RESUMEN
PURPOSE: Gastroenteropancreatic neuroendocrine tumors are a heterogeneous group of low incidence neoplasms characterized by a low proliferative activity and slow growth. Their response to targeted therapies is heterogeneous and often does not lead to tumor shrinkage. Thus, evaluation of the therapeutic response should differ from other kind of tumors. METHODS: To answer relevant questions about which techniques are best in the assessment of progression or treatment response a RAND/UCLA-based consensus process was implemented. Relevant clinical questions were listed followed by a systematic search of the literature. The expert panel answered all questions with recommendations, combining available evidence and expert opinion. Recommendations were validated through a questionnaire and a participatory meeting. RESULTS: Expert recommendations regarding imaging tools for tumor assessment and evaluation of progression were agreed upon. Available imaging techniques were reviewed and recommendations for best patient monitoring practice and the best way to evaluate treatment response were formulated.
Asunto(s)
Neoplasias Intestinales/diagnóstico por imagen , Neoplasias Intestinales/patología , Tumores Neuroendocrinos/diagnóstico por imagen , Tumores Neuroendocrinos/patología , Neoplasias Pancreáticas/diagnóstico por imagen , Neoplasias Pancreáticas/patología , Neoplasias Gástricas/diagnóstico por imagen , Neoplasias Gástricas/patología , Diagnóstico por Imagen/métodos , Progresión de la Enfermedad , HumanosRESUMEN
We have already shown that seminal collection method affects seminal plasma composition and sperm quality in Corriedale rams. In this study, we evaluated the effect of seminal plasma collected by electroejaculation or artificial vagina on sperm resistance to cryodamage. Seminal plasma of five rams of the Corriedale breed collected by artificial vagina or electroejaculation was added before freezing to sperm cells collected by the two methods, and post-thaw quality parameters were evaluated. We found that seminal plasma has no effect on sperm resistance to cryodamage. However, we observed significantly higher percentages of sperm with intact and functional plasma membrane, intact acrosome and greater fertilizing potential after thawing in samples obtained by electroejaculation. This study demonstrates that sperm collected by electroejaculation are more resistant to damage caused by cryopreservation than those collected by artificial vagina.
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Criopreservación/veterinaria , Eyaculación/fisiología , Estimulación Eléctrica/métodos , Preservación de Semen/veterinaria , Semen/fisiología , Ovinos/fisiología , Animales , MasculinoRESUMEN
This study was designed to evaluate in suckling early pregnant beef cows with and without eCG-pre-stimulation: (i) the influence of day gestation (from 40 to 101 days) and the consecutive eCG treatments on the follicular growth induced by means of ultrasound-guided transvaginal follicle ablation (FA; all follicles ≥ 5 mm) and the number and quality oocytes recovered by ovum pick-up (OPU) and (ii) the possible effects of repeated hormonal stimulation and FA/OPU on pregnancy outcome. Twelve suckling early pregnant Angus cows (40 days post fixed-time artificial insemination) were randomly assigned to each of two groups (n=6 group(-1)). Group 1 treatments included: FA (Day 0), eCG (1600 IU; Day 1) and OPU (Day 5). Group 2: as cited Group 1 with no eCG treatment. In both groups, OPU was repeated five times (Days 45, 59, 73, 87 and 101 of gestation). The numbers (mean ± SEM) of class II (5-9 mm; 4.3 ± 0.9) and class III (≥10 mm; 2.5 ± 0.4) follicles visualized per cow per OPU session in eCG-treated cows were greater (P<0.05) than for non-treated cows (0.9 ± 0.1 and 0.9 ± 0.1, respectively). In contrast, the number (mean ± SEM) of class I (<5mm) follicles per cow per OPU session was lower for cows with eCG treatment (2.8 ± 0.4) than for non-treated cows (5.7 ± 0.5). The mean number of aspirated follicles was not significantly different (P<0.05) between eCG-treated cows and non-treated cows at 45 and 59 days of pregnancy. However, the mean number of aspirated follicles was greater (P=0.03) in eCG-treated cows than non-treated cows from 73 day of pregnancy onwards. The numbers (mean ± SEM) of recovered oocytes and viable oocytes/cow/session were greater (P<0.05) for eCG-treated cows (2.2 ± 0.2 and 1.6 ± 0.4, respectively) than for non-treated cows (1.0 ± 0.2 and 0.9 ± 0.2, respectively). No donor pregnancies were lost either during or following OPU procedure. We can conclude that (1) eCG-treated pregnant suckled cows can be a source of oocytes for IVF at least to 100 days of gestation and (2) repeated FA/eCG treatment/OPU procedures did not affect the pregnancy outcome.
