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PubMed2005

The effect of prolonged cold storage of eland (Taurotragus oryx) cauda epididymides on the spermatozoa: possible implications for the conservation of biodiversity.

The objectives of this study were to investigate the effects of prolonged storage of cauda epididymides at 4 degrees C on spermatozoa, and to determine the practicality of utilising epididymal sperm, harvested from testes collected during routine culling of game animals, in assisted reproductive technologies. Testes from eland (Taurotragus oryx) were collected and epididymides removed and maintained at 4 degrees C. Sperm motility, viability, morphology and membrane integrity were examined at 12 h intervals for 108 h. Sperm motility and viability were significantly lower at the end of the experiment than at the start (P < 0.05) and there was individual variation in the rate at which motility and viability declined. The total number of normal sperm decreased significantly with prolonged storage at 4 degrees C. Midpiece defects were the most common and head and tail abnormalities were rare. A significant decrease in acrosomal and nuclear membrane integrity was observed with prolonged cold storage but there was no significant change in cell membrane integrity. However, about 30% of epididymal sperm survived for 3 days at 4 degrees C and more than 10% survived for 4 days, and it should be possible to use sperm from culled animals in some assisted reproductive technologies.

Acrosome↗
PubMed2004

Maternal and neonatal outcomes in 54 triplet pregnancies managed in an Australian tertiary centre.

BACKGROUND: To provide current data on maternal and neonatal outcomes in triplet pregnancies in an Australian population. METHODS: Retrospective case note review of all triplet pregnancies managed within a single Australian tertiary centre. RESULTS: Fifty-four sets of triplets were managed from January 1996 to October 2002. A total of 59% resulted from the use of assisted reproductive technologies. The median gestation at delivery was 32.5 weeks (range: 21-36 weeks); 14% delivered prior to 28 weeks and 43% delivered before 32 weeks. Preterm labour and preterm rupture of membranes were the most common antenatal complications occurring in 57 and 22% of pregnancies, respectively. A total of 93% of pregnancies were delivered by Caesarean section and 37% of mothers experienced at least one post-partum complication. A total of 96% of neonates were liveborn, with a median birthweight of 1644 g (range: 165-2888 g). The two most common neonatal complications were jaundice and hypoglycaemia in 52 and 43% of liveborn neonates, respectively. A total of 28% of neonates were below the 10th centile for gestational age and sex. A total of 8% of neonates demonstrated congenital anomalies. The perinatal mortality at a gestational age of 20-24 weeks was 100%, 22% at 25-28 weeks and zero for those babies born at 29 weeks or beyond. CONCLUSION: Assisted reproductive technologies contribute significantly to the incidence of triplet pregnancies. Gestational age at delivery and perinatal mortality is comparable to published international data. Triplets born in a tertiary centre beyond 28 weeks gestation have a very favourable prognosis in the newborn period.

Adult↗
PubMed2003

Methylation imprints of the imprint control region of the SNRPN-gene in human gametes and preimplantation embryos.

Imprinting is an epigenetic mechanism leading to mono-allelic expression of imprinted genes. In order to inherit the differential epigenetic imprints from one generation to the next, these imprints have to be erased in the primordial germ cells and re-established in a sex-specific manner during gametogenesis. The exact timing of the imprint resetting is not yet known and the use of immature gametes in assisted reproductive technologies may therefore lead to abnormal imprinting and related diseases. Imprinting is associated with differential allelic methylation in a CpG-context. We studied the methylation patterns of the imprint control (IC) region of the human SNRPN-gene in human spermatozoa, oocytes in different developmental stages [germinal vesicle (GV), metaphase I and metaphase II oocytes] and in preimplantation embryos using the bisulphite sequencing technique. In the spermatozoa, almost all potential methylation sites were unmethylated whereas mainly methylated patterns were found in the oocytes at different developmental stages. In the embryos, an average methylation pattern of 53% was found indicating that the imprints, which have been set during gametogenesis, are stably maintained in the preimplantation embryo. Our results indicate that the maternal imprints for the IC-region of the human SNRPN-gene are already re-established at the GV stage and that they are not re-established in a late oocyte stage or after fertilization as previously reported. Recent advances in assisted reproductive technologies raise questions concerning safety and the epigenetic risks involved. Our study was the first to check the methylation imprints in human pre-implantation embryos and oocytes at different developmental stages.

