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M Kataoka

Publications and source records attributed to M Kataoka.

At least 163 records · Page 9Linked to original sources
PubMed1998

Escherichia coli transformant expressing the glucose dehydrogenase gene from Bacillus megaterium as a cofactor regenerator in a chiral alcohol production system.

Escherichia coli JM109 (pGDA2) overexpressing the glucose dehydrogenase (GDH) gene from Bacillus megaterium IWG3 was examined for use as a cofactor regenerator. In the asymmetric reduction of ethyl 4-chloro-3-oxobutanoate by E. coli JM109 (pKAR) which is an aldehyde reductase-overproducing transformant, E. coli JM109 (pGDA2) can act as an NADPH regenerator with NADP+ and glucose, similarly to commercially available GDH.

Alcohols↗
PubMed1998

Purification and characterization of NADPH-dependent carbonyl reductase, involved in stereoselective reduction of ethyl 4-chloro-3-oxobutanoate, from Candida magnoliae.

A NADPH-dependent carbonyl reductase was purified to homogeneity from Candida magnoliae AKU4643 through four steps, including Blue Sepharose affinity chromatography. The enzyme catalyzed the stereoselective reduction of ethyl 4-chloro-3-oxobutanoate to the corresponding (S)-alcohol with a 100% enantiomeric excess, which is a useful chiral building block for the chemical synthesis of pharmaceuticals. The relative molecular mass of the enzyme was estimated to be 76,000 on high performance gel filtration chromatography and 32,000 on SDS polyacrylamide gel electrophoresis. The enzyme reduced alpha-, beta-keto esters and conjugated diketones in addition to ethyl 4-chloro-3-oxobutanoate. The enzyme activity was inhibited by quercetin and HgCl2, but not by EDTA. The N-terminal amino acid sequence of the enzyme showed no apparent similarity with those of other oxidoreductases.

Acetoacetates↗
PubMed1998

Hepatic and splenic sarcoidosis evaluated by multiple imaging modalities.

We present a case of hepatosplenic sarcoidosis. A 51-year-old Japanese male, who was diagnosed to have sarcoidosis 4 years previously, was presented to our hospital because of dry cough and anorexia with weight loss. He had tender hepatosplenomegaly. A dynamic abdominal computed tomography (CT) revealed multiple small low-density areas in both liver and spleen, as well as in magnetic resonance imaging (MRI). The laparoscopic photographs showed many small whitish nodules surfacing on the liver and several tumorous nodules on the spleen. Multiple imaging modalities including dynamic CT and MRI are valuable for detecting focal hepatic and splenic lesions of sarcoidosis.

Biopsy↗
PubMed1998

[2-methoxyestradiol induces p53 independent apoptosis in pancratic carcinoma and inhibits growth of lung metastasis].

2-methoxyestradiol (2-ME) is able to inhibit growth of certain tumors. We were interested in studying this effect of 2-ME on pancreatic cancer. In three out of four cell lines, 2-ME induced 50-90% growth inhibition after 48 hours treatment with 2 microM 2-ME. TUNEL staining for apoptosis revealed that after treatment with 2 microM 2-ME for 48 hours 37-97% of these cells underwent apoptotic cell death (p < 0.005-0.0001). Since all cell lines used harbor a p53 mutation, this apoptosis appears to be p53 independent. One of these cell lines (MIAPaCa-2) was used for the in vivo experiment in nude mice. After a daily oral administration of 1 mg 2-ME for three weeks, the number of lung metastases could be reduced by 59%, as compared to the control non treated group (p < 0.0005). No signs of toxicity were seen. It appears that 2-ME is a potent compound for the treatment of pancreatic cancer, which might be interesting for clinical application.

2-Methoxyestradiol↗
PubMed1998

[Effects of various Ringer's solutions on acid-base balance in rats in hemorrhagic shock and with hepatic dysfunction].

