In a sequential study the pathogenesis of chronic polyarthritis occurring spontaneously in MRL mice was analysed by light microscopy. A total of 128 MRL mice of both substrains (MRL/Mp-lpr/lpr and +/+) and different age groups was studied. In 50 lpr/lpr mice, tinctorial and histochemical methods were applied for the identification of fibrin/fibrinoid, iron compounds, amyloid, and proteoglycan. The earliest lesions seen in mice of substrain lpr/lpr at the age of 2 months were proliferation of synovial lining cells and loss of tinctorially demonstrable proteoglycan in the articular cartilage. Beginning at 3 months, severe joint destruction associated with pannus formation was encountered usually in knee, carpal and tarsal joints. Besides inflammatory processes in tendons, nerves and musculature fibrinoid-necrotising panarteritis occurred in the intra- and extraarticular tissue. Furthermore, fibrin-containing exudations and deposits of fibrinoid material, occurred in the synovium of large joints and in the periarticular connective tissue of phalangeal joints. The occurrence of these morphological changes, destructive arthritis, vasculitis and periarticular inflammatory changes, was, at the age of 3 months, associated with a highly significant increase of circulating immune complexes. In mice of substrain +/+ aged 1 year and older, arthritic changes with synovial lining cell proliferation, cartilage destruction and inflammatory periarticular lesions developed.

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[Morphologic studies of reactive changes in the joint cartilage in experimental erysipelas arthritis].

In experimentally Erysipelothrix rhusiopathiae-induced polyarthritis of pigs, important pathomechanisms of bacterial invasion of the articular cartilage matrix were studied. Furthermore, observations were made concerning inflammatory cartilage changes in the transitional zone of the distal femur condyle. The morphological changes were a loss of proteoglycans, proliferation and transformation of cartilage cells, compensatory formation of collagenous fibers progressing to cartilage fibrosis and pannus formation. As histology only represents a static picture, different methods are necessary to finally verify the dynamics of this process. It appears likely, that cartilage and pannus combined, and synergistically after fibroblastic transformation, produce a reparative scar in the area of cartilage alteration.

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[Frequency of appearance of persistent BVD virus infections and their effects on the cattle population].

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Animals↗

PubMedDate not supplied

[Cerebellar hypoplasia and hydranencephaly in cattle after transplacental bovine diarrhea virus infection].

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Anencephaly↗

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[Enzyme, enzyme-histochemical and immunohistological studies in chronic erysipelas polyarthritis of swine].

The chronic Erysipelas-polyarthritis in pigs has been considered an animal model resembling human rheumatoid arthritis. Fifteen specifically pathogenfree (SPF) pigs 45 days old were experimentally infectec with strain T 28 of Erysipelothrix rhusiopathiae-bacteria. During the subsequent 32 weeks several enzymatic, immunohistological and microbiological parameters were monitored. Compared to 5 age and sex matched healthy controls the infected pigs showed increased activity of plasma acid phosphatase starting 4 weeks after the infection. Acid phosphatase activity was usually enhanced in synovial fluid of chronically ill animals. Histochemically increased activity of acid phosphatase, beta-glucuronidase and beta-acetylglucosaminidase was found in lining cells and fibroblasts of the synovial membrane of chronically diseased joints. Immunohistochemically Erysipelas-antigen was demonstrated in the synovial membrane even of those inflamed joints from which no living bacteria had been isolated. The microbiological and immunohistochemical results correlated positively with the enzymehistochemical data. The release of lysosomal enzymes from cells of the synovial membrane in chronically diseased joints due to the influence of Erysipelas-bacteria and the possible implications of persistent bacteria on the perpetuation of chronic Erysipelas-polyarthritis are discussed.

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PubMedDate not supplied

[Immunopathologic aspects of chronic erysipelas polyarthritis in swine].

Chronic erysipelas polyarthritis in pigs is considered to be an animal model closely resembling human rheumatoid arthritis. In an experimental study using SPF pigs infected with Erysipelothrix rhusiopathiae several immunopathological aspects were studied for up to 14 months after infection. After an initial febrile phase a progressive polyarthritis and discospondylitis developed at 2 weeks after infection. Quantitative determination of IgG and IgM revealed a significant increase in these immunoglobulins both in the serum and the synovia from arthritic joints. Arthritic joints containing viable Erysipelothrix bacteria at termination of the experiment have a higher content of IgG and IgM than bacteriologically negative joints. During the entire experiment the rheumatoid factor titer, determined by the Waaler Rose test, remained relatively low with increases and decreases. The Erysipelothrix antibody titers are highly significant. The total complement activity in the serum increases discontinuously and shows fluctuations similar to those of the rheumatoid factor titer. The highest enzyme activities of acid phosphatase and lactate dehydrogenase are demonstrable in the synovial fluid of arthritic joints with positive bacteriological or immunohistological findings. These joints also have the greatest numbers of IgG-producing plasma cells. By means of immunohistological methods Erysipelothrix antigen can be demonstrated in macrophages of the proliferating synovial membrane. Finally, there is a discussion of the pathogenic significance for the perpetuation of chronic polyarthritis of Erysipelothrix persisting in arthritic joints in spite of focal immune reactions.

Acid Phosphatase↗

PubMedDate not supplied

[Immunopathology and pathogenesis of chronic erysipelas polyarthritis of swine].

Several immuno-pathological aspects of polyarthritis following experimental infection with erysipelas in pigs were studied for two years. Aseptic and specifically pathogenfree animals were infected subcutaneously and intravenously-intraarticularly with living erysipeals bacteria (erysipelothrix rhusiopathiae) of serotype B. After an initial febrile phase a progressive polyarthritis and disco-spondylitis developed. Some animals also developed thrombo-endocarditis. Hypergammaglobulinemia and high titers of specific antibodies were observed during the whole experimental period. Antiglobulin factors, however, were not detected in the serum or the synovium. In some animals collagen antibodies were demonstrated in synovial tissue. Bacterial examination of the synovium showed that erysipelas bacteria were present in arthritic joints for months. Living erysipelas bacteria were isolated 24 months after the experimental infection from synovial tissue of two pigs. The polyarthritis was characterised by exudates rich in fibrin, villous proliferation, pannus formation, cartilage erosions, and peri-articular fibrosis. IgG and specific erysipelas antibodies were demonstrated in plasma cells from synovial tissue by immuno-histological methods. The findings emphasize the morphological resemblance of the erysipelas induced chronic polyarthritis in pigs to human rheumatoid arthritis.

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