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Biomedical subjects

S Hara

Publications and source records attributed to S Hara.

At least 199 records · Page 11Linked to original sources
PubMed1997

Effect of mild cold exposure on whole-body and net hindquarters glucose metabolism in sheep.

Isotope dilution using [U-13C]glucose was combined with measurement of hindquarters arteriovenous difference and blood flow to examine the effect of mild cold exposure on whole-body and net hindquarters glucose metabolism in sheep. Determinations were carried out in a thermoneutral environment (20 +/- 1 degrees C) and on day 5 of mild cold exposure (4 +/- 1 degrees C). Whole-body blood glucose turnover rate was 1.56 and 1.91 mg kg-1 min-1 in the thermoneutral environment and during mild cold exposure, respectively. Net hindquarters glucose uptake was 0.79 and 1.19 mg kg-1 min-1, corresponding to 50 and 61% of whole-body turnover rate, respectively. These results suggest that in sheep the contribution of glucose uptake by the hindquarters tended to increase during mild cold exposure, even though whole-body blood glucose turnover rate did not increase significantly.

Animals↗
PubMed1997

4-(5',6'-Dimethoxybenzothiazolyl)benzoyl fluoride and 2-(5',6'-dimethoxybenzothiazolyl)benzenesulfonyl chloride as sensitive fluorescence derivatization reagents for amines in high-performance liquid chromatography.

4-(5',6'-Dimethoxybenzothiazolyl)benzoyl fluoride (BHBT-COF) and 2-(5',6'-dimethoxybenzothiazolyl)-benzenesulfonyl chloride (BHBT-SOCI) have been developed as highly sensitive and selective fluorescence derivatization reagents for primary and secondary aliphatic amines in HPLC. These reactivities were investigated using n-propylamine, n-heptylamine and N-methylhexylamine as model compounds to optimize the derivatization conditions. Both reagents readily reacted with the amines in basic media to give the corresponding fluorescent derivatives, which were separated isocratically by reversed-phase (C18) liquid chromatography with aqueous methanol. The detection limits (signal-to-noise ratio = 3) of BHBT-COF for primary and secondary amines are approximately 3 and 30 fmol, respectively, and those of BHBT-SOCI are approximately 3 and 300 fmol, respectively, for an injection volume of 20 microliters. Both reagents gave no fluorescent derivatives for aromatic amines.

Amines↗
PubMed1997

The effects of medetomidine and xylazine on gastrointestinal motility and gastrin release in the dog.

The effect of medetomidine, a potent and highly selective alpha2-adrenoceptor agonist, on the motility of the gastric antrum, duodenum, mid-jejunum and ileum was investigated in ten dogs. Its effect on the release of gastrin was also determined. Administration of medetomidine intramuscularly (i.m.) at a dose of 40 microg/kg inhibited the motility of the gastric antrum, duodenum, mid-jejunum and ileum significantly, in comparison to administration of xylazine intramuscularly at a dose of 2.0 mg/kg. The release of gastrin was also significantly decreased in dogs receiving medetomidine. It was found to inhibit the motility in the gastric antrum and duodenum longer than in the mid-jejunum and ileum, presumably by acting specifically on alpha2-adrenoceptors, likely at the peripheral level. Medetomidine also inhibited the gastric contraction associated with gastrin secretion.

Adrenergic alpha-Agonists↗
PubMed1997

A comparative study of medetomidine-butorphanol-ketamine and medetomidine-ketamine anaesthesia in dogs.

The anaesthetic and cardiopulmonary effects of medetomidine (20 micrograms/kg)-butorphanol (0.1 mg/kg)-ketamine (MBK) (2.5, 5.0, 7.5 mg/kg) and medetomidine (40 micrograms/kg)-ketamine (5.0 mg/kg) (MK) were compared in dogs. The induction time (time from the initial injection of the sedative to lateral recumbency) by medetomidine-butorphanol (6.0 +/- 2.3 min) was significantly shorter than that by medetomidine alone (10.4 +/- 2.9 min). The duration of anaesthesia induced by MK was shorter than that by MBK2.5. The analgesic effects of MBK were more potent than those of MK. Mean arterial blood pressure increased significantly after administration of the sedatives, and then decreased to base-line value after the ketamine injection and remained stable throughout the experimental period. Respiratory rate decreased gradually after the administration of each sedative and was depressed until 60 min after the ketamine injection. MBK anaesthesia is effective and widely available for therapeutic procedures depending upon the selection of the ketamine dose.

Analgesics, Opioid↗
PubMed1997

Experimental IgA nephropathy induced by a low-dose environmental mycotoxin, nivalenol.

