Enzyme-linked immunosorbent determination of the binding component to salivary glycoprotein from Streptococcus mitis ATCC 9811.
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Animals↗
Biomedical subjects
S Shibata
Publications and source records attributed to S Shibata.
The pathophysiological role of water-sodium balance and renal dopaminergic activity in overweight patients with essential hypertension.
Studies were conducted to evaluate the role of water-sodium balance and renal dopaminergic activity in the hypertensive mechanisms of overweight patients with essential hypertension (EHT). The body mass index (BMI) was correlated positively with arterial pressure, plasma volume, extracellular fluid volume, or total exchangeable sodium and negatively with plasma noradrenaline concentration or plasma renin activity in patients with EHT. Fractional excretion of sodium (FENa) was significantly lower in overweight patients with EHT than that in normal-weight patients with EHT. Hypotensive effects of sodium restriction or the natriuretic response to infused dopamine was more remarkable in overweight than in normal-weight patients with EHT. Urinary excretion of free dopamine (UDA) was correlated positively with simultaneously measured urinary excretion of sodium or FENa and negatively with the natriuretic response to dopamine infusion. In addition, UDA was positively correlated with the BMI in normal-weight patients with EHT, whereas the relation between UDA and BMI was significantly negative in overweight patients with EHT. These findings suggest that the expansion of body fluid volume and sodium might result from the blunted natriuretic ability due to an attenuation of the renal dopaminergic activity in overweight patients with EHT. The expansion of body fluid volume and sodium may play an important role in the hypertensive mechanisms of overweight patients with EHT.
Adult↗
[Effect of radiation therapy on extracerebral cavernous hemangioma in the middle fossa].
We report three cases of extracerebral cavernous hemangiomas in the middle fossa all of which had received radiotherapy. Follow-up study with serial computed tomography during and after irradiation were presented. In Case 1, radiotherapy after partial removal of the tumor reduced the tumor's size and CT number, and facilitated total removal. In Case 2 as well, irradiation was started before the operation. The tumor responded very well to irradiation and showed significant reduction in the size and CT number of the tumor with a dose of about 3,000 rads. Subtotal removal was possible. In Case 3, the tumor responded very well clinically to irradiation, and vertigo were much improved with a dose of about 3,000 rads, and CT scan at that time showed significant reduction in the size and CT number of the tumor, therefore she only received radiation therapy, no surgical intervention. It is concluded that in cases of extracerebral cavernous hemangioma with massive hemorrhage, radiation of up to 3,000 rads was a method of choice. The treatment results in an increased probability of total removal of the tumor, and moreover the possibility of eliminating surgery.
Adult↗
[Brain edema after surgery of lateral ventricle tumors].
We reported five cases of lateral ventricle tumors all of which developed severe brain edema between 9 days and 8 years after surgery. Follow-up study with serial computed tomography before and after surgery were presented. Based on a review of the literature, a possible causal mechanism is suggested: 1) The cerebrospinal fluid diffuses into the white matter through the surgically damaged ependyma and caused severe postoperative edema; and 2) surgical blockade of the flow of cerebral interstitial fluid to drain into the fenestrated vessels of the choroid plexus and other periventricular areas caused severe postoperative edema.
Adolescent↗
Cachectin/TNF as well as interleukin-1 induces prostacyclin synthesis in cultured vascular endothelial cells.
Cachectin/tumor necrosis factor (cachectin/TNF) has been shown to be capable of stimulating prostacyclin (PGI2) production by vascular endothelial cells in vitro. The stimulation of PGI2 by cachectin/TNF is comparable to that observed with interleukin-1, the monokine previously suggested to be the principal mediator of this effect. The ability of cachectin/TNF to stimulate PGI2 production suggests that it may play a role in producing depressed blood pressure or shock. If so, it might be possible to prevent such adverse effects with the aid of anti-inflammatory agents.
6-Ketoprostaglandin F1 alpha↗
The contractile action of palytoxin in the isolated rabbit urinary bladder.
