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Biomedical subjects

H Taguchi

Publications and source records attributed to H Taguchi.

At least 289 records · Page 16Linked to original sources
PubMed1993

Chaperonin from Thermus thermophilus can protect several enzymes from irreversible heat denaturation by capturing denaturation intermediate.

Chaperonin isolated from Thermus thermophilus is stable up to 80 degrees C. Taking advantage of this heat stability, we have studied the effects of chaperonin on heat denaturation of several relatively heat labile enzymes. When the enzymes are incubated at their denaturating temperatures, the presence of T. thermophilus chaperonin in the solution has little effect on the rate of apparent inactivation of the enzyme. However, this inactivation is not irreversible since most activity is recovered when the solution is shifted to the second incubation at a moderate temperature with concomitant addition of MgATP. When the chaperonin is omitted from the solution, no recovery is observed. Recovery of the activity is also dependent on MgATP in the second incubation and 50% of recovery is attained at 5 microM MgATP. When the chaperonin is added after starting the incubation at a denaturing temperature, recovery of the activity becomes poorer as the delay of chaperonin addition increases. The critical temperature of the incubation at which irreversible denaturation occurs to the enzymes is elevated 8-15 degrees C by inclusion of T. thermophilus chaperonin in the solution. The heat stability of captured proteins by the chaperonin, assessed as retention of the ability to resume productive folding under optimal conditions, is measured more accurately using chemically produced folding intermediate-chaperonin complexes. The ability is lost at about 78 degrees C being irrespective of variable heat stability of individual enzymes. These results indicate that during heat denaturation proteins assume a common structure which is recognizable by the chaperonin. Once a protein with this structure is captured by T. thermophilus chaperonin, it retains the ability to resume productive folding even after exposure to the otherwise denaturing high temperature. Its heat stability seems to be limited solely by heat stability of chaperonin.

Adenosine Triphosphate↗
PubMed1993

Central nervous system involvement of adult T-cell leukemia-lymphoma with multinucleated giant cells in the brain, skin, and kidney.

BACKGROUND: A case of central nervous system (CNS) involvement in a patient with adult T-cell leukemia-lymphoma (ATLL) with multinucleated giant cells (MNGC) is presented. METHODS: A 48-year-old woman with human T-lymphotropic virus type I (HTLV-I) antibody titer had multiple focal brain symptoms and skin eruptions without lymphadenopathy, hepatosplenomegaly, or increased abnormal lymphocytes in the peripheral blood. No spastic paraparesis of the lower limbs was found. The encephalopathy was progressive, and she died 5 months later despite repeated intrathecal administration of methotrexate, cytosine arabinoside, and prednisolone and monthly systemic chemotherapy with doxorubicin, cyclophosphamide, vincristine, and prednisolone. RESULTS: Postmortem examinations identified unusual ATLL lesions composed of marked infiltrations of atypical mononuclear cells and bizarre MNGC with histiocytic granulomatous reactions in the leptomeninges, brain tissues along the Virchow-Robin spaces, skin, and kidney. Immunohistochemical stains confirmed the T-cell nature of such mononuclear cells and partially T-cell and partially macrophage nature of the MNGC, although no evidence of HTLV-I expression was found. CONCLUSIONS: ATLL presenting with CNS symptoms is rare. It was assumed that the direct cytopathic effects of HTLV-I were responsible for the formation of the MNGC after considering the similarity with MNGC in encephalopathy caused by the human immunodeficiency virus.

Brain↗
PubMed1993

Zymobacter palmae gen. nov., sp. nov., a new ethanol-fermenting peritrichous bacterium isolated from palm sap.

Zymobacter palmae gen. nov., sp. nov. was proposed for a new ethanol-fermenting bacterium that was isolated from palm sap in Okinawa Prefecture, Japan. The bacterium is gram-negative, facultatively anaerobic, catalase-positive, oxidase-negative, nonsporeforming and peritrichously flagellated. It requires nicotinic acid for growth. It ferments hexoses, alpha-linked di- and tri-saccharides, and sugar alcohols (fructose, galactose, glucose, mannose, maltose, melibiose, saccharose, raffinose, mannitol and sorbitol). Fifteen percent of maltose in broth medium is effectively fermented, whereas glucose with a concentration higher than 10% delayed growth initiation and decreased growth rates. Maltose is fermented to produce ethanol and CO2 with a trace amount of acids. Approximately 2 mol of ethanol are produced from 1 mol moiety of hexose of maltose. The organism possesses ubiquinone-9. The G + C content of the DNA is 55.8 +/- 0.4 mol%. Major cellular fatty acids were palmitic and oleic acids and cyclopropanic acid of C19:0. Characteristic hydroxylated acid was 3-hydroxy dodecanoic acid. The bacterium is distinct from other ethanol-fermenting bacteria belonging to the genera Zymomonas Kluyver and van Niel 1936 and Saccharobacter Yaping et al. 1990 with respect to chemotaxonomic and other phenotypic characters to warrant to compose a new genus and a new species. The type strain is strain T109 (= IAM 14233).

