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PubMed2003

Screening of some variables influencing the results of embryo transfer in the ewe. Part II: two-day-old embryos.

Each of sixty Rasa aragonesa ewes received two embryos on Days 2-3 of the estrous cycle (Day 0=estrus) from 27 donors of the same breed that were superovulated with pFSH. The influence of several variables on fertility and prolificacy after transfer was studied by discriminant analysis. Our results showed that the main variables contributing to higher fertility were: in the donor-recipient couple, degree of estrus synchrony between them (better if donors were in estrus before recipients); in recipients, interval from FGA withdrawal to estrus onset, prolificacy in the previous lambing, age (all, better if inferior to the mean) and interval from the previous lambing (better if superior to the mean); in donors, ovulation rate (better if lower than the mean); and in embryos, developmental stage (better if superior to the mean). Likewise, the main variables contributing to higher prolificacy were: in donors, body condition score (better if higher than the mean) and weight (better if inferior to the mean); and in recipients, plasma progesterone concentration at transfer (better if inferior to the mean). The percentage of ewes correctly classified as lambing or not was 71.7% (P<0.01), and 72.5% of the ewes were correctly classified as having one or two lambs (P<0.05). Whether the criteria we have found for optimum results after transfer are applicable or not to conditions other than ours will need to be confirmed.

Age Factors↗
PubMed1981

Role of haem in the induction of cytochrome P-450 by phenobarbitone. Studies in chick embryos in ovo and in cultured chick embryo hepatocytes.

The role of haem synthesis during induction of hepatic cytochrome P-450 haemoproteins was studied in chick embryo in ovo and in chick embryos hepatocytes cultured under chemically defined conditions. 1. Phenobarbitone caused a prompt increase in the activity of 5-aminolaevulinate synthase, the rate-limiting enzyme of haem biosynthesis, and in the concentration of cytochrome P-450. This induction response occurred without measurable initial destruction of the haem moiety of cytochrome P-450. 2. When intracellular haem availability was enhanced by exogenous haem or 5-aminolaevulinate, phenobarbitone-medicated induction of cytochrome P-450 was not affected in spite of the well known repression of 5-aminolaevulinate synthase by haem. These data are consistent with the concept that haem does not regulate the synthesis of cytochrome P-450 haemoproteins. 3. Acetate inhibited haem biosynthesis at the level of 5-aminolaevulinate formation. When intracellular haem availability was diminished by treatment with acetate, phenobarbitone-medicated induction was decreased. 4. This inhibitory effect of acetate on cytochrome P-450 induction was reversed by exogenous haem or its precursor 5-aminolaevulinate. These data suggest that inhibition of haem biosynthesis does not decrease synthesis of apo-cytochrome P-450. Moreover, they indicate that exogenous haem can be incorporated into newly formed aop-cytochrome P-450.

5-Aminolevulinate Synthetase↗
PubMed1999

Antioxidant systems of the avian embryo: tissue-specific accumulation and distribution of vitamin E in the turkey embryo during development.

Tissue-specific accumulation of tocopherols and tocotrienols in turkey tissues during embryonic development and their susceptibility to lipid peroxidation were investigated. Fertile turkey eggs were incubated using standard commercial conditions. Embryonic tissues were collected at 16, 22, 25 d of incubation and from day-old poults (referred to as day 29) and alpha-; beta- + gamma- and delta-tocopherols and respective tocotrienols were analysed by HPLC. A turkey diet provided to the parent hens contained the complete range of tocopherols and tocotrienols. Between days 16 and 22 of embryo development, the alpha-tocopherol concentration in the liver remained constant and then increased significantly (P<0.01) reaching a maximum just after hatching. Similar changes were observed for the other tocopherols and tocotrienols. The accumulation of alpha-tocopherol in the yolk sac membrane (YSM) started after day 20 of development and at hatching the alpha-tocopherol concentration in the YSM was twice that of beta- + gamma-tocopherols and 15 times greater than that of alpha-tocotrienol. In the kidney, heart, lung, muscle and adipose tissues a gradual increase in tocopherol and tocotrienol concentrations took place between days 20 and 25 of development with a sharp increase in particular of alpha-tocopherol between days 25 and 29. There was a discrimination between tocopherols and tocotrienols during their assimilation from the diet by the parent hen and during metabolism by the developing turkey embryo. Tissue-specific features in the susceptibility to lipid peroxidation were found with the brain being the most susceptible to lipid peroxidation at day 25 and in day-old poults.

