986 resultados para Testosterona, Hormones sexuals
Resumo:
This paper describes the adsorption of 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) from aqueous solution by decomposed peat. The peat presented a good adsorption process, close to 76.2% for E2 removal and approximately 55.0% for EE2. Moreover, the results indicated a probable multi-layered process. Adsorption isotherms were well fitted by Freundlich model. The data were evaluated considering the pseudo-first-order and pseudo-second-order approaches, being the second more significant mechanism in the rate-controlling step. Thermodynamic data revealed that hormones adsorption onto peat is spontaneous under the employed experimental conditions. The results confirmed the potential of this adsorbent to be employed for effluents treatment.
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The marine environment is certainly one of the most complex systems to study, not only because of the challenges posed by the nature of the waters, but especially due to the interactions of physical, chemical and biological processes that control the cycles of the elements. Together with analytical chemists, oceanographers have been making a great effort in the advancement of knowledge of the distribution patterns of trace elements and processes that determine their biogeochemical cycles and influences on the climate of the planet. The international academic community is now in prime position to perform the first study on a global scale for observation of trace elements and their isotopes in the marine environment (GEOTRACES) and to evaluate the effects of major global changes associated with the influences of megacities distributed around the globe. This action can only be performed due to the development of highly sensitive detection methods and the use of clean sampling and handling techniques, together with a joint international program working toward the clear objective of expanding the frontiers of the biogeochemistry of the oceans and related topics, including climate change issues and ocean acidification associated with alterations in the carbon cycle. It is expected that the oceanographic data produced this coming decade will allow a better understanding of biogeochemical cycles, and especially the assessment of changes in trace elements and contaminants in the oceans due to anthropogenic influences, as well as its effects on ecosystems and climate. Computational models are to be constructed to simulate the conditions and processes of the modern oceans and to allow predictions. The environmental changes arising from human activity since the 18th century (also called the Anthropocene) have made the Earth System even more complex. Anthropogenic activities have altered both terrestrial and marine ecosystems, and the legacy of these impacts in the oceans include: a) pollution of the marine environment by solid waste, including plastics; b) pollution by chemical and medical (including those for veterinary use) substances such as hormones, antibiotics, legal and illegal drugs, leading to possible endocrine disruption of marine organisms; and c) ocean acidification, the collateral effect of anthropogenic emissions of CO2 into the atmosphere, irreversible in the human life time scale. Unfortunately, the anthropogenic alteration of the hydrosphere due to inputs of plastics, metal, hydrocarbons, contaminants of emerging concern and even with formerly "exotic" trace elements, such us rare earth elements is likely to accelerate in the near future. These emerging contaminants would likely soon present difficulties for studies in pristine environments. All this knowledge brings with it a great responsibility: helping to envisage viable adaptation and mitigation solutions to the problems identified. The greatest challenge faced by Brazil is currently to create a framework project to develop education, science and technology applied to oceanography and related areas. This framework would strengthen the present working groups and enhance capacity building, allowing a broader Brazilian participation in joint international actions and scientific programs. Recently, the establishment of the National Institutes of Science and Technology (INCTs) for marine science, and the creation of the National Institute of Oceanographic and Hydrological Research represent an exemplary start. However, the participation of the Brazilian academic community in the latest assaults on the frontier of chemical oceanography is extremely limited, largely due to: i. absence of physical infrastructure for the preparation and processing of field samples at ultra-trace level; ii. limited access to oceanographic cruises, due to the small number of Brazilian vessels and/or absence of "clean" laboratories on board; iii. restricted international cooperation; iv. limited analytical capacity of Brazilian institutions for the analysis of trace elements in seawater; v. high cost of ultrapure reagents associated with processing a large number of samples, and vi. lack of qualified technical staff. Advances in knowledge, analytic capabilities and the increasing availability of analytical resources available today offer favorable conditions for chemical oceanography to grow. The Brazilian academic community is maturing and willing to play a role in strengthening the marine science research programs by connecting them with educational and technological initiatives in order to preserve the oceans and to promote the development of society.
