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Biomedical subjects

H Hashimoto

Publications and source records attributed to H Hashimoto.

At least 631 records · Page 35Linked to original sources
PubMed1994

Effects of volatile anesthetics, enflurane, isoflurane, and halothane on ventricular delayed activation in a canine myocardial infarction model.

The authors examined the effects of volatile anesthetics (enflurane, isoflurane, and halothane) on ventricular activation in a canine myocardial infarction model. Enflurane at 1 minimum aveolar concentration further delayed or blocked delayed activation in the infarcted zones with only slight effects on activation of the normal zones. Halothane showed similar and comparable effects on ventricular activation to those of enflurane. Although isoflurane also showed similar effects, they were of a lesser extent. Enflurane and halothane, but not isoflurane, inhibited ventricular stimulation-induced arrhythmias. Thus, enflurane and halothane produced marked depression of delayed activation in myocardial infarction, which may affect, that is, inhibit or provoke, ventricular arrhythmias in myocardial infarction.

Animals↗
PubMed1994

Benign glandular peripheral nerve sheath tumor. A case report.

The glandular peripheral nerve sheath tumor is a rare variant of nerve sheath neoplasms in which the focally occurring glands are lined by cells showing divergent differentiation. The vast majority of the reported nerve sheath tumors harboring these glands have been malignant. We herein present a case of benign glandular peripheral nerve sheath tumor in a 43-year-old woman who had no evidence of von Recklinghausen's disease. Histologically, the tumor is composed of spindle cell component and collections of glandular component. The glandular component occupied the central two-thirds of the lesion and was lined by a single layer of nonciliated cuboidal or columnar cells. No mitotic figures were recognized in the spindle cell area. This spindle cell area had neurofibroma-like features rather than schwannoma. Many of the spindle cells had positive reaction products for S-100 protein. The glandular lining epithelium were positive for cytokeratins (CAM 5.2, AE1/AE3, PKK1) and EMA. Some epithelial cells were immunoreactive for CEA, chromogranin, somatostatin and Leu-7. These immunohistochemical findings support the neuroendocrine differentiation of the epithelial element from the schwannian component.

Adult↗
PubMed1994

Galactosylsucrose and xylosylfructoside alter digestive tract size and concentrations of cecal organic acids in rats fed diets containing cholesterol and cholic acid.

Influences of galactosylsucrose and xylosylfructoside on body mass gain, the digestive tract mass and concentrations of organic acids such as acetic, propionic, butyric, lactic and succinic acid in the cecum were compared among rats fed a cholesterol-enriched fiber-free diet [cholesterol 6 + cholic acid 1.5 (g/kg)] containing either galactosylsucrose, xylosylfructoside or sucrose (100 g/kg) or the above fiber-free diet without test sugar (control) for 21 d. Body mass gain was greater in rats fed sucrose, but not in rats fed galactosylsucrose or xylosylfructoside, than in control rats. The mass of the small intestine and colon plus rectum was larger in rats fed xylosylfructoside than in control rats. Cecal contents and cecal tissue mass were heavier, water content of cecal contents was higher, and pH and ammonia concentration of cecal contents were lower in rats fed diets containing xylosylfructoside than in control rats. Galactosylsucrose had similar effects, although not all differences were significant. The concentration of hydrogen ion in cecal contents positively correlated to total cecal concentration of measured organic acids and to amount of cecal contents. Total concentration of measured organic acids in cecal contents positively correlated to cecal tissue mass. The estimated contribution of galactosylsucrose, xylosylfructoside and sucrose for body mass deposition were 0.19, -0.29 and 0.51 (g body mass gained/g sugar), respectively.

Ammonia↗
PubMed1994

A study on the metabolism of spermidine in mammals: purification and identification of a newly identified metabolite, 2-oxo-1-pyrrolidinepropionic acid, in rat urine.

