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Biomedical subjects

M Miwa

Publications and source records attributed to M Miwa.

At least 271 records · Page 15Linked to original sources
PubMed1984

Nucleotide sequence analysis of human T-cell leukemia virus type II.

The total nucleotide sequence of an infectious clone of human T-cell leukemia virus type II (HTLV-II) provirus was determined. The provirus has 8,952 nucleotides with a long terminal repeat (LTR) at each end. The LTR consists of 341 +/- 1 bases of U3, 248 +/- 1 bases of R, and 201 bases of U5 regions. There are gag, pol, and env coding frames in this order from the 5' end of the provirus as in other avian or mammalian retroviruses. A coding frame that can code 178 amino acid residues found between gag and pol is supposed to be for a protease that hydrolyses a gag precursor protein to matured gag proteins. The gag and protease genes and the pol and env genes, respectively, partly overlap. In the region termed X between env and 3' LTR, there are three major open reading frames. Oligopeptides deduced from the sequence of one of the open reading frame in HTLV-I were synthesized chemically, and antibodies against these peptides were raised in rabbits. With these antibodies, 41 kdalton and 38 kdalton proteins were detected in cells infected with HTLV-I and HTLV-II, respectively.

Base Sequence↗
PubMed1984

Pseudotype viruses bearing envelope antigens of Japanese isolates of human T-cell leukemia viruses type I.

We tried to transmit human T-cell leukemia virus type I (HTLV-I) into non-lymphoid cells and found that S+L- CCC cat cells were permissive for HTLV-I. Using these HTLV-positive cat cells, vesicular stomatitis virus (VSV) pseudotypes bearing envelope antigens of Japanese isolates of HTLVs were prepared and their reactivities with human or rabbit serum were examined. Japanese HTLV2M, HTLV10Y, and HTLVMT-2 pseudotypes and American HTLVPL pseudotype were neutralized by sera of Japanese and American patients with adult T-cell leukemia/lymphoma (ATL) and rabbit antisera against HTLV. Each serum showed similar antibody titers against different pseudotypes. Thus, envelope antigens of four HTLVs that reacted with the human and rabbit sera were considered to belong to a single serotype.

Animals↗
PubMed1984

Clinical implications of anti-HTLV antibody titer, abnormal lymphocytes in HTLV carriers and HTLV genome negative adult T-cell leukemia-lymphoma.

Abnormally large lymphocytes with Pelger-like nuclear lobulation have been found in peripheral blood of smoldering adult T-cell leukemia-lymphoma (ATL) patients. They are also found in quite low percentage in peripheral blood of healthy HTLV carriers. Therefore, it has become difficult to discriminate smoldering ATL having only abnormal lymphocytes from a healthy human T-cell leukemia virus (HTLV) carrier only by morphology and serology. We found that patients with smoldering ATL with visceral organ involvement such as skin or lung lesions had much higher titer (about 1 : 1,000) of anti-HTLV antibodies than those with other subtypes of ATL (about 1 : 250); the difference was highly significant (p less than 0.001). In addition, the period of survival of patients with smoldering ATL having antibody with high titer was much longer than that of patients with other subtypes of ATL, suggesting the role of a host immune response. Four cases of HTLV-negative ATL were found to have the same chromosomal abnormality as that has been seen in HTLV-positive typical ATL; the situation was quite similar to Burkitt's lymphoma. Since it has been considered that HTLV does not include oncogenes, a common oncogenic mechanism, ATL specific cellular oncogenes, might exist: they might be activated by HTLV or a mechanism other than a virus.

Antibodies, Viral↗
PubMed1984

Inhibition of gastric secretion by a new H2-antagonist, YM-11170 in healthy subjects.

