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Biomedical subjects

K Yoshimura

Publications and source records attributed to K Yoshimura.

At least 523 records · Page 29Linked to original sources

[A successfully operated case of atrial septal defect with pheochromocytoma].

A 16 year-old male, who had marked hypertension and complained of palpitation, hyperhidrosis, headache and weight-loss, was diagnosed as atrial septal defect with pheochromocytoma. The first operation was performed for tumor on September 3, 1981. The hemodynamic change was recorded through the operation. The total systemic peripheral resistance and the total pulmonary resistance were improved after surgery. The systemic and pulmonary blood pressure were also decreased to normal level after surgery, although pulmonary arterial flow was increased. On one hundred and third day after this operation, radical correction for the cardiac malformation was performed. Operative and postoperative course were uneventful and the patient is free from all untoward complaints at this moment. Blood or urine catecholamine levels have also improved and are within normal limits.

Adolescent↗

[Treatments and diagnosis of lung cancer--field study results: report from japan lung cancer TNM classification committee].

The results of 4,931 lung cancer cases treated during 1970-72 were examined to evaluate the factors (especially N factors) influencing the prognosis of lung cancer. The background factors examined included T-factor, N-factor, M-factor, clinical stage, histological type, age and sex. The prognosis was also examined according to treatment method. The 5-year survival rate in the curative resection only group was 42.6%, in curative resection + chemotherapy 52.1%, and in curative resection + chemotherapy 52.1%, and 54.8%. The results suggest improved 5-year survival by multimodality treatment.

Adenocarcinoma↗

Application of an irreversible opiate antagonist (beta-FNA, beta-funal-trexamine) to demonstrate dynorphin selectivity for K-opioid sites.

Application of 100 nM beta-FNA for 60 minutes to isolated longitudinal muscles-myenteric plexus preparations from the guinea pig ileum caused a marked antagonism of the inhibitory action of normorphine and leucine enkephalin without greatly affecting the inhibitory potency of dynorphin or ethylketocyclazocine. The interaction of beta-FNA with the normorphine (mu-opiate receptors) appears to be non-equilibrium. Pretreatment with beta-FNA caused a significant increase in the apparent naloxone dissociation constant for normorphine and leucine enkephalin but not for dynorphin or ethylketocyclazocine. The results lend further support to the hypothesis that normorphine and the enkephalins activate preferentially mu-opiate receptors on the ileum, whereas dynorphin interacts predominantly at k-opiate sites.

Animals↗

Potency of three opiate antagonists to reverse the inhibitory activity of dynorphin, enkephalins and opioid-like alkaloids on the guinea pig ileum.

To test the hypothesis that dynorphin is a K-opiate agonist acting on the myenteric plexus, the potency of two benzomorphan antagonists (Win 44, 441 and Mr 2266) to block the inhibitory action of dynorphin, enkephalins and opioid alkaloids was determined on the longitudinal muscle preparation of the guinea pig ileum. The effectiveness of these antagonists was compared to that of naloxone. Antagonistic potency was established by calculating the apparent antagonist dissociation constant, Ke, as derived from Schild plots. Win 44, 441 and Mr 2266 were about 7-8 times more potent than naloxone against dynorphin, dynorphin-(1-13) or ethylketocyclazocine. Although the Ke obtained with Win 44, 441 or Mr 2266 against dynorphin or ethylketocyclazocine were significantly lower than those of naloxone, the values obtained for these antagonists did not differ significantly in the case of each of these agonists. With respect to the antagonism of the enkephalins or normorphine, Win 44, 441 was the most potent antagonist. Its Ke value for the enkephalins was 2.5-3 times lower than those for dynorphin or ethylketocyclazocine and in comparison to naloxone, Win 44, 441 was about 5 times more potent. Although Mr 2266 was a potent antagonist of dynorphin, ethylketocyclazocine, the enkephalins or normorphine, it showed no selectivity of action. The fact that the 3 opiate antagonists evidenced similar Ke values for dynorphin and ethylketocyclazocine, but different ones for the enkephalins or normorphine supports the conclusion that dynorphin activates preferentially K- but not mu-opiate receptors in the myenteric plexus.