Autoantigens↗
PubMed1998

Complications of medically assisted conception in 3,500 cycles.

OBJECTIVE: To investigate the incidence of complications in the use of assisted reproductive technology in the management of infertile couples. DESIGN: Retrospective study. SETTING: The Egyptian IVF & ET Center, Maadi, Cairo, Egypt. PATIENT(S): Two thousand nine hundred twenty-four patients underwent IVF-ET or intracytoplasmic sperm injection (ICSI) in 3,500 cycles. INTERVENTION(S): IVF-ET, ICSI, ejaculate sperm, epididymal sperm aspiration, and testicular sperm extraction. MAIN OUTCOME MEASURE(S): Complications of the procedure and complications of pregnancy in 702 patients. RESULT(S): Fifteen hundred ovum pickups for IVF-ET and 2,000 ovum pickups for ICSI were performed. Clinical pregnancy occurred in 1,078 patients (30.8%). Four groups of complications were identified. Complications of the procedure occurred in 291 patients (8.3%). Complications of pregnancy included ectopic pregnancy in 1.9%, heterotopic pregnancy in 0.2%. abortion in 20.6%, multiple pregnancy in 28%, pregnancy-induced hypertension in 10%, preterm labor in 21.5%, low birth weight in 30.5%, and intrauterine death in 2%. Coincidental complications occurred in five patients (0.15%). Other complications that were difficult to measure included psychological breakdown and socioeconomic problems. CONCLUSION(S): Assisted reproductive technology is effective for the management of infertility and has an acceptable incidence of complications. Complications rarely endanger the life of the patient. When this line of treatment is offered, the indications should be definitive. Patients should be monitored properly and measures should be taken to minimize the incidence of complications.

Chi-Square Distribution↗
PubMed1994

Covering embryo cultures with mineral oil alters embryo growth by acting as a sink for an embryotoxic substance.

PURPOSE: Assisted reproductive technologies require the use of culture media for gametes and embryos. Culture media and conditions intended for use in human in vitro fertilization are tested prior to use by evaluating their ability to support normal development of mouse embryos. RESULTS: Development to blastocysts of two-cell mouse embryos was equivalent for embryos cultured in center well dishes alone (93 +/- 10%, mean +/- SD) and embryos cultured in center well dishes with an overlay of 1 ml of mineral oil (94 +/- 5%). In contrast, no development of two-cell-stage mouse embryos occurred in an embryotoxic medium when cultured in center well dishes. However, when this medium was covered with an overlay of mineral oil, development to blastocyst was no different than that of controls (96 +/- 5%). Similar results were found with cultures of one-cell-stage mouse embryos. CONCLUSION: These results indicate that in some circumstances the presence of mineral oil can significantly alter the outcome of embryo culture. Further, these results reinforce the necessity of directly testing the exact culture conditions to be used for assisted reproductive technologies.

Analysis of Variance↗
PubMed2005

One last chance for pregnancy: a review of 2,705 in vitro fertilization cycles initiated in women age 40 years and above.

OBJECTIVE: To describe live birth rates and predictors of success in 1-year age increments for women > or =40 years when initiating assisted reproductive technologies (ART). DESIGN: Retrospective database analysis. SETTING: A large university-affiliated infertility center. PATIENT(S): One thousand two hundred sixty-three women undergoing 2,705 ART cycles at age 40 or above. INTERVENTION(S): Couples undergoing ART. MAIN OUTCOME MEASURE(S): Pregnancy and live birth rates per cycle start were determined based on 1-year increments in women aged > or =40. Predictors of success, including number of embryos transferred, number of fetal heartbeats, availability of embryos for cryopreservation, and cycle day 3 FSH levels, were analyzed. RESULT(S): The overall live birth rate per cycle start was 9.7%. Cumulative live birth rates in women ranged from 28.4% if starting ART at age 40 to 0 by age 46. The overall spontaneous abortion rate was 32.6% (range, 23.9%-66.7%). Higher pregnancy rates were predicted by the greater number of embryos available for transfer, by the availability of excess embryos for cryopreservation, and by the presence of two fetal heartbeats on ultrasound. The outcome of the first IVF cycle did not predict the outcome of subsequent cycles. CONCLUSION(S): Assisted reproductive technology has a reasonable chance for success (>5%) up until the end of the forty-third year. Twins on initial ultrasound, large numbers of embryos available for transfer, and the presence of excess embryos for cryopreservation predict higher live birth rates.

