SUMMARY Thirty two domestic dogs with naturally occurring polyarthritis were investigated to determine the contribution of autoimmunity in the pathological mechanisms. Comparisons were made with canine infective arthritis (12 dogs), osteoarthritis (32), and osteoarthritis secondary to rupture of the cranial cruciate ligament (19). Rheumatoid factors, immune complexes, and complement fixation (Clq binding) were measured in sera and synovial fluids. Compared with normal dogs (32), dogs with rheumatoid arthritis (RA) had increased serum and synovial fluid immune complexes and rheumatoid factors. Increases were generally also seen in dogs with other arthropathies, however. Rheumatoid factors were higher in sera than in synovial fluids. Rheumatoid factors correlated with immune complex levels and complexed rheumatoid factor only in the group of dogs with RA. Both rheumatoid factors and immune complexes may contribute to the pathogenesis of canine RA but are considered to arise as a result of non-specific inflammatory mechanisms in the non-rheumatoid groups.

To study the prevalence of ectoparasites and their clinicopathological effects on backyard poultry, 300 poultry of both sexes and different ages were examined in different areas of Patuakhali district from July 2005 to May 2006. Of them 86.67% were infested with one or more species of ectoparasites. Six species of lice such as Menacanthus stramineus (74%), Menopon gallinae (63%), Lipeurus caponis (48%), Cuclotogaster heterographus (25%), Goniodes gigas (18%), and Goniocotes gallinae (14%), two species of mites namely Dermanyssus gallinae (57%), Knemidocoptes mutans, (43%) and one species of fly, Simulium sp. (3.7%) were identified. Among these, M. stramineus was the most common. Aged above 5 months, 100% poultry were infested with ectoparasites but cocks and broody hens were severely infested. In broody hens, prevalence of D. gallinae was the highest (97.3%). K. mutans (43%) was mostly found in adult poultry aged above two years. The affected birds were emaciated with rough plumage, dandruff, and petechial haemorrhages on the highly infested skin. Small ulcerative lesions were common in Dermanyssus gallinae infestation in which the engorged, red parasites stacked tightly. In K. mutans infestation, legs were rough, swollen with scaly appearance, which was from tibiotarsal joint downwards to the joint of the toes. Some of the severely affected birds showed lameness but no malformation was observed. Histopathologically, scaly leg was characterized by hyperkeratosis and acanthosis. In tissue sections, the mites were observed as transverse or cross section in the deeper parts of the stratum corneum or the superficial layers of the stratum malpighii of the skin and rarely go deeper. In some area of skin, there were losses of epithelium. In advanced cases, there was secondary pyogenic infection; characterized by severe pus cell infiltration in the dermis. The present study suggests that ectoparasitic infestation is very common in the backyard poultry of Bangladesh and they are associated with the production of some clinicopathological effects variable degree.

Pigeons (n=300) were examined during July 2007 to June 2008 in different areas of Mymensingh district. Of the pigeons examined, 202 (67.3%) were infected by Trichomonas gallinae (Rivolta, 1878). Prevalence of Trichomonas gallinae was higher in female pigeon (70.9%) than male pigeon (63.8%). Adult pigeons aged >3 months were comparatively more affected (75%) than the squab aged <30 days (72.1%) and the younger aged between 30 days to 90 days (64.7%). T. gallinae infection was significantly (P<0.01) lower in summer (48.4%) than rainy (69.8%) and winter (69.3%) seasons. Pathological lesions were confined in the crop, proventriculus and liver. There was an accumulation of greenish fluid and/or cheesy material in the crop and proventriculus. At necropsy, yellowish to grayish necrotic lesions were evident in the crop and proventriculus. On the other hand, the liver became congested where congestion of sinusoids and focal accumulation of heterophils in the parenchyma were found. But, no microscopic lesions were seen in the crop and proventriculus although gross lesions were more prominent in these two organs.

Summary Serum thyroxine was significantly higher in 59 patients with hepatocellular carcinoma than in normal subjects, patients with uncomplicated cirrhosis (48), or other primary tumours with or without hepatic metastases (50). Elevated thyroxine levels appeared attributable to high levels of thyroxine binding globulin which showed a positive linear correlation with serum thyroxine in all groups studied. Despite this hyperthyroxinaemia all patients appeared clinically euthyroid and, consistent with this, T3 was elevated in only one patient and the free thyroxine index was normal in all. Amongst a group of 25 cirrhotic patients who were followed-up for between 12 and 72 months, there was a striking dissociation between the TBG values of those destined to develop HCC and those who did not. In the former group TBG rose steadily with time whereas in the latter group levels remained stable, or, more often, fell. The rises in TBG occurred prior to any clinical signs of tumour development and may be one of the earliest serological changes to occur during carcinogenesis in the cirrhotic liver.Changes in the serum levels of thyroid hormones and their binding proteins in patients with cirrhosis are welldocumented (Chopra et al., 1974;Hepner & Chopra, 1979; Lumholtz et al., 1978;Nomura et al., 1975). Most studies have shown a normal thyroxine (T4) level with impaired conversion to triiodothyronine (T3) resulting in low levels of T3 and high levels of reverse T3 (rT3). Despite this, clinical evidence of hypothyroidism is uncommon and direct measurement of free T4 (fT4) or the free thyroxine index has usually given normal values (Green et al., 1970;Liewendahl et al., 1983). In contrast, hyperthyroxinaemia has been described in some patients with hepatocellular carcinoma (HCC), a frequent complication of long-standing cirrhosis (Gershengorn et al., 1976;Kalk et al., 1982;Nelson, 1979). The hyperthyroxinaemia has been attributed to elevated levels of thyroxine binding globulin (TBG) but whether abnormalities of other thyroid binding proteins such as albumin and prealbumin are also involved has not been determined. There are also no data on how levels of TBG change before diagnosis of HCC or whether such changes are specific for HCC or occur generally in malignant disease.In the present study we have measured the serum thyroid hormones together with their binding proteins in a large series of patients with HCC and various control groups including uncomplicated cirrhosis and other primary tumours with or without hepatic metastases. In healthy volunteers recruited from the ho6pital staff. None of the subjects studied was receiving drugs known to interfere with thyroid function. In all patients with HCC the serum samples studied were those collected at the time of diagnosis and prior to any treatment.The stored serial sera (which had been frozen once and not previously thawed before the assay) came from patients included in a prospective study of the development of HCC in cirrhosis (Zaman et al., 1985). These comprised 25 pati...

Autoimmunity to collagen was investigated in several naturally occurring arthropathies of the dog. Increased levels of serum anti-native collagen type II antibody, as assessed by ELISA, were shown in 72.4% of dogs with rheumatoid arthritis (RA), 88% of dogs with infective arthritis (IA) and 52% of dogs with osteoarthritis (OA) (p less than 0.001). The mean levels of antibody in cruciate disease patients (CR) were also significantly increased compared to control dogs (p less than 0.01). Serum anti-collagen antibody in OA dogs correlated with that in precipitated serum immune complexes. There was also a correlation between anti-collagen antibody level in synovial fluid and in synovial fluid complexes in dogs with rupture of the cranial cruciate ligament. In all patient groups, collagenase digestion of polyethylene glycol (PEG) precipitates from sera and synovial fluids caused a significant rise in specific antibody levels to collagen, indicating the presence of collagen-anti-collagen complexes in all arthropathies. In dogs with RA, the levels of collagen-specific antibody in synovial fluid complexes correlated with the total IgG in these complexes. These findings implicate collagen-anti-collagen complexes in the pathogenesis of naturally occurring joint diseases in the dog, but they are unlikely to be the primary aetiological mechanism.