Asunto(s)
Gonadotropinas Equinas/farmacología , Recuperación del Oocito , Oocitos/efectos de los fármacos , Ovario/efectos de los fármacos , Preñez , Animales , Animales Lactantes , Bovinos , Gonadotropina Coriónica/administración & dosificación , Gonadotropina Coriónica/farmacología , Esquema de Medicación , Femenino , Fármacos para la Fertilidad Femenina/administración & dosificación , Fármacos para la Fertilidad Femenina/farmacología , Edad Gestacional , Gonadotropinas Equinas/administración & dosificación , Recuperación del Oocito/métodos , Oocitos/fisiología , Ovario/fisiología , Inducción de la Ovulación/métodos , Inducción de la Ovulación/veterinaria , Óvulo/efectos de los fármacos , Embarazo , Preñez/efectos de los fármacosRESUMEN
Previous research from our laboratory in beef cattle suggests that the pre-ovulatory follicle size, maturity and subsequent susceptibility to gonadotropin are influenced by the length of progestagen treatment in artificial insemination programme in beef cows. To test this hypothesis, two experiments were conducted. In experiment 1, 35 anoestrous beef cows received an intravaginal sponge containing 200 mg of medroxyprogesterone acetate. The treatment lasted for 7 (n = 12), 8 (n = 11) or 9 (n = 12) days. Half of the animals in each group were injected with 0.7 mg of oestradiol benzoate (EB) at device removal (0 h) and the other half 24 h later. In experiment 2, 38 cycling beef cows were treated with the same protocols as in experiment 1. Ultrasound examinations were performed to determine the follicular diameter at device removal (dominant follicle), interval to ovulation and ovulatory follicle diameter. The dominant follicle of anoestrous cows with progestagen for 7 days (8.4 ± 1.6 mm) resulted smaller (p < 0.05) than the cows treated for 8 (10.5 ± 1.6 mm) and 9 days (10.6 ± 1.2 mm). However, regardless of the length of the treatments, ovulation time after device removal was longer (p < 0.05) when EB was injected 24 h after withdrawal than at 0 h in anoestrous cows (EB0 = 52.7 ± 4.0 h; EB24 = 70.8 ± 6.2 h) and in cyclic cows (EB0 = 50.0 ± 21.0 h; EB24 = 73.0 ± 20.0 h). In anoestrous cows, the treatment with progestagen for 9 days and EB at 24 h increased the diameter of the ovarian follicle (p = 0.033) but did not affect the diameter of the ovulatory follicle in cyclic cows. In conclusion, increasing the length of progestagen treatment for 8 or 9 days compared to 7 days increased the diameter of the dominant follicle, in anoestrous and cyclic beef cows. Oestradiol benzoate administered at device removal resulted in a shorter interval from device removal to ovulation compared with EB injection 24 h after the end of a progestagen treatment.