Adult↗
PubMed1993

The likelihood of pregnancy with IVF and GIFT in Australia and New Zealand.

OBJECTIVE: To determine the likelihood of pregnancy for couples entering the New Reproductive Technology (NRT) programs in Australia and New Zealand, by combining the data from nearly all the practising units. DESIGN: All units practising in-vitro fertilisation (IVF) and/or gamete intrafallopian transfer (GIFT) were contacted and asked to provide data on patients treated and pregnancy rates. These figures were then combined to produce life tables to determine the likelihood of pregnancy with repeated attempts. SETTING: IVF/GIFT units in five States of Australia, the Australian Capital Territory and New Zealand. Eighteen of the 22 units provided data to be analysed. PATIENTS: Data were available for analysis on 18,089 cycles of IVF resulting in 3034 clinical pregnancies, and 6308 cycles of GIFT resulting in 1724 clinical pregnancies. MAIN OUTCOME MEASURES: This was either "clinical pregnancy" (the presence of products of conception on ultrasound examination), or "viable pregnancy" (a pregnancy developing to at least 20 weeks of gestation). RESULTS: After four attempts at IVF, half the couples achieved a pregnancy, whereas four attempts at GIFT resulted in two-thirds of the couples achieving pregnancy. CONCLUSION: Both IVF and GIFT are effective and successful options for infertile or subfertile couples. New Reproductive Technology should be readily available in every advanced clinic dealing with subfertile couples in the 1990s.

Australia↗
PubMed1999

Obstetric outcome and psychological follow-up of pregnancies after embryo reduction.

The obstetric outcome and psychological follow-up of the parents after embryo reduction performed at Sahlgrenska University Hospital between 1993 and 1997 in 13 women treated for infertility is described. A comparison is made with non-reduced multiple pregnancies, both spontaneous and multiple pregnancies after assisted reproduction technology. Altogether 10 triplets, two quadruplets and one quintuplet pregnancy underwent embryo reduction. The surgical procedure was performed in gestation week 7-8 by transvaginal, ultrasound-guided aspiration of embryonic tissue. The psychological follow-up included personal interviews and psychological evaluations by a Psychological General Well-being Scale (PGWB) and Beck's Depression Inventory (BDI). In 11 cases reduction was performed to twin pregnancies. In two cases of triplets after in-vitro fertilization and transfer of two embryos, reduction was performed on the monozygotic, monochorionic twins. No complete miscarriages occurred. Ten women delivered twins and three women delivered singletons. The mean gestation length was 40.4 weeks for singletons and 35.9 weeks for twins. The mean birthweight was 3411 g for singletons and 2392 g for twins. No complications related to the reduction were detected in the children.The psychological follow-up showed that the psychological well-being of the parents was good. However, the events around the reduction were experienced as chaotic and emotionally disturbing. One woman regretted the reduction. All couples emphasized that avoidance of high order pregnancies should be of primary importance. In conclusion, embryo reduction appears to improve the perinatal outcome of multiple pregnancies obtained after assisted reproduction technology. It is important that the surgical procedure is performed at a centre with experience of this type of intervention, by a limited number of surgeons and in a regulated manner. Psychologically, however, the intervention is traumatic and psychological management is essential for good final outcome.

Adult↗
PubMed2004

[Prognosis of the reproduction health care in the Czech Republic until 2010: II. Planned parenthood].

