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Biomedical subjects

Y Uchida

Publications and source records attributed to Y Uchida.

At least 559 records · Page 31Linked to original sources
PubMed1988

Pathomorphological changes in experimentally induced canine myocardial infarction.

We performed a pathological study of experimental canine myocardial infarction (MI) induced by coronary thrombosis which was made by endothelial denudation and induction of luminal stenosis in 20 dogs (Group I). Another model of experimental MI by coronary ligation was also evaluated in Groups II and III. Thirteen dogs of Group I and 7 of Group II underwent persistent coronary occlusion for 6-8 h (Group IA and Group IIA), and 7 of Group I and 7 of Group II underwent coronary reperfusion with intravenous urokinase (UK) (20,000 IU/kg) in Group IB for 5 h following temporary coronary occlusion for 3 h (Groups IB and IIB). The remaining 5 dogs underwent coronary reperfusion for 5 h following intravenous 20,000 IU/kg UK after 3 h ligation. Microscopically, myocardial hemorrhage was present in 6 (86%) Group IB, 4 (31%) Group IA and in no Group IIA dogs (p less than .025 and p less than .005 vs. IB). Four Group IIB and 3 Group III dogs also showed myocardial hemorrhage. Moderate hemorrhage was present only in Group I and slight hemorrhage was frequently observed in reperfused hearts. Contraction band necrosis (CBN) was present in 8 (62%) Group IA, all Group IB, all Group IIB, and 4 (80%) Group III dogs. However, there was no hemorrhage with CBN in Group IIA (p less than .005 vs. IIB). Marked CBN was present only in Group I.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Preventive effects of batroxobin on experimental canine coronary thrombosis.

The thrombolytic effects of urokinase (UK) and preventive effects of batroxobin, heparin, and aspirin on the recurrence of thrombosis in the coronary artery were studied in 118 anesthetized dogs with severe endothelial denudation and luminal stenosis of the coronary artery. Occlusive thrombi developed in 68 (58%) preparations (dogs), accompanied by a decrease of coronary blood flow and pressure, an electrocardiographic ST elevation, and epicardial cyanosis. An intravenous infusion of 20,000 IU/kg of UK reopened the occluded coronary artery in all 32 preparations with 1-h-old thrombi, in 6 (86%) of 7 preparations with 2-h-old thrombi, and in 5 (83%) of 6 preparations with 3-h-old thrombi. However, recanalization was not observed in preparations with thrombi more than 4-h-old. Occlusion recurred within 6 h after recanalization in 2 (18%) of 18 preparations pretreated with batroxobin (1-2 BU/kg) (p less than .005 vs. control UK group), in 1 (14%) of 7 preparations administered a continuous infusion of 30 U/kg per h of heparin (p less than .05 vs. control UK group), in 4 (57%) of 7 preparations pretreated with 2 mg/kg of aspirin, and in 7 (64%) of 11 preparations not pretreated (control UK group). Complete prevention was observed only in the group administered 2 BU/kg of batroxobin. Histologically, these thrombi closely simulated clinical arterial thrombi. Myocardial hemorrhage and contraction band necrosis were observed in the reperfused hearts. In conclusion, experimental canine coronary thrombi more than 4-h-old were resistant to thrombolytic therapy, and batroxobin and heparin were effective in the prevention of coronary reocclusion.

Animals↗
PubMed1988

Brainstem auditory evoked potentials in Chiari-II malformation.

Brainstem function in patients with Chiari-II malformation was evaluated by brainstem auditory-evoked potentials (BAEPs). All cases had associated hydrocephalus, some of which were shunted. The effect of the shunting operation on the wave forms was examined as well as the age-wave relationships. Although the shunting operation resulted in shortened brainstem conduction time, the overall postshunt responses were still far from normal. Another significant finding was that whereas there were remarkable abnormalities in recorded waveforms in cases younger than 8 years, normal or almost normal responses were obtained in all cases older than 8. BAEP abnormalities could not be correlated with the severity of meningomyelocele, nor was the predictive value of response in assessing potential risk of symptomatic Chiari malformation established.

Adolescent↗
PubMed1988

Fiberoptic angioscopy of cardiac chambers, valves, and great vessels using a guiding balloon catheter in dogs.

