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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Permeação transdérmica de formulações tópicas contendo hormônios sexuais e ecotoxicidade aquática de micro e nanopartículas de titanato de bário

Polonini , Hudson Caetano 16 April 2014 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-01-22T14:30:44Z No. of bitstreams: 1 hudsoncaetanopolonini.pdf: 5158429 bytes, checksum: e80426644833041649bdb5efa0029dcc (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-01-25T18:54:38Z (GMT) No. of bitstreams: 1 hudsoncaetanopolonini.pdf: 5158429 bytes, checksum: e80426644833041649bdb5efa0029dcc (MD5) / Made available in DSpace on 2016-01-25T18:54:38Z (GMT). No. of bitstreams: 1 hudsoncaetanopolonini.pdf: 5158429 bytes, checksum: e80426644833041649bdb5efa0029dcc (MD5) Previous issue date: 2014-04-16 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / No capítulo primeiro, objetivou-se avaliar o desempenho de permeação do veículo transdérmico magistral Pentravan para sistemas de distribuição transdérmica contendo Progesterona (P), Estradiol (E2) e Estriol (E3), isoladamente ou em associação de E2 + E3 (Biest). Um modelo experimental de pele humana feminina excisada foi utilizado para prever a permeação e a retenção das substâncias ativas em todas as camadas da pele. Além disso, o processo de fabricação para as formulações foi avaliado quanto à uniformidade de conteúdo das emulsões. Os métodos analíticos eco-friendly desenvolvidos para quantificação de hormônios sexuais femininos em emulsões transdérmicas foram adequados aos objetivos, o que foi comprovado através da validação dos mesmos. A avaliação do processo de manipulação das emulsões revelou que as embalagens à vácuo atualmente utilizadas por farmácias magistrais foram adequadas ao uso, e a utilização de moinho de rolos desempenhou papel fundamental na uniformidade de conteúdo de Eemuls e Biest. As taxas de liberação in vitro dos fármacos a partir de suas formulações foram adequadamente altas, e todas as formulações seguiram cinética de pseudo-primeira ordem, típica de produtos semissólidos. O estudo de permeação ex vivo demonstrou que todos as formulações foram capazes de promover a absorção transdérmica dos hormônios em quantidades comparáveis às praticadas atualmente por produtos industrializados. No capítulo segundo, duas partículas de titanato de bário (BT), da ordem micrométrica e manométrica, foram avaliadas quanto ao seu impacto em ambientes aquáticos. Uma caracterização dos materiais foi realizada. A seguir, utilizou-se duas algas (Chlorella vulgaris e Euglena gracilis) e uma cianobactéria (Anabaena flos-aquae) como organismos-modelo para avaliação da toxicidade. Tanto BT MP (micropartícula) quanto BT NP (nanopartícula) se mostraram carregadas negativamente, facilmente agregáveis, com uma taxa de liberação de íons Ba2+ para os meios de cultura que não ultrapassa 1,5%. BT mostrou um efeito tóxico estatisticamente significativo (p<0,05) no crescimento e na viabilidade celular de C. vulgaris desde 1 ppm, o que parece ser mediado por um estresse oxidativo induzido pelas próprias partículas ou pelos íons Ba2+ liberados no meio de cultura. BT tem um efeito tóxico muito baixo no crescimento de A. flos-aquae, porém ambas partículas afetam a viabilidade celular desde a menor concentração testada, o que ocorre por efeito indireto das mesmas no estresse oxidativo das células. BT apresentou um efeito tóxico estatisticamente significativo (p<0,05) no crescimento e na viabilidade celular de E. gracilis desde 1 ppm, efeito relacionado à endocitose das partículas numa quantidade tal que levou a uma ruptura de suas membranas. BT induziu estresse em todos os organismos-teste, o que foi evidenciado pelo aumento na atividade da superóxido dismutase, pela diminuição da eficiência fotossintética e pela dimuição dos níveis intracelulares de ATP. O comportamento de BT em meios de cultura sintéticos e naturais são diferentes, sendo os efeitos tóxicos mais pronunciados quando o crescimento é dado em água do Rio Sena. O tamanho de BT parece não influenciar os efeitos produzidos sobre o crescimento dos micro-organismos – embora a inibição do crescimento tenha sido pronunciada com o nanomaterial. / In Chapter 1, we aimed to evaluate the performance of the transdermal permeation of Pentravan vehicle for transdermal delivery of coumpounded systems containing progesterone (P), estradiol (E2) and estriol (E3), alone or as a combination of E2 + E3 (Biest). An experimental model of female excised human skin was used to predict the permeation and the retention of the active substances in all skin layers. Moreover, the manufacturing process for formulations were evaluated for content uniformity of the emulsions. The eco-friendly methods developed for quantification of female sex hormones in transdermal emulsions were appropriate, which has been proven through validation studies. The evaluation of the coumpounding process for the emulsions showed that the vacuum packaging currently used by pharmacies are suitable for use, and the use of roll mill played a key role in the uniformity of content for Eemuls and Biest. The in vitro release rates of the drugs from their formulations were adequately high, and all formulations followed pseudo-first order kinetics, typical of semisolid product. The ex vivo permeation study showed that all the formulations were able to promote transdermal absorption of hormones comparable to those currently practiced by industrialized products. In chapter 2, two particles of barium titanate (BT), micro- and nanosized, were evaluated for their impact on aquatic environments. A detailed characterization of the materials was carried out. We used two algae (Chlorella vulgaris and Euglena gracilis) and a cyanobacterium (Anabaena flos-aquae) as model-organisms for assessing toxicity. Both BT MP (microparticle) and BT NP (nanoparticle) were negative, easily aggregated, with a release rate of Ba2+ ions to media that did not exceed 1.5%. BT has a statistically significant toxic effect on cell growth and viability of C. vulgaris, from 1 ppm, which appears to be mediated by oxidative stress induced by the particles themselves or by Ba2+ ions released into the culture medium. BT has a very low toxic effect on the growth of A. flos-aquae, but both particles affect cell viability since the lowest concentration tested, which occurs by indirect effect on the cells. BT has a statistically significant toxic effect on cell growth and viability of E. gracilis, from 1 ppm, related to the effect of endocytosed particles in such an amount that a rupture of their membranes was caused. BT was able to stress all test-organisms, which was evidenced by the increase in superoxide dismutase activity, decreased photosynthetic efficiency and the decreased intracellular ATP levels. The behavior of BT in means of synthetic and natural culture was different, and the most pronounced toxic effects occurred when growth was given in water from the River Seine. The size of BT did not influence the effects on the growth of microorganisms - although growth inhibition has been more pronounced with the nanomaterial.
42

