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J Kaufman P N Olson T J Reimers T A Allen S F Soderberg T M Nett S L Wheeler W E Wingfield 《American journal of veterinary research》1985,46(2):486-492
Serum concentrations of thyrotropin (TSH), prolactin, thyroxine, and 3,5,3'-triiodothyronine in 15 euthyroid dogs and 5 thyroidectomized and propylthiouracil-treated dogs after thyrotropin-releasing hormone (TRH) administration were measured. Although thyroidectomized and propylthiouracil-treated dogs had higher (P less than 0.01) base-line concentrations of TSH in serum than did euthyroid dogs, concentrations of TSH after TRH administration varied at 7.5, 15, and 30 minutes with 14 of 45 samples obtained from healthy dogs having lower TSH concentrations than before TRH challenge. Similarly, concentrations of 3,5,3'-triiodothyronine in the serum of euthyroid dogs 4 hours after TRH administration were similar (P less than 0.05) to concentrations before TRH challenge. Although the mean concentration of thyroxine in serum was elevated (P less than 0.05) 4 hours after administration of TRH to euthyroid animals, as compared with base-line levels, the individual response was variable with concentrations not changing or decreasing in 4 dogs. Therefore, the TRH challenge test as performed in the current investigation was of limited value in evaluating canine pituitary gland function. Although mean concentrations of TSH in serum were higher (P less than 0.05) in euthyroid dogs after TRH administration, the response was too variable among individual animals for accurate evaluation of pituitary gland function. Concentrations of prolactin in the sera of dogs after TRH administration, confirmed previous reports that exogenously administered TRH results in prolactin release from the canine pituitary and indicated that the TRH used was biologically potent. 相似文献
33.
P.J. Burns PhD M.J. Jawad MS J.M. Weld MVB MRCVS W.C. Kaufman DVM D.M. Witherspoon DVM PhD E.A. Wilson MD R.H. Douglas PhD 《Journal of Equine Veterinary Science》1984,4(5):202-208
Testicular diameters and monthly blood samples were obtained from 83 stallions aged 4 to 22 years that were maintained on Central Kentucky Thoroughbred stud farms. The effects of age, season, and exposure to increased photoperiod (16 hours light/day, December 15 to April 1) on testicular diameters and plasma concentrations of FSH, LH and testosterone were studied.The results indicated that Thoroughbred stallions show distinct seasonal and age related changes in most of the reproductive parameters studied and that exposure of such stallions to increased photoperiod produced significant alterations in these changes. Although lighting stimulated testicular growth and testosterone secretion early in the breeding season such changes were short lived. Lighted stallions appeared to become refractory to the lighting program since both testicular size and plasma testosterone concentrations were significantly reduced by June. 相似文献
34.
C Valiente Y Corrada PE de la Sota PG Blanco D Arias C Gobello 《Reproduction in domestic animals》2009,44(S2):156-159
Gonadotropin-releasing hormone (GnRH) antagonists are particularly useful when a rapid inhibitory effect on the gonadal axis is required. The aim of this study was to test the efficacy and clinical safety of a low and high dose of the third generation GnRH antagonist, acyline, on pregnancy termination in female dogs. The effect of the antagonist on the progesterone (P4 ) serum concentration was also described. Twenty-one mid-pregnant bitches were randomly assigned to a single subcutaneous (SC) dose of a placebo (PLACE; n = 7), a low (ACY-L; 110 μg/kg; n = 6) or high (ACY-H; 330 μg/kg; n = 8) dose of acyline. The animals were followed up for 15 days. All ACY treated but no placebo-treated animals terminated their pregnancy by abortion (p < 0.01). The ACY-L and ACY-H groups interrupted their pregnancy 7 ± 1.9 and 6.4 ± 1.3 days after treatment, respectively (p = 0.7). A significant interaction between treatment and day was found (p < 0.01) for P4 serum concentrations when PLACE was compared with both ACY groups. No difference was found for this hormone between both ACY groups (p > 0.05) where P4 diminished throughout the study. The decreasing rate varied among animals and was closely related to the time of abortion when P4 reached basal concentrations. In PLACE animals, gestation progressed normally and P4 did not change throughout the study (p > 0.05). None of the bitches presented side effects. It was concluded that acyline safely terminated mid-pregnancy by permanently decreasing P4 serum concentrations. 相似文献
35.
