The Experts below are selected from a list of 198 Experts worldwide ranked by ideXlab platform
G E Hofmann - One of the best experts on this subject based on the ideXlab platform.
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the effect of paternal age on outcome in assisted reproductive technology using the Ovum donation model
Reproductive Sciences, 2014Co-Authors: Isela Robertshaw, Jane Khoury, M E Abdallah, Pradeep Warikoo, G E HofmannAbstract:Objective:To determine the effect of paternal age (PA) on implantation and live birth rates in an Ovum donation program. Design: Retrospective study.Methods:A total of 237 Ovum donor cycles were reviewed. All donors were stimulated with gonadotrophin-releasing hormone agonist (GnRHa) downregulation and human menopausal gonadotropin. Recipients were prepared with GnRHa downregulation and estradiol/progesterone replacement. Embryo transfers were done at blastocyst stage under ultrasound guidance. The effect of PA on outcome was analyzed controlling for number and grade of embryos transferred. Outcome was not pregnant (NP), spontaneous abortion (SAb), and live births (LBs).Results:Of the 237 cycles, 36 resulted in NP (15.2%), 39 in SAb (16.5%), and 162 in LB (68.4%). The mean PA (MPA) was significantly different between the 3 groups, and implantation rates also declined with increasing MPA (P =.01). Overall, the mean number and grade of embryos transferred were 2.1 ± 0.4 and 1.3 ± 0.4, respectively. The NP c...
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an insight into early reproductive processes through the in vivo model of Ovum donation
The Journal of Clinical Endocrinology and Metabolism, 1991Co-Authors: Daniel Navot, Paul A Bergh, Maryanne C Williams, John G Garrlsi, Ida Guzman, B Sandler, Patricia Schreinerengel, G E Hofmann, L GrunfeldAbstract:To gain insight into early reproductive processes we have prospectively designed Ovum donation protocols to elucidate several phenomena relating to embryo implantation and pregnancy sustenance. Artificial endometrial cycles with variable follicular phases were induced in 60 recipients by sequential estrogen and progesterone. A total of 964 oocytes were retrieved throughout 43 Ovum donation attempts, for an average of 22.4 (range, 16–41) eggs/retrieval. The overall delivery rate per egg retrieval (donors and recipients combined) was 72.1% (31 of 43). The shortest estrogen stimulation (short follicular phase) resulting in ongoing pregnancies was 5 days in duration, while the longest (long follicular phase) was 35 days in duration before progesterone initiation. Utilization of variable length follicular phases, artificially extended the stage of endometrial receptivity to over 4 weeks. To assess the window of implantation, same age embryos were transferred onto endometrium of different maturational stages. P...
Stig Falkpetersen - One of the best experts on this subject based on the ideXlab platform.
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the fate of dietary lipids in the arctic ctenophore mertensia Ovum fabricius 1780
Marine Biology, 2008Co-Authors: Martin Graeve, Marte Lundberg, Marco Boer, Gerhard Kattner, Stig FalkpetersenAbstract:Lipids of the Arctic ctenophore Mertensia Ovum, collected from Kongsfjorden (Svalbard) in 2001, were analysed to investigate seasonal variability and fate of dietary lipids. Total lipids, lipid classes and fatty acid and alcohol compositions were determined in animals, which were selected according to age-group and season. Changes in lipids of age-group 0 animals were followed during growth from spring to autumn. Total lipids increased from May to September. Lipids as percentage of dry mass were lowest in August indicating their use for reproduction. Higher values occurred in September, which may be due to lipid storage for overwintering. Wax esters were the major lipid class accounting for about 50% of total lipids in age-group 0 animals from July and August. Phospholipids were the second largest lipid fraction with up to 46% in this age-group. The principal fatty acids of M. Ovum from all age-groups were 22:6(n-3), 20:5(n-3) and 16:0. Wax ester fatty alcohols were dominated by 22:1(n-11) and 20:1(n-9) followed by moderate proportions of 16:0. The unique feature of M. Ovum lipids was the high amount of free fatty alcohols originating probably from the dietary wax esters. In May, free alcohols exhibited the highest mean proportion with 14.6% in age-group 0 animals. We present the first data describing a detailed free fatty alcohol composition in zooplankton. This composition was very different from the alcohol composition of M. Ovum wax esters because of the predominance of the long-chain monounsaturated 22:1(n-11) alcohol accounting for almost 100% of total free alcohols in some samples. The detailed lipid composition clearly reflected feeding of M. Ovum on the herbivorous calanoid species, Calanus glacialis and C. finmarchicus, the abundant members of the zooplankton community in Kongsfjorden. Other copepod species or prey items seem to be less important for M. Ovum.
Martin Graeve - One of the best experts on this subject based on the ideXlab platform.
