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Biomedical subjects

T Uchida

Publications and source records attributed to T Uchida.

At least 685 records · Page 38Linked to original sources
PubMed1992

Heterotopic ossification and other perioperative complications of acetabular fractures.

Thirty-eight operatively treated fractures of the acetabulum were evaluated retrospectively for perioperative complications. Functionally significant heterotopic ossification (Brooker class III or IV) developed in 23% of those patients who did not receive adequate prophylactic irradiation or indomethacin. Irradiation and indomethacin were effective in the prevention of severe heterotopic ossification. The development of severe heterotopic ossification (class III or IV) was associated with increased time from injury to operation. We conclude that prophylaxis against heterotopic ossification is warranted to decrease the incidence of this potentially preventable complication in patients who incur significant time delays prior to surgery. Other significant complications included avascular necrosis (26%), infection (13%), and neural injury (16%). Avascular necrosis developed in one patient who did not have a documented dislocation.

Acetabulum↗
PubMed1992

Chronic effect of oral cholestyramine, a bile salt sequestrant, and exogenous cholecystokinin on insulin release in rats.

Oral cholestyramine, a bile salt sequestrant, stimulates pancreatic exocrine secretion and growth chiefly by increasing cholecystokinin (CCK) release. In this report, we examine pancreatic insulin content and insulin release from the isolated perfused pancreas in rats given oral cholestyramine (4%, wt/wt) or subcutaneous CCK-8 (1 micrograms/kg every 8 h) for 2 weeks. Cholestyramine significantly increased pancreatic weight by 32%. CCK administration significantly increased pancreatic weight by 15%. Total pancreatic content of protein and DNA were also increased significantly by cholestyramine and pancreatic protein content was increased significantly by CCK administration. Total pancreatic insulin content was not affected by cholestyramine or CCK. Both cholestyramine and CCK significantly increased the first phase of glucose (8.4 mM)-stimulated release of insulin [mean insulin output (ng/min): control, 2.0 +/- 0.1; cholestyramine, 2.7 +/- 0.2; CCK, 2.6 +/- 0.2]. Cholestyramine also significantly enhanced the second phase of glucose-stimulated release of insulin. Insulin release stimulated by CCK-8 (10(-10) M) was not affected by oral cholestyramine or CCK treatment. These findings indicate that oral cholestyramine and exogenous CCK have a stimulatory effect on beta cell function. Since pancreatic insulin content was not affected by cholestyramine and CCK treatment, cholestyramine and CCK may increase the sensitivity of beta cells to glucose. The absence of a stimulatory effect of cholestyramine and CCK administration on insulin release in response to CCK-8 may be related to a down-regulation of CCK receptors on beta cells.

Administration, Oral↗
PubMed1992

Rickettsia japonica sp. nov., the etiological agent of spotted fever group rickettsiosis in Japan.

We propose the name Rickettsia japonica sp. nov. (with type strain YH [= ATCC VR-1363]) for a serologically specific species of spotted fever group rickettsiae that are pathogenic for humans (J. Infect. Dis. 159:1122-1126, 1989; J. Clin. Microbiol. 28:1177-1180, 1990). The biologic and genomic characteristics of the organism (G+C content, 31.2 +/- 0.7 mol%) are essentially the same as those of other pathogenic spotted fever group rickettsiae, although the R. japonica isolates cause a persistent infection in Vero cells for many subcultures.

Animals↗
PubMed1992

Hepatitis E virus: cDNA cloning and expression.

Viral hepatitis E is endemic, frequently provoking epidemic outbreaks in many developing countries. We have attempted to clone the viral genome and to develop an antibody assay system. A lambda gt11 cDNA library was constructed from the bile juice containing putative causative viruses and was immunoscreened by the antisera obtained from patients and monkeys infected with hepatitis E. Three virus-specific clones were isolated and were revealed to overlap one another in sequence, with 1,459 nucleotides in total length. These clones direct the synthesis of polypeptides probably having common immunological epitope(s). Immunoplaque assay revealed the occurrence of antibodies against this epitope in the sera from experimental monkeys with the convalescent phase and from patients of Myanmar, Nepal and India. The data indicate that the cDNA fragments are useful for immunodiagnosis of hepatitis E.

Amino Acid Sequence↗
PubMed1992

Sequence comparison of the capsid region of hepatitis E viruses isolated from Myanmar and China.

