382 resultados para estrous synchronization
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Ethnopharmacological relevance: In Brazil, a phytotherapeutic preparation produced from a standardized tincture of Cinchona calisaya Weddel such that each mL of product contains 400 mu g of quinine, known in Portuguese as Agua Inglesa (R) (English water), is indicated by the manufacturer as a tonic, appetite stimulant, and digestive. However, this preparation has long been used in folk medicine as a female fertility stimulant. Despite its widespread use in folk medicine to stimulate female fertility, no study has been undertaken to assess the potential teratogenic and genotoxic effects of this phytotherapeutic preparation. The aim of the present study was to investigate possible toxic reproductive effects in mice caused by exposure to Agua Inglesa (R), either before mating or during the pre- and post-embryo implantation periods. The genotoxic potential was evaluated using the micronucleus assay.Material, Methods, and Results: Virgin female mice, with at least one estrous cycle evidenced by vaginal cytology, were divided into five groups of 15 individuals each (Group I - control, Group II - treated with ethanol solution at 16%, Groups III, IV and V treated with phytotherapeutic preparation at 1.5 mL/kg/day, 3.0 mL/kg/day and 4.5 mL/kg/day, respectively). After the first 28 days of treatment, females were caged individually with adult fertile males. Pregnant females continued to receive treatment for seven days (preimplantation period). Body weight was recorded weekly during treatment. Signs of toxicity (weight loss, food intake, piloerection, apathy, prostration, diarrhea, seizures, behavioral changes, and locomotion) were also observed. The females were sacrificed on the 15th day of pregnancy, uterine horns were evaluated for implantation, and the placental index was recorded. In the micronucleus test, 2000 polychromatic erythrocytes (PCE) per animal, obtained from bone marrow, were scored. Results The results showed that exposure of the females during the pre- and post-implantation periods did not significantly alter the reproductive capacity (p < 0.05); however, in higher dose (three times human dose)reduction of fetal weight was observed. There was no difference between the control and phytotherapeutic preparation (p > 0.05) in terms of the average number of micronucleated polychromatic erythrocytes.Conclusions: Although folk medicine suggests that the Agua Inglesa (R) preparation is useful as a female fertility stimulant, no such effect was confirmed in mice. (C) 2014 Elsevier Ireland Ltd. All rights reserved.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Modern protocols to synchronize ovulations for timed artificial insemination and timed embryo transfer that include manipulations in the proestrus period (i.e., between luteolysis and estrus) affect fertility in cattle. Specifically, stimulating pre-ovulatory follicle growth and exposure to estrogens after CL regression increase the proportion of cows pregnant and decrease late embryo mortality. Such effects may be due to both preovulatory actions of estrogens and post-ovulatory actions of progesterone, as concentrations of the later hormone may be changed in response to manipulations conducted during proestrus. In the first portion of this paper we describe strategies used recently to manipulate the proestrus period in protocols for synchronization of ovulation, and to present evidence of their effects on fertility. Manipulations of timing and prominence of sex steroids during the proestrus and early diestrus that affect fertility may act on targets such as the endometrium. This tissue expresses receptors for both estrogens and progesterone and these hormones change endometrial function to support conceptus growth and pregnancy maintenance. However, specific cellular and molecular mechanisms through which fertility is affected via manipulations of the proestrus are poorly understood. In the second portion of this paper we describe a well-defined animal model to study changes in endometrial function induced by manipulations conducted during the proestrus. Such manipulations induced endometrial changes on sex steroid receptors expression, cell proliferation, oxidative metabolism and eicosanoid synthesis in the uterus, but not on glucose transport to uterine lumen. In summary, evidence is accumulating to support a positive role of increasing duration and estrogen availability during the proestrus on fertility to synchronization protocols. Such positive effects may be through changes in endometrial function to stimulate conceptus growth and survival.
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The recombinant bovine somatotropin (rbST) at first, had its widespread use in dairy cows in order to increase milk production. Currently, it has been studied frequently and use their influence both in bovine milk, such as cutting. Its production has been an evolution to the science, using bacteria to produce recombinant DNA. Most authors that have studied and obtained positive results, such as increasing the number of ovarian follicles larger than five millimeters, among others. Its action takes place directly on the ovary, follicles, corpus luteum, the granulosa cells, oviduct, myometrium, endometrium and placenta, where they were found receptors, or indirectly through the release of insuline like growth factor-1 (IGF-1). Therefore, the objective of this work is to explain the importance of bST in bovine as well as the usefulness of this, its mechanism of action and the benefits it can bring when combined with other biotechnology, such as superovulation, embryo transfer, synchronization of estrus, and others
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Synchronization in nonlinear dynamical systems, especially in chaotic systems, is field of research in several areas of knowledge, such as Mechanical Engineering and Electrical Engineering, Biology, Physics, among others. In simple terms, two systems are synchronized if after a certain time, they have similar behavior or occurring at the same time. The sound and image in a film is an example of this phenomenon in our daily lives. The studies of synchronization include studies of continuous dynamic systems, governed by differential equations or studies of discrete time dynamical systems, also called maps. Maps correspond, in general, discretizations of differential equations and are widely used to model physical systems, mainly due to its ease of computational. It is enough to make iterations from given initial conditions for knowing the trajectories of system. This completion of course work based on the study of the map called ”Zaslavksy Web Map”. The Zaslavksy Web Map is a result of the combination of the movements of a particle in a constant magnetic field and a wave electrostatic propagating perpendicular to the magnetic field. Apart from interest in the particularities of this map, there was objective the deepening of concepts of nonlinear dynamics, as equilibrium points, linear stability, stability non-linear, bifurcation and chaos