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In vitro release of bioidentical hormones in four different liposomal transdermal emulsions (containing testosterone, progesterone, estradiol, or estradiol and estriol) was assessed. For this purpose, novel high-performance liquid chromatography methods were developed and validated in an eco-friendly manner and used to determine the in vitro release of such products. The methods were suitable for our intended goal, and the emulsions employed were found to be effective as transporting candidates for the efficient release of hormones in the transdermal delivery of human sexual steroids.
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Endometriosis is a common hormone-dependent gynecological disease leading to severe menstrual and/or chronic pelvic pain with or without subfertility. The disease is defined by the presence of endometrium-like tissue outside the uterine cavity, primarily on the pelvic peritoneum, ovaries and infiltrating organs of the peritoneal cavity. The current tools for diagnosis and treatment of endometriosis need to be improved to ensure reliable diagnosis and effective treatment. In addition, endometriosis is associated with increased risk of ovarian cancer and, therefore, the differential diagnosis between the benign and malignant ovarian cysts is of importance. The long-term objective of the present study was to support the discovery of novel tools for diagnosis and treatment of endometriosis. This was approached by exploiting genome-wide expression analysis of endometriosis specimens. A novel expression profiling -based classification of endometriosis indicated specific subgroups of lesions partially consistent with the clinical appearance, but partially according to unknown factors. The peritoneum of women with endometriosis appeared to be altered in comparison to that of healthy control subjects, suggesting a novel aspect on the pathogenesis of the disease. The evaluation of action and metabolism of sex hormones in endometrium and endometriosis tissue indicated a novel role of androgens in regulation of the tissues. In addition, an enzyme involved in androgen and neurosteroid metabolism, hydroxysteroid (17beta) dehydrogenase 6, was found to be highly up-regulated in endometriosis tissue as compared to healthy endometrium. The enzyme may have a role in the pathogenesis of endometriosis or in the endometriosis associated pain generation. Finally, a new diagnostic biomarker, HE4, was discovered distinguishing patients with ovarian endometriotic cysts from those with malignant ovarian cancer. The information acquired in this study enables deeper understanding of endometriosis and facilitates the development of improved diagnostic tools and more specific treatments of the disease
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Adsorption is one of the most commonly used methods in water treatment processes. It is attractive due to it easy operation and the availability of a wide variety of commercial adsorbents. This doctoral thesis focuses on investigating and explaining the influence of external phase conditions (temperature, pH, ionic strength, acidity, presence of cosolutes) on adsorption phenomena. In order to cover a wide range of factors and phenomena, case studies were chosen from various fields where adsorption is applied. These include the adsorptive removal of surface active agents (used in cleaning chemicals, for example) from aqueous effluents, the removal of hormones (estradiol) from drinking water, and the adsorption of antibiotics onto silica. The latter can beused to predict the diffusion of antibiotics in the aquatic system if they are released into the environment. Also the adsorption of living cells on functionalized polymers to purify infected water streams was studied. In addition to these examples, the adsorptive separation of harmful compounds from internal water streams within a chemical process was investigated. The model system was removal of fermentation inhibitors from lignocelluloses hydrolyzates. The detoxification of the fermentation broth is an important step in the manufacture of bioethanol from wood, but has not been studied previously in connection with concentrated acid hydrolyzates. New knowledge on adsorption phenomena was generated for all of the applications investigated. In most cases, the results could be explained by combining classical theories for individual phenomena. As an example, it was demonstrated how liquid phase aggregation could explain abnormal-looking adsorption equilibrium data. In addition to the fundamental phenomena, also process performance was of interest. This aspect is often neglected in adsorption studies. It was demonstrated that adsorbents should not be selected for a target application based on their adsorption properties only, but regeneration of the spent adsorbent must be considered. It was found that using a suitable amount of organic co-solvent in the regeneration can significantly improve the productivity of the process.
