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Biomedical subjects

S Tamura

Publications and source records attributed to S Tamura.

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

The effect of cholera toxin and cholera toxin B subunit on the nasal mucosal membrane.

The effects of the self-adjuvanting substances, cholera toxin (CT) and cholera toxin B subunit (CTB), on rabbit nasal mucosal membrane, were investigated by using Ussing chambers. The control nasal mucosa (lateral wall), isolated from rabbits and mounted in the chamber, showed transepithelial potential difference, short-circuit current and conductance of -10 mV, 200 microA cm-2 and 20 mS cm-2, respectively. These parameters were compared with mucosa isolated from human inferior conchae, showing that rabbit nasal mucosa may be usable to understand effects on human mucosa. When the mucosa was exposed to various concentrations of CTB and CT, the short-circuit current and conductance of the mucosa increased with increasing concentration. CTB showed gradual increase in the short-circuit current when added in the same molar concentration as the B subunit contained in CT, which caused drastic changes by increasing the current to infinite value. Furthermore, the total amount of transepithelially fluxed CTB, which occurred rapidly after addition to the mucosal side of the chambers, increased with increasing CTB concentration. On the other hand, less flux was observed after addition of CT. These changes could be blocked by addition of ganglioside GM1. This demonstrates that the effect of CTB on the rabbit mucosal membrane are different from those of CT, although both CT and CTB act specifically on the membrane via the CTB receptor, ganglioside GM1.

Adenylyl Cyclases↗
PubMed1991

Protection against alcohol-induced gastric mucosal injury by nitecapone.

1. The mechanism of gastric mucosal protection by an anticular agent, nitecapone, against injury was investigated in rats with and without indomethacin pretreatment. 2. Animals received intragastrically either a dose of nitecapone or vehicle alone, followed by ethanol given at various intervals up to 5 hr, and their gastric mucosa subjected to histologic and physicochemical assessment. 3. Ethanol caused extensive gastric hemorrhagic lesions which were essentially prevented by nitecapone at doses of 30 mg and higher per kg body weight. The maximal protection was achieved by 1.5 hr which persisted up to 4 hr and was not thwarted by indomethacin. 4. Physicochemical measurements revealed that nitecapone evoked 78% increase in mucus gel dimension, and showed 21% increase in phospholipids, and the content of sulfo-(22%) and sialomucins (72%). This was accompanied by 1.6-fold increase in mucus viscosity, 31% increase in H+ retardation capacity and 2.2-fold increase in hydrophobicity. 5. The results suggest that the gastroprotective action of nitecapone occurs through the enhancement of the physicochemical characteristics of mucus layer.

Animals↗
PubMed1991

Characterization of beta-D-xyloside-induced glycosaminoglycans and oligosaccharides in cultured human skin fibroblasts.

Human skin fibroblasts were incubated in the presence of a fluorogenic xyloside, 4-methylumbelliferyl beta-D-xyloside. Three fluorogenic components were isolated and purified from the culture medium by gel permeation high-performance liquid chromatography. Their structures were then characterized by enzymatic digestion, fast-atom-bombardment mass spectrometry, gas-liquid chromatography, and electrophoresis on cellulose acetate membrane. The results showed that one of the components was a mixture of dermatan sulfate (70%) and chondroitin sulfate (30%), bearing the 4-methylumbelliferone at the reducing termini, and having an average molecular weight of 9,200. The others had the structures galactosyl-galactosyl-xylosyl-4-methylumbelliferone and galactosyl-xylosyl-4-methylumbelliferone, respectively, representing the linkage region between the glycosaminoglycan chains and core protein, except that 4-methylumbelliferone replaced the amino acid. Moreover, it was demonstrated that these oligosaccharides were intermediates of glycosaminoglycan synthesis, not depolymerized products.

Adult↗
PubMed1991

Estimating tissue permeability and other bioelectrical parameters using membrane voltage and short-circuit current.

