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Y Ishihara

Publications and source records attributed to Y Ishihara.

At least 217 records · Page 12Linked to original sources
PubMed1988

Effects of nitroprusside on lung mechanics and hemodynamics after endotoxemia in awake sheep.

We examined the effects of intravenous sodium nitroprusside (NP) infusion on pulmonary arterial pressure (Ppa), pulmonary vascular resistance (PVR), dynamic compliance (Cdyn), resistance to airflow across the lungs (RL), and alveolar-arterial O2 pressure gradient (PAO2-PaO2) (room air) after endotoxemia in awake sheep. NP infused 2.5 h after endotoxin administration immediately reduced mean Ppa from 30 +/- 3 to 17 +/- 3 (SE) cmH2O, PVR from 6.3 +/- 0.7 to 4.8 +/- 0.5 cmH2O.l-1.min, and RL from 340 +/- 48 of base line to 205 +/- 73% and increased Cdyn from 54 +/- 5 of base line to 80 +/- 14% without affecting PAO2--PaO2. Ppa and lung mechanics returned immediately to preinfusion levels when NP was stopped. In vitro experiments with NP showed a dose-dependent relaxation of preconstricted pulmonary artery and vein, carbachol-preconstricted sheep tracheal strips, and bronchial rings. We conclude that NP reverses pulmonary hypertension and lung mechanics abnormalities after endotoxin and that this is due to effects of NP on airway and vascular smooth muscle. The return of these abnormalities after NP cessation suggests the continued presence of vascular and airway-constricting factors late after endotoxin. The lack of effect of NP on blood oxygenation suggests that deleterious effects on hypoxic vasoconstriction are offset by improved lung mechanics.

Animals↗
PubMed1987

Roles of gastric motility changes in cytoprotection induced by acetazolamide and cysteamine in rats.

The present study was undertaken using acetazolamide (AZ) and cysteamine (Cys) to investigate the relationship between gastric motor activity and the phenomenon of "cytoprotection" in rats. Both AZ (10-100 mg/kg) and Cys (10-100 mg/kg), given either p.o. or s.c., significantly reduced the formation of gastric mucosal injury caused by HCl-ethanol (1 ml of 60% ethanol in 150 mM HCl, p.o.). The protective effect of Cys appeared within 10 min, reached the maximal levels 30 min later, while that of AZ appeared from 30 min after administration and became potent with a latency period after treatment. Neither indomethacin (IM: 5 mg/kg, s.c.) nor N-ethylmaleimide (NEM: 5 mg/kg, s.c.) significantly affected the protective effect of Cys, whereas that of AZ was almost totally antagonized by IM. Both AZ and Cys, given either intragastrically or s.c., significantly inhibited gastric motor activity measured as intraluminal pressure recordings, but had minimal effect on acid and alkaline secretion. IM significantly attenuated the inhibitory effect of AZ on the motor activity, while NEM did not affect the inhibited motor responses caused by AZ and Cys. A significant relationship was found between the inhibitory effects of these two drugs on gastric motor activity and HCl-ethanol-induced mucosal injury, the correlation coefficient being 0.819 (P less than 0.01). When the mucosal folds were visualized with Gentian Violet (1 ml of 0.5% v/v, p.o.), both AZ and Cys significantly prevented the localized staining along the mucosal folds, suggesting dissolution of the folds. These results suggest that both AZ and Cys protect the gastric mucosa against injury caused by HCl-ethanol, probably through a dissolution of mucosal folds due to inhibition of gastric motor activity.

Acetazolamide↗
PubMed1987

[The clinical study of 794 patients with an upper urinary tract stone analyzed by infrared spectroscopy].

During the 48-year period from January, 1938 to December, 1985, upper urinary tract stones obtained from 794 patients were analyzed by infrared spectroscopy in our Department. Their clinical manifestations were studied, mainly in relation to stone composition. The ratio of males to females was 3.0 to 1. In recent years, the incidence of females tended to increase. In the age distribution, twenties were most frequent followed by thirties together with fourties before 1965, but after 1966, the thirties were most frequent, and fourties and fifties increased. The composition of 794 stones was as follows. The most frequent type was calcium oxalate combined with calcium phosphate (43.1%), followed by calcium oxalate (39.8%) and calcium phosphate (9.6%). Magnesium ammonium phosphate stones were found in 1.6% and uric acid stones in 2.9%. Calcium oxalate stones, uric acid stones and oxalate-containing stones were found more frequently in males than in females. On the other hand, magnesium ammonium phosphate stones, calcium phosphate stones and phosphate-containing stones were found less frequently in males than in females. There was a high occurrence of calcium phosphate stones and uric acid stones in patients older than 60 years old. The occurrence of calcium oxalate stones and uric acid stones increased and that of phosphate-containing stones decreased after 1966. Most of the recurrent stones revealed the same or similar composition as the initial stones.

