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Biomedical subjects

H Telhag

Publications and source records attributed to H Telhag.

At least 19 recordsLinked to original sources

Prevention of joint destruction in antigen-induced arthritis.

In rheumatoid arthritis (RA) erosive joint changes are the dominating cause of chronic disability. In a cohort of patients with RA followed from early stages of the disease, we have observed a much larger prevalence of destructions in hips than in knee joints. The latter were frequently injected with triamcinolone hexacetonide in contrast to the former. In order to elucidate a possible role of local glucocorticoids we studied the antigen-induced arthritis model of Dumonde and Glynn in rabbits which, untreated, caused advanced joint destruction in 3/5 animals, whereas 0/14 animals receiving 3 injections of triamcinolone hexacetonide developed no such changes. The treatment was effective when started up to 2 weeks after induction of the arthritis. It is suggested that locally administered glucocorticoids may prevent or delay large joint destruction in RA.

Animals↗

Proteoglycan alterations during developing experimental osteoarthritis in a novel hip joint model.

Degenerative hip joint disease was induced in dogs by extra-articular surgery that created a condition that mimics hip dysplasia. Decreased acetabular coverage of the femoral head gave altered mechanical load, with ensuing cartilage degeneration. For comparison, degenerative knee joint disease was induced in other dogs by transection of the anterior cruciate ligament of the knee. The femoral head articular cartilage showed macroscopic signs of degeneration within a month. No macroscopical changes of synovitis were present. Chemical analysis of cartilage samples showed loss of proteoglycans. Guanidine hydrochloride extracts of the cartilage contained proteoglycan fragments that could be separated by equilibrium density gradient centrifugation in cesium chloride. The data indicate that proteoglycans are fragmented by proteolytic cleavage and lost from the cartilage. The proteoglycans remaining in the tissue are smaller and have lost the ability to aggregate with hyaluronic acid. Similarly, in experimental knee joint osteoarthritis, the proteoglycan content of the cartilage decreased. The structural changes of those proteoglycans remaining were of a different nature, with no changes in proteoglycan size or aggregation properties, possibly indicating that both degradation and repair took place in the knee articular cartilage and/or that fragments were rapidly lost from the tissue. This may follow from different surgical procedures, only the one used for the hip joint being extra-articular, or from the different anatomy and physiology of the hip joint and the knee joint.

Animals↗

Papain-induced mitosis of chondrocytes in adult joint cartilage: an experimental study in full-grown rabbits.

When diluted papain is injected intra-articularly into the knee joints of adult rabbits, slowing progressing, degenerative changes develop in the articular cartilage. After intravenous injection of crude papain no significant degenerative changes are found. With the aid of radioactive thymidine, it is possible to demonstrate that the chondrocytes recover their ability to divide before any degenerative changes can be found. At the same time the matrix loses its staining properties with Safranin-O and toluidine blue.

Animals↗

A double-blind comparative evaluation of tolmetin versus naproxen in osteoarthritis.

A double-blind, between patient trial was carried out in 70 patients with osteoarthritis of the knee or hip joint. Patients were allocated at random to treatment with either 800 mg tolmetin sodium daily or 500 mg naproxen daily over a period of 12 weeks, both drugs being given in identical capsule form in a dosage of 2 capsules twice daily. The results of assessments of functional and subjective parameters before nad during treatment suggest that tolmetin sodium was at least as effective as naproxen in relieving pain and the incidence of side-effects as naproxen in relieving pain and the incidence of side-effects in the two groups was similar.

Clinical Trials as Topic↗

Content and synthesis of nucleic acids in the cartilage in chondromalacia patellae.

The content and the synthesis of nucleic acids in chondromalacian, osteoarthritis and normal cartilage was compared. The chondromalacian cartilage differed from osteoarthritis in that the content of nucleic acids was less. Also, the cell density was less in chondromalacian than in normal cartilage as opposed to previous findings in osteoarthritis. The synthesis of DNA was greater in chondromalacian than in normal cartilage but less than in osteoarthritis. With regard to the RNA synthesis, however, the chondromalacian cartilage showed a higher rate than both normal and osteoarthritic cartilage.

Adolescent↗

Scattered mitosis in adult joint cartilage after partial chondrectomy. A histological, autoradiographical and biochemical study in rabbits.

