Author
Howard D. Dorfman
Bio: Howard D. Dorfman is an academic researcher from New York University. The author has contributed to research in topics: Cyst & H&E stain. The author has an hindex of 5, co-authored 6 publications receiving 2303 citations.
Topics: Cyst, H&E stain, Arthritis, Rheumatoid arthritis, Debridement
Papers
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TL;DR: For thirty-two areas of cartilage from nine osteo-arthritic and four "normal" femoral heads a histologic-histochemical grade was assigned as an index of severity of the osteo -arthritic process.
Abstract: For thirty-two areas of cartilage from nine osteo-arthritic and four "normal" femoral heads a histologic-histochemical grade was assigned as an index of severity of the osteo-arthritic process. The DNA and hexosamine concentrations were determined as indicators of cell density and polysaccharide con
2,168 citations
TL;DR: Osteoid osteomas stained with the Bielschowsky axon stain, demonstrated nerve fibers within the matrix of the nidus in sixteen of eighteen lesions studied, postulated that tue neural elements demonstrated are sensitive to changes in vascular pressure.
Abstract: Osteoid osteomas stained with the Bielschowsky axon stain, demonstrated nerve fibers within the matrix of the nidus in sixteen of eighteen lesions studied. These fibers were associated with blood vessels and were found in greatest abundance adjacent to arterioles. Routine hematoxylin and eosin stains failed to reveal these fibers. Similar but less prominent findings were evident in two of the three osteoblastomas studied.
The pain of these lesions may be mediated by the autonomic nervous system via these nerve fibers. It is postulated that tue neural elements demonstrated are sensitive to changes in vascular pressure.
126 citations
TL;DR: A case of anaplastic fibrosarcoma arising at the site of an old infarct in the femoral shaft of a caisson worker is reported and sarcomata in association with other non-neoplastic bone lesions is discussed.
Abstract: A case of anaplastic fibrosarcoma arising at the site of an old infarct in the femoral shaft of a caisson worker is reported. References to similar cases are cited. The occurrence of sarcomata in association with other non-neoplastic bone lesions is discussed.
53 citations
19 citations
TL;DR: A case is presented in which a bone cyst developed at a fracture site in the fibula and the evolution of the lesion is documented by serial roentgenograms and its pathological features are presented.
Abstract: Trauma has been indicted as the cause of some types of bone cysts, but the development of a cyst in the course of healing of a fracture in a long bone has not been previously reported. A case is presented in which a bone cyst developed at a fracture site in the fibula. The evolution of the lesion is documented by serial roentgenograms and its pathological features are presented. The pathogenesis of this cyst and its possible relationship to other cystic lesions is discussed.
18 citations
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TL;DR: The OARSI cartilage OA histopathology grading system appears consistent and simple to apply as discussed by the authors, however, further studies are required to confirm the system's utility, as well as their reproducibility and validity.
1,813 citations
TL;DR: A semi-quantitative scoring system that can be applied universally to instability, enzymatic, transgenic and spontaneous OA models may be a useful tool for both new and experienced scorers to sensitively evaluate models and OA mechanisms, and also provide a common paradigm for comparative evaluation across the many groups performing these analyses.
1,701 citations
TL;DR: The data suggest that collagenase(s) produced by chondrocytes is (are) involved in the cleavage and denaturation of type II collagen in articular cartilage, that this is increased in OA, and that MMP-13 may play a significant role in this process.
Abstract: We demonstrate the direct involvement of increased collagenase activity in the cleavage of type II collagen in osteoarthritic human femoral condylar cartilage by developing and using antibodies reactive to carboxy-terminal (COL2-3/4C(short)) and amino-terminal (COL2-1/4N1) neoepitopes generated by cleavage of native human type II collagen by collagenase matrix metalloproteinase (MMP)-1 (collagenase-1), MMP-8 (collagenase-2), and MMP-13 (collagenase-3). A secondary cleavage followed the initial cleavage produced by these recombinant collagenases. This generated neoepitope COL2-1/4N2. There was significantly more COL2-3/4C(short) neoepitope in osteoarthritis (OA) compared to adult nonarthritic cartilages as determined by immunoassay of cartilage extracts. A synthetic preferential inhibitor of MMP-13 significantly reduced the unstimulated release in culture of neoepitope COL2-3/4C(short) from human osteoarthritic cartilage explants. These data suggest that collagenase(s) produced by chondrocytes is (are) involved in the cleavage and denaturation of type II collagen in articular cartilage, that this is increased in OA, and that MMP-13 may play a significant role in this process.
997 citations
TL;DR: This review presents a summary of the hierarchical features for articular cartilage and diarthrodial joints and tables of known material properties for cartilage to summarize how the multi-scale interactions in articular Cartilage provide for its unique material properties and tribological characteristics.
886 citations
TL;DR: The reaction patterns of chondrocytes in osteoarthritis can be summarized in five categories: proliferation and cell death (apoptosis); changes in synthetic activity and degradation; changes in phenotypic modulation of the articular chondROcytes; and formation of osteophytes.
Abstract: The reaction patterns of chondrocytes in osteoarthritis can be summarized in five categories: (1) proliferation and cell death (apoptosis); changes in (2) synthetic activity and (3) degradation; (4) phenotypic modulation of the articular chondrocytes; and (5) formation of osteophytes. In osteoarthritis, the primary responses are reinitiation of synthesis of cartilage macromolecules, the initiation of synthesis of types IIA and III procollagens as markers of a more primitive phenotype, and synthesis of active proteolytic enzymes. Reversion to a fibroblast-like phenotype, known as 'dedifferentiation', does not appear to be an important component. Proliferation plays a role in forming characteristic chondrocyte clusters near the surface, while apoptosis probably occurs primarily in the calcified cartilage.
758 citations