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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.Item Studies on the pathological effects of fipronil and their amelioration by curcumin in rats(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2010) Senthilkumar, T; Divakaran Nair, NThe present study entitled ‘Pathological effects of Fipronil and their amelioration by curcumin in rats’ was undertaken by administering with fipronil in group I animals and both fipronil and curcumin in group II animals for 28 days. Group III administered with honey served as control. The weekly body weights, clinical signs, haematology, biochemical parameters, mortality pattern, gross pathology and histopathology of various organs were analysed to study the effect. The oxidative damage of the liver was assessed by the estimation of lipid peroxides, reduced glutathione and superoxide dismutase. A significant decrease in the mean body weights was observed in group I and II. ALT, AST, cholesterol and creatinine levels showed a significant increase in the group I and significantly lower levels in group II. Total protein, albumin, globulin, PCV and Hb levels were significantly lower in group I but significantly higher in group II. TLC, ESR and DLC revealed no variation. Group I showed significantly higher lipid peroxides and lower glutathione and superoxide dismutase levels in the liver. Group II showed significantly lower lipid peroxides and higher glutathione and superoxide dismutase levels in the liver. The animals showed dullness and inappetance in the treatment groups. Mortalities were observed in both groups. Hepatomegaly and focal necrotic spots in the liver, enlargement of thyroid were the major gross lesions in group I. Gross lesions were less in group II. Smaller and cystic dilatation of acini, hyperplasia and fibrosis of thyroid, necrosis, hypertrophy and individualization of hepatocytes, tubular and glomerular degeneration and necrosis of the kidney, alveolar septal thickening, peribronchial lymphoid cell hyperplasia and bronchostenosis of the lung, predominance red pulp of spleen, desquamation and fusion of villi and goblet cell hyperplasia in the intestine, hyalinization of cardiac muscle fibers were observed in group I animal. Uniform sized follicular acini of thyroid, prominent kupffer cell reaction of hepatocytes,mild degeneration of tubules of kidney, predominance of white pulp of spleen, glial cell response in the brain, glandular hyperplasia of intestine were the major findings in group II animals. The study revealed that fipronil is thyrotoxic, hepatotoxic and nephrotoxic to rats and curcumin has good ameliorating effect against fipronil toxicity.Item Studies on sequential post-mortem changes of isolated chicken eye(Centre for Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2010) Arya Aravind; Vijayan, NThe present investigation was undertaken to study the sequential postmortem changes of different components of chicken eye and to choose an ideal fixative. Six eyes each were fixed at zero hour, half hour, one hour, one and a half hours, two hours, four hours and twelve hours in ten per cent neutral buffered formalin and gluteraldehyde fixative. Eyes were fixed for a minimum of three weeks. A clean cut was made near to the midline of the fixed eye slightly to one side of it, so that the origin of the optic nerve and pupil were included in the sections. The eye consisted of three tunics; tunica fibrosa consisting of cornea and sclera, tunica vasculosa with choroid, ciliary body and iris and tunica interna consisted of retina. The postmortem changes were mostly appreciated in the cornea, which included condensation of the nucleus of the epithelium of cornea, interepithelial detachment and exfoliation of epithelium. The cytoplasm revealed vacuolar and degenerative changes and there was separation of collagen fibres of corneal stroma. The corneal endothelium showed swelling, lysis and detachment. The presence of lysed erythrocytes was prominent after two hours in the choroid. As the time interval advanced, there were varying degrees of dispersion of melanin pigment. The swelling of the cytoplasm of the ciliary body was more evident in the non- pigmented epithelial layer. The epithelium of the iris showed detachment and fragmentation. Retinal detachment was noticed from zero hour of fixation in GF fixative and ten per cent NBF fixative. The changes were prominent in the ganglion cells which showed condensation of the nuclei along with vacuolar and lytic changes of the cytoplasm. Postmortem changes of pecten were appreciated by the lysed erythrocytes in the capillaries along with the vacuolar degeneration and lytic changes affecting melanocytes and hyalocytes. PAS positive areas were detected in the Descemet’s membrane and Bowman’s membrane of cornea, lens capsule, pecten and layer of rods and cones of retina. Masson’s trichrome staining proved to be useful to appreciate the changes in the collagen fibres, muscles and epithelium. The histometry of the eyeball showed a significant decrease in thickness of cornea at 120 minutes when compared with zero hour in neutral buffered formalin fixative. From the study it can be concluded that GF fixative is a better fixative for eye than 10 per cent NBF fixative.
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