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Biomedical subjects

M Miwa

Publications and source records attributed to M Miwa.

At least 289 records · Page 16Linked to original sources

Polyoma virus minichromosomes: poly ADP-ribosylation of associated chromatin proteins.

The host nuclear enzyme poly(ADP-ribose) polymerase has been shown to be associated with the replicative intermediate and mature forms of polyoma virus minichromosomes. Minichromosome-associated histones H2A and H2B as well as several nonhistone proteins were poly ADP-ribosylated by endogenous poly(ADP-ribose) polymerase. In addition, minichromosome fractions catalyzed the formation in vitro of dimers of endogenous histone H1 linked by poly(ADP-ribose). Poly ADP-ribosylated polyoma virus minichromosome chromatin labeled in vivo with [3H]thymidine could be retained and eluted from anti-poly(ADP-ribose) immunoglobulin G-Sepharose. Pulse-labeled replicative intermediate minichromosomes were retained better on the antibody columns than were mature minichromosomes labeled for 2.5 h. The possible role of poly ADP-ribosylation of viral nucleosomes during polyoma replication or transcription is discussed.

Chromatin↗

Enhancement of antitumor activity of bleomycin by benzamide in vitro and in vivo.

The cytotoxic effects of bleomycin on HeLa cells in culture were enhanced by incubation of the cells with benzamide, a potent inhibitor of poly(ADP-ribose) polymerase, at concentrations at which benzamide alone did not show any cytotoxicity. Benzamide plus bleomycin display enhanced therapeutic effects against Ehrlich ascites tumor cells in vivo. On daily treatment with various doses of bleomycin plus benzamide for 10 days, mice with Ehrlich ascites tumors survived longer than mice on treatment with bleomycin alone.

Animals↗

Poly(ADP-ribose): structure, quantification, and biological significance.

We have been working on poly(ADP-Rib) since our discovery of it. This lecture will review recent findings on this polymer obtained in our laboratory. Poly (ADP-Rib) has long been thought to be a linear homopolymer attached to nuclear protein. The ribose-ribose bond of poly(ADP-Rib) was shown to be an alpha(1" leads to 2') ribosidic bond. There are two molecular forms of poly(ADP-Rib), namely low molecular weight (L) and high molecular weight (H) poly(ADR-Rib) molecules. The L and H fractions of poly(ADP-Rib) are separable by gel filtration, sucrose density gradient centrifugation and polyacrylamide gel electrophoresis. Physicochemically the L and H forms differ in their molecular size, solubility in high salt, rate of hydrolysis by venom phosphodiesterase and circular dichroism (CD) spectrum. However, the two forms have a similar ultraviolet (UV) absorption spectrum, both show a similar hyperchromicity on heating to 98 degrees C or hydrolysis with snake venom phosphodiesterase and give similar results on ordinary chain length determination. The great discrepancy in size observed by physicochemical methods and by the ordinary chain length method indicates the presence of a branching structure in poly(ADP-Rib). The branching structure was proved by demonstrating the presence of a unique compound, 2'[1"-ribosyl-2"(1"'-ribosyl)]adenosine-5',5",5"'-tris(phosphate) and by electron microscopy. The amount of poly(ADP-Rib) was determined by our new method, consisting of tritium labeling and high performance liquid chromatography. The merit of this method is that it can determine the recovery of poly(ADP-Rib) exactly and that its sensitivity is high. The amount of poly(ADP-Rib) changed dramatically when human promyelocytic leukemia cells were induced to differentiate by dimethyl sulfoxide or 12-O-tetradecanoylphorbol-13-acetate. The use of inhibitors of poly (ADP-Rib) polymerase in combination with bleomycin, a DNA damaging antitumor drug, potentiated the antitumor activity of bleomycin against Ehrlich ascites carcinoma cells in vivo.

Animals↗

[Activities of pyrimidine nucleoside phosphorylase in brain tumors and antitumor effect of 5'-DFUR].