In order to study the metabolism of spermidine in mammals, radioactive spermidine was injected intraperitoneally into a rat and urine was collected for analysis. Incorporation of radioactivity into putreanine, isoputreanine, spermidic acid, and N-aminopropylpyrrolidin-2-one was confirmed by ion-exchange chromatography, thin layer chromatography, and paper electrophoresis, the highest radioactivity being observed in the non-polar and acidic fraction of the collected urine. A radioactive compound was purified from the non-polar and acidic fraction, and identified as 2-oxo-1-pyrrolidinepropionic acid by comparison of its behavior on ion-exchange chromatography and thin layer chromatography with that of authentic 2-oxo-1-pyrrolidinepropionic acid, and recrystallization with the authentic compound. Acid hydrolysis of the radioactive compound produced radioactive spermidic acid, confirming the identification. To examine the interconversion between isoputreanine and N-aminopropylpyrrolidin-2-one, these compounds were deuterated and then intraperitoneally injected into a rat. Analysis of 24-h urine by gas-chromatography-mass-spectrometry indicated no interconversion between the two metabolites of spermidine under these conditions. An intracerebroventricular injection of radioactive spermidine into a rat showed that radioactivity was also incorporated into the metabolites of spermidine in the brain, and oxidative deamination of the aminopropyl moiety of spermidine was thought to be dominant in the central nervous system and vice versa in peripheral organs.

Amino Acids, Diamino↗
PubMed1994

Effects of MS-551, a new class III antiarrhythmic drug, on programmed stimulation-induced ventricular arrhythmias, electrophysiology, and hemodynamics in a canine myocardial infarction model.

We examined the effects of MS-551 (1,3-dimethyl-6-[(2-[N-(2-hydroxyethyl)-3-(4- nitrophenyl)propylamino]ethylamino] 2,4(1H,3H)-pyrimidinedione hydrochloride), a new class III antiarrhythmic drug, on programmed electrical stimulation (PES)-induced ventricular arrhythmias, the effective refractory period (ERP), intraventricular conduction, and hemodynamics in a canine myocardial infarction (MI) model. MS-551 was administered intravenously (i.v.) in two consecutive doses; the first dose (low dose) was 0.5 mg/kg/min after a bolus injection of 0.3 mg/kg, and a second dose (high dose) was 0.1 mg/kg/min after a bolus injection of 0.3 mg/kg. PES induced ventricular tachycardia (VT) or ventricular fibrillation (VF) in 10 of 12 animals. MS-551 abolished or lessened the ventricular arrhythmias in 7 of 10 animals at both doses. ERP was significantly prolonged by MS-551 in both the normal and infarcted zones in a dose-dependent fashion. Ventricular conduction of a premature excitation induced by a premature stimulation with various coupling intervals was decreased only at a coupling interval approximating that of ERP. MS-551 at either low or high dose did not significantly change the heart rate (HR), mean blood pressure (MBP), cardiac output (CO), or maximum rate of increase in left ventricular pressure (LVP) significantly. MS-551 produced a suppression of the PES-induced ventricular arrhythmias through prolongation of ERP without having any significant effect on hemodynamics in a canine MI model.

Animals↗
PubMed1994

A case of Goltz syndrome presenting as congenital incomplete alopecia.

A 5-year-old Japanese girl had had localized, incomplete hair loss on the scalp, minimal distichia, and a small papillomatous eruption on the right upper eyelid since birth. The diagnosis of Goltz syndrome was made by histological findings such as upward extension of the subcutaneous tissue to the papillary dermis and marked diminution in the thickness of the dermis, although typical linear atrophy-like eruptions and other mesoectodermal dysplasia were absent.

Alopecia↗
PubMed1994

An immunohistochemical study of sebaceous carcinoma with anti-keratin monoclonal antibodies: comparison with other skin cancers.

Formalin-fixed and paraffin-embedded tissue specimens of six cases of extraocular sebaceous carcinoma were studied immunohistochemically with eight anti-keratin monoclonal antibodies, 34 beta B4, 35 beta H11, Ks13.1, Ks19.1, PKK1, LP34, KL1 and AE1. The staining patterns of sebaceous carcinoma were compared with those of normal sebaceous glands and other skin cancers which should be distinguished from sebaceous carcinoma histopathologically. The other skin cancers compared were eccrine porocarcinoma, malignant clear cell hidradenoma, extramammary Paget's disease with underlying adenocarcinoma, malignant trichilemmoma, and squamous cell carcinoma. Most cases of sebaceous carcinoma were stained with 35 beta H11, Ks19.1, LP34, KL1 and AE1, while normal sebaceous glands were positive only with 35 beta H11, LP34, KL1 and AE1. By immunostaining, sebaceous carcinoma was distinguishable from extramammary Paget's disease with underlying adenocarcinoma, squamous cell carcinoma, malignant trichilemmoma, and eccrine porocarcinoma, but was not clearly distinguishable from malignant clear cell hidradenoma. These findings demonstrate that sebaceous carcinoma shows positive reactions with antibodies to simple epithelial keratin, probably as a result of neoplastic transformation, and that immunohistochemical examination using anti-keratin monoclonal antibodies is useful in distinguishing sebaceous carcinoma from several other skin cancers.