Sex differences in COVID-19 infections / Könsberoende skillnader i COVID-19 infektioner

Spahi, Majlinda January 2020 (has links)
The Coronavirus disease 2019 (COVID-19) outbreak have shown that there may be sex-dependent differences in morbidity and mortality among individuals contracted with the disease. The aim of the study was to analyse the extent that sex differences appear in COVID-19 infections and to explore whether any differences are due to intrinsic factors in the sexes that cause sex-bias in the disease susceptibility and mortality. The study presents an age and sex-disaggregated analysis of reported cases of total infections, intensive care cases, and deaths across 13 countries due to the disease. The results demonstrated that there is a general trend for the disease prevalence, and it shows a female bias among the proportion of individuals infected with COVID-19. However, males appear to require more intensive care treatment and higher rates of death when compared to females. The results also show that more women than men are reportedly infected by the corona virus up to a certain age. After the age of 60, the proportion of men affected is higher than women, and it is also at this age that the death rate among men increases significantly. In conclusion, the results of this work indicate that males could possibly be at a significantly higher risk of severe disease and death than females, and that the patterns of sex bias in intensive care cases to some extent follows the expected pattern if sex hormones played a role in influencing the immune system response to COVID-19. / Utbrottet av Coronavirus sjukdomen 2019 (COVID-19) har visat att det kan finnas könsberoende skillnader i sjuklighet och dödlighet bland individer som drabbats av sjukdomen. Syftet med studien var att analysera i vilken utsträckning könsskillnader förekommer i COVID-19-infektioner och att undersöka om skillnaderna beror på inre faktorer hos könen som möjligtvis orsakar könsfördomar i sjukdomens mottaglighet och dödlighet. Denna studie presenterar en ålder-och könsfördelad analys av totala antalet rapporterade fall, intensivvårdsfall och dödsfall i 13 länder till följd av COVID-19. Resultaten visade att det finns en generell trend för sjukdomens utbredning, och den visar en högre andel kvinnor än män som har smittats med COVID-19. Men det är män som är mer i behov av intensivvård och har högre dödsnivåer i jämförelse med kvinnor. Resultaten visar även att fler kvinnor än män smittas av coronaviruset upp till en viss ålder. Efter 60-årsåldern är andelen drabbade män högre än kvinnor, det är även vid den här åldern som dödsnivån bland män ökar markant. Sammanfattningsvis indikerar resultaten av denna studie att män eventuellt skulle kunna ha en betydligt högre risk för en allvarligare sjukdom och död än kvinnor.
43

