bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidence for the upregulation of osteogenic protein‐1 mRNA expression in musculoskeletal neoplasms
Authors: Weber Kristy L. , Bolander Mark E. , Rock Michael G. , Pritchard Douglas , Sarkar Gobinda 
Published: February 2005

AbstractLittle is known about bone and cartilage tumors at the molecular level; thus, the identification of genes associated with these tumors may be useful as markers and therapeutic targets. To address this issue and to test the hypothesis that abnormal expression of one or more growth factors in the transforming growth factor‐β superfamily is associated with musculoskeletal neoplasia, degenerate primers based on the conserved sequences in these genes were made for screening tumor samples by reverse transcription‐polymerase chain reaction. First, these primers were used to obtain a comparative profile between a low‐grade chondrosarcoma and its dedifferentiated high‐grade counterpart in the same patient. This experiment identified an amplified DNA product in the high‐grade sample that was identical to osteogenic protein‐1/bone morphogenetic protein‐7. Osteogenic protein‐1 mRNA expression was 17‐fold greater in this high‐grade sample than in the low‐grade one. Osteogenic protein‐1 was highly expressed (three of three) in human osteosarcoma cell lines but was not expressed (zero of four) in normal osteoblast samples. Screening for gene expression of osteogenic protein‐1 in 57 osteosarcomas and chondrosarcomas indicated that 44% (range: 38–52%) of them were positive for osteogenic protein‐1 mRNA. Screening of breast and prostate tumors revealed a similar association with osteogenic protein‐1 mRNA expression.
Skeletal anomalies in the adriamycin‐exposed prenatal rat: A model for VATER association
Authors: Kotsios Christine , Merei Jamal , Hutson John M. , Graham H. Kerr 
Published: February 2005

AbstractVertebral and radial anomalies are prominent features of VATER vertebral defects, anorectal anomaly, tacheoesophageal fistula with esophageal atresia, and radial dysplasia association. It has been shown that exposure of the rat fetus to adriamycin produces a spectrum of anomalies, including esophageal atresia and other features of VATER association. We aimed to document the skeletal defects found in rats exposed to teratogenic doses of adriamycin in utero. Vertebral, rib. and limb anomalies were found in 54, 54, and 35% of these examined fetuses, respectively. The range of bone lesions seen in this animal model was similar to the range of lesions seen in infants born with VATER association.
Increased content of type‐VI collagen epitopes in human ostearthritic cartilage: Quantitation by inhibition ELISA
Authors: Swoboda Bernd , Pullig Oliver , Kirsch Thorsten , Kladny Bernd , Steinhäuser Bernhard , Weseloh Gerd 
Published: February 2005

AbstractType‐VI collagen is an integral part of the extracellular cartilage matrix. However, the exact amounts of type‐VI collagen in normal and osteoarthritic human cartilage still are not known. In this study, we describe an inhibition enzyme‐linked immunosorbent assay that was developed to quantitate type‐VI collagen epitopes found in guanidinium chloride extracts from normal and osteoarthritic human cartilage. In 31 cartilage samples from various localizations of healthy adult human knees, type‐VI collagen epitopes accounted for approximately 0.40% of the total collagen content. Interestingly, type‐VI collagen epitopes increased about 4‐fold in osteoarthritic cartilage. A statistically significant increase of type‐VI collagen epitopes was found during early stages of the disease, with only a superficial roughening of the cartilage surface and a loss of proteoglycans. Thus, these findings indicate that type‐VI collagen is a minor component of normal human articular cartilage and that the amount of type‐VI collagen epitopes increases significantly during early stages of osteoarthritis.
Generation of nitric oxide by lapine meniscal cells and its effect on matrix metabolism: Stimulation of collagen production by arginine
Authors: Cao M. , Stefanovic‐Racic M. , Georgescu H. I. , Miller L. A. , Evans C. H. 
Published: February 2005