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The growth of breast cancer is regulated by hormones and growth factors. Recently, aberrant fibroblast growth factor (FGF) signalling has been strongly implicated in promoting the progression of breast cancer and is thought to have a role in the development of endocrine resistant disease. FGFs mediate their auto- and paracrine signals through binding to FGF receptors 1-4 (FGFR1-4) and their isoforms. Specific targets of FGFs in breast cancer cells and the differential role of FGFRs, however, are poorly described. FGF-8 is expressed at elevated levels in breast cancer, and it has been shown to act as an angiogenic, growth promoting factor in experimental models of breast cancer. Furthermore, it plays an important role in mediating androgen effects in prostate cancer and in some breast cancer cell lines. We aimed to study testosterone (Te) and FGF-8 regulated genes in Shionogi 115 (S115) breast cancer cells, characterise FGF-8 activated intracellular signalling pathways and clarify the role of FGFR1, -2 and -3 in these cells. Thrombospondin-1 (TSP-1), an endogenous inhibitor of angiogenesis, was recognised as a Te and FGF-8 regulated gene. Te repression of TSP-1 was androgen receptor (AR)-dependent. It required de novo protein synthesis, but it was independent of FGF-8 expression. FGF-8, in turn, downregulated TSP-1 transcription by activating the ERK and PI3K pathways, and the effect could be reversed by specific kinase inhibitors. Differential FGFR1-3 action was studied by silencing each receptor by shRNA expression in S115 cells. FGFR1 expression was a prerequisite for the growth of S115 tumours, whereas FGFR2 expression alone was not able to promote tumour growth. High FGFR1 expression led to a growth advantage that was associated with strong ERK activation, increased angiogenesis and reduced apoptosis, and all of these effects could be reversed by an FGFR inhibitor. Taken together, the results of this thesis show that FGF-8 and FGFRs contribute strongly to the regulation of the growth and angiogenesis of experimental breast cancer and support the evidence for FGF-FGFR signalling as one of the major players in breast cancers.
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Photosynthesis, the process in which carbon dioxide is converted into sugars using the energy of sunlight, is vital for heterotrophic life on Earth. In plants, photosynthesis takes place in specific organelles called chloroplasts. During chloroplast biogenesis, light is a prerequisite for the development of functional photosynthetic structures. In addition to photosynthesis, a number of other metabolic processes such as nitrogen assimilation, the biosynthesis of fatty acids, amino acids, vitamins, and hormones are localized to plant chloroplasts. The biosynthetic pathways in chloroplasts are tightly regulated, and especially the reduction/oxidation (redox) signals play important roles in controlling many developmental and metabolic processes in chloroplasts. Thioredoxins are universal regulatory proteins that mediate redox signals in chloroplasts. They are able to modify the structure and function of their target proteins by reduction of disulfide bonds. Oxidized thioredoxins are restored via the action of thioredoxin reductases. Two thioredoxin reductase systems exist in plant chloroplasts, the NADPHdependent thioredoxin reductase C (NTRC) and ferredoxin-thioredoxin reductase (FTR). The ferredoxin-thioredoxin system that is linked to photosynthetic light reactions is involved in light-activation of chloroplast proteins. NADPH can be produced via both the photosynthetic electron transfer reactions in light, and in darkness via the pentose phosphate pathway. These different pathways of NADPH production enable the regulation of diverse metabolic pathways in chloroplasts by the NADPH-dependent thioredoxin system. In this thesis, the role of NADPH-dependent thioredoxin system in the redox-control of chloroplast development and metabolism was studied by characterization of Arabidopsis thaliana T-DNA insertion lines of NTRC gene (ntrc) and by identification of chloroplast proteins regulated by NTRC. The ntrc plants showed the strongest visible phenotypes when grown under short 8-h photoperiod. This indicates that i) chloroplast NADPH-dependent thioredoxin system is non-redundant to ferredoxinthioredoxin system and that ii) NTRC particularly controls the chloroplast processes that are easily imbalanced in daily light/dark rhythms with short day and long night. I identified four processes and the redox-regulated proteins therein that are potentially regulated by NTRC; i) chloroplast development, ii) starch biosynthesis, iii) aromatic amino acid biosynthesis and iv) detoxification of H2O2. Such regulation can be achieved directly by modulating the redox state of intramolecular or intermolecular disulfide bridges of enzymes, or by protecting enzymes from oxidation in conjunction with 2-cysteine peroxiredoxins. This thesis work also demonstrated that the enzymatic antioxidant systems in chloroplasts, ascorbate peroxidases, superoxide dismutase and NTRC-dependent 2-cysteine peroxiredoxins are tightly linked up to prevent the detrimental accumulation of reactive oxygen species in plants.