Hepatitis E viruses (HEVs) were isolated during epidemics, one from Myanmar (formerly called Burma) and one from China and were partially sequenced. Another HEV Myanmar strain from sporadic hepatitis was previously sequenced by us. A cDNA sequence comparison was performed among them in the 3'-terminal region, approximately 750-base long. This region contained at least two immunological epitopes and was considered to correspond to the structural protein. The nucleotide sequence identity was 97.2% between the two Myanmar strains and 93.3 and 92.5% between the two Myanmar and the China strain. The deduced amino acid sequence identity ranged from 98.4 to 100.0% among the three strains. Thus this segment was well conserved on the amino acid level among the different strains isolated from these two Asian countries, although the China strain diverged more from the Myanmar strains on the nucleotide sequence level. This data may provide important information for the development of a vaccine and for identification of the virological link between different geographical locations.

Amino Acid Sequence↗
PubMed1992

Seroepidemiology of spotted fever group rickettsiae in small field rodents in Japan.

To clarify the geographic distribution of spotted fever group (SFG) rickettsiae in Japan, small field rodents captured in endemic and nonendemic areas were screened for anti-SFG rickettsia antibodies by the immunofluorescence test. Among total 716 specimens tested, 73-75% of rodents were antibody-positive against Rickettsia japonica and/or Rickettsia montana, showing different degree of antibody-positive proportions among each species of the rodents. Interestingly, these profiles were not different in the rodents from each endemic and nonendemic areas, indicating that the SFG rickettsiae are prevailing in the wider areas where patients have not been found yet.

Animals↗
PubMed1992

Diuretic action of the novel loop diuretic torasemide in the presence of angiotensin II or endothelin-1 in anaesthetized dogs.

The effects of torasemide (0.1 and 1 mg kg-1, i.v.) and furosemide (3 mg kg-1) on renal haemodynamics and excretory responses in the presence of angiotensin II and endothelin-1 was examined in anaesthetized dogs. Angiotensin II or endothelin-1 was continuously infused into the renal artery throughout the experiment and a bolus of torasemide or furosemide was injected into the bracheal vein. Continuous intrarenal arterial (i.r.a.) infusion of angiotensin II, at a dose of 5 ng kg-1 min-1, increased renal vascular resistance (RVR) and decreased renal blood flow (RBF) and glomerular filtration rate (GFR), but had no effect on systemic mean arterial pressure (MAP). Urinary excretion of sodium (UNaV) and urine flow (UF) were significantly decreased during angiotensin II infusion. Intravenous injections of torasemide in the presence of angiotensin II caused a dose-dependent increase in UF, UNaV and urinary excretion of potassium (UKV), while a decrease in RVR was accompanied by an increase in RBF. UKV was greater in the furosemide group than in the torasemide group, despite both groups having the same degree of aquaresis and natriuresis. Continuous i.r.a. infusion of endothelin-1, 1.5 ng kg-1 min-1, produced effects similar to those of angiotensin II on renal haemodynamics; however, the onset of action was extremely slow compared with the effects produced by angiotensin II. Endothelin-1 caused a significant decrease in UF, UNaV and UKV only at a later period, despite a relatively early depression of renal haemodynamics. Torasemide and furosemide also produced a sufficient diuretic action in this model.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗
PubMed1992

Torasemide, but not frusemide, increases intracellular cAMP and cGMP content in the aorta of the renal hypertensive rat.

Repeated oral administration of the novel loop diuretic torasemide (3 mg kg-1) and frusemide (30 mg kg-1) for 7 days, elicited a significant fall in the systolic blood pressure in the one-kidney, one-clip Goldblatt renal hypertensive rat (RHR). The hypotensive action was greater in the torasemide group than in the frusemide group. Furthermore torasemide increased intracellular cAMP and cGMP content in aorta of RHR. Frusemide caused no effect. It is hypothesized that the increase in adenosine- or guanosine-nucleotides is involved in the antihypertensive action of torasemide, but not in that of frusemide.

Animals↗
PubMed1992

Structural requirements of peptide YY for biological activity at enteric sites.