We investigated the effects of bicarbonated Ringer's solution (BR) on arterial blood acid-base balance, and compared these with the effects of lactated Ringer's solution (LR) and acetated Ringer's solution (AR) in rats in hemorrhagic shock. Rats underwent 70% reduction of hepatic blood flow and blood shedding of 1.5% of body weight. Each solution was infused through the femoral vein at a rate of shed blood volume x 8.hr-1 for 30 min under urethane anaesthesia. After the blood shedding, arterial blood pH and HCO3-decreased but plasma lactate concentration increased. These parameters improved significantly in the BR group compared with those in the LR group. However, the LR group showed the lowest blood pH and the highest plasma lactate concentration among the groups. These results suggest that BR has superior effects on the arterial blood acid-base balance and glucose metabolism in rats in hemorrhagic shock and with hepatic dysfunction.

Acid-Base Equilibrium↗
PubMed1998

[Clinical usefulness of 201Tl-chloride scintigraphy for the evaluation of metastatic bone lesions].

201Tl-Chloride scintigraphy (early and delayed images) was performed in 40 patients with suspected metastatic bone lesions. The sensitivity and specificity of 201Tl scanning for detecting metastatic bone lesions were 66.7% and 77.4%, respectively. The uptake ratio of 201Tl per voxel of the lesions to the normal site was significantly different between the metastatic bone lesion and benign lesions. In 20 sites of 15 patients, 201Tl-Chloride scintigraphy was performed before and after radio- or radiothermotherapy. There was a significant difference in the mean uptake ratios in the early and delayed scans between before and after therapy. The mechanism of intracellular uptake of 201Tl is considered to be one of active transport, which might make 201Tl an accurate indicator of the viability of tumor cells and metabolic activity as long as there is sufficient blood flow to prompty transport 201Tl to tumor cells. Thus it would seem that decreased uptake of 201Tl and change in retention index after therapy depends partially on tumor blood flow. In conclusion, 201Tl-Chloride scintigraphy is very useful not only for clinically detecting metastatic bone lesions but also for assessing the therapeutic effects.

Aged↗
PubMed1998

Effects of BX661A, a new therapeutic agent for ulcerative colitis, on reactive oxygen species in comparison with salazosulfapyridine and its metabolite sulfapyridine.

5-[4-(2-Carboxyethylcarbamoyl)phenylazo]salicylic acid disodium salt dihydrate (CAS 80573-04-2, BX661A) is developed as a therapeutic agent for ulcerative colitis. To clarify its mechanism of action, the effects of BX661A and its metabolites 5-aminosalicylic acid (5-ASA) and 4-aminobenzoyl-beta-alanine (4-ABA) on reactive oxygen species: superoxide radicals (O2-) generated by hypoxanthine and xanthine oxidase, hydrogen peroxide (H2O2), hypochlorite radicals (OCl-) and hydroxyl radicals (OH.), were investigated and compared with the effects of 2-hydroxy-5-[[4-[(2-pyridinylamino)sulfonyl]phenyl]azo]-benzoic acid (CAS 599-79-1, salazosulfapyridine, SASP) and its metabolite 4-amino-N-2-pyridinyl-benzenesulfonamide (CAS 144-83-2, sulfapyridine, SP). 1. BX661A, SASP and 5-ASA inhibited O2- radical production in a concentration-dependent manner (IC50 = 0.14, 0.13 and 0.19 mmol/l, respectively). The effects of 4-ABA and SP on O2- radical production were weak (IC50 = > 10 and > 3 mmol/l, respectively). In contrast, superoxide dismutase inhibited O2- radical production in a concentration-dependent manner (IC50 = 1.7 U/ml). 2. BX661A, SASP, 4-ABA and SP had no H2O2 scavenging effects. 5-ASA scavenged H2O2, but its maximal scavenging action was 51.3%. In contrast, catalase scavenged H2O2 in a concentration-dependent manner (IC50 = 0.47 U/ml). 3. BX661A, SASP and 5-ASA scavenged OCl- radicals in a concentration-dependent manner (IC50 = 69.5, 73.8 and 21.7 mumol/l, respectively). 4-ABA and SP had no OCl- radical scavenging effects. In contrast, nordihydroguaiaretic acid (NDGA) scavenged OCl- radicals in a concentration-dependent manner (IC50 = 8.7 mumol/l). 4. BX661A and SASP scavenged OH. radicals in a concentration-dependent manner; the maximal scavenging values were 39.5 (10 mmol/l) and 48.6% (3 mmol/l), respectively. 4-ABA and SP had no OH. radical scavenging effects. In contrast, 5-ASA scavenged OH. radical in a concentration-dependent manner (IC50 = 1.46 mmol/l). These results suggest that BX661A has O2- and OCl- radical scavenging effects and that 5-ASA has O2-, OCl- and OH. radical scavenging effects. Therefore, these effects may be partially involved in the therapeutic effects of BX661A on ulcerative colitis.