Animal Feed↗
PubMed1999

Successful non-surgical management of a heterotopic abdominal pregnancy following embryo transfer with cryopreserved-thawed embryos.

Heterotopic pregnancy is an increasingly common complication of assisted reproductive technology. Abdominal pregnancy is a rare and life-threatening form of ectopic pregnancy that can present as the extrauterine portion of a heterotopic pregnancy. We present the case of a cryopreserved-thawed embryo transfer that resulted in a simultaneous intrauterine and abdominal pregnancy first recognized at 10 weeks gestation. Ultrasound-guided transvaginal injection of potassium chloride into the abdominal pregnancy resulted in asystole and spontaneous resorption of the ectopic fetus, while the intrauterine pregnancy continued and resulted in a liveborn vaginal delivery at full term. Selective embryo reduction using a non-surgical approach in a haemodynamically stable patient can therefore be considered in the management of heterotopic abdominal pregnancy if diagnosed relatively early.

Adult↗
PubMed2000

Embryo implantation and GnRH antagonists: embryo implantation: the Rubicon for GnRH antagonists.

When gonadotrophin-releasing hormone (GnRH) was discovered, the agonist and antagonist of GnRH were developed to control the release of FSH and LH by the gonadotrophs. More than 10 years of research were needed to develop a GnRH antagonist free of histamine release. Recent studies have shown that these GnRH antagonists are effective in preventing a rise in LH during ovarian stimulation in IVF. However, a decrease in ongoing pregnancies seems to suggest that implantation rates per transferred embryo are reduced in GnRH antagonist-stimulated cycles. In my opinion, these data highlight an area less well known to clinicians: the role of the GnRH antagonist at the cellular level in extrapituitary tissues. There are sufficient data in the literature suggesting that GnRH antagonist is an inhibitor of the cell cycle by decreasing the synthesis of growth factors. Given that, for folliculogenesis, blastomere formation and endometrium development, mitosis is everything; the interaction between the GnRH antagonist and the GnRH receptor (present in all these cells and tissues) may compromise the mitotic programme of these cells. This is the Rubicon for the GnRH antagonist: to demonstrate irrevocably that, at the minimal doses necessary to suppress LH release, it does not affect processes such as implantation, embryo development and folliculogenesis.

Animals↗
PubMed1990

Comparison of concurrent pregnancy rates for in-vitro fertilization--embryo transfer, pronuclear stage embryo transfer and gamete intra-fallopian transfer.

Concurrent pregnancy and implantation (sacs/embryos transferred) rates were compared for 84, 77 and 49 cases of in-vitro fertilization-embryo transfer (IVF-ET), pronuclear stage embryo transfer (PROST) and gamete intra-Fallopian transfer (GIFT), respectively. All cases reported occurred during an 18-month interval since the initiation of PROST by our programme. Leuprolide acetate was used with follicle stimulating hormone and human menopausal gonadotrophin for follicular stimulation of all but donor oocyte cases (n = 9). Clinical pregnancy (per transfer) and implantation rates were significantly higher (P less than 0.03) for PROST (52.4%, 20.2%) in comparison with IVF-ET (26.9%, 11.4%). Rates for GIFT (48.9%, 18.4%) were not significantly higher (P = 0.10, 0.14) than for IVF-ET. This was probably due to the lower number of GIFT than PROST procedures performed. The total pregnancy rate for GIFT (biochemical, ectopic and clinical combined) was significantly greater (P less than 0.05) than for IVF-ET. Pregnancy and implantation rates for PROST and GIFT were similar. These results support the use of PROST rather than IVF-ET for all cases in which the woman has one functional Fallopian tube. Furthermore, to maintain equivalent rates of pregnancy with PROST and GIFT, it is suggested that GIFT should not be used for cases of male-factor infertility without first documenting normal rates of in-vitro fertilization with PROST.