Sex-specific Acute Cerebrovascular Response to Photothrombotic Stroke in Mice Requires Rho-kinase

Raman-Nair, Joanna 21 June 2022 (has links)
With high energy consumption and a low capacity for energy storage, the brain is highly dependent on a continuous supply of oxygen and nutrients from the bloodstream. Ischemic stroke, caused by the occlusion of a cerebral blood vessel, compromises cerebral blood flow (CBF), resulting in detrimental effects on brain homeostasis, vascular function, and neuronal health. Sex differences in ischemic stroke are known, with women having lower rates of stroke due to a protective role of estrogens on vascular health, and more severe strokes following reduced estrogen production after menopause. Rho-associated protein kinase (ROCK), an important regulator of vascular tone, also regulates vascular function in a sex-specific manner, and its deletion is neuroprotective following ischemic stroke. The current study explores the overlapping roles of ROCK and endogenous hormone influence on the acute CBF response to a photothrombotic (PT) model of ischemic stroke in mice. CBF was measured following stroke in the somatosensory cortex in mice with a heterozygous deletion of the ROCK2 isoform (ROCK2+/-) and in wild-type (WT) littermates. To remove endogenous hormones, male mice were gonadectomized (Gdx) and female mice were ovariectomized (Ovx), and control animals received a sham surgery (“intact”) prior to stroke induction. Intact WT males showed a delayed CBF drop compared to intact WT females, where peak drop in CBF wasn’t observed until 48 hours following stroke. Gonadectomy in males did not alter this response, however ovariectomy in females produced a “male-like” response. ROCK2+/- males also showed such phenotypic response, and Gdx did not alter this response, suggesting ROCK2 deletion or endogenous male hormones do not alter CBF response in males in this stroke model. Alternatively, intact ROCK2+/- females showed a striking difference in CBF values compared to intact WT females, where they displayed higher CBF values immediately post-stroke and also showed a peak drop in CBF at 48 hours post-stroke. Ovx did not change the CBF response in ROCK2+/- females. Overall, there is a marked difference between males and females in their acute CBF responses to PT stroke, which appears to be mediated by endogenous female sex hormones and ROCK2. All groups except for intact WT females show a delayed drop in CBF values, reaching a maximal drop in CBF at 48 hours following stroke induction. This may be due to hyperreactivity of female platelets and upregulation of RhoA/ROCK signaling in female platelets. Further research is required to confirm this speculation. This study reveals important sex-differences and the involvement of ROCK2 in acute CBF responses to PT stroke in mice.
44

The Complexity of Interactions Between Female Sex Hormones and Chlamydia Trachomatis Infections