OBJECTIVE: To prepare a prognosis of development of contraception, artificial termination of pregnancy and asisted reproductive technologies until 2010, based on the trend in their indicators in the previous years. DESIGN: A retrospective epidemiological study to be used as a basis for the prognosis SETTING: Mother and Child Care Institute, Prague - Podolí METHODS: For outlining the probable trend in the use of various types of contraceptives (IUD) as well as for artificial termination of pregnancy, evaluated according to their internationally recognised indicators, the extrapolation of the trends in these criteria prevalent in the period 1995-2002 was used. RESULTS: The prognosis of increase in the number of female users of hormonal contraception at the expense of IUD as well as the decrease in the number of women solving their problem with unwanted pregnancy by artificial termination of pregnancy (ATP), based on the said extrapolation of their indicators with a prospect until 2010, is probably overly optimistic. Due to probable changes in the political, social and economic circumstances as well as in the women's attitudes, it is expected that this trend will slow down. This is why it is expected that the number of female users of hormonal contraception will increase merely to 500 and that the women using IUD will decrease to 50 per 1,000 fertile women. Also, as concerns the number of ATPs, it is expected that it will decrease merely just below 10 for every 1,000 fertile women and to 20 for every 100 births. Even if the trends of all these indicators slow down, it can be expected that they will reach the average levels reported in the countries of Western Europe. As for the trend in asisted reproductive technologies (ART), whose share in the total number of births will rise, the main emphasis will be put on consistent nationwide registration, amendments to legislation and research mainly in the area of psycho-neurological development of these children, as recommended by the WHO. CONCLUSION: The expected rate of growth of the number of female users of effective contraception and the expected rate of decline of the number of ATPs, corresponding to the trend of the recent years, will probably decrease by 2010 but the average levels reported by the countries of Western Europe will still be reached. According to the recommendation of the WHO, the trend in some forms of ART will require research in the field of psycho-neurological development of the children from these pregnancies until they reach adulthood as well as some amendments to legislation.

Abortion, Induced↗
PubMed2001

Follicular development in cryopreserved Common Wombat ovarian tissue xenografted to Nude rats.

The Northern Hairy-nosed Wombat (Lasiorhinus krefftii) is a highly endangered marsupial species and every possible option for sustaining the species needs to be explored. One important approach may be the development of assisted reproductive technologies in the non-endangered Common Wombat (Vombatus ursinus) and Southern Hairy-nosed Wombat (Lasiorhinus latifrons) for application in breeding the Northern Hairy-nosed Wombat. In this study, it was examined whether cryopreserved Wombat ovarian tissue would develop following xenografting to immunologically deficient rats. Ovarian tissue was collected from Common Wombats (n = 3) and cryopreserved as small cortical pieces. After thawing the cortical pieces were grafted underneath the kidney capsule of Nude rats (n = 16). The grafts were recovered at 2, 4, and 10 weeks after transplantation and their gross and histological appearance investigated. Two weeks after grafting (n = 2), the tissue was revascularized and healthy primordial follicles were present. At week 4 (n = 2), some follicular development was present. At week 10, six rats received human chorionic gonadotrophin (hCG) to trigger follicle and oocyte maturation while another six rats were not given any treatment. The administration of hCG did not induce preovulatory follicles and oocyte maturation although type 5 follicles were present in ovarian tissue collected 10 weeks posttransplantation in both treated and untreated groups. This study demonstrates for the first time that Wombat ovarian tissue can survive and function when grafted into immunocompromized rats and that Wombat ovarian follicles can be recruited to growth and development in an ovarian xenograft. This model system has the potential to produce mature oocytes from endangered species for use in assisted reproductive technologies such as in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), and mature oocytes from non-endangered species for nuclear transfer which may be necessary for the preservation of critically endangered species.

Animals↗
PubMed2001

In vitro fertilization for cancer patients and survivors.

OBJECTIVE: To determine in vitro fertilization (IVF) outcome in cancer patients. DESIGN: Retrospective record review. SETTING: Academic, hospital-based assisted reproductive technology (ART) program. PATIENT(S): Sixty-nine women undergoing 113 IVF/gamete intrafallopian transfer (GIFT) cycles after cancer treatment in one partner, and 13 women undergoing 13 IVF cycles for embryo cryopreservation before chemotherapy/radiation. INTERVENTION(S): IVF, intracytoplasmic sperm injection (ICSI), assisted hatching, and gamete intrafallopian transfer as indicated. MAIN OUTCOME MEASURE(S): Delivery rate, spontaneous abortion rate, number of embryos cryopreserved, cancer diagnosis, systemic or local cancer treatment, female age, amount of gonadotropin used, treatment duration, peak estradiol level, and number of oocytes and embryos. RESULT(S): The women undergoing IVF after chemotherapy had poorer responses to gonadotropins than did the women with locally treated cancers even though they were younger (33.5 +/- 1.3 vs. 36.5 +/- 0.5 years; P<.05). The delivery rates after the women had undergone chemotherapy tended to be lower among the systemic treatment group than it was for the local cancer treatment group: (13.3% [2 of 15] vs. 40% [14 of 56, P=NS]). The women who had cryopreserved all embryos before chemotherapy produced more oocytes (18.7 +/- 3.2 vs. 14.5 +/- 1.2) and embryos (11.3 +/- 1.9 vs. 7.5 +/- 0.7) than did the women who had had a history of local cancer treatment. Male factor infertility as a result of cancer treatment is well treated with IVF or intracytoplasmic sperm injection, where indicated (32% delivery rate/cycle), with no difference between the frozen sperm banked before cancer treatment and fresh sperm produced after treatment. CONCLUSION(S): Chemotherapy diminishes the response to ovulation induction in assisted reproductive technologies. IVF with cryopreservation of embryos allows embryo banking before chemotherapy for women who have been newly diagnosed with cancer. Factors related to the partner affect the success of IVF for male factor infertility as a result of cancer treatment.

