| 1. |
- Bentham, J, et al.
(författare)
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A double-staining technique for detection of growth hormone and insulin-like growth factor-I binding to rat tibial epiphyseal chondrocytes.
- 1993
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Ingår i: The Journal of endocrinology. - 0022-0795. ; 137:3, s. 361-7
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Tidskriftsartikel (refereegranskat)abstract
- In the present study a double-staining technique was developed to investigate simultaneous GH and insulin-like growth factor-I (IGF-I) binding to chondrocytes in a monolayer cell culture. Rat tibial epiphyseal chondrocytes were isolated by enzymatic digestion and cultured in monolayer. GH and IGF-I were labelled with biotin. The affinity of the biotin-labelled ligands was compared with unlabelled ligands in a radioreceptor assay. To study the distribution of GH and IGF-I binding in the monolayer, chondrocytes were incubated with biotinylated ligands with or without an excess of unlabelled ligands, followed by incubation with Vectastain ABC complex, which was then reacted with diaminobenzidine (DAB). Double staining was accomplished by carrying out the first reaction with DAB in the presence of nickel ammonium sulphate to give a black precipitate, followed by incubation with the second ligand, then ABC complex and finally DAB in the absence of nickel ammonium sulphate to give a brown stain. The presence of type-II collagen was demonstrated by immunohistochemistry and used as a marker for differentiated chondrocytes. Biotin-labelled GH and biotin-labelled IGF-I exhibited dose-dependent displacements of 125I-labelled GH and 125I-labelled IGF-I respectively from the chondrocytes in a radioreceptor assay. The displacement curves were identical to those of unlabelled ligands indicating that the affinity was unaltered. Binding of biotinylated GH to cells was seen throughout the culture in regions where there was little or no type-II collagen staining. IGF-I binding was predominantly localized to cells at high density; areas which also showed a high degree of staining for type-II collagen.(ABSTRACT TRUNCATED AT 250 WORDS)
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| 2. |
- Brittberg, Mats, 1953, et al.
(författare)
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Autolog broskcellstransplantation. Smärtlindring och återställd ledfunktion är målet : Autologous cartilage cell transplantation. The goal is pain relief and restored joint function
- 1995
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Ingår i: Nordisk medicin. - 0029-1420. ; 110:12, s. 330-4
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Tidskriftsartikel (refereegranskat)abstract
- Chondral and osteochondral damage is a common result of trauma to the joints. The capacity of cartilage to heal such damage is poor, and repetitive wear on joint surfaces that do not heal results in impaired joint function, which can culminate in full blown arthrosis. Thus, it is important to improve our knowledge of cartilage regenerative potential, and develop methods to forestall progression to arthrosis by promoting the early healing of cartilage damage. Autologous cartilage cell transplantation may be a mean of healing cartilage damage. A method of cultivating autologous chondrocytes for transplantation in the treatment of isolated damage to articular cartilage of the knee is presented in the article.
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| 3. |
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| 4. |
- Brittberg, Mats, 1953, et al.
(författare)
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Cellular aspects on treatment of cartilage injuries.
- 1993
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Ingår i: Agents and actions. Supplements. - 0379-0363. ; 39, s. 237-41
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Tidskriftsartikel (refereegranskat)abstract
- Cellular aspects on articular cartilage growth and development are discussed. Cells with chondrogenic potential are described and current treatment models for cartilage injuries are considered. A rabbit model for treatment of articular cartilage defects with autologous cultured and transplanted chondrocytes for treatment of knee cartilage defects in humans are discussed.
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| 5. |
- Brittberg, Mats, 1953, et al.
(författare)
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Rabbit articular cartilage defects treated with autologous cultured chondrocytes.
