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Results 401 - 450 of 1205
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Jerez Adriana - - 2003
Topological and histological analyses of Mabuya mabouya embryos at different developmental stages showed an extraembryonic membrane sequence as follows: a bilaminar omphalopleure and progressive mesodermal expansion around the whole yolk sac at gastrula stages; mesodermal split and formation of an exocoelom in the entire embryonic chamber at neurula stages; beginning ...
Kim Won Kyu - - 2003
BACKGROUND: The existing data on intestinal rotation during human development are contradictory regarding the timing of major events, and as such an exact timetable for rotation of the intestine in humans is not yet available. METHODS: We studied the initial formation and rotation of the intestine by microdissection and histological ...
Lagutina Irina - - 2004
In this study, we compared the developmental capacity of bovine haploid and diploid androgenetic and parthenogenetic embryos obtained by different methods. Androgenetic embryos were produced by piezo-intracytoplasmic sperm injection (ICSI) or in vitro fertilization (IVF) of enucleated oocytes with or without subsequent pronuclear transfer from one haploid zygote to another. ...
Ruiz i Altaba Ariel - - 2003
The Sonic hedgehog (Shh) pathway plays an important role in the development of many tissues and organs. The secreted ligand Shh has been shown to act as a mitogen, morphogen and survival factor in different contexts whereas the three Gli transcription factors act as Shh mediators in a context-dependent combinatorial ...
Kolibianakis E M - - 2003
The ability of human embryos to survive the freezing and thawing process is reflected in their implantation potential. Although cryopreservation appears to affect adversely the capacity of human embryos to implant, it has also been shown to enhance consistently IVF outcome. Moreover, despite the reduced implantation potential of cryopreserved embryos ...
Henning H J - - 2003
A series of three experiments was conducted to test the functional status of the uterus and embryos in prepubertal gilts. In Exp. 1, gilts were induced to ovulate by treating with gonadotropins followed by hCG 72 or 96 h later, and were artificially inseminated 24 h after hCG. Five of ...
Sinawat Supat - - 2003
BACKGROUND: The aims of this study were to determine whether preimplantation exposure of mouse embryos to ammonium resulted in abnormal fetal development and to evaluate similar risks to the outcome of human assisted conception. METHODS: Mouse embryos cultured from the 1-cell stage were exposed to 0.3 mmol/l ammonium chloride for ...
Salumets Andres - - 2003
BACKGROUND: The study aim was to investigate the impact of the developmental stage of embryos on pregnancy outcome of frozen embryo transfer (FET). METHODS: The survival rates of embryos after thawing and pregnancy outcome following FET were compared retrospectively between three cryopreservation strategies utilizing either zygote, day 2 or day ...
Robles V - - 2003
Successful fish embryo cryopreservation is still far from being achieved. Vitrification is considered the most promising option. Many factors are involved in the success of the process. The choice of a proper vitrification solution, the enzymatic permeabilization of embryos to increase cryoprotectant permeability, the adequate container for embryo loading, and ...
Wolf E - - 2003
Early embryonic development, implantation and maintenance of a pregnancy are critically dependent on an intact embryo-maternal communication. So far, only few signals involved in this dialogue have been identified. In bovine and other ruminants, interferon tau is the predominant embryonic pregnancy recognition signal, exhibiting antiluteolytic activity. However, this is just ...
Pivko J - - 2003
Early bovine precompacted embryos (1 to 8 blastomeres) were analysed by electron microscopy. The volume density of cellular components was determined by morphometric analysis to quantify the ultrastructure of early bovine embryos produced either in vivo or in vitro both after fertilisation by intracytoplasmic sperm injection (ICSI) or from electrically ...
Philipp Tom - - 2003
The morphology of monosomy X in embryos was documented by means of transcervical embryoscopy prior to evacuation in 24 cases of missed abortion. The embryos ranged in size from 13 mm to 26 mm CRL and were all developed beyond the sixth week of development. The embryonic phenotype varied from ...
Beraldi Rosanna - - 2003
We have investigated the sensitivity of pre-implantation embryos obtained by natural breeding (NB) or in vitro fertilization (IVF) to extremely low-frequency magnetic fields (ELF-MF). Fertilized eggs obtained by NB were removed from mothers 12h after mating and cultured in vitro for 5 days under continuous ELF-MF exposure (constant strength of ...
