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Biomedical subjects

T Shibuya

Publications and source records attributed to T Shibuya.

At least 343 records · Page 19Linked to original sources
PubMed1986

Descending protocerebral neurons related to the mating dance of the male silkworm moth.

Descending protocerebral neurons in the male silkworm moth brain responding to the sexual pheromone (Bombykol) were identified. The neurons responded well with a tonic type of response and the high-frequency spikes evoked continued even after the end of the stimulus. Characteristics of the dose-response curves of the neurons to the pheromone remarkably resembled those of the wing vibration which is one of the mating behavioral components of the male moths.

Animals↗
PubMed1986

Prostaglandin modulation of the postnatal development of T and B lymphocytes in the spleens of newborn mice.

The effects of prostaglandin E2 (PGE2) on postnatal development of the T and B cells in the spleen were studied to investigate the relationship between in vivo PG concentration and immunological development of peripheral lymph organs after birth. The development of the T and B cells were suppressed by the PGE2 injection, while augmented by the indomethacin injection. Especially in the T cells, cellular immigration from the thymus to the spleen was suppressed by the PG injection. Therefore, in vivo PG concentration in postnatal period might have some affect on the development of peripheral lymph organs, and the cellular traffic from central to peripheral lymph organs.

Animals↗
PubMed1986

Developmental alterations in maturing rats caused by chronic prenatal and postnatal diazepam treatments.

The post treatment effects of early prenatal, late prenatal, early postnatal or combined prenatal and neonatal treatment with diazepam on the development of pain sensitivity, acoustic startle responsiveness, and benzodiazepine receptors in the cerebral cortex were investigated in rats between 14 and 90 days of age. Tail-flick latency was significantly decreased by combined prenatal and neonatal and by early prenatal diazepam treatment, but not by diazepam during the last half of gestation or during the neonatal period alone. Acoustic startle response was decreased by either late prenatal or neonatal diazepam treatment, but not by early prenatal treatment alone. Density of benzodiazepine receptors in the cortex was increased from postnatal day 1 to 21 by either early or late prenatal diazepam treatment. Neonatal diazepam treatment suppressed cortical benzodiazepine receptor or development until postnatal day 21; thereafter, receptor density increased to significantly higher values than in controls at 90 days of age. The results demonstrate that diazepam can alter development of pain sensitivity by actions during early gestation, startle responsiveness by actions late in pregnancy, and cortical benzodiazepine receptors by actions throughout gestation and the early postnatal period.

Acoustic Stimulation↗
PubMed1986

Comparison of typical and atypical benzodiazepines on the central and peripheral benzodiazepine receptors.

The affinities of typical and atypical benzodiazepines (BZs) for 3H-flunitrazepam (FLU) and 3H-Ro 5-4864, "peripheral" BZ, binding sites in the central nervous system (CNS) were compared. Each dissociation constant (Kd) value of the 3H-FLU binding sites in the cerebellum, cortex, hippocampus and spinal cord showed the similar results, although the binding maximum (Bmax) for the cortex and cerebellum yielded the largest value and the smallest Bmax appeared in the spinal cord. In contrast, Bmax for 3H-Ro 5-4864 binding sites were about three-fold higher in the spinal cord than in the cerebellum. Among the drugs tested, brotizolam demonstrated the highest affinity for 3H-FLU binding sites in the four regions. Typical and atypical BZs did not normally show different affinities for the two BZ receptor subtypes, except for CL 218,872 and Ro 5-4864. A series of compounds including Ro 5-4864, PK 11195, diazepam and brotizolam had high affinity for the 3H-Ro 5-4864 binding sites in the cerebellum and spinal cord. Other BZs did not show affinity for "peripheral" BZ binding sites in the CNS. In conclusion, brotizolam (or atypical BZ) had the binding affinity to both "central" and "peripheral" BZ receptors, like diazepam (a typical BZ).

Animals↗
PubMed1986

Effects of Suanzaorentang on behavior changes and central monoamines.

Previously, it was found that the ancient Chinese remedy of Suanzaorentang could be a promising anxiolytic drug (Chen and Hsieh, 1985a, Chen and Hsieh, 1985b). To understand the mechanism of the action of Suanzaorentang, the effects of Suanzaorentang on behavior changes and central monoamines and their metabolites were studied in rats. It was found that Suanzaorentang significantly (1) prolonged the period from the onset of clonic to tonic convulsions induced by pentylenetetrazol or picrotoxin, (2) prolonged the sleep duration induced by hexobarbital, (3) reduced locomotor activity, (4) enhanced the hypomotility induced by alpha-MT, (5) reduced the locomotor stimulation produced by levodopa plus benserazide, and (6) reduced central HVA, VMA, and 5-HIAA, but had no significant effects on central DA, NA, and 5-HT. These facts implied that Suanzaorentang decreased the turnover rate of central monoamines and central catecholaminergic activity.

