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Biomedical subjects

T Shiosaka

Publications and source records attributed to T Shiosaka.

At least 19 recordsLinked to original sources

Mutations in the envelope protein of Japanese encephalitis virus affect entry into cultured cells and virulence in mice.

The nucleotide sequences of the envelope protein of the Kamiyama 1 strain of Japanese encephalitis (JE) virus and a passaged mutant (Kamiyama 2 strain) were determined. Two amino acid differences, Ser-Phe at residue 364 and Asn-Ile at residue 367, distinguished Kamiyama 2 from Kamiyama 1. Six neutralization-resistant variants were selected from these two strains using a JE species-specific monoclonal antibody with neutralization and hemagglutination-inhibition reactivities. All variants had a single amino acid substitution at residue 52 and significantly reduced reactivity with other JE species-specific monoclonal antibodies. The variants derived from Kamiyama 2 strain showed reduced virulence in 3-week-old mice after peripheral inoculation but were as virulent as the parent virus when inoculated intracranially. These variants also showed altered early virus-cell interaction but not replication and reproduction in Vero cells. These findings indicate that the mutations at residues 52, 364, and 367 affect early virus-cell interaction in Vero cells and virulence in mice.

Amino Acid Sequence

Inhibitory effect of tumor necrosis factor on gene expression of hormone sensitive lipase in 3T3-L1 adipocytes.

Recombinant human tumor necrosis factor (TNF) depressed the activities of both lipoprotein lipase (LPL) and hormone sensitive lipase (HSL) in 3T3-L1 adipocytes, 3 to 24 h after its introduction to the cells. HSL gene expression, as measured by Northern blotting analysis with 32P-labeled cloned HSL-cDNA, was also suppressed. These results suggested that the reduction in HSL activity caused by TNF resulted from inhibited gene expression of the enzyme.

Adipose Tissue

[Blast crisis of chronic myelogenous leukemia with blasts expressing both immature B lymphocyte- and myelomonocyte-associated antigens and differentiating into basophils in vitro].

A 43-year-old woman with Ph1-positive chronic myelogenous leukemia (CML) was diagnosed as having blastic crisis. The phenotype of blasts was CD9+, CD10+, CD19+, CD11b+ and CD33+, suggesting the B Lymphoid and myeloid mixed lineage. Two color analysis of CD10 and CD33 revealed that 50% of blast cells had both B lymphocyte- and myelomonocyte-associated surface markers. Rearrangement of the immunoglobulin heavy chain gene was detected. After culturing blasts with 12-o-tetradecanoyl-phorbol 13 acetate (TPA), basophilic granules appeared in cytoplasm of the cells. These granules were positive for toluidine blue staining. This finding that the biphenotypic blasts expressing both B lymphoid and myelomonocytoid features differentiated into basophils suggests that blasts of this case are derived from a common progenitor of B lymphoid and myeloid lineages including basophil.

Adult

Expression of selected genes in differentiated HL-60 cells and primary cells from human leukemias.

Expression of three clones (6-1E, 7-3G and 9-5C) selected from a chronic lymphocytic leukemia cDNA library was studied by nucleic acid hybridization in human promyelocytic leukemia cells (HL-60) treated with chemical inducers of cell differentiation and in primary cells derived from 27 patients with leukemia or myelodysplastic syndrome. The differentiation of HL-60 cells into macrophage-like cells upon induction by 12-0-tetradecanoyl phorbol-13-acetate (TPA) was accompanied by rapid induction of the expression of 6-1E and 7-3G genes. The levels of expression of the 9-5C gene were not altered during macrophage-monocytic or granulocytic differentiation of HL-60 cells. The expression of the 6-1E and/or 7-3G gene was induced by TPA in four of 6 samples derived from patients who achieved complete remission, but not in any of the acute nonlymphocytic leukemia samples from patients who failed to achieve complete remission. These findings suggest that expression of the 6-1E and 7-3G genes is related to macrophage-monocytic differentiation and that alterations of these gene expressions in fresh leukemia cells after one hour of TPA treatment are of prognostic significance in predicting the response to therapy.

Base Sequence

A case of primary liver cell cancer complicating lupoid hepatitis.

We report a male patient with lupoid hepatitis who developed primary liver cell cancer 8 years after the onset of lupoid hepatitis. Primary liver cell cancer is thought to be a rare complication of lupoid hepatitis. To our knowledge, this complication has been previously reported in only 6 patients. The etiology of chronic active hepatitis is not known, but is strongly suspected to be associated with an autoimmune mechanism. There is evidence of an increased incidence of malignancy in other forms of autoimmune disease, and this may represent a further contributing factor to the development of primary liver cell cancer in cases of chronic active hepatitis.