Acrospiroma↗
PubMed1994

Carotid arterial impedance during oscillated blood flow.

Blood perfusion of systemic circulation is influenced by the physical characteristics of artery. Several investigations proposed that the physical parameters of vessels are determined by neurological factors, hormonal factors, and physical properties of arteries among others. In this study, arterial impedance was estimated because it may express the condition of vessels. To examine the change of arterial impedance according to the blood flow pattern, the typical sine wave blood flow (oscillated flow) was used during total cardiopulmonary bypass (CPB) because it is considered the most simple pulsatile flow. CPB using oscillated blood flow was performed in acute experiments on adult goats. Total systemic flow was controlled to remain at approximately 80 ml/min. Carotid arterial flow, aortic pressure, central venous pressure, and systemic flow were measured. Total peripheral resistance, carotid arterial resistance, systemic impedance, and carotid arterial impedance were calculated to evaluate blood flow distribution during CPB. This study suggested that the parameters of carotid arterial blood flow changed according to the change of flow frequency during oscillated blood flow. This change may occur because arterial impedance was influenced by flow frequency; therefore, the blood flow of the carotid artery was significantly changed according to the change of the frequency component of blood flow.

Animals↗
PubMed1994

A case of ductal sweat gland carcinoma connected to syringocystadenoma papilliferum arising in nevus sebaceus.

We report a case of a tumor arising in the preauricular region in a 50-year-old woman. The histopathological findings revealed it to be a ductal sweat gland carcinoma connected to a syringocystadenoma papilliferum (SCAP) arising in a nevus sebaceus. Mucinous stroma, considered to be deposition of hyaluronic acid, was also observed in the ductal carcinoma portion. The immunohistochemical and ultrastructural findings in the ductal carcinoma were compared with those in the SCAP. The proliferating cell nuclear antigen labeling index of the cells in the ductal carcinoma was higher than that of those in the SCAP. Both the ductal sweat gland carcinoma and SCAP showed findings compatible with the ductal segment of a sweat gland.

Adenocarcinoma↗
PubMed1994

Immunohistochemical and ultrastructural study of hepatic sinusoidal linings during dichloropropanol-induced acute hepatic necrosis.

An acute phase of severe hepatic necrosis induced by dichloropropanol was examined immunohistochemically and ultrastructurally, in order to study chronological changes of sinusoidal morphology during acute hepatic injury. Male Wistar rats were injected with 1,3-dichloro-2-propanol (DC2P) and sacrificed at various intervals after the injections. DC2P-injected rats showed zonal necrosis of the centrilobular space with a peak from 24 to 48 h after the injection. Destruction of sinusoidal linings appeared at 4 h, and was gradually aggravated along the advancing hepatocytic necrosis. Monocytic influx into the necrotic areas was initiated at 6 h. At 48 h, collapsed centrilobular spaces showed a loss of most sinusoidal structures with active phagocytosis of macrophages, proliferation of perisinusoidal cells, and accumulation of collagen fibrils. At 72 h, there were many regenerating sinusoidal structures, which were composed of rather thick and less fenestrated endothelium and underlying multilayered processes of mesenchymal cells, along the regenerating hepatocytes. In these areas, occasional junctions between regenerating hepatocytes and mesenchymal cells were seen. Reconstruction of sinusoidal linings was closely related to the hepatocytic regeneration, and a hepatocytic-mesenchymal interaction might participate in this morphodynamic course of the sinusoidal reconstruction.

Acute Disease↗
PubMed1994

Long-term inhibition of NO synthesis promotes atherosclerosis in the hypercholesterolemic rabbit thoracic aorta. PGH2 does not contribute to impaired endothelium-dependent relaxation.

