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LFC Brito AD Barth NC Rawlings RE Wilde DH Crews Jr PS Mir JP Kastelic 《Reproduction in domestic animals》2007,42(5):502-508
The objective of the present study was to characterize changes in serum metabolic hormones concentrations from 20 weeks before to 20 weeks post-puberty in bulls and to investigate the associations of metabolic hormones concentrations with testicular development. Leptin concentrations increased from 16 weeks before puberty to 8 weeks post-puberty and insulin concentrations increased from puberty to 8 weeks post-puberty. Growth hormone concentrations decreased after 4 weeks post-puberty, whereas IGF-I concentrations increased from 8 weeks before puberty to 8 weeks post-puberty. During this period, testicular growth was accelerated and testosterone secretion increased substantially, without any significant changes in gonadotropin secretion. Monthly circulating concentrations of leptin, IGF-I and insulin accounted for 63% of the variation in scrotal circumference and 59% of the variation in paired testes volume. In conclusion, the secretion of metabolic hormones was not associated with changes in gonadotropins concentrations. Furthermore, the associations of leptin, IGF-I and insulin concentrations with testes size indicated that these hormones might be involved in a gonadotropin-independent mechanism regulating the testicular development in peripubertal bulls. 相似文献
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H P Riemann R Ruppanner P Willeberg C E Franti W H Elliott R A Fisher O A Brunetti J H Aho J A Howarth D E Behymer 《Journal of the American Veterinary Medical Association》1979,175(9):911-913
Serotests were conducted on axis (Axis axis) and fallow (Dama dama) deer at Point Reyes National Seashore to determine their status with respect to nine diseases enzootic to the native black-tailed deer (Odocoileus hemionus columbianus) or to resident dairy cattle. In the exotic deer, the proportion of animals that were seropositive included: anaplasmosis, 35%; bluetongue, 48%; brucellosis, 0%; bovine viral diarrhea, 2%; infectious bovine rhinotracheitis, 3%; leptospirosis, 7%; parainfluenza-3, 49%; toxoplasmosis, 8%; and Q fever, 51%. The prevalence of antibodies among a small sample of the black-tailed deer included anaplasmosis, 100%; toxoplasmosis, 29%; and Q fever, 57%. The antibody prevalences in a sample of dairy cattle in the area included anaplasmosis, 19%; toxoplasmosis, 8%; and Q fever, 100%. 相似文献
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C Gmachl F Capasso EE Narimanov JU Nockel AD Stone J Faist DL Sivco AY Cho 《Science (New York, N.Y.)》1998,280(5369):1556-1564
High-power and highly directional semiconductor microcylinder lasers based on an optical resonator with deformed cross section are reported. In the favorable directions of the far-field, a power increase of up to three orders of magnitude over the conventional circularly symmetric lasers was obtained. A "bow-tie"-shaped resonance is responsible for the improved performance of the lasers in the higher range of deformations, in contrast to "whispering-gallery"-type modes of circular and weakly deformed lasers. This resonator design, although demonstrated here in midinfrared quantum-cascade lasers, should be applicable to any laser based on semiconductors or other high-refractive index materials. 相似文献
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Restriction-endonuclease analysis of Australian isolates of Leptospira interrogans serovar hardjo from cattle with agalactia and abortion 总被引:1,自引:0,他引:1
SUMMARY Polyacrylamide gel electrophoresis and agarose gel electrophoresis were used to resolve restriction endonuclease digests of 20 Australian isolates of Leptospira interrogans cultured from urine samples of cattle with agalactia and abortion. The restriction endonuclease profiles of 19 isolates closely matched the profiles of L interrogans serovar hardjo subtype hardjobovis reference strains. The remaining isolate had a different restriction profile from subtype hardjobovis and subtype hardjoprajitno reference strains and was serologically identified as serovar pomona. Silver staining of polyacrylamide gels gave enhanced resolution of restriction fragments compared with the traditional method of ethidium bromide staining of agarose gels. 相似文献
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Objective To determine whether a drug detected in the blood or urine of a racing animal could have penetrated through the skin from a topically applied preparation.
Design Blood and urine of dogs and horses were analysed after topical administration of three common nonsteroidal anti-inflammatory preparations.
Experimental method Dimethylsulphoxide was analysed using a gas chromatograph with a flame photometric detector. Phenylbutazone, its metabolites and lignocaine were analysed using a gas chromatograph with a mass selective detector.
Results Dimethylsulphoxide, phenylbutazone and ligno-caine were detected in dog urine after muliple applications of the preparations. The maximum concentration of dimethyl-sulphoxide in dog urine correlated with the concentration of dimethylsulphoxide in the preparation. Phenylbutazone penetrated the skin more effectively from the cream than from the solution or gel preparations. This penetration was independent of the concentration of dimethylsulphoxide.
Conclusion The superior penetration of phenylbutazone from the cream can be explained by it being present as a neutral molecule in an hydrophobic medium. It is proposed that phenylbutazone penetrates the skin of greyhounds most effectively by a hydrophobic lipid route which is likely to be different from the path by which dimethylsulphoxide penetrates the skin. 相似文献
Design Blood and urine of dogs and horses were analysed after topical administration of three common nonsteroidal anti-inflammatory preparations.
Experimental method Dimethylsulphoxide was analysed using a gas chromatograph with a flame photometric detector. Phenylbutazone, its metabolites and lignocaine were analysed using a gas chromatograph with a mass selective detector.
Results Dimethylsulphoxide, phenylbutazone and ligno-caine were detected in dog urine after muliple applications of the preparations. The maximum concentration of dimethyl-sulphoxide in dog urine correlated with the concentration of dimethylsulphoxide in the preparation. Phenylbutazone penetrated the skin more effectively from the cream than from the solution or gel preparations. This penetration was independent of the concentration of dimethylsulphoxide.
Conclusion The superior penetration of phenylbutazone from the cream can be explained by it being present as a neutral molecule in an hydrophobic medium. It is proposed that phenylbutazone penetrates the skin of greyhounds most effectively by a hydrophobic lipid route which is likely to be different from the path by which dimethylsulphoxide penetrates the skin. 相似文献
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