Thesis (M.S.)--University of Michigan, 1982.

Thesis (M.S.)--University of Michigan, 1989.

Thesis (M.S.)--University of Michigan, 1982.

Thesis (M.S.)--University of Michigan, 1982.

Thesis (M.S.)--Brock University, 2009. / Includes bibliographical references (leaves 73-83).

Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (leaves 73-81).

Introduction A broad understanding of adolescent sexual behaviour is crucial: sexual experience and risky sexual behaviour are prevalent among adolescents. Many studies have been done and opinions have been given about adolescent behaviour regarding contraception and safe sexual practices. There seems to be sufficient knowledge, but passing it on to adolescents is inadequate. The aim of this study was to identify the factors that influence the use of contraceptive methods amongst 16 year old adolescents attending high schools in George, South Africa. Method This was a descriptive, cross-sectional study. Consent from parents/guardians and assent from study participants were obtained. Three high schools in George were randomly selected. All 16 year old learners attending these 3 schools, which assented and consented, were invited to voluntarily complete a self-administered questionnaire, specifically developed for this study. Results One hundred and eighty four 16-year old adolescents voluntarily took part. The male: female ratio was fairly equal. The average age of sexual debut was 15 years, with 42% using contraception at the time of the study. 33% of the sexually active respondents were not using contraception. Knowledge about contraception was reasonably good, with school, home and friends playing pivotal roles. Condoms were perceived to be to easiest available by the sexually active and non-active respondents, whereas injectable contraception was perceived easily available by the sexually active participants, but not by the sexually inactive participants. Contraception is being used mostly by instruction from parents, but peer pressure plays a role here too, as indicated by 20% of the respondents. The most popular reasons for not using contraception whilst being sexually active include: Sensation loss with condoms and partner pressure. Conclusion 16 year old adolescents attending high schools in George do not differ much from their peers nationally and internationally. Their sexual debut is slightly earlier; therefore their contraception use debut is also earlier. Their knowledge regarding contraceptive methods is acceptable, showing that previous educational programmes are bearing fruit and still need to continue. Friend/peer factors play an important role in the decision making of the respondents. This has been shown in their knowledge gain, access to and reasoning behind the use or non-use of contraception. These should be considered in new strategies aiming to improve the educational programmes.

This study investigated factors contributing to adolescent mothers' non-utilisation of contraceptives in the Piet Retief (Mkhondo) area. Contraceptives, emergency contraceptives and termination of pregnancy services are available free of charge. Nevertheless the number of adolescent mothers continues to increase in this area. Structured questionnaires were completed by 107 adolescent mothers. Most respondents (70,0%) received no sex education prior to their pregnancies, and were not knowledgeable about contraceptives. Subsequent to the birth of their babies, only 59,81% used contraceptives, risking further pregnancies. Adolescents, from the age of 12, should receive sex education. Availability of contraceptives during weekends could help adolescents to postpone their pregnancies. Health education should be given to the mothers in the Piet Retief (Mkhondo) area so that they can provide more effective sex education (including contraception) to their daughters. / Health Studies / M.A. (Health Studies)