Autoimmune Diseases

Preferentially expressed genes in stomach adenocarcinoma cells.

cDNA clones complementary to mRNA of neoplastic cells of human stomach tissue were used to examine quantitative changes in the mRNA levels of specific genes in neoplastic cells. Poly(A)+ RNA from poorly differentiated adenocarcinoma cells of a female patient with stomach cancer was used for construction of a complementary DNA (cDNA) library. Screening of the 18,000 colonies utilizing 32P-cDNAs derived from normal human tissue and stomach carcinoma tissue samples was used to select clones likely to represent sequences preferentially expressed in stomach carcinoma cells. Twenty-six recombinants were initially selected and further analysis of these clones indicated that eight (4-3D, 9-2D, 9-4G, 29-1G, 29-6F, 37-1B, 115-5A and 52-5F) contain sequences preferentially expressed in stomach carcinoma cells. We have identified the 9-4G, 29-1A, and 29-6F genes which are differentially expressed in human neoplasia.

Adenocarcinoma

Phenotypic and genotypic analysis of chronic myelogenous leukaemia with T lymphoblastic and megakaryoblastic mixed crisis.

A case of blast crisis in chronic myelogeneous leukaemia (CML) in which two distinct cell lineages were involved is presented. The phenotype of blasts in lymph nodes was T11 (CD2)+, Ia+, TdT+, suggesting T cell lineage. On the other hand, blasts in bone marrow and peripheral blood expressed platelet glycoprotein IIb/IIIa complex on their surface, suggesting megakaryocyte lineage. Cytogenetic analysis of lymph node and bone marrow cells revealed the abnormalities, inv(7) (p15q34) and t(1;3) (q23;q21), respectively, as well as the presence of the Ph1 chromosome in both cell types. Rearrangement of the T cell receptor beta-chain gene was detected in lymph node blasts, although blast cells in peripheral blood showed a germ line configuration. The involvement of T cell and megakaryocyte lineages in the blast crisis phase of CML was confirmed in our phenotypic and genotypic analysis, and the pathogenic association between blast crisis lineages and the additional chromosome abnormalities present is discussed.

Blast Crisis

Structure and function of adenylate kinase isozymes in normal humans and muscular dystrophy patients.

Two isozymes of adenylate kinase from human Duchenne muscular dystrophy serum, one of which was an aberrant form specific to DMD patients, were separated by Blue Sepharose CL-6B affinity chromatography. The separated aberrant form possessed a molecular weight of 98,000 +/- 1,500, whereas the normal serum isozyme had a weight of 87,000 +/- 1,600, as determined by SDS-polyacrylamide gel electrophoresis, gel filtration, and sedimentation equilibrium. The sedimentation coefficients were 5.8 S and 5.6 S for the aberrant form and the normal form, respectively. Both serum isozymes are tetramers. The subunit size of the aberrant isozyme (Mr = 24,700) was very similar to that of the normal human liver isozyme, and the subunit size of the normal isozyme (Mr = 21,700) was very similar to that of the normal human muscle enzyme. The amino acid composition of the normal serum isozyme was similar to that of the muscle-type enzyme, and that of the aberrant isozyme was similar to that of the liver enzyme, with some exceptions in both cases.

Adenylate Kinase

Hepatic triglyceride lipase and lipoprotein lipase activities in post-heparin plasma of patients with various cancers.

The total post-heparin lipolytic activity (PHLA) and hepatic triglyceride lipase (HTGL) and lipoprotein lipase (LPL) activities in post-heparin plasma of patients with various cancers were measured. In patients with cancers, PHLA was similar to that of controls, but the HTGL activity was decreased and the LPL activity was increased. Thus, in cancer patients the ratios of HTGL to PHLA were lower, and the ratios of LPL to PHLA were higher than in controls. No correlation was found between the plasma lipid level and HTGL or LPL activity.

Aged

Intracellular distribution of various enzymes concerned with DNA synthesis from normal and regenerating rat liver, and Yoshida sarcoma.

During the fractionation of various enzymes concerned with DNA synthesis from the postmicrosomal supernatant fraction of various tissues, DNA polymerace [EC 2.7.7.7], thymidine kinase [EC 2.7.1.75], dTMP kinase [EC 2.7.4.9], deoxycytidine kinase [EC 2.7.1.74], and deoxycytidine monophosphokinase (dCMP kinase) [EC 2.7.4.14] were found in the pellet fraction of postmicrosomal supernatant. Further, the uridine kinase [EC 2.7.1.48] and aspartate transcarbamylase [EC 2.1.3.2] activities of postmicrosomal supernatant from various tissues were also present in this pellet fraction. The activities of DNA polymerase, thymidine kinase, uridine kinase, and aspartate transcarbamylase from normal and regenerating rat liver, and Yoshida sarcoma were higher in the pellet fraction than in the supernatant. On the other hand, the activities of dTMP kinase, dCMP kinase, and orotidine-5'-phosphate decarboxylase [EC 4.1.1.23] were lower in the pellet fraction than in the supernatant. The pellet fractions of regenerating rat liver and Yoshida sarcoma showed a remarkable incorporation of various precursors (thymidine, dTMP, deoxycytidine, and dCMP) into DNA in the presence of a suitable DNA template, ATP and all four deoxynucleoside 5'-triphosphates for DNA synthesis. Normal adult rat liver catalyzed a much smaller incorporation of all these precursors, except for dCMP.

Animals