65 research outputs found

    Update on adrenal steroid hormone biosynthesis and clinical implications

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    Steroid biosynthesis is a complex process in which cholesterol is converted to steroid hormones with the involvement of multiple enzymes and cofactors. Inborn conditions affecting adrenal steroidogenesis are relatively common in paediatric practice and have serious implications on patient mortality and morbidity. This paper provides an overview of novel insights into human adrenal steroid biosynthesis. Inborn errors of steroidogenesis associated with congenital adrenal hyperplasia are discussed, with a particular focus on the pathophysiology and clinical features of 21-hydroxylase deficiency. The final section of the review presents more recent findings and clinical implications of adrenal-specific androgen biosynthesis

    Fatigue crack propagation in HSLA steel specimens subjected to unordered and ordered load spectra

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    Prediction of fatigue crack propagation in metallic structures subjected to dynamic random load spectra, containing variable overloads and underloads, is challenging because of possible retardation and acceleration effects. In this paper, fatigue crack growth behaviour under random spectrum load is investigated on ESE(T) specimens made of DNV 460 steel, which is an HSLA steel widely used in the offshore industry. A reference spectrum composed of a sequence of random loads is transferred into various reduced and ordered spectra. Reduced spectra have been defined based on a peak-valley segmentation algorithm and on the deletion of non-damaging events. Ordered spectra consist of block loading sequences determined by rainflow counting methods. Specific control software has been developed that allows to execute the K (stress intensity factor) controlled experimental program and perform on-line crack growth measurement using a material compliance method. The different spectra are compared in terms of total crack extension and retardation in crack growth rate. Algorithms for crack growth simulation have been implemented in Abaqus using both existing and adapted plastic zone models. Numerical results are critically compared to the experimental data

    Use of yeast (Saccharomyces cerevisae), yeast cell wall (SSCW), organic acids and avilamycin in broilers feeding

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    This study was accomplished with 2.520 chickens males to verify the effect of the simbiótics use in the feeding of males chickens (yeasts Saccharomyces cerevisae and mananoligossacharides), comparatively the added of aluminosilicate of sodium cellular wall of yeasts and calcium, a mixture of organic acids constituted by lactic acid, citric acid and fumaric acid, a growth promoter (Avilamicin) and a negative control. The diets were the corn base and soy crumb. A completely randomized experimental design was used, and the obtained data were evaluated by analysis of variance and test of Tukey at a level of 5%. The appraised parameters were: ration consumption, weight gain, alimentary conversion and European Factor of Efficiency (EEF). In the initial apprenticeship of life of the birds (1 to 21 days of age), the growth promoter's inclusion presented an inferior result to the other tested treatments, that you/they didn't differ amongst themselves. Being considered the total period (1 to 42 days of age) the analysis of the European Factor of Efficiency that whole summarize the results and economical of the treatments, it allows to end that the substitution of antibiotics for simbiotics (yeasts and mananoligossaccharides) it is a viable and economical alternative.Foi realizado um estudo com 2.520 frangos de corte machos para verificar o efeito do uso de simbióticos na alimentação de frangos de corte (leveduras Saccharomyces cerevisae e mananoligossacarideos), comparativamente a parede celular de leveduras acrescido de aluminosilicato de sódio e cálcio, uma mistura de ácidos orgânicos constituída por ácido lático, acido cítrico e ácido fumárico, um promotor de crescimento (Avilamicina) e um controle negativo. As dietas foram a base de milho e farelo de soja. Foi utilizado um delineamento inteiramente casualizado e os dados obtidos avaliados pela análise da variância e teste de Tukey ao nível de 5%. Os parâmetros avaliados foram: consumo de ração, ganho de peso, conversão alimentar e Fator de Eficiência Europeu (EEF). No estágio inicial de vida das aves (1 a 21 dias de idade), a inclusão do promotor de crescimento apresentou um resultado inferior aos demais tratamentos testados, que não diferiram entre si. Considerando-se o período total (1 a 42 dias de idade) a análise do Fator de Eficiência Europeu que sumariza todos os resultados zootécnicos e econômicos dos tratamentos, permite concluir que a substituição de antibióticos por simbióticos (leveduras e mananoligossacarídeos) é uma alternativa viável e econômica.  

