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Biomedical subjects

Y Uchida

Publications and source records attributed to Y Uchida.

At least 487 records · Page 27Linked to original sources
PubMed1991

[Measurement of serum eosinophil cationic protein levels in bronchial asthma].

We investigated the possibility of a relationship between the serum levels of eosinophil cationic protein (ECP) and the clinical parameters in asthma. A specific question was whether or not serum ECP changes with a circadian rhythm. Eighty nine children with bronchial asthma and sixteen normal, non-atopic subjects were studied. Serum ECP, eosinophil counts (Eo) and pulmonary functions were measured 4 or 5 times a day. ECP was quantitated by a specific radioimmunoassay. Serum ECP and Eo were significantly higher in the patients with bronchial asthma than in non-atopic subjects. Serum ECP levels were higher during asthma attacks and at 24 hours after attacks than those in stable conditions (free of attacks for more than 7 days). Although no circadian rhythm was observed in ECP changes, the patients with bronchial asthma showed a significantly greater variation of serum ECP levels than the non-atopic subjects. There was no significant correlation between serum ECP levels and 2- or 8-week attack score before the ECP measurement. These results suggest that serum ECP increases in bronchial asthma, especially in its acute exacerbation phase, and may reflect eosinophil activation in vivo.

Adolescent↗
PubMed1990

Intravenously infused adenosine increases the blood flow to brown adipose tissue in rats.

The effects of intravenously infused adenosine (ADO) and its analogues, N6-R(-)-phenylisopropyladenosine (R-PIA), 5'-N-ethylcarboxamide adenosine (NECA), on the blood flow to interscapular brown adipose tissue were studied in urethane-anesthetized rats. ADO and NECA, but not R-PIA, caused a dose-dependent increase in interscapular brown adipose tissue blood flow. The relative potency of these compounds to increase this blood flow was NECA greater than ADO greater than R-PIA. Infusing R-PIA and NECA intravenously caused a fall in diastolic blood pressure and heart rate whereas an infusion of ADO up to 380 nmol/rat per min did not elicit any systemic cardiovascular effect. A 10-mg/kg dose of alkylxanthines such as caffeine, 8-phenyltheophylline (8-PT) and 8-sulfophenyltheophylline (8-SPT) inhibited the half-maximum responses of interscapular brown adipose tissue blood flow to ADO by 41, 71 and 65% respectively indicating that caffeine is less potent than 8-PT and 8-SPT. The ADO uptake inhibitor, dipyridamole, significantly potentiated the ADO effect. These results suggest that the increased interscapular brown adipose tissue blood flow caused by ADO might possibly be mediated by A2 receptors.

Adenosine↗
PubMed1990

Activation of keratinization of keratinocytes from fetal rat skin with N-(O-linoleoyl) omega-hydroxy fatty acyl sphingosyl glucose (lipokeratinogenoside) as a marker of epidermis.

To elucidate the functional significance of sphingolipids altered in the epidermal differentiation, we examined, the effects of sphingolipids on the activity of transglutaminase and the formation of cornified envelopes in the keratinocytes from fetal rat skin. N-(O-linoleoyl) omega-hydroxy fatty acyl sphingosyl glucose (lipokeratinogenoside) that was characteristically contained in the mammalian epidermis, as well as nonhydroxy fatty acid-containing GalCer and GlcCer, significantly enhanced the activity and the formation, but no or rather inhibited activity was observed with ceramides, GalCer with alpha-hydroxy fatty acid, saponified lipokeratinogenoside, etc. This indicates that skin-characteristic lipokeratinogenoside functions to regulate the transglutaminase for the formation of cornified envelopes in the process of keratinization.

Animals↗
PubMed1990

The method of choice for the determination of 2,5-hexanedione as an indicator of occupational exposure to n-hexane.

To identify the method of choice for analysis of urine for 2,5-hexanedione (2,5-HD) as an indicator of occupational exposure to n-hexane, the end-of-shift urine samples of 36 n-hexane exposed male workers and 30 non-exposed male workers were analyzed for 2,5-HD under three conditions of hydrolysis, i.e. enzymic hydrolysis at pH 4.8, acid hydrolysis at pH 0.5, and without hydrolysis. The 2,5-HD concentrations thus determined were examined for correlation with 8-h, time-weighted average exposure concentrations of n-hexane measured by diffusive sampling. The regression analysis showed that the 2,5-HD concentrations without any hydrolysis correlated best with the intensity of exposure to n-hexane. No 2,5-HD was detected in the urine of the non-exposed subjects under the analytical conditions with no hydrolysis. Thus, the analysis without hydrolysis was considered to be the method of choice from the viewpoint of simplicity in analytical procedures, sensitive separation of the exposed from the non-exposed, and quantitative increase in the amount of 2,5-HD after n-hexane exposure.

