Enzyme Immunoassays for the Determination of Ovine LH and FSH   总被引：2，自引：0，他引：2  

GM Peclaris  A Pappa  K Deligiannis  K Koutsotolis 《Reproduction in domestic animals》2003,38(5):367-372

The development of competitive enzyme immunoassays for ovine plasma LH (oLH) and FSH (oFSH) is described. Standards and plasma samples were preincubated with diluted antiserum to oLH or oFSH and the reacted solution (100 μl per well) was transferred to plates previously coated with oLH or oFSH, respectively. The second antibody used was anti‐rabbit IgG horseradish peroxidase. The measuring range was 0.39–50 ng/ml for each hormone and the 50% relative binding sensitivity was 9 ng/ml for oLH. The respective value for oFSH was 3.5 or 34 ng/ml with different hormone and antibody preparations used for the assay. The enzyme immunoassays were used to determine oLH and oFSH levels in plasma from ewes of two breeds during the oestrous cycle. The assays detected the first FSH surge coincident with the LH surge, the second FSH surge about 24 h later and the periodic fluctuations of FSH concentrations during the luteal phase of the oestrous cycle. These enzyme immunoassays are an efficient and economic alternative to the established radioimmunoassays (RIA) for oLH and oFSH.  相似文献   

The kinetics-based enzyme-linked immunosorbent assay for coronavirus antibodies in cats: calibration to the indirect immunofluorescence assay and computerized standardization of results through normalization to control values.   总被引：3，自引：0，他引：3       下载免费PDF全文

J E Barlough  R H Jacobson  D R Downing  T J Lynch    F W Scott 《Canadian journal of veterinary research》1987,51(1):56-59

The computer-assisted, kinetics-based enzyme-linked immunosorbent assay for coronavirus antibodies in cats was calibrated to the conventional indirect immunofluorescence assay by linear regression analysis and computerized interpolation (generation of "immunofluorescence assay-equivalent" titers). Procedures were developed for normalization and standardization of kinetics-based enzyme-linked immunosorbent assay results through incorporation of five different control sera of predetermined ("expected") titer in daily runs. When used with such sera and with computer assistance, the kinetics-based enzyme-linked immunosorbent assay minimized both within-run and between-run variability while allowing also for efficient data reduction and statistical analysis and reporting of results.  相似文献   

Performance and endocrine responses of group housed weaner pigs exposed to the air quality of a commercial environment     

C. Lee  L.R. Giles  J.L. Downing  A.C. Kirby 《Livestock Production Science》2005,93(3):255-262

The growth performance and endocrine responses of male weaner pigs (3 to 8 weeks of age) was evaluated in two different environments (clean and dirty) and housing (single or groups of 10 pigs/pen) conditions. The dirty environment contained significantly elevated ammonia, carbon dioxide and dust levels compared with the clean environment. Pigs grew faster and consumed more feed in the clean environment and this was associated with reduced plasma cortisol concentrations compared with pigs in the dirty environment. Pigs housed in groups in the dirty environment had increased β-endorphin and decreased IGF-I concentrations compared to group housed pigs in the clean environment. Feed conversion efficiency did not differ due to environment or group housing. Plasma concentration of cortisol, β-endorphin, IGF-I and IGF-II did not differ between single and group housed pigs. Activity of the hypothalamic-pituitary-adrenal (HPA) axis was greater in response to environmental conditions than group housing, and this was associated with reduced growth in weaner pigs.  相似文献   

AAHA/AAFP pain management guidelines for dogs & cats     

American Animal Hospital Association;American Association of Feline Practitioners;AAHA/AAFP Pain Management Guidelines Task Force Members  Hellyer P  Rodan I  Brunt J  Downing R  Hagedorn JE  Robertson SA 《Journal of the American Animal Hospital Association》2007,43(5):235-248

Pain management in dogs and cats has undergone a dramatic evolution in the past decade. Current approaches focus on anticipation and prevention of pain, as well as both pharmacologic and nonpharmacologic management techniques. The veterinary team plays an essential role in educating pet owners about recognizing and managing pain in their pets.  相似文献   

Extinction and ecosystem function in the marine benthos     

Solan M  Cardinale BJ  Downing AL  Engelhardt KA  Ruesink JL  Srivastava DS 《Science (New York, N.Y.)》2004,306(5699):1177-1180

Rapid changes in biodiversity are occurring globally, yet the ecological impacts of diversity loss are poorly understood. Here we use data from marine invertebrate communities to parameterize models that predict how extinctions will affect sediment bioturbation, a process vital to the persistence of aquatic communities. We show that species extinction is generally expected to reduce bioturbation, but the magnitude of reduction depends on how the functional traits of individual species covary with their risk of extinction. As a result, the particular cause of extinction and the order in which species are lost ultimately govern the ecosystem-level consequences of biodiversity loss.  相似文献   