Asunto(s)
Bovinos/fisiología , Estradiol/análogos & derivados , Sincronización del Estro/métodos , Medroxiprogesterona/farmacología , Animales , Esquema de Medicación , Estradiol/administración & dosificación , Estradiol/farmacología , Femenino , Hormona Luteinizante/sangre , Hormona Luteinizante/metabolismo , Medroxiprogesterona/administración & dosificación , Folículo Ovárico/efectos de los fármacos , Folículo Ovárico/fisiología , Ovulación/fisiologíaRESUMEN
Two experiments were conducted to determine the effect of estradiol benzoate (EB) and intravaginal progestagen treatment on ovarian follicular dynamics and superstimulatory response in eCG-treated llamas. The purpose of Experiment 1 was to evaluate the effect of EB and progestagen treatment starting at different phases of dominant follicle (DF1) development on regression pattern and subsequent follicle wave emergence (WE2) in lactating and non-lactating llamas. Early lactating (n=24, 30+/-4 days postpartum) and non-lactating (n=24) females were assigned in equal numbers (n=8) to one of three groups according to the phase of DF1 (growing, static or regressing) determined by ultrasonography from day -3 to day 0. At day 0, llamas received an intravaginal sponge (MPA, 150 mg) and 5mg of MPA (i.m.). Half of the females (n=4) of each group were injected with 2mg (i.m.) of EB and half were not (control group). A 2 x 2 x 3 (lactational status, EB treatment and follicular phases) factorial design was used. Each sponge was removed 8 days later. Ovaries were monitored from day 0 to day 12. Daily blood samples were taken to determine 17beta-estradiol (E(2)) profiles from day 0 to day 8. The DF1 regression pattern was not affected (P>0.05) by the phase of follicle wave at the start of the treatment or any interactions among main effects. Follicle wave emergence in EB-treated llamas was delayed (P<0.05) by 2.3 days compared with non-treated llamas. Following EB treatment, plasma concentrations of E(2) were greater (P<0.05) from day 1 to day 5 in the treated than in non-treated females, but not from day 6 onward (P>0.05). Experiment 2 was designed to evaluate the effect of this treatment on the ovarian superovulatory response and embryo yield following eCG treatment administered on day of follicular wave emergence as determined in the Experiment 1. The same lactating (n=18, 61+/-4 days postpartum) and non-lactating (n=18) llamas at random stages of follicle wave were treated as those in Experiment 1 and received 1200IU of eCG at the time of WE2 (EB-treated=day 6.5 and non-treated=day 4.5). Llamas were mated 5 days after sponge withdrawal. A second mating was allowed 24h later. Embryos were collected between 7 and 8 days after the first mating and blood samples were taken to determine progesterone (P(4)) concentrations. The mean number of follicles on day of mating and the number of CL on day of embryo collection were not affected by lactational status, EB treatment or their interactions (P>0.05). Ovulation rate and mean (+/-SEM) number of recovered embryos for EB treatment group (67.5% and 2.4+/-0.4) were greater (P<0.05) than for no EB treatment (51.1% and 1.1+/-0.4). Plasma P(4) concentrations and number of CL per llama were correlated (r=0.49; P=0.014). In conclusion, progestagen plus EB treatment facilitates the prediction of the emergence of a new follicular wave approximately 6 days after treatment and resulted in a higher ovulation rate and embryo production in ovarian superstimulated llamas regardless of lactational status.
Asunto(s)
Camélidos del Nuevo Mundo/fisiología , Embrión de Mamíferos , Estradiol/análogos & derivados , Lactancia/fisiología , Progestinas/administración & dosificación , Superovulación/efectos de los fármacos , Administración Intravaginal , Animales , Cruzamiento , Gonadotropina Coriónica/administración & dosificación , Cuerpo Lúteo/efectos de los fármacos , Estradiol/administración & dosificación , Femenino , Caballos , Folículo Ovárico/efectos de los fármacos , Folículo Ovárico/fisiología , Ovulación/efectos de los fármacos , Embarazo , Progesterona/sangre , Recolección de Tejidos y ÓrganosRESUMEN
