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H J Goverde E M Aarden L A Bastiaans C M Thomas R Rolland 《Journal of steroid biochemistry》1988,31(6):927-930
In order to investigate variations in the microenvironment of oocytes within a cohort of maturing follicles the follicular volumes as well as the intrafollicular concentrations of oestradiol (E2) and progesterone (P) were measured in the golden hamster. At 10 h before ovulation the follicular volumes varied from 0.009 to 0.037 mm3 (mean +/- SD: 0.0187 +/- 0.0071 mm3; n = 36). Large follicles (greater than 0.025 mm3; n = 8) contained statistically significantly lower E2 and P levels (30.1 +/- 10.4 and 517 +/- 113 mumol/l, respectively) than the medium sized group (less than 0.025 and greater than 0.015 mm3; n =20): 46.9 +/- 16.0 (P less than 0.02) and 919 +/- 264 (P less than 0.0001) mumol/l, respectively. Small follicles (less than 0.015 mm3) showed the highest steroid levels: 97.0 +/- 33.3 and 1590 +/- 517 mumol/l for E2 and P (P less than 0.001 versus the medium sized group values). Correlation coefficients for the steroid concentrations and the follicular volumes appeared to be -0.674 for E2 and -0.612 for P (P less than 0.001). At the time studied a positive correlation between E2 and P concentrations in the follicles was found: r = 0.655 (P less than 0.001). The mean ratios of intrafollicular over serum steroid concentrations appeared to be approx 36 x 10(3) in the case of E2 and about 17 x 10(3) in the case of P. These results clearly show that there is an inverse relationship between follicular volume and intrafollicular steroid concentrations. The presence of a fine regulatory mechanism for a collective maturation of follicles is hypothesized. 相似文献
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M. Tardy C. Fages G. Dupre M. F. Costa J. Bardakdjian B. Rolland 《Neurochemical research》1985,10(6):809-817
Astroglial cells in primary cultures bind [3H]flunitrazepam with a high affinity on a single type of site and on a number of binding sites which increased during astroglial growth and differentiation. These binding sites show a particular pharmacological spectrum characterized by an inhibition of high affinity by RO-5-4864 (4-chlorodiazepam), an anticonvulsant of the benzodiazepine family and by an inhibition of binding of lower affinities by diazepam clonazepam and clobazam. RO-5-4864 and clonazepam compete for the same binding site in astroglia. The heat stability and the hormonal modulation by thyroxine are similar for astroglia and neuronal-cells. Benxodiazepines modulate the astroglial 5-HT receptor. Such an effect could be a possible physiological response to benzodiazepines for astroglial cells in primary cultures. 相似文献
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Protection of 3- and 17 beta-hydroxyl groups of estrone and estradiol as tetrahydropyranyl ether derivatives led to mixtures of 2'(R)- and 2'(S)-diastereoisomers which were separated by crystallization (3-tetrahydropyranyl ethers), or by thin-layer chromatography (17-tetrahydropyranyl ethers), and characterized by 1H and 13C nuclear magnetic resonance (NMR). Assignments for NMR signals of estradiol 3,17 beta-ditetrahydropyranyl ether were facilitated by comparison with those of its 15 zeta, 16 zeta-dideuterio analog and by 2D 1H-13C heteroshift correlation experiments. Diastereoisomers of 3-tetrahydropyranyl ether derivatives could be identified through the 13C NMR doublet signals of the anomeric C-2' and the aromatic C-4 carbon atoms in CDCl3. Diastereoisomers of 17-tetrahydropyranyl ether derivatives were recognized from characteristic modifications of 1H NMR signals of H-2', H-6', H-1, H-17, and 18-CH3 protons as well as from the 13C NMR doublet signals corresponding to C-2', C-4', C-6', C-12, C-13, C-16, and C-17 carbon atoms. Low-temperature experiments showed a splitting of the C-2', C-6', and C-17 13C NMR signals of each of the two 17-tetrahydropyranyl ether isomers. The downfield signal (equatorial conformer) of the three resulting doublets was more intense for the 17-tetrahydropyranyl ether 2'(S)-isomer, whereas the upfield signal (axial conformer) was more intense for the 2'(R)-isomer. 相似文献
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Ramsay JH 《BMJ (Clinical research ed.)》1994,308(6941):1445-1446
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B. Le Rü Sophie Renard Marie-Rose Allo J. Le Lannic J. P. Rolland 《Entomologia Experimentalis et Applicata》1995,77(1):31-36
The ultrastructure of the sensory receptors located on the labium of the cassava mealybugPhenacoccus manihoti Matile-Ferrero (Homoptera, Pseudococcidae) was studied with scanning and transmission electron microscopes. Trichoid hairs
of probable mechanoreceptive function are distributed over the labium. Uniporous chemosensilla which possess a mechanoreceptive
dendrite, multiporous chemosensilla and mechanoreceptive pegs are present on the tip of the labium. The presence of contact
and olfactory chemoreceptors on the labial tip ofP. manihoti suggests that tapping it on the cassava leaf provides the pest with information about the chemical nature of the leaf surface.
ORSTOM 相似文献
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Simultaneous concentration of Salmonella and enterovirus from surface water by using micro-fiber glass filters. 下载免费PDF全文
A method using micro-fiber glass filters (8-micrometers porosity) at pH 3.5 was successfully used for simultaneous concentration of Salmonella and enterovirus from Meurthe River samples, collected 8 km south of Nancy, France. A concentration of 10-liter samples was indispensable and permitted recovery of several enterovirus and Salmonella serotypes in concentrations of 1.3 most probable number of cytopathogenic units per liter and 18 bacteria per liter, respectively. 相似文献
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