Base Sequence↗
PubMed1993

The isolation of Cryptococcus neoformans from pigeon droppings and serotyping of naturally and clinically sourced isolates in China.

This is the first report on the isolation of Cryptococcus neoformans from pigeon droppings in China and their serotypes. C. neoformans colonies which produced brown colonies on caffeic acid-cornmeal agar were found in Twenty-five out of thirty-six samples of pigeon droppings. Fifty-one colonies randomly picked from the positive samples were identified as C. neoformans by a commercially available kit for carbon source assimilation test and Christensen's urea agar. Forty (78%) out of the 51 strains were serotyped as A and 11 (22%) as AD. At the same time, seventeen out of nineteen clinical isolates were serotyped as A and 2 as B. There are three findings in our results. One is that only C. neoformans var. neoformans strains could be isolated from pigeon droppings, although the variety gattii strains were found in the clinical isolates obtained in the same geographic site in China. The second is that serotype A strains were most frequently seen in natural and clinical materials in the southeast part of China, and serotype AD strains were isolated in pigeon droppings but not in clinical materials. The third is that the coexistence of serotype A and AD cells of C. neoformans strains in same samples of pigeon droppings were observed.

Animals↗
PubMed1993

Thallium-201 scintigraphy in the evaluation of thyroid nodules. A retrospective study of 246 cases.

There is controversy at present concerning the value of Tl-201 scintigraphy in the diagnosis of malignant thyroid nodules. The usefulness of Tl-201 scintigraphy in differentiating benign from malignant nodules was evaluated retrospectively. Tl-201 scintigraphy was performed in 101 patients with malignant thyroid nodules and in 145 with benign nodules. Early and late images were examined to compare Tl-201 uptake in nodules and normal thyroid tissue. The visual method resulted in 74% of sensitivity and 58% of specificity for the detection of malignant nodules including incidental cancers. Excluding incidental cancers, 87% sensitivity and 58% specificity were achieved. Small cancers, including incidental cancers less than 1.5 cm in diameter and small number of viable tumor cells in a large tumor also gave negative Tl-201 scintigraphic results. Forty-two percent of the benign lesions gave false positive Tl-201 scintigraphic results. It is concluded that Tl-201 scintigraphy is a sensitive and useful method to use in diagnosing malignant thyroid nodules, but is not a specific method even with late scan, for the detection of malignant thyroid nodules.

Adenocarcinoma, Follicular↗
PubMed1993

Effect of Pinellia ternata tuber on the efferent activity of the gastric vagus nerve in the rat.

Effect of intraduodenal infusion with the hot aqueous extract of Pinellia ternata tuber on the efferent discharges in the gastric branch of the vagus nerve was observed in the anesthetized rat. The infusion of the extract in doses of 2-15O mg per animal (c.a. 300 g, b.wt.) resulted in a dose-related increase in efferent activity of the vagal gastric nerve. The enhancement of the nerve activity following administration of 150 mg of this substance lasted longer than 90 min. It was observed that the suppressive effect on vagal gastric activity due to apomorphine and copper sulfate was antagonized by prior administration of the extract. From these observations it is suggested that Pinellia tuber acts as a facilitatory agent on gastric function.

Animals↗
PubMed1993

The role of the diurnal variation of urinary pH in determining stone compositions.

The diurnal variation of urinary pH and urinary excretion of stone-forming constituents were investigated on 79 stone patients. Composition of the stones was analyzed by means of infrared spectrophotometry. In uric acid stone patients urinary pH was low during the 24-hour period. In mixed calcium oxalate-calcium phosphate stone patients urinary pH was low in the early morning but high in the daytime and at night. In magnesium ammonium phosphate stone patients urinary pH was high throughout the entire day. On the other hand, urinary excretion of calcium was high in the mixed calcium oxalate-calcium phosphate stone patients and low in uric acid or magnesium ammonium phosphate stone patients. These findings suggested that the diurnal variation of urinary pH and urinary excretion of calcium might have an important role in determining stone composition.

Adult↗
PubMed1993

Pyridoxine toxicity to cultured fibroblasts caused by near-ultraviolet light.