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ABSTRACTThe study was conducted with shoot tip explants of neem (Azadirachta indica A. Juss) to identify a viable regenerative process. Shoot tips were obtained from neem embryos cultured alternatingly in DKW medium supplemented with BAP and medium without hormones. Initial shoot development was influenced by cotyledon presence. Basal callus, excised from in vitro stem base, also presented organogenic potential. In some cases, plant lines, obtained from each seed, presented different characteristics. The most common characteristic observed in vitro was callus formation at the stem base. However, the rarest characteristics were stem callus formation and leaf senescence. The regenerated shoot tips were further subculture and rooted on a medium supplemented with IBA so that complete plants could be obtained. The rooted plants were transplanted to a greenhouse and successfully acclimatized. No significant differences in in vivo development were observed between neem plants from callus and from shoot tip propagation.
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Ginecomastia é o aumento da mama masculina que pode acometer até 65% dos indivíduos deste sexo na fase infanto-puberal, compreendida entre 13 e 16 anos. Tem como principais causas hepatite ou cirrose hepática, carcinoma ou doenças inflamatórias pulmonares crônicas, carcinomas ou disfunções testiculares, tumores glandulares (pituitária, supra-renal), alterações dos níveis séricos de testosterona, síndromes genéticas (síndrome de Klinefelter, p.ex.), uso de drogas como heroína, maconha ou anabolizantes e hanseníase. Podemos classificar a ginecomastia quanto ao volume, quanto aos tecidos que a compõem (gordurosa ou pseudoginecomastia, glandular e mista), ou quanto ao tratamento necessário para sua correção cirúrgica (pequena, moderada e grave). O tratamento das formas mais graves de ginecomastia é muito diferente daquele aplicado às formas mais suaves, pois nas formas graves, além da ressecção dos tecidos gorduroso e glandular, existe a necessidade de ressecção da pele em excesso e o reposicionamento do complexo aréolo-mamilar. O objetivo deste trabalho é descrever uma técnica cirúrgica específica para estes pacientes portadores de formas graves de ginecomastia, através de dois pedículos dermogordurosos, um lateral e um medial, com aproximadamente 2cm de espessura, mantendo assim a nutrição do complexo aréolo-mamilar. Esses pedículos são delimitados entre as bissetrizes dos quadrantes súpero-lateral e ínfero-lateral, e súpero-medial e ínfero-medial, tendo o mamilo como vértice. Na área de pele excessiva periareolar, obtida através do pinçamento interdigital, é realizada a desepidermização dos pedículos lateral e medial e ressecção de toda pele e tecido celular subcutâneo até a fáscia peitoral nas regiões superior e inferior aos pedículos; a síntese é realizada em dois planos, sendo periareolar a cicatriz resultante. Foram operados com esta técnica vinte pacientes com forma grave de ginecomastia, com média etária de 23,3 anos; sendo seis pacientes da raça negra. O bom posicionamento do complexo aréolo-mamilar e uma cicatriz periareolar resultante, bem como a retirada de conteúdo suficiente, foram as principais vantagens observadas. Como complicações, tivemos assimetria das placas aréolo-mamilares em dois casos, nos quais havia acentuada diferença entre os dois lados na avaliação pré-operatória; cicatrização hipertrófica em um paciente da raça negra, cuja cicatriz foi atenuada com injeções intracicatriciais de triancinolona; necrose parcial de aréola em um caso, cuja ferida cicatrizou por segunda intenção, dispensando qualquer tratamento local posterior; deiscência de sutura periareolar em um caso, no qual foi feita a ressutura, com bom resultado, e quatro pacientes apresentaram coleção sero-hemática subcutânea, que foram drenadas e não apresentaram recidiva.
