Thumbnail Image

Theses

Browse

1992 - 19945
Reset filters
Subject: Veterinary Pathology × Author: KAU × End date: 1994 × Start date: 1990 × Thesis Type: M.V.Sc. ×
Reset filters

Search Results

Now showing 1 - 5 of 5
  • Thumbnail Image
    ThesisItemOpen Access
    Homologous and heterologous transplantation of bovine ethmoid carcinoma cells
    (Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1994) Ajith Jacob George; KAU; Ramachandran, K M
    Homologous and heterologous transplantation of bovine ethmoid carcinoma cells were attempted to assess the xenograftic efficiency of the neoplasm. Tumour tissue for the study was obtained from seven clinically affected cows. Histopathologically the tumours were classified as adenocarcinoma, papillary adenocarcinoma, undifferentiated carcinoma and squamous cell carcinoma. Tumour tissue/cell culture was successfully carried out using trypsinised single cell suspension and tumour tissue gragments. Calves were used as homologous hosts and rats, mice and rabbits were used as heterologous hosts. Cyclophosphamide, hydrocortisone and cyclosporine A were used as immunosuppressants. Transplantation was carried out subcutaneously or intraperitoneally. The inoculum consisted of trypsinised single cell suspension, tumour tissue fragments and cell suspension from tissue culture. Neoplastic cells failed to grow in immunosuppressed calves, rats and rabbits. Whereas, the tumour cells obtained by trypsinisation were successfully transplanted in mice immunosuppressed with cyclosporine A. The tumour growth was evident from the second week onwards. In immunosuppressed animals the total leucocyte count, differential leuocyte count and alphanapthyl acetate esterase positive lymphocyte count were very low compared to their controls. The results of the present study indicated that mice could be used as an experimental model for the studies on bovine ethmoid carcinoma.
  • Thumbnail Image
    ThesisItemOpen Access
    Neoplasms of the duck with special reference to hepatocarcinogenesis
    (Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1992) Leena Devi, T; KAU; Valsala, K V
    At the Centre of Excellence in Pathology during the period from 1989 – 1991 six hundred and eighteen ducks were subjected to detailed post – mortem examination and out of this one hundred and thirty six ducks showed hepatosis, one hundred and twenty six ducks had hepatitis and sixteen ducks had hepatic tumours. At the Government duck farm, Niranam, 14,360 ducks were examined and 46.92 per cent of ducks had hepatic lesions. However, tumours were not recorded. The possible aetiological role of aflatoxin for hepatosis and hepatic tumour was indicated. An experiment was designed taking duck as a model to assess the carcinogenic affect of genotoxic carcinogen aflatoxin and non – genotoxic carcinogen clofibrate. Aflatoxin was administered to twelve ducks at the dose rate of 0.04165 mg/kg body weight every third day for a period of six months. Hepatic tumours were recorded in four ducks out of the six ducks sacrificed on the 90th day and in all the six ducks sacrificed on the 180th day. The body weight, haemoglobin, ESR, total serum protein, albumin, globulin, serum enzymes such as AST, ALT, GGT and ALP were estimated at fortnightly intervals. Clinically there was reduction in the body weight, haemoglobin, total serum protein, albumin and globumin levels by the third month. There was significant increase in ESR, serum AST, ALT, GGT and ALP levels when compared to the control ducks. These clinical changes were attributed to hepatosis and heapatic tumours. Hepatosis characterised by moderate to severe enlargement of the liver with scattered greyish white nodules of varying sizes were the chief lesions encountered in aflatoxin fed ducks at autopsy. The tumours encountered were classified as hepatocellular carcinoma (6) and cholangiocellular carcinoma (4). The gross and histopathological features of these lesions were described in detail. Histochemically the activity of GGT and ALP was moderate to severe in the liver tumours. The sequence of histological changes seen was hapatic degeneration necrosis and tumour formation. Clofibrate was given at the dose rate of 0.05 g/kg body weight per day for six months. In these ducks the liver has a cooked appearance with few focal greyish white patches when sacrificed at the sixth month. There was significant reduction in the body weight, haemoglobin, total serum protein, albumin and globulin levels and serum cholesterol level at the third and sixth month. However, ESR, serum SGOT, SGPT, GGT and ALP showed significant increase as compared to the control ducks. These clinical