Palytoxin at 10(-10)-10(-7) M caused contractions of the detrusor muscle from rabbit urinary bladder in a concentration-dependent manner. The response to palytoxin was markedly inhibited by indomethacin (a cyclooxygenase inhibitor) or nordihydroguaiaretic acid (a lipoxygenase inhibitor) at 10(-5) M. Indomethacin and nordihydroguaiaretic acid also inhibited the response to arachidonic acid at 10(-3) M. A Ca2+-free medium with EGTA or nifedipine at 10(-5) M, nearly abolished the responses to palytoxin and arachidonic acid. Tetrodotoxin, phentolamine, atropine and chlorpheniramine (all at 10(-5) M) had a slight or no inhibitory effect on the response to palytoxin. These results suggested that in the rabbit bladder, the contractile effect of palytoxin is mainly dependent on an increase in metabolites of arachidonic acid.
Acrylamides↗
Effects of dibutyryl cyclic adenosine monophosphate and dibutyryl cyclic guanosine monophosphate on neuron activity of suprachiasmatic nucleus in rat hypothalamic slice preparation.
In order to elucidate the role of cyclic nucleotides in the suprachiasmatic nucleus, we examined the effect of dibutyryl cyclic AMP (c-AMP) and dibutyryl cyclic GMP (c-GMP) on single neuronal activity of the suprachiasmatic nucleus of the rat. A hypothalamic slice about 300 micron thick, including the suprachiasmatic nucleus, was cut coronally using a vibratome. By means of bath- as well as iontophoretic application, c-AMP and c-GMP caused mainly an inhibition and facilitation in suprachiasmatic neuronal activity, respectively. The present results suggest that c-AMP and c-GMP play an important role in regulation of suprachiasmatic neuronal activity as a second messenger and that these two nucleotides may function as a reciprocal messenger.
Animals↗
Studies on the effects of primary therapy for DIC following circulatory arrest.
Comparative studies in early treatment for DIC caused by circulatory arrest were carried out on three groups of dogs during 300 min from the recovery of circulatory arrest: a heparin group, a FOY (gabexate mesilate) group, and a FUT-175 (nafamostat mesilate) group. The parameters employed were platelet count, prothrombin time (PT), activated partial prothrombin time (APTT), fibrinogen, antithrombin-III (AT-III), and fibrin or fibrinogen degradation products (FDP). In the heparin group, there was less of a drop in the platelet count and the level of AT-III than in the control group, but the FDP levels were the same as in the control group. The PT and APTT remained within normal limits in the FOY group and no decrease was observed in either platelet count or AT-III levels. In addition, FDP levels were kept within normal limits. In the FUT-175 group, prolongation of APTT, no decline in the platelet count and AT-III levels, and normal levels of FDP were observed. The results of these experiments indicate the importance of early treatment for DIC. Judging from the parameters, better results were obtained in the FOY and FUT-175 group than in the heparin group.
Animals↗
Effect of monoamines on field potentials in the suprachiasmatic nucleus of slices of hypothalamus of the rat evoked by stimulation of the optic nerve.
The effects of the application of serotonin, histamine, noradrenaline and dopamine to the bath on field potentials in the suprachiasmatic nucleus evoked by stimulation of the optic nerve were studied using a hypothalamic slice. Stimulation of the contralateral optic nerve evoked fast positive and late large negative waves in the suprachiasmatic nucleus. The monoamines produced a dose dependent suppression of the amplitude of the negative wave but did not affect that of the positive waves, and the order of potency was serotonin greater than noradrenaline greater than dopamine greater than or equal to histamine. The negative wave was suppressed by phenylephrine (0.1-10 microM) in a dose-dependent manner, whereas it was unaffected by isoproterenol (0.1-10 microM). The suppression of the negative wave produced by the application of histamine and noradrenaline was antagonized by the H1-receptor antagonist, diphenhydramine and the alpha 1-receptor antagonists, phenoxybenzamine and phentolamine. Therefore, the suppression of the negative wave by histamine and noradrenaline was mediated by the H1-receptor and alpha 1-receptor, respectively. The present study indicates that monoamines may play an inhibitory role in the regulation of neurotransmission in the retinohypothalamic pathway to the suprachiasmatic nucleus.
Animals↗
Influence of excitatory amino acid receptor antagonists and of baclofen on synaptic transmission in the optic nerve to the suprachiasmatic nucleus in slices of rat hypothalamus.