Berry, Amy, Hall, Jennifer V. 15 June 2019 (has links)
Recent Findings: Recent data support previous work indicating that estrogen enhances chlamydial development via multiple mechanisms. Progesterone negatively impacts Chlamydia infections also through multiple mechanisms, particularly by altering the immune response. Conflicting data exist regarding the effect of synthetic hormones, such as those found in hormonal contraceptives, on chlamydial infections. Summary: Numerous studies over the years have indicated that female sex hormones affect C. trachomatis infection. However, we still do not have a clear understanding of how these hormones alter Chlamydia disease transmission and progression. The studies reviewed here indicate that there are many variables that determine the outcome of Chlamydia/hormone interactions, including (1) the specific hormone, (2) hormone concentration, (3) cell type or area of the genital tract, (4) hormone responsiveness of cell lines, and (5) animal models.
45

Understanding the Role of Androgen Receptor Signaling in Modulating p38-alpha Mitogen-Activated Protein Kinase in Experimental Autoimmune Encephalomyelitis

Voorhees, Grace Kathryn 01 January 2019 (has links)
Multiple Sclerosis (MS) is an inflammatory autoimmune disease of the central nervous system, characterized by axonal demyelination and multifocal inflammation. Like many autoimmune diseases, it is a sexually dimorphic disease, being 3-4 times more common in females than in males. p38α MAP kinase (MAPK) has an integral role in modulating inflammatory processes in autoimmunity. Conditionally ablating p38α MAPK in myeloid cells in B6 mice shows a sex difference in the animal model of MS, experimental autoimmune encephalomyelitis (EAE). In the absence of sex hormones, this sex difference was reversed, suggesting a role for sex hormones in modulating p38α MAPK signaling in EAE. Based on these findings, we hypothesized that pro-inflammatory functions in EAE is p38-indepdendent in the presence of androgens and p38-dependent in the presence of estrogens. For the purposes of this project, the role of androgens was evaluated. Both in vivo and in vitro techniques were used to assess how androgen receptor (AR) signaling: 1) impacts EAE pathogenesis, and 2) impacts the role of p38α in EAE pathogenesis and macrophage function. To this end, using Cre-Lox technology, we generated mice deficient in: 1) AR globally or conditionally in macrophages, as well as 2) mice doubly deficient in AR and p38α. In vivo results from p38α-sufficient global AR knockout mice show no effect of global AR deletion on EAE pathogenesis. Surprisingly, results from p38α-sufficient conditional AR knockout mice showed significant worsening in disease compared to WT counterparts, suggesting that AR signaling in myeloid cells has a protective role in EAE pathogenesis. These findings implicate a protective role for AR signaling in EAE. Studies with mice doubly deficient in p38α and AR to determine whether AR regulates the role of p38α in EAE are ongoing, but so far show no effect on AR deletion on the role of p38α MAPK. Further studies with larger cohorts of mice are needed elucidate the relationship between AR and p38α MAPK signaling in myeloid cells in EAE pathogenesis. In vitro studies using the immortalized macrophage cell line RAW 264.7 showed that pharmacologic inhibition of p38 MAPK after stimulation with LPS reduced the production of classic pro-inflammatory cytokines IL-6 and TNFα, and effect that was not affected by treatment with 5-dihydrotestosterone, suggesting that the AR does not modulate the role of p38α in cytokine production. These findings implicate no direct role of AR signaling on the functional role of p38α MAPK in the myeloid cell lineage in inflammatory and autoimmune responses.
46

Sex-dependent differences in human reward processing : A systematic review

Nyqvist Ghashghaian, Simon January 2022 (has links)
Much work has been done in the neuroscience of reward processing, such as; mapping brain areas, key neurotransmitters, and connectivity patterns related to different aspects of reward-related behavior. There are a lot of suggested behavioral and neural sex differences in reward processing, primarily based on animal studies of reward behavior. This review aimed to systematically review publications on human neurofunctional sex differences in reward processing, and provide a more stable footing for future research in the field. Two searches through Web of Science and Scopus for publications that combined neuroimaging with behavioral tasks for examining functional sex differences in neural reward processing. The searches produced nine studies (n=9) that were included after the screening process. There are significant differences between males and females in reward processing, specifically in the striatum, orbitofrontal cortex, prefrontal cortex, nucleus accumbens, and insula. However, the full extent of these differences, and the underlying causes, are still not clear. There is a lack of control for important confounding factors in the present field of sex differences in reward processing. Future research in this field has to consider all of the underlying factors that cause men and women to differ, such as the impact of gonadal hormone fluctuations and societal pressures. If these factors were taken into account, data of higher validity and generalizability could have been produced.
47