AbstractSlices of lapine meniscus produced large amounts of nitric oxide after stimulation with interleukin‐1, tumor necrosis factor α, or a mixture of lapine synovial cytokines known as chondrocyte‐activating factors. Monolayer cultures of meniscal cells produced from the proteolysis of meniscal tissue contained a mixed population of chondrocytic and fibroblastic cells. These cultures also produced large amounts of nitric oxide in response to cytokines. Monolayer cultures of meniscal cells produced by the explant method, in contrast, were uniformly fibroblastic and did not produce nitric oxide in response to cytokines. We conclude that menisci contain two populations of cells, one fibroblastic and the other chondrocytic. The chondrocytic cells are responsible for generating most of the nitric oxide in response to cytokines. Endogenously generated nitric oxide suppressed the synthesis of collagen and proteoglycan by menisci but protected proteoglycan from the catabolic effects of interleukin‐1. The inhibitory effect of nitric oxide on collagen synthesis occurred without greatly altering the abundance of mRNAs encoding the various collagen α chains. During further investigation, arginine was unexpectedly found to stimulate the synthesis of collagen and, to a lesser degree, of noncollagenous proteins but not of proteoglycans. Fragments of meniscus, but not meniscal cells in monolayer culture, increased their production of matrix metalloproteinases. lactate, and, especially, prostaglandin E2 in response to interleukin‐1. Inhibition of nitric oxide production with NG‐monomethyl‐L‐arginine enhanced production of matrix metalloproteinases but had little effect on the synthesis of lactate or prostaglandin E2.
Effect of combined axial compressive and anterior tibial loads on in situ forces in the anterior cruciate ligament: A porcine study
Authors: Li Guoan , Rudy Theodore W. , Allen Christina , Sakane Masataka , Woo Savio L‐Y. 
Published: February 2005

AbstractThis study investigated the impact of a combination of axial compressive and anterior‐posterior tibial loads on the in situ forces in the anterior cruciate ligament. An axial compressive load is believed to contribute to increased stability of the knee joint; however, its effect on in situ forces in the anterior cruciate ligament has not been clearly defined, to our knowledge. It was hypothesized that the application of an axial compressive load, when combined with an anterior tibial load, would result in larger in situ forces in the anterior cruciate ligament than those caused by an isolated anterior tibial load. With use of a porcine knee model, the results confirmed this hypothesis; the addition of a 200 N axial compressive load to a 100 N anterior tibial load increased knee stability by reducing anterior‐posterior tibial translation and internal‐external tibial rotation and also caused a significant increase in in situ forces in the anterior cruciate ligament (p < 0.05). Specifically, there was a 34% increase in the in situ force at 30° of flexion, a 68% increase at 60° of flexion, and an 84% increase at 90° of flexion compared with those for an isolated anterior tibial load of 100 N. Additionally, there was a statistically significant increase of the in situ forces in the anterior cruciate ligament at 60 and 90° as compared with those at 30°. These results suggest that axial compressive loads on the knee may play a role in injury of the anterior cruciate ligament when the knee is flexed.
Endothelin‐1 is upregulated during skeletal muscle ischemia and reperfusion
Authors: Hvaal K. , Øie E. , Attramadal H. , Halvorsen V. , Svindland A. , Nordsletten L. , Skjeldal S. 
Published: February 2005

AbstractThe aim of the present study was to test the hypothesis that the vasoconstrictive peptide endothelin‐l is upregulated in ischemia and reperfusion in skeletal muscle. Sixty‐eight Wistar rats were included in the series: 12 served as controls that did not undergo the procedure, 16 underwent sham operations, and 40 were subjected to a modified tourniquet ischemia for 3 hours and 20 minutes. Of the 40 rats, 16 were killed at the end of the ischemic period, 16 underwent reperfusion for 2 hours, and eight underwent reperfusion for 72 hours. Areas of necrosis were measured by morphometry in hematoxylin and eosin‐stained cross sections of the anterior tibial muscles that had been reperfused for 72 hours. Sections from the controls, the muscles that had not been reperfused and the reperfused muscles were immunostained for endothelin‐1. Serum endothelin‐1 levels in blood samples from the aorta were determined with a commercial enzyme immunoassay kit. The anterior tibial muscle was harvested for preproendothelin‐1 mRNA analysis with RNase protection assay. The hematoxylin and eosin‐stained sections showed extensive necrosis with an acellular core of no reperfusion. The muscular core demonstrated weak immunostaining for endothelin‐1 in all sections, a subfascial narrow brim of fibers showed enhanced immunoreactivity at the end of ischemia, and all fibers outside the core stained by 2 hours after the start of reperfusion. After 72 hours of reperfusion. the fibers outside the core stained positive in a checkerboard‐like pattern. There were no differences in serum endothelin‐1 levels between the groups. Preproendothelin‐1 mRNA analysis with RNase protection assay showed 2‐fold upregulation at the end of ischemia and 4‐fold upregulalion'after 2 hours of reperfusion (p = 0.001). This study supports the hypothesis that both ischemia and reperfusion upregulate endothelin‐1 in skeletal muscle.
Biomechanical analysis of limited intercarpal fusion for the treatment of Kienböck's disease: A three‐dimensional theoretical study
Authors: Iwasaki Norimasa , Genda Eiichi , Barrance Peter J. , Minami Akio , Kaneda Kiyoshi , Chao Edmund Y. S. 
Published: February 2005

