1000 resultados para embryo recovery


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The objective of the present study was to evaluate the effects of double uterine flushing on the recovery of embryos/ova in cattle. Two hundred and ten embryo recovery procedures were conducted using a double uterine flushing method, and the results were compared with 432 conventional single-flushing procedures. Cyclic Limousin (n = 403) and Guzera (n = 239) donor cows received an intravaginal progesterone releasing device and 2 mg of estradiol benzoate on Day 0. Between Days 5 and 9, donors received decreasing doses of FSH, which ranged from 200 to 300 IU (Bos indicus) and 300 to 500 IU (Bos taut-us). on the afternoon of Day 7, donors received an injection of 500 mu g cloprostenol and progesterone implants were removed 12 It later (morning of Day 8). Artificial insemination was performed between 14 and 26 h after first detection of behavioral estrus. Cows were randomly assigned to have embryos recovered by a double-flushing method (n = 210) or the conventional single-flushing procedure (n = 432). For the double-flushing procedure, after first flushing the whole uterus with 1 L of Dubelco's Phosphate Buffered Saline (DPBS), a Foley catheter was positioned in the uterine body to permit refilling of the uterus with fresh DPBS (80-150 mL). The catheter was closed with the plunger of a disposable 5 mL syringe, and the donors were allowed to rest in a holding area for 30 min. Thereafter, a second flush was performed to recover the solution remaining in the uterus. Animals from the control group were subjected to a single uterine flush. From 2 10 double-flushing procedures, 1409 viable embryos were recovered. In comparison, from 432 cows receiving the single-flushing procedure, 1993 embryos were recovered. Double flushing increased (P < 0.05) the number of embryos recovered per procedure compared to single flushing (6.7 +/- 0.4 versus 4.6 +/- 0.2, respectively; mean +/- S.E.M.). When double flushing was performed, average recovered embryos/ova increased (P < 0.05) from 8.3 +/- 0.4 to 12.7 +/- 0.7 in Limousin and from 7.9 to 11.5 in Guzera. Also, utilization of double flushing increased (P < 0.05) the number of viable embryos from 4.7 +/- 0.3 to 6.9 +/- 0.5 in Limousin and from 4.5 +/- 0.4 to 6.4 +/- 0.7 in Guzera. Mean total embryos/ova was similar (P > 0.05) between the control group and after the first uterine flushing in the double-flushing group; therefore, both flushings were conducted efficiently. In conclusion, double uterine flushing increased embryo recovery in cattle. (C) 2004 Elsevier B.V. All rights reserved.

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The aim of this study was to evaluate the effect of delaying ovulation subsequent to superstimulation of follicular growth in beef cows (Bos indicus) on embryo recovery rates and the capacity of embryos to establish pregnancies. Ovulation was delayed by three treatments using either progesterone (CIDR-B®) or a GnRH agonist (deslorelin). Multiparous Nelore cows (n = 24) received three of four superstimulation treatments in an incomplete block design (n = 18 per group). Cows in Groups CTRL, P48 and P60 were treated with a CIDR-B device plus estradiol benzoate (EB, 4 mg, i.m.) on Day-5, while cows in Group D60 were implanted with deslorelin on Day-7. Cows were superstimulated with FSH (Folltropin-V® 200 mg), from Day 0 to 3, using twice daily injections in decreasing amounts. All cows were treated with a luteolytic dose of prostaglandin on Day 2 (08:00 h). CIDR-B devices were removed as follows: Group CTRL, Day 2 (20:00 h); Group P48, Day 4 (08:00 h); Group P60, Day 4 (20:00 h). Cows in Group CTRL were inseminated at 10, 20 and 30 h after first detected estrus. Ovulation was induced for cows in Group P48 (Day 4, 08:00 h) and Groups P60 and D60 (Day 4, 20:00 h) by injection of LH (Lutropin®, 25 mg, i.m.), and these cows were inseminated 10 and 20 h after treatment with LH. Embryos were recovered on Days 11 or 12, graded and transferred to synchronized recipients. Pregnancies were determined by ultrasonography around Day 100. Data were analyzed by mixed procedure, Kruskal-Wallis and Chi-square tests. The number of ova/embryos, transferable embryos (mean ± S.E.M.) and pregnancy rates (%) were as follows, respectively: Group CTRL (10.8 ± 1.8, 6.1 ± 1.3, 51.5), P48 (12.6 ± 1.9, 7.1 ± 1.0, 52.3), P60 (10.5 ± 1.6, 5.7 ± 1.3, 40.0) and D60 (10.3 ± 1.7, 5.0 ± 1.2, 50.0). There were no significant differences among the groups (P > 0.05). It was concluded that fixed time AI in association with induced ovulation did not influence embryo recovery. Furthermore, pregnancy rates in embryos recovered from cows with delayed ovulation were similar to those in embryos obtained from cows treated with a conventional superstimulation protocol. © 2002 Elsevier B.V. All rights reserved.

