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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of assisted reproduction and genetics 12 (1995), S. 406-412 
    ISSN: 1573-7330
    Keywords: in vitro fertilization ; estradiol ; fertilization rates ; pregnancy rates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective Exogenous estradiol (E2) has a well-recognized interceptive action when administered shortly after ovulation. The influence of extremely elevated levels of endogenous E2 on human oocyte fertilization and implantation are unclear. The purpose of this study was to evaluate a potential antinidatory role of extremely high endogenous E2 concentrations on implantation and pregnancy duringin vitro fertilization-embryo transfer (IVF-ET). Methods Twenty-five patients receiving human menopausal gonadotropins (hMG) following midluteal GnRHa administration for IVF-ET, in which the maximal E2 concentration was 〉5000 pg/ml (range 5358–16,344 pg/ml) were studied. Cycle parameters including oocyte and embryo characteristics, fertilization, cleavage, and implantation rates as well as pregnancy outcomes were compared to those of 25 patients treated contemporaneously whose treatment cycles had peak E2 values 〈3500 pg/ml. Patients groups were matched for age, infertility diagnoses, duration of infertility and stimulation protocol. Results Cycles characterized by very high endogenous E2 levels resulted in significantly more oocytes per retrieval (21.4± 1.7 versus 8.4± 0.6;P 〈 0.0001), fewer postmature oocytes (1.6%± 1.0% versus 14%± 5.0%;P 〈 0.03), and a decreased fertilization rate (63%±4.0% versus 73%±3.0%;P 〈 0.04) compared to control cycles. There were no differences in the overall mean morphologic grade or cleavage rates between groups. However, high E2 cycles were associated with a significantly increased implantation rate (14%±4.0% versus 8.0%±4.0%;P 〈 0.01) and pregnancy rate per embryo transfer (62%±16% versus 36%±16%;P 〈 0.01) compared to controls. The incidence of spontaneous abortion did not differ between groups. Conclusions Extremely high endogenous E2 levels do not appear to adversely affect implantation or overall cycle pregnancy rates in IVF-ET cycles. However, impaired fertilization rates in such cycles support a potential adverse effect on oocyte quality.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of assisted reproduction and genetics 4 (1987), S. 107-110 
    ISSN: 1573-7330
    Keywords: in vitro fertilization ; human menopausal gonadotropins ; luteinizing hormone release ; estradiol levels ; hypothalamic pituitary axis ; follicle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This study demonstrates that luteinizing hormone (LH) release may occur despite sustained elevations of estradiol E2 in women receiving human menopausal gonadotropin. Mean levels of E2 did not correlate with the LH surge, however, the follicle number and a rapid rise in E2 did. Therefore, it appears that the protective influence of inhibitory proteins secreted by multiple follicles can be overridden, allowing spontaneous LH release.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of assisted reproduction and genetics 4 (1987), S. 153-158 
    ISSN: 1573-7330
    Keywords: serum ; fractions ; effects ; in vitro fertilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To examine the effect of various fractions of human fetal cord serum (HCS) on mouse embryos cultured in vitro, heat-inactivated HCS was separated by ultrafiltration into five distinct fractions: Fractions A, MW〉30,000; B, MW 30,000−10,000; C, MW 10,000−5000; D, MW 5000−1000; and E, MW 〈1000. Seven hundred twentyeight single-cell embryos were cultured in TYH- 280 medium supplemented with 8 mg/ml bovine serum albumin (BSA) and a 20% concentration of Fraction A, B, C, D, or E, whole HCS, or BSA alone. Embryos cultured with Fraction A or E or whole HCS demonstrated a significantly reduced growth rate (P〈0.01), while embryos cultured with Fraction D demonstrated a significantly increased growth rate (P〈0.01). Additionally, 649 singlecell embryos were cultured in medium which was supplemented with 8 mg BSA/ml and a 0, 1,2, or 5% concentration of Fraction A or E. Fraction E displayed toxicity even at a 1% concentration (P〈 0.07), while Fraction A demonstrated growth inhibition at a 5% concentration (P 〈0.05) but increased the hatching rate at a 1% concentration (P 〈 0.01). Finally, 635 single-cell embryos were cultured with four distinct fractions of HCS obtained from a Sephacryl S-200 column: Fractions I, MW 100,000; II, MW 70,000−100,000; III, MW 30,000−70,000; and IV, low molecular weight (〈5000). Fraction I or III significantly reduced the embryo growth rate as seen with Fraction A (P〈0.01) and Fraction II significantly increased only the hatching rate (P〈0.01), while Fraction IV significantly increased the growth rate as seen with Fraction D. In conclusion, HCS contains embryo growth inhibitory properties in the high (〉30,000) and low (〈1000) molecular weight components, while growth promoting factors are found in the 1000−5000 MW fraction. It also seems that there are some factors in the 70,000−100,000 MW fraction which may promote the ability of the embryo to hatch.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1573-7330
