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H Uchiyama

Publications and source records attributed to H Uchiyama.

At least 145 records · Page 8Linked to original sources
PubMed1993

Liquid chromatography-mass spectrometry for the determination of medetomidine and other anaesthetics in plasma.

A liquid chromatographic-atmospheric pressure chemical ionization mass spectrometric method is presented for the simultaneous determination of medetomidine and other anaesthetic drugs in solutions and dog plasma. The drugs examined were flumazenil, butorphanol, atropine, ketamine, xylazine, medetomidine, atipamezole and midazolam. The separation was carried out on a reversed-phase column using methanol-0.1 M ammonium acetate (3:2) as eluent.

Anesthetics↗
PubMed1993

Isolation and characterization of Xenopus follistatin and activins.

Xenopus follistatin and activins were purified from a Xenopus laevis cell line (XTC-F1) by four purification steps consisting of consecutive affinity chromatography on dextran sulfate-Sepharose and Sulfate Cellulofine, fast protein liquid chromatography gel permeation, and reverse-phase high performance liquid chromatography (HPLC). Our results thus obtained indicated that almost equimolar amounts of activins A, AB, and B were found to be present as a complex with follistatin (activin-binding protein) in the conditioned medium of XTC-F1 cells. Reverse-phase HPLC of the complex gave Xenopus follistatin and activins A, AB, and B. The purified Xenopus follistatin showed four major bands in a molecular mass range from 34 to 39 kDa by SDS-polyacrylamide gel electrophoresis under nonreducing conditions. The ability of each form of the protein to specifically bind activin was determined by activin-binding assay and ligand blotting analysis. Each protein was found to have the same NH2-terminus and its sequence was very homologous to that of mammalian follistatin. Several criteria including immunoblotting analysis and various functional assays revealed the existence of three isoforms of activins A, AB, and B in Xenopus, as in mammals. Xenopus activins significantly induced both ventral and dorsal mesoderm in explants of Xenopus blastula cells that would otherwise form epidermis. In a dose-dependent manner of each isoform of activin, the induced explants were able to differentiate into blood-like cells, coelomic epithelium, mesenchyme, muscle, and notochord. The induction patterns of three Xenopus activins were essentially the same. The mesoderm induction by the purified Xenopus activins was shown to be inhibited stoichiometrically by the purified Xenopus follistatin. These results indicate that Xenopus XTC-F1 cells secrete several molecular forms of follistatin/activin-binding protein and three isoforms of activins AB and B in addition to activin A.

Activins↗
PubMed1993

Catheter ablation with radiofrequency current of ventricular tachycardia originating from the right ventricle.

Catheter ablation of ventricular tachycardia (VT) with radiofrequency current would be safer than the conventional ablation with direct current shocks. Seven patients who had eight morphologically distinct symptomatic monomorphic VTs underwent catheter ablation with radiofrequency current. The mean age +/- SD was 52 +/- 16 years, and the mean cycle length of the clinical VT was 298 +/- 36 milliseconds. Sustained VT was induced by programmed stimulation with or without isoproterenol in four patients and developed during the infusion of isoproterenol alone in two patients. Of these, four VTs were entrained with rapid pacing. The ablation was attempted at the site of earliest activation through the distal electrode and the external patch electrode on the back during VT in seven episodes in six patients. In the other patient it was applied during sinus rhythm. Energy was 40 to 50 W in the first case and 30 to 40 W in the others, and was given for 30 seconds. All VTs were terminated within 6 seconds, 3.6 +/- 0.8 seconds after the application of the radiofrequency current. Additional current was given to one to four predetermined sites by mapping. The mean number of applications was 4.0 +/- 1.3 sites. Except in the first patient, VT was eliminated successfully and VT was not induced by programmed stimulation, by the administration of isoproterenol, or by treadmill exercise testing. VT did not recur during the follow-up period of 6.8 +/- 1.1 months.

Adult↗
PubMed1993

Prediction of engraftment after peripheral blood stem cell transplantation by CD34-positive cells in grafts.

A total of 91 peripheral blood stem cell collections were performed in 26 children with various malignant tumors and peripheral blood stem cell transplantations (PBSCT) were performed in 15 of the children. There was a positive correlation between logarithm of total CD34+ cells/kg and logarithm of colony-forming unit-granulocyte macrophage (CFU-GM)/kg (r = 0.86). The time elapsed until the white blood cells (WBC) exceeded 1000/microL was related to both CFU-GM (r = 0.67) and CD34+ cell count (r = 0.60). The number of days elapsed until platelet count exceeded 5 x 10(4)/microL was not related to the logarithm of CFU-GM count/10(5) per kg transfused (r = 0.47), but was related to the logarithm of CD34+ cell counts/10(6) per kg transfused (r = 0.73). The number of days elapsed until the reticulocytes exceeded 10% was not related to the logarithm of CFU-GM count/10(5) per kg (r = 0.52), but was related to the logarithm of CD34+ cell counts/10(6) per kg transfused (r = 0.91). Although CD34+ cell counts correlated with the number of CFU-GM, bone marrow regeneration rates in three lineages were predicted more accurately by the number of CD34+ cells transfused than by the number of CFU-GM. These results suggest that measurement of the CD34+ cell count may be useful in predicting bone marrow regeneration rate after PBSCT.