Evaluating the acute toxic effects of drugs or toxins is based mainly on studies which require the use of light microscopy. Recently, the effects of such substances on biological membranes, such as the nasal membrane, has been studied using the traditional Ussing chambers, which make it possible to study the transepithelial flux of drugs across membranes and to measure some bioelectrical parameters. A model is described, with which the changes in the membrane permeability, for sodium, potassium and chlorine, can be calculated directly, based on values obtained from the Ussing chamber system. Also, an experiment is described for evaluating the toxic effects of the cholera toxin B subunit, by measuring these changes in isolated rabbit nasal mucosa.

Animals↗
PubMed1991

Exercise-induced phospholipid degradation in the equine skeletal muscle and erythrocytes.

To understand the pathogenesis of equine exercise-induced myopathies and hemolysis, changes of phospholipid peroxidation products in the equine middle gluteal muscle and erythrocytes following the high-speed treadmill exercise were studied. In the skeletal muscle, the peroxidized phosphatidylethanolamine (PE) were increased at 24 hours after the exercise. The malondialdehydes (MDAs) were also increased as the protein-bound MDAs following exercise. In the erythrocytes, the peroxidized PE were significantly decreased at 24 hours after the exercise. The protein-bound MDAs were significantly increased at 5 min after the exercise and returned to the base values at 24 hours after the exercise. These findings indicate that the PE is more susceptible to in vivo oxidative effects than the other phospholipid classes, and the accumulation of the protein-bound MDAs is considered to play some cytotoxic roles in the equine skeletal muscle and erythrocytes following exercise.

Animals↗
PubMed1991

[The localization and production of interleukin-1 in pharyngeal epithelium].

Interleukin-1 (IL-1) has been thought to be one of the essential cytokines mainly produced by macrophage. The function of IL-1 are not only activates T-lymphocytes, but also regulates immune responses to several antigens and effects on local and systemic immune reactions. Recently, it is reported that epidermal keratinocytes produces IL-1, and attention has been paid to local immune reaction mediated with this cytokine. In this study, we performed immunohistochemistry and immunoblotting on the pharyngeal epithelial keratinocytes and we evaluated the production of IL-1 by these cells. Pharyngeal mucous membrane of each region reacted strongly against anti-IL-1 alpha antibody, on the contrary, anti-IL-1 beta antibody comparatively only weakly. Strong reactivity was often observed on the basal layer, then it was seemed that some important relationship exists between the production of IL-1 and maturation of pharyngeal keratinocytes. Infiltration of T-lymphocytes was observed in proportion to the increase of epithelial reactivity against IL-1. There seemed to be no correlation between expression of HLA-DR antigen on keratinocytes and reactivity of IL-1. In immunoblotting study, the 31kD band, intracellular immature molecule, was identified besides 17 and 52kD. From this finding, it was suggested that IL-1 is derived from pharyngeal keratinocytes. In conclusion, the present study is helpful for well-understanding of local cellular immunity of pharyngeal mucous membrane.

Adult↗
PubMed1991

Expression of immunoreactive E-cadherin adhesion molecules in human cancers.

E-cadherin (E-CD), a Ca(2+)-dependent adhesion molecule, plays a major role in the maintenance of intercellular junctions in normal epithelial cells in most organs. The expression of E-CD in human carcinoma samples (esophagus, stomach, and breast) was investigated using immunohistochemical staining, which was performed on surgical specimens using a monoclonal antibody for human E-CD. E-cadherin was strongly expressed in all normal epithelium examined. However E-CD expression in primary tumors of esophagus (11 of 15: 73%), stomach (5 of 20: 25%), and breast (9 of 20: 45%) was reduced, and 68% of these (esophagus: 8 of 11, stomach: 4 of 5, breast: 5 of 9) displayed heterogeneous E-CD expression. In some tumor cells with reduced E-CD expression, E-CD molecules were located in the cell cytoplasm. These results indicate that there are human cancer cells in which E-CD-related intercellular adhesion is impaired.

Adenocarcinoma↗
PubMed1991

[A case of paragonimiasis Miyazakii with bilateral pleural and pericardial effusion].