Aminosalicylic Acids↗
PubMed1998

Determination of the active moiety of BX661A, a new therapeutic agent for ulcerative colitis, by studying its therapeutic effects on ulcerative colitis induced by dextran sulfate sodium in rats.

5-[4-(2-Carboxyethylcarbamoyl)phenylazo]salicylic acid disodium salt dihydrate (CAS 80573-04-2, BX661A) is being developed as a therapeutic drug for ulcerative colitis. To determine the active therapeutic moiety of BX661A, the therapeutic effects with single and combined administration of 5-aminosalicylic acid (5-ASA), 4-aminobenzoyl-beta-alanine (4-ABA) and 4-amino-N-2-pyridinyl-benzenesulfonamide (CAS 144-83-2, sulfapyridine, SP) on ulcerative colitis induced by dextran sulfate sodium (DSS) in rats were investigated, and the following results were obtained. 1. BX661A at doses of 30, 100 and 300 mg/kg (p.o.) dose-dependently decreased the erosion area (mm2) in the large intestine with % inhibition values of 28.7, 49.1 and 61.6%, and the shortening of the large intestine with % inhibition values of 17.1, 25.7 and 48.6%, respectively. Salazosulfapyridine (SASP) at doses of 30 and 100 mg/kg (p.o.) decreased the erosion area (mm2) in the large intestine with % inhibition values of 30.7 and 45.3%, respectively, but did not improve the shortening of the large intestine. However, at a dose of 300 mg/kg (p.o.) SASP, the % inhibition value of the erosion area in the large intestine was reduced. 2. A single intrarectal administration of 5-ASA (105 mg/kg, i.r.) significantly decreased the erosion area (mm2) in the large intestine, but a single administration of 4-ABA or SP did not show any significant effect on the erosion area. Combined administration with 5-ASA (105 mg/kg, i.r.) and 4-ABA (142.8 mg/kg, i.r.) significantly decreased the erosion area (mm2) in the large intestine with a % inhibition value of 63.8%. On the other hand, the efficacy of 5-ASA disappeared with combined administration with SP (% inhibition value of 7.3%). These results suggest that 5-ASA is the active moiety for the therapeutic effects of BX661A and indicate that the efficacy of 5-ASA disappears with the combined use of SP, but not of 4-ABA. Therefore, it seems that BX661A is clinically safe and more effective than SASP in the treatment of patients with ulcerative colitis.

Alanine↗
PubMed1998

[Allergic bronchopulmonary aspergillosis effectively treated with itraconazole].

A 23-year-old man with bronchial asthma presented with fever, cough, and sputum. A chest X-ray examination showed pulmonary infiltrations in the left upper and lower lung fields with central bronchiectasis. Although his temperature came down with antibiotics, pulmonary infiltrations persisted with cough and sputum. Following bronchoscopy and an allergological examination, the patient was given a diagnosis of allergic bronchopulmonary aspergillosis (ABPA) based on Rosenberg's criteria, including peripheral blood eosinophilia, a high serum IgE level, immediate skin reaction to Aspergillus antigen, positive precipitating antibodies, and Aspergillus fumigatus in sputum. The patient was treated with itraconazole instead of corticosteroids. His respiratory symptoms, eosinophilia, and pulmonary infiltration then disappeared, and his IgE serum level gradually decreased. An antifungal agent alone was effective in treating this ABPA patient.

Adult↗
PubMed1998

Effects of BX661A, a new therapeutic agent for ulcerative colitis, on chemotaxis and reactive oxygen species production in polymorphonuclear leukocytes in comparison with salazosulfapyridine and its metabolite sulfapyridine.

