Submitted by Cristhian Reynaldo Gomez Bautista (cristhian_rey88@hotmail.com) on 2018-06-06T19:32:09Z No. of bitstreams: 1 Dissertação_Final.pdf: 1036748 bytes, checksum: 062ca5e9451ec3a79709fe89e619d109 (MD5) / Approved for entry into archive by Silvana Alvarez null (silvana@ict.unesp.br) on 2018-06-06T19:44:21Z (GMT) No. of bitstreams: 1 bautista_crg_me_sjc.pdf: 1036748 bytes, checksum: 062ca5e9451ec3a79709fe89e619d109 (MD5) / Made available in DSpace on 2018-06-06T19:44:21Z (GMT). No. of bitstreams: 1 bautista_crg_me_sjc.pdf: 1036748 bytes, checksum: 062ca5e9451ec3a79709fe89e619d109 (MD5) Previous issue date: 2018-05-30 / A diabetes mellitus, doença caracterizada pelo aumento da glicemia no sangue, é um dos mais importantes problemas de saúde pública do mundo, com incidência crescente, sobretudo em países em desenvolvimento. Novas terapias medicamentosas para controlar os níveis de glicose no sangue têm sido desenvolvidas, entre elas, os inibidores da enzima dipeptidil peptidase-4 (DPP-4) como a sitagliptina. Pesquisas atuais mostram que este medicamento, além do controle da glicemia, contribui na estimulação da formação e inibição da reabsorção óssea e possui ação anti-inflamatória. O objetivo deste trabalho foi avaliar os efeitos da sitagliptina no tecido ósseo em ratos diabéticos e não diabéticos. Foram utilizados 38 ratos machos, divididos em 4 grupos: Grupo diabético tratado com sitagliptina (GDS- 10 mg/Kg/dia); Grupo diabético (GD); Grupo normoglicêmico tratado sitagliptina (GNS-10 mg/Kg/dia); Grupo normoglicêmico (GN). Para indução da diabetes os animais receberam solução 10% de frutose na água de beber por 14 dias, após o quê receberam 40 mg/Kg de estreptozotocina via intraperitoneal. Quatro semanas depois, avaliou-se a glicemia e iniciou-se o tratamento com sitagliptina nos grupos GDS e GNS, que continuou por mais 4 semanas, quando ocorreu a eutanásia. A glicemia e a resistência à insulina (HOMA-IR) foram avaliadas também no dia da eutanásia. As tíbias foram removidas e avaliadas a porcentagem de volume ósseo (BV/TV), espessura trabecular (Tb.Th), número de trabéculas (Tb.N) e a separação de trabéculas (Tb Sp) da metáfise tibiana por microtomografia computadorizada. Os dados foram submetidos à análise estatística, ao nível de 0,05. Os animais dos grupos GD e GDS apresentaram maior glicemia que os animais dos demais grupos, mas não houve diferença entre os grupos com relação aos dados de HOMA-IR, evidenciando a indução de diabetes do tipo I. Os animais diabéticos apresentaram menor BV/TV e Tb.N, e maior Tb.Sp. Não houve diferença com relação à Tb.Th. O modelo experimental foi eficaz para a indução da diabetes, mas o tratamento com sitagliptina não foi suficiente para reverter os efeitos da diabetes no tecido ósseo. / Diabetes mellitus, a disease characterized by increased blood glucose levels, is one of the most important public health problems in the world, with a growing incidence, especially in developing countries. New drug therapies to control blood glucose levels have been developed, including dipeptidyl peptidase-4 (DPP-4) inhibitors such as sitagliptin. Current research shows that this drug, in addition to glycemic control, contributes to stimulate the formation and inhibition of bone resorption and has an anti-inflammatory action. The aim of this study was to evaluate the effects of sitagliptin on bone tissue in diabetic and non-diabetic rats. Thirty-eight male rats were divided into four groups: Diabetic group treated with sitagliptin (GDS-10 mg / kg / day); Diabetic group (GD); normoglycemic group treated with sitagliptin (GNS-10 mg / kg / day); normoglycemic group (GN). For induction of diabetes the animals received 10% solution of fructose in the drinking water for 14 days, after which they received 40 mg / kg streptozotocin intraperitoneally. Four weeks later, glycemia was evaluated and sitagliptin treatment was started in the GDS and GNS groups, which continued for another 4 weeks, when euthanasia occurred. Blood glucose and insulin resistance (HOMA-IR) were also evaluated on the day of sacrifice. Bone volume (BV/TV), trabecular thickness (Tb.Th), number of trabeculae (Tb.N) and trabeculae separation (Tb.Sp) of the tibial metaphysis were evaluated by computerized microtomography. Data were submitted to statistical analysis at the 0.05 level. The animals of groups GD and GDS presented higher glycemia, but there was no difference regarding HOMA-IR, evidencing diabetes type I induction. The animals in which diabetes was induced presented lower BV/TV and Tb.N, and higher Tb.Sp. There was no difference among groups in TB.Th. The experimental model was sufficient for the induction of diabetes, but treatment with sitagliptin was not enough to reverse the effects of diabetes on bone tissue.

In biomechanical analyses, the position of long bone cross-section under study is defined relatively to biomechanical length (BML) of the bone. In damaged bones where BML can not be measured, the position of the cross-section has to be estimated. Sládek et al. (2010) studied the effect of inaccurately located femoral and tibial midshafts on the cross-sectional parameters in a pooled-sex sample from a single period. In the present study we aim to test whether the effect of inaccurately located femoral and tibial midshafts on the cross-sectional parameters is sample-specific and/or sex-specific. We used femora of 29 females and 25 males and tibiae of 24 females and 36 males from two different periods (Late Eneolithic and Early Bronze Age; early modern period). 29 cross-section CT scans per bone obtained at each 1% interval from 40% to 60% of BML and at each 5% interval from 20-40% and 60-80% of BML were available to us. We digitized the cross-section scans and computed the error ranges of the cross-sectional parameters. We compared the mean percentage difference (MD%) and mean accuracy range (MAR) between samples and sexes. Our results are in concordance with the results of Sladek et al. (2010): the cross-sectional parameters most sensitive to positioning error are tibial second moments of area (MAR...