Orientador: Elcio Marcantonio Junior / Coorientador: Luis Carlos Spolidorio / Banca: Paulo Sérgio da Silva Santos / Banca: Juliana Rico Pires / Banca: Helder Antonio Rebelo Pontes / Banca: Cleverton Roberto de andrade / Resumo: O objetivo deste projeto foi desenvolver, em ratos, modelos experimentais de osteonecrose induzida pelos bisfosfonatos por meio da combinação de uma série de fatores de risco para esta doença, como o uso prolongado de altas doses de alendronato por via parenteral, procedimentos cirúrgicos operatórios e o estresse crônico. Os parâmetros foram estabelecidos por meio de análise histológica descritiva e por escores, análise radiográfica de alvéolos dentais, estereometria de alvéolos dentais e implantes, torque de remoção dos implantes e avaliação de marcadores do metabolismo ósseo e do estresse. No primeiro e segundo estudos foram administradas altas doses diárias ou semanais de alendronato, respectivamente, associado a exodontias dos primeiros molares inferiores. No terceiro e quarto estudos foram administradas altas doses semanais de alendronato, associado à indução de estresse crônico e instalação de implantes osseointegráveis na maxila e/ou na metáfise tibial. De um modo geral, os resultados dos estudos demonstraram que a terapia com alendronato foi associada à supressão significativa do metabolismo ósseo. Nos estudos 1 e 2, após as extrações dentais, observou-se o desenvolvimento de áreas de exposição e necrose óssea, associadas à presença de infecção significativa, especialmente na região de septo inter-dental. No estudo 3 observou-se que a indução de estresse crônico apresentou efeitos negativos sobre o metabolismo e volume do tecido ósseo neoformado nas espiras dos implantes tibiais, os quais não foram observados nos animais tratados com alendronato. Ao contrário, nestes animais, observou-se uma melhora significativa nos parâmetros de osseointegração. Já o estudo 4 demonstrou que a administração de alendronato resultou no desenvolvimento expressivo de áreas... (Resumo completo, clicar aesso eletrônico abaixo) / Abstract: This study aimed to develop, in rodents, experimental models of bisphosphonatesinduced osteonecrosis through the association of several risk factors to this disease, including the long-term therapy with high dosages of alendronate by parenteral route, surgical procedures and chronic stress. The parameters were established by descriptive and scored histological analysis, radiographic evaluation of alveolar sockets, stereometry of alveolar sockets and implants, torque removal of implants and biomarkers of bone metabolism and stress. In the first and second studies, it was administered daily or weekly high doses of alendronate, respectively, associated to the lower first molar extractions. In the third and fourth studies it was administered weekly high doses of alendronate plus chronic stress induction and osseointegrated implants in the maxillae and/or tibia. In general, the outcomes of this study demonstrated that alendronate therapy was associated to a markedly bone turnover suppression. In the first and second studies, after tooth extraction, it was observed the development of exposed and necrotic bone associated to a significant infectious process, especially at the inter-radicular area. In the study three the chronic stress was related to deleterious effects on the bone metabolism and volume among tibial implants threads, which weren't presented in animals treated with alendronate. On the contrary, in these animals, it was observed a markedly increase in the osseointegration parameters. On the other hand, the fourth study showed that the alendronate treatment resulted in the substantial development of osteonecrosis regions associated to infection at lateral areas of maxillary bone implant cavity, even with absence of exposed bone areas. In this way, we conclude that the alendronate therapy suppress significantly the bone... (Complete abstract click electronic access below) / Doutor