This study was conducted to investigate in early postpartum suckled beef cows with and without FSH pre-stimulation: (i) the influence of the postpartum period on the number and quality of oocytes recovered by ovum pick-up (OPU), (ii) the overall efficiency of the OPU/IVP embryos from days 30 to 80 postpartum and (iii) if repeated OPU negatively affect fertility following a fixed-time artificial insemination protocol. After parturition suckled Angus cows (n = 30) were divided in three groups (n = 10 group(-1)). All cows were anestrous at the commencement of experimental treatments (30.0 +/- 3.2 days postpartum, mean +/- SD; range 25-34 days). Group 1 treatments included: dominant follicle ablation (DFA), FSH treatment and OPU procedure 5 days after DFA. A total of 9 mg FSH (Ovagen) was administered s.c. once a day over 2 days at equal doses (4.5 + 4.5mg). For fertility test the cows received an intravaginal progesterone treatment from Days 78 to 86 postpartum and were fixed-time artificially inseminated (FTAI) at 56 and 72 h after device removal. Group 2: as cited for Group 1 with no FSH treatment. In both groups, OPU was repeated four times (Days 35, 49, 63 and 77 postpartum) and the collected oocytes classified as viable were in vitro matured, fertilized and presumptive embryos cultured for 8 days. Group 3 (Control FTAI): cows that had not previously aspirations were FTAI as Groups 1 and 2. Pregnancy was diagnosed by means ultrasonography 39 days after FTAI. The numbers (mean +/- SEM) of follicles visible and aspirated at the time of OPU in FSH-treated cows were greater (P < 0.05) than in non-treated cows (10.6 +/- 0.6 and 8.4 +/- 0.4 vs. 8.0 +/- 0.5 and 4.6 +/- 0.3, respectively). Following FSH treatment, the number (mean +/- SEM) of recovered oocytes per cow per OPU session and percentage of viable oocytes were greater in the treated (P < 0.05) than in non-treated animals (3.0 +/- 0.1 and 39.5% vs. 1.5 +/- 0.1 and 30.0%). The cleavage and embryo development rates were similar (P > 0.05) for both groups (14.8 and 6.4% vs. 16.6 and 5.5%). After FTAI the pregnancy rates were not different (P > 0.05) among groups (70, 60 and 90% for Groups 1, 2 and 3, respectively). We can conclude that (1) FSH-treated suckled postpartum cows can be a source of oocytes for in vitro fertilization and (2) repeated DFA/OPU applied during postpartum period did not affect the subsequent fertility following FTAI.
Asunto(s)
Desarrollo Embrionario/fisiología , Fertilidad/fisiología , Inseminación Artificial/veterinaria , Recuperación del Oocito/métodos , Inducción de la Ovulación/métodos , Periodo Posparto , Animales , Biopsia con Aguja Fina , Bovinos , Femenino , Fertilidad/efectos de los fármacos , Hormona Folículo Estimulante/administración & dosificación , Hormona Folículo Estimulante/farmacología , Masculino , Folículo Ovárico/diagnóstico por imagen , Folículo Ovárico/patología , Periodo Posparto/fisiología , Embarazo , Factores de Tiempo , Resultado del Tratamiento , Ultrasonografía , Vagina/diagnóstico por imagenRESUMEN
Synchronization of estrous and fixed-time artificial insemination (FTAI) was conducted during the reproductive season of 2008 (March-April) in a local red deer breeding farm in Argentina. Multiparous suckling hinds (n=38) were artificially inseminated following hormonal treatment (intravaginal sponge containing 100mg of medroxiprogesterone acetate). At the time of sponge removal (day 12) 250 IU of eCG and 500 microg of PGF2alpha were given to each hind. The FTAI was performed at 48-55 h after device removal with cryopreserved semen imported from New Zealand. Rectal-transcervical AI method (similar to that in cattle) was performed and semen was deposited within the uterine body (n=28) or the cervix (n=10). Pregnancy was diagnosed by means of ultrasonography 44 days after FTAI. The overall pregnancy rate was 36.8% (14/38). Percentage of does that became pregnant with intrauterine seminal deposition was 42.9% (12/28) whereas pregnancy rate in the hinds with intracervical AI was 20% (2/10; P=0.27).
