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ThesisItem Open Access Pathology of the reproductive organs in experimental hypothyroidism in goats(Department of Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1982) Nemali Mohan, Reddy; KAU; Rajan, AA survey study was conducted to assess the role of hypothyroidism in the etiology of reproductive disorders in goats. Lowered functional activity of the thyroid was associated with postpartum anoestrum, repeat breeding and delayed puberty. An experimental model of controlled hypothyroid state was induced in goats, using different dose regimes of thiourea with the objective of studying the sequence of physiopathological changes in hypothyroidism and its influence on reproduction. Clinically healthy young and adult cross-bred goats of both sexes were employed for the study. The animals were divided into control, Treatment I (T1) and Treatment II (T2) groups. Groups T1 and T2 were administered thiourea orally at the rate of 50 mg/kg and 100 mg/kg body weight respectively. Clinical symptoms and growth rate were studied. Protein bound iodine, total serum protein and serum cholesterol were estimated. Haematological data were collected and the semen characteristics were evaluated. On the 90th day of the experiment both control and experimental animals were sacrificed leaving at least one animal in each group. These animals were maintained without treatment with thiourea for a further period of 90 days and sacrificed. Cross lesions and histopathological changes in tissues were recorded. Weakness, lethargy, depression, reduced feed intake, subcutaneous oedema of varying degree, loss of libido in males and anoestrum in females were the important clinical features observed. There was stunting of growth and apparent reduction in weight of the animals dosed with thiourea. On discontinuation of treatment with thiourea all the clinical signs manifested disappeared and the animals gained weight progressively. There was significantly decrease in the protein bound iodine, and increase in the total serum protein and cholesterol level in all the animals dosed with thiourea. The values reached the normal level on discontinuation of treatment with thiourea. Microcytic hypochronic anaemia was evident in hypothyroid goats. There was improvement in haemogram values on withdrawal of thiourea administration. Reduction in quantity and quality of semen was observed in hypothyroid goats. The semen appeared normal in quality and quantity on discontinuation of thiourea administration. Gelatinisation of subcutaneous fat and hypertrophy and dilation of the left verntricle were the common findings at autopsy. There was significant increase in the relative weight of the thyroid, pituitary and the adrenal gland. Histologically the thyroid glands exhibited varying degree of hyperplasia and hypertrophy. Predominant histological changes in the pituitary was hyperplasia and hypertrophy of basophil cells and degenerative changes in the acidophils. Adrenal gland showed hypertrophy and depletion of fat in the zona fasciculata. On discontinuation of treatment with thiourea all the lesions disappeared. A significant decrease in the relative weight of the testis and epididymis was observed in all the goats dosed with thiourea. Histologically the seminiferous tubules were small and lined by single layer of spermatogonial cells. Some tubules contained degenerated and desquamated cells without any evidence of sperms. The tubules of the epididymis were small in size and the lining cells showed deciliation and desquamation. These degenerative changes were found to be reversible on discontinuation of treatment with thiourea. The accessory sexual glands, the seminal vesioles and the prostate weighed less in hypothyroid goats. Histologically the cells lining the glands were small inactive, vaculated and hyalinised. After discontinuation of administration of thiourea the reparative changes were almost normal. There was significant decrease in the relative weight of the ovary and uterus in all the animals dosed with thiourea. Histologically ovaries were found to be inactive and only few scattered immature follicles were seen. Uterine glands were few and non secretary type. The lining epithelial cells did not show active mitosis. On discontinuation of treatment with thiourea the weight of the ovary and uterus increased and histologically ovaries and uterus were found to be normal. Kids and female goats were more susceptible to the effects of hypothyroidism. The significant pathological changes observed in the reproductive organs have clarified the importance of hypothyroidism in inducing sub-fertility and infertility in goats. The reversible nature of the lesion was also proved.ThesisItem Open Access Ochratoxicosis in quails (Coturnix coturnix japonica) with special reference to Inununopathological response(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1992) Amir Abbas, Farshid; KAU; Rajan, AIn this investigation the pathological effects of OA in quail embryo and adult quail were studied with special reference to the immune system. Ochratoxin A (OA) was inoculated into the quail embryos, at the dose rate of 0.02 ^g per embryo. There was 68.66 per cent mortality which clearly indicated the direct action of OA. The embryos which were sacrificed on the 13th and 16th day of incubation showed significant reduction in the body weight, weight of bursa of Fabricius, spleen and thymus. Histological changes in these lymphoid organs were, atrophy, necrosis and depletion of lymphoid elements. Ultrastructurally the changes were time