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Biomedical subjects

H Taguchi

Publications and source records attributed to H Taguchi.

At least 307 records · Page 17Linked to original sources
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↗
PubMed1993

[Effects of morphine, buprenorphine and butorphanol on airway dynamics of the rabbit].

An investigation was made on the effects of morphine, buprenorphine, and butorphanol on airway dynamics with special reference to the airway smooth muscle in rabbits. After tracheostomy under anesthesia, the animals were ventilated with a Servo 900B ventilator, and airway resistance (R) and total compliance (C) were measured according to the method of Norlander, and the effect of each drug was examined. Intravenous injection of morphine 0.2 mg.kg-1 increased R significantly at 10 and 20 minutes after its administration in nontreated animals and changed R insignificantly in animals pretreated with intravenous administration of chlorpheniramine 2.5 mg, an antihistaminic. It is considered that the increase in R after the administration of morphine in the nontreated animals is due to histamine release. Buprenorphine 0.8 micrograms.kg-1 and butorphanol 0.1 mg.kg-1 brought no significant changes in R in both nontreated and the chlorpheniramine pretreated animals. C decreased in all the groups including the control group which received mechanical ventilation alone without any drug administration.

Airway Resistance↗
PubMed1993

Space microbiology--lethality, mutagenicity and cytological effects of terrestrial microorganisms by irradiation of cosmic proton under simulated space condition.

We have been discussing in connection with a space quarantine. The subject is not merely an academic problem, but it contains a fundamental problem which avoid the contamination of other planets by terrestrial microflora. The space environments in the solar system were simulated by using an apparatus of cryostat (low temperature of 110-310K, high vacuum of 1 x 10(-8) torr) and proton irradiation from the Van de Graaff generator. After exposure to a barrage of protons corresponding to about 250 years in solar space, Tobacco mosaic virus, Bacillus subtilis spore, Staphylococcus aureus. Micrococcusflavus, Clostridium mangenoti spore and Aspergillus niger spore showed considerably high survival rates. Furthermore, it was found firstly that an irradiation of proton induced considerable mutation frequency compared to that of spontaneous and caused also the cytological effects based on a damage of chromosome.

Bacteria↗
PubMed1993

[Bronchial asthma--airway inflammation and asthma--role of airway epithelium].

The importance of airway inflammation in the pathophysiology of bronchial asthma has been recognized recently. This inflammation is organized by the interaction between inflammatory cells and the cells which compose airway structures. We studied the role of airway epithelium in airway hyperresponsiveness and airway inflammation, which are the major characteristics of bronchial asthma, and demonstrated a close relationship between them. On the bases of these data and the data reported by many other researchers, and from the point of view of airway inflammation, we discussed the possible roles of airway epithelium in bronchial asthma.

Animals↗
PubMed1993

Bilateral uveitis in a rabbit experimentally infected with human T-lymphotropic virus type I.

BACKGROUND: Among the various diseases associated with human T-lymphotropic virus type I (HTLV-I) infection, HTLV-I-associated uveitis has been proposed as a distinct clinical entity. EXPERIMENTAL DESIGN: Four rabbits experimentally infected with HTLV-I by blood transfusion from an HTLV-I-infected rabbit were observed for development of disease more than 3.5 years. Ophthalmologic, pathologic, hematologic, and virologic studies were performed on a rabbit that developed signs of uveitis. RESULTS: One of four rabbits developed bilateral uveitis 3.5 years after infection with HTLV-I. Ophthalmologic examination revealed opacities of the anterior chamber, lens, and vitreous body, as well as ciliary injection. Histologic examination demonstrated marked thickening of Descemet's membrane with degeneration of the corneal endothelial cells and mononuclear cell infiltration in the iris and choroid. The normal structure of the retina was almost completely replaced by gliosis. Gene amplification of cells from the left anterior chamber by polymerase chain reaction using pX primers disclosed the presence of HTLV-I sequences and an HTLV-I producing cell line (UV-1) was established from cells of the right anterior chamber. CONCLUSIONS: This is the first indication that rabbits may serve as an animal model of HTLV-I-related uveitis.

Animals↗
PubMed1992

Unusual amino acid substitution in the anion-binding site of Lactobacillus plantarum non-allosteric L-lactate dehydrogenase.

In Lactobacillus plantarum non-allosteric L-lactate dehydrogenase (L-LDH), the highly conserved His188 residue, which is involved in the binding of an allosteric effector, fructose 1,6-bisphosphate [Fru(1,6)P2], in allosteric L-LDH is uniquely substituted by an Asp. The mutant L. plantarum L-LDH, in which Asp188 is replaced by a His, showed essentially the same Fru(1,6)P2-independent catalytic activity as the wild-type enzyme, except that the Km and Vmax values were slightly decreased. However, the addition of Fru(1,6)P2 induced significant thermostabilization of the mutant enzyme, as in the case of many allosteric L-LDHs, while Fru(1,6)P2 showed no significant effect on the stability of the wild-type enzyme, indicating that only the single-point mutation, G-->C, sufficiently induces the Fru(1,6)P2-binding ability of L. plantarum L-LDH. The mutant enzyme showed higher thermostability than the wild-type enzyme in the presence of Fru(1,6)P2. In the absence of Fru(1,6)P2, on the other hand, the mutant enzyme was more labile below 65 degrees C but more stable above 70 degrees C.

Allosteric Regulation↗
PubMed1992

Structure of holo-chaperonin studied with electron microscopy. Oligomeric cpn10 on top of two layers of cpn60 rings with two stripes each.

A structural model of holo-chaperonin, known as a protein-folding control protein comprising 60 kDa (cpn60) and 10 kDa polypeptides (cpn10), is proposed based on the electron microscopic images of holo-chaperonin from Thermus thermophilus and cpn60 from Paracoccus denitrificans. Isolated Paracoccus cpn60 shows very similar images to those of Escherichia coli tetradecameric cpn60, a seven-membered ring in the top view and a rectangular shape with four stripes in the side view. However, a small number of half-thick rectangles with two stripes are also seen which indicates that a single cpn60-heptamer ring has two stripes parallel to the plane of the ring. Thermus holo-chaperonin shows a bullet-like shape in the side view, and antibody against cpn10 binds only to the round side of the bullet. We conclude that a single cpn60-heptamer ring with two stripes stacks into two layers, and a cpn10 oligomer binds to one side of the layers.

Amino Acid Sequence↗