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S Tsuruta

Publications and source records attributed to S Tsuruta.

107 records · Page 6Linked to original sources

Structure-dependent variation in the mutagenic, prophage-inducing and antibacterial activities of 5-nitro-2-furamide derivatives.

A comparative survey of the mutagenic, prophage-inducing and antibacterial activities of 3 structure-related series of 5-nitro-furan derivatives including 5-nitro-2-furohydrazide imide, 5-nitro-2-furamide oxime and 5-nitro-2-furohydrazide has been undertaken. Among the compounds assayed, the 5-nitro-2-furohydrazide imide series was found to be most active with regard to mutagenic and antibacterial activities against Salmonella typhimurium TA100 and prophage-inducing activity in Escherichia coli GY5027. A clear correlation was observed between the chemical structure and the mutagenic and prophage-inducing activities which were approximately correlated to the antibacterial activity.

Anti-Bacterial Agents↗

Fv-1 determinants in xenotropic murine leukemia viruses studied with biological assay systems: Isolation of xenotropic virus with N-tropic Fv-1 activity in the cryptic form.

By a biological assay system using phenotypically mixed ecotropic and xenotropic murine leukemia viruses, we investigated whether in the virions of a xenotropic virus there is N- or B-tropic Fv-1 determinant in active form. The existence of N-tropic Fv-1 determinant was demonstrated in SL-XT-1 xenotropic virus isolated from the spleen of a 3-month-old SL mouse, and the N-tropic Fv-1 tropism was confirmed by analysis of the phenotypically mixed viruses harvested from clonal SC-1 cells doubly infected with the SL-XT-1 and B-tropic ecotropic viruses. However, neither N- nor B-tropic Fv-1 determinant was demonstrated in any xenotropic viruses isolated from embryo cells of BALB/c, NZB, or DBA/2 mice, or Cas E #1-IU, and xenotropic-like virus isolated from a wild mouse.

Animals↗

[Experimental and clinical studies of cefmenoxime in the field of obstetrics and gynecology].

The study group was organized to evaluate the usefulness of cefmenoxime (CMX) injection, a new synthetic cephalosporin, for the treatment of infections in the field of obstetrics and gynecology. Fundamental and clinical studies were made by the society and the following results were obtained. 1. The peak distribution of CMX's MIC for E. coli, Klebsiella sp., Enterobacter sp., Bacteroides sp. and Peptococcus sp. isolated from obstetrical and gynecological infections with relatively high frequencies area 0.1, less than or equal to 0.05, 0.2, 3.13, 1.56 micrograms/ml, respectively, with an inoculation of 10(6) cells/ml. 2. When 1 g of CMX is administered by intravenous drip infusion for 1 hour, the maximum concentrations in various tissues of female genital organs were as follows: 14.2 and 13.2 micrograms/g in ovary and oviduct, respectively, at 1.20 hours after the start of administration, and 16.9 and 26.3 micrograms/g in corpus uteri and cervix uteri, respectively, after 1 hour. As for the transfer to the exudate in the pelvic dead cavity, the peak concentration was 15.6 micrograms/ml after 2.13 hours. 3. In the clinical studies, CMX was given to 258 cases with female genital organ infections and others. As for the clinical effects, with exclusion of 3 cases in which other antibiotics are concomitantly used, responses were excellent in 76 cases, good in 162 cases and poor in 17 cases, among 255 cases in total. The efficacy rate was 93.3%. The efficacy rates by diseases were 97.1% (68/70) for intrauterine infections, 88.8% (79/89) for intrapelvic infections, 98.4% (62/63) for adnexitis, and 100% (23/23) for infections of external genital organs. As for the clinical effects on causative bacteria, the efficacy rates were 100% (19/19) for single infections due to Gram-positive bacteria, 94.8% (55/58) for single infections due to Gram-negative bacteria, and 88.2% (15/17) for single infections due to anaerobic bacteria. And its efficacy rates were 89.6% (69/77) for mixed infection cases. Side effects were observed in 2 cases (0.8%); 1 case with eruption, and 1 case with diarrhea and vomiting. As for abnormal laboratory findings, lower white blood cell count was observed in 2 cases and elevation of the values regarding hepatic functions in 9 cases. All cases were returned to the normal after the completion of the administration. Cefmenoxime showed a satisfactory clinical efficacy and a potent bacteriological effect in treatment of the infections in the field of obstetrics and gynecology, and it has been concluded that cefmenoxime will be useful addition to the antibiotics for the therapy of these infections.

