Quantification of multi-oocyte follicles in ovaries of bitches / [Quantificação de folículos multiócitos em ovários de cadelas]

The objective of this study was to quantify the number and frequency of monocyte (MnOF) and multi-oocyte (MtOF) follicles in ovaries of bitches subjected to ovary salpingohysterectomy (OSH). Right and left ovaries of 38 bitches were collected after OSH, prepared, and a histological analysis was carried out. The ovaries were subjected to surface and deep histological cuts; the follicles were classified, and the number of follicles and cumulus oophorus complexes (COC) per follicle were quantified for each histological cut. MnOF and MtOF were found in all ovaries, at different developmental stages; primary follicles were grouped in the ovarian cortex, and follicles at other follicular stages presented a random distribution. MtOF containing two, three, four, or more COC were found in the ovaries of bitches, with a decreasing frequency trend, according to the number of COC in the MtOF. The effect of the age, number of estrus, estrus interval, and number of progenies per delivery was not significant for the number and frequency of MtOF in the ovaries of the bitches, whereas the size, number of pregnancies, use and number of contraceptive applications had some effect on the number and frequency of MtOF in the ovaries of the bitches.(AU)

Objetivou-se, com este estudo, quantificar o número e a frequência de folículos monocitários (MOF) e polioocitários (POF) provenientes de ovários de cadelas submetidas à ovariossalpingo-histerectomia (OSH). Para tanto, coletaram-se os ovários (direito e esquerdo) de 38 cadelas após OSH, com posterior preparação e análise histológica. Cada ovário foi submetido a dois cortes histológicos (superficial e profundo) onde se quantificou o número e a classificação dos folículos, bem como o número de complexos cumulus oophorus (COCs) por folículo em cada corte histológico. Observaram-se MOF e POF em todos os ovários estudados, em diferentes estádios de desenvolvimento, sendo os folículos primários agrupados no córtex ovariano, frente a uma distribuição aleatória dos outros estádios foliculares. FOPs contendo dois, três, quatro ou mais COCs foram observados nos ovários de todas as fêmeas estudadas, e sua frequência tendeu a diminuir de acordo com o número de COC presente no POF. Não se observou influência da idade, do número e do intervalo de estros, assim como do número de filhotes por gestação sobre o número/frequência de FOP nos ovários das cadelas estudadas, enquanto o porte, o número de gestações, o uso e o número de contraceptivo apresentaram algum grau de influência sobre o número/frequência de FOP nos ovários das cadelas estudadas.(AU)

Unscrambling the oocyte and the egg: clarifying terminology of the female gamete in mammals.

Most reproductive biologists who study female gametes will agree with the 16th century anatomist William Harvey's doctrine: 'Ex Ovo Omnia'. This phrase, which literally translates to 'everything from the egg', recognizes the centrality of the egg in animal development. Eggs are most impressive cells, capable of supporting development of an entirely new organism following fertilization or parthenogenetic activation. Not so uniformly embraced in the field of reproductive biology is the nomenclature used to refer to the female germ cell. What is an oocyte? What is an egg? Are these terms the same, different, interchangeable? Here we provide functional definitions of the oocyte and egg, and how they can be used in the context of mammalian gamete biology and beyond.

SIRT2 functions in aging, autophagy, and apoptosis in post-maturation bovine oocytes.