    Thalamocortical connectivity in experimentally-induced migraine attacks: A pilot study

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    In this study we used nitroglycerin (NTG)-induced migraine attacks as a translational human disease model. Static and dynamic functional connectivity (FC) analyses were applied to study the associated functional brain changes. A spontaneous migraine-like attack was induced in five episodic migraine (EM) patients using a NTG challenge. Four task-free functional magnetic resonance imaging (fMRI) scans were acquired over the study: baseline, prodromal, full-blown, and recovery. Seed-based correlation analysis (SCA) was applied to fMRI data to assess static FC changes between the thalamus and the rest of the brain. Wavelet coherence analysis (WCA) was applied to test time-varying phase-coherence changes between the thalamus and salience networks (SNs). SCA results showed significantly FC changes between the right thalamus and areas involved in the pain circuits (insula, pons, cerebellum) during the prodromal phase, reaching its maximal alteration during the full-blown phase. WCA showed instead a loss of synchronisation between thalami and SN, mainly occurring during the prodrome and full-blown phases. These findings further support the idea that a temporal change in thalamic function occurs over the experimentally induced phases of NTG-induced headache in migraine patients. Correlation of FC changes with true clinical phases in spontaneous migraine would validate the utility of this model

    CARACTERÍSTICAS E INCIDÊNCIA DO TUMOR VENÉREO TRANSMISSÍVEL (TVT) EM CÃES E EFICIÊNCIA DA QUIMIOTERAPIA E OUTROS TRATAMENTOS

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    html> Com o objetivo de estabelecerem-se parâmetros segundo a predisposição racial, etária, sexual, localização da incidência do TVT em cães, além das modalidades de diagnóstico e tratamento, foi realizado um estudo estatístico em 52 clínicas de Curitiba e Região Metropolitana, em 1998. Constatou-se que o TVT é principalmente encontrado em animais do sexo feminino que permanecem abandonados nas ruas ou ainda aqueles que freqüentemente atingem as vias públicas. Também concluiu-se que a história e o exame físico dos pacientes, freqüentemente, constituíram-se meios de diagnóstico para o TVT em cães. Entre as modalidades de tratamento, observou-se que a cirurgia foi empregada somente nos casos que exigiam citorredução neoplásica prévia à terapia com agentes anticancerígenos. O sulfato de vincristina na dose de 0,5 a 1,0 mg/ m2 , administrado semanalmente via endovenosa, durante 6 semanas consecutivas, constituiu-se em opção eficaz no controle do TVT, pois não se observou colateralidade, recidivas e/ou metástases nos cães tratados nesse período. A survey on the incidence and the therapeutic procedures of the canine transmissible venereal tumor, the stickers lymphosarcoma Abstract A survey has been carried out on the incidence by breed, age, sex and dogs wondering habits of the canine transmissible venereal tumor (TVT) and the therapeutic procedures to which they were submitted. The survey was carried out during 1998 in 52 Veterinary Clinics from Curitiba and its Metropolitan Region. Among 42 cases of TVT recorded during that year, 61.9% (n = 26) were female and 38.09 (n = 16) male dogs. The higher incidence of TVT in female dogs may be due to the fact that they stay abandoned or wondering in streets. Among the therapeutic procedures used for the treatment of TVT bearing dogs, surgical neoplasia citoreduction is frequently used previously to the administration of anticancerous drugs. A weekly intravenous administration of Vincristine - 0.5 - 1.0 mg/m2 - during 6 successive weeks, constitutes the best option for the treatment and control of TNT. No bad effects, recidivism and/or metastasis were found in dogs subjected to this therapeutic procedure

    Efeito da aplicação de diferentes tratamentos térmicos no conteúdo de resíduo de anticoccidiano em carne de frango.

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    Resumo: Anticoccidianos são compostos utilizados na prevenção de uma doença parasitária muito comum na criação de frangos de corte. A nicarbazina é um complexo constituído por 4,4´-dinitrocarbanilida (DNC) e 2-hidroxi-4,6- dimetil-pirimidina (HDP) amplamente utilizado como anticoccidiano. Contudo, a deposição de DNC em carne de frango é uma preocupação recorrente. O objetivo deste estudo foi avaliar o efeito de tratamentos térmicos convencionais sobre o conteúdo de DNC em carne de frango. A carne contaminada com DNC foi obtida de frangos alimentados com ração contendo nicarbazina (180 mg.kg-1 ). Foram realizados 2 experimentos com carne de frango submetida ao aquecimento por cozimento, grelha, micro-ondas, fritura e forneamento. No primeiro, realizou-se avaliação cinética da degradação de DNC na carne, enquanto que no segundo comparou-se a eficiência dos tratamentos. As concentrações de DNC na carne foram determinadas por LC-MS/MS. Os resultados indicaram que os tratamentos induziram a degradação de DNC na faixa de 52 a 69%. O cozimento foi o procedimento mais eficiente dentre os tratamentos avaliados. A degradação nos procedimentos com grelha, micro-ondas e fritura não diferiu (p?0,05) do valor para o cozimento. A redução dos níveis de DNC foi associada à hidrólise desta molécula. Considerando a legislação atual, que regulamenta o monitoramento de DNC, confirmou-se que os tratamentos podem tornar a carne mais segura ao consumidor
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