Asunto(s)
Ciervos/fisiología , Inseminación Artificial/veterinaria , Preñez/fisiología , Animales , Argentina , Clima , Estro/fisiología , Sincronización del Estro/métodos , Femenino , Inseminación Artificial/métodos , Inseminación Artificial/estadística & datos numéricos , Masculino , Embarazo , Estaciones del Año , Ultrasonografía Prenatal/métodos , Ultrasonografía Prenatal/veterinariaRESUMEN
To evaluate ovarian response in Angus cows previously treated with progesterone (P4), animals were randomly assigned to two groups: T600 group (n=14), 600 mg of P4/day. P4 was injected from days 3 to 7 of the estrous cycle. On day 7, superovulatory treatments began. The control group (n=12) was given vehicle only. The superovulatory treatments in the control group began on days 7-9 of the estrous cycle. The superovulatory total treatment dose of 400mg NIH FSH P1 was given twice a day over a 4-day period. Ultrasonography of the ovaries was conducted 3 days preceding the initiation of superovulatory treatment, every 24h. In both groups, an additional ultrasonographic evaluation was made at 24h after the end of superovulatory treatment. Blood samples were collected 4 days preceding the initiation of superovulatory treatment, every 24h. Additional samples were taken from the P600 group for 12 day after of initiation of superovulatory treatment every 24h, except on the fifth day after the initiation of superovulatory treatment. In the P600 group, P4 concentrations were greater than in the control group (P<0.01) and remained over 1 ng/ml up to day 11 after beginning of superovulatory treatment. The diameter of the dominant follicle was larger in the animals of the control group (P<0.01). Cows of the P600 group had a greater number of Class I (3-4mm) follicles (P<0.01). A significant day and treatment effect (P<0.01) were observed in Class II (5-9 mm) follicles. Effects due to treatment on the number of Class III follicles (P<0.05) were observed. In the P600 group, no estrous post-superovulatory was observed and there were no ovulations that occurred. Conversely, 100% of the cows of the control group showed estrous. In the P600 group, there were a greater number of Class III follicles (P<0.01) and a lesser number of Class II follicles (P<0.05) at 24h after the end of superovulatory. In the control group, 66.7% of the cows responded to superovulatory treatments. In conclusion, the daily administration of 600 mg of P4, from days 3 to 7 of the estrous cycle, produces an increase of plasma concentrations of this hormone from day 4, resulting in changes in follicular dynamics (absence of follicles greater than 10mm of diameter and an increase of the population of Class I follicles). As to the ovarian stimulation using Folltropin V in animals receiving a daily injection of 600 mg of P4 from days 3 to 7 of the estrous cycle, a greater population of follicles>or=10mm developed by 24h after superovulatory treatments were completed.
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Bovinos/fisiología , Ovario/efectos de los fármacos , Progesterona/administración & dosificación , Progesterona/farmacología , Superovulación/efectos de los fármacos , Animales , Esquema de Medicación/veterinaria , Ciclo Estral , Femenino , Progesterona/sangreRESUMEN
Two multiple ovulation and embryo transfer (MOET) programs with fresh, frozen and vitrified red deer embryos were carried out during the reproductive season of 2005 and 2006 in a local breeding farm in Argentina. Multiparous (n=10 and 9, respectively) weaned hinds were used as donors for each year. The estrous synchronization treatment of donors and recipients consisted of inserting an ovine intravaginal sponge containing medroxiprogesterone acetate (MAP) for 12 days. Superovulation was conducted with a total dose of 180 mg of NIH-FSH-P1 (Folltropin-V, Bioniche, Belleville, Ontario, Canada), given i.m. in eight decreasing doses every 12h (40, 40; 27, 27; 15, 15; 8, 8 mg), from days 10 to 13. Donor females were mated with one stag of proven fertility. The recovery rate was 84.1% (122/145), obtaining 45.1% (55/122) of transferable embryos, 24.6% (30/122) of degenerated embryos and 30.3% (37/122) of unfertilized oocytes. Pregnancy rates after transfer of fresh, OPS vitrified/warmed and ethylene glycol (EG) frozen/thawed embryos were 64.3% (18/28), 53.3% (8/15) and 70.0% (7/10), respectively. Vitrification and freezing with ethylene glycol procedures constitute an interesting alternative for red deer embryo cryopreservation.
