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Biomedical subjects

H Taguchi

Publications and source records attributed to H Taguchi.

At least 271 records · Page 15Linked to original sources
PubMed1995

Dairy farmers have increased methacholine bronchial responsiveness independent of sensitization to mold antigens.

Patients with farmer's lung disease (FLD) and dairy farmers have nonspecific bronchial hyperresponsiveness. To examine the factors determining bronchial hyperresponsiveness among dairy farmers, we studied airway functions, airway responses to inhaled methacholine, serum total IgE levels, and antigen-specific IgE levels in 37 dairy farmers and 11 local control subjects. The 37 dairy farmers consisted of three groups; 12 farmers with episodes of FLD (FLD group), 13 farmers with serum antibody to Micropolyspora faeni (MF) and/or Thermoactinomyces vulgaris (TV) but without episodes of FLD (Ab(+) group), and 12 farmers without serum antibodies to MF and TV and without episodes of FLD (Ab(-) group). Pulmonary function tests showed small airways disorders among farmers (each of the three groups versus control subjects; p < 0.05). Methacholine provocation test, utilizing PD35Grs (a cumulative dose of methacholine that induces 35% reduction in respiratory conductance [Grs]), showed bronchial hyperresponsiveness in each group of dairy farmers compared with that in control subjects (Log PD35Grs, mean +/- SEM: 1.22 +/- 0.18, 1.00 +/- 0.17, and 1.20 +/- 0.20, respectively, versus 2.10 +/- 0.09; p < 0.001). However, there was no statistically significant difference in bronchial responsiveness among the three groups of dairy farmers. In addition, there was no significant difference in serum total IgE levels and specific IgE antibodies among the four groups. These results suggest that the bronchial hyperresponsiveness to methacholine among dairy farmers is not due to past episodes of FLD or sensitization to MF and/or TV, but is possibly due to the occupational environment of dairy farming.

Antibodies, Bacterial↗
PubMed1995

Amino acids and peptides. XL. Synthesis of Ac-Tyr-Val-Ala-Asp-MCA using newly developed acetylating reagent.

2-Acetoxy-3-benzyl-5-methyl-6-isobutylpyrazine was prepared by cyclization of H-Phe-Leu-CH2Cl, followed by acetylation with acetic anhydride. This pyrazine derivative can react with amino groups of amino acids or peptides to produce acetyl amino acids or acetyl peptides without acetylation of hydroxy group of Tyr, Ser and Thr. Using this acetylating reagent, Ac-Tyr-Val-Ala-Asp-MCA, which is a specific substrate of the interleukin-I (IL-I) processing enzyme, was prepared.

Alkylating Agents↗
PubMed1995

Role of histidine 188 in fructose 1,6-bisphosphate- and divalent cation-regulated L-lactate dehydrogenase of Lactobacillus casei.

A fructose 1,6-bisphosphate [Fru(1,6)P2] and divalent cation-regulated allosteric L-lactate dehydrogenase (L-LDH) (EC 1.1.1.27) of Lactobacillus casei was highly produced in Escherichia coli cells, together with its mutant enzyme, in which His-188 was replaced by Asp. Under acidic conditions, the mutant enzyme showed positive allosteric regulations by the substrate pyruvate and its analogues, like the wild-type enzyme, but not by Fru(1,6)P2, which even inhibited the stimulative effects of the alternative activation factors. In addition, Mn2+ ions also showed greatly reduced inhibitory effects on the mutant enzyme. Under neutral conditions, on the other hand, the reaction of the mutant enzyme was slightly enhanced by Fru(1,6)P2, but not further stimulated by additional Mn2+ ions, unlike the case of the wild-type enzyme. These results indicate that His-188 is, though not essential for the regulation by the alternative factors, essential for the cooperative regulation by Fru(1,6)P2 and divalent cations in L. casei L-LDH.

Amino Acids↗
PubMed1995

Effect of octreotide on ventilation and dyspnea sensation in a patient with cirrhotic hypoxemia.

We examined the long-term effects of octreotide, a somatostatin analogue, on ventilation in a case of cirrhotic hypoxemia. After daily administration of octreotide for one month, the dyspnea on exertion was notably ameliorated, although pulmonary gas exchange was only slightly improved. The octreotide therapy reduced the hypoxic ventilatory drive, which may be one reason for the relief of the dyspnea sensation.

Chronic Disease↗
PubMed1995

Sequence and phylogenetic analyses of human T cell lymphotropic virus type 1 from a Brazilian woman with adult T cell leukemia: comparison with virus strains from South America and the Caribbean basin.