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Oxytocin has been used to promote cervical dilation with the objective to access uterus both in artificial insemination and transcervical embryo recovery in sheep and goats. The objective of this study was to test the effect of two routes of oxytocin administration on nonsurgical embryo recovery efficiency in Santa Inês ewes after induction of synchronous estrus. Results of this study showed that nonsurgical transcervical embryo recovery can be efficiently done in some ewes; a higher number of individuals is needed to conclude that transcervical embryo recovery can be efficiently done in ewes and surgery embryo collections can be avoided in near to 60% of pluriparous Santa Inês ewes; and that the route of oxytocin administration did not affect the parameters evaluated.

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Equine pituitary extract (EPE), has been reported to induce multiple ovulation in mares, however ovulation rates are poor in comparison to those obtained in other species. Attempts to improve the effectiveness of EPE for induction of superovulation in cyclic mares has focused on daily frequency of EPE treatment. Two experiments were performed to compare the ovarian response of cyclic mares given EPE once or twice-daily. Mares were assigned to one of two treatment groups 6 to 8 days after ovulation: prostaglandin was given once and EPE (25 mg) was given once daily (Group 1) or twice daily (Group 2). In Experiment 1, more (P < 0.05) follicles 35 mm were detected in mares treated with EPE twice daily (6.1 +/- 3.1) than in mares treated once a daily (2.0 +/- 0.6). In a second experiment, the embryo recovery rates of mares given the two EPE protocols used in Experiment 1 were compared. The number of ovulations per mare was higher (P < 0.05) for mares treated twice-daily (7.1 +/- 5.1, range 3 to 18) than for mares treated once daily (2.4 +/- 1.8, range 1 to 6). The number of embryos produced per mare was higher (P < 0.05) in mares in Group 2 (3.5) than in Group 1 (1.6).Although it is not clear whether the increased ovulation rate is due specifically to dose or frequency, twice-daily administration of a high dose of EPE significantly improved follicular development, ovulation and embryo recovery over the standard treatment of once-daily injection. (C) 2001 by Elsevier B.V.

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The use of equine FSH (eFSH) for inducing follicular development and ovulation in transitional mares was evaluated. Twenty-seven mares, from 3 to 15 years of age, were examined during the months of August and September 2004, in Brazil. Ultrasound evaluations were performed during 2 weeks before the start of the experiment to confirm transitional characteristics (no follicles larger than 25 mm and no corpus luteum [CL] present). After this period, as the mares obtained a follicle of at least 25 mm, they were assigned to one of two groups: (1) control group, untreated; (2) treated with 12.5 mg eFSH, 2 times per day, until at least half of all follicles larger than 30 mm had reached 35 mm. Follicular activity of all mares was monitored. When most of the follicles from treated mares and a single follicle from control mares acquired a preovulatory size ( : 35 mm), 2,500 IU human chorionic gonadotropin (hCG) was administered IV to induce ovulation. After hCG administration, the mares were inseminated with fresh semen every other day until ovulation. Ultrasound examinations continued until detection of the last ovulation, and embryo recovery was performed 7 to 8 days after ovulation. The mares of the treated group reached the first preovulatoiy follicle (4.1 +/- 1.0 vs 14.9 +/- 10.8 days) and ovulated before untreated mares (6.6 +/- 1.2 vs 18.0 +/- 11.1 days; P <.05). All mares were treated with prostaglandin F-2 alpha (PGF(2 alpha)), on the day of embryo flushing. Three superovulated mares did not cycle immediately after PGF(2 alpha), treatment, and consequently had a longer interovulatory interval (22.4 vs 10.9 days, P < 0.05). The mean period of treatment was 4.79 1.07 days and 85.71% of mares had multiple ovulations. The number of ovulations (5.6 vs 1.0) and embryos (2.0 vs 0.7) per mare were higher (P < 0.05) for treated mares than control mares. In conclusion, treatment with eFSH was effective in hastening the onset of the breeding season, inducing multiple ovulations, and increasing embryo production in transitional mares. This is the first report showing the use of FSH treatment to recover embryos from the first cycle of the year.