Gretchen J.A. Hansen Natalie C. Ban Michael L. Jones Les Kaufman Hazel M. Panes Maï Yasué Amanda C.J. Vincent 《Biological conservation》2011,(6):1866-1875
Systematic approaches to site selection for marine protected areas (MPAs) are often favored over opportunistic approaches as a means to meet conservation objectives efficiently. In this study, we compared analytically the conservation value of these two approaches. We locate this study in Danajon Bank, central Philippines, where many MPAs were established opportunistically based on community preference, with few if any contributions from biophysical data. We began by identifying the biophysical data that would have been available when the first MPA was created in Danajon Bank (1995). We next used these data with the reserve selection software Marxan to identify MPAs that covered the same area as is protected under the current set of MPAs (0.32% of the total study area) and that would protect the greatest number of conservation targets at the lowest cost. We finally compared the conservation value of the current MPAs to the value of those selected by Marxan. Because of the dearth of biophysical data available in 1995 and the small area currently under protection, Marxan identified multiple configurations of MPAs that would protect the same percentage of conservation targets, with little differentiation among sites. Further, we discovered that the costs of obtaining and analyzing these data to be used for conservation planning would have been large relative to resources typically available to conservation planners in developing countries. Finally, we found that the current set of MPAs protected more ecological features than would be expected by chance, although not as many as could be protected using a systematic approach. Our results suggest that an opportunistic approach can be a valuable component of conservation planning, especially when biophysical data are sparse and community acceptance is a critical factor affecting the success of an MPA. 相似文献
36.
A. Nachmias Z. Kaufman L. Livescu L. Tsror A. Meiri P. D. S. Caligari 《Phytoparasitica》1993,21(3):245-255
The interaction of two diseases — Verticillium wilt, caused byVerticillium dahliae, and early blight, caused byAlternaria solani — with salinity was investigated. The use of a system of two overlapping overhead irrigation lines enabled results to be obtained under a continuous gradient of salinity. Three cultivars were investigated, namely, Cara, Désirée and Nicola. The results illustrate the increase in symptom expression of the two diseases, as well as in associated characters such as height and maturity, in the presence of salt. Differences existed between cultivars in their response to the diseases in the presence of varying levels of salt. 相似文献
37.
Harmelin A Pinthus JH Friedmann-Morvinski D Kaufman K Brenner O 《Veterinary immunology and immunopathology》2002,86(3-4):245-249
Canine transmissible venereal tumor (CTVT) is primarily a tumor of adult dogs with a high incidence of spontaneous regression. We recently reported a xenograft model of CTVT (XTVT) in NOD/SCID mice. XTVT cells retain cytological and histological features of CTVT as well as characteristic rearranged LINE/c-MYC junction [Am. J. Vet. Res. 62 (2001) 907]. In this paper, we demonstrate that XTVT cells maintain ultrastructural characteristics of CTVT and do not express MHC classes I and II molecules. 相似文献
38.
House flies were collected from dairies in New York state and the levels of resistance to commercially available insecticide formulations were measured on painted and unpainted plywood panels. Dimethoate was ineffective on all surfaces. The wettable powder permethrin formulation was more toxic than the emulsifiable concentrate formulation. The wettable powder cyfluthrin formulation was also more toxic than the recently developed liquid formulation. In general, the best house fly control was obtained on flat latex painted plywood panels and the poorest control on gloss latex painted panels. It is highly unlikely that producers obtain adequate control with dimethoate and permethrin. 相似文献
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