Search PubMed⌕ Search

Biomedical subjects

T Honda

Publications and source records attributed to T Honda.

At least 487 records · Page 27Linked to original sources
PubMed1993

Modification by CO2 of endothelin-1-induced contraction of isolated guinea pig trachea.

To investigate the effect of changes in CO2 tension on airway smooth muscle tone induced by various agonists, contractile responses to acetylcholine, histamine and endothelin-1 (ET-1) were studied in isolated guinea pig tracheae at very low PCO2 (16 +/- 0 mmHg, n = 38), moderately low PCO2 (28 +/- 0 mmHg, n = 23), normal PCO2 (38 +/- 1 mmHg, n = 70) or high PCO2 (94 +/- 1 mmHg, n = 32). The minimum concentration of ET-1 (10(-10) M) needed to induce contractions was lower than that of acetylcholine (10(-7) M) and histamine (10(-7) M) at normal PCO2. Changes in PCO2 did not significantly affect acetylcholine- or histamine-induced contractions. In contrast, very low and moderately low PCO2 attenuated the contractions induced by ET-1, but high PCO2 potentiated those induced by a high concentration of ET-1. Very low PCO2 with normal pH and with high pH attenuated the contractions caused by ET-1, whereas normal PCO2 with high pH did not. These results suggest that ET-1-induced airway smooth muscle contraction can be modified by PCO2 per se. Aspirin and indomethacin potentiated the responses to ET-1 at very low PCO2 more than at normal PCO2, but attenuated the responses to low concentration of ET-1 at high PCO2. These results also suggest that cyclooxygenase-related eicosanoids are involved in the effects of PCO2 on ET-1-induced contractions.

Acetylcholine↗
PubMed1993

Characterization and expression of a novel Na(+)-inorganic phosphate transporter at the liver plasma membrane of the rat.

BACKGROUND: Phosphate transport across the plasma membrane of the intestine and kidney occur by an Na(+)-dependent process. The mechanism by which phosphate enters the hepatocytes across the basolateral membrane is not known. Therefore, our study was designed to investigate whether the plasma membranes of the liver possess a specialized transport system for translocation of phosphate into the hepatocyte. METHODS: Liver plasma membrane vesicles and expression of liver poly(A)+ RNA into Xenopus laevis oocytes was used. RESULTS: Phosphate was driven into the intravesicular space as depicted by the equation y = 493.96x + 0.001, r2 = 0.96. Inwardly directed Na+ and pH gradients stimulated phosphate uptake, with a Vmax of 0.58 +/- 0.03 and 0.22 +/- 0.03 nmol/mg protein/10 s, at pH 6.1 and 7.4, respectively (P < 0.05). Km values were 0.39 +/- 0.07 and 0.25 +/- 0.1 mmol/L, respectively. To confirm the presence of a phosphate carrier, the liver Na+ phosphate transporter was expressed in X. laevis oocytes. The size-selected messenger RNA encoding for the phosphate transporter was 1.6 kilobases (kb) with kinetic parameters of Vmax 6.75 +/- 0.9 pmol/mg protein/5 min and Km of 0.29 +/- 0.1 mmol/L, compared with a Vmax of 0.41 +/- 0.03 pmol/mg protein/5 min and a Km of 0.085 +/- 0.022 mmol/L for water injection. Colonic poly(A)+ RNA did not stimulate phosphate uptake in the oocytes. CONCLUSION: The combined studies of plasma membrane vesicles and the expression system into X. laevis oocytes confirm the presence of an Na(+)-phosphate transporter at the liver plasma membranes.

Animals↗
PubMed1993

Clonal fibroblastic cell lines established from a heavily exposed atomic bomb survivor.

Two clonal fibroblast cell lines with simple chromosome aberrations-one with del(3)(p24) and the other with t(1;16)(q21;q11.2)-were established from a high dose (5.14 Gy) female atomic bomb survivor by serial culture of skin fibroblasts. These two types of clonal cells showed a more extended life span than did the cells with 44 other types of chromosome aberrations and normal cells. In addition to these results, a prominent clonal population was observed in the peripheral blood cells in this subject. It is assumed that these clonal populations arose in vivo as a result of radiation exposure to the atomic bomb.

Aged↗
PubMed1993

Cloning of the genes that control formation of the fimbrial colonization factor antigen III (CFA/III) from an enterotoxigenic Escherichia coli.

