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Biomedical subjects

M Kurachi

Publications and source records attributed to M Kurachi.

At least 145 records · Page 8Linked to original sources
PubMed1986

A pharmacokinetic study of clomipramine in regions of the brain.

The pharmacokinetic profiles of clomipramine (CMP) and the serial changes of its concentration in specific brain regions were investigated in rats after an acute treatment with intravenous CMP (10 mg/kg). The CMP concentrations in plasma declined triexponentially and fitted a three-compartment open model. The brain to plasma concentration ratio showed a constant value, 22.2 +/- 4.9, 30 minutes after the injection. Regional brain differences in the CMP distribution and accumulation were also found. Four hours after the injections, the hippocampus was found to have the highest drug concentration, and the concentrations in this region were in the following order; thalamus, striatum, amygdala, cortex greater than pons + medulla oblongata greater than hypothalamus, bulbus olfactorius + septum, mesencephalon greater than cerebellum. Particularly, unique kinetics were observed in the cortex, amygdala and hippocampus.

Animals↗
PubMed1985

The action of taurine on the response to glutamate in the motoneuron of the isolated frog spinal cord.

Using the sucrose gap method, the effect of taurine on the response to glutamate in the ventral root of the isolated frog spinal cord was investigated. The depolarization induced by glutamate was reduced by taurine and the inhibitory action of taurine was antagonized by strychnine, but not by picrotoxin or bicuculline. This action of taurine was also unaffected by tetraethylammonium, 4-aminopyridine and Ringer deficient in sodium ions, but was affected by chloride-free Ringer. Potassium-free Ringer abolished the effect of taurine on the amplitude of the response to glutamate, but not on the rising phase of the depolarization induced by glutamate. Taurine also abolished the after-hyperpolarization induced by glutamate and this was reduced by ouabain or lithium ions. These findings suggest that taurine acts on a glycine receptor to inhibit the response to glutamate, that the action of taurine partly depends on chloride ions, and that taurine inhibits the sodium pump.

Animals↗
PubMed1985

Olivary hypertrophy in a case with palatal myoclonus: light- and electron-microscopic study.

This is a report on the ultrastructural finding of the olivary hypertrophy in a case with palatal myoclonus. By light microscopy two types of neuronal changes were observed in the inferior olivary nucleus, i.e. the central chromatolysis and cytoplasmic vacuolation. Both types were also recognized by electron microscopy and the cytoplasmic vascuolation was identified as the vesiculated endoplasmic reticulum. In the reactive astrocytes, mitochondria were strikingly proliferated.

Adult↗
PubMed1985

Regional cerebral blood flow in schizophrenic disorders.

Regional cerebral blood flow was measured using a 133Xe inhalation technique in 16 schizophrenic patients and 20 healthy volunteers. The bilateral frontal blood flows in the patient groups were significantly lower than in the control group. In addition, the patient group having auditory hallucination showed a significantly increased blood flow predominantly in the left temporal region. On the other hand, the patient group without auditory hallucination showed a slightly increased flow in the right temporal region. These findings indicate that there are a hypofrontal activity and also a hypertemporoparietal activity in schizophrenics.

Adult↗
PubMed1985

Inhibitory action of taurine on motoneuron of frog spinal cord.

Using the sucrose gap method, the effect of taurine on the spinal cord of the bullfrog was investigated. Taurine inhibited the spontaneous potential and the ventral root reflex potential elicited by the stimulation of the dorsal root. The excitability of motoneuron did not necessarily diminish following taurine application. Taurine inhibited the responses induced by excitatory neurotransmitter candidates such as, glutamate and substance P, in a concentration dependent manner in the preparation, where the neurotransmission was abolished by Ca2+-deprivation and/or Mg2+-supplement. From these results, the depressant action of taurine on the electrical activities in the frog spinal cord may be interpreted, in part, by the inhibition of the response evoked by excitatory transmitter at postsynaptic site.

Animals↗
PubMed1984

Central pontine myelinolysis with extrapontine lesions.