Orientadores: Dora Maria Grassi-Kassisse, Regina Celia Spadari-Bratfisch / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-11T11:39:37Z (GMT). No. of bitstreams: 1 Almeida_Julianade_D.pdf: 1515697 bytes, checksum: cf7b29c6343aa3e81992652c33e8c1f3 (MD5) Previous issue date: 2008 / Resumo: A literatura é escassa quanto à modelos de estresse relacionados ao estudo da utilização periférica de glicose, com o objetivo de compreender os mecanismos através dos quais a situação de estresse possa levar a resistência à insulina. Nosso modelo de estresse induzido por choques nas patas aplicados em três dias consecutivos em ratos apresenta um quadro metabólico bastante semelhante àquele apresentado em quadros iniciais de diabetes tipo 2, tornando-se fundamental o estudo da captação de glicose pelos tecidos neste modelo animal. Considerando que o modelo de estresse por choque nas patas promove alterações fisiológicas que têm repercussões endócrinas e metabólicas possíveis de serem demonstradas in vivo e in vitro, os objetivos deste trabalho foram investigar a captação periférica de glicose em ratos estressados utilizando as técnicas de ivGTT, clamp euglicêmico-hiperinsulinêmico e captação de glicose em adipócitos isolados. Nossos resultados demonstraram que: a captação de glicose pelos adipócitos isolados de ratos estressados está menos sensível a insulina e mais sensível a noradrenalina quando comparado aos adipócitos de ratos controle; a estimulação adrenérgica da captação de glicose é principalmente mediada pelo a1-AR; a estimulação do ß2-AR não teve efeito em adipócitos de ratos controle, mas inibiu significativamente a captação de glicose pelos adipócitos isolados de ratos estressados, que pode ser uma troca da via de sinalização Gs para Gi; os adipócitos isolados de tecido adiposo epididimal de ratos estressados não apresentam alteração na produção de lactato basal e nem estimulada quando comparado aos provenientes de ratos controle; os adrenoceptores do subtipo a1 estão envolvidos na captação de glicose in vivo demonstrada pelos ensaios de ivGTT; o modelo de choque nas patas alterou a sensibilidade dos receptores de insulina, avaliada pelo ensaio de clamp euglicêmico-hiperglicêmico apenas em parte da população estudada. Este conjunto de dados permite concluir que a indução de estresse por choques nas patas causa alterações na captação periférica de glicose, principalmente através da sinalização adrenérgica, que caracterizam este modelo como uma importante ferramenta para o estudo de alterações metabólicas induzidas pelo estresse / Abstract: There are few animal models to study the peripheral glucose uptake alterations induced by stress. Rat foot-shock stress model induces metabolic alterations similar to diabetes type 2. Considering that rat foot-shock stress model causes physiological alterations which are possible to be studied carrying out experiments in vivo or in vitro we claim in this work evaluate glucose uptake in stressed rats throughout ivGTT, clamp euglycemic-hyperinsulemic, glucose uptake and lactate production in isolated adipocytes. Our results show that: glucose uptake by isolated stressed rat adipocytes is decreased by insulin and increased by a1-AR agonists; besides ß2-AR stimulation significantly inhibit glucose uptake induced by a1-AR; there is no alteration in lactate production by isolated adipocytes rats; a1-ARs are involved in glucose uptake demonstrated in ivGTT assays; sensitivity to insulin receptors were decreased in some rats when available by clamp assays. All these results together suggested that stress induced by foot-shock in rats induces alterations in glucose uptake, mainly throughout adrenergic mechanisms, and this model could be very useful as a tool to study metabolic alterations during stress response / Doutorado / Fisiologia / Doutor em Biologia Funcional e Molecular

Doctor of Philosophy / Department of Horticulture, Forestry, and Recreation Resources / Dale J. Bremer / Steven J. Keeley / High temperature and drought may reduce quality in cool-season turfgrasses during summer in the transition zone. Texas bluegrass hybrids (HBG) are genetic crosses between native Texas bluegrass (Poa arachnifera Torr.) and Kentucky bluegrass (Poa pratensis L.) (KBG) that resemble KBG but may have greater drought and heat resistance than other cool-season grasses. The objectives of four studies were to evaluate high temperature, drought, and lower mowing height effects on HBG compared with KBG ('Apollo') and tall fescue (Festuca arundincea Schreb.)(TF, 'Dynasty'), compare their rooting characteristics, and investigate their membrane lipid molecular species compositional differences. Under high temperature (35/25°C, 14h light/10h darkness), HBG ('Thermal Blue') had greater quality and gross photosynthesis (Pg), and lower electrolyte leakage than KBG and TF in a growth chamber study. The combination of high temperature and drought (60% ET replacement) caused rapid declines in quality, but HBG generally performed better. In field and greenhouse studies, TF had more roots deeper in the profile than two HBG ('Reveille' and Thermal Blue) and KBG under well-watered conditions. In the field, quality and Pg were greatest in TF among turfgrasses. Performances in quality and Pg generally ranked: TF > Reveille >= Thermal Blue = KBG. In a separate mowing height and drought field study, HBG (Thermal Blue) generally had lower quality and Pg than KBG at both high (7.62 cm) and low (3.81 cm) heights but particularly at the low height. Drought resistance and tolerance to low mowing in Thermal Blue was similar to or poorer than in KBG. Under supra-optimum temperature (35 /25°C and 40 /30°C, 14h light/10h darkness), the ratio of digalactosyldiacylglycerol (DGDG) to monogalactosyldiacylglycerol (MGDG) was highest in HBG (Thermal Blue) and lowest in TF. Heat tolerance was also associated with higher phosphatidylethanolamine (PE) content, higher phosphatidylglycerol (PG) content, and reduced overall unsaturation compared with heat-sensitive. Results suggest that 40 membrane lipid molecules are potential biomarkers for heat tolerance and that compositional changes in lipids in response to heat may contribute to differences in heat tolerance among cool-season grasses. Generally, studies indicated greater heat resistance, but not drought resistance, in HBG than in KBG or TF.

