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Biomedical subjects

M Kurachi

Publications and source records attributed to M Kurachi.

At least 127 records · Page 7Linked to original sources
PubMed1988

Does family history of schizophrenia influence age at onset of schizophrenia?

The relation between age at onset of schizophrenia diagnosed using DSM-III criteria and the presence or absence of this illness among first-degree relatives was investigated in 2417 patients. The mean age at onset among those with a family history of schizophrenia was slightly and nonsignificantly earlier than that of schizophrenic patients without a positive family history. The former developed their illness before the age of 25 years more frequently than did the latter.

Adolescent↗
PubMed1988

[Reliable induction of generalized seizures in hippocampal kindling triggered with low-frequency electrical stimulations].

To assess the appropriateness of hippocampal low-frequency kindling as an experimental model of epilepsy, we stimulated, bipolarly, left ventral hippocampus of 8 cats with 2 mA biphasic square wave pulses (1 msec duration) once a day. The pulse-interval was set at 300 msec. Recording electrodes were inserted in right ventral hippocampus, bilateral amygdaloid and bilateral globus pallidus. EEG was monitored before, during and after the delivery of stimulation. If the triggering of epileptic afterdischarge was observed on EEG monitoring, the delivery of stimulation was stopped immediately. Generalized convulsive seizures developed in all subjects within a mean of 26.2 days. In all seizures self-sustained epileptic afterdischarge, defined as epileptiform spikes three times the base line amplitude with a frequency greater than the stimulating pulse-interval (300 msec) in the stimulated hippocampus lead, was triggered abruptly. Therefore we could measure the number of stimulating pulses required for the triggering of epileptic afterdischarge, defined as pulse-number threshold, definitely in all cases. At the completion of kindling the pulse-number threshold was measured at 12.3 +/- 0.9 (+/- SE). After five generalized convulsions were induced we tested the stability of the pulse-number threshold and the duration of triggered epileptic afterdischarge. Both the two measures did not change statistically at the interstimulation interval from 24 hrs to 96 hrs. In addition we carried out testing with antiepileptic and antipsychotic drugs. Phenobarbital (10 mg/kg, i.p.) increased the pulse-number threshold and the after discharge duration simultaneously. Haloperidol (3 mg/kg, i.p.), oppositely, decreased the pulse number threshold and the after discharge duration.

Animals↗
PubMed1987

Serial changes of the susceptibility of epileptogenic focus during hippocampal kindling induced with low-frequency electrical stimulation in cats.

Cats were stimulated in the dorsal hippocampus with low-frequency square wave pulses. All subjects were kindled until generalized convulsion occurred. In the early stage of the kindling process, an increase in the interpulse interval and a decrease in the number of stimulating pulses required for the provocation of epileptic afterdischarge were observed, but in the late stage a decrease in the former and an increase in the latter were observed. It appears from these data that completion of hippocampal kindling is accompanied by a decrease in excitability at the site of stimulation subsequent to an increase in the same.

Animals↗
PubMed1987

Acute effect of some psychotropic drugs on low-frequency amygdaloid kindled seizures.

We assessed the acute effects of some psychotropic drugs on amygdaloid-kindled seizures produced by low-frequency stimulation. We used the number of stimulating pulses required for the induction of epileptic afterdischarge (pulse-number threshold, PNT) as an indicator for the seizure-generating threshold, and the duration of the epileptic afterdischarge (AD duration, ADD) as an indicator for the duration of the induced seizures. Methamphetamine and atropine elevated the PNT and reduced the ADD. Haloperidol reduced the PNT at all tested doses and reduced the ADD at high dosage. Imipramine elevated the PNT at low doses and reduced the PNT at high dosage. Imipramine also reduced the ADD. Reserpine at high dose elevated the PNT without affecting the ADD.

Amygdala↗
PubMed1987

Lennox-gastaut syndrome with and without Dandy-Walker malformation.

The authors present two siblings suffering from Lennox-Gastaut syndrome. One of them also had the Dandy-Walker malformation. His seizures were difficult to control with anticonvulsant drugs, and somnolence and cerebellar ataxia easily occurred during administration of low dose anticonvulsants. On the other hand, his brother did not have this malformation, and his seizures were easily controlled. The relationship of seizure control to the Dandy-Walker malformation is discussed.

Child↗
PubMed1987

Morbidity risk of schizophrenia to parents and siblings of schizophrenic patients.

In order to estimate the familial morbidity risk of schizophrenia, parents and siblings of 1,691 inpatients meeting the DSM-III criteria for schizophrenia were investigated on the basis of a review of medical records, family history data and/or personal interviews. The morbidity risks of schizophrenia to parents and siblings of the schizophrenic probands were 4.0% and 4.1%, respectively, which were greater than the morbidity risk in the general population. Siblings of 118 probands whose parents suffered from schizophrenia were at a significantly greater risk of schizophrenia than siblings of 1,493 probands whose parents did not have schizophrenic illness. These findings support the notion of familial transmission of schizophrenia. A total of 16.4% of the schizophrenic probands had at least one first-degree relative with schizophrenia. This is significantly greater in the female probands than in the male probands.

Adult↗
PubMed1987

A simultaneous analytical method for catecholamines, indoleamines, and related compounds in 11 rat brain regions.

A simple high-performance liquid chromatographic method that allows the determination of 10 biogenic amines and related compounds for crude brain extracts has been developed. The compounds that can be quantified comprise norepinephrine, epinephrine, 3,4-dihydroxyphenylacetic acid, 3-methoxy-4-hydroxyphenylglycol, dopamine, 5-hydroxyindole-3-acetic acid, homovanillic acid, 3-methoxytyramine, 5-hydroxytryptamine and tryptophan. The detection system involves a three electrode-coulometric determination followed by fluorometric determination. This method is highly selective and sensitive, and in the present study, the usefulness of this methodology was confirmed by applying it to the determination of the levels of these various substances in 11 rat brain regions.

Animals↗
PubMed1987

Acute effect of TRH, flunarizine, lithium and zotepine on amygdaloid kindled seizures induced with low-frequency stimulation.

We assessed the acute effects of various drugs on amygdaloid kindled seizures induced with low-frequency stimulations. We used the number of stimulating pulses required for the induction of epileptic afterdischarge (pulse-number threshold; PNT) as an indicator of the seizure generating threshold and the duration of induced seizures (AD duration; ADD) as an indicator of the seizures. TRH increased the PNT without affecting the ADD at a high dose (1.2 mg/kg). Flunarizine decreased the PNT and ADD simultaneously at a high dose (50 mg/kg). Lithium increased the PNT without affecting the ADD at two doses (100 mg/kg, 200 mg/kg). Zotepine decreased the PNT without affecting the ADD at two doses (8 mg/kg, 16 mg/kg). We propose that the technique of low-frequency kindling is a useful experimental model in assessing the effects of antipsychotic or antiepileptic drugs on the excitability of the limbic regions.

Amygdala↗