| 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. |
- 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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| 8. |
- 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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| 9. |
- Ohlsson, Claes, 1965, et al.
(författare)
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Effect of growth hormone and insulin-like growth factor-I on DNA synthesis and matrix production in rat epiphyseal chondrocytes in monolayer culture.
- 1992
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Ingår i: The Journal of endocrinology. - 0022-0795. ; 133:2, s. 291-300
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Tidskriftsartikel (refereegranskat)abstract
- The influence of various culture conditions was studied on the effect of GH and insulin-like growth factor-I (IGF-I) on DNA and matrix synthesis in epiphyseal rat chondrocytes in monolayer culture. Chondrocytes from enzymatically digested rat tibia epiphyseal growth plates were seeded in 48-well culture plates and precultured for 10 days in Ham's F-12 medium supplemented with 1% (v/v) newborn calf serum and 1% (v/v) of a serum substitute. After preculture, the medium was changed to Ham's F-12 medium supplemented with 1% serum from hypophysectomized rats, and the effect of GH and IGF-I on DNA synthesis ([3H]thymidine incorporation) and matrix production ([35S]sulphate uptake) was studied during an additional 96-h culture period. Isotopes were present during the last 24 h of culture. Both hGH and IGF-I stimulated DNA synthesis in a dose-dependent manner. A maximal effect of GH was seen at a concentration of 25 micrograms/l (60 +/- 11% stimulation over control) and for IGF-I at 10 micrograms/l (162 +/- 12%). The stimulatory effects of the same concentrations of human GH (hGH) and IGF-I on [35S]sulphate uptake were 135 +/- 25 and 320 +/- 42% respectively. In-vitro pulse labelling revealed that GH did not produce a response during the first 3 days of culture (after addition of GH) but was effective during days 4 and 5 of culture. In contrast, IGF-I was effective throughout the culture period. Pretreatment of cells with GH or IGF-I for 2.5 days showed that GH but not IGF-I produced a sustained effect on [3H]thymidine uptake. In order to study the influence of cell density on the effect of GH and IGF-I on DNA synthesis, the effect of added peptides was evaluated after different preculture periods (5-15 days). A maximal stimulatory effect of hGH was seen at a cell density of 150,000-300,000 cells/cm2. GH had no significant effect at a low (less than 100,000 cells/cm2) or a high (greater than 400,000 cells/cm2) cell density. The magnitude of the stimulatory effect of IGF-I was the same at densities between 10,000 and 250,000 cells/cm2, but was reduced at higher cell densities (over 250,000 cells/cm2). Chondrogenic properties of cells that had been cultured for 15 days were verified in vitro by positive alcian blue staining and identification of type II collagen, and in vivo by development of cartilage nodules in nude mice.(ABSTRACT TRUNCATED AT 400 WORDS)
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| 10. |
- Ohlsson, Claes, 1965, et al.
(författare)
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Effects of tri-iodothyronine and insulin-like growth factor-I (IGF-I) on alkaline phosphatase activity, [3H]thymidine incorporation and IGF-I receptor mRNA in cultured rat epiphyseal chondrocytes.
- 1992
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Ingår i: The Journal of endocrinology. - 0022-0795. ; 135:1, s. 115-23
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Tidskriftsartikel (refereegranskat)abstract
- The effects of tri-iodothyronine (T3) and insulin-like growth factor-I (IGF-I) on [3H]thymidine incorporation, alkaline phosphatase (ALP) activity and IGF-I receptor mRNA levels were studied in rat epiphyseal chondrocytes cultured in monolayer. Chondrocytes from enzymatically digested rat tibia epiphyseal growth plates were seeded in monolayer culture and precultured for 7-14 days in Ham's F-12 medium supplemented with 10% (v/v) newborn calf serum and 1% (v/v) of a serum substitute. After preculture the medium was changed to Ham's F-12 medium containing 1% (v/v) serum from hypophysectomized rats, and the effects of T3 and/or IGF-I on DNA synthesis ([3H]thymidine incorporation), ALP activity (a late marker of differentiated epiphyseal chondrocytes) and IGF-I receptor mRNA levels were studied. ALP activity was increased by T3 in a dose-dependent manner with a maximal response at 10 micrograms T3/l (678 +/- 86% compared with control culture). The increase in ALP activity was accompanied by a concomitant decrease in [3H]thymidine incorporation (52 +/- 14% compared with control culture). Human GH (hGH; 50 micrograms/l) and IGF-I (25 micrograms/l) had no stimulatory effect on ALP activity. However IGF-I (10 micrograms/l) exerted an inhibition on the T3 (10 micrograms/l)-induced increase in ALP activity (64 +/- 9% compared with T3-treated culture). T3 (3 micrograms/l) inhibited the increase in [3H]thymidine incorporation caused by 25 micrograms IGF-I/l (51 +/- 13% compared with IGF-I-treated culture). Furthermore, IGF-I receptor mRNA levels were increased by 10 micrograms T3/l (137 +/- 4.2% compared with control culture) while no effect of hGH (50 micrograms/l) or IGF-I (25 micrograms/l) was demonstrated. Both T3 and IGF-I were shown to interact with epiphyseal chondrocytes and both substances seemed to affect cell proliferation and maturation and therefore longitudinal bone growth. Furthermore, the results indicated that IGF-I is important for proliferation of the cells while T3 initiates the terminal differentiation of epiphyseal chondrocytes.
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