5-[4-(2-Carboxyethylcarbamoyl)phenylazo]salicylic acid disodium salt dihydrate (CAS 80573-04-2, BX661A) is developed as a therapeutic agent for ulcerative colitis. To clarify the mechanisms of action of BX661A, the effects of BX661A and its metabolites 5-aminosalicylic acid (5-ASA) and 4-aminobenzoyl-beta-aline (4-ABA) on polymorphonuclear (PMN) leukocyte chemotaxis and production of reactive oxygen species (ROS) from PMN cells were investigated and compared with the effects of 2-hydroxy-5-[[4-[(2-pyridinylamino)sulfonyl]phenyl]azo]-benzoic acid (CAS 599-79-1, SASP) and its metabolite 4-amino-N-2-pyridinyl-benzenesulfonamide (CAS 144-83-2, SP). 1. BX661A, SASP and SP concentration-dependently inhibited guinea pig PMN cell chemotaxis induced by zymosan-activated serum (IC50 = 1.39, 2.17 mmol/l, respectively) and by N-formyl-methionyl-leucyl-phenylalanine (FMLP) with IC50 values of 0.55, 0.06 and 0.66 mmol/l, respectively. 5-ASA and 4-ABA weakly affected the PMN cell chemotaxis induced by zymosan-activated serum (both IC50 values > or = 10 mmol/l) and by FMLP (IC50 > or = 10 and 8.05 mmol/l, respectively). 2. BX661A, SASP and SP concentration-dependently inhibited human PMN cell chemotaxis induced by FMLP with IC50 values of 0.68, 0.05 and 2.68 mmol/l, respectively, but both IC50 values of 5-ASA and 4-ABA were > 10 mmol/l. 3. BX661A, SASP, 5-ASA, 4-ABA and SP inhibited ROS production from rat PMN cells stimulated by FMLP in a concentration-dependent manner (IC50 = 58.4, 27.5, 0.61, 1242 and 13.9 mmol/l, respectively). 4. BX661A, SASP, 5-ASA, 4-ABA and SP inhibited ROS production from human PMN cells stimulated by FMLP in a concentration-dependent manner (IC50 = 67.4, 46.1, 0.69, 748 and 8.31 mumol/l, respectively). These results suggest that BX661A itself has inhibitory effects against PMN cell chemotaxis and ROS production from PMNs and that 5-ASA, which is the active moiety of BX661A, has a potent inhibitory effect against ROS production from PMNs. Therefore, these effects may be partially involved in the therapeutic effects of BX661A on ulcerative colitis.

Aminosalicylic Acids↗
PubMed1997

Structural and functional roles of modules in hemoglobin. Substitution of module M4 in hemoglobin subunits.

The alpha- and beta-subunits of human hemoglobin consist of the modules M1, M2 + M3, and M4, which correspond to the exons 1, 2, and 3, respectively (Go, M. (1981) Nature 291, 90-92). To gain further insight into functional and structural significance of the modules, we designed two kinds of chimeric hemoglobin subunits (chimeric alphaalphabeta- and betabetaalpha-subunits), in which the module M4 was replaced by the partner subunits. CD spectra in the far-UV region showed that the secondary structure of the chimeric alphaalphabeta-subunit drastically collapsed, while the chimeric betabetaalpha-subunit conserved the native globin structure (Wakasugi, K., Ishimori, K., Imai, K., Wada, Y., and Morishima, I. (1994) J. Biol. Chem. 269, 18750-18756). SAXS data also suggested a partially disordered structure of the chimeric alphaalphabeta-subunit. Based on tryptophan fluorescence spectra and computer modeling from x-ray structures of native globins, steric constraint between Trp14 and Tyr125 would be induced in the chimeric alphaalphabeta-subunit, which would perturb the packing of the A- and H-helices and destabilize the globule structure. On the other hand, such a steric constraint was not found for the counterpart chimeric subunit, the betabetaalpha-subunit. The different stabilities of these module-substituted globins imply that modules would not always be stable "structural" units, and interactions between modules are crucial to construct stable globin subunits.

Circular Dichroism↗
PubMed1997

Inhibition of osteoblastic cell differentiation by conditioned medium derived from the human prostatic cancer cell line PC-3 in vitro.

