VITRO FERTILIZATION

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Noninvasive chromosome screening of human embryos by genome sequencing of embryo culture medium for in vitro fertilization

Noninvasive chromosome screening of human embryos by genome sequencing of embryo culture medium for in vitro fertilization

in vitro-fertilized embryos free of chromosomal abnormalities and to improve the clinical outcome of in vitro fertilization (IVF). A disadvantage of PGS is that it requires biopsy of the preimplantation human embryo, which can limit the clinical applicability of PGS due to the invasiveness and complexity of the process. Here, we present and validate a noninvasive chromosome screening (NICS) method based on sequencing the genomic DNA secreted into the culture medium from the human blastocyst. By using multiple annealing and looping-based amplification cycles (MALBAC) for whole-genome amplification (WGA), we performed next-generation sequencing (NGS) on the spent culture medium used to culture human blastocysts ( n = 42) and obtained the ploidy information of all 24 chromosomes. We validated these results by comparing each with their corresponding whole donated embryo and obtained a high correlation for identification of chromosomal abnormalities (sensi- tivity, 0.882, and specificity, 0.840). With this validated NICS method, we performed chromosome screening on IVF embryos from seven couples with balanced translocation, azoospermia, or recurrent pregnancy loss. Six of them achieved successful clinical pregnancies, and five have already achieved healthy live births thus far. The NICS method avoids the need for embryo biopsy and therefore substan- tially increases the safety of its use. The method has the potential of much wider chromosome screening applicability in clinical IVF, due to its high accuracy and noninvasiveness.

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Bovine in vitro fertilization and cloning for beef and milk production

Bovine in vitro fertilization and cloning for beef and milk production

Technical feasibility has been adequately demonstrated to lend encouragement to international trade of bovine embryos resulting from in vitro fertilization (IVF). Major barriers to widespread implementation of IVF technology have included oversized calves, dystocias, elevated stillbirths and neonatal deaths primarily following embryo transfer (ET) of fresh in vitro produced (IVP) embryos since successful cryopreservation reflected in acceptable pregnancy rates has not been widely demonstrated. The proclivity of oocytes and resulting IVP embryos to adsorb viruses not easily removed by washing procedures established as efficacious for in vivo embryos represents another cause for concern. In addition to IVF, bovine embryos can be produced by initiating embryonic development of enucleated oocytes using skin fibroblast or granulosa cell nuclei to replace the genetic blueprints normally provided by the gametes. Although cloning by nuclear transfer (NT) has been demonstrated to result in calves by several groups current NT procedures require large numbers of oocytes since very low proportions result in IVP embryos and more importantly, pregnancy losses, dystocias, oversized offspring and neonatal deaths represent formidable problems to be resolved. Expenses incurred in production and maintenance of NT calves can predictably limit early impact of cloning apart from production and expansion of highly valued transgenic cattle employed for production of biological products for world markets. By contrast, it seems likely that ET of IVP embryos resulting from IVF can supersede artificial insemination to enhance world-wide reproduction of desirable beef and dairy cattle in the near future.

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In vitro fertilization (IVF) in mammals: epigenetic and developmental alterations  Scientific and bioethical implications for IVF in humans

In vitro fertilization (IVF) in mammals: epigenetic and developmental alterations Scientific and bioethical implications for IVF in humans

The advent of in vitro fertilization (IVF) in animals and humans implies an extraordinary change in the environment where the beginning of a new organism takes place. In mammals fertilization occurs in the maternal oviduct, where there are unique conditions for guaranteeing the encounter of the gametes and the first stages of development of the embryo and thus its future. During this period a major epigenetic reprogramming takes place that is crucial for the normal fate of the embryo. This epigenetic reprogramming is very vulnerable to changes in environmental conditions such as the ones implied in IVF, including in vitro culture, nutrition, light, temperature, oxygen tension, embryo‑maternal signaling, and the general absence of protection against foreign elements that could affect the stability of this process. The objective of this review is to update the impact of the various conditions inherent in the use of IVF on the epigenetic profile and outcomes of mammalian embryos, including superovulation, IVF technique, embryo culture and manipulation and absence of embryo‑maternal signaling. It also covers the possible transgenera‑ tional inheritance of the epigenetic alterations associated with assisted reproductive technologies (ART), including its phenotypic consequences as is in the case of the large offspring syndrome (LOS). Finally, the important scientific and bioethical implications of the results found in animals are discussed in terms of the ART in humans.

