摘要:

AbstractEpiphyseal transplantation has long been a goal of orthopaedic surgeons. While microvascular surgery has raised hopes that this goal could be achieved, factors other than blood supply also appear capable of affecting the function of the epiphysis. Basic reserch into the biology of the epiphysis appears to be required. This would be faciliated with a model of epiphyseal transplantation using a small mammal. The purpose of this experiment was to develop such a model in the mouse. Developing CD1 mouse or Lewis rat limb tissue was used to replace knee tissue that had been resected from CD1 postnatal mouse hosts. Donor tissue ranged from 14‐day embryonic mouse to 9‐day postnatal mouse or 18‐ and 19‐day fetal rat, which has a gestation similar to the mouse. The murine tissue is known to be avascular prior to the sixth postnatal day. The limbs were analyzed radiographically and histologically. The results show that epiphyseal replacement could be studied using developing tissue donors in a murine model. The results suggest that donor tissue prior to vascularization and tissue combinations with the least developmental time mismatch (the least heterochronicity) produced relatively the best, although still abnormal ep

ISSN:0736-0266    

DOI:10.1002/jor.1100060202

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

年代:1988

数据来源: WILEY

摘要:

AbstractThe distribution of intracellular and extracellular lectin‐binding glycoconjugates of the reserve cell zone of growth plate cartilage was studied in the distal radial growth plate of 4‐week‐old Yucatan swine using a postembedment method on Epon‐embedded sections. Direct comparisons were made to articular, tracheal, and auricular cartilages not involved in endochondral ossification. All patterns of lectin binding that in the growth plate were restricted to the reserve cell zone were also patterns characteristic of tracheal, articular, and auricular cartilages. These included: (a) pericellular binding with peanut agglutinin (PNA) without prior digestion with neuraminidase; (b) pericellular binding with wheat germ agglutinin (WGA) at 24 h; (c) intracellular cytoplasmic binding to concanavalin A (CON‐A),Lens culinarisagglutinin (LCA), andLotus tetragonobolusagglutinin (LTA) after periodic acid oxidation; and (d) a lack of pericellular binding with CON‐A and ricin agglutinin 1 (RCA‐1) after periodic acid oxidation. We conclude that reserve zone chondrocytes lack specific phenotypic markers as defined by lectin‐binding affinity that are found in the cellular zones of the growth plate that undergo calcification and vascularization. The reserve zone has identical lectin‐binding affinities to the three structural cartilages used as controls. One interpretation of these results is that the reserve zone may not be involved directly in endochondral ossification, but may have a structural function in growt

ISSN:0736-0266    

DOI:10.1002/jor.1100060203

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

年代:1988

数据来源: WILEY

摘要:

AbstractThe effects of highly purified human monocyte‐derived interleukin‐1 (IL‐1) on bovine nasal cartilage breakdown were investigated. Cartilage degradation was determined by quantifying the fraction of total proteoglycan released from cartilage during 8 days of culture. The response appeared to be chondrocyte‐dependent, for IL‐1 stimulated proteoglycan (PG) release from living but not from dead (frozen‐thawed) cartilage. IL‐1 action on living cartilage was heat labile and concentration dependent, with significant effect at 5 U/ml and maximal effect at 10–20 U/ml. Kinetic studies showed significant stimulation of PG release by 3 days of incubation with 10 U/ml IL‐1. Studies in which IL‐1 was removed on day 1 or day 4 showed that the cartilage‐degrading effect of this monokine was reversible. Although IL‐1 caused little change in the Sepharose CL‐2B chromatographic profile of released PGs using an associative elution buffer, a significant shift to lower mol wt was observed under dissociative conditions. To probe the mechanism of IL‐1 action, cartilage samples were incubated with IL‐1 in the presence of the protein synthesis inhibitor, cycloheximide, or the lysosomal membrane‐stabilizing steroid, hydrocortisone. Cycloheximide at 5–10 μg/ml completely blocked IL‐1–induced breakdown. On the other hand, 3 × 10−7Mhydrocortisone had little or no effect on IL‐1 action. IL‐1 was also shown to stimulate

ISSN:0736-0266    

DOI:10.1002/jor.1100060204

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

年代:1988

数据来源: WILEY

摘要:

