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  • 1
    Digitale Medien
    Digitale Medien
    Does the zona pellucida select spermatozoa from the medium with higher fertilizing potential? (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 36 (1993), S. 377-381 
    Details
    ISSN: 1040-452X
    Schlagwort(e): Acrosome reaction ; In vitro fertilization ; Sperm microinjection ; Sperm selection ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: The present study was carried out to test whether the zona pellucida selects spermatozoa with higher fertilization potential. Fertilization rates of mouse oocytes after sperm microinjection under the zona pellucida (SMUZ) of zona-bound spermatozoa and of spermatozoa incubated in the absence of oocytes and treated (acid-treated group) or not (control group) with acid Tyrode's solution were compared. SMUZ was performed at 15, 30, 60, and 90 min after the insemination of fresh oocytes required for selecting spermatozoa bound to the zona pellucida. At these times, the percentages of acrosome-reacted spermatozoa (PARS) were evaluated using the chlortetracycline fluorescence method. Fertilization rate in the three groups analysed increased from 25.9% to 47.3% in the control group, from 29.3% to 44.0% in the acid-treated group, and from 19.5% to 40.0% in the zona-bound group from 15 to 90 min after insemination, respectively. The global fertilization potential was significantly lower in the zona-bound group compared to the other two groups. The PARS in the zona-bound group at 15 (11.48 ± 3.02); 30 (16.74 ± 3.71), and 90 (19.68 ± 3.68) min after insemination were significantly (P 〈 0.05) lower than those found in the acid-treated group (39.26 ± 6.69, 38.20 ± 6.24, and 42.83 ± 5.39, respectively). At 90 min after insemination, the PARS in the zona-bound group was also significantly (P 0.05) lower than the control group (36.72 ± 4.51). No significant correlation between either time and PARS or PARS and fertilization rate was observed. It appears that the zona pellucida does not select from the medium spermatozoa with higher fertilization potential. © 1993 Wiley-Liss, Inc.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mrd.1080360314
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  • 2
    Digitale Medien
    Digitale Medien
    Biochemical changes in cervical mucus-factor infertility (1985)
    New York, NY : Wiley-Blackwell
    Gamete Research 12 (1985), S. 265-274 
    Details
    ISSN: 0148-7280
    Schlagwort(e): cervical mucus ; infertility ; sialic acid ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Cervical-factor infertility has generally been attributed to the presence of antispermatozoal antibodies in the secretions of the uterine cervix, despite the fact that the incidence of sperm-specific antibodies in these women is generally low. We report here a modification in the structure of the cervical mucus of patients with a diagnosed cervical factor. Cervical mucus from patients with a cervical factor of nonimmunological origin, collected during the periovulatory phase of the menstrual cycle, had (1) a significant decrease in the content of glycosidically bound sialic acid and (2) an increased ability to act as an acceptor for sialic acid from cytidine-5′-monophospho-N-acetylneuraminic acid (CMP-sialic acid) when incubated with an exogenous sialyltransferase; in comparison to mucus from normal fertile women. Both siaiyltransferase and fucosyltransferase activities were detected in cervical mucus, but there was no difference between fertile normal and cervical-factor patients using the assays described. These results reinforce a possible role for sialic acid residues and their associated glycosyltransferases in the regulation of spermatozoal-cervical mucus interaction.