Adolescent↗
PubMed1993

Incidence of latex allergy in atopic children and hospital workers in Japan.

The incidence of latex-induced allergy has been reported to be increasing in Europe and the US but not in Japan. We thus measured latex-specific IgE antibodies and latex-specific IgG antibodies in sera from 196 atopic children with low serum IgE levels (under 1,000 U/ml; group 1), 108 atopic children with high serum IgE levels (over 1,000 U/ml; group 2) and 601 hospital employees (group 3). Atopic children were diagnosed as having asthma, atopic dermatitis and/or food intolerance. One out of group 1 (0.5%) and 11 out of group 2 (10.2%) were found to have latex-specific IgE by radioallergosorbent assay (RAST), and 7 were further found to be positive for latex antigen by skin test. Fifty-five percent of group 1, 65% of group 2 and 9.7% of group 3 were found to have latex-specific IgG over 100 units/ml by enzyme linked immunosorbent assay (ELISA). Prior to our diagnosis most of the children and employees did not realize they were allergic to latex. These data suggest that caution should be taken regarding latex allergy when atopic children have to be operated upon as atopic children tend to be sensitized to the latex antigen after even minimal contact with latex products.

Adolescent↗
PubMed1993

Interleukin-6 functions as an intracellular growth factor in hairy cell leukemia in vitro.

The role of interleukin-6 (IL-6) in the growth of B cell derived hairy cell leukemia (HCL) was characterized. Purified hairy cells (HCs) did not increase DNA synthesis in vitro in response to exogenous IL-6; however, they expressed IL-6 receptor (IL-6R) mRNA and bound directly fluorochrome labeled IL-6. IL-6 mRNA was not detectable in tumor cells by Northern blotting, but was evident using PCR amplification. Although intracytoplasmic IL-6 protein was not demonstrable, HCs did secrete low levels of IL-6. Neutralizing antibody to IL-6 did not inhibit HC DNA synthesis. Since tumor necrosis factor (TNF) is a growth factor for HCL, we determined whether the TNF effect could be IL-6-mediated. TNF markedly augmented in vitro DNA synthesis by HCs. TNF did not alter IL-6R expression or IL-6 binding; however, IL-6 mRNA and IL-6 protein were detectable after 3-d culture of HCs with TNF. In addition, IL-6 secretion by HCs was markedly augmented by TNF. Finally, although neither IL-6 nor anti-IL-6 antibody altered TNF-induced DNA synthesis by HCs, IL-6 antisense oligonucleotide inhibited TNF-induced DNA synthesis and IL-6 secretion by HCs. Therefore, IL-6 does not directly affect the growth of HCL, but rather mediates TNF-induced DNA synthesis via an intracytoplasmic mechanism.

Antigens, Surface↗
PubMed1993

Survival and impact of genetically engineered Pseudomonas putida harboring mercury resistance gene in aquatic microcosms.

The survival of wild-type and genetically engineered Pseudomonas putida PpY101 that contained a recombinant plasmid pSR134 conferring mercury resistance were monitored in aquatic microcosms. We used lake, river, and spring water samples. The density of genetically engineered and wild-type P. putida decreased rapidly within 5 days (population change rate k -0.87 approximately -1.00 day-1), then moderately after 5 to 28 days (-0.10 approximately -0.14 day-1). The population change rates of genetically engineered and wild-type P. putida were not significantly different. We studied the important factors affecting the survival of genetically engineered and wild-type P. putida introduced in aquatic microcosms. Visible light exerted an adverse effect on the survival of the two strains. The densities of genetically engineered and wild-type P. putida were almost constant until 7 days after inoculation in natural water filtered with a 0.45-micron membrane filter, or treated with cycloheximide to inhibit the growth of protozoa. These results suggested that protozoan predation was one of the most important factors for the survival of two strains. We examined the impact of the addition of genetically engineered and wild-type P. putida on indigenous bacteria and protozoa. Inoculation of genetically engineered or wild-type P. putida had no apparent effect on the density of indigenous bacteria. The density of protozoa increased in microcosms inoculated with genetically engineered or wild-type P. putida at 3 days after inoculation, but after 5 to 21 days, the density of protozoa decreased to the same level as the control microcosms.

