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Biomedical subjects

T Kitagawa

Publications and source records attributed to T Kitagawa.

At least 577 records · Page 32Linked to original sources
PubMed1985

Induction by X-irradiation of adenosine triphosphatase-deficient islands in the rat liver and their characterization.

The potential of X-rays to induce preneoplastic lesions in the rat liver was studied in order to clarify the reason why X-rays are ineffective in inducing hepatocellular carcinoma in this animal. Male newborn rats at 8 or 22 days of age received whole body X-ray irradiation of 100 to 400 rads. After weaning they were fed either basal diet or a diet containing 0.05% phenobarbital as a promoter. X-rays induced numerous adenosine triphosphatase-deficient islands appearing in the liver by wk 22 of age. However, they were generally small, gamma-glutamyl transpeptidase-negative, and did not clearly respond to the promoting stimulus of phenobarbital. No hepatic tumors were observed by 22 mo after radiation, even in phenobarbital-treated animals. Thus the X-ray-induced enzyme-altered islands differ somewhat qualitatively from those induced by potent hepatic carcinogens and their preneoplastic potential if at all present may be very low. Similarities between these X-ray-induced lesions and some types of spontaneous enzyme-altered islands are pointed out.

Adenosine Triphosphatases↗
PubMed1985

[Postoperative prophylactic irradiation of lung cancer].

Eighty-three patients with resected lung cancer were studied to determine whether postoperative prophylactic irradiation improves survival. All patients had mediastinal lymph node metastases and underwent relative curative surgery. Thirty patients received postoperative irradiation, and another 52 were followed without further treatment. The 5-year survival rate was 19.2% in the surgery alone group and 20% in the postoperative irradiation group. No increase in survival time was noticed in the postoperative irradiation group. The 5-year survival rate was not influenced by histologic types, presence or absence of subcarinal lymph node metastases and right or left thoracotomy in either group.

Adenocarcinoma↗
PubMed1985

Proton therapy in Japan.

There are two facilities for clinical trials with protons in Japan: the National Institute of Radiological Sciences (NIRS), Chiba, and the Particle Radiation Medical Science Center (PARMS), University of Tsukuba. At the National Institute of Radiological Sciences, patient treatment with the 70 MeV proton beam began in November 1979, and 29 patients were treated through December 1984. Of 11 patients who received protons only, 9 have had local control of the tumor. Two of the 9 patients, suffering from recurrent tumor after radical photon beam irradiation, developed complications after proton treatment. In the patients treated with photons or neutrons followed by proton boost, tumors were controlled in 12 of 18 patients (66.6%), and no complications were observed in this series. Malignant melanoma could not be controlled with the proton beam. A spot-beam-scanning system for protons has been effectively used in the clinical trials to minimize the dose to the normal tissues and to concentrate the dose in the target volume. At the Particle Radiation Medical Science Center, University of Tsukuba, treatment with a vertical 250 MeV proton beam was begun in April 1983, and 22 patients were treated through February 1984. Local control of the tumor was observed in 14 of 22 patients (63.6%), whereas there was no local control in the treatment of glioblastoma multiforme. There have been no severe complications in patients treated at PARMS. The results suggest that local control of tumors will be better with proton beams than with photon beams, whereas additional modalities are required to manage radioresistant tumors.

Adult↗
PubMed1985

Development of enzyme immunoassay for chromomycin A3 and olivomycin using beta-D-galactosidase as a label.

An antibody specific for chromomycin A3 (CHM; byname, toyomycin) was produced in sufficiently high titer in rabbits by immunization with a CHM-bovine serum albumin conjugate, prepared using diazotized p-aminobenzoic acid as a coupling agent. CHM was also coupled with beta-D-galactosidase (EC 3.2.1.23) using diazotized m-aminobenzoic acid and was used as a tracer. With these reagents, a double-antibody enzyme immunoassay for CHM and for the CHM homologue olivomycin was developed which was highly sensitive and accurate enough to measure as little as 10 and 50 pg of each drug per assay tube, respectively. The enzyme immunoassay did not cross-react with mithramycin and drugs commonly used with CHM in combination chemotherapy for cancer treatment. Using this assay, drug levels were easily determined in blood and urine of rats following administration of CHM in a single dose of 2.0 mg/kg i.v. The sensitivity and specificity of the enzyme immunoassay for CHM and olivomycin should provide a valuable new tool for use in pharmacokinetic and toxicity studies of these drugs.