Electrical stimulation of the optic nerve evoked two positive waves with short latency, followed by a large negative wave in the suprachiasmatic nucleus of slices of hypothalamus of the rat. The latency to peak of the two positive waves and the large negative wave were 2.7 +/- 0.1, 6.1 +/- 0.1 and 10.3 +/- 0.5 msec, respectively. Only the large negative wave disappeared in low calcium Ca2+-high magnesium (Mg2+) Krebs solution and with the addition of tetrodotoxin (1 microM) all the waves disappeared. Baclofen inhibited the large negative wave in a dose-dependent manner but not the two positive waves. Excitatory amino acid antagonists also inhibited only the large negative wave, i.e. it was reduced to about 70% by 1 mM glutamic acid diethyl ester and to about 50% by both 1 mM 2-amino-4-phosphonobutyric acid and 1 mM DL-2-amino adipic acid. All waves were unaffected by 0.1 mM atropine, hexamethonium and curare. These results indicate that two positive waves, induced by stimulation of the optic nerve are attributed to nerve conduction and the large negative wave to the neurons of the suprachiasmatic nucleus, and that the neuronal pathway from the optic nerve to the suprachiasmatic nucleus may include aspartate and/or glutamate as an excitatory neurotransmitter.
Acetylcholine↗
Inhibitory action of insulin on suprachiasmatic nucleus neurons in rat hypothalamic slice preparations.
In order to elucidate a role of insulin on neurons in the suprachiasmatic nucleus (SCN) involved in the generation of circadian feeding behavior, we examined the effect of insulin on SCN neuronal activity at in vitro condition. Bath application of insulin (1-100 microU) mainly inhibited the SCN neuronal activity, and this inhibitory effect was still observed in a Ca2+-free Krebs solution. The present result strongly suggests that insulin directly inhibits SCN neurons and may explain an increase in food intake by insulin infusion into the SCN during the light period.
Animals↗
Changes in brain catecholamine levels following olfactory bulbectomy and the effect of acute and chronic administration of desipramine in rats.
Bilateral olfactory bulbectomy of the rat caused marked changes of noradrenaline level in several brain regions accompanied with the development of mouse-killing behavior (muricide). Noradrenaline level increased in the medial amygdala, ventromedial and lateral hypothalamus in muricidal olfactory bulbectomized rats (OB rats) but not in non-muricidal OB rats, while dopamine level decreased in the lateral hypothalamus in muricidal OB rats. Acute administrations of desipramine not only suppressed muricide of OB rats but normalized noradrenaline change in ventromedial hypothalamus and dopamine change in lateral hypothalamus. Chronic administration of desipramine also suppressed muricide and normalized noradrenaline changes in ventromedial and lateral hypothalamus and medial amygdala. These findings suggest that the increase in noradrenaline levels in the medial amygdala, ventromedial and lateral hypothalamus may be important for the induction of muricide in OB rats, and muricide was suppressed by desipramine in accordance with the normalization of increased noradrenaline levels, and that the change in dopaminergic function in the lateral hypothalamus may also be important for this muricide.
Aggression↗
The inhibitory action of melatonin on the contractile response to 5-hydroxytryptamine in various isolated vascular smooth muscles.
The effects of melatonin on the contractile responses to 5-hydroxytryptamine (5-HT), norepinephrine (NE), angiotensin-1 (AT-1) and potassium were determined on the rabbit isolated aorta, iliac and renal arteries. Melatonin, at 10(-4) or 10(-3) M inhibited the response to 5-HT in the aorta, iliac and renal arteries. Melatonin, at 10(-3) M, had a negligible effect on the responses to NE and AT-1 in all preparations used. The potassium-induced contraction of all 3 preparations used was slightly inhibited by only the high concentration of melatonin (10(-3) M). In a Ca+-free medium with EGTA (0.1 mM), the residual response to 5-HT (10(-5) or 10(-4) M) were inhibited by melatonin (10(-4) or 10(-3) M) in all preparations used. In a Ca2+-free medium with EGTA (0.01 mM), nifedipine (10(-6) M) and 5-HT (5 X 10(-7) M), application of Ca2+ (2 mM) resulted in a tonic contraction, related to receptor operated channels, of all preparations. This Ca2+ dependent, nifedipine insensitive contraction was markedly inhibited or abolished by melatonin at 10(-5) and 10(-4) M. These results demonstrated that melatonin had a generally greater inhibitory effect on the response to 5-HT than those to NE, AT-1 and potassium in vascular smooth muscles. Also the results suggest that action of melatonin on the 5-HT induced contraction is more related to interference with Ca2+ influx through receptor operated channels than release of intracellular Ca2+ from the store site.
