摘要:

AbstractCytokines and proteases are thought to play a role in the destruction of cartilage and the development of osteoarthritis. The purpose of this study was to document chronological involvement of interleukin‐1 beta (IL‐1β), tumor necrosis factor‐alpha (TNF‐α), stromelysin (MMP‐3), fibronectin, and alteration in the chondroitin sulphate sulfation pattern. Canine patellae underwent a closed‐joint impact to induce the development of osteoarthritis. The animals were killed at 2, 12, 24, and 52 weeks. The patellar damage included cracks in the superficial zone of cartilage and the zone of the calcified cartilage‐bone interface, vertical step‐off fractures in the zone of calcified cartilage, and loss of proteoglycan around the cracks in the deep and superficial zones of cartilage. With avidin‐biotin immunohistochemistry, these specimens were stained with antibodies to IL‐1β, TNF‐α, MMP‐3, fibronectin, and altered proteoglycan sulfate with the monoclonal antibody 3‐B‐3. Three of the four specimens obtained at 2 weeks demonstrated a strong cellular and weak matrix staining‐pattern for IL‐1β, TNF‐α, MMP‐3, and fibronectin around the cracks in the superficial and transitional zones of cartilage. No consistent staining pattern was noted in the cracks in the deep zone. None of the specimens obtained at 12, 24, or 52 weeks stained for these antibodies. No staining for the abnormal sulfation with the 3‐B‐3 antibody was evident in any specimen. The specimens obtained at 52 weeks showed healing of the step‐off fractures and a filling‐in of the proteoglycan loss. This model probably reflects the short‐term cartilaginous changes in the patella after trauma; thus, only transient ele

ISSN:0736-0266    

DOI:10.1002/jor.1100110302

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractLumbar spines collected postmortem were assigned to one of two groups: group 1—three spines with healthy discs, or group 2—three spines with severely degenerated discs. The proteoglycans (PGs) of the cartilaginous end‐plate (CEP) were extracted with 4Mguanidinium chloride containing protease inhibitors and were purified by caesium chloride density gradient ultracentrifugation. On Sepharose CL‐2B chromatography, the most dense 20% of the gradient (the A1 fraction) showed two subfractions, one eluting near the void volume and one partitioned by the gel. Both fractions resembled those of the nucleus pulposus and the anulus fibrosus in the number of components seen on agarose‐polyacrylamide gel electrophoresis. Both fractions changed with ageing/degeneration; the ratio of keratan sulphate to chondroitin sulphate, which was about 1 in group 1, increased to about 3 in group 2; the hydrodynamic volumes fell; the electrophoretically distinguishable component of lowest mobility disappeared while new, highly mobile components appeared; and the water content decreased slightly. Clearly, the PGs of the CEP of degenerated intervertebral discs differed from those of healthy discs; this supports the view that the CEP participates in the process of ageing/degeneration in

ISSN:0736-0266    

DOI:10.1002/jor.1100110303

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThere have been very few studies on the metabolism of the intervertebral disc. One possible reason is that lumbar discs suitable for in vitro synthesis studies are difficult to obtain. We have examined some properties of coccygeal discs to see if those discs are a suitable alternative. The properties measured appear similar to those of lumbar discs, with collagen content lowest in the nucleus and highest in the outer annulus, while hydration and glycosaminoglycan content were highest in the nucleus and of a similar level to those of canine lumbar discs (approximately 83% water). The discs were under mechanical load in vivo, resulting in an equilibrium swelling pressure of 0.25–0.3 MPa. The35S‐sulphate incorporation rate was 2–5 × 10−5mmol/g dry weight per hour in the inner annulus and nucleus, in comparison with 2–3 × 10−5mmol/g dry weight per hour in rabbit and canine lumbar discs. Coccygeal discs are a readily obtainable and cheap source of disc material, and they are easy to dissect out. Since the general properties of these discs are similar to those of lumbar discs, we suggest that they are a suitable model for the study of the metabolic and other properties of

