The Experts below are selected from a list of 12 Experts worldwide ranked by ideXlab platform
K. Elisabeth Norin - One of the best experts on this subject based on the ideXlab platform.
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DEVELOPMENT OF Germfree Animal CHARACTERISTICS IN CONVENTIONAL RATS BY ANTIBIOTICS
Acta Pathologica Microbiologica Scandinavica Section B Microbiology, 2009Co-Authors: Bengt E. Gustafsson, K. Elisabeth NorinAbstract:Conventional (CONV) rats were fed by stomach tube for five days with either benzylpenicillin, ampicillin, tetracykline, oxitetracykline, neomycin, bacitracin + neomycin, kanamycin or colistin. On the 2nd-3rd day all the Animals developed one or several of the following symptoms or characteristics typical for Germfree (GF) rats: no coprostanol formation, no stercobilin production, a GF pattern after gel electrophoresis of fecal supernatant and proteolytic activity in the feces. Under the same conditions succinylsulfathiazole or metronidazole had much less pronounced effects than the antibiotics. When clofibrate, acetylsalicylic acid or ferrous sulphate were administered the effects were none or negligible. The GF characteristics persisted for several weeks after the end of the administration of the drugs. In some instances this was the case up to 7 weeks, when the Animals were contaminated by anal route with a suspension of the cecum contents from intact CONV Animals. On the 2nd day after this treatment the GF characteristics had disappeared.
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Influence of antibiotics on some intestinal microflora associated characteristics.
Anaerobe, 1997Co-Authors: K. Elisabeth NorinAbstract:Abstract Intestinal functions related to the presence of microbes in host organisms are normally heavily influenced by administration of antimicrobial drugs. We have investigated the effect of several antibiotics in man and rat, on some MACs (Microflora Associated Characteristics). A MAC is defined as the recording of any anatomical structure, biochemical or physiological function in the host organism which is influenced by microflora. When functional, active microbes are absent as in Germfree Animals, healthy newborns, or in relation to antimicrobial therapies, a MAC defined as a GAC (Germfree Animal Characteristic). Faecal samples have been collected prior to, during and up to several weeks after the antimicrobial administration in order to investigate different MAC/GAC patterns. Microbial conversion of cholesterol to coprostanol, bilirubin to urobilinogen and 7-alpha-dehydroxylation of cholic acid have been investigated to evaluate hepatic/intestinal co-functions, and degradation of intestinal mucin in order to evaluate the integrity in the intestinal mucosa. Furthermore, degradation of the dietary derived β-aspartylglycine, the level of faecal trypsin and production of short chain fatty acids were investigated to evaluate dietary/intestinal co-functions. It is concluded that each antimicrobial drug creates its own profile, both with regard to duration and function.
Bengt E. Gustafsson - One of the best experts on this subject based on the ideXlab platform.
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DEVELOPMENT OF Germfree Animal CHARACTERISTICS IN CONVENTIONAL RATS BY ANTIBIOTICS
Acta Pathologica Microbiologica Scandinavica Section B Microbiology, 2009Co-Authors: Bengt E. Gustafsson, K. Elisabeth NorinAbstract:Conventional (CONV) rats were fed by stomach tube for five days with either benzylpenicillin, ampicillin, tetracykline, oxitetracykline, neomycin, bacitracin + neomycin, kanamycin or colistin. On the 2nd-3rd day all the Animals developed one or several of the following symptoms or characteristics typical for Germfree (GF) rats: no coprostanol formation, no stercobilin production, a GF pattern after gel electrophoresis of fecal supernatant and proteolytic activity in the feces. Under the same conditions succinylsulfathiazole or metronidazole had much less pronounced effects than the antibiotics. When clofibrate, acetylsalicylic acid or ferrous sulphate were administered the effects were none or negligible. The GF characteristics persisted for several weeks after the end of the administration of the drugs. In some instances this was the case up to 7 weeks, when the Animals were contaminated by anal route with a suspension of the cecum contents from intact CONV Animals. On the 2nd day after this treatment the GF characteristics had disappeared.
Humberto Garcia - One of the best experts on this subject based on the ideXlab platform.
