1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
Permanent URI for this communityhttp://localhost:4000/handle/123456789/1
Browse
32 results
Search Results
Item Pathology of the reproductive organs in experimental hypothyroidism in goats(Department of Pathology, College of Veterinary and Animal Sciences, 1982) Nemali Mohan Reddy; 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.Item Ochratoxicosis in the goat(Department of Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1983) Maryamma, K I; Krishnan Nair, MAn experimental study was carried out to delineate the pathological effects of ochratoxin in goats. A comparative assessment of ochratoxin production by A. ochraceus and A. sulphureus on what and rice under static and shake cultures was also made. A. ochraceus was found to be a better toxin producing strain in both substrates under static and shake cultures systems and wheat was a better substrate than rice. Toxicity studies were conducted in Sannen – Malabari cross-bred goats of 1 to 3 months age. Purified ochratoxin produced in the laboratory was administered by oral, intra-peritoneal and intravenous routes. The different dose levels adopted were 2.5 mg/kg body weight, 1 mg/kg body weight and 0.5 mg/kg body weight. The synergistic effect of ochratoxin and aflatoxin in goats was studied by adminstering the crystalline toxins simultaneously (Makor Chemicals, Israel) by itraperitoneal route. The parameters of study were: clinical signs, haematological and biochemical alterations, pathological changes in urine, and macroscopic, microscopic and ultra-structural alterations in organs. Varying degree of clinocopathological changes were noticed in the test animals. The animals became weak and listless and in general there was reduction of total erythrocyte count, PCV, haemoglobin and lymphocyte count. Serum protein level was lowered while BUN and creatinine and blood coagulation time were high. There was rise in ALP, SGOT and SGPT in some of the test animals. The changes and degree of variation depended on the dose, total quantity and rate of administration of the toxin and duration of the experiment. More severe alterations were noticed when ochratoxin and aflatoxin were administered simultaneously. Important changes in the urine were lowering of pH, albuminurea and presence of epithelial cells and casts. Pathological changes varied in severity in different organs and were observed in the following descending order: kidney, liver, intestines, stomach, lymph nodes, spleen, thymus, genital organs, endocrines. In the kidneys, the order of intensity of pathological alterations was: proximal convoluted tubules, Henle’s loop, distal convoluted tubule, glomeruli, collecting tubules. Retrogressive changes of different degree and necrosis of the lining epithelial cells of tubules and endothelium and epithelium of glomeruli were the important lesions. Changes in glomeruli and Bowman’s capsule noticed in the higher dose group included shrinkage of glomeruli and presence of proteinaceous material in the capsular space. Eosinophilic granular casts and PAS positive bodies were present in the lumen of tubules. The necrobiotic renal changes were more intense when orchatoxin and aflatoxin were administered simultaneously. Hepatic lesions were mainly fatty infiltration, necrosis of hepatocytes and haemorrhage. The changes were most severe in combined toxicity. Mallory bodies and mild biliary hyperplasia were noticed in a few sections. Necrosis and subsequent depletion of lymphocytes wee the lesions in lymph nodes, spleen and thymus in some test animals. Degenerative changes were also noticed in testis, ovary, pituitary, adrenals and pancreas in experimental groups. In the combined toxicity group the pathological effect was more intense. At the ultra-structural level, the hepatcytes as well as the epithelial cells in the kidney showed severe changes. The cell organelles were either completely damaged or showed partial configurational alterations. Mitochondria showed changed in the density of matrix as well as disorientation and destruction of the limiting membranes and cristae. Cytolysosomes incorporating damaged cell organelles were abundant. Disaggregation of ribosomes and fragmentation of ER were noticed. In the glomerulus, there was destruction of the basement membrane and disruption of the regular arrangement of the foot processes of podocytes. In the cytoplasm of hepatocytes, Mallory bodies and lipid droplets were present. Varying degree of nuclear changes like clumping, condensation and disappearance of chromatin and fragmentation of nucleolus and nuclear membrane were observed. Changes occurred in the tight junctions of epithelial cells of bile ducts. Pathological alterations were more pronounced when ochratoxin was administered by the pwerenteral route. Oral administration of toxin also effected structural alterations which indicated that some fraction of ochratoxin escaped degradation in the rumen. From this study it became evident that aflatoxin potentiated the effect of ochratoxin. The structural damage to the cells might be due to the inhibition of oxidative enzymes which is reflected by the extensive ultra- structural alteration observed in the mitochondria and RER. Biochemical changes like high BUN and creatinine were evidently due to necrobiotic changes in the kidney. Interference in the synthesis of proteins due to