Stoncius Darius - - 2003
The spontaneous levels of micronuclei in erythrocytes were established in embryos of the black-headed gull of two natural populations. In total 216 blood samples from the same number of individuals were examined. A statistically significant decrease in the number of spontaneous micronucleated erythrocytes was found after 13 days of incubation. ...
Seshagiri P B - - 2003
In mammals, extensive remodeling of uterine endometrial matrix occurs during reproductive cycle and blastocyst implantation. This is regulated by a variety of molecules such as hormones, growth factors, cytokines and proteases. In this article, we review the current state of knowledge available on various proteases and their inhibitors functionally involved ...
Thibault Charles - - 2003
Production of cloned embryos by nuclear transfer from adult somatic cells is a novel and promising technique in animal biotechnology. In spite of numerous reported viable offspring in various species, the efficiency of the technique remains very low. Embryonic and fetal mortality occurs all along pregnancy and during the peri-natal ...
Kobayashi Toshihiro - - 2003
Somatic embryogenesis in carrot (Daucus carota) is autonomously inhibited by 4-hydroxybenzyl alcohol (4HBA), which is produced by embryogenic cells. Because somatic embryogenesis is used as a model of zygotic embryogenesis, we assayed for 4HBA in carrot seeds and analyzed the effect of 4HBA on seed formation to determine whether 4HBA ...
Bafrani Hassan Hassani - - 2003
This study was conducted on cryoprotective activity of ethylene glycol (ETG) and propanediol (PROH) on cleavage rate of mouse zygotes. Mouse oocytes were excised from fallopian tube of gonadotropin-treated mice, then inseminated with spermatozoa. After 16.5-17.5 h, zygotes were randomly allocated into three groups; control, toxicity, and frozen. In the ...
Itoh Takeshi - - 2003
This study examined which component of the egg, the nucleus or cytoplasm, is involved in the timing of the start of gastrulation in the Xenopus embryo, and when it starts to measure time. First, nuclei of cells of 256-cell stage embryos were transplanted to enucleated eggs 60 min after activation. ...
Hasler J F - - 2003
Recombinant bovine somatotropin (rbST) has been shown to increase follicular growth in cattle and some studies have demonstrated an increase in superovulatory response for rbST-treated cows. Pregnancy rates have also been shown to increase when rbST was administered around the time of insemination or prior to embryo transfer. The application ...
Iwamatsu Takashi - - 2003
The see-through stock in the medaka Oryzias latipes, causes pigments to be absent from the whole body and has a transparent body in the adult stage as well as during embryonic stages. To establish a standard table of growth stages for this model fish, morphological features were examined during the ...
Cho Chung-Hyun - - 2003
The null mutation of cardiac Na(+)-Ca(2+) exchanger (NCX1) gene in mice caused death of embryo in utero at embryonic day (ED) 9.0-9.5 and this embryonic lethality appears resulted from abnormal heart development. In the present study, we investigated whether transgenic re-expression of NCX1 in mutant cardiac myocytes could rescue these ...
Liu Y - - 2003
The objective of this study was to determine whether anorectal malformations (ARMs) and anterior sacral myelomeningocele share the same embryogenic pathway in a mouse model. Etretinate (Ro 10-9359) was administrated to C57BL/6 mice on gestation day 9 (E9). Sections of embryos and fetuses from E9.5 to E18 were observed by ...
Racowsky Catherine - - 2003
Controlling multiple pregnancies in patients undergoing artificial reproductive procedures requires consideration of single embryo transfers. Therefore, refinements for embryo evaluation are needed that select for the most developmentally competent embryo. The present study was designed to identify day 3 and day 5 morphological predictors of viability following transfers in which ...
Alexander Peter G - - 2003
BACKGROUND: Congenital axial skeletal defects affect two to three individuals per 1,000 live births. Without strong evidence for heritability, the cause is assumed to be multi-factorial. Carbon monoxide (CO), an increasingly prevalent environmental toxicant, is a potential environmental component in the etiology of these defects. The chick embryo is a ...