    Keywords: follicular fluid ; follicular proteins ; in vitro fertilization ; oocyte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The present study was carried out from in vitro fertilization (IVF) attempts to analyze further the total and specific protein contents of 47 follicular fluids yielding one oocyte. The aim was to find correlations between the follicular concentrations of such proteins and the occurrence of coupled oocyte cleavage. These findings would be used as markers of IVF outcome. Two groups of follicular samples were distinguished: one group with cleavage occurrence (25 cases) and another group without cleavage or even fertilization (22 cases). In the group with cleavage a significantly higher level was observed for six proteins: C3 complement fraction and ceruleoplasmin (P 〈0.02), α-antitrypsin and transferrin (P 〈0.01), and α2-macroglobulin and β2-microglobulin (P 〈0.001). The data are discussed with respect to changes in follicle permeability with advancing maturity.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of assisted reproduction and genetics 11 (1994), S. 33-37 
    ISSN: 1573-7330
    Keywords: epidermal growth factor ; preimplantation embryo development ; in vitro fertilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose Enhanced embryo maturity and advanced stages of cleavage at the time of embryo transfer are associated with superior pregnancy rates in in vitrofertilization procedures. This study was performed to assess the potential usefulness of epidermal growth factor (EGF) to enhance the development of murine preimplantation embryos cultured in vitro.Two-cell stage mouse embryos were cultured for 72 hr with EGF at concentrations of 0.1 to 100 ng/ml. The percentage of embryos which developed to the expanded and hatching blastocyst stage at 72 hr was determined. Results The percentage of fully expanded and hatching murine blastocysts at 72 hr was significantly higher following incubation with EGF at concentrations of 2 ng/ml (44±4.1%; p〈0.02), 20 ng/ml (41±3.2%; P=0.04), 50 ng/ml (43±2.5%; P〈0.04), and 100 ng/ml (46±3.6%; P=0.001) compared to controls. This effect of enhanced embryonic development by EGF was neutralized by coincubation with 1.0 Μg/ml of anti-EGF antibody. Conclusion EGF at concentrations of 2 to 100 ng/ml significantly enhanced the percentage of expanded and hatching murine blastocysts at 72 hr.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 237 (1993), S. 400-407 
    ISSN: 0003-276X
    Keywords: Human embryo ; Crown-rump length ; Greatest length ; Computer analysis ; Vaginal ultrasound ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Accurate information on the normal growth rate of the human embryo is fundamental to a better understanding of the embryonic period of pregnancy. Crown-rump length measured previously in utero (N = 227) with vaginal ultrasound in 107 in vitro fertilization (IVF) or gamete intrafallopian transfer (GIFT) singleton pregnancies was compared to the greatest length of fixed human embryos from the Carnegie collection, of known developmental stage whose postovulatory ages were estimated from menstrual histories. Average crown-rump length in utero was 60% of the greatest length of the fixed specimens prior to postovulation day 33, but were equal after postovulation day 40. The growth rate of in utero embryos and fixed specimens, analyzed by computer using exponential equations, was compared to linear and polynomial equations used in previously published embryo growth tables. The exponential equation, length = exp(a + b/age), fit in utero measurements best, while the equation length = exp[a + b/exp(age)] fit the fixed specimens best. Differences between length in utero and in fixed specimens may be related to distortion of the fixed embryos resulting from the formalin fixation, to ultrasound distortion, to curling of the embryo, or to incorrectly estimated ages of the fixed specimens. Study of human embryos in utero is now practical with vaginal ultrasound. © 1993 Wiley-Liss, Inc.
