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Biomedical subjects

S Fujii

Publications and source records attributed to S Fujii.

At least 757 records · Page 42Linked to original sources
PubMed1985

Effects of calcium on electrical propagation in early embryonic precontractile heart as revealed by multiple-site optical recording of action potentials.

The effects of Ca2+ on electrical propagation in early embryonic precontractile chick hearts were studied optically using a voltage-sensitive merocyanine-rhodanine dye. Spontaneous optical signals, corresponding to action potentials, were recorded simultaneously from 25 separate regions of the eight-to-nine-somite embryonic primitive heart, using a square photodiode array. Electrical propagation was assessed by analyzing the timing of the signals obtained from different regions. Electrical propagation in the heart was suppressed by either lowering or raising extracellular Ca2+. Similar effects were produced by a Ca2+ ionophore (A23187). We have also found that electrical propagation across the primordial fusion line at the midline of the heart was enhanced by increasing, and depressed by lowering, external Ca2+. One possible interpretation is that intercellular communication in the embryonic precontractile heart is regulated by the level of the intracellular Ca2+ concentration, and it is suggested that intercellular communication across the primordial fusion line strongly depends on external Ca2+.

Action Potentials↗
PubMed1985

Phosphorus-31 nuclear magnetic resonance and electronic spectroscopic studies of adrenodoxin reductase and its binary complex with NADP+.

The 31P NMR spectra of NADPH-adrenodoxin reductase and its complex with NADP+ are reported. The spectrum of adrenodoxin reductase showed two doublets arising from the phosphorus nuclei in the pyrophosphate group of FAD. Both doublets were shifted upfield to different extents in comparison with those of free FAD. Further, one of the doublets of phosphorus nuclei of the pyrophosphate group of bound NADP+ in the complex of adrenodoxin reductase and NADP+ was considerably shifted upfield in comparison with that of free NADP+. The spectrum of the complex of the reductase and NADP+ showed that the resonance of the 2'-phosphate group of NADP+ bound to the reductase was shifted downfield by 1.37 ppm compared with that of free NADP+ in the dianionic state. The 2'-phosphate resonance of bound NADP+ was independent of pH within the physiological range, whereas that of free NADP+ changed according to its ionization. The resonance of the 2'-phosphate group of NADP+ bound to the reductase also revealed that the ratio for the complex of NADP+ and the reductase was 1:1, and that this complex formation was inhibited by a high KCl concentration. These results were confirmed by electronic spectroscopic studies.

Adrenal Cortex↗
PubMed1985

Intermolecular fructosyl and levanbiosyl transfers by levan fructotransferase of Arthrobacter ureafaciens.

A purified levan fructotransferase preparation from the culture of the bacterium Arthrobacter ureafaciens, which produces di-D-fructose 2,6':6,2' dianhydride (difructose anhydride IV) from levan by an intramolecular levan fructosyl transfer (ILFT) reaction, was found to produce a trioligofructan and a tetraoligofructan from levan in the presence of levanbiose, indicating the intermolecular fructosyl and levanbiosyl transfer (LFT and LBT) reactions. The tri- and tetraoligofructans were identified to be levantriose and -tetraose respectively. Increase in the levanbiose concentration brought about increased production of both oligofructans with decreased formation of difructose anhydride IV, supporting the previous theory proposed by Tanaka et al. (1983) that the ILFT, LFT, and LBT reactions are catalyzed by the same enzyme. In addition, there existed a roughly stoichiometric relationship between the increase and decrease in the productions of these oligofructans, and the LBT reaction was found to occur more intensively than the LFT reaction. Acceptor specificity of the LFT and LBT reactions was studied using fifteen sugars including mono-, di-, and trisaccharides. The enzyme showed both of the reactions only with levanbiose, -triose, and kestose, indicating that the exposed non-reducing levanbiosyl residue was essential for the acceptor and suggesting the existence of a levanbiosyl acceptor site on the enzyme molecule.

Arthrobacter↗
PubMed1985

Promoting effect of the new chymotrypsin inhibitor FK-448 on the intestinal absorption of insulin in rats and dogs.

FK-448 is a potent and specific inhibitor of chymotrypsin, which enhances the intestinal absorption of insulin in rats and dogs resulting in a decrease in blood glucose levels in these animals. In dogs, the immunoreactive insulin (IRI) level of plasma rose proportionally to the decrease in blood glucose level. From in-vitro data, insulin was inactivated by pancreatic enzymes or the supernatants of intestine or liver homogenates. FK-448 suppressed the digestion of insulin by pancreatic enzymes and its enhancement of the intestinal absorption of insulin was found to be related to its inhibition of digestive enzymes, especially chymotrypsin.