Salumets Andres - - 2003
BACKGROUND: The reduction of multiple pregnancies by using elective single embryo transfers (eSET) requires critical and careful selection of the embryo for transfer. The current study was undertaken to assess whether early cleavage could be used as a marker of embryo competence in eSET procedures. METHODS: The study included analysis ...
Moussa M - - 2003
Equine embryos have been successfully transferred after 24h cooled storage in Ham's F-10. The aim of this study was to compare the viability of equine embryos in vitro and in vivo after 6 and 24h cooled storage using three media and to examine the relationship between embryo size and viability ...
White Phillip H - - 2003
During vertebrate embryogenesis, paraxial mesoderm gives rise to somites, which subsequently develop into the dermis, skeletal muscle, ribs and vertebrae of the adult. Mutations that disrupt the patterning of individual somites have dramatic effects on these tissues, including fusions of the ribs and vertebrae. The T-box transcription factor, Tbx6, is ...
Herrler Andreas - - 2003
The process of implantation and trophoblast invasion is currently considered as the most limiting factor for the establishment of pregnancy. Molecular interactions at the embryo-maternal interface during the time of adhesion and subsequent invasion are crucial to the process of embryonic implantation. Both partners, the mother as well as the ...
Hatta Toshihisa - - 2003
Effects of stimulation of the maternal immune system on abnormal pregnancy induced with 5-azacytidine (5ACDR) administration at embryonic day 7.5 (E7.5) were examined in mice treated with recombinant interleukin 1beta (IL-1beta) at E6.5 (5ACDR + IL-1 at E6.5) or E9.5 (5ACDR + IL-1 at E9.5), OK432 (5ACDR + OK432) at ...
Vicente José Salvador - - 2003
The aim of this study was to assess the application of a cryopreservation program to preserve two selected rabbit lines. One of them was selected by litter size at weaning, line V (Synthetic breed). The second, line R (synthetic breed), was selected by growth rate. In this study, embryos were ...
Kovacs Gabor T - - 2003
OBJECTIVES: To review the choices of couples relinquishing frozen embryos and the outcomes of embryo donation at a major in-vitro fertilisation (IVF) clinic. DESIGN AND SETTING: Retrospective audit of 11.5 years of data (1991-2002) from the Monash University IVF clinic, Melbourne. PARTICIPANTS: Couples who make decisions regarding the fate of ...
Tatham B G - - 2003
Water buffalo are renowned for difficulties in the implementation of assisted reproductive technologies, with both males and females being problematic. In this study, we used cattle oocytes to assess the effect of treatments with heparin and caffeine on buffalo spermatozoa and subsequent fertilization and embryo development in vitro. There was ...
Clark David A - - 2003
Human reproduction is an inefficient process. There is a high rate of loss of early pregnancies, often before the mother (or physician) knows she is pregnant. Genetic abnormalities can explain much of the wastage, but can it explain all of the failures? As embryos bear paternal and embryonic antigens foreign ...
Ahmed R. Al-Himaidi
The effect of Salajeet on development of mice embryo was studied. A total of 71 pregnant female mice were given Salajeet (250 and 500 mg kg<sup>-1</sup>) orally via needle tube, daily from day 8-12 of pregnancy. All the treated and control animals showed no differences in the number of the ...
Kirkman Maggie - - 2003
As part of a larger study on donor-assisted conception, this paper reports research which explored the ways in which women who have donated or received eggs or embryos interpret such donations in the context of motherhood. Narrative analysis of women's accounts revealed that egg and embryo donations are not interpreted ...
Paria B C - - 2002
There are reports of adverse effects of cannabinoids on pregnancy outcome including retarded embryo development and pregnancy failure. Thus, discoveries of endogenous cannabinoid-like lipid mediators and cannabinoid receptors raise questions about their pathophysiological roles during normal pregnancy. We previously reported that anandamide, an endogenously produced arachidonate derivative (endocannabinoid), is synthesized ...
Askjaer Peter - - 2002
The small GTPase Ran has been found to play pivotal roles in several aspects of cell function. We have investigated the role of the Ran GTPase cycle in spindle formation and nuclear envelope assembly in dividing Caenorhabditis elegans embryos in real time. We found that Ran and its cofactors RanBP2, ...