Peptide YY (PYY) is a colonic hormone consisting of 36 amino acids that is a potent inhibitor of pancreatic exocrine, gastric acid, and insulin secretion. The objective of the present experiments was to characterize the structural requirements of PYY for inhibition of pancreatic exocrine, gastric acid, and insulin secretion, using conscious dogs prepared with gastric and pancreatic fistulas. Intravenous administration of PYY-(1-36), PYY-(3-36), or PYY-(4-36) (400 pmol.kg-1 x h-1) inhibited cholecystokinin-8-stimulated (25 pmol.kg-1 x h-1) pancreatic exocrine secretion (P < 0.05); however, PYY-(1-10), PYY-(1-20), PYY-(6-36), PYY-(10-36), PYY-(13-36), PYY-(24-36), and PYY-(27-36) did not inhibit pancreatic exocrine secretion. Intravenous administration of PYY-(1-36), PYY-(3-36), or PYY-(4-36) (200, 400, 800 pmol.kg-1 x h-1) inhibited pentagastrin (0.5 microgram.kg-1 x h-1)-stimulated gastric acid secretion (P < 0.05), as well as 2-deoxy-D-glucose-stimulated insulin release (75 mg/kg) in a dose-related manner. PYY-(6-36), PYY-(13-36), and [Leu31, Pro34] neuropeptide Y did not inhibit either gastric acid secretion or insulin release. In the gastric acid and insulin secretion bioassays, PYY-(1-36) was significantly more potent than PYY-(3-36) and PYY-(4-36); however, in the pancreatic exocrine secretion bioassay, the inhibitory effects of PYY-(3-36) and PYY-(1-36) did not differ significantly. PYY-(4-36) was less potent than PYY-(1-36) on pancreatic exocrine secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Cytoplasmic filaments in the endothelial cells of the sheathed capillary: an ultrastructural and immunocytochemical study in the pig spleen.

Cytoplasmic filaments of the endothelial cells of sheathed capillaries in the pig spleen were identified and their ultrastructure was studied. Two types of cytoplasmic filaments were found: intermediate filaments (diameter: 10 nm) which filled most of the interior of the cells, and thin filaments (diameter: 5 nm) which were located just beneath the cell membrane and filled the lateral cytoplasmic processes. In immunocytochemical preparations, the intermediate filaments were positive for vimentin and desmin, and were negative for keratin. Staining of the thin filaments with heavy meromyosin resulted in arrowhead formations. These observations suggest that the intermediate filaments maintain the cytoarchitecture, possibly protecting the cell from structural alterations induced by blood pressure changes. Concurrently, thin filaments may facilitate the passage of red blood cells and blood platelets through the interendothelial fenestrae of the sheathed endothelial cell to the reticular meshwork in the capillary sheath.

Animals↗
PubMed1992

Preparation and evaluation of eudragit gels. V. Rectal gel preparations for sustained release and avoidance of first-pass metabolism of lidocaine.

The release of lidocaine from hydrogel and xerogel preparations was remarkably suppressed compared with polyethylene glycol (PEG) 2000 suppository. The release rate of lidocaine from hydrogel and xerogel increased with the increase in the amount of sodium hydroxide incorporated within the range of 3 to 7 milliequivalent (meq). After an oral administration of lidocaine HCl solution, the plasma concentration of lidocaine was considerably lower than that after intravenous administration for all time periods. The absolute bioavailability (F(oral)) was 5.63%. For the Witepsol S-55 and PEG 2000 suppositories, the plasma levels of lidocaine were higher than those for the oral preparation, and Cmax and area under the concentration-time curve (AUC) values significantly improved (p < 0.01). The absolute bioavailabilities were 21.3 and 29.6%, respectively. On the other hand, Eudispert hv-hydrogel and xerogel preparations showed the characteristics of a sustained-release preparation, especially the xerogel preparation with 5 meq NaOH. Absolute bioavailability for hydrogel and xerogel preparations increased significantly (p < 0.05) by approximately 1.7-3.4 folds compared with those of Witepsol S-55 and PEG 2000 suppositories.

Acrylic Resins↗
PubMed1992

Utility of mixture of commercially available polymers as constituents of sustained-release microcapsules containing cefadroxil or theophylline.

Hydroxy propyl methyl cellulose acetate succinate high grade (AS-HG) and ethyl cellulose (EC) mixture microcapsules containing cefadroxil or theophylline were prepared by a solvent evaporation method in liquid paraffin dissolved sorbitan tri-stearate as a dispersing agent, and their sustained-release properties were evaluated. The microcapsules prepared with AS-HG:EC (in a 2:5 weight ratio) mixture containing 20% of cefadroxil or theophylline exhibited apparent zero-order releasing pattern in pH 6 to 8, at 50 rpm and 37 degrees C (paddle method). These microcapsules were administered orally to beagle dogs and the plasma concentrations of cefadroxil or theophylline were measured periodically. As a result of in vivo investigation, a satisfactory sustained-release plasma pattern and an apparent zero-order process in the gastrointestinal absorption were confirmed by deconvolution analysis of both drugs.

