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Biomedical subjects

G Yagi

Publications and source records attributed to G Yagi.

At least 55 records · Page 3Linked to original sources
PubMed1993

Interleukin-1 beta augments release of norepinephrine, dopamine, and serotonin in the rat anterior hypothalamus.

We investigated the effects of interleukin-1 beta (IL-1 beta), administered directly into the rat anterior hypothalamus (AHY), on monoamine release in the same region by using a brain microdialysis technique and an HPLC-electrochemical detection system. First, to study the local effects of IL-1 beta, we used a microdialysis probe equipped with a microinjection tube for administering IL-1 beta in the same region into which the probe had been inserted. IL-1 beta (1 ng) injected directly into the AHY elicited release of norepinephrine (NE), dopamine (DA), and 5-HT, as well as increases in their metabolites, 4-hydroxy-3-methoxyphenylglycol, 3,4-dihydroxyphenylacetic acid, 4-hydroxy-3-methoxyphenylacetic acid, and 5-hydroxyindole-3-acetic acid, in the AHY. Vehicle alone exerted no effect on monoamine release. Although the elevated levels of NE and DA persisted for more than 6 hr after injection of IL-1 beta, the elevated levels of 5-HT were transient. Second, in order to investigate whether this effect of IL-1 beta is a direct action in the AHY, we performed in vitro experiments using hypothalamus slices. IL-1 beta (0.1 and 1 nM) increased the levels of each monoamine released from hypothalamic slices in a dose-dependent manner. These findings suggest that IL-1 beta acts directly on the hypothalamus to induce release of NE, DA, and 5-HT. Third, the roles of prostaglandins (PGs) in NE release in the AHY elicited by direct injection of IL-1 beta were examined.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗
PubMed1992

Plasma homovanillic acid, plasma anti-D1 and -D2 dopamine-receptor activity, and negative symptoms in chronically mediated schizophrenia.

We have investigated the relationship between the concentration of homovanillic acid in human plasma (pHVA) and plasma anti-D1 and anti-D2 dopamine receptor activity in chronic schizophrenic patients whose neuroleptic dosage was changed. The change in pHVA level correlated with that in anti-D1, not anti-D2 activity, thus suggesting that the neuroleptic-induced changes in pHVA concentration may be associated with the blocking of D1- as well as D2- receptors. The change of scores on the Scale for the Assessment of Negative Symptoms did not significantly correlate with changes in anti-D1 or anti-D2 activity, but did so correlated with the change in pHVA level.

Antipsychotic Agents↗
PubMed1992

Treatment of tardive dyskinesia with ceruletide: a double-blind, placebo-controlled study.

The effectiveness of a once-weekly i.m. injection of ceruletide (0.8 microgram/kg) in suppressing the symptoms of neuroleptic-induced tardive dyskinesia (TD) was evaluated in a double-blind, placebo-controlled, matched-pairs study. Global evaluation of the severity of TD symptoms over the 8-week study period revealed a significant improvement with ceruletide as compared with placebo. Analysis of the therapeutic response to ceruletide over the course of treatment revealed a slow, but long-lasting improvement of TD symptoms. Side effects, which were mild and transient, consisted mainly of nausea and epigastric discomfort. The incidence of side effects did not differ between the ceruletide- and placebo-treated groups. Ceruletide appears to be a novel and practical treatment that can substantially alleviate the symptoms of dyskinesia.

Adult↗
PubMed1992

Nortriptyline response in elderly depressed patients.

1. Depressed geriatric patients were treated with nortriptyline (NT) for 6 weeks. The authors measured serum levels of NT and 10-hydroxynortriptyline (10-OH-NT) using a column-switching HPLC method, and examined aging effects on NT steady-state levels to NT doses (doses/kg) ratios and NT levels to 10-OH-NT levels ratios as well as clinical response and propensity for side effects. 2. There was no significant relationship between the ages and the NT serum levels to NT doses (doses/kg) ratios, the ages and the 10-OH-NT levels to NT levels ratios, or the ages and the clinical response or the %improvement of Hamilton Scores. 3. Then the authors divided the subjects into two groups: a younger group and an elderly group with the cut off age of 60. The elderly group received significantly smaller doses of NT and had significantly lower serum levels of NT. The elderly group had tendency to have lower serum levels of 10-OH-NT. However, no significant difference was found in the improvement scores or the %improvement of depression. The elderly patients did not have higher propensity for unnegligible side effects.

Adult↗
PubMed1991

Serum interleukin-6 in schizophrenic patients.