M.Phil. / This study examined the relationship between vocational stress and physical health and well being. To address this issue schoolteachers participated in a controlled physical exercise program for eight consecutive weeks. Two groups were established and subjects were classified as being part of a control group and an exercise group. The psychological parameters were assessed through the use of the Occupational Stress Inventory questionnaire which functioned as a pre and post-test and which showed the significant improvements made in Physical Strain, Role Overload, Psychological Strain, Interpersonal Strain and Vocational Strain scales. This suggests that the teachers experienced and reported fewer complaints about physical health issues, work-related issues, psychological disturbances, and less disruption in interpersonal relationships. Accordingly, the overall mental state of the teachers improved significantly. The physiological parameters were assessed by using the resting heart rate readings; recorded on a daily basis throughout the study. The results presented in this study show that the eight-week physical exercise program explained 56 per cent of the variance in the resting heart rate. This result demonstrates that the teachers contributed to their physical health by participating in the exercise program. Additionally, these results seem to suggest that prolonged participation in a program of physical exercise would result in the maintenance of effective coping skills to combat stress. The practical implications of these findings are reviewed with an eye to assisting teachers to better health and well being.

M.A. / Please refer to full text to view abstract

M.Sc. / The current study sought to investigate the relationship between stress and illness, while examining the effects of daily stressors, depression, hardiness, social support and coping skills on this relationship. The information gathered was then used to design a time and cost effective questionnaire to predict people prone to stress-related illness. This questionnaire has been called the Stress Fitness Scale. The subjects (n = 44) were split into three groups (healthy, ill, and neither ill nor healthy) according to their scores on Gurin's Psychosomatic Symptom List for non-parametric statistical analysis. Scores on the Hardiness Scale, Perceived Social Support Friends and Family, Beck Depression Inventory, COPE, Hassles and Uplifts Scale and Life Experiences were analysed and significant differences were found between the ill and healthy groups in all five areas using a Mann-Whitney U test. An intercorrelation matrix was performed and significant correlation was found between Stress Fitness and the other scales, although not for all the sub-scales. Many of these correlations corresponded with the differences found between the two groups using the Mann-Whitney U test. Item analysis was performed on the Stress Fitness Scale. Significant inter correlation was found for all the items of the Prone sub-scale, and all but three items of the Protect sub-scale. Although further research is necessary, from this limited study the Stress Fitness Scale appears to provide a time and cost effective way of predicting people prone to stress-related illness.

Sundays Thicket and Spekboomveld vegetation in the Eastern Cape have experienced intensive and extensive degradation due to over-browsing by domestic stock. The Subtropical Thicket Restoration Project aims to take advantage of the high carbon sequestration potential of Portulacaria afra (Spekboom) and other Thicket species, to rehabilitate degraded Thicket by restoring biodiversity and ecosystem services, create job opportunities and socio-economic upliftment in local communities, and promote the trade of carbon credits generated by planting and „farming‟ with Spekboom truncheons, rather than domestic stock. Plant material (seeds and length of stem) was sourced from the farm Krompoort, outside Uitenhage in the Eastern Cape. The effectiveness of four different rooting media i.e. plain pool filter sand and 1:1 mixtures of pool filter sand with perlite, potting soil and Thicket soil, on the rooting of ten Thicket species, were tested. Species with the greatest percentage strike and mean root length on stem cuttings were succulent species, Crassula ovata (84 percent strike) and Portulacaria afra (97 percent), as was expected. The application of rooting hormone Seradix© No. 3 did not significantly promote cutting strike or increase mean root length in C. ovata and P. afra. Woody canopy shrub species with the greatest cutting strike and mean root length, overall, were Rhigozum obovatum (24 percent), Lycium cinereum and L. oxycarpum (21 percent), and Searsia longispina (19 percent). These species, as well as Grewia robusta (4 percent), are considered „easy-to-root‟ species, or of sufficient functional value in terms of their spinescence, flower and fruit production, and soil-binding capabilities. Very low percentage strike (<1 percent) and mean root length were achieved in Azima tetracantha, Carissa bispinosa and Gymnosporia polyacantha subsp. polyacantha. These species are considered unsuitable for propagation for rehabilitation purposes. Crassula ovata, L. cinereum, L. oxycarpum, P. afra and S. longispina cuttings produced longer roots when planted in Thicket soil, the same having been found in R. obovatum cuttings planted in perlite. Thicket soil was, therefore, best at promoting cutting strike and root growth in „easy-to-root‟ species. Plain pool filter sand was the only medium in which A. tetracantha, C. bispinosa and G. robusta, cuttings rooted, and perlite the only medium in which G. polyacantha subsp. polyacantha cuttings rooted. Potting soil did not promote significant cutting strike or root growth in any of the species tested. Physiological variables i.e. photosynthetic efficiency (chlorophyll a fluorescence, Fv/Fm) and stomatal conductance (mmol H2O m-2 s-1) were measured for ten Thicket species, including Portulacaria afra. Control plants were watered well once a week, and treatment plants were dried out for 30 days, rewatered on the 30th day and their recovery from drought stress monitored for a further 17 days. Species that responded poorly to drought stress were Gymnosporia buxifolia and Putterlickia pyracantha. In addition to Portulacaria afra, species that showed the fastest recovery and resprout after rewatering, were: Crassula ovata, Ehretia rigida, Grewia robusta, Lycium ferocissimum, Rhigozum obovatum and Searsia longispina. These species produced the smallest decline in volumetric moisture content of soil, and had the lowest decline in photosynthetic efficiency and stomatal conductance during simulated drought. Unlike C. ovata and P. afra, which are CAM or C3-CAM switching species, mortality of transplants will most likely be high, if not total, during transplantation, as this study was done at lower light and temperature, and higher humidity levels than experienced at rehabilitation sites. This study has shown that the reintroduction of propagated woody canopy shrubs and trees into degraded Thicket sites does not appear to be a practical or economical method of actively restoring biodiversity to rehabilitation sites. As woody climax species have been shown to return to sites planted with Spekboom truncheons through „natural regeneration‟ within approximately 50 years, future research efforts should focus on optimising restoration site selection and planting techniques in order to maximize carbon sequestration potential of planted truncheons, which will, in the long term, result in an environment that can support regeneration of the biodiversity to something resembling intact Thicket.

