bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amplification of c‐myc oncogene and absence of c‐Ha‐ras point mutation in human bone sarcoma
Authors: Barrios Carlos , Castresana Javier S. , Ruiz Juan , Kreicbergs Andris 
Published: February 2005

AbstractThe genomic organization of four oncogenes, c‐myc, c‐myb, c‐Ha‐ras, and v‐fms, was analyzed in 21 patients with malignant bone tumors. Amplification of the c‐myc proto‐oncogene without rearrangement was the sole abnormality detected in four tumors: two chondrosarcomas, one osteosarcoma, and one lymphoma of bone. DNA hybridizations with c‐myb, c‐Ha‐ras, and v‐fms probes disclosed no structural gene abnormalities. Point mutations at the 12th codon of the c‐Ha‐ras gene were investigated with the polymerase chain reaction technique; no alterations were detected. The observed amplification of the c‐myc there was not related to histologic type, grade, surgical stage, or ploidy level of the tumors. The results indicated that c‐myc amplification, presumed to be involved in the development of malignancy in a variety of solid tumors, is encountered sporadically in malignant bone tumors; however, this occurs without relation to common histopathologic features. The clinical significance of oncogene amplification in bone sarcoma remains to be established.
Effects of transforming growth factor beta on cells derived from bone and callus of patients with osteogenesis imperfecta
Authors: Mörike Martin , Windsheimer Elke , Brenner Rolf , Nerlich Andreas , Bushart Gregor , Teller Walter , Vetter Ulrich 
Published: February 2005

AbstractWe studied the influence of transforming growth factor beta (TGF‐β) on cultured bone cells derived from two patients with osteogenesis imperfecta (OI) and from human controls. Additionally, cells from a hyperplastic callus that had developed spontaneously at the femur of the patient in Case 1 and cells from a normal fracture callus were included in the study. TGF‐β increased the synthesis of total protein and collagen of all cells without changing the pattern of interstitial collagens. Proliferation was stimulated by TGF‐β in the OI bone cells from Case 1, in cells from the central part of the hyperplastic callus, and in cells from the fracture callus. In Case 2, proliferation of bone cells was decreased by low concentrations of TGF‐β. Alkaline phosphatase (AP) activity was enhanced by TGF‐β in normal human bone cells, not affected in bone cells from the patient in Case 2 or in cells from the central part of the hyperplastic callus, and inhibited in bone cells and cells from the peripheral part of the hyperplastic callus of Case 1 and in cells from the fracture callus. We conclude that TGF‐β has common and specific effects on cultured human cells derived from different types of skeletal tissues. Simultaneous stimulation of collagen synthesis and AP activity by TGF‐β was restricted to normal human bone cells and might reflect their mature state of osteoblastic differentiation. Cells derived from bone of both patients with OI, from the hyperplastic callus, and from the fracture callus showed a different response pattern to TGF‐β. The difference in response to TGF‐β of bone cells from the two patients with OI might be related to the development of a hyperplastic callus in one of them (Case 1). This study indicates that the effects of TGF‐β on cells isolated from human skeletal tissues depend on their metabolic state and their stage of maturation and might be correlated with the formation of a hyperplastic callus in OI.
Treatment of experimental osteomyelitis with antibiotic‐impregnated bone graft substitute
Authors: Cornell C. N. , Tyndall D. , Waller S. , Lane J. M. , Brause B. D. 
Published: February 2005

AbstractThe model of Norden was used to induce osteomyelitis in the left tibia of New Zealand White rabbits. Twenty‐one days following inoculation, the animals had primary debridement and then were randomized into one of three treatment groups. Group I received no additional treatment; in Group II, plain hydroxyapatite beads were packed into the defect; and in Group III, gentamicin crobefat‐loaded hydroxyapatite beads were packed into the defect. The animals were observed for 40 days after the primary debridement and then were killed. The intensity of infection was determined by swab cultures and quantitative bacterial cultures of the debrided material. At primary debridement, all of the animals in each group were equally infected. At the time of secondary debridement, only the animals in Group III had a statistically significant reduction in infection (p < 0.001). In this study, we demonstrated that an antibiotic‐loaded osteoinductive ceramic bead can effectively eliminate bacteria from an osteomyelitic cavity.
Ultrastructural immunolocalization of type‐VI collagen and chondroitin sulphate in ligament
Authors: Bray D. F. , Bray R. C. , Frank C. B. 
Published: February 2005

