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Biomedical subjects

M Fushimi

Publications and source records attributed to M Fushimi.

27 records · Page 2Linked to original sources
PubMed1985

Transforming activity of the c-Ha-ras oncogene having two point mutations in codons 12 and 61.

A recombinant plasmid carrying the human c-Ha-ras gene with two point mutations in codons 12 and 61 was constructed and its transforming activity on mouse NIH 3T3 cells was compared with those of genes with a single mutation in either codon 12 or 61. Quantitative analyses revealed that the gene with two mutations had essentially the same transforming activity as the genes with single mutations. These results indicate that a single mutation of the c-Ha-ras gene in either codon 12 or 61 is sufficient to activate the gene and that neither of the two mutation sites involved in activation of the gene needs to be intact for transforming activity.

Animals↗
PubMed1984

A novel combination of K-ras and myc amplification accompanied by point mutational activation of K-ras in a human lung cancer.

Amplifications of two oncogenes, c-K-ras-2 and c-myc, were found in a human lung giant cell carcinoma (LGCC) Lu-65, which is maintained in nude mice. The extent of c-K-ras-2 and myc amplifications were estimated to be 10- and 8-fold, respectively, by means of the Southern hybridization procedure. In addition, NIH3T3 cells were transformed by transfection of Lu-65 DNA and the transforming gene was identified as c-K-ras-2. c-K-ras-2 genes were cloned from a gene library of Lu-65 and a single point mutation causing a substitution of cysteine for glycine in codon 12 was found by DNA sequencing. It was concluded that the amplification of the c-myc and c-K-ras-2 genes are accompanied by point mutational activation of c-K-ras-2 in the human LGCC Lu-65. This is the first report of multiple gene amplification accompanied by a point mutation of oncogenes in human cancer cells, providing further support for the idea that co-operation of at least two activated cellular oncogenes is required for carcinogenesis.

Amino Acid Sequence↗
PubMed1984

Rapid measurement of oestradiol and oestriol by high-performance liquid chromatography after automatic pretreatment.

A fluorometric liquid chromatographic method was developed for measurements of unconjugated oestradiol and oestriol in the serum of pregnant women. The serum samples are injected directly into the apparatus and pass to a pretreatment column, where oestrogens are adsorbed while hydrophilic components such as proteins and carbohydrates are not. The oestrogens then pass into a separation column containing a new type of polymer gel. The mobile phase consists of an acetonitrile-water mixture, and separation is achieved by a reversed-phase mechanism. The eluent is monitored for fluorescence. Data on the reproducibility and recovery by this method and the correlation of values with those obtained by radioimmunoassay are reported. Results on the increases of oestradiol and oestriol in the serum during pregnancy are also reported.

Autoanalysis↗
PubMed1984

Molecular cloning and the total nucleotide sequence of the human c-Ha-ras-1 gene activated in a melanoma from a Japanese patient.

The transforming gene of malignant melanoma tissue obtained from a Japanese patient and maintained in nude mice has been cloned in its biologically active form and identified as the c-Ha-ras-1 gene, a homologue of the viral Ha-ras gene. Nucleotide sequence analysis revealed that the genetic alteration responsible for the transforming activity of the melanoma oncogene was localized to a single point mutation in the second exon. The transversion of adenine to thymine results in the substitution of leucine for glutamine as amino acid residue 61 of the predicted p21 protein. Other nucleotide sequences spanning a 2.9-kilobase segment including the entire exons and introns were found to be exactly the same as those in a proto-oncogene from a normal Caucasian reported previously, except for base alterations explained as polymorphic differences.

Base Sequence↗
PubMed1983

A highly sensitive determination of individual serum bile acids using high-performance liquid chromatography with immobilized enzyme.

We have developed a highly sensitive method for the simultaneous determination of individual bile acids in serum using high-performance liquid chromatography (HPLC) combined with immobilized 3 alpha-hydroxysteroid dehydrogenase. Both the HPLC column and the immobilized-enzyme column are suitable for use with alkaline solutions necessary in working with this enzyme system. With this method we were able to determine simultaneously fifteen different serum bile acids.

3-Hydroxysteroid Dehydrogenases↗
PubMed1981

Pluripotent, erythrocytic and granulocytic hemopoietic precursors in chronic granulocytic leukemia.