Pyridoxine, like riboflavin, has absorption in the range of near ultraviolet (UVA; 320-400 nm) radiation and is known to decompose after long irradiation with germicidal lamps. Thus, the possibility of UVA-induced pyridoxine photosensitization was studied in cultured normal human, hydroa vacciniforme, and xeroderma pigmentosum fibroblasts. Cytotoxicity caused by the sensitization was measured by post-UVA colony formation. Pyridoxine showed strong cytotoxic effect after UVA radiation and the effect remained for at least 60 min after UVA radiation. Although the cytotoxicity decreased a little when pyridoxine was irradiated under anaerobic conditions, the amount of hydrogen peroxide produced by UVA radiation was hardly cytotoxic and the rate of photodecomposition of pyridoxine was slower under anaerobic conditions than aerobic ones. Thus, the toxicity seemed to depend mostly on the photoproducts of pyridoxine. The UVA-induced pyridoxine cytotoxicity was not due to DNA damage that is to be excision-repaired because group A and C xeroderma pigmentosum fibroblasts were killed as in the case of normal human fibroblasts.

Absorption↗
PubMed1993

Neutralizing antibody to vesicular stomatitis virus (HTLV-I) pseudotype in infants born to seropositive mothers.

Breast feeding is the major route of mother-to-child transmission of human T-cell leukemia virus type I (HTLV-I). Our experiments with rabbits have shown that passive immunization is capable of blocking cell-to-cell infection of HTLV-I by blood transfusion or breast feeding. In this study, sera were collected serially from 3 infants born to seropositive mothers and were tested for the presence of neutralizing antibody to vesicular stomatitis virus (HTLV-I) pseudotype as well as antibodies to viral structural proteins. There was a good correlation between neutralizing and viral antibody titers, both of which were detectable until 3-6 months after birth. Whether maternally transmitted neutralizing antibody is protective against perinatal infection of HTLV-I remains to be studied.

Adult↗
PubMed1993

Screening for thyroid diseases in an iodine sufficient area with sensitive thyrotrophin assays, and serum thyroid autoantibody and urinary iodide determinations.

OBJECTIVE: The present study was designed to investigate the prevalence of thyroid dysfunction and its relation to thyroid autoantibodies and urine iodide concentration in apparently healthy people residing in Sapporo, a city of northern Japan, where the iodine intake is high. DESIGN AND SUBJECTS: Serum TSH and thyroid autoantibodies, and urine iodide were measured in 4110 people (2931 men and 1179 women) (age 45.6 +/- 10.3 years (mean +/- SD)) who were recruited at the hospital for medical examinations. RESULTS: The thyroid autoantibodies were positive in 6.4% of males and 13.8% of females with an age-related increase. Of the people with positive antibodies, 87.2% had normal TSH values (0.15-5.0 mU/l) as measured by a sensitive assay. The prevalence of unsuspected hyperthyroidism as defined by suppressed TSH values was 0.61%, of which 64% was diagnosed as Graves' disease based on positive thyrotrophin receptor antibody results. The prevalence of unsuspected hypothyroidism, as evidenced by supranormal TSH, was 0.68% for males and 3.13% for females with an age-related increase. Of those with hypothyroidism, 45.5% were autoantibody positive. The overall prevalence of Hashimoto's thyroiditis was 13.11% for females and 6.15% for males. The urine iodide levels of hypothyroidism with a positive autoantibody of 38.5 (17.7-83.9) mumol/l and a negative autoantibody of 34.9 (17.9-67.9) mumol/l were both significantly higher than that of normal subjects (26.9 (14.6-49.6) mumol/l) (P < 0.01). When iodine intake was restricted for 6-8 weeks for hypothyroid subjects, the elevated TSH and thyroglobulin and low free T4 levels were reversed in the autoantibody negative but not in the positive group. CONCLUSIONS: This study provides further information on the prevalence of thyroid dysfunction and autoimmune thyroid diseases in an iodine sufficient area. In addition, it suggests that more than half of the patients with unsuspected hypothyroidism were negative for autoantibodies and that the excessive iodine intake may be involved in causing latent hypothyroidism.

Adult↗
PubMed1993

Analysis of ploidy and sexual characteristics of natural isolates of Cryptococcus neoformans.