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Type 2 diabetes mellitus is an epidemic health problem. Approximately, 90% of diabetic patients are overweight or are obese. The current increase in the prevalence of obesity has been associated with an increase in the prevalence of type 2 diabetes. Bariatric surgery is the most effective treatment for morbid obese patients in terms of controlling weight and co-morbidities. Sustained normal plasma concentration of glucose has been reported in most diabetic morbid obese patients, which has been managed surgically. Available data show a significant alteration in the production of some gastrointestinal hormones, which might explain the improvement of glucose metabolism following these procedures. Diabetic patient improvements following some bariatric surgeries seems to be an independent factor unrelated to the amount of weight loss. The authors reviewed data published on the effects of bariatric surgery in diabetic patient improvements and the possible mechanisms responsible for this control.
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OBJETIVO: Avaliar a influência da icterícia colestática na variação ponderal. MÉTODOS: Foram utilizados 64 ratos adultos, distribuídos em seis grupos: F1 (n=6) - fêmeas normais, F2 (n=6) - fêmeas laparotomizadas, F3 (n=20) - fêmeas ictéricas, M1 (n=6) - machos normais, M2 (n=6) - machos laparotomizados, M3 (n=20) - machos ictéricos. A icterícia foi obtida com ligadura e secção do ducto biliopancreático. Os pesos dos animais foram registrados semanalmente, durante sete semanas. No 14º dia de experimento, dosaram-se as bilirrubinas séricas e os hormônios gonadais. Após a sétima semana, realizou-se estudo histológico do fígado. RESULTADOS: Os animais dos grupos F3 e M3 apresentaram bilirrubinas elevadas e diminuição da massa corpórea, quando comparados com os demais grupos. As diferenças ponderais foram significativas a partir da quarta semana entre as fêmeas e da quinta semana entre os machos. Nos animais ictéricos houve aumento do estradiol e diminuição da progesterona e da testosterona total. Septos de fibroses perivenular e periportal, colangite e hiperplasia de ductos biliares ocorreram no fígado dos animais ictéricos. Nenhum animal apresentou cirrose. CONCLUSÃO: Ocorreu redução do peso corpóreo murino em presença de icterícia colestática em ambos os sexos.
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The antiandrogenic therapy (ADT) for prostate cancer represents an additional risk factor for the development of osteoporosis and fragility fractures. Still, bone health of patients on ADT is often not evaluated. After literature research we found that simple preventive measures can prevent bone loss in these patients, resulting in more cost-effective solutions to the public health system and family when compared to the treatment of fractures.
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Objetivo: analisar os níveis dos esteróides sexuais endógenos e gonadotrofinas em mulheres com e sem câncer de endométrio. Métodos: foi realizado estudo clínico-comparativo com 20 mulheres na pós-menopausa com câncer de endométrio e 20 mulheres na pós-menopausa, sem câncer de endométrio. A idade, o tempo de menopausa e o índice de massa corpórea foram utilizados como variáveis de emparelhamento. Os níveis plasmáticos dos esteróides sexuais endógenos foram medidos por métodos de radioimunoensaio e imunoenzimático. Para análise estatística utilizamos o teste "t" de Student. Resultados: os níveis de androstenediona (A), testosterona total (t) e testosterona livre (TL) foram mais elevados nas mulheres com câncer de endométrio e os níveis de hormônio luteinizante (LH) foram significativamente menores nessas mulheres. Também observamos que a razão (E1/A) mostrou valores significativamente menores no grupo de mulheres com câncer, ao passo que a razão (E2/E1) não apresentou diferenças nos dois grupos. Conclusões: destacamos a potencialidade dos esteróides sexuais e gonadotrofinas na gênese do adenocarcinoma de endométrio em mulheres na pós-menopausa.