Enterotoxigenic Escherichia coli strain 260-1 produces colonization factor antigen III and heat-labile enterotoxin. A 55-kb plasmid controlling the expression of the colonization factor antigen was isolated from this strain after it was labeled with ampicillin resistance transposon, Tn3. When this plasmid was introduced into E. coli K-12 strains, it induced the formation of pili that were morphologically and immunologically identical to those on the surface of 260-1 cells, as examined by electron microscopic observation and with the specific antiserum. The physical map of the plasmid was constructed, and the 17.4-kb region was found to be responsible for the expression of the pili.

Agglutination Tests↗
PubMed1993

Ultrastructural study of extramammary Paget's disease--histologically showing transition from bowenoid pattern to Paget's disease pattern.

Histological, immunohistochemical, and ultrastructural studies were performed on two cases of histologically unusual extramammary Paget's disease. Histologically, the central area of the lesions showed a bowenoid pattern, and the peripheral area showed typical extramammary Paget's disease. The transition zone showed an intermediate pattern. All these areas were positive for CEA and EMA, and negative for S-100 protein. Ultrastructurally, in the intermediate pattern, the tumour cells had abundant cytoplasmic glycogen, and the widened intercellular spaces contained numerous glycogen particles, which were probably secreted by the tumour cells. It is well known that eccrine glands, but not apocrine glands, secrete glycogen particles. Therefore, the present findings suggest that some cases of extramammary Paget's disease are a proliferation of germinative cells with eccrine gland differentiation.

Aged↗
PubMed1993

Development of an enzyme-labeled oligonucleotide probe for the cholera toxin gene.

An alkaline phosphatase-conjugated 30-mer oligonucleotide probe was developed to detect the cholera toxin gene (ctx) in Vibrio cholerae O1. For rapid identification, V. cholerae O1 was grown on selective agar (thiosulfate-citrate-bile salts agar) or in alkaline peptone water and organisms were transferred directly to nylon membranes. Lysis of cells, denaturation of DNA, neutralization, and hybridization were carried out on the membrane. These procedures required only 3 h for completion. The results of the hybridization test with 88 clinical and 20 environmental isolates agreed almost exactly with the results of the immunological tests (anti-cholera toxin antibody-sensitized latex agglutination tests). The specificity of the probe was also tested with strains of enterotoxigenic Escherichia coli, V. cholerae non-O1, and Vibrio mimicus.

Alkaline Phosphatase↗
PubMed1993

Structural analysis of CGRP receptors on gastric smooth muscle and pancreatic acinar cells.

Calcitonin gene-related peptide (CGRP) immunoreactivity is widely distributed in the central nervous system and gastrointestinal (GI) tract, and specific receptors have been described on many GI tissues. In the present study, we compared CGRP receptors on gastric smooth muscle cells with those on pancreatic acini from guinea pig with the use of chemical cross-linking techniques combined with various enzymatic digestions. 125I-labeled rat CGRP-I demonstrated temperature-dependent saturable binding to both acinar and gastric smooth muscle cell membranes. After binding, membranes were incubated with 1 mM disuccinimidyl suberate (DSS), solubilized with sodium dodecyl sulfate (SDS), and subjected to SDS-polyacrylamide gel electrophoresis. Cross-linked radioactivity was analyzed by autoradiography. A single broad radioactive band [molecular weight (M(r)) 57,000] was seen on cell membranes from both tissues and after cross-linking to intact cells. These bands were not altered by addition of dithiothreitol. This radioactive band was not detected without DSS present or with addition of 10 microM rCGRP-I. rCGRP-I inhibited cross-linking with half-maximal inhibition of 32 nM with membranes from both tissues, and there was a close correlation between its ability to inhibit binding and to inhibit cross-linking. Cross-linking was not inhibited by non-CGRP related peptides. With membranes from both tissues, N-glycanase digestion increased the mobility of the original band. Neuraminidase digestion only slightly increased the mobility of the original band; however, the subsequent addition of O-glycanase showed no additional effect on both membranes. Endoglycosidase H digestion had no effect in either tissue. The present results demonstrate that on both tissues the cell membrane receptor for CGRP is an N-linked sialoglycoprotein. The apparent M(r) of this sialoglycoprotein is 57,000, and this polypeptide does not contain disulfide-linked subunits or O-linked carbohydrates.

Animals↗
PubMed1993

Measurement of cardiac chamber volumes by cine magnetic resonance imaging.

