Search PubMed⌕ Search

Biomedical subjects

M Kitada

Publications and source records attributed to M Kitada.

At least 199 records · Page 11Linked to original sources
PubMed1984

Purification and properties of cytochrome P-450 from untreated monkey liver microsomes.

Untreated monkey liver cytochrome P-450 (monkey P-450) has been purified to a specific content of 14.9 n mole/mg protein. The purified preparation was apparently homogeneous and the minimum molecular weight was estimated to be 50,000 by SDS-PAGE. Absolute spectrum of the oxidized form showed peaks at 565, 535 and 417 nm. The monkey P-450 was active in the mixed function oxidation of benzphetamine, aminopyrine, ethylmorphine, aniline and 7-ethoxycoumarin in the presence of rat liver NADPH-cytochrome P-450 reductase and DLPC. Anti monkey P-450 IgG could not inhibit rat P-450s (PB P-450, MC P-448(1) and MC P-448(2] catalyzed 7-ethoxycoumarin O-deethylation activities.

Animals↗
PubMed1984

The interaction between two forms of cytochrome P-450 during drug oxidation in the reconstituted system containing limited amount of NADPH-cytochrome P-450 reductase.

The activities of drug oxidation in a reconstituted system which contains two forms of cytochrome P-450 and a limiting amount of NADPH-cytochrome P-450 reductase were determined. Cytochrome P-450 (termed MC P-4481 and MC P-4482) purified from liver microsomes of 3-methyl-cholanthrene-treated rats was active in both 2- and 4-hydroxylation of biphenyl but cytochrome P-450 (termed PB P-450) purified from liver microsomes of phenobarbital-treated rats was active in 4-hydroxylation of biphenyl only. PB P-450, MC P-4481 and MC P-4482 were most active toward benzphetamine N-demethylation, aniline hydroxylation and 7-ethoxycoumarin O-deethylation, respectively. PB P-450 inhibited the activity of biphenyl 2-hydroxylation supported by MC P-4481 or MC P-4482. On the contrary, no inhibition of PB P-450 supported benzphetamine N-demethylation was observed when MC P-4481 or MC P-4482 was added to the system containing PB P-450 and limited amount of the reductase. The apparent Km of PB P-450 for the reductase obtained from double reciprocal plot of the reductase concentration and the activity of biphenyl hydroxylase or benzphetamine N-demethylation was lower than that of MC P-4481 or MC P-4482. These and other results suggest that there is a certain hierarchy among the cytochrome P-450 species for receiving electrons from reductase.

Animals↗
PubMed1984

Voltage-dependent proton fluxes in liposomes.

Liposomes containing buffered KCl were prepared from bacterial lipids, were diluted into K+-free media and were treated with valinomycin to induce the formation of a diffusion potential (delta psi). Upon formation of such a potential, substantial proton influx was observed, as assayed by the quenching of 9-aminoacridine fluorescence. Complete reversal of fluorescence quenching occurred when the potential was collapsed by addition of KCl or when methylamine was added. Studies of proton influx as a function of the theoretical magnitude of the delta psi indicated that the phenomenon occurred only above a delta psi of about -60 mV. Establishment of a Na+ diffusion potential also resulted in proton influx. Treatment of K+-loaded liposomes with N,N'-dicyclohexylcarbodiimide did not reduce the delta psi-dependent proton influx. Moreover, proton influx could be demonstrated upon imposition of a diffusion potential in liposomes prepared from a synthetic lipid. The proton fluxes associated with generation of a diffusion potential in liposomes may complicate studies of reconstituted systems in which proton translocation should occur, and may affect the magnitude of the electrochemical proton gradient that is operant under some conditions.

Aminacrine↗
PubMed1984

Purification and characterization of the cytochrome oxidase from alkalophilic Bacillus firmus RAB.

A cytochrome oxidase was purified 52-fold from membranes of alkalophilic Bacillus firmus RAB by extraction with Triton X-100, ion-exchange and hydroxyapatite chromatography, and gel filtration. On denaturing gels, the purified enzyme dissociated into two subunits of 56,000 and 40,000 Mr as well as a cytochrome c with an Mr of approximately 14,000. Heme contents calculated for an enzyme with a molecular weight of 110,000 were found to be 2 mol of heme a and 1 mol of heme c per mol of cytochrome oxidase; approximately 2 mol of copper per mol of purified enzyme was also found. Enzyme activity was observed in assays using reduced yeast or horse heart cytochrome c. Activity of the purified enzyme was optimal at pH 6.0 and in the presence of added lipids. Impure, membrane-associated activity exhibited a broader pH range for optimal activity extending to alkaline values.