Human T cell lymphotropic virus type 1 (HTLV-1) is endemic in South America and the Caribbean basin. To clarify the genetic and phylogenetic relationship between an HTLV-1 strain isolated from a Brazilian woman with adult T cell leukemia and viral isolates from elsewhere in South America and from other geographic regions, selected regions of the gag, pol, env, and pX genes were amplified and directly sequenced. The overall sequence similarities between the Brazil-R-1 strain and the Japanese prototype ATK strain were 98.7% based on 1,295 nucleotides and 99.1% based on 429 amino acids. Phylogenetic analysis indicated that strain Brazil-R-1 clustered with other Brazilian and South American HTLV-1 isolates and was more closely related to Caribbean isolates from Martinique and Guadeloupe than to virus strains from other geographic regions. These data suggest a common source of HTLV-1 infection in the Caribbean basin and South America.

Amino Acid Sequence↗
PubMed1995

[Extracorporeal shock wave lithotripsy for urinary calculi in an ileal reservoir following reconstruction of the urinary bladder].

A new method for reconstruction of the urinary bladder was introduced by Taguchi in 1977. It consisted of two components; making of pseudo-urethra and the reconstruction of urinary reservoir in the pelvis. The latter was made of the ileum and the peritoneum with temporary use of Japanese paper. This operative method was applied to a 28-year-old female patient when she had cystectomy and bilateral ureterostomy. Thereafter she had has no trouble for 13 years. However, her recent rentogenogram showed urinary tract calculi in the reservoir. Endoscopic treatment was not indicated because of the deformed reservoir and the inflexible pseudourethra. Thus, extracorporeal shock wave lithotripsy (ESWL) was applied to the case with successful results. We herrin reported the case and discussed the usefulness of ESWL for urinali calculi in the ileal reservoir.

Adult↗
PubMed1995

[Treatment of adult T-cell leukemia].

The treatment strategy for adult T-cell leukemia has not been established. CHOP derived combination chemotherapy protocols such as VEPA and VEPAM have failed to yield high complete remission rates and long survivals. Second or third generation combination chemotherapy regimens using alternative non-cross resistant drugs also have not achieved satisfactory results. A new multi-institutional trial attempting to increase dose intensity supported by granulocyte colony-stimulating factor is bringing improved remission rates and survival times. Other strategies using autologous bone marrow or peripheral blood progenitor cells should be studied as a next step.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

[A case report of a 6-year-old boy with intracranial yolk sac tumor treated by VAB-6 regimen].

Several clinical trials have demonstrated that cisplatin-based chemotherapy for primary intracranial germ-cell tumors is effective as a neoadjuvant chemotherapy. In this report, we describe a 6-year-old boy, Down syndrome and Hirschsprung's disease with intracranial pure yolk sac tumor treated by combined chemotherapy with cisplatin, vinblastine, bleomycin and cyclophosphamide (modified VAB-6 regimen). He had been admitted to our hospital because of intractable vomiting, and left facial nerve palsy since 1 month before. An MRI revealed an enlarged mass, 4cm in diameter, in the left cerebello-pontine angle with uniformal enhancement by Gd-DTPA, and bilateral ventricular dilatation. He was found to have increased serum alpha-fetoprotein level (AFP 11, 786ng/ml), but not human chorionic gonadotropin beta-subunit. After a partial resection of the tumor, diagnosed as pure yolk sac tumor, and ventriculo-peritoneal shunt, three courses of combined chemotherapy with cisplatin, bleomycin, vinblastine and cyclophosphamide (modified VAB-6 therapy) were carried out. The serum AFP level returned to normal, and the tumor mass entirely disappeared (a complete response) on MRI after the second course of chemotherapy. However, cisplatin-induced vomiting and mild neutropenia and renal tubular injury developed after the third course of chemotherapy. Irrespective of administration of recombinant human G-CSF and broad spectrum antibiotics, he suffered from pneumonia and died of septic shock and multiple organ failure. Autopsy showed microscopic residual tumors. The combination chemotherapy with cisplatin, bleomycin, vinblastine and cyclophosphamide is effective for initial treatment of childhood intracranial yolk sac tumor. It is necessary, however, to reevaluate the cisplatin dosage and treatment schedule in order to reduce such side effects as bone marrow suppression and renal damage.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Adherence of Helicobacter pylori to cultured human gastric carcinoma cells.

