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Biomedical subjects

J Stefanovic

Publications and source records attributed to J Stefanovic.

At least 73 records · Page 4Linked to original sources
PubMed1977

Subacute (de Quervain's) thyroiditis: association with HLA-Bw35 antigen and abnormalities of the complement system, immunoglobulins and other serum proteins.

The HLA antigens in 40 patients with subacute thyroiditis were investigated. An association between subacute thyroiditis and HLA-Bw35 antigen as previously reported, was confirmed. Further immunological observations included a decrease in Serum Clq, C4 and C3 activator levels; conversely, there was an increase in serum C3, IgM, alpha1-acid glycoprotein and alpha1-antitrypsin levels. Serum IgA levels were decreased in those patients who were Bw35 negative, but were normal in the patients who were Bw-35 positive, with serum alpha2-macroglobulin levels the opposite was found. These studies support the view that a genetic factor(s), viz., the major histocompatibility system, plays a role in the pathogenesis of subacute thyroiditis. A "nosological clustering" around the Bw35 antigen as a marker for viral susceptibility is suggested.

Adult↗
PubMed1977

Interaction of intracellular proteases and immune mechanisms.

Intracellular proteases play an important role both in nonspecific and specific immune reactions. Results concerning the interaction of these enzymes with phagocytic factors responsible for killing microorganisms are presented. In inflammatory foci, proteases released from destroyed leukocytes have been found to modify the function of antibodies present. They particularly reduce their complement fixation activity. Macrophages with differing proteolytic activity demonstrated diverse effects on the formation of antibodies tested by Jerne's plaque technique in young rabbits immunized with sheep erythrocytes. Whereas alveolar macrophages diminished antigen immunogenicity, peritoneal macrophages enhanced it.

Animals↗
PubMed1976

Localization of antibacterial activity and hydrolytic enzymes in subcellular fractions of rabbit and chicken polymorphonuclear leukocytes.

Polymorphonuclear leukocytes of rabbits and chickens after homogenization in 0.34 M saccharose or after multiple freezing and thawing were subjected to differential centrifugation at 150, 800, 10 000 and 50 000 X g. In the fractions obtained in this manner, total bactericidal activity as well as the activity of myeloperoxidase (E.C. 1. 11. 1. 7), catalase (E.C. 1.11.1.6), lysozyme (E.C. 3.2.1.17), cathepsin D (E.C. 3.4.4.23) and E, beta-D-glucuronidase (E.C. 3.2.1.31) and acid phosphatase (E.C. 3.1.3.2) were determined. Antibacterial activity was found in all fractions from rabbit leukocytes, but only in the first fraction from chick leukocytes. The fractions from rabbit leukocytes contained all enzymes under study while in the fractions from chicken leukocytes the presence of myeloperoxidase, catalase or cathepsin E could not be demonstrated. The highest bactericidal activity was found in the second obtained from the homogenate or rabbit leukocytes. The highest specific activity of myeloperoxidase and homogenate of rabbit leukocytes. The highest specific activity of myeloperoxidase and the lowest activity of cathepsin D were also demonstrated in this fraction. The addition of pepstatin to rabbit leukocytes before their disintegration resulted in the inhibition of the activity of cathepsin D and E and in an increase in the specific activity of myeloperoxidase as well as in total bactericidal activity in the individual fractions. These results testify that microbicidal mechanisms of phagocytes from individual species may differ and when the structure of lysosomes is damaged, the liberated hydrolytic enzymes may gradually inactivate antibacterial substances.

Acid Phosphatase↗