Animals↗
PubMed1985

Changes in polypeptide pattern of rat liver cells during chemical hepatocarcinogenesis.

Administration of 2-acetylaminofluorene to rats for 12 weeks induces hyperplastic nodules (HPNs) and later well-differentiated hepatocellular carcinomas (HCCs) in the liver. Total cellular proteins from normal liver, HPN, and HCC were analyzed by two-dimensional gel electrophoresis with a high resolution. Several hundred polypeptides were well resolved as seen by Coomassie blue staining, forming a reproducible and characteristic pattern for each tissue. The polypeptide patterns were very similar among normal liver, HPN, and HCC. Especially the proteins of HPN and HCC were almost indistinguishable. These neoplastic lesions, however, were clearly different from control liver in that a new spot p35-6.6 (designated by molecular weight X 10(-3) and pl) appeared, and five polypeptides, p57-6.9, p57-6.7, p26-6.9, p26-6.6, p26-6.4, increased dramatically in amount as compared with normal liver. These last three spots were found to be a new type of glutathione S-transferase as judged from the specific binding to the antibody. The same changes in polypeptide pattern were found in HCCs induced by other chemical carcinogens, diethylnitrosamine and 3'-methyl-4-dimethylaminoazobenzene, but not in regenerating and neonatal livers. Fetal liver showed a rather different pattern than adult liver, but only p26-6.6 was increased among the spots characteristic of HPN and HCC. Protein phosphorylation was also examined for these cells by incubating tissue slices with 32PO4. After alkali treatment of the gels to eliminate serines phosphorylation, several dozens of phosphoproteins were clearly detected. The patterns of the labeled spots were again very similar among control liver, HPN, and HCC. Only the intensity of a spot designated p57-6.6 increased markedly in both HPN and HCC. This spot was further resolved by an expanded pH gradient into four distinct spots, the major one of which contained phosphothreonine. Similar changes in phosphorylation were noted in hepatomas induced by diethylnitrosamine and 3'-methyl-4-dimethylaminoazobenzene but not in regenerating, fetal, and neonatal livers. These changes are discussed in terms of gene expression relevant to malignant transformation of hepatic cells.

2-Acetylaminofluorene↗
PubMed1985

[A case of renal cell carcinoma developing from a dysplastic kidney].

A case of renal cell carcinoma developing from a unilateral dysplastic kidney is reported. A 33-year-old woman was admitted to our hospital because of lumbago due to metastatic cancer to the bones. She was treated with interferon and combination chemotherapies, but died nine and a half months after initiation of the therapy. Autopsy revealed a widely metastasized renal cell carcinoma originating from a dysplastic left kidney. This is the second such case in the literature. Clinical management of renal dysplasia should take into consideration the possibility of developing malignancy.

Adult↗
PubMed1984

Heterologous enzyme immunoassay for puromycin aminonucleoside using beta-D-galactosidase as a label.

A heterologous enzyme immunoassay (EIA) was developed to quantify puromycin aminonucleoside (PA). This double antibody assay was based on the use of anti-puromycin (PU) antibody and used beta-D-galactosidase-labeled PA conjugate prepared via N-(m-maleimidobenzoyloxy)succinimide. The standard curve of the assay ranged from 1 ng to 30 ng, and the lower limit of detection was 22.7 nM (1 ng/tube). The EIA was found to be approximately 20 times more sensitive than the homologous EIA for PA with anti-PA antibody and PA-beta-D-galactosidase conjugate. The heterologous EIA was free from interference by any purine or pyrimidine analogs and drug levels were easily determined in rat tissue following i.v. administration at a dose of 15 mg/kg. The sensitivity and specificity of the EIA should provide a valuable new tool for use in pharmacokinetic and toxicity studies of PA.

Animals↗
PubMed1984

Enzyme immunoassay with high sensitivity and accuracy for specific antibody to neocarzinostatin.

A quantitative enzyme immunoassay (EIA) for specific antibody to neocarzinostatin (NCS) is described which uses enzyme-labeled anti-rabbit IgG antibody, solid-phase NCS and standard purified specific antibody to NCS. The dose of the standard was determined by sandwich EIA for rabbit IgG. The lower detection limit was 3 ng of the specific antibody per tube. The accuracy of the assay was excellent and a comparative study with the sandwich EIA for rabbit IgG showed good correlation. The antiserum to NCS of the highest titer was found to contain 0.6 mg and 40 mg per ml of specific antibody to NCS and of normal IgG, respectively. The accuracy of the assay results and the purity of the standard was established by 2 recovery tests for anti-NCS antibody.

