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Biomedical subjects

H Kaiya

Publications and source records attributed to H Kaiya.

At least 55 records · Page 3Linked to original sources
PubMed1988

Regional distribution of phosphoinositide-specific phospholipase C activity in rat brain.

The phosphatidylinositol (PI) and phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolytic activities of phosphoinositide-specific phospholipase C (PLC) were measured in membrane and cytosol fractions from 7 discrete areas of the rat brain. Both the PI-PLC and PIP2-PLC specific activities were found to differ significantly among the 7 discrete brain areas. In the membrane fraction, the PIP2-PLC activity was higher than that of PI-PLC in each region, suggesting that the PLC in membranes prefers PIP2 to PI as substrate. The PIP2-PLC activities in the membrane were high in prefrontal cortex and cerebellum, but rather low in medulla oblongata and hypothalamus. The PI-PLC specific activity in the cytosol was significantly higher than that in the membrane of all brain areas examined. The PI-PLC specific activity in membranes is inversely proportional to its activity in the cytosol. In the cytosol fraction, the distribution pattern of PI-PLC specific activity resembled that of PIP2-PLC. These results indicate that PLCs are differently distributed in various regions of rat brain, and suggest the regional differences in neuronal transduction.

Animals↗
PubMed1988

Substance P involved in mental disorders.

1. This review clarifies the involvement of substance P (SP) in mental disorders, especially schizophrenia. One of the main SP pathways in the brain is the striatonigral pathway. SP applied in the substantia nigra activates the nigro-striatal dopamine system. 2. Administration of antipsychotic drugs decreased SP concentration in the substantia nigra. Some post mortem studies of schizophrenic patients showed elevated SP concentration in some brain regions. Effects of baclofen, a SP antagonist, on schizophrenic patients are uncertain. 3. SP may be involved in the pathophysiology of schizophrenia.

Animals↗
PubMed1987

Presenile dementia combined with amyotrophy: a review of 34 Japanese cases.

Thirty-four Japanese cases exhibiting presenile dementia combined with amyotrophy were reviewed with four case reports. The clinical feature of dementia was generally unspecific and could not be clearly diagnosed as Pick's disease or Alzheimer's disease. But most of these patients did not exhibit manifest visual agnosia or apraxia suggesting 'posterior dementia'. Brain CTs showed mild diffuse atrophy with non-circumscribed fronto-temporal accentuation. PSD (periodic synchronous discharge on EEG) as seen in Creutzfeldt-Jakob disease (CJD) was not noted in any of these cases. Although individual neurological findings were not contradictory to amyotrophy lateral sclerosis (ALS), the clinicopathologic findings, on the whole, could be regarded as indicative of an atypical spinal progressive muscular atrophy. The brain pathology lacked specific changes. A mild to moderate degree of glial proliferation, subcortical gliosis and a moderate spongy state of the upper cortical layers were seen mainly in the fronto-temporal area. Nigral degeneration was observed in half of the cases. No Pick's cells, Pick's balls, Alzheimer's neurofibrillary changes or senile plaques were observed except in two cases, in whom it could be regarded as physiological. Brain weight was lighter than that of normal Japanese but heavier than that of Pick's disease, Alzheimer's disease or CJD. The brain pathology was similar to that of progressive subcortical gliosis. We have concluded that the disease under discussion might be a new disease entity.

Amyotrophic Lateral Sclerosis↗
PubMed1986

Morphological changes in rat striatal boutons after chronic methamphetamine and haloperidol treatment.

Dopaminergic (DA) synaptic boutons were identified in rat striatum with an electron microscopic histochemical method. In rats which developed behavioral hypersensitivity after treatment with methamphetamine (MAP) for about 2 weeks, significantly fewer DA boutons were found. This effect was specific to DA boutons without mitochondria and was not seen in boutons with mitochondria. The density of granular synaptic vesicles in DA boutons, however, did not change significantly. These morphological changes would represent a high capability of nerve cells to reorganize synaptic connections under altered chemical environments, but they could not be related uniquely to behavioral hypersensitivity, as similar effects were observed in rats treated with haloperidol which did not develop behavioral hypersensitivity. Peculiarly, the effects of MAP treatment on both behavior and DA boutons were prevented by combined administration of haloperidol.

Animals↗
PubMed1986

Gilles de la Tourette's syndrome and schizophrenia.

