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M Sugi

Publications and source records attributed to M Sugi.

At least 37 records · Page 2Linked to original sources
PubMed1989

[Clinical application of immunoassays for cardiac myosin light chains].

We developed four types of immunoassays for cardiac myosin light chains (LC), which are two radioimmunoassays (RIA) for canine and human LC, and an immunoradiometric assay (IRMA) and an enzyme-linked immunosorbent assay (ELISA) for human LC. The first two assays make use of polyclonal antibodies and the last two use monoclonal antibodies. By using these immunoassays, we studied the release of cardiac LC into the serum following acute myocardial infarction (AMI). In experimental AMI in dogs, cardiac LC appeared in the serum within 4-12 hours, reached the maximum at 2-5 days and returned to normal at 7-10 days. This long time-course was suggested due to the continuous liberation of LC from the infarcted myocardium on the basis of a quick disappearance rate of LC from the circulation. The peak LC values were found to correlate well with the histological infarct size. Similar results were also obtained regarding the time-course of circulating LC in clinical patients with AMI. Thus LC measurement seems useful for diagnosis of AMI as well as for estimating the extent of myocardial damage. We also developed an IRMA and an ELISA for human LC by using anti-human LC monoclonal antibodies for a more rapid LC assay and for a consistent supply of antibodies. These assays showed sufficiently high sensitivities to measure 1-100 ng/ml of serum LC. Especially, serum LC can be assayed within 2.5 hours by our ELISA. Such progress in immunoassays for cardiac LC has made the measurement of LC an important laboratory test for the diagnosis of AMI.

Animals↗
PubMed1988

Establishment of three bleomycin-resistant human carcinoma cell lines and their cross-resistance to other antitumor agents.

Three bleomycin-resistant (BLMr) human carcinoma cell lines (HeLa-BLMr, KB-BLMr, and Hepd-uvBLMr) were established in culture by progressively increasing the concentration of bleomycin (BLM). HeLa-BLMr and KB-BLMr were obtained after 5 and 2 months of incubation with BLM, whereas the establishment of Hepd-uvBLMr required 3 months of incubation with BLM after ultraviolet treatment. These cells have been successfully subcultured for more than 150 passages during more than 2 years in the presence of 1 microgram/ml of BLM. The degrees of BLM resistance were 20-fold, 11.6-fold, and 186-fold for HeLa-BLMr, KB-BLMr, and Hepd-uvBLMr, respectively, and the resistant phenotype of both HeLa-BLMr and Hepd-uvBLMr was stable when they were cultured for 30 passages in BLM-free medium, but unstable in KB-BLMr. Although each cell line exhibited cross-resistance to 3 to 5 other antitumor agents including peplomycin, combined use of BLM with a polyene antibiotic, a calcium channel blocker, or a poly(ADP-ribose) polymerase inhibitor overcame the BLM resistance in vitro to various degrees.

Aged↗
PubMed1988

Further characterization of bleomycin-resistant HeLa cells and analysis of resistance mechanism.

Bleomycin (BLM)-resistant HeLa cells (HeLa-BLMr), which have been subcultured for more than 150 passages during over 2 years in the presence of 1 micrograms/ml of BLM and stably possess a 20-fold-increased BLM-resistance in vitro, were further characterized. The nude mouse tumors produced by HeLa-BLMr were significantly less sensitive (P less than 0.005-0.01) to BLM administration than those produced by HeLa cells, and the cells primarily cultured from nude mouse tumors of HeLa-BLMr and transplanted serially 5 times in the absence of BLM also exhibited a similar degree of BLM resistance to that of HeLa-BLMr cultured in BLM-containing medium. The BLM-resistance mechanism of HeLa-BLMr was partially analyzed. The cells showed about 40% decreased accumulation and 2-3 times reduced retention of [3H]peplomycin, a novel BLM analog, as compared to HeLa cells, but the BLM-hydrolase activity was at almost the same level as that of HeLa cells when determined by HPLC. Furthermore, alkaline sucrose gradient analysis of cellular DNA after BLM treatment revealed that the damaged DNA was more efficiently repaired in HeLa-BLMr than in HeLa cells. These results suggest that decreased drug accumulation and retention, and elevated DNA repair activity are the main mechanism of BLM resistance in HeLa-BLMr.

Animals↗
PubMed1988

Heterogeneity of beta-type myosin isozymes in the human heart and regulational mechanisms in their expression. Immunohistochemical study using monoclonal antibodies.

To investigate the existence of heterogeneity of beta-type myosin isozymes (HC beta) in human hearts, immunohistochemical studies using monoclonal antibodies (MoAbs) raised against human ventricular myosin heavy chains were performed. Two types of MoAbs recognized some muscle fibers in the atrium, whereas both reacted with all ventricular muscle fibers. Since atrial muscle fibers reactive with each MoAb were found to be clearly different, the existence of two immunologically distinct HC beta (beta 1, and beta 2) was suggested in the atrium. By using affinity chromatography, two molecular variants of HC beta were isolated from the bovine atrium, and differences in the primary structure of beta 1 and beta 2 were confirmed by analysis of peptides produced by chymotryptic digestion. In pressure-overloaded human atria, myofibers containing beta 1 and/or beta 2 increased in accordance with decrement of myofibers containing alpha-type myosin isozyme (P less than 0.01). But they differed in expression during the developmental stage, since beta 2 did not exist in the early embryonic bovine heart, but beta 1 did. Thus, there are two distinct HC beta whose expression is regulated by at least two factors: pressure overload and developmental stage.

Adult↗
PubMed1987

Monoclonal antibody to human beta interferon: characterization and application.

