摘要:

AbstractThe purpose of this study was to test whether cartilage serves as the source or repository of antigenic components active in the stimulation of inflammation in rheumatoid arthritis through an analysis of peripheral blood lymphocyte proliferation. Articular cartilage samples were obtained from patients with osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis undergoing joint replacement surgery. Each sample was homogenized and characterized biochemically with respect to the content of proteoglycan, collagen, and immunoglobulin. Proteoglycan content of rheumatoid cartilage was reduced by 71% when compared to osteoarthritic cartilage; the proteoglycan content of ankylosing spondylitis cartilage was reduced by 40% when compared to osteoarthritic cartilage. Immunoglobulins were detectable in all cartilage samples when analyzed by ELISA or endoplate titration. Lymphocyte proliferation, quantified by uptake of3H‐thymidine, was unaltered by addition of cartilage fragments, low (saline) and high salt extracts (2.0 M CaCl2), or cartilage residues. Both autologous and heterologous lymphocytes were tested against the cartilage samples with no difference in reactivity. Purified bovine articular proteoglycans and Type II collagen were also inactive. Although tetanus toxoid and phytohemaglutinin were effective stimulants of proliferation, lymphocytes from arthritis patients were suppressed relative to those of normal individuals. Analysis of arthritic articular cartilage by these techniques failed to demonstrate the presence of antigen(s) stimulating proliferation of peripheral blood lymphocyte

ISSN:0736-0266    

DOI:10.1002/jor.1100040301

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe release of proteoglycans from explant cultures of articular cartilage from immature and mature rabbits has been studied with the following results. At both ages the tissue proteoglycan was released in two phases: an initial extensive release (day 0 to 3) and a period of slow release (day 4 to 15). The percentage released in the initial phase was, however, significantly greater for mature (55%) than immature (38%) explants. At both ages the newly synthesized proteoglycans (in vivo labeled) were also released in two kinetic pools. Thus, graphical analysis of release data readily resolved the disappearance curves into two linear components with in vitro half‐lives of 1 day and 22 days. Again, the percentage in the short half‐life pool was much greater for mature (70%) than immature (40%) explants. At both ages the initial release was largely chondrocyte‐mediated since freeze‐thawing the tissue before culture markedly reduced proteoglycan release. At both ages the released proteoglycans were smaller than equivalent preparations of extracted proteoglycans and they were much less capable of forming aggregates with hyaluronate. The results show that there are age‐dependent changes in rabbit articular cartilage that increase the proportion of proteoglycans, both total and newly synthesized, that are susceptible to rapid chondrocyte‐mediated catabolism in expla

ISSN:0736-0266    

DOI:10.1002/jor.1100040302

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

年代:1986

数据来源: WILEY

摘要:

AbstractSecreted and intracellular arylsulfatase B (ASB) activities were measured in normal and osteoarthritic (OA) human chondrocyte cultures in the absence and presence of monensin, ammonium chloride, and chloroquine. Of the three agents added, only monensin produced a significant stimulation of secreted enzyme activity. Osteoarthritic cells consistently exhibited a threefold higher level of secreted specific ASB activity than did normal cells, with or without monensin. When compared with normal cells, OA cells also consistently exhibited a twofold heightened intracellular specific enzyme activity both in the absence or presence of monensin. With increasing dosage of monensin, secreted and intracellular ASB activity increased for both OA and normal cells. Total enzyme activity of secreted and intracellular ASB was found to be cell density dependent. No inhibition of secreted or intracellular ASB activity was observed for sparsely plated cultures. In contrast to sparse cultures, an inhibition of secreted ASB, with or without monensin, was observed in densely plated cultures. Intracellular total activity was not inhibited by high‐density cultures. Secreted ASB activity was found to be time‐dependent after passage. Enzyme activity was maximal at 6 h in both OA and normal cells and decreased by the end of 24 h both in serum‐free medium and in serum‐free medium with monensin. When compared with normal cells, OA cells expressed higher levels of ASB activity under all test conditions. This heightened activity therefore appears to be a property inherent in the OA chon

