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  • 1
    ISSN: 0032-8332
    Schlagwort(e): Baboons ; Ovary ; Steroids ; Gonadotropins ; Follicular phase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The purpose of this study was to determine and compare the follicular phase steroid hormone secretion into the utero-ovarian vein by the ovary with a dominant follicle and the contralateral ovary in the same baboon. Serial utero-ovarian vein blood from both sides was collected in 25 baboons by the use of a laparoscope on alternate days, starting on day 1 or 3 of the cycle and continuing through 2 to 3 days post-ovulation. Approximately 3–4 days before the day of expected ovulation, samples were collected at 8-hr intervals. Steroids estradiol (E2) and progesterone (P) were measured in all utero-ovarian vein plasma by radioimmunoassay. In the peripheral plasma, E2, P, LH, and FSH measurements were carried out. Concentrations of steroids were significantly higher on the side of the ovulating ovary by day 5 before ovulation. Individual plots however, indicated that some baboons may establish the dominant side as early as day 11 before ovulation. The preovulatory gonadotropins had a differential effect on the two ovaries. For example, E2 values on the ovulatory side ovary declined after increases in LH/FSH, whereas on the contralateral side these values had increased. Both sides showed increases in the level of P with the increases in LH. The mean interval from E2 peak to LH peak was 24 hrs and LH peak to ovulation was 24 hrs.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 1573-8272
    Schlagwort(e): XAD-16 and NPA-1 ; invertase ; α-glucosidase ; grafting ; ultrasonic irradiation ; adsorption ; desorption ; enrichment factors
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract In the present work Amberlite® XAD-16 and Indion® NPA-1, Polystyrene Divinylbenzene macroreticular spherical resins, have been evaluated quantitatively as supports for the adsorption and isolation of the yeast proteins and the enzymes, invertase and α-glucosidase. Modification of these supports has been carried out by surface grafting using acrylate polymers to reduce the hydrophobicity and nonspecific adsorption of proteins. Good grafting efficiency, in excess of 90%, has been obtained using ultrasonic irradiation for the surface activation of polystyrene resins. XAD-16 has higher adsorption capacities for the total yeast proteins as well as for both the enzymes, α-glucosidase and invertase, than NPA-1 in its respective native and grafted form. Adsorption capacities of XAD-16 and NPA-1 in their respectivenative and grafted forms for α-glucosidase are higher than the capacities for invertase. Nonspecific adsorption of total proteins has been reduced considerably after the grafting of acrylate polymers on hydrophobic supports. At the same time selectivity for the adsorption of both the enzymes has been enhanced on grafted supports. The overall solid-liquid adsorption mass transfer coefficient values (K l a) estimated for adsorption of invertase on XAD are lower than those for α-glucosidase. Native and grafted resins could be regenerated and reused for adsorption of α-glucosidase for two regeneration cycles studied. Storage stability of invertase and α-glucosidase is the same on native and grafted form of XAD-16 and is more than the enzymes in the free form.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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