Seven stable mouse hybridomas secreting monoclonal antibodies to human fibroblast beta interferon (IFN-beta) were isolated, all seven of which belonged to IgGl subclass and kappa type. While neutralizing the antiviral activity of human fibroblast IFN-beta, they failed to neutralized both that of human IFN-alpha and human IFN-gamma. These monoclonal antibodies neutralized the antiviral activity of human fibroblast IFN-beta but not that of human IFN-alpha and IFN-gamma. Two of the seven monoclonal antibodies, YSB-1 and YSB-2, showed particularly high neutralization titers in the ascitic fluid. Monoclonal antibodies were purified from cultures of hybridoma grown in a serum-free medium. The purified monoclonal antibodies, YSB-1(5 micrograms/ml) and YSB-2(1 microgram/ml), neutralized IFN-beta from 10EU/ml to 1EU/ml. Human fibroblast IFN-beta was purified to 3.5 X 10(7) IU/mg protein (1.0 X 10(8) IU/mg protein in the peak fraction) by the monoclonal antibody (YSB-2) affinity column chromatography, whereas human recombinant IFN-beta obtained from E.coli was also purified to 6.5 X 10(7) IU/mg protein (1.1 X 10(8) IU/mg protein in the peak fraction) by the monoclonal antibody (YSB-1) affinity column chromatography.

Animals↗
PubMed1987

Early plaster treatment for fractures of the femoral shaft in childhood.

A protocol for the treatment of fractures of the middle third of the femur by the early application of a hip spica has been evaluated in 191 children aged 10 years or less. Children without other injuries spent only a few days in hospital for the application and later removal of the spica. At all ages, anterior angulation of less than 20 degrees and valgus angulation of less than 15 degrees were accepted at the one-week review. Acceptance of shortening varied with the age of the child and the stage of treatment, but was 10% or less of the femoral length at the time of spica removal. At late review leg-length discrepancy was rare and clinically insignificant. This method of treatment was simple and effective. It dramatically reduced the cost of care and freed a number of children's hospital beds.

Aftercare↗
PubMed1986

Electrical stimulation of hybridoma cells producing monoclonal antibody to cAMP.

Electrical stimulation was applied to hybridoma cells in order to activate metabolic activities and increase the monoclonal antibody production. Hybridoma cells that produce monoclonal antibody to adenosine 3':5'-cyclic monophosphate were placed on a transparent glass electrode immersed in medium and subjected to electric pulses (pulse shape, alternating rectangular; field strength, 4 X 10(3) V X m-1; frequency, 5 kHz; pulse mode, 0.5 min application and 4.5 min pause). After 48 h of incubation, the concentration of lactic acid in the medium reached 8.4 mM, approx. 30% higher than that obtained without electric stimulation. Similarly, cell growth rate was promoted by the electric stimulation, reaching a maximum stimulation after 40 h. When the hybridoma was cultured for 48 h with electrical stimulation, the antibody concentration in the medium reached 22.3 microgram X ml-1, approx. 10% higher than the control, with a concomitant 16% increase in cell concentration. Longer periods of electric pulse application, however, caused an inhibitory effect on the hybridoma growth. The most probable cause of the inhibition are reactive oxygen species such as superoxide and hydrogen peroxide, which are inevitably generated by electrolysis. The presence of superoxide dismutase (EC 1.15.1.1) reduced the inhibitory effects. In conclusion, metabolic activities including monoclonal antibody production were activated by the electrical stimulation.

Animals↗
PubMed1986

[Effect of filipin, a polyene antibiotic, on human tumor cell killing in vitro by peplomycin].

Four kinds of cultured human tumor cell lines sensitive or resistant to bleomycin (BLM) were examined for the effect of filipin, a polyene antibiotic, on peplomycin (PEP)-induced cell killing. Although PEP was more effective than BLM against BLM-resistant HeLa cells (HeLa-BLMr), neoplastic cells derived from salivary gland (HSG) and melanoma cells (MEC), these three cell lines were still at least ten times more resistant to PEP than epidermoid carcinoma cell lines including HeLa cells by comparison of IC50, and showed lower cellular accumulation of 3H-PEP as compared with HeLa cells. When these lines were pretreated with filipin, 3H-PEP accumulation by the cells was increased 1.33-, 2.34-, 1.91- and 1.14-fold in HeLa, HeLa-BLMr, HSG and MEC cells, respectively. Combination use of PEP and filipin resulted in a remarkable enhancement of cytocidal effect in HeLa-BLMr and HSG cells (100- and 25-fold decrease of IC50, respectively), and a slight enhancement in HeLa cells, but not in MEC cells. It is therefore suggested that there are differences among cell types in the potentiation of PEP-induced cell killing by filipin.

Bleomycin↗
PubMed1985

IgA . K type myeloma with severe postextraction bleeding.

A case of multiple myeloma detected by the first symptom of severe postextraction bleeding was presented. Although laboratory data showed severe anemia, rouleaux formation of erythrocytes, abnormal hemostatic parameters, elevated erythrocyte sedimentation rate and hyperglobulinemia, no involvement of bones such as the jaws, skull, ribs or sternum was demonstrated roentgenologically. Final diagnosis obtained by immunoelectrophoresis was Ig A . K type myeloma. During a therapeutic period with melphalan and predonine, bleeding from the extracted wound was repeated. 2 months after the onset of the first symptoms, the patient died of systemic bleeding. Autopsy findings revealed many hemorrhagic sites in the lungs, stomach, kidney and bladder and the existence of plasma cell-like tumor cells in the bone marrow of lumber vertebra and sternum.

Electrophoresis↗