The applicability of fiberoptic angioscopy with a guiding balloon catheter to observe the cardiac chambers, valves and the great vessels was examined in anesthetized dogs. A No. 11 French guiding balloon catheter (balloon diameter 50 French) was introduced through either the right jugular vein or the right femoral vein into the right heart, and then a fiberscope (4.3 French in diameter) was introduced through the catheter into the right heart in 10 dogs. The balloon was inflated with air and gently pushed against the luminal surface, warm saline was infused through the catheter to displace the blood, and the luminal surfaces were photographed on 16 mm color cinefilms. Pulmonary angioscopy was also performed in these dogs. Similarly, the guiding catheter and fiberscope were introduced through the right common carotid artery into the left ventricle for observation of the luminal changes in the other 10 dogs. The luminal surfaces of the superior vena cava, right atrium, right ventricle, and pulmonary artery could be observed in all dogs. The trabeculae of the left ventricle, contracting and relaxing synchronously with the cardiac beat, could also be observed in all dogs. However, observations of the tricuspid valve, aortic valve, papillary muscle, and chordae were successful in only some dogs. Postmortem examinations revealed no obvious endocardial or intimal damage. The results indicate the applicability and safety of angioscopy guided by a balloon catheter for observations of the luminal changes in the cardiac chambers and great vessels.

Animals↗
PubMed1988

Fiberoptic study on the effects of transluminal angioplasty in experimental occlusive arterial thrombosis.

Percutaneous transluminal coronary angioplasty has been proposed as definitive therapy for coronary recanalization of occluded coronary arteries in patients with acute myocardial infarction (AMI). The effects of transluminal angioplasty (TA) on experimental occlusive canine arterial thrombi that closely simulated the clinical condition was examined by a fiberoptic method. Experimental arterial thrombosis was produced by endothelial denudation and induction of luminal stenosis. Eighteen dogs that showed total occlusion of the iliac artery with thrombi were evaluated. Seven dogs (group A) with 6-hour-old thrombi received 20,000 IU/kg intravenous urokinase (UK) but did not show recanalization. TA was performed with a Gruentzig or Simpson-Robert balloon catheter and its effect was evaluated by a vascular fibroscope. Eight dogs (group B) with 6-hour-old thrombi underwent primary TA. After TA, less than 50% luminal obstruction with residual thrombi was visualized in five dogs (71%) of group A and four dogs (50%) of group B. Residual thrombi showed a doughnut-like or globular type shape and consisted of dense fibrin networks and compact platelet aggregates. All dogs in group B received 20,000 IU/kg intravenous UK after TA, but most of them showed progression of thrombus size despite UK infusion. In conclusion, the results suggest (1) that TA is effective in recanalization of an occluded artery with aged thrombus that is resistant to thrombolytic therapy and (2) that vascular fiberscope is a useful method for evaluation of the effects of TA on occlusive arterial thrombus.

Angioplasty, Balloon↗
PubMed1988

Isolation and identification of prostaglandin I 2 stimulating factor from human plasma.

To isolate and identify the plasma factor which stimulates prostaglandin I 2 production by rat aortic ring, a human plasma fraction which showed a major stimulating activity on prostaglandin I 2 production was purified by ultrafiltrate, Sephadex G-10 gel filtration and QAE-Sephadex column chromatography. The purified plasma factor was identified as uric acid by its ultraviolet and infrared absorption spectroscopy, and 1H nmr and 13C nmr spectroscopy. The stimulating activity of the purified plasma factor and that of authentic uric acid coincided with each other. The stimulating potency of uric acid at its physiological concentration in human plasma (about 50 micrograms/ml) was half of the deproteinized human plasma, and was about 30 fold stronger than that of L-tryptophan, a cofactor of prostaglandin hydroperoxidase.

Adult↗
PubMed1988

Treatment of tardive dyskinesia with ceruletide.

1. Seven patients with TD were treated with a single dose of ceruletide 0.8 microgram/kg i.m. 2. EMG and MV were recorded, and the average power spectrum was computed. 3. Effect of ceruletide on TD within 2 hr after injection was varied (3 cases: inhibitory, 2 cases: facilitatory, 2 cases: no effect). 4. Two patients with severe TD, who showed improvement after a single administration, received repeated administration of ceruletide (0.6 microgram/kg i.m.) and their TD symptoms were recorded on videotape for blind consensus ratings. In both patients ceruletide caused a marked decrease in severity of TD, and the effects lasted for several weeks. 5. The present findings might contribute to further understanding of the role of CCK in the brain and to the treatment of TD.

Adult↗
PubMed1988

Alteration of gastrin-producing cells in rat antral mucosa after truncal vagotomy.

Gastrin-producing cells (G cells) were studied in the rat antral mucosa after truncal vagotomy. Significant elevation of circulating gastrin levels was observed from 12 hours after the operation and this was sustained throughout the entire experimental period. Upon light microscopic observation, G cells showing positive immunostaining for G17 were significantly increased in number at 2 days, 1, 2 and 3 weeks after the operation and were a more prominent cell type than G cells containing positive reaction product for G34 throughout the entire experimental period. Ultrastructural changes occurred predominantly in G cells, which showed hypertrophy of Golgi complexes and noticeable increases in the amounts of rough endoplasmic reticulum between 2 days and 3 months after the operation. During these periods, secretory granules apparently increased in number and displayed various degrees of electron density. Immature, highly electron-dense granules appearing in or near the Golgi stacks mainly showed localization of immuno-gold particles for G34, whereas mature granules with low electron-density predominantly demonstrated a positive reaction product for G17. The Golgi apparatus and rough endoplasmic reticulum were free of any immunoreaction for either G34 or G17.