AIMS: Sirtuins have been implicated in the aging process, however, the functions of SIRT2 in post-maturation aging of oocytes are not fully understood. The purpose of the present investigation was to assess the roles of SIRT2 in aged oocytes and mechanisms involved. MAIN METHODS: The fresh MII oocytes were aging in vitro, and treated with SIRT2 inhibitor (SirReal2), autophagy activator (Rapamycin), and autophagy inhibitor (3-Ma) for 24 h, respectively. Oocyte activation, cytoplasmic fragmentation, and spindle defects, mitochondrial distribution, ROS levels, ATP production, mitochondrial membrane potential, and early apoptosis were investigated. Western blotting was performed to determine LC3-II accumulation, SQSTM1 degradation, and caspase-3 activity. KEY FINDINGS: SIRT2 expression gradually decreased in a time-dependent manner during oocyte aging. Treatment with SirReal2 significantly increased the rates of oocyte activation, cytoplasmic fragmentation, and spindle defects. In particular, the high ROS levels, abnormal mitochondrial distribution, low ATP production, and lost ΔΨm were observed in SirReal2-exposed oocytes. Further analysis revealed that LC3-II accumulation and SQSTM1 degradation were induced by SIRT2 inhibition. By performing early apoptosis analysis showed that oocyte aging was accompanied with cellular apoptosis, and SIRT2 inhibition increased apoptosis rates of aged oocytes. Importantly, upregulating autophagy with Rapamycin could mimic the effects of SIRT2 inhibition on apoptosis by increasing caspase-3 activation, whereas downregulating autophagy with 3-MA could abolish those effects by blocking caspase-3 activation. SIGNIFICANCE: Our results suggest that SIRT2 inactivation is a key mechanism underlying of cellular aging, and SIRT2 inhibition contributes to autophagy-dependent cellular apoptosis in post-maturation oocytes.

Phosphoric acid and phosphorylation levels are potential biomarkers indicating developmental competence of matured oocytes.

Here, we aimed to identify biomarkers for mice oocyte maturation in metaphase II in vivo and in situ using Raman spectroscopy. Principal component analysis of 324 Raman data points of oocytes at Phase I, II, III, and IV showed that the phosphoric acid concentration uniformly increased in oocytes with higher developmental competence than in oocytes at other maturation stages, and proteins were more phosphorylated. The maturation phases were successfully predicted by linear discriminant analysis with high accuracy (90.7%) using phosphoric molecular information mentioned above. Furthermore, detections of higher concentration of unsaturated fatty acids in overmatured oocytes indicated that a decline in metabolic activity due to overmaturation induced a surplus of these lipid components. Upon assessing invasiveness by laser irradiation, about 50% irradiated oocytes progressed to morula and blastocyst stages in good conditions. Thus, Raman spectroscopy holds promise in evaluating oocyte maturation and quality based on molecular information in infertility treatment.

Efeito do estresse térmico calórico agudo e crônico sobre a qualidade oocitária de bovinos de raças adaptadas / Effect of acute and chronic caloric heat stress on oocyte quality of adapted breeds cattle

Nos trópicos, o uso de raças adaptadas tem sido uma estratégia para minimizar o efeito do estresse térmico calórico (ETC). No entanto, faltam informações que quantifiquem o estresse e o seu efeito sobre a reprodução dessas raças. O objetivo deste estudo foi avaliar a qualidade do oócito recuperado e alguns parâmetros fisiológicos indicadores de ETC em bovinos de raças adaptadas. Animais Bos taurus x Bos indicus (n=6) e Bos taurus (raça Pantaneira; n=12), localizados na região de transição entre o Cerrado e o Pantanal brasileiro, foram submetidos à aspiração folicular guiada por ultrassonografia (OPU) em diferentes condições climáticas. Foram realizadas oito sessões de OPU, com intervalo mínimo de sete dias e máximo de 54 dias entre as coletas. Para caracterização climática, foi realizado o cálculo do índice de temperatura e umidade (ITU). Foram quantificados os ITUs do dia da OPU, sete dias antes e 60 dias antes de cada sessão. Os parâmetros fisiológicos e a viabilidade oocitária de fêmeas das raças Girolando e Pantaneira não foram afetados negativamente por ITUs entre 72 e 78. O ETC crônico (60 dias) parece afetar a viabilidade oocitária de doadoras na raça Pantaneira quando ITU é superior a 75.(AU)

In tropical regions, the use of adapted breeds has been a strategy to minimize the effect of heat stress (HS) in cattle. However, information quantifying stress and its effect on reproduction of these breeds is lacking. The aim of this study was to evaluate the quality of the recovered oocyte and some physiological parameters that indicate HS in adapted breed. Bos taurus x Bos indicus (n=6) and Pantaneira (n=12) cows, located in the transition region between Cerrado and Brazilian Pantanal, underwent follicular aspiration guided by ultrasound (OPU) in different weather conditions. Eight sessions of OPU were carried out, with a minimum interval of 7 days and maximum 54 days between sessions. For weather characterization, the temperature and humidity index (THI) was calculated. THI of the day of OPU, 7 days before and 60 days before each session were calculated. The physiological parameters and oocyte viability of Girolando and Pantaneira cows were not negatively influenced under ITU between 72 and 78. The chronic HS (60 days)may affect the oocyte viability of Pantaneira donors when ITU is over 75.(AU)

The NOBOX protein becomes undetectable in developmentally competent antral and ovulated oocytes.