Human prostatic carcinoma frequently metastasizes to bone tissue and activates bone metabolism, especially bone formation, at the site of metastasis. It has been reported that an extract of prostatic carcinoma and conditioned medium (CM) of a human prostatic carcinoma cell line, PC-3, established from a bone metastastic lesion, stimulate osteoblastic cell proliferation. However, there is little information about the effect of PC-3 CM on the differentiation of osteoblastic cells. In this study, we investigated the effect of PC-3 CM on the differentiation of two types of osteoblastic cells, primary fetal rat calvaria (RC) cells containing many undifferentiated osteoprogenitor cells, and ROS 17/2.8, a well-differentiated rat osteosarcoma cell line. PC-3 CM inhibited bone nodule formation and the activity of alkaline phosphatase (ALPase), an osteoblastic marker enzyme, on days 7, 14, and 21 (RC cells) or 3, 6, and 9 (ROS 17/2.8 cells) in a dose-dependent manner (5-30% CM). However, the CM did not affect cell proliferation or cell viability. PC-3 CM was found to markedly block the gene expression of ALPase and osteocalcin (OCN) mRNAs but had no effect on the mRNA expression of osteopontin (OPN), the latter two being noncollagenous proteins related to bone matrix mineralization. These findings suggest that PC-3 CM contains a factor that inhibits osteoblastic cell differentiation and that this factor may be involved in the process of bone metastasis from prostatic carcinoma.

Alkaline Phosphatase↗
PubMed1997

Trifluoroethanol-induced conformational transition of hen egg-white lysozyme studied by small-angle X-ray scattering.

The trifluoroethanol (TFE)-induced conformational transition of hen lysozyme was studied with the combined use of far-UV circular dichroism (CD) and small-angle X-ray scattering. At pH 2.0 and 20 degrees C, the addition of TFE to the native lysozyme induced a cooperative transition to an intermediate state with an increased helical content (TFE state). Small-angle X-ray scattering measurements indicated that the TFE state has a radius of gyration which is 20% larger than that of the native state and assumes a chain-like conformation with some remaining globularity. The TFE-induced transition curves obtained by CD and the small-angle X-ray scattering measurements agreed well, consistent with a two-state transition mechanism. A singular value decomposition analysis of Kratky plots of the small-angle X-ray scattering profiles indicated that two basic scattering functions reproduce the observed spectra, further confirming the validity of a two-state approximation.

Animals↗
PubMed1997

The last phase of the reprotonation switch in bacteriorhodopsin: the transition between the M-type and the N-type protein conformation depends on hydration.

In order to elucidate the mechanism of the reprotonation switch of bacteriorhodopsin, the protein conformation of the M intermediate of the D96N mutant was examined at various hydration conditions by X-ray diffraction and FTIR spectroscopy. We observed two distinct protein conformations at different levels of hydration. One is like in the N photointermediate, although in this case with an unprotonated Schiff base. It is stabilized in highly hydrated samples. The other is a protein conformation identical to that in the normal M intermediate of wild-type bacteriorhodopsin, which is stabilized in partially dehydrated samples. The hydration dependence of the structural transition between the M-type and the N-type conformations suggests that there is a change in the binding of water at the cytoplasmic surface. Thus, more water molecules bind in the N-type structure than in the M-type. This is consistent with the idea that the conformational change from the M-type to the N-type corresponds to the opening of the proton channel to the cytoplasmic surface by tilt of the cytoplasmic end of helix F, and that this is required for proton transfer from Asp-96 to the retinal Schiff base.

Asparagine↗
PubMed1997

A circular dichroism study of preferential hydration and alcohol effects on a denatured protein, pig calpastatin domain I.

Pig calpastatin domain I (CSD1), a proteinase inhibitor that specifically blocks activity of calpain I and II, is a good candidate protein for studying conformational variations in the denatured form of protein. An extensive structural characterization of CSD1 reported in the first part of this work has shown that CSD1 at neutral pH is in an expanded and flexible conformation without secondary and tertiary structures. Next, we further studied cosolvent effects of protein-stabilizers, polyols and sulfate salts, as well as protein-destabilizers, alcohols, on the conformation of CSD1 monitored by far- and near-UV CD spectroscopy. We found that both groups of cosolvents at high concentration induce highly helical structures of CSD1, but without specific tertiary interactions. Based on the results on the polyols and the sulfate salts, we have suggested that the preferential hydration is one of the thermodynamic forces to induce secondary structures in the denatured state of protein. Variations in isodichroic points of changes in far-UV CD spectrum as functions of cosolvent species and their concentration have exhibited complexity of the processes. The present study implies that protein stability in the presence of cosolvents is often determined by free energy difference between the folded and the highly structured denatured state, not between the folded and the random state.

