Biomedical subjects
Publications and source records attributed to S Fukui.
Physical mapping of Bacillus subtilis temperate phage phi 105 DNA was carried out by using restriction endonucleases EcoRI, SmaI, and KpnI, and a new revised EcoRI cleavage map is presented. In addition, the EcoRI cleavage maps of six specialized transducing phages carrying sporulation genes of B. subtilis were revised.
In order to investigate left ventricular performance during exercise in patients with myocardial infarction and evaluate the effects of sublingual isosorbide dinitrate (ISDN) on left ventricular performance, we performed a symptom-limited multigraded exercise test using a bicycle ergometer in supine position. Thirty-seven patients with myocardial infarction were evaluated in order to clarify the hemodynamic responses to exercise with and without sublingual ISDN. Patients were subdivided into 3 groups according to the level of pulmonary capillary pressure (PCP) and cardiac index (CI) at peak exercise as follows: Group I (14 patients); PCP less than 18 mmHg, CI greater than or equal to 5.0 or CI less than 5.0 L/min/m2, Group II (11 patients); PCP greater than or equal to 18 mmHg, CI greater than or equal to 5.0 L/min/m2, Group III (12 patients); PCP greater than or equal to 18 mmHg, CI less than 5.0 L/min/m2. Exercise capacity without ISDN (control study) was correlated with left ventricular performance during exercise. Although left ventricular performance in patients who complained of dyspnea or chest pain at peak exercise was worse than those who complained of leg fatigue, we could not predict hemodynamics during exercise from the level of hemodynamic parameters at rest in each patient. Determinant factors of left ventricular performance during exercise were age, previous history of myocardial infarction, the severity of coronary artery lesion and the extent of left ventricular wall motion abnormality which was estimated by left ventriculogram as an index of infarct size. After sublingual ISDN (ISDN study), exercise capacity was improved. No patient terminated exercise because of chest pain and only one did because of dyspnea.(ABSTRACT TRUNCATED AT 250 WORDS)
In order to evaluate the effect of coronary care on the immediate mortality rate of acute myocardial infarction and to clarify the problems in coronary care, we attempted to investigate the immediate mortality rate and causes of deaths in 492 patients with acute myocardial infarction who had admitted to the hospital within 24 hours after the onset of infarct from January, 1972 to December, 1981. Three hundred and seventy-nine were men and 113 were women, and their mean age was 61.8 years ranging from 28 to 91 years. One hundred and twenty-seven patients had a previous history of myocardial infarction and 365 patients had none. One hundred and ninety patients of these 365 patients without a previous infarction had anterior infarction, 152 patients inferior infarction and 23 patients subendocardial infarction. All patients were subdivided into four stages according to the time of the onset of infarct: Stage 1 (29 patients); 1972-1975, Stage 2 (101 patients); 1976-1977, Stage 3 (148 patients); 1978-1979 and Stage 4 (214 patients); 1980-1981. No significant differences in age, sex and infarct site among the four periods were found. Time interval between the onset of infarct and admission shortened serially and the ratio of reinfarction to initial infarction increased. Immediate mortality rate (within four weeks after the onset of infarct) was 20.5% in all patients. Immediate mortality rate in Stage 1 was 24.1%, 26.7% in Stage 2, 23.0% in Stage 3 and 15.4% in Stage 4, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Twenty-four autopsy cases of liver cell carcinomas were investigated by Feulgen-DNA cytofluorometry (NIKON SPM-RF 1-D) on paraffin-embedded tissue materials. The methods employed for tissue preparation and cytofluorometry were previously reported by us. The ploidy pattern based on cytofluorometry of the liver cell carcinomas exhibited wide DNA content distributions, in which many S phase cells having intermediate DNA content values ranging from diploid level to various, higher ploidy levels were included. From the comparative studies on both the histopathological findings and the ploidy pattern of the liver cell carcinomas, it was indicated that the peak value of the DNA content distribution was shifted from the diploid to the tetraploid level with the increasing appearance of the polyploid cells, and also that the degree of polyploidization appeared to correspond to the extent of the histological malignancy.