Animals↗
PubMed1988

[The effects of TMB-8, an intracellular Ca2+ antagonist, on impaired left ventricular relaxation by global ischemia in dog].

The effects of TMB-8, an inhibitor of Ca2+ release from the intracellular store site, on impaired left ventricular relaxation caused by global ischemia were examined in 45 anesthetized dogs. In the non-ischemic group, the intracoronary infusion of 100 micrograms/min TMB-8 suppressed the decrease in T, an index of left ventricular relaxation, by increasing the atrial pacing rate. In the ischemic group, the intracoronary infusion of 30 and 100 micrograms/min TMB-8 suppressed the increases of T and left ventricular end-diastolic pressure caused by ischemia and increase of pacing rate. The results indicate that TMB-8 suppresses the ability of relaxation in non-ischemic myocardium and prevents the impairment of left ventricular relaxation induced by left ventricular global ischemia.

Animals↗
PubMed1988

[Effects of 3,4-diaminopyridine on the contractions of guinea-pig tracheal smooth muscle induced by histamine and prostaglandin D2].

Effects of 3,4-diaminopyridine (DAP), which decreases the membrane K conductance, on the contractions of guinea-pig tracheal smooth muscle induced by histamine and prostaglandin D2 (PGD2) were investigated. Pretreatments with 5 X 10(-4) and 10(-3) M DAP increased the excitability of histamine-induced contraction. The increment of the excitability by DAP was not suppressed by tetrodotoxin (TTX), but by nifedipine (Nif). Pretreatment with 10(-3) M DAP did not affect the contraction induced by PGD2. The results suggest that DAP increases the excitability of histamine-induced contraction by activating the voltage-dependent Ca channels and that PGD2 contracts tracheal smooth muscle through a mechanism different from that of histamine.

4-Aminopyridine↗
PubMed1988

[Effects of prazosin, SGB-1534, dobutamine and isoproterenol on congestive heart failure in dogs].

Effects of prazosin, dobutamine, isoproterenol and SGB-1534, a new alpha-blockade, on congestive heart failure (CHF) in dogs were investigated. The model was made by protease injection into the left ventricular free wall, saline loading, and dextran and methoxamine infusions. By this maneuver, left atrial pressure (LAP), systemic vascular resistance (SVR) and left ventricular end-diastolic pressure (LVEDP) were markedly increased, aortic blood flow (AoBF) was decreased, and systemic blood pressure was unchanged. In this model, the intravenous administration of prazosin (0.1 approximately 10.0 micrograms/kg, i.v.) increased AoBF and decreased LAP in a dose-dependent manner. The improvement of the CHF by prazosin was considered to result from its vasodilating action. SGB-1534 (0.1 approximately 10.0 micrograms/kg, i.v.) improved the CHF mainly through its vasodilating and positive inotropic actions, which is because SGB-1534 decreased SVR and increased Vmax. The magnitudes of vasodilation by SGB-1534 was greater than those by prazosin. These data indicate that SGB-1534 is useful in the treatment of CHF. Both dobutamine (5 approximately 100 micrograms/kg, i.v.) and isoproterenol (0.001 approximately 0.1 micrograms/kg, i.v.) improved the CHF through their vasodilating and positive inotropic actions in the canine CHF. The ratio of positive inotropism/vasodilation was greater for dobutamine than isoproterenol. The vasoconstriction by the large dose of dobutamine might participate in this difference between dobutamine and isoproterenol.

Adrenergic alpha-Antagonists↗
PubMed1988

The distribution and structure of the lymphatic system in dog atrioventricular valves.

A morphological study of the lymphatic system in atrioventricular (AV) valves of adult dogs and puppies was carried out using a series of techniques including India ink injection, a hydrogen peroxide technique, light microscopy, and electron microscopy. Lymphatic capillaries were found in all cusps of the AV valves, and were shown to extend delicate networks in the subendocardium of the atrial side of the valves. The extent of their development varied among cusps, being most prominent in the anterior cusp of the mitral valve. Marked differences were noted in the intravalvar distribution between lymphatic capillaries and blood microvessels. The ultrastructures of the lymphatic capillaries in the AV valves were also demonstrated.

Animals↗
PubMed1988

[Clinical study on transfer into lung tissue and postoperative prophylactic effect of new cephamycin antibiotics, particularly cefotetan and cefbuperazone].

