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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

[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↗
PubMed1992

IgD myeloma presenting as a testicular tumor: establishment and characterization of an IgD-secreting myeloma cell line.

A 72-year-old man presented with a left testicular tumor and underwent orchiectomy. The tumor was massively infiltrated with myeloma cells bearing monoclonal cytoplasmic IgD lambda. Three months after orchiectomy, he developed huge abdominal masses and subsequently ascites containing numerous myeloma cells. An IgD-secreting myeloma cell line, designated delta-47, was established from the ascites. This cell line expressed CD4 and CD38, but lacked Fc and complement receptors, surface immunoglobulin, CD19, HLA-DR, and PCA-1. CD30 was detected on the cultured cells but not on the ascites tumor cells. Delta-47 cells secreted the same immunoglobulin (IgD lambda) as was found in the patient's serum. The light chain had a molecular weight of 35 kD which was larger than that of the normal light chain. Chromosome analysis of delta-47 revealed an aneuploid karyotype with complex abnormalities including 1q+, 2p+, and 14q+. To our knowledge, this is the only IgD-secreting myeloma cell line and would provide a useful tool for the study of IgD production and IgD myeloma.

ADP-ribosyl Cyclase↗
PubMed1992

Survival rates of some terrestrial microorganisms under simulated space conditions.

In connection with planetary quarantine, we have been studying the survival rates of nine species of terrestrial microorganisms (viruses, bacteria, yeasts, fungi, etc.) under simulated interstellar conditions. If common terrestrial microorganisms cannot survive in space even for short periods, we can greatly reduce expenditure for sterilizing space probes. The interstellar environment in the solar system has been simulated by low temperature, high vacuum (77 k, 4 x 10(-6) torr), and protons irradiation from a Van de Graaff generator. After exposure to a barrage of protons corresponding to about 250 years of irradiation in solar space, Tobacco mosaic virus, Bacillus subtilis spores, Aspergillus niger spores and Clostridiun mangenoti spores showed survival rates of 82%, 45%, 28%, and 25%, respectively. Furthermore. pathogenic Candida albicans showed 7% survival after irradiation corresponding to about 60 years in space.

Bacteria↗
PubMed1992

Effects of verapamil on histamine-induced changes in lung mechanics.

The effects of verapamil on airway resistance and total thoracic compliance were studied in 15 rabbits with histamine-induced changes in lung mechanics. The animals, after being tracheotomized under anaesthesia, were subjected to mechanical ventilation in a time-cycled, volume-limited mode. Airway pressure and gas flow signals measured by a pneumotachograph and integrated for volume, were registered on a recorder. Each animal was given histamine hydrochloride in an isotonic solution of sodium chloride at a rate of 0.05 micrograms.kg-1.min-1 through a peripheral venous line. Verapamil was infused intravenously in an isotonic solution of sodium chloride at a rate of 20 micrograms.kg-1.min-1 after the initiation of histamine. Verapamil reduced the histamine-induced increase in airway resistance by 20% at 20 min after the start of administration.

Airway Resistance↗
PubMed1992

Epitope homology between bacterial heat shock protein and self-proteins in the host cell.

Mouse monoclonal antibodies (MAbs) showing distinct reactivity against the 60-kilodalton (kDa) antigen heat shock protein of Yersinia enterocolitica, designated cross-reacting protein antigen (CRPA), have previously been established. The reactivities of these MAbs (5C3 and 3C8) against mouse and human host cells were studied by Western blotting and flow cytometric analysis. The results indicated that epitopes on the bacterial 60-kDa heat shock protein are present on various molecules in mouse spleen cells and human B cells. An epitope recognized by MAb 5C3 was expressed on the mouse and human host cell surface, and an epitope recognized by MAb 3C8 was also expressed on the human host cell surface.

Animals↗
PubMed1992

[Studies on the effect of combination of amphotericin B and flucytosine on Candida albicans by flow cytometry].