AbstractImmunological methods were used to determine the identity of the major components comprising a network of electron‐dense seams (described by the authors in a previous work) within the extracellular matrix of medial collateral ligament (MCL) from humans and rabbits. Tissue obtained from MCL midsubstance was subjected to pre‐embedding labelling with colloidal gold at the electron microscopic level with monoclonal antibodies (MAbs) against type‐VI collagen and chondroitin sulphate (CS), before and after digestion with chondroitinase ABC and testicular hyaluronidase. Tissue labelled with anti‐type‐VI MAbs showed gold conjugates attached to the microfilamentous component of the seams both before and after enzyme digestion, which confirmed the identity of the beaded microfilaments as type‐VI collagen. Treatment of the tissue with anti‐CS MAbs resulted in labelling of undigested tissue only. In these treatments, gold particles were found attached to granules that were interspersed throughout the network of type‐VI microfilaments. Both the granules and gold labels were absent from the network following enzyme digestion. Thin nonbeaded microfilaments that did not label with anti‐type‐VI MAbs also were present within the seams. The loss of these nonbeaded microfilaments following enzyme digestion suggested that they might represent strands of hyaluronan. The codistribution and seqestering of type‐VI collagen and CS within discrete seams or channels suggests that these regions of the MCL midsubstance may contain higher concentrations of water than the surrounding dense fibrillar matrix.
Determination of the in situ loads on the human anterior cruciate ligament
Authors: Takai Shinro , Woo Savio L‐Y. , Livesay Glen A. , Adams Douglas J. , Fu Freddie H. 
Published: February 2005

AbstractA noncontact, kinematic method was used to determine the lengths and in situ loads borne by portions of the human anterior cruciate ligament (ACL) by the combination of kinematic data from the intact knee and load‐length curves of the isolated ACL. Specimens from knees of cadavers of young people were tested in passive flexion and extension as well as with 100 N of anterior tibial drawer at 0, 30, 45, and 90° of flexion. The results showed that the in situ load on the whole ACL (as much as 129 N) can exceed the magnitude of the applied anterior tibial drawer. The load distribution within the ligament changes with flexion of the knee. The anterior and posterior portions share the anterior drawer force equally toward full extension. However, at flexion >45°, the anterior portion supports 90–95% of the load. This information is important for the determination of the function of the entire ACL and of its subportions in response to external loading of the intact knee. In particular, the preferential loading found for one of the portions of the ACL demonstrates that successful operative reconstruction of this ligament may not be achieved simply by reproduction of its gross anatomy; consideration of the role of the ligament in the overall kinematics of the knee is necessary.
Effect of reconstruction of the anterior cruciate ligament on proprioception of the knee and the heel strike transient
Authors: Co Fred H. , Skinner Harry B. , Cannon W. Dilworth 
Published: February 2005

AbstractAbnormal proprioception of the knee joint has been documented after rupture of the anterior cruciate ligament (ACL) and may result in the loss of muscular reflexes. Excessive loading from the lack of muscular control may predispose the joint to osteoarthrosis. To investigate this problem, 10 patients were studied at an average of 31.6 months after ACL reconstruction. Three tests of joint proprioception and measurements of the vertical component of heel strike force during normal gait were used. A normal control group also was studied. For two of the proprioception tests (reproduction of passive motion and relative reproduction), there were no statistical differences among the uninjured (control) limbs, the normal contralateral limb of patients with a reconstructed ACL, and the extremity with a reconstructed ACL. In the third test (threshold of detection of motion), which previously has been shown to be adversely affected by ACL injury, the measurements for both extremities of patients with a reconstructed ACL were more accurate than those for the control group. The reconstructed extremity performed less accurately than the contralateral extremity (p < 0.05). The heel strike transient (vertical component of ground reaction force at heel strike) for uninjured and ACL‐reconstructed limbs was not significantly different. In fact, the extremity with the reconstructed ACL had a lower transient than the uninjured extremity. Heel strike transients in patients with a reconstructed ACL were higher than those in the controls, but the differences were significant only when corrected for velocity of gait. These results indicate that a well done ACL reconstruction with appropriate rehabilitation can result in proprioception that is essentially equal to that of the contralateral limb.
Repair of articular cartilage injury following intra‐articular chymopapain‐induced matrix proteoglycan loss
Authors: Williams James M. , Ongchi Dennis R. , Thonar Eugene J‐M. A. 
Published: February 2005

