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Biomedical subjects

S Taniguchi

Publications and source records attributed to S Taniguchi.

At least 631 records · Page 35Linked to original sources
PubMed1986

fos oncogene transfer to a transformed rat fibroblast cell line enhances spontaneous lung metastasis in rat.

When investigating the relationship of different oncogenes to metastasis, we found that transfer of the v-fos oncogene into a transformed rat cell line augmented spontaneous lung metastasis. The metastatic potential of the cell lines examined depended on the manner of integration and the extent of transcription of the fos genes. Thus, the fos oncogene is probably involved in certain events related to acquisition of metastatic potential.

Animals↗
PubMed1986

Expression of epidermal growth factor receptors on normal human gastric epithelia and gastric carcinomas.

Tissues of normal human gastric mucosae and 15 advanced gastric carcinomas were studied immunohistologically for the presence of receptors for epidermal growth factor (EGF) by use of a murine monoclonal antibody (528IgG), which reacts with the binding domain of human EGF receptor. On normal gastric mucosae, only parietal cells showed positive staining. On cancer tissues, definite staining was observed in 9 of 15 cases. Their staining intensities were variable and weaker in general compared to those of either gastric parietal cells or normal tonsilar squamous epithelium. No apparent correlation of EGF receptor staining with the grade of histologic differentiation or lymph node metastases of these gastric carcinomas was noted.

Aged↗
PubMed1985

Effects of calmodulin antagonists and calmodulin on phospholipid base-exchange activities in rabbit platelets.

Effects of various calmodulin antagonists and calmodulin on the incorporation of serine, ethanolamine and choline into the corresponding phospholipids, such as phosphatidylserine, phosphatidylethanolamine and phosphatidylcholine by Ca2+-stimulated base-exchange reactions in rabbit platelet membranes were studied. Under a Ca2+-EGTA buffer system, the incorporation of three bases were stimulated by Ca2+ in a biphasic manner. Minimum requirement of free Ca2+ for the reactions was found to be around 0.5 microM and maximal incorporation took place at high Ca2+ concentrations (3-5 mM). Various calmodulin antagonists such as chlorpromazine, trifluoperazine and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide, not only activated the three reactions but also greatly enhanced their sensitivity to Ca2+ (K0.5, 0.1-0.3 microM). In the absence of Ca2+, however, the drugs did not show any effect on the reactions. The concentrations of the drugs required for half maximal stimulation were approx. 30-40 microM. Although platelet membranes contained endogenous calmodulin (0.3-0.6 microgram/mg of membrane protein), the addition of exogenous calmodulin inhibited choline exchange activity but had no or little effect on serine or ethanolamine exchange activity. The results suggest that in the presence of low Ca2+ concentrations, these drugs markedly stimulate base-exchange activities, and choline exchange activity may be regulated by calmodulin.

Animals↗
PubMed1985

Histamine metabolism in skin of MRL/l mice.

Of several murine autoimmune models, MRL/Mp-lpr/lpr (MRL/l) mice are the most attractive from a dermatopathological point of view, because their skin lesions resemble the erythematous lesions of systemic lupus erythematosus (SLE). In order to clarify the pathogenesis of lupus dermatoses, histamine and its metabolizing activities in the skin of MRL/l mice were investigated. The specific activities of histamine-N-methyltransferase (HMT) in the skin of MRL/l mice were significantly lower than those in the skin of control mice i.e., MRL/Mp-+/+ (MRL/n), C57BL/6J, and BALB/c mice. In the dorsal lesional skin of MRL/l mice, HMT activities were markedly lower than those in normal abdominal skin. In addition, age-related analysis of HMT levels in the dorsal skin of MRL/l mice revealed that HMT activities reached their maximum at the age of 2 or 3 months and then decreased at 4 or 5 months when skin manifestation appeared: however, HMT activities in the abdominal skin increased almost linearly with age. There were no significant differences in histamine content in these mice, and diamine-oxidase activities were not detected in any skin specimens. From these results, it is suggested that impaired histamine metabolism is a particular biochemical feature of the skin of MRL/l mice.