The oocyte-specific NOBOX protein is an important player during oocyte growth. Its absence in Nobox-/- mice arrests the transition from primordial to growing follicles and down-regulates the expression of a number of genes, including Oct4, a transcription factor crucial in the acquisition of oocyte developmental competence. Despite its role during folliculogenesis, a clear description of the expression of NOBOX throughout oocyte growth is lacking. Here, we have analysed the pattern of expression of both the Nobox gene (qRT-PCR) and its protein (immunofluorescence) during folliculogenesis, classifying the oocytes based on their size (six classes: 10-30, 31-40, 41-50, 51-60, 61-70, 71-80 microm) and chromatin organisation (NSN, Non Surrounded Nucleolus or SN, Surrounded Nucleolus). Significant differences were observed in Nobox transcription in the group of 41-50 microm (NSN > SN), 71-80 microm (NSN > SN) and in developmentally incompetent metaphase II-derived NSN (MII(NSN)) or competent metaphase II-derived SN (MII(SN)) oocytes (MII(NSN) > MII(SN)). The NOBOX protein is expressed throughout oocyte growth in the nucleus of ovarian NSN and in MII(NSN) oocytes; in contrast, beginning with SN oocytes of 61-70 microm, it becomes almost undetectable. Our data, while being in line with the hypothesis of a regulative role of NOBOX on Oct4 gene expression at the primordial/primary stage, when both transcription factors are coincidentally expressed, also indicate that this role might not be maintained in the subsequent growing stages. Furthermore, the sharp difference of NOBOX expression in developmentally incompetent or competent oocytes makes this protein a putative marker of their quality.

T-type Ca2+ current activity during oocyte growth and maturation in the ascidian Styela plicata.

Voltage-dependent calcium currents play a fundamental role during oocyte maturation, mostly L-type calcium currents, whereas T-type calcium currents are involved in sperm physiology and cell growth. In this paper, using an electrophysiological and pharmacological approach, we demonstrated, for the first time in oocytes, that T-type calcium currents are present with functional consequences on the plasma membrane of growing immature oocytes of the ascidian Styela plicata. We classified three subtypes of immature oocytes at the germinal vesicle stage on the basis of their size, morphology and accessory cellular structures. These stages were clearly associated with an increased activity of T-type calcium currents and hyperpolarization of the plasma membrane. We also observed that T-type calcium currents oscillate in the post-fertilization embryonic stages, with minimal amplitude of the currents in the zygote and maximal at 8-cell stage. In addition, chemical inhibition of T-type calcium currents, obtained by applying specific antagonists, induced a significant reduction in the rate of cleavage and absence of larval formation. We suggest that calcium entry via T-type calcium channels may act as a potential pacemaker in regulating cytosolic calcium involved in fertilization and early developmental events.

Artificial intelligence techniques for embryo and oocyte classification.