Administration, Oral↗
PubMed1992

[Preparation of stable W/O/W type multiple emulsion containing water-soluble drugs and in vitro evaluation of its drug-releasing properties].

The stable water-in-oil-in-water (W/O/W) multiple emulsion was prepared by a two-step procedure for emulsification using glyceryl tricaprylate (Panasate-800) as the oil phase. The water-soluble drugs such as cefadroxil, cephradine, 4-aminoantipyrine, and antipyrine were selected and entrapped separately in the inner aqueous phase of W/O/W multiple emulsion. In consideration of parenteral administration, pH 7.4 phosphate buffered saline was used in both inner and outer aqueous phases. Moreover, these multiple emulsions could be significantly stable for a month at room temperature by the addition of hydrophilic polymer like gelatin and of amino acid like lysine to the inner aqueous phase.

Ampyrone↗
PubMed1992

The response to drug therapy in unstable angina on the basis of coronary angiography findings.

Among 366 unstable angina pectoris patients at our hospital, myocardial infarction was common (15.7%) in those with attacks of chest pain lasting for at least 20 min. There was also a high incidence (30.3%) when chest pain continued after the start of inpatient treatment. To investigate the etiology of unstable angina, coronary arteriography was performed in both the unstable and stable stages in these patients and the results were compared. The role of coronary spasm and coronary thrombosis in unstable angina was investigated, and the efficacy of continuous infusion of either diltiazem or isosorbide dinitrate as treatment for these patients was compared. Coronary arteriography in the unstable stage showed, no clear differences in the morphology of the stenotic site and the degree of stenosis between the patients with and without infarcts when urokinase or isosorbide dinitrate were injected into the coronary arteries. When drug treatment was effective, the angina was stabilized without any improvement in the degree of stenosis or the morphology of the involved coronary vessel. Thus, it was difficult to predict the response to treatment from coronary arteriography performed in the unstable stage. Diltiazem was more effective than isosorbide dinitrate, and it appears that some action other than coronary dilatation was involved in achieving the remission of unstable angina.

Angina, Unstable↗
PubMed1992

Ultrastructural and immunocytochemical studies of enamel tufts in human permanent teeth.

Enamel tufts were exposed after decalcification of the enamel matrix and their fine structures and immunocytochemical characteristics were examined. Under the binocular microscope and the scanning electron microscope (SEM), enamel tufts appeared as corrugated ribbon-like structures located on the dentine parallel to the tooth axis. SEM observation disclosed enamel tufts as bundles of well extended tubular structures with cross striations attributable to hypocalcified enamel sheaths. Plate-like structures were observed at the center of enamel tufts, where they ran parallel to the enamel tufts. Under the transmission electron microscope (TEM), the plates of tufts revealed their origin in the superficial layer of the dentine, penetrating the hypercalcified zone adjacent to the dentine-enamel (D-E) junction, and then reaching the tuft region. The plates of tufts ran mainly along the enamel sheaths and partially across the prisms in the tuft region. THe protein-A-gold technique revealed an intense immunoreactivity for amelogenin over the superficial layer of the dentine, but over the enamel prisms in the tufts nor over the plates of tufts. The immunoreactivity for 13-17 kd protein was detected over the filamentous structures closely associated with the enamel sheaths in the enamel tuft. Thus our study disclosed that enamel tufts consist of both well extended hypocalcified enamel prisms and plates of tufts. The major organic component of the enamel tufts is suggested to be 13-17 kd protein rather than amelogenin.

Amelogenin↗
PubMed1992

Successful treatment of idiopathic plasmacytic lymphadenopathy with polyclonal hypergammaglobulinemia.

A 51-year-old male was admitted because of eyelid edema and anosmia, which developed in 1985. He showed bilateral cervical lymphadenopathy, with nodes larger than 2 x 2 cm, and remarkable eyelid edema. Anemia, hyperimmunoglobulinemia with hypo-albuminemia (no M-protein) and liver dysfunction were found. Bone marrow, renal function, urine analysis and LDH level were normal. Cervical lymph node biopsy showed interfollicular proliferation of plasma cells without any malignant appearance. On day 3 of oral prednisolone (PD), anosmia abruptly improved from day 7, eyelid swelling, cervical lymphadenopathy and gammopathy subsided gradually. Since PD was tapered off, no relapse has been observed thus far.

Castleman Disease↗