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Biomedical subjects

H Taguchi

Publications and source records attributed to H Taguchi.

At least 451 records · Page 25Linked to original sources
PubMed1985

Immunoelectron microscopic study on the cross-reactivity of antibodies to adult T-cell leukemia-associated antigens in human and monkey sera.

The cross-reactivity of antibodies to adult T-cell leukemia (ATL)-associated antigens (ATLA) in human and monkey sera was investigated by indirect immunoperoxidase and immunoferritin methods using a human cell line (MT-2) carrying a type C virus (HTLV), two monkey cell lines (Si-1 and Si-3) carrying HTLV, and a monkey cell line (Si-2) carrying a type C virus isolated from an anti-ATLA-positive monkey. Anti-ATLA-positive but not-negative human and monkey sera gave positive immunoperoxidase reaction with all four virus-positive cell lines when studied by light microscopy. Electron microscopic findings revealed ferritin or peroxidase labeling of virus particles and plasma membranes of these four cell lines with antibody-positive but not-negative human and monkey sera. These results clearly indicate the cross-reactivity of anti-ATLA antibodies in human and monkey sera at light and electron microscopic levels, and the presence of antigenic determinants common to the surface of type C virus particles of human and monkey origin.

Animals↗
PubMed1985

Optimum conditions for ursodeoxycholic acid production from lithocholic acid by Fusarium equiseti M41.

Ursodeoxycholic acid dissolves cholesterol gallstones in humans. In the present study optimum conditions for ursodeoxycholic acid production by Fusarium equiseti M41 were studied. Resting mycelia of F. equiseti M41 showed maximum conversion at 28 degrees C, pH 8.0, and dissolved oxygen tension of higher than 60% saturation. Monovalent cations, such as Na+, K+, and Rb+, stimulated the conversion rate more than twofold. In the presence of 0.5 M KCl, the initial uptake rate and equilibrium concentration of lithocholic acid (substrate) were enhanced by 5.7- and 1.7-fold, respectively. We confirmed that enzyme activity catalyzing 7 beta-hydroxylation of lithocholic acid was induced by substrate lithocholic acid. The activity in the mycelium was controlled by dissolved oxygen tension during cultivation: with a dissolved oxygen tension of 15% and over, the activity peak appeared at 25 h of cultivation, whereas the peak was delayed to 34 and 50 h with 5 and 0% dissolved oxygen tension, respectively. After reaching the maximum, the 7 beta-hydroxylation activity in the mycelium declined rapidly at pH 7.0, but the decline was retarded by increasing the pH to 8.0. Several combinations of operations, such as pH shift (from pH 7 to 8), addition of 0.5 M KCl, and dissolved oxygen control, were applied to the production of ursodeoxycholic acid in a jar fermentor, and a much larger amount of ursodeoxycholic acid (1.2 g/liter) was produced within 96 h of cultivation.

Culture Media↗
PubMed1985

Antitumor activity of methanol extract from roots of Agrimonia pilosa Ledeb.

To evaluate the antitumor activity of Agrimonia pilosa LEDEB., the effects of the methanol extract from roots of the plant (AP-M) on several transplantable rodent tumors were investigated. AP-M significantly prolonged the life span of S180-, Meth-A fibrosarcoma- and MM-2 mammary carcinoma-bearing mice by intraperitoneal (i.p.) pre- or postmedication. AP-M also inhibited the growth of S-180 solid type tumor. On the other hand, the prolongation of life span induced by AP-M on S-180 ascites type tumor-bearing mice was markedly minimized or abolished by the pretreatment of cyclophosphamide. AP-M showed considerably strong cytotoxicity on MM-2 cells in vitro, but the effect was diminished to one-tenth by the addition of serum to the culture. Against the host animals, the peripheral white blood cells in mice were significantly increased from 2 to 5 days after the i.p. injection of AP-M. On 4th day after the injection of AP-M, the peritoneal exudate cells which possessed the cytotoxic activity on MM-2 cells in vitro were also increased to about 5-fold those in the non-treated control. The spleen of the mice was enlarged, and the spleen cells possessed the capacity to uptake 3H-thymidine. However, AP-M did not show direct migration activity like other mitogens against spleen cells from non-treated mice. These results indicate that the roots of Agrimonia pilosa contain some antitumor constituents, and possible mechanisms of the antitumor activity may be some host-mediated actions and direct cytotoxicity.

Animals↗
PubMed1985

[The ionic heterogeneity of human prolactin (PRL) from amniotic fluid].

