bluuebunny/crossref_metadata_2025_split huggingface dataset:
Angular deformities and forearm function
Authors: Sarmiento Augusto , Ebramzadeh Edward , Brys David , Tarr Richard 
Published: February 2005

AbstractAngular deformities were created in cadaver forearms at proximal, middle, and distal third levels of the radius and ulna separately, and at middle and distal third levels of both bones, to determine the corresponding limitations of pronation and supination. The ranges of pronation and supination were recorded using a rotational motion measurement apparatus instrumented with a 360° goniometer. These experimental results were compared to data obtained from clinical and radiographic examination of 105 patients with similar residual deformities following treatment of fractures by nonsurgical means, to evaluate the accuracy of the experimental model and to determine if loss of rotational motion could be predicted based on radiographic findings. With cadaver forearms, on the average, angulation of 10° of the radius or ulna in coronal or sagittal planes limited pronation and supination by <24°, whereas angulation of 10° of both the radius and the ulna limited pronation and supination by <18%. Comparison of experimental results with clinical findings showed that, despite the errors involved in measuring forearm deformities in patients using biplanar radiographs, the experimental results predicted the clinical loss of pronation and supination to within 17% for the fractures of the radius, and within 8% accuracy for the fractures of the ulna.
The effect of hypothermic ischemia on the α‐adrenergic mechanisms of the canine tibia vascular bed
Authors: Davis T. R. C. , Wood M. B. , Vanhoutte P. M. 
Published: February 2005

AbstractThe effect of hypothermic ischemia on α‐1 and ‐2 adrenergic receptor mediated vasoconstriction has been studied in an in vitro perfused canine tibia preparation. Bones were perfused at a constant rate with aerated (95% O2, 5% CO2) modified Krebs Ringer solution and the effect of bolus injections of norepinephrine (0.025–6.4 nmol) on the perfusion pressure was studied. For all bones the first dose‐response curve was produced under control conditions. In one group the second dose‐response curve was generated during a constant infusion of prazosin (α‐1 adrenergic antagonist); in another it was produced during a constant infusion of rauwolscine (α‐2 adrenergic antagonist); in the control group it was generated under control conditions. The results demonstrate that, after 48 h of hypothermic ischemia, α‐1 adrenergic‐mediated vasoconstriction was significantly attenuated (p < 0.001). However, α‐2 adrenergic‐mediated vasoconstriction was unaffected by increasing periods of hypothermic ischemia.
Pattern analysis of electromyographic linear envelopes exhibited by subjects with uninjured and injured knees during free and fast speed walking
Authors: Shiavi Richard , Zhang Li‐Qun , Limbird Thomas , Edmondstone Mary Ann 
Published: February 2005

AbstractWe wished to determine whether anterior cruciate ligament (ACL) injury caused changes in patterns of activity of individual or groups of muscles that control the knee joint. The electromyographic (EMG) patterns of six muscles in 26 individuals with uninjured knees and 20 individuals with ruptured ACL were studied during free and fast speed walking. A previously developed clustering technique was used for analysis. This technique involves making the Fourier transform of the average linear envelope (LE) of each muscle for each subject and using the amplitude and phases angles of the lower frequency harmonics as features to describe a pattern. These features are then grouped to subdivide the population of EMG patterns into different types. The results of analyses on single muscles showed that there exists a typical or “normal” pattern for each muscle which most uninjured and some injured subjects exhibit as well as several atypical patterns which mostly injured subjects exhibit, and that the atypical patterns are much more evident a fast walking speed. The characteristic of atypical patterns with respect to normal include time shifts in the peak of major phases of activity, the absence of a second phase of activity, and the existence of additional phases of activity. Synergy analysis showed that if one muscle has an atypical pattern, then several do; i.e., ACL injury induces major changes in the control strategy of the knee. The implications are that for rehabilitation programs one must focus on the training and strengthening of more than one muscle, and that for reconstructive procedures the changes in mechanics of the joint can possibly induce a significant change in its control strategy.
Influence of continuous infusion of interleukin‐1α on the core protein and the core protein fragments of the small proteoglycan decorin in cartilage
Authors: Witsch‐Prehm P. , Karbowski A. , Ober B. , Kresse H. 
Published: February 2005

