Pub Date : 2013-01-01DOI: 10.7546/CR-2013-66-6-13101331-10
Iliyana Sazdova, Bilyana M. Ilieva, M. Shkodrova, A. Milusheva, M. Chichova, R. Schubert, Ferenc Fülüp, L. Lubomirov, H. Gagov
The aim of this research is to study the obestatin signalling on in vitro heart preparations of Rana ridibunda frog using pharmacological tools dissolved in or added to 0.1% or 0.01% dimethyl sulfoxide (DMSO). The application of increasing amounts of obestatin in the concentration range 1–1000 nmol/l significantly decreased the force of contraction of excised frog hearts in the presence of 0.1% DMSO. Propranolol entirely inhibited the effect of obestatin in the presence of DMSO without affecting the amplitudes of the force of contraction. Pertussis toxin, PP2 and U0126 completely blocked the obestatininduced decrease of the force of frog heart contractions. In the presence of XE991, 10 mol/l obestatin had no effect on the maximal force of contraction of the same preparations. Obestatin decreased the force of contraction when applied together with an inhibitor of cAMP-dependent protein kinase (PKA). It is suggested that the negative inotropic effect of obestatin observed in the presence of 0.1% DMSO is due to neuronal KCNQ channels modulation followed by a �-adrenergic receptor-dependent and PKA-independent decrease of the contraction force. Our data reveal for the first time the participation of neuronal MAPK kinase in obestatin signalling in the heart.
{"title":"OBESTATIN SIGNALLING IN EXCISED FROG HEART","authors":"Iliyana Sazdova, Bilyana M. Ilieva, M. Shkodrova, A. Milusheva, M. Chichova, R. Schubert, Ferenc Fülüp, L. Lubomirov, H. Gagov","doi":"10.7546/CR-2013-66-6-13101331-10","DOIUrl":"https://doi.org/10.7546/CR-2013-66-6-13101331-10","url":null,"abstract":"The aim of this research is to study the obestatin signalling on in vitro heart preparations of Rana ridibunda frog using pharmacological tools dissolved in or added to 0.1% or 0.01% dimethyl sulfoxide (DMSO). The application of increasing amounts of obestatin in the concentration range 1–1000 nmol/l significantly decreased the force of contraction of excised frog hearts in the presence of 0.1% DMSO. Propranolol entirely inhibited the effect of obestatin in the presence of DMSO without affecting the amplitudes of the force of contraction. Pertussis toxin, PP2 and U0126 completely blocked the obestatininduced decrease of the force of frog heart contractions. In the presence of XE991, 10 mol/l obestatin had no effect on the maximal force of contraction of the same preparations. Obestatin decreased the force of contraction when applied together with an inhibitor of cAMP-dependent protein kinase (PKA). It is suggested that the negative inotropic effect of obestatin observed in the presence of 0.1% DMSO is due to neuronal KCNQ channels modulation followed by a �-adrenergic receptor-dependent and PKA-independent decrease of the contraction force. Our data reveal for the first time the participation of neuronal MAPK kinase in obestatin signalling in the heart.","PeriodicalId":50652,"journal":{"name":"Comptes Rendus De L Academie Bulgare Des Sciences","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75544552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-01-01DOI: 10.7546/CR-2013-66-1-13101331-5
N. Georgieva, R. Bryaskova, N. Lazarova, D. Peshev, R. Tzoneva
New hybrid materials based on polyvinyl alcohol (PVA) and γ-aminopropyltriethoxyxilane (APTEOS), 3-mercaptopropyltriethoxysilane (MPTEOS) and tetraethoxysilane (TEOS) were prepared. To determine the thermal stability of the hybrid materials, thermogravimetric analysis (TGA) was performed. The new materials were tested for biofilm formation and biosorption studies. They were tested as matrices for immobilization of Trichosporon cutaneum R57 capable to remove Cr(VI) from aqueous solutions. The use of APTEOS and MPTEOS as precursors, incorporated new NH– and SH– bonds, which ensured additional binding places for cells immobilization. The presence of SH– and NH– groups in the hybrid matrices resulted in apparently higher Cr(VI) sorption capacity of the immobilized Tr. cutaneum R57 cells due to the incorporation of additional adsorption sites in the matrix through the PVA functionalities. The synthesized PVA/APTEOS materials proved efficient for use in biosorption applications.