The ionic heterogeneity of prolactin (PRL) secreted in the human amniotic fluid was investigated using new precise chemical techniques. From five liters of amniotic fluid, the PRL fractions were purified with 70% ammonium sulfate precipitation, ethanol fractionation, desalting by gel filtration on Sephadex G-25, and ion-exchange chromatography using Mono Q on Fast Protein Liquid Chromatography (FPLC). The last FPLC was repeated until homogeneous preparations were obtained. Hormonal activity of each fraction was determined with a NIADDK radioimmunoassay (RIA) kit for human PRL. The PRL activity of the finally-purified component was also assayed by radioreceptor analysis (RRA) using rat liver cell membranes as the receptor. From the amniotic fluid, seven components of the PRL were eluted at NaCl concentrations from 0.065M to 0.13M in 0.02M Tris-HCl, pH 8.0. The RRA/RIA values of these seven components were different from each other (from 0.32 to 0.97). The lower the NaCl concentrations, the higher the RRA/RIA values were. The molecular weight of each component determined by gel filtration on TSK-SW 3000 with HPLC, was similar (MW 23,000) corresponding to "small-PRL".

Amniotic Fluid↗
PubMed1985

[A case of embryonal rhabdomyosarcoma of the kidney].

A case of embryonal rhabdomyosarcoma of the left kidney is reported. A 16-year-old boy was admitted with the complaint of left abdominal pain and fever on January 6, 1983. Radiological examination showed a tumor of the left kidney; and, nephrectomy was performed. Histopathologically the entire tumor was composed of undifferentiated round cells. Diagnosis of embryonal rhabdomyosarcoma was made on the basis of special stains including immunohistochemical study with nervous tissue specific enolase. Although radiation and chemotherapy were performed postoperatively, the tumor recurred and the patient died on October 22, 1983. The problems of differential diagnosis of embryonal rhabdomyosarcoma from sarcomatous types of nephroblastoma, particularly rhabdoid tumor and other undifferentiated renal tumors were discussed. Fifteen rhabdomyosarcoma of the kidney including our case have been reported in the Japanese literature.

Adolescent↗
PubMed1985

[Clinical study of eosinophilic cystitis (2). Clinical observation on 5 cases of eosinophilic cystitis].

Clinical observations were performed on 5 cases of eosinophilic cystitis that had been diagnosed by our criteria. In all 5 cases some kind of allergic diseases was found. General urinalysis did not show any definite tendency, but eosinophils in urine were found in 4 cases. Cystoscopy revealed only chronic inflammation and submucosal hemorrhage in 4 cases, and the other case showed ulcerative changes. A positive to immediate skin reaction was seen in 2 of the 4 cases. IgE RAST was positive for mite, house dust and mugwort in 1 of these 2 cases. In this case immediate allergic reaction was suspected as part of the cause of the cystitis.

Adult↗
PubMed1984

L-Lactate dehydrogenase from Thermus caldophilus GK24, an extremely thermophilic bacterium. Desensitization to fructose 1,6-bisphosphate in the activated state by arginine-specific chemical modification and the N-terminal amino acid sequence.

Heat-stable and fructose-1,6-bisphosphate-activated L-lactate dehydrogenase (EC 1.1.1.27) has been purified from an extremely thermophilic bacterium, Thermus caldophilus GK24 [Taguchi, H., Yamashita, M., Matsuzawa, H. and Ohta, T. (1982) J. Biochem. (Tokyo) 91, 1343-1348]. N-terminal sequence analysis of the first 34 amino acids of the enzyme indicates that the N-terminal arm region (first 1-20 residues) known for the vertebrate L-lactate dehydrogenases is completely missing in the T. caldophilus enzyme, while there is a high homology of sequence between the regions which are considered to be part of the NAD-binding domain. The C-terminal amino acid of the enzyme was phenylalanine. Analysis of the amino acid composition showed that T. caldophilus enzyme contained much more arginine and fewer lysine than other bacterial and vertebrate L-lactate dehydrogenases. On modification reaction with 2,3-butanedione in the presence of NADH and oxamate, an enhanced activity of the T. caldophilus L-lactate dehydrogenase was obtained independently of fructose 1,6-bisphosphate, and the modified enzyme was desensitized to fructose 1,6-bisphosphate. Amino acid analysis indicated that such a desensitization in the active state was caused by the modification of only one arginine residue per the enzyme subunit. Desensitization of the enzyme was inhibited in the presence of fructose 1,6-bisphosphate. A similar desensitization was observed using 1,2-cyclohexanedione instead of 2,3-butanedione. The enzyme was irreversibly modified with 2,3-butanedione and characterized. The irreversibly modified enzyme also showed an enhanced activity independently of fructose 1,6-bisphosphate, and its pyruvate saturation curve was similar to that of the native enzyme measured in the presence of fructose 1,6-bisphosphate. Fructose 1,6-bisphosphate, which increases the thermostability of the native enzyme, did not affect that of the modified enzyme, while thermostability of the modified enzyme slightly decreased. Amino acid analysis indicated that only the arginine content was decreased by the modification. These results show that arginine residue(s) exist in the binding site for fructose 1,6-bisphosphate on the enzyme, and that the arginine residue(s) play some important role in the allosteric regulation of the enzyme activity.

Allosteric Regulation↗