Adult↗
PubMed2005

Chicken embryo extract mitigates growth and morphological changes in a spontaneously immortalized chicken embryo fibroblast cell line.

The SC-1 spontaneously immortalized chicken embryo fibroblast (CEF) cell line has been established recently. Although this cell line had been in culture for over 3 yr, its growth rate has remained lower than that of primary CEF cells, and the morphology has not been as uniform as observed in primary cells. In the present study, the SC-1 cell line was treated with chicken embryo extract (CEE) to determine whether growth rates could be increased and cell morphology enhanced. The CEE also was tested on primary CEF cells, another spontaneously immortalized CEF cell line (DF-1), and on 2 other nonvirally and nonchemically immortalized CEF cell lines (BCEFi and HCEFi). Results indicated that concentrations of CEE > or = 100 microg/mL inhibited growth of all cells tested. However, addition of 50 microg of CEE/mL enhanced the growth rate and improved the morphology of the SC-1 cells. Addition of CEE to the other immortal or primary CEF cells did not increase the growth rate or change their morphology. Analysis of mRNA expression revealed that SC-1 cells treated with 50 microg of CEE/mL had lower levels of the p16(INK4a) alternate reading frame sequence (ARF) and E2F-1 than untreated SC-1 cells. The increased growth rate and improved morphology of the SC-1 cells achieved with CEE treatment were retained following removal of CEE, and these improvements should aid in increasing the utility of the SC-1 cell line as a cellular/molecular reagent.

Animals↗
PubMed2006

Is elective single embryo transfer a cost-effective alternative to double embryo transfer?

Elective single embryo transfer (eSET) is increasingly being considered as a means to reduce twin pregnancies associated with in vitro fertilisation treatment. However, it is important to consider the cost-effectiveness of alternative strategies when considering a change in policy. A review of the literature showed only five studies assessing both costs and consequences of strategies involving eSET compared with double embryo transfer. Several limitations in these studies prevent a definitive conclusion on the cost-effectiveness of eSET being reached. Future economic evaluations need to compare strategies relevant to routine practice, include all relevant costs, measure and value longer term outcomes appropriately, and assess the cost-effectiveness of eSET across different subgroups of women.

Cost-Benefit Analysis↗
PubMed1983

Comparison of the continuous cell line 293 with human embryo kidney cells and human embryo fibroblast cells for the cultivation of ocular viruses.

The continuous cell line 293 was evaluated as a replacement for primary human embryo kidney (HEK) cells in the cultivation of ocular viruses. The 293 cells were found to be as sensitive as HEK cells and human embryo fibroblast (HEF) cells for the cultivation of adenoviruses and herpes simplex virus (HSV) respectively. As a continuous cell line, 293 cells are preferable to HEK and HEF cells for the routine isolation of ophthalmic viruses.

Adenoviridae↗
PubMedDate not supplied

Human research cloning, embryos, and embryo-like artifacts.

Research suggests that cloning is incapable of producing a viable embryo when it is used on primate eggs. In fact, the entity created may not qualify as an embryo at all. If the results stand, cloning avoids the moral objections typically lodged against it, and cloning is itself an "alternative source" of stem cells.

Blastocyst↗
PubMed1988

Antagonists of embryo-derived platelet-activating factor prevent implantation of mouse embryos.

