977 resultados para Follicular atresia


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The objective was to determine the relationship among the diameter of ovarian follicles, ovulation rate, and gene expression of the LH receptor (LHR) in Nelore cattle. In Experiment 1, ovulation was synchronized in 53 Nelore cows. Three days after ovulation, ovaries were assessed with ultrasonography, all cows were given 6.25 mg LH im, and they were allocated into three groups, according to diameter of their largest ovarian follicle: G1 (7.0-8.0 mm); G2 (8.1-9.0 mm); and G3 (9.1-10.0 mm). For these three groups, ovulation rates were 9, 36, and 90%, respectively, (P < 0.03; each rate differed significantly from the other two). In Experiment 2, granulosa and theca cells were subjected to total RNA extraction, and gene expression of the LHR was determined by RT-PCR. Follicles were allocated in three groups based on their diameter (similar to the Experiment 1), which were denoted Groups A, B, and C. Expression of the LHR gene in granulosa cells was lower in Group A than Group C (P < 0.05). However, there were no significant differences among groups in expression of the LHR gene in theca cells. We concluded that ovulatory capacity in Nelore cattle was related to increased follicular diameter and expression of the LHR gene in granulosa cells. (C) 2012 Elsevier B.V. All rights reserved.

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This study examined the effect of treating mares with equine pituitary extract (EPE) alone or in combination with hCG on the recovery rate of immature follicles by transvaginal follicular aspiration (ovum pick-up; OPU). Ten normally cycling crossbred mares aged 3-15 years and weighing 350-400 kg were subjected to each of three treatments in a random sequence with each exposure to a new treatment separated by a rest cycle during which a spontaneous ovulation occurred. The treatments were (1) superovulated with 25 mg EPE and treated with 2500 IU hCG, (2) superovulation with 25 mg EPE, and (3) control (no exogenous treatment). Treatments 7 days after spontaneous ovulation; and all the follicles > 10 mm were aspirated 24 h after the largest follicle achieved a diameter of 27-30 mm for control group, and most follicles reached 22-27 mm for the EPE alone treatment. To the group EPE+hCG, when the follicles reached 22-27 mm, hCG was administered, 24 h before OPU. Superovulation increased the number of follicles available for aspiration. The total number of follicles available for aspiration was 61 in the EPE/hCG group. 63 in the EPE group and 42 in the control. The proportion of follicles aspirated varied from 63.5% to 73.8%. Oocyte recovery rate ranged from 15.0% to 16.7% and the proportion of mares that yielded at least one oocyte was 70% (7/10) in the EPE/hCG, 60% (6/10) in the EPE alone and 50% (5/10) in control group. The EPE/hCG treatment had a higher proportion of follicles with expanded granulose cells (64.4%) than the control (3.3%: p < 0.05) and the EPE treatment (25.0%). The intervals from spontaneous ovulation to aspiration were similar for all treatments (11-12 days). However, superovulatory treatment significantly increased the aspiration to ovulation interval from 15 +/- 4 days for control to 27 +/- 15 days for EPE (p < 0.05) and to 23 +/- 13 days for EPE/hCG treatment with commensurate increases in the time between spontaneous ovulations. (c) 2008 Elsevier B.V. All rights reserved.

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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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A finalidade deste artigo é avaliar o efeito da expansão rápida da maxila (ERM) no padrão respiratório. Por intermédio de um caso clínico, será relatado como indivíduos com atresia da maxila e problemas respiratórios podem se beneficiar com a expansão rápida da maxila. Outro aspecto que deve-se salientar é como profissionais da área da saúde, principalmente ortodontistas e otorrinolaringologistas, têm à sua disposição exames complementares para o diagnóstico do paciente com Respiração Bucal

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OBJETIVO: na presente pesquisa utilizou-se o aparelho Hyrax tendo como objetivo avaliar as alterações transversais e verticais da maxila. Foram selecionados 20 pacientes de ambos os gêneros, entre 7 e 11 anos de idade, que apresentavam mordida cruzada posterior uni ou bilateral. METODOLOGIA: foram realizadas telerradiografias em norma frontal (PA) antes e após a expansão. A fim de evitar que a falta de padronização dessas radiografias pudesse influenciar nos resultados, idealizou-se um método de padronização para tais radiografias. RESULTADOS E CONCLUSÕES: os resultados mostraram que a correção da mordida cruzada posterior com o aparelho Hyrax, que ocorreu em todos os casos, foi em função tanto da abertura da sutura palatina mediana como também da inclinação dos molares. A medida JgE-JgD relacionada com a expansão maxilar aumentou significantemente em todos os casos tratados. Nas avaliações dentárias, as medidas verticais não apresentaram diferenças significantes, ao contrário das medidas transversais (FTE-FTD; FBE-FBD; LO.BTE; LO.BTD; BTE.BTD). A largura da cavidade nasal também aumentou significantemente (CNE-CND). O método de padronização proposto permite, portanto, utilizar as medidas que avaliam a expansão rápida da maxila, através das radiografias póstero-anteriores, com segurança, também no sentido vertical.