An autopsy case of central pontine myelinolysis (CPM) was reported. The patient, a 48-year-old man, with a long history of alcoholic intake appeared in a hospital with the diagnosis of alcoholic hepatitis and the neurologic symptoms of delirium tremens. During the hospital course he fell into "locked in" with concomitant development of marked hyponatremia (92 mEq/1). An autopsy revealed typical CPM and the extra-pontine myelinolytic lesions distributed symmetrically in the thalami, subthalamic nuclei, and lateral geniculate bodies. Spongiosis was also found in the deep layer of the cerebral cortex and in the putamen. It was suggested that CPM occur in close association with marked hyponatremia and the extrapontine involvement be likely to manifest in the deep layer of the cerebral cortex, putamen, thalamus, and lateral geniculate body, where the myelin cylinders form an interlacing network embedding large neurons and oligodendrocytes.

Alcoholism↗
PubMed1984

CT findings of the interval form of carbon monoxide poisoning compared with neuropathological findings.

Cerebral computed tomography findings were described in 2 clinical cases of the interval form of carbon monoxide poisoning and comparison with postmortem CT finding of an autopsy case was made. There was low density in the bilateral frontal region, centrum semiovale and pallidal parts. In the course of the disease, the degree of low density in the white matter showed a tendency to diminish but it became more apparent in the pallidal parts. Myelinopathic white matter lesion in an autopsy material was recognized as a low density area in CT, which is identical with that seen in clinical cases.

Adult↗
PubMed1984

Effect of a muscle relaxant, chlorphenesin carbamate, on the spinal neurons of rats.

The effects of chlorphenesin carbamate (CPC) and mephenesin on spinal neurons were investigated in spinal rats. CPC (50 mg/kg i.v.) inhibited the mono-(MSR) and poly-synaptic reflex (PSR), the latter being more susceptible than the former to CPC depression. Mephenesin also inhibited MSR and PSR, though the effects were short in duration. CPC had no effect on the dorsal root potential evoked by the stimulation of the dorsal root, while mephenesin reduced the dorsal root-dorsal root reflex. The excitability of motoneuron was reduced by the administration of CPC or mephenesin. The excitability of primary afferent terminal was unchanged by CPC, while it was inhibited by mephenesin. Neither CPC nor mephenesin influenced the field potential evoked by the dorsal root stimulation. Both CPC and mephenesin had no effect on the synaptic recovery. These results suggest that both CPC and mephenesin inhibit the firing of motoneurons by stabilizing the neuronal membrane, while mephenesin additionally suppresses the dorsal root reflex and the excitability of the primary afferent terminal. These inhibitory actions of CPC on spinal activities may contribute, at least partly, to its muscle relaxing action.

Action Potentials↗
PubMed1984

[The appraisal of biliary drainage for intrahepatic gall stones, with special reference to an end-to-side hepaticojejunostomy].

Between 1961 and 1983, eighty-six patients with intrahepatic gall stones were identified from a group of 1,140 patients admitted for cholelithiasis. Surgical procedures performed in this series were 37 choledochotomies with external biliary drainages, 33 transduodenal papilloplasties, 37 bilioenteric anastomosis and 15 hepatectomies. In the long term follow up studies after surgical treatment by each procedures, the favorite results were obtained in 41.2% of cases with choledochotomies with external drainages, in 34.4% of cases with transduodenal papilloplasties, in 82.4% of cases with bilioenteric anastomosis and in 88.7% of cases with hepatectomies. Hepatectomy seemed to be a most effective treatment for the prevention of recurrence of stones. However, if the calculi were in the right or both of hepatic lobes, hepatectomy might be a high risk operation and technical proficiency were required in operation. In such cases, we performed an end to side anastomosis between the common hepatic duct and the jejunum (Roux en Y anastomosis) for the postoperative endoscopic lithotomy. In this operation the jejunal stump was made to be an enterocutaneous fistula for the later percutaneous endoscopic lithotomy. This operation has the following advantages; 1) the time of operation were shortened in the removal of stones because of this operation were performed for the postoperative endoscopic lithotomy, 2) retrograde cholangitis was less likely to develop than other operations, 3) retained stones dropped into bowel easily by making a big anastomotic stoma, 4) the cholangioscope could be inserted into either bile ducts of the right and left hepatic lobes, 5) the fistula would be able to be reused for the endoscopic treatment at later recurrence of intrahepatic gall stones.

Adult↗