- 1996
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Ingår i: Clinical orthopaedics and related research. - 0009-921X. ; :326, s. 270-83
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Tidskriftsartikel (refereegranskat)abstract
- Adult New Zealand rabbits were used to transplant autologously harvested and in vitro cultured chondrocytes into patellar chondral lesions that had been made previously and were 3 mm in diameter, extending down to the calcified zone. Healing of the defects was assessed by gross examination, light microscope, and histological-histochemical scoring at 8, 12, and 52 weeks. Chondrocyte transplantation significantly increased the amount of newly formed repair tissue compared to the found in control knees in which the lesion was solely covered by a periosteal flap. In another experiment, carbon fiber pads seeded with chondrocytes were used as scaffolds, and repair significantly increased at both 12 and 52 weeks compared to knees in which scaffolds without chondrocytes were implanted. The histologic quality scores of the repair tissue were significantly better in all knees in which defects were treated with chondrocytes compared to knees treated with periosteum alone and better at 52 weeks compared to knees in which defects were treated with carbon scaffolds seeded with chondrocytes. The repair tissue, however, tended to incomplete the bonding to adjacent cartilage. This study shows that isolated autologous articular chondrocytes that have been expanded for 2 weeks in vitro can stimulate the healing phase of chondral lesions. A gradual maturation of the hyalinelike repair with a more pronounced columnarization was noted as late as 1 year after surgery.
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| 6. |
- Brittberg, Mats, 1953, et al.
(författare)
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Treatment of deep cartilage defects in the knee with autologous chondrocyte transplantation.
- 1994
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Ingår i: The New England journal of medicine. - 0028-4793. ; 331:14, s. 889-95
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND. Full-thickness defects of articular cartilage in the knee have a poor capacity for repair. They may progress to osteoarthritis and require total knee replacement. We performed autologous chondrocyte transplantation in 23 people with deep cartilage defects in the knee. METHODS. The patients ranged in age from 14 to 48 years and had full-thickness cartilage defects that ranged in size from 1.6 to 6.5 cm2. Healthy chondrocytes obtained from an uninvolved area of the injured knee during arthroscopy were isolated and cultured in the laboratory for 14 to 21 days. The cultured chondrocytes were then injected into the area of the defect. The defect was covered with a sutured periosteal flap taken from the proximal medial tibia. Evaluation included clinical examination according to explicit criteria and arthroscopic examination with a biopsy of the transplantation site. RESULTS. Patients were followed for 16 to 66 months (mean, 39). Initially, the transplants eliminated knee locking and reduced pain and swelling in all patients. After three months, arthroscopy showed that the transplants were level with the surrounding tissue and spongy when probed, with visible borders. A second arthroscopic examination showed that in many instances the transplants had the same macroscopic appearance as they had earlier but were firmer when probed and similar in appearance to the surrounding cartilage. Two years after transplantation, 14 of the 16 patients with femoral condylar transplants had good-to-excellent results. Two patients required a second operation because of severe central wear in the transplants, with locking and pain. A mean of 36 months after transplantation, the results were excellent or good in two of the seven patients with patellar transplants, fair in three, and poor in two; two patients required a second operation because of severe chondromalacia. Biopsies showed that 11 of the 15 femoral transplants and 1 of the 7 patellar transplants had the appearance of hyaline cartilage. CONCLUSION. Cultured autologous chondrocytes can be used to repair deep cartilage defects in the femorotibial articular surface of the knee joint.
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| 7. |
- Carlsson, Björn, 1958, et al.
(författare)
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Expression and physiological significance of growth hormone receptors and growth hormone binding proteins in rat and man.
- 1991
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Ingår i: Acta paediatrica Scandinavica. Supplement. - 0300-8843. ; 379
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Tidskriftsartikel (refereegranskat)abstract
- The molecular structure of the GH receptor has recently been characterized and the receptor identified as a member of a new receptor superfamily that includes the prolactin receptor and several cytokine receptors. No obvious signal transducing domain has been identified on any of these related receptors. One possible signalling mechanism involves receptor interaction with other membrane-associated proteins that function as mediators of signal transduction. Whether such a mechanism is involved in signal transduction of the GH receptor is not known. Another common feature of these receptors is the presence of soluble forms such as the GHBP. The functions of these proteins in the circulation and at the level of the target cell remain to be resolved.