AbstractThe intra‐articular injection of 0.02, 0.2, or 2.0 mg of chymopapain (CP) into the knee of adolescent rabbits caused the loss of more than 50% of the proteoglycans (PGs) in the cartilaginous tissues within the joint. Sequential measurements of cartilage‐derived keratan sulfate epitope in serum and analyses of articular cartilage slices 2 days after the injection revealed that 0.02 mg of CP was nearly as effective as higher doses (0.2 or 2.0 mg of CP) in causing the depletion. The degradation and depletion of PGs in articular cartilage were shown to be localized to the joint and did not affect articular cartilage in the contralateral knee joint (no injection) or other cartilaginous tissues in the body. On day 9, partial replenishment of the articular cartilage PGs had occurred, irrespective of the dose used, and the articular surface within the joint remained intact. However, by day 21, articular cartilage in joints injected with 2.0 mg of CP had begun to show progressive degenerative changes, and these changes became more severe with time. In contrast, joints injected with 0.2 mg of CP continued to repair successfully by the reestablishment of a matrix that retained its integrity and appeared to remain functional for at least 6 months. These results suggest that the model may prove useful for the study of the repair processes that follow matrix injury and severe depletion of PGs from the articular cartilage matrix.
The cartilage end‐plate and intervertebral disc in scoliosis: Calcification and other sequelae
Authors: Roberts S. , Menage J. , Eisenstein S. M. 
Published: February 2005

AbstractThe morphology and composition of the intervertebral disc and also of the cartilage end‐plate were studied in patients with idiopathic or congenital scoliosis. The cartilage end‐plate was investigated because of its function as an epiphyseal plate in humans and the associaition between growth and progression of the scoliotic curve. The proteoglycan and water contents were reduced in both structures in specimens from scoliotic patients, particularly toward the concavity of the curve, compared with autopsy material. The distribution of some collagen types differed in tissue from scoliotic patients and autopsy tissue. Calcification of the cartilage end‐plate, and sometimes of the adjacent disc, occurred in all but three scoliotic patients, whereas there was minimal calcification in the autopsy specimens. We suggest that, although these changes are probably a secondary response to altered loading in the scoliotic patients, they may be highly significant to the progression of the scoliotic curve.
Effects of exercise and polysulfated glycosaminoglycan on repair of articular cartilage defects in the equine carpus
Authors: Todhunter R. J. , Minor R. R. , Wootton J. A. M. , Krook L. , Burton‐Wurster N. , Lust G. 
Published: February 2005

AbstractOur aim was to determine if mild to moderate postoperative exercise and intra‐articular polysulfated glycosaminoglycan result in improved repair of large, experimentally induced osteochondral defects in a weight‐bearing surface of equine joints. Arthroscopic debridement was used to produce fullthickness defects in a weight‐bearing area of the radial carpal bones in 18 ponies. The ponies were randomly assigned to two groups balanced for age: nine animals in the exercise and nine in the no exercise group. Six ponies in each group were medicated weekly for 5 weeks with an intra‐articular injection of polysulfated glycosaminoglycan in one middle carpal joint beginning at the time of operation. Walking (twice daily) was begun 6 days postoperatively, and by the twelfth week postoperatively the ponies were trotting for 25 min and walking for 15 min twice daily. At the time of the ponies' death, 17 weeks postoperatively, each defect had an average of 50–75% coverage with repair tissue. Exercised, medicated joints had a significantly smaller area of coverage with repair tissue than exercised, nonmedicated joints. Cartilaginous repair tissue from exercised ponies contained significantly more glycosaminoglycan and type‐II collagen (r= 0.53, p < 0.05). The ratio of hydroxylysine to hydroxyproline was significantly lower and the ratio of collagen content to total protein was significantly higher in the repair tissue of medicated joints than in the repair tissue of nonmedicated joints; this is consistent with the presence of less type‐II collagen in the repair tissue in medicated joints. We concluded that postoperative exercise was beneficial and that the immediate postoperative use of intra‐articular polysulfated glycosaminoglycan was detrimental to the development of cartilaginous repair tissue in large osteochondral defects of equine joints.
Knee joint contact pressure decreases after chronic meniscectomy relative to the acutely meniscectomized joint: A mechanical study in the goat
Authors: Bylski‐Austrow D. I. , Malumed J. , Meade T. , Grood E. S. 
Published: February 2005