A Gilles de la Tourette's syndrome (TS) patient is described who experienced a schizophrenic episode 11 years after TS onset. Analogies and differences between the two syndromes are reviewed, leading to the conclusion that TS is a definite entity independent from schizophrenia, but that they share some common features of symptomatology and pathophysiology and have closely related anatomical lesions.

Adolescent↗
PubMed1984

Abnormal phosphatidylinositol-cycle of platelet membrane in schizophrenia--a preliminary study.

Phosphatidylinositol (PI)-cycle in the platelet membrane was examined in eight untreated patients with psychotic symptoms. A defect of PI-cycle in the transformation from 1,2-diacylglycerol into phosphatidic acid was found in three patients, who were diagnosed as having Schizophrenic Disorders or Schizophreniform Disorder according to the DSM-III criteria. Two out of the three patients were reexamined while undergoing neuroleptic medication, and they showed the same abnormality in PI-cycle. Further studies were required to determine the nature of the abnormality in PI-cycle in the platelets of schizophrenics.

Adolescent↗
PubMed1983

Decreased level of beta-endorphin-like immunoreactivity in cerebrospinal fluid of patients with senile dementia of Alzheimer type.

beta-Endorphin-like immunoreactivity in cerebrospinal fluid(CSF) was observed to decrease in patients with Huntington's disease and dementia due to brain vascular disease. The greatest decrease was seen in patients with presenile and senile dementia of Alzheimer type(SDAT). The immunoreactivity significantly correlated with psychological functions when examined using a dementia rating scale (r=0.51, p less than 0.01, for all dementia, r=0.65, p less than 0.02, for only SDAT). These results suggest that a B-endorphin-like substance may be related in the pathophysiology of dementia.

Adult↗
PubMed1983

Platelet aggregation response in schizophrenia and prostaglandin E1.

Platelet aggregation response to various stimulants was examined in 18 unmedicated schizophrenic patients, 13 medicated patients, and 13 control subjects. Platelet aggregation response to epinephrine decreased only in unmedicated schizophrenic patients. Clinical improvement in seven patients after neuroleptic medication was significantly correlated with an increase in platelet aggregation response to arachidonic acid, and nonsignificantly to epinephrine, dopamine, and serotonin. The inhibitory effect of prostaglandin E1 on platelet aggregation response to adenosine diphosphate was investigated in seven unmedicated schizophrenic patients, six medicated patients, and eight controls. The inhibitory effect of prostaglandin E1 on platelet aggregation response to adenosine diphosphate was significantly reduced in all unmedicated schizophrenic patients. Neuroleptic medication had some effect in normalizing aberrant sensitivity to prostaglandin E1 in those patients, although acute medication induced an adverse reaction in the controls.

Adenosine Diphosphate↗
PubMed1983

Effects of subchronic treatment of methamphetamine haloperidol on the rat brain levels of GABA, glutamate and aspartate.

Centrally active amino acids (GABA, glutamate, aspartate) were assayed enzyme-fluorometrically in five brain regions of the rat after a 16-day administration of methamphetamine (2.5 mg/kg, i.p.) and haloperidol (2.5 mg/kg, i.p.), or both agents together. Methamphetamine caused no statistically-significant changes in the GABA contents in any brain areas, a significant decrease in the glutamate content of the striatum, hippocampus and midbrain and an increase in the aspartate content of the hypothalamus. Haloperidol treatment resulted in no changes in the GABA content, a significant decrease in the glutamate content of the striatum and a significant increase in the aspartate content in the frontal cortex. The treatment with both agents caused a significant decrease in the GABA content of the hypothalamus. The combined administration normalized a lowering of the glutamate levels in the striatum caused by methamphetamine and haloperidol, respectively, and increased the level of aspartate in the hypothalamus caused by methamphetamine and in the frontal cortex caused by haloperidol.

Animals↗
PubMed1982

Abnormal platelet aggregation response in Huntington's disease.

Platelet aggregation response to epinephrine, dopamine, serotonin, adenosine diphosphate, arachidonic acid, and collagen was examined in seven patients with Huntington's disease and nine of their relatives. All patients, except for two cases that were in terminal states, showed enhanced response to all the stimulants, especially to dopamine and epinephrine. The platelet aggregation response in many relatives also deviated from the normal limit. The relationship between platelet aggregation abnormality in Huntington's disease and the pathophysiology of the disease was discussed from the view of a generalized membrane defect hypothesis in Huntington's disease, and of disturbed cathecholamine metabolism, both in the CNS and periphery. A possibility that platelet aggregation response examination will be a useful screening test of offspring at risk was proposed.

