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Biomedical subjects

Y Fukumoto

Publications and source records attributed to Y Fukumoto.

At least 145 records · Page 8Linked to original sources
PubMed1986

Involvement of three intracellular messenger systems, protein kinase C, calcium ion and cyclic AMP, in the regulation of c-fos gene expression in Swiss 3T3 cells.

In quiescent cultures of Swiss 3T3 cells, platelet-derived growth factor or fibroblast growth factor known to induce both protein kinase C activation and Ca2+ mobilization raised c-fos mRNA. This action of the growth factors was mimicked by the specific activators for protein kinase C, such as phorbol esters and a membrane-permeable synthetic diacylglycerol, and also by the Ca2+ ionophores, such as A23187 and ionomycin. Prostaglandin E1 known to elevate cyclic AMP also raised c-fos mRNA, and this action was mimicked by 8-bromo-cyclic AMP, dibutyryl cyclic AMP and forskolin. These results suggest that expression of the c-fos gene is regulated by three different intracellular messenger systems, protein kinase C, Ca2+ and cyclic AMP, in Swiss 3T3 cells.

Alprostadil↗
PubMed1986

Effects of the intravenous administration of magnesium sulfate on corrected serum calcium level and nephrogenous cyclic AMP excretion in normal human subjects.

The effect of intravenous magnesium sulfate infusion on corrected serum calcium level and parathyroid function assessed by determination of nephrogenous cAMP (NcAMP) excretion were studied in normal human subjects. Significant hypermagnesemia induced by the magnesium sulfate infusion for 120 minutes was accompanied by a gradual and progressive decrease in the corrected serum calcium level. NcAMP excretion fell rapidly, reaching a nadir between 60 and 120 minutes after the infusion began, and after that rose above the baseline excretion. Urinary calcium excretion gradually increased, reaching a peak between 120 and 180 minutes after the infusion began and then gradually decreased. Since magnesium was given as the sulfate, it is not clear whether these changes were attributable to magnesium or sulfate or both. As a control study, we performed intravenous sodium sulfate infusion. The sodium sulfate infusion caused slight hypocalcemia, slight hypercalciuria, and a significant increase in NcAMP excretion. These findings indicate that the hypocalcemia and the hypercalciuria caused by the magnesium sulfate infusion is mainly due to the effect of magnesium, and that the decrease in NcAMP excretion during the infusion is due to the effect of magnesium alone. We conclude that the hypocalcemia caused by the magnesium sulfate infusion is mainly due to the renal calcium loss, and that the inhibition of parathyroid function caused by hypermagnesemia may be only partially involved in the early phase of this hypocalcemia.

Adult↗
PubMed1986

Effects of intraportal prostacyclin on hepatic bile flow in the rat.

Prostaglandins including prostacyclin (PGI2) have been demonstrated to have choleretic properties in dogs and in this study the effect of PGI2 on bile flow in rats has been investigated. PGI2 at a dose of 250 ng kg-1 min-1 was infused into the mesenteric vein of biliary cannulated rats and bile samples were collected every 10 min. Administration of PGI2 did not produce any significant changes in bile flow and in the output of bile acids or sodium, potassium and bicarbonate as compared to controls infused with buffer alone. Similarly no differences in pancreatic juice flow or bicarbonate output were observed between PGI2 treated rats and controls. No hypotension was observed at this dose of PGI2 given intraportally indicating inactivation by the liver. Thus in the rat, unlike the dog, no effects of PGI2 on bile flow were observed but this could be related to the route of administration.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

Epidermal growth factor increases c-myc mRNA without eliciting phosphoinositide turnover, protein kinase C activation, or calcium ion mobilization in Swiss 3T3 fibroblasts.

Incubation of quiescent cultures of Swiss 3T3 cells with epidermal growth factor (EGF) caused an increase in c-myc mRNA. Under these conditions, EGF did not induce phosphoinositide turnover, formation of diacylglycerol, formation of inositol tris-, bis-, and monophosphates, protein kinase C activation, or Ca2+ mobilization. Although it has been reported that both protein kinase C and Ca2+ may be responsible for the platelet-derived growth factor- and fibroblast growth factor-induced increases in c-myc mRNA in Swiss 3T3 cells (Kaibuchi, K., Tsuda, T., Kikuchi, A., Tanimoto, T., Yamashita, T., & Takai, Y. (1986) J. Biol. Chem. 261, 1187-1192), these results indicate that neither protein kinase C nor Ca2+ is involved in the EGF-induced increase in c-myc mRNA, and that an unidentified system may be involved in this reaction.

