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Biomedical subjects

M Ueno

Publications and source records attributed to M Ueno.

At least 451 records · Page 25Linked to original sources
PubMed1988

Effects of reactive oxygen metabolites on erythropoietin production in renal carcinoma cells.

The present studies were undertaken to determine the effects of reactive oxygen metabolites on erythropoietin (Ep) biosynthesis in Ep-producing renal carcinoma (RC) cells using a sensitive radioimmunoassay for Ep. Xanthine (10-5M) and increasing concentrations of xanthine oxidase (8 x 10(-7) to 5 x 10(-4) units/ml) produced a significant dose-related increase in Ep production at a concentration of greater than or equal to 4 x 10(-6) units/ml, whereas xanthine alone had no effect. Catalase, a scavenger of hydrogen peroxide (H2O2), in concentrations of 50 to 500 micrograms/ml produced a significant inhibition of the increase in Ep production induced by xanthine-xanthine oxidase; while no effect was seen on basal levels of Ep production and the growth of RC cells. Glucose oxidase (greater than or equal to 0.032 mU/ml), a direct H2O2 generator, and exogenous H2O2 (greater than or equal to 4 x 10(-6)M) added to the incubation mixture, caused a significant enhancement of Ep production in a dose-dependent manner. Xanthine-xanthine oxidase, glucose oxidase, and H2O2 in the above concentrations did not produce significant cytotoxicity (51Cr release or trypan blue dye exclusion). The present data suggests that H2O2, a reactive oxygen metabolite may play a significant role in Ep production.

Animals↗
PubMed1988

Two-dimensional high-performance liquid chromatographic system for the direct determination of tocopherol derivatives in plasma.

A procedure for the quantitative extraction of tocopherol derivatives from plasma was systematically developed using an efficient liquid-liquid distribution process. An aqueous stationary phase was coated on silica gel or diatomaceous earth powder in a closed-bed glass column prepared by slurry packing. A liquid-liquid chromatographic system provided with a detector was introduced as a preliminary extraction process. Liquid-solid chromatography followed as the second dimension of the separation and was used to determine alpha-tocopherol nicotinate in the extract. Stationary and mobile phases in the two-dimensional liquid chromatographic system were optimized to determine tocopherol derivatives. A highly sensitive quantitation method for alpha-tocopherol nicotinate in plasma was developed by using liquid-liquid and liquid-solid chromatography in conjunction with column switching by a tube-type micro-evaporator.

Animals↗
PubMed1988

Utilization of diethyl-beta-cyclodextrin as a sustained-release carrier for isosorbide dinitrate.

Heptakis(2,6-di-O-ethyl)-beta-cyclodextrin (2) was prepared and its physicochemical properties, such as aqueous solubility and surface activity, were compared with those of beta-cyclodextrin (1) and heptakis(2,6-di-O-methyl)-beta-cyclodextrin (3). A possible utility of 2 as a sustained-release drug carrier was examined using a water-soluble drug, isosorbide dinitrate. The dissolution and release rates of isosorbide dinitrate from capsule and tablet forms were significantly retarded by the complexation with 2. The sustained-release pattern of isosorbide dinitrate was produced for a long period after the oral administration of a single dose of capsule or tablet containing the 2 complex to rats. The results indicated that 2 may serve as a hydrophobic drug carrier for sustained-release of isosorbide dinitrate.

Animals↗
PubMed1988

A1 and A2 adenosine receptor regulation of erythropoietin production.