Animals↗
PubMed1985

Where does phosphoglycolate come from in red cells?

The hypothesis that human red cells contain activity of ribulose-1,5-diphosphate (Ru-1,5-P2) oxygenase, an enzyme that catalyzes the synthesis of phosphoglycolate, was examined. The putative Ru-1,5-P2 oxygenase was partially purified from human red cells using DE-52 chromatography and (NH4)2SO4 fractionation by monitoring Ru-1,5-P2-dependent 3-phosphoglycerate formation. The synthesis of [32P]phosphoglycolate from [1-32P]Ru-1,5-P2 was attempted in the presence of the partially purified preparation of the provisional Ru-1,5-P2 oxygenase. There was no formation of radioactive phosphoglycolate even under 100% oxygen gas, indicating the absence of this enzyme activity in human red cells. Together with our previous report that glycolate kinase in human red cells is not responsible for the synthesis of phosphoglycolate in vivo, these studies raise the questions whether there is actually phosphoglycolate in red cells as well as whether novel pathways for its synthesis exist.

Diphosphoglyceric Acids↗
PubMed1985

Inhibitory effect of a new synthetic protease inhibitor (FUT-175) on the coagulation system.

The inhibitory effects of 6-amidino-2-naphthyl-4-guanidinobenzoate X dimethanesulfonate (FUT-175) on the human Hageman factor fragment (HFf), factor Xa, thrombin, plasma kallikrein, and plasmin were studied. FUT-175 inhibited plasma kallikrein most (IC50 = 3.0 X 10(-9) M), followed by HFf (IC50 = 3.3 X 10(-7) M). FUT-175 was found to have an anticoagulant effect in the APTT and PT assay systems of human plasma. The concentration of FUT-175 for twofold increase in the clotting time in the APTT assay system was 5 X 10(-7) M.

Anticoagulants↗
PubMed1985

Prostacyclin production reduced in diabetics with vascular complications.

Concentrations of plasma 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), a stable metabolite of prostacyclin, were measured by radioimmunoassay before and after 3 min of induced ischemia in 45 diabetics and 23 controls matched for age. In the 45 diabetics, 15 had no vascular complications (group I), 10 had a macroangiopathy (group II), 10 had a microangiopathy (group III) and 10 had both macroangiopathy and microangiopathy (group IV). Plasma levels of 6-keto-PGF1 alpha before forearm ischemia were significantly lower in group IV diabetics than in non-diabetic controls (188 +/- 17 pg/ml and 245 +/- 14 pg/ml, respectively). After 3 min of ischemia, plasma 6-keto-PGF1 alpha concentrations were increased in control subjects by 34% and by 21% in group I diabetics. In group III diabetics as well as diabetics with atherosclerotic vascular lesions (groups II and IV), no significant change was observed after 3 min of ischemia. These results suggest that impaired vessel wall prostacyclin production may to some extent be responsible for the development of diabetic retinopathy and nephropathy as well as atherosclerotic vascular complications.

6-Ketoprostaglandin F1 alpha↗
PubMed1985

Genome type analysis of adenovirus type 4 isolates, recently obtained from clinically different syndromes in some areas in Japan.

DNA cleavage analyses with EcoRI, HindIII and BamHI were carried out to investigate genome types of recent Ad 4 isolates obtained from acute respiratory disease (8 strains), and ocular disease (11 strains) in Japan. DNA cleavage patterns of all 19 isolates studied were identical regardless of whether they were recovered from respiratory tract or conjunctiva, but were distinct from that of the prototype strain.

Adenoviridae Infections↗
PubMed1985

Crystal structure of a left-handed RNA tetramer, r(C-br8G)2.

The crystal structure of the modified RNA tetramer, r(C-br8G-C-br8G), was determined by x-ray methods. The crystals are trigonal and belong to the space group P3212. There are three independent tetramers in the unit cell and each forms a left-handed duplex similar to Z-DNA regarding the orientations of the base moiety and the sugar puckerings in guanosine and cytidine. The effect of the additional bromine atom and 2'-hydroxy group on the stabilization of the Z-form structure are also described.

Crystallization↗
PubMed1985

A comparison of alprazolam, gefarnate and their combination in treatment of peptic ulcer patients--an application of life table analysis.