AbstractSeveral studies have shown that meniscectomy causes an immediate, acute increase in knee joint contact pressure and that changes in pressure distribution cause remodeling of bone and soft tissue. Presumably, this remodeling in turn affects contact pressures. This study tested the hypothesis that medial compartment contact pressure increases immediately after medial meniscectomy and then decreases with time. Supporting hypotheses regarding medial compartment contact area and lateral compartment pressures also were tested. Unilateral medial meniscectomy was performed on seven adult goats. Four or 8 months later, contact pressure and area were measured in vitro in the involved joints, as well as in the contralateral joints, before and after removal of the meniscus. The medial compartment pressures of the chronically meniscectomized joints were significantly less than those of the acutely meniscectomized paired joints but remained significantly greater than those of the intact joints. For the 4 and 8 month groups combined, the mean pressures of the acutely and chronically meniscectomized joints were greater than the pressures of the paired intact joints by 70 and 42%, respectively. The mean medial compartment contact areas of the acute and chronic joints were lower than those of the intact joints by 60 and 50%, respectively; mean lateral compartment pressures remained the same. This study indicates that joint remodeling reduces joint contact pressures. It also suggests that the effectiveness of a treatment to reduce pressure concentrations may be determined only by comparison, at the same postoperative time of the pressure with that of the chronically meniscectomized joint, since pressures decreased with time without treatment.
Duration of pain and muscular adaptations in patients with dysfunction of the cervical spine
Authors: Weber Barbara R. , Uhlig Yvonne , Grob Dieter , Dvorák Jiri , Müntener Markus 
Published: February 2005

AbstractBiopsies of the sternocleidomastoid and omohyoid muscle were taken from 24 patients who underwent arthrodesis for cervical dysfunction of different etiologies. The two muscles, which are involved differently in movements of the head and cervical spine, were investigated histochemically. Muscle fibers were classified as type I, IIA, IIB, or IIC (transitional fibers) according to the pH lability of myofibrillar ATPase and calculated relative distribution. In both muscles, fiber transformations (as evidenced by an increase in the relative amount of type‐IIC fibers) were regularly observed within the first 2 years after the onset of the symptoms. The occurrence of the transformation processes was independent of the patient's age and sex and was the same for the different etiologies. Since the overall fiber composition of the muscles remained essentially unchanged, the fiber transformations must occur alternatingly in both directions (from “slow” to “fast” and the reverse). Muscles of patients with a long case history showed no greater signs of fiber transformation. Therefore, fiber transformations in response to cervical dysfunction occur in the initial stage of the disease and involve different types of muscles. The muscles then return to a “stable” condition, independent of the continuation of the dysfunction and the chronic neck pain.
A method for production and characterization of metal prosthesis wear particles
Authors: Rogers Susan D. , Pearcy Mark J. , Hay Shelley J. , Haynes David R. , Bramley Allan , Howie Donald W. 
Published: February 2005

AbstractThe wear of joint prostheses generates wear particles that produce an inflammatory response in the surrounding tissues and may contribute to bone resorption resulting in prosthetic loosening. Although the effects of particles produced from prosthetic materials have been studied extensively in vitro and in vivo, little attention has been paid to the standardisation of methods for the generation and characterization of these particles. This paper describes a reproducible method for generation of metal particles by the abrasive shaking of joint replacement components. Particular attention was given to the production of metal particles that closely resembled particles found around solid and loose human prostheses. To achieve this, particle size, size distribution, chemical composition, and shape were characterized. Particles that were 0.5–3.0 μm in diameter were isolated by differential sedimentation, and the distribution of particle sizes was determined with use of a Coulter Multisizer. Chemical composition was measured by atomic absorption spectrophotometry, and transmission electron microscopy was used to characterize particle shape. The techniques were shown to be reproducible, since there was little variation between batches over a lengthy time period. These or similar methods of particle production and characterization should be an essential part of future in vitro and in vivo studies of wear particles.
Stress‐Generated potentials in bone: Effects of bone fluid composition and kinetics
Authors: Kowalchuk Roman M. , Pollack Solomon R. 
Published: February 2005