The effects of adenosine (ADE) and ADE agonists on erythropoietin (Ep) production were determined using percent (%) 59Fe incorporation in red cells of exhypoxic polycythemic mice. The hemisulfate salt of ADE produced a significant increase in % 59Fe incorporation in response to hypoxia in concentrations of 400 to 1600 nmol/kg/day (i.v.). 5'-N-ethyl-carboxamideadenosine (NECA), a selective A2 receptor agonist, increased radioiron incorporation in a dose-dependent manner (10-100 nmol/kg/day, i.v.). In contrast, N6-cyclohexyladenosine (CHA), a selective A1 receptor agonist, did not affect radioiron incorporation in concentrations up to 1600 nmol/kg/day (i.v.). Albuterol, a beta 2-adrenergic agonist, enhanced % 59Fe incorporation in polycythemic mice and low doses of CHA (50 and 100 nmol/kg/day), which were not effective alone on % 59Fe incorporation in polycythemic mice exposed to hypoxia, inhibited the enhancement in radioiron induced by albuterol (25 and 100 micrograms/kg/day, i.p.) plus hypoxia. Theophylline (20 and 80 mg/kg/day, i.p.), a well-known antagonist of ADE receptors, blocked the ADE and NECA enhancement in radioiron incorporation at a dose of theophylline alone which produced only a slight enhancement of % 59Fe incorporation. These results suggest that ADE may both inhibit through A1 receptor activation and increase via A2 receptor stimulation the production of Ep.

Adenosine↗
PubMed1988

Immunohistochemical demonstration of vasopressin nerve fibers in the cerebral artery.

Vasopressin-immunoreactive nerve fibers were demonstrated in the cerebral pial arteries by peroxidase immunohistochemistry. In the large pial artery (proximal part of the middle cerebral artery), they ran longitudinally to the long axis of the vessel. They ran in a spiral pattern in the distal part of the middle cerebral artery. Even in small arteries, vasopressin nerve fibers were found arranged in a longitudinal fashion. The present morphological data suggest that vasopressin nerve fibers in the cerebral artery may play a role in cerebral circulation.

Animals↗
PubMed1988

Clinical alterations in normotensive offspring with parental hypertension.

The influence of a family history of hypertension on body mass index, serum lipids, uric acid, blood sugar and haematocrit was investigated in 579 young normotensives aged 19-35 years with or without a parental history of hypertension. Body mass index, total cholesterol, triglycerides and uric acid were significantly higher in offspring with a parental history of hypertension than in those without. There were no differences in blood sugar and haematocrit between the two groups. Multivariate analysis revealed that a parental history of hypertension influenced levels of body mass index, triglycerides and uric acid, independently of the level of blood pressure.

Adult↗
PubMed1988

Factors causing age-dependent changes in phenytoin tissue and serum binding in rats.

The factors that cause age-dependent changes in phenytoin tissue and serum protein binding in rats were studied. It was confirmed that the age-dependent changes in the concentration of tissue constituents to which phenytoin bound mainly governed the change in phenytoin tissue binding. The concentration of the tissue constituents, protein and phospholipid, was changed by the water content in tissues in the growth process of rats. The increase in serum protein binding of phenytoin in the growth process of rats was caused by changes in both serum albumin concentration and binding parameters of phenytoin to serum albumin. The changes in binding parameters of phenytoin to serum albumin were led by those in the molar rations of free fatty acids to albumin.

Aging↗
PubMed1988

[Effect of a conjugate of adriamycin and an antibody to human alpha-fetoprotein (AFP) on AFP-producing hepatic tumors].

We have studied the effect of an anti-FP antibody coupled via a dextran bridge to adriamycin on six AFP-producing liver tumors (3 cases with hepatoma and 3 cases with liver metastases from an AFP-producing gastric cancer). Results have revealed that MR was observed in 2 out the 5 of surviving evaluated cases. The toxicity of this conjugate was not evident in all cases, except for a low-grade fever. Further, an autopsy revealed no remarkable change in the histology of the case that had ended in death. These results indicate that this conjugate can be considered one of the treatment therapies available for a nonresectable AFP-producing tumor.

Aged↗
PubMed1988

[Reevaluation of clinical efficacy of piperacillin against complicated urinary tract infections].

