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Biomedical subjects

D Hamerman

Publications and source records attributed to D Hamerman.

At least 19 recordsLinked to original sources

The distribution of S-100 protein in articular cartilage from osteoarthritic joints.

The distribution and localization of S-100 protein was compared with safranin-O staining and H and E morphology in relatively unaffected, degenerative, and osteophytic regions of human articular cartilage from 26 joints obtained at the time of total joint replacement for osteoarthritis. S-100 protein immunoreactivity in osteophyte cartilage was more intense than in unaffected regions and comparable to the staining intensity found in metaplastic cartilage tufts in degenerating cartilage. Immunoreactivity for S-100 protein appeared more prominent in the deep layers of osteophyte cartilage adjacent to areas of matrix calcification.

Adult

Risk factors associated with immobility.

In nursing homes, immobility and related complications are major problems with profound health care and financial implications. We conducted a retrospective study to identify risk factors associated with immobility. We compared factors in 34 nonambulatory residents with those in 12 independent ambulatory residents who served as controls. Factors associated with immobility included contractures, severe dementia, poor vision, and history of hip/leg fractures. Factors not associated with immobility included age, osteoarthritis, mild to moderate dementia, weight gain, and broad categories of selected medications. The immobile patients were further analyzed by subgrouping into those with and without contractures. Contractures were significantly associated with severe dementia. The finding that immobility was not identified on problem lists for 85% (29) of the immobile residents and that for 29% (10) reasons for immobility could not be ascertained suggest that immobility is frequently not documented as a major problem in medical records nor adequately evaluated.

Activities of Daily Living

Osteoarthritis.

Osteoarthritis (OA) is one of the most common chronic diseases and the most frequent cause of rheumatic complaints in the older population. While still regarded primarily as an expression of a degenerative disease of cartilage accompanying the aging process, newer concepts in many areas have emerged. In particular, these concepts relate to cellular interactions among joint components, biochemistry and ultrastructure of cartilage, biomechanics, pharmacology and antiarthritic drugs, surgical approaches to the repair of arthritic joints, and population studies. However, it is still very difficult at this time to put together a coherent picture of the evolution of OA, and this profoundly limits our understanding of the disease process. In population studies we often rely on physical inspection of joints or complaints of pain, both of which may be of limited value despite extensive damage to the articular cartilage. This makes us dependent on x-rays for case finding, and these are costly and difficult to do. Longitudinal studies are not feasible because we are talking about a survey that should extend for several decades. We have limited access to samples of joint components for biochemical studies in the 20 to 40-year-old population, although surgical intervention for menisceal injury should offer an opportunity to observe conditions where the evolution of OA is often accelerated. This discussion, written by an internist, is an attempt to survey aspects of the present state of our knowledge, albeit incomplete, of OA involving the joints of the extremities. It is hoped that orthopaedic surgeons in particular will be stimulated to explore further the evolution of OA, an area to which they have contributed so significantly.

Animals

Parvovirus associated antigen in the synovial membrane of patients with rheumatoid arthritis.

Homogenates of synovium from patients with rheumatoid arthritis (RA) and osteoarthritis (OA) were centrifuged on caesium chloride density gradients to obtain isolates of a density similar to that of parvoviruses. Six of 11 RA isolates and none of six OA isolates reacted with an antiserum raised against a rheumatoid associated, parvovirus-like agent (RA-1 virus). An anti-B19 parvovirus antiserum did not react with any of the isolates tested. Electron microscopy of negatively stained preparations of the isolates showed that small particles of diameter 10 nm were abundant in most of the RA isolates (11/13) but absent from all OA isolates. Such particles, whose identification is unknown, were also present in RA-1 positive lysates prepared from cultured RA synovial cells. These results suggest that the RA-1 virus can be directly identified in RA synovial tissue and that the virus appears to be unrelated to the human B19 parvovirus.

Antigens, Viral

Growth factors with heparin binding affinity in human synovial fluid.

Synovial effusions were obtained from the knees of 15 subjects with joint trauma, menisceal or ligamentous injury, or osteoarthritis. Heparin-Sepharose affinity chromatography of these synovial fluids revealed, in general, three major peaks of mitogenic activity as measured by incorporation of 3H-thymidine into 3T3 cells. Gradient elution patterns showed activities at 0.5M NaCl, which is characteristic of platelet derived growth factor, and at 1.1M NaCl and 1.6M NaCl, indicative of acidic and basic fibroblast growth factors, respectively. The identities of these mitogenic fractions were confirmed by specific immunologic and receptor-binding assays. The presence of platelet derived, acidic and basic fibroblast growth factors in the synovial fluid may contribute to wound healing in the arthritic joint.