Animals↗
PubMed1986

Suanzaorentang, and anxiolytic Chinese medicine, affects the central adrenergic and serotonergic systems in rats.

Previously, we found that the ancient Chinese remedy of Suanzaorentang was a promising anxiolytic drug (Chen and Hsieh, 1985; Chen and Hsieh, 1985a). We also found that Suanzaorentang decreased the turnover rate of central monoamines and central catecholaminergic activity (Hsieh, et al., 1986). In this study, we found that 5-hydroxytryptophan (5-HTP) induced decrease in locomotor activity was significantly antagonized by Suanzaorentang, p-chlorophenylalanine (p-CPA) induced increase in locomotor activity was significantly inhibited by Suanzaorentang, Suanzaorentang had no significant effects on baclofen, muscimol, aminooxyacetic acid (AOAA) and thiosemicarbazide induced changes in locomotor activity, Suanzaorentang significantly decreased vanillylmandelic acid (VMA) in striatum and hippocampus, homovanillic acid (HVA) in hippocampus and 5-hydroxyindol acetic acid (5-HIAA) in striatum and hypothalamus, Suanzaorentang significantly reversed the alpha-methyltyrosine (alpha-MT) produced decrease in DA concentrations in striatum and hippocampus, and (6) Suanzaorentang significantly reversed the p-CPA produced decrease in 5-HT concentrations on amygdala. These facts implied that Suanzaorentang might decrease the serotonergic activity but have no significant effect on GABAergic activity. The main locus of action might be in the limbic system.

Animals↗
PubMed1986

Immunological studies on Crohn's disease. VI. Increased chemiluminescent response of peripheral blood monocytes.

Oxidative metabolic activity can be measured by a luminol-dependent chemiluminescence (CL) assay. To investigate the phagocytic activity of blood cells, CL responses were assessed in 26 patients with Crohn's disease (CD) and 26 healthy controls, using heparinized peripheral blood. Significantly (p less than 0.005) increased CL responses of whole blood cells were found in 26 patients with CD. However, CL activity was not directly related to disease activity nor to other clinical parameters. The CL responses did not correlate with the number of white blood cells, neutrophils nor monocytes. In consideration of the increased CL, there is the possibility that functional abnormalities in some components of blood cells leads to elevations in CL responses of whole blood cells. To obtain support for this proposal, blood cells were separated into neutrophils and monocytes, and CL of neutrophils or monocytes were studied, using the same number of each type of cells as that of the controls. The oxidative metabolism of monocytes from CD patients was significantly (p less than 0.005) higher than that of controls, while the phagocytic activity of neutrophils was similar to that in the controls. These data suggest that elevations in CL activity of whole blood cells were not due to alterations of the neutrophils but rather to abnormalities in the monocytes. Further attention directed to the significance of monocyte function in the pathogenesis of CD is warranted.

Crohn Disease↗
PubMed1986

[Regional coronary outflow and coronary reserve assessed by the thermodilution technique: an experimental study].

Coronary blood flow distribution and coronary flow reserve were experimentally evaluated by the thermodilution technique. Using a special catheter with two external thermistors 5 cm apart, the great cardiac vein (GCV) outflow and coronary sinus (CS) outflow were measured. Coronary inflows in the left anterior descending (LAD) and circumflex (LCX) arteries were measured by electromagnetic flow probes during arterial occlusion or bolus arterial injection of nitroglycerin and dipyridamole injection in a peripheral vein. On the LAD side, the venous flow due to the interventions increased both GCV and CS outflows, while the interventions in the LCX increased CS outflow without significant changes in the GCV flow. LAD inflow and GCV outflow, and LCX inflow and (CS-GCV) flow correlated well, and there were significant close correlations between each inflow and outflow. Coronary reserve in the LAD and LCX was studied in successive 70% and 90% stenoses produced by a calibrated constrictor. Maximal coronary flow was obtained during reactive hyperemic response after coronary artery occlusion. Although there was no significant coronary reserve in the coronary inflow or outflow in the basal state, coronary reserve in the GCV and CS decreased significantly in stenoses of the LAD and LCX. These results suggest that this method allows practical assessment of drainage from the LAD and LCX areas and that stenosis greater than 70% can be estimated from the changes in regional venous outflows. This method may be helpful in evaluating regional coronary hemodynamics clinically.

Animals↗
PubMed1986

[Clinical investigation of the therapeutic effects of cefmenoxime in the treatment of infections complicated by hematological diseases].