Forty-six inpatients with complicated urinary tract infections (UTI) were treated with 2 g piperacillin (PIPC) twice a day through drip intravenous infusion. After 5 days, evaluation was made using the criteria proposed by the UTI Committee in Japan. The overall clinical efficacy was rated "excellent" in 4 (8.9%), "moderate" in 22 (47.8%), and "poor" in 20 (43.5%) cases with a total efficacy rate of 56.5% (26/46). We previously presented the clinical efficacy of PIPC in 74 cases with complicated UTI. Herein, a total of 120 cases were analyzed and these cases were divided into two groups. The overall clinical efficacy, bacteriological response, type of infection, background of patients and its safety were evaluated. Almost no change was seen for four years. Also this study revealed the usefulness against Enterococcus infections. In conclusion, PIPC is still a useful antimicrobial agent against complicated UTI even after the appearance of many new Cephems.

Adolescent↗
PubMed1988

Sudden death in hypertrophic cardiomyopathy, a guideline to prevention in daily life.

To establish guidelines for individuals with hypertrophic cardiomyopathy (HCM) to follow in their daily lives and minimize the chance of sudden death (SD), circumstances of SD in 24 autopsied definite HCM cases were compared with those with 905 autopsied cases of other heart diseases. Circumstances of symptoms experienced in daily activities of 35 age-matched surviving HCM cases were also studied. In the autopsied HCM cases, SD occurred during exertion more frequently (79.2%) than in the other autopsied cardiac patients (22.7%). Sudden changes in pace or movement accompanied by mental excitement, such as hurrying to board a train, were more frequent causes of SD in HCM (47.4%) than in other cardiac patients (8.3%). In the surviving HCM cases, symptoms of distress occurred frequently during very hard work or with sudden rapid movement. Thus, one probable daily guideline for HCM sufferers would appear to be not only to eliminate very hard work but also to lead mentally and physically quiet and relaxed life.

Adolescent↗
PubMed1988

Long-term prognosis of malignant hypertension; difference between underlying diseases such as essential hypertension and chronic glomerulonephritis.

A long-term prognosis was studied in 69 patients with malignant hypertension, followed for an average of 56 months. Overall survival rate was 90% for a 5-year period, although the prognosis was different between two major underlying diseases, namely the 5-year survival was 79% for 33 essential hypertension (EHT) and 100% for 26 chronic glomerulonephritis (CGN); the difference is significant (p less than 0.01). In contrast, the 5-year rate for renal survival, defined as the probability of surviving without hemodialysis, was 37% in all cases. However, there was significant difference in the renal survival between EHT (60% for a 5-year period) and CGN (4% for a 18-month period). Multivariate analyses of the Cox's proportional hazards model revealed that the long-term change in renal function was different between the two groups, namely more rapid deterioration in the CGN group. These results indicate that a long-term prognosis of malignant hypertension is influenced by the underlying diseases and hemodialysis besides antihypertensive treatment may increase survival in malignant hypertension associated with severely damaged renal function.

Adult↗
PubMed1987

Asymmetric disposition of detergents within vesicle bilayer and its effect on ion permeation through the membrane.

Phospholipid vesicles were prepared by detergent removal using hydrophobic porous beads, Amberlite XAD-2, or dialysis from detergent-phospholipid mixed micelles. The liposomes formed were found to be mostly unilammellar vesicles. The vesicle diameter was estimated, by both quasi-elastic light-scattering and gel-exclusion chromatography on Sephacryl S-1000, to be 80 nm for the vesicles formed by removal of octaethylene glycol monododecyl ether by the bead method. The effect of detergents within a bilayer on ion permeation was demonstrated. When the content of octaethylene glycol monododecyl ether reached a molar ratio of 0.2, the intrinsic ion selectivity of the phospholipid membrane between anion and cation was diminished. The ion permeability measured for vesicles with detergent incorporated into initially detergent-free vesicles was about 10-times greater than that for vesicles with detergent remaining following the process of detergent removal. This observation was explained by the different disposition of the detergent in the bilayer, that is, when vesicles were formed by the removal of detergent from mixed micelles, the residual detergent became distributed in both the outer and inner leaflets, and when the detergent was incorporated into initially detergent-free vesicles, the detergent became distributed only in the outer leaflet within the experimental time limits. This idea was supported by the NMR studies. It was also found that, as a detergent, octaethylene glycol monododecyl ether has a stronger effect on ion permeation than octyl glucoside.

Anions↗