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Biomedical subjects

S Yano

Publications and source records attributed to S Yano.

At least 613 records · Page 34Linked to original sources
PubMed1983

Two-dimensional ultrasonography of the brain: its diagnostic usefullness in herpes simplex encephalitis and cytomegalic inclusion disease.

We have used brain ultrasonography in diagnosing and following up two infants, one with herpes simplex encephalitis and the other with cytomegalic inclusion disease. It was found that this technique was very useful to observe the changes of the brain parenchyma such as cystic degeneration and periventricular calcification. Also because it is non-invasive and an easy procedure, ultrasonography can be applied even for infants in critical condition when needed.

Calcinosis↗
PubMed1983

Gastric blood flow responses to autonomic nerve stimulation and related pharmacological studies in rats.

The effects of autonomic nerve stimulation on rat gastric blood flow (GBF) were studied using a cross thermocouple method. Stimulation of the periarterial nerve bundles along the left gastric artery produced a decrease in GBF which was antagonized by phenoxybenzamine (0.05 mg kg-1 i.v.), but not by propranolol (1 mg kg-1 i.v.). Stimulation of the vagus nerves elicited an increase in GBF, within a latency of 20 s, which was not apparently affected by atropine (0.15 and 1.5 mg kg-1 i.v.) but was completely blocked by hexamethonium (10 mg kg-1 i.v.). The GBF increase due to acetylcholine (0.25 micrograms rat-1 i.a.), was markedly blocked by atropine (0.15 mg kg-1 i.v.). Vagal stimulation also produced both the cholinergic excitation and non-cholinergic inhibition of gastric motility. The vagally induced GBF increase was little affected by any pretreatment with phentolamine, propranolol, indomethacin or aprotinin. These results suggest that sympathetic nerve stimulation creases GBF through alpha-adrenoceptors and parasympathetic nerve stimulation increases GBF through a non-cholinergic mechanism in rats and that the GBF increase may result from a primary dilator effect of vagal stimulation on the blood vessels because of the immediate initiation of the response.

Animals↗
PubMed1983

Effects of some prostaglandins on urinary bladder and urethra isolated from the dog.

Effects of prostaglandins (PGs) E1, E2, E2 and F2 alpha on the vesical and urethral smooth muscles of dogs were isometrically investigated in vitro. In vesical smooth muscles, 10(-8)-10(-6) PGE1/ml produced biphasic responses in the dome preparations; relaxation at 10(-8) g/ml and contractions at 10(-7)-10(-6) g/ml. In the trigone preparations, 10(-8)-10(-6) g PGE1/ml caused dose-dependent contractions. 10(-8)-10(-6)M g PGE2/ml and 10(-7)-10(-6) g PGF2 alpha /ml induced dose-dependent contractions of the dome and the trigone preparations. In urethral smooth muscles, 10(-8)-10(-6) g PGE1/ml and 10(-8)-10(-6) g PGE2/ml produced dose-dependent relaxations, while 10(-8)-10(-6) g PGF2 alpha /ml caused dose-dependent contractions. Results indicate that PGE, particularly PGE2, is able to stimulate micturition through vesical contraction and urethral relaxation.

Alprostadil↗
PubMed1983

Augmentation of bethanechol-stimulated gastric secretion by lowering body temperature in water-immersed rats.

The present study was designed to elucidate influences of hypothermia on gastric secretory response to secretagogues (bethanechol, histamine and tetragastrin) in rats exposed to restraint plus water immersion (36 and 25 degrees C) stress. In vagotomized rats provided with a pH microelectrode, decrease in intragastric pH by bethanechol (75 micrograms/kg, i.p.) was markedly produced under the water-immersion at 25 degrees C and the extent of the pH decrease was significantly greater than that observed under the water-immersion at 36 degrees C. However, intragastric pH decrease by histamine (1 mg/kg, i.v.) or tetragastrin (60 micrograms/kg/20 min, i.v.) was not affected by varying water temperatures. Using a technique of pyloric ligation, gastric acid and pepsin responses to bethanechol were measured at doses of 50-100 micrograms/kg in vagotomized rats and also at doses of 0.5-1.0 mg/kg in vagally intact rats. Stimulation of acid and pepsin secretion by bethanechol was provoked only under the water-immersion at 25 degrees C. As compared with the values obtained under the water-immersion at 36 degrees C, a significant augmentation of bethanechol-stimulated secretion was seen for acid and pepsin output in vagotomized rats and seen for acid output in vagally intact rats under the water-immersion at 25 degrees C. These results suggest that hypothermia may operate some mechanism for increasing the secretory responsiveness of the stomach to cholinomimetics.

Animals↗
PubMed1983

Natural killer cell activity associated with aging and sex in humans.

