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Biomedical subjects

K Ohta

Publications and source records attributed to K Ohta.

At least 721 records · Page 40Linked to original sources

Clinical studies of aclacinomycin A (ACM).

Aclacinomycin A (ACM) is a new anthracycline antibiotic, isolated from Streptomyces galilaeus. This agent is presenting major chemical differences from the conventional anthracycline DNR and ADM, as a class II anthracyclines which inhibit more RNA than DNA. In clinical studies, good CR responses ranging about 30% in AML patients depend upon their background. Toxicities consisted of mainly upper GI tract and bone marrow. Cardiac toxicities, especially late cumulative effects are not reported. Some responses noted in malignant lymphomas and breast carcinoma, but needed further studies, including possibility of cross resistance and differentiation effects.

Aclarubicin↗

Clinical studies of (2''R)-4'-O-tetrahydropyranyl adriamycin (THP).

(2'' R)-4'-O-Tetrahydropyranyl Adriamycin (THP) is a new antitumor agent discovered among series of similar anthracycline compound synthesized by Umezawa et al. Phase I study revealed dose limiting factor of leukopenia with upper GI toxicity. Alopecia, cardiac failure and transient hepatic failure were extremely mild. Definite responses were demonstrated in acute leukemia, lymphoma, ovarian carcinoma, head and neck carcinoma, breast carcinoma and GU carcinoma. Pharmacokinetic studies revealed rapid cell uptake and outputs in bile (20%) and urine (8%) in 24 hours. Transfer to third spaces were poor but definite. In vivo a part of THP was converted to ADM in the liver, but not in other tissues including tumors. THP would be an extremely interesting compound, because of comparable spectrum of responses to various tumors with extremely low toxicity compared with other anthracycline compounds.

Acute Disease↗

Granulomatous lung disease by Thermoactinomyces vulgaris antigen in C5 deficient and sufficient mice.

Hypersensitivity pneumonitis (HP) is a granulomatous lung disease with pulmonary lymphocytic infiltration supposed to be caused by type III and type IV allergic mechanisms. In type III allergy, compliment activation plays an important role. In this study, we adopted the intranasal administration of the ultrasonified Thermoactinomyces vulgaris(Tv) antigen to mice, which causes granulomatous lung lesions. We used C5 (the fifth component of compliment) deficient B10D2/oSnJ mice and C5 sufficient B10D2/nSn control mice for the above murine model of HP to see if late components of compliment (C5-9) are concerned in the granuloma formation of HP. The result was that both C5 deficient and sufficient mice formed histologically similar granulomatous lung lesions with lymphocytic infiltration. Our data indicate that C5 is not necessary for the granulomatous lung lesions of HP by the Tv antigen.

Actinomyces↗

[Continuous intra-arterial infusion chemotherapy by implantable catheter access connected with a continuous infusion pump].

Eleven non-resectable cancer patients have been successfully treated by means of a one-shot and continuous intra-arterial infusion chemotherapy, utilizing an implantable vascular access device (Catheter Access) connected to a continuous infusion pump (Nipro portable syringe infusion pump) via a non-corning needle (Nipro coreless needle set). This result suggests that this simple and inexpensive method can be applied not only for cancer chemotherapy but also for intravenous hyper-alimentation and for treatment of epidural anesthesia.

Aged↗

Sera from patients with multiple sclerosis react with human cell T lymphotropic virus-I gag proteins but not env proteins--Western blotting analysis.