The antifungal effects of amphotericin B (AMPH) and flucytosine (5-FC) on three strains of Candida albicans were studied by flow cytometry (FCM). When the IFM4954 and IFM4949 were treated with AMPH or 5-FC alone, cytograms of cell distribution changed at the concentration of 1/2 MIC, respectively. Next, the effect of combination of AMPH and 5-FC were examined. Cytogram of cell distribution of IFM4954 and IFM4949 changed under the combination of 1/4 MIC of AMPH and 1/4 MIC of 5-FC, namely a synergic effect was observed. In conclusion, FCM is a useful apparatus for analysis of the effect of antifungal agents.

Amphotericin B↗
PubMed1992

Blood pressure response to hyperinsulinemia in salt-sensitive and salt-resistant rats.

We investigated the role of insulin in salt-sensitive hypertension in Dahl salt-sensitive and salt-resistant rats. The rats were kept in metabolic cages, and sodium intake and urinary sodium excretion were measured. In salt-sensitive rats receiving a 0.3% NaCl diet, sodium retention was significantly greater at weeks 1 and 2 in rats that received an insulin infusion than in those receiving a saline infusion. Mean arterial blood pressure and plasma norepinephrine levels were significantly higher at week 3 in insulin-treated rats than in saline-treated rats (mean arterial pressure, 137 +/- 3 mm Hg versus 119 +/- 3 mm Hg, p < 0.05; plasma norepinephrine, 0.40 +/- 0.02 ng/ml versus 0.27 +/- 0.01 ng/ml, p < 0.05). Insulin did not influence sodium retention, mean arterial pressure, or plasma norepinephrine in salt-resistant rats. Coadministration of an alpha-blocker (bunazosin, 10 mg/kg per day for 3 weeks) in salt-sensitive rats abolished the insulin-induced elevations in mean arterial pressure and sodium retention. When salt-sensitive rats were fed a low salt diet (0.03% NaCl), insulin did not raise mean arterial pressure. Thus, insulin elevated blood pressure only in the salt-sensitive model. The sympathetic nervous system and sodium retention in the early phase of insulin overload may contribute to elevation of mean arterial pressure in this model.

Animals↗
PubMed1992

Purification and characterization of a thermostable carboxypeptidase (carboxypeptidase Taq) from Thermus aquaticus YT-1.

A thermostable carboxypeptidase, which we named carboxypeptidase Taq, was purified from Thermus aquaticus YT-1 and characterized. The molecular weight of the enzyme was estimated to be about 56,000 and 58,000 on SDS-polyacrylamide gel electrophoresis and gel filtration, respectively, indicating that the enzyme has a monomeric structure. The optimum pH of the enzyme was 8.0, and the optimum temperature for the reaction was 80 degrees C. The enzyme activity was dependent on cobalt ion and was inhibited by metal-chelating reagents, indicating that the enzyme is a metalloenzyme. The enzyme had high thermostability independent of cobalt ion; about 90% of its activity remained even after treatment at 80 degrees C for 5 h. The enzyme showed broad substrate specificity, although proline at the C-terminus of peptides was not cleaved. The enzyme released amino acids sequentially from the C-terminus.

Amino Acid Sequence↗
PubMed1992

Immunohistochemical detection of Pneumocystis carinii in transbronchial lung biopsy specimens: antigen difference between human and rat Pneumocystis carinii.

Transbronchial lung biopsy specimens, from three patients with non-AIDS-related Pneumocystis carinii pneumonia (PCP) and rat lung tissue in which PCP was induced by the administration of dexamethasone, were studied to determine the diagnostic usefulness of an immunohistochemical method using commercially available anti-Pneumocystis monoclonal antibody, 3F6, on formalin-fixed, paraffin-embedded tissue. PC was consistently stained a bright red color and unambiguously identified in all three human lung specimens, but not stained in lung tissues at autopsy from patients with various fungal pneumonias. In contrast, PC was weakly stained in PCP-induced rat lungs. The present study indicates human PC and rat PC to be antigenically different in terms of the existence of the 82 kilo-dalton (kD) antigen against which 3F6 is directed.

Adult↗