We examined whether prostaglandin (PG) H2, as an endothelium-dependent contracting factor, or the disturbed production of endothelium-derived relaxing factor, impairs endothelium-dependent relaxation and whether long-term inhibition of nitric oxide (NO) synthesis aggravates atherosclerosis in hypercholesterolemic rabbits. Male New Zealand White rabbits were fed one of the following diets: (1) standard chow; (2) 2% cholesterol-supplemented chow; (3) standard chow with 80 micrograms/mL N omega-nitro-L-arginine methylester (L-NAME), an NO synthetase inhibitor, in their drinking water; or (4) 2% cholesterol-supplemented chow with 80 or 160 micrograms/mL L-NAME in their drinking water. The rabbits were fed these diets for 8 or 12 weeks. Then aortic rings were obtained, and changes in isometric tension were recorded. Intimal atherosclerotic areas of the thoracic aortas were subsequently measured by planimetry. The cholesterol-supplemented diet significantly impaired endothelium-dependent aortic relaxation to acetylcholine. Pretreatment with the thromboxane A2/PGH2 receptor antagonist ONO-3708 did not reverse this impaired response. Vessels from both normocholesterolemic and hypercholesterolemic rabbits given L-NAME showed more impaired endothelium-dependent relaxation than those from their dietary counterparts not given L-NAME. Morphometric analysis revealed marked enlargement of intimal atherosclerotic areas in aortas from L-NAME-treated hypercholesterolemic rabbits compared with those from untreated hypercholesterolemic rabbits. These findings suggest that PGH2 does not contribute to impaired endothelium-dependent relaxation and that long-term administration of L-NAME promotes atherosclerosis by inhibition of NO synthesis in the hypercholesterolemic rabbit thoracic aorta.

Animals↗
PubMed1994

The relationship between serum levels of interleukin-6 and thyroid hormone in children with acute respiratory infection.

To determine whether monocyte-derived humoral factors such as tumor necrosis factor-alpha (TNF alpha), interleukin-1 beta (IL-1 beta), and IL-6 modulate serum thyroid hormone levels in infectious disorders, we measured serum levels of these monocyte-derived products, T3, T4, and C-reactive protein (CRP) in 59 out-patients with acute respiratory infection, aged 5 months to 15 yr (mean +/- SD, 5.7 +/- 4.2 yr). To minimize individual variation in their clinical and nutritional conditions, we selected out-patients with fever lasting for at least 3 days who had no severe disturbance of food intake. Serum T3 concentrations tended to be low in these subjects; 3 (5.1%) had levels below 1.2 nmol/L, L, and 13 (22.0%) had levels below 1.5 nmol/L. Serum T3 levels in 22 patients with elevated IL-6 (> 15 pg/mL) were significantly lower than those in 19 patients with normal IL-6 (< or = 5 pg/mL; T3, 1.7 +/- 0.4 vs. 2.2 +/- 0.6 nmol/L; P < 0.05). The serum IL-6 concentration was correlated inversely with the serum T3 level (r = -0.324; P = 0.012) as well as the T3/T4 ratio (r = -0.279; P = 0.032). Furthermore, a significant negative correlation was observed between CRP (induced mainly by IL-6) and T3 (r = -0.408; P = 0.001) or the T3/T4 ratio (r = 0.302; P = 0.020). On the other hand, TNF alpha was measurable in only 9 of 59 patients, and there was no correlation between TNF alpha and levels of thyroid hormone, CRP, or IL-6. Serum IL-1 beta was weakly detected in only 1 patient. On follow-up study of 10 of these patients, the serum T3 and T3/T4 ratio increased significantly with a reciprocal decrease in IL-6 and CRP during convalescence. No remarkable change in the serum T4 level was observed in our study. Our data suggest that the euthyroid sick syndrome is relatively common in children with acute respiratory infection, and IL-6 appears to mediate this syndrome in infectious disorders.

Acute Disease↗
PubMed1994

Synergistic interaction between class I antiarrhythmic drugs and halothane in depressant effects on ventricular activation in a canine myocardial infarction model.

Previous studies have showed that halothane has depressed ventricular activation in a canine myocardial infarction model. It is also well known that class I antiarrhythmic drugs depress ventricular activation in the infarcted myocardium. In the present study, we examined whether some electrophysiologic interactions between halothane and two class I antiarrhythmic drugs, lidocaine and procainamide, occur in a canine myocardial infarction model. Halothane, lidocaine and procainamide prolonged the activation time in the infarcted zone, and the combination of halothane and either lidocaine or procainamide markedly prolonged the activation time or blocked the delayed activation in the infarcted zone. Although the mechanism of the interaction is not clear, the present results suggest a synergistic interaction between halothane and class I antiarrhythmic drugs. Therefore, care should be taken that doses of class I antiarrhythmic drugs during halothane anesthesia will not be an overdose.

Animals↗
PubMed1994

Comparison of electrophysiologic and hemodynamic effects of SD-3212, a new antiarrhythmic drug, and flecainide in a canine myocardial infarction model.

