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Biomedical subjects

M Hatanaka

Publications and source records attributed to M Hatanaka.

At least 235 records · Page 13Linked to original sources
PubMed1989

The effects of a prostacyclin analog OP-41483 on pulmonary oxygen toxicity in an isolated heart-lung autoperfusion model.

Using an isolated canine heart-lung autoperfusion model, the effect of prostacyclin analog (OP-41483) on pulmonary oxygen toxicity was investigated. Twenty-four mongrel dogs were divided into four groups. Groups 1 and 2 inspired oxygen at concentrations (FiO2) of 0.95 and 0.6, respectively, while groups 3 and 4 received OP-41483 (0.1 micrograms/kg/min) in addition to FiO2 of 0.95 and 0.6. Autoperfusion was performed for five hours, and during the experiments the systolic blood pressure was maintained at 100 mmHg and the cardiac output at 40 ml/kg/min. After five hours of perfusion, PaO2 decreased significantly (P less than 0.01) from 410 +/- 49 mmHg to 237 +/- 38 mmHg in group 1, and also decreased significantly (P less than 0.01) from 368 +/- 44 mmHg to 243 +/- 26 mmHg in group 2. However, no significant changes in PaO2 were observed in groups 3 and 4. The pathological examinations clearly revealed perivascular edema and vascular dilation in groups 1 and 2, whereas no abnormal pathological findings were seen in groups 3 and 4. The above results indicate that OP-41483, when administered at the low dose of 0.1 micrograms/kg/min, induces no circulatory changes and exerts an effective action with respect to the prevention of pulmonary edema.

Animals↗
PubMed1989

Nucleolar targeting signal of human T-cell leukemia virus type I rex-encoded protein is essential for cytoplasmic accumulation of unspliced viral mRNA.

The posttranscriptional regulator (rex) of human T-cell leukemia virus type I is known to be located predominantly in the cell nucleolus and to induce the accumulation of gag and env viral mRNAs. The N-terminal 19 amino acids of rex-encoded protein (Rex) has been shown to be sufficient to direct hybrid proteins to the cell nucleolus. We have studied the function of the nucleolar targeting signal (NOS) of rex by using full-length proviral DNA and mutant rex expression plasmids. Partial deletions of the NOS sequence abolished the accumulation of unspliced cytoplasmic mRNA, although the gene products of rex mutants were found in the nucleoplasm. These results indicate that NOS sequence, or nucleolar localization of Rex, is essential for Rex function.

Animals↗
PubMed1989

Expression of oncogenes during rat chemical hepatotumorigenesis promoted by estrogen.

To elucidate the role of oncogene expression in hepatocarcinogenesis, we examined the expression of 4 cellular oncogenes (c-myc, c-fos, Ha-ras and c-erbA) in liver tissues induced by chemical agents. Four groups of male Sprague-Dawley rats were examined in the present study. Rats of the first and second groups were given a single intraperitoneal injection of diethylnitrosamine (DEN), 200 mg/kg body weight. Two weeks later, these rats were divided into two groups; the DEN-C group received no further medication, whereas the DEN-DES group was given diethylstilbestrol (DES), 0.5 mg/day, for 12 months. The DEN group was given DEN, 100 ppm, in drinking water for five months as the hepatocellular carcinoma (HCC) group. The DES group was given DES, 0.5 mg/day, from the start for 8 months. Rats of the DEN-DES and DEN groups developed grossly visible hepatic tumors. Significantly higher levels of c-myc gene expression were observed in tissues of HCC of the DEN group and in neoplastic nodules of the DEN-DES groups than in the DES and DEN-C group. The increase of c-myc mRNA seemed to begin after 1 month of treatment and became significant at 4 months in the DEN-DES group. On the other hand, no significant differences in mRNA levels of c-fos, Ha-ras and c-erbA were observed among these four groups. Although the significance of increased c-myc gene expression in neoplastic liver is still not known, it is conceivable that the persistent elevation of c-myc gene expression in the DEN and DEN-DES groups might contribute to the development of rat chemical hepatotumorigenesis.