One hundred and thirty-nine patients with endoscopically confirmed peptic ulcers (gastric and duodenal) entered a double blind comparative evaluation of alprazolam (1.2 mg/day), gefarnate (300 mg/day) and their combination in treatment of peptic ulcer. Healing of ulcers was confirmed by endoscopic examinations. For evaluation of the treatment effect, the "life table" method was applied to the analysis of the data. The results revealed that ulcer healing with the combination was faster by two weeks than that with alprazolam or gefarnate alone. The difference did not reach the statistical significance in all the subjects who fulfilled the entry criteria. There was, however, a statistical difference between treatments in the patients having manifest psychic symptoms such as anxiety, insomnia and depressive mood (p less than 0.05 by generalized Kruskal-Wallis test and p less than 0.1 by Logrank test). The rate of patients who had psychic symptoms before entry and had not been cured of ulcers at the 4th week of treatment was 61% on the combination treatment as compared to 96% on the gefarnate treatment and 93% on the alprazolam treatment.

Actuarial Analysis↗
PubMed1985

[A light and electron microscopic study of papillary hidradenoma of the vulva].

Papillary hidradenoma is a rare benign tumor, which occurs mostly on the labia major or in the perianal region. Two cases were studied by light and electron microscopy. Light microscopically, these lesions were seen to consist of papillary adenomatous structures, whose lumina were lined by two to three layered cuboidal epithelial cells. Nuclear atypia and mitotic figures of these epithelial cells were rare. Nipple-like projections of their eosinophilic cytoplasm toward the lumina, resembling those of "apocrine" secretion, were frequently observed. Electron microscopy revealed that the epithelial cells lining the lumina had many secretory granules, lysosome-like structures with lipid, and large atypical mitochondria in their cytoplasm. The apical portion of the cytoplasm, which contained numerous secretory granules, often protruded toward the lumina. These ultrastructural features were considered to be similar to those of apocrine gland secretory cells. Moreover, in the basal layer of epithelium, spindle-shaped cells with features of typical myoepithelial cells were identified. These light and electron microscopic findings suggest that papillary hidradenoma of the vulva is one of the tumors of skin appendages with direction of differentiation toward the apocrine glands.

Adenoma, Sweat Gland↗
PubMed1985

[Sequential measurement of serum CA 125 levels in Krukenberg's tumor].

CA 125 is a tumor marker for ovarian cancer developed by hybridoma technology. In the present study, the levels of CA 125 were sequentially measured in the serum of five patients with Krukenberg's tumor originating in the gastrointestinal tract. Four out of the five (80%) had elevated serum CA 125 levels, i.e., greater than 35 U/ml and, in most cases, these levels decreased after resection of the ovarian tumor. Serum CA 19-9 and CEA levels were also increased in two (40%) and three (60%) patients, respectively, and, in these positive cases, reflected the clinical course. The results indicated the clinical usefulness of these cancer markers in Krukenberg's tumor.

Antigens, Neoplasm↗
PubMed1985

A case of postpartum hemolytic uremic syndrome with severe elevations of liver enzymes.

An unusual case of multifocused postpartum thrombotic microangiopathy was encountered in a woman with pregnancy-induced hypertension, which presented clinical features different from those generally seen in postpartum hemolytic uremic syndrome or thrombotic thrombocytopenic purpura. These changes included acute disseminated intravascular coagulation, severe elevations of liver enzymes, severe renal dysfunction, and hemolytic anemia. The patient was treated successfully with heparin, gabexate mesilate, furosemide, fresh whole blood, and large doses of corticosteroid with antibiotics, and she recovered completely without sequelae. The hypothetical pathogenesis of the complex symptoms of this catastrophic clinical condition is proposed.

Adult↗
PubMed1985

Glycolate kinase activity in human red cells.

Human red cells manifest glycolate kinase activity. This activity copurifies with pyruvate kinase and is decreased in the red cells of subjects with hereditary pyruvate kinase deficiency. Glycolate kinase activity was detected in the presence of FDP or glucose-1,6-P2. In the presence of 1 mmol/L FDP, the Km for adenosine triphosphate (ATP) was 0.28 mmol/L and a half maximum velocity for glycolate was obtained at 40 mmol/L. The pH optimum of the reaction was over 10.5 With 10 mumol/L FDP, 500 mumol/L glucose-1,6-P2, 2 mmol/L ATP, 5 mmol/L MgCl2, and 50 mmol/L glycolate at pH 7.5, glycolate kinase activity was calculated to be approximately 0.0013 U/mL RBC. In view of this low activity even in the presence of massive amounts of glycolate, the glycolate kinase reaction cannot account for the maintenance of the reported phosphoglycolate level in human red cells.

Adenosine Triphosphate↗