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Biomedical subjects

Y Midorikawa

Publications and source records attributed to Y Midorikawa.

At least 55 records · Page 3Linked to original sources
PubMed1992

A study of biohazard protection for farming modules of lunar base CELSS.

For the Closed Ecological Life Support System (CELSS) of a manned lunar base which is planned to be built on the moon early in the 21st century, several proposed programs exist to grow vegetables inside a farming module. At the 40th IAF (Malaga, 1989) the author et al presented a proposal for supplying food and nutrients to a crew of eight members, a basic concept which is based on growing four kinds of vegetables. This paper describes measures for biohazard protection in farming modules. In this study, biohazard protection means prevention of the dispersion of plant diseases to other plant species or other portions of farming beds.

Agriculture↗
PubMed1992

An alkaloid, cepharanthine, potentiates the bactericidal effect of methylglyoxal bis (cyclopentylamidinohydrazone) on Staphylococcus aureus.

Antiproliferative effects of combined treatment with methylglyoxal bis(cyclopentylamidinohydrazone) (MGBCP), a polyamine biosynthesis inhibitor, and cepharanthine, a biscoclaurine alkaloid, on methicillin- and gentamicin-resistant Staphylococcus aureus were investigated. The bactericidal effect of MGBCP on S. aureus was potentiated by the cepharanthine treatment. Cellular polyamine levels of the bacteria treated with both MGBCP and cepharanthine were much lower than those of the bacteria treated with MGBCP alone. On the contrary, the cellular MGBCP concentration was much higher in the cepharanthine-treated bacteria. Thus, cepharanthine was considered to enhance the incorporation of MGBCP into the bacteria. The combination of MGBCP and cepharanthine resulted in greater suppression of macromolecular synthesis in the bacteria that might have caused greater suppression of bacterial growth.

Alkaloids↗
PubMed1991

Evaluation of the antimicrobial activity of methylglyoxal bis(guanylhydrazone) analogues, the inhibitors for polyamine biosynthetic pathway.

Metabolic and antiproliferative effects of methylglyoxal bis(butylamidinohydrazone) (MGBB) and methylglyoxal bis(cyclopentylamidinohydrazone) (MGBCP), inhibitors for polyamine biosynthetic pathway, on Escherichia coli, Shigella sonnei, Aeromonas sobria, Aeromonas hydrophila and Vibrio cholerae were investigated. MGBB at the concentration of 100 mumol/l depleted intracellular putrescine and spermidine concentrations of E. coli to 25 and 20% of the controls, respectively, while MGBCP depressed their concentrations to 38 and 24%, respectively. In these polyamine-depleted E. coli cells the syntheses of RNA, DNA and protein decreased to 13, 54 and 29% of the control, respectively, with MGBB and to 23, 71 and 55%, respectively, with MGBCP. The minimum inhibitory concentrations (MIC) of MGBB for the growth of A. sobria, E. coli, A. hydrophila, V. cholerae and Sh. sonnei were estimated to be 50, 160, 240, 285 and 320 mumol/l, respectively, whereas those of MGBCP were slightly higher for respective bacteria.

Bacteria↗
PubMed1991

Bactericidal effect of 15-deoxyspergualin on Staphylococcus aureus.

15-Deoxyspergualin (DSG), an immunosuppressive agent used in organ transplantation, exerts metabolic and antiproliferative effects on methicillin- and gentamicin-resistant Staphylococcus aureus and other bacteria (e.g. Sarcina lutea, Bacillus subtilis, Shigella sonnei, Salmonella typhi and Citrobacter freundii). DSG, at the concentration of 20 mg/l, depleted intracellular putrescine and spermidine in S. aureus to 43 and 40% of the controls, respectively. In these polyamine-depleted S. aureus cells, the synthesis of protein, DNA and RNA was decreased to 20, 85, 78% of the controls. The minimal inhibitory concentrations (MIC) of DSG for growth of S. aureus, S. lutea, B. subtilis, S. sonnei, S. typhi and C. freundii were 17, 13, 7, 15, 4, and 29 mg/l, respectively.

Bacteria↗
PubMed1990

Modulation of the immune response to transplanted tumors in rats by selective depletion of neutrophils in vivo using a monoclonal antibody: abrogation of specific transplantation resistance to chemical carcinogen-induced syngeneic tumors by selective depletion of neutrophils in vivo.

The role of neutrophils in transplantation immunity to syngeneic rat tumors was examined using a monoclonal antibody (RP-3) that depletes rat neutrophils selectively in vivo. We used 2 chemical carcinogen-induced transplanted tumors of different antigenic specificity (KMT-17 and KDH-8 of WKA rat origin). When neutrophils were selectively depleted by i.p. injection of RP-3 at the time of in vivo priming with X-irradiated tumor cells, the growth of subsequently s.c. transplanted identical tumors was not inhibited, in contrast to the group of rats immunized without RP-3 treatment. Tumor growth was also not inhibited when the immune rats were treated with RP-3 at the time of identical viable tumor cell challenge. These results suggest that neutrophils play a role in both the priming and effector phases of specific transplantation resistance to syngeneic tumors.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1989

Contamination of drinking water during collection and storage.