A ocorrência de trombose está freqüentemente associada com a presença de um ou mais fatores de riscos, os quais podem ser genéticos e/ou adquiridos, tais como as mudanças hormonais que ocorrem durante a gravidez, a terapia de reposição hormonal e o uso de contraceptivos hormonais combinados (CHC). A inflamação, por sua vez, é uma importante resposta do organismo às agressões e envolve vários mecanismos biológicos relacionados entre si e altamente regulados, tais como: coagulação, fibrinólise, ativação do sistema complemento (SC), antioxidação e regulação hormonal. Fisiologicamente, os sistemas complemento e da coagulação compartilham componentes. A ativação do fator XII da coagulação é controlada pela mesma proteína reguladora da ativação do sistema complemento, o inibidor de C1. A deficiência do inibidor de C1 leva a uma patologia conhecida como angioedema hereditário. No entanto, uma manifestação clínica similar ao angioedema tem sido descrita em mulheres que usam CHC ou recebem terapia de reposição hormonal com estrogênio (E). Esta influência do estrogênio na coagulação e no SC também é evidenciada pela ação regulatória do E sobre a expressão do fator XII e dos seus níveis plasmáticos. Considerando o efeito pleiotrópico do E, e as interações do SC e da hemostasia, o objetivo desse estudo foi avaliar o efeito de diferentes CHC sobre: a) a atividade hemolítica (AH) do SC e ativação das vias clássica/lectina e alternativa; b) a atividade opsonizante do SC em mediar o burst oxidativo dos neutrófilos; e c) a função dos receptores para complemento (CR) em mediar o burst oxidativo dos neutrófilos. Nós estudamos 5 CHC diferentes e observamos que a) drospirenona + 30g E mostrou uma tendência a aumentar o burst oxidativo mediado por CR; b) gestodeno + 20g E mostrou redução da capacidade opsonizante do SC; c) levonorgestrel + 30g E e gestodeno + 20g E promoveram uma redução no número de neutrófilos positivos para a expressão de CR1; d) drospirenona + 30g E e drospirenona + 20g E promoveram um aumento da AH da via clássica (VC) do SC; e) levonorgestrel + 30g E promoveu uma redução da AH da VC do SC; f) drospirenona + 30g E, gestodeno + 20g E e levonorgestrel + 30g E promoveram uma diminuição do nível sérico de C4d, produto da ativação das vias clássica/lectina do SC; g) levonorgestrel + 30g E apresentou um aumento da concentração sérica de inibidor de C1; h) nenhum dos CHC mostrou diferenças na ativação da via alternativa do SC. Os resultados mostram a importância de considerar os diferentes grupos de CHC nas comparações com o Grupo Controle, uma vez que algumas diferenças foram significativas apenas para CHC em particular. Estas observações podem contribuir para o entendimento dos mecanismos envolvidos na fisiopatologia dos processos inflamatórios associados ao uso de estrogênios. / The occurrence of thrombosis is often associated with the presence of one or more risk factors, which may be genetic and/or acquired, such as hormonal changes that occur during pregnancy, hormone replacement therapy and the use of combined hormonal contraceptives (CHC). The inflammation in turn, is an important body\'s response to the aggression and involves several biological mechanisms related and highly regulated, such as coagulation, fibrinolysis, activation of the complement system (CS), oxidation and hormonal regulation. Physiologically, the complement and coagulation systems share components. Activation of coagulation factor XII is controlled by the same regulatory protein activation of the complement inhibitor C1. The deficiency of C1 inhibitor leads to a condition known as hereditary angioedema. However, a clinical manifestation similar to angioedema has been reported in women using CHC or receiving hormone replacement therapy with estrogen (E). The influence of E on coagulation and the CS is also evidenced by the regulatory action of E on the expression of factor XII and its plasma levels. Considering the pleiotropic effects of E, and the interactions of CS and hemostasis, the goal of this study was to evaluate the effect of different CHC on: a) hemolytic activity (HA) CS and activation of classical/lectin and alternative pathways, b) the opsonizing activity of the CS in mediating the oxidative burst of neutrophils, and c) the function of receptors for complement (CR) in mediating the oxidative burst (OB) of neutrophils. We studied 5 different CHC and data showed: a) drospirenone + 30g E increase of the OB neutrophils mediated by CR; b) gestodene + 20g E had a reduced opsonizing ability; c) levonorgestrel + 30g E and gestodene + 20g E promoted a reduction of neutrophils positive for the expression of CR1, d) drospirenone + 30g E and drospirenone + 20g E promoted an increase in HA for classical pathway (CP); e) levonorgestrel + 30g E reduced the HA for CP; f) drospirenone + 30g E and gestodene + 20g E and levonorgestrel + 30g E reduced the serum level of C4d; g) levonorgestrel + 30g E showed an increase of the serum level of C1 inhibitor; h) none of CHC showed differences in activation of the alternative pathway in CS. The results show the importance of considering the different groups of CHC in comparison with the control group, since some differences were significant only for CHC in particular. These observations may contribute to the understanding of the mechanisms involved in the pathophysiology of inflammatory processes associated with estrogen use.