Oral administration of YM-11170 (5-20 mg) inhibited both basal and tetragastrin-induced gastric secretion of acid and pepsin in healthy volunteers. YM-11170 was at least 20 times more potent than cimetidine in inhibiting stimulated acid secretion. The area under the plasma concentration of YM-11170 vs time curve correlated positively to both dose and percent inhibition of acid output in response to tetragastrin. YM-11170 significantly inhibited basal and stimulated acid secretion even 10 h after a 20-mg dose. A plasma level of YM-11170 required for 50% inhibition of stimulated acid secretion was found to be 13 ng/ml. These results indicate that YM-11170 is a very potent inhibitor of gastric acid secretion and that twice daily medication of 20 mg YM-11170 is recommendable for further antisecretory studies with ulcer patients.

Administration, Oral↗
PubMed1983

Relationship between histone H1 poly(adenosine diphosphate ribosylation) and histone H1 phosphorylation using anti-poly(adenosine diphosphate ribose) antibody.

The chromatin-associated enzyme poly(ADP-Rib) polymerase catalyzes the posttranslational modification of histones. Antibody to poly(ADP-Rib) has been coupled to Sepharose, and the resultant immunoadsorbent was used to fractionate, specifically, histone H1 subpopulations undergoing this nuclear protein modification. When this method of separation was used, it was additionally observed that poly-(ADP-ribosylated) H1 species were highly accessible to in vitro phosphorylation by nuclear protein kinase. Phosphorylated H1 molecules were retained by the anti-poly(ADP-Rib)-Sepharose column due to the presence of endogenous poly-(ADP-Rib) components. Degradation of the latter moieties on phosphorylated H1 reversed their adsorption to the column.

Adenosine Triphosphate↗
PubMed1983

A new tumor promoter, dihydroteleocidin B, enhances cell growth and the production of murine leukemia virus by fibroblasts.

The effects of tumor promoters on the expression of murine leukemia virus (MuLV) were studied in tissue culture. Dihydroteleocidin B, an indole alkaloid, recently found to be a tumor promoter, enhanced not only the production of Moloney MuLV (M-MuLV) by a mouse fibroblast cell line, C3H2K, persistently infected with M-MuLV, but also growth on the C3H2K cells. The production of infectious M-MuLV by M-MuLV-infected C3H2K cells that had been treated with dihydroteleocidin B for 1-7 days was four or five times higher than that of control cells. C3H2K cells grew faster and became stationary at higher cell densities in the presence of dihydroteleocidin B than in its absence. The tumor-promoting phorbol ester phorbol-12, 13-didecanoate and 12-O-tetradecanoylphorbol-13-acetate also enhanced the production of M-MuLV, but their effects were not so strong as that of dihydroteleocidin B. These tumor promoters, however, did not induce production of endogenous MuLV in C3H2K or K-BALB cells.

Alkaloids↗
PubMed1983

Size and shape of poly(ADP-ribose): examination by gel filtration, gel electrophoresis and electron microscopy.

Digestion of the poly(ADP-ribose) with snake venom phosphodiesterase yielded phosphoribosyl-AMP and AMP in a ratio of 30 to 1, indicating the "chain length" of 30 if the poly(ADP-ribose) is a linear molecule as previously supposed. Gel filtration and gel electrophoresis, however, revealed a very heterogeneous size distribution, the average size being, much longer than (ADP-ribose)30. Electron microscopy of poly(ADP-ribose) showed an irregularly branched figure. Molecules with more than ten branched portions were observed. These results are in agreement with the recent identification of the chemical structure of the branched portion in poly(ADP-ribose).

Animals↗
PubMed1983

Effect of poly(ADP-ribose)polymerase inhibitors on the frequency of sister-chromatid exchanges in Bloom syndrome cells.

