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Biomedical subjects

S Yoshikawa

Publications and source records attributed to S Yoshikawa.

At least 181 records · Page 10Linked to original sources
PubMed1987

Complement-induced thrombus formation on the surface of poly(N-vinylpyrrolidone)-grafted polyethylene.

The role of complement activation in thrombogenesis was investigated on the surface of hydrophilic monomer-graft copolymerized polyethylene (PE) tubes. N-vinylpyrrolidone (NVP)-grafted tubes activated in an in vitro complement system of canine serum; but no activation occurred in 2-hydroxyethyl methacrylate (HEMA)-grafted tubes. The relative patent time for NVP-grafted tubes implanted in canine peripheral veins was shorter than that for HEMA-grafted tubes and adhesion of numerous leucocytes was observed on the luminal surfaces of the NVP-grafted tubes. Decomplementation by prior administration of cobra venom factor elongated the relative patent time for NVP-grafted tubes only and also inhibited the adhesion of leucocytes onto them. These results suggest that the complement activation participates in thrombus formation on the polymer surfaces in canine veins.

Animals↗
PubMed1987

Treatment of adult T cell leukemia with mega-dose cyclophosphamide and total body irradiation followed by allogeneic bone marrow transplantation.

A 43-year-old patient with adult T cell leukemia (ATL) was treated with mega-dose cyclophosphamide and total body irradiation (TBI) followed by bone marrow transplantation (BMT) from his HLA-identical sibling who was not a carrier of ATL virus. After BMT, ATL cells rapidly decreased and disappeared, and the engraftment of marrow was confirmed on day 20. The patient showed normal hematologic recovery. However, he died on day 205 with interstitial pneumonitis caused by cytomegalovirus infection. Neither autopsy findings nor serologic and cytologic examinations showed any evidence of ATL relapse after BMT. This pilot study suggests that mega-dose chemotherapy and TBI followed by allogeneic BMT should be considered for such treatment of ATL.

Adult↗
PubMed1986

Treatment of leukemia and myelodysplastic syndromes with orally administered N4-palmitoyl-1-beta-D-arabinofuranosylcytosine.

N4-Palmitoyl-1-beta-D-arabinofuranosylcytosine (PLAC) was administered PO to 76 patients with acute leukemia, myelodysplastic syndromes (MDSs), and myeloproliferative disorders (MPDs). Of 20 patients with acute myelogenous leukemia, 2 achieved complete remission, and the only patient with acute lymphoblastic leukemia achieved partial remission. Remission was reached with PLAC 100-300 mg/day 25-66 days after the start of therapy. Among 22 patients with MDS, 1 patient achieved a good response and 8 achieved partial response. Responses were reached with PLAC 50-200 mg/day 7-153 days (median, 33 days) after the start of therapy. Improvement of polycythemia was observed in all 5 patients with polycythemia vera, and reduction of thrombocytosis was observed in 5 out of 6 patients with essential thrombocythemia and myelofibrosis. An antileukemia effect was noted in 1 of 5 with chronic myelogenous leukemia. Major side effects were gastrointestinal toxicities and myelosuppression. In spite of the disadvantages, such as unpredictable absorption and a lower response rate to acute leukemia compared with its parent compound, this antileukemia Ara-C analogue that is administrable PO will be useful in the treatment of MDSs and MPDs, which do not necessarily require admission to hospital, and in the treatment of acute leukemia of the aged, a condition for which intensive chemotherapy is not appropriate.

Administration, Oral↗
PubMed1986

Gamma-interferon production capacity and T lymphocyte subpopulation after allogeneic bone marrow transplantation.

T cell phenotypes after bone marrow transplantation (BMT) were investigated using monoclonal antibodies (moAbs) reactive to lymphocyte cell surface antigens. Patients' T cells showed decreased percentages of OKT4, 4A and 9.3-positive T cells, and increased percentages of OKT8, human Ia, and Leu-7-positive T cells. These changes in T cell phenotype persisted for a long period after BMT and had no correlation with the occurrence of graft-versus-host disease (GVHD). No lymphocyte activation antigens such as TIA (Tac) or transferrin receptor (5E9) were detected after BMT. The capacity of the patients' lymphocytes to produce gamma-interferon (IFN-gamma) was measured after incubation of lymphocytes with mitogen. Patients' lymphocytes produced significantly lower levels of IFN-gamma than the normal controls. This failure of IFN-gamma production showed no correlation with stimulation index of mitogen blastogenesis or changes of T cell population. Thus, not only T cell phenotype but also measurement of IFN-gamma production of lymphocyte may be useful in detecting immunological abnormalities in patients who receive BMT.

Adolescent↗
PubMed1986

Device of anoxic chamber system and repair of potentially lethal damage of anoxic cells in vitro.