Based on the hypothesis that IgA nephropathy (IgAN) is triggered by some exogenous antigen(s) which induces dysregulation of the mucosal immune system, we developed an experimental model of orally induced IgAN by an environmental mycotoxin, nivalenol (NIV), which often contaminates agricultural products in Southeast Asia and Japan. In the present study, low doses of oral NIV reproducibly induced significant IgA deposits in the glomerular mesangium and elevated serum IgA levels in mice irrespective of the strain; the degree of immunopathological changes analogous to human IgAN was associated with the dose and duration of NIV treatment. Furthermore, a competitive enzyme-linked immunosorbent assay with an NIV analogue-protein conjugate disclosed that the IgA antibody in the sera from the NIV model mice had a higher affinity to the mycotoxin. Conclusively, these findings suggest that NIV induces some pathological changes in mice which resemble those in human IgAN, and that this mycotoxin is associated with pathogenesis in some types of glomerulonephritis.

Animals↗
PubMed1997

Lysophosphatidylcholine promotes cholesterol efflux from mouse macrophage foam cells.

We examined the effects of lysophosphatidylcholine (lyso-PC) on promoting cholesterol efflux from macrophage foam cells. Mouse peritoneal macrophages were converted to foam cells by incubation with [3H]cholesteryl linoleate-labeled or unlabeled acetyl-LDL. When these cells were incubated with lyso-PC, [3H]cholesterol release was promoted in relation to both dose and time, and cellular cholesterol mass was decreased, while medium cholesterol mass was increased. These cholesterol efflux-promotive effects of lyso-PC were confirmed by the fact that the lyso-PC-treated cells showed less oil red O staining than the control cells. ApoE secretion, estimated by Western blotting of the medium, was also augmented by lyso-PC. Both the cholesterol and apoE released by lyso-PC treatment were floated by ultracentrifugation of the medium after its density had been adjusted to 1.210 g/mL. By electron microscopic analysis, vesicular lipoproteins were observed in ultracentrifugally concentrated conditioned medium of lyso-PC. Monensin, a protein secretion inhibitor, effectively inhibited [3H]cholesterol release induced by lyso-PC but not by apoA-I. These results suggest that lyso-PC may inhibit the development of atherosclerosis or enhance its regression by stimulating cholesterol efflux from macrophage foam cells.

Animals↗
PubMed1997

Effect of intraluminal pressure on the intimal thickening in injured rabbit carotid arteries in an organ-culture system.

We developed an organ culture system in order to examine the effect of intraluminal pressure on intimal thickening in injured arteries. After endothelial denudation, an excised rabbit common carotid artery was incubated at 37 degrees C in a glass bottle perfused with Dulbecco's modified Eagle medium containing 10% fetal calf serum at a constant flow rate of 6 ml/h at various static pressure of 60, 95, 130, 165, or 200 cmH2O. Intimal thickening, which consisted of smooth muscle cells and extracellular matrix, increased in a time- and pressure-dependent manner up to 130 cmH2O. Excessive pressured (165 and 200 cmH2O), however, caused necrosis in the media. These results suggest that a rise in intraluminal pressure accelerates intimal thickening in injured arteries.

Animals↗
PubMed1997

An established hybridoma clone producing a monoclonal antibody against Vibrio anguillarum.

Vibrio anguillarum is a pathogenic microorganism of vibriosis, an infectious disease found in various fish species. A mouse hybridoma clone, named C5, that produced a monoclonal antibody to V. anguillarum was established. The specific reaction of C5 antibody with V. anguillarum was confirmed by the pre-adsorption effect of the V. anguillarum cells in ELISA and a cell immunoprecipitation experiment. Western blotting analysis indicated that the C5 antibody recognized a high molecular weight substance extracted from cells with detergents.

Animals↗
PubMed1997

Chemical restraint of African lions (Panthera leo) with medetomidine-ketamine.

Effects of a combination of medetomidine-ketamine as a chemical restraint and antagonistic effects of atipamezole on this combination were investigated in 5 lions. The medetomidine (47.6-58.4 micrograms/kg) and ketamine (1.9-5.7 mg/kg) combination provided complete immobilization with good analgesia and muscle relaxation in 4 lions, while one lioness was poorly sedated by medetomidine, and additional injections of medetomidine and ketamine were required. The duration of anesthesia seemed to be much longer than one hour in 4 of the lions. Atipamezole, at four times the preceding dose of medetomidine, provided a smooth recovery and animals were able to stand up 17-61 min after its injection. Side effects were limited to vomiting after walking in 3 of 5 lions.

Anesthetics, Dissociative↗
PubMed1997

Apolipoprotein E Sendai (arginine 145-->proline): a new variant associated with lipoprotein glomerulopathy.