Electrophysiologic and hemodynamic effects of SD-3212, a new antiarrhythmic drug, were examined and compared with those of flecainide, a class Ic antiarrhythmic drug, in a canine myocardial infarction model. The doses of SD-3212 were 1 mg/kg bolus injection followed by 0.1 mg/kg/min infusion and 3 mg/kg bolus injection followed by 0.3 mg/kg/min infusion, while those of flecainide were 0.3 mg/kg bolus injection followed by 0.03 mg/kg/min infusion and 1 mg/kg bolus injection followed by 0.1 mg/kg/min infusion. SD-3212 at the high dose prolonged the effective refractory period and QT interval, and depressed ventricular delayed conduction. Flecainide at the high dose also prolonged the effective refractory period and depressed ventricular delayed conduction. Flecainide reduced a maximal rate of rise of left ventricular pressure at the high dose, while SD-3212 did not significantly change it. Neither of the drugs significantly affected mean arterial blood pressure or cardiac output. Thus, SD-3212 may produce antiarrhythmic effects with less cardiac depressant effect than flecainide.

Animals↗
PubMed1994

Impaired microvascular vasodilator reserve in chronic cigarette smokers--a study of post-occlusive reactive hyperemia in the human finger.

To assess the vasodilator reserve in microcirculation, post-occlusive reactive hyperemia was examined in 21 chronic cigarette smokers (mean age; 50 +/- 7 years) and 21 non-smokers (mean age; 51 +/- 6 years), who were all healthy males. Reactive hyperemia was induced by occluding the digital artery at the base of the middle finger, and the increase in skin blood flow (delta flow) was analyzed with a laser Doppler flowmeter. Occlusion time was increased in a step-wise manner from 30 sec up to 300 sec. Baseline skin blood flow was similar in both groups (smoker, 27 +/- 9 ml/min/100 g; non-smoker, 25 +/- 10 ml/min/100 g, NS). The delta flow in smokers was significantly less (23%-59%) than that in non-smokers. Furthermore, the reduced delta flow in smokers was inversely correlated with Brinkmann's smoking index (r = 0.567, p < 0.01). These results indicate that chronic cigarette smoking impairs the microvascular response to transient ischemia, and that this impairment correlates with the intensity of the smoking habit.

Adult↗
PubMed1994

Electrophysiologic interaction between class I antiarrhythmic drugs and volatile anesthetics in depressant effects on ventricular activation in a canine myocardial infarction model.

Previous studies showed that volatile anesthetics depressed ventricular delayed activation in a canine myocardial infarction model. It is well known that class I antiarrhythmic drugs depress the ventricular activation in the infarcted myocardium. In the present study, we examined the electrophysiologic interaction between volatile anesthetics (sevoflurane, isoflurane) and class I antiarrhythmic drugs (lidocaine, procainamide) in effects on the ventricular delayed activation in a canine myocardial infarction model. The conduction time of the premature stimulation-induced ventricular excitation was measured in both normal and infarcted zones of the ventricle. An interval from the premature stimulus artifact to the epicardial activation was measured on bipolar electrograms as an index of conduction time, i.e., activation time. In the infarcted zone, the volatile anesthetics and class I antiarrhythmic drugs prolonged the activation time in the infarcted zone, and the combination of the volatile anesthetics and the class I antiarrhythmic drugs markedly prolonged the activation time or blocked the delayed activation. In the normal zone, a similar synergistic interaction was observed, but the effect of these drugs was less compared with that in the infarcted zone. From these results, possible mechanisms to explain the synergistic interaction were discussed.

Anesthetics↗
PubMed1994

Acceptor specificities of alpha-mannosidases from jack bean and almond, and transmannosylation of branched cyclodextrins.

Jack bean alpha-mannosidase had a wide acceptor specificity and could transfer mannosyl residues to various acceptors such as D-fructose, L-arabinose, maltose, lactose, and sucrose. The structures of the transferred products of branched cyclodextrins (CDs) (glucosyl-beta CD, maltosyl-alpha CD, and maltosyl-beta CD) were found to be alpha-D-mannosyl-(1-->6)-alpha-D-glucosyl-(1-->6)-beta CD, alpha-D-mannosyl- (1-->6)-alpha-D-glucosyl-(1-->4)-alpha-D-glucosyl-(1-->6)-alpha CD and alpha-D-mannosyl-(1-->6)-alpha-D-glucosyl-(1-->4)-alpha-D-glucosyl-(1--> 6)- beta CD, respectively. Almond alpha-mannosidase also produced the same transmannosylated products of branched CDs.

Carbohydrate Sequence↗