Animals↗
PubMed1984

Follow-up study of the arrhythmic graduates from the schools under the heart disease program for students in Osaka.

A long term follow-up study of arrhythmic graduates from junior or senior high schools under the Heart Disease Program in Osaka was performed by mailing questionnaires. The age of the total 515 subjects ranged from 20 to 38 years, 26.9 years on an average. From 397 graduates (77%), answers to questionnaires were obtained. We could confirm 92 graduates were alive (18% of total subjects) among the 118 graduates who did not return their answers to the questionnaires. The following is what we could confirm through the present study: The prognoses of simple premature beats, Wenckebach type heart block and complete right bundle branch block are good in young adults. The prognosis of sick sinus syndrome does not warrant an optimistic prognosis even in young adults. The prognosis of WPW syndrome in young adults is not always fair if they have a history of paroxysmal tachycardia. From 95 to 97% of the graduates with arrhythmia as a whole answered that their daily lives are quite similar to those of healthy people. Attitudes toward daily life and medical checks were also studied.

Activities of Daily Living↗
PubMed1984

A network data base system for children with cardiac disease--echocardiographic data of MCLS.

We developed a computer-assisted network data base system for children with cardiac diseases. It aims at storage and exchange of medical information from many hospitals to prevent school children from sudden death caused by heart diseases. The computer system used was PANAFACOM U-1500 introduced at Shimane Medical University Hospital in 1980. The format of the questionnaire is designed to standardize the computer-assisted data-entry method among different hospitals. The entries of questionnaires are composed of basic information about the patient and laboratory information. The former is identification data of the patient, and the latter principally the values of M-mode echocardiographic measurement. Two types of output-tables were made from the data base. One is a table of each disease, and the other each hospital.

Child↗
PubMed1984

Effect of successive administration of zopiclone, a new class of minor tranquillizer, on mouse liver microsomal mono-oxygenase system.

Oral administration of zopiclone to mice (10 mg/kg daily) for 14 days had no significant effect on body weight, liver weight, hepatic microsomal protein or cytochrome P-450 contents but produced significant increases in the activities of NADPH-cytochrome c reductase, NADH-ferricyanide reductase, aniline hydroxylation and aminopyrine N-demethylation.

Aminopyrine N-Demethylase↗
PubMed1983

Effect of acetone on aniline hydroxylation by a reconstituted system.

Acetone stimulated NADPH-dependent aniline hydroxylation catalysed by cytochrome P-450 purified from phenobarbital-treated rats. No activation by acetone occurred in a reconstituted system containing cytochrome P-448 purified from 3-methylcholanthrene-treated rats. Cumene hydroperoxide-supported aniline hydroxylation catalysed by cytochrome P-450 was not increased by the addition of acetone at the concentration which stimulated NADPH-dependent aniline hydroxylation in the reconstituted system. The NADPH-dependent cytochrome P-450 reduction was stimulated by acetone in the presence or absence of aniline. On the other hand, acetone did not exhibit any stimulatory effect on NADPH-dependent reduction of cytochrome P-448. The stimulatory effect of acetone on aniline hydroxylation was decreased with increasing pH of the reaction media. Furthermore, in the system containing cytochrome P-450, the ratio of product to hydrogen peroxide formation was virtually unchanged by the addition of acetone.

Acetone↗
PubMed1983

Purification and characterization of a pancreatic cancer-associated antigen (PCAA) from normal colonic mucosa.

The same antigenic substance as pancreatic cancer-associated antigen (PCAA), sharing an identical immunogenicity with Gelder's POA, was isolated and purified from normal colonic mucosa. Purified colonic PCAA (PCAAc) is a glycoprotein with a molecular weight of approximately 600,000; it consists of 30% carbohydrates and 70% peptides, and appears to be an N-glycosidic glycoprotein. Antiserum raised against purified PCAAc showed one fused line with our original anti-PCAA antiserum to ascites fluid from patients with pancreatic cancer and extract from normal colonic mucosa. Circulating PCAAc levels assayed by rocket immunoelectrophoresis showed significant elevation in sera of patients with carcinoma of the pancreas. It is concluded that PCAA might be a new tumor-associated antigen which is produced ectopically during oncogenesis.