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¿Es un acto de amor humano la fecundación in vitro? : una propuesta de análisis ético = Is an act of human love the in vitro fertilization? : a proposal ethical analysis / Emilio García Sánchez

¿Es un acto de amor humano la fecundación in vitro? : una propuesta de análisis ético = Is an act of human love the in vitro fertilization? : a proposal ethical analysis / Emilio García Sánchez

Since 1978, when the first test tube baby, Louis Brown, was born, thousands of children have been born every year through in vitro fertilization. Many families keep attending fertility clinics in order to receive some treatment for their infertility problems and have a child. Children born in this way are worthy human beings. Their parents love them and devote themselves to their children admirably, showing real parental love. However, does this loving kindness justify, from an ethical point of view, any way of desiring and having a son or daughter? Is it really an act of human love to long for a child and satisfy this desire using artificial methods? Is it equally human and worthy to wish them choosing in vitro fertilization than to wish them through an intimate and loving relationship, in which the child emerges as a result of interpersonal donation? I answer these questions by analyzing the ethics proposal formulated by Rhonheimer and Ca- rrasco de Paula. In short, only the intimate and loving sexual union between a man and a woman —as long as it is unconditional love— may be the dignity cause of the existence of a human being. And such union and unconditional requirement are absent in vitro fertilization.

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La ejecución del fallo sobre fecundación in vitro contra Costa Rica: un reto jurisprudencial para el Sistema Interamericano de DDHH / Implementation of the In Vitro Fertilization Judgment against Costa Rica: a Jurisprudential Challenge for the...

La ejecución del fallo sobre fecundación in vitro contra Costa Rica: un reto jurisprudencial para el Sistema Interamericano de DDHH / Implementation of the In Vitro Fertilization Judgment against Costa Rica: a Jurisprudential Challenge for the...

In Artavia Murillo et al. v. Costa Rica (“in vitro fertilization” case), the Inter–American Court of Human Rights struck down the Costa Rican ban on artificial reproduction and ordered public funding of in vitro fertilization (IVF) through its Social Security system. During the procedure by which the court supervises compliance with the judgment, the Inter–American Court intervened directly in the national legal system by nullifying a ruling of the Constitutional Chamber of the Costa Rican Supreme Court that had invalidated an executive decree issued by the President, and conditioned the authorization and regulation of IVF to the approval of an Act by the Legislature. This extraordinary intervention in a national legal system by the Inter–American Court on Human Rights raises jurisprudential questions on the execution of its judgments at the national level, as well as on the court’s scope of authority during monitoring of compliance procedures, particularly in cases where a norm may, as in this case, imply morally controversial issues, political polarization at the domestic level and clear partiality on the part of the Court in favor of the Executive, as described in this article.

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A novel function for CRISP1 in rodent fertilization: Involvement in sperm zona pellucida interaction

A novel function for CRISP1 in rodent fertilization: Involvement in sperm zona pellucida interaction

As a first approach to investigate the potential involvement of CRISP1 in sperm-ZP interaction, we evaluated the effect of a polyclonal antibody against rCRISP1 (anti-CRISP1) on in vitro fertilization. For this purpose, zona-intact rat eggs were added to drops containing sperm preincubated for 30 min in medium containing either anti-CRISP1 or normal rabbit serum. Results showed that the presence of the antibody during gamete co-incubation produced a significant decrease in the percentage of fertilized eggs compared with controls (Fig. 1A), with no presence of sperm in the perivitelline space. As previously reported [27], sperm agglutination or alterations in sperm motility were not observed during the incubation (data not shown), indicating that the inhibition in fertilization was not due to a deleterious effect of the antibody. As a second approach to the same question, the effect of purified rCRISP1 on fertilization was evaluated with the premise that if the sperm protein interacts with the ZP during fertilization, exposure of the eggs to rCRISP1 should competitively inhibit gamete interaction. In this case, zona-intact rat eggs were co-incubated with sperm in a medium containing either OA (as a control) or rCRISP1 at a concentration known to inhibit sperm fusion ability without affecting other sperm functional parameters [10]. Results revealed that rCRISP1 produced a significant decrease in the percentage of fertilized eggs compared with controls (Fig. 1B), with no presence of perivitelline sperm. Together, these results suggest an inhibitory effect of both the antibody and the protein at a step prior to sperm-egg fusion.