In order to study radiation responses of anoxic plateau phase cells in vitro, an air-tight anoxic chamber was devised in which Chinese hamster V-79 or Swiss mouse NIH3T3 cells were deoxygenated by replacing the air with saturatedly humidified N2 gas. The cells as adhered on the culture plate, which was contained in the anoxic chamber, were x-irradiated. The deoxygenated condition in the anoxic chamber was maintained as long as necessary. Oxygen enhancement ratio obtained by the anoxic chamber was about 2.6. Repair of potentially lethal damage of the anoxic plateau phase cells was observed to the same extent of that of the oxic cells.

Animals↗
PubMed1986

[82 drawings and their most common names, image agreement, adequacy of complexity, and familiarity].

For use in experiments investigating semantic processing of nonverbal materials, 82 drawings of familiar objects are presented, along with their most common names, the mean ratings of image agreement, adequacy of complexity, and familiarity. Most concepts were exemplars from one of 10 familiar categories (animals, insects, vehicles etc.). Names and ratings were obtained from 81 undergraduates and graduate students. The moderate correlation (r = .40) was found between percentage of the most common name and image-agreement rating, but the other correlations were negligible. The mean ratings of three variables except adequacy of complexity were compared with those of Matsukawa (1983), obtained from Japanese subjects using Snodgrass and Vanderwart's (1980) drawings. The high correlation between familiarity of both studies (r = .88) indicates that this variable is not affected by visual characteristics of the particular stimulus set. The possible uses of the present stimulus set were suggested.

Adolescent↗
PubMed1986

[Phase II study of mitoxantrone in patients with acute leukemia].

A phase II study of acute leukemia with mitoxantrone (MIT) was conducted by the Tokai Blood Cancer Study Group. The drug efficacy was evaluable in 31 cases (14 of ALL and 17 of ANLL) out of 37 entered at 13 institutions. Five cases were for first induction remission and 26 cases for re-induction remission; ages ranged from 7 to 69 (median: 43); 18 males and 13 females. MIT dosage was intravenous injection of 3-6 mg/m2/day X 5 consecutive days as a rule. Of the 14 cases of ALL, 2 achieved CR and 3, PR; the efficacy rate was 36%. Of the 17 cases of ANLL, 4 achieved CR and 3, PR: the efficacy rate was 41%. Of the 5 first induction remission cases, 3 achieved CR, and 1, PR, the efficacy rate being 80%, whereas out of the 26 re-induction remission cases, 3 achieved CR, 5 PR, and the efficacy rate was 31%. In 3 of 6 cases of CR, large cumulative doses of anthracyclines such as DNR 140 mg plus ACR 410 mg, DNR 360 mg plus ADR 120 mg plus ADR 120 mg, and DNR 240 mg plus ADR 540 mg, had been administered previously in each case. As to complications, sepsis and other infections were observed at the rates of 15% and 32%, respectively, from which it was inferred that in therapy with mitoxantrone, leukopenia should be observed carefully. The major non-hematological toxicity was gastrointestinal symptoms, but the degree was mild. From the results of this trial, it was concluded that mitoxantrone was an effective form of therapy for acute leukemia. Further clinical trials on mitoxantrone in combination with other drugs are scheduled.

Acute Disease↗
PubMed1985

Resonance Raman study on photoreduction of cytochrome c oxidase: distinction of cytochromes a and a3 in the intermediate oxidation states.

Occurrence of photoreduction of bovine cytochrome c oxidase was confirmed with the difference absorption spectra and oxygen consumption measurements for the enzyme irradiated with laser light at 406.7, 441.6, and 590 nm. The resonance Raman spectra were obtained under the same experimental conditions as those adopted for the measurements of oxygen consumption and difference absorption spectra. The photoreduction was more effective upon irradiation at shorter wavelengths and was irreversible under anaerobic conditions. However, upon aeration into the cell, the original oxidized form was restored. It was found that aerobic laser irradiation produces a photo steady state of the catalytic dioxygen reduction and that the Raman scattering from this photo steady state probes cytochrome a2+ and cytochrome a3(3)+ separately upon excitations at 441.6 and 406.7 nm, respectively. The enzyme was apparently protected from the photoreduction in the spinning cell with the spinning speed between 1 and 1500 rpm. These results were explained satisfactorily with the reported rate constant for the electron transfer from cytochrome a to cytochrome a3 (0.58 s-1) and a comparable photoreduction rate of cytochrome a. The anaerobic photoreduction did give Raman lines at 1666 and 214 cm-1, which are characteristic of the ferrous high-spin cytochrome a3(2)+, but they were absent under aerobic photoreduction. The formyl CH = O stretching mode of the a3 heme was observed at 1671 cm-1 for a2+a3(2)+CO but at 1664 cm-1 for a2+a3(2)+CN-, indicating that the CH = O stretching frequency reflects the pi back-donation to the axial ligand similar to the oxidation state marker line (v4).

Animals↗