dependent. There were changes in the shape of the nucleus with condensation of granular and fibrillar components of the nucleoli. The adverse immunobiological effect of OA on the developing lymphoid organs was established by histological and ultra structural studies. OA at the dose rate of 50 /ag/bird/day for a period of 60 days was administered through oesophageal intubation. Pathological changes were sequentially documented with special reference to the immune system. In the OA fed quails, the clinical signs included emaciation and hyperexcitation at the later part of the experiment. There was highly significant reduction in the body weight, weight of bursa of Fabricius, spleen and thymus. The reduction in the weight of lymphoid organs gave evidence to the adverse effects of OA on the immune system. There was reduction in the total erythrocyte count (TEC), haemoglobin (Hb) concentration and packed cell volume in OA fed birds indicating the significant damaging effect on the haemopoietic sytem. Estimation of total serum protein (TSP), serum globulin (SGI) and serum immunoglobulin fractions clarified the biological adverse effect of OA on the humoral immune system. Highly significant reduction in total leukocyte count (TLC) and T cell dependent lymphopenia proved the immunosuppressive effect of OA. There was reduction in T cells, increase migration indices in response to Fowl pox antigen in leukocyte migration inhibition test (LMIT), the reduction in the cutaneous response to 2,4-dinitrochlorobenzene (DNCB) and phytohaemagglutinin-M (PHA-M) and spleen indices in the graft versus host reaction (GVHR), clarified the immunotoxicity of OA on the cell-mediated immune system.ThesisItem Open Access Embryo mortality in chicken(Department of Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1987) Lalithakunjamma, C R; KAU; Krishnan Nair, MThe nature of embryomortality in hatcheries and the posiible causes for embrypathies were studied. Experimental studies were conducted by inoculating Oxytetracycline, Ochratoxin A, Citrinin and a combination of ochratoxin A and Citrinin and avian influenza virus. Ultrastructural studies were conducted to elucidate the subcellular changes in the liver and kidneys of the embryo after administration of the mycotoxins. The various abnormalities noticed were early embryonic death, curled embryos, dead in shell, live sticky embryos, oedema of head and neck emphalitis and septicaemia, gastroachisis with herination of yolk sac, coelosoma, dwarfs, curled toe, microphthalmia, anopthalmia, brachycephaly, parrot beak, crossed beak, brachygnatha, streptosomia and a few cases of diprosopus, polymeliaThesisItem Open Access Cellular response in inflammatory reaction in the duck(Department of Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1985) Valsala, K V; KAU; Krishnan, Nair MThe cellular dynamics in ducks associated with inflammatory response induced by various immunogenic and non-immunogenic agents was studied for the first time. The inflammatory response was induced in the web of ducks using turpentine, dextran sulphate, talc, Staphylococcus aureus, homologus erythrocytes and Freund’s complete adjuvant. The biopsy specimens were collected from half an hour up to 21 days at specific time intervals and examined to assess the cellular response and the chronology of cellular events taking place during the emigration process was depicted. The comparative features of cellular events taking place when different agents were employed were also clarified. The light microscopic studies were supported by electron microscopic studies. Irrespective of the agents employed to elicit the inflammatory reaction it was found that there was emigration of heterophils and monocytoid cells from the arterioles and venules concurrently even though there was quantitative difference in the number of emigrating cells due to different agents. Initially there was high predominance of heterophils in the exudate and later there was predominance of macrophages or lymphocytes. Participation of basophils was also evident at the initial stages. Lymphoid foci formation with germinal centres particularly when antigenic stimulus was used was a characteristic feature. It was demonstrated that monocytoid mononuclear cells transformed into macrophages, epithelioid cells and giant cells. The morphological features of the heterophilic granules were studied by electromicroscopy. Large dense granules with one or two electron dense core and light granules with fibrillary matrix were seen. The process of endocytosis of the foreign body involved fusion of phagosomes. The active heterophil was demonstrated to contain more glycogen. The transformation of monocytoid cells into macrophages was demonstrated to be associated with increase in size and number of endoplasmic reticulum and formation of well developed golgi complex and lysosomes. Epithelioid cells were devoid of phagolysosomes. It was clarified that the lymphocytes underwent transformation into plasma cells under antigenic stimulation. The plasmacytoid transformation was evidenced by formation of rough surfaced endoplasmic reticulum. The systemic response to Ranikhet disease virus and Duck plague virus was studied. The tissue destruction and cellular response to RD virus were meagre. Heterophilic and monocytoid cell reaction was still the initial response. In duck plague infection there was progressive necrosis and this was associated with pronounced lymphoidreaction indicative of an immunologic reaction. In Ranikhet disease infection thelymphoid reaction was not as pronounced as in duck plague virus infection.