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DIGESTIBILIDAD IN VITRO DE DIETAS PARA OVINOS CON DIFERENTE NIVEL DE INCLUSION DE GRANO DE FRIJOL (Phasenius vulgaris l.)  ./

DIGESTIBILIDAD IN VITRO DE DIETAS PARA OVINOS CON DIFERENTE NIVEL DE INCLUSION DE GRANO DE FRIJOL (Phasenius vulgaris l.) ./

En cuanto a la digestibilidad In Vitro de la materia orgánica, si se encontró diferencia significativa en la inclusión de fríjol. Al realizar la comparación de medias se mostró como mejor tratamiento a la dieta 1 , es decir el mejor coeficiente de digestibilidad es el testigo que no incluye grano de fríjol, en esta variable se observo un buen porcentaje de digestibilidad (94%) en promedio. La conclusión del estudio indica que la inclusión de fríjol en la dietas, no afecta la digestibilidad de la materia seca, en cuanto a materia orgánica afecta significativamente, observándose un buen coeficiente de digestibilidad.

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Potassium fertilization of cauliflower and broccoli in a potassium-rich soil

Potassium fertilization of cauliflower and broccoli in a potassium-rich soil

Fertilizing agricultural soils is one of the most expensive agricultural practices, although its economic return is usually high due to its effects on productivity, product uniformity and qual- ity (Ricci et al., 1995). In horticulture, because fertilization has a high economic return, farmers usually do not economize when applying fertil- izers to the plants.

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Uso de manitol y sorbitol en la conservación in vitro de dos ecotipos comerciales de aguaymanto (Physalis peruviana)

Uso de manitol y sorbitol en la conservación in vitro de dos ecotipos comerciales de aguaymanto (Physalis peruviana)

Physalis peruviana L., “Aguaymanto”, es una especie oriunda de los andes peruanos que en los últimos años ha cobrado importancia comercial debido a las propiedades de su fruto como alimento funcional. El presente trabajo evaluó el efecto de la adición de dos agentes osmóticos, manitol y sorbitol, sobre el crecimiento y desarrollo de microesquejes cultivados in vitro. El estudio se desarrolló utilizando material vegetal procedente de las regiones Cajamarca y Junín (Caj 04, Caj 05, Jun 01 y Jun 03), para la futura elaboración de un medio de cultivo que permita la conservación a mediano plazo de esta especie. En el estudio se utilizó el medio formulado por Murashige y Skoog (1962), al que se le adicionó una concentración de 20 g/L de manitol, sorbitol, o ambos osmolitos al mismo tiempo. Los experimentos contaron con controles negativos de medio MS (1962) sin reguladores osmóticos. Evaluaciones realizadas a los 50, 100 y 130 días para las variables: longitud de plántula, número de nudos y número de explantes vivos fueron analizadas estadísticamente utilizando un Diseño Completo al Azar (DCA) en arreglo factorial. Los explantes pudieron ser conservados efectivamente durante el periodo de evaluación. Los resultados experimentales mostraron que tanto el medio in vitro conteniendo ambos reguladores osmóticos como el material vegetal procedente de la región Cajamarca mostraron las mejores respuestas a las variables en estudio.

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Pasantía en el Laboratorio de Biotecnología Animal de la Facultad De Ciencias Agrarias del Politécnico Colombiano Jaime Isaza Cadavid

Pasantía en el Laboratorio de Biotecnología Animal de la Facultad De Ciencias Agrarias del Politécnico Colombiano Jaime Isaza Cadavid

35 congelan. Este choque osmótico es conocido como "efecto solución", y puede llegar a ser dañino para la sobrevivencia del embrión debido a la pérdida del equilibrio de las soluciones intra y extracelulares, respuestas químicas y osmóticas de las células a dichos efectos. El máximo daño en el embrión durante el enfriamiento ocurre de -15 a -16 ºC debido a la fase de transición de la membrana lipídica. Esta fase se ve afectada por la fusión de los liposomas afectando el termo comportamiento de las membranas en la transición de líquido a gel y la velocidad de penetración de los crio protectores. El daño celular incluye pérdida de microvellosidades, disrupción de la membrana plasmática, cambios mitocondriales, hinchamiento del retículo endoplásmico, pérdida de uniones entre células así como fractura de zona pelúcida. La etapa del desarrollo más apropiada para la vitrificación en etilenglicol es la mórula compacta y blastocito temprano de embriones producidos in vivo o in vitro, así como también se ha demostrado que embriones producidos in vitro tienen menor tolerancia a la congelación debido a la formación de hielo intracelular, aumento en la concentración de lípidos y enzimas que digieren la zona pelúcida, lo que los hace más sensibles al enfriamiento y a la invasión de virus, bacterias y hongos, motivo por el cual es que se usa la vitrificación. Otro aspecto a considerar es la calidad de los embriones a vitrificar, ya que cuando se congelan embriones de buena calidad, se obtienen mejores resultados que cuando se congelan aquellos de calidad regular.