Lipoprotein glomerulopathy (LPG) is a novel disease characterized by proteinuria, lipoprotein thrombi in the glomeruli, and increased concentration of plasma apolipoprotein (apo) E. It is believed that a genetic disorder of apo E may be present and associated with the disease. Three patients with LPG were examined in this study. The patients' DNA sequences were analyzed, and a nucleotide G to C point mutation in exon 4 of the apo E gene was confirmed in each patient. This missense mutation denotes amino acid substitution of the proline residue for arginine residue at position 145 of apo E. This variant (apo E Sendai) may cause a marked molecular conformational change of the apo E. These findings suggest that a novel variant is etiologically related to LPG.

Aged↗
PubMed1997

Correlation between blood parameters and symptomatic vasospasm in subarachnoid hemorrhage patients.

Serial changes in platelet and white blood cell (WBC) counts and other blood parameters were analyzed in 103 patients with aneurysmal subarachnoid hemorrhage (SAH). The WBC counts during days 3-5, 6-8, 9-11, and 12-14 after the onset of SAH were significantly higher in patients with than in patients without symptomatic vasospasm. Platelet counts during days 0-2, 3-5, 6-8, 9-11, 12-14, 15-17, 18-21, and 22-28 after SAH were significantly higher in patients with than in patients without symptomatic vasospasm. Monitoring of platelet and WBC counts may provide an indicator of the occurrence of symptomatic vasospasm.

Adult↗
PubMed1997

The regional distribution and cellular localization of mRNA encoding rat prostacyclin synthase.

The cloned cDNA for rat prostacyclin synthase was found to contain a 1503-bp open reading frame which encoded a 501-amino acid protein sharing 84.0% identity with the human enzyme. RNA blot analysis revealed that the rat prostacyclin synthase mRNA, as a single species of 2.1 kb, is expressed abundantly in the aorta and uterus. High levels of expression were also observed in the stomach, lung, heart, testis, liver, and skeletal muscle. Low but significant expression was also seen in the brain and kidney. Furthermore, the regional distribution and cellular localization of prostacyclin synthase mRNA were examined by in situ hybridization analysis of rat tissue sections. The definitive signals for the mRNA were localized in smooth muscle cells of the arteries, bronchi and uterus, and in the cells of the fibrous tunic surrounding the seminiferous tubules, which are characterized as smooth muscle cells. Besides smooth muscle cells, signals were also detected in the fibroblasts of the heart myocardium, lung parenchyma cells and kidney inner medulla tubules and interstitial cells.

Amino Acid Sequence↗
PubMed1997

[Geometrical distribution of newly formed blood vessels in diabetic retinopathy].

Outbreak sites of newly formed blood vessels (NFVs) in proliferative diabetic retinopathy (PDR) were analyzed geometrically. A montage was made of fluorescein fundus angiography photographs of 109 eyes and applied to a two dimensional x-y plane in which the center of the optic disc was taken as the origin. Thus each NFV acquired a coordinate value (x, y). After a coordinate transformation of this x-y plane designed to correct the parafoveal distortion of vascular distribution, a polar coordinate value (r, theta) of the NFV was calculated. The frequencies of NFVs were analyzed statistically relating to both theta, which is the angle around the origin, and r, which is the distance from the origin. The average theta was 2.74 +/- 1.72 (mean +/- standard deviation) radians and the outbreak frequency of NFVs showed a homogeneous distribution which was not influenced by any difference in theta. As for r, the frequency corrected as a truncated distribution at r = 0 showed a normal distribution with an average of 1.45 +/- 0.8. The outbreak of NFVs in PDR is a phenomenon in which accidental elements are strongly concerned and it is thought to be difficult to predict the site at early stage of retinopathy.

Adult↗
PubMed1997

[Two operative cases of quadricuspid aortic valve].

We report two cases of rare congenital anomaly of quadricuspid aortic valve. Case 1, an 81-year-old man was operated on because of aortic regurgitation without diagnosis of a quadricuspid aortic valve. He underwent aortic valve replacement with a 21 mm Hancock-II successfully. Case 2, a 40-year-old woman suffering from aortic regurgitation was diagnosed as quadricuspid aortic valve, before surgery using echocardiography and aortography. She underwent aortic valve replacement with a 21 mm H-P St. Jude Medical prosthesis successfully. Both cases were regarded as type c (2 equal larger cusps, 2 equal smaller cusps) by Hurwitz's classification. Thirty cases of quadricuspid aortic valve are reviewed in the Japanese literature including our two cases. All cases underwent aortic valve replacement because of aortic regurgitation. In 19 cases, it was possible to diagnose that those valves were quadricuspid before surgery, using echocardiography and aortography. In conclusion, it is necessary to take quadricuspid aortic valve into consideration in the case of aortic regurgitation.

Adult↗