AbstractThe local influences of physical exercise on thickness and glycosaminoglycan (GAG) content of canine articular cartilage were measured by microspectrophotometry of Safranin O‐ and periodic acid‐Schiff (PAS)‐stained tissue sections. Female Beagle dogs were housed in individual cages (bottom 0.9 × 1.2 m) and divided into runner (n = 6) and control (n = 8) groups. The trainig program started at the age of 15 weeks. During the subsequent 10 weeks, the dogs were accustomed to running on a treadmill inclined 15° uphill. Thereafter, the dogs ran 1 h daily, 5 days a week, at a speed of 4 km/h for 15 weeks. At the age of 40 weeks, the dogs were killed, and the samples for histology were taken from 11 different anatomical locations of the right knee (stifle) joint. The thickness of the uncalcified cartilage increased 19–23% on the lateral condyle and patellar surface of the femur, whereas the enhancement was smaller in other parts of the trained cartilage. The calcified cartilage did not show thickness alterations. Total GAGs were augmented by 28% in the summits on the femoral condyles, more on the medial than lateral side. The increased GAGs appeared to be predominantly chondroitin sulphates and were localized in the intermediate, deep, and even in the calcified zones, whereas the superficial zone did not show changes. There was a concomitant increase of non‐GAG oligosaccharides in the intermediate and deep zones, but not in the calcified cartilage. As judged from the enhanced GAG content and thickness, it is considered that moderate running exercise locally alters the biological properties of young articular cartilage at regions bearing the highest load

ISSN:0736-0266    

DOI:10.1002/jor.1100060205

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

年代:1988

数据来源: WILEY

摘要:

AbstractMale white Leghorn chickens were exercised on a treadmill at 70–80% of their maximal oxygen consumption starting at 4 weeks and continuing up to 20 weeks of age. The effect of the strenuous exercise regime on the extracellular matrix of menisci was followed through studies of proteoglycans and collagen. Avian menisci contain type I collagen, chondroitin sulfate proteoglycans, which increase with age in amount and degree of aggregation, and dermatan sulfate proteoglycans, which decrease with age. Five weeks of exercise cause a premature decrease of dermatan sulfate proteoglycans, while the chondroitin sulfate–containing molecules become significantly more aggregrated than those of the tissue of age‐matched controls. Strenuous exercise also causes a significant decrease in the number of pyridinoline crosslinks per mole of collagen in the menisci of young runners. The exercise‐induced changes of proteoglycan and collagen occur only during the period of active growth, and all parameters return to normal when the animals reach skeletal maturity. The early proteoglycan aggregation and dermatan sulfate decrease induced by exercise are probably an adaption to the increased loading. Although the mechanism by which strenuous exercise reduces or delays the formation of collagen pyridinoline crosslinks in menisci of skeletally immature animals is unknown, their decrease could negatively affect the mechanical properties of the tissue during the period of active

ISSN:0736-0266    

DOI:10.1002/jor.1100060206

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

年代:1988

数据来源: WILEY

摘要:

AbstractA three‐dimensional stochastic mathematical muscle model of the knee joint has been developed and applied to a study in which the influence of both mechanical and physiological factors were examined in relation to the prediction of muscular forces about the joint. The model includes a representation of the proximal portion of the tibia and distal portion of the femur along with a mathematical expression of the patellar mechanism and 13 muscles crossing the knee joint. The model accounts for the rolling and gliding movement of the tibial‐femoral articulation. The computational technique involves equilibrating three components of external moments at the knee joint to the internal moments generated by muscular forces and soft tissue. The variables contained in the moment equilibrium equation are randomly chosen based on the choice of the tibial‐femoral contact point. The randomness of the variables, reflected in the final solution, defines a stochastic process in the context of the present model. Studies with the model indicated that a very important mechanical aspect of the model was the capability to simulate the moving contact point between the tibia and femur. The moving contact point increased the mechanical advantage of the quadriceps muscles by 50%, which corresponded to in vivo EMG measurements. Muscle force predictions during normal gait have shown the capability of the model to determine the presence of synergistic and antagonistic muscle a

ISSN:0736-0266    

DOI:10.1002/jor.1100060207

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

年代:1988

数据来源: WILEY

摘要:

AbstractThe energy expenditure of level walking was measured in 260 normal male and female subjects walking around a 60.5m‐circular outdoor track. Subjects were divided into four age groups (children, 6–12 years; teens; young adults, 20–59 years; and senior adults, 60–80 years). Oxygen consumption was measured with a modified Douglas Bag technique during the fourth and fifth minutes of each trial. Standard tables according to age and sex were derived for the average energy expenditure (rate of oxygen uptake, energy cost per meter, and heart rate) and for the gait characteristics (speed, cadence, stride length) at the subjects' customary slow, normal, and fast walking speeds. Statistical analysis was performed to determine the energy–speed relationship for the different age groups to derive normative tables for the rate of oxygen uptake throughout the range of customary walking v