A 38-year-old man was admitted to our hospital for further examination of bilateral pleural and pericardial effusion. He had complained of dyspnea on exertion occurring six months after ingestion of raw freshwater crabs, Patomon dehaani. X-ray films and CT scan of the chest taken on admission revealed massive bilateral pleural and pericardial effusion. High serum IgE level and eosinophilia were noted on laboratory examination. Antibody against Paragonimus Miyazakii antigen was detected in patient's serum as well as pleural and pericardial fluids by the Ouchterlony test. The patient was treated effectively by Bithionol.

Adult↗
PubMed1991

[A case of diphenylhydantoin-induced pneumonitis].

A 60-year-old man had been administered diphenylhydantoin (DPH) for prevention of convulsive seizures following clipping of an aneurysm of the middle cerebral artery. About one month after the commencement of DPH administration, he developed cough and low grade fever. He was treated with various antibiotics, but his condition increasingly worsened. Chest X-ray film revealed bilateral interstitial processes throughout the entire lung fields. Transbronchial lung biopsy was performed and the obtained specimen showed histological findings compatible with drug-induced pneumonitis. Administration of DPH was stopped immediately and 50 mg/day of prednisolone was started. The patient's condition rapidly improved, and the abnormal shadows on chest X-ray film gradually diminished. The lymphocyte stimulation test by DPH was positive with a stimulation index of 282%.

Humans↗
PubMed1991

Enhancement of the physicochemical qualities of gastric mucus by sofalcone.

The effect of prolonged administration of an antiulcer drug, sofalcone, on the physicochemical properties of gastric mucus was investigated. The experiments were conducted with groups of rats receiving twice daily for three consecutive days a dose of 100 mg/kg sofalcone, while the control group received daily doses of vehicle. The rats were sacrificed 16 h after the last dose and gastric mucosa subjected to physicochemical measurements. The results revealed that sofalcone evoked a 23% increase in mucus gel dimension, while sulfo- and sialomucins content of the gel increased by 54 and 25%, respectively. These changes were accompanied by a 16% increase in mucus H+ retardation capacity, 2-fold increase in viscosity, and a 39% increase in the gel hydrophobicity. The mucus elaborated in the presence of sofalcone contained 67% more covalently bound fatty acids, exhibited 10% lower content of protein, 30% higher content of carbohydrate, and 18% higher content of lipids. The mucus of the sofalcone group also showed an increase in the proportion of the high molecular weight mucus glycoprotein form, which in the control group accounted for about 30% of gel mucin, while its content in mucus gel of animals receiving sofalcone reached the value of 50%. The results indicate that sofalcone enhances the protective qualities of mucus component of gastric mucosal barrier.

Alcian Blue↗
PubMed1991

[Flow cytometric DNA analysis of uterine endometrial carcinoma].

The DNA content in individual cells from 40 cases of histopathologically normal endometria, 15 of endometrial hyperplasia and 68 of endometrial adenocarcinoma was measured by flow cytometry. An aneuploid cell population was found in 50% of malignant endometria, but in the remaining endometrial carcinomas, the flow cytometrical findings showed no difference from those of benign tissue. Aneuploidy was more common (77.8%) in poorly differentiated tumors than in highly differentiated tumors (35.5%). Two and more aneuploid cell populations were found in 8 cases of 34. The DNA indices of aneuploid tumors were classified into 3 groups: hyperdiploidy, low hyperdiploidy (DNA index range: 1.04-1.2) and high hyperdiploidy (DNA index range: More than 1.2). The proportion of tumors with a high DNA index tended to increase as tumors became less differentiated. In normal endometria the fraction of cells with DNA content corresponding to the s-phase (s-fraction) was 8 +/- 3% on average in the proliferative phase. In well differentiated diploid tumors the s-fraction was 12 +/- 6%, but in moderately and poorly differentiated tumors it was higher (16.0% and 19.0%).

Adenocarcinoma↗
PubMed1991

[A simultaneous operation of CABG and bilateral femoropopliteal bypass: report of a successful case].