    Zusätzliches Material: 4 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mrd.1120120305
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  • 3
    Digitale Medien
    Digitale Medien
    Ultrastructural observations on cortical granules in human follicular oocytes cultured in vitro (1982)
    New York, NY : Wiley-Blackwell
    Gamete Research 5 (1982), S. 191-198 
    Details
    ISSN: 0148-7280
    Schlagwort(e): cortical granules ; ultrastructure ; oocyte maturation ; in vitro culture ; fertilizability ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: The fine structure, distribution, and fate of cortical granules in human oocytes cultured in vitro are reported.Follicular maturation in women with blocked Fallopian tubes was induced by clomiphene citrate and human chorionic gonadotropin, and preovulatory eggs were obtained by improved methods of laproscopy and oocyte recovery. These oocytes were then inseminated and cultured in a modified Ham's F10 medium for 3 to 72 hr to assess their fertilizability.Cortical granules were observed in all 17 unfertilized oocytes investigated, which had completed various stages of meiotic maturation. A marked increase in their numbers was observed in oocytes cultured for 3 to 6 hr. There was no evidence of spontaneous cortical granule release in any of the oocytes studied.It is concluded that cortical maturation expressed by proliferation of cortical granules is as significant a criterion as nuclear maturation in assessing maturity and fertilizability of oocytes cultured in vitro. A short sojourn in culture before insemination could improve chances of normal fertilization and embryo development, which has been recently achieved in our laboratory.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mrd.1120050209
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  • 4
    Digitale Medien
    Digitale Medien
    The effects of ultrarapid freezing on meiotic and mitotic spindles of mouse oocytes and embryos (1988)
    New York, NY : Wiley-Blackwell
    Gamete Research 21 (1988), S. 385-401 
    Details
    ISSN: 0148-7280
    Schlagwort(e): spindles ; oocytes ; embryos ; microtubules ; cryopreservation ; electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Preovulatory mouse oocytes and 2-cell embryos were frozen with dimethyl sulfoxide and propanediol by an ultrarapid method. The survival of frozen oocytes was low (33-34%) compared to that of 2-cell embryos (78-79%) with either cryoprotectant. Development to blastocysts after postthaw culture was about 7-15% for oocytes and 79-80% for the embryos.Ultrarapid freezing preserves cell structure quite well as revealed by electron microscopy, but meiotic oocytes and late 2-cell embryos undergoing mitosis showed evidence of spindle disorganization involving loss or clumping of microtubules resulting in some scattering of chromosomes. Embryos developed from frozen eggs showed clear evidence of micronuclear formation and incomplete incorporation of chromosomal material into main nuclei. These experiments confirm our observations on freezing of human oocytes and show that spindle microtubules are sensitive to freeze-thawing and that cryopreservation could cause chromosomal aberrations during early development. A cautious approach to the introduction of oocyte freezing in human in vitro fertilization (IVF) programs is advocated.
    Zusätzliches Material: 20 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mrd.1120210407
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  • 5
    Digitale Medien
    Digitale Medien
    The human pronuclear ovum: Fine strcture of monospermic and polyspermic fertilization in vitro (1985)
    New York, NY : Wiley-Blackwell
    Gamete Research 12 (1985), S. 385-398 
    Details
    ISSN: 0148-7280
    Schlagwort(e): in vitro fertilization ; pronuclear ova ; one-cell embryo ; monospermy ; polyspermy ; syngamy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: The fine structure of pronuclear ova (monospermy and polyspermy) and one-cell embryos has been investigated in our IVF programme. Sixteen oocytes were collected at laparoscopy after appropriate hormonal stimulation and were matured and fertilized in vitro by methods that have given rise to normal pregnancies.Pronuclear ova showing monospermic fertilization had two vesicular pronuclei surrounded by aggregations of cellular organelles. The male pronucleus was closely associated with a sperm axoneme, while the female pronucleus was dismantling its envelope and condensing its chromatin ahead of its counterpart in late pronuclear ova. Each pronucleus had dispersed chromatin, dense compact nucleoli, and intranuclear annulate lamellae. Smooth endoplasmic reticulum, annulate lamellae, Golgi complexes, and mitochondria formed a conspicuous part of the perinuclear ooplasm. The one-cell embryos were either in syngamy or in the process of undergoing first cleavage. Positive evidence of cortical granule release and second polar bodies were detected in the perivitelline space. A block to polyspermy seemed to operate at the level of the inner zona.Dispermic and polyspermic ova had 3-16 pronuclei resembling those of monospermic ova and had sperm tails in the ooplasm. Sperm were also seen penetrating the inner zona and were occasionally found in the perivitelline space. Incomplete cortical granule release and early signs of cytoplasmic fragmentation were noted in polyspermic ova.Both normal and abnormal features of these ova are reported and compared with pronuclear structure in vivo and in vitro.