To study the possible involvement of human T cell lymphotropic virus type I (HTLV-I)-related agent in Japanese multiple sclerosis (MS), we performed a Western blotting analysis, using purified viral antigens, on sera from 46 patients with MS, nine patients with other neurologic diseases, and 11 healthy controls. Of 46 MS patients, 11 (24%) had antibodies reactive with antigens corresponding to the group-specific antigen (gag) proteins (p15, p19, and p24), although the prevalence was lower than that reported in a recent study using an enzyme-linked immunosorbent assay (ELISA). Despite the lower frequency of immunoreactivity, Western blotting technique had merits of identification of multiple antigens and higher specificity for detection of antibodies than ELISA. Those sero-positive patients consisted of four cases with IgG antibodies reactive mainly to the gag p24 and/or p15, four with IgM antibodies mainly to the gag p24 and/or p19, and three with both IgG and IgM antibodies. These immunostaining patterns of MS sera were clearly distinguishable from those of adult T cell leukemia patients who had antibodies to the envelope (env) proteins and its precursors in addition to the gag proteins. The antibody in MS sera was generally of low titer and reactive at a high serum concentration (1/10 dilution). None of the sera from patients with other neurologic diseases and healthy controls had the viral antibodies. These findings indicate that at least one quarter of Japanese MS patients have antibody responses to a hitherto unidentified agent related to HTLV-I, which possibly plays a part, primarily or secondarily, in the pathogenesis of those patients.

Adolescent↗

Naturally occurring antibody response to DNA is associated with the response to retroviral gp70 in autoimmune New Zealand mice.

The spontaneous occurrence of retroviral gp70 immune complexes (ICs) in the blood of autoimmune New Zealand black and (New Zealand black X New Zealand white)F1 ([NZB X NZW]F1) mice is determined by a single dominant locus of the NZB strain (provisionally designated Agp-1). A combined effect of 2 unlinked dominant NZB loci (Ads-1 and Ads-2) is required for the production of anti-double-stranded DNA (anti-dsDNA) antibodies in these mice. The present genetic studies using (NZB X NZW)F1 X NZW backcross mice and their second through fourth generation progeny revealed that Agp-1 and Ads-1 exist in common or are closely linked on chromosome 17 of NZB mice and are related to the occurrence of renal disease. The renal disease and the serum level of both anti-dsDNA antibodies and gp70 ICs were more intense in (NZB X NZW)F1 hybrids than in NZB mice, indicating the contribution of NZW genes. In (NZB X NZW)F1 mice, a single dominant locus from the NZW strain, Agp-3, intensified the magnitude of gp70 IC formation, and a combined effect of 2 unlinked dominant loci from the NZW strain, Ads-3 and Ads-4, acted to increase the serum titers of anti-dsDNA antibodies. This study clearly indicates that the NZW loci Agp-3 and Ads-3 exist in common or are tightly linked on chromosome 17, are closely linked to the H-2 complex, and are associated with the severity of renal disease in (NZB X NZW)F1 hybrids.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

Quantitative surface analysis of Cardiothane 51 by FT-IR-ATR spectroscopy.

Surface analysis has been carried out for Cardiothane 51 samples as commercially available balloon pumps and cast films prepared from the solution. Silicone contents on surfaces have been quantitatively determined by FT-IR-ATR spectroscopy coupled with a subtraction technique. The contents on the air-facing surface vary from 0.7 to 5.3% among six balloon pumps examined; three of them contain less silicone on the air-facing surface than on the substrate-facing surface, whereas just the opposite is true for one, and the other two have nearly and quite an equal content of it between the two surfaces. Silicone contents on surfaces of cast films vary also from a sample to another even when sample films were prepared from the same Cardiothane solution, indicating difficulty in quality control of Cardiothane surfaces. An appreciable fraction of silicone was found not to be covalently bonded to polyurethane in Cardiothane 51 for the cast film samples.

Biocompatible Materials↗

Amphibian metallothionein. Induction in the frogs Rana japonica, R. nigromaculata and Rhacophorus schlegelii.

Cadmium (Cd) was injected intramuscularly into three species of frogs to examine the number of isoforms in the induced metallothionein (MT). The induced MT was shown to consist of a single isoform in the three species of frogs Rana japonica, R. nigromaculata and Rhacophorus schlegelii. Native MT in the livers of R. japonica and R. nigromaculata was copper (Cu)-MT and the induced MT in the three species was Cd, Cu-MT, the Cd/Cu ratio in the induced MT being different from species to species. The effect of Cd injections on the concentrations of 10 elements in the livers and kidneys of the Rana species was not significant except for Cu.

Amphibians↗