ISSN:0736-0266    

DOI:10.1002/jor.1100040303

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe initial effects of chymopapain, a chemonucleolytic agent, on the intervertebral disc of dogs were studied by light and electron microscopic techniques. Fragments of nucleus pulposus and annulus fibrosis were incubated with chymopapain up to 24 h in vitro. Proteoglycans and matrix proteins were rapidly removed, while collagen fibers remained intact up to 24 h. For several hours, most cells remained normal in appearance with only slight swelling and an increased number of vacuoles. After exposure to the protease for 24 h cells in both the annulus and nucleus showed extensive membrane damage and some were necrotic, but many survived relatively intact. These results suggest that, similar to the results of the digestion of cartilage with other proteases, the cells of the disc can survive brief chymopapain exposure during chemonucleolysis procedures and could serve as a source for regenerating tissue. The nature of the regeneration may depend on the extracellular scaffold that remains and the nutrition available to tissue as well as the age and biomechanical state of the disc. As for clinical significance, chemonucleolysis is an important nonsurgical alternative for treating prolapsed disc. The cells of nucleus and annulus can survive short‐term exposure to treatment, and thus be responsible for partial regeneration of the tissue. This regeneration may be important in preventing long‐term degenerative disease in the facet joints caused by increased pressure due to decreased disc hei

ISSN:0736-0266    

DOI:10.1002/jor.1100040304

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe myoelectric activity of selected trunk muscles at the L3 level was studied during the development of a controlled isometric axial torque. Muscle activity was recorded with surface electrodes bilaterally over the erector spinae muscles, the rectus abdominus, the obliques externus, and the obliques internus. Subjects applied graded isometric axial torque efforts with the addition of a Valsalva. The largest myoelectric activities were recorded over the obliques externus and internus. The side of the muscle developing the torque did show the greatest myoelectric activity, but considerable antagonistic activity was also present. Neither the rectus abdominus nor the internal oblique muscles showed any difference from side to side. The calculated forces in the rectus abdominus and the erectores spinae were high, suggesting that a considerable amount of the muscle contraction was used to control the posture. A Valsalva did not decrease myoelectric activity, but did increase the torque developed.

ISSN:0736-0266    

DOI:10.1002/jor.1100040305

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe bovine spine has been frequently selected as the model for in vitro mechanical studies. A comparative anatomical study has been presented describing important differences and similarities between selected areas in the adult human and calf thoracolumbar spinal segment. Differences in column length and curvature were observed. The total length of the adult bovine vertebral column was found to be on average 209 cm longer than the adult human spine. Equivalent throacolumbar lengths were obtained by selecting 6–8 week‐old dairy calves, which because of their young age had the benefit of consistent bone density. The bovine spine was found to have only a single cervical lordotic curve and a single thoracolumbar kyphotic curve (2). A quantitative comparison of selected dimensions of vertebrae T6, T12, and L3 was performed, and significant findings are discussed. The bovine spinous processes were found to be on average 111% greater in length at level T6, which contributed to a 56% greater total anterior/posterior length at this level in comparison to the vertebrae of an adult male. A 23% greater bovine intertransverse length at level L3 was also shown. The orientation of the human and bovine superior facets, while being in the same general plane and direction, varied as much as 10.5 and 107% at vertebral level L3 on the two axes measured. These significantly different measurements were considered important factors that can influence experimental results when using the bovine spine as a mo

ISSN:0736-0266    

DOI:10.1002/jor.1100040306

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe relationships between cancellous bone apparent density, trabecular orientation, and stress are developed and a mathematical theory describing these relationships is proposed. The bone is assumed to be a self‐optimizing material. Using a continuum model, sufficient conditions are developed which ensure that, for a given stress encountered during normal activity, the theory will predict both trabecular orientation and apparent density. Using two special approaches, one based on optimizing strain energy density (stiffness) and the other on optimizing strength, the relationship between apparent density and stress is derived. This is the first time that a single theory has been advanced to predict both the orientation and apparent density of cancellous bon