Asunto(s)
Criopreservación/veterinaria , Ciervos/fisiología , Transferencia de Embrión/veterinaria , Embrión de Mamíferos/fisiología , Inducción de la Ovulación/veterinaria , Animales , Transferencia de Embrión/métodos , Sincronización del Estro , Glicol de Etileno , Femenino , Masculino , Inducción de la Ovulación/métodos , Embarazo , SuperovulaciónRESUMEN
UNLABELLED: The present study investigated the effect of estrous cow serum (ECS) during culture of bovine embryos on blastocyst development and survival after cryopreservation by slow freezing or vitrification. Embryos were derived from in vitro maturation (IVM) and in vitro fertilization (IVF) of abbatoir-derived oocytes. At Day 3, embryos were cultured in three different media: Charles Ronsenkrans medium + amino acids (CR1aa; without bovine serum albumin (BSA)) + 5% estrous cow serum (CR1-ECS), CR1aa + 3 mg/mL BSA (CR1-BSA) or CR1aa + 5% ECS + 3 mg/mL BSA (CR1-ECS-BSA). At 7.5 d post-insemination (PI), blastocyst yield and quality were evaluated; blastocysts and expanded blastocysts from each media were cryopreserved by Open Pulled Straw (OPS) vitrification method or slow freezing (1.5 M ethylene glycol, EM). Total blastocyst yield did not differ among CR1-ECS, CR1-BSA and CR1-ECS-BSA (30.9, 33.1 and 32.9%, respectively, P < 0.05). Embryo survival (hatching rate) was higher in vitrified versus slow-frozen embryos (43% versus 12%, respectively, P < 0.01), and in embryos cultured in CR1-BSA (40.3%) compared with those cultured in serum-containing media (CR1-ECS, 21.5% and CR1-ECS-BSA, 19.8%; P < 0.01). IN CONCLUSION: (a) it was possible to produce in vitro bovine embryos in serum-free culture medium without affecting blastocyst yield and quality; (b) serum-free medium produced the best quality embryos (in terms of post-cryopreservation survival); and (c) vitrification yielded the highest post-cryopreservation survival rates, regardless of the presence of serum in the culture medium.
Asunto(s)
Blastocisto , Bovinos/embriología , Criopreservación/veterinaria , Técnicas de Cultivo de Embriones/veterinaria , Estro/sangre , Análisis de Varianza , Animales , Blastocisto/citología , Blastocisto/fisiología , Supervivencia Celular , Criopreservación/métodos , Medios de Cultivo/química , Medio de Cultivo Libre de Suero , Técnicas de Cultivo de Embriones/métodos , Estro/fisiología , Femenino , Fertilización In Vitro/veterinaria , Masculino , Factores de TiempoRESUMEN
To determine a dose of progesterone (P4) that allow ovarian follicular wave control, Aberdeen Angus cows were randomly assigned into four groups: T600 (n=5), 600 mg of P4/day; T400 (n=5), 400 mg of P4/day; T200 (n=4), 200mg of P4/day and Control (n=4) (excipient only). Progesterone was injected from day 3 to 9 of estrous cycle. Ultrasonographies and blood sample collections were performed daily from day 2 to 10 and on day 15 of the estrous cycle. Additionally, an ultrasonographic study was conducted on day 13. Progesterone concentrations were different among all groups (P<0.01). The diameter of the dominant follicle was greater for control than for T200, T400 and T600 groups (P<0.01); there was no difference between T200 and T400 (P>0.05), but they had a greater diameter follicle than the T600 group (P<0.01). The growth rate of the dominant follicle between day 3 and 7 of estrous cycle was greater for control group (1.63+/-0.3 mmday(-1)) than for T200 (0.56+/-0.19 mmday(-1), P<0.05), T400 (0.6+/-0.23 mmday(-1), P<0.05) and T600 (0.11+/-0.13 mmday(-1), P<0.01) groups. The mean number of class I follicles (3-4mm) per day for the entire experimental period was less for the control group than for T200 (P<0.05), T400 and T600 (P<0.01) groups (3.7+/-1.3; 5.3+/-1.3; 6.6+/-1.8 and 8.1+/-1.9, respectively). The mean number for the T200 group was less than for T600 (P<0.05) and similar for T400 and T600 groups (P>0.05). The number of class III follicles was greater for control group than for the other groups (P<0.01). T200 and T400 groups had similar numbers of class III follicles (P>0.05) and both had greater numbers of follicles than the T600 group (P<0.05). The diameter of the corpus luteum of the T600 group (15.8+/-1.6 mm) was less than for control (21.0+/-2.5 mm, P<0.01), T200 (19.3+/-2.7 mm, P<0.01) and T400 (20.0+/-2.2 mm) groups (P<0.05). The mean diameter of corpus luteum of T200 was similar to T400 (P>0.05), but different from the control group (P<0.05). In conclusion, the daily intramuscular administration of 200mg or more of progesterone from day 3 to 9 of the estrous cycle indicates that plasma concentrations of progesterone can be used to modify the pattern of follicular development during the follicular wave. From day 5 of the estrous cycle, progesterone concentrations greater than 15 ng/ml (T600 group: 600 mg/day of progesterone from day 3 to 9 of the estrous cycle) inhibit dominant follicle development, increase the class I follicle populations (3-4 mm) and diminish the development of the corpus luteum.