Abortion, Spontaneous↗
PubMed2002

Stimulation and growth of antral ovarian follicles by selective LH activity administration in women.

Intensive FSH stimulation is a key tool of assisted reproduction technology but can cause severe complications through the development of an excessive number of small ovarian follicles. We tested the hypothesis that, in the late stages of ovulation induction, LH activity in the form of low-dose human CG (hCG) can stimulate and selectively modulate ovarian follicle function and growth, independently of FSH administration. Four groups of GnRH agonist-suppressed normoovulatory women (10 each group) received recombinant human FSH (r-hFSH) (150 IU/d) for 7 d followed by: group A, r-hFSH 150 IU/d alone; group B, r-hFSH 50 IU/d and hCG 50 IU/d; group C, r-hFSH 25 IU/d and hCG 100 IU/d; group D, hCG 200 IU/d alone. Despite several days of lowered or absent r-hFSH administration, 70% of hCG-treated patients successfully completed treatment. In these subjects, preovulatory E2 levels and large (>14 mm diameter) ovarian follicle development were not reduced; conversely, the number of small (<10 mm diameter) ovarian follicles was significantly decreased in groups B-D vs. group A. Low-dose hCG administration did not cause follicle luteinization. We conclude that, following FSH priming, LH activity administration can: 1) stimulate folliculogenesis for several days, in spite of rapidly declining FSH levels; and 2) hasten small follicle demise. Therefore, LH activity administration could be used to design radically novel ovulation induction regimens that, by partly or completely replacing mid-/late follicular phase FSH administration, may reduce costs and improve safety of assisted reproduction technology.

Adult↗
PubMed2004

The effect of oocyte quality on development.

Oocyte quality affects early embryonic survival, the establishment and maintenance of pregnancy, fetal development, and even adult disease. Quality, or developmental competence, is acquired during folliculogenesis as the oocyte grows, and during the period of oocyte maturation. Assisted reproductive technologies involving ovarian hyperstimulation, or collection of immature oocytes followed by maturation in vitro, perturb this process and result in oocytes with reduced quality. In domestic livestock species, offspring have been produced using in vitro oocyte maturation, although only a small percentage of the original pool of immature oocytes is capable of developing to the blastocyst stage and subsequently resulting in pregnancy. In vitro maturation, as it is currently undertaken, does not support the correct development of oocyte competence. Follicle size affects oocyte quality, potentially implicating messenger RNA or protein stores as factors involved in oocyte competence. Oocytes from preantral follicles grown in vitro are competent to resume meiosis, although development to the blastocyst stage is decreased. An offspring from oocytes produced using this technique was normal at birth but experienced delayed onset health issues, highlighting the importance of oocyte quality long after embryogenesis. Metabolism may play a critical role in oocyte quality because glycolytic activity in mature oocytes is correlated with increased embryonic development. Communication between the oocyte and its surrounding cumulus cells is also important for the development of a competent oocyte. Ovarian stimulation causes delayed embryonic development, increased abnormal blastocyst formation, fetal growth retardation, and increased fetal loss. Thus, although meiosis and even early development may be completed successfully, there are a variety of other processes occurring within the cytoplasm of the oocyte that are required for complete developmental competence. However, the cellular mechanisms that impart oocyte quality are unclear. Until the mechanisms involved in oocyte quality are elucidated, any effort to use assisted reproductive technologies in animals for production or biomedical purposes will be inefficient at best.

