ABSTRACT
OBJECTIVES: To assess the reproducibility of the Fédération Cynologique Internationale (FCI) classification over time, and between assessors and to evaluate the benefit of computer-assisted measurement of the Norberg angle and of its percentile ranking by breed for the diagnosis of canine hip dysplasia, and for the selection of couples for breeding. METHODS: During the time period of 2006 to 2010, 5094 hip radiographs were evaluated according to the FCI rules, and 4400 have been submitted for statistical analysis. A system of computer-assisted image analysis (Digimizer(®) , MedCalc Software Ltd, Mariakerke, Belgium) was used to measure the Norberg angle. The Norberg angle value of individual dogs was expressed as percentile rank by breed. RESULTS: The agreement between individual assessors was highly significant (P<0·001), but there were important variations over time of the ratio of classes A or B. The Norberg angle and the percentile rank accurately discriminated between dogs with or without canine hip dysplasia, with positive and negative likelihood ratios of 6·31 and 0·21, respectively, for the Norberg angle at criterion value of 102·2°, and 4·21 and 0·18 for the percentile rank at criterion value of the 25th percentile. CLINICAL SIGNIFICANCE: The percentile rank of the Norberg angle may be a valuable tool for breeding selection.
Subject(s)
Breeding , Hip Dysplasia, Canine/diagnosis , Hip Joint/anatomy & histology , Hip Joint/diagnostic imaging , Radiography/veterinary , Animals , Dogs , Female , Hip Dysplasia, Canine/classification , Hip Dysplasia, Canine/diagnostic imaging , Image Processing, Computer-Assisted , Male , Predictive Value of Tests , Radiography/methods , Radiography/standards , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
The influences of follicle-stimulating hormone (FSH), gonadal steroids, and culture time were studied in relation to inhibin B production by Sertoli cells of immature rats cultured in vitro. Sertoli cell-enriched cultures were established from 18-day-old rats and were maintained in medium supplemented with insulin, transferrin, and epidermal growth factor at 34 degrees C. A recently developed ELISA for the measurement of inhibin B was used to assess the effects of recombinant human FSH (rh FSH), testosterone (T), and estradiol (E2) on inhibin B production and accumulation in the culture media of Sertoli cell-enriched cultures and to optimize the cell culture system to serve as a bioassay for the detection and quantification of estrogens and estrogenlike substances. Prolonging the incubation time (24, 48, or 72 hours) of Sertoli cells with control medium without rh FSH, T, or E2 resulted in a time-dependent increase of inhibin B production. Incubation with rh FSH (1, 2.5, 5, or 10 U/L) caused a dose- and time-dependent increase of inhibin B production by Sertoli cells (but not by cultured Leydig cells), reaching a plateau at 5 U/L rh FSH. Addition of T in concentrations of 2.88, 5, or 50 ng/ml to medium without rh FSH and E2 significantly lowered the daily production rate of inhibin B (P < 0.05). In contrast, addition of E2 (0.01 and 0.1 ng/ml) caused a dose-responsive increase in inhibin B production after 24 and 48 hours. The relative increment of inhibin B production induced by E2 was maximal after 24 hours in the presence of 2.5 U/L rh FSH (acting synergistically) and in the absence of T. When these conditions are implemented, the Sertoli cell culture system may serve as a bioassay for estrogenic substances, and it may reflect the possibly harmful effect they may have on spermatogenesis.