Adenosine Diphosphate↗
PubMed1982

Plasma glutamate decarboxylase activity in neuropsychiatry.

Plasma glutamate decarboxylase (GAD) activity was measured in patients with endogenous psychoses and neurologic diseases. Unmedicated schizophrenic patients showed no difference in plasma GAD levels compared to controls. Administration of neuroleptics together with anticholinergic agents increased plasma GAD activity in schizophrenic patients. Compared to controls, patients with major depression and bipolar illness showed significantly lower GAD activity. No effect of antidepressants and minor tranquilizers on plasma GAD activity was found. Relatively lower GAD activity was shown in neurotic patients. The enzyme activity in plasma of patients with Huntington's chorea (HC) was lower than control levels. The plasma GAD concentrations correlated with cerebrospinal fluid concentrations in five HC patients.

Adolescent↗
PubMed1982

[Effects of zotepine, a psychotropic agent, on the serum uric acid level of inpatients at a psychiatric hospital].

UNLABELLED: Serum uric acid levels were examined and compared to diagnostic groups of inpatients of a mental hospital. An action lowering serum uric acid level of zotepine was further evaluated in those patients. RESULTS: (1) In patients receiving some kind of psychotropic drugs, except for zotepine, mean serum uric acid level of patients with epilepsy in both sexes was significantly lowered in comparison with that of schizophrenia. Mean serum uric acid levels of male and female patients with alcoholism and organic brain disease were higher than that of schizophrenia without any statistical significance. (2) Mean serum uric acid level of patients treated with various psychotropic drugs, except for zotepine, was higher than that of patients receiving zotepine. (3) Zotepine decreased serum uric acid level parallel with its dosage (r=0.70, p less than 0.001) with a mean reduced rate of 54.1% (p less than 0.001), when serum uric acid levels of 32 patients were examined 3 times over 3 months before and during zotepine administration, respectively. (4) Maximum reduction of serum uric acid level occurred in 3-6 days following zotepine application. Controversely, it takes about 4 weeks to recover baseline level of serum uric acid after stopping zotepine administration. (5) Zotepine had no significant effect not only on the results of creatinine clearance test, but also on BUN level. However, it significantly increased level of uric acid clearance, and rate between uric acid clearance and creatinine clearance. The rate of uric acid clearance vs creatinine clearance correlated with the dosage of zotepine given. Zotepine is thought to decrease serum uric acid level via selective blocking of tubular reabsorption of uric acid in the kidney.

Adult↗
PubMed1981

Two types of dopaminergic nerve terminals in the rat neostriatum. An ultrastructural study.

In the neostriatum 7.7% of all boutons absorbed alpha-methylnoradrenaline, thus staining their synaptic vesicles profiles granular. These presumably monoaminergic synapses were divided into two types according to ultrastructural features. Type A was composed of a relatively large axon terminal and a dendritic spine with postsynaptic membrane thickening. The axon terminal of type B, that is a bouton en passant, was smaller than the postsynaptic profile, while the synaptic contact was symmetrical. Following nigral coagulation, both types of synapse degenerated. It is concluded that both types of synapse are dopaminergic.

Animals↗
PubMed1981

Substance P-like immunoreactivity in plasma of psychotic patients and effects of neuroleptics and electroconvulsive therapy.

Radioimmunoassay of substance P (SP)-like reactivity, using N alpha-tyrosyl-SP, was performed in plasma of psychotic patients. Schizophrenic patients under neuroleptic medication over 1 year, and those patients with organic brain disease showed a significant increase in immunoreactivity. The immunoreactivity in unmedicated schizophrenic patients just before treatment and in depressed patients, both bipolar and major, did not differ significantly from that of controls. The immunoreactivity in unmedicated schizophrenics was followed after medication for a maximum of 5 months. The reactivity decreased in five cases, and increased in three cases. No definite pattern could be discerned between changes in the immunoreactivity, the type of medication administered, and the resultant response to the therapy. Chlorpromazine injection caused no definite acute effect on the plasma level of SP-like immunoreactivity for 120 minutes. Electroconvulsive therapy increased the plasma level of SP-like immunoreactivity for 90 minutes in a male schizophrenic patient.

Adolescent↗