No description available.

The purpose of this study was to characterize Johne’s disease in Mississippi cattle. Nine hundred eighteen animals from 23 sale barns in Mississippi were tested for Mycobacterium avium subspecies paratuberculosis (MAP). Ten milliliters of blood and 4-10 grams of feces were collected from cattle over two years of age presented to the attending auction veterinarian. Information obtained at the time of collection included the animal’s sex, type, and reproductive status. Serum samples were screened by an enzyme-linked immunosorbent assay (ELISA) for MAP. Shedding status was determined using polymerase chain reaction (PCR) on corresponding fecal samples. Overall, 17.3% (4/23) of sale barns had at least one animal sero-positive for MAP and 0.54% (5/918) were PCR positive. These results show a Johne’s disease prevalence similar to the estimate of 0.4% of animals infected found by the USDA NAHMS Beef ‘97 study, emphasizing the need for continued prevention and control practices.

No description available.

No description available.

No description available.

No description available.

No description available.

At late times during the infection of human KB cells with Adenovirus type 2 (Ad 2), the ultraviolet (uv) sensitivity of transcription was assayed by DNA-RNA hybridization across the length of the genome. Assuming that the majority of the nuclear transcripts at this time of infection are read from the rightward transcribing DNA strand, the resulting plot of the surviving fraction of viral transcription vs. genome position indicates two transcription units are responsible for the transcription from selected DNA restriction fragments of the genome were also obtained. The uv inactivation cross sections generated from such curves identified a long, uv sensitive transcript originating from the major late promoter at approximately 17 map units, and a shorter, less uv sensitive from approximately 63 map units on the genome. The shorter transcription unit accounts for about one third to a half of the viral nuclear RNA synthesized from the right hand 30 to 40% of the genome. The majority of the late viral nuclear transcripts, however, originated at approximately 17 map units and terminated at around 60-70 map units. Similar experiments examining the uv sensitivity of cytoplasmic poly A RNA production at various sites across the length of the genome are consistent with two rightward transcribing transcription units expressed during late Ad 2 infection. The transcriptional organization of late Ad 2 gene expression was also approached through uv transcription unit mapping experiments by examining the uv sensitivities of the synthesis of late Ad 2 proteins for which the approximate gene locations are known. The effect of uv on Ad 2 nuclear transcription was also reflected at the polypeptide level indicating two transcription units are responsible for the synthesis of mRNA coding for late viral proteins. The differential radiosensitivities of late protein synthesis confirmed the relative gene positions on the Ad 2 genome. / Thesis / Master of Science (MS)

O objetivo do presente trabalho foi avaliar a perda da hermeticidade do sistema de embalagens plásticas flexíveis utilizadas para o envase de carne bovina cozida e desidratada (Beef Jerky) que é realizado por meio da aplicação de vácuo, atmosfera modificada e a inserção de absorvedores de oxigênio. Durante 1 (um) mês foram realizadas avaliações dos defeitos que ocasionam a perda da hermeticidade na produção do Beef Jerky em três plantas fabris localizadas no Brasil. Os defeitos encontrados foram mapeados, identificados e avaliados por meio de análises microscópicas da estrutura do filme flexível, análises de oxigênio do espaço livre da embalagem e ensaios de verificação dos canais de solda. Os resultados apresentados nesta pesquisa demonstraram que as origens da perda da hermeticidade estão relacionadas a fatores físicos, biológicos e humanos. Após a realização de melhorias como a alteração da linha de produção e treinamento dos operadores, o aumento da espessura da solda e a redução da quantidade de vácuo aplicada, houve a redução de 33,66%, 51,32% e 43,59% de defeitos de hermeticidade respectivamente. Foi observado também que a taxa de permeabilidade ao O2 da embalagem (TPO2) pode ser reduzida e consequentemente a barreira mecânica pode ser aumentada possibilitando a redução de defeitos mecânicos nas embalagens. A substituição dos sachês absorvedores, que podem ser danificados pelo contato com o produto, por sistemas de embalagens ativas que contém o princípio ativo incorporado ao filme também foi proposta, porém não foi recomendada uma vez que o oxigênio residual não atingiu menos que 1% de oxigênio após 72 horas. O resultado preliminar demonstrou que este sistema é menos eficiente do que o atual e que novos estudos e aprimoramentos da tecnologia devem ser realizados para que a aplicação das embalagens no sistema de envase de Beef Jerky seja eficiente. / The objective of the present study was to evaluate the leakage of the flexible plastic packaging system used for the packaging of Beef Jerky, which is carried out through the application of vacuum, modified atmosphere and the insertion of oxygen absorbers. During 1 month were made evaluations of the defects that causes the leakage in the production of Beef Jerky at three plants located in Brazil. The defects were mapped, identified and evaluated through microscopic analysis of the flexible film structure, oxygen analyzes of the packaging headspace and the seal channels verification tests. The results presented in this research demonstrated that the origins of leakage are related to physical, biological and human factors. After improvements such as the alteration of the production line and training of the operators, the increase of the seal thickness and the reduction of the applied vacuum amount, there was noted a reduction of 33,66%, 51,32% e 43,59% of sealing defects, respectively. It has also been observed that the package O2 transmission rate (OTR) can be reduced and consequently the mechanical barrier can be increased enabling reduction of mechanical defects in the packages. The replacement of the absorbent sachets, which may be damaged by contact with the product, for the active packaging systems containing the active principle incorporated in the film was also proposed, but it was not recommended since the residual oxygen did not reach less than 1% of after 72 hours. The preliminary result has shown that this system is less efficient than the current one and that further studies and improvements of the technology must be made so that the application of the packages in the system of Beef Jerky packaging will be efficient.

Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Jarmila Králová Supervisor: Dr. Kathryn Taylor, Ph.D., PharmDr. Martina Čečková, Ph.D. Title of diploma thesis: Zinc induced activation of breast cancer cell lines and the involvement of MAP kinase The aim of this work was to investigate the effect of zinc on various signalling pathways in breast carcinoma cell lines MCF7 and TamR cells. The differences between signalling pathways in MCF7 cell line and TamR cells were evaluated with a special focus on a role of MAP kinase, which activation is believed to be linked with malignant diseases. An effect of zinc on various cellular kinases in 0, 2, 5, 10, 15 and 20 minute of zinc treatment was analyzed in MCF7 cells transfected by wild and mutant type of ZIP 7, TamR cells and TamR cells pre-treated with MAP kinase inhibitor (PD) using the methods of western blotting and fluorescent microscopy. We show here the dependence of activation of pMAP kinase and other important oncogenic kinases (such as Lyn, Src and STAT3) on zinc release into cytoplasm. According to our results, MAP kinase is activated very upstream and it can stimulate many important protein kinases as Src Y418 , STAT3 S727 and Lyn Y396 in tamoxifen-resistant breast cancer...