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Biomedical subjects

K Endo

Publications and source records attributed to K Endo.

At least 721 records · Page 40Linked to original sources

Phenylalanine dehydrogenase of Bacillus badius. Purification, characterization and gene cloning.

Phenylalanine dehydrogenase produced by Bacillus badius IAM 11059 was purified from the crude extract of B. badius to homogeneity, as judged by disc gel electrophoresis. The enzyme has an isoelectric point of 3.5 and a relative molecular mass, Mr, of 310,000-360,000. The enzyme is composed of identical subunits with an Mr 41,000-42,000. The substrate specificity of the enzyme in the oxidative deamination reaction was high for L-phenylalanine, but rather low in the reductive amination reaction, with phenylpyruvate, p-hydroxyphenylpyruvate, and 2-oxohexanoate. The gene for the enzyme was cloned into Escherichia coli with plasmid pBR322 as a vector. The enzyme was expressed in high level in E. coli. The enzyme produced by E. coli transformant was purified to homogeneity and shown to be identical to that of B. badius IAM 11,059 with respect to the specific activity, Mr, subunit structure and amino acid composition.

Amino Acid Oxidoreductases↗

Novel phenylalanine dehydrogenases from Sporosarcina ureae and Bacillus sphaericus. Purification and characterization.

NAD+-dependent phenylalanine dehydrogenases were purified 1,500- and 1,600-fold, and crystallized from Sporosarcina ureae SCRC-R04 and Bacillus sphaericus SCRC-R79a, respectively. The purified enzymes were homogeneous as judged by disc gel electrophoresis. The enzyme from S. ureae has a molecular weight of 305,000, while that of B. sphaericus has a molecular weight of 340,000. Each is probably composed of eight subunits identical in molecular weight. The S. ureae enzyme showed a high substrate specificity in the oxidative deamination reaction acting on L-phenylalanine, while that of B. sphaericus acted on L-phenylalanine and L-tyrosine. The enzymes had lower substrate specificities in the reductive amination reaction acting on alpha-keto acids. The Sporosarcina enzyme acted on phenylpyruvate, alpha-ketocaproate, alpha-keto-gamma-methylthiobutyrate and rho-hydroxyphenylpyruvate. The Bacillus enzyme acted on rho-hydroxyphenylpyruvate, phenylpyruvate, and alpha-keto-gamma-methylthiobutyrate. The enzyme from B. sphaericus catalyzes The enzyme from B. sphaericus catalyzes the transfer of pro-S (B) hydrogen from NADH.

Amino Acid Oxidoreductases↗

A sensitive and practical assay for thyroid-stimulating antibodies using FRTL-5 thyroid cells.

A sensitive, precise and practical assay for thyroid stimulating antibodies was developed in which poorly differentiated rat thyroid cells (FRTL-5) were exposed to crude immunoglobulin fractions precipitated from serum with 15% polyethylene glycol under hypotonic conditions. After the incubation at 37 degrees C for 2 h, cAMP released into Hank's medium without NaCl was determined by radioimmunoassay. The removal of NaCl from the isotonic Hank's medium greatly enhanced cAMP production in response to both TSH and thyroid stimulating antibodies. The assay was sensitive enough to elicit an approximately 30-fold increase in cAMP at 10 mU/l bovine TSH. Thyroid stimulating activities measured using FRTL-5 cells significantly correlated with those measured using cultured porcine (r = 0.918, N = 72) or human (r = 0.830, N = 23) thyroid cells. Thyroid stimulating activities were detected in all of the 50 patients with hyperthyroid Graves' disease, the 14 patients with recurrent hyperthyroid Graves' disease, and the 25 patients with ophthalmic Graves' disease. Thyroid stimulating activity was also detected in some patients (9/24, 37.5%) with Hashimoto's thyroiditis whose serum TSH concentrations were higher than 30 mU/l. However, it was completely abolished by pre-treatment of the sera with anti-TSH antibodies. Although thyroid stimulating activities were detected in one of the patients with simple goitre (N = 10) and in one with thyroid cancer (N = 10), none of the patients with silent thyroiditis (N = 7), adenomatous goitre (N = 11), and thyroid adenoma (N = 9) were positive for thyroid stimulating antibodies.

Animals↗

[Diagnosis of adrenal medullary diseases in patients with sporadic or hereditary medullary thyroid carcinoma. A report of 37 cases with 8-year follow-up study].