Calcium↗
PubMed1986

Hypercalcemia in glucocorticoid withdrawal.

We found severe hypercalcemia in the course of hydrocortisone withdrawal in a patient who had undergone unilateral adrenalectomy to resect a cortisol-hypersecreting adenoma. Serum calcium gradually but progressively increased after unilateral adrenalectomy. Severe hypercalcemia developed on the 77th postoperative day (the 15th day after discontinuing hydrocortisone replacement). The serum concentration of calcium, PTH, 25(OH)D, and 1,25(OH)2D were 8.0 mEq/l, less than 100 pg/ml, 10.1 ng/ml and 29.6 pg/ml, respectively. This hypercalcemia was accompanied by marked urinary hydroxyproline excretion and less calcium excretion in the urine than the prevailing level of serum calcium. Serum concentrations of 25(OH)D, 1,25(OH)2D and PTH were not elevated during the severe hypercalcemia. We concluded that the hypercalcemia in this patient was due in part to enhanced bone resorption and increased renal tubular reabsorption of calcium as a result of glucocorticoid withdrawal, but not to the elevation of serum PTH or serum 25(OH)D and serum 1,25(OH)2D.

Adenoma↗
PubMed1986

Hyperphosphatemia as a detectable laboratory manifestation of glucocorticoid withdrawal syndrome.

We found hyperphosphatemia in five patients who had undergone unilateral adrenalectomy (ADX) for resection of cortisol-producing adenomas. The mean (+/- SEM) serum inorganic phosphorus level, theoretical renal phosphorus threshold and percent tubular phosphorus reabsorption rose from the preoperative level of 3.3 +/- 0.2 mg/dl, 2.6 +/- 0.2 mg/dl and 82.1 +/- 0.6%, to 6.0 +/- 0.2 mg/gl, 7.4 +/- 0.4 mg/dl and 95.9 +/- 1.0%, respectively, after ADX (P less than 0.001, P less than 0.001, P less than 0.001). Urinary phosphorus excretion decreased from 549 +/- 40 to 294 +/- 108 mg/day after ADX (P less than 0.05). Changes in serum calcium, serum sodium, serum potassium, serum chloride and creatinine clearance were not significant after ADX. Hyperphosphatemia may be the only abnormality found in serum electrolytes in glucocorticoid deficiency. It thus seems that hyperphosphatemia may be regarded as one of the clinical manifestations of the glucocorticoid withdrawal syndrome.

Adenoma↗
PubMed1985

Proton nuclear magnetic resonance study of the third component of complement: solution conformation of the carboxyl-terminal segment of C3a fragment.

A proton nuclear magnetic resonance (NMR) study is reported of des-Arg-C3a, which is a 76-residue fragment obtained from the N-terminal portion of the alpha chain of the third component of human complement. A method of carboxypeptidase digestion/difference spectroscopy [Endo, S., & Arata, Y. (1985) Biochemistry 24, 1561-1568] was used for the spectral assignments for Ala-76, Leu-75, Gly-74, His-72, His-67, and Ala-48. On the basis of the NMR results obtained for these residues, we conclude that in aqueous solution (1) the C-terminal segment Leu-73-Ala-76 is free from interactions with the rest of the C3a molecule and (2) the major part of the C-terminal segment takes an ordered conformation. We also suggest that the presence of a core, which is formed by segment Tyr-15-Tyr-59 [Huber, R., Scholze, H., Paques, E. P., & Deisenhofer, J. (1980) Hoppe-Seyler's Z. Physiol. Chem. 361, 1389-1399], is essential for the C-terminal segment in maintaining the ordered structure in aqueous solution. 1H NMR spectral data were also obtained for the intact C3 from human and porcine sources. The resonances for the C2-H protons of His-67 and His-72, which exist in the C3a part of the human C3 molecule, were assigned. Comparisons of the results obtained with those for des-Arg-C3a demonstrate that upon cleavage of C3a very little change, if any, is induced in microenvironments of His-67 and His-72 and a piece of segment that contains His-72 is exposed to solvent and highly flexible.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1985

An improved method for preparation of C1-depleted serum and its application to hemolytic assay of C1.

Serum depleted of the first component of complement (C1D) was prepared by treating fresh human serum with Sepharose-IgG in the presence of triethylenetetramine-N,N,N',N'',N''',N'''-hexa-acetic acid and di-isopropyl fluorophosphate at acidic pH (5.2). The total hemolytic activity of this C1D could be increased to approximately 75% of that of the original serum by the addition of excess purified C1. A linear relation was obtained on determination of C1 hemolytic activity using C1D, and the C1 titers of sera from patients measured by this simple method showed a good correlation with those measured using intermediate cells.