AbstractDecorin, a collagen‐binding small proteoglycan, is considered to have a specific function in the organization or stability of the collagen network. Therefore, alteration of its molecular properties may be of pathophysiological relevance during the development of cartilage damage. It is shown here that normal cartilage from rabbit knee‐joint contains glycosaminoglycan chain‐bearing core protein fragments of 39, 23, and 18 kDa, each one amounting to ∼5–6% of the intact decorin core protein. Continuous infusion of human recombinant interleukin‐1α for 14 days (200 ng/day) into a knee‐joint led in condylar cartilage to a reduction in the amount of intact core protein from 2 μg/mg wet tissue to about 1.1 μg/mg. The increase in its quantity found after infusion of heat‐inactivated interleukin‐1 was not statistically significant. The concentration of all three core protein fragments became reduced to a similar extent as the intact core protein under the influence of the cytokine, and additional fragments were not found. Surprisingly, there was a much smaller response to interleukin‐1‐treatment in patellar cartilage.
Cortical bone microperfusion: Response to ischemia and changes in major arterial blood flow
Authors: Swiontkowski Marc F. , Senft David 
Published: February 2005

AbstractIn order to investigate the effects of short‐term ischemia on cortical bone microperfusion, an isolated porcine tibia diaphyseal preparation based on intact nutrient vessels was developed. Laser Doppler flowmetry (LDF) was utilized to assess continuously the cortical microcirculation and the response to short‐term ischemia. The femoral artery was isolated and clamped to develop the condition of bone ischemia. On release of the clamp, reactive hyperemia was documented in all animals. Using a roller pump connected to a segment of femoral artery, the same preparation was utilized to investigate the effect of a changing femoral artery flow on the cortical microcirculation. A positive correlation between LDF output and change in arterial inflow (r = 0.64) was defined. This model has the potential for studying the effect of ischemia on bone cell viability.
Endothelial control of long bone vascular resistance
Authors: Davis T. R. C. , Wood M. B. 
Published: February 2005

AbstractThis in viro study investigates whether intraosseous endothelial cells can regulate long bone blood flow by secretion of vasodilator prostaglandin and EDRF (endothelium‐derived relaxing factor). Canine tibia were perfused through the nutrient artery at a constant flow rate, and the increases in perfusion pressure caused by standard doses of norepinephirine were recorded first under control conditions and then during acetylcholine infusion. Acetyl‐ choline attenuated the norepinephrine pressure responses (−62±3%). This attenuatintg effect of acetylcholine was partially abolished by inhibition of pros‐taglandin synthesis (−20±6%) and completely abolished by inhibition of EDRF synthesis (+73±43%) or combined inhibition of prostaglandin and EDRF synthesis (+134±30%). These results are statistically significant (p < 0.0001) and suggest that both EDRF and vasodilator prostaglandin are synthesized by intraosseous endothelial cells, and can modify long bone vascular resistance. Thus, as in other organs, intraosseous endothelial cells may provide bone with an autoregulatory control mechanism and enable it to respond to a diverse group of vasodilator stimuli.
Intramuscular wire electromyography of the subscapularis
Authors: Kadaba M. P. , Cole A. , Wootten M. E. , McCann P. , Reid M. , Mulford G. , April E. , Bigliani L. 
Published: February 2005

AbstractThe action of the subscapularis muscle is an important component in maintaining shoulder stability. Because of its relative inaccessibility, there have been few electromyographic (EMG) studies of its normal patterns of activity. The subscapularis is innervated by two or more distinct nerves, and therefore the upper and lower parts of the muscle may have different functional roles depending on the position of the humerus. The purpose of this study was to develop safe, reproducible insertion paths to the upper and lower parts of the subscapularis. Six subjects with no previous history of shoulder injury were evaluated. The paths of insertion were designed based on previous anatomical studies as well as dissections. Two pairs of intramuscular wire electrodes were inserted: one directed toward the upper subscapularis and one toward the lower subscapularis. Electrode locations were confirmed using posteroanterior and lateral radiographs and through electrical stimulation. EMG data were recorded during isometric internal rotation exercises with the humerus in 0 or 90° abduction. Significant differences were observed in the EMG activity recorded from the two pairs of electrodes. The EMG activity of the upper subscapularis either remained the same or decreased in going from 0 to 90° abduction, while that of the lower subscapularis increased. The observed differential response confirmed that the electrodes were in different parts of the subscapularis. These preliminary results suggest that in future EMG studies, the subscapularis should be considered as at least two independent muscle units.
Efficacy of autograft and freeze‐dried allograft to enhance fixation of porous coated implants in the presence of interface gaps
Authors: Kienapfel H. , Sumner D. R. , Turner T. M. , Urban R. M. , Galante J. O. 
Published: February 2005

