1,863 research outputs found

    Effects of oxidative stress during human and animal reproductions: A review

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    Given its high ability to damage important cellular components (lipids, proteins and deoxyribonucleic acid), oxidative stress is now recognized as one of the most common mechanisms associated with development of a variety of diseases and natural events such as pregnancy. During reproduction period, there is a change in the pro-oxidant and antioxidant balance due to the body and circulation modifications that are inherent to the pregnancy process. The present paper discusses the role of oxidative stress on the reproduction process. More effective defense strategies are needed to decrease the deleterious effects of oxidative-stress-induced gestation. This approach could be achieved by antioxidant status alteration. Further clinical and experimental studies are needed for better understanding of oxidative stress mechanism and the impact of antioxidant supplementation on reproduction

    Dez anos de acompanhamento de uma série de casos de neoplasias epiteliais primárias da glândula lacrimal: características clínicas, tratamento cirúrgico e achados histopatológicos

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    PURPOSE: To describe and analyze the features of a cases series of patients with primary epithelial neoplasms of the lacrimal gland, its surgical treatment, and histopathological findings. METHODS: Retrospective evaluation of files from patients with primary epithelial neoplasms of the lacrimal gland in the period from 1997 to 2007. All patients with primary epithelial tumors of the lacrimal gland were included in this study. Data on gender, age, clinical features, surgical treatment, histopathological findings and follow-up were collected. The slides with histological sections of the tumors were reviewed by the same pathologist. RESULTS: During the study period, there were 12 patients, 5 (41.7%) with benign tumors, all pleomorphic adenomas (benign mixed tumor) and 7 (58.3%) with malignant neoplasms, thus distributed: four cases of adenoid cystic carcinoma, two of mucoepidermoid carcinoma and one carcinoma expleomorphic adenoma. Globally, patients mean age was 54.1 years-old (ranging from 14 to 70 years-old), with mean age of 52.4 years-old (ranging from 14 to 65 years-old) for benign neoplasms, and 55.3years-old for malignant neoplasms (ranging from 26 to 70 years-old). Clinical follow-up information, ranging from 2 to 10 years-old, was available for all patients. Three patients developed distant metastasis and died of disease. CONCLUSIONS: The most frequent primary epithelial neoplasms of the lacrimal gland were pleomorphic adenoma and adenoid cystic carcinoma during the study period. Malignant tumors were more frequent than benign tumors. The histopathological diagnosis and the disease initial stage can play a significant role in patient's survival.OBJETIVO: Descrever e analisar as características de uma série de casos de portadores de neoplasias epiteliais primárias da glândula lacrimal, o tratamento cirúrgico, assim como os achados histopatológicos. MÉTODOS: Avaliação retrospectiva dos arquivos de pacientes com neoplasias epiteliais primárias da glândula lacrimal, no período de 1997 até 2007. Todos os pacientes com tumores epiteliais primários da glândula lacrimal foram incluídos neste estudo. Foram analisados os dados sobre sexo, idade, características clínicas, tratamento cirúrgico, achados histopatológicos e seguimento dos pacientes. As lâminas com secções histológicas dos tumores foram revisadas pelo mesmo patologista. RESULTADOS: No período do estudo, foram encontrados 12 pacientes, sendo 5 (41,7%) portadores de tumores benignos, todos adenomas pleomórficos (tumor benigno misto), e 7 (58,3%) com neoplasias malignas, assim distribuídos: quatro casos de carcinoma adenóide cístico, dois de carcinoma mucoepidermóide e um de carcinoma ex-adenoma pleomórfico. Analisando-se de modo global, a idade média dos portadores foi de 54,1 anos (variando de 14 a 70 anos); com média de idade de 52,4 anos (variando de 14 a 65 anos) para neoplasias benignas, e 55,3 para neoplasias malignas (variando de 26 a 70 anos). Informações do seguimento, variando de 2 a 10 anos, estavam disponíveis para todos os pacientes. Três pacientes desenvolveram metástases distantes e morreram devido à doença. CONCLUSÕES: A maioria das neoplasias epiteliais primárias da glândula lacrimal foi o adenoma pleomórfico e o carcinoma adenóide cístico no período de estudo. Os tumores malignos foram mais frequentes que os benignos. O diagnóstico histopatológico e o estadiamento inicial da doença podem desempenhar uma papel significante na sobrevida do paciente.Santa Casa de Misericórdia São Paulo Department of Ophthalmology Corneal and External Disease ServiceUniversidade Federal de São Paulo (UNIFESP) Department of OphthalmologySanta Casa de Misericórdia São Paulo Department of Pathology Ophthalmic Pathology ServiceSanta Casa de Misericórdia São Paulo Department of Ophthalmology Oculoplastics ServiceSanta Casa de Misericórdia São Paulo Department of OphthalmologyUNIFESP, Department of OphthalmologySciEL

    Jasmonate promotes auxin-induced adventitious rooting in dark-grown Arabidopsis thaliana seedlings and stem thin cell layers by a cross-talk with ethylene signalling and a modulation of xylogenesis

