Biomedical subjects

P A Kopp

Publications and source records attributed to P A Kopp.

3 recordsLinked to original sources

PubMed1997

Adherence of Borrelia burgdorferi to granulocytes of different animal species.

Adherence of 4 Borrelia (B.) burgdorferi strains (z7/22, z7/27, z7/41, PBi) to polymorphonuclear granulocytes from different domestic animals (horses, cattle, sheep, dogs) was investigated. All 4 strains adhered to the granulocytes. Binding assays indicated that the adherence occurred between structures on the surface of the borreliae ("binding-sites") and on the membranes of the granulocytes ("receptors"). The "receptors" consisted of 4 fractions (A, B, C, and D) with components differing in molecular weight (MW) and binding activity for proteins on the surface of B. burgdorferi. Fraction A (MW 80000) had the highest binding activity for B. burgdorferi.

Animals↗

PubMed1995

Isolation and characterization of fibronectin-binding sites of Borrelia garinii N34.

Adherence of bacteria to host cell membranes is one of the initial steps of microbial pathogenicity. Numerous studies have suggested that fibronectin promotes this interaction in some bacterial species. In this study, we have examined the ability of Borrelia garinii to bind fibronectin. The binding of fibronectin to the spirochete was specific and saturable. Scatchard plot analysis of the binding data revealed two types of ligands on the spirochetal surface, one with high affinity and one with low affinity for fibronectin. The fibronectin-binding sites were solubilized from the surface of B. garinii N34 by lysozyme treatment. Fast protein liquid chromatography (FPLC) purification of the solubilized binding sites resulted in one band with a high fibronectin-binding activity and a molecular weight of ca. 147,000. FPLC-purified binding sites, fibronectin, and antibodies to fibronectin inhibited the adherence of the spirochete to epithelial cells competitively. These data provide strong support for the hypothesis that fibronectin-binding sites on the surface of B. garinii are involved in the adherence of the spirochete to their respective host cells.

Bacterial Adhesion↗

PubMed1993

Morphological and functional polymorphism within clonal thyroid nodules.

Thirty-nine thyroid nodules, removed because of recent growth, were analyzed morphologically by serial histological sections for the classical histomorphological hallmarks of follicular cell replication and for immunohistochemically demonstrable overexpression of the growth-associated ras-gene product p21ras. Clonal analysis was performed using the highly informative probe M27 beta that detects polymorphisms on the locus DXS255 of the X-chromosome. Twenty-four nodules were of clonal and 15 nodules were of poly-clonal origin. Only 3 out of the 24 clonal nodules were histomorphologically uniform. In all others, the structural hallmarks of active growth and the P21ras growth-marker expression were remarkably heterogeneous throughout the tumors. There were no histomorphological characteristics distinguishing these clonal tumors from polyclonal nodules. Even if a clonal thyroid tumor may be originally homogeneous in respect to the parameters studied here, mechanisms must exist that create wide heterogeneity of growth and of morphogenetic potential among the individual follicular cells during further expansion of the nodule. Thus, clonal nodules are much more common in nodular goiters than hitherto assumed on grounds of the classical morphological criteria. The diagnosis of a true monoclonal nodule can no longer rely on morphological and functional criteria alone but requires molecular or cytogenetic analysis of clonality.

Adult↗