Jorge Colaço

Estimation of rat mammary tumor volume using caliper and ultrasonography measurements

Mammary tumors similar to those observed in women can be induced in rats by intraperitoneal administration of N-methyl-N-nitrosourea. Determining tumor volume is a useful and quantitative way to monitor tumor progression. In this study, the authors measured dimensions of rat mammary tumors using a caliper and using real-time compound B-mode ultrasonography. They then used different formulas to calculate tumor volume from these tumor measurements and compared the calculated tumor volumes with the real tumor volume to identify the formulas that gave the most accurate volume calculations. They found that caliper and ultrasonography measurements were significantly correlated but that tumor volumes calculated using different formulas varied substantially. Mammary tumors seemed to take on an oblate spheroid geometry. The most accurate volume calculations were obtained using the formula V = (W2 × L)/2 for caliper measurements and the formula V = (4/3) × π × (L/2) × (L/2) × (D/2) for ultrasonography measurements, where V is tumor volume, W is tumor width, L is tumor length and D is tumor depth.

PASSIVE HIP LAXITY IN ESTRELA MOUNTAIN DOG - DISTRACTION INDEX, HERITABILITY AND BREEDING VALUES

Two hundred and fifteen Estrela Mountain Dogs (EMD) were examined using the PennHIP method between 2002 and 2006. Passive hip laxity (PHL) was estimated calculating the distraction index (DI). Pedigree information was obtained from the Portuguese Kennel Club. The heritability and breeding values were estimated using the linear Animal Model. The DI, using as reference the worst joint of each animal, ranged from 0.15 to 1.12 (0.55 +/- 0.19). The PHL was equal in right and left sides, and was higher in females than in males (P > 0.05 and P <0.01 in the t-test, respectively). The estimated heritability was 0.83 +/- 0.11. The mean breeding values for PHL were stable in EMD born between 1991 and 2003, and showed an improvement in 2004 and 2005. The data confirm high PHL in breeds with high prevalence and severity of canine hip dysplasia. The high heritability indicates that the DI could be reduced in the breed if PHL were used as a selection criterion. The early favourable evolution of DI breeding values could be related with the increase of voluntary radiographic hip screening in the last years, and the subsequent introduction of hip quality as a breeding criterion.

Assessment of the exposure to heavy metals in Griffon vultures (Gyps fulvus) from the Iberian Peninsula

Griffon vultures (Gyps fulvus), by virtue of their position at the top of the food chain and as obligate scavengers, are at risk of accumulating and concentrating heavy metals in their tissues and may be more predisposed to their toxic effects. The aim of this study is to investigate heavy metal concentrations in Griffon vultures in Portugal and Catalonia, Spain and to determine if heavy metal concentrations in the blood of weak and/or injured Griffon vultures admitted to wildlife rehabilitation centres (WRC) reflect contamination profiles in the local, free-living and outwardly healthy population. Whole-blood samples taken from 121 Griffon vultures caught in the wild or admitted to WRC in Portugal and Catalonia, Spain were examined for cadmium (Cd), mercury (Hg) and lead (Pb) by inductively coupled plasma mass spectrometry (ICP-MS). Cd and Hg were not detected in most samples (98.3% and 95%, respectively), while Pb was detected in all birds in concentrations ranging between 4.97 and 300.23 µg/dl. Birds admitted to WRC had significantly lower Pb concentrations (24.15 ± 15.07 and 25.98 ± 18.04 µg/dl in Portugal and Catalonia, Spain, respectively) than animals caught in the wild (29.67 ± 13.19 and 42.22 ± 50.08 µg/dl in Portugal and Catalonia, Spain, respectively) (p<0.05). This may be explained by the fact that malnutrition was the main cause of admission of Griffon vultures to WRC, as ingestion has been described as the most significant pathway for Pb exposure in raptors. Therefore Griffon vultures admitted to WRC do not seem to be representative of the local, free-flying populations, so it remains necessary to continue catching when one intends to monitor Pb exposure in this species. The population of vultures captured in Catalonia, Spain showed the highest mean blood Pb concentration, perhaps due to the municipal rubbish dump located near the feeding station, with rubbish providing a significant fraction of their trophic needs. The ingestion of game meat with bullet fragments in carcasses or with Pb shots embedded in their flesh could also be the cause of the high blood Pb concentrations found in some vultures. The potential risk of Pb exposure in Griffon vulture populations must be given consideration, since most individuals evaluated had Pb concentrations between 20 and 100µg/dl, which is considered to be subclinical exposure to Pb, and which is above the threshold level at which Pb can affect antioxidant system in this species (15 µg/dl).

Somatic cell score genetic parameter estimates of dairy cattle in Portugal using fractional polynomials.

Milk somatic cell count is an indicator trait for mastitis resistance. Genetic parameters for somatic cell score in the Portuguese Holstein-Friesian population were estimated by modeling the pattern of genetic correlation over the first 3 lactations (days in milk) with a random regression model. Data records from the first 3 lactations were from the national database of the Portuguese Holstein Association herds. Heritability estimates ranged from 0.05 at the beginning of the lactation for the 3 lactations, to 0.07 at the end of the lactation period for the first and third lactations, to 0.09 for the second lactation. This increase in the heritability values was due to an increase in the genetic variance and a decrease in the residual variances. Genetic correlations evaluated for monthly time points were high (0.65 to 0.99) for all 3 lactations, whereas phenotypic correlations were much less than the genetic correlations (0.13 to 0.62).

Curvature Radius Measurements From the Ulnar Trochlear Notch in Large Dogs.

Assessing the ulnar trochlear notch (UTN) radiographic anatomy has been considered important, but difficult, in the diagnosis of elbow dysplasia. The purpose of this study was to evaluate UTN curvature of natural elbows in radiographs, using a methodology applied to disarticulated joints. The methodology was implemented and validated using dedicated software created by the authors. Mediolateral extended (MLE) and mediolateral flexed (MLF) elbow views were used from 20 joints from canine cadavers that were over 20 kg. After arranging the bones to avoid radiographic overlapping of the bones, an additional mediolateral radioulnar (MLRU) view was made. Curvature radius measurements from the central ridge of the UTN of each elbow were acquired in the MLRU view, using the software. The measurements were repeated in a second session, to determine repeatability. Then similar UTN measurements were taken from the MLE and MLF views, to determine reproducibility. Intraclass correlation coefficient (ICC) for repeatability and reproducibility of measurements were above 0.98 (95% confidence interval limits >0.75). The 95% limits of agreement (LA) for repeatability were −2.98 to 3.19 mm. The 95% LA for reproducibility between MLRU and MLE views were −4.32 to 3.75 mm. The 95% LA for reproducibility between MLRU and MLF views were −5.02 to 4.07 mm. The methodology and software are determined to be both precise and suitable to evaluate the UTN in MLE and MLF elbow views of large breed dogs, for anatomical and clinical purposes. In the future it would be useful to characterize normal and dysplastic UTN of different dog breeds. Anat Rec, 298:1748–1753, 2015.