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ThesisItem Open Access Biology of neoplastic cells of ethmoid carcinoma(Department of Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1985) Madan Sing, Karki; KAU; Rajan, AAttempts were made to propagate the ethmoid carcinoma cells in vitro to study the biological behaviour of the neoplastic cells and their relationship with the host. Efforts were also made to transplant the neoplastic cells in laboratory animals and tumour bearing natural hosts so as to lay out a model system for further investigation. In vitro propagation was tried by obtaining the tumour tissues from nine cows and three goats. Cells were grown in Hank’s balanced salt solution (HBSS). TC – 199 and Dulbecco’s modified Eagle’s medium with 10 to 20 per cent calf serum. The cell suspension was seeded into tissue culture bottles, milk diluting bottles and test tubes and incubated at 370 C. No growth was observed in the cultures made from the tumour tissue of cows. The tumour cells from two goats grew in monolyerand were maintained for nine days. There was no difference in growth of cells in different media employed. Insulin supplementation in the media did not cause any difference in the growth of the cells. Subsequently the cells died even after subculturing and changing of the media. Absence of certain unknown factors required by the neoplastic cells for growth was considered responsible for failure of the growth. Transplantation studies were carried out in autologous, homologous and heterologous species of animals using the tumour tissue framgments, homogenate, filtrate and cell suspension. No autograft or heterotransplant were successful. Homologous transplantation resulted in a firm painless growth at the site of injection. The growth initiated a cell – mediated immune response at the site of implantation. Failure of neoplastic cells to grow in the other hosts was considered to be due to rejection of the transplants by the host’s immune system.ThesisItem Open Access Pathology of hypothyroidism in pigs(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences,Mannuthy, 1995) Prasanna, K S; KAU; Sreekumaran, TAn experimental model of hypothyroid state was induced in piglets, using thiourea with the objectives of studying the sequence of clinico pathological changes and its influence on the animal health and growth. Tweleve Large White Yorkshire male piglets of 2 – 3 months age were selected for the study. The animals were divided into control group of six animals and experimental group of six animals. Experimental hypothyroidism was induced by feeding thiourea daily for a period of three months at the dose level of 50 mg per kg body weight. Haemogram, body weight, plasma proteins, serum cholesterol and serum thyroxine values were estimated at periodic intervals. The piglets were subjected to detailed autopsy after sacrifice. Gross lesions were recorded and detailed histopathological examination of tissues was carried out. During the course of experiment all the experimental animals recorded stunted growth and appreciable reduction in feed intake and alopecia of neck and shoulder regions. There was significant increase in blood cholesterol values and plasma protein level in thiourea fed group. A significant reduction in serum thyroxine level was also recorded. There was significant increase in the relative weight of thyroid, adrenal and pituitary glands of experimental animals. Gelatinisation of subcutaneous fat and dilatation of right ventricles were common findings at autopsy. Histologically the thyroid glands exhibited varying degree of hyperplastic changes and depletion of colloid in the follicles. Hyperplasia and hypertrophy of the lining epithelium was also observed. Predominant histological changes in the pituitary was hyperplasia and hypertrophy of the basophil cells and degranulation of the acidophil cells. Adrenal glands showed diffuse hyperplasia of zonafasiculata and accessory cortical nodule formation. Skin revealed acanthosis, hyperkeratosis and keratinisation of harifollicles. In all the hypothyroid animals testis showed varying degree of tubular degeneration. A random survey study was conducted to assess the thyroid status of pigs from different parts of Kerala using serum thyroxine as the marker. This concluded that most of the animals had the normal range of serum thyroxine levels.ThesisItem Open Access Determination Of Permissible Level Of Aflatoxin In Broiler Chicken Feed(Department of Pathology, College of Veterinary and Animal Sciences,Mannuthy, 1999) Arulmozhi A; KAU; Koshy VargheseThe study was undertaken to assess the effect of various levels of aflatoxin on the performance of broilers and to establish the permissible level of aflatoxin in the broiler feed. One hundred and eighty day old broiler chicks were divided into six groups