDH2*1/2 genotypes, it was found that ADH2 and ADH3 played important rates. Alcoholics with the heterozygous ALDH2*1/2 genotype showed a significantly higher frequency of ADH2*1/1 than ones with the homozygous ALDH2*1/1 genotype. We assume ADH2*1 plays an important role in the development of alcoholism in alcoholics with the heterozygous ALDH2*1/2 genotype.

Adult↗

Haloperidol inhibits neuronal nitric oxide synthase activity by preventing electron transfer.

The effect of a neuroleptic, haloperidol (HP), on nitric oxide formation catalyzed by neuronal nitric oxide synthase (n-NOS) in the porcine brain was investigated. HP inhibited n-NOS activity noncompetitively versus L-arginine as a substrate, decreasing the maximal velocity (Ki value for HP = 31 microM). HP also inhibited the CaM-dependent NADPH consumption by n-NOS (IC50 = 221 microM). These data demonstrate the possibility that HP may mediate some neuronal functions through inhibiting NO release by preventing either the electron transfer through n-NOS or the formation of the activated reduced species of oxygen necessary for the formation of citrulline. And an interaction of HP with CaM may possibly affect the consumption of NADPH and n-NOS enzyme activity.

Animals↗

[The ethanol elimination pharmacokinetics--the effects of genotypes of ALDH2 and CYP2E1 on the ethanol metabolism].

The effects of the genotypes of CYP2E1, ALDH2, ADH upon the blood ethanol and acetaldehyde levels were investigated. The predicting 95% confidence bounds determined on regression analysis of the data suggested that after venous injection of ethanol, the blood ethanol and acetaldehyde concentrations in a volunteer normal homozygous for ALDH2 (ALDH2*1/1) were significantly lower than that heterozygous (ALDH2*1/2). And the blood ethanol and acetaldehyde concentrations in a volunteer with C2 allele (C1/C2) were significantly lower than that in (C1/1). However, there were no significant differences in the blood ethanol and acetaldehyde concentrations between volunteers with ADH2*1/1 and ALDH2*1/2. It is possible that the ALDH2*1 and C2 alleles may correspond to the lower blood ethanol and acetaldehyde concentrations after intravenous administrations of 0.2 g /kg of ethanol.

Adult↗

Developmental changes of cyclin dependent kinase 5 subcellular localization in the rat cerebellum.

Cyclin dependent kinase 5 (Cdk5) phosphorylates tau protein, a microtubule-associated protein, at pathological sites in vitro as well as in Alzheimer's disease brain. The enzyme is therefore regarded as an important candidate responsible for the progression of Alzheimer's disease. We and others have suggested that the enzyme has physiological roles in brain development and maturation. In this study, we investigated the exact distribution and developmental changes of the enzyme in cerebellum by immunohistochemistry and non-radioactive in situ hybridization. Immunohistochemistry demonstrated that Cdk5 was consistently expressed in the cerebellum at all developing stages. However, the subcellular localization of Cdk5 dramatically changed during maturation of the cerebellum. In the early neonatal stage, Cdk5 was strongly expressed in the cell bodies of neurones. With neuronal maturation Cdk5 immunoreactivity changed its subcellular localization from the cell body to axon. In terminally differentiated neurons, the immunoreactivity was only detected in the axon. These results suggest that subcellular localization of Cdk5 is strictly regulated and may play an important role in neuronal maturation.

Alzheimer Disease↗

CYP2E1 genotypes and serum LAP in Japanese alcoholics.

The genotypes of the ALDH2 and CYP2E1 loci of Japanese alcoholic patients were determined to investigate the susceptibility to alcoholic liver injury. In alcoholics with a liver-function disorder, a significant association was observed between the genotypes of the CYP2E1 loci and the serum level of a liver-derived enzyme, LAP. However, there was no significant association between the ALDH2 genotypes and liver dysfunction.

Alcoholism↗

Morphological changes in the hippocampus in amygdaloid kindled mouse.

To clarify the origin and maintenance of epileptogenesis, morphological changes in the hippocampus of amygdaloid-kindled mice were analyzed at different stages of kindling. The granule cell size in dentate gyrus and the pyramidal cell size in CA1 were clearly decreased depending on seizure stage. The cell size in CA2 was increased and density in dentate gyrus and CA2 was reduced, significantly. The morphological changes in hippocampus associated with kindling must be closely related to the acquisition and the maintenance of epileptogenesis. The results support the hypothesis that seizure-induced damage of neurons may lead to formation of new synaptic connections that produce abnormal hyperexitability and result in seizures.

Amygdala↗

The drug-drug interaction effects of haloperidol on plasma carbamazepine levels.

The metabolic interaction between carbamazepine (CBZ) and haloperidol (HP) was studied in Japanese schizophrenic patients treated with HP but not with CBZ and with both CBZ and HP. The serum CBZ concentrations in patients treated without HP were significantly decreased (p < 0.05), on average approximately 40%, as compared to those in patients treated with both CBZ and HP, whereas the serum HP concentrations in patients treated with both HP and CBZ were significantly decreased (p < 0.05), as compared to those in patients treated with HP but not with CBZ. The effect of HP, which prevents the serum CBZ level from decreasing, was shown in this study.

Anticonvulsants↗