Roberto Leotta

Morphometrical approach for predicting regional lymph node micrometastatic load in canine mast cell tumours: preliminary results.

Canine cutaneous mast cell tumours (MCTs) have a variable biologic behaviour, and accurate staging is necessary to dictate therapy and predict outcome. Regional lymph node (RLN) involvement is a relevant prognostic factor. While obvious lymph node (LN) metastases are relatively easy to be diagnosed, micrometastatic disease recognition is challenging. The main aim of the study was to evaluate the number of mast cells (MCs) in the LNs of clinically healthy dogs (n = 4, group 1), dogs with inflammatory diseases (n = 31, group 2) and dogs with cutaneous MCT (n = 27, group 3), including animals with no RLN metastases (subgroup 3.1), those with occasional MCs in RLNs (3.2) and those with obvious RLN metastasis (3.3). MCs also were morphometrically evaluated for the following nuclear parameters: mean nuclear area (MNA), mean nuclear perimeter (MNP), largest to smallest diameter length (LS ratio), mean nuclear form factor and coefficient of variation of nuclear area. The average percentages of MCs were 0.0 and 0.01 in groups 1 and 2, respectively, and 0.07, 2.4 and 47.1 in subgroup 3.1, 3.2 and 3.3. MNA and MNP were significantly higher in subgroup 3.3 than in group 2 (P < 0.05). MNA and MNP in subgroup 3.2 suggested the presence of neoplastic MCs; this prediction of micrometastatic load correlated with outcome. Analysis of preliminary results shows that nuclear morphometry is useful to detect micrometastatic disease in RLN of dogs bearing cutaneous MCTs.

Use of linear discriminant analysis to characterise three dairy cattle breeds on the basis of several milk characteristics

Abstract To characterise individuals of differents breeds on the basis of milk composition and to identify the best set of variables a linear discriminant analysis (LDA), on 14 milk production traits, was performed on milk samples from 199 cows of different breeds (respectively, 127 subjects were Italian Friesians (IF), 62 were German Friesians (GF), and 10 were Jerseys (J) and all came from the same breeding farm in Tuscany. The variables were: test day milk yield (kg milk), % Fat, % Protein,% Lactose, % solid non fat (SNF), % total solid (TS), pH and titratable acidity (TA); five rheological variables: r, k20, a30, a45, and somatic cell counts /ml (SCC); and one hygiene-related variable: total bacterial count (TBC). The analysis performed on the 14 variables, with regard to the three breeds, allowed us to identify 10 of these as variables useful for discrimination (leaving out kg milk, pH, a45, and TBC). The most important variables were the percentage of Fat and TS for the first canonical variate and SNF, Lactose and Protein for the second. Fat and TS play an important role since they present significant values (even if opposite sign) in the two variates. The resulting classification of subjects was satisfactory: 79% of the Italian Friesians, 73% of German Friesians and 100% of the Jersey cows were classified correctly.

Morphometric Evaluation of Interrenal Gland and Kidney Macrophages Aggregates in Normal Healthy Rainbow Trout (Oncorhynchus mykiss) and after Bacterial Challenge with Yersinia ruckeri

Macrophage aggregates (MA) occur in various organs of fish as discrete aggregations of pigmented macrophages. The study presented herein investigates the quantitative modifications from normal anatomical condition, of interrenal gland (IG) and kidney MA in six treatment groups of adult rainbow trout submitted to either specific or aspecific immune stimulation and subsequently challenged with Yersinia ruckeri. Routinely stained tissue sections from both IG and kidney were analysed. The percentage of tissues occupied by MA and the MA density (number/mm(2)) were calculated on at least 10 randomly selected nonoverlapping fields taken from each tissue section. MA morphometric findings from challenged fish were compared to those from a control group. Results showed that fish from control group displayed a statistically significant (P < 0.05) higher percentage of tissue occupied by MA and MA density. Among different treatment groups, anti-Yersinia ruckeri immunized fish, which did not show clinical signs of disease after bacterial challenge, displayed higher values of morphometric parameters compared with symptomatic fish from other groups. Our study demonstrates that the quantification of the area occupied by MA might be an efficient parameter to evaluate the general condition of a salmonid population since it positively correlates with the health status and negatively with stress factor such as the acute bacterial infection.

Latent variable models on performance tests in guide dogs. 1. Factor analysis

Abstract The research has been conducted on behavioural test results obtained from 143 dogs of pedigreed stock reared in the National Guide Dog School (SNCG) of Scandicci (Firenze, Italy), consisting mostly of Labradors and Golden Retrievers, but also including German Shepherds. All dogs have been reared under quite uniform conditions and tested individually under similar conditions. The results following the 11 administered subtests, [that constitute variables in our analysis], were expressed in scores ranging from 1 to 5 and used after calculation of the rank averaged scores. The analysis of the Pearson and partial correlations between the variables points out a clean distinction in two groups. The first consists of variables related to characters of sociability and to relationship with the handler, with expression of dominance/submissiveness and the second to characters of reaction to external stimuli with expressions of fearfulness/curiosity. Results of factor analysis led us to reject the one factor model and accept a model with two factors, in which: 1) Factor I identifies variables of the group tied to the fearfulness/curiosity; 2) Factor II identifies the variables of the group tied to sociability and to relationship with the handler. The two factors are correlated, indicating the presence of some non negligible, indirect effects. One out of the eleven variables has not shown important evidence of contribution to any of the factors.