of 30 birds each and were given feed containing graded levels of aflatoxin at 0, 20, 40, 60, 80 and 100 ppb for a period of 45 days. Feed intake, weekly body weight gain, feed efficiency, haemogram, serum profile, organ weight, residual aflatoxin in tissues and pathological changes in liver, kidney, bursa and spleen were studied at fortnightly intervals to evaluate its dose related effects. A dose dependent decrease in the daily feed intake and mean body weights were noticed in all the groups. The cumulative FeR was extremely poor at 80 and 100 ppb levels at sixth week of age. The toxicopathological changes in the birds varied in its intensity in relation with the level of aflatoxin in the feed, with most severe changes being at higher dose levels. The values of haemoglobin, PCV, total leucocyte count, Iymphocytes, total serum protein and albumin showed a decrease whereas the ESR, heterophil and serum enzyme were increased. The aflatoxin, even at 20 ppb levels caused degenerative and necrotic changes in liver and kidneys and the intensity of the lesions increased with higher levels of toxin. Attempt for regeneration and repair processes were well pronounced by the 30th and 45th day. Lymphoid depletion was a characteristic feature in bursa and spleen. Degeneration and lysis of lymphocytes with cys; formation was also seen in bursal follicles. Residual aflatoxin was detected in the liver and muscle in all groups by the 45th day. The net returns from the toxin treated birds showed a dose related decline compared to control and the loss in profit at 20 ppb level was marginal About 24 per cent of the poultry feed samples tested during the period from January to July 1999 were contaminated with aflatoxin quantitatively ranging from 20 to 200 ppb. The results of the present study shows that even at 20 ppb aflatoxin causes cellular and subcellular damage to the tissues. However, the economic loss at this level was marginal when compared to higher dose levels. Hence 20 ppb can be considered as permissible level in broiler chicken feed.ThesisItem Open Access Immunopathologic and toxic effects of endosulfan in chick embryo(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2004) Kalai Selvan, P; KAU; Divakaran Nair, NThe present study was undertaken to investigate the immunopathologic and toxic effects of endosulfan in chick embryo. The embryos were exposed to endosulfan at various dose levels through different routes. The weight of the embryo, bursa, thymus and spleen, histopathology of the lymphoid organs, liver, kidney and brain and quantification of the preformed maternal IgY level in the egg yolk were the parameters analysed to study the effects. Endosulfan was found to be teratogenic at the grven dose levels. The abnormalities observed were agenesis of beak, crossed beak, short lower beak, eventration of viscera and curled toe. Endosulfan did not cause any significant gross changes in the developing embryos except mild haemorrhages. Endosulfan treatment did not produce any significant reduction in the weight of the embryos as well as the weight of the lymphoid organs. On histopathological examinations endosulfan was found to be nephrotoxic and hepatotoxic to the embryos. Varying degrees of degeneration and necrosis was evident in kidney and liver. Effect on the bursa, thymus and spleen were mild to moderate where in the degenerative changes predominated. Dose dependent increase in the involution process of the thymus as evidenced by increase in the Hassal's zone was observed. The lesions in the developing lymphoid organs reflected that endosulfan is toxic to the system and going to affect the immunocompetency by way of immunosuppression and thereby rendering the chicks susceptible to various diseases. The study indicated that the endosulfan treatment did not have any effect on the preformed maternal immunoglobulin level in the egg yolk.ThesisItem Open Access Pathology of cardio-pulmonary disorders in canines(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2003) Pradeep, M; KAU; Vijayan, NThe present study was undertaken to assess the prevalence and pathology of various cardiac and pulmonary disorders in dogs. The data collected from the autopsy records maintained at the Centre of Excellence in Pathology, Mannuthy and seventy eight samples of heart and lungs from necropsy cases formed the basis of the study. Ninety nine per cent cases showed varying types of cardiac and pulmonary lesions. The highest incidence in the heart was dilated (75.32 per cent) and hypertrophic (15.58 per cent) cardiomyopathies. The other lesions found were hydropericardium, cardiac tamponade, haemorrhage, myocarditis, endocarditis, endocardial fibroelastosis, valvular blood cyst coronary arteriosclerosis and mural. thrombus. Myocardial infarction was found to be confined to the left ventricles and