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Organic fertilization: An alternative to produce jalapeño pepper under greenhouse conditions

Organic fertilization: An alternative to produce jalapeño pepper under greenhouse conditions

The results obtained showed that VCT, prepared from the VC (made with horse and goat manure with alfalfa straw, mixed in a 1:1 ratio by volume), caused positive effects on development indicators of jalapeñ o pepper. During this study, the organic production of jalapeñ o pepper under protected conditions and using organic fertilizers resulted in a high yield. The use of VCT, C and VC can be considered as an alternative fertilization method for organic production in greenhouses, since they contain soluble nutrients that can satisfy the nutrient demand of this plant.

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Estudio de la composición de los gránulos corticales y del oolema de ovocitos porcinos y bovinos madurados y fecundados in vitro

Estudio de la composición de los gránulos corticales y del oolema de ovocitos porcinos y bovinos madurados y fecundados in vitro

En contraste con la reacción de zona, el papel del contenido de los GCs en el bloqueo de la polispermia a nivel del oolema es muy controvertido (Wolf y Hamada, 1979; Horvath et al., 1993; Tatone et al., 1994), puesto que diferentes ensayos in vitro indican que el contenido de los CGs de ratona liberado tras la activación eléctrica no evita o disminuye el número de espermatozoides que penetran los ovocitos libres de ZP comparados con el control, indicando así que el contenido de los GCs en el oolema no produce ningún tipo de modificación como sucede en la ZP (Horvath et al., 1993; Sengoku et al., 1995). Poco se conoce del mecanismo que regula el bloqueo de la polispermia a nivel del oolema, lo que si está claro es su participación en conjunto con la ZP en especies como la porcina (Hunter y Nichol, 1988; Hunter, 1990). Estas conclusiones se obtienen tras la incubación de ovocitos libres de ZP de diferentes especies, en las que se puede observar que pocos ovocitos son penetrados por más de un espermatozoide, reforzando así el papel del oolema en el bloqueo de la polispermia (Wolf, 1978; Zuccotti et al., 1991; Horvath et al., 1993; Sengoku et al., 1995). Algunos autores indican que el oolema de los embriones pierde la capacidad de fusionar espermatozoides (Binor et al., 1982; McAvey et al., 2002) y que, de alguna manera, el oolema de zigotos es diferente al de ovocitos no fecundados, especialmente a nivel de su distribución lipídica (Wolf, 1978). El bloqueo de la polispermia a nivel de oolema también se ha asociado con la pérdida o enmascaramiento de receptores localizados en éste y que participan en la fusión del espermatozoide (Zuccotti et al., 1991; Blobel et al., 1992).

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Fecundación in vitro postmortem

Fecundación in vitro postmortem

IVF postmortem é uma técnica pela qual o sêmen é extraído do homem morto agora para fertilizar o óvulo da esposa viva. O ob- jetivo desta revisão de literatura é determinar e comparar as diferentes opções de IVF post- mortem em vários países. Metodologia: revi- são da literatura nas bases de dados diferentes que você retornar uma pesquisa em Inglês ou Espanhol com alta relevância para o tema e está disponível em texto completo como cri- tério de inclusão, com a ausência de qualquer um dos critérios de exclusão acima. Resultado: atualmente na Espanha estão autorizados a re- alizar esta técnica com uma série de requisitos e condições legais, mas em outros países há muito discrepância em algum uso desta técni- ca de qualquer forma não são permitidos, en- quanto no acesso outros é livre para qualquer viúva que deseja dentro das primeiras horas da morte do homem. Discussão: Poucos países têm legislação sobre postmortem fertilização in vitro, e muito poucos que permitem a téc- nica, mesmo com autorização prévia do sexo

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Rice Response to Potassium Fertilization in the Uruguayan Flooded Management System

Rice Response to Potassium Fertilization in the Uruguayan Flooded Management System