Animals↗
PubMed1985

One point dilution enzyme-linked immunosorbent assay (ELISA) for Toxoplasma gondii seroepidemiological surveys.

A one point dilution enzyme-linked immunosorbent assay (ELISA) procedure suitable for determining immunoglobulin G (IgG) antibody levels to Toxoplasma gondii (T. gondii) in community seroepidemiological surveys is described. A two-fold serial dilution ELISA procedure was first used to determine the IgG titers in 56 and 83 sera earlier screened by the Sabin-Feldman dye test (DT) and the indirect hemagglutination test (IHA), respectively. The regression rate of the results by the DT and ELISA was 0.92. Comparison of the results by the IHA and the two-fold serial dilution ELISA gave regression coefficient of 0.92. Using the absorbance values for the test sera at dilutions of 1:20, standard curves made by plotting the optical density versus the corresponding dilution factor of a control sera were used to estimate the antibody levels. The regression coefficient of the results by the two-fold serial dilution method and those by the curves for sera with titers of up to 1:320 was 0.97. The curves could not, however, estimate accurately the antibody level in sera with titers above 1:320. The one point dilution ELISA described is a useful epidemiological tool for the screening of IgG antibody to Toxoplasma gondii in the community. However, larger series are required to confirm our observations.

Antibodies↗
PubMed1985

Recombinant gamma-interferon and lipopolysaccharide enhance 1,25-dihydroxyvitamin D3-induced cell differentiation in human promyelocytic leukemia (HL-60) cells.

The induction of cell differentiation by a combination of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3], recombinant gamma-interferon (rec gamma-IFN), and a lipopolysaccharide from E. coli (LPS) was studied in a clonal population (clone-9) of human promyelocytic HL-60 leukemia cells in vitro. Treatment of clone-9 cells with 10(-9) to 10(-7)M 1,25-(OH)2D3 yielded a macrophage cell differentiation. The addition of 10 or 100 U/ml of gamma-IFN and 2 or 10 micrograms/ml LPS caused a further increase in expression of the different differentiation markers. The most pronounced effects involved increases in cell attachment to the surface of tissue-culture Petri dishes and in lysozyme, nonspecific esterase, and cytolytic activities. The combined treatment with 1,25-(OH)2D3 and rec gamma-IFN and LPS also caused an increase in the percent of multinucleated giant cells. These results indicate the effectiveness of combining different agents in inducing cell differentiation in HL-60 cells. A similar approach may be useful in controlling myeloid leukemias in vivo.

24,25-Dihydroxyvitamin D 3↗
PubMed1984

Bacteriological study of periodontal lesions in two sisters with juvenile periodontitis and their mother.

A total of five bacteriological samples from the periodontal pockets of two sisters with localized juvenile periodontitis and their mother with advanced periodontitis was studied. Gram-negative anaerobic rods were predominant in the samples. Bacteroides intermedius and Bacteroides loescheii were the most predominant species. The antigenicity and bacteriocinogenicity of these isolates were quite similar. Serum immunoglobulin G antibody levels of the subjects to gram-negative periodontopathic bacteria were measured by using the micro-enzyme-linked immunosorbent assay. The levels of antibodies to saccharolytic black-pigmented Bacteroides species were significantly higher than the levels in healthy young females.

Adolescent↗
PubMed1984

Distributions and recoveries of complement components during cold ethanol fractionation of human plasma.

The distributions and recoveries of the hemolytic activities and quantities of protein of complement components during cold ethanol fractionation were studied. Most of the components were recovered in Cohn's fraction III, with slight activities in fractions I and IV. The hemolytic activities of C1 and C5 were recovered in high yields in fraction III. The recoveries of activities of late components of complement (C6-C9) in fraction II + III were also high. These results suggest that many complement components can be isolated from Cohn's ethanol fractions.

Cold Temperature↗
PubMed1984

Curious manifestations in cavernous hemangioma of the liver.

We report a cavernous hemangioma of the liver with some curious findings. Angiography showed a hypervascular lesion and the arterioportal shunt which commonly is regarded as a pathognomonic sign of malignancy. Laparoscopy showed a well-defined, reddish-purple elevated lesion with a central umbilication. As the patient was a painter and dealing with vinyl chloride monomer, we suspected the possibility of hemangiosarcoma. The lesion proved to be a cavernous hemangioma with central fibrous replacement probably in consequence of thrombosis of some cavernous spaces.

Angiography↗