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Biomedical subjects

S Otsuki

Publications and source records attributed to S Otsuki.

At least 91 records · Page 5Linked to original sources
PubMed1989

[Korsakoff's syndrome as a prominent feature of bilateral paramedian thalamic infarction--a case report].

We reported the first Japanese case of bilateral paramedian thalamic infarction associated with prominent Korsakoff's syndrome. 53-year-old man suffered from semicoma on the morning of September 16th, 1988. After recovery of consciousness disturbance, neurological examination revealed vertical eye gaze palsy, areflexia of lower extremities, apathy with hypersomnia and amnesia. Amnesia was accompanied with prominent confabulation, disorientation and lack of insight into his own disability. While X ray-CT revealed only ambiguous low density area in the bilateral thalamus, MRI of horizontal section by short spin echo revealed symmetrical low signal area restricted in the paramedian area of bilateral thalamus, and that of coronal section revealed characteristic butterfly-shaped lesion. Left BAG revealed that both posterior thalamoperforating arteries showed type 3 variation of Percheron's classification which arisen from artery arcade bridging between both side of interpeduncular segment of posterior cerebral artery. He showed gradual improvement in apathy with hypersomnia and disorientation but not in Korsakoff's syndrome nor ophthalmoplegia.

Alcohol Amnestic Disorder↗
PubMed1989

[Two siblings of juvenile Parkinson's disease dystonic type (Yokochi type 3) and hereditary progressive dystonia with marked diurnal fluctuation (Segawa)].

Two siblings of juvenile parkinson's disease dystonic type (JPA Yokochi type 3) and hereditary progressive dystonia with marked diurnal fluctuation (Segawa, HPD) were reported. The family had consanguinity. The elder brother suffered from resting tremor of legs, left foot dystonia and left pes equinovarus at the age of 12 years and 5 months. At the age of 15, he developed tremor and rigidity of upper extremities. These symptoms did not show diurnal fluctuation and markedly responded to L-dopa treatment. He implicated wearing-off phenomenon at the age of 16, and on-off phenomenon and L-dopa-induced dyskinesia at the age of 18. He was diagnosed as JPA Yokochi type 3. The younger brother suffered from left pes equinovarus, right scoliosis and foot dystonia at the age of 8 years. These symptoms showed remarkable diurnal fluctuation, which ameliorated after sleep or rest and worsened afternoon. He noticed fine postural tremor of upper extremities at psychological tense state and right pes varus at the age of 16. He received L-dopa at the age of 17 and became to be remission. He was diagnosed as HPD. Since these two disorders related to basal ganglia show similar clinical symptoms mainly consisting of foot dystonia and similar clinicopharmacological response to L-dopa, it has been assumed that shared abnormalities in pathomechanism can exist between them. This study indicates that the same gene-regulated abnormality may participate in the development of these two disorders.

Child↗
PubMed1989

[Anticonvulsant effects of bifemelane hydrochloride on kindled seizures from the amygdala and hippocampus in rats].

The anticonvulsant affects of bifemelane hydrochloride, a novel therapeutic drug for cerebrovascular dementia, were investigated in the kindling model of epilepsy in rats. The results obtained were as follows. (i) Both the seizure stage and afterdischarge duration of kindled seizures from the amygdala and hippocampus were significantly suppressed following systemic injection of bifemelane hydrochloride (5-30 mg/kg) in a dose-dependent manner. (ii) The efficacy of anticonvulsant action on kindled seizures from the hippocampus was more potent than from the amygdala. (iii) The maximum anticonvulsant effects were observed between 1 and 4 h after injection, and this time course was very similar to that of the previously reported increasing effects of bifemelane hydrochloride on noradrenaline levels in the rat brain. Thus, it is suggested that these anticonvulsant effects in kindling may be mediated by central noradrenergic systems. These results indicate that bifemelane hydrochloride has a potent anticonvulsant action on kindled seizures and may be useful for dementia patients with epilepsy or other seizure disorders.

Amygdala↗
PubMed1988

Effects of acute and long-term treatment with methamphetamine on substance P concentration and receptor numbers in the rat brain.

To examine biochemical changes in brain substance P (SP) systems associated with development of behavioral sensitization induced by methamphetamine (MAP), regional substance P-like immunoreactivity (SP-LI) and SP receptor binding in the rat brain were measured after acute and long-term MAP administration. Single administration of 8 mg/kg MAP significantly reduced the striatal SP-LI concentration 1 h after the injection. This reduction was blocked by pretreatment with haloperidol. Although repeated administration of 4 mg/kg MAP for 14 consecutive days did not affect the SP-LI concentration in any brain regions including the striatum, it decreased specific SP receptor binding in the striatum and increased those in the frontal cortex. Scatchard analysis of saturation isotherm of specific SP binding revealed that the decreased specific SP binding in the striatum resulted from a decrease in the maximal number (Bmax) of SP receptors and that increased binding in the frontal cortex resulted from an increase in Bmax. These changes in SP receptor binding lasted for at least 7 days. It is emphasized that the persisting changes induced by long-term MAP administration in the SP receptor may contribute to behavioral sensitization to MAP in rats and may be associated with neuronal mechanisms in MAP psychosis.

