Thesis (Ph. D.)--Michigan State University. Dept. of Animal Science, 2008. / Title from PDF t.p. (viewed on July 23, 2009) Includes bibliographical references. Also issued in print.

Thesis (Ph. D.)--University of California, Riverside, 2010. / Includes abstract. Available via ProQuest Digital Dissertations. Title from first page of PDF file (viewed May 17, 2010). Includes bibliographical references. Also issued in print.

Thesis (Ph.D.)--McMaster University, 2004. / Advisor: William J. Muller. Includes bibliographical references (p. 145-186). Also available online.

Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-01-21T09:58:13Z No. of bitstreams: 0 / Made available in DSpace on 2015-01-21T09:58:13Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:52:25Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:43Z (GMT). No. of bitstreams: 0 / Neste trabalho, estão descritos os métodos de seleção, calibração e de determinação dos fatores de correção, as características físicas dos dosímetros termoluminescentes, o procedimento de cálculo para converter a leitura do dosímetro em dose absorvida e a metodologia para se determinar a dose de entrada. Foram investigadas a praticidade e a utilidade das medidas de dose de entrada com os dosímetros termoluminescentes, bem como a exatidão e a reprodutibilidade no fornecimento da dose diária. As medidas de dose de entrada foram realizadas em cinco pacientes com diagnóstico de câncer de mama tratadas com um feixe de fótons de 6 MV. Não foram detectados grandes desvios entre a dose medida e a dose esperada (os valores concordaram em ± 5%), devido à excelente estabilidade do equipamento de tratamento, ao sistema automático de verificação e à boa exatidão no ajuste diário do tratamento. Uma boa precisão pode ser alcançada quando os fatores de correção para cada parâmetro de influência na resposta do dosímetro são cuidadosamente determinados e aplicados para converter o sinal termoluminescente em dose absorvida. O estudo demonstrou a viabilidade do uso dos dosímetros termoluminescentes para a dosimetria in vivo e sua utilidade como parte de um programa de garantia de qualidade em um serviço de radioterapia. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-01-21T09:58:13Z No. of bitstreams: 0 / Made available in DSpace on 2015-01-21T09:58:13Z (GMT). No. of bitstreams: 0 / Neste trabalho foram realizados testes de estabilidade e de caracterização de uma câmara de ionização de ar-livre com cilindros concêntricos da marca Victoreen, modelo 481. Os testes foram feitos utilizando feixes diretos de mamografia como uma contribuição para a implantação desta câmara como sistema padrão primário para a grandeza kerma no ar. Os testes de caracterização realizados foram: curva de saturação, eficiência de coleção de íons, efeito de polaridade, linearidade da resposta com a taxa de kerma no ar e linearidade da resposta com a variação volumétrica. O teste de eficiência de coleção de íons possibilitou a determinação do fator de correção para recombinação iônica. A maioria dos testes realizados esteve em conformidade com os limites estabelecidos por normas internacionais. Foram obtidos os fatores de correção para atenuação de fótons no ar para as qualidades de mamografia com filtros de alumínio e molibdênio. Foram determinados também os fatores de correção para transmissão e espalhamento de fótons nas bordas do diafragma para as qualidades de mamografia com filtro de alumínio e para a qualidade padrão de mamografia com filtro de molibdênio. / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / Post-natal mammary gland development is a complex process in which epithelial proliferation and branching of lactiferous ducts is followed by extensive formation of lobuloalveolar units that produce milk. Classical nuclear factor-kappa B (NF-κB) p65/p50 transcription factors are dynamically induced in the mammary gland during pregnancy, and inhibitor of NF-κB-alpha (IκB-α) deficiency leads to hyperplasia of the mammary epithelium. To further elucidate the role of NF-κB factors in mammary development, we examined NF-κB subunit expression in the mammary glands of transgenic mice expressing the IκB-α S32/36A super-repressor (SR) protein under control of the mouse mammary tumor virus (MMTV)-long terminal repeat promoter, in which mammary gland development is transiently delayed, but not completely blocked. Developmental recovery correlated with induction of RelB/p52 NF-κB complexes, which failed to interact with an IκB-α fusion protein and potently induced cyclin D1 and c-myc promoter activities. Activation of IκB-α kinase alpha (IKKα) and NF-κB inducing kinase (NIK) was detected by day 5.5, and were hypothesized to be responsible for the induction of ReIB/p52. In support of this hypothesis, we found that constitutively active IKKα induced p52, RelB, and cyclin D1 in untransformed mammary epithelial cells. Moreover, mammary tumors induced by high-dose 7,12-dimethylbenz(a)anthracene (DMBA) treatment in wild type FVB/N mice, displayed increased RelB/p52 binding activity. These results implicate activation of RelB/p52 complexes by the alternative NF-κB signaling pathway in branching of lateral ducts and alveolar development during mammary gland development, and in mammary carcinogenesis. / 2031-01-01