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    Background: Adventitious roots (ARs) are often necessary for plant survival, and essential for successful micropropagation. In Arabidopsis thaliana dark-grown seedlings AR-formation occurs from the hypocotyl and is enhanced by application of indole-3-butyric acid (IBA) combined with kinetin (Kin). The same IBA + Kin-treatment induces AR-formation in thin cell layers (TCLs). Auxin is the main inducer of AR-formation and xylogenesis in numerous species and experimental systems. Xylogenesis is competitive to AR-formation in Arabidopsis hypocotyls and TCLs. Jasmonates (JAs) negatively affect AR-formation in de-etiolated Arabidopsis seedlings, but positively affect both AR-formation and xylogenesis in tobacco dark-grown IBA + Kin TCLs. In Arabidopsis the interplay between JAs and auxin in AR-formation vs xylogenesis needs investigation. In de-etiolated Arabidopsis seedlings, the Auxin Response Factors ARF6 and ARF8 positively regulate AR-formation and ARF17 negatively affects the process, but their role in xylogenesis is unknown. The cross-talk between auxin and ethylene (ET) is also important for AR-formation and xylogenesis, occurring through EIN3/EIL1 signalling pathway. EIN3/EIL1 is the direct link for JA and ET-signalling. The research investigated JA role on AR-formation and xylogenesis in Arabidopsis dark-grown seedlings and TCLs, and the relationship with ET and auxin. The JA-donor methyl-jasmonate (MeJA), and/or the ET precursor 1-aminocyclopropane-1-carboxylic acid were applied, and the response of mutants in JA-synthesis and -signalling, and ET-signalling investigated. Endogenous levels of auxin, JA and JA-related compounds, and ARF6, ARF8 and ARF17 expression were monitored. Results: MeJA, at 0.01 μM, enhances AR-formation, when combined with IBA + Kin, and the response of the early-JA-biosynthesis mutant dde2–2 and the JA-signalling mutant coi1–16 confirmed this result. JA levels early change during TCL-culture, and JA/JA-Ile is immunolocalized in AR-tips and xylogenic cells. The high AR-response of the late JA-biosynthesis mutant opr3 suggests a positive action also of 12-oxophytodienoic acid on AR-formation. The crosstalk between JA and ET-signalling by EIN3/EIL1 is critical for AR-formation, and involves a competitive modulation of xylogenesis. Xylogenesis is enhanced by a MeJA concentration repressing AR-formation, and is positively related to ARF17 expression. Conclusions: The JA concentration-dependent role on AR-formation and xylogenesis, and the interaction with ET opens the way to applications in the micropropagation of recalcitrant species

    The Silences Framework: A Method for researching sensitive themes and marginalized health perspectives (English version)

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    Objective: To describe the experience of applying of The Silences Framework to underpin health research investigating Tuberculosis/HIV/AIDS coinfection . Method: The Silences Framework originally developed following a study exploring the decisions and silences surrounding black Caribbean men living in England, discussing the themes 'sexual health' and 'ethnicity'. Following this study a conceptual a theory for research on sensitive issues and health care of marginalized populations was developed called 'Screaming Silences' which forms the foundation of The Silences Framework. Screaming Silences define research areas and experiences that are poorly studied, little understood or silenced. Results: The Silences Framework supports researchers in revealing "silences" in the subjects they study - as such results may reflect how beliefs, values, and experiences of some groups influence their health. This framework provides the application of four complementary stages: working the silences, hearing silences, voicing silences and working with the silences. The analysis occurs cyclically and can be repeated as long as the silences inherent in a study are not revealed. Conclusion: this article presents The Silences Framework and the application of the notion of "sounds of silence", mapping an antiessentialist theoretical framework for its use in sensitive research in health and nursing areas, being a reference for other researchers in studies involving marginalized populations. KEYWORDS: Inequalities in health. Methods. Nursing. Coinfection. Research. Tuberculosis. Acquired immunodeficiency syndrome

    Pivotal Role of Toll-Like Receptors 2 and 4, Its Adaptor Molecule MyD88, and Inflammasome Complex in Experimental Tubule-Interstitial Nephritis

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    Tubule-interstitial nephritis (TIN) results in decreased renal function and interstitial inflammation, which ultimately leads to fibrosis. Excessive adenine intake can cause TIN because xanthine dehydrogenase (XDH) can convert this purine into an insoluble compound, which precipitates in the tubuli. Innate immune sensors, such as Toll-like receptors (TLR) and inflammasome complex, play a crucial role in the initiation of inflammation. The aim of this study was to evaluate the roles of TLR-2 and -4, Myd88 and inflammasome complex in an experimental model of TIN. Here, we show that wild-type (WT) mice fed adenine-enriched food exhibited significant renal dysfunction and enhanced cellular infiltration accompanied by collagen deposition. They also presented higher gene and protein expression of pro-inflammatory cytokines. In contrast, TLR-2, -4, MyD88, ASC and Caspase-1 KO mice showed renoprotection associated with expression of inflammatory molecules at levels comparable to controls. Furthermore, treatment of WT animals with allopurinol, an XDH inhibitor, led to reduced levels of uric acid, oxidative stress, collagen deposition and a downregulation of the NF-kB signaling pathway. We concluded that MyD88 signaling and inflammasome participate in the development of TIN. Furthermore, inhibition of XDH seems to be a promising way to therapeutically target the developing inflammatory process
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