Environmental Monitoring↗
PubMed1990

Biological monitoring of occupational exposure to isopropyl alcohol vapor by urinalysis for acetone.

The relationship of the intensity of occupational vapor exposure to isopropyl alcohol (IPA) with urinary excretion of acetone and unmetabolized IPA was studied in 99 printers of both sexes, who were exposed to up to 66 ppm IPA (as time-weighted average), together with toluene, xylenes, methyl ethyl ketone and/or ethyl acetate. Acetone and IPA concentrations in urine were studied also in 34 non-exposed subjects. Acetone was detectable in the urine of most of the non-exposed, and the urinary acetone concentration increased in proportion to the IPA exposure intensity (r = 0.84 for observed, non-corrected values), whereas the correction for creatinine concentration or specific gravity of urine did not give a larger correlation coefficient. IPA itself was not found in the urine of the non-exposed, and was detectable in urine of only those who were exposed to IPA above a certain level, e.g. 5 ppm. The present study results suggest that urinary acetone is a valuable index for biological monitoring of occupational exposure to IPA as low as 70 ppm.

1-Propanol↗
PubMed1990

Urinary excretion of unmetabolized acetone as an indicator of occupational exposure to acetone.

Acetone concentrations in urine samples from 28 workers exposed to acetone in a fiber-reinforced plastics factory were determined by directly injecting urine supernate into a gaschromatograph with FID detectors. Acetone concentrations in the urine from ten nonexposed subjects were also determined. The 8-h time-weighted exposure intensity of individual workers was monitored by means of diffusive sampling. Acetone concentration in urine and acetone concentration in the breathing zone showed a linear correlation to each other. The study results indicate that the correlation coefficient is high enough to enable use of the urinary level of acetone as an indicator of occupational exposure to acetone.

Acetone↗
PubMed1990

Percutaneous fiberoptic angioscopy of the left ventricle in patients with dilated cardiomyopathy and acute myocarditis.

Left ventricular luminal changes were examined by percutaneous fiberoptic angioscopy in 13 patients with dilated cardiomyopathy and in four patients with acute myocarditis. Angioscope-guided endomyocardial biopsy was also performed in six patients with dilated cardiomyopathy and in two with acute myocarditis. A balloon-tipped guiding catheter (9F) was introduced through the right femoral artery into the left ventricle, the balloon was inflated, and a 1.6 or 4.3F fiberscope was introduced through the catheter into the ventricle so as to locate the fiberscope tip at the tip of the catheter shaft. The balloon was then pushed against the desired portion of the ventricle and warmed saline was infused to observe the luminal changes. In contrast to the patients without organic heart disease whose left ventricular luminal surface was brown in color, the luminal surface was white or light yellow in four, light brown in one, bluish-white in one, with white and brown portions distributed in a mosaic pattern in four, and it was reddish brown in the remaining one patient with dilated cardiomyopathy. Mural thrombi were observed in two of the patients. The luminal surface was light brown in one, reddish brown in one, rose in one, and red in one patient with acute myocarditis. Thrombi and scattered bleeding were observed in two and one of these patients, respectively. The changes in luminal coloration in patients with dilated cardiomyopathy and acute myocarditis had no obvious relation to left ventricular volume and ejection fraction. Angioscope-guided biopsy revealed that the white and light yellow portions were due to endocardial fibrosis, that the endocardia of brown portions were not fibrotic, and that the myocardium in the red portions contained mononuclear cells, indicating inflammation. The results indicate that the angioscopic features of the left ventricular luminal surface were not uniform in patients with dilated cardiomyopathy or in those with acute myocarditis, and that angioscopy can be used as a guiding tool for endomyocardial biopsy.

Acute Disease↗
PubMed1990

Stability and conformation of porcine phosphofructokinase M and L.