The effect of inhibitors of poly(ADP-ribose)polymerase, benzamide (Bam) and m-aminobenzamide (m-AB), on sister-chromatid exchanges (SCEs) and cell growth, was examined in lymphoblastoid cell lines from a normal adult (KS-64) and from a Bloom syndrome patient (BS1-2). The presence of Bam and m-AB increased the levels of SCEs in KS-64 and BS1-2 lymphoblastoid cells. Though the net increase was similar in the two types of cell, the relative increase was much lower in the BS1-2 cells. Bam and m-AB increased the number of SCEs in BS1-2 cells to levels of 95.4 +/- 3.24 and 98.1 +/- 3.23 per cell, respectively, as compared with the baseline level of 75.5 +/- 2.16. On the other hand, when KS-64 cells were treated with Bam and m-AB, the number of SCEs increased to 27.1 +/- 1.98 and 28.6 +/- 2.71 per cell, respectively, compared with the baseline number of 6.7 +/- 0.41 per cell. These inhibitors of poly(ADP-ribose)polymerase also inhibited cell growth at concentrations which induced SCEs in KS-64 as well as in BS1-2 cells. No significant decrease in the poly(ADP-ribose)polymerase activity or in the amount of poly-(ADP-ribose) was detected in BS1-2 cells as compared with KS-64 cells. The mechanism by which SCEs are increased in BS1-2 cells is discussed.

Benzamides↗
PubMed1983

Hematoporphyrin derivative and laser photoradiation in the diagnosis and treatment of bladder cancer.

Diagnosis and treatment of 8 patients with malignant bladder tumors were performed with intravenous administration of hematoporphyrin derivative, followed by krypton-ion laser violet light photoradiation and argon-dye laser red light photoradiation therapy. Fluorescence permitting localization and evaluation of the lesion was recognized in all 8 patients. Photoradiation with red argon-dye laser light obtained complete remission in 6 patients, with followup from 6 to 18 months. To our knowledge this is the first report describing total regression of bladder tumors obtained by photoradiation. Swelling and edema were noted within 20 minutes after argon-dye laser photoradiation therapy of bladder tumors. Necrosis and partial covering of the tumor by a whitish necrotic mass were noted after 3 days. The whitish mass covered the entire tumor at 7 to 14 days. Gradual exfoliation of the mass was followed by disappearance of the tumor and regeneration of normal mucosa at 9 to 10 weeks.

Adult↗
PubMed1983

Immunological evidence for the in vivo occurrence of a crosslinked complex of poly(ADP-ribosylated) histone H1.

The poly(ADP-ribosylation) of histones, which occurs within a limited and functionally specific domain of chromatin, is a novel post-translational modification. However, in the past it has been difficult to study this process in living cells because the substrate of the reaction (NAD) does not permeate the plasma membrane. In the current study, antibodies specific for histone H1 and poly(ADP-ribose) were used to study the occurrence of poly(ADP-ribose)+ species of H1 in vivo. Perchloric acid-extracted proteins from synchronously growing HeLa cells were fractionated by electrophoresis and transferred to nitrocellulose, and the transferred moieties were allowed to react with the specific antibodies and then with 125I-labeled protein A. The results conclusively demonstrate the natural occurrence of poly(ADP-ribose)-crosslinked complexes of histone H1 (i.e., H1 dimer), at the S/G2 phase transition of the cell cycle.

Cell Cycle↗
PubMed1983

Establishment and characterization of 10 cell lines derived from patients with adult T-cell leukemia.

By using human T-cell growth factor (TCGF), 10 cell lines were established from tissue samples of 10 patients with adult T-cell leukemia (ATL). Three cell lines were adapted to growth in medium lacking TCGF. The surface markers of all cell lines were characteristic of inducer/helper T cells, i.e., OKT3+, OKT4+, OKT6-, OKT8-, OKIa1+, and human Lyt2+ and Lyt3+, except that one cell line was OKT3-. The expression of the viral antigen was examined during establishment of 8 of the 10 cell lines. The viral antigen was not expressed in leukemic cells before cultivation. In 5 lines, the viral antigen was detected by immunofluorescent staining after a short period of cultivation. However, 3 cell lines, ATL-6A, ATL-9Y, and ATL-1K did not express the viral antigen during short-term culture: the ATL-6A and ATL-9Y cell lines became positive for the viral antigen after 5 and 2 months of cultivation, respectively; the ATL-1K cell line remained antigen-negative throughout a culture period of 13 months. Southern blot hybridization assay showed that all of the cell lines, including the viral antigen-negative ATL-1K cell line, contained the viral genome. Thus, the retrovirus was associated with all 10 cell lines established from ATL patients, but there was a heterogeneity in the expression time of the retroviral antigen in leukemic cells maintained in vitro. Our findings suggested that the expression of the viral antigen was not required for maintenance of the leukemic state in vivo and for growth of leukemic cells in vitro.