One of the most relevant aspects in assisted reproduction technology is the possibility of characterizing and identifying the most viable oocytes or embryos. In most cases, embryologists select them by visual examination and their evaluation is totally subjective. Recently, due to the rapid growth in the capacity to extract texture descriptors from a given image, a growing interest has been shown in the use of artificial intelligence methods for embryo or oocyte scoring/selection in IVF programmes. This work concentrates the efforts on the possible prediction of the quality of embryos and oocytes in order to improve the performance of assisted reproduction technology, starting from their images. The artificial intelligence system proposed in this work is based on a set of Levenberg-Marquardt neural networks trained using textural descriptors (the local binary patterns). The proposed system was tested on two data sets of 269 oocytes and 269 corresponding embryos from 104 women and compared with other machine learning methods already proposed in the past for similar classification problems. Although the results are only preliminary, they show an interesting classification performance. This technique may be of particular interest in those countries where legislation restricts embryo selection. One of the most relevant aspects in assisted reproduction technology is the possibility of characterizing and identifying the most viable oocytes or embryos. In most cases, embryologists select them by visual examination and their evaluation is totally subjective. Recently, due to the rapid growth in our capacity to extract texture descriptors from a given image, a growing interest has been shown in the use of artificial intelligence methods for embryo or oocyte scoring/selection in IVF programmes. In this work, we concentrate our efforts on the possible prediction of the quality of embryos and oocytes in order to improve the performance of assisted reproduction technology, starting from their images. The artificial intelligence system proposed in this work is based on a set of Levenberg-Marquardt neural networks trained using textural descriptors (the 'local binary patterns'). The proposed system is tested on two data sets, of 269 oocytes and 269 corresponding embryos from 104 women, and compared with other machine learning methods already proposed in the past for similar classification problems. Although the results are only preliminary, they showed an interesting classification performance. This technique may be of particular interest in those countries where legislation restricts embryo selection.

Use of metaphase I oocytes matured in vitro is associated with embryo multinucleation.

OBJECTIVE: To evaluate the impact of oocyte maturational stage at retrieval on embryo multinucleation. DESIGN: Retrospective study. SETTING: Private institution for assisted reproduction. PATIENT(S): A total of 412 patients undergoing 500 intracytoplasmic sperm injection (ICSI) cycles between August 2006 and September 2010. INTERVENTION(S): Routine ICSI laboratory procedures. MAIN OUTCOME MEASURE(S): Normal and abnormal fertilization; embryo development; arrest at pronuclear stage; failure to undergo first mitotic division; presence of embryo multinucleation; embryo quality; pregnancy, implantation, and miscarriage rates. RESULT(S): A significantly lower percentage of multinucleation was found in embryos originating from metaphase II (MII) oocytes when compared with MI-II- and MI-derived oocytes. Significantly fewer multinucleated cells per embryo were observed in MII-derived oocytes. Clinical pregnancy and implantation rates were significantly higher when only embryos derived from MII oocytes were transferred. CONCLUSION(S): Embryo multinucleation rate increases when in vitro-matured (2-5 hours incubation) MI (MI-II) oocytes are used instead of in vivo-matured oocytes in ICSI. Furthermore, all other ICSI outcome parameters are also compromised. The use of donated gametes does not modify these results.

Testing and interpreting measures of ovarian reserve: a committee opinion.

Currently, there is no uniformly accepted definition of decreased ovarian reserve (DOR), as the term may refer to three related but distinctly different outcomes: oocyte quality, oocyte quantity, or reproductive potential. Available evidence concerning the performance of ovarian reserve tests is limited by small sample sizes, heterogeneity among study design, analyses and outcomes, and the lack of validated outcome measures.

A new classification of a preovulatory oocyte maturation stage suitable for the synchronization of ovulation in controlled reproduction of Eurasian perch Perca fluviatilis L.

To improve controlled reproduction of Eurasian perch Perca fluviatilis, the criteria for the evaluation of final oocyte maturation stages were revised. The new classification covers six preovulatory maturational stages (I -VI) from the end of vitellogenesis to germinal vesicle breakdown (GVBD) and was based on macroscopic changes of preovulatory oocytes (position of the germinal vesicle, GVBD, oil droplets coalescence). The observation was performed during out-of-season artificial reproduction with the use of a single hCG injection (500 IU/kg). The classification was subsequently verified with the controlled reproduction of wild female perch with the use of hormonal stimulation (500 IU hCG/kg of body weight at 12°C). The females were at different maturational stages and constituted respective experimental groups (I-VI). During the experiment, ovulation appeared to be considerably synchronized within particular groups. Statistical differences in latency time (time between hormonal treatment and ovulation) were found between experimental groups (mean latency time: 110, 92, 68, 49, 29 and 18 h in groups representing VI, V, IV, III, II and I stage of the proposed classification, respectively). The proposed classification and the results presented in the study allowed for effective synchronisation of ovulation. The use of our new oocyte maturation classification may positively influence the effectiveness of Eurasian perch production.