Animals↗
PubMed1993

[A comparison of two delivery devices on the bronchodilatory effects of procaterol from a metered dose inhaler].

The bronchodilatory response to procaterol delivery by a metered dose inhaler with a spacer device (Volumatic) and a corniced extension tube was studied in a double blind manner in 18 asthmatic children, who were brought to our emergency room with acute attacks. The mean percent increase in forced expiratory volume in 1 second (FEV1) with the Volumatic was 55.6 +/- 39.3%, and 46.2 +/- 37.4% with the extension tube. There were no significant differences in the mean percent increase in FEV1, forced vital capacity (FVC), maximal flow rate at 50% of vital capacity (V50), maximal flow rate at 25% of vital capacity (V25) and peak expiratory flow rate (PEFR) between the two devices. It is concluded that there is no difference in the bronchodilatory effects of the two devices. The corniced extension tube has the advantage of being less expensive and more convenient to carry around.

Acute Disease↗
PubMed1993

[INH preventive therapy in Chiba Prefecture--before and after the renewal of the guideline].

To prescribe or withhold isoniazid (INH) for tuberculin skin test reactors is a difficult question in our country where BCG coverage rate is high. The guideline for INH preventive therapy renewed in 1989 says that the decision should be made according to the maximum erythema diameter of tuberculin skin test considering if the patient is a contact or non-contact, BCG vaccinated or non-vaccinated. In addition, evidence of recent infection is also important. We reported the INH preventive therapy in Chiba prefecture before and after the renewal of the guideline. There were 347 cases before and 571 after the renewal of the guideline. The cases of which maximum erythema diameter were coincided with the recommendation of the guideline were 50.2% and 78.6% respectively. Close contacts of infectious tuberculosis, i.e. cases founded out in extraordinary health examination and household contacts examination, showed high coincidence rate. On the contrary, tuberculin-positive infants found in routine health examination, who are neither contacts nor BCG vaccinated, showed low coincidence rate and seemed to be administered INH by their home- or school-doctors' own standards. These trends were the same before and after the renewal of the guideline.

Adolescent↗
PubMed1992

Chemical change involved in the oxidative-reductive depolymerization of heparin.

A solution of hog intestinal heparin (average M(r) 12,000, anti-clotting activity 168 USP units/mg) in 0.2 M phosphate buffer (pH 7.2), was incubated in the presence of Fe2+ for 20 h at 50 degrees under an O2 atmosphere to yield oxidative-reductively depolymerized heparin (ORD heparin, average M(r) 3,000, anti-clotting activity 34 USP units/mg). Chemical analysis of the ORD heparin showed a 22, 26, and 14% loss of hexosamine, uronic acid, and N-acetyl group, respectively, but no remarkable loss of both total and N-sulfate groups. 1H and 13C NMR spectroscopic analysis indicated no decrease in the amount of L-iduronic acid 2-sulfate, but a marked loss of nonsulfated uronic acid (73 and 39% loss of D-glucuronic acid and L-iduronic acids, respectively, the sum of which corresponds to the chemically determined loss of total uronic acid). The results indicated that the ORD reaction of heparin proceeds essentially by destruction of monosaccharide units, except L-iduronic acid 2-sulfate residues, due to oxygen-derived free radicals, followed by secondary hydrolytic cleavage of the resulting unstable residues.

Carbohydrates↗
PubMed1992

Characterization of adhesion molecules on human myeloma cell lines.

In multiple myeloma, malignant plasma cells are localized in marrow and rarely circulate in peripheral blood. To investigate the role of adhesion proteins in this process, we determined the expression and function of adhesion molecules on cell lines derived from patients with myeloma. The U266, ARH-77, IM-9, and HS-Sultan cell lines strongly expressed beta 1 and alpha 4 integrins (89% to 98% positive), confirming that VLA-4 is the principal integrin on these cell lines. The U266 and IM-9 cell lines also expressed alpha 3 integrin on 15% to 20% cells. In contrast, all lines lacked cell surface alpha 2, alpha 5, and alpha 6 integrin expression (< 5% positive). These cell lines adhered to fibronectin (20% to 40% specific binding), without significant binding to either collagen or laminin. Adhesion of these cell lines to fibronectin was partially blocked with either anti-beta 1 integrin monoclonal antibody (MoAb) (75% inhibition), anti-alpha 4 integrin MoAb (75% inhibition), or RGD peptide (50% inhibition), but was unaffected by anti-alpha v beta 3 or anti-alpha IIb beta 3 MoAbs. Moreover, the combination of anti-beta 1 plus RGD peptide or anti-alpha 4 plus RGD peptide inhibited binding to fibronectin by 80% and 95%, respectively. Finally, pretreatment and coculture of the IM-9 cell line with interleukin-6 (IL-6) resulted in a 52% decrease in specific binding to fibronectin (30% +/- 6% to 15% +/- 6%; P = .001), associated with a decrease in the number of cells expressing VLA-4 and a decrease in intensity of VLA-4 expression. These data suggest that myeloma cells adhere to fibronectin through VLA-4 as well as through RGD-dependent mechanisms, and that this binding can be downregulated by IL-6. Future studies of binding of both myeloma cell lines and freshly isolated tumor cells to extracellular matrix proteins and to marrow stroma may enhance our understanding of localization and trafficking of cells within the bone marrow microenvironment.

