摘要:

AbstractNuclear deoxyribonucleic acid (DNA) ploidy was determined by flow cytometry for nine histologically benign giant cell tumors that developed systemic metastases and for eight tumors that did not metatasize. Specimens from the primary tumor, local recurrences, and pulmonary metastases were evaluated. No feature of the DNA ploidy pattern was identified to distinguish giant cell tumors that metastasized from those did not. The mean percentage of diploid (G0/G1 peak, 2C) cells was 81% in the metastasizing group and 80% in the nonmetastasizing group. The DNA ploidy pattern of the primary tumors was not different from that of their metastases. No DNA aneuploid patterns were observed among the benign tumors.

ISSN:0736-0266    

DOI:10.1002/jor.1100070402

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

年代:1989

数据来源: WILEY

摘要:

AbstractCell lines derived from human sarcomas have been previously shown to produce a protein growth factor which, similar to platelet‐derived growth factor (PDGF), can induce competence for mitosis in fibroblasts. Whether this factor production is an important feature of sarcomas in vivo or simply an artefact caused by long‐term culture conditions is unclear, however. We demonstrated growth factor activity in conditioned medium from six of 11 primary sarcoma cultures, utilizing flow cytometric analysis of DNA to monitor the presence of sarcoma cells in cultures. Cells isolated from control tissues failed to show a similar mitotic eff

ISSN:0736-0266    

DOI:10.1002/jor.1100070403

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

年代:1989

数据来源: WILEY

摘要:

AbstractTo assess the degree of success of anterior cruciate ligament (ACL) replacement using the patellar tendon (PT) autograft, 29 New Zealand white rabbits underwent ACL reconstruction using a medial one‐third PT autograft. The femur–ligament–tibia complexes were evaluated at 0, 6, 30, and 52 weeks postoperatively for gross and histologic appearances and tensile load to failure properties. Grossly, the autografts did not resemble the control ACLs. Histologically, the autografts progressed from being hypercellular with a random collagen fiber bundle organization to having a near normal cellularity with a more parallel collagen fiber bundle pattern. Anteroposterior knee laxity was more than two times that of the control knees 52 weeks after reconstruction. Biomechanically, the PT autografts plateaued at 30 weeks postoperatively. The ultimate load and stiffness were 15 ± 5% and 24 ± 6% of the control ACLs, respectively. At 52 weeks, the appearance of the PT autograft had some general histologic similarities as compared with the native ACL. However, these similarities did not extend to the functional properties of the au

ISSN:0736-0266    

DOI:10.1002/jor.1100070404

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

年代:1989

数据来源: WILEY

摘要:

AbstractRapid degeneration of the anterior cruciate ligament (ACL) has been observed following acute ACL rupture. An understanding of this process might explain some of the poor clinical results of primary ACL repair. We created a surgical rabbit model of acute ACL injury and developed an in vitro assay for collagenase activity in the ACL and menisci. Microscopic evaluation revealed a rapidly degenerative process in injured ACLs, with loss of cellularity and matrix organization. This was associated with a significant increase in collagenase activity and a decrease in total collagen of the injured ACLs as compared with sham‐operated controls. These findings confirm the observation that cut ACL ligament ends rapidly degenerate. This degenerative process might be partly due to a response of cells intrinsic to the ACL to injury. Left unchecked, this process may be detrimental to surgical attempts for primary ACL repai

ISSN:0736-0266    

DOI:10.1002/jor.1100070405

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe short‐term effect of cryopreservation on specific mechanical behaviors of bovine articular cartilage has been investigated. A flat‐ended nonporous indentor was used in a nondestructive, repetitive, axisymmetric unconstrained testing system. Cyclical indentation from a fixed position to a fixed load was applied until a steady‐state load‐deformation relationship (limit cycle) was achieved. Indentation behaviors measured from the limit cycles of each articular cartilage specimen before and after treatment were compared. Testing was done in vitro using fresh, mature bovine radiocarpal joints. Twenty pairs of cartilage‐subchondral bone cores from anatomically similar sites on contralateral joints were separated into three groups; thickness controls, dimethylsulfoxide (DMSO) controls, and cryopreserved experimental samples. Thickness controls and DMSO controls were used to examine the isolated effects of the thickness measurement and DMSO incubation techniques on articular cartilage indentation characteristics. Experimental samples were cryopreserved using DMSO, their thicknesses similarly measured and indentation behaviors examined. Following testing, histological and histochemical assessment of the specimens confirmed the nondestructive nature of the tests. Intra‐ and intergroup comparisons of controls and experimentals revealed no statistical differences in the mechanical behaviors measured from the limit cycle or in cartilage thickness. These results indicate that the cryopreservation protocol used did not have an effect that we could measure on these specific mechanical behaviors of articula

ISSN:0736-0266    

DOI:10.1002/jor.1100070406

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe purpose of this study was to see if kinetic and biochemical heterogeneity could be documented in vertebrate chondroepiphyseal regions as they develop from mesenchymal condensations to cartilage. The kinetics of developing proximal and distal femoral chondroepiphyseal regions were studied from early limb bud stage to newborn animals in chicks, mice, and rabbits with thymidine autoradiography. Proteoglycan synthesis in the proximal femoral chondroepiphyseal region of the rabbit was studied with radioactive sulfate incorporation at 28 days of gestation and at 1 and 4 days after birth. The results indicated that these kinetic and biochemical characteristics of the developing chondroepiphyseal regions became heterogeneous very early in development. This early programming of populations of cells for division and for different biochemical functions existed during the fetal period when heterogeneity has been described histologically but has not been well documented.

