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  • Biochemistry and Biotechnology  (9)
  • in vitro fertilization  (5)
  • Electrochemical detection  (3)
  • 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
    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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  • 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
    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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  • 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
    ISSN: 0887-3585
    Keywords: X-ray crystallography ; pAR5 mutant ; allosteric enzyme ; ligand-induced negative cooperativity ; alternative amino acid conformations ; coordinate error ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The X-ray crystal structure of CTP-ligated T state aspartate transcarbamoylase has been refined to an R factor of 0.182 at 2.5 Å resolution using the computer program X-PLOR. The structure contains 81 sites for solvent and has rms deviations from ideality in bond lengths and bond angles of 0.018 Å and 3.722°, respectively. The cytosine base of CTP interacts with the main chain carbonyl oxygens of rTyr-89 and rIle-12, the main chain NH of rIle-12, and the amino group of rLys-60. The ribose hydroxyls form polar contacts with the amino group of rLys-60, a carboxylate oxygen of rAsp-19, and the main chain carbonyl oxygen of rVal-9. The phosphate oxygens of CTP interact with the amino group of rLys-94, the hydroxyl of rThr-82, and an imidazole nitrogen of rHis-20. Recent mutagenesis experiments evaluated in parallel with the structure reported here indicate that alterations in the hydrogen bonding environment of the side chain of rAsn-111 may be responsible for the homotropic behavior of the pAR5 mutant of ATCase. The location of the first seven residues of the regulatory chain has been identified for the first time in a refined ATCase crystal structure, and the proximity of this portion of the regulatory chain to the allosteric site suggests a potential role for these residues in nucleotide binding to the enzyme. Finally, a series of amino acid side chain rearrangements leading from the R1 CTP allosteric to the R6 CTP allosteric site has been identified which may constitute the molecular mechanism of distinct CTP binding sites on ATCase. © 1993 Wiley-Liss, Inc.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 17 (1993), S. 329-334 
    ISSN: 0887-3585
    Keywords: bacterial toxins ; superantigens ; X-ray crystallography ; crystallization ; Staphylococcus aureus ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Native toxic shock syndrom toxin 1 (TSST-1) purified from Staphylococcus aurius has been crystallized in four different forms. The highest resolution data (2.05 Å) was collected from orthorhombic crystals belonging to the space group C2221. The unit cell dimension are a = 108.7 Å, b = 177.5 Å, c = 97.6 Å. Rotation function analysis of this from indicates that there is trimer of toxin molecules in the asymmetric unit with a local 3-fold axis parallel to the crystallographic c axis. Crystals of a double mutant of TSST-1 have been grown which has a single molecule in the asymmetric unit and diffract to 1.9 Å. The space group is P21 with unit cell parameters of a = 44.4 Å, b = 34.0 Å, c = 55.2 Å, β = 93.0°. © 1993 Wiley-Liss, Inc.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 27 (1985), S. 1735-1738 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Stillage obtained from ethanol production of grain sorghum was separated into two fractions: thin stillage and wet solids. A portion of the thin stillage was recycled as cooking water in subsequent fermentation runs using both bench- and full-scale ethanol production plants. When thin stillage replaced 50-75% of the cooking water, large increases occurred in solids content, COD, and EC of the resulting thin stillage. It was found that while the volume of thin stillage requiring treatment or disposal was reduced, there was little reduction in the total pollutant load. Stillage rcycling had little effect on the quality of the stillage wet solids fraction. At the high levels of stillage recycle used, ethanol yield was reduced after three to five runs of consecutive recycling.
    Additional Material: 5 Tab.
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  • 9
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This study reports some findings on the effects of centrifugation on the viability of mammalian cells. The authors used Burkitt lymphoma cells cultivated in a synthetic medium containing 10% fetal calf serum for all experiments. Batch centrifugations were conducted in a RC2-B centrifuge (Ivan Sorvall, Incorporated, Norwalk, Connecticut USA) operated at 0 and 25°C. During centrifugation we exposed the cells to gravitational fields ranging from 24,800 to 42.200g. The results showed that at, 0°C and 25,800 or 42,000g no loss in cell viability occurred for up to 90 min exposures in the centrifugal field. However, at 25°C and for gravitational fields of 24,800 and 42,000g, there were appreciable losses in cell viability. Continuous centrifugation studies in the Sharples supercentrifuge (Division of Penn Salt Corporation, Warminister, Pennsylvania USA) were also conducted with bowl speeds up to 28,000 rpm (19,000g) and flow rates ranging from 1.4 to 20 1, hr. Slight, losses in cell viability were noted and postulated as caused by the shear stresses encountered by the cells. Some pumping studies using the lymphoma cells substantiate this conclusion.
    Additional Material: 4 Ill.
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  • 10
    ISSN: 0006-3592
    Keywords: RGD ; FMDV ; internalization ; integrins ; cell binding ; β-galactosidase ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The G-H loop of foot-and-mouth disease virus is a disordered protrusion of the VP1 protein exposed on the virion surface. This short stretch includes an arginine-glycine-aspartic acid tripeptide, a recognized integrin-binding motif, which is responsible for cell attachment and infection. Eight copies of a peptide reproducing the amino acid sequence of this FMDV ligand have been displayed in solvent-exposed regions on an enzymatically active recombinant β-galactosidase. This viral peptide segment enables the chimeric enzyme to bind mammalian cell lines with different efficiencies, probably depending on the number of suitable cell receptors present on each of them. Moreover, it also promotes the internalization of the attached enzyme, which is transiently active inside the cells. These results suggest further exploration of the potential use of short adhesion peptides of viral origin as cell attachment tags to direct the targeted delivery of both genes and enzymes, instead of whole, infectious viruses. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 59:294-301, 1998.
    Additional Material: 6 Ill.
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