Animals↗
PubMed2005

The effect of Mycoplasma mycoides ssp. mycoides LC of bovine origin on in vitro fertilizing ability of bull spermatozoa and embryo development.

Several Mycoplasma species may adversely affect bovine spermatozoa viability and embryo development. Mycoplasma mycoides ssp. mycoides large-colony (LC) has been isolated from naturally aborted bovine fetuses and from bull semen. The objective of this study was to evaluate whether M. mycoides ssp. mycoides LC contaminated bovine ejaculates could (i) impair in vitro fertilizing ability of bull spermatozoa, (ii) impair embryo development, and (iii) evaluate potential spread by reproductive technologies. In the present study, spermatozoa of 10 fertile bulls were contaminated with M. mycoides ssp. mycoides LC, at a final concentration of 1.5 million CFU/ml and incubated for 60 min before evaluating spermatozoa motility and acrosome reaction inducibility with calcium ionophore. In addition, in vitro contaminated semen of a bull previously shown to have a good in vitro fertilizing ability, was used in an IVF procedure. Embryo development stage on Day-7 of culture was evaluated. Spermatozoa and embryos at morula and blastocyst stages were routinely processed for transmission electron microscopy observation. Both mean total and progressive motility decreased (P < 0.01 ) upon spermatozoa incubation with Mycoplasma. One-hour incubation with calcium ionophore increased the percentage of acrosome-reacted spermatozoa, although Mycoplasma contamination reduced calcium ionophore treatment efficacy (P < 0.05). Ultrastructurally, Mycoplasma microorganisms appeared as moderately electron-dense sphere-shaped particles, adhering to cell membranes. Sperm mid-piece sections showed numeric aberrations of the central singlets such as nine + zero or nine + one of the axonemal complex. Further morphological abnormalities included partial or total absence of dinein arms and radial fibers, with lack of the bridge and the central ring in 35.00 +/- 4.20% of contaminated cells, whereas these abnormalities were not observed in uninfected ones. The IVF trials showed that two-four cell blocks were higher (P < 0.05) in the infected group. Ultrastructure of Day-7 contaminated embryos showed Mycoplasma particles adhering and infiltrating the outer layer of the zona pellucida. Our investigations suggest that M. mycoides ssp. mycoides LC contaminating the bovine ejaculate induced adverse effects on in vitro spermatozoa-fertilizing ability and embryonic development. Some satisfactory quality transferable embryos could be produced in contaminated IVF systems. This could imply a potential transmission of this microorganism through reproductive technologies.

Acrosome Reaction↗
PubMed2003

Cumulus cells steroidogenesis is influenced by the degree of oocyte maturation.

BACKGROUND: The possibility to predict the ability of a germ cell to properly sustain embryo development in vitro or in vivo as early as possible is undoubtedly the main problem of reproductive technologies. To date, only the achievement of nuclear maturation and cumulus expansion is feasible, as all the studies on cytoplasmic maturation are too invasive and have been complicated by the death of the cells analyzed. The authors studied the possibility to test the cytoplasmic quality of pig oocytes by evaluating their ability to produce steroidogenesis enabling factor(s). To this aim, oocytes matured under different culture conditions that allowed to obtain gradable level of cytoplasmic maturation, were used to produce conditioned media (OCM). The secretion of the factor(s) in conditioned media was then recorded by evaluating the ability of the spent media to direct granulosa cells (GC) steroidogenesis. METHODS: In order to obtain germ cells characterized by a different degree of developmental competence, selected pig oocytes from prepubertal gilts ovaries were cultured under different IVM protocols; part of the matured oocytes were used to produce OCM, while those remaining were submitted to in vitro fertilization trials to confirm their ability to sustain male pronuclear decondensation. The OCM collected were finally used on cumulus cells grown as monolayers for 5 days. The demonstration that oocytes secreted factor(s) can influence GC steroidogenesis in the pig was confirmed in our lab by studying E2 and P4 production by cumulus cells monolayers using a radioimmunoassay technique. RESULTS: Monolayers obtained by growing GC surrounding the oocytes for five days represent a tool, which is practical, stable and available in most laboratories; by using this bioassay, we detected the antiluteal effect of immature oocytes, and for the first time, demonstrated that properly matured germ cells are able to direct cumulus cells steroidogenesis by inhibiting E2 production (P < 0.01). Nevertheless, only fully competent oocytes were able to suppress estrogens production, while those cultured under unfavourable conditions were unable to exert any inhibitory effect on the functions of cumulus cells (P < 0.01). CONCLUSION: These results demonstrated that good quality oocytes can be easily selected on the basis of their ability to affect granulosa cell steroidogenesis thus reducing failures in reproductive technologies due to the transfer of fertilized oocytes with a scarce ability to sustain embryo development.