ISSN:0736-0266    

DOI:10.1002/jor.1100110304

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractSix techniques of proximal femoral replacement were compared in vitro with the use of compression, bending, and torsional testing in a canine model. One femur of each pair was osteotomized in the midshaft region, and the proximal portion was replaced with one of six techniques. These techniques included (a) a segmental proximal femoral endoprosthesis cemented into the distal femur with no allograft (technique Es); (b) a long‐stem endoprosthesis press‐fit into an allograft and cemented into the distal femur with a transverse osteotomy (technique AT); (c) the same construct as technique AT, but with a step‐cut at the osteotomy (technique AS); (d) a long‐stem endoprosthesis interlocked into an allograft and cemented into the distal femur with a transverse osteotomy (technique AI); (e) a short‐stem endoprosthesis cemented into an allograft combined with one plate laterally stabilizing the allograft to the distal femur with a transverse osteotomy (technique AP1); and (f) the same construct as technique AP1, but with an additional plate cranially (technique AP2). A long‐stem endoprosthesis cemented into the contralateral intact femur served as the control. Techniques that involved a long‐stem endoprosthesis and cementing distally (AT, AS, and AI) were more resistant in torsion than the plated replacement techniques (AP1and AP2). The segmental replacement construct (ES) was equal to or stronger than all other techniques under each testing condition. In torsion, the addition of a step‐cut (AS) significantly lowered angular displacement of the reconstruction when compared with the reconstruction with a transverse osteotomy (AT) (p ≤ 0.05). Bones with one‐plate fixation (AP1) were significantly weaker in torsional stiffness and maximum torque and in mediolateral bending (p ≤ 0.05) than all other techniques. The addition of a second plate (AP2) increased the mechanical properties of the construct so that it was greater than the one‐plate method and was equal to (bending and compression) or still weaker (torsion) than the other techniques. The results indicate that segmental replacement methods and allograft/endoprosthetic composites that involve long‐stem endoprostheses fixed with cement are mechanically superior to methods that involve short‐stem endoprostheses with single or double pla

ISSN:0736-0266    

DOI:10.1002/jor.1100110305

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractOsteonecrosis of the femoral head was induced in dogs by a process of deep freezing, accompanied by stripping of the soft‐tissue attachments from the femoral neck and intertrochanteric area, in an effort to develop an experimental model to study treatment modalities for avascular necrosis of the hip. Immediate uniform necrosis was created in a defined area. Thereafter, spontaneous healing originated mainly from the adjacent viable bone by migration of undifferentiated mesenchymal tissue into the necrotic bone, genesis of fibrosis, and, finally, formation of new bone. Osteogenesis occurred primarily through intramembranous ossification without a preexisting template. Quantitative measurements showed a difference in the rates of ingrowth and revascularization of the necrotic area during the fibrotic and osteogenic phases of the healing. The de novo osteogenesis was slower than the migration of fibrosis. These findings indicate that, without osteotomy, we can reproducibly create necrosis of bone in a defined area of the proximal femur and induce a reparative process that incompletely heals the defect. Although it does not fully simulate the human disorder of osteonecrosis, our experimental surgical model provides a basis for further laboratory investigation into the management of avascular necrosis of the femoral hea

ISSN:0736-0266    

DOI:10.1002/jor.1100110306

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe extent of immobilisation‐induced adaptations of muscle length and muscle weight is known to be profoundly influenced by the position (or length) at which the muscle is immobilised. However, the effect of the full range of positions of immobilisation on subsequent adaptations of muscle length and weight has not yet been investigated. To examine further the effect of position of immobilisation, we used cast‐immobilisation of the hind limbs of 23 rabbits, in various positions between full plantar flexion and full dorsi‐flexion. Six muscles from non‐immobilised rabbits were used as the controls. After 10 days of immobilisation, the wet weight of the soleus muscle and the resting length and resting stiffness of the soleus muscle‐tendon unit were determined. Immobilisation in a shortened position was associated with a significantly greater decrease in length and weight than was immobilisation in a lengthened position. In addition, immobilisation produced significant increases in the resting stiffness of muscle‐tendon units, although there was no evidence of a position‐dependent increase in stiffness. Muscle weight was influenced by the position of immobilisation in a nonlinear way. The data support the views that the pre‐immobilisation resting length of the muscle represents a threshold length and that immobilisation at lengths longer than this retards immobilisation