Four studies were conducted to investigate the effect and site of action of exogenous and endogenous opioids on pituitary growth hormone (GH) and prolactin (PRL) secretion in Holstein calves. In the first study, the effect of the opioid agonist DAMME (D-Ala²⁺,N-Me-Phe⁴,Met(O)⁵-01 enkephalin) on plasma GH and PRL secretion was measured in Holstein calves in fall season. Plasma concentrations of both GH and PRL increased in response to DAM ME injection. Pretreatment with either the lipid soluble opioid antagonist naloxone (NAL), which readily penetrates the blood brain barrier (BBB), or the peripherally acting antagonist methyl levallorphan mesiltate (MLM), blocked the PRL response to DAMME. Naloxone, but not MLM, negated the GH response to DAMME. In spring, the experiment was repeated with similar results. In the second experiment, the opioid antagonists NAL and MLM were administered alone to detennine whether endogenous opioids mediate basal GH and PRL secretion, and the site of action of any of opioid-mediation of basal GH and PRL. In fall, NAL administration increased both plasma GH and PRL secretion. Methyl levallorphan mesilate did not affect PRL, but increased plasma GH concentrations. In spring, a second trial using 5 different doses of each antagonist was conducted. Naloxone did not affect GH levels at any dose in spring, but decreased plasma PRL at the same dose which increased plasma PRL in fall. Plasma PRL was again unaffected by MLM, but plasma GH was increased by 3 separate doses of MLM. The third experiment was designed to determine if the increases in plasma PRL seen after DAMME administration were mediated via dopaminergic mechanisms. Plasma PRL in calves again increased in response to DAMME injection alone. In calves pre-treated with the long-acting dopamine agonist 2-Br-&alp. ergocryptine (CB 154), plasma PRL was unresponsive to DAMME injection. The pituitaries of calves treated with CB 154 in this experiment were able to respond to thyrotropin-releasing hormone (TRH) injection with increased PRL secretion. In the final experiment, the role of growth hormone-releasing hormone (GRH) in facilitating GH release after DAMME injection was investigated, and whether endogenous opioidergic mechanisms play a role in mediating the effects of exogenous GRH on GH secretion. Plasma GH concentrations increased in calves receiving either DAMME or D-ala²⁺, fragment 1- 29 amide, a synthetic GRH. The immediate increase in plasma GH concentrations after GRH injection in calves pre-treated with DAMME was approximately 5 fold less than that in calves not pre- treated with DAMME. Calves receiving DAMME and GRH in combination also produced a GH response curve with greater area under it than either compound alone, indicating possible synergism between the synthetic GRH and a DAMME-sustained release of endogenous GRH. Naloxone administration concomitantly with synthetic GRH did not alter the ability of the synthetic GRH to increase GH secretion overall, compared to synthetic GRH alone. In conclusion, these studies are the first to indicate that dairy breeds are able to respond to exogenous opioids with increased secretion of pituitary GH and PRL, as is known to occur in other mammalian species. Also, they indicate that opioid receptors mediating pituitary GH secretion to exogenous opioids in Holstein calves are located somewhere within the BBB, and those mediating PRL secretion are at a site outside the BBB. It appears from these studies that endogenous opioids within the BBB play a role in regulating basal PRL secretion, and that this regulation differs in fall and spring. A role for endogenous opioids in the regulation of GH secretion in Holstein calves may exist also, at least in fall, but the results are less conclusive. The peripheral opioid antagonist MLM alone may facilitate increased GH secretion in Holstein calves via an agonistic, not antagonistic, mechanism. These studies indicate that the increased PRL secretion seen following opioid administration in Holstein calves is mediated through a dopaminergic mechanism. It appears that endogenous opioids do not mediate the pituitary response to exogenous GRH in Holstein calves, and that GH increases after DAMME injection are facilitated, at least in part, by increased release of endogenous GRH. / Ph. D.

Cyclosporine (CsA), a fungal peptide with remarkable anti-lymphocytic properties, has been shown to be an effective immunosuppressive agent. In three separate experiments, mice receiving CsA at various doses (8 mg/kg/day in the first two experiments and 70-100 mg/kg/day in the third), were implanted with ovine mammary tissue expants at various sites (subcutaneous dorsum, ovarian fat-pad, and cleared mammary gland fat-pad). After different periods of time, (day 3, 7, 14, 21, and 35) implants were removed, fixed, stained, and embedded. Epithelial morphology of the implants was evaluated via a grading system that classified epithelium from 1 (poor) to 5 (excellent). Leukocyte type and number was determined in subepithelial stroma of implants in the third experiment. In the first two experiments, histological evaluation revealed that the transplanted tissue did not survive, regardless of site of implantation or developmental stage of donor tissue. In experiment three higher, dosages of CsA and different donor tissue were used, this resulted in significantly higher (P < .05) mean epithelial scores (indicative of healthier epithelium) for two CsA treated groups vs two control groups (3.75 and 2.33 vs 2.0 and 1.25, respectively). Within each treatment group (CsA and control), one group of mice received exogenous estrogen and progesterone (EjP) implants. CsA treated mice receiving E/P had significantly higher (P < .05) epithelial scores than those not receiving hormones (3.68 vs 2.83). The reverse was true for lymphocyte number (18.9 vs 40.5 cells per 117,600 um² of subepithelial stroma) which were significantly less in CsA + E/P treated mice. The overall correlation between lymphocyte number and epithelial score was -.55 (P < .0001). These results indicate that ovine mammary tissue xenografted into mice treated with high doses of CsA, are capable of surviving for extended periods of time (at least 35 days). / Master of Science

Master of Science