AIM: To examine the binding activity of Helicobacter pylori to cultured gastric epithelial cells using flow cytometry. MATERIALS AND METHODS: We evaluated the adherence of 15 H. pylori strains to cultured gastric cancer (MKN45) cells by flow cytometric analysis. Other bacterial strains were also analysed for their adherence to MKN45 cells. In addition, we examined the effect of fetuin on the adherence of H. pylori to MKN45 cells. RESULTS: H. pylori strains adhered to MKN45 cells at rates of between 49 and 93.7%, with a mean of 75.3%. In contrast, the rates of Escherichia coli, Shigella flexneri, Vibrio cholerae and Yersinia enterocolitica adherence to MKN45 cells were 69.1, 5.9, 11.7 and 33.1%, respectively. Fetuin had no inhibitory effect on the adherence of H. pylori to MKN45 cells in the flow cytometric analysis. CONCLUSIONS: A flow cytometric analysis using MKN45 cells proved to be an objective and sensitive method for evaluating the adherence of H. pylori, showing close adherence between this organism and gastric epithelial cells.

Bacterial Adhesion↗
PubMed1994

Isolation of the stable hexameric DnaK.DnaJ complex from Thermus thermophilus.

A DnaK homolog (T.DnaK) has been purified as a stable complex with a DnaJ homolog (T.DnaJ) from a thermophilic bacterium, Thermus thermophilus. This complex has an approximate molecular size of 300 kDa and appears to contain three copies of each of T.DnaK and T.DnaJ molecules. Consistently, trigonal ring structures with a diameter (trigonal apex-to-apex) of about 11 nm were observed with electron microscopy. The complex has no endogenously bound AT(D)P and is stable in the presence of Mg-AT(D)P. It possesses a weak ATPase activity and retains about 3 mol of ADP/mole of the complex when incubated with Mg-ATP. This complex is able to interact with the reduced carboxymethylated alpha-lactalbumin which we used as a model unfolded protein.

Adenosine Triphosphatases↗
PubMed1994

Requirement of a COOH-terminal pro-sequence for the extracellular secretion of aqualysin I (a thermophilic subtilisin-type protease) in Thermus thermophilus.

Thermus thermophilus cells harboring an expression plasmid for the aqualysin I gene secrete the mature enzyme into the medium. In an Escherichia coli expression system, a precursor of the enzyme with the C-terminal pro-sequence is accumulated in the cells, and upon treatment at 65 degrees C the active enzyme is produced. One- to 10-amino acid residue deletions, as well as complete 105-residue deletion of the C-terminal pro-sequence from the C-terminus, did not affect the production of the enzyme in E. coli cells. T. thermophilus cells harboring plasmids for mutant precursors with one- and three-residue deletions secreted the enzyme extracellularly. However, transformants harboring plasmids for mutant precursors with deletions of five or more amino acid residues could not be obtained. These results suggest that the C-terminal pro-sequence plays an important role in the extracellular secretion of the enzyme in T. thermophilus cells.

Amino Acid Sequence↗
PubMed1994

Chimeric YACs were generated at unreduced rates in conditions that suppress coligation.

Chimerism is a major limitation of current YAC libraries. A method based on partially filled-in ends of restriction fragments was designed to avoid coligation as a possible source of chimeras. Model experiments using plasmid DNA as an insert showed that coligation was clearly avoided by this method. Pilot collections of YACs with an average insert size of 650kb were then constructed with and without the partial fill-in treatment. Starting from a mixture of a equal amounts of human and mouse DNA, none of 108 clones was positive by hybridization with both Alu and B2 probes, again suggesting that coligation was effectively blocked. However, 4 out of 10 clones still hybridized to 2 or more locations by FISH on chromosomes in human metaphase spreads, level similar to that in the clones made without the partial fill-in step. These results strongly suggest that chimeric clones generally arise by a mechanism independent of coligation, presumptively based on recombination.

Animals↗
PubMed1994

Monomeric chaperonin-60 and its 50-kDa fragment possess the ability to interact with non-native proteins, to suppress aggregation, and to promote protein folding.