Amino Acids↗
PubMed1983

Respiratory chain of the alkalophilic bacterium Bacillus firmus RAB and its non-alkalophilic mutant derivative.

The membrane-bound respiratory chain components of alkalophilic Bacillus firmus RAB were studied by difference spectroscopy and oxidation-reduction potentiometric titrations. Cytochromes with the following midpoint potentials were identified at pH 9.0: a-type cytochromes, +110 and +210 mV; b-type cytochromes, +20, -120, -280, and -400 mV; and cytochrome c, +60 mV. Only the higher-potential cytochrome a showed an upward shift in midpoint potential when titrated at pH 7.0. Parallel studies of a non-alkalophilic mutant derivative of B. firmus RAB, strain RABN, revealed the presence of only one species each of a-, b-, and c-type cytochromes which exhibited midpoint potentials of +110, -150, and +160 mV, respectively, at pH 7.0. Membranes of both strains were found to contain menaquinone. At pH 9.0, NADH caused the reduction of essentially all of the cytochromes that were seen in fully reduced preparations of wild-type B. firmus RAB membranes. By contrast, at pH 7.0, NADH failed to appreciably reduce the b-type cytochromes. These findings may relate to our recent proposal that an inadequacy in energy transduction (production of a proton motive force) by the alkalophilic respiratory chain at pH 7.0 is what precludes the growth of B. firmus RAB at a neutral pH.

Bacillus↗
PubMed1983

The problems in controlling heart disease among elementary, junior and senior high school students--an analysis of fatal cases.

An analysis of cardiac fatal cases from elementary, junior and senior high school students of Osaka revealed the following features: 1) The mortality rate of the cardiacs under the heart disease program is two times as high in senior high school students as in elementary school and junior high school students. The same rate for males is significantly higher than the rate for females. 2) The mortality rate according to types of heart disease is the highest among cardiomyopathy. This rate is followed by the rates for acquired valvular heart disease, for unoperated congenital heart disease and for operated congenital heart disease in that order. However, the actual number of fatal case is largest among those with congenital heart disease exceeding more than half of the total number of deaths. 3) Recently the mortality rate showes a decreasing tendency. The number of deaths due to chronic congestive heart failure has decreased, but sudden deaths have increased. 4) Sudden deaths are mostly encountered in moderate or severe cardiac cases. Therefore, it is mandatory to accurately locate the cases with high potentiality for sudden death and to place them under proper supervision. 5) In one third of the cases of sudden death, no significant physical or behavioral causes were found to trigger the death. It seems to be difficult to prevent all the sudden deaths, therefore, it is important to establish successful emergency programs.

Activities of Daily Living↗
PubMed1983

[Pancreatic cancer-related antigen (PCAA) and pancreatic tissue antigen (PaA)--their chemical compositions, tissue localization, and clinical significance].

PCAA, a glycoprotein antigen identified and purified from ascited fluid of a pancreatic cancer patient and sharing the identical immunogenicity with Gelder's POA (Shimano, 1981) and PaA, a novel pancreas tissue antigen (Loor, 1981) purified from saline extract of human pancreas were studied. (1) Chemical composition: The purified PCAA from ascites fluid of a pancreatic cancer patient has a molecular weight of 10,000,000. The same antigenic substance as PCAA was also isolated and purified from normal colonic mucosa. Amino acid compositions of these antigens were similar. PCAA appeared to be a N-glycosidic glycoprotein. Antisera against these antigens were immunologically identical to Gelder's anti-POA in gel diffusion. The purified PaA has a molecular weight of 44,000, a sedimentation coefficient of 3.4S and an isoelectric point of 4.9. (2) Tissue localization: In pancreatic cancer tissues, PCAA and PaA were detected at apical cytoplasm of cancer cells, though positive cells were in different proportions and with different distribution each other. PCAA-positive cells were well differentiated while PaA-positive cells were less differentiated in histology. (3) Serum levels: A sensitive and reproducible sandwich-type enzyme immunosorbent assay has been developed for quantitation of PCAA and PaA. Using 18.6 micrograms/ml (mean + 2 S.D. of normal controls) as an upper limit, 43 of 76 pancreatic cancer (56%) and 34 of 167 other diseases (20%) had an elevated PCAA level. Using 21.5 ng/ml as an upper limit, 50 of 76 pancreatic cancer (66%) and 13 of 167 other diseases (8%) had an elevated PaA level. The sensitivity of simultaneous assay of PCAA and PaA for the detection of pancreatic cancer increased to be 90% (69/76) while false positive was 24% (40/167). The results indicate that combination assay of PCAA and PaA may be useful in immunodiagnosis of pancreatic cancer.