parameters suggested hepatosis. Histologically there was moderate fatty change, focal disassociation of hepatocytes and biliary hyperplasia. Histochemical expression of ALP was moderate to intense in the liver and there was moderate to severe proliferation of peroxisomes. There was histological evidence of preneoplastic changes although no tumours were seen. By this investigation the high sensitivity of ducks to aflatoxin was clarified and the tumour induction potential of afiatoxin in ducks was evaluated and the nature of hepatic tumours induced and delineated. Clofibrate was demonstrated to induce hepatosis and preneoplastic changes in the hepatic tissue and the possible carcinogenic potential of clofibrate was indicated.
  • Thumbnail Image
    ThesisItemOpen Access
    Immunopathological response of ducks in aflatoxicosis
    (Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1992) Balakrishnan, P; KAU; Maryamma, K I
    The immunopathological effects of AFB1 in ducks were studied in this investigation. Both cell – mediated as well as humoral immune system were assessed using suitable immunological markers. White Pekin ducklings were maintained on aflatoxin free feed. AFB1 was administered orally to the 4 week old experimental ducklings at a dose level of 0.075 mg/kg body weight on every alternate day till the end of the experiment. There was reduction in ANAE positive T cells and reduction in the cutaneous response to 2, 4 – dinitrochlorobenzene (DNCB) and phytohaemagglutinin – M (PHA – M) confirming the immunotoxicity of AFB1 on the cell – mediated immune system. The assessment of phagocytic response of reticulo- endothelial cells also indicated a reduced activity in the AFB1 fed ducks. The humoral immune system was evaluated by estimating the total serum protein (TSP), serum globulin (SGI) and various serum immunoglobulin fractions. The AFB1 at the above dose level had significant biological effect on the humoral immune system. It was further confirmed by reduction in the antibody titre in the AFB1 fed ducks vaccinated with RDF1 vaccine. The gross and histopathological features of AFB1 induced toxicity consisted of enlarged, pale and friable liver with haemorrhages, congested kidney with petechial haemorrhages, atrophied spleen, thymus, bursa of Fabricius and caecal tonsils. There was marked histopatological changes in the liver. It being the primary target organ in case of toxicity induced by AFB1. Fatty changes, paracentral and centrilobular necrosis, Proliferation of bile ducts and ductules, severe disorganization of hepatic cords and grouping of hepatocytes with acini – like formations, were seen in the liver. Tubular degeneration and focal necrosis were seen in the kidney. The lymphoid organs like bursa of Fabricius, spleen, thymus and caecal tonsils showed degenerative changes and loss of lymphoid elements. There were loss of follicular pattern with interstitial fibrosis and necrobiotic changes in lymphoid elements in the bursa of Fabricius. The thymus revealed atrophy, necrosis, interstitial edema and intense lympholytic changes. Caecal tonsils revealed haemorrhages, degeneration of lymphoid cells and necrosis. In this investigation the immunosuppressive effects of AFB1 on the humoral and cell – mediated immune system of ducks were evaluated. Regular screening of feed for AFB1 was advocated as a routine farm practice to prevent the deleterious effect of AFB1 on the health and productivity of ducks.
  • Thumbnail Image
    ThesisItemOpen Access
    Pathology of the liver in quails
    (Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1992) Krupeshasharma, S R; KAU; Rajan, A
    A study was undertaken to assess the prevalence and nature of different types of lesions encountered in the liver of Japanese quails. To study the incidence of hepatic disorders in Japanese quails data were collected from the autopsy records maintained at the Centre of Excellence in pathology, College of Veterinary and Animal Sciences, Mannuthy for a period of six years from 1986 – 1991. The overall incidence of liver lesions was 34.09 per cent. The incidence was high in quails aged above 6 weeks and low in quail chicks. During the course of this investigation for the period 1990 to 1991, 575 livers with well defined gross lesions were examined for histopathological changes. The different type of lesions encountered were congestion (42.08 per cent), fatty change (30.26 per cent), subcapsular haemorrhage (0.34 per cent), abscesses (0.34 per cent), necrosis (6.78 per cent), Marek’s disease (18.43 per cent) and hepatitis (1.73 per cent). Congestion was the most common lesion observed. The incidence of congestion