Monensin toxicity in preruminant dairy heifers     

Gabor LJ  Downing GM 《Australian veterinary journal》2003,81(8):476-478

Four-to six-week-old calves from a seasonal dairy herd in North Western Tasmania were presented for veterinary attention due to the occurrence of sudden deaths. Necropsy examination of one of the calves revealed several small pale foci of 1 cm diameter on the epicardium. Mortalities were found to be caused by monensin that was added to the milk diet as part of a vitamin/mineral commercial premix that also controlled coccidiosis. No cases of monensin toxicity in preruminant calves have been previously documented, although there have been numerous reports in older cattle and other species.  相似文献   

Haemorrhagic enteritis of turkeys     

KE ARZEY  GM CROSS 《Australian veterinary journal》1990,67(11):413-413

  相似文献   

THE SCIENTIFIC BASIS OF SCIENCE TEACHING     

Downing ER 《Science (New York, N.Y.)》1921,53(1368):250-252

  相似文献   

The Control of Reactive Oxygen Species Influences Porcine Oocyte In Vitro Maturation          下载免费PDF全文

GM Alvarez  SA Morado  MP Soto  GC Dalvit  PD Cetica 《Reproduction in domestic animals》2015,50(2):200-205

The aim of this study was to examine the effect of varying intracellular reactive oxygen species (ROS) levels during oocyte in vitro maturation with enzymatic ROS production systems (xanthine + xanthine oxidase or xanthine + xanthine oxidase + catalase), scavenger systems (catalase or superoxide dismutase + catalase) or cysteine on porcine oocyte maturation. Oocyte ROS levels showed an increase when H₂O₂ or O₂?^‐ production systems were added to the culture medium (p < 0.05). On the other hand, the presence of ROS scavengers in the maturation medium did not modify oocyte ROS levels compared with the control after 48 h of maturation, but the addition of cysteine induced a decrease in oocyte ROS levels (p < 0.05). The ROS production systems used in this work did not modified the percentage of oocyte nuclear maturation, but increased the decondensation of sperm head (p < 0.05) and decreased the pronuclear formation (p < 0.05). In turn, the addition of O₂?^‐ and H₂O₂ scavenging systems during in vitro maturation did not modify the percentage of oocytes reaching metaphase II nor the oocytes with decondensed sperm head or pronuclei after fertilization. However, both parameters increased in the presence of cysteine (p < 0.05). The exogenous generation of O₂?^‐ and H₂O₂ during oocyte in vitro maturation would not affect nuclear maturation or later sperm penetration, but most of the spermatozoa cannot progress to form the pronuclei after fusion with the oocyte. The decrease in endogenous ROS levels by the addition of cysteine would improve pronuclear formation after sperm penetration.  相似文献   

Phosphofructokinase and Malate Dehydrogenase Participate in the In Vitro Maturation of Porcine Oocytes     

E Breininger  BE Vecchi Galenda  GM Alvarez  C Gutnisky  PD Cetica 《Reproduction in domestic animals》2014,49(6):1068-1073

Oocyte maturation depends on the metabolic activity of cumulus–oocyte complex (COC) that performs nutritive and regulatory functions during this process. In this work, the enzymes [phosphofructokinase (PFK) and malate dehydrogenase (MDH)] were tested to elucidate the metabolic profile of porcine COCs during the in vitro maturation (IVM). Enzymatic activity was expressed in U/COC and U/mg protein (specific activity) as mean ± SEM. In vitro maturation was performed with 2‐oxoglutarate (5, 10 and 20 mm ) or hydroxymalonate (30, 60 and 100 mm ) inhibitors of PFK and MDH, respectively. The PFK and MDH activities (U) remained constant during maturation. For PFK, the U were (2.48 ± 0.23) 10^?5 and (2.54 ± 0.32) 10^?5, and for MDH, the U were (4.72 ± 0.42) 10^?5 and (4.38 ± 0.25) 10^?5 for immature and in vitro matured COCs, respectively. The specific activities were significantly lower after IVM, for PFK (4.29 ± 0.48) 10^?3 and (0.94 ± 0.12) 10^?3, and for MDH (9.08 ± 0.93) 10^?3 and (1.89 ± 0.10) 10^?3 for immature and in vitro matured COCs, respectively. In vitro maturation percentages and enzymatic activity diminished with 20 mm 2‐oxoglutarate or 60 mm hydroxymalonate (p < 0.05). Viability was not affected by any concentration of the inhibitors evaluated. The U remained unchanged during IVM; however, the increase in the total protein content per COC provoked a decrease in the specific activity of both enzymes. Phosphofructokinase and MDH necessary for oocyte IVM would be already present in the immature oocyte. The presence of inhibitors of these enzymes impairs the meiotic maturation. Therefore, the participation of these enzymes in the energy metabolism of the porcine oocyte during IVM is confirmed in this study.  相似文献