Istanbul consensus workshop on embryo assessment: proceedings of an expert meeting.

This paper reports the proceedings of an international consensus meeting on oocyte and embryo morphology assessment. Following background presentations about current practice, the expert panel developed a set of consensus points to define the minimum criteria for oocyte and embryo morphology assessment. It is expected that the definition of common terminology and standardization of laboratory practice related to embryo morphology assessment will result in more effective comparisons of treatment outcomes. This document is intended to be referenced as a global consensus to allow standardized reporting of the minimum dataset required for the accurate description of embryo development. This paper reports the proceedings and outcomes of an international consensus meeting on human oocyte and embryo morphology assessment. An expert panel developed a series of consensus points to define the minimum criteria for such assessments. The definition of common terminology, and standardization of laboratory practices related to these morphological assessments, will permit more effective comparisons of treatment outcomes around the world. This report is intended to be referenced as a global consensus to allow standardized reporting of the minimum descriptive criteria required for routine clinical evaluations of human embryo development in vitro.

The Istanbul consensus workshop on embryo assessment: proceedings of an expert meeting.

BACKGROUND: Many variations in oocyte and embryo grading make inter-laboratory comparisons extremely difficult. This paper reports the proceedings of an international consensus meeting on oocyte and embryo morphology assessment. METHODS: Background presentations about current practice were given. RESULTS: The expert panel developed a set of consensus points to define the minimum criteria for oocyte and embryo morphology assessment. CONCLUSIONS: It is expected that the definition of common terminology and standardization of laboratory practice related to embryo morphology assessment will result in more effective comparisons of treatment outcomes. This document is intended to be referenced as a global consensus to allow standardized reporting of the minimum data set required for the accurate description of embryo development.

Genetic parameters for oocyte number and embryo production within a bovine ovum pick-up-in vitro production embryo-production program.

Genetic factors influencing the outcome of bovine ovum pick-up-in vitro production (OPU-IVP) and its relation to female fertility were investigated. For the first time, genetic parameters were estimated for the number of cumulus-oocyte complexes (Ncoc), quality of cumulus-oocyte complexes (Qcoc), number and proportion of cleaved embryos at Day 4 (Ncleav(D4), Pcleav(D4)), and number and proportion of total and transferable embryos at Day 7 of culture (Nemb(D7), Pemb(D7) and NTemb(D7), PTemb(D7), respectively). Data were recorded by CRV (formally Holland Genetics) from the OPU-IVP program from January 1995 to March 2006. Data were collected from 1508 Holstein female donors, both cows and pregnant virgin heifers, with a total of 18,702 OPU sessions. Data were analyzed with repeated-measure sire models with permanent environment effect using ASREML (Holstein Friesian). Estimates of heritability were 0.25 for Ncoc, 0.09 for Qcoc, 0.19 for Ncleav(D4), 0.21 for Nemb(D7), 0.16 for NTemb(D7), 0.07 for Pcleav(D4), 0.12 for Pemb(D7), and 0.10 for PTemb(D7). Genetic correlation between Ncoc and Qcoc was close to zero, whereas genetic correlations between Ncoc and the number of embryos were positive and moderate to high for Nemb(D7) (0.47), NTemb(D7) (0.52), and Ncleav(D4) (0.85). Genetic correlations between Ncoc and percentages of embryos (Pcleav(D4), Pemb(D7), and PTemb(D7)) were all close to zero. Phenotypic correlations were in line with genetic correlations. Genetic and phenotypic correlations between Qcoc and all other traits were not significant except for the phenotypic correlations between Qcoc and number of embryos, which were negative and low to moderate for Nemb(D7) (-0.20), NTemb(D7) (-0.24), and Ncleav(D4) (-0.43). Results suggest that cumulus-oocyte complex (COC) quality, based on cumulus investment, is independent from the total number of COCs collected via OPU and that in general, a higher number of COCs will lead to a higher number of embryos produced. The correlation between the estimated breeding values for Ncoc and PTemb(D7) of sires in this study and the sires breeding index for female-fertility based on the Dutch cattle population was close to zero. This study revealed OPU-IVP traits (Nemb(D7), NTemb(D7), and Ncoc) that could be of potential value for selection. Introduction of such traits in breeding programs would enhance the number of offspring from superior donors as well as improve the cost efficiency of OPU-IVP programs.

