A study of the histological classification and grading of canine malignant mammary tumours in Trinidad

Objective: Mammary gland tumors are a common occurrence in dogs, cats and humans but a rarity in other species. Histologically, grading these tumors evaluates the relevant prognostic variables which may be useful in treatment. The objective of this study was to classify canine malignant mammary tumours according to their morphological and staining characteristics using a standardized histologic classification scheme. Design and Methodology: A total of n = 78 canine mammary gland tumours (CMTs) were diagnosed during the period March 2013 to April 2017. CMTs were evaluated subsequent to routine tissue processing for microscopic evaluation followed by statistical analyses. Results: The two main tumour groups examined were malignant epithelial neoplasms and malignant epithelial neoplasms ­ special types, n= 69 (88.5%) and n= 9 (11.5%) respectively. The majority, n= 62 (79.5%) of tumours were classified as low grade or well differentiated (grade 1), n= 14 (17.9%) of tumours were intermediate grade or moderately differentiated (grade 2) and n= 2 (2.6%) of tumours were classified as high grade or poorly differentiated (grade 3). The significance of age or breed predilection could not fully be determined with this small sample size n = 78, however, all the dogs in this study were female. Conclusion: This study is the first of its kind to be conducted in Trinidad, which fully applies a standardized classification scheme as an independent prognostic indicator of CMTs.

Experimental myocardial necrosis in rats: role of arjunolic acid on platelet aggregation, coagulation and antioxidant status.

Arjunolic acid, a new triterpene and a potent principle from the bark of Terminalia arjuna, has been shown to provide significant cardiac protection in isoproterenol induced myocardial necrosis in rats. To further explore the mechanism of action of arjunolic acid, antiplatelet activity, anticoagulant assays, electrocardiographic changes, serum marker enzymes, antioxidant status, lipid peroxide and myeloperoxidase (MPO) have been measured and the results are compared with a potent cardioprotective drug, acetyl salicylic acid (ASA). Administration of isoproterenol produces electrocardiographic changes such as decreased R amplitude and increased ST segment elevation and has resulted in an increase in serum marker enzyme levels as well as a decrease in enzymatic and nonenzymatic antioxidant levels. Arjunolic acid at an effective dosage of 15 mg/kg body wt. (pre and post treatment), when administered intraperitoneally (i.p.), effects a decrease in serum enzyme levels and the electrocardiographic changes get restored towards normalcy. Arjunolic acid treatment is also shown to prevent the decrease in the levels of superoxide dismutase, catalase, glutathione peroxidase, ceruloplasmin, alpha-tocopherol, reduced glutathione (GSH), ascorbic acid, lipid peroxide, MPO and the cardioprotection is confirmed by the histopathological studies. This study shows that the cardioprotection of arjunolic acid pre and post treatment could possibly be due to the protective effect against the damage caused by myocardial necrosis.

An in vitro and in vivo evaluation of the virulence of egg drop syndrome virus for the chicken reproductive tract.

The virulence of strains of egg drop syndrome (EDS) 1976 virus for the female reproductive tract of chickens was assessed in vitro using oviduct organ cultures (OOC) prepared from precociously induced oviducts in young chicks by oestrogen treatment. Ciliostasis, haemagglutination and virus titres in infected OOC supernatants, histology and immunoperoxidase test results indicated the pathogenic ability of the four viruses for the precocious oviducts. One of the isolates, EDS TN4, produced higher virus titres in the supernatants of infected OOC and more severe glandular atrophy and necrosis, but caused slightly delayed ciliostasis. When this isolate was used in vivo, virus could not be detected by haemagglutination, but was detected in a few birds using a polymerase chain reaction on the allantoic fluids of infected duck embryos. Ciliostasis of OOC and histological lesions were confined to early stages of infection. This technique could be a pointer to possible variations in virulence of EDS virus isolates, and warrants further investigation. The potential value of OOC from young chickens for EDS diagnosis is emphasized.

Pathogenicity and immunosuppressive properties of infectious bursal disease virus field isolates and commercial vaccines in India.

The pathogenicity and immunosuppressive properties of two field isolates of infectious bursal disease. virus (IBDV) and five commercial IBDV live virus vaccines marketed in India were evaluated in this study. The pathogenicity of the wild type viruses and vaccines were based on mortality, the bursa:body weight ratio and microscopic lesions in the bursa in 3-week-old chicks that received these viruses. The immunosuppressive effects of these viruses were evaluated by measuring the antibody responses to sheep red blood cells, Brucella abortus plain antigen and Newcastle disease virus (NDV) vaccine in one-day-old chicks. One field isolate (N35/93) was found to be more pathogenic and immunosuppressive than the other (N45/92) while none of the commercial mild Lukert type vaccines were found to be pathogenic. One of the vaccine strains marked as Mild Lukert type was highly immunosuppressive; one was moderate and one could be classified as mild. Both the intermediate vaccines tested were highly immunosuppressive.