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Biomedical subjects

S Furusawa

Publications and source records attributed to S Furusawa.

At least 19 recordsLinked to original sources
PubMed1992

[Assay of flow cytometry for the effect of cepharanthine on resistance to doxorubicin].

The biochemical activity of cepharanthine and the possible mechanism by which it reverses the resistance to doxorubicin in P388 leukemia cells were examined in vitro. The microfluorometric analysis of the cellular level of doxorubicin in drug-resistant cells showed that cepharanthine markedly enhanced the sensitivity of doxorubicin against resistant cells in the cellular level. Cepharanthine also enhanced the inhibitory effect of doxorubicin on the incorporation of thymidine into DNA in resistant cells. The analysis of DNA histogram obtained by flow cytometry showed that doxorubicin exerted its growth-inhibitory effect by blocking the cell cycle at the G2 phase in P388 cells. At higher concentrations, doxorubicin prolonged the S phase and inhibited cell cycle progression to the G2/M phase in cells. The treatment with cepharanthine potentiated these blocking effects induced by doxorubicin in cells. It seems that the modifications of the biological effect of doxorubicin by cepharanthine are due to the change of their ability to induce DNA damage in cells.

Alkaloids↗
PubMed1992

[The effect of aging on observation in hearing in the same individuals over a 5 year period].

The purpose of this study was to investigate the process of changes in hearing of pure tones with aging. Among individuals who had undergone thorough medical examination for the purpose of annual health-checks, 293 males (586 ears) whose hearing level had been examined for five years or more were enrolled in this study. Cases having conductive deafness or known sensori-neural deafness were excluded. Since the most typical change with aging is observed at 8 kHz, the investigation was carried out only on hearing at 8 kHz. Hearing level increasingly declined with advancing age. Hearing distribution for young subjects showed a peak in the normal hearing level range. This peak decreased with aging, and another peak appeared at 50 dB. Investigation of differences in hearing in the individuals over the five years showed that most subjects had a hearing level difference of 0 dB up to 54 years of age. From 55 years old onward, however, the difference was 5 dB. This indicates that gradual deterioration of hearing level with aging occurs most frequently. On the other hand, in some subjects, deafness progressed faster. Thirty-four and a half percent of the subjects had deteriorations of 20 dB or more in a single year during the entire observation period. A deterioration of 20 dB or more was noted in 4% of the young and 8% of the elderly. Such rapid progression of deafness was believed to be involved in formation of the 50 dB peak in the hearing distribution.

Adult↗
PubMed1992

Comparative effects of G-CSF, GM-CSF and IL-3 on cytosine arabinoside- and daunorubicin-mediated cytotoxicity of acute myeloid leukemia cells and normal myeloid progenitors.

We carried out an in vitro study on the combined effects of three CSF (G-CSF, GM-CSF and IL-3) plus the cycle-specific chemotherapeutic drugs [cytosine arabinoside (Ara-C) and daunorubicin (DNR)] on the proliferation and cytotoxicity of blasts and clonogenic cells (CFU-AML) in the AML-193 cell line, in AML patients and in normal bone marrow CFU-GM. The number of surviving blasts and/or DNA synthesis in blasts treated with CSF plus Ara-C or DNR was greater than those treated without CSF in the AML-193 cell line, and in some AML patients. On the other hand, the Ara-C- and DNR-mediated cytotoxicity of CFU-AML was not abrogated by CSF in any instance, but rather, it was significantly enhanced by all the CSF in the majority of instances. Although the enhancement was clearer when Ara-C was used, compared with DNR, there were no significant differences among the enhancing effects of the CSF. Under the same culture conditions as those for CFU-AML, all of the CSF significantly enhanced the Ara-C-mediated cytotoxicity of day 7 normal CFU-GM, although to a lesser extent than in CFU-AML. However, none of the CSF significantly affected the Ara-C-mediated cytotoxicity of day 14 normal CFU-GM or the DNR-mediated cytotoxicity of day 7 or day 14 normal CFU-GM. These results suggest that in the selection of a strategy entailing combined use of cycle-specific drugs plus CSF to increase the antileukemic effectiveness of chemotherapy in AML, G-CSF is preferable to GM-CSF or IL-3, since it has fewer potential clinical side effects, and that, furthermore, DNR may be as useful as Ara-C.

Acute Disease↗
PubMed1979

[Challenge test].

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Chemical and Drug Induced Liver Injury↗
PubMed1979

Clinical features of 22 cases with "inter-sterno-costo-clavicular ossification". A new rheumatic syndrome.

We present 22 cases with inter-sterno-costoclavicular ossification. Clinical and pathological findings show that abnormal ossification observed in this situation is due to non-suppurative chronic inflammation of the soft tissues around the sterno-costo-clavicular region such as the costo-clavicular ligament. We have classified X-ray findings into three stages according to the extent of the ossification; localized, generalized, and hyperostotic, and show that the disease progressed in this sequence. A considerable number of the patients showed abnormal X-ray findings in the spine or the sacro-iliac joint. Frequent association of pustulosis palmaris et plantaris was noted in this disease. Most of the cases were treated effectively with anti-inflammatory drugs, but a few cases required surgical resection of the ossified mass with the clavicle or the first rib in order to relieve the severe pain.

Adult↗
PubMed1979

Therapeutic activity of pretazettine, a narcissus alkaloid, on spontaneous AKR leukemia.

A narcissus alkaloid, pretazettine hydrochloride (PTZ) has been shown to be active against spontaneous AKR leukemia. The long-term treatment with PTZ begining at 5--7 months of age of a group of AKR mice containing 10--20% of advanced leukemic mice significantly prolonged the life span of the group. The therapeutic effectiveness of PTZ has been compared with several standard antileukemic drugs. PTZ decreased the AKR virus titer in the circulating blood of mice and its antiviral activity in AKR virus infected NIH/3T3 cells has been confirmed by XC assay.

AKR murine leukemia virus↗
PubMed1978

Therapeutic activity of pretazettine on Rauscher leukemia: combination of antiviral activity and cellular protein inhibition.

Pretazettine hydrochloride (PTZ) has been found to inhibit protein synthesis, without being inhibitory to DNA and RNA, in Rauscher leukemic blood cells in mice for at least 6 h after its administration. With comparison to Virazole and cycloheximide, the specific anti-Rauscher virus activity of PTZ has been demonstrated only in acutely-infected NIH/3T3 cells but not in chronically-infected cells. It is not certain that the inhibitory action of PTZ on reverse transcriptase is contributory to its therapeutic activity in leukemic mice.

Alkaloids↗