Full-grown rabbits were operated on and subjected to total or partial chondrectomy of the cartilage in the patellar groove. In one group, only arthrotomy was performed in the control knee. The animals were killed at various times after the operation. Histologically, proliferation of the synovial cells at the joint margins, as well as osteoblastic activity, could be seen; later, osteophyte formation was observed. There were only minimal signs of degenerative changes in the cartilage. The biochemical investigation did not show any difference in the nucleic acids of the cartilage, either in relation to the time after the operation had taken place or in relation to the size of the trauma. In the knees where the cartilage was excised, thymidine-labelled chondrocytes were seen scattered in the joint. The number of labelled chondrocytes showed a rising tendency up to 14 days postoperatively, but no peak value was seen. In the arthrotomized knee joints, labelled chondrocytes were occassionally seen. It is possible that the scattered mitosis is the result of a reduction in the concentration of normal cell-specific inhibitors of mitosis, so-called chalones.

Animals↗

Papain-induced changes in the knee joints of adult rabbits.

Rapidly progressing joint disease can be produced in the rabbit by intra-articular injection of concentrated papain. With the use of radioactive thymidine it is possible to demonstrate that the cartilage cells recover their ability to divide by mitosis at the same time as degenerative changes appear in the cartilage. Clusters of chondrocytes arise by mitosis of chondrocytes and not by a floating together of cartilage cells.

Animals↗

The effect of osteotomy and cartilage damage on mitotic activity. An experimental study in rabbits.

In 15 rabbits, osteotomy and osteotomy including cartilage damage were performed. With autoradiography (3H-thymidine) it was shown that only one knee in the osteotomy group had labeled chondrocytes in the tibial cartilage. In the knees with articular damage, labeled chondrocytes were found in the femur as well, which could be the result of a factor liberated from the damaged cartilage, a factor stimulating mitotic activity.

Animals↗

Osteochondritis dissecans. A histologic and autoradiographic study in man.

Surgically excised cylindrical specimens from 14 adult patients with osteochondritis dissecans in the knee joint were studied with histologic and autoradiographic techniques. The lesions were found to be composed of normal hyaline cartilage with no pathological changes. In the bone part of the specimens there were well-defined fissures at various distances from the tidemark. On both sides of the fissure, but especially on the OD side, there were scattered osteonecroses in complete disarray. No tetracycline fluorescence activity could be seen in the lesions.

Adult↗

Nucleic acids in human normal and osteoarthritic articular cartilage.

During operations on joints of patients with osteoarthritis, specimens of severely degenerated cartilage of the femoral head were removed and cartilage from knee joints taken at meniscectomy was used as control material. DNA and RNA concentrations were reduced in advanced osteoarthritis, while the synthesis of DNA and RNA was increased in relation to the number of cells in the tissue. The result showed that in advanced osteoarthritis the remaining chondrocytes are metabolically very active.

Adult↗

The subchondral bone in osteoarthritis and rheumatoid arthritis of the knee. A histological and microradiographical study.

Specimens of the joint surfaces of the tibia from patients with OA and RA were exposed were examined for bone mineralization, bone formation, osteoid tissue and bone resorption. Judging from the appearance of the osteoblasts in OA the sclerotic changes are mainly focal with relatively little osteogenesis. No osteoclasia was seen in the sclerotic areas. Breakdown of the mineralized cartilage is followed by the development of cysts with highly cellular connective tissue with high osteoblastic activity and osteoclasia. Osteoid tissue is relatively sparse. The changes in RA are more diffuse with a more active osteoblastic activity and widespread zones of osteoid tissue as well as resorption by osteoclasts. It appears as if the increased uptake of 85Sr in OA is more dependent on the occurrence of relatively inert osteosclerosis than on a rapid turnover of the bone tissue.

Arthritis, Rheumatoid↗

Nucleic acids in articular cartilage from rabbits of different ages.

The joint cartilage of immature, adult and old rabbits was examined. The joint cartilage in adult and old rabbits contained less nucleic acids than that in young rabbits. The synthesis of DNA decreases with advancing age, while no difference was found in the concentration of nucleic acids between adult and old rabbits.

Age Factors↗