ISSN:0736-0266    

DOI:10.1002/jor.1100060208

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

年代:1988

数据来源: WILEY

摘要:

AbstractGait analysis was used to compare the ground reaction forces, ankle and foot rotations in the sagittal plane, and the center of pressure pattern beneath the right feet of seven normal subjects walking barefoot, with and without their right ankles taped in the neutral position. Instrumentation included a force plate, ankle goniometer, and two accelerometers mounted on top of the foot. The ground reaction forces showéd no change between the same ankle, taped and untaped. Taping served to reduce the range of ankle rotations in the sagittal plane by ∼20%, with a subsequent increase in the rotation about the metatarsal heads during heel‐up. Hell‐up occurred earlier in stance when the ankle was taped than with no taping. The vertical force graph was integrated over time when the center of pressure was located beneath the heel and the ball, resulting in two impulse measurements. The heel impulse decreased for each of the 7 subjects and 6 of the 7 subjects displayed an increase in the ball impulse due to taping, indicating that taping served to shift the load‐time history away from the heel and toward the ball. The results of this study may apply to fused ankle patients, who may suffer forefoot abnormalities subsequent to ankle fusion

ISSN:0736-0266    

DOI:10.1002/jor.1100060209

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

年代:1988

数据来源: WILEY

摘要:

AbstractShoulder pain correlated to manual labour is an increasing problem. The etiology is multifactorial and often unclear. High local muscle load and muscle ischemia in the supraspinatus muscle is present in elevated arm positions, as shown in several electromyographic studies. The purpose of this study was to evaluate intramuscular pressure (IMP) as a way to describe local muscle load in the supraspinatus muscle. Measurements were made in 15 arm positions, and with hand loads of 0, 1, or 2 kg weight, in 12 shoulders. The IMP was recorded with microcapillary infusion technique. The method was found to be suitable in recording IMP at rest and during exercise. High intramuscular pressures, i.e., above 50 mm Hg (6.7kPa), were seen in moderate humeral abduction. The IMP increased further in abduction up to 90°, where mean IMP was 122 mm Hg (16.2 kPa). Added hand load increased intramuscular pressure in all positions except in shoulder flexion of 135°. The study thus demonstrated that intramuscular pressure offers important information about the load on the supraspinatus muscle in different positions of the arm. The results indicate that fatigue and shoulder pain related to elevated arm positions may be caused by muscle ischemia induced by the high intramuscular pressure present in these position

ISSN:0736-0266    

DOI:10.1002/jor.1100060210

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

年代:1988

数据来源: WILEY

摘要:

AbstractSpecific pulsing electromagnetic fields (PEMFs) have been used to stimulate growth and repair of osteogenic tissues; however, the basis for this specificity is unknown. Previously, we determined the relevant electromagnetic field parameters of the clinically used PEMF and independently verified the beneficial effects of PEMFs on the rabbit fibula fracture healing model. The goal of the present study was to develop an in vitro model that would permit the effectiveness of various electric and magnetic field components of the PEMF to be determined.The costochondral junction (CCJ) of the 21‐day‐old rat was exposed in vitro to PEMFs with various electric and magnetic field component amplitudes. Response of this model to PEMFs was determined by nondestructive macrophotographic measurement of CCJ growth. Preliminary data indicated that temperature effects were present in this in vitro system. Subsequent experiments designed to separate the effects of temperature and PEMFs on the growth of CCJs in tissue culture were performed.Results indicate that accurate and frequent temperature measurements must be made for in vitro models being used to study effects of PEMFs. Small temperature differences induced by the coils used to produce PEMFs in the CCJ experimental system can have significant stimulatory effects, and the combined effects of temperature and PEMFs are not linearly additive in this model. Furthermore, our results suggest that thermal and PEMF stimuli could affect macrophotographically measured growth of the CCJ by separate mechanisms or could have a synergistic effect. Therefore, PEMF stimulation experiments should be performed under strictly “athermal” con

ISSN:0736-0266    

DOI:10.1002/jor.1100060211

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

年代:1988

数据来源: WILEY