Animals↗
PubMed2004

Vitrification of pronuclear-stage mouse embryos on solid surface (SSV) versus in cryotube: comparison of the effect of equilibration time and different sugars in the vitrification solution.

The cryopreservation of pronuclear-stage embryos has particular importance in transgenic technology and human assisted reproductive technology (ART). The objective of this study was to improve the efficiency of cryopreservation of pronuclear-stage mouse embryos. Two vitrification methods (solid surface vitrification (SSV) vs. vitrification in cryotube) have been compared with special emphasis on the effect of the exposure of the embryos to the solutions for various times and the sugar content (trehalose, sucrose, or raffinose) of the vitrification solutions. Pronuclear-stage embryos were either exposed to 1 M dimethyl sulfoxide (DMSO) + 1 M propylene-glycol (PG) solution for 2, 5, 10, or 15 min or not exposed to this "equilibration" solution. The vitrification solutions consisted of 2.75 M DMSO and 2.75 M PG in M2 medium supplemented with 1 M trehalose (DPT), 1 M sucrose (DPS), or 1 M raffinose (DPR). In the cryotube method, groups of 15-25 embryos were transferred into a 1.8 ml cryotube containing 30 microl of DPT, DPS, or DPR. After 30 sec, the cryotubes were directly plunged into liquid nitrogen (LN(2)) and stored for 1 day to 1 month. Vitrified samples were warmed by immersing the cryotubes in a 40 degrees C water bath and then immediately diluted with 300 microl of 0.3 M trehalose, sucrose, or raffinose in M2. In the SSV method, after equilibration 15-20 embryos were exposed to DPT, DPS, or DPR solutions for around 20 sec before being dropped in 2-microl drops onto a pre-cooled (-150 to -180 degrees C) metal surface. Vitrified droplets were stored in cryovials in LN(2). Warming was performed by transferring the vitrified droplets into 0.3 M solutions of trehalose, sucrose, or raffinose at 37 degrees C, respectively. Results showed that both SSV and cryotube vitrification methods can result in high rates of in vitro blastocyst development (up to 58.3 and 68.5% with DPR, respectively), not statistically different from that of the controls (58.3 and 64.4%). Even without the equilibration step prior to vitrification, relatively high-survival rates have been achieved, except for the DPS solution. In conclusion, vitrification of pronuclear-stage mouse embryos can result in high rates of in vitro development to blastocyst, and the use of raffinose in the vitrification solution is advantageous to improve cryosurvival.

Animals↗
PubMed2001

Ethnographic critique and technoscientific narratives: the old mole, ethical plateaux, and the governance of emergent biosocial polities.

A reading of the puzzle novel Vienna Blood, by Adrian Mathews, is juxtaposed to three ethnographic sketches of contemporary ethical plateaus or domains of ethical challenge--the challenges of informed public consent to new technologies, the seductions to do whatever is medically possible (sometimes at the expense of quality of life or the good death'). and the power of money in driving the biotechnological industries. Vienna Blood deals with precautionary germplasm modification and chemical camouflage justified as protection against ethnically-targeted biological warfare, and touches on a series of technologies such as new reproductive technologies, genetic engineering, and cryptographic attacks and defenses, as well as the ability to evade regulatory controls. Such technoscientifically informed novels are useful as cautionary tales, in exploring the complexity and interaction among new technologies, and the phantasmagoria that help drive new technologies. They are not so good at thinking through institutional development: a challenge for ethnography and new social theory. Ethnography, like novels, can function as checks on the mechanisms of abstraction and universalization that frequently bedevil the non-anthropological, non-cross-culturally or cross-temporally comparative, social sciences. Questions are raised about new or emergent biosocialities, forms of governance, and forms of cultural critique.

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