Thirty-seven patients with medullary thyroid carcinoma were investigated to determine the status of adrenal medulla by computed tomography and 131I-metaiodobenzylguanidine (131I-MIBG) scintigraphy as well as measurements of urinary catecholamine excretion. Patients were followed up for 8 years in maximum. Fifteen patients belonged to multiple endocrine neoplasia type 2 including patients with incomplete phenotype. Computed tomography demonstrated adrenal tumors or enlargement in all 6 patients with urinary epinephrine (E) more than 30 micrograms/day, 4 of them were confirmed to have pheochromocytoma or adrenal medullary hyperplasia by surgery. In 2 patients with E less than 30 micrograms/day and epinephrine to norepinephrine (E/N) ratio more than 0.3 suggesting adrenal medullary hyperfunction, computed tomography revealed small adrenal tumors. Three of the remaining 7 patients with E less than 30 micrograms/day and E/N ratio less than 0.3 had equivocal enlargement of unilateral gland on computed tomography. 131I-MIBG scintigraphy demonstrated tracer uptake in adrenal glands with tumor more than 1cm in diameter. One of 2 adrenal glands with medullary hyperplasia showed a faint adrenal image on the scintiscan, but the other showed no tracer uptake. Pheochromocytoma became manifest in 4 patients during the follow-up period, 4, 13, 14 and 34 years after thyroid surgery. None of 22 patients with sporadic medullary thyroid carcinoma showed adrenal abnormalities on the examinations mentioned above.

Adrenal Gland Neoplasms↗

[Clinical study of carumonam].

To evaluate the clinical efficacy of carumonam (CRMN, AMA-1080), the drug was used in the treatment of 10 patients including 4 with pneumonia and each with acute tonsillitis, chronic bronchitis, Mycoplasma pneumonia, primary atypical pneumonia (PAP), chronic pyelitis, and acute cystitis. Since beta-lactam antibiotics were not active against Mycoplasma pneumonia and PAP, these diseases were excluded from the clinical efficacy evaluation of CRMN. Responses were excellent in 1 patient and good in 7. Side effects were not observed. The laboratory test recognized slight elevations of GOT, GPT and eosinophilia in 1 patient and a slight leucopenia in another upon the administration of CRMN.

Adult↗

Localization of human osteogenic sarcoma xenografts in nude mice by a monoclonal antibody labeled with radioiodine and indium-111.

Monoclonal antibody OST7 reacts specifically with human osteogenic sarcoma. Whole immunoglobulin G (IgG) and the F(ab')2 fragment of OST7 were labeled with radioiodine and indium-111 (111I), and injected into athymic nude mice bearing xenografts of human osteogenic sarcoma (KT005). All radiolabels retained their antigen-binding activities allowing clear visualization of transplanted tumors. Tissue distribution, however, varied. The net tumor concentration of 111In-lableled whole IgG was higher and was retained longer than that of radioiodinated one, but 111In-labeled antibody showed a lower tumor-to-liver and tumor-to-kidney ratio. In radioiodinated OST7, F(ab')2 fragments provided much better images with much higher tumor-to-tissue ratios than whole IgG. Using F(ab')2 fragments as a carrier for 111In, little image improvement was obtained due to the high radioactivity in the liver and kidney. The different distributions among these radiolabels suggest that the choice between intact igG and F(ab')2 fragments and between radioiodine and 111In depends on the intended use.

Animals↗

Preparation and properties of antitumor monoclonal antibodies labeled with metallic radionuclides indium-111, gallium-67, and technetium-99m.

In this study, metallic radionuclides such as 111In, 67Ga, or 99mTc produced clear visualization in scintigraphic imaging of tumors; they have short half-lives and can easily be used in the radiolabeling of monoclonal antibodies by using bifunctional chelating agents. Under selected conditions, these radiolabeled antibodies were stable both in vitro and in vivo with no loss of the antigen-binding activity. Despite high background imaging of the liver and kidney, transplanted tumors in nude mice were clearly visualized with 111In-, 67Ga-, and 99mTc-labeled antibodies at 6, 24, or 48 hours after the injection. Although tissue distribution in the liver, kidney, and bone was different among radionuclides used for the labeling, all tumor to blood ratios were higher than those of radioiodinated monoclonal antibodies. These results provide a good basis for studies of the clinical usefulness of 111In-, 67Ga-, and 99mTc-labeled monoclonal antibodies for radioimmunoimaging.

Animals↗