{"title":"PVA-BASED HYBRID MATERIALS FOR IMMOBILIZATION OF TRICHOSPORON CUTANEUM R57 EFFICIENT IN REMOVAL OF CHROMIUM IONS","authors":"N. Georgieva, R. Bryaskova, N. Lazarova, D. Peshev, R. Tzoneva","doi":"10.7546/CR-2013-66-1-13101331-5","DOIUrl":"https://doi.org/10.7546/CR-2013-66-1-13101331-5","url":null,"abstract":"New hybrid materials based on polyvinyl alcohol (PVA) and γ-aminopropyltriethoxyxilane (APTEOS), 3-mercaptopropyltriethoxysilane (MPTEOS) and tetraethoxysilane (TEOS) were prepared. To determine the thermal stability of the hybrid materials, thermogravimetric analysis (TGA) was performed. The new materials were tested for biofilm formation and biosorption studies. They were tested as matrices for immobilization of Trichosporon cutaneum R57 capable to remove Cr(VI) from aqueous solutions. The use of APTEOS and MPTEOS as precursors, incorporated new NH– and SH– bonds, which ensured additional binding places for cells immobilization. The presence of SH– and NH– groups in the hybrid matrices resulted in apparently higher Cr(VI) sorption capacity of the immobilized Tr. cutaneum R57 cells due to the incorporation of additional adsorption sites in the matrix through the PVA functionalities. The synthesized PVA/APTEOS materials proved efficient for use in biosorption applications.","PeriodicalId":50652,"journal":{"name":"Comptes Rendus De L Academie Bulgare Des Sciences","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73076763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-01-01DOI: 10.7546/CR-2013-66-1-13101331-6
A. Georgieva, A. Kril, Diliana D. Simeonova, I. Ivanov, G. Radoslavov
The LSCC-SF-MC29 cell culture model system was further characterized by studies on the provirus content of the cells, the host range and the subgroup specificity of the produced virus. The transforming potential of the Mc29 virus was evaluated by the focus-forming and colony-forming assays on primary cell cultures and continuous cell lines of avian and mammalian origin. The in ovo effects of the myelocytomatosis virus Mc29 on 15I line White Leghorn chicken embryos were studied by routine histopathological methods. Six avian leucosis virus-specific proviral sequences were detected by PCR analysis in the genome of LSCC-SF-MC29 cells. The presence of a Mc29 provirus-specific sequence located in the gag-myc region was confirmed. Using primers designed to differentiate ALV subgroups, amplification product was obtained with subgroup B/D-specific PCR primers. As it was expected, the subgroup E-specific PCR primers amplified the endogenous ALV sequences. In vitro studies on the host range of Mc29 virus showed that the primary cultures of chicken and hamster cells and a continuous hamster cell line were susceptible, while the cultures of primary quail cells and of a permanent line of duck embryo cells were resistant to the transforming effect of the virus. In ovo, the inoculated Mc29 virus induced hyperplasic and preneoplastic lesions in the embryonal liver and pancreas and myxomas of the neck.
{"title":"NOVEL MODELS OF AVIAN LEUCOSIS VIRUS-INDUCED CARCINOGENESIS","authors":"A. Georgieva, A. Kril, Diliana D. Simeonova, I. Ivanov, G. Radoslavov","doi":"10.7546/CR-2013-66-1-13101331-6","DOIUrl":"https://doi.org/10.7546/CR-2013-66-1-13101331-6","url":null,"abstract":"The LSCC-SF-MC29 cell culture model system was further characterized by studies on the provirus content of the cells, the host range and the subgroup specificity of the produced virus. The transforming potential of the Mc29 virus was evaluated by the focus-forming and colony-forming assays on primary cell cultures and continuous cell lines of avian and mammalian origin. The in ovo effects of the myelocytomatosis virus Mc29 on 15I line White Leghorn chicken embryos were studied by routine histopathological methods. Six avian leucosis virus-specific proviral sequences were detected by PCR analysis in the genome of LSCC-SF-MC29 cells. The presence of a Mc29 provirus-specific sequence located in the gag-myc region was confirmed. Using primers designed to differentiate ALV subgroups, amplification product was obtained with subgroup B/D-specific PCR primers. As it was expected, the subgroup E-specific PCR primers amplified the endogenous ALV sequences. In vitro studies on the host range of Mc29 virus showed that the primary cultures of chicken and hamster cells and a continuous hamster cell line were susceptible, while the cultures of primary quail cells and of a permanent line of duck embryo cells were resistant to the transforming effect of the virus. In ovo, the inoculated Mc29 virus induced hyperplasic and preneoplastic lesions in the embryonal liver and pancreas and myxomas of the neck.","PeriodicalId":50652,"journal":{"name":"Comptes Rendus De L Academie Bulgare Des Sciences","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72588222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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