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the fate of dietary lipids in the arctic ctenophore mertensia Ovum fabricius 1780
Marine Biology, 2008Co-Authors: Martin Graeve, Marte Lundberg, Marco Boer, Gerhard Kattner, Stig FalkpetersenAbstract:Lipids of the Arctic ctenophore Mertensia Ovum, collected from Kongsfjorden (Svalbard) in 2001, were analysed to investigate seasonal variability and fate of dietary lipids. Total lipids, lipid classes and fatty acid and alcohol compositions were determined in animals, which were selected according to age-group and season. Changes in lipids of age-group 0 animals were followed during growth from spring to autumn. Total lipids increased from May to September. Lipids as percentage of dry mass were lowest in August indicating their use for reproduction. Higher values occurred in September, which may be due to lipid storage for overwintering. Wax esters were the major lipid class accounting for about 50% of total lipids in age-group 0 animals from July and August. Phospholipids were the second largest lipid fraction with up to 46% in this age-group. The principal fatty acids of M. Ovum from all age-groups were 22:6(n-3), 20:5(n-3) and 16:0. Wax ester fatty alcohols were dominated by 22:1(n-11) and 20:1(n-9) followed by moderate proportions of 16:0. The unique feature of M. Ovum lipids was the high amount of free fatty alcohols originating probably from the dietary wax esters. In May, free alcohols exhibited the highest mean proportion with 14.6% in age-group 0 animals. We present the first data describing a detailed free fatty alcohol composition in zooplankton. This composition was very different from the alcohol composition of M. Ovum wax esters because of the predominance of the long-chain monounsaturated 22:1(n-11) alcohol accounting for almost 100% of total free alcohols in some samples. The detailed lipid composition clearly reflected feeding of M. Ovum on the herbivorous calanoid species, Calanus glacialis and C. finmarchicus, the abundant members of the zooplankton community in Kongsfjorden. Other copepod species or prey items seem to be less important for M. Ovum.
Isela Robertshaw - One of the best experts on this subject based on the ideXlab platform.
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the effect of paternal age on outcome in assisted reproductive technology using the Ovum donation model
Reproductive Sciences, 2014Co-Authors: Isela Robertshaw, Jane Khoury, M E Abdallah, Pradeep Warikoo, G E HofmannAbstract:Objective:To determine the effect of paternal age (PA) on implantation and live birth rates in an Ovum donation program. Design: Retrospective study.Methods:A total of 237 Ovum donor cycles were reviewed. All donors were stimulated with gonadotrophin-releasing hormone agonist (GnRHa) downregulation and human menopausal gonadotropin. Recipients were prepared with GnRHa downregulation and estradiol/progesterone replacement. Embryo transfers were done at blastocyst stage under ultrasound guidance. The effect of PA on outcome was analyzed controlling for number and grade of embryos transferred. Outcome was not pregnant (NP), spontaneous abortion (SAb), and live births (LBs).Results:Of the 237 cycles, 36 resulted in NP (15.2%), 39 in SAb (16.5%), and 162 in LB (68.4%). The mean PA (MPA) was significantly different between the 3 groups, and implantation rates also declined with increasing MPA (P =.01). Overall, the mean number and grade of embryos transferred were 2.1 ± 0.4 and 1.3 ± 0.4, respectively. The NP c...
I Marin - One of the best experts on this subject based on the ideXlab platform.
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morphology toxin composition and molecular analysis of dinophysis Ovum schutt a dinoflagellate of the dinophysis acuminata complex
Harmful Algae, 2008Co-Authors: Nicolas Raho, Gemita Pizarro, Laura Escalera, B Reguera, I MarinAbstract:Abstract This work provides a morphological, toxinological and molecular description of Dinophysis Ovum Schutt, a species included in the Dinophysis acuminata complex, and often misidentified as D. acuminata Claparede and Lachmann. A dinoflagellate bloom occurred in the Galician Rias Baixas (NW Spain) in June 2006, where D. Ovum was the overwhelmingly dominant (97%) Dinophysis species, accompanied by small numbers of D. acuminata, and other Dinophysis spp., Protoperidinium spp. and Ceratium spp. D. Ovum was discriminated from D. acuminata at the light microscope on the basis of their different cell contours; it had only okadaic acid (OA) (7.1 pg cell−1) as a detectable lipophilic toxin component. Molecular analyses of the ITS1-5,8S-ITS2 rDNA region showed that D. Ovum was grouped in a common clade of small-sized species of Dinophysis, close to D. sacculus. Analyses of mitochondrial genes (Cytochrome c oxydase 1) of D. Ovum and D. acuminata showed this region exhibited a much higher variability −25 bp difference between the 2 species under study and was therefore more appropriate than rDNA genes for phylogenetic analyses of Dinophysis spp. This is the first report of lipophilic shellfish toxins in D. Ovum, and of analyses of mitochondrial genes to discriminate between different species of Dinophysis.