Animals

A cartilage-derived growth factor enhances hyaluronate synthesis and diminishes sulfated glycosaminoglycan synthesis in chondrocytes.

Cartilage-derived growth factor purified to homogeneity by affinity chromatography on columns of heparin-Sepharose was mitogenic for early passage bovine fetal chondrocytes. Hyaluronate and sulfated glycosaminoglycan synthesis in these cells was analyzed by differential enzymatic digestion of the glycosaminoglycans labeled with [14C] glucosamine or [35S]. It was found that chondrocyte proliferation was accompanied by about a four-fold increase in hyaluronate synthesis over a two-day period, while the synthesis of sulfated glycosaminoglycans decreased by about 2-fold. Chromatographic analysis of the sulfated glycosaminoglycans showed decreases in chondroitin 4 and 6 sulfates. It was concluded from these results that cartilage-derived growth factor was a proliferative factor for chondrocytes and differed from the somatomedins.

Animals

Release of interleukin-1 from human synovial tissue in vitro.

During the enzymatic disaggregation of human synovium, used in the process of isolating synoviocytes, a factor was liberated into the culture medium that exhibited the thymocyte mitogenic properties of interleukin-1. Like interleukin-1, this synovial-derived mitogen could be isolated using an affinity column of antihuman leukocytic pyrogen. By gel filtration and isoelectric focusing, the mitogen cofractionated with human monocyte-derived interleukin-1. Finally, the isolated mitogen was shown to exhibit other properties of interleukin-1: stimulation of the secretion of interleukin-2, enhancement of the titer of acute-phase proteins in vivo, and stimulation of the release of prostaglandin E2 from human synoviocyte cultures. These observations suggest that interleukin-1 can be derived from the human synovium.

Chromatography, Affinity

Osteoarthritis. Emerging evidence for cell interactions in the breakdown and remodeling of cartilage.

Interactions among the cells of joint components appear to contribute to the dynamic events associated with breakdown of the cartilage matrix and remodeling of the articular surface in osteoarthritis. The mediator interleukin-1 may be one of the stimuli that induce release of hydrolytic factors from synovial membrane cells and chondrocytes, which contribute to the degradation of collagen and proteoglycans in the cartilage matrix. The remodeling process is associated with chondrocyte proliferation and vascular and cellular ingrowth from subchondral bone with osteophyte formation. It is postulated that growth factors isolated from cartilage and bone may contribute to repair and remodeling of the articular end of the joint.

Cartilage, Articular

The four biochemically distinct species of human interleukin 1 all exhibit similar biologic activities.

The supernatants of human monocytes incubated with endotoxin are able to stimulate the proliferation of murine thymocytes in the presence of PHA. This is known as LAF (lymphocyte activating factor) activity and is a characteristic activity of interleukin 1 (IL 1). The LAF activity can be resolved into four major fractions: a 15,000 dalton (pI 7), a 15,000 (pI 5.5), a 35,000 (pI 7), and a 35,000 (pI 5.5) fraction. To determine whether these four fractions shared the other biologic activities ascribed to IL 1, they were compared in a series of bioassays. When standardized with respect to their LAF activities, the four fractions did not differ significantly as mitogens for murine thymocytes, inducers of IL 2, murine or human B cell activators, human chondrocyte or synoviocyte stimulants, or inducers of acute phase proteins in vivo. On the other hand, the samples differed markedly as stimulators of porcine synoviocytes, with the 15,000 dalton (pI 5.5) fraction being the only strongly active fraction. These results are consistent with the hypothesis that all four LAF could be products of a single gene, although the porcine receptor may be able to distinguish between them. If this is the case, all four fractions can properly be termed IL 1.

Animals

Ombudsmen (medical-psychiatric) rounds. An approach to meeting patient-staff needs.

Ombudsmen rounds conducted jointly by a medical attending physician (ombudsman) and a psychiatrist bring the entire staff on each of the medical wards of Montefiore Hospital together weekly. An attempt is made to address both staff and patient needs on an inpatient medical service. Through group discussions and patient interviews, in which the patient has an opportunity to express his own feelings about his illness and his care, the staff becomes aware of the psychosocial issues that are universally evoked by illness and hospitalization. All staff members are also encouraged to relate their reactions to the patient and their interactions with each other. The ombudsmen-rounds concept maximizes the use of the internist and liaison psychiatrist, and makes psychosocial-medical teaching routine on the medical service in a contemporary teaching hospital where the practice of holistic medicine has been so difficult to implement.

Adult