The position of the germinal vesicle and the chromatin organization together provide a marker of the developmental competence of mouse antral oocytes.

Based on their chromatin organization, antral oocytes can be classified into two classes, namely surrounded nucleolus (SN, chromatin forms a ring around the nucleolus), and not surrounded nucleolus (NSN, chromatin has a diffuse pattern). Oocytes of both classes are capable of meiotic resumption, but while SN oocytes, following fertilization, develop to term, NSN oocytes never develop beyond the two-cell stage. A recent study has shown that the position of the germinal vesicle (GV) can be used as a morphological marker predictive of oocyte meiotic competence, i.e. oocytes with a central GV have a higher meiotic competence than oocytes with an eccentric GV. In the present study, we have associated both markers with the aim of identifying, with more accuracy, the oocytes' developmental competence. Following their isolation, antral oocytes were classified on the basis of both SN and NSN chromatin configuration and their GV position, matured to metaphase II and fertilized in vitro. We demonstrated that the position of the GV is a good marker to predict the oocytes' developmental competence, but only when associated with the observation of the chromatin organization.

The morphology of porcine oocytes is associated with zona pellucida glycoprotein transcript contents.

We hypothesized that oocyte morphology may be associated with the accumulation of specific mRNAs encoding proteins responsible for the gamete fertilization ability. Therefore, the aim of the study was to evaluate the transcript levels of porcine zona pellucida (pZP1, pZP2, pZP3 and pZP4) glycoproteins in oocytes classified by a four-grade morphological scale (I-IV) accounting for either a homogeneous cytoplasm and a complete cumulus oophorus (grade I) or a heterogenous cytoplasm and decreased number of cumulus layers in the other grades (II, III and IV). We observed a significant increase of all investigated pZP glycoprotein mRNAs in grade I oocytes as compared to other grades (p<0.05). Our observations suggest that porcine oocyte morphology is associated with pZP transcript contents and may be related to an increased fertilization ability of higher quality oocytes.

Regulatory networks define phenotypic classes of human stem cell lines.

Stem cells are defined as self-renewing cell populations that can differentiate into multiple distinct cell types. However, hundreds of different human cell lines from embryonic, fetal and adult sources have been called stem cells, even though they range from pluripotent cells-typified by embryonic stem cells, which are capable of virtually unlimited proliferation and differentiation-to adult stem cell lines, which can generate a far more limited repertoire of differentiated cell types. The rapid increase in reports of new sources of stem cells and their anticipated value to regenerative medicine has highlighted the need for a general, reproducible method for classification of these cells. We report here the creation and analysis of a database of global gene expression profiles (which we call the 'stem cell matrix') that enables the classification of cultured human stem cells in the context of a wide variety of pluripotent, multipotent and differentiated cell types. Using an unsupervised clustering method to categorize a collection of approximately 150 cell samples, we discovered that pluripotent stem cell lines group together, whereas other cell types, including brain-derived neural stem cell lines, are very diverse. Using further bioinformatic analysis we uncovered a protein-protein network (PluriNet) that is shared by the pluripotent cells (embryonic stem cells, embryonal carcinomas and induced pluripotent cells). Analysis of published data showed that the PluriNet seems to be a common characteristic of pluripotent cells, including mouse embryonic stem and induced pluripotent cells and human oocytes. Our results offer a new strategy for classifying stem cells and support the idea that pluripotency and self-renewal are under tight control by specific molecular networks.