ISSN:0736-0266    

DOI:10.1002/jor.1100110307

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe appearance of noncollagenous proteins and proteoglycans during induction of cartilage and bone by implanted demineralized bone powder was studied by immunohistochemistry with polyclonal antibodies. Three bone proteins (osteopontin, sialoprotein, and a 62 kDa protein) were present in the bone powder grains before implantation. They appeared to be lost slowly from the granulation tissue but reappeared when bone formation started. The raw powder also contained a cartilage protein, biglycan (S1), chondrocalcin, cartilage oligomeric matrix protein, and the large proteoglycan aggrecan. The amounts of these molecules, however, increased significantly both within and outside the grains on cartilage formation. Cartilage matrix protein (148 kDa protein) appeared sparsely. The 58 kDa protein and fibromodulin (59 kDa protein), particularly the latter, were prevalent in fibrillar bundles. Antibodies against the laminin‐staining vessel basement membranes showed an abundant occurrence of capillaries within the matrix grains in the granulation tissue and in the precartilaginous tissue. Bone powder made noninductive by 4Mguanidine HCl did not induce cartilage and did not stain for antibodies against bone proteins or for molecules restricted to cartilag

ISSN:0736-0266    

DOI:10.1002/jor.1100110308

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractFetal thyroid hormone (RT3) is considered metabolically inactive and is present in high concentration in fetuses and in some patients with end‐stage malignant disease. In a virus‐induced erythroleukemia cell model, RT3was found to stimulate the growth of the erythroleukemia cells in culture. The focus of this research was to test the effect of RT3, at several concentrations, on the growth of naturally occurring human sarcomas in cell culture. Cloned cell lines of Ewing sarcoma, rhabdomyosarcoma, and osteogenic sarcoma were grown in multiple flasks of serum‐free medium containing varying concentrations of RT3, ranging from 10−8and 10−5M. Cells grown in serum‐free medium containing no RT3were used as a control. RT3significantly increased the growth (total protein) of the rhabdomyosarcoma cell line in culture at concentrations between 10−8and 10−6M, with the maximum effect at 10−7M. The growth of one cell line of Ewing sarcoma was not affected by RT3for any of the concentrations tested. The growth of two Ewing sarcomas and one osteogenic sarcoma was significantly stimulated by RT3but only at the highest concentration of 10−5M. The growth of the other osteogenic sarcoma cell line was significantly increased at concentrations of 10−6and 10−7M. The stimulatory effect of RT3on several sarcoma cell lines in culture suggests the presence of a specific receptor in the neoplastic cells and the possibility that RT3may be useful as a model for new

ISSN:0736-0266    

DOI:10.1002/jor.1100110309

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractWe studies the expression of the members of the β1 integrin family and extracellular matrix ligands in osteosarcoma tissues. Immunostaining of primary osteosarcomas with use of specific antibodies for α1‐α6 integrin subunits, fibronectin, type‐I collagen, and laminin gave characteristic patterns: despite the diffuse expression of type‐I collagen in all 16 osteosarcomas, collagen receptors were detected in only one. Laminin and laminin receptors were expressed poorly. In contrast, the α4 and α5 fibronectin receptors were found in 100 and 75%, respectively, which correlates very well with the strong expression of fibronectin in the stroma. The other ligand for α4, vascular cell adhesion molecule‐1, was not expressed in the seven specimens tested. Therefore, primary osteosarcomas closely interact with fibronectin through α4 and possibly α5 subunits of the β1 integrin. We also examined the expression the expression was detected in all six specimens, however, the change varied. In contrast, osteosarcoma cells obtained from invasive portions of tumors exhibited new and augmented expression of certain integrins in two of the three cases in which their ligands wer

ISSN:0736-0266    

DOI:10.1002/jor.1100110310

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractResistance to combination chemotherapy remains a challenge in the treatment of osteosarcoma yet has not been studied extensively in this tumour. One mechanism of multiple drug resistance is increased expression of the multidrug resistance gene (mdr1). The level of mdr1 messenger RNA (mRNA) expression has been found to correlate with the degree of drug resistance in a number of tumour cell lines in vitro, which suggests that it also may be useful as a predictor of similar resistance in vivo. Using a highly sensitive assay based on the polymerase chain reaction to measure the amount of mdr1 mRNA, we detected various levels of mdr1 expression in 18 osteosarcoma specimens from 15 patients with resectable nonmetastatic osteosarcoma. At follow‐up at a minimum of 30 months later, a trend toward a worse outcome was observed in patients with tumours exhibiting high levels of mdr1 expression. The results of this pilot study suggest that a larger scale prospective investigation of the effect of mdr1 gene expression on outcome in osteosarcoma is warrante

ISSN:0736-0266    

DOI:10.1002/jor.1100110311

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY