Biomedical subjects

T Miyazaki

Publications and source records attributed to T Miyazaki.

At least 433 records · Page 24Linked to original sources

PubMed1994

Chronic myeloid leukemia presenting ALL-type BCR/ABL transcript.

We investigated the breakpoints of the bcr gene in 46 Ph1-positive CML cases by Southern blot analysis of bcr rearrangement, and in 17 CML cases by a combination of Southern blot analysis and RT-PCR. By Southern blot, the breakpoint was not identified on M-bcr in three CML cases, of which one case showed the P210-type bcr/abl transcript and two cases showed the ALL-type (P190-type) bcr/abl transcript with or without P210 transcript. Later two cases showed unique hematological profiles such as thrombocytosis, mild myelofibrosis, and relative resistance to alkylating agents. Therefore, the present study suggests that expression of the P190-type transcript may affect clinical and hematological findings in CML.

Adult↗

PubMed1994

Experimental growth retardation produced by transient period of uteroplacental ischemia in pregnant Sprague-Dawley rats.

OBJECTIVE: Introduction of experimental growth retardation, which was based on the hypothesis of uteroplacental postischemic hypoperfusion, was attempted by a transient period of uteroplacental ischemia in dated-pregnant Sprague-Dawley rats. STUDY DESIGN: On day 17 of gestation right uterine horn circulation was occluded for 5 to 60 minutes in 35 dams. The fetuses were delivered by cesarean section and studied on day 21 of gestation. For each experiment the fetuses in the right horn served as the ischemia group and those in the left horn were used as the control group. RESULTS: Statistical analysis by Wilcoxon signed-rank test demonstrated a significant decrease in the fetal weights and in the liver-to-body weight ratios, in contrast to an increase in the brain-to-body weight ratios in the 60-minute ischemia group, compared with those in the control group. This ischemia resulted in a 14% incidence of fetal deaths. CONCLUSION: Ischemia of a single uterine horn circulation in pregnant rat for 60 minutes should readily serve as a suitable model for asymmetric intrauterine growth retardation.

Animals↗

PubMed1994

Point mutation of K-ras gene codon 12 in biliary tract tumors.

BACKGROUND/AIMS: Point mutations of the K-ras gene have been reported in a wide variety of human tumors. However, there might be conflicting data about its presence or incidence in biliary tract tumors. The aim of this study is to elucidate the presence and types of point mutation in biliary tract tumors, including gallbladder carcinoma and adenoma, extrahepatic bile duct carcinoma, and ampullary carcinoma. METHODS: Mutation bands detected in modified two-step polymerase chain reaction were eluted from agarose gel and analyzed by dideoxy sequencing method. RESULTS: Of 20 biliary tract tumors showing a mutation band, G to A single base substitutions were confirmed in 15 cases as the most frequent changes, which were divided into changes for aspartic acid (GAT) and (14) serine (AGT) (1). Changes for valine (GTT) were found in two cases. In extrahepatic bile duct carcinoma, duplicate mutations (GA/TT) were found in two cases and triplicate mutation (A/GA/TT) in one case. The adenoma portion of one "cancer in adenoma" case of gallbladder showed the single base transition (GAT) in the second position, same as in the carcinoma portion. CONCLUSIONS: Most of the biliary tract tumors comprised point mutation in K-ras gene codon 12, and G to A transition was the most frequent.

Adenoma↗

PubMed1994

Diazotization reaction of nitric oxide trapped by hemoglobin.

The present study addresses to determine whether hemoglobin within red blood cells can be utilized as a spin-trap agent for nitric oxide. We demonstrate the diazotization method coupled with a gel filtration chromatography, which is simply due to the separation of nitrosylhemoglobin from nitrite, nitrate or other low molecular nitroso-compounds in biological systems and to the liberation of nitric oxide from nitrosyl heme-complexes in the acidic condition. The amount of nitric oxide can be estimated by the difference of absorbances at 542 nm between diazo-compounds formed by Griess reagent and hemichrome by phosphoric acid. Our results indicate that hemoglobin in red cells as a spin-trap agent would be useful for monitoring nitric oxide in the circulation under the several disease states.

Chromatography, Gel↗

PubMed1994

Effect of herbimycin A, an inhibitor of tyrosine kinase, on protein tyrosine kinase activity and phosphotyrosyl proteins of Ph1-positive leukemia cells.

Herbimycin A, a benzoquinonoid anasamycin antibiotic, preferentially inhibited the in vitro growth of Ph1-positive leukemia cell lines. On the other hand, genistein, which was developed as an inhibitor of receptor-type tyrosine kinase, and other protein kinase inhibitors showed no selective inhibition of Ph1-positive leukemia cell growth. Herbimycin A also displayed an abrogative effect on the transformation of murine hematopoietic cells by transfection with a bcr/abl oncoprotein-expressing retroviral vector. The antitumor action of herbimycin A on Ph1-positive leukemia cells is related to an inhibition of activity of bcr/abl protein tyrosine kinase and a subsequent reduction of the constitutive phosphotyrosyl proteins, however, the antibiotic has no effect on the expression of bcr/abl mRNA and oncoprotein. Therefore, herbimycin A may provide an important insight into the oncogenic action of bcr/abl oncoprotein and the future development of oncoprotein-targeted therapeutic agents.

Antibiotics, Antineoplastic↗

PubMed1994

Recipient-mediated effect of a traditional Chinese herbal medicine, ren-shen-yang-rong-tang (Japanese name: ninjin-youei-to), on hematopoietic recovery following lethal irradiation and syngeneic bone marrow transplantation.

Ren-shen-yang-rong-tang (Japanese name: Ninjin-youei-to, NYT), a traditional Chinese herbal medicine, was evaluated for recipient-mediated effect on hematopoietic recovery in a murine model of syngeneic bone marrow transplantation (BMT). BALB/c recipient mice were preconditioned with a lethal total body irradiation (TBI) at a dose of 6.5 Gy and transplanted with syngeneic bone marrow (BM) cells. NYT treatments, given intraperitoneally (i.p.) once per day for 3 consecutive days in a dose of 0.625 mg, were performed either before or after TBI and BMT to assess any recipient-mediated effect of this compound. NYT pretreatment was as effective as NYT posttreatment in enhancing the total number of colony-forming unit erythroid (CFU-E) and colony-forming unit granulocyte-macrophage (CFU-GM) per marrow and spleen after TBI and BMT. NYT pretreatment caused a significant increase in marrow and splenic CFU-E and CFU-GM numbers over a prolonged period following TBI and BMT, and affected late-stage erythropoiesis (CFU-E) more profoundly than early-stage erythropoiesis (burst-forming unit erythroid, BFU-E). NYT pretreatment significantly accelerate recovery of not only erythrocyte and leukocyte counts but also platelet counts after transplantation with a limited number (1 x 10(5)) of BM cells. The same treatment, however, was significantly less effective in hematopoietic recovery after transplantation with a minimal number (1 x 10(4)) of BM cells, indicating that NYT accelerates recovery of donor-derived rather than recipient-derived cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Analysis of epitopic residues introduced into the hybrid peptide vaccines prepared according to the cassette theory.

In our previous study, we prepared a synthetic peptide vaccine (46F/HA127-133/54A) against influenza strain A/Aichi/2/68 (H3N2) virus by introducing haemagglutinin (HA) 127-133 to an I-Ab,b binding component that consisted of residues 43-46 and 54-58 of an I-Ab,d binding peptide, 46F50V54A. This hybrid peptide vaccine induced considerable immunological responses against A/Aichi/2/68 as well as against the peptide vaccine in I-Ab mice. In the present study, we have attempted to increase the immunogenicity of the peptide vaccine by introducing HA peptides of various lengths into the I-Ab,d binding components consisting of residues 43-46 and 54-58 or 43-47 and 53-58 of 46F50V54A. We demonstrate here that, among the peptide vaccines prepared, 46F/HA127-133/54A (18 mer) consisting of HA127-133 and the I-Ab,d binding component constructed from 43-47 and 53-58 of 46F50V54A induces the most vigorous T-cell responses and neutralizing antibodies against A/Aichi/2/68 in both I-Ab and I-Ad mice.

Amino Acid Sequence↗

PubMed1994

Accuracy of titanium cast crowns obtained from calcia base mold.

A calcia base investment has high stability even with melted titanium and, therefore, can produce an excellent titanium casting. In this study, titanium powder was distributed to a calcia base investment as an expanding agent, and the firing temperature of the mold was controlled at 800 degrees C. The calcia base investment with 6.1% wt titanium powder expanded 1.7% during 2 h heating at 800 degrees C. The marginal discrepancies between the die and the titanium crown were improved by the addition of the titanium powder to the investment. The mean thickness of the cement layer between the epoxy teeth and the crown using 6.1% wt titanium powder content was from 40-80 microns.

Calcium Compounds↗

PubMed1994

Effects of 15-deoxyspergualin on proliferative responses and cytokine gene expression in vitro.

15-deoxyspergualin (DSG)-treated BALB/c spleen cells showed increased spontaneous proliferation and increased alloreactive mixed lymphocyte reactions (MLRs) when a 3-h treatment was carried out. However, when spleen cells were treated with DSG for 5 days without washing out DSG, decreased spontaneous proliferation was observed, although alloreactive MLRs against C3H/He and C57BL/6 alloantigens were increased. In contrast, cyclosporin A (CsA) induced markedly decreased alloreactive MLRs. Decreased concanavalin A (Con A)- and pokeweed mitogen (PWM)-induced responses were observed in spleen cells treated with DSG for 3 h; whereas increased phytohemagglutinin (PHA)-induced responses were observed. On the other hand, increased Con A- and PHA-induced responses were observed in spleen cells treated with DSG for 2 days, whereas PWM-induced responses were decreased. CsA-treatment induced markedly decreased mitogen-induced responses. These results suggest that the immunosuppressive mechanism of DSG differs from that of CsA. Reverse transcriptase-polymerase chain reaction (RT-PCR) method showed that interleukin 1 beta (IL-1 beta), IL-2, IL-3, IL-4, IL-5, and leukemia inhibitory factor (LIF) mRNA expression in DSG-treated spleen cells were increased by Con A stimulation, thus indicating that DSG modulates cytokine gene expression and inducing immunosuppressive mechanisms different from CsA.

Animals↗

PubMed1994

Crystallization and preliminary X-ray diffraction studies of the alpha-amylase inhibitor coded 0.19 from wheat kernel.

The alpha-amylase inhibitor coded 0.19 (0.19AI) from wheat kernel is a dimeric protein which inactivates exogenous alpha-amylases. Crystals of 0.19AI were grown at room temperature and pH 7.0 from a protein solution with a low salt concentration. They were trigonal, belonged to space group P3(1) or P3(2), and had unit cell dimensions of a = b = 79.3 A and c = 60.8 A. The crystals diffract X-rays to at least 2.0 A resolution and are stable to X-ray beams. The asymmetric unit appears to contain two 0.19AI dimers. A potential heavy-atom derivative was prepared by soaking the crystal in a HgCl2 solution.

Crystallization↗

PubMed1994

Existence of lipoprotein lipase in human sarcomas and carcinomas.

Aqueous extracts of acetone/ether powders of surgically obtained specimens of human tumors hydrolyzed 3H-labeled triolein in a dose-dependent manner. The lipolytic activity in these extracts was inhibited by anti-lipoprotein lipase (LPL) IgG dose-dependently, 25 micrograms of anti-LPL IgG causing 95% inhibition of the activity. Thus, LPL accounts for most of the lipolytic activity in extracts of acetone/ether powders of the tumors. All sarcomas and carcinomas examined contained LPL activity. Western blotting showed that they gave a band corresponding to that of human adipose tissue LPL (M(r) = 57,000). Immunocytochemical studies showed that LPL was present in cultured human osteosarcoma cells and distributed throughout the cells. We determined the proliferating cell nuclear antigen (PCNA)-labeling index as an indicator of the proliferative activity of tumor cells and measured LPL activity in extracts of tumors in areas corresponding to those used for determining the PCNA-labeling index. In malignant fibrous histiocytomas, the PCNA-labeling index in area a, which corresponds to the subcapsular region, was higher than that in area b, which corresponds to the central region. The LPL activity in area a was 10 times that in area b. In rectal cancer, the index in area c, which corresponds to the subserosal region, was higher than that in area d, which corresponds to the submucosal region. The LPL activity in area c was 1.9 times that in area d. These findings indicate heterogeneity in the distributions of LPL activity within tumors and higher levels of LPL activity in tumors that are proliferating actively.

Antigens, Neoplasm↗

PubMed1994

Cytokine gene expression in the mixed lymphocyte culture in allogenic bone marrow transplants as a predictive method for transplantation-related complications.

We have investigated cytokine gene expression in the two-way mixed lymphocyte cultures (MLC) enhanced by concanavalin A to assess whether this is a useful predictive method for severe graft-versus-host disease (GVHD) and graft failure in nine allogeneic bone marrow transplantation (allo-BMT) patients. Our present study revealed that increased IL-2, IL-5 and IFN-gamma mRNA expression and IL-2 and IFN-gamma production in the MLC in two cases with severe lethal transplantation-related complications (graft failure and grade III acute GVHD). These findings suggest that increased cytokine mRNA expression and cytokine products in this assay may be predictive of the development of transplantation-related complications.

Adolescent↗

PubMed1994

A human monoclonal antibody to high-frequency red cell antigen Jra.

A human-mouse heterohybridoma (HMR0921) secreting human monoclonal IgG3, lambda antibody was produced from peripheral blood lymphocytes of a healthy blood donor with serum antibody to Jra, by EBV transformation and hybridization with mouse myeloma cell line P3X63Ag8.653. The reactivity of HMR0921 antibody was assessed by antiglobulin test with a panel of red cells including 14 different rare blood types. Only Jr(a-) red cells were negative. The strict specificity of this antibody to Jra antigen was further confirmed by absorption test with fluorescence flow cytometry. On screening of 28,744 blood donor samples by HMR0921 antibody, we detected 19 agglutination-negative samples, which were confirmed as Jr(a-) by conventional anti-Jra antisera. Therefore, our HMR0921 antibody is extremely useful for detecting rare Jr(a-) blood.

Animals↗

PubMed1994

Differential diagnosis of focal liver lesions: role of spin-echo and contrast-enhanced dynamic MR imaging.

PURPOSE: To evaluate the role of spin-echo (SE) and contrast material-enhanced dynamic magnetic resonance (MR) imaging in the differential diagnosis of focal liver lesions. MATERIALS AND METHODS: Conventional T1- and T2-weighted SE and fast low-angle shot dynamic MR imaging were performed in 300 focal liver lesions on a 1.5-T MR imager. Findings at both SE and dynamic imaging were analyzed by means of univariate and multivariate analysis. RESULTS: Although considerable overlap existed, signal intensity on T2-weighted images, tumor margin, and internal architecture were significant factors for SE imaging. For dynamic imaging, the hemodynamics and pattern of enhancement were significant factors. A logistic regression analysis revealed 86% of lesions were correctly categorized with these parameters. CONCLUSION: A specific diagnosis of liver lesions can be obtained in most cases by combining parameters obtained from SE and dynamic MR images.

Contrast Media↗

PubMed1994

Gm haplotypes in chronic inflammatory demyelinating polyradiculoneuropathy in Japanese patients.

We studied the serum Gm allotype of 58 patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and 236 nonrelated normal controls in Japan. The incidences of the Gm phenotype and haplotype in the patients were not significantly different from those in the normal controls. When CIDP was classified into two subgroups in terms of clinical course, the chronic relapsing (CR) and chronic nonrelapsing type (CNR), the distribution of all Gm haplotypes was significantly different between CR and CNR (total chi 2 = 8.319; corrected p < 0.05). Our findings suggest that the clinical course of CIDP may be associated with the Gm haplotype.

Chronic Disease↗

PubMed1994

Progression of glomerular sclerosis in experimental uremic rats by administration of indole, a precursor of indoxyl sulfate.

In uremia there is a marked elevation of serum levels of indoxyl sulfate due to its decreased renal clearance. Indoxyl sulfate is synthesized in the liver from indole which is produced by bacteria in the intestines. To determine the role of indoxyl sulfate in the progression of chronic renal failure, we administered indole, the precursor of indoxyl sulfate, to subtotally nephrectomized uremic rats. The oral administration of indole increased the serum levels of creatinine and blood urea nitrogen and decreased creatinine, inulin, and p-aminohippuric acid clearances. The glomerular sclerosis index in the indole-treated rats was higher than in the control uremic rats. After oral administration, indole could not be detected in the urine, but large amounts of its metabolite, indoxyl sulfate. Thus, indole administration stimulated glomerular sclerosis in a uremic model through the production of indoxyl sulfate.

Animals↗

PubMed1994

Plasma interleukin 8 levels are increased by hemodialysis.

The effects of hemodialysis on plasma interleukin 8 (IL-8) levels and the expression of IL-8 mRNA in peripheral blood mononuclear cells (PBMC) were studied in uremic patients undergoing maintenance hemodialysis (HD) using regenerated cellulose dialyzers. The plasma IL-8 levels in the patients after HD sessions were significantly higher than before HD. Comparison of the IL-8 mRNA levels obtained from PBMC before and after HD indicated that the expression of IL-8 mRNA was increased by HD. The enhancement of production of IL-8 in PBMC during HD may be responsible for inflammatory complications and impaired host defense in HD patients.

Adult↗

PubMed1994

Biological activity and structural characterization of alkaline-soluble polysaccharides from the kernels of Prunus mume Sieb. et Zacc.

The fruits of Prunus mume Sieb. et Zacc. (Japanese name, ume) have been used as a traditional drug and health food. In order to study the active components of P. mume, the polysaccharide fractions were extracted with cold water, hot water and aqueous sodium hydroxide from the kernels of P. mume. We found that some of the polysaccharide fractions exhibited various types of biological activities such as mitogenesis, activation of the alternative pathway of complement and activation of clot formation in human plasma. A polysaccharide, P-1, obtained from the cold 0.5 M NaOH extract was purified by ion-exchange chromatography and gel-filtration, P-1 contained 62.0% neutral sugar as glucose and 38.4% uronic acid (as galacturonic acid), and was free from protein. The neutral sugars of P-1 were arabinose, xylose, rhamnose and galactose in a molar ratio of 9.4:3.4:1.1:1.0, following analysis by gas-liquid chromatography. In addition, galacturonic acid was identified by thin-layer chromatography. The molecular weight of P-1 was found to be more than 2,000,000 by gel-filtration on Toyopearl HW 65F. P-1 showed mitogenic activity towards spleen cells of both C3H/HeN and C3H/HeJ, suggesting that it was free from bacterial endotoxic lipopolysaccharides.

Animals↗