Animals↗
PubMed1988

Regulation of dopamine release by the autoreceptor after repeated methamphetamine treatment in rats: an intracerebral dialysis study.

A group of rats received intraperitoneal injections of methamphetamine (MAP) once a day for 14 days. Seven days after the last injection, the striatal dopamine efflux and its inhibition by a low dose (100 micrograms/kg) of apomorphine were examined by in vivo intracerebral dialysis. The extent of inhibition was not altered after the MAP pretreatment, which does not suggest the presence of subsensitivity of dopamine auto-receptors.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1988

Inhibitory effects of carbamazepine on clonidine-induced aggressive behavior in mice.

A behavioral study was made of the effect of carbamazepine (CBZ) on aggressive behavior evoked by high dose of clonidine in mice. This aggressive behavior has been reported to involve blockade of central adenosine receptors with which CBZ has been suggested to interact. After a single injection of clonidine (50 mg/kg i.p.), aggressive responses such as attacking and biting began within 5-10 min, were most marked at 20 min and usually ceased within 60 min. This behavior was attenuated by CBZ (45 mg/kg i.p.) but potentiated by caffeine (20 mg/kg i.p.). In addition, it was markedly inhibited by haloperidol (1.0 mg/kg i.p.), but unaffected by prazosin (1.5 mg/kg i.p.) and yohimbine (1.0 mg/kg i.p.). The inhibitory effect of CBZ on the aggressive behavior was dose-dependent at doses ranging from 15 to 60 mg/kg, while a high dose of CBZ alone induced sedation. The stimulatory effect of caffeine on the aggressive behavior was antagonized by pretreatment with CBZ (50 mg/kg i.p.). These results suggest that the receptor involved in clonidine-induced aggressive behavior was not mediated through the alpha-2 adrenoreceptor, but rather the adenosine receptor, and that the effect of carbamazepine on the adenosine receptor was agonistic in contrast with the effect of caffeine (an adenosine antagonist).

Adenosine↗
PubMed1988

[Effect of amygdaloid kindling on thyrotropin-releasing hormone, somatostatin, cholecystokinin and substance P contents of the amygdala/piriform cortex and hippocampus of rats].

Recently, several systems of neuropeptides have been demonstrated to have anticonvulsant action in some forms of epilepsy to some extent. However, considerably less knowledge has been taken to their involvement in convulsive disorders either with regard to the development, expression or control of seizures. In this study, therefore, we examined the influence of amygdaloid kindling, an experimental model of temporal lobe epilepsy, on thyrotropin-releasing hormone (TRH), somatostatin (SS), cholecystokinin (CCK) and substance P (SP) content in the amygdala/piriform cortex and hippocampus. Male Sprague-Dawley rats were implanted bipolar electrodes into the left amygdala under pentobarbital anesthesia. Daily kindling stimulation was made to the left amygdala with 1 sec, 60 Hz, 400 microA, until 5 consecutive fully kindled generalized convulsive seizures were elicited. Subsequently, amygdaloid kindled rats were decapitated 30 min, 24 hrs, 48 hrs, 7 days and 21 days after the last amygdaloid stimulation, and the amygdala/piriform cortex and hippocampus were dissected. Control animals only received chronic electrodes, but no stimulation was delivered. The immunoreactivity of TRH, SS, CCK and SP was examined by methods of specific radioimmunoassay. The TRH content in these two brain regions significantly increased 24 hrs after the last kindled convulsion. This increase became maximal 48 hrs after the last convulsion: about 3-fold and 4-fold of the control in the amygdala/piriform cortex and hippocampus, respectively. Such increases in the TRH content tended to persist for 7 days, but returned to the control level 21 days after the last convulsion.(ABSTRACT TRUNCATED AT 250 WORDS)

Amygdala↗
PubMed1987

Behavioral sensitization to methamphetamine in the rat: an ontogenic study.

The behavioral effect of repeated methamphetamine (MAP) treatment was observed in young rat to establish the ontogenetic period crucial to methamphetamine sensitization. Animals were treated with MAP (2 mg/kg, SC) once daily for 5 days (Group 1: postnatal days 2-6, G-2: 7-11, G-3: 12-16, G-4: 17-21, G-5: 22-26, G-6: 27-31). Control animals were similarly treated with an equal volume of saline. On the 35th postnatal day, all rats were challenged with MAP (2 mg/kg, IP). Behavioral sensitization to MAP was not found in G-1, G-2, G-3 or G-4, although responsiveness to MAP was observed in rats after the 2nd postnatal day. The animals in G-5 and G-6 showed hypersensitivity to MAP in locomotor activity and stereotyped behavior. These findings indicate that the period crucial to behavioral sensitization to MAP corresponds to the period of presynaptic dopamine autoreceptor formation in the rat brain.