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| 8. |
- Isaksson, Olle, 1943, et al.
(författare)
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Regulation of cartilage growth by growth hormone and insulin-like growth factor I.
- 1991
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Ingår i: Pediatric nephrology (Berlin, Germany). - 0931-041X. ; 5:4, s. 451-3
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Tidskriftsartikel (refereegranskat)abstract
- A number of studies have shown that growth hormone (GH) and insulin-like growth factor-I (IGF-I) have important regulatory roles for skeletal growth. However, it has been a matter of controversy whether GH acts directly on cells in the growth plate or if the growth-promoting effects of GH are mediated by liver-derived (endocrine-acting) IGF-I. With the recognition that GH regulates the production of IGF-I in multiple extra-hepatic tissues, autocrine and paracrine functions of IGF-I have been suggested as important components of GH action. This review focuses on recent developments in our understanding of the cellular mechanisms by which GH promotes longitudinal bone growth and the inter-relationship between GH and IGF-I in the growth plate.
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| 9. |
- Nilsson, Anders, 1958, et al.
(författare)
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Expression of functional growth hormone receptors in cultured human osteoblast-like cells.
- 1995
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Ingår i: The Journal of clinical endocrinology and metabolism. - 0021-972X. ; 80:12, s. 3483-8
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Tidskriftsartikel (refereegranskat)abstract
- Recent clinical studies indicate that GH is important for bone remodeling. Patients with GH deficiency exhibit decreased bone density, and GH substitution increases bone density in these patients. The aim of the present study was to investigate the presence of GH receptors and the effects of GH on cultured human osteoblast-like cells. Primary cultures of human osteoblast-like cells were established from trabecular bone. Northern blot analysis, using a probe recognizing exon 10 of the human GH receptor, revealed a 4.7-kilobase transcript corresponding to the human GH receptor. Cultured osteoblast-like cells expressed, as determined by RNase protection assay, approximately one fourth of the GH receptor messenger RNA levels found in liver. Binding studies using 125I-labeled GH revealed a single class of receptors with approximately 2000 binding sites per cell and an association constant (Ka) of 2.6 x 10(9) M-1. GH stimulation of the cultured cells resulted in increased [3H]thymidine incorporation, suggesting that the GH receptors are functional. In summary, the present study shows that cultured human osteoblast-like cells express functional GH receptors.
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| 10. |
- Nilsson, Anders, 1958, et al.
(författare)
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Hormonal regulation of longitudinal bone growth.
- 1994
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Ingår i: European journal of clinical nutrition. - 0954-3007. ; 48 Suppl 1
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Tidskriftsartikel (refereegranskat)abstract
- The regulation of postnatal somatic growth is complex. Genetic, nutritional factors and hormones exert regulatory functions. Hormones that have an established role in the regulation include growth hormone (GH), thyroid hormone and sex steroids. GH promotes mainly the growth of the long bones in terms of final height, while the action of the sex steroids and thyroid hormone is less well known. Longitudinal bone growth is the result of chondrocyte proliferation and subsequent endochondral ossification in the epiphyseal growth-plates. The growth-plate is a cartilaginous template that is located between the epiphysis and the metaphysis of the long bones. GH and insulin-like growth factor-I (IGF-I) have different target cells in the epiphyseal growth-plate. GH stimulates the slowly dividing prechondrocytes in the germinative cell layer while IGF-I promotes the clonal expansion in the proliferative cell layer of a GH primed cell. Thyroid hormone blocks the clonal expansion and stimulates chondrocyte maturation. IGF-I mRNA is primarily regulated by GH, and IGF-I is produced in several tissues such as the liver, muscle, fat and epiphyseal growth plates. However, IGF-I mRNA is also increased during compensatory growth of heart and kidneys and by estrogen in the Fallopian tube in the rat. Nutrition, i.e. energy from fat and carbohydrates and proteins, also influences the final height, but the cellular mechanism of action is not known. The aim of this article is to review hormonal action on longitudinal bone growth.
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