Drinking water contamination during abstraction, storage and use was determined in a suburban community in Rangoon, Burma, by detecting faecal coliforms (FC) with membrane filtration method. Increasing contamination during water collection, from the source to home storage, was found in all the studied households using 4 different types of drinking water. The implications of the findings are discussed.

Bacillus↗
PubMed1987

Production of factor(s) that render polymorphonuclear leukocytes cytostatic from spleen cells stimulated with a streptococcal preparation, OK-432.

We previously reported the augmentation of tumor cytotoxicity of polymorphonuclear leukocytes (PMN) by in vivo administration of a streptococcal preparation, OK-432 (S. Watabe et al., J. Natl. Cancer Inst., 72: 1365-1370, 1984). The present study was undertaken to elucidate the mechanisms of the phenomena. Mouse and rat spleen cells were stimulated in vitro with OK-432. The culture supernatants from the stimulated spleen cells (OK sup) contained factor(s) that rendered mouse and rat PMN cytostatic [neutrophil activating factor (NAF)]. The stimulation of spleen cells with a small dose of OK-432 (0.05 micrograms/ml) resulted in the production of maximum NAF, and NAF was produced soon (12 h) after OK-432 stimulation. NAF was partially inactivated with 60 degrees C 30-min treatment, and completely inactivated with 100 degrees C 10 min. NAF was sensitive to pH 2 treatment. The treatment of PMN with OK sup for 5 min at 37 degrees C was sufficient to induce cytostatic activity of PMN. That OK sup contained gamma-interferon and recombinant gamma-interferon showed NAF activity indicate that gamma-interferon is a NAF in OK sup.

Animals↗
PubMedDate not supplied

Inhibition of malaria-infected erythrocytes by deoxyspergualin: effect on in vitro growth of malarial cultures.

The effect of deoxyspergualin (DSG) on the K1 strain of human malarial parasite Plasmodium falciparum in vitro was studied to test a possible new antimalarial chemotherapy. Hypoxanthine labeled with tritium (3H) was used to assess macromolecular synthesis. The inhibitory effects of DSG on the parasite peaked after 72 h of incubation. Parasitemia without DSG treatment was 9%, whereas at a DSG concentration of more than 156 microg/ml it was less than 1%. The amount of [3H]hypoxanthine taken up decreased with increasing DSG concentration. DNA synthesis of malarial activity decreased with increasing DSG concentration. These findings provide more evidence for the effects of DSG on this malarial parasite. As in previous in vivo studies done with DSG, the in vitro findings showed that DSG may be a new antimalarial drug.

Animals↗
PubMedDate not supplied

15-Deoxyspergualin, an immunosuppressive agent, used in organ transplantation showed suppressive effects on malarial parasites.

Deoxyspergualin (DSG), which was discovered to be an immunosuppressive agent, was examined for its in vivo effect on parasites of rodent malaria. Although the mice that were not treated by DSG had an increased parasite percentage (% parasitemia) until they died, those that were treated with DSG had a decreased parasitemia and finally had 0% parasites. The spleens of infected mice became small by DSG treatment. Parasitemia of mice increased again after DSG treatment was stopped. However, DSG was a polyamine inhibitor. The two other types of polyamine inhibitors used in this study were not effective for decreasing the % parasitemia of Plasmodium berghei. Only DSG was available and the survival time of mice increased. The antiprotozoal effects shown by DSG-even this chemical is an immunosuppressive agent-suggest that there is a relation between the inhibition of the polyamine synthetic pathway or immunosuppression of DSG and the suppressive effect of malarial parasites.

Animals↗
PubMedDate not supplied

Hepatocellular carcinoma followed by Waldenström's macroglobulinemia: a case report.

A case of hepatocellular carcinoma associated with Waldenström's macroglobulinemia is reported. During treatment and follow-up of hepatocellular carcinoma, a 54-year-old man was found to have a progressive monoclonal increase in serum IgM level and subsequently was diagnosed as having Waldenström's macroglobulinemia. Chemotherapy was carried out to prevent hyperviscosity syndrome due to Waldenström's macroglobulinemia without any surgical management for hepatocellular carcinoma. The association of these diseases is quite rare; only 6 cases have been reported in the literature, and this is the first case in which hepatocellular carcinoma preceded Waldenström's macroglobulinemia.

Blood Viscosity↗
PubMedDate not supplied

Mass-forming inflammatory periductal fibrosis mimicking hilar bile duct carcinoma.

A case of a rare benign biliary lesion at the hepatic hilum mimicking hilar bile duct carcinoma is reported. A 73-year-old man was found to have gastric cancer by gastrointestinal fiberscopy. Dilated right intrahepatic bile ducts and a 2-cm mass in the right hepatic duct were demonstrated by further imaging investigations. He was finally diagnosed as having hilar bile duct and gastric carcinomas, and underwent right portal vein embolization followed by a single-stage extended right hepatectomy and total gastrectomy. Pathologically, however, the lesion in the right hepatic duct showed inflammatory changes with periductal fibrosis, without any signs of malignancy. A literature search revealed 11 such cases including the present one.

Aged↗