Age Factors↗
PubMed1985

Impaired histamine metabolism in the Arthus reaction induced in guinea-pig skin.

The activities of two histamine-metabolizing enzymes, histamine-N-methyltransferase (HMT) and diamine oxidase (DAO), were examined in various types of experimentally induced cutaneous inflammations in guinea pigs. In intact guinea-pig skin, the specific activities of HMT and DAO were 24.8 +/- 1.7 pmol/min per milligram of protein or 0.930 +/- 0.097 pmol/min per milligram of the wet weight of skin specimen, and 6.0 +/- 0.7 pmol/min per milligram of protein or 0.189 +/- 0.011 pmol/min per milligram of the wet weight, respectively. Both enzyme activities were markedly reduced in skin lesions of the Arthus reaction (P less than 0.005), while those in dinitrochlorobenzene allergic dermatitis, croton-oil dermatitis, and the intact areas in Arthus-reaction-induced animals were almost within the normal limits. The activity of HMT decreased linearly with time from the onset of the Arthus reaction, reaching about 20% of the control activity at 48 h; the activity of DAO decreased even from the early stages of the reaction, and this decrease continued throughout first 48 h of the reaction. These results suggest that impaired histamine metabolism in the skin lesions of the reaction plays a distinct role in the formation and development of the Arthus reaction.

Amine Oxidase (Copper-Containing)↗
PubMed1985

Methyltransferase and phospholipase A2 activity in membranes of neutrophils and lymphocytes from patients with bacterial and viral infections.

Phospholipid methylation and phospholipase A2 activation in the cell membrane are necessary for the induction of cell function in neutrophils and lymphocytes. We assessed the activity of membrane-associated methyltransferase and phospholipase A2 in neutrophils and lymphocytes from patients with acute and severe bacterial and viral infections. In bacterial patients, methyltransferase and phospholipase A2 activities of neutrophils were significantly enhanced, and [3H]methyl incorporation of lymphocytes was slightly increased. In viral infections, only phospholipase A2 activity of the lymphocytes was increased. These enhanced enzyme activities paralleled disease activity of the two disorders. The methylated products detected by two-dimensional thin-layer chromatogram were confined to methylated phospholipids, indicating that our assay system measures specifically the activity of methyltransferase which mediates the translocation of membrane phosphatidylethanolamine (PE) to phosphatidylcholine (PC) and lyso-PC(LPC). The two enzymatic activities of both neutrophils and lymphocytes in bacterial infections and phospholipase A2 of lymphocytes may, in part, have some correlation to the defense mechanism in these two disorders.

Adult↗
PubMed1985

Glottal source-vocal tract interaction.

The problem of glottal source-vocal tract interaction is treated. The effect of the first formant load on the waveform of glottal volume flow is investigated by solving a nonlinear differential equation which describes the variation of pressure drop across the first formant load. The glottal volume flow is calculated under the influence of supraglottal and subglottal formant loads. The estimation of the glottal area function is discussed as an application of the theory developed.

Glottis↗
PubMed1985

Protection by glucose and derivatives against the lethal toxicity of mitomycin C in bacteria.

Agents capable of preventing the toxicity of mitomycin C (MMC) were investigated by a cytotoxicity assay utilizing the E. coli strain WP2 uvrA, a strain sensitive to the bactericidal action of MMC. Of various compounds, mixtures, and rat tissue extracts assayed, the solution of liver extracts and yeast extracts and DULBECCO's modified EAGLE's medium (DMEM) exhibited potent activity in protecting the cells against the MMC toxicity. A further analysis of the individual components of DMEM revealed that glucose is the active principle responsible for the protection seen with DMEM. A similar protection has been observed with the use of mannose, mannitol, 2-deoxyglucose, D-glucuronic acid, glucosamine, and N-acetylglucosamine of 16 sugar derivatives tested. The protection by glucose was specific to treatment of cells with MMC but not with UV-irradiation, cis-diamminedichloroplatinum (II), 4-nitroquinoline 1-oxide, or furylfuramide. Unlike the bacterial cells, there was no protective response in the mammalian cells in culture and in mice, given a lethal dose of MMC, concurrently with glucose or each derivative. The possible mechanisms involved in this prevention of MMC toxicity by glucose are discussed.