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This study was designed to compare embryo recovery rates and pregnancy rates of athletic and breeding Quarter Horse mares in a tropical warm climate. Thirty-nine barrel racing mares in training and 135 breeding mares as control donors were included. During the training period, the ambient temperature ranged from 31 degrees C to 36 degrees C and the average humidity from 70% to 90%. After the detection of a 35-mm follicle by ultrasound, ovulation was induced with 1 mg of deslorelin acetate (i.m), and insemination was performed 24 hours later with cooled and fresh semen from different fertile stallions. Embryos were collected on day 8 postovulation. The body temperature (rectal) was evaluated from eight athletic donor mares randomly selected from the same studied group. A total of 138 and 657 embryo collections were carried out on training and breeding mares, respectively, with a total of 105 (76%) and 466 (71%) embryos collected (P > .05). Similarly, no differences (P > .05) were observed for the pregnancy rates on day 15 (82/105, 78% vs. 370/466,79%), and day 40 (73/105, 69% vs. 328/466,70%) between the training and breeding donor mares. Just after training, the body temperature increased to an average of 39.4 degrees C and the respiratory rate from 14.5 to 35.3 breaths per minute. The results of the present study showed that embryo production from appropriately trained donor mares in good condition were similar to non-athletic broodmares. (C) 2011 Published by Elsevier B.V.

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The objective was to evaluate the effects of giving prostaglandin F(2 alpha) (PGF) to donor mares 48 h prior to embryo collection. Non-lactating donor mares (n = 20 estrous cycles in 10 mares), ranging from 2.5 to 10 y of age and 400 to 500 kg of body weight were used from September 2004 to February 2005 in the southern hemisphere (Brazil). Donor mares were randomly assigned in a cross-over design study. During a Treated cycle, 7.5 mg PGF was given 48 h prior to embryo collection, whereas in the Control cycle, 7.5 mg PGF was given at embryo collection. In Treated Cycles, serum progesterone concentrations decreased between the day of PGF treatment and the day of embryo collection (13.9 +/- 5.4 and 0.5 +/- 0.3 ng/mL, respectively; P < 0.05). In Treated versus Control cycles, the interovulatory interval was shorter (14.9 +/- 0.9 vs 17.5 +/- 1.1 d, P < 0.05). However, there was no significant difference between these groups for the interval from PGF to ovulation (average, 9.8 d), embryo recovery rate (average, 75%), embryo quality, uterine protein concentration, and pregnancy rate in recipient mares (average, 87% at 15 d after ovulation, with no pregnancy loss detected by 60 d). In conclusion, giving donor mares PGF 48 h prior to embryo collection reduced the average interovulatory interval by approximately 2.5 d, thereby potentially increasing the numbers of embryos that could be collected during a breeding season, with no deleterious effects on embryo recovery rate, embryo quality, or pregnancy rate in recipient mares. (c) 2011 Elsevier B.V. All rights reserved.

