S. Vairamuthu

Induction of apoptosis by fungal culture materials containing cyclopiazonic acid and T-2 toxin in primary lymphoid organs of broiler chickens

Thirty-six, twenty-eight-day-old broiler chicks were randomly distributed into three groups of 12 birds each. Two groups were fed diets containing 10 ppm cyclopiazonic acid (CPA) and 1ppm T-2 toxin, respectively, to determine the mechanism of cell death in spleen and thymus at 6, 12, 24, and 36 h of post-treatment. The other group served as control. T-2 toxin treated group showed significant (P < 0.01) induction of apoptosis in thymus with peak induction at 24 h post-treatment where as, no significant differences were observed between the control and CPA groups. The CPA toxin treated group showed significant (P < 0.01) induction of apoptosis in spleen with peak induction at 24 h post-treatment. No significant differences were observed between the control and T-2 toxin group even though the latter showed a slight increase in the quantity of apoptotic cells at 36 h post-treatment in spleen. The semi-thin sections stained with toluidine blue from the spleen of CPA treated group exhibited crescent margination of chromatin against the nuclear envelope and shrinkage of lymphoid cells without any surrounding inflammation, the characteristics of apoptosis. The apoptotic thymocytes from T-2 fed birds appeared shrunken with condensed nucleus and showed crescent margination of chromatin against the nuclear envelope without any surrounding inflammation when compared with well-defined nuclei with dispersed chromatin in normal thymocytes. Ultrastructurally, splenocytes of the CPA treated group and thymocytes of the T-2 toxin treated birds showed apoptotic bodies characterized by crescent margination of the chromatin against the nuclear envelope. The study indicates that one route of the CPA and T-2 toxin induced cell death in lymphoid organs of broiler chicken is by apoptosis.

Time course studies on the initiation of complement activation in acute myocardial infarction induced by coronary artery ligation in rats.

This study attempted to probe the role of complement activation in promoting acute myocardial infarction (AMI) induced by coronary artery ligation (CAL) in rats. The surgical technique used in this study significantly reduced early mortality (95% survival rate) and also reduced the variation in infarct size (33± 1.87%) at 32 h after surgery. Time course studies on the initiation of AMI at various time points were carried out using physiological, biochemical, histopathological and electron microscopical techniques. Serum markers and activities of lysosomal hydrolases were found to be significantly elevated at the 8th hour post ligation. Histological studies showed polymorphonuclear cells emigration and total coagulation necrosis. Transmission electron micrograph exhibited mild distortion of muscle fibres and mitochondrial rupture with disrupted cristae. Immunoblotting studies confirmed the presence of α2-macroglobulin which supported the inflammatory response at 8th h of post ligation. The initiation of the complement (C) activation was observed by the increase in the level of the soluble form of the membrane attack complex (sC5b-9) in serum and left ventricle. Immunoexpression studies confirmed the initiation of the terminal C activation as shown by the expression of C5, C6, C7, C8, C9 and sC5b-9 complex at the 8th h of AMI. This study conclusively demonstrated that initiation of the C activation was observed to be significant at the 8th h of AMI induced by CAL in rats. (Mol Cell Biochem 268: 149–158, 2005)

Thymic Hassall’s corpuscles in Nandanam chicken - light and electronmicroscopic perspective ( Gallus domesticus )

The present study was aimed to study the light and electron microscopic studies of thymic Hassall’s corpuscles was done in various age groups of Nandanam Chicken ranging from day-old to forty weeks. Hassall’s corpuscles are special, unique structures present in thymic medulla and also in the cortex of all the age groups of Nandanam chicken (from hatch to forty weeks) in the present study. Size of the Hassall’s corpuscles in the medulla is larger than the ones present in the cortical region of thymus. The Hassall’s corpuscles are made up of structureless eosinophilic mass surrounded by concentrically arranged reticuloepithelial cells. Under electron microscope, the Hassall’s corpuscles were composed of reticuloepithelial cells interconnected by many desmosomes. The epithelial cells had abundance of cytoplasmic fibrils and desmosomes with few mitochondria and ribosomes. The nucleus was oval or round which was slightly indented. The centre of the Hassall’s corpuscles was appeared either solid or cystic. The cystic corpuscles had cell debris within the cyst lumen.

Early Diagnosis of Canine Mammary Tumours Using Nipple Aspirate Fluid Cytology and Find Needle Aspiration Cytological Techniques

In the present study clinical evaluation of canine mammary tumour cases to the Small Animal Surgical Out Patient Ward of the Madras Veterinary College Teaching Hospital, Department of Clinics, Chennai – 600 007 between September 2005 and June 2006 was done. During the study period of 10 months, out of 100 dogs screened for mammary gland involvement, 88 showed mammary neoplasms and 12 were nonneoplastic. . NAF (Nipple aspirate fluid) was attempted in 651 glands of 83 dogs, of which, 346 glands of 72 dogs yielded NAF. Out of 346 glands, 224 were asymptomatic NAF yielders were mostly 6 10 years (44.44 per cent). Pure breeds (73.61 per cent) yielded NAF mostly and 94.44 per cent were intact. There was 30.63 per cent yield from the inguinal glands. NAF was mostly creamy white, dirty, watery and sticky. Cellularity was moderate (52.89 per cent). Immunostained NAF smears revealed high epithelial:macrophage ratio in malignant type. Fine needle aspiration biopsy (FNAB) was taken from 144 glands of 101 dogs including one necropsy case, 93 were malignant and 14 were benign tumours. NAF findings correlated well with FNAB and histopathology in the diagnosis of canine mammary tumours (88.89 per cent).