Adolescent↗
PubMed1986

Isolation and characterization of lipocortin (lipomodulin).

Lipocortin is a phospholipase inhibitory protein whose synthesis is induced in various cells by glucocorticoids. At least three species with molecular weights of 40,000, 30,000, and 15,000 are presently known. This protein mimics the anti-inflammatory action of glucocorticoids in vitro as well as in vivo. The synthesis of the protein appears to be associated with the MHC genes.

Animals↗
PubMed1986

Effect of thromboxane synthetase inhibitors (OKY-046, OKY-1580) on experimentally induced air embolism in anesthetized dogs.

We investigated the effects of OKY-046 and OKY-1580, thromboxane A2 (TxA2) synthetase inhibitors, on plasma levels of 6-keto PGF1 alpha and TxB2 in anesthetized dogs with experimentally induced air embolism. The percentage increase of tracheal pressure induced by room air infusion was suppressed significantly by premedication with OKY-046. The percentage increase of pulmonary artery blood pressure was suppressed significantly by premedication with OKY-046 compared to that in control group. By room air infusion after the premedication with OKY-046 and OKY-1580, systemic artery blood pressure did not show any significant changes. Plasma 6-keto PGF1 alpha level showed a marked increase by an intravenous infusion of room air, and such an increase became more predominant by the premedication with OKY-046 and OKY-1580. On the other hand, plasma TxB2 level showed a marked increase by an intravenous infusion of room air, and such an increase became less predominant by the premedication with OKY-046 and OKY-1580. These results may suggest that OKY-046 and OKY-1580 are not only TxA2 synthetase inhibitors but also PGI2 synthetase accelerators and are useful drugs for treatment and prevention of thromboembolism.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

Primary leptomeningeal ependymoblastoma. Case report.

Ependymoblastoma is considered to be a primitive malignant glioma with ependymal differentiation. This rare tumor occurs in very early life and shows rapid growth and a diffuse infiltration through the leptomeningeal space. The tumor cells are highly immature, with numerous mitoses and multilayered ependymal rosettes. The ependymoblastoma described in this report was found in a 17-year-old girl. In spite of detailed clinical and postmortem examinations, no definite primary site was identified in the neuraxis. The lesion spread predominantly throughout the leptomeningeal space. Histological analysis strongly suggested that this tumor originated from a heterotopic glial nest in the subarachnoid space. The absence of immunohistochemical neural tissue markers, glial fibrillary acidic protein, S-100 protein, neuron-specific enolase, and neurofilaments ruled out neuronal or glial differentiation. The authors were unable to find any previous report of primary leptomeningeal ependymoblastoma.

Adolescent↗
PubMed1985

Effect of coenzyme Q10, a quinone derivative, on guinea pig lung and tracheal tissue.

In the present investigation, the effect of coenzyme Q10 (E-0216) on histamine or SRS-A (slow-reacting substance of anaphylaxis) release from passively sensitized guinea pig lung tissue and on the actions of various bronchoactive-agents in isolated perfused guinea pig tracheal strips was studied. The amount of histamine and SRS-A released from passively sensitized guinea pig lung tissue by the challenge of antigen showed a marked decrease by preincubating with coenzyme Q10. The percentage inhibition of histamine and SRS-A was biggest at the concentration of 10 micrograms/ml of coenzyme Q10. Prostaglandin F2 alpha-, acetylcholine-, serotonin-, and bradykinin-induced contractile responses in guinea pig tracheal strips did not show any significant increase by continuous infusion of coenzyme Q10 (0.05-5.0 micrograms/ml). On the other hand, histamine-induced contractile responses showed a significant increase by continuous infusion of 0.5 microgram/ml of coenzyme Q10. Isoprenaline (isoproterenol)- and salbutamol-induced relaxation responses in guinea pig tracheal strips did not show any significant decrease by continuous infusion of coenzyme Q10 (0.05-5.0 micrograms/ml). On the other hand, prostaglandin E2-induced relaxation responses showed a significant decrease by continuous infusion 0.05-5.0 micrograms/ml of coenzyme Q10.

Albuterol↗