interventricular septum in all the encountered cases (5.19 per cent). Pulmonary congestion (70.51 per cent), haemorrhage (32.47 per cent) and edema (31.17 per cent) were observed with higher incidence rate. The other lesions found in the lungs were bronchitis, emphysema, pneumonia, collapse, infarction, mineralization, ossification, anthracosis and endarteritis obliterans. Metastatic osteosarcoma in the lungs, metastatic lymphosarcoma in the heart and lungs were also observed. The incidence of cardio-pulmonary disorders encountered was relatively high. The need and scope for investigation into the pathological disorders of the heart and lungs of canines were highlighted.ThesisItem Open Access Gastrointestinal and neurotoxic effects of cypermethrin in rats(Centre For Excellence In Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2008) Remya Nair, R; KAUThe present study entitled ‘Gastrointestinal and neurotoxic effects of cypermethrin in rats’ was undertaken to investigate the potential toxic effects of cypermethrin in rats with particular emphasis on its effect on the nervous and digestive system.The clinical signs, gross pathology, histopathology, haematology and biochemical parameters were analysed to study the effects. Cypermethrin was found to be neurotoxic and gastroenterotoxic at the given dose levels. Oral administration of cypermethrin in medium and high doses produced nervous signs in animals. However cypermethrin did not cause any significant variation in the body weight of animals. All haematological parameters evaluated showed a dose dependent reduction in its value. Biochemical parameters assessed revealed hepatotoxic and multisystemic effects of cypermethrin. Gross lesions observed in the intoxicated groups were bloat, congestion of lungs, heart, brain, pulmonary haemorrhage and degenerative changes in liver and kidneys. On histopathological examination, cypermethrin was found to be neurotoxic, hepatotoxic, enterotoxic, pneumotoxic, cardiotoxic and nephrotoxic as evidenced by varying degrees of degeneration and necrosis in various organs examined. Effects on all organs were mild to moderate degenerative changes at the low dose level. Medium and high dose intoxicated groups revealed necrotic changes, extensive haemorrhages, congestion in organs like liver, kidney and lungs apart from the changes observed in low dose group animals. Haemodynamic disturbances were manifested in the forms of congestion and haemorhages in lungs, heart, liver and kidneys. The histopathological evaluation revealed no cypermethrin induced toxic effects on the oesophagus. Spinal cord lesions were observed only in the lowest dose group. Brain lesions were only degenerative changes. These findings suggested that biochemical effects rather than structural changes were involved in toxicity.ThesisItem Open Access Pathology of the reproductive system in ducks(Department of Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1986) Jayakumar, P M; KAU; Valsala, K VA study was conducted on the pathology of the reproductive system in ducks. A survey conducted on the prevalence of diseases based on the data for a period of 11 years at the Government Duck Farm, Niranam revealed the incidence of hepatosis (64.58%), hepatitis (9.07%), enteritis (8.58%), tuberculosis (2.61%) and miscellaneous disorders (15.13%). The latter category included pulmonary edema, omphalitis and transport stress. In a separate study, the reproductive organs of 194 female ducks and 26 male ducks were examined systematically and gross and histopathological lesions encountered were studied. The diseases encountered in females were hypoplasia of left ovary and oviduct (20%), impaction of oviduct (5.45%), haemorrhagic cyst in the ovary (7.27%), salpingoperitonitis (10.9%), oophoritis (49.09%), cystic right oviduct (1.82%), mycotic salpingitis (1.82%) and tuberculous salpingitis (3.63%). In males atrophic testis (66.3%) and seminoma (33.3%) were the diseases recorded. Experimentally, pure aflatoxin B1 and ochratoxin A were administered to six ducks each, at the rate of 25 µg per duck daily for a period of three months. Clinically all the experimental ducks showed unthriftiness. But it was more pronounced in aflatoxin group. In both aflatoxin and ochratoxin group, the birds showed reduced weight gain and decreased feed intake. There was reduction in the weight of the testis in both aflatoxin and ochratoxin groups. Histologically, in the aflatoxin group, marked disruption in the organisation of germinal epithelium, absence of sperm bundles and edema of the interstitial tissue were the lesions observed. In the ochratoxin group, the basement membrane was found to be unaffected. Both aflatoxin and ochratoxin were found to cause degenerative changes in the testicular tissue. However, aflatoxin was found to cause more pronounced changes than