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Biomedical subjects

Y Yanagawa

Publications and source records attributed to Y Yanagawa.

At least 127 records · Page 7Linked to original sources

Isolation of Campylobacter pyloridis from human gastric mucosa and characterization of the isolates.

Biopsy specimens of human gastric mucosa of patients with gastric complaints and subjected to endoscopic examination were cultured microaerobically, and Campylobacter pyloridis was detected in 46 out of 80 cases (57.5%). The organism was found in 13 out of 22 patients with gastritis, 11 out of 16 with gastric ulcer scar, 7 out of 16 with gastric ulcer, 3 out of 9 with gastric polyp, 4 out of 5 with gastric carcinoma, 2 out of 2 with esophagus carcinoma, and 6 out of 9 with other gastric diseases. The isolates were identified as C. pyloridis, demonstrating its characteristic features such as positive for oxidase and catalase, negative for reduction of nitrite and nitrate, positive for urease, no growth at 25 C, growth at 37 C, not tolerant to 1% glycine, and resistant to nalidixic acid. Positive alkaline phosphatase activity was considered as an additional feature characteristic for the strains of C. pyloridis. The major cellular fatty acids were tetradecanoic acid and 19-carbon-cyclopropane acid. This pattern is unique among Campylobacter species. The survival of the organism for a longer period than 60 min at pH 2.5 indicates its significant resistance to acidic environment.

Biopsy↗

Mu-conotoxins share a common binding site with tetrodotoxin/saxitoxin on eel electroplax Na channels.

The binding characteristics of conotoxin GIIIA purified from the venom of a marine snail, Conus geographus, with regard to electroplax membranes from Electrophorus electricus were studied using a radiolabeled monopropionyl derivative of the toxin (3H-Pr-CGIIIA). 3H-Pr-CGIIIA bound specifically to a single class of saturable binding sites in electroplax membranes with a dissociation constant of 1.1 +/- 0.2 nM and a maximal binding capacity of 11 +/- 2 pmol/mg of protein. The latter value was similar to the number of specific binding sites (10 +/- 2 pmol/mg of protein) for 3H-lysine-tetrodotoxin (3H-Lys-TTX). Monopropionyl CGIIIA and CGIIIA had similar inhibitory effects on the binding of 3H-Lys-TTX (1 nM) to electroplax membranes with IC50 values of 3.5 and 0.9 nM, respectively. The association and dissociation of 3H-Pr-CGIIIA and electroplax membranes were much slower than those of 3H-Lys-TTX and the membranes. Mu-Conotoxins (CGIIIA and CGIIIB) and guanidinium toxins (TTX and saxitoxin) inhibited 3H-Pr-CGIIIA (1 nM) binding to electroplax membranes with IC50 values of 0.6, 1.1, 7.1, and 2.2 nM, respectively. However, several other kinds of neurotoxins and local anesthetics known to interact with Na channels did not affect 3H-Pr-CGIIIA binding. These findings indicate that mu-conotoxins must be classified in the same group of Na channel inhibitors as guanidinium toxins, since they competed with guanidinium toxins for binding sites on the Na channel. The peptide mu-conotoxins should be useful in studies on the functional and structural domains of Na channel proteins.

Aconitine↗

Blockade of [3H]lysine-tetrodotoxin binding to sodium channel proteins by conotoxin GIII.

Conotoxin GIII from Conus geographus inhibited the binding of [3H]lysine-tetrodotoxin (4 nM) to electroplax membranes from Electrophorus electricus and to the rat brain P2 fraction with IC50 values of 13 nM and 7.9 microM, respectively. This inhibition observed with electroplax membranes was irreversible. These and physiological findings (Life Sci., 21 (1977) 1759-1770 suggest that conotoxin GIII inhibits Na channel activation by its interaction with the tetrodotoxin binding site of the Na channel. The differences in structures related to the activation of Na channels between the eel electroplax and the rat brain are indicated.

Animals↗

Cardiovascular manifestations in Fabry's disease. A high incidence of mitral valve prolapse in hemizygotes and heterozygotes.

Cardiovascular manifestations of Fabry's disease were studied clinically in 10 hemizygous males and 13 heterozygous females. Mitral valve prolapse was found in 5 of 9 hemizygotes and in 5 of 13 heterozygotes examined by echocardiography. Ordinary medical examinations revealed cardiomyopathy in some asymptomatic females, and the diagnosis of the Fabry heterozygote was established by demonstration of specific inclusion bodies in the biopsied myocardium and low alpha-galactosidase activity in leukocytes. Renovascular hypertension of juvenile onset and thromboembolism were also found in 7 patients. It was concluded that Fabry's disease should always be considered in cases of mitral valve prolapse, cardiomyopathy, renovascular hypertension and thrombosis of unknown etiology, and that the Fabry patients should be followed carefully for the early detection of cardiovascular involvements in this disease.

Adolescent↗

Gastrointestinal decontamination in the compromised host and its clinical significance.

The result documenting the disappearance of obligate anaerobic bacteria as the predominant intestinal organisms with the onset of septicemia from S. marcescens calls for exploration into the clinical significance of anaerobic bacteria in the intestine in relationships between gut flora and host. The finding that no significant difference could be seen between the rates of septicemia under protective isolation and in uncontrolled environments is indicative of the fact that the disease most likely originated as an infection of endogenous nature. In the five cases of leukemia in children with bone marrow transplantation cited in this presentation, not one case of bacterial or fungal infection was recorded. The establishment of endogenous infections surrounding the results presented herein is discussed in terms of the biological phenomena of the interaction between intestinal flora and host, and between the intestinal bacterial flora.