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A implementação de estratégias visando à conservação de espécies medicinais apresenta grande importância, tanto do ponto de vista ecológico quanto econômico. Petiveria alliacea L., espécie da família Phytolacaceae, conhecida como guiné, erva-de alho, erva-tipi ou amansa-senhor, pode ser encontrada desde a América Central até a América do Sul. Esta espécie possui ampla utilização medicinal, devido à presença, em sua composição, de vários polissulfetos, como o DTS (dibenziltrissulfeto), com propriedades antifúngica, antineoplásica e imunomodulatória, entre outras. O objetivo deste trabalho foi a conservação in vitro de germoplasma de Petiveria alliacea obtido de diferentes populações ocorrentes no Rio de Janeiro, através de métodos baseados em cultura de tecidos e criopreservação. Plantas obtidas através da germinação in vitro foram utilizadas como matrizes para a micropropagação através da multiplicação de meristemas pré-existentes em meio MS sem reguladores de crescimento, e embriões somáticos foram obtidos de forma direta a partir da cultura de explantes foliares das linhagens estudadas (Magé MG; Marechal Hermes MH; Niterói NT; Vila Isabel VI e Planta envasada AL), em presença de PIC (20μM) e 2,4D (22,6 μM), após 60 dias de cultivo. Os ápices caulinares das plantas micropropagadas e os embriões somáticos obtidos foram submetidos à criopreservação através de técnicas de vitrificação, encapsulamento-vitrificação e encapsulamento-desidratação, com a avaliação da pré-cultura e de soluções crioprotetoras (PVS2 e PVS3), em diferentes concentrações e tempos de exposição. Os resultados mostraram uma taxa de 100% de germinação in vitro. As condições para a pré-cultura de ápices foram padronizadas, entretanto não foram obtidos resultados positivos após o descongelamento. Por outro lado, os embriões da linhagem AL (linhagem embriogênica em cultura há 24 meses) mantiveram sua capacidade multiplicativa (100%) (embriogênese secundária) quando submetidos à desidratação em sacarose (0,5M) e expostos às soluções de vitrificação PVS2 e PVS3 pelos menores tempos (15 e 30 minutos). Os diferentes meios de recuperação apresentaram respostas variáveis em relação à capacidade multiplicativa dos embriões. O encapsulamento/vitrificação foi a técnica que promoveu maior tolerância dos embriões ao congelamento. A recuperação dos embriões através de multiplicação após a criopreservação abre uma perspectiva de conservação de genótipos com alta produção de polissulfetos, de interesse para a indústria farmacêutica

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Le développement et la survie de l’embryon dépendent des nutriments fournis par les sécrétions utérines. Les objectifs de cette étude étaient de déterminer l’effet de la surovulation (SOV) sur la bactériologie et cytologie utérine et sur les paramètres biochimiques utérin et sérique et leurs effets sur le nombre d’embryons transférables (ET). Deux groupes de vaches Holstein (groupe I, non lactante, n=7 et groupe II, lactante, n=28) ont été respectivement induites en chaleur ou surovulées et ensuite inséminées. Au jour 7 du cycle œstral (J7) et lors du jour de la récolte (JR), un prélèvement individuel de sang et de liquide de lavage utérin a été fait pour l’analyse du statut bactériologique et cytologique de l’utérus et la mesure de la concentration de plusieurs paramètres biochimiques présélectionnés. Les embryons récoltés ont été évalués selon les critères de l’IETS. La SOV a donnée une moyenne de 7.39 ± 6.22 ovocytes/embryons dont 3.32 ± 4.81 ET. Il n’y avait pas de variation significative de la bactériologie et cytologie utérine des deux groupes entre J7 et JR. La concentration sérique de l’urée (P=0.0001), d’E2 (P=0.006); la concentration utérine du Glu (P=0.002), de Ck (p=0.0007), de LDH (P <0.0001), de PT (P=0.004), de P4 (P=0.008), de PGFM (P<0.0001) du groupe I et la concentration sérique de P4 (P<0.0001), de PGFM (P<0.0001); la concentration utérine de LDH (P=0.002), de PGFM (P<0.0001) du groupe II ont été significativement élevées à JR qu’à J7. La concentration utérine et sérique de l’urée (P<0.0001 et P<0.0001), de LDH (P<0.0001 et P=0.008), la concentration sérique de P4 (P=0.0002) et la concentration utérine de PT (P=0.0003) à JR du groupe II étaient différente du groupe I. Il n’y avait pas d’association entre la bactériologie et cytologie utérine et le nombre d’ET. Cependant, le nombre d’ET a été positivement corrélé avec la concentration sérique d’IGF-1 à J7 (r=0.45; P=0.001) et la concentration sérique de P4 à JR (r=0.43; P<0.05) et négativement corrélé avec la concentration utérine et sérique de PGFM à la fois à J7 (r=-0.54; P<0.005 et r=-0.67; P<0.001) et à JR (r=-0.48; P<0.01 et r=-0.57; P<0.002). Ces résultats suggèrent que la SOV induit des changements au niveau sérique et utérin qui affectent le nombre d’ET récoltés.

