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991.
A study of experimental contamination of foods with spores of toxigenic micromycetes (Aspergillus flavus andPenicillium verrucosum) was realized. Samples of bread, apricot jam, Edam cheese, processed cheese and half-fat dried milk purchased on the market
were used for experimental contamination. Aflatoxins and ochratoxin A were determinated in experimental contaminated foodstuffs. 相似文献
992.
Mycotoxins are naturally occurring secondary metabolites produced by several toxigenic microscopic fungi on a variety of crops, especially cereal grains and further foodstuffs. Series of experimental research projects on the determination of mycotoxins (aflatoxins, cyclopiazonic acid, ochratoxin A, patulin, deoxynivalenol, fumonisin B1, T-2 toxin, zearalenone, sterigmatocystin, alternaria toxins) in several foods were realized in the National Reference Centre for Microscopic Fungi and Mycotoxins in the 90th years. The aim of our work was an estimation of dietary exposure to mycotoxins and risk assessment. The method of a solid phase extraction (SPE), liquid — liquid extraction and immunoaffinity chromatography (f. e. R-Biopharm, VICAM) were used to elaborate for sample analyses of mycotoxins in our projects. The mycotoxins were detected most frequently by chromatographic methods (HPTLC, HPLC, GC) and immunochemical methods (ELISA). Average dietary exposure has been calculated by multiplying of concentration data for specific foods with their consumption rates per 1 kg of b. w. per day. The estimation of the dietary exposure dose of mycotoxins for the Czech population is presented. 相似文献
993.
Huong L. Vu Serge Troubetzkoy Huan H. Nguyen Michael W. Russell Jiri Mestecky 《Nucleic acids research》2000,28(7):e18
Accurate quantification of nucleic acids by competitive (RT)–PCR requires a valid internal standard, a reference for data normalization and an adequate mathematical model for data analysis. We report here an effective procedure for the generation of homologous RNA internal standards and a strategy for synthesizing and using a reference target RNA in quantification of absolute amounts of nucleic acids. Further, a new mathematical model describing the general kinetic features of competitive PCR was developed. The model extends the validity of quantitative competitive (RT)–PCR beyond the exponential phase. The new method eliminates the errors arising from different amplification efficiencies of the co-amplified sequences and from heteroduplex formation in the system. The high accuracy (relative error <2%) is comparable to the recently developed real time detection 5′-nuclease PCR. Also, corresponding computer software has been devised for practical data analysis. 相似文献
994.
Zhang J Wrage EL Vankova R Malbeck J Neff MM 《The Plant journal : for cell and molecular biology》2006,46(5):834-848
Cytokinins are a class of phytohormones that play a critical role in plant growth and development. sob5-D, an activation-tagging mutant, shows phenotypes typical of transgenic plants expressing the Agrobacterium tumefaciens isopentenyltransferase (ipt) gene that encodes the enzyme catalyzing the first step of cytokinin biosynthesis. The sob5-D mutant phenotypes are caused by over-expression of a novel gene, SOB5. Sequence analysis places SOB5 in a previously uncharacterized family of plant-specific proteins. A translational fusion between SOB5 and the green fluorescent protein reporter was localized in the cytoplasm as well as associated with the plasma membrane when transiently expressed in onion epidermal cells. Analysis of transgenic plants harboring an SOB5:SOB5-beta-glucuronidase (GUS) translational fusion under the control of the SOB5 promoter region showed GUS activity in vegetative tissues (hydathodes and trichomes of leaves, shoot meristems and roots) as well as in floral tissues (pistil tips, developing anthers and sepal vasculature). Cytokinin quantification analysis revealed that adult sob5-D plants accumulated higher levels of trans-zeatin riboside, trans-zeatin riboside monophosphate and isopentenyladenine 9-glucoside when compared to the wild-type. Consistent with this result, AtIPT3 and AtIPT7 were found to be up-regulated in a tissue-specific manner in sob5-D mutants. Physiological analysis of the sob5-D mutant demonstrated reduced responsiveness to exogenous cytokinin in both root-elongation and callus-formation assays. Taken together, our data suggest a role for the novel gene SOB5 in cytokinin-mediated plant development. 相似文献
995.
