Showing papers by "L. Stefan Lohmander published in 1991"

Dose-dependent stimulation of bone induction by basic fibroblast growth factor in rats.

Abstract: Implantation of demineralized bone matrix in rodents elicits a series of cellular events leading to the formation of new bone inside and adjacent to the implant. This process is believed to be initiated by an inductive protein present in bone matrix, and local growth factors may further regulate the process. We have previously shown that local application of recombinant human basic fibroblast growth factor (bFGF) in a carboxymethyl cellulose gel to demineralized bone matrix implants increases the bone yield as measured by calcium content 3 weeks after implantation in rats. We now report that this increase was seen at 3 and 4 weeks, but not earlier or later. Further, the stimulatory effect was seen with doses from 3 to 75 ng per implant. A dose of 0.6 or 380 ng did not increase the bone yield, and 1,900 ng had a marked inhibitory effect. This narrow dosage optimum may reflect the complex actions of the growth factor.

Markers of cartilage metabolism in arthrosis

Abstract: The mechanisms involved in the disease process in arthrosis are largely unknown, with genetics, joint malalignment, overload or trauma, obesity, and aging as some of the known or suspected contributing factors Even less well known is how these general factors are translated into disease mechanisms at the cell and tissue levels However, it may be argued that degradation of cartilage matrix is a key event at some time in the development of arthrosis During this process, fragments of matrix molecules and other chondrocyte products are released into the joint fluid and eventually into other body fluids These molecules can be used as markers of cartilage metabolism to monitor joint disease In addition, by identifying the proteases and the structure of the released matrix fragments, we may improve our understanding of the cellular mechanisms active in cartilage degradation Such information offers improved diagnostic and prognostic tools for rational treatment aimed at retarding cartilage destruction in arthrosis

Proteoglycan epitope in synovial fluid in gonarthrosis : 28 cases of tibial osteotomy studied prospectively for 2 years

Abstract: High tibial osteotomy was performed for medial gonarthrosis in 28 patients. Preoperatively, and at 3, 12, and 24 months after surgery, clinical and radiographic examinations were made, and joint-fluid samples were aspirated. Arthroscopy was performed preoperatively and at 24 months. Immunoassay of proteoglycan epitope in joint fluid showed an increase in concentration at all times as compared with a reference population with normal knee joints. An increase in both the concentration and the total amount of proteoglycan epitope in joint fluid was noted at 3 months postoperatively with a return to preoperative values at later times. Regrowth of fibrocartilage did not correlate with proteoglycan epitope data

Dehydration inhibits matrix synthesis and cell proliferation: An in vitro study of rabbit flexor tendons

Abstract: Segments of the deep flexor tendon of the rabbit were exposed to air; the effects of dehydration on in vitro synthesis of proteoglycan, collagen, non-collagenous protein, and cell proliferation were compared with tendon segments that were kept moist with physiologic saline. After 20 min of expo-sure to air, the tendons lost half and after 40 min all of their ability to synthesize matrix components and to proliferate, whereas irrigated tendons remained viable during the entire experiment.