    Additional Material: 1 Ill.
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 210 (1984), S. 491-502 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The ultrastructure of the parotid gland was examined in the little brown bat. The seromucous acinar cells contained abundant granules of variable morphology. These granules were characterized by a submembranous dense layer consisting of fine parallel slats. In some bats, the matrix of the granules was structureless, whereas in others it consisted of closely packed but randomly arranged bundles of tubules. The intercalated ducts had a highly developed rough endoplasmic reticulum, often containing large numbers of intracisternal granules. In contrast, only a few secretory granules were present in the supranuclear cytoplasm. The striated ducts, which exhibited the characteristic basal striations consisting of vertically oriented mitochondria and highly folded plasmalemmas, contained numerous small dense granules in a subluminal band. These granules had a paracrystalline substructure with a periodicity of 8 nm. Excretory ducts strongly resembled striated ducts. They showed the same kind of basal striations and about half their constituent cells contained small paracrystalline granules.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A new pH indicator, seminaphthofluorescein (SNAFL)-calcein acetoxymethyl ester, was used for intracellular pH (pHi) measurement in living MDCK cells with a laser scanning confocal microscope (LSCM) equipped with an Argon/Krypton laser and dual-excitation and dual-emission (FITC/Texas Red) filter set. SNAFL-calcein excitation maxima are ∼492/540 nm (acid/base) and emission maxima are ∼535/625 nm (acid/base) with a pKa value at ∼7.0. The absorption/emission spectra of SNAFL-calcein indicate that the ratio of emission intensities of its basic/acidic forms is pH dependent. With an Argon/Krypton LSCM, we were able to monitor the acidic and basic forms of this dye simultaneously using dualexcitation (488/568 nm) and dual-emission (525-614 nm/∼615 nm) wavelengths (λs). The simultaneous dual-excitation/emission LSCM system allows for efficient recording of pHi dynamics (time resolution ≍ 1 sec) in living cells. We have analyzed emission stability of the dye at different temperatures (22°C and 37°C) and constant pH, and at the same temperature (22D°C) but various pHs (6.6, 7.0, and 7.4). Bleaching rate is slightly higher at 37°C than that at 22°C. The basic form of the dye (λEm ≍ 625 nm) has a slightly higher bleaching rate than the acidic form (λEm ≍ 535 nm) in standard culture medium (pH 7.3) at either 22°C or 37°C. The pHi in MDCK cells calculated from ratio images (535 nm/625 nm) was 7.19 ± 0.03 (mean ± SEM, n = 20). Calibration experiments show that the useful pH range of SNAFL-calcein appears to be between 6.2 and 7.8, as the dye is difficult to calibrate outside this pH range. © 1995 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    BioEssays 11 (1989), S. 124-127 
    ISSN: 0265-9247
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The body plan of the frog is set-up by a rearrangement of the egg cytoplasm shortly after fertilization. Microtubules play several roles in this critical developmental event.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 10 (1989), S. 223-237 
    ISSN: 0197-8462
    Keywords: geomagnetic field ; biogenic magnetite ; bacterial magnetotaxis ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Magnetotactic bacteria from freshwater and marine sediments orient and navigate along geomagnetic field lines. Their magnetotactic response is based on intracellular, single magnetic domains of ferrimagnetic magnetite, which impart a permanent magnetic dipole moment to the cell.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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