Donación de ovocitos / Oocyte donation

Objetivo: Conocer el marco legal y científico, indicaciones, resultados, aspectos emocionales y controversias existentes relacionadas con la técnica de donación de ovocitos en reproducción asistida. Material y métodos: Revisión de las principales guías de práctica clínica publicadas en la bibliografía internacional (ESHRE, American Society for Reproductive Medicine, Royal College of Obstetricians and Gyneacologist [RCOG]). Resultados: La tasa de embarazo obtenida mediante esta técnica varía entre el 30 y 50% en función de las fuentes consultadas. La prestación asumida por el Servicio Andaluz de Salud sólo cubre el 17% de las indicaciones que se hacen en sanidad privada. Conclusiones: La donación de ovocitos es una técnica que obtiene buenos resultados en el segmento poblacional con peor pronóstico reproductivo. Su extensión difiere sustancialmente entre el sector privado y el público. Con la generalización de la técnica han aparecido nuevas controversias no del todo resueltas. El escaso número de donantes y los aspectos morales son los dos principales factores que limitan la extensión de la técnica (AU)

Objective: To determine the legal and scientific framework, indications, results, emotional issues, and current debates related to oocyte donation in assisted reproduction. Material and methods: We reviewed the main clinical practice guidelines published in the international literature (ESHRE, American Society for Reproductive Medicine, Royal College of Obstetricians and Gynecologists). Results: The pregnancy rate obtained by this technique varied between 30% and 50%, depending on the sources consulted. The services provided by the Andalusian Health Service covered only 17% of the indications covered by private health providers. Conclusions: Oocyte donation provides good results in the segment of the population with the worst reproductive prognosis. The use of this technique differs substantially between the private and public sectors. With the widespread use of this technique, new controversies have appeared that have not been entirely resolved. The two main factors limiting wider use of oocyte donation are the low number of donors and moral issues (AU)

Vitrification: an effective new approach to oocyte banking and preserving fertility in cancer patients

INTRODUCTION: Oocyte cryopreservation is a useful tool for preserving the fertility of cancer patients at risk of losing ovarian function due to undergoing potentially sterilising therapies. Results obtained with different cryopreservation protocols have been disappointing, particularly those obtained with slow cooling procedures. The efficacy of vitrification as an application in clinical practice has recently been demonstrated. The aim of this study is to report results obtained with the Cryotop method of oocyte vitrification in a population of healthy women and to point out its potential usefulness for fertility preservation in oncological patients. MATERIALS AND METHODS: The study population consisting of non-oncological patients included 47 oocyte donors and 57 recipients undergoing an oocyte donation cycle of assisted reproductive technology (ART). A total of 693 mature metaphase II oocytes were collected following ovarian stimulation using long protocol down-regulation plus gonadotropin administration. Vitrification was carried out by means of the Cryotop method. Oocytes were donated to a compatible recipient after endometrial preparation. RESULTS: Of the 693 oocytes, 666 (96.1%) survived. A total of 487 (73.1%) were fertilised successfully. One hundred and seventeen embryos were transferred to 57 recipients. Pregnancy rate per transfer and implantation rates were 63.2% and 38.5% respectively. Twenty-eight healthy babies were later born. CONCLUSIONS: Oocyte cryo-banking by means of the Cryotop vitrification method represents a viable option for healthy women, producing excellent survival rates and a clinical outcome similar to that obtained with fresh oocytes. This approach could potentially be used in cancer patients who want to safeguard their fertility. Cancer patients could potentially benefit from this approach by storing their oocytes before the onset of the oncological therapy (AU)

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Smart microrobots for mechanical cell characterization and cell convoying.

This paper deals with the effective design of smart microrobots for both mechanical cell characterization and cell convoying for in vitro fertilization. The first microrobotic device was developed to evaluate oocyte mechanical behavior in order to sort oocytes. A multi-axial micro-force sensor based on a frictionless magnetic bearing was developed. The second microrobotic device presented is a cell convoying device consisting of a wireless micropusher based on magnetic actuation. As wireless capabilities are supported by this microrobotic system, no power supply connections to the micropusher are needed. Preliminary experiments have been performed regarding both cell transporting and biomechanical characterization capabilities under in vitro conditions on human oocytes so as to demonstrate the viability and effectiveness of the proposed setups.