THE INFLUENCE OF ESTROGEN AND SPRINT INTERVAL EXERCISE ON BRACHIAL ARTERY ENDOTHELIAL FUNCTION IN HEALTHY ADULTS / FACTORS INFLUENCING ENDOTHELIAL FUNCTION

Shenouda, Ninette 14 June 2018 (has links)
Endothelium-dependent vasodilation is an important marker of vascular function. Brachial artery flow-mediated dilation (FMD) is a noninvasive assessment of peripheral artery endothelial function that is associated with coronary artery endothelial function and is an index of cardiovascular health. This thesis sought to investigate factors that may influence the brachial artery FMD response in humans, particularly the sex hormone estrogen and low-volume sprint interval training (SIT). We first demonstrated the intra-individual consistency of the FMD response pattern in healthy young adults and introduced visual data screening as a tool for improving data accuracy. Having established best practices for FMD data analysis, we investigated the brachial artery FMD response in adults with different estrogen profiles: men, premenopausal women with a natural menstrual cycle (NAT), and premenopausal women using combined oral contraceptive pills (OCP). Our findings suggest that estrogen does not augment FMD during high-estrogen phases of a NAT or OCP cycle compared to low-estrogen phases or to men. We also investigated the acute and chronic brachial artery FMD response to a 3x20-s low-volume SIT model. Following a single SIT session, FMD was unchanged in men or women. These findings demonstrate that estrogen does not influence endothelium-dependent dilation at rest or following intense intermittent exercise, but also suggest that low-volume SIT may be an insufficient stimulus for eliciting changes in endothelial function. This stimulus magnitude postulation was further supported by a 12-wk exercise training study, whereby vascular changes were evident following moderate-intensity continuous training but not SIT. Taken together, this work suggests that controlling for menstrual cycle phase and/or OCP use in premenopausal women may not be necessary, making it more feasible to include women as research participants, and highlights the need for future characterization of the minimum low-volume interval stimulus that evokes improvements in endothelial function in healthy young adults. / Thesis / Doctor of Philosophy (PhD) / The endothelium is the inner lining of an artery that separates it from the flowing blood. A healthy endothelium responds to increases in blood flow by producing substances that enable an artery to widen. The projects in this thesis examined whether the responsiveness, and overall function, of the endothelium in healthy young adults is enhanced by the sex hormone estrogen or by “all-out” cycling sprints, an exercise protocol that has gained appeal for its time-efficiency. We demonstrated that estrogen does not enhance endothelial function in women, compared to men, at any phase of a menstrual or birth control pill cycle. A single session or 12-weeks of the intense but brief interval exercise also does not enhance endothelial function. This work suggests it may be easier to include women in future research assessing this measure and that this particular interval exercise protocol may not enhance endothelial function in healthy adults.
48

The effect of Lactobacilli and female sex hormones on the innate immune responses of vaginal epithelial cells.

Lam, Jeffrey H.Y. January 2019 (has links)
The female genital tract represents the first line of defence against HIV. Biological factors such as female sex hormones, and the vaginal microbiota are known to affect HIV susceptibility at this site. The female sex hormone estradiol is known to play a protective role, whereas the progestin based contraceptive medroxyprogesterone acetate increases HIV susceptibility HIV. In addition, a Lactobacilli dominant vaginal microbiota is generally protective against HIV. Therefore, in this study, we aimed to elucidate the effects of female sex hormones, and Lactobacilli on the innate immune response of vaginal epithelial cells. / Thesis / Master of Science (MSc)
49

Contribuição da via STIM1/Orai1 para as diferenças relacionadas ao sexo na entrada de cálcio em miócitos vasculares durante a hipertensão arterial. / Activation of STIM1/Orai1 mediates sex-differences in the calcium influx in vascular miocytes from hypertensive rats.