1. The inactivation of porcine liver enzyme in the presence of urea proceeded more rapidly than that of porcine heart muscle enzyme. 2. The inactivation of both enzymes by urea was protected by allosteric activators, but inhibitors had no effect. 3. The circular dichroism spectrum of liver enzyme in the near ultraviolet region was markedly affected by urea, whereas that of heart muscle enzyme was not, except for the band at 255 nm.

Animals↗
PubMed1990

Benzene exposure in a Japanese petroleum refinery.

Time-weighted average (TWA) intensity of exposure of workers to benzene vapor during a shift was monitored by diffusive sampling technique in a Japanese petroleum refinery. The subjects monitored (83 in total) included refinery operators, laboratory personnel and tanker-loading workers. The results showed that the time-weighted average exposures are well below 1 ppm in most cases. The highest exposure was recorded in 1 case involved in bulk loading of tanker ships, in which exposure of over 1 ppm might take place depending on operational conditions. The observation was generally in agreement with levels previously reported.

Benzene↗
PubMed1990

Determination of biological peptide leukotrienes C4 and D4 by fluorometric detection combined with high-performance liquid chromatography.

A fluorometric procedure combined with high-performance liquid chromatography (HPLC) has been developed to separate and quantitate peptide-leukotrienes (p-LTs) C4 and D4. The method is based on pre-column dansylation of the amino terminus of the p-LTs. Its application for the determination of the amounts of p-LTs C4 and D4 in human blood and sputum is also described. The lower limit of detection of p-LTs with this method is 1 pmol.

Chromatography, High Pressure Liquid↗
PubMed1990

Effects of vascularized bone graft on surrounding necrotic bone: an experimental study.

Several difficult problems arise in the treatment of necrotic bone disorders such as femoral head necrosis or Kienböck's disease for which no definitive treatment as yet exists. The recent literature has recommended vascularized bone transfers as suitable for these disorders, but there have been few experimental studies done and resulting effects are still currently obscure. Using a rabbit model, the effects of vascularized bone graft on the surrounding necrotic bone were analyzed. Results suggest that the periosteal muscle cuff remains as fibrous or fatty tissue and interferes with the bony union between the graft and the host bone; the graft was found to be gradually resorbed. The main function of the procedure appears to be the provision of vessels into avascular bone.

Angiography↗
PubMed1990

Chronic treatment with talipexole dihydrochloride on abnormal involuntary movement in humans.

Two cases of severe dystonia and dyskinesia were treated with talipexole, a dopamine autoreceptor agonist, and the metabolites of dopamine, norepinephrine, and serotonin in cerebrospinal fluid (CSF) were determined. Despite significant reductions in these metabolites in CSF, behavioral amelioration of these cases could not be observed. The present findings argue for further studies to explore the clinical usefulness of dopaminergic agonists such as talipexole.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1990

Dynamics of gastrin-producing cells in the rat after truncal vagotomy. Evaluation by double immunostaining for bromodeoxyuridine and little gastrin.

The mechanism of hyperplasia of gastrin-producing cells (G-cells) in the rat antral mucosa after truncal vagotomy was studied using double immunostaining for bromodeoxyuridine (BrdU) and little gastrin (G17). With single labeling of BrdU, a few G-cells (less than 1%) showed positive immunostaining for BrdU in the nucleus throughout the experimental period in both vagotomized rats and those given a sham operation. The labeled cells in both groups demonstrated a linear increase of BrdU labeling in an identical number of cells for each experimental time-point. The labeling index of the G-cells increased rapidly from day 2 to day 6 and attained a maximum level of 44.0% on day 10 in the vagotomized group after cumulative labeling. Even in this group, however, many G-cells showed no BrdU immunoreactivity throughout the experimental period. These cells did not replicate during the experimental period, but showed an intense reaction product for G17 in their cytoplasm after vagotomy. The present study indicates that the most important factor involved in G-cell hyperplasia observed after truncal vagotomy is the activation of pre-existing G-cells to synthesize and release hormone, together with the rapid maturation of progenitor cells to mature G-cells.

Animals↗
PubMed1990

Lupus nephritis with adult T cell leukemia.

A 64-year-old Japanese male patient with lupus nephritis associated with adult T cell leukemia (ATL) is described. Percutaneous renal biopsy demonstrated findings consistent with membranous lupus nephritis. To our knowledge, this is the first case of lupus nephritis complicated by ATL, suggesting that human T cell leukemia virus type I may be correlated not only to outbreaks of ATL but also to lupus nephritis/systemic lupus erythematosus.

Humans↗