The objective of this study was to determine if there is a difference in pre-harvest stress and carcass characteristics between kosher and not-qualified-as kosher cattle. Cattle that had a shorter time from gate to exsanguination and a lower vocalization score were more likely to qualify for kosher. Kosher carcasses had a larger REA, a higher WBSF value, tended to have a heavier HCW. At each individual day, kosher steaks had lower L*, a*, and b* values. These data suggest that body composition and stress level may play a factor in the likelihood of a beef animal to qualify for kosher, and there is a defined quality difference between kosher and nonkosher steaks.

Decades of research have shown long-term effects of early caregiving adversity on stress physiology and limbic brain regions, two key biological systems that are implicated in risk for internalizing disorders. Although stress physiology and limbic brain structure undergo significant maturational change during childhood and adolescence, and reciprocally influence each other, the effects of early caregiving adversity on these developmental processes is not well understood. In the current study, we used an accelerated longitudinal design to assess the development of stress physiology, amygdala, and hippocampal volume following early institutional care. Previously Institutionalized (PI; N = 93) and comparison (COMP; N = 161) youth (ages 4-20 years old) completed 1-3 waves of data collection, each spaced approximately 2 years apart, for diurnal cortisol (N = 239, providing a total of 380 diurnal datasets), structural MRI (N = 156, providing a total of 306 scans) and parent-reported internalizing symptoms (N = 133, providing a total of 227 time points). We observed a developmental shift in morning cortisol in the PI group, with blunted levels in childhood and heightened levels in late adolescence. PI history was associated with reduced hippocampal volume and reduced growth of the amygdala, resulting in smaller volumes by adolescence. Results also suggested feed-forward brain-to-hormone mechanisms, such that both amygdala and hippocampal volumes were prospectively associated with morning cortisol levels two years later. Finally, amygdala and hippocampal volumes were independently associated with internalizing scores across the entire sample. These results indicate that adversity-related physiological and neural phenotypes are not stationary during development but instead exhibit dynamic and interdependent changes from early childhood to early adulthood.

The literature on alcohol is replete with studies attempting to determine whether or not the relief of tension (i.e.; certain hypothesized aversive states such as fear, anxiety, and frustration, which ~an influence behavior) plays a role in the etiology of moderate and excessive drinking by humans. The classic presentation of the tension reduction hypothesis (TRH) by Conger (1956) provided the impetus for the analysis of chronic alcohol consumption using animal subjects. By applying established behaviorist principles to the problem of chronic excessive drinking he developed a theory which accounts fer this behavioral phenomenon. ·According to his theory, the response of drinking alcohol is one of many possible tension reducing responses in the organism's repertoire. This theory suggests that the human user of alcohol exhibits the drinking response as a consequence of some tension state and that the sedative action of alcohol serves as a reinforcer of the response by reducing the tension state.