    Zusätzliches Material: 15 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mrd.1120120406
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  • 6
    Digitale Medien
    Digitale Medien
    Ultrastructure of cortical granule release and zona interaction in monospermic and polyspermic human ova fertilized in vitro (1982)
    New York, NY : Wiley-Blackwell
    Gamete Research 6 (1982), S. 225-234 
    Details
    ISSN: 0148-7280
    Schlagwort(e): in vitro fertilization ; electron microscopy ; cortical reaction ; zona reaction ; monospermy ; polyspermy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Cortical granule release and interaction with the zona pellucida are reported in monospermic and polyspermic fertilized ova and early human embryos cultured in vitro.Twenty-seven preovulatory oocytes from women with tubal or idiopathic infertility were recovered by laparoscopy, after induction of follicular maturation with clomid and human chorionic gonadotropin. These were then inseminated with husband's or donor sperm, cultured for 3-72 hr, routinely fixed in glutaraldehyde/osmium and examined ultrastructurally.Evidence of cortical granule release was observed in all ova and embryos investigated and their contents were identified either at the egg surface or in the perivitelline space or interacting with the inner zona, apparently reinforcing its structure. The latter is very likely the morphological expression of the zona reaction.Delayed release was seen in certain regions of normally fertilized ova and particularly in polyspermic ova, where massive “explosions” of granules occurred. This was attributed to delayed cortical maturation. The mechanics of release were similar in both monospermic and polyspermic ova. Spontaneous dehiscence was also described in one injured unfertilized oocyte.The significance of the cortical and zona reactions as an effective block to polyspermy at the level of the inner zona, which becomes more impenetrable to supplementary sperm, is discussed.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mrd.1120060306
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  • 7
    Digitale Medien
    Digitale Medien
    Parthenogenetic activation of unfertilized mouse oocytes by exposure to 1,2-propanediol is influenced by temperature, oocyte age, and cumulus removal (1989)
    New York, NY : Wiley-Blackwell
    Gamete Research 24 (1989), S. 269-279 
    Details
    ISSN: 0148-7280
    Schlagwort(e): propanediol ; dimethylsulfoxide ; ethanol ; hyaluronidase ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Cumulus-intact and -denuded unfertilized oocytes from two mouse strains were exposed to 1.5 m ethanol (EtOH) or two cryoproteclant solutions, 1.5 M propanediol (PROH) or 1.5 M dimethylsulfoxide (DMSO), for 4.5 min at 27°C, and the proportion of activating or degenerating oocytes studied. Exposure to DMSO did not significantly increase activation above that of oocytes not exposed to DMSO. Treatment of oocytes in PROH resulted in the activation of up to 87% of viable oocytes. This was significantly higher (P 〈01) than in control oocytes and comparable to the rate of activation after treatment with EtOH (59-96% activation). In solutions at 1°C, 47% of control oocytes were activated, which was not significantly different from the rate of activation in EtOH (36%) or PROH (50%) at 1°C. Following treatment with PROH, up to 87% of oocytes degenerated within a period of 6 h in vitro. The age of the oocytes (h post hCG) and the time of cumulus removal with the enzyme hyaluronidase, relative to the time of exposure to the chemicals, influenced the level of degeneration in most groups. Significantly fewer oocytes degenerated when cumulus cells were removed before treatment (0-31%) than when the cumulus was left intact throughout the treatment and 6 h culture period (10-87%). Exposure to PROH at 1°C reduced oocyte degeneration to 5%. We conclude that PROH causes significantly greater losses of oocytes as a result of parthenogenetic activation and degeneration than of exposure to DMSO.
    Zusätzliches Material: 5 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mrd.1120240304
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