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.

The effects of fulvine on human and rat mitotic chromosomes

With increasing interest in mutagenicity an array of agents such as chemicals and drugs are being defined as chromosome damaging agents. The activities of these agents were reviewed. An intensive investigation of the mutagenic potential of fulvine was undertaken for three reasons. 1. Fulvine is still widely consumed in Jamaica as a herbal remedy which causes a well defined pathological condition - veno - occlusive disease of the liver (VOD). 2. Fulvine was found to cause chromosome damage in previous screening experiments. 3. Fulvine is a member of the pyrrolizidine group of alkaloids which are known to have mutagenic effects. The mutagenic activities were investigated by in vivo studies in children who have recovered from VOD and experimentally in rats. Serial examination of 3 members of a family recently recovered showed a decline of the percentage of cells with damage to normal over a five month period. No abnormalities were detected in 7 recovered children. Fulvine was administered to rats at varying dosages of 0.08 mg/gm, 0.04 mg/gm, 0.02 mg/gm, 0.01 mg/gm, and repeated administrations of 0.04 mg/gm body weight. Chromosomal abnormalities were produced which included gaps, breaks, bivalent and quadriradial configurations, ring chromosomes, dicentrics, abnormal metacentrics and submetacentrics, chromatic exchanges. Tetraploidy was rarely detected. The abnormalities were comparable in type to those seen in human VOD. At all dosages exchanges predominated over other types of abnormalities. Abnormalities were induced within 48 hours after fulvine administration at a threshold dosage of 0.02 mg/gm. Mitotic inhibition and liver damage were more marked in 12 weanling rats treated with doses of 0.08 mg/gm body weight of fulvine. The model for investigation of fulvine as a mutagenic agent was evaluated (AU)

Post-mortem and histo-pathologic notes on twenty fatal cases of bact. paratyphosum c infection in British Guiana

The findings of twenty autopsies which were performed on cases of bact. paratyophsum c infection in the Demerara River District of British Guiana between 1926-1932 are recorded. Hyperaemia of the distal portion of the ileum was noted in only seven cases, sometimes with haemorrhagic extravasations without visible ulceration. The lymphatic structures of the bowel and the mesenteric glands were hardly affected. Pulmonary complications ranging fron congestion to lobar pneumonia were found in nearly all cases. The spleen presented very variable degrees of enlargement usually with evidence of concomitant or pre existent malaria. Suppurative localisation of the infection were noted in five cases.Histological examinations were performed in eighteen cases and in nine or 50 per cent revealed the presence of colony-like masses of bacteria in the capillaries and small vessels of the main viscera, particularly the liver, kidney and spleen. Cellular reaction was conspicuously absent. These bacterial agglomerations were found also in cases selected only three hours after death,and cultures taken during the autopsy from various viscera confirmed that they were due specifically to Bact. paratyohosum C. This finding corresponds to those reported in animals naturally infected or with Bact. suipestifer suis. (AU)