Inhibitors of platelet activation, alprazolam, iloprost and SRI 63-441, were used to demonstrate the necessity of embryo-derived platelet-activating factor (PAF) activity for the establishment of pregnancy in mice. In a splenectomized mouse bioassay 6 micrograms alprazolam inhibited, for 3 h, the thrombocytopenia induced by 0.1 micrograms PAF; 4 micrograms iloprost and 0.5 microgram SRI 63-441 were effective for 6 and 12h respectively. The administration of 2 micrograms iloprost/30 g body weight on Days 1 and 4 of pregnancy and twice daily on Days 2 and 3 caused a 50% reduction (P less than 0.0005) in the number of implantation sites in the uterus at Day 8 of pregnancy, without affecting (P greater than 0.05) the number of corpora lutea. A similar reduction in the number of implantation sites was achieved with 20 micrograms SRI 63-441/30 g body weight/day. The reduction in implantation rate was evident on Day 5 of pregnancy by visualizing the implantation sites with pontamine sky blue. SRI 63-441 had no effect on peripheral blood progesterone concentrations from Day 1 to Day 9 of pregnancy, and did not appear to inhibit implantation by blocking the preimplantation surge of oestradiol. The number and morphology of blastocysts flushed from the uterus of Day 4 inhibitor-treated mice was not different (P greater than 0.05) from the controls. The cleavage rate and morphology of embryos cultured from the 2-cell to blastocyst stage in media containing SRI 63-441 or iloprost (10 micrograms/ml) were normal, precluding a gross toxic effect. Simultaneous administration of 1 microgram PAF-acether to treated animals re-established pregnancy rates to levels not significantly different (P greater than 0.05) from the controls.

Alprazolam↗
PubMed2004

Effects of embryo culture on global pattern of gene expression in preimplantation mouse embryos.

Culture of preimplantation embryos affects gene expression. The magnitude of the effect on the global pattern of gene expression, however, is not known. We compared global patterns of gene expression in blastocysts cultured from the one-cell stage in either Whitten's medium or KSOM + amino acids (KSOM/AA) with that of blastocysts that developed in vivo, using the Affymetrix MOE430A chip. The analysis revealed that expression of 114 genes was affected after culture in Whitten's medium, whereas only 29 genes were mis-expressed after culture in KSOM/AA. Expression Analysis Systematic Explorer was used to identify biological and molecular processes that are perturbed after culture and indicated that genes involved in protein synthesis, cell proliferation and transporter function were down-regulated after culture in Whitten's medium. A common set of genes involved in transporter function was also down-regulated after culture in KSOM/AA. These results provide insights as to why embryos develop better in KSOM/AA than in Whitten's medium, and highlight the power of microarray analysis to assess global patterns of gene expression.

Amino Acids↗
PubMed2000

In vitro manipulation of nonhuman primate gametes for embryo production and embryo transfer.

Since nonhuman primates are closely related to humans and share many physical similarities, they are important for use in research areas such as human infectious diseases, reproduction, physiology, endocrinology, metabolism, neurology and longevity. To develop and maintain these animals, we must establish techniques for in vitro manipulation of spermatozoa and eggs. For a decade my research group has been conducting basic research to establish embryo manipulation techniques and to clarify the reproductive phenomena in nonhuman primates. This article summarizes the past research on in vitro manipulation of nonhuman primate gametes, from collection of reproductive cells and in vitro fertilization to the birth of offspring after embryo transfer, as well as the current status of these research areas. The studies summarized here will directly lead to the development of standard techniques for practical and comprehensive use in nonhuman primates.

Animals↗
PubMed2001

Cumulative pregnancy rates after four embryo transfers of either fresh or frozen embryos.

PURPOSE: To evaluate in the modern era of in vitro fertilization (IVF) cumulative probability of pregnancy for the first four embryo transfers (ET) irrespective of whether the embryos were fresh or frozen. METHODS: Retrospective review over a 2 1/2 year period. Cumulative probability of pregnancy for four consecutive cycles of either fresh or frozen ETs divided into four age groups. RESULTS: The cumulative clinical and viable pregnancy rates after four ETs were 92% and 88%; 87% and 82%; 83% and 69%; and 68% and 52% for age groups <30, 30-34, 35-39, and 40-44. The cumulative rates decline with age. CONCLUSIONS: Pregnancy rates per transfer for the first four ETs regardless of age are similar even in IVF centers that emphasize frozen ETs.