Animals↗
PubMed1997

Isolation and characterization of D-threonine aldolase, a pyridoxal-5'-phosphate-dependent enzyme from Arthrobacter sp. DK-38.

D-Threonine aldolase is an enzyme that catalyzes the cleavage of D-threonine into glycine and acetaldehyde. Its activity was found in several genera of bacteria such as Arthrobacter, Alcaligenes, Xanthomonas, and Pseudomonas, but not in yeasts or fungi. The enzyme was purified to homogeneity from one strain, Arthrobacter sp. DK-38. The enzyme appeared to consist of a single polypeptide chain with an apparent molecular mass of 51 kDa. This enzyme, as well as L-threonine aldolase, requires pyridoxal 5'-phosphate (pyridoxal-P) as a coenzyme. Unlike other pyridoxal-P enzymes, D-threonine aldolase also requires a divalent cation such as Co2+, Ni2+, Mn2+, or Mg2+ for its catalytic activity. The enzyme completely lost its activity in the absence of either pyridoxal-P or a divalent cation. A divalent cation was also essential for the thermal stability of the enzyme. The metal-free enzyme tends to become thermally unstable, resulting in the irreversible loss of its catalytic activity. The enzyme is strictly D-specific for the alpha-position, whereas it cannot distinguish between threo and erythro forms at the beta-position. Thus, D-threonine and D-allothreonine act as substrates of the enzyme, but their kinetic parameters are different; the Km and Vmax values are 3.81 mM and 38.8 micromol x min(-1) x mg(-1) toward D-threonine, and 14.0 mM and 102 micromol x min(-1) x mg(-1) toward D-allothreonine. respectively. The aldolase reaction is reversible, and the enzyme is therefore able to produce nearly equimolar amounts of D-threonine and D-allothreonine through C-C bond formation between glycine and acetaldehyde. The enzyme also acts, in the same manner, on several other D-beta-hydroxy-alpha-amino acids, including D-beta-phenylserine, D-beta-hydroxy-alpha-aminovaleric acid, D-beta-3,4-dihydroxyphenylserine, and D-beta-3,4-methylenedioxyphenylserine.

Acetaldehyde↗
PubMed1997

Risk factors for development of radiation pneumonitis following radiation therapy with or without chemotherapy for lung cancer.

PURPOSE: To determine the risk factors contributing to development of radiation pneumonitis (RP) in patients with lung cancer who undergo radiation therapy to the thorax. METHODS AND MATERIALS: Development and severity of RP were retrospectively analyzed for 89 patients with lung cancer who underwent radiation therapy with or without chemotherapy at the National Shikoku Cancer Center Hospital between 1991 and 1995. The severity of RP was determined using a modified grading scale based on that of the Radiation Therapy Oncology Group and the European Organization for the Research and Treatment of Cancer. RESULTS: Fifty-two (58%) patients developed RP: 34 patients with Grade 1, 5 with Grade 2, 8 with Grade 3, and 5 with Grade 5 RP. Severe RP tended to develop earlier than less severe RP, but not to a significant extent (p = 0.151). On logistic regression analysis including both patient condition and treatment factors, development of Grade 1 or more severe RP was most frequently observed for Stage I-II disease (p = 0.011). The use of chemotherapy, large daily radiation dose, and once-daily fractionation (vs. twice-daily fractionation) were possibly related to the development of RP (p = 0.057, p = 0.069, and p = 0.092, respectively). For the group of 48 patients who underwent chemoradiation therapy, the use of large daily radiation dose was a significant risk factor for RP (p = 0.014). In addition, the use of once-daily fractionation was a marginally significant risk factor (p = 0.052). Among chemotherapy drugs administered, cisplatin was a favorable factor (p = 0.011), while adriamycin was a risk factor (p = 0.061). CONCLUSIONS: In radiation therapy for lung cancer, administration of a large daily dose should be avoided in order to prevent RP, particularly when radiation therapy is combined with chemotherapy.

Adult↗