Cardiac chamber volumes (both atria and ventricles) in 19 healthy volunteers were measured noninvasively by cine magnetic resonance imaging (MRI). First, cardiac localization was determined from the coronal image by 0.5-T superconducting magnetic imager. Then, transaxial ECG gated multislice spin echo images were obtained from the bottom to the top of the heart. In the last step, cine MRI was performed at each level of all these transaxial spin echo MR images involving the heart. Each cardiac chamber volume at the same phase was calculated by adding chamber areas in each anatomic section multiplied by slice thickness. Left ventricular (LV) end-diastolic volume (EDV) 132.0 +/- 26.9 mL) and LV end-systolic volume (ESV) (47.8 +/- 13.9 mL) were smaller than right ventricular (RV) EDV (141.1 +/- 24.8 mL) and RVESV (57.0 +/- 12.6 mL), respectively (p < 0.01). LV stroke volume (84.3 +/- 17.9 mL) was equivalent to RV stroke volume (84.2 +/- 17.6 mL) (r = 0.91, p < 0.01). Left atrial (LA) and right atrial (RA) maximal volumes were 75.8 +/- 15.4 mL and 84.4 +/- 18.7 mL, respectively. LA minimal volume (37.5 +/- 10.7 mL) was smaller than RA minimal volume (47.8 +/- 12.2 mL). These values measured by cine MRI are satisfactory and cine MRI will be a useful method of determining cardiac chamber volumes, especially atrial volumes.

Adult↗
PubMed1993

Precise assessment of myocardial damage associated with secondary cardiomyopathies by use of Gd-DTPA-enhanced magnetic resonance imaging.

To evaluate the myocardial damage in patients with secondary cardiomyopathies, the authors examined gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA)-enhanced magnetic resonance imaging (MRI) in 5 patients (2 with cardiac amyloidosis, 2 with acute myocarditis, 1 with cardiac thyrotoxicosis). MR images were performed at 1.5-T by using a spin echo pulse sequence before and after intravenous administration of Gd-DTPA (0.2 mmol/kg). All patients revealed distinct high-intensity areas on postcontrast images. Moreover, MRI with Gd-DTPA could determine the severity and precise regions of myocardial damage associated with secondary cardiomyopathies. It is suggested that gated cardiac MRI with Gd-DTPA enhancement is useful for detecting the myocardial damage in secondary cardiomyopathies.

Acute Disease↗
PubMed1993

Automatic suspension device for gait training.

The automatic suspension device (REHABOT) suspends the patient's body in a standing position allowing the patient to walk around the circular handrail without forward propulsion. Reduction of body weight is accurately maintained automatically while safely supporting the patient. The device was used for 23 patients with orthopaedic disorders or central nervous system disorders who were chosen because of their initial difficulties with gait training in parallel bars. Its advantages are that (1) it may be used for patients with open wounds or cardiac problems, or patients using prostheses or orthoses, (2) preparation and walking practice are simpler both for patients and staff than the therapeutic pool and walking trolley, (3) running costs are lower than the therapeutic pool. Its drawbacks are that the initial cost is relatively high, only one patient can be trained at a time, and the effect of warm water is missing. The automatic suspension device will become one of the new and fundamental pieces of equipment for gait training, especially for hospitals where there are many elderly patients and also severely and multiple disabled persons.

Adolescent↗
PubMed1993

Stable chromosome aberrations among A-bomb survivors: an update.

Analysis of data on stable chromosome aberrations collected between 1968 and 1985 by the Radiation Effects Research Foundation (RERF) on 1703 individuals exposed to A-bomb radiation in Hiroshima and Nagasaki, Japan, reveals different dose-response relationships in the two cities, as well as significant effects of both time of assay and age at exposure. In Hiroshima, the proportion of cells with aberrations increased by 0.080 per sievert at low doses, assuming a constant neutron radiation RBE of 10 relative to gamma radiation, for assays performed during the latest period (1981-1985). In Nagasaki, the low-dose increase was 0.0126 per sievert. There was evidence that radiation exposure was more effective for producing stable aberrations at some younger ages at exposure, although the interpretation of this interaction is difficult. Modeling neutron and gamma-ray components of dose separately in a way which allows the neutron RBE to vary with dose yielded an estimated low-dose limiting value of RBE of 707 (95% confidence bound 200-infinity), with a low-dose response of approximately 0.008 aberrations per sievert. This RBE is much higher than the published RBEs for induction of aberrations in vitro. The high estimated RBE and the differences in dose response by city both are suggestive of systematic dose estimation errors in which either neutrons were underestimated in Hiroshima or gamma rays were overestimated in Nagasaki.

Adolescent↗
PubMed1993

[A case of rheumatoid arthritis with obstructive bronchiolitis appearing after D-penicillamine therapy].