damage of hepatic cells and escape of protein molecules due to alteration in the podocyte foot processes and basement membranes may account for the reduced serum protein levels. The nature of organellar destruction and configurational changes in the cells indicate the toxic potency of the mycotoxin on the biological system.Item Pathology of cardio-pulmonary disorders in canines(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2003) Pradeep, M; 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.Item Gastrointestinal and neurotoxic effects of cypermethrin in rats(Centre For Excellence In Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2008) Remya Nair, RThe 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.Item Synergistic effect of alfatoxin B1 and ochratoxin A in chick embryos(Centre for Excellence in Pathology, College of Veterinary and Animal Sciences,Mannuthy, 2001) Rony Ray John; Lalithakunjamma, C RThe present study was taken up to investigate the synergistic effects of the mycotoxins AFBl and OA on chick embryos, the variations in the susceptibility to the toxins both individually and in combination. Embryomortality, teratogenicity and reduced embryonic weight were some of the deleterious effects observed in the inoculated chick embryos. The abnormalities seen were more in the combined toxin treated group and they included stunted embryos,' evisceration, herniation of yolk sac, beak abnormalities, cranioschisis and oedema of head and neck. Both the liver and kidney were equally damaged and extensi ve haemorrhage into the parenchyma of all the organs was the main histological lesion observed in addition to degenerative and necrotic changes. This study showed that mycotoxins deleteriously affect a number of parameters associated with embryonic growth.Item Efficacy of argyrrophilic nucleolar organizer region count test for in vivo biomaterial evaluation(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences,Mannuthy, 2001) Umashankar, P R; Divakaran Nair, NThe efficacy of argyrophilic Nucleolar organizer Region (AgNOR) count test in the evaluation of biomaterial was assessed in this study utilizing a reactive (medium chromic catgut) and a non-reactive (Polypropylene) material. The materials were implanted into rat gluteus muscle for a duration of seven and 14 days and sham surgery done on a separate group of animals served as the control. The tissue response such as inflammation, muscle degeneration and peri-implant scar thickness around the reactive and non-reactive implant and the controls at seven and 14 days were studied using H&E and special stains for collagen. Besides this the estimation of collagen of the reactive and non-reactive material implanted tissue was studied. The observations made in this were compared with the fibroblast proliferation response at the respective durations as assessed by the AgNOR count estimation. On histopathological evaluation, the reactive material showed an initial acute inflammatory response with mild fibrosis and collagen deposition which subsequently settled into a chronic form with severe fibrosis and more collagen deposition at the end of 14 days. Non-reactive material elicited an acute inflammation initially (seven days post implantation) which settled into a mild chronic response at 14 days post implementation. Mild fibrosis and less collagen deposition were noticed in the peri-implant area at both the duration. Observations on fibroblast proliferation as assessed by AgNOR count test well correlated to the above findings. The AgNOR counts observed with reactive material at seven days and 14 days were 1.97 + 0.03 and 2.23 + 0.02 respectively. The counts for non-reactive material were 1.81 + 0.01 and 1.67 + 0.02 at seven and 14 days post implantation respectively. The collagen content of the reactive and non-reactive implanted tissue did not reveal any statistically significant difference as compared with the respective control. From this investigation it was proved that AgNOR count test could be reliably applied for biomaterial evaluation even at seven days duration and it formed a valuable adjunct to the routine method employed in the in vivo evaluation of biomaterials.Item Studies on the ameliorative effect of vitamin E on paraquat toxicity in rats(Centre for Excellence in Pathology, College of Veterinary and Animal Sciences,Mannuthy, 2010) Divya, V S; Vijayan, NThe present study entitled ‘Studies on the ameliorative effect of vitamin E on paraquat toxicity in rats’ was undertaken by administering the animals with paraquat dichloride and vitamin E for a period of 28 days. The weekly body weights, clinical signs, haematology and biochemical parameters were analysed. Of the twelve animals in each group, six animals were sacrificed at the end of second week and remaining at the end of forth week. The gross pathology and histopathology of various organs were studied. The oxidative damage of the lungs and kidneys was assessed by the estimation of lipid peroxides and reduced glutathione. None of the animals in the experimental groups revealed any clinical signs of toxicity except for one rat each from paraquat alone treated group and paraquat plus vitamin E treated group which became weak towards the end of experiment. Although, all the groups showed a gradual increase in body weight, those animals treated with paraquat alone and those with paraquat and vitamin