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The Doppler ultrasound allows the assessment of blood flow and the differentiate vessels according to each spectral pattern, location and organ that irrigate, helping the examinations and disease diagnosis. The main methods used are Pulsed Doppler, Color Doppler and Power Doppler. In Brazil veterinary medicine, it shows progress since 1990, but its use is limited by the equipment high cost, the need for operator experience and patient cooperation. There are studies in obstetrics and reproduction of dogs and cats, such as evaluation of the testicular vasculature, including the use of contrast material, and attempts to evaluate prostate in healthy dogs or pathological conditions (cancer and testicular torsion , orchitis and benign prostatic hyperplasia; estrous cycle monitoring, evaluation of irrigation in follicles and corpus luteum, uterus and breasts (mammary tumors) in bitches; monitoring pregnancy from the assessment of maternal, fetal and placental hemodynamics, both in dogs as in cats, and aspirations for early detection of pregnancy in dogs. However, new studies are still required, given the lack of these species, especially cats
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The age which heifers reach puberty depend on factors like genetics, environment and nutrition. Puberty in heifers can be defined as the onset of reproductive competence, the ability to ovulate a fertile oocyte with an estrous behavior and development of a corpus luteum with normal lifespan. The metabolic signals that trigger puberty are not yet fully defined. In Brazil, where most beef cattle are zebu, the age at puberty is very advanced, mainly these animals are feed with a poor diet. Many researches are trying to discover the metabolic signals that trigger puberty and anticipate better economic return in breeding farms. It has been demonstrated that the cascade of endocrine events that culminate in puberty can be hastened by an alternative management scheme that involves increased nutrient intake between 3 and 7 months of life. Different diet concentrations, different products and by-products have been used in research to achieve puberty early (less than 300 days of age). The hormonal induction of puberty, especially with the use of progestagens, has been developed in heifers as an alternative tool to improve reproductive efficiency in herds, increasing the amount of pregnant heifers in breeding season
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The aim of the present study was to examine tapping synchronization in children with and without Developmental Coordination Disorder (DCD). Participants were 27 children from which 13 diagnosed with motor difficulties composed the DCD group and 14 children with typical development (TD) the comparison group. The experimental task consisted of performing 25 continuous tapping on a surface of an electronic drum with the preferred hand. Participants were required to tap in synchrony with an auditory bip generated by customized software. Three interval values the tapping task were tested: 470 ms, 1000 ms, 1530 ms. The dependent variables were constant error (CE) and absolute error (AE) and standard deviation of absolute error (SD of AE). The ANOVA 2 x 3 x 3 (Group X Age x Interval) with repeated measures in the last factor for the CE indicated significant interaction among Group X Age X Interval. For the AE and SD of AE the ANOVAs yielded significant main effect of Interval and a significant interaction between Group X Interval. The results of the present study indicated that children with DCD were less accurate and more variable in the tapping synchronization than children with TD. Differences in performance between DCD and children with TD become larger as the interval of the auditory signal increases.
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In the last years Brazil has achieved a leading position in worldwide cattle breeding. This country is consolidating the practice of an intensive and technical level cattle breeding, due to greater emphasis on reproductive efficiency and genetic improvement. The attention given to reproductive efficiency became to enhance the genetic improvement process, by exploiting the full reproductive potential of the animals. The biotechniques applied to reproduction arised to expand the reproductive potential for greater economic return. Are the most important reproductive biotechniques the FTAI and in vivo and in vitro embryo production for embryo transfer. Different hormonal treatments are consolidating to interfere with normal physiology in order to achieve the desired goals. The FTAI works to increase the reproductive rates of cattle through pre-booked artificial insemination in all the females in reproduction, without the need for estrous detection. The in vivo and in vitro embryo production aims to distribute the genetics of males and females genetically improved by transferring their embryos to genetically inferior females. Superovulation treatments designed to prevent the mechanism of dominance, which results in many follicles ovulating simultaneously for in vivo embryo production. To the in vitro embryo production, the technique of ovarian puncture guided by transvaginal ultrasound allows to aspirate a number of quality oocytes. The application of biotech is based on knowledge of the female and ovarian reproductive physiology and knowledge of their acting in different breeds and environments.
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It is known that exposure to substances in the environment can contribute to various reproductive disorders, especially if such exposure occurs during critical periods of development such as the intra-uterine and postnatal. The female reproductive system may be the target of androgens, both as a result of exposure to environmental chemicals, or by pathological conditions (polycystic ovary syndrome or congenital adrenal hyperplasia).Usually, little attention is given off in relation to the study of androgenic effects in the female reproductive axis. This study aims to evaluate the effects of exposure to androgens on the development, structure and reproductive function in rats whose mothers were exposed to testosterone propionate from gestational day 12 (DG12) after weaning - postnatal day 21 (DPN21) . For this purpose, pregnancy rats were divided into four groups: a control group that received corn oil (vehicle) and three groups receiving testosterone propionate in doses of 0.05 mg / kg / day, 0.1 mg / kg / day and 0.2 mg / kg / day, all under the same experimental conditions. The possible effects of exposure were assessed using reproductive parameters, such as a measure of anogenital distance, count areolas / nipples, age at vaginal opening and first estrus (puberty indicative installation), weight and histological evaluation of the reproductive organs ( uterus and ovaries), weight of the kidneys, liver and pituitary hormone levels, regularity of the estrous cycle, sexual behavior and fertility. Such analysis is important in understanding the effects of androgen exposure on the female genital system, especially on the reproductive potential, and processes that may involve morphofunctional changes. In these experimental conditions, it is concluded that treatment with PT caused reduction in body weight and initial masculinization in females without cubs, however, commit further sexual development
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Pós-graduação em Medicina Veterinária - FCAV
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Pós-graduação em Medicina Veterinária - FCAV
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Pós-graduação em Cirurgia Veterinária - FCAV