AbstractIt is now generally accepted that stress‐generated potentials (SGPs) at low frequencies are due to an electrokinetic phenomenon in the small interior surfaces of bone and are directly proportional to the zeta potential, a property of the poorly characterized bone surface‐bone fluid interface. We hypothesized that this interface would be labile and might explain the controversy over whether or not the polarity of SGPs can invert under certain conditions. In this paper, the effects of alterations in the steeping fluid on SGPs for 87 samples from 15 animals were examined in four‐point bending for steeping times of ⩽65 h. Calcium and fluoride in distilled‐deionized water and constant ionic strength solutions produced concentration‐dependent inversions in the SGP sign. A new steady state was reached in approximately 18 h. The effects of the fluoride anion (unlike the calcium cation) apparently were reversible. The results strongly suggest that the zeta potential at the labile bone surface‐bone fluid interface can undergo dramatic changes, not only in magnitude but also in sign. The results further suggest that the preparation of bone samples is critical to the understanding of this interface in vivo, and they support the hypothesis that SGPs have a role in bone remodeling.
Effects of parathyroid hormone‐related peptide on chick growth plate chondrocytes
Authors: Loveys Luke S. , Gelb Daniel , Hurwitz Shepard R. , Puzas J. Edward , Rosier Randy N. 
Published: February 2005

AbstractParathyroid hormone‐related peptide (PTHrP) and parathyroid hormone (PTH) have similar biological effects in vitro that are mediated through the PTH receptor. PTH receptors have been demonstrated in the zone of provisional calcification and the hypertrophic zone of the cartilaginous growth plate. The current study examined the biological effects of PTHrP on chick growth plate chondrocytes. Chondrocytes were exposed to varying doses of PTHrP for 24 h, and the incorporation of radioactive thymidine into DNA was used as an index of proliferation. A dose‐dependent stimulation of proliferation was seen, with a maximal 27‐fold increase at 50 nM PTHrP. A dose‐dependent stimulatin of cAMP was seen, with a maximal effect at a dose of 50 nM. Proteoglycan synthesis, measured by incorporation of radioactive sulfate, was stimulated, with a maximal effect of 65% at 1 nM. Collagen synthesis and alkaline phosphatase activity from both cellular and matrix vesicle sources decreased in a dose‐dependent fashion, with a maximal inhibition of 50% of the control value. The physiologic significance of the PTH and PTHrP‐responsiveness of growth plate chondrocytes is uncertain at the present time. It is possible that PTH or PTHrP, or both, act as a systemic, developmental modulator of cellular proliferation and differentiation in the growth plate.
Experimental model in vivo for quantitative assessment of bone resorption inhibition
Authors: Pazzaglia Ugo E. , Zatti Giovanni , Nucci Amalia Di , Coci Anna , Cherubino Paolo 
Published: February 2005

AbstractQuantitative assessment of bone resorption inhibition in vivo is not easily accomplished; methods relying on a count of osteoclasts are questionable, and histomorphometric evaluation of the bone mass presents several technical problems as well. The authors developed a simple method to measure the inhibition of bone resorption by study of the proximal tibial metaphysis of growing rats: the height of the perichondrial bone ring was taken as an index of the balance between osteoblastic and osteoclastic activity because any agent that inhibits osteoclasts (without interference with osteoblasts) produces an increase in the height of this anatomical structure. Since the ring is well demarcated by surrounding tissues, its height can be measured with accuracy and used for quantitative assessment of bone resorption inhibition. This model was tested with salmon calcitonin, and it provides evidence in vivo that this hormone inhibits osteoclastic bone resorption.