AbstractAutogenous cancellous bone and freeze‐dried allogeneic cancellous bone were tested in a total of 41 adult male mongrel dogs. In each humerus, an implant with a commercially pure titanium fiber metal porous coating was placed in an overreamed cavity so that a uniform 3‐mm gap was present between the implant and host cancellous bone. Graft material was placed in the gap of one humerus while the gap of the other humerus was left empty and served as a paired negative control. Histologically, both autograft and allograft appeared to aid repair of the defect, but quantitatively only autograft enhanced new bone formation within the defect. Treatment with autograft significantly increased the amount of bone ingrowth within the implants by nearly three‐fold at 4 weeks and eight‐fold at 8 weeks. The enhancing effect was recognizable as early as 2 weeks. The strength of fixation was increased by nearly seven‐fold at 4 weeks and two‐fold at 8 weeks in the autograft group, but this was only statistically significant at 4 weeks. Treatment with allograft did not enhance bone ingrowth at any time period, but had a small positive effect on strength of fixation at 4 weeks.
The effect of intramedullary polymethylmethacrylate on healing of intercalary cortical allografts in a canine model
Authors: Straw R. C. , Powers B. E. , Withrow S. J. , Cooper M. F. , Turner A. S. 
Published: February 2005

AbstractThe purpose of this study was to evaluate the effect of intramedullary polymethylmethacrylate (PMMA) bone cement on the healing of intercalry allografts. Thirteen adult beagles had bilateral intercalary femoral allografts implanted. The medullary canal of one randomly assigned allograft in each dog was filled with PMMA. Healing was followed clinically and femora were evaluated radiographically, biomechanically, histologically, and histomorphometrically 9 months after surgery. There was an increased percent of eroded surface at the endosteal area of the center region of grafts containing PMMA and there was an increased percent osteoblast surface in this area in grafts not containing PMMA. There was an increased percent eroded surface at the periosteal area in the center region in grafts not containing PMMA and there was an increased percent osteoblast surface at the periosteal area in the graft adjacent to the host junction in grafts containing PMMA. There was no significant difference between PMMA‐treated and untreated allografts in any other parameters measured. The results from this study suggest that, although the pattern of incorporation is altered, intramedullary PMMA does not appear to effect allograft healing adversely.
Characterization of the intrinsic properties of the anterior cruciate and medial collateral ligament cells: An in vitro cell culture study
Authors: Nagineni Chandrasekharam N. , Amiel David , Green Melvin H. , Berchuck Matthew , Akeson Wayne H. 
Published: February 2005

AbstractThe poor healing abilities of the anterior cruciate ligament (ACL) in contrast to those of the medial collateral ligament (MCL) are well known. Different intrinsic properties of the constituent cells of these ligaments have been proposed to be one of the factors in the differential repair mechanisms. To examine this hypothesis, we have established primary cell lines of ACL and MCL from the tissue explants of approximately similar dimensions and have studied their behavior in vitro. The outgrowth of cells from ACL explants was slower than from MCL explants, as shown by the size of the surrounding clusters of cells. Both ACL and MCL cultures exhibited typical fibroblastic morphology. No significant differences were observed in either attachment or growth of cells from the attached explants derived from various segments of ACL and MCL. Growth curves of ACL and MCL cultures at both passage numbers 2 and 6 showed a slower rate of proliferation of ACL cells than MCL cells (p < 0.005). DNA synthesis measured in terms of [3H]thymidine incorporation (CPM/103 cells) of both log phase (ACL = 607.5 ± 5.4 vs. MCL = 1356.4 ± 11.3) and confluent (ACL = 83.0 ± 3.6 vs. MCL = 189.8 ± 5.4) cultures, supports the conclusion that differential proliferation rates of these cells exist in culture. FITC‐phalloidin staining (for actin) of later passage cultures (P3‐P5) showed a spread‐out appearance of ACL cells and an elongated appearance of MCL cells. Relatively more stress fibers were seen within ACL cells. SDS‐PAGE and Western blot analysis of cellular proteins revealed higher actin (43 kDa) content in ACL cells than in MCL cells. In vitro wound closure assay was performed by creating a uniform wound of 0.6 mm width in the confluent layer of ACL and MCL cultures. By 48 h postwounding, cell‐free zones created in ACL cultures were occupied partially by single cells in a nonconfluent fashion. In contrast, the wounded zone in the MCL cultures was almost completely covered by the cells. Results presented in this report demonstrate a lower proliferation and migration potential of ACL cells in comparison with MCL cells. These differences in intrinsic properties of ACL and MCL cells that were observed in vitro might contribute to the differential healing potentials of these ligaments in vivo.
Correlating magnetic resonance imaging with the biochemical content of the normal human intervertebral disc
Authors: Weidenbaum M. , Foster R. J. , Best B. A. , Saed‐Nejad F. , Nickoloff E. , Newhouse J. , Ratcliffe A. , Mow V. C. 
Published: February 2005