AbstractAlthough several types of intercarpal fusion have been advocated for the treatment of Kienböck's disease, the clinical outcome of each procedure is still inconclusive. The joint load and ligament tension based on a three‐dimensional model were measured to determine which intercarpal fusion procedures unload the lunate and whether they alter the force transmission through the entire wrist joint. Ten theoretical models of wrists were used to simulate three different operative procedures: capitate‐hamate fusion, scapho‐trapezial‐trapezoidal fusion, and scaphocapitate fusion. A discrete element analysis technique was used to perform these investigations. The joint force and ligament tension of normal wrists and of simulated operative procedures were calculated according to the deformation of each spring element, simulating the articular cartilage and the carpal ligaments. Scaphocapitate and scapho‐trapezial‐trapezoidal fusions significantly decreased the joint force at the radiolunate joint and the lunocapitate joint compared with the intact wrist. In contrast, these fusions significantly increased this value at the radioscaphoid joint in comparison with the intact wrist. In the midcarpal joint, scaphocapitate fusion also increased the joint force at the scapho‐trapezial‐trapezoidal joints and at the triquetral‐hamate joint, whereas scapho‐trapezial‐trapezoidal fusion increased it at the scaphocapitate joint. Capitate‐hamate fusion yielded no significant changes of the joint forces through the entire wrist joint. In the analysis of ligament tension, scaphocapitate and scapho‐trapezial‐trapezoidal fusions significantly decreased the tension only in the dorsal scapholunate ligament. These findings demonstrate that scaphocapitate and scapho‐trapezial‐trapezoidal fusions are effective in decompressing the lunate. By contrast, capitate‐hamate fusion is ineffective in reducing lunate compression. Although scaphocapitate and scapho‐trapezial‐trapezoidal fusions are recommended for the treatment of Kienböck's disease, clinicians should consider that the increase of force transmission through the radioscaphoid and the midcarpal joints may lead to early degenerative changes after these procedures have been performed.
Damage type and strain mode associations in human compact bone bending fatigue
Authors: Boyce Todd M. , Fyhrie David P. , Glotkowski Mark C. , Radin Eric L. , Schaffler Mitchell B. 
Published: February 2005

AbstractWhen compact bone is subjected to fatigue loading, it develops matrix microdamage, which reduces the tissue's ability to resist fracture. The relative influence of different strain modes on damage and strength in compact bone has not been characterized, to our knowledge. In this study, the nonuniform strain field produced by four‐point bending was used to introduce fatigue damage into tibial bending beam specimens from men 40‐49 years old. The specimens were then bulk‐stained with basic fuchsin to mark damage surfaces and were examined histologically and with confocal microscopy to describe damage morphologies and position relative to tension and compression‐strained regions of the specimen. Histomorphometric methods were used to quantify the amounts of different types of bone microdamage. Three major types were observed. In regions subjected to tensile strains, the bone had focal regions of diffusely increased basic fuchsin staining (i.e., diffuse microdamage). Confocal microscopy of these regions showed them to be composed of extensive networks of fine, ultrastructural‐level cracks. In compressive strain regions, the tissue developed linear microcracks in interstitial areas similar to those originally described by Frost. Fine, tearing‐type (wispyappearing) cracks were observed near and in the plane of the neutral axis. The paths of these fine cracks were not influenced by microstructural boundaries. Other minor damage morphologies (sector‐stained osteons, delamination of regions of lamellae, and intraosteonal cracking) were observed, but their distribution was unrelated to local strain field. Thus, in fatigue of human compact bone, the principal mechanisms of matrix failure (i.e., linear microcrack, diffuse damage foci, and tearing‐type damage) are strongly dependent on local strain type.
Analysis of the kinematics of different hip simulators used to study wear of candidate materials for the articulation of total hip arthroplasties
Authors: Ramamurti Balaji S. , Estok Daniel M. , Jasty Murali , Harris William H. 
Published: February 2005

