Immunohistochemical differentiation of reactive from malignant mesothelium as a diagnostic aid in canine pericardial disease

Objectives

To develop a provisional immunohistochemistry panel for distinguishing reactive pericardium, atypical mesothelial proliferation and mesothelioma in dogs.

Materials and Methods

Archived pericardial biopsies were subject to haematoxylin and eosin staining, immunohistochemistry for cytokeratin, vimentin, insulin‐like growth factor II mRNA‐binding protein 3, glucose transporter 1 and desmin. Samples were scored for intensity and number of cells stained.

Results

Ten biopsies of reactive mesothelium, 17 of atypical mesothelial proliferation, 26 of mesothelioma and five of normal pericardium were identified on the basis of haematoxylin and eosin staining. Cytokeratin and vimentin were expressed in all biopsies, confirming mesothelial origin. Normal pericardial samples had the lowest scores for insulin‐like growth factor II mRNA‐binding protein 3, glucose transporter 1 and desmin. Mesothelioma and atypical proliferative samples were similar to each other, with higher scores for insulin‐like growth factor II mRNA‐binding protein 3 and glucose transporter 1 than the reactive samples. Desmin staining was variable. Insulin‐like growth factor II mRNA‐binding protein 3 was the best to distinguish between disease groups.

Clinical Significance

An immunohistochemistry panel of cytokeratin, vimentin, insulin‐like growth factor II mRNA‐binding protein 3 and glucose transporter 1 could provide superior information compared with haematoxylin and eosin staining alone in the diagnosis of cases of mesothelial proliferation in canine pericardium, but further validation is warranted.     

The influence of rapid growth on sodium salicylate pharmacokinetics in male turkeys

The aim of this study was to assess the influence of growth on the pharmacokinetics of sodium salicylate (SS) in male turkeys. SS was administered intravenously at a dose of 50 mg/kg. Plasma drug concentrations were assessed by high‐performance liquid chromatography, and pharmacokinetic parameters were calculated by noncompartmental analysis. As the age increased from 6 to 13 weeks (body weight increase from 2.35 to 9.43 kg), median body clearance decreased from 1.34 to 0.87 ml/min/kg. This caused a significant increase in the median mean residence time from 3.42 to 4.44 hr. Elimination phase proved to be biphasic and two elimination half‐lives (T_1/2el) were distinguished. Whereas T_1/2el1 was found to increase with age by 128%, T_1/2el2 represented a later but faster and less age‐dependent phase of elimination (increase by 56% in the respective groups). Volume of distribution decreased with age. These effects may lead to different therapeutic response to SS in turkeys of different age and body weights.     

Feeding behavior of feedlot lambs fed diets containing levels of cassava wastewater

In this study, we evaluated the effects of including cassava wastewater in the diet on the feeding behavior of feedlot lambs in 35 male uncastrated Santa Inês × Dorper crossbred lambs at an approximate age of 3 months, with an average live weight of 20.0?±?3.4 kg. Diets were formulated with hay of cassava shoots (roughage) and a concentrate based on corn and soybean, with a roughage:concentrate ratio of 50:50, plus inclusion of cassava wastewater at the levels of 0, 12, 24, 36, or 48 g/kg of the total diet. Feeding behavior was evaluated between the 46th and 52nd days of the experiment. Increasing cassava wastewater levels in the diet reduced (P?<?0.05) the intakes (kg/day) of dry matter and neutral detergent fiber as well as the efficiency of rumination (g/cud and g/h) of dry matter and neutral detergent fiber. The other behavioral parameters were not affected by wastewater inclusion in the diet. Therefore, the inclusion of up to 48 g/kg of cassava wastewater on fresh matter of diets is not recommended for feedlot lambs.     

Pharmacokinetic profiles of the two major active metabolites of metamizole (dipyrone) in cats following three different routes of administration

This study was performed to determine pharmacokinetic profiles of the two active metabolites of the analgesic drug metamizole (dipyrone , MET), 4‐methylaminoantipyrine (MAA), and 4‐aminoantipyrine (AA), after intravenous (i.v., intramuscular (i.m.), and oral (p.o.) administration in cats. Six healthy mixed‐breed cats were administered MET (25 mg/kg) by i.v., i.m., or p.o. routes in a crossover design. Adverse clinical signs, namely salivation and vomiting, were detected in all groups (i.v. 67%, i.m. 34%, and p.o. 15%). The mean maximal plasma concentration of MAA for i.v., i.m., and p.o. administrations was 148.63 ± 106.64, 18.74 ± 4.97, and 20.59 ± 15.29 μg/ml, respectively, with about 7 hr of half‐life in all routes. Among the administration routes, the area under the plasma concentration curve (AUC) value was the lowest after i.m. administration and the AUC_EV/i.v. ratio was higher in p.o. than the i.m. administration without statistical significance. The plasma concentration of AA was detectable up to 24 hr, and the mean plasma concentrations were smaller than MAA. The present results suggest that MET is converted into the active metabolites in cats as in humans. Further pharmacodynamics and safety studies should be performed before any clinical use.