The effect of aging and sex on natural killer (NK) cell activity in humans was investigated. The results showed that there were no significant differences in both the age- and sex-related NK cell activities with or without polyinosinic acid-polycytidylic acid stimulation. On the other hand, the mitogenic response of peripheral blood lymphocytes in the aged group (aged 70 to 86 years) was found to be significantly depressed in compared with that in the young adult group (aged 20 to 30 years). These data suggest that the NK cell activity of the aged subjects is operative, and may be important in defense against neoplasia since extensive immunodeficiencies are known to be associated with aging.

Adult↗
PubMed1983

Studies of the blood flow pattern in the left and right ventricular outflow tract using pulsed Doppler echocardiography.

In this paper, we reported that the main blood flow velocity in the LVOT and RVOT manifests characteristic variations with Doppler echocardiography. The volume over-load in the right heart changed the blood flow velocity pattern and the site of peak velocity in RVOT. And then, that in the left heart changed the blood flow velocity pattern and the site of peak flow in LVOT. We found a small "a" wave, which caused Ia on PCG can be recognized in LVOT during the isovolumic contraction phase. The small "a" wave and "a/H" ratio are useful criteria for detecting the changes of left ventricular contractility. There were linear correlate plot between EDP or peak-dP/dT and "a" or "a/H" in cases of HCM and IHD significantly.

Blood Flow Velocity↗
PubMed1983

Superoxide anion and hydrogen peroxide release by macrophages from mice treated with Nocardia rubra cell-wall skeleton: inhibition of macrophage cytotoxicity by a protease inhibitor but not by superoxide dismutase and catalase.

Peritoneal macrophages obtained from male BALB/c mice intraperitoneally injected with Nocardia rubra cell-wall skeleton (N-CWS) showed abundant superoxide anion and hydrogen peroxide release in response to opsonized zymosan used as a trigger. These N-CWS-induced macrophages also showed marked cytolytic activity against syngeneic Meth A fibrosarcoma targets. To examine the possible role of superoxide anion and/or hydrogen peroxide in the lysis of Meth A cells, N-CWS-induced macrophages were assayed with Meth A targets in the presence of superoxide dismutase, catalase, or both. However, addition of these agents to the assays, in doses which abolished detectable superoxide anion and/or hydrogen peroxide release from the effector cells, had no inhibitory effects on the cytotoxicity of N-CWS-induced macrophages. In contrast, both a protease inhibitor and actinomycin D could inhibit the cytolysis of Meth A targets by N-CWS-induced macrophages. These data raise the possibility that protease(s) rather than oxygen intermediates might be involved in the cytotoxicity of N-CWS-induced macrophages against tumor cells.

Animals↗
PubMed1982

Evolution of infectious mononucleosis into Epstein-Barr virus carrying monoclonal malignant lymphoma.

A monoclonal malignant lymphoma was diagnosed in a 30-month-old Japanese boy, who, since the age of 12 months, had had chronic, recurrent infectious mononucleosis manifested by repeated episodes of severe cough and high fever accompanied by marked lymphadenopathy and hepatosplenomegaly and high serum Epstein-Barr virus (EBV) antibody titres. The diagnosis of Burkitt's lymphoma was made when a cervical lymph-node biopsy specimen revealed massive proliferation of immature B-cells with starry-sky histiocytes. These lymph-node cells were characterised by a translocation between chromosomes 10 and 17. There were approximately 9 EBV genome-equivalents per cell. Most cells were positive for nuclear antigen (EBNA); early antigen (EA) and viral capsid antigen (VCA) were also detected. The presence of EBV was supported by finding that the cell-free lymph-node extract transformed cord-blood lymphocytes into EBNA-positive blast cells. The proportion of EA-positive and VCA-positive cells increased rapidly in culture for 24 h, then the positive cells degenerated rapidly and completely. The cells also contained numerous herpes-type virus particles. The child improved considerably with cytostatic treatment and has been in remission for 2 years.

Antibodies, Viral↗
PubMed1982

Effects of acetylcholine on the tone and miniature contractions of isolated dog urinary bladder.

Effects of acetylcholine on the tone and miniature contractions of dog urinary bladder were investigated in vitro. In both dome and trigone preparations, cumulative administrations of acetylcholine produced dose-dependent increases in the tone, which were dose-dependently depressed by prior administration of atropine and augmented by neostigmine. The frequency of miniature contractions in the dome and trigone was dose-dependently increased by acetylcholine. The dose-response curves of the frequency for acetylcholine were shifted to the right by atropine and to the left by neostigmine in both preparations. The amplitude of miniature contractions in both preparations was not significantly changed by acetylcholine. A computer analysis showed that changes in the tone of the bladder had the positive correlation to the frequency of miniature contractions. The results indicate that acetylcholine would act on the urinary bladder through activation of muscarinic receptors, and that there is the positive correlation between changes in the tone and the frequency of miniature contractions.