We examined serum interleukin-6 (IL-6) in 90 schizophrenic patients in remission and 90 normal controls using enzyme-linked immuno-sorbent assay (ELISA). We found a significant difference in variation between the schizophrenic and the control groups (F = 10.9, P less than .002). The difference in distribution was also statistically significant by Kolmogorov-Smirnov (chi-square = 45.0, P less than .001). Eight patients had aberrantly high serum levels of interleukin-6. Since the higher levels of IL-6 are characteristically found in several autoimmune disorders, our finding suggests a link between schizophrenia and immune response, which could be either autoimmune or a process induced by reactivation of viruses.

Adolescent↗
PubMed1991

Potentiation by a sodium channel activator of effects of lithium ion on cyclic AMP, cyclic GMP and inositol phosphates.

The effects of the lithium ion (Li+) on receptor-mediated synthesis of second messengers were determined, when cellular sodium channels were quiescent or excited, using the murine neuroblastoma clone (N1E-115). In this clone, lithium inhibited the receptor-mediated synthesis of cyclic AMP and cyclic GMP and it also increased the accumulation of inositol phosphates by a receptor-mediated process. When veratridine (20 microM) excited the sodium channel, the effects of lithium were potentiated. However, tetrodotoxin, a sodium channel blocker, completely prevented this potentiation. These results suggest that when neurons are depolarizing actively and intraneuronal levels of lithium increase by entry through the sodium channel, lithium has a more potent intracellular effect. As a result, lithium would have more potent and selective effects in those pathologically-active neurons underlying manic-depressive disorder.

Animals↗
PubMed1991

Clinical variants of tardive dyskinesia in Japan.

Involuntary movement disorders were investigated in a psychiatric hospital in Japan. The prevalence of tardive dyskinesia was 9.9% and four clinical variants of tardive dyskinesia could be classified. Of the 716 patients, tardive dystonia was identified in 15 cases, tardive akathisia in one, respiratory dyskinesia in two and rabbit syndrome in 17. The existence of tardive forms for acute dystonic reactions and akathisia suggests that any type of acute extrapyramidal symptoms can have a tardive form.

Adult↗
PubMed1991

Two possibly distinct prostaglandin E1 receptors in N1E-115 clone: one mediating inositol trisphosphate formation, cyclic GMP formation, and intracellular calcium mobilization and the other mediating cyclic AMP formation.

Prostaglandin E1 (PGE1)-mediated transmembrane signal control systems were investigated in intact murine neuroblastoma cells (clone N1E-115). PGE1 increased intracellular levels of total inositol phosphates (IP), cyclic GMP, cyclic AMP, and calcium ([Ca2+]i). PGE1 transiently increased inositol 1,4,5-trisphosphate formation, peaking at 20 s. There was more than a 10-fold difference between the ED50 for PGE1 at cyclic AMP formation (70 nM) and its ED50 values at IP accumulation (1 microM), cyclic GMP formation (2 microM), and [Ca2+]i increase (5 microM). PGE1-mediated IP accumulation, cyclic GMP formation, and [Ca2+]i increase depended on both the concentration of PGE1 and extracellular calcium ions. PGE1 had more potent intrinsic activity in cyclic AMP formation, IP accumulation, and cyclic GMP formation than did PGE2, PGF2 alpha, or PGD2. A protein kinase C activator, 4 beta-phorbol 12 beta-myristate 13 alpha-acetate, had opposite effects on PGE1-mediated IP release and cyclic GMP formation (inhibitory) and cyclic AMP formation (stimulatory). These data suggest that there may be subtypes of the PGE1 receptor in this clone: a high-affinity receptor mediating cyclic AMP formation, and a low-affinity receptor mediating IP accumulation, cyclic GMP formation, and intracellular calcium mobilization.

Animals↗
PubMed1991

Coping style of schizophrenic patients in the recovery from acute psychotic state: a preliminary study.

This study was undertaken to clarify a clinically effective coping style of 13 schizophrenic patients during recovery from an acute psychotic state. Sixteen recovered depressives served as the control group. A comparison of the coping behavior profile between the two groups revealed that changes in physical activity were significantly more frequent in the schizophrenics (62%) than in the depressives (25%).

Acute Disease↗
PubMed1990

A statistical trial of subclassification for tardive dyskinesia.

The authors applied a statistical method to subclassify tardive dyskinesia (TD) in 71 psychiatric patients. Based on two-step statistical procedures and findings reported previously, TD is considered to consist of 2 subgroups: a classical dyskinesic group and a dystonic group. Symptoms manifested in the former group are seen most frequently in the oral region while the latter group, which is usually called tardive dystonia, is manifested by movement disorders in the trunk and extremities, predominantly. Abnormal movements occurring in the facial region characterize a population whose members may belong to either group.

Adult↗