Contraceptivos orais combinados (COCs) são largamente utilizados e bem aceitos para se obter a contracepção. Estima-se que mais de 100 milhões de mulheres ao redor do mundo fazem uso deste método contraceptivo. Embora seja alcançada a contracepção, estas usuárias estão predispostas ao desenvolvimento de tromboembolismo venoso (TEV) ou arterial (TEA), e ao desenvolvimento de aterosclerose, em virtude da alteração hemostática causada pela dose de estrógeno e tipo de progesterona utilizada nas formulações. Como forma de obter uma formulação dita \"ideal\" e na esperança de que os efeitos adversos que podem ocorrer em detrimento da composição da formulação contraceptiva sejam minimizados, a literatura aponta um contraceptivo recentemente lançado, cuja composição contém o Valerato de Estradiol (chamado de estrógeno natural pela indústria farmacêutica) como componente estrogênico e o Dienogest como progesterona sintética, integrando o grupo dos assim classificados novos progestágenos. OBJETIVO: Dentro do contexto que acima apresentamos, o projeto de pesquisa teve como objetivo avaliar duas formulações contraceptivas, através de um estudo experimental comparativo, onde como grupo controle utilizamos o clássico Levonorgestrel (LVG) e Etinilestradiol (EE), para compará-lo com o novo progestágeno lançado no mercado brasileiro em 2011, composto por Dienogest (DNG) e Valerato de estradiol (17? Estradiol - metabólito ativo) - ambos medicamentos isolados e em mistura, representados por MIX I (LVG+EE) e MIX II (DNG+17?), respectivamente. Pelo fato de pouco se saber sobre os efeitos deste novo progestágeno sobre os fatores vasoativos, hemostáticos e inflamatórios, propusemos aqui trabalhar com cultura de células endoteliais extraídas de cordão umbilical humano, estimulá-las com agente inflamatório LPS e/ou TNF? para posteriormente dosar os seguintes fatores: em Célula Endotelial de Veia Umbilical Humana (HUVEC) - moléculas de adesão VCAM-I, ICAM-I e E-Selectina (sobrenadante e superfície celular de HUVEC); fatores vasoativos derivados do endotélio (NO, Prostaglandina PGE2 e Endotelina ET-1 - sobrenadante) e citocinas pró-inflamatórias IL-1? e IL-6 no sobrenadante. Em Célula Endotelial de Artéria Humana (HAEC): Fator Tecidual. Os medicamentos reduziram a expressão de moléculas de adesão no sobrenadante e na superfície celular, regularam a produção de fatores vasoativos derivados do endotélio, reduziram a produção de citocinas pró-inflamatórias e reduziram também a expressão de fator tecidual, de maneira preventiva e terapêutica. A mistura dos contraceptivos representada por MIX I e MIX II apresentou diferenças significativas quando comparadas aos demais grupos de estudo e MIX II apresentou maior efetividade na redução de alguns fatores aqui estudados, conferindo uma proteção endotelial. Desta maneira, podemos concluir que o novo progestágeno lançado no mercado brasileiro apresentou efeitos antitrombóticos e anti-inflamatórios, por reduzir de maneira significativa os níveis de moléculas de adesão, fatores vasoativos, fatores pró-inflamatórios e fator hemostático / Combined oral contraceptives (COCs) are widely used and well accepted to provide contraception. It\'s estimated that over 100 million women around the world make use of this contraceptive method. Although contraception is achieved, these users are predisposed to developing venous thromboembolism or arterial and development of atherosclerosis due to the change caused by the hemostatic dose of estrogen and progestin type used in the formulations. In order to get a said formulation \"correct\" and hoping that the adverse effects that may occur at the expense of the contraceptive formulation composition are minimized, the literature indicates a contraceptive recently launched, whose composition contains Estradiol valerate (called natural estrogen by the pharmaceutical industry) as estrogen component and the Dienogest as synthetic progesterone, integrating the group of so classified new progestins. OBJECTIVE: Within the context that we present above, the research project aimed to evaluate two contraceptive formulations, through a comparative experimental study, where as the control group used the classic Levonorgestrel (LVG) and ethinylestradiol (EE), to compare it with the new progestin released in Brazil in 2011, composed of Dienogest (DNG) and estradiol valerate (17? Estradiol - active metabolite) - both alone and in combination medications, represented by MIX I (LVG plus EE) and MIX II (DNG plus 17?), respectively. \'Cause little is known about the effects of the progestogen on the new vasoactive factors, hemostatic and inflammatory proposed here work with cultured endothelial cells derived from human umbilical cord stimulus them with LPS inflammatory agent and / or TNF? to further quantitate the following factors: HUVEC (Human Umbilical Vein Endothelial Cell) - adhesion molecules VCAM-I, ICAM-I and E-selectin (supernatant and cell surface); endothelium-derived vasoactive factors (NO, PGE2 and Endothelin ET-1 - culture supernatant) and pro-inflammatory cytokines as IL-1? and IL-6 in the supernatant. HAEC (Human Arterial Endothelial Cell): Tissue factor on primary cell culture of umbilical cord artery. The drugs reduced the expression of adhesion molecules in the supernatant and the cell surface reduced the production of endothelium-derived vasoactive factors, regulated the production of cytokines proinflammatory and also reduced the expression of tissue factor, preventive and therapeutic way. The mixture of contraceptives represented by MIX MIX I and II showed significant differences when compared to the other study groups and MIX II showed greater effectiveness in reducing some factors studied here, giving an endothelial protection. Thus, we can conclude that the new progestogen released in Brazil showed antithrombotic effects and anti-inflammatory, to reduce significantly the levels of adhesion molecules, vasoactive factors, proinflammatory factors and hemostatic factor.