Chaperonin-60 is usually isolated as a tetradecameric form arranged as two stacked seven-member rings, and this structure has been considered to be required for promoting protein folding. However, monomeric chaperonin-60 (cpn60m), isolated from holo-chaperonin of Thermus thermophilus, and its proteolytic 50-kDa fragment, which lacks amino-terminal 78 amino acid residues, can interact with non-native rhodanese and lactate dehydrogenase, suppress formation of aggregates, and promote productive folding under the appropriate conditions. However, different from tetradecameric chaperonin-60, folding promoted by cpn60m and the 50-kDa fragment produces lower yields of active enzymes and does not require ATP or chaperonin-10. These effects are not due to transient reassembly of cpn60m into a tetradecamer during the reaction, since immobilized cpn60m and the 50-kDa fragment, both of which can not reassemble into a tetradecamer, can still promote protein folding. An excess amount of the 50-kDa fragment shows an inhibitory effect on MgATP-triggered holochaperonin-dependent folding, indicating the 50-kDa fragment and holo-chaperonin can interact with the same species of non-native proteins. Thus, cpn60m has an intrinsic activity as a molecular chaperone and amino-terminal region of cpn60 is dispensable for this activity.

Amino Acid Sequence↗
PubMed1994

Folding intermediate binds to the bottom of bullet-shaped holo-chaperonin and is readily accessible to antibody.

Holo-chaperonin from Thermus thermophilus (Thermus holo-cpn) is a bullet-shaped particle where chaperonin-10 heptamer locates at one axial end of the cylindrical body of chaperonin-60 tetradecamer. Thermus holo-cpn promotes in-vitro folding of denatured 3-isopropylmalate dehydrogenase (IPMDH) from the same bacterium. We observed the complexes of Thermus holo-cpn and folding intermediates of IPMDH by immuno-electron microscopy after decoration by single layer labeling with anti-IPMDH IgG or by double layer labeling with anti-IPMDH IgG as first layer and antibodies against IgG as second layer. Images of the electron microscope showed that anti-IPMDH IgG was bound to the bottom end of the bullet-shaped Thermus holo-cpn. This result provides direct evidence that the folding intermediate binds to the axial end, which is opposite to the end where chaperonin-10 heptamer resides, of the cylindrical body of chaperonin-60 tetradecamer, and that bound folding intermediate in the complex is sufficiently exposed to the outside to be accessible by antibody.

3-Isopropylmalate Dehydrogenase↗
PubMed1994

Essential role of arginine 235 in the substrate-binding of Lactobacillus plantarum D-lactate dehydrogenase.

Substitutions of the conserved Arg-235 with Lys and Gln induced drastic decreases in the catalytic efficiency of Lactobacillus plantarum D-lactate dehydrogenase (D-LDH). Both the mutant enzymes showed a marked resistance to 2,3-butanedione, by which the wild-type enzyme is rapidly inactivated unless NADH and oxamate are present. The pKa of the catalytic His was markedly shifted to the alkaline side by the Arg-to-Gln substitution, while it was not significantly shifted by the Arg to Lys substitution. The Arg-to-Lys replacement, by which the catalytic efficiency was less damaged, also induced decreases in kcat/Km for alternative substrates, such as 2-ketobutyrate, by approximately 10,000-fold, virtually the same level as in the case of pyruvate. Although both the wild-type and mutant enzymes exhibited lower kcat/Km for the alternative substrates than that for pyruvate, in the case of the mutant enzyme, the decrease in kcat/Km for the alternative substrates was mostly due to a decrease in kcat, while it was caused mainly by an increase in Km in the wild-type enzyme, suggesting that the mutant enzyme tends to form a nonproductive enzyme-substrate complex, in particular with more unfavorable substrates. The pH-dependence of the kinetic constants also indicated that there is a nonproductive binding that does not require the protonated or deprotonated form of the catalytic His residue. These results strongly suggest that Arg-235 plays an essential role in the tight and correct binding of substrate to the binding site of D-LDH, as in the case of Arg-171 in L-LDH.

Arginine↗
PubMed1994

Detection and characterization of antibodies to bacterial heat-shock protein 60 in sera of patients with primary biliary cirrhosis.

The enzyme-linked immunosorbent assay (ELISA) with bacterial heat-shock protein 60 (HSP60) purified from Yersinia enterocolitica (Ye) revealed that the antibodies directed against YeHSP60 existed in sera of patients with primary biliary cirrhosis (PBC). To characterize the epitope specificity of the antibodies in patients, the epitope mapping of HSP60 by means of the antibodies was performed. The results have suggested that the epitope recognized with anti-HSP60 antibodies in PBC relates to the amino acid sequence of YeHSP60 molecule as follows: DLGQAKRVVINKDTTIIIDGVGDEAAIQGRLAQIRQQIEEATSDYDKEK.

Amino Acid Sequence↗