was 42.08 per cent. It was highest in quail chicks. In adults, in many cases, congestion was associated with other hepatic lesions whereas in quail chicks, congestion was observed as the only change in most of the cases. Out of 575 livers examined, hepatic abscesses were seen in two livers. In one liver gross abscesses were seen, where as in the other case abscesses were seen only in histologic sections. The incidence of fatty change was highest in adults. It was found that fatty change was the significant hepatic response to various toxic conditions in quails. Disintegration of the reticular fibres in case of extensive fatty change was demonstrated. Subcapsular haemorrhage was seen in two livers. Hepatitis was relatively uncommon in quails. It was recorded in 10 cases out of 575 livers examined. Marek’s disease lesions were noticed in 106 livers. Pathological features of Marek’s disease lesions in the liver of quails, were discussed in detail. S. typhimurium was isolated from three cases of hepatitis. Experimental infection was induced in quails with and without immunosuppression. It was observed that the hepatic lesions were more extensive and mortality was higher in immunosuppressed quails. The possible role of stress in enhancing the pathogenicity in field situations was clarified. The zoonotic importance of S. typhimurium infection was discussed. Hepatic toxicity of dietary monensin was studied. Hepatic steatosis was the consistent finding. It was clarified that liver is the target organ in monensin toxicity in quails. The practical importance of this toxicity was highlighted.
  • Thumbnail Image
    ThesisItemOpen Access
    Assessment of the biological characteristics of the neoplastic cells of ethmoid carcinoma in cattle
    (Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1992) Gangadharan, B; KAU; Rajan, A
    Ethmoid carcinoma is an important neoplastic condition of domestic animals. Two hundred and eighty five positive cases were reported to the centre of Excellence in Pathology, during 1989 to 1991. The incidence was reported throughout the year though highest was during March (12.92 per cent) and lowest was in June and September (5.78 per cent). The report of the incidence was more from Thrissur district (21.57 per cent) compared to other districts of Kerala. Twenty – three animals were procured from various farms of the University (7) private owners, in and around Thrissur, and neighbouring districts, like Malappuram, Palakkad, Ernakulam and Kottayam (16). Histopathologically the tumours were diagnosed as Papillary adenocarcinoma (2), Adenocarcinoma (14), Squamous cell carcinoma (3), Transitional cell carcinoma (2) and Undifferentiated carcinoma (2). Efforts were made to culture ethmoid carcinoma cells in vitro, using various tissue culture media. However, the efforts were not successful in most cases. In one case RPMI – 1640 (Hi Media) with 10 per cent foetal calf serum was found to support the growth of ethmoid carcinoma cells in vitro. Histochemically GGT was demonstrated in tissue sections. There was no difference in the expression pattern of GGT in different histological types like adenocarcinoma and squamous cell carcinoma. This was considered as an indirect evidence for the involvement of a genotoxic carcinogen like aflatozin in the causation of this tumour. Special staining with luxol fast blue to demonstrate mitochondria was carried out in tumour sections. Diffuse greenish colouration of the cytoplasm of the neoplastic cells was observed indicating pronounced mitochondrial proliferation and/or damage of the mitochondria irrespective of the histological types like adenocarcinoma and squamous cell carcinoma. AgNOR count in ethmoid carcinoma was evaluated. An average count of 1.79 + 0.08 was observed in adenocarcinoma cases, whereas squamous cell carcinoma cases showed an average AgNOR count of 2.05 + 0.24. This difference was not statistically significant. Serum zinc level and copper level of sinus tumor animals was compared with that of normal animals. Tumor animals had a serum zinc level of 0.99 + 0.11 ppm, and serum copper levels was 0.86 +0.06 ppm. The serum zinc level in normal animals was 1.35 + 0.23 ppm and serum copper level was 1.04 + 0.07 ppm. Though, there was a reduction in serum zinc and copper levels in tumour animals compared to normal animals, it was not statistically significant. Parentage of six ethmoid carcinoma animals of University Livestock Farm, Mannuthy was examined. Two ethmoid carcinoma animals of the University Livestock Farm, Mannuthy had a common sire. This aspect requires further study to clarify the genetic predisposition to this condition, if any.