Adolescent↗

Differential regulation of albumin gene expression by heparin-binding epidermal growth factor-like growth factor in alpha-fetoprotein-producing and -nonproducing human hepatoma cells.

The effects of heparin-binding epidermal growth factor-like growth factor (HB-EGF) on albumin gene expression were analyzed in alpha-fetoprotein (AFP)-producing and AFP-nonproducing human hepatoma cells, HuH-7 and huH-1/cl.2, in which the AFP silencer is inactive and active, respectively. HB-EGF selectively suppressed the AFP enhancer activity, resulting in decreased levels of both albumin and AFP mRNA in HuH-7 cells. In contrast, HB-EGF did not influence the albumin transcripts in huH-1/cl.2 cells or primary culture of rat hepatocytes, although the AFP enhancer activity was reduced by HB-EGF in huH-1/cl.2 cells as well as in HuH-7 cells. These results indicate that the AFP silencer interacts with the AFP enhancer to block its activity regulating both the albumin and AFP promoters, and that HB-EGF downregulates the albumin gene expression only in the absence of the AFP silencer through the repression of the AFP enhancer activity.

Animals↗

Beta-lipoproteins influence the serum level of hepatitis C virus.

Low density lipoprotein receptor (LDLR) has been proposed as a candidate receptor for hepatitis C virus (HCV). According to previous reports, free beta-lipoproteins in a human serum may regulate the rate of hepatocyte infection by competing with the virus. Therefore, serum HCV levels should be regulated by the rise and fall of serum beta-lipoproteins since the infection rate of virions influences HCV replication in hepatocytes and release of virions by hepatocytes. In this study, we examined the relationship between serum beta-lipoproteins and HCV-antigen (Ag) levels in patients with chronic type C hepatitis. Patients were selected based on strict criteria to eliminate other factors that might influence serum HCV levels. Serum concentrations of beta-lipoproteins and HCV-Ag were measured two or more times within 3 months for each patient. The result showed that HCV-Ag levels were negatively correlated with the increased beta-lipoproteins. The results support the concept that LDLR is a HCV receptor and that beta-lipoproteins competitively inhibit the infection of hepatocytes with HCV through the LDLR.

Binding, Competitive↗

Retrovirus-mediated gene therapy for hepatocellular carcinoma: selective and enhanced suicide gene expression regulated by human alpha-fetoprotein enhancer directly linked to its promoter.

We have previously reported that a retrovirus vector (LNAF0.3TK) carrying a herpes simplex virus thymidine kinase gene regulated only by the 0.3-kb human alpha-fetoprotein (AFP) promoter provides ganciclovir (GCV)-mediated cytotoxicity in high AFP-producing human hepatoma cells but not in low AFP-producing cells. In the present study, a retrovirus vector (LNAF0.3(E+)TK), in which herpes simplex virus thymidine kinase gene expression is under the control of a human AFP enhancer directly linked to its promoter, was constructed and compared with LNAF0.3(E+)TK. In the intermediate and low AFP-producing human hepatoma cells PLC/PRF/5 and huH1/cl.2, respectively, as well as in the high AFP-producing human hepatoma cells (HepG2), LNAF0.3(E+)TK sensitized these cells to GCV in vitro but did not affect cell growth in nonhepatoma cells (HeLa). In an animal model using athymic mice harboring PLC/PRF/5 cells, GCV treatment resulted in more pronounced growth inhibition in the LNAF0.3(E+)TK virus-infected cells than in the LNAF0.3(E+)TK virus-infected cells. These results indicate that the human AFP enhancer that is directly linked to its promoter involves selective and enhanced tumoricidal activity in gene therapy for hepatocellular carcinoma.

Animals↗