Acetylcholine↗
PubMed1982

Effects of adrenergic drugs on miniature contractions of isolated dog urinary bladder.

Isolated dog urinary bladder showed spontaneous miniature contractions under a steady state. In dome preparations, norepinephrine and isoproterenol decreased the frequency of miniature contractions, while epinephrine produced biphasic responses on it; increase by low concentration and decrease by high concentrations. The height of miniature contractions was decreased by these drugs. In trigone preparations, norepinephrine and epinephrine increased the frequency of miniature contractions, while isoproterenol decreased it. These drugs decreased the height of miniature contractions. In both preparations, phentolamine enhanced the decreases in frequency and height by norepinephrine, epinephrine and isoproterenol, while propranolol depressed or reversed them. A computer analysis showed positive and significant correlations between changes in tension development of bladder and frequency and height of miniature contractions. Results indicate that miniature contractions in both dome and trigone of isolated dog urinary bladder are increased by activation of alpha-adrenoceptors and decreased by activation of beta-adrenoceptors.

Animals↗
PubMed1982

The etiology of caffeine-induced aggravation of gastric lesions in rats exposed to restraint plus water-immersion stress.

Caffeine augmented formation of gastric lesions in rats exposed to restraint plus water-immersion stress for 3 h, together with inhibition of gastric secretion and gastric motility. The etiology of the lesion aggravation by caffeine was studied by measuring several parameters which were relevant to the mucosal defensive factors. Caffeine increased the susceptibility of gastric mucosa to erosive action of acid when simultaneously combined with the stress procedure. Injection of caffeine via an intraperitoneal route, but not via an intraarterial route, caused a decrease in gastric tissue blood flow when no marked fall in body temperature was seen. This indicates that the caffeine-induced decrease in gastric tissue blood flow is not due to its direct action on the gastric mucosal vessels. Hexosamine content of gastric wall tissues, however, was not significantly changed in caffeine-pretreated rats at 3 h after stress. These results suggest that caffeine aggravates stress-induced gastric lesions through some mechanism in reducing mucosal blood flow which is responsible for liability of mucosal autodigestion.

Animals↗
PubMed1982

Stress procedures lowering body temperature augment gastric motility by increasing the sensitivity to acetylcholine in rats.

Exposure of rats to restraint plus water-immersion (25 degrees C) stress produces a marked increase in gastric motility with hypothermia. Although this phenomenon was generally considered to be due to centrally mediated cholinergic mechanisms, the present study was designed to elucidate some local peripheral mechanism in enhancing gastric motility with hypothermia. After the onset of water-immersion (37-17 degrees C), body temperature rapidly varied depending on water temperature and gastric motility changed in its pattern with stress duration; increase in gastric motility reached a maximum at 25 degrees C but declined at 17 degrees C. These alterations of gastric motility pattern were not primarily associated with activation or decline of the sympatho-adrenal system. In these stressed rats, either vagally intact or vagotomized, contractile responses of the stomach to i.v. or i.a. administration of bethanechol and acetylcholine, but not to that of histamine, were markedly augmented by lowering body temperature. Similar observations were noted in rats exposed to restraint plus cold (6 degrees C) stress. These results emphasize the possibility that augmentation of gastric motility during water-immersion (25 degrees C) occurs at least in part through local peripheral mechanisms of increasing the contractile sensitivity of the stomach to acetylcholine with hypothermia.

Acetylcholine↗
PubMed1982

Immunological studies on an unusual case of primary pulmonary amyloidosis with hilar adenopathy.

A rare case of primary pulmonary amyloidosis with hilar lymphadenopathy is described. Immunological studies showed decreases in serum IgG and IgM levels. However, both pokeweed mitogen (PWM)-induced IgG production and proliferation of peripheral blood B cells were not disordered. The response of peripheral blood lymphocytes (PBL) to stimulation with PWM, phytohemagglutinin, or concanavalin A was found to be normal. In addition, the proportion of E and EAC rosette-forming cells in PBL from this patient did not differ from that in PBL from normal donors. The positive response of skin test to recall antigens also gave an evidence that the patient had not a depression in systemic cell-mediated immunity. These findings contrast with those previously described for systemic amyloidosis in man and in animals.

Amyloidosis↗
PubMed1982

Studies on a new antibiotic M-92 produced by Micromonospora. I. Taxonomy of M-92 producing Micromonospora and antibiotic production therefrom.

An isolate (strain MCRL 0404) producing a new antibiotic, M-92, was identified as a new strain of Micromonospora for which the name Micromonospora verruculosa sp. nov. was proposed. A water-infusion of dried sea tangle and dried shiitake was utilized for the production of M-92. When this strain was fermented in the medium containing this infusion, M-92 accumulated in the mycelium at about 10 times that in the broth at the peak level.

Anti-Bacterial Agents↗