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INTRODUÇÃO: o problema transversal em Ortodontia pode ser de origem dentária, esquelética ou uma combinação de ambas e pode ser tratado de várias maneiras de acordo com o tipo de tecido envolvido e o arco dentário acometido. em se tratando de um problema esquelético e maxilar, o ortodontista poderá lançar mão da disjunção ortopédica, dependendo da idade óssea, obtendo uma correção da atresia, um alinhamento dentário espontâneo resultante do aumento no perímetro do arco e um sorriso mais amplo, beneficiando esteticamente o paciente. Porém, este tratamento de disjunção mandibular se torna inviável, já que este osso tem sua sutura fusionada precocemente. A expansão neste caso é alveolar e sua estabilidade é questionada. OBJETIVO: relatar um caso clínico, apresentando uma nova alternativa de tratamento para o apinhamento inferior: a Distração Osteogênica da Sínfise Mandibular (DOSM). Neste procedimento, é feita uma osteotomia sagital na sínfise, criando-se uma sutura artificial para que uma separação óssea seja conseguida, utilizando uma mecânica com aparelho disjuntor de Hyrax modificado. RESULTADOS: os resultados do tratamento apresentado mostram uma melhora na forma do arco, diminuição do corredor bucal, correção do apinhamento dentário e também uma estabilidade do tratamento, sem dano aos tecidos adjacentes. Neste caso clínico, a DOSM se mostrou uma excelente opção de tratamento.

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The objective of this study was to evaluate protocols for synchronizing ovulation in beef cattle. In Experiment 1, Nelore cows (Bos indicus) at random stages of the estrous cycle were assigned to 1 of the following treatments: Group GP controls (nonlactating, n=7) received GnRH agonist (Day 0) and PGF2 alpha (Day 7); while Groups GPG (nonlactating, n=8) and GPG-L (lactating, n=9) cows were given GnRH (Day 0), PGF2a (Day 7) and GnRH again (Day 8, 30 h after PGF2 alpha). A new follicular wave was observed 1.79+/-0.34 d after GnRH in 19/24 cows. After PGF2a, ovulation occurred in 19/24 cows (6/7 GP, 6/8 GPG, 7/9 GPG-L). Most cows (83.3%) exhibited a dominant follicle just before PGF2a, and 17/19 ovulatory follicles were from a new follicular wave. There was a more precise synchrony of ovulation (within 12 h) in cows that received a second dose of GnRH (GPG and GPG-L) than controls (GP, ovulation within 48 h; P<0.01). In Experiment 2, lactating Nelore cows with a visible corpus luteum (CL) by ultrasonography were allocated to 2 treatments: Group GPE (n=10) received GnRH agonist (Day 0), PGF2a (Day 7) and estradiol benzoate (EB; Day 8, 24 h after PGF2 alpha); while Group EPE (n=11), received EB (Day 0), PGF2a (Day 9) and EB (Day 10, 24 h after PGF2a). Emergence of a new follicular wave was observed 1.6+/-0.31 d after GnRH (Group GPE). After EB injection (Day 8) ovulation was observed at 45.38+/-2.03 h in 7/10 cows within 12 h. In Group EPE the emergence of a new follicular wave was observed later (4.36+/-0.31 d) than in Group GEP (1.6+/-0.31 d; P<0.001). After the second EB injection (Day 10) ovulation was observed at 44.16+/-2.21 h within 12 (7/11 cows) or 18 h (8/11 cows). All 3 treatments were effective in synchronizing ovulation in beef cows. However, GPE and, particularly EPE treatments offer a promising alternative to the GPG protocol in timed artificial insemination of beef cattle, due to the low cost of EB compared with GnRH agonists. (C) 2000 by Elsevier B.V.

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Compared to Bos taurus breeds, Bos indices breeds of cattle present several differences in reproductive physiology. Follicular diameter at deviation and at the time of ovulatory capability are smaller in B. indicus breeds. Furthermore, B. indicus breeds have a greater sensitivity to gonadotropins, a shorter duration of estrus, and more often express estrus during the night. These differences must be considered when setting up embryo transfer programs for B. indicus cattle. In recent studies, we evaluated follicular dynamics and superovulatory responses in B. indicus donors with the objective of implementing fixed-time AI protocols in superstimulated donors. Protocols using estradiol and progesterone/progestrogen releasing devices to control follicular wave emergence were as efficacious as in B. taurus cattle, allowing the initiation of superstimulatory treatments (with lower dosages of FSH than in B. taurus donors) at a self-appointed time. Furthermore, results presented herein indicate that delaying the removal of progesterone/progestogen-releasing devices, combined with the administration of GnRH or pLH 12 h after the last FSH injection, results in synchronous ovulations, permitting the application of fixed-time AI of donors without the necessity of estrus detection and without compromising the results. (c) 2005 Elsevier B.V. All rights reserved.

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In the present short review superovulation treatments commonly used for Bos taurus and/or Bos indicus will be addressed with emphasis in recent superstimulation protocols associated with pharmacological manipulation of the follicular dynamics to improve donor management and potentially embryo yield. Results obtained after superovulation treatments in which the time of LH surge is selectively delayed as an attempt to improve embryo yield are presented and discussed. (C) 2001 by Elsevier B.V.