We report here an extensive examination of the ploidy of a basidiomycetous yeast. The ploidy of 34 strains of Cryptococcus neoformans var. neoformans, isolated mostly from Japanese patients, was determined by means of quantitative fluorescence microscopy after DNA staining with propidium iodide. The sexual characteristics of the strains including the two tester strains were as follows. Twenty-four strains were of the heterothallic alpha type, 1 was of the heterothallic a type, and 2 were self fertile; the remaining 7 showed no sexual response. The following strains were found to be haploid: the heterothallic a strain, 20 of the 24 heterothallic alpha strains, and 3 of the 7 asexual strains. Thus, the C. neoformans strains were mostly haploid, as the sexual response of this organism suggests. Both of the self-fertile strains and four of the seven asexual strains were diploid. Unexpectedly, 4 of the 24 heterothallic alpha strains were diploid.

Cryptococcus neoformans↗
PubMed1993

Survival rate after vitreous surgery in patients with diabetic retinopathy.

We studied factors affecting the survival rate after vitreous surgery in 73 patients with diabetic retinopathy, who had undergone vitreous surgery between 1982 and 1987, according to the life-table theory and multivariate analysis. The 5-year survival rate was 84.8%; the mean age at death was 62.1 +/- 7.1 (mean +/- SD) years; the mean postoperative survival time was 34.0 +/- 25.2 months; the most common cause of death having been cardiovascular disease, which occurred in 5 of the 13 (38.5%) patients who had died. Patients with triopathy essentially require very careful systemic management, because this state was definitively associated with a decline in postoperative survival.

Aged↗
PubMed1993

Development of active center-directed plasmin and plasma kallikrein inhibitors and studies on the structure-inhibitory activity relationship.

The molecule of trans-4-aminomethylcyclohexanecarbonylphenylalanine 4-carboxymethylanilide (8), which is a potent and selective inhibitor of plasma kallikrein, can be divided into three parts (P1, P1' and P2'), each of which contains one of the rings. In order to study the role of each part in the manifestation of potent and selective inhibitory activity and the relationship between the structure and inhibitory activities toward plasmin, plasma kallikrein, urokinase and thrombin, each part was substituted with various other moieties to give many kinds of analogs and their inhibitory activities against the above enzymes were examined. Among them, trans-4-aminomethylcyclohexanecarbonyl-O-2-bromobenzyloxycarbon yltyrosine 4-acetylanilide (12) inhibited plasmin and plasma kallikrein with IC50 values of 2.3 x 10(-7) M and 3.7 x 10(-7) M, and K(i) values of 1.2 x 10(-7) M and 1.3 x 10(-7) M, respectively.

Amino Acid Sequence↗
PubMed1993

Amino acids and peptides. XXXVI. Synthesis of enkephalin chloromethyl ketone and evaluation of its inhibitory activity against endopeptidase 22.19.

Boc-Tyr-Gly-Gly-Phe-Leu-Ch2Cl was synthesized by the conventional solution method. During the course of acid hydrolysis (6N HCl, 110 degrees C, 18h) of Boc-Phe-Leu-CH2Cl, side reaction occurred, resulting in low recovery of Phe residue on amino acid analysis. The inhibitory activity of the synthesized Boc-Tyr-Gly-Gly-Phe-Leu-CH2Cl against endopeptidase 22.19, an enzyme related to the metabolism of opioid peptides, was examined.

Amino Acid Chloromethyl Ketones↗
PubMed1993

Bloom's syndrome complicated by myelodysplastic syndrome and multiple neoplasia.

The patient, a Japanese male born to a highly consanguineous family, was diagnosed as Bloom's syndrome at the age of 33 when he presented with diabetes mellitus and refractory anemia with excess blasts. Chromosome abnormalities of bone marrow cells included 5q-, -7/7q-, and unusual translocations. During the ensuing years, he developed squamous cell carcinoma of the external auditory meatus, adenocarcinoma of the colon, and squamous cell carcinoma of the tonsil. The patient died of pneumonia at the age of 38. Autopsy revealed intestinal polyposis and hemochromatosis secondary to massive blood transfusions.

Adult↗
PubMed1993

[Eosinophilic cystitis].

Nine cases were diagnosed to be eosinophilic cystitis on the basis of histological criteria and clinical observations were made on these cases. In all cases, a past history of allergic or collagen diseases were revealed. Eosinophils in urine were present in 8 out of 9 cases and allergic tests were then performed. Histamine release from biopsied bladder tissue, incubated with anti-IgE, were first examined and a higher level than control was found. Next, intravesical provocation test (IgE RAST positive allergen was introduced into vesical cavity) revealed the appearance of bladder irritabilities within 30 minutes and release of urinary histamine within 3 hours. In 3 cases, provocation tests by eating food were performed and 2 out of 3 cases showed a positive reaction. These results show that allergy may be related to the development of eosinophilic cystitis in part.

Adolescent↗