A 62-year-old man with both coronary artery disease and leg ischemia was successfully treated with a combined revascularization procedure. Coronary artery bypass grafting (CABG) was carried out using in situ left internal thoracic artery and right gastroepiploic artery grafts, and bilateral femoropopliteal bypass grafting were performed reversed saphenous vein grafts simultaneously. The patient recovered well and experienced neither angina nor intermittent claudication.

Coronary Artery Bypass↗
PubMed1991

Prospective randomized study on the effect of ranitidine against injection ulcer after endoscopic injection sclerotherapy for esophageal varices.

Thirty-five consecutive patients undergoing endoscopic injection sclerotherapy for esophageal varices were randomly allocated to either ranitidine-administered group (18 patients) or ranitidine-nonadministered group (17 patients), in an attempt to evaluate the efficacy of ranitidine for prevention and healing of postinjection ulcer with a prospective randomized trial. Two of seventeen patients in the nonadministered group dropped out of this trial because of development of gastric ulcer, so 18 patients in the first group were evaluated and compared with the 15 remaining patients in the second group. Sclerotherapy was performed with 5% ethanolamine oleate and 0.6% polydocanol; the mean number of injection courses and the mean amount of sclerosant were the same in both groups. Moreover, there was no significant difference between the two groups in either the occurrence rate or the size of injection ulcer 1 wk after the last session. However, the persistence rate of ulcer 1 month after last injection in the ranitidine-administered group was significantly lower than that in the ranitidine-nonadministered group (6.3% vs. 38.5%, p less than 0.05). Our study demonstrated that ranitidine administration will help to hasten healing of postinjection ulcer, although it was not effective for prevention of injection ulcer.

Adult↗
PubMed1991

[Coombs negative autoimmune hemolytic anemia in a patient with myelodysplastic syndrome].

A 29 year-old-man who had been diagnosed as having myelodysplastic syndrome (MDS) in August 1985 was re-admitted to our hospital because of fever and palpitation. His peripheral blood showed severe pancytopenia and bone marrow findings remained to be compatible with MDS (refractory anemia), but karyotype of bone marrow cells revealed 7 monosomy in 17 of 20 metaphases examined. Other laboratory findings revealed decreased serum haptoglobin, positive urine hemosiderin and the normal resistance of red cell membrane. In addition, both Ham test and sugar water test were negative. The titer of cold agglutinin was low, Donath-Landsteiner antibody was not detected. These findings suggested the association of autoimmune hemolytic anemia (AIHA), although both direct and indirect Coombs' test were negative. After administration of 50mg of prednisolone daily, the frequency of red cell transfusion was markedly decreased and transfused red cell life span was prolonged from 10.4 days to 27 days. Afterward, his hematological status rapidly transformed into that of acute nonlymphocytic leukemia about 13 months after admission and he died of gastrointestinal bleeding and cerebral bleeding. Cases of MDS with immunological disorder have been reported. This is, however, the first case of MDS associated with Coombs negative AIHA.

Adult↗
PubMed1991

[Hemochromatosis].

Explore the source record for details and available documents.

Diabetes Mellitus↗
PubMed1991

[L-asparaginase-induced hyperlipidemia in a case of acute lymphoblastic leukemia].

A 15-y-o girl who had relapsed acute lymphoblastic leukemia, followed by the two-years complete remission, was treated with a reinduction chemotherapy including methotrexate, vincristine, L-asparaginase and dexamethasone (MOAD). During the chemotherapy, a remarkable hyperlipidemia has developed. The plasma levels of triglyceride and total cholesterol reached 14,450 mg/dl and 1,750 mg/dl, respectively. The laboratory data strongly suggest that L-asparaginase could induce this hyperlipidemia of Friedrickson type V. We could successfully reduce the levels of triglyceride and total cholesterol to the normal range by LDL-apheresis, and treat the patient with the chemotherapy excluding L-asparaginase to attain the second CR.

Adolescent↗