AbstractWe developed an analytical technique to determine the paths traced by specific points on the femoral head against the acetabulum in the human hip joint during gait. The purpose of the study was to apply this technique to the mechanical hip simulators chosen to conduct wear tests on polymeric acetabular liners used in total hip replacements. These simulators differ from one another in the type of motion produced, apart from other variables such as type of lubricant and head position. Due to the variation in the kinematics between the machines, the paths traced by the points on the femoral head against the acetabular liner ranged from simple linear traces to figure‐8 loops and quasi‐elliptical paths during a single simulator cycle. The distances traveled by these points during the same period also varied appreciably among the different hip simulator designs. These results are important when combined with other studies that have shown that kinematics can play an important role in the outcome of in vitro wear experiments. The kinematic differences quantified in this study can partially explain the substantial differences in wear data reported from different simulator designs and also underscore the usefulness of the technique described in this study in judging the results from different hip simulator experiments.
Fiber‐based anterior cruciate ligament model for biomechanical simulations
Authors: Martelli S. , Joukhadar A. , Zaffagnini S. , Marcacci M. , Lavallee S. , Champleboux G. 
Published: February 2005

AbstractAlthough accurate predictions of the behavior and function of the anterior cruciate ligament would aid in diagnosis and operative treatment, no agreement exists on the best way to model the ligament with a reliable description of its mechanical and geometric features. We propose a new model of the anterior cruciate ligament based on multiple viscoelastic curvilinear fibers. This model was used for quasi‐static simulations of the passive motion of eight porcine knees, after registration of the passive trajectories and digitization of the surface of the ligament in flexion. Simulations of anterior cruciate ligament deformations during passive motion predicted a fiber strain of less than 20%, low insertion forces, and isometric anterior fibers. The model explains actions of the ligament fibers, as reported in the literature, better than classic models based on linear fibers and consistent with the mechanical properties of the anterior cruciate ligament.
Can an isometer predict the tensile behavior of a double‐looped hamstring graft during anterior cruciate ligament reconstruction?
Authors: Wallace Michael P. , Hull M. L. , Howell Stephen M. 
Published: February 2005

AbstractAn isometer, a highly compliant spring‐scale device for measuring suture displacement, has been used intraoperatively by surgeons to select the optimal placement of the femoral tunnel for an anterior cruciate ligament graft. The isometer measures the displacement of a suture centered in a tibial tunnel and attached to an intraarticular location on the femur before the femoral tunnel is drilled. Because the placement of the femoral tunnel strongly impacts the tensile behavior of an anterior cruciate ligament graft and because surgeons have used the amount of suture displacement to guide the placement of the femoral tunnel, the objective of this study was to determine the ability of an isometer to predict graft tension. In 14 patient undergoing reconstructive surgery of the anterior cruciate ligament, an isometer was used to measure suture displacement during passive knee motion for a provisional femoral tunnel location. An electrogoniometer recorded the flexion angle of the knee. The femoral tunnel was drilled. A double‐looped semitendinosus and gracilis autograft was inserted around a post in the femoral tunnel, and the tension in the four limbs of the graft exiting the tibial tunnel was measured during passive knee motion. Graft‐tension versus knee‐flexion‐angle curves revealed that each knee exhibited one of two distinct curve shapes: L‐shaped, characterized by the maximum tension occurring at full extension and a nearly flat profile from 35 to 90° of flexion, or U‐shaped, with elevated tensions at 80–90° of flexion (p < 0.001) reaching at least half of the tension in full extension. Because the shapes of the suture‐displacement versus flexion‐angle curves were more consistently L‐shaped, the intraoperative measurement of suture displacement was not a useful predictor of either the increase in tension in the graft with flexion or the maximum tension in the graft.
Experimental testing of a DEXA‐derived curved beam model of the proximal femur
Authors: Beck Thomas J. , Mourtada Firas A. , Ruff Christopher B. , Scott William W. , Kao George 
Published: February 2005