Angiotensin I↗
Potent alpha-adrenoceptor blocking action of SGB-1534, a new quinazoline antihypertensive agent in vitro experiments.
SGB-1534 inhibited the contractile response to norepinephrine (NE), methoxamine (MO) and electrical transmural stimulation in the rabbit aorta, basilar and cat coronary arteries and only in the rabbit aorta its inhibitor action was a competitive manner. In the rabbit aorta, the potency (pA2) of SGB was greater than that of prazosin, whereas in the other preparations, the effect of SGB was comparable to that of prazosin. In the rabbit aorta, both SGB and prazosin abolished the contraction induced by transmural stimulation. In the guinea-pig vas deferens, SGB failed to affect the inhibitory effect of clonidine on the response to electrical field stimulation. SGB had no inhibitory effects on the contractile response to potassium, 5-hydroxytryptamine, PGF2 alpha and an excess Ca2+ and the relaxing response to isoproterenol in the vascular tissues. In the electrically driven left atria of guinea-pigs, SGB had no effect on the electromechanical parameters and the isoproterenol induced inotropic effect. On the specific binding of [3H]prazosin in the rabbit aorta, the inhibitory effect of SGB was greater than that of prazosin and phentolamine.
Adrenergic alpha-Antagonists↗
Optic nerve stimulation-induced increase of release of 3H-glutamate and 3H-aspartate but not 3H-GABA from the suprachiasmatic nucleus in slices of rat hypothalamus.
This study investigates the possibility of glutamate and/or aspartate as an excitatory transmitter in the retinohypothalamic fibers' terminal within the anterior hypothalamus, including the suprachiasmatic nucleus (SCN). We studied the release of 3H-Glu and 3H-Asp from the SCN of rat hypothalamic slices produced by optic nerve stimulation. Stimulation of the optic nerve released 3H-Glu, 3H-Asp but not 3H-GABA, while stimulation of the SCN released all three. These releases were suppressed in both Ca2+ free Krebs and tetrodotoxin (TTX) 1 microM containing Krebs. The present result with previous electrophysiological observations strongly suggest that glutamate and/or aspartate are included in this retinohypothalamic termination, while GABA is included in intrinsic and/or extrinsic neurons of the SCN, excluding the terminal of the retinohypothalamic fibers.
Animals↗
Effect of Oriental plant drugs on platelet-aggregation. II. Effect of qian-hu coumarins on human platelet aggregation.
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Coumarins↗
Biochemical mechanisms of aminoglycoside cell toxicity. I. The uptake of gentamicin by cultured skin fibroblasts and the alteration of lysosomal enzyme activities.
In order to study the toxicity of aminoglycoside, human skin fibroblasts were used as a model for basic studies, since they are known to have a specific aminoglycoside-binding site and to translocate the drug into the cells. Following the exposure of fibroblasts to gentamicin for 3 days, the cells formed many osmiophilic lamellar materials (myeloid bodies) in the lysosomes, while the other cellular structures appeared to remain normal. Although gentamicin was intensively accumulated within the lysosomes, intralysosomal pH, determined by the fluorescence intensity ratio method using fluorescein-isothiocyanate-labeled dextran, did not alter. Among the lysosomal enzymes, the activities of six different glycosidases were unchanged. On the other hand, sphingomyelinase and acid lipase activities were greatly decreased, while phospholipase A activity was increased. These results indicate that the lipid metabolism of fibroblasts is altered by gentamicin treatment, and that perturbation of intralysosomal pH can not be the cause of the changes observed in cell lysosomal enzyme activities.
Cells, Cultured↗
Actinides produced by 12C + 242Pu and 16O + 238U reactions.
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Journal Article↗