772 resultados para Lh


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pós-graduação em Química - IQ

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O presente trabalho envolveu três experimentos: Influência da imunização passiva contra estradiol (E2) e a aspiração do maior folículo (F1) no momento do desvio folicular esperado, sobre a ocorrência do desvio folicular observado. Também foi objetivo verificar o efeito desses tratamentos sobre o perfil de hormônio folículo estimulante (FSH), hormônio luteinizante (LH) e inibina total circulante. Para tanto, os animais foram imunizados com dose única de soro anti-E2 (G anti-E2) ou o F1 foi aspirado no momento do desvio esperado (GAF1). O plasma sangüíneo foi obtido no período pré e póstratamento. O intervalo entre o dia da aplicação do soro (desvio esperado) e o dia da detecção do desvio foi em média o mesmo para o G anti-E2 e controle. No GAF1, a eliminação do maior folículo provocou atraso no momento da detecção do desvio folicular entre o segundo (F2) e o terceiro (F3) maior folículo, comparado ao controle. Em ambos os tratamentos o perfil de FSH, LH e inibina total foi similar ao controle. O experimento 2 tratou de um projeto piloto visando dominar a técnica de colheita de fluido dos grandes folículos ovarianos por meio de punção com agulha fina e o efeito desse procedimento sobre o folículo e às concentrações hormonais. Foram utilizados dois grupos de animais, G1 o folículo foi mantido intacto (controle) e G2 foi utilizada uma punção folicular quando o maior folículo atingiu diâmetro ~35 mm. Ultrasonografia ovariana foi realizada desde o ínicio da detecção de um folículo ~25mm, seguindo até a detecção da ovulação. O terceiro experimento objetivou verificar a influência de gonadotrofina coriônica humana (hCG) em folículos de 30 ou 35mm sobre as concentrações de hormônios esteróides e fatores intrafoliculares. A colheita do fluido folicular foi realizada imediatamente antes e 30 horas após a aplicação... (Resumo completo, clicar acesso eletrônico abaixo)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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In cattle, proestrus begins with the initiation of luteolysis and ends with initiation of estrus and the GnRH/LH surge. This period is marked by a dramatic decrease in circulating progesterone (P4) that reaches a nadir by about 36-48 h in cows undergoing natural or prostaglandin F2 alpha (PGF)-induced luteolysis. Inadequate luteolysis is a cause of reduced fertility particularly in timed AI programs with small elevations in circulating P4 reducing fertility. Increasing circulating estradiol (E2) during proestrus is dependent on presence, size, and function of the dominant follicle and this varies during natural proestrus, due to whether animals have two or three follicular waves, and during PGF-induced proestrus, according to stage of the follicular wave at time of PGF treatment. Inadequate circulating E2 can limit fertility and increase pregnancy loss in some specific circumstances such as in cows with low BCS and in cows during heat stress. Thus, studies to optimize the length of proestrus and the concentrations of E2 and P4 during proestrus could produce substantial improvements in fertility and reductions in pregnancy loss.

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The modernization of image equipaments associate to the veterinary professionals qualification allowed an advance in diagnosis veterinary medicine, and, consequently, in premature pregnancy diagnosis in bitches. Currently, owners and creators search for information related to pregnancy detection, fetal development and viability and litter size determination. Through diagnosis methods as radiology and ultrasonography, associated to clinics aspects, the diagnosis of early pregnancy become more acurated and precise, allowing more quality in the accompaniment of prenatal of these bitches. Ultrasonographic exams help the accompaniment of these pregnancies through of visuals recourses, which can supply information related to pregnancy detection, embrionary and fetal development, fetal viability e litter size determination through fetals mensurations. The radiographic study has as principal indication the fetal counting, and has been the most acurated for this analyses. It may be done after the da s after the luteini ing hormone surge, when occurs the fetal mineralization. Due to its importance in the present time and in small animals clinic, the objective of this study is to discuss the main radiographics and ultrassonographics aspects of the diagnosis of pregnancy in bitches

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Climate change in tropical countries, like Brazil, causes major problems in dairy production due to an increase of heat stress effects. In recent years, milk production in Brazil increased 36.07%. The Southeast region remains a leader in production with herds of high producing Holstein cattle (mostly), which is more susceptible to heat stress. Thermal stress decreases fertility in direct and indirect ways. Conception rates are reduced of 40-60% during cooler months of the year and 10-20% in the warmer months. Negative effects of heat stress involve changes in reproductive hormones, follicular development, oocytes, and embryos, and decreased dry matter intake. Several studies discuss change in reproductive hormones, such as reduction in plasma concentration of GnRH, LH, and oestradiol, which lead to decreased detection of estrus and ovulation. Various methods are being studied to bypass these negative effects and increase the fertility of dairy cows under heat stress. Cooling systems are the most advantageous and can be associated with technologies such as ET and TAI

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pós-graduação em Medicina Veterinária - FCAV

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fungi isolated from marine organisms have been shown to produce several interesting secondary metabolites with important biological activities. Such chemical diversity may be associated to environmental stress conditions and may represent an important source of NCE for bioprospection. Quinolactins belong to a rare fungi-alkaloid class with a unique N-methyl-quinolone moiety fused to a lactam ring and present several bioactivities1. Fungi strain Dm1 was isolated from red alga Dichotomaria marginata, collected from Brazil SE coast, and was grown in sterile rice solid media at 26oC 2, which was then extracted with MeOH. The MeCN fr. from the MeOH extract was chromatographed over Sephadex LH-20 and fr. 4 afforded quinolactin (QL) alkaloids B1, B2 and A, whereas fr. 5 afforded quinolactin D1 after purification by HPLC-DAD. Structural determination of pure compounds was based on HRMS, UV, and NMR spectral analyses, in addition to comparison with literature data and Antimarin® databank. UV data indicated the presence of similar chromophores with λmax at ca. 247 and 320nm. HRMS and tandem MS analyses using both negative and positive ion modes for the isolated compounds indicated their molecular formula and structural features, as for QL B1: C15H16O2N2 [M+H 257], which showed one fragment at m/z 214 [-CHNO]; QL B2: C15H16O3N2 [M+H 273], with product ions at m/z 230 [-CHNO.] and m/z 186 [-C4H9NO.]; for QL A: C16H18N2O2 [M+H 271], which presented one ion at m/z 214, due to loss of fragment (-C4H9) from the molecular ion; and for QL D1: C16H18N2O3 [M+H 287], with product ions at m/z 186 [-CHNO] and m/z 230 [-C4H9]. Such data suggested fragmentation proposals, e.g. for Quinolactin B1 (Fig. 1), which confirmed the structures of the isolated quinolactins, and may represent an important contribution for the sustainable exploration of marine biodiversity.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)