A 56-year-old woman was diagnosed as having rheumatoid arthritis in 1983. She was treated with D-penicillamine in addition to non-steroid anti-inflammatory drugs from April 1990. In August she noticed shortness of breath on exertion. Chest X-ray films showed bilateral interstitial shadows, and chest CT revealed bilateral multiple wedge-shaped shadows extending distally. Blood gas analysis showed severe hypoxemia and pulmonary function tests demonstrated decreased %VC, FEV1.0% and diffusion capacity. Open lung biopsy specimens revealed infiltration of inflammatory cells and fibrotic change in the walls of bronchioles. She was diagnosed as having obstructive bronchiolitis. Corticosteroid therapy and discontinuation of D-penicillamine therapy stopped the progression of her symptoms, and she was discharged on corticosteroid maintenance treatment and home oxygen therapy.

Arthritis, Rheumatoid↗
PubMed1993

[A case of surgical treatment of patent ductus arteriosus using left heart bypass in an adult].

This paper describes a new operative method for patent ductus arteriosus using left heart bypass. A 57-year-old woman with patent ductus arteriosus associated with severe pulmonary hypertension was successfully operated upon. Because of aneurysmal dilatation and calcification of the aortic side of the ductus, PDA was divided under left heart bypass with centrifugal pump. Postoperative course was uneventful, and is now well.

Ductus Arteriosus, Patent↗
PubMed1993

[Analysis of bronchoalveolar lavage fluid in a case of high altitude pulmonary edema].

A 29-year-old male climber developed high altitude pulmonary edema (HAPE), progressing from headache and dyspnea to disturbance of consciousness in the Japan Alps. He was admitted to Shinshu University Hospital. Physical examination on admission revealed a cyanotic patient with coarse crackles and wheezes in bilateral lungs. Chest X-ray film showed bilateral patchy infiltrates. Arterial blood gases indicated severe hypoxemia, and respiratory alkalosis; pH 7.452, PO2 35.5 Torr, PCO2 31.6 Torr. Right heart catheterization showed noncardiogenic pulmonary edema, analysis of bronchoalveolar lavage (BAL) fluid was as follows; cells 2.05 x 10(5)/ml (alveolar macrophages 61.5%, neutrophils 25.5%, lymphocytes 13.0%), protein concentration 91 mg/dl. Cellular and protein analysis of BAL has been shown to be of value to clarify the pathogenesis of the permeability edema in patients with HAPE.

Adult↗
PubMed1993

[A case of left atrial plication for mitral valvular disease with giant left atrium].

A case of plication of giant left atrium complicating mitral valvular disease is reported. The patient was a 44-year-old female with mitral stenosis and regurgitation, whose respiratory function was severely disturbed. Chest X-ray showed severe stenosis of the left main bronchus and widening of the tracheal bifurcation secondary to compression by the left atrium. Mitral valve replacement and left atrial plication was performed. Postoperative respiratory weaning was uneventful and respiratory function was improved. We concluded that plication is very beneficial in patients with giant left atrium who have signs of compression of the bronchus and lungs.

Adult↗
PubMed1993

[Proteoglycan abnormality in a nanophthalmos sclera].

We examined a scleral specimen obtained from a nanophthalmos eye with uveal effusion at the surgery, using cuprolinic blue (CB) dye binding and electron microscopy. The nanophthalmic sclera was separated into two areas electron microscopically. One was an area composed of tightly packed collagen fibers, the other with irregularly arranged collagen fibers. In irregular areas, several abnormal findings, such as twisting or fraying, were detected in collagen fibers, which were surrounded by fine fibrous materials. Furthermore, CB-positive materials were fewer in number and less in size and electron density around the collagen fibers and in fine fibrous materials than in the normal eye. Since the nanophthalmic sclera in this study showed some abnormalities both in collagen fibers and in proteoglycans, we suggest that the function and/or interaction of both of these were abnormal, which might be related to the onset of uveal effusion.

Adult↗
PubMed1992

Characterization of two forms of hemagglutinin/protease produced by Vibrio cholerae non-O1.

Two forms (34 kDa and 32 kDa) of hemagglutinin/protease produced by Vibrio cholerae non-O1 were characterized. The hemagglutinin/protease purified by immunoaffinity column chromatography using a monoclonal antibody was essentially a 34-kDa form. By incubation of the purified 34-kDa form at 37 degrees C, it was processed (autodigested) to the 32-kDa form. The N-terminal 20 amino acid sequences of both the 34- and 32-kDa forms were identical, suggesting that proteolytic processing at the C-terminal region of the 34-kDa hemagglutinin/protease resulted in the 32-kDa form. With this shift, protease activity increased, but hemagglutinating activity decreased, suggesting that the C-terminal region of the hemagglutinin/protease is related to hemagglutinating activity.

Amino Acid Sequence↗