Animals↗

The course of Angiostrongylus cantonensis infection in athymic nude and neonatally thymectomized mice.

BALB/c athymic nude and thymus-reconstituted nude mice and neonatally thymectomized BALB/c mice were infected with stage 3 larvae of Angiostrongylus cantonensis and the worm burdens of the mice were determined at various times after infection. When the nude and thymectomized mice were exposed to the parasite, some worms were found to migrate from the brain to lungs but died there without reaching maturity. This pulmonary arterial migration of the worms in the nude did not occur following thymic reconstitution. These data suggest that the inability of murine intracranial worms to migrate to the lungs is at least in part due to thymus-dependent mechanisms, and also that the failure of worm maturation in mouse lungs might be due to thymus-independent immune mechanisms and/or nonimmunological mechanisms.

Angiostrongylus↗

Hemodynamic responses to prostacyclin (PGI2) in the conscious sheep.

Hemodynamic responses to prostacyclin (PGI2) were studied in sheep in the conscious state as well as under pentobarbital-halothane anesthesia. PGI2 in doses of 0.02-1.0 microgram/kg were administered as a bolus into the right or left atrium in the conscious sheep. PGI2 decreased systemic arterial pressure (PSA), systemic (SVR) and pulmonary vascular resistance (PVR) and increased cardiac output (CO) and heart rate (HR) in a dose-dependent manner. The changes of each parameter were almost similar regardless of the sites of administration. Pulmonary arterial pressure (PPA) was increased. There was no change in left (PLA) or right atrial pressure (PRA). A bolus administration of 0.5 microgram/kg of PGI2 in the anesthetized sheep produced a decrease in PSA, SVR and PVR, and increase in CO and HR. PPA remained unchanged when administered into the right atrium and increased slightly when administered into the left atrium. PLA and PRA did not change. Comparing hemodynamic responses to 0.5 microgram/kg of PGI2 of the conscious and anesthetized states, decrease in PSA was smaller and increases in CO and HR were greater in the former. Decreases in SVR and PVR were similar in both states. Increase in PPA was greater in the conscious sheep. This data confirms that PGI2 dilates the systemic as well as the pulmonary circulation of the sheep and an inactivation of this compound in the lungs is minimal. Furthermore, it may be suggested that general anesthesia significantly alters hemodynamic responses to PGI2 in the sheep.

Animals↗

Transport of L-cysteine and reduced glutathione through biological membranes.

Comparative studies were carried out on in vivo and in situ absorption in rats and in vitro uptake by red cells of L-cysteine (CySH) and reduced glutathione (GSH). After oral administration of CySH, the plasma and liver CySH levels and liver GSH level significantly increased, but the plasma GSH level did not. In contrast to the results with CySH, when GSH given orally at a dose equivalent to that of CySH either on a weight or molar base, no increase in the levels of GSH was observed at either dose level. In a rat small intestine recirculation system in situ, CySH added to the recirculation perfusate disappeared progressively with time from the perfusate, indicating that transportation occurred across the intestinal wall, but with GSH such disappearance was not observed. CySH was taken up well by rabbit erythrocytes in vitro, but GSH was not. It was concluded, therefore, that CySH passes through biological membranes and serves as a good source of SH groups, whereas GSH is ineffective when given orally because of its poor absorption from the digestive tract and/or poor ability to permeate through the membrane.

Animals↗

A possible association of Y chromosome heterochromatin with stature.

A correlation between Y chromosome length and stature was statistically analyzed in a normal male population of 142 Japanese students with a mean age of 24.0 years. Evidence was obtained that increased length of the heterochromatic band Yq12 may be associated with increased height: The correlation coefficient between band Yq12 length and height was 0.17, statistically significant at the 5% level. And, taller males had longer Y chromosomes, in which the mean length of band Yq12 was significantly longer than that of shorter males. No correlation was seen between length of the euchromatic band Yq11 and stature. The present study reveals a possible effect of Yq heterochromatin on the development of body height in man.

Adult↗