Recent nutritional surveys and studies of response to the addition of potassium (K) in various non-irrigated crops have shown that this nutrient is one of the limitings of the crop production in Uruguay. In rice, although there is national information of studies of K fertilization, it is only for some varieties, with management practices different from the current ones, with non-consistent results. The aim of this study was to explore the response to K in commercial rice crops on sites located in the main area of rice production of Uruguay, the Laguna Merín Basin. During the crop season of 2011-12 and 2012-13, K-response trials were installed in three commercial rice crops in soils with 0.14, 0.19, and 0.25 cmol kg -1 exchangeable K, measured with acetate

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Efecto de factores de crecimiento sobre la tasa de maduración de ovocitos y desarrollo embrionario in vitro de alpaca

Efecto de factores de crecimiento sobre la tasa de maduración de ovocitos y desarrollo embrionario in vitro de alpaca

resultados permiten inferir que, aparentemente, el desarrollo de embriones provenientes de ovocitos madurados sin factor de crecimiento (Tratamiento 5) presenta menores tasas de división embrionaria; por lo que, presentaría mayor tasa de embriones en estadíos más avanzados; sin embargo, los resultados indican que, respecto al estadío de mórulas este tratamiento presenta una media porcentual menor (23,30 ± 6,54%) en comparación con los otros tratamientos; 26,72% ± 11,26%; 30,12 ± 11,00%; 32,01 ± 11,35% y 33,53 ± 19,99%, para los tratamientos 1, 2, 3 y 4, respectivamente. Además, cabe indicar que los ovocitos madurados en este tratamiento (sin FC), no han llegado a desarrollarse hasta el estadío de blastocisto y que, a la vez, este tratamiento presenta una mayor cantidad de embriones degenerados (75,86 ± 6,12%) respecto a los otros tratamientos. Estos resultados pueden explicarse, en base a estudios que han demostrado, que el uso de FC en los medios de cultivo utilizados para la producción in vitro de embriones, reduce de manera considerable la apoptosis celular, por lo que, en muchas investigaciones realizadas en bovinos, se emplean estos en los medios para la MIV, FIV y CIV; de manera independiente o en combinación de una con otra. 11

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Infertilidad masculina y fragmentacin del ADN espermtico: Un problema actual

Infertilidad masculina y fragmentacin del ADN espermtico: Un problema actual

Spermatic DNA contributes one half of the genetic material to offspring. Currently, the parameters obtained through a seminogram do not provide complete information on the potential fertilization of the semen and the ability to produce a healthy embryo and an on-going pregnancy. This is the reason why the interest in developing techniques to assess sperm DNA fragmentation has been increased, as damage during spermatogenesis can occur at any stage of the process, this being a multifactorial phenomenon and not entirely delimited yet. Nowadays the infertility is an increasing global problem, and it has been shown that the quality of the DNA in the sperm can affect fertilization; this is why the evaluation of sperm DNA integrity, in addition to the study of the sperm parameters may provide additional information on the quality of the spermatozoa, resulting in great help to identify the causes of male infertility and thus can be used to better guide couples with infertility issues.

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Response to Nitrogen and Phosphorus Fertilization in Lignocellulosic Crops

Response to Nitrogen and Phosphorus Fertilization in Lignocellulosic Crops

though in A. donax the increase was not significant. There was no response to fertilization with P. Differences in biomass production did not generate differences in soil carbon content at the end of the evaluation. In spite P. virgatum intermediate yield, it was the species with the lowest moisture content (16 %), which is favorable as raw material for energy production. The yield were the expected ones for our region, with an annual variability attributable to climatic conditions and that can be increased with N fertilization .

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Fertilization efficiency and gamete viability in the ascidian Pyura praeputialis in Chile

Fertilization efficiency and gamete viability in the ascidian Pyura praeputialis in Chile