Antigens, CD↗
PubMed1992

Specific erythroid differentiation of mouse erythroleukemia cells by activins and its enhancement by retinoic acids.

Activin A has been shown to induce hemoglobin production in various hematopoietic cells. Such activities of three structurally distinct activins (activin A, activin AB, and activin B) were compared using F5-5 mouse erythroleukemia cells. Activin A and AB had similarly potent inducing activities whereas that of activin B was much lower. The erythroid inducing activity of activins was suppressed by follistatin, an activin-binding protein but not by inhibin A and inhibin B. Retinoic acids (both all-trans and 13-cis) had weak erythroid differentiation activity. In addition, clear synergistic erythroid induction occurred when retinoic acid and activin A were mixed together. These results indicate that retinoic acid may modulate activin-induced erythropoiesis in vivo.

Activins↗
PubMed1992

Isolation and characterization of native activin B.

To examine whether activin binds to follistatin, an activin-binding protein, to form a complex in vivo, we attempted to purify activin-follistatin complex from porcine follicular fluid. Our results thus obtained indicated that almost equimolar amounts of activins A, AB, and B are present as a complex with follistatin in the follicular fluid. Reverse-phase high performance liquid chromatography of the purified complex yielded follistatin and activins A, AB, and B. The activity of the purified activin B was found to be significantly lower than those of other activins in various assay systems such as stimulation of follicle-stimulating hormone secretion, induction of erythrodifferentiation, and potentiation of expression of gonadotropin receptors on ovarian cells. Moreover, binding of 125I-activin A to erythroleukemic cells which are activin-responsive was competed by activin B with approximately 10-fold lower potency compared with other activins. In contrast to these results, activin B was proved to have a potent Xenopus mesoderm-inducing activity, comparable with that of other activins. This indicates that, unlike activins A and AB, activin B can only elicit mesoderm-inducing activity and cannot function in other biological systems, suggesting a specific role of activin B in early development and unknown biological functions.

Activins↗
PubMed1992

Denitrification by fungi.

Many fungi in the centre of the group of Fusarium and its teleomorphs were shown to be capable of reducing nitrite anaerobically to form nitric oxide (NO), nitrous oxide (N2O), and/or dinitrogen (N2). Several strains could reduce nitrate as well. Nitrous oxide was the major product of the reduction of nitrate or nitrite. Several fungi could also form N2. When [15]nitrite was used as substrate for the N2-forming denitrification, 15N2O, 15NO, and 14N15N were obtained as the products. These results demonstrated that, unexpectedly, many fungi have denitrifying abilities. It was also shown that the fungal system contains a unique reaction, formation of a hybrid dinitrogen.

Anaerobiosis↗
PubMed1992

Changes in plasma thrombomodulin antigen in rabbit developing endotoxin-induced disseminated intravascular coagulation and the effect of heparin.

Soluble thrombomodulin (TM) antigen level was 1.64 +/- 0.64 microgram/ml (n = 18, mean +/- S.D.) in plasma of normal male rabbits as measured by enzyme immunoassay, and the antigen consisted of subspecies of 94, 83 and 51 kd. When disseminated intravascular coagulation (DIC) was induced by intravenous infusion of endotoxin into rabbits, the TM antigen level in plasma was elevated to about 1.5 times of the control value, and an increase in the 83 kd subspecies as well as the appearance of new subspecies of 76 and 48 kd was observed concomitantly with disappearance of the 94 kd subspecies in plasma. Elevation of the antigen level and disappearance of the 94 kd subspecies caused by infusion of endotoxin were reduced by simultaneous infusion of heparin. Addition of leukocytes stimulated with endotoxin plus FMLP to cultured endothelial cells induced release of TM antigen to the medium accompanying cell injury as measured by 51Cr release, which was prevented by treatment with heparin. It was suggested that the increase in plasma TM antigen level in parallel with the generation of DIC reflected endothelial injury of rabbits, and that the elevation of TM antigen and the endothelial cell injury were prevented by heparin treatment.

Animals↗