Valente C Guedes RC Moreira R Iley J Gut J Rosenthal PJ 《Bioorganic & medicinal chemistry letters》2006,16(15):4115-4119
The synthesis of phosphonate derivatives of N-phenyl- and N-benzyl-gamma- and delta-sultams, and their application in the Wittig-Horner reaction with N-Boc-L-phenylalanine aldehyde to afford E- and Z-isomers, are described. These compounds were further processed to provide five dipeptide vinyl sultams, which were found to be inactive against papain at concentrations up to 50 microM. In contrast, vinyl sultams demonstrated weak activity against recombinant falcipain-2 and Plasmodium falciparum W2. 相似文献
996.
Mackova J Stasikova J Kutinova L Masin J Hainz P Simsova M Gabriel P Sebo P Nemeckova S 《Cancer immunology, immunotherapy : CII》2006,55(1):39-46
The Bordetella adenylate cyclase toxoid (CyaA) targets cells expressing the αMβ2 integrin receptor CD11b/CD18 (CR3 or Mac-1) and can penetrate into cytosol of professional antigen-presenting cells, such
as dendritic cells. This allows us to use CyaA for delivery of passenger antigens into the cytosolic pathway of processing
and MHC class I-restricted presentation, which can promote induction of antigen-specific CD8+ cytotoxic T-lymphocyte immune responses. We show here that vaccination with a genetically detoxified CyaA336/E7 protein,
carrying the full-length oncoprotein E7 of the human papilloma virus 16 inserted at position 336 of the cell-invasive AC domain
of CyaA, induces an E7-specific CD8+ T-cell immune response and confers on mice protective, as well as therapeutic immunity against challenge with TC-1 tumor
cells expressing the E7 oncoprotein. The therapeutic efficacy of priming with the CyaA336/E7 vaccine could further be enhanced
by a heterologous booster immunization with a highly attenuated modified vaccinia virus Ankara (MVA) expressing the E7 protein
fused to the lysosome-associated membrane protein (LAMP1). These results establish the potential of CyaA as a new antigen
delivery tool for prime/boost immunotherapy of tumors.
This paper won the poster prize at the conference “Progress in Vaccination against Cancer 4”, PIVAC 4, held in Freudenstadt-Lauterbad,
Black Forest, Germany, from 22 to 25 September 2004. For further material on this conference, please see the series of Symposium
Papers, published 相似文献
997.
Zerbe O Neumoin A Mares J Walser R Walser R Zou C 《Journal of receptor and signal transduction research》2006,26(5-6):487-504
In this review a structural approach developed to answer the question whether hormones from the neuropeptide Y (NPY) family are recognized directly from solution or from the membrane-bound state is described. The chosen strategy is built onto a comparison of a set of peptides with well-known pharmacology and investigates whether similarities of structures of pharmacologically related peptides are higher in solution or in the membrane-bound state. Moreover, we have established the membrane-association mode of these peptides and contributed to our understanding of the structural features of these hormones both when placed in bulk solution and when bound to membranes. As a result we propose a receptor recognition pathway that includes initial association with the membrane and requires the peptides to come off the membrane to diffuse into the binding pocket of the receptor. This review also presents methodology recently developed by us to simulate the structural transition the peptides undergo when diffusing from bulk solution onto the membrane. 相似文献
998.
New work by Bruno et al. (2006) describes a mechanistic switch of the proliferation-promoting Che-1 activator of E2F-target genes into a cell-cycle inhibitor in response to DNA damage, through Che-1 relocalization to, and activation of, the p53 tumor suppressor gene. 相似文献
999.
Cernakova I Kvasnicova M Lovasova Z Badova N Drabek J Bouchalova K Trojanec R Hajduch M 《Biomedical papers of the Medical Faculty of the University Palacky, Olomouc, Czechoslovakia》2006,150(1):113-116
We report here a case of a newborn with hypotrophy and somatic stigmatization: microcephaly, facial dysmorphism, heart defect and immunodeficiency syndrome. The proband's karyotype was 46,XY,dup(4)(q28q35.2) de novo with chromosomal breaks in 4% of metaphases. We demonstrate the usefulness of a combination of physical examination, classical cytogenetics, FISH and PCR techniques in order to establish correct diagnosis because of overlap of some clinical and cytogenetic features of Nijmegen breakage syndrome (NBS) and duplication 4q in our patient. Although FISH technique detected translocation t(14q;21q) in 4 metaphases, deletion 657del5 in exon 6 of the NBS1 gene associated with NBS in Slavic population was not confirmed. We compare in this report similarity of the clinical picture of our patient, NBS cases and other patients carrying a duplication of the distal part of 4q as described in the literature. 相似文献
1000.