Therapeutic effects on cefmenoxime hemihydrochloride (CMX, Bestcall), a new synthetic cephem antibiotic, were examined in the treatment of various infections complicated with hematological diseases. The number of patients treated with CMX was 37 including 5 cases of sepsis or suspected sepsis, 14 cases of pneumonia or suspected pneumonia, 5 cases of upper respiratory diseases, 2 cases of urinary tract infections and 11 cases of other infections. All of these infections were complicated with hematological diseases: Acute leukemia, 13 cases; chronic myelocytic leukemia, 1 case; adult T cell leukemia, 3 cases; malignant lymphoma, 8 cases; Hodgkin's disease, 2 cases and myeloma, 3 cases. CMX were administered by a single intravenous injection or by a drip infusion. The dose was between 2 and 6 grams per day. Good to excellent clinical results were obtained in 25 out of 37 cases, total effective rate of 67.6%. No clinical side effects or abnormal laboratory findings attributable to CMX were observed except for light diarrhea in 2 cases. By the clinical investigation, it was demonstrated that CMX was one of safe and effective antibiotics for treating infections in the compromised hosts complicated with hematological diseases.

Acute Disease↗
PubMed1986

Effect of milbemycin D against microfilariae of Litomosoides carinii.

The filaricidal effect of milbemycin D, a compound closely related to ivermectin, was studied in vivo and in vitro using Litomosoides carinii. Microfilaria (mf) densities in the peripheral blood of cotton rats, Sigmodon hispidus, were reduced to less than 3% of initial densities within 24 hours after treating either subcutaneously or orally at doses of 0.05 to 50 mg/kg body weight. In cotton rats treated with diethylcarbamazine at a single dose of 200 mg/kg, mf densities were reduced transiently but recovered to initial levels within 2 weeks, whereas they remained at less than 20% of the initial levels in rats treated with milbemycin D even with a single dose of 0.05 mg/kg. No microfilaricidal effect was observed in cotton rats treated with milbemycin D at a dose of 50 mg/kg for 5 consecutive days. The microfilaricidal effect of milbemycin D was also shown in vitro in RPMI 1640 medium. The minimal effective dose of this compound was estimated to be between 1 and 10 micrograms/ml of medium.

Animals↗
PubMed1986

Skin test and radioallergosorbent test with extracts of larval and adult midges of Tokunagayusurika akamusi Tokunaga (Diptera: Chironomidae) in asthmatic patients of the metropolitan area of Tokyo.

Prick test and radioallergosorbent test to extracts of larval and adult midges, Tokunagayusurika akamusi (Tokunaga) were done in randomly selected asthmatic patients in the metropolitan area of Tokyo, Japan. Thirty-eight percent of 303 asthmatic patients were prick-test positive to either larval or adult midges, and 32.4% of 105 asthmatic patients were positive to either extracts by RAST, while only one out of 20 normal individuals was positive to RAST. These positive rates in the asthmatic patients were the second to the positive rates of prick test and RAST using mite antigen. Antigens from midges seem to be the second important allergens in the metropolitan area of Tokyo.

Asthma↗
PubMed1985

Olfactory receptor cell responses of pigeon to some odors.

A preparation has been developed in the pigeon which allows recording of the electrical activity from an olfactory nerve twig containing the nonmyelinated axons of a small group of olfactory receptor cells. The pigeon's response to n-amylacetate is vigorous and stable, like that of other air-breathing animals. Responses in the olfactory receptor cells in the pigeon increased in magnitude with increase in the odor concentration. An olfactory nerve twig produced a different magnitude of responses to the various odor stimuli. When an odor stimulation was applied to the olfactory mucosa, the two different olfactory nerve twigs which were separated from the same olfactory nerve bundle produced a different magnitude of responses. The differences may be dependent on several factors.

Animals↗
PubMed1985

The effect of some drugs on the mitral cell odor-evoked responses in the gecko olfactory bulb.

The activity of odor-evoked olfactory mitral cell response of the gecko was recorded extracellularly by glass microelectrodes. The activities of the mitral cell observed during the presentation of the odor (n-amyl acetate) could be described as excitation, suppression or zero. The present experiments were undertaken to study the neural activities of the mitral cell in the olfactory bulb by perfusion application of some drugs (cobalt chloride, carnosine, norepinephrine, GABA and D-L-homocysteate) on the olfactory bulb surface or iontophoretic application of some drugs (carnosine, norepinephrine, GABA and D-L-homocysteate) to the glomerulus and the external plexiform layer to change the physiological environment. The effect of the drugs suggested that the synaptic neurons on the mitral cell have different chemical characteristics.

Action Potentials↗