Animals↗
PubMed1984

A histopathological study of the percutaneous implantation of polyester fibers.

A histopathological study was made on scalp biopsies at 1 day, 1 week, 2 weeks, 1 month, 2 months, 5 months, and 20 months following implantation of synthetic fibers developed as artificial hair in Japan, in order to determine the histological conditions of its fixation over an extended period. In addition, the operative technique and materials for implantation were explored.

Biocompatible Materials↗
PubMed1984

Phospholipid transmethylation in the membrane of human neutrophils and lymphocytes.

Phospholipid transmethylation in the microsomal fraction of stimulated and unstimulated human leukocytes was measured in a recently developed assay system. Microsomal fraction was prepared from neutrophils, unseparated lymphocytes, T lymphocytes, and non-T lymphocytes by sonication and subsequent ultracentrifugation. Two hundred micrograms of microsomal protein was reacted with S-adenosyl-L-[methyl-3H]methionine. In unstimulated cells, incorporation of methyl-3H into phospholipid was 0.60 +/- 0.06 pmol min-1 mg protein in neutrophil membrane, 0.84 +/- 0.075 in unseparated lymphocytes, 1.23 +/- 0.17 in T lymphocytes, and 0.71 +/- 0.085 in non-T lymphocytes (mean +/- SE). Stimulation of neutrophils with opsonized zymosan or concanavalin A (Con A), and of lymphocytes with Con A, phytohemagglutinin, or pokeweed mitogen increased 15 to 30%. The resulting methylated phospholipids were identified and quantitated by two-dimensional thin-layer chromatography. The inhibitor 5'-S-isobutyl-5'-deoxyadenosine (SIBA) inhibited transmethylation 47-55%. This assay system appears to measure specifically the activity of methyltransferases which mediate the transmethylation of membrane phospholipid; the assay should find important applications in the study of membrane lipid metabolism in human health and disease.

Chromatography, Thin Layer↗
PubMed1984

A new method of closing the ventricular septal defect in corrected transposition of the great arteries.

A new method of closing a perimembranous malalignment ventricular septal defect (VSD) in corrected transposition of the great arteries (TGA) of the [S,L,L] type is presented. The method consists of combined approaches to the VSD through both a right atriotomy and an aortotomy without a ventriculotomy. The VSD is patched obliquely from the morphological right ventricular side of the septum, cranially through the aortic valve to the left ventricular side of the septum, caudally through the mitral valve. Although this method has been successfully applied in only one adult patient, some advantages may be expected: (1) prevention of trauma to the His bundle, which runs along the anterosuperior rim of the VSD on the left ventricular side; and (2) prevention of trauma to the tricuspid, mitral, and aortic valves without having to open the ventricles. We believe that this new method warrants a further trial as possibly better for closure of the VSD in corrected TGA of the [S,L,L] type.

Adult↗
PubMed1984

Spin-label studies of erythrocyte deformability. IV. Relation of electron spin resonance spectral change with deformation and orientation of erythrocytes in shear flow.

Electron spin resonance (ESR) spectra of spin-labeled human erythrocytes in shear flow are simulated to derive semi-empirical relations of the ESR spectral change with deformation and orientation of the cells by using a modified theoretical model developed for deformation and orientation of liquid drops. The six observed spectra at different shear stress values were simultaneously simulated by adjusting only two parameters. One parameter can be related to the ratio of the internal to the external viscosity, and the other to the elastic property of the cell membrane. From these results we have derived a semi-empirical relationship between the average deformation index or the orientation angle with a spectral measure, which characterizes the spectral shape change induced by shear stress. Thus, it becomes possible to obtain improved quantitative information on the rheological behavior of red blood cells by using the spin-label ESR method.

Electron Spin Resonance Spectroscopy↗