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  • 1
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature medicine 1 (1995), S. 798-803 
    ISSN: 1546-170X
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Medicine
    Notes: [Auszug] Among the many clinical applications of the polymerase chain reaction (PCR) is its potential use in preimplantation diagnosis of genetic disorders. Performing PCR on single blastomeres from early cleavage stage (six-to eight-cell) human embryos should, in principle, enable reliable determination of ...
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of assisted reproduction and genetics 12 (1995), S. 462-466 
    ISSN: 1573-7330
    Keywords: zona photoablation ; blastomere biopsy ; mouse embryo ; implantation ; blastocyst
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose A xenon-chloride non-contact laser system was evaluated for opening the mouse zona pellucida prior to embryo biopsy. Methods A 308 nm beam was directed into the rear inlet of an inverted microscope, and exited to the target through a 100 X quartz objective. Following laser opening of the zona, blastomere removal was performed. Results Eight-cell mouse embryos (n = 611) were isolated for this study. Ninety-one percent of laser biopsy embryos proceeded to the blastocyst stage compared to 94% for acidified Tyrode's biopsied embryos and 83% for zona-intact controls. Many of the laser exposed embryos, however, exhibited morphologic aberrations such as isolated blastomere arrest and embryo growth delay. Thirtyfour percent of the laser biopsy embryos implanted compared with 47% and 37% for acid biopsied and control embryos, respectively. A significant decrease in fetal development following laser zona opening, however, was noted. Conclusions Though this laser system does allow for blastocyst formation and implantation following biopsy, the possible detrimental effects on embryonic and fetal development should be further evaluated.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1573-7330
    Keywords: embryo ; preimplantation ; diagnosis ; X chromosome ; Y chromosome ; chromosome 8
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Results Simultaneous detection of X and Y chromosomes was performed on 68 blastomeres with this technique. The FISH efficiency for gender determination was 95.5% (65/68). In addition, rehybridization with chromosome 8-specific probes was performed to determine the ploidy of blastomeres with more than two sex chromosomes.
    Abstract: Conclusion This technique offers an alternative to polymerase chain reaction for the preimplantation diagnosis of X-linked diseases and can also be used for ploidy assessment.
    Notes: Purpose To use a 6-hr fluorescence in situ hybridization (FISH) procedure involving fluorochrome-labeled probes to determine the gender of blastomeres from arrested biopsied human embryos.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of assisted reproduction and genetics 10 (1993), S. 276-279 
    ISSN: 1573-7330
    Keywords: in vitro fertilization ; polymerase chain reaction ; in situ hybridization ; single pronucleated zygotes ; preimplantation genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Results The presence of a Y chromosome in the embryo was considered proof that fertilization had occurred. Twenty-one dividing embryos originating from single pronucleated zygotes were analyzed using the polymerase chain reaction or fluorescence in situ hybridization. In total, 43% (9/21) of the embryos showed Y chromosomes.
    Abstract: Conclusion It can be extrapolated that more than 80% of them originated from fertilized eggs.
    Notes: Purpose Diploidy in embryos developing from single pronucleated zygotes can occur following parthenogenetic activation or by asynchronous inflation of pronuclei following fertilization. To distinguish between these two mechanisms, sexing was performed.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1573-7330
    Keywords: subzonal sperm insertion ; partial zona dissection ; sperm factors ; oligoasthenoteratozoospermia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Subzonal sperm insertion and partial zona dissection were applied in 250 in vitro fertilization cycles in couples (n =200) with abnormal semen analyses; 61 clinical pregnancies were established (24% per egg retrieval). Patients were selected without using minimal cutoff criteria. The study included patients with 0% normal sperm forms (strict criteria), no motile sperm (but some live cells), and sperm counts which could be assessed only after centrifugation. Patients were categorized into three subsets. Group A (n =116 cycles) failed to fertilize in a previous cycle. Group B (n =40) was excluded from IVF due to the severity of sperm profiles, such as a maximum of 2% normal forms. Group C (n =94) constitutes those patients for whom a standard cycle could possibly result in failure. Monospermic fertilization rates were 18% (A), 19% (B), and 24% (C). The incidences of embryo replacement were 63% (A), 53% (B), and 69% (C). Rates of clinical pregnancy were 22% (A), 23% (B), and 28% (C). The presence of one, two, or three semen abnormalities did not correlate with the outcome of microsurgical fertilization. Twenty-two percent of patients with combined oligoasthenoteratozoospermia became pregnant. Moreover, ongoing pregnancies were established in instances with 0% normal sperm forms and no progressively motile spermatozoa. It is concluded that stringent cutoff criteria may not be necessary when both partial zona dissection and subzonal sperm insertion are performed efficiently.
    Type of Medium: Electronic Resource
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