ochratoxin. From the studies made, it was concluded that both aflatoxin and ochratoxin can induce degenerative changes in the testis and it was surmised that this would lead to subfertility and infertility. The need for feeding a diet free of mycotoxins to ensure profitable duck farming was stressed.ThesisItem Open Access Hepato-renal pathology in canines(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2001) Lakshmi, R; KAU; Koshy VargheseThe present investigation was undertaken to assess the prevalence and pathology of the liver and kidney disorders in canines. The results of the present investigation and the evaluation of data from the records revealed a high incidence of liver (76 percent) and kidney (85 per cent) disorders. A detailed systematic examination of one.hundred cases of canine carcasses brought for autopsy during the period of investigation was conducted and the gross and histopathological lesions were studied in detail and were classified based on age, sex and breed. Vascular and degenerative changes were the predominant lesions in these organs. The other lesions recorded in the liver were necrosis (15 cases), hepatitis (19 cases), fibrosis (9 cases) and cirrhosis (2 cases). One case each of cholangiocarcinoma, hepatic cyst and adhesion of diaphragm and the liver was encountered in the present study. Among kidney disorders, glomerular lesions were predominant next to vascular and degenerative changes. A total of 59 cases had some lesions in the glomeruli of which, 32 hadglomerulonephritis. PGN was the predominant type of glomerulonephritis. Males had a higher predilection for PGN and it was common in animals less than three years of age. MN and MPGN were common in animals more than three years of age. The high incidence of glomerular lesions and their possible causes were discussed. Tubulo-interstitial nephritis was observed in 16 cases. Interstitial nephritis was common in males while both cases of pyelonephritis were seen in females. Acute interstitial nephritis was seen in animals less than five years of age while all cases of chronic interstitial nephritis was seen in animals more than five years of age. Bacterial isolations were obtained in the liver or kidney or both in only 14 cases. Viral etiology was suspected in two cases where intranuclear inclusions were seen in the hepatocytes and the glomerular epithelium. The high incidence of vascular lesions without any evidence for infectious etiology in rest of the animals suggested the involvement of some toxic factors. The importance of identifying the specific etiology in these suspected cases of toxic conditions and the need and scope for further studies in these lines were highlighted.ThesisItem Open Access Immunopathological response of the duck (Anas platyrrhyncos domesticus) to sublethal dose of selected agro-chemicals(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1998) Vijayan, N; KAU; Valsala, K VThe study was conducted with the objective of assessing the teratologic, embryotoxic and immunopathologic effects of two agro-chemicals carbofuran and 2,4-D used in agricultural operations, on duck embryos and ducklings. The embryological studies included the observation on the embryonic defects and weight of the lymphoid organs along with the histopathologic and ultrastructural studies of the lymphoid organs like the bursa, spleen and thymus. The results showed that the contamination of the eggs with the above chemicals caused moderate deleterious effects on the lymphoid system, though no teratologic effects could be observed. The histological and ultrastructural changes also confirmed the deleterious effects at the tissue and cellular level. The immune system of the ducks exposed to the above chemicals for two different durations were assessed using a battery of tests. The humoral immune system was assessed based on the body weight, lymphoid organ weight, haematological evaluation, serum biochemical evaluation and the evaluation of HI titre against NDV. The cell-mediated immune system was assessed by the skin reactivity tests to DNCB and PHA. LMIT and GVHR were also employed to assess the cell-mediated immune system. The histological and ultrastructural studies were also conducted after six weeks and ten weeks of the experiment. The assessment of the immunological profile employing these elegant tests revealed that these agro-chemicals caused mild but significant suppression of the cell-mediated and humoral immune response. By this investigation it was clarified that these agro-chemicals have mild to moderate degree of immunotoxic effect when exposed for a short duration, but the changes were severe when exposed for longer duration. From the .studies, it was demonstrated that the immunotoxic effect of carbofuran is more compared to 2,4-D (herbicide) and the changes were dose and time dependent.
