184 resultados para ovum
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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In the last years, the embryo in vitro production for every domestic species and mainly for bovine has attained a notorius status. This reproductive biotechnical procedure associate with ultrasound-guided ovum pick up (OPU) has been more and more incorporated and spread in our cattle herds, ranking up Brazil already at the top of the list in number of in vitro embryo produced. Some significant advantages provided, such as the possibility of using the premature or pregnant animals oocytes, without necessarily requiring the use of hormonal treatment, to make it possible to generate pregnancy at a shorter period of time, the rationalization in the use of semen and optimization in the use of sexed semen were determinant factors for OPU/IVP to reach this outstanding position. Nevertheless, right now the possibility of IVP embryo cryopreservation, just now is the biggest impediment for maximizing the use of this biotechnology, due to both lack of efficient methods and low laboratory produced embryo cryotolerance. Nowadays, the most used methods of IVP embryo cryopreservation are: slow freezing and vitrification. Traditionally, slow freezing is still the most used methods for in vivo and in vitro produced embryo cryopreservation. However, more recently vitrification - although still not commercially used in large scale - has been presenting satisfactory results in IVP embryo cryopreservation, according to searches
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Pós-graduação em Medicina Veterinária - FCAV
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Pós-graduação em Medicina Veterinária - FCAV
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In epidemiological surveys, the evaluation of soil contamination by Toxocara canis eggs requires a quick and easy method for the isolation of parasite eggs from soil samples. The efficiency of flotation methods is influenced by sample size, soil texture, degree of soil contamination, pretreatment, flotation solutions and time of flotation. This investigation was designed to evaluate the influence of soil texture in the recovery of T. canis eggs with the centrifugal flotation technique of Dada (Dada, B.J.O., 1979. A new technique for the recovery of Toxocara eggs from soil. J. Helminthol., 53: 141-144). Four types of soil (clay silt, sandy, silty clay and sand) were artificially contaminated with T. canis eggs (200 eggs per gram). Zinc sulphate (specific gravity 1.20) and sodium dichromate (specific gravity 1.35) were used as flotation solutions. Twenty replicated examinations were performed for each type of soil and flotation solution. There was a statistically significant difference in the results depending on soil type. The highest recovery percentages were observed in soils rich in sand (62.5% for sand and 38.0% for sandy soil). Differences were also observed with different flotation solutions. Sodium dichromate solution was more efficient for recovering T. canis eggs, regardless of the soil texture. © 1994.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Manipulation of follicle development to ensure optimal oocyte quality and conception rates in cattle
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Over the last several decades, a number of therapies have been developed that manipulate ovarian follicle growth to improve oocyte quality and conception rates in cattle. Various strategies have been proposed to improve the responses to reproductive biotechnologies following timed artificial insemination (TAI), superovulation (SOV) or ovum pickup (OPU) programmes. During TAI protocols, final follicular growth and size of the ovulatory follicle are key factors that may significantly influence oocyte quality, ovulation, the uterine environment and consequently pregnancy outcomes. Progesterone concentrations during SOV protocols influence follicular growth, oocyte quality and embryo quality; therefore, several adjustments to SOV protocols have been proposed depending on the animal category and breed. In addition, the success of in vitro embryo production is directly related to the number and quality of cumulus oocyte complexes harvested by OPU. Control of follicle development has a significant impact on the OPU outcome. This article discusses a number of key points related to the manipulation of ovarian follicular growth to maximize oocyte quality and improve conception rates following TAI and embryo transfer of in vivo-and in vitro-derived embryos in cattle.
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STUDY QUESTION Does intrauterine application of diluted seminal plasma (SP) at the time of ovum pick-up improve the pregnancy rate by ≥14% in IVF treatment? SUMMARY ANSWER Intrauterine instillation of diluted SP at the time of ovum pick-up is unlikely to increase the pregnancy rate by ≥14% in IVF. WHAT IS KNOWN ALREADY SP modulates endometrial function, and sexual intercourse around the time of embryo transfer has been suggested to increase the likelihood of pregnancy. A previous randomized double-blind pilot study demonstrated a strong trend towards increased pregnancy rates following the intracervical application of undiluted SP. As this study was not conclusive and as the finding could have been confounded by sexual intercourse, the intrauterine application of diluted SP was investigated in the present trial. STUDY DESIGN, SIZE, DURATION A single-centre, prospective, double-blind, placebo-controlled, randomized, superiority trial on women undergoing IVF was conducted from April 2007 until February 2012 at the University Department of Gynaecological Endocrinology and Reproductive Medicine, Heidelberg, Germany. PARTICIPANTS/MATERIALS, SETTING, METHODS The study was powered to detect an 14% increase in the clinical pregnancy rate and two sequential tests were planned using the Pocock spending function. At the first interim analysis, 279 women had been randomly assigned to intrauterine diluted SP (20% SP in saline from the patients' partner) (n = 138) or placebo (n = 141) at the time of ovum pick-up. MAIN RESULTS AND THE ROLE OF CHANCE The clinical pregnancy rate per randomized patient was 37/138 (26.8%) in the SP group and 41/141 (29.1%) in the placebo group (difference: -2.3%, 95% confidence interval of the difference: -12.7 to +8.2%; P = 0.69). The live birth rate per randomized patient was 28/138 (20.3%) in the SP group and 33/141 (23.4%) in the placebo group (difference: -3.1%, 95% confidence interval of the difference: -12.7 to +6.6%; P = 0.56). It was decided to terminate the trial due to futility at the first interim analysis, at a conditional power of 62%. LIMITATIONS, REASONS FOR CAUTION The confidence interval of the difference remains wide, thus clinically relevant differences cannot reliably be excluded based on this single study. WIDER IMPLICATIONS OF THE FINDINGS The results of this study cast doubt on the validity of the concept that SP increases endometrial receptivity and thus implantation in humans. STUDY FUNDING/COMPETING INTEREST(S) Funding was provided by the department's own research facilities. TRIAL REGISTRATION NUMBER DRKS00004615.