Giachini, Fernanda Regina Casagrande 07 July 2010 (has links)
Os distúrbios na regulação da concentração de cálcio (Ca2+) citoplasmático contribuem para a patogênese da hipertensão arterial. Evidências sugerem que as moléculas de interação estromal (STIM) atuam como sensores dos estoques intracelulares de Ca2+, enquanto as proteínas Orai representam as subunidades que formam os canais de Ca2+ ativados pela liberação de Ca2+ (CRAC). Neste estudo avaliamos a participação de STIM1/Orai1 na regulação das concentrações de Ca2+ citoplasmático e na ativação da contração vascular em aortas de ratos hipertensos. Nossos resultados sugerem que a ativação de STIM1/Orai1 pode representar um novo mecanismo que modula alterações vasculares nos níveis de Ca2+ intracelular na hipertensão arterial e que contribui para as diferenças sexuais de reatividade vascular em animais hipertensos. / Disturbance in the regulation of cytoplasmic calcium (Ca2+) concentration contributes to the pathogenesis of hypertension. Evidences suggest that the stromal interaction molecule (STIM) acts as a sensor of intracellular Ca2+ stores, whereas Orai proteins are the subunits that form CRAC channels. In this study, we evaluated the role of STIM1/Orai1 in the regulation of cytoplasmic Ca2+ concentrations and in the activation of contraction in aortas from hypertensive rats. We also studied how the differential activation of this pathway contributes to sex differences observed between hypertensive rats, as well as the protective effects of the female sex hormones in the vasculature. Our results suggest that activation of STIM1/Orai1 may represent a new mechanism that modulates intracellular Ca2+ concentration during hypertension and contributes to sex differences in the vascular reactivity of hypertensive animals.
50

Avaliação do papel dos hormônios sexuais femininos em modelo murino de asma experimental. / Evaluation of the role of female sex hormones in a murine model of experimental asthma.

Accetturi, Beatriz Golegã 09 September 2014 (has links)
Mulheres asmáticas na pós-menopausa podem apresentar piora dos sintomas, portanto neste trabalho investigamos o papel dos hormônios sexuais femininos (HSF) sobre a inflamação alérgica pulmonar. A re-exposição ao antígeno exacerbou a inflamação alérgica pulmonar e a liberação de mediadores no pulmão dos animais alérgicos ovariectomizados (OVx). O valor da reatividade traqueal foi semelhante ao observado nos animais alérgicos Sham/OVx. O tratamento com estrógeno exacerbou a inflamação pulmonar, mas atenuou a reatividade das vias aéreas. O tratamento com progesterona não alterou o número de células do lavado broncoalveolar e atenuou a reatividade das vias aéreas, apesar acentuar a produção de muco e de colágeno. O tratamento com estrógeno em associação com a progesterona atenuou a inflamação pulmonar aos valores encontrados nos animais alérgicos Sham/OVx. Nossos estudos apontam para uma possível dissociação entre os efeitos moduladores dos HSF sobre a resposta inflamatória, notadamente no recrutamento celular e as alterações de mecânica respiratória. / Asthmatic postmenopausal women may experience worsening of symptoms, so in this work we investigated the role of female sex hormones (HSF) on pulmonary allergic inflammation. The re-exposure to antigen exacerbated allergic lung inflammation and release of mediators in the lungs of ovariectomized allergic mice (OVX ) . The value of tracheal reactivity was similar to that observed in allergic Sham/OVx . Treatment with estrogen exacerbated pulmonary inflammation but attenuated airways reactivity. Treatment with progesterone did not alter the number of cells in bronchoalveolar lavage and attenuated airways reactivity, although enhance mucus production and collagen. Treatment with estrogen in combination with progesterone attenuated lung inflammation to the values found in allergic animals Sham/OVx. Our studies point to a possible dissociation between the modulatory effects of HSF on the inflammatory response, especially on cell recruitment and alterations in respiratory mechanic.

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