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Effect of Intestinal Microflora Suppression on Liver Carcinogenicity of Dimethylnitrosamine in Syrian Hamsters: Brief Communication " 2
2016Co-Authors: Lori A. Love, Alain Pelfrene, Humberto GarciaAbstract:ABSTRACT-Liver tumors induced by dimethylnitrosamine showed an increased incidence in Syrian hamsters with intestinal microflora suppressed by antibiotics, as compared with the inci-dence in Animals not treated with antibiotics. The possible mech-anisms, including metabolic alterations caused by changes in the normal microflora population, were discussed.-J Natl Cancer Inst 58: 1835-1836, 1977. Numerous studies have indicated that interaction be-tween dietary constituents and chemical carcinogens may be responsible for the geographic and socioeco-nomic variations in the incidence of certain forms of cancer. For example, diets having a high content of fat and Animal protein are considered among the most important causal factors associated with colon cancer in man (1-9). Another major consideration is the presence of intestinal microflora, which may convert dietary com-ponents and endogenous secretions into cocarcinogens and/or carcinogens (10-13). Germfree, as opposed to conventional, Animals have shown a decreased tumor incidence in actual tumor number and in target organs when a carcinogen requir-ing metabolic activation was administered. The opposite was true when a direct acting carcinogen was given (14-17). In the present study, we used conventional Syrian hamsters and those with intestinal microflora sup-pressed by a combination of antibiotics. An attempt was made to determine the effect on carcinogenesis by the potent liver carcinogen DMN in normal versus sup-pressed microfloral populations and to correlate these results with those in Germfree Animal studies
Lori A. Love - One of the best experts on this subject based on the ideXlab platform.
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Effect of Intestinal Microflora Suppression on Liver Carcinogenicity of Dimethylnitrosamine in Syrian Hamsters: Brief Communication " 2
2016Co-Authors: Lori A. Love, Alain Pelfrene, Humberto GarciaAbstract:ABSTRACT-Liver tumors induced by dimethylnitrosamine showed an increased incidence in Syrian hamsters with intestinal microflora suppressed by antibiotics, as compared with the inci-dence in Animals not treated with antibiotics. The possible mech-anisms, including metabolic alterations caused by changes in the normal microflora population, were discussed.-J Natl Cancer Inst 58: 1835-1836, 1977. Numerous studies have indicated that interaction be-tween dietary constituents and chemical carcinogens may be responsible for the geographic and socioeco-nomic variations in the incidence of certain forms of cancer. For example, diets having a high content of fat and Animal protein are considered among the most important causal factors associated with colon cancer in man (1-9). Another major consideration is the presence of intestinal microflora, which may convert dietary com-ponents and endogenous secretions into cocarcinogens and/or carcinogens (10-13). Germfree, as opposed to conventional, Animals have shown a decreased tumor incidence in actual tumor number and in target organs when a carcinogen requir-ing metabolic activation was administered. The opposite was true when a direct acting carcinogen was given (14-17). In the present study, we used conventional Syrian hamsters and those with intestinal microflora sup-pressed by a combination of antibiotics. An attempt was made to determine the effect on carcinogenesis by the potent liver carcinogen DMN in normal versus sup-pressed microfloral populations and to correlate these results with those in Germfree Animal studies
Alain Pelfrene - One of the best experts on this subject based on the ideXlab platform.
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Effect of Intestinal Microflora Suppression on Liver Carcinogenicity of Dimethylnitrosamine in Syrian Hamsters: Brief Communication " 2
2016Co-Authors: Lori A. Love, Alain Pelfrene, Humberto GarciaAbstract:ABSTRACT-Liver tumors induced by dimethylnitrosamine showed an increased incidence in Syrian hamsters with intestinal microflora suppressed by antibiotics, as compared with the inci-dence in Animals not treated with antibiotics. The possible mech-anisms, including metabolic alterations caused by changes in the normal microflora population, were discussed.-J Natl Cancer Inst 58: 1835-1836, 1977. Numerous studies have indicated that interaction be-tween dietary constituents and chemical carcinogens may be responsible for the geographic and socioeco-nomic variations in the incidence of certain forms of cancer. For example, diets having a high content of fat and Animal protein are considered among the most important causal factors associated with colon cancer in man (1-9). Another major consideration is the presence of intestinal microflora, which may convert dietary com-ponents and endogenous secretions into cocarcinogens and/or carcinogens (10-13). Germfree, as opposed to conventional, Animals have shown a decreased tumor incidence in actual tumor number and in target organs when a carcinogen requir-ing metabolic activation was administered. The opposite was true when a direct acting carcinogen was given (14-17). In the present study, we used conventional Syrian hamsters and those with intestinal microflora sup-pressed by a combination of antibiotics. An attempt was made to determine the effect on carcinogenesis by the potent liver carcinogen DMN in normal versus sup-pressed microfloral populations and to correlate these results with those in Germfree Animal studies