Animals↗
PubMed1989

Late-phase accumulation of inositol phosphates stimulated by prostaglandins D2 and F2 alpha in neuroblastoma x glioma hybrid NG108-15 cells.

The accumulation of inositol phosphates (IPs) in response to prostaglandins (PGs) was studied in NG108-15 cells preincubated with myo-[3H]inositol. As a positive control, bradykinin caused accumulation of IPs transiently at an early phase (within 1 min) and continuously during a late phase (15-60 min) of incubation in the cells. PGD2 and PGF2 alpha did not significantly cause the accumulation of IPs at an early phase but significantly stimulated inositol bisphosphate (IP2) and inositol monophosphate (IP) formation at late phase of incubation. The maximum stimulation was obtained at greater than 10(-7) M concentrations of these PGs, the levels being three-and twofold for IP2 and IP1, respectively. 9 alpha, 11 beta-PGF2 has a slight effect but PGE2 and the metabolites of PGD2 and PGF2 alpha have no effect up to 10(-6)M. The effects of PGD2 and PGF2 alpha were not additive, but the effect of each PG was additive to that of bradykinin at a late phase of incubation. Inositol 1-monophosphate was mainly identified in the stimulation by 10(-5) M PGD2 and 10(-5) M PGF2 alpha, whereas both inositol 1-monophosphate and inositol 4-monophosphate were produced in the stimulation by 10(5) M bradykinin. Depletion of extracellular Ca2+ diminished the stimulatory effect of PGD2 and PGF2 alpha and late-phase effect of bradykinin, but simple Ca2+ influx into the cells by high K+, ionomycin, or A23187 failed to cause such late-phase effects. These results suggest that PGD2 and PGF2 alpha specifically stimulate hydrolysis of inositol phospholipids.

Animals↗
PubMed1989

Identification of a transforming gene of human papillomavirus type 16.

Previously, we observed sequential two-step alteration, growth stimulation, and progression to a more malignant state in NIH 3T3 cells transfected by human papillomavirus type 16 (HPV-16) DNA. In this study, we prepared a cDNA library from RNA extracted from cells transfected with the HPV-16 DNA and isolated cDNA clones which had growth-stimulating activity. Analysis of these cDNA clones indicated that the E7 open reading frame alone is responsible for inducing both steps of this cell transformation.

Animals↗
PubMed1989

[Synthetic cephalosporins. V. Synthesis and antibacterial activity of 3-alkylthio-7 beta-[(Z)-2-(2-aminothiazol-4-yl)-2-(O-substituted oxyimino)acetamido]cephalosporins and related compounds].

3-Alkylthio-7 beta-[(Z)-2-(2-aminothiazol-4-yl)-2-(O-substituted oxyimino)acetamido]cephalosporins (6 and 7) and the 3-methoxy analogues (10) were prepared by coupling diphenylmethyl 7-amino-3-alkylthio-3-cephem-4-carboxylate (1 and 2) or diphenylmethyl 7-amino-3-methoxy-3-cephem-4-carboxylate with (Z)-2-(2-tritylaminothiazol-4-yl)-2-(O-substituted oxyimino)acetic acid (4), followed by deprotection and subjected to examination of antibacterial activities. The pivaloyloxymethyl esters (8 and 9) of the compounds (6 and 7) were also prepared and oral activities of these esters were compared with those of the parent compounds (6 and 7). The cephalosporins (6a-j and 7a-c) had potent and wide antibacterial spectra against Gram positive and Gram negative bacteria which were comparable to those of cefixime or cefteram. Among them, the cephalosporins (6f and 7c) and the pivaloyloxymethyl esters (8b and 9b) had good in vivo efficacy in mice against infections of Escherichia coli No. 29 and especially 8b showed high urinary recovery in mice.

Animals↗
PubMed1989

cDNA cloning of human calpastatin: sequence homology among human, pig, and rabbit calpastatins.

cDNA of human calpastatin, an inhibitor protein specific for calpain (EC 3.4.22.17; Ca2(+)-dependent cysteine proteinase) was isolated by screening of a library prepared from human liver mRNA with pig calpastatin cDNA fragment as a probe. The primary structure of human calpastatin was deduced from the nucleotide sequence of the cDNA and compared with that of pig and rabbit calpastatins already reported. Human calpastatin consisted of 673 amino acid residues and had 78% and 77% identity to pig or rabbit calpastatins, respectively. Human calpastatin had a domain structure with four internally repetitive sequences and one N-terminal non-homologous sequence like the other calpastatins. Human calpastatin had two deletions, 22 and 13 residues long in domain L and domain 1, respectively, compared to pig or rabbit calpastatins.

Amino Acid Sequence↗
PubMed1989

Cloning and expression of the genes for calpains and calpastatins.

Calpain and calpastatin are known to be very widely distributed in animal cells. Although the physiological roles of calpain have not yet been clarified, the proteinase-proteinase inhibitor system has been suggested to play important roles in various cellular functions coupled with Ca2+ mobilization. By nucleotide sequencing of the cloned cDNAs, the primary structures of calpains and calpastatins have recently been disclosed. The expression of the genes for calpains and calpastatins in vitro as well as in vivo is being studied using cDNAs and their fragments. This paper reviews several topics on the recent progress of calpain research.

Amino Acid Sequence↗
PubMed1988

Fulminant clonal expansion of large granular lymphocytes. Characterization of their morphology, phenotype, genotype, and function.

A 39-year-old woman exhibited abrupt malignant transformation of the large granular lymphocytes (LGL) after a chronic course of T gamma-lymphoproliferative disease (T gamma-LPD). The T gamma-lymphocytes were CD2+, CD3-, CD8-, CD16+, Leu7-, and Leu19+ with morphologic characteristics of LGL. Newly appearing LGL were much larger and had more prominent azurophilic granules. Although fundamentally they had the same phenotype as the LGL in chronic stage, they showed increased Ia-like antigen and decreased CD16 antigen expressions. Immunoglobulin (Ig) G-kappa type monoclonal component was detected in the patient's serum. The LGL showed a germ-line configuration for T-cell receptor (TCR) beta and gamma chain genes, whereas the clonal chromosomal abnormalities indicated the neoplastic nature of the LGL. The LGL exhibited competent natural killer (NK), interleukin 2 (IL2) activated killer (AK), and antibody-dependent cell-mediated cytotoxicity (ADCC) activities. The LGL may have derived from NK cells at their mature stage with prethymic phenotype and may have influenced the homeostasis of the patient's humoral immune response.

Adult↗
PubMed1988

Sequence requirements for nucleolar localization of human T cell leukemia virus type I pX protein, which regulates viral RNA processing.

The posttranscriptional regulator (p27x-III) of human T cell leukemia virus type I (HTLV-I) is located predominantly in the cell nucleolus. A highly basic amino-terminal sequence (NH2-Met-Pro-Lys-Thr-Arg-Arg-Arg-Pro-Arg-Arg-Ser-Gln-Arg-Lys-Arg-Pro-Pro -Thr- Pro) in this protein, when fused to the amino termini of beta-galactosidase and p40x of HTLV-I, acts as an autonomous signal capable of directing the hybrid proteins to the cell nucleolus.

Amino Acid Sequence↗
PubMed1988

Malignant histiocytosis with rearrangement of the heavy chain gene and evidence of monocyte-macrophage lineage.

A unique case of malignant histiocytosis (MH) is reported. Its origin from the monocyte-macrophage system was indicated by expression of highly specific myeloid cell markers (My4, MCS2, and cytoplasmic lysozyme), diffuse activity of acid phosphatase and NaF-sensitive alpha-naphthyl acetate esterase, lack of immunologic markers specific for other cell lineages, and germ line configuration of the immunoglobulin light chain gene and the T-cell receptor beta-chain gene. Its neoplastic nature was suggested by the single rearranged band of the immunoglobulin heavy chain gene.

Adult↗
PubMed1988

Detection of hypermethylation of the c-abl genomic locus in the spleen of juvenile LE rats.

Tumor induction by treatment with polycylic hydrocarbons depends on age and the strains of rats used. Juvenile LE rats are very sensitive to the induction of leukemia and chromosomal breaks by intravenous DMBA injection. We have previously demonstrated a chromosomal translocation in chromosome 3 and 12 in a DMBA induced LE rat leukemia cell K3D. In our present communication we have examined the c-abl expression in the leukemic cell line as well as in the LE rats at different ages. We found that in the leukemic cell K3D the c-abl expression is elevated both at the level of mRNA and protein. In the preleukemic stage, highly elevated expression of c-abl mRNA was detected exclusively in the spleen of the juvenile LE rats. Furthermore this high expression of the c-abl gene correlates well with hypermethylation of possible cytosine residue in the c-abl genomic locus.

Animals↗
PubMed1988

Analysis of structure-function relationship of pig calpastatin by expression of mutated cDNAs in Escherichia coli.

Structure-function relationships in pig calpastatin were investigated. Calpastatin is an endogenous inhibitor protein specifically acting on calpains (Ca2+-dependent cysteine endopeptidases). We recently cloned and sequenced the cDNA for pig heart calpastatin and determined the amino acid sequence of the molecule from the nucleotide sequence. Various deletion mutants in one of the four internally repetitive domains (Domain 3, approximately 140 amino acid residues) were created by in vitro site-directed mutagenesis of a cloned cDNA fragment and expressed in Escherichia coli. Deletion of a conserved region on either the amino-terminal or carboxyl-terminal side caused a drastic loss of inhibitory activity against calpain I (low Ca2+-requiring form) and, to a lesser degree, against calpain II (high Ca2+-requiring form). Inhibitory activities were below the detectable level in mutants deleted further toward the central region. Substitution of two amino acids in the latter region of the wild-type Domain 3 protein caused a drastic loss of activity against both calpains. The creation of lowered affinity inhibitors enabled us to perform a conventional kinetic analysis which showed the mode of inhibition to be competitive. Prediction of the secondary structure of Domain 3 suggests that both the amino- and carboxyl-terminal conserved regions form alpha-helical structures, which are largely located in the interior of the calpastatin molecule, whereas the central region does not form alpha-helix or beta-structure. The central region contains a 12-residue consensus sequence common to Domains 1, 2, and 4, and this portion is predicted to be located on the surface of the calpastatin molecule. These results suggest that the central conserved region of each domain of calpastatin is an area for direct interaction either with the active center of calpain or a region in close proximity, and the rest of the domain is a region stabilizing the functionally important tertiary structure of the domain.

Amino Acid Sequence↗
PubMed1988

Pig heart calpastatin: identification of repetitive domain structures and anomalous behavior in polyacrylamide gel electrophoresis.

Isolation and nucleotide sequencing of the complementary DNA for pig heart calpastatin have been completed. The amino acid sequence of 713 residues predicted from the nucleotide sequence contains five domains, each composed of approximately 140 amino acid residues. A unique N-terminal domain is followed by four mutually homologous domains. The best fit alignment of these four domains gives residue identities between any two domains of 22.5-36.0%. The analysis of the sequence similarities by several methods also suggests the existence of additional shorter repeats at intervals of 60-80 residues. The calculated molecular weight of pig calpastatin of 713 amino acid residues (Mr 77,122) is significantly lower than the value of purified pig heart calpastatin (Mr 107,000) estimated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE). The expression of the calpastatin genes in Escherichia coli and the detection of the translation products of 713, 366, and 140 amino acid residues by the specific anti-calpastatin antibody indicate that the products always migrate considerably slow on SDS-PAGE, giving an average of 1.53 for the ratio of the molecular weight estimated by SDS-PAGE to the value calculated from the amino acid sequences. It is most likely that the discrepancy in the molecular weight is caused by an anomalous behavior of calpastatin in SDS-PAGE.

Amino Acid Sequence↗
PubMed1988

Synthesis of proteins in Escherichia coli immunoreactive with sera from individuals infected with human T-cell leukemia virus type I.

The env-pX IV fused gene of human T-cell leukemia virus type I (HTLV-I) was inserted into lac promoter-directed expression vectors for production of viral proteins in bacteria. Resulting recombinant plasmids, pK13 and pK15, directed synthesis of fused proteins of 59 kDa (Env-p40x) and 100 kDa (Gag-Env-p40x), respectively. Western blot analysis showed that these proteins were reactive with sera of patients with adult T-cell leukemia (ATL) and retained multiple antigenic determinants of viral proteins. In combination with recombinant Gag protein [S. Itamura, K. Shigesada, M. Imai, N. Kobayashi, T. Hamakado, T. Harada and M. Hatanaka, Gene 38, 57-64 (1985)], these bacterially synthesized proteins may provide a useful tool for differential diagnosis of ATL by detecting serum antibodies against individual viral proteins and for analysis of viral gene functions.

Antibodies, Viral↗
PubMed1988

Immortalization of murine leukocytes by oncogenes. II. Phenotypic characterization of transformants immortalized by v-src or Ha-ras oncogenes: expression of B220, a B-cell lineage specific antigen.

In the course of study to obtain murine dendritic cell lines using oncogenic retroviruses, we have established several immortalized cell lines with characteristics different from those of dendritic cells. The transformants were mainly round nonadherent cells, capable of growing in soft agar, and negative for nonspecific esterase activity. Profiles of cell surface antigens were examined by indirect immunofluorescence technique. The cell lines were positive for Fc receptor (2.4G2), J11d (J11d.2), and B220 (RA3-3A1/6.1) antigens and negative (or dull positive in small percentages) for Ia (M5/144.15.2), IL-2 receptor (3C7), Thy-1 (B5-5), Mac-1 (M1/70.-15.11.5), and macrophage (F4/80) antigens. They were negative for both surface and cytoplasmic immunoglobulins. Several clones were established from these transformant cell lines and cell surface antigens were examined. Antigenic profiles of these clones were very similar to those of the parental cell lines. Some of these clones, however, seemed to increase their Ia antigen expression. The results suggest that the transformants originated from early B-lineage cells.

Animals↗
PubMed1988

Expression of oncogenes in human liver disease.

To elucidate the role of oncogene expression in hepatocarcinogenesis, we examined the expression of 8 cellular oncogenes by dot blot and/or northern blot analysis in neoplastic, cirrhotic and non-cirrhotic human liver tissues obtained at surgery. Significantly higher levels of c-myc gene expression were observed in tissues of hepatocellular carcinoma (HCC) and adjacent cirrhotic tissues than in apparently normal liver tissues or those of chronic hepatitis (normal-chronic hepatitis). There was a tendency to higher c-myc mRNA levels in HCC than in liver cirrhosis. However, when tumorous and adjacent cirrhotic tissues from the same patient were compared, c-myc mRNA levels were not consistently higher in HCC. No significant differences in mRNA levels of c-fos, N-myc, N-ras, Ha-ras, c-erbA, c-erbB and c-abl were observed among the HCC, cirrhosis and normal-chronic hepatitis groups. Although the significance of increased c-myc gene expression in liver cirrhosis and HCC is still not known, it is conceivable that the persistent elevation of c-myc gene expression in cirrhosis contributes to the development of HCC.

Carcinoma, Hepatocellular↗