Alves Cláudia - - 2002
Preimplantation genetic diagnosis (PGD) is an alternative to prenatal diagnosis for couples at risk of transmitting genetic disorders to their offspring. We present a fluorescence in situ hybridization (FISH) analysis of embryos obtained after seven PGD cycles in six couples with Robertsonian translocations and male factor infertility: 4 der(13;14), 1 ...
Christensen V L - - 2002
Storage of fertilized eggs for more than 10 d prior to incubation decreases embryonic viability. The hypothesis was tested that embryos may grow differently following egg storage. Eggs from which embryos survived following storage (ST) were compared to eggs from a second line that did not (NOST). Three identical, independent ...
Hasler J F - - 2002
Techniques for sex determination of bovine embryos have evolved from karyotyping of older preimplantation embryos some 25 years ago to the current variety of widely used polymerase chain reaction (PCR) protocols. Although highly accurate, most PCR protocols for sex determination have included an electrophoresis step. The present work is a ...
Damilakis J - - 2002
The aim of the current study was to estimate the embryo/fetus radiation doses and risks associated with spinal and hip dual X-ray absorptiometry (DXA) scans performed on the pregnant mother. The results were compared with the embryo/fetus dose from a thoracolumbar radiograph and pelvic radiograph. Posteroanterior (PA) lumbar spine and ...
Kobayashi-Miura Mikiko - - 2002
During the early postimplantation period, rodent embryos survive in a relatively anaerobic environment in utero and are vulnerable to a high oxygen pressure. They become resistant to oxygen stress when they are exposed to a higher oxygen pressure after the uteroplacental circulation is established. However, it is unknown how embryos ...
Yonemoto Hisashi - - 2002
OBJECTIVE: To visualize embryonal and early fetal surface features using transvaginal (3-D) ultrasound. METHODS: Seventy patients at 5-11 weeks of gestation (10 at each week) were studied. RESULTS: 3-D ultrasound could visualize the surface morphology, showing its clinical applicability. From 5 to 6 weeks the embryo was observed in the ...
Tazawa Hiroshi - - 2002
Heart rate (HR) in avian embryos developing inside an eggshell has been measured by various means while maintaining adequate gas exchange through the eggshell. This is an important requirement in order to avoid adverse effects of impeding gas exchange on the cardiac rhythms of developing embryos. The present report is ...
Machtinger R - - 2002
The purpose of this study was to assess the effects of long-term cryopreservation on the survival and implantation rates of embryos. We performed a matched case-control study comparing 101 women whose embryos were transferred after cryopreservation for 2-9 years, with 101 control women whose embryos were transferred after 6 months ...
Quenby Siobhan - - 2002
Recent data on recurrent miscarriage (RM) is discussed in the framework of the selection failure hypothesis which states, 'Recurrent miscarriage is the result of failure of the prevention of 'poor quality' embryos implanting, allowing embryos that are destined to fail to implant and present clinically as recurrent miscarriage. Thus, recurrent ...
Chi Hee-Jun - - 2002
BACKGROUND: Ethylene glycol (EG) has been successfully used as a cryoprotectant for vitrification of mammalian formula embryos (including human embryos) due to its low formula weight and high permeation into cells compared with other cryoprotectants, including propylene glycol (PROH). This study was carried out to evaluate the permeation and toxicity ...
Aoyama Naoyoshi - - 2002
Maternal hyperthermia induces severe malformations in the central nervous system (CNS) in both humans and laboratory animals. These phenomena are accompanied by apoptotic cell death, especially in the developing CNS. Cardiovascular malformations in conjunction with skeletal and CNS abnormalities have been reported in embryos of laboratory animals. In rats, hyperthermic ...
Isiklar Aycan - - 2002
OBJECTIVE: To evaluate the relationship between embryo cleavage time and implantation and pregnancy rates in women undergoing intracytoplasmic sperm injection (ICSI) for male factor infertility. STUDY DESIGN: A total of 78 patients undergoing their first ICSI cycle were evaluated prospectively. Embryos were assessed for early cleavage to the two-cell stage ...
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