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Drilling at ODP Site 641 (on the western margin of Galicia Bank, off northwestern Spain) revealed a thin, but pronounced, interval of black shale and gray-green claystone. Our high-resolution study combines the sedimentology, micropaleontology (palynomorphs and others), organic and inorganic geochemistry, and isotopic values of this layer to demonstrate the distinct nature of the sediment and prove that the sequence represents the local sedimentary expression of the global Cenomanian/Turonian Oceanic Anoxic Event (OAE) of Schlanger and Jenkyns (1976), Arthur and Schlanger (1979), and Jenkyns (1980), also called the Cenomanian/Turonian Boundary Event (CTBE). The most striking evidence is that the strong positive d13C excursion characterizing the CTBE sequences in shallow areas can be traced into a pronounced deep-sea expression, thus providing a good stratigraphic marker for the CTBE in various paleosettings. The isotopic excursion at Site 641 coincides with an extremely enriched trace metal content, with values that were previously unknown for the Cretaceous Atlantic. Similar to other CTBE occurrences, the organic carbon content is high (up to 11%) and the organic matter is of dominantly marine origin (kerogen type II). The bulk mineralogy of the CTBE sediments does not differ significantly from the general trend of Cretaceous North Atlantic sediments (dominance of smectite and zeolite with minor amounts of illite and scattered palygorskite, kaolinite, and chlorite); thus, no evidence for either increased volcanic activity nor a drastic climatic change in the borderlands was found. Results from Site 641 are compared with the CTBE section found at Site 398, DSDP Leg 47B (Vigo Seamount at the southern end of the Galicia Bank).
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Site details: The raised bog Fláje-Kiefern (50°429N, 13°329 E; 760 m a.s.l.; size ca. 500x500 m) lies in the Krusné Hory Mountains (Erzgebirge), Czech Republic, about 10 km from Georgenfelder Moor in Germany. Hejny and Slavík (1988) described the phytogeographic region of the Krusne Hory Mountains as 'a region of mountain flora and vegetation, with thermophilous species largely missing. In the natural forests, conifers, especially spruce (Picea excelsa) prevail. The deforested areas have been converted into meadows and pastures'. The climate is cool with annual average temperatures of about 5°C and annual precipitation of about 900 mm. The bedrock is Precambrian crystallinicum.
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In recent years a global increase in jellyfish (i.e. Cnidarians and Ctenophores) abundance and a rise in the recurrence of jellyfish outbreak events have been largely debated, but a general consensus on this matter has not been achieved yet. Within this debate, it has been generally recognised that there is a lack of reliable data that could be analysed and compared to clarify whether indeed jellyfish are increasing throughout the world ocean as a consequence of anthropogenic impact and hydroclimatic variability. Here we describe different jellyfish data sets produced within the EU program EUROBASIN, which have been assembled with the aim of presenting an up to date overview on the diversity and standing stocks of North Atlantic jellyfish. Abundance and species composition were determined in samples collected in the epipelagic layer (0- 200m), using a net well adapted to quantitatively catching gelatinous zooplankton. The samples were collected in spring-summer (April-August) 2010-2013, in inshore and offshore North Atlantic waters, between 59-68LatN and 62W-5ELong. Jellyfish were also identified and counted in samples opportunistically collected by other sampling gears in the same region and in two coastal stations in the Bay of Biscay and in the Gulf of Cadiz. Continuous Plankton Recorder (CPR) samples collected in 2009-2012 were re-analysed with the aim of identifying the time and location of jellyfish blooms across the North Atlantic basin.
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The spatial variation in mesozooplankton biomass, abundance and species composition in relation to oceanography was studied in different climatic regimes (warm Atlantic vs. cold Arctic) in northern Svalbard waters. Relationships between the zooplankton community and various environmental factors (salinity, temperature, sampling depth, bottom depth, sea-ice concentrations, algal biomass and bloom stage) were established using multivariate statistics. Our study demonstrated that variability in the physical environment around Svalbard had measurable effect on the pelagic ecosystem. Differences in bottom depth and temperature-salinity best explained more than 40% of the horizontal variability in mesozooplankton biomass (DM/m**2) after adjusting for seasonal variability. Salinity and temperature also explained much (21% and 15%, respectively) of the variability in mesozooplankton vertical distribution (ind./m**3) in August. Algal bloom stage, chlorophyll-a biomass, and depth stratum accounted for additional 17% of the overall variability structuring vertical zooplankton distribution. Three main zooplankton communities were identified, including Atlantic species Fritillaria borealis, Oithona atlantica, Calanus finmarchicus, Themisto abyssorum and Aglantha digitale; Arctic species Calanus glacialis, Gammarus wilkitzkii, Mertensia ovum and Sagitta elegans; and deeper-water inhabitants Paraeuchaeta spp., Spinocalanus spp., Aetideopsis minor, Mormonilla minor, Scolecithricella minor, Gaetanus (Gaidius) tenuispinus, Ostracoda, Scaphocalanus brevicornis and Triconia borealis. Zooplankton biomasses in Atlantic- and Arctic-dominated water masses were similar, but biological ''hot-spots'' were associated with Arctic communities.