Antigens, Neoplasm↗
PubMed1982

Serum total cholesterol, triglyceride level, and dietary intake in Japanese students aged 15 years.

The authors surveyed serum cholesterol and triglyceride levels in 238 male and 217 female students aged 15 years in Osaka, Japan, in 1977, as well as dietary intake, using a 24-hour record in 81 male and 61 female students. Serum cholesterol and triglyceride levels of Japanese students were 163.6 mg/dl and 81.7 mg/dl, respectively, for males, and 182.2 mg/dl and 78.9 mg/dl for females. For female students, those who participated in a school sports club regularly during the previous three years had cholesterol levels 10 mg/dl lower than the subjects who had not participated in a sports club; these active students also had smaller skinfold thickness, although there was no difference in other anthropometric measurements. Although the dietary intake of Japanese students was found to be westernized, compared with that of Japanese adults, Japanese students reported low fat intake (25-30% of energy), high polyunsaturated/saturated fatty acid ratio (1.1-1.2), and high carbohydrate intake (55-61% of energy), differing considerably from US students.

Adolescent↗
PubMed1982

Bioenergetic properties and viability of alkalophilic Bacillus firmus RAB as a function of pH and Na+ contents of the incubation medium.

The bioenergetic properties and viability of obligately alkalophilic Bacillus firmus RAB have been examined upon incubation in alkaline and neutral buffers in the presence or absence of added Na+. At pH 10.5, cells incubated in the absence of Na+ exhibited an immediate rise in cytoplasmic pH from less than 9.5 to 10.5, and they lost viability very rapidly. Viability experiments in the presence or absence of an energy source further suggested that the Na+-dependent mechanism for pH homeostasis is an energy-requiring function. The Na+/H+ antiporter, which catalyzes the vital proton accumulation at alkaline pH, was only slightly operational at pH 7.0; both whole cells and vesicles exhibited net proton extrusion even in the presence of Na+. Moreover, cells incubated in buffer at pH 7.0 were actually more viable in the presence of Na+ than in its absence. Thus, the inability of B. firmus RAB to grow at neutral pH is not due to excessive acidification of the cytoplasm. Rather, the transmembrane electrical potential, delta psi, generated at pH 7.0 was found to be much lower than at alkaline pH. The very low delta psi compromised several cell functions, e.g., Na+/solute symport and motility, which in this and other alkalophiles specifically depend upon delta psi and Na+.

Adenosine Triphosphate↗
PubMed1982

The natural history of congenital heart disease in young adults.

Under the Heart Disease Program for elementary school children and junior high school students in Osaka City, the cardiac patients found through mass examination are supposed to be checked annually by the program's staff. After their graduation from junior high school, however, the cardiac patients leave our medical jurisdiction. In order to gather information from those graduates, we have mailed and continue to mail questionnaires to them once every 5 years. By analyzing that information, we sought to describe the natural history of congenital heart disease in young adults. The study revealed that among graduates older than 20 years of age as of March 31, 1978, 17.5% underwent initial cardiac surgery; 1.8% were found to have no more cardiac lesions due to spontaneous healing; 12.3% answered that they had no significant changes; 2.0% were found to have deteriorated cardiac lesions and 2.1% of the graduates had died. Eight point one per cent of the graduate did not answer, although minimum data as to whether they were alive or not was gathered. The mortality rates were calculated by using all follow-up data. It was revealed that the mortality rate for cardiac patients under 14 years of age, for those between 15 and 20 years of age and for those older than 21 years of age are 14 times, 6 times and 3 times as high as the general population in each age group, respectively. The mortality rate for those with mild cases of cardiac lesions is 3 times higher than the general population. It is 13 times higher among moderate cases and 77 times higher among severe cases when compared to the general population.

Adolescent↗