Activities of pyrimidine nucleoside phosphorylase in brain tumors were measured and their relationship to a clinical course of the patients was investigated. Pyrimidine nucleoside phosphorylase is said to exist more quantitatively in malignant tumors such as Sarcoma 180, Ehrlich ascites carcinoma, Walker 256, and hepatoma, and very little in normal tissues. In brain tumors the activities were measured by bioassay and compared to that of Sarcoma 180. When the activity of Sarcoma 180 was expressed to be 100%, those of brain tumors were as follows: ten cases of normal brain less than 8.5; six cases of glioblastoma 39.3 +/- 30.7; five cases of astrocytoma 22.0 +/- 13.8; five cases of meningioma 22.4 +/- 13.7; two cases of oligodendroglioma 8.1 and 11.3; two cases of sarcoma 94.3 and 145.4; chordoma 48.0; ependymoblastoma 3.7; plexus papilloma 22.5; parotid cancer 43.4; ten cases of metastatic brain tumors from lung cancer 61.5 +/- 41.6; two cases from breast cancer 28.0 and 68.8; that from thyroid cancer 10.0; that from gastric cancer 13.5; malignant melanoma 77.2. In 12 cases of gliomas (glioblastoma, astrocytoma, oligodendroglioma) the mean activity was highest in glioblastoma (39.3), followed by astrocytoma (22.0) and oligodendroglioma (9.7). The postoperative survival time became shorter in gliomas with the higher activities. In metastatic brain tumors from lung, breast, and gastric cancer, the average time from the diagnosis of primary cancer to brain metastasis was shorter in cases with high activities and longer in cases with low activities.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Agents↗

Atypical adult T-cell leukemia-lymphoma: diverse clinical manifestations of adult T-cell leukemia-lymphoma.

The diverse clinical manifestations of 10 cases of so-called adult T-cell leukemia-lymphoma (ATL)-related T-cell malignancies are described. These cases were anti-ATLA [antibody to ATL virus (ATLV)-associated antigen (ATLA)] positive, and tumor cells had the inducer/helper T-cell phenotype and expressed ATLA when cultured, indicating that these diseases are the same as typical ATL, even though their clinical diagnoses were different from ATL. Accordingly, they are called atypical ATL. Clinically, they could be divided into two subtypes, smoldering type and lymphoma type. In the smoldering type, the disease usually started with skin lesions and rarely with lung lesions. After a prodromal stage of several years, the disease progressed insidiously to the leukemic stage without additional manifestations. The flower cells characteristic of typical ATL were observed in only a small percentage of peripheral lymphoid cells. In two of the five patients the disease progressed to typical ATL after several years from onset. All five patients are alive with a long survival time, more than 6 yr in four, and had high titers of anti-ATLA, suggesting that anti-ATLA might have some role in regulating the proliferation of ATL cells in vivo. In the lymphoma type, morphological diagnosis was not always specific for discriminating ATL-related from ATL-unrelated T-cell lymphomas. Detection of anti-ATLA in the patient's serum and of ATLA in cultured tumor cells, examination of the sera of members of the patient's family for anti-ATLA, and observation of typical flower cells in the peripheral blood though the patients had neither lymphocytosis nor leukemic changes, seem to be useful for the discrimination, especially in an ATL-nonendemic area. Members of the family of a patient with anti-ATLA positive T-lymphoma in an ATL-nonendemic area were also anti-ATLA positive, indicating that healthy ATLV carriers in an ATL-nonendemic area exist as a family colony. This is responsible for sporadic outbreaks of ATL in an ATL-nonendemic area. In summary, the disease entity of ATL is considered, at present, to be a malignancy of inducer/helper T-cells transformed by ATLV or HTLV (human T-cell leukemia virus). In this sense, diverse clinical manifestations of ATL should be recognized as events of viral oncogenesis and host immune response.

Adult↗

Anti-ATLA (antibody to adult T-cell leukemia-lymphoma virus-associated antigen)-negative adult T-cell leukemia-lymphoma.