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The inactive complex of diol dehydrase with hydroxocobalamin was resolved by treatment with SO2-3, followed by dialysis to remove SO2-3, giving the apoenzyme which was reconstitutable into catalytically active holoenzyme upon addition of adenosylcobalamin ("re-activation"). Spectral evidence showed that the enzyme-bound hydroxocobalamin undergoes a Co beta-ligand exchange reaction forming sulfitocobalamin. Sulfitocobalamin was bound to diol dehydrase only loosely, and therefore dissociated from the enzyme. In contrast, neither the enzyme-hydroxocobalamin-5'-deoxyadenosine nor the enzyme-hydroxocobalamin-adenosine complex was resolved and thus re-activated by this procedure. It was shown spectroscopically that the hydroxocobalamin in these complexes does not react with SO2-3, or even with CN-, indicating that the OH group in the Co beta-position was blocked spatially by these enzyme-bound nucleosides. Neither O2-inactivated holoenzyme nor the holoenzyme inactivated suicidally by glycerol or 1,2-ethanediol during dehydration reaction was also re-activated by the same procedure. The complex of the enzyme with cyanocobalamin or methylcobalamin was not resolvable by the SO2-3 treatment. This was because these cobalamins bound to the enzyme were not subject to a ligand exchange reaction with SO2-3.
A fluorescent oxidation product of the molybdenum cofactor was isolated from Escherichia coli nitrate reductase (EC 1.9.6.1) and bovine milk xanthine oxidase (EC 1.2.3.2), which showed a visible absorption band at 395 nm and was dephosphorylated by alkaline phosphatase but not by phosphodiesterase I. The dephosphorylated species was oxidized by periodate to thieno[3,2-g]pterin-2-carbaldehyde which was quantitatively converted to thieno[3,2-g]pterin-2-carboxylic acid by subsequent treatment with Ag2O in 2 N NaOH. These results indicate that the oxidation product of the molybdenum cofactor is a thieno[3,2-g]pterin derivative with an unidentified side chain in the 2 position.
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Lowe's syndrome (oculo-cerebro-renal syndrome) has been studied biochemically. The disease was characterized by proteinuria, sialic aciduria and the excretion of undersulfated chondroitin sulfate A due mainly to malfunction of renal tubules. However, cultured skin fibroblasts from patients were found also to produce markedly undersulfated glycosaminoglycans. The undersulfation was caused by depressed sulfation rather than by increased desulfation. Subsequent studies have revealed that degradation of active sulfate (adenosine 3'-phosphate 5'-phosphosulfate, PAPS) was markedly elevated in the cells from patients whereas PAPS biosynthesis or sulfate transfer of sulfate from PAPS to glycosaminoglycan acceptors were normal. The enzyme involved in PAPS degradation was then identified as a nucleotide pyrophosphatase which is capable of degrading various nucleotides. The level of the enzyme activity in patients' cells was about ten times higher than that in normal cells and the level in heterozygotes were intermediate between patients and normal individuals. It was suggested that Lowe's syndrome is caused by elevation of biosynthesis of a nucleotide pyrophosphatase having a capacity to degrade PAPS due to a defect in regulating the enzyme synthesis.
Candida tropicalis, a representative alkane- and higher fatty acid-utilizing yeast, can grow on propionate used as sole carbon and energy source. Initial pH of the medium markedly affected the growth of the yeast on propionate. In propionate-grown cells, several enzymes associated with peroxisomes and/or participating in propionate metabolism were induced in connection with the appearance of the characteristic peroxisomes. Acetate-grown cells of this yeast had only few peroxisomes, while alkane-grown cells contained conspicuous numbers of the organelles. As compared with alkane-grown cells, some specific features were observed in peroxisomes and enzymes associated with the organelles of propionate-grown cells: The shape of peroxisomes was large but the number was small; unlike localization of catalase in peroxisomes of alkane-grown cells, the enzyme of propionate-grown cells was mainly localized in cytoplasm; as for carnitine acetyltransferase localized almost equally in peroxisomes and mitochondria in alkane-grown cells, propionate-grown cells contained mainly the mitochondrial type enzyme. A propionate-activating enzyme, which was different from acetyl-CoA synthetase, was also induced in cytoplasm of propionate-grown cells. The role of carnitine acetyltransferase and the propionate-activating enzyme in propionate metabolism is discussed in comparison with the role of carnitine acetyltransferase and acetyl-CoA synthetase in acetate metabolism.