Adult↗
PubMedDate not supplied

[Statistical and frequency-amplitude characteristics of ultra-weak emissions of loach eggs and embryos under normal conditions and on their optic interactions. II. Changes in characteristics of ultra-weak emissions upon optic interaction of groups of embryos of different ages. ].

We compared the characteristics of ultraweak emissions from groups of loach embryos of different ages in the presence or absence of optic interaction. The percentage of zero values of emission gradually increased during the first hour of optic interaction. The number and height of rare big pulses estimated by the value of kurtosis increased in parallel. In addition, the correlation between the Fourier spectra of optically interacting samples decreased at a higher rate than in the absence of optical contact. Just after the 1-hour optic interaction was terminated, the number of high pulses decreased in a younger interacting group and increased in the older one and the farther away the partner groups were in developmental stages, the more pronounced these differences were. Measurements of the Fourier spectra after long-term (12-22-hour) optic interactions have shown that an "exchange" of autocorrelation characteristics of the spectra took place among the samples: the sums of autocorrelation coefficients were inverted in the vast majority of cases, often with an "overshoot" or, at least, were smoothed over with reference to the control samples. We conclude that the previously described effects of optic interactions between groups of loach embryos of different ages could be due to changes in the frequency spectra of their ultraweak emissions.

Animals↗
PubMed1977

Cell transplantation into immunodeficient chicken embryos. Reconstituting capacity of cells from the yolk sac at different stages of development and from the liver, thymus, bursa of Fabricius, spleen and bone marrow of 15-day embryos.

Cyclophosphamide-treated 18-day-old chicken embryos were transplanted with histocompatible cells from the yolk sac at different stages of development and from the liver, thymus, bursa of Fabricius, spleen and bone marrow of 15-day-old-embryos. At the age of 36 days, the cell recipients were studied to determine the reconstitution capacity of the transplanted cells. The parameters used include the survival pattern, gain of body weight, antibody-forming capacity, response of peripheral blood lymphocytes to Con A, weight and microscopic morphology of the bursa of Fabricius, and weight of spleen and thymus. By all the criteria employed, only bursa cells were capable of a functional and morphological reconstitution of the recipient's humoral immune system. These data indicate that the role of the yolk sac as the first generator of prebursal stem cells remains questionable. In addition, these findings confirm the previous observations that, as a differentiation site of the B-cell lineage, the bursa of Fabricius precedes the bone marrow during ontogenetic development.

Animals↗
PubMed1985

[Hypothalamo-hypophyseal correlates in the chick embryo: thyrotropic activity of adenohypophyseal grafts from donor embryos of various ages. Effect or pretreatment with TRH].

Adenohypophyses from 10 to 18-day-old chick embryonic donors grafted in 3 days chick embryos, thus disconnected from the hypothalamus, had a partially autonomous thyrotrophic activity. However this functional autonomy was greater in grafts from donors aged 10 or 11 days than from older embryos or from 11-day donors pretreated with T.R.H. before grafting. This strongly suggests that hypothalamo-adenohypophysis-thyroidal relationship establish normally between 11 and 12 days of embryonic life.

Animals↗
PubMed1986

In ovo interference of embryo non-lethal avian infectious bronchitis viruses (IBV) with velogenic Newcastle disease virus and embryo adapted IBV.

Avian infectious bronchitis virus (IBV) interfered with the lethal effects of velogenic Newcastle disease virus (NDV) and embryo adapted IBV in eggs previously inoculated with non-lethal IBV. Greater interference was noted in eggs superinfected with embryo adapted IBV than velogenic NDV. The interference could be eliminated by treating the initial IBV with homologous anti-IBV serum.

Animals↗