Five cases of adult T-cell leukemia-lymphoma (ATL) having typical clinicohematologic and morphologic features but negative for anti-ATLA [antibody to ATL virus (ATLV)-associated antigen (ATLA)] are presented. Some differences in immunologic, epidemiologic, and serologic data between anti-ATLA-positive and -negative ATLs are also described. Expression of ATLA in early primary cultured leukemic cells was found to be negative in three patients tested (Cases 1, 2 and 4), however, a long-term cultured cell line, ATL-6A, derived from peripheral blood leukemia cells from Case 1, was found to express ATLA. Mother of Case 1 and a daughter of Case 2 were anti-ATLA negative. These results indicate that ATLV was involved in certain anti-ATLA-negative ATL patients, at least in Case 1, and that the patient had no detectable immune response against ATLV and ATLA. However, in other cases in which no ATLA reactivity of serum and no ATLA expression in cultured leukemic cells were observed, another possibility such as activation of an unknown cellular oncogene specific for ATL without ATLV involvement may be considered. In order to prove these possibilities definitely, it is necessary to elucidate whether or not proviral DNA of ATLV is integrated into chromosomal DNA of ATL cells and to find a cellular oncogene specific for ATL in the future.

Adult↗

[Fundamental and clinical study of T-1982 (cefbuperazone) in the field of obstetrics and gynecology].

Laboratory and clinical investigation of T-1982 (cefbuperazone) in the field of obstetrics and gynecology were carried out and the following results were obtained. The peak concentrations of 18.1-36.0 micrograms/ml were noted in pelvic cavity fluid at 1-3 hours after intravenous injection or drip infusion of 1 g of T-1982 in 3 cases after total hysterectomy for diffuse uterine cancer, then the concentrations decreased very slowly and were over 10 micrograms/ml at 6 hours after administration. Transfer rate of the drug into pelvic cavity fluid was 33-66% of the serum concentrations. In clinical trial, a total of 5 cases including 4 cases of external genital infections and 1 case of pelvic infection were treated with T-1982, and the results were evaluated as good in 3 cases, poor in 1 case and unknown in 1 case. Side effects were observed in 1 case who showed slight increase of GOT and GPT.

Abscess↗

Monoclonal antibodies against poly(ADP-ribose) recognize different structures of poly(ADP-ribose).

The characteristics of two monoclonal antibodies to poly(ADP-Rib) and the various structures of poly(ADP-Rib) recognized by these monoclonal antibodies have been examined. One antibody, IgG monoclonal antibody 10H, reacted with most parts of poly (ADP-Rib) molecules, and its binding was only slightly inhibited by Ado(P)-Rib-P, a monomer unit of the polymer. On hydrolysis of poly(ADP-Rib) protected by the antibody hydrolytic products, such as Ado(P)-Rib-P and Ado(P)-Rib(P)-Rib-P, were almost the same as those from control poly(ADP-Rib). The other antibody, IgM monoclonal antibody 16B, recognized only some parts of poly(ADP-Rib) molecules of larger size, and its binding was not inhibited by Ado(P)-Rib-P. Branched portions were considerably concentrated in parts protected by this antibody. These two monoclonal antibodies are suggested to recognize different structures of poly(ADP-Rib): possibly IgG antibody 10H recognizes linear portions whereas IgM antibody 16B recognizes branched portions of the polymer. These monoclonal antibodies should be useful in studies on the structures, including unknown structures and the locations of these structures in poly(ADP-Rib).

Antibodies, Monoclonal↗

Bifid tail of the pancreas: a case presenting as a gastric submucosal tumor.

A 49-yr-old male was admitted to our hospital because of epigastric discomfort and a suspected tumor of the stomach on barium meal examination at the Center for Automated Multiphasic Health Test and Services. The tumor shadow of the stomach was initially considered as the "type II" gastric carcinoma according to the Borrmann's classification. Multiple endoscopical and electrocautery cutting biopsies revealed that the tumor occurred in the submucosal layer and was composed of normal pancreatic tissue. A computed tomogram showed a large mass on the pancreatic body which was adjacent to gastric wall. Selective angiography of the celiac trunk revealed that the gastric submucosal lesion was supplied by the transverse pancreatic artery. Endoscopic retrograde pancreatography showed that Wirsung's duct had a divergence in the body of the pancreas and one of the branched ducts headed for the posterior wall of the gastric body. On the basis of these results, a diagnosis was made of the rare pancreatic anomaly, "bifid tail of the pancreas." One of the tails formed the gastric submucosal tumor. This report emphasizes the potential diagnostic value of combined study of endoscopic retrograde pancreatography and computed tomography in determining the presence of pancreatic anomaly.

Cholangiopancreatography, Endoscopic Retrograde↗