Asunto(s)
Bovinos/fisiología , Folículo Ovárico/efectos de los fármacos , Folículo Ovárico/fisiología , Progesterona/administración & dosificación , Animales , Cuerpo Lúteo/diagnóstico por imagen , Cuerpo Lúteo/efectos de los fármacos , Cuerpo Lúteo/fisiología , Relación Dosis-Respuesta a Droga , Ciclo Estral , Femenino , Folículo Ovárico/diagnóstico por imagen , Progesterona/sangre , UltrasonografíaRESUMEN
The exploitation of the domestic animals species of South American camelids is of great social importance for the native people living in the High Andes. The reproductive physiology of these species is a unique challenge in the development of advanced breeding techniques. At present, the cryopreservation of embryos has not been developed and very few investigations have been conducted. The objective of the present work was to evaluate the in vivo survival of vitrified llama embryos after transfer to recipient females. Donors females were treated with a CIDR-estradiol benzoate-eCG regimen and were mated naturally 6 days after CIDR withdrawal. One ovulatory dose (8 microg) of GnRH was administered immediately after mating. A second mating was allowed 24 h later. Embryo recovery was performed nonsurgically between 8 and 8.5 days after the first mating. Twenty-two ova/embryos were recovered from 12 donor females. Hatched blastocysts were exposed to vitrification solution (20% glycerol + 20% ethylene glycol + 0.3 M sucrose + 0.375 M glucose + 3% polyethylene glycol (P/V)) in three steps, and after loading into 0.25 ml straws, were plunged into liquid nitrogen. For embryo transfer, recipients animals were ovulation-synchronized using GnRH administered at the same time as donors. A total of eight vitrified-warmed embryos and 12 fresh embryos were nonsurgically transferred to four and six recipient females, respectively (two embryo per recipient). The pregnancy rates were 50 and 33.3% for recipients that had received vitrified embryos and fresh embryos, respectively. The results demonstrated the effectiveness of this simple vitrification method for cryopreservation of llama embryos.
Asunto(s)
Camélidos del Nuevo Mundo/embriología , Criopreservación/veterinaria , Transferencia de Embrión/veterinaria , Fertilización In Vitro/veterinaria , Animales , Cruzamiento , Camélidos del Nuevo Mundo/fisiología , Criopreservación/métodos , Crioprotectores , Femenino , Fertilización In Vitro/métodos , Viabilidad Fetal/fisiología , Embarazo , Índice de Embarazo , Manejo de Especímenes/veterinaria , SuperovulaciónAsunto(s)
Fertilización In Vitro , Países en Desarrollo , Transferencia de Embrión , Femenino , Humanos , Masculino , Oocitos/citología , Ultrasonografía , VenezuelaRESUMEN
PIP: The study reports on 1624 cases of pregnancy in girls aged 14 or less, treated at a Venezuelan hospital over a 30-year period. The frequency of such cases was 1.95/1000 admissions to the maternity clinic, i.e., 1 case for every 512. The most common ages were 13 and 14, only 33 cases were of ages 11 and 12. 70.7% were single. The most common age of puberty was 12 and of 1st sexual relations, 13. 95.5% were primipara. 49.1% had not received prenatal care. The frequency of abortions was normal, but premature births were higher than normal at 17.2%. The incidence of mola and toxemia was considerably above average. On the other hand, there was a very low incidence of multiple pregnancies. There were no major alterations in the process of delivery. The sex and average weight of the newborn were within normal limits, as were the number of congenital malformations and the perinatal death rate.^ieng