ISSN:0736-0266    

DOI:10.1002/jor.1100070407

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

年代:1989

数据来源: WILEY

摘要:

AbstractIn isolated chondrocytes from the growth plate, there is an increase in both the cytosolic ionized calcium concentration and in total cell calcium content as the cells approach the mineralization front. The reserve zone chondrocytes have a cytosolic ionized calcium concentration, [Ca2+]i, of 124 ± 23 nMand a total cell calcium content, CaT, of 12.8 ± 6.8 nmol/mg cell protein. Proliferative zone chondrocytes have a [Ca2+]iof 172 ± 29 nMand a CaTof 16.1 ± 11.8 nmol/mg cell protein. Hypertrophic zone chondrocytes have a [Ca2+]iof 273 ± 49 nMand a CaTof 35.8 ± 16 nmol/mg protein. Chondrocytes isolated from the entire growth plate have a [Ca2+]iof 132 ± 29 nMand a CaTof 13.2 ± 2.5 nmol/mg cell protein. Chondrocytes isolated from noncalcifying hyaline cartilage have a [Ca2+]iof 85 ± 10 nMand a CaTof 11.5 ± 1.4 nmol/mg cell protein. There appears to be a correlation between intracellular calcium accumulation, an increase in the intracellular ionized calcium concentration, and the process of cartilage matrix miner

ISSN:0736-0266    

DOI:10.1002/jor.1100070408

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

年代:1989

数据来源: WILEY

摘要:

AbstractCatabolic factors from synovium, or catabolins, may be important in the pathogenesis of osteoarthritis. The synovial production of catabolin in osteoarthritis was studied using the experimental model of osteoarthritis induced by section of the anterior cruciate ligament. At 1, 4, and 32 weeks after operation, the synovium was harvested, cultured, and the synovial conditioned medium assayed for catabolic activity. The synovial conditioned medium from the operated joints was significantly more capable of inducing cartilage destruction (p<0.05) than was the synovial conditioned medium from the unoperated knees. However, when the results were expressed relative to the weight of synovium, the differences were not significant. These results suggest that the increased production of catabolic synovial factors in early experimental osteoarthritis is probably a result of the synovial hypertrophy.

ISSN:0736-0266    

DOI:10.1002/jor.1100070409

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

年代:1989

数据来源: WILEY

摘要:

AbstractIntraarticular pressure (IAP) was continuously monitored during continuous passive motion (CPM) of five normal and 11 abnormal human knees using a new fiberoptic, transducer‐tipped Camino catheter. IAP varied in a consistent hysteresis pattern in the normal knees, with subatmospheric pressures recorded at intermediate angles of joint flexion. A similar pattern was recorded in the abnormal knees without cruciate ligament pathology, whereas considerable variability was noted in the knees with cruciate ligament abnormality. IAP was lower in the extension to flexion than in the flexion to extension portion of the CPM cycle, providing evidence of intraarticular fluid flow during portions of the CPM cycle. IAP changes were consistent with “physiologic compartmentation” within the knee at extremes of joint position. Capsular viscoelastic changes and/or synovial fluid volume changes were observed during CPM. The therapeutic mechanism of continuous passive motion may be related to cyclic variation of the intraarticular pre

ISSN:0736-0266    

DOI:10.1002/jor.1100070410

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

年代:1989

数据来源: WILEY

摘要:

AbstractThis study was intended to delineate whether electrical stimulation could significantly reduce the amount of joint contracture in a rat model. Rat knees were surgically immobilized in 150° of flexion. Two groups of rats had sham electrodes, and two groups were electrically stimulated. All rats were killed 14 days after surgery. The degree of joint contracture was assessed by measuring the femorotibial angles with a 0.015‐Nm extension moment applied. When the electrical current was applied in a transverse manner, there was a statistically significant reduction in the amount of posterior capsule (p<0.005) and anterior cruciate ligament (ACL) (p<0.005) contracture. When the electrical current was applied longitudinally, no significant difference in the amount of joint contracture was found. These findings support the hypothesis that electrical stimulation can inhibit joint contracture. These findings also suggest that the effect occurs when the electrical current is applied transversoly as opposed to longitudinal

ISSN:0736-0266    

DOI:10.1002/jor.1100070411

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

年代:1989

数据来源: WILEY