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Biomedical subjects

K Tabata

Publications and source records attributed to K Tabata.

At least 73 records · Page 4Linked to original sources
PubMed1994

An antitumor, branched (1-->3)-beta-D-glucan from a water extract of fruiting bodies of Cryptoporus volvatus.

A water-soluble, (1-->6)-branched (1-->3)-beta-D-glucan (H-3-B) was isolated from a hot-water extract of the fruiting bodies of the fungus, Cryptoporus volvatus (Basidiomycetes). Enzymatic analysis using exo-(1-->3)-beta-D-glucanase and methylation analysis indicated that this polysaccharide has a main chain composed of beta-(1-->3)-linked D-glucopyranosyl residues, and single, beta-(1-->6)-linked D-glucopyranosyl residues attached as side chains to, on average, every fourth sugar residue of the main chain. This structure was confirmed by 13C NMR spectra of the glucan in Me2SO-d6. The weight-average molecular weight (Mw) of H-3-B was determined to be 44.0 x 10(4) by gel permeation chromatography equipped with a low-angle laser-light-scattering photometer. The electron microscopic observations showed that H-3-B and its sonicated sample (S-H-3-B, Mw = 13.7 x 10(4)) can be described as linear worm-like chains. The mass per unit length for native and sonicated H-3-B was determined to be 1750 and 1780 g mol-1 nm-1, respectively, from the contour lengths obtained by electron microscopy and the molecular weights. These values are in good agreement with that expected for the triple stranded structure. A sample denatured in 0.1 M NaOH and subsequently renatured by neutralization showed a mixture of linear and cyclic structures, and larger aggregates with less well-defined morphology. The H-3-B and S-H-3-B had antitumor activity against the Sarcoma 180 tumor.

Animals↗
PubMed1994

A carotenogenic gene cluster exists on a large plasmid in Thermus thermophilus.

In Thermus thermophilus HB27, the crtB gene encoding phytoene synthase was found to exist on the large plasmid, pTT27. One of the carotenoid under-producing mutants, Crt31, carried a derivative of pTT27 (pTT27') in which deletion and inversion were observed near the crtB gene. T. thermophilus HB8 also contained a large plasmid which showed homology to pTT27 and the crtB gene. These results suggested that genes for carotenoid biosynthesis occurred as a cluster on a large plasmid in Thermus thermophilus. This is the first report to show directly that carotenogenesis is plasmid-encoded in microorganisms.

Alkyl and Aryl Transferases↗
PubMed1994

Molecular cloning and sequence analysis of the proC gene encoding delta 1-pyrroline-5-carboxylate reductase from an extremely thermophilic eubacterium Thermus thermophilus.

A gene library of the extremely thermophilic bacterium, Thermus thermophilus HB27, was constructed in Escherichia coli, and recombinant plasmids able to complement proC mutants of HB27 were obtained. Using the plasmids, the complete nucleotide sequence of the proC gene encoding delta 1-pyrroline-5-carboxylate reductase (P5CR) [EC 1.5.1.2] was determined. The deduced amino acid sequence showed a significant homology to those of P5CRs of E. coli, soybean and human. The proC gene of T. thermophilus was expressed in E. coli and the activity of heat-resistant P5CR was determined. The mutation sites of two HB27 proC mutants were also determined.

Amino Acid Sequence↗
PubMed1994

An improved sandwich ELISA method for the determination of immunoreactive schizophyllan (SPG).

As it is important to determine the optimal serum concentration of schizophyllan (SPG) when it is used as an anti-cancer drug, we devised a solid-phase ELISA. We also developed a sandwich ELISA using murine anti-SPG monoclonal antibody as the first antibody and rabbit anti-SPG serum as the second antibody in order to improve the detection sensitivity. This assay was able to determine SPG concentrations over 1.0 ng/ml and the absorbance at 490 nm was directly proportional to the SPG concentration. SPG in rabbit serum, obtained after intravenous and intramuscular injection (SPG; 10 mg/kg), was determined by this sandwich ELISA. Furthermore, the sensitivity of this ELISA method was compared with that of the Limulus test. The Limulus test is able to detect SPG in physiological saline (pH 6.3) at concentrations greater than 1.0 microgram/ml, but the sensitivity increased when SPG was dissolved in alkaline solution (pH 12.0), enabling SPG to be measured almost down to 1.0 ng/ml. These data suggest that our sandwich ELISA may be used for the measurement of SPG in blood or tissue.

Animals↗
PubMed1994

Monoclonal antibody to proteoglycan derived from Grifola frondosa (Maitake).

A murine monoclonal antibody (MAb) was prepared by immunizing BALB/c mice with a proteoglycan fraction derived from Grifola frondosa (Maitake mushroom), followed by the hybridization of spleen cells with mouse myeloma cells. The MAb (subclass; Ig G2b), designated MPG2, reacted with schizophyllan (SPG), curdlan, scleroglucan, laminarin and lentinan, but not with dextran, pullulan, mannan and xylan. Immunohistochemistry (ABC-GO method) showed that MAb MPG2 reacted with lysosomal proteoglycan and (1-->6)-beta-branched laminaritriose taken up by rabbit peritoneal macrophages. These results suggest that this MAb may recognize mainly (1-->3)-beta-D-glucan, and may be useful for determining the immunological properties of Grifola frondosa-derived proteoglycan.

Animals↗
PubMed1994

The inhibitory effect of sulfated schizophyllans and related oligosaccharides on coagulation and fibrinolysis.

Sulfated schizophyllans and sulfated oligosaccharides were prepared and their inhibitory effects on coagulation and fibrinolysis were examined. Some sulfated schizophyllans, which had a sulfur content of more than 10%, prolonged prothrombin time (PT) and thrombin time (TT). Interestingly, some sulfated schizophyllans and related oligosaccharides were able to inhibit plasmin toward fibrinolysis and amidolysis.

Amino Acid Sequence↗
PubMed1994

Construction of a new teichuronopeptide-defective derivative from alkaliphilic Bacillus sp. C-125 by cell fusion.

Cell walls of facultative alkaliphilic Bacillus sp. C-125 are composed of peptidoglycan, teichuronic acid, and teichuronopeptide. A mutant lacking teichuronic acid, or defective in both teichuronic acid and teichuronopeptide has been isolated from the organism. We now constructed another type of a cell-wall defective mutant that was defective in teichuronopeptide but had teichuronic acid, by cell fusion using protoplasts prepared from a wild-type strain and a mutant defective in teichuronopeptide and teichuronic acid. This mutant grew more poorly than wild type or a teichuronic acid-defective strain of C-125. The growth, however, was faster than that of the parental strain defective in both teichuronic acid and teichuronopeptide.

Bacillus↗
PubMed1994

[A case of "forme fruste" of tuberous sclerosis having been treated as genuine epilepsy].

A 30-year-old man had signs of a lumbosacral skin plaque, called "shagreen patch", and mental retardation. He had been treated as genuine epilepsy for more than twenty years. Neither significant abnormalities nor facial angiofibroma (adenoma sebaceum) were detected on physical and neurological examinations. Brain CT revealed calcified subependymal nodules. A T2-weighted brain MRI presented high signal intensity regions affecting the cerebral cortex, which suggested tuberous lesions. Echocardiography showed high echoic lesions on the left ventricular wall and papillary muscles, suggesting calcification. The case was diagnosed as suffering from "forme fruste" of tuberous sclerosis. The three criteria typical of tuberous sclerosis (facial angiofibroma, seizure and mental retardation) were not satisfied. The "forme fruste" variant is less known, because the pattern of involvement varies, and it may clinically simulate genuine epilepsy.

Adult↗
PubMed1993

Physical map of the extremely thermophilic bacterium Thermus thermophilus HB27 chromosome.

The physical map of the chromosome of Thermus thermophilus HB27 was constructed using three restriction enzymes; EcoRI, SspI and MunI by applying pulsed-field gel electrophoresis techniques. Although the genome size of 1.82 Mb was almost the same as that (1.74 Mb) reported for T. thermophilus HB8 [Borges, K.M., and P.L. Bergquist. (1993) J. Bacteriol. 175, 103-110], the MunI cleavage maps were different. A 240 kb plasmid was detected in HB27, and its physical map was also constructed. In addition, several genes were located on the chromosomal physical map.

Chromosome Mapping↗
PubMed1993

Augmentation of protective immune responses against Sendai virus infection by fungal polysaccharide schizophyllan.

When treated with fungal polysaccharide schizophyllan, mice survived otherwise lethal Sendai virus infection. Both intraperitoneal and oral administrations were effective when sonicated schizophyllan with a relative molecular mass (M(r)) of 4.6 x 10(5) was used. Antiviral antibody in the serum could be detected at an earlier time after virus infection and virus spread in the lung was more efficiently inhibited in schizophyllan-treated mice than in untreated controls. Schizophyllan also augmented protective immune responses induced by low doses of a live Sendai virus vaccine that were insufficient to confer complete protection against challenge infection with a virulent strain. On the other hand, schizophyllan did not influence interferon production in mice whether or not infected with Sendai virus. The present results suggest that schizophyllan confers better protection against virus infection through augmentation of antiviral immune responses and can be used as an immune enhancer.

Adjuvants, Immunologic↗
PubMed1993

Detection of immunoreactive schizophyllan by solid-phase enzyme-linked immunosorbent assay.

In order to detect immunoreactive schizophyllan (SPG), one of the beta-1,3-glucans in solution, a murine anti-schizophyllan monoclonal antibody, SPG1-HS, was used as a primary antibody for solid-phase enzyme-linked immunosorbent assay (ELISA). Polysaccharide-bovine serum albumin (BSA), and polysaccharide-bovine hemoglobin (Hb) conjugate were prepared as an antigen. The absorbance at 490 nm in ELISA was directly proportional to the SPG concentration in SPG-BSA or SPG-Hb conjugates, allowing the accurate measurement of SPG at concentrations of more than 1.0 microgram/ml. Also, this ELISA detected SPG in SPG-BSA and SPG-Hb conjugates in human serum in a similar manner. These results suggest that this ELISA is applicable for the determination of SPG concentration in SPG-BSA and SPG-Hb conjugates in human tissue and blood.

Animals↗
PubMed1993

Aquastatin A, an inhibitor of mammalian adenosine triphosphatases from Fusarium aquaeductuum. Taxonomy, fermentation, isolation, structure determination and biological properties.

A new inhibitor of mammalian adenosine triphosphatases, designated aquastatin A, has been isolated from a fungus identified as Fusarium aquaeductuum. The structure of this compound has been determined by MS and NMR analyses. It inhibits Na+/K(+)-ATPase with an IC50 value of 7.1 microM, and H+/K(+)-ATPase with an apparent IC50 value of 6.2 microM.

Adenosine Triphosphatases↗
PubMed1992

[A case of chronic multifocal myositis].

A 61-year-old civil engineer began to have slowly progressive muscle atrophy in the right shoulder and the left arm at 56 years of age. Muscle wasting became manifest in the left thigh at 59 years and in the right thigh at 60 years. He had mild difficulty in climbing and descending stairs. On examination, although he had notable muscle atrophy in the right trapezius and proximal muscles in the upper and lower extremities, his muscle strength was relatively well preserved. The muscle atrophy was asymmetrical; the right periscapular region and the left upper and lower extremities were more markedly atrophic. In addition, multiple foci of the striking muscle atrophy were noted in the upper trunk and the proximal limb muscles. Fasciculation was not present. Deep tendon reflexes were normal with no pathologic reflexes. Except for a moderately elevated serum creatine kinase level of 709 Ul/l (normal 40-170) and mildly elevated serum myoglobin level of 100 ng/ml (normal < 60), no laboratory tests showed abnormal values suggesting an inflammatory process. Motor and sensory nerve conduction velocities were within normal limits. Electromyography disclosed myopathic and neuropathic changes. Computed tomography (CT) of skeletal muscles showed asymmetrical muscle atrophy and patchy low-density foci. In biopsied left quadriceps and right gastrocnemius muscles which showed partially low density on CT, there was marked variation in muscle fiber size, with necrotic and regenerating fibers, an increased number of centrally placed nuclei, and interstitial fibrosis. There were numerous foci of mononuclear inflammatory cellular infiltration, especially around the blood vessels.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic Disease↗
PubMed1991

[A case of acute water intoxication showing triphasic waves on EEG].

We reported a case of acute water intoxication from compulsive water-drinking, who showed triphasic waves on EEG. The patient was a 50-year-old man who had been undergoing medical treatment in a mental hospital since he was suffering from schizophrenia diagnosed at the age of 35. He had sometimes had a tendency to drink a large amount of water since 45 years old. He began to drink water compulsively since three days ago. He vomited just after he drank excessive water with his mouth directly to the tap for several minutes, and soon fell into loss of consciousness. He was transmitted to our hospital because of acute consciousness disturbance on the next day. On neurological examination, he was profoundly comatose with miosis and conjugate deviation to the right side. His extremities showed decorticate posturing. On admission, serum sodium level was 101 mEq/l, and plasma osmolality was 208 mOsm/l. Serum enzymes derived from muscle and myoglobin were markedly elevated. But there was no laboratory evidence of the other metabolic disorders such as hepatic or renal disease. Computed tomography of the brain disclosed severely diffuse swelling with largely obliterated sulci and narrowed ventricles. EEG showed triphasic waves predominantly over centro-parieto-occipital portion, behind which there was slow wave activity with a loss of normal alpha wave activity. Immediately, treatment began by a combination of saline and glyceol infusion for the purpose of correcting severe hyponatremia, subsequently removing brain edema. As serum sodium level gradually returned to normal, the brain CT findings were getting better.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1990

Immunopharmacological study of sulfated schizophyllan (SPG). I.--Its action as a mitogen and anti-HIV agent.

Sulfated schizophyllans of differing sulfur content were prepared and their mitogenic activities and effects on human immunodeficiency virus (HIV) were investigated in vitro. The sulfated schizophyllans were found to possess mitogenic activity. Anti-viral activity was evaluated in terms of cytopathic effect, and by the fluorescence antibody technique, reverse transcriptase assay and cell proliferation assay. Schizophyllans with a higher sulfur content showed potent anti-HIV effects on Molt-4 clone No. 8 or MT-4 cells infected with HIV as well as on lymphocytes from AIDS patients. It is suggested that the sulfur content of schizophyllans is the most important factor for inhibiting growth of HIV, rather than molecular weight or kinds of sugar component. Thus, sulfated schizophyllans appear applicable as anti-HIV drugs.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Preparation of polyclonal antibodies to an anti-tumor (1----3)-beta-D-glucan, schizophyllan.

Antibodies against Schizophyllan (SPG) or SPG conjugated with bovine serum albumin (BSA) were raised in rabbits by multiple subcutaneous immunization. The titer of SPG-reactive antibodies in the antiserum to SPG-BSA conjugate was significantly higher than in the antiserum to SPG as assessed by enzyme-linked immunosorbent assay (ELISA). The SPG-reactive antibodies purified by affinity chromatography using a Protein A-Sepharose CL-4B column interacted with the SPG-BSA conjugate spotted on a nitrocellulose membrane filter in a dose-dependent manner, but the anti-SPG antibodies did not interact with BSA. Immunocytochemical staining has also shown that the anti-SPG antibodies reacted with SPG taken up by mouse peritoneal macrophages.

Animals↗
PubMed1990

[Basic studies on abdominal injuries. Part 1: Degree of depression of abdominal wall by compression].

The degree of depression of the abdominal surface by compression was measured in 121 healthy adult male having an average age of 20.4 years. Three disks of different sizes (10, 25, and 45 mm in diameter) were attached to the edge of the baresthesiometer, and pressures of 1, 3 and 5 kg were applied to the 10 mm disk, and 1, 3, 5, and 7 kg to the other disks. The regions tested were the medial abdomen approximately 2 cm above the umbilicus and the left and right flanks at the level of umbilicus. The higher the pressure administered, the greater the depression formed on each disk. Severe pain occurred in the nonanesthetized person, and it was difficult to increase the pressure to a higher level than 7 kg. At each pressure, the smallest disk produced larger depression than did the other two. The degree of depression was related to the total pressure administered rather than to the amount of pressure per unit area. The distribution of measured value was shown to be normal. After the largest depression for each region had been determined, a pressure of 7 kg was imposed on the 25-mm disk. On the medial abdomen, the anatomical position generated a mean depression of 6.3 cm, and the spine position a depression of 5.04 cm. On the flank, mean value of the depression was approximately 5.7 cm, and did not differ between the anatomical and supine positions and between the right and left flanks.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Injuries↗