AbstractThis study was designed to test whether, using curved beam theory, a structural model of the proximal femur derived from two‐dimensional dual energy x‐ray absorptiometry could be used to predict femoral strength in an experimental simulation of a fall on the greater trochanter. A set of 22 fresh cadaveric femoral specimens were scanned with use of two‐dimensional dual energy x‐ray absorptiometry and then were tested to failure in a materials testing system, under three‐point loading, with the ground impact vector, aligned within the plane and along the bisector of the femoral neck‐shaft angle. Failure locations generally corresponded to stress peak locations predicted by the curved beam model. Predicted failure loads correlated well with measured failure loads for femoral neck fractures (r = 0.89; percent SE of estimate = 23%) and somewhat less well for intertrochanteric fractures (r = 0.83; percent SE of estimate = 29%). Overall predictions for failure load calculated from the maximum stress peak value over both locations corresponded to measured failure loads with an r value of 0.91 (percent SE of estimate = 21%). This kind of structural approach to the analysis of data for hip bone mass has the potential to provide mechanistic interpretations of the statistical associations frequently shown between conventional bone mineral measures and either hip fracture risk in vivo or bone strength in vitro.
Use of mesenchymal stem cells in a collagen matrix for achilles tendon repair
Authors: Young Randell G. , Butler David L. , Weber Wade , Caplan Arnold I. , Gordon Stephen L. , Fink David J. 
Published: February 2005

AbstractThis investigation tested the hypothesis that delivering mesenchymal stem cell‐seeded implants to a tendon gap model results in significantly improved repair biomechanics. Cultured, autologous, marrowderived mesenchymal stem cells were suspended in a collagen gel delivery vehicle; the cell‐gel composite was subsequently contracted onto a pretensioned suture. The resulting tissue prosthesis was then implanted into a 1‐cm‐long gap defect in the rabbit Achilles tendon. Identical procedures were performed on the contralateral tendon, but only the suture material was implanted. The tendon‐implant constructs were evaluated 4, 8, and 12 weeks later by biomechanical and histological criteria. Significantly greater load‐related structural and material properties were seen at all time intervals in the mesenchymal stem cell‐treated tendons than in the contralateral, treated control repairs (p < 0.05), which contained suture alone with natural cell recruitment. The values were typically twice those for the control tissues at each time interval. Load‐related material properties for the treated tissues also increased significantly over time (p < 0.05). The treated tissues had a significantly larger cross‐sectional area (p < 0.05), and their collagen fibers appeared to be better aligned than those in the matched controls. The results indicate that delivering mesenchymal stem cell‐contracted, organized collagen implants to large tendon defects can significantly improve the biomechanics, structure, and probably the function of the tendon after injury.
Method to assess in vivo knee stability longitudinally in an animal model of ligament injury
Authors: Maitland Murray E. , Leonard Tim , Frank Cyril B. , Shrive Nigel G. , Herzog Walter 
Published: February 2005

AbstractThe purpose of this study was to develop a method to prospectively quantify passive knee stability in an animal model of joint injury over time. Knee stability is defined here as the amount of translation or rotation of the tibia relative to the femur for a given application of force or moment, respectively. Five animals that had undergone transection of the anterior cruciate ligament and three control animals that had undergone a sham operation were anaesthetized and positioned in a stereotaxic frame. Motion of the tibia relative to the femur was quantified with use of reflective markers secured to modified bone pins and a three‐dimensional motion analysis system. External forces and moments in the transverse plane of the tibia were measured with use of force transducers based on a strain‐gauge design. Longitudinal measurements of knee stability were made before either sham surgery (control animals) or transection of the ligament (experimental animals), immediately after surgery, and at 2 and 4 months after transection. The results showed that the animals tolerated the procedures well and that systematic measurements could be obtained. The method described here has the practical advantage over cross‐sectional experimental designs in that the number of subjects can be decreased while maintaining statistical power and has the further conceptual advantage that individual changes can be accounted for over time.