The following findings were obtained in our clinical study on the transfer of cefotetan (CTT) and cefbuperazone (CBPZ), new antibiotics of cephamycin series, into the lung tissue and on their postoperative prophylactic effect. 1. The mean serum concentration 30 minutes after the start of an intravenous drip infusion of 1 g of CTT over a period of 30 minutes was 99.4 micrograms/ml, and it decreased gradually thereafter with the half-life of 2.45 hours. After an intravenous drip infusion of 1 g of CTT over a period of 1 hour, the mean peak concentration of 104.1 micrograms/ml appeared 1 hour after the start of the infusion, and mean concentrations at 2, 4 and 6 hours after the infusion were 63.4, 34.3 and 27.0 micrograms/ml, respectively, with the half-life of 2.35 hours during phase beta. 2. Following 30 minutes of an intravenous drip infusion of CTT, the tissue CTT level in normal lung tissues was Tmax 1.82 hours and Cmax 19.8 micrograms/g. After 1 hour of an intravenous drip infusion the mean concentration in the tissues was at the peak of 39.7 micrograms/g in 2 hours after the start of an administration, while mean levels at 3, 4 and 6 hours after an administration were 32.2, 22.2 and 8.76 micrograms/g, respectively, with Tmax of 1.82 hours and Cmax of 30.5 micrograms/g. 3. Following an intravenous drip infusion of 1 g of CBPZ over a period of 1 hour, the mean serum drug concentration 1 hour after the start of infusion was at its peak, 83.3 micrograms/ml, while mean values at 2, 4 and 6 hours after the start of an administration were, respectively, 40.4, 19.8 and 9.62 micrograms/ml, with the beta-phase half-life of 2.03 hours. 4. By 1 hour after the start of intravenous drip infusion of CBPZ, the mean tissue level in normal lung tissues was at the peak of 31.6 micrograms/g, while mean levels at 3, 4 and 8 hours after an administration were 16.2, 11.0 and 4.56 micrograms/g, respectively, with Tmax of 1.67 hours and Cmax of 21.9 micrograms/g. 5. Infused CBPZ was transferred into bronchiole tissues. Drug concentrations in these tissues at 3 and 5 hours after the start of the infusion were 7.87 and 4.85 micrograms/g, respectively, with their ratios to the peak serum level were 9.4 and 5.8%, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1988

[The pathogenesis of adenocarcinoma of the stomach after successful radiotherapy of squamous cell carcinoma of the lower intrathoracic esophagus--case report].

A case of a gastric cancer developed 3 years and 11 months after radiotherapy for esophageal cancer is reported. A 76-year-old man with a squamous cell carcinoma of the lower intrathoracic esophagus had received 50 Gy of irradiation as treatment. Thereafter, signs of the esophageal cancer disappeared radiologically and endoscopically, and a pathological biopsy of specimens taken from the site revealed no further cancer cells. The patient remained well for 3 years and 11 months after radiotherapy, at which time he again was admitted to hospital, having been diagnosed as having a gastric cancer. On admission, an upper G-I series showed a shadow defect along the lesser curvature of the upper-middle stomach but no evidence of any stenosis in the lower intrathoracic esophagus. Endoscopically, the mucosal surface of the esophagus was normal, and biopsy specimens taken from the site in the esophagus that had been treated with irradiation 3 years 11 months ago revealed no recurrence of his esophageal cancer. Endoscopical examination of the stomach showed an infiltrative tumor with ulceration, and a subsequent histological examination revealed a poorly differentiated adenocarcinoma. Upon a laparotomy, a metastasis was detected in the perigastric and paraaortic lymph nodes and the cancer had invaded the retroperitoneum. The stomach could not be removed and he died 3 months after the laparotomy.

Adenocarcinoma↗
PubMed1988

Distinct differences in lipid composition between epidermis and dermis from footpad and dorsal skin of guinea pigs.

All lipids, including neutral lipids, phospholipids and glycolipids, in the dermis and epidermis from footpad and dorsal skin of guinea pigs were quantitatively determined, and distinct and characteristic differences in lipid composition were observed in both regions. Ceramides, cerebrosides and cholesterol sulfate were abundant in the epidermis, the amounts being 8.8-12.0, 2.8-4.0 and 6.0-6.5 times higher than those in the dermis, respectively, whereas sulfatide was predominantly found in the dermis. Four and six bands of ceramides, and three and four bands of cerebrosides were detected for the lipids from both the epidermis and dermis on TLC, respectively, two of the ceramides and one of the cerebrosides being found to be esterified. Cerebrosides in the epidermis were predominantly glucocerebrosides, whereas those in the dermis comprised a mixture of gluco- and galactocerebrosides. In addition, an esterified cerebroside, glucosyl N-(O-linoleoyl-omega-hydroxylignoceroyl) sphingosine, was present in the epidermis as a tissue-characteristic compound and this finding seems to be common for several animal species. The marked differences in lipid components between the epidermis and dermis should be quite useful for discriminating these functionally as well as histologically different regions on a biochemical basis.

Animals↗