Using methylcellulose culture techniques, we investigated the behavior of committed and pluripotent hemopoietic precursors (CFUMIX) in marrow cells and blood from patients with chronic granulocytic leukemia (CGL) in the chronic phase whose marrow cells showed the presence of Ph1 chromosomes. The relative concentrations of the marrow precursors in CGL were nearly equal to those in control patients. The mean nucleated cell count in marrow fluid from the patients, however, was 6.3 times that of control values. As a result, the mean concentrations per unit volume of the hemopoietic precursors in CGL were significantly higher than those in control patients. Furthermore, the presence of erythropoietin (Ep) independent BFUE giving rise to erythropoietic bursts in the medium without the addition of Ep was demonstrable in marrow cells and blood. In the peripheral blood, the increment in numbers of CFUC, CFUE, BFUE, and CFUMIX in accordance with the leucocyte count was observed. The present results are consistent with the theory that the clonal expansion in CGL occurs at the level of pluripotent hemopoietic precursors and suggest that CFUMIX in CGL can differentiate into CFUE along the erythropoietic pathway and that a regulatory defect in CGL in present in both granulocytic cells and erythrocytic cells.

Adult↗
PubMed1980

Pluripotent hemopoietic precursors in vitro (CFUMIX) in aplastic anemia.

When human marrow cells were cultured in a medium containing alpha-medium, methylcellulose, fetal calf serum, bovine serum albumin, erythropoietin, and leucocyte-conditioned medium, mixed colonies composed of erythrocytic cells and granulocytes were formed. The clonal nature of the mixed colonies was confirmed by the linear relationship between the numbers of cells plated and the number of colonies, and the absence or presence of Y-chromatin in the mixed colonies in a co-culture experiment with male and female cells. Using the methylcellulose cell culture techniques, the pluripotent hemopoietic precursors (CFUMIX) in marrow cells from 15 patients with aplastic anemia were assayed. In the control subjects of patients with iron-deficiency anemia, lymphoadenitis, reactive leucocytosis or Hodgkin's disease, 8 X 10(5) marrow cells in 4 dishes produced 12.7 +/- 6.9 (mean +/- SD) mixed colonies. On the other hand, 8 X 10(5) marrow cells from patients with aplastic anemia formed only 2.1 +/- 5.5 (mean +/- SD) mixed colonies. Furthermore, the marrow cells from 5 patients who were repeatedly receiving transfusions contained no CFUMIX which give rise to mixed colonies. The present results provided the first direct evidence that pancytopenia in most patients with aplastic anemia results from a reduced influx into the compartment of maturing hemopoietic cells from the compartment of pluripotent hemopoietic precursors.

Adult↗
PubMedDate not supplied

Induction of bone loss by bile duct ligation in rats.

Metabolic bone loss is the most common complication of chronic liver disease. However, there is little information available about bone loss in rats with a ligated bile duct, a biliary-type of experimental cirrhosis model. Therefore, in this study, the effect of bile duct ligation (BDL) on bone mineral density (BMD) and plasma insulin-like growth factor-I (IGF-I) levels was examined in rats. Two weeks after BDL operation, the rats with a ligated bile duct showed a pronounced and significant decrease in both trabecular and cortical BMD of the femur. In these rats, decreases in food intake and plasma IGF-I levels plus elevated levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and bilirubin were also observed. When the effect of dietary restriction (30% or 50%) over 2 weeks was then investigated in normal rats, 50% food restriction resulted in a significant decrease in femoral trabecular bone density although BMD was unchanged by 30% dietary restriction. The plasma levels of IGF-I were also decreased in food-restricted rats. Thus, the decrease in femoral bone density in 50% food-restricted rats was less potent compared with BDL rats; nevertheless, the decrease in plasma levels of IGF-I was almost equally potent in both BDL and food-restricted rats. Overall, this study showed that BDL operation resulted in a pronounced bone loss in rats, but also that this bone loss might not be merely due to the decreases in food intake and plasma IGF-I levels. These results suggest that BDL in rats is a useful experimental cirrhosis model for evaluating the bone loss associated with chronic liver disease.

Animals↗