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The mechanisms that reduce the viability of plant somatic embryos following cryopreservation are not known. The objective of the present study was to evaluate the sensitivity of cocoa (Theobroma cacao L.) somatic embryos at different stages of an encapsulation-dehydration protocol using stress-related volatile hydrocarbons as markers of injury and recovery. The plant stress hormone ethylene and volatile hydrocarbons derived from hydroxyl radicals (methane) and lipid peroxidation (ethane) were determined using gas chromatography headspace analysis. Ethylene and methane were the only volatiles detected, with both being produced after each step of the cryogenic protocol. Ethylene production was significantly reduced following exposure to liquid nitrogen, but then increased in parallel with embryo recovery. In contrast, the production of methane was cyclic during recovery, with the first cycle occurring earlier for embryos recovered from liquid nitrogen and desiccation than those recovered from earlier steps in the protocol. These results suggest that loss of somatic embryo viability during cryopreservation may be related to the oxidative status of the tissue, and its capacity to produce ethylene. This study has demonstrated that headspace volatile analysis provides a robust non-destructive analytical approach for assessing the survival and recovery of plant somatic embryos following cryopreservation.

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Equine pituitary extract (EPE) has been reported to induce heightened follicular development in mares, but the response is inconsistent and lower than results obtained in ruminants undergoing standard superovulatory protocols. Three separate experiments were conducted to improve the ovarian response to EPE by evaluating: (1) effect of increasing the frequency or dose of EPE treatment; (2) use of a potent gonadotropin-releasing hormone agonist (GnRH-a) prior to EPE stimulation (3) administration of EPE twice daily in successively decreasing doses. In the first experiment. 50 mares were randomly assigned to one of four treatment groups. Mares received (1) 25 mg EPE once daily; (2) 50 mg EPE once daily (3) 12.5 mg EPE twice daily; or (4) 25 mg EPE twice daily. All mares began EPE treatment 5 days after detection of ovulation and received a single dose of cloprostenol sodium 7 days postovulation. EPE was discontinued once half of a cohort of follicles reached a diameter of greater than or equal to35 mm and hCG was administered. Mares receiving 50 mg of EPE once daily developed a greater number (P = 0.008) of preovulatory follicles than the remaining groups of EPE-treated mares, and more (P = 0.06) ovulations were detected for mares receiving 25 mg EPE twice daily compared to those receiving either 25 mg EPE once daily and 12.5 mg EPE twice daily. Embryo recovery per mare was greater (P = 0.05) in the mares that received 12.5 mg EPE twice daily than those that received 25 mg EPE once daily. In Experiment 2, 20 randomly selected mares received either 25 mg EPE twice daily beginning 5 days after a spontaneous ovulation. or two doses of a GnRH-a agonist upon detection of a follicle greater than or equal to35 mm and 25 mg EPE twice daily beginning 5 days after ovulation. Twenty-four hours after administration of hCG, oocytes were recovered by transvaginal aspiration from all follicles greater than or equal to35 mm. No differences were observed between groups in the numbers of preovulatory follicles generated (P = 0.54) and oocytes recovered (P = 0.40) per mare. In Experiment 3, 18 mares were randomly assigned to one of two treatment groups. Then, 6-11 days after ovulation, mares were administered a dose of PGF(2gamma) and concomitantly began twice-daily treatments with EPE given in successively declining doses, or a dose of PGF(2alpha), but no EPE treatment. Mares administered EPE developed a higher (P = 0.0004) number of follicles :35 mm, experienced more (P = 0.02) ovulations, and yielded a greater (P = 0.0006) number of embryos than untreated mares. In summary, doubling the dose of EPE generated a greater ovarian response, while increasing the frequency of treatment, but not necessarily the dose. improved embryo collection. Additionally, pretreatment with a GnRH-a prior to ovarian stimulation did not enhance the response to EPE or oocyte recovery rates. (C) 2002 Elsevier B.V. All rights reserved.

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