Adolescent↗

A recognizable pattern of the midface of retinoblastoma patients with interstitial deletion of 13q.

In our study, we found a recognizable pattern of the midface in three retinoblastoma patients with interstitial deletion of chromosome 13 in lymphocytes. Further photographs of patients reported by other authors confirmed our conclusion that the midface in children with interstitial deletion of 13q from q12 to q22, always involving q14, is characterized by prominent eyebrows, broad nasal bridge, bulbous tip of the nose, a large mouth with a thin upper lip, and a long philtrum. This midface pattern could not be recognized in patients with normal karyotypes, suggesting that the critical segment for the midface phenotype as well as for retinoblastoma may exist in band 13q14.

Child, Preschool↗

Bacteriophage distribution in human faeces: continuous survey of healthy subjects and patients with internal and leukaemic diseases.

In order to elucidate the ecological role of bacteriophages in the human intestine, we analysed the numbers of coliphages and of coliphage strains present in faecal samples collected from healthy individuals and from patients with certain intestinal diseases. The isolated phages were grouped according to their serological properties. The samples with low phage titres, observed in both healthy subjects and patients, contained mainly temperate phages (many were related to phi 80 and lambda), and those with higher titres, observed in patients, contained virulent phages. From successive surveys of coliphages and their host, Escherichia coli, in faecal samples of each subject, it was concluded that temperate phages are maintained in the human intestine through spontaneous induction of lysogenic bacteria. Qualitative and quantitative differences existed between phages isolated from faecal samples from healthy subjects and from patients. Simultaneous changes in the distribution patterns of coliphages and of the clinical symptoms were observed in a continuous survey of a leukaemic patient in a protective environmental ward.

Coliphages↗

Measurement of plasma renin activity by a simple solid phase radioimmunoassay.

A solid phase RIA in which an antibody adsorbed onto polystyrene balls was developed to determine PRA. Complete inhibition of converting enzyme and angiotensinase during enzymatic reaction was achieved by phenyl methyl sulfonyl fluoride and EDTA combination. Pepstatin A was found to be an effective agent to block angiotensin I generation during the RIA, and the sample can be directly incubated at room temperature for RIA without any special treatment to inhibit renin activity. The intra- and interassay coefficients of variation (CV) were 5.5-6.9% and 3.7-8.2%, respectively. The recovery was 91.9-117% of added angiotensin I. The assay is sufficiently sensitive and reliable for routine use and correlates acceptably (r = 0.996) with an established RIA. The antibody-adsorbed balls were compared to the soluble antibody with respect to thermodynamic parameters. It was found that the apparent equilibrium constant of the antibody-adsorbed ball was reduced to approximately 1/2 sec of soluble antibody, which was predominately due to the decrease in unitary entropy change by adsorption.

Angiotensin I↗

[Gastrin radioimmunoassay with polyethylene glycol method].

125I-labelled gastrin with high immunological activity and high specific radioactivity of 22.2 approximately 25.9 GBq (600 approximately mCi)/mg (0.5 iodine atom/1 gastrin molecule) was prepared by chloramine-T method using the amount of 100 molar ratio of chloramine-T to gastrin. As results of gastrin radioimmunoassay with polyethylene glycol (PEG) method, intra- and interassay coefficient of variation (C.V.) were 3.6 approximately 7.6% and 5.7 approximately 10.4%, respectively. The average recoveries of 2 levels of gastrin added to serum samples were 104 +/- 11.9% and 105 +/- 9.7%. The correlation coefficient of gastrin values obtained with dextrancoated charcoal (DCC) method and present method was r = 0.973. Antibody used in this study have a characteristic to strongly recognize the tyrosin residue at 12 position and the methionyl residue at 15 position on gastrin (1-17).

Antibody Specificity↗

[A simple solid phase radioimmunoassay for plasma renin activity (author's transl)].

A solid phase radioimmunoassay (RIA) in which plasma renin activity (PRA) can be measured in a single test tube throughout enzymatic reaction and determination of angiotensin-I (A-I) generated was developed. Two hundred micro 1 of plasma samples was incubated with phenylmethylsulfonyl fluoride (PMSF) and ethylenediamine tetraaceticacid (EDTA) at pH 6.0 or 7.4 at 37 degrees C for 1 hr, then the generated A-I was determined by solid phase RIA under 3 hr of incubation time at room temperature. An antibody absorbed onto polystyrene beads was used for B/F separation of RIA. The combination of PMSF and EDTA gave significant inhibition of angiotensinase and converting enzyme. Pepstatin A, proteolytic enzyme inhibitor, was found to be effective to block the renin activity during the incubation for RIA at room temperature. Recoveries of A-I added at two levels of 1.0 4.0 ng/ml to plasma sample incubated at 37 degrees C for 1 hr were 102 +/- 28.6% and 105 +/- 15.2%, respectively. Intra-assay precision (CV) ranged from 2.5 to 10.3% and inter-assay from 7.0 to 13.7% with four pooled sera. PRA obtained under enzymatic reaction of pH 6.0 showed approximately twice as much as that of pH 7.4. The assay correlated closely with the other established solid phase radioimmunoassay kit (r = 0.996). Normal values of PRA were 1.03 +/0 0.78 ng/mg/hr (n = 66) at supine position and 1.33 +/- 1.15 ng/ml/hr at upright position. The method for the measurement of PRA, described in this paper, can be clinically used as one of convenient methods froms its simplicity and reproducibility.

Female↗