(e.g. lack of gamete manipulation, selection of optimal observation times, hydrodynamic conditions), we sug- gest that biofoam in P. praeputialis (1) is linked to spawning and might act as a mechanism that enhances fertilization in this species (Castilla et al. 2007); and (2) enhances settlement on top of or nearby P. praeputialis matrices. Moreover, we suggest that fertilization suc- cess could also be modified by distance from the spawning site, which is supported by the similar values of fertilization success in the biofoam areas and the coincident reduction in areas without biofoam (Fig. 7). Our results show a less abrupt reduction in fertiliza- tion success in undiluted eggs maintained in a viscous mass than in diluted eggs. The literature suggests that egg longevity in marine free-spawning invertebrates is modified by a combination of endogenous and exoge- nous factors such as contaminant bacteria and sedi- ment abrasion (Epel et al. 1998, Meidel & Yund 2001). However, the experiment conducted to assess Pyura praeputialis egg longevity under laboratory conditions was conducted with FSW, without the presence of sed- iment. Therefore, we tentatively suggest that the egg longevity figures computed from our regression of fer- tilization success on egg age correspond to the endo- genous loss of egg viability. Maximum fertilization suc- cess recorded under laboratory conditions was almost twice that recorded under natural conditions using egg cages. This may suggest that our field protocol of exposing eggs to seawater inside plastic cages might have limited sperm access, with a consequent negative effect on fertilization success. However, under such conditions, low fertilization success was accompanied by high levels of developmental failure, which sug- gests an excess of sperm and polyspermy in biofoam areas. Moreover, similar values for fertilization success when naturally spawned or stripped eggs were im- mersed in biofoam seawater suggests that the manipu- lative protocols performed to remove mature eggs had not obscured any unknown behaviour that enhances fertilization success under natural conditions (reviewed by Yund 2000). Therefore, the high levels of developmental failure strongly suggest that our manipulative conditions inside the plastic cages per- mitted a high rate of contact between eggs and sperm. The laboratory experiments on fertilization were con- ducted with eggs that were obtained from large-size reared adult specimens. However, the field experi- ments were conducted with eggs that were obtained from a random pool of naturally spawned or stripped specimens. This may be the origin of differences in egg diameter recorded in our laboratory (Expt 4) and field (Expt 7) experiments. Published evidence for P. stoloni- fera suggests that fertilization kinetics are strongly affected by egg size, with large eggs requiring less concentrated sperm suspensions than small eggs (Mar-

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Tecnologa de embriones en los felinos domsticos (Felis catus)

Tecnologa de embriones en los felinos domsticos (Felis catus)

The first trials of assisted reproduction in felines were first reported in the 1930’s, from 1935 to 1939. Over the last decades, great progress has been made, especially in IVP. However, some problems still persist, representing obstacles for a better efficien- cy of assisted reproduction in cats, and, conse- quently, in wild felids. To resolve these limitations, new investigations are needed to try to improve the efficiency of IVM techniques and oocyte cryopreser- vation and to eliminate the blockade of in vitro embryo development. In addition, a less invasive ET and a more effective interspecies pregnancy, including ET of NT-derived embryos, are also re- quired. Even so, the cat has been a model for studies on wild felids, and the studies conducted thus far have shown the importance of these techniques for the preservation of wild fauna. In addition, recent studies reported success in IVF in at least one-third of the wild felid species, obtaining offspring of tigers (P. tigris), wild cats (Felis sylvestris spp), lynx caracals (Caracal caracal) and ocelots (Leopardus par- dalis) after ET of cryopreserved or fresh IVP embry- os. 4,13,14,70,88

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GNRH antagonists in oocyte donor cycles: the key to safe, simple and efficient stimulation protocols

GNRH antagonists in oocyte donor cycles: the key to safe, simple and efficient stimulation protocols

at the follicular level by studying follicular fluid obtained during oocyte retrieval (25). The study of luteal phase endo- crine profiles also showed significantly lower steroid levels after GnRH agonist triggering as compared with triggering with hCG (26–28). This is due to a quick, irreversible luteol- ysis that could be mediated by pituitary down-regulation and/ or by some other as yet unknown mechanism (15, 29). This fact is of particular interest in the prevention of OHSS as it is universally acknowledged that the syndrome is closely re- lated to the presence of multiple overstimulated corpora lu- tea. The concept of GnRH agonist triggering has gained wide popularity after demonstrating complete prevention of clinically significant OHSS in high-risk patient groups (6, 7). Nonetheless, subsequent randomized clinical trials that evaluated pregnancy outcome in IVF cycles dampened the initial enthusiasm (8, 9). Griesinger et al. (21) in their meta-analysis analyzing the three available randomized clin- ical trials at the time of writing concluded that GnRH agonist triggering yields a comparable number of oocytes capable of undergoing fertilization and subsequent embryonic cleavage as compared with hCG. The proportion of mature oocytes, fertilization rates, and mean embryo score were also compa- rable. This hypothesis was further supported in a follow-up study of the previously mentioned randomized clinical trials that evaluated live-birth rates after frozen-thawed embryo

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