Aging↗
PubMed1987

Haloperidol prevents the methamphetamine-induced apomorphine subsensitivity of dopamine metabolism in rat striatum.

Our previous experiment showed that the sensitivity of striatal dopaminergic metabolism to apomorphine was lowered after pretreating rats with methamphetamine. This study further demonstrated that haloperidol administered with methamphetamine prevented the effect of the methamphetamine pretreatment. Since gamma-butyrolactone was administered in combination with apomorphine so as to remove complications which might arise from the modification of impulse flow through the striatonigral feedback loop, it is possible that the observed effect of apomorphine upon striatal dopaminergic metabolism and its antagonism with haloperidol may be mediated by autoreceptors of dopaminergic axon terminals in rat striatum.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1987

Effectivity of zotepine in refractory psychoses: possible relationship between zotepine and non-dopamine psychosis.

We reported the results of a survey of patients who suffered from schizophrenia with predominate hallucinatory and delusional states, and who had been unresponsive to a variety of antipsychotics like haloperidol but responded more favorably to zotepine. In 10 of the 22 zotepine-responsive patients in this study, there was marked improvement with zotepine. Considering the results from previous drug treatment, the phenothiazines (especially levomepromazine) surpassed the butyrophenones in efficacy, suggesting that zotepine might resemble levomepromazine clinically. After administration of zotepine, cenesthesic hallucination, behavior caused by hallucination, egorrhoe, affective symptoms, and catatonic symptoms were markedly improved. However, insight into disease and negative symptoms were minimally improved after administration of zotepine. Zotepine was effective in the refractory psychoses due to its potent action on the delusional dynamics, in spite of producing little marked improvement in such main symptoms as hallucination and delusion. The authors speculate that zotepine's potent activity at serotonin-1 receptors may lead to a beneficial effect in refractory psychoses, just as in the case of its antimanic effect.

Adolescent↗
PubMed1987

Effect of chronic administration of haloperidol (intermittently) and haloperidol-decanoate (continuously) on D2 dopamine and muscarinic cholinergic receptors and on carbachol-stimulated phosphoinositide hydrolysis in the rat striatum.

It has been reported that apomorphine-induced stereotypy is sensitized after a chronic intermittent administration of haloperidol (HPD), but not after a chronic continuous exposure to haloperidol-decanoate (HPD-D). The present study was undertaken to investigate changes in the D2 dopamine and muscarinic receptors in the rat striatum after the administration of HPD intermittently and HPD-D continuously. The number of striatal [3H]spiperone binding sites increased significantly after HPD-D, but did not change after HPD. Neither the number of [3H](-)QNB binding sites nor carbachol-stimulated phosphoinositide hydrolysis changed after either HPD or HPD-D. These results indicate that the increase in striatal D2 receptors in rats administered HPD-D represents behavioral and biochemical tolerance, and that neither the D2 dopamine receptor supersensitivity nor muscarinic receptor hyposensitivity underlies sensitization of apomorphine-induced stereotypy.

Animals↗
PubMed1987

Diffuse Lewy body disease: an autopsy case.

A 67-year-old male patient initially showed memory disturbance followed by tremors a year later. The symptoms rapidly aggravated to dementia and Parkinsonian symptoms, and the patient died 2 years and 6 months after the onset at the age of 69 years and 5 months. Autopsy revealed numerous senile plaques in the cerebral cortex and Alzheimer's neurofibrillary tangles in the inferior temporal lobe and hippocampus. A number of Lewy bodies were found in the cerebral cortex and brain stem. Lewy bodies were found abundantly in the third layer of the pyramidal cells in the gyrus parahippocamalis. The distribution of Lewy bodies in the cerebral cortex was similar to that of inflated cells in Pick's disease.

Aged↗
PubMed1987

Transformation of human leukocytes by co-cultivation with HTLV-1-associated myelopathy patients' leukocytes.

Sera and cerebrospinal fluid (CSF) from patients with human T-cell leukemia virus type 1 (HTLV-1)-associated myelopathy (HAM) were analyzed by Western blotting, and normal human leukocytes were transformed by co-cultivation with HAM patients' leukocytes. The sera and CSF from all HAM patients formed specific bands with HTLV-1 viral proteins, including p19, p24, p28, p32, p40 and p53. After 2-3 weeks of co-cultivation, scattered foci of cell aggregates were noted on macrophage sheets. Surface markers of the transformed cells were OKT3(+), OKT4(+), OKT8(-), IL-2 receptor(+) and EBNA(-). Chromosome analysis showed a normal karyotype. HTLV-1 viral genome was integrated into DNA isolated from transformed cell lines. Electron microscopy revealed type C virus particles in transformed T-cell lines. These results indicate that peripheral leukocytes from HAM patients can transform HTLV-1-negative leukocytes and HAM patients have the potential to acquire adult T-cell leukemia in the future.

Adult↗