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Objetivo: avaliar as alterações morfológicas e morfométricas produzidas pelo tamoxifeno e pelos estrogênios conjugados no epitélio mamário de ratas em estro permanente. Métodos: foram utilizadas 33 ratas adultas, induzidas a estro permanente com 1,25 mg de propionato de testosterona e divididas ao acaso em três grupos: GI -- que receberam apenas água, servindo como controle (n = 12); GII -- tratadas com 500 mig de tamoxifeno diariamente (n = 10); GIII -- tratadas com 30 mig de estrogênios conjugados ao dia (n = 11). O primeiro par mamário abdômino-inguinal dos animais foi extirpado e processado para estudo morfológico e morfométrico. Os dados foram analisados estatisticamente pela análise de variância por postos de Kruskal-Wallis (p < 0,05). Resultados: o estudo morfológico revelou sinais de atrofia epitelial e o estudo morfométrico exibiu redução estatisticamente significante do número médio de ductos e alvéolos nos grupos II (10,1 e 1,9, respectivamente) e III (11,1 e 3,5, respectivamente) em relação ao grupo I (25,0 e 6,6, respectivamente). Não houve diferença estatística entre os grupos II e III. Conclusões: os resultados deste estudo indicam que tanto o tamoxifeno como os estrogênios conjugados, nas doses e no tempo utilizado, produziram atrofia no epitélio mamário de ratas em estro permanente.
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Objetivos: testar a atividade supra-renal por meio de um estímulo potente sobre sua camada reticular com o intuito de aferir a atividade da 3b-hidroxiesteróide desidrogenase (3beta-HSD) e da 21-hidroxilase (21OH). Métodos: concentrações plasmáticas de 17alfaOH-pregnenolona, 17alfaOH-progesterona, cortisol, progesterona, androstenediona, deidroepiandrosterona (DHEA), sulfato de deidroepiandrosterona (SDHEA) e testosterona livre foram determinadas em 39 mulheres, sendo 13 normais (2 utilizadas como piloto) e 26 com hirsutismo idiopático nos tempos 0, 12 e 24 horas após injeção de ACTH-depot. Resultados: entre as mulheres hirsutas, identificamos respostas que permitem indicar qualquer bloqueio nas diversas etapas da esteroidogênese, conduzindo ao diagnóstico de função supra-renal diminuída em graus leve/moderado. As concentrações de 17aOH-pregnenolona partiram de 2,0 para 24,6 ng/ml, as de cortisol aumentaram de 2,1 para 45,3 e 38,4mig/dL, as de 17alfaOH-progesterona sofreram incremento de 50,7 para 346 e 218 ng/dL e os níveis de progesterona se elevaram de 0,3 para 4,4 e 2,2 ng/ml. Entre os hormônios da camada reticular verificamos aumento do SDHEA de 274,7 para 495,5 e 505,8 ng/dL, os de androstenediona de 1,1 para 4,0 e 4,5 ng/mL, os de testosterona livre de 1,3 para 1,8 e 2,7 pg/mL e os de DHEA de 2,4 para 4,7 e 8,5 ng/mL. Na avaliação individualizada uma paciente revelou defeito de 3beta-HSD e duas outras, provável defeito de 21OH. Conclusões: estes achados sugerem que o teste com ACTH-depot pode ser utilizado para excluir a supra-renal como possível fonte hiperandrogênica em mulheres com hirsutismo, com ou sem anovulação crônica.