A 69-year-old female was admitted to the hospital because of tarry stool and dyspnea on exertion. Multiple hemangiomas were noticed on the tongue, right arm and abdomen. Gastrointestinal examination revealed multiple polypoid lesions in the stomach and small intestine. In addition, coronary artery-left ventricular fistula formation and pulmonary arteriovenous malformation were shown by angiography. Compared with other reported cases of blue rubber bleb nevus syndrome, the present case was unique because of the coronary artery-left ventricular fistula, heart failure and the familiar incidence of heart failure.
The chemical class separation of coal-pyrolyzed products and the photochemical reaction of these fractions with nitrogen oxides in the experimental chamber, and the application of a short-term mutagenicity test were investigated. The altered products from the fraction hydroxy polycyclic aromatic compounds in a simulated atmosphere containing a small volume of nitrogen oxides under irradiation with a xenon lamp were the most potent mutagenic fraction among all the fractions tested against Salmonella typhimurium, both TA98 and TA100, with or without S9.
The membrane-bound enzyme responsible for the breakdown of 3'-phosphoadenosine 5'-phosphosulfate (PAPS) has been purified 1,900-fold from detergent-solubilized human placenta, using chromatographies on Con A-Sepharose, Blue Sepharose, AMP-Agarose, and Sepharose CL-6B, and sucrose density gradient centrifugation. The enzyme required Mg2+ and showed the optimum activity at pH 9.4. The preparation was free of alkaline phosphatase [EC 3.1.3.1], phosphodiesterase [EC 3.1.4.1], and 5'-nucleotidase [EC 3.1.3.5] activities, which enabled investigation of the substrate specificity and kinetic properties of the enzyme without interference by secondary reactions due to the above activities. The enzyme cleaved the pyrophosphate linkages of NAD and various sugar nucleotides and the phosphodiester linkage of p-nitrophenyl-thymidine 5'-monophosphate (PNTP), as well as the phosphosulfate linkages of PAPS and its biosynthetic precursor, adenosine 5'-phosphosulfate (APS), with apparent Km values of 0.12-0.33 mM. Relative activities towards PNTP and PAPS did not change during the purification procedures starting from the homogenate. This, together with the data of kinetic studies using two substrates simultaneously, led us to conclude that the activities towards all the substrates tested were due to one and the same nucleotide pyrophosphatase.
Spores of Curvularia lunata were immobilized by entrapment with photo-cross-linkable resin prepolymers and incubated to form mycelium in potato dextrose broth containing cortexolone (Reichstein compound S) as an inducer of steroid 11beta-hydroxylase. In a buffer system containing 2.5% dimethyl sulfoxide, this immobilized mycelium hydroxylated cortexolone to hydrocortisone. The activity of this mycelium was comparable to the activity of free mycelium. Dimethyl sulfoxide did not inhibit hydroxylase activity at the concentration used and was effective in dissolving the product. Of the various photo-cross-linkable resin prepolymers examined, use of ENT-4000, whose main chain was polyethylene glycol 4000 (chain length, approximately 40 nm), resulted in maximum hydroxylation activity of the entrapped mycelium. The chain length of prepolymers affected markedly mycelial growth in the gels and, subsequently, the activity of the entrapped mycelium. The immobilized hydroxylation system was more stable than the system in free mycelium and could be reactivated by incubation of the entrapped mycelium in potato dextrose broth containing cortexolone. The system was tested 50 times during 100 days of operation and was found to carry out the desired transformation with overall yields of 60%.
The yeast Saccharomyces cerevisiae was transformed with restriction endonuclease-digested (linear) DNAs containing the replication origin of the yeast 2 microns plasmid and selectable markers with efficiencies of 10(3) to 10(4), 10(3), and 10(2) to 10(3) transformants per microgram of DNA in the cases of transformations with linear DNAs containing the same cohesive ends, flush ends, and non-complementary cohesive ends, respectively. The results of a restriction analysis of the circular plasmids recovered from transformed cells suggested that the linear DNA molecules were ligated to produce circular forms in the recipient protoplasts.
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