ISSN:0736-0266    

DOI:10.1002/jor.1100040307

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

年代:1986

数据来源: WILEY

摘要:

AbstractA nonimmobilized rat tibial fracture model of endochondral osseous repair was examined for the unique localizations of specific collagen genetic types. At various stages of the healing process, the demineralized callus was reacted with immunofluorescent antibodies directed against the type specific forms of matrix collagen. Type III collagen rapidly appeared (day 8–10) and remained in the primitive mesenchymal callus until remodeled. It was particularly prominent in the highly vasoformative regions and the pericallus encapsulation but not present in preexisting cortical and neoformed lamellar bone. The type II collagen, a marker of cartilage, was uniquely located only in areas of chondroid differentiation and calcification. Type II collagen was absnet from all bone and was not identified beneath the repairing intact periosteum. The differentiating chondrocytes synthesized type II collagen on an underlayer of type III collagen already within the mesenchymal matrix. From these studies of genetically unique collagen markers, it appears that only in areas of motion or anoxia does an intermediate of chondroid tissue appear. The utilization of specific type II and type III collagen immunofluorescent antibodies has facilitated the understanding of the fracture repair process and has acted as an indicator for unique matrix component

ISSN:0736-0266    

DOI:10.1002/jor.1100040308

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe effect on intramedullary oxygen tension of 100% oxygen exposure at 1, 2, 2.4, and 3 atm pressure was studied in 12 New Zealand white rabbits with chronic right tibial osteomyelitis. The model, modified from that described by others, incorporates a multipuncture silastic closure plug placed transcortically in the proximal tibial metaphysis through which platinum needle, polarographic electrode oxygen tension determinations can be made without repeat surgical exposure. In 40% of the control, left, noninfected tibial metaphyses the baseline oxygen tension with the animals breathing room air at sea level was suboptimal for leukocyte bacterial killing. This oxygen tension was depressed further in the infected right tibia. Medullary canal oxygen tension increased in response to hyperbaric oxygen exposure in both the infected and noninfected tibiae. Whereas the amount of the oxygen tension increase varied with the presence of infection and depth of dive, neither the time for oxygen tension to plateau nor the time required for return to baseline tension after completion of hyperbaric oxygen exposure varied with the presence of infection or depth of dive. After completion of hyperbaric oxygen exposure, the oxygen tension within the medullary canal returned to baseline within 15 min.

ISSN:0736-0266    

DOI:10.1002/jor.1100040309

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

年代:1986

数据来源: WILEY

摘要:

AbstractStressed bone generates an electrical potential, the sign of which reverses in the presence of specific concentrations of sodium, potassium, or calcium ions. A study was designed to test the hypotheses, drawn from stress‐generated potential (SGP) studies, that the reversal in polarity of the zeta potential of bone is the cause of this SGP polarity reversal. The zeta potential of bone particles, prepared from fresh bovine metatarsals as homogeneous 5 μm dispersions, was measured by free‐fluid electrophoresis in different concentrations of sodium chloride. The zeta potential of bone particles reversed sign at a sodium ion concentration that was the same as that found to reverse measured SGPs, namely 0.74 molar. This finding is consistent with the hypothesis that streaming potentials are the cause of SGPs in fluid‐saturated bone. It was possible to obtain electrophoretic mobility histograms, and hence zeta‐potential histograms, of bone particles by using a Pen Kem, Inc. (Bedford Hills, NY, U.S.A.) “3000” Automated Electrokinetic Analyzer. At sodium ion concentrations at which bone particles were nearly neutral, the zeta‐potential histograms indicated a broad distribution of particle charge, with some particles being negative, some positive, and some neutral. In addition, it was found that particles prepared from Formalin‐fixed bone produced the same electrokinetic results as those prepared from fresh bone, and that the addition of MOPS buffer caused the zeta potential to invert sign from negative to positive values at ion concentrations exc

ISSN:0736-0266    

DOI:10.1002/jor.1100040310

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

年代:1986

数据来源: WILEY