Antigens, Surface↗
PubMed1983

Detection of lymphocytes producing a human retrovirus associated with adult T-cell leukemia by syncytia induction assay.

Recently 10 T-cell lines were established from patients with adult T-cell leukemia (ATL). During establishment of these cell lines, it was found that when T-cell lines expressing the ATL-associated retroviral antigen were cocultivated with 8C cat cells, multinucleated syncytia were formed. Retroviral antigen-negative T-cell lines did not induce syncytia. Peripheral blood lymphocytes obtained from ATL patients did not express the retroviral antigen before cultivation in vitro but became positive for the retroviral antigen after cultivation for a short period; these retroviral antigen-positive lymphocytes, but not retroviral antigen-negative lymphocytes, induced syncytia upon cocultivation with 8C cells. Peripheral blood lymphocytes isolated from patients with chronic lymphocytic leukemia of T-cell origin or Sézary syndrome or from normal adults and lymph node cells from a patient with immunoblastic lymphadenopathy-like T-cell lymphoma did not express the retroviral antigen even after cultivation in vitro and did not induce syncytia upon cocultivation with 8C cells. Thus, there was complete agreement between the presence of the retroviral antigen in established T-cell lines or freshly isolated peripheral blood lymphocytes and their ability to induce syncytia. Syncytia formation was enhanced 5- to 20-fold by the presence of Polybrene and inhibited by addition of plasma of ATL patients to the cocultures. Syncytia were detected within 4 hr on cocultivation of 8C cells with the retroviral antigen-positive T-cells, indicating that most syncytia were formed by early polykaryocytosis. After cocultivation, a clone of 8C cells that harbored the ATL virus genome and had syncytia-inducing activity was isolated. These findings indicate that the retrovirus associated with ATL has syncytia-inducing activity. Syncytia induction assay using 8C cells will be useful for detection and characterization of human retrovirus associated with T-cell malignancies.

Adult↗
PubMed1983

Immunoaffinity fractionation of the poly(ADP-ribosyl)ated domains of chromatin.

Antibody to poly(ADP-ribose) has been covalently coupled to Sepharose and utilized to isolate selectively oligonucleosomes undergoing the poly(ADP-ribosyl)ation reaction from the bulk of chromatin. Approximately 12% of the unfractionated oligonucleosomes were bound to the immunoaffinity column and these represented essentially 100% of the original poly(ADP-ribosyl)ated nucleosomal species in the unfractionated chromatin. Poly(ADP-ribosyl)ated chromatin was not bound by preimmune IgG columns. KSCN eluted the modified nucleosomes in the form of nucleoprotein complexes. The eluted chromatin components were shown to contain poly(ADP-ribosyl)ated histones as well as automodified poly(ADP-ribose) polymerase. By using [3H]lysine- and [3H]arginine-labeled chromatin, it was shown that the poly-(ADP-ribosyl)ated histones, attached to stretches of oligonucleosomes bound to the column, had a 6-fold enrichment of the modification compared to histones of the unfractionated chromatin. This indicated that non-poly(ADP-ribosyl)ated nucleosomes, connected and proximal to the modified regions, were copurified by this procedure. This allowed characterization of the oligonucleosomal DNA around poly(ADP-ribosyl)ated chromatin domains to be compared with the unbound bulk chromatin. The data indicated that immunofractionated poly(ADP-ribosyl)ated oligonucleosomal DNA contained significant amounts of internal single-strand breaks compared with bulk chromatin. The bound nucleo-protein complexes were found to be enzymatically active for poly(ADP-ribose) polymerase after elution from the antibody column. In contrast, the unbound nucleosomes, representing 90% of the unfractionated chromatin, were totally inactive in the poly(ADP-ribosyl)ation reaction.

Chromatin↗