E showed a reduced weight gain when compared with the control group. The AST, ALT, ALP and creatinine values showed a significant increase in treatment groups compared to the control. In vitamin E treated group, a slight decrease was noticed in these biochemical parameters. Hb and PCV values showed a significant decrease and the total leukocyte count showed a significant increase in treatment groups when compared to control group. There was no variation in the erythrocyte sedimentation rate and differential leukocyte count. In vitamin E treated group, a slight increase in Hb and PCV values were noticed. There was an increase in the lipid peroxides and concurrent reduction in the glutathione in the lung and kidney homogenate which indicated oxidative damage. Gross lesions were almost similar in both treatment groups. The congestive changes were noticed in lungs, kidneys and liver. The histopathological changes noticed in paraquat alone treated group were congestion, haemorrhage, focal areas of necrosis with proliferation of fibroblasts in the lungs, thickening of the interalveolar septa. The bronchi revealed desquamation of proliferated epithelium. Degenerative changes in the renal tubules, focal necrotic changes in the liver and varying degrees of degenerative changes in the heart, stomach, intestine and brain were the other lesions noticed. These lesions became more intensified in animals treated for four weeks. In vitamin E treated group, a slight reduction in the intensity of lesion was noticed. The bronchial epithelium was intact. Mild proliferation of fibroblasts and congestive changes were also noticed in the lungs. Focal necrotic changes were noticed in the kidneys and liver. Mild degenerative changes were noticed in the heart and intestine. The study revealed that the vitamin E is not completely suitable for management of the renal and pulmonary disorders in subacute paraquat toxicity in rats.Item Pathology of the reproductive system in ducks(Department of Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1986) Jayakumar, P M; 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.Item Immunopathological response of kids in pneumonia(Department of Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1986) Anilkumar, T V; Rajan, AThe immunopathological response of kids spontaneously affected with pneumonia and kids experimentally dosed with aflatoxin was evaluated, for the first time, employing various immunological markers. Attempts were also made to modulate the immune response of kids for the first time using levamisole. There was enhancement of the immune response in pneumonic kids as evidenced by leukocytic response, number of T-lymphocyte sub-population in the peripheral blood, in vitro neutrophil activity, concentration of gammaglobulin in the serum and cutaneous response to 2, 4-Dinitrochlorobenzene and phytohaemagglutinin. Immunological background of kids fed aflatoxin (at the rate of 0.25 mg/kg body weight) was evaluated, Immunostimulation (in first 15 days) was followed by immunosuppression (from 15 days until death). The kids developed pneumonia and died. It was concluded that at a dose rate of 0.25 mg/kg body weight aflatoxin caused immunosuppression in goates. At a dose rate of 3.75 mg/kg body weight (s/C) levamisole induced immunostimulation in kids. It did not cause immunomodulation in pneumonic kids.Item Immunopathological response of pigs In aflatoxicosis(Department of Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1986) Gopalakrishnan Nair, M; Maryamma, K IThe immune response of pigs fed aflatoxin at two different dose levels. 0.1 and 0.2 mg/kg body weight was studied. The reduction in weight gain observed in the aflatoxin fed pigs was associated with decreased feed consumption and total serum protein concentration. There was increase in ESR and decease in PCV, haemoglobin and total erythrocyte count in the toxin fed groups. The neutrophilic and lymphocytic count did not show any significant variation except when the animals contracted mange infection. Following infection there was slight neutrophilia. The cell-mediated immune response was assessed employing ANAE, PHA and DNCB as markers. A decrease in the immune response was documented in the aflatoxin fed pigs. The humoral immune response was found to be suppressed as evidenced by a decrease in the concentration of total serum protein and gammaglobulin in the toxin fed groups. The phagocytic activity of neutrophils and macrophages was assessed using Nitroblue tetrazolium (NBT) test. The data revealed a decreased phagocytic activity. Haemorrhages were seen in almost all the visceral organs.The liver of aflatoxin fed animals was enlarged and icteric. The gall bladder was distended and oedematous. Fetty change centrilobular necrosis, haemorrhage, bilary hyperplasia, fibrous tissue proliferation, reticular collapse and focal lymphocytic infilteration were the characteristic histological features. Haemorrhage and haemosiderosis evident in the spleen. Tubular degeneration and focal haemorrhages were seen in the kidney. The thymus and the lymphnodes revealed depletion of lymphoid cells and focal areas of haemorrhage. Some of the lymphnodes revealed reactive proliferative response. Regular screening of feed for aflatoxin was advocated as a routine farm operation to prevent the deleterious effect of aflatoxin on the health and productivity of pigs.