Animals↗
PubMed1984

Resonance Raman study of the aa3-type cytochrome oxidase of thermophilic bacterium PS3.

Resonance Raman spectra of the aa3-type cytochrome oxidase of thermophilic bacterium PS3, which has a simpler subunit composition than the mitochondrial enzymes but very similar enzymatic properties, are investigated under various conditions and compared with those of mitochondrial enzymes. The intensities of the two marker lines of reduced cytochrome a3 at 1667 and 213 cm-1 had different dependences on the incubation temperatures and pH. With regard to the incubation temperature dependence, the intensity of the 1667-cm-1 line, the peripheral CH = O stretching mode of the a3 heme, behaved in nearly the same way as that of the oxidase activity whereas the intensity of the 213-cm-1 line, the Fe-histidine stretching mode of the a3 heme, exhibited a similar dependence to that of the proton pumping activity. The 213-cm-1 line disappeared upon binding of carbon monoxide, upon raising the pH above 9.2, or after incubating above 55 degrees C. The Raman line at 1611 cm-1, which was recently suggested to probe the proton pump activity [Babcock, G.T., & Callahan, P.M. (1983) Biochemistry 22, 2314-2319], remained unaltered after incubation at 60 degrees C for 20 min despite a reduction of proton pumping activity to one-third. This argues against the proposed mechanism. The frequencies of the Raman lines were the same for the intact membrane and the isolated enzyme in the reduced state. The Raman spectra of cytochrome oxidase isolated from bacterium, yeast, and bovine heart were different in the lower frequency region below 600 cm-1 but closely alike in the higher frequency region above 1200 cm-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Protein kinase activity on the cell surface of a macrophage-like cell line, J774.1 cells.

Protein kinase activity was demonstrated on the cell surface of a murine macrophage-like cell line, J774.1 cells, and was characterized in detail. When intact cells were incubated with [gamma-32P]ATP, a transfer of [32P]phosphate into acid-insoluble materials of the cells occurred. This reaction was Mg2+-dependent but cAMP-independent, and Mg2+ could be substituted for by Mn2+. The reaction products were found to be proteins, as revealed by SDS-polyacrylamide gel electrophoresis and autoradiography, with phosphomonester linkages to serine and threonine residues, but not to tyrosine. The results of experiments with chemical and enzymatic treatments as well as Con A-Sepharose column chromatography ruled out the possibility that an acyl-phosphate linkage or phosphomannosylglycopeptide was present in the reaction products. The protein kinase(s) and the reaction products were located on the cell surface of the cells, as shown by the fact that the products were removed by mild trypsinization of cells carefully controlled so that the cells remained in an intact state. Phosphorylation of exogenous proteins (phosvitin and casein) by intact cells further supported the location of the enzyme. The phosphorylated proteins of the cells were found to be metabolically stable and remained on the cell surface even at 120 min after the phosphorylation reaction. Possible roles of ecto-protein kinase activity in macrophage functions and macrophage-activation are also discussed.

Animals↗
PubMed1984

On the role of protein phosphorylation in the ATP-dependent permeabilization of transformed cells.

Incubation of transformed mouse fibroblasts with external ATP in alkaline medium low in divalent cations causes an increase in the permeability of the plasma membrane to nucleotides and other small molecules. Previous suggestions that the phosphorylation of a 44,000 dalton membrane protein is involved in this permeabilization process have been pursued. Fractionation of cells that had been incubated with [gamma-32P]ATP revealed that the labeled 44K phosphoprotein was found in both the membrane and mitochondrial fractions. Incubation of fractions isolated from unlabeled cells with [gamma-32P]ATP resulted in substantial formation of 32P-44K in the mitochondrial fraction and less incorporation in the membrane fraction. The 44,000 dalton protein was identified as the alpha-subunit of mitochondrial pyruvate dehydrogenase by partial proteolytic mapping and immunological cross-reactivity with antibodies prepared against bovine pyruvate dehydrogenase. The phosphorylation of this protein in whole cells by externally added ATP is suppressed by inclusion in the incubation medium of carboxyatractyloside (CAT) and EDTA. These substances have no effect on ATP-dependent permeabilization, indicating that the phosphorylation of pyruvate dehydrogenase is not involved in this process.

Adenosine Triphosphate↗