AbstractMagnetic resonance imaging was used to determine the T2 relaxation times of prepared proteoglycan solutions and of normal human intervertebral disc tissue from the annulus fibrosus (AF) and nucleus pulposus (NP). The collagen, proteoglycan, and water contents of the disc tissue samples were determined by biochemical assays after they were scanned. Correlations among 1/T2, collagen, proteoglycan, and water contents of the tissue samples and among 1/T2, water, and proteoglycan contents of the proteoglycan solutions were calculated. A moderate negative correlation between 1/T2 and water content was noted for the tissue samples, and a very high negative correlation was found between 1/T2 and water content for the proteoglycan solutions. The very high positive correlation between 1/T2 and proteoglycan content of the proteoglycan solutions is probably due to this negative correlation between 1/T2 and water content. There was no significant correlation between 1/T2 and proteoglycan content of the tissues. The moderate positive correlation between 1/T2 and collagen content is probably due to the high negative correlation between collagen content and water content. No significant correlation was found between the collagen and proteoglycan contents of the tissues. Thus it appears that the data confirm previous reports in the literature that the collagen of the disc tissue functions to control its water content.
Fibrillar collagen‐biphasic calcium phosphate composite as a bone graft substitute for spinal fusion
Authors: Zerwekh Joseph E. , Kourosh Sohrab , Scheinberg Robert , Kitano Tatsuro , Edwards Martin L. , Shin Deahwan , Selby David K. 
Published: February 2005

AbstractThe osteoconductive capacity of fibrillar collagen‐biphasic calcium phosphate composition was compared to autogenous bone in a canine spinal fusion model. All animals underwent a standard intervertebral body fusion (L2–L4) with rigid internal fixation and received either autogenous bone alone or a mixture of the ceramic and autogenous bone (3:1) as the graft material. Animals were followed for 12 months and the quality of fusion in each animal assessed by biomechanical testing and histological analysis. The fused L2–L4 segment of each dog was embedded in bone cement and mounted in a specially designed mechanical tester for testing in flexion, extension, and side bending. Overall, the mean rigidity of the fusion mass was not significantly different between the two groups [10.5 ± 4.1 (SD) for autogenous bone vs. 11.3 ± 1.7 for the ceramic plus autogenous bone, p > 0.05]. Similar findings were obtained for mean bending moment, compressive load, angular deformation, and energy absorbed for the two groups. Histological analysis was performed on transverse nondecalcified specimens. Quantitation of bone ingrowth using back‐scattered electron imaging disclosed no significant differences in the amount of new bone formed at the graft site between autogenous bone and the ceramic plus autogenous bone recipients (23.4 ± 10% vs. 25.8 ± 8.8%) when correction for the autogenous bone volumes was performed. Light microscopic analysis of toluidine blue‐stained transverse sections demonstrated new bone growth around and through the ceramic bone graft material. These results suggest that use of a collagen‐biphasic calcium phosphate ceramic and autogenous bone mixture (3:1) provides a suitable osteoconductive alternative to the use of autogenous bone and results in the formation of a mechanically competent fusion mass not significantly different from that obtained with autogenous bone alone.
Three‐Dimensional mechanical properties of the thoracolumbar junction
Authors: Oxland Thomas R. , Lin Ruey‐Mo , Panjabi Manohar M. 
Published: February 2005

AbstractThe thoracolumbar junction region is a frequent site of spinal trauma. Accurate knowledge of the normal mechanical behavior of the intervertebral joints in this region is of importance to the clinician in treating the spinal injuries. The present study documented the complete three‐dimensional motions of levels T11–T12 and T12‐L1 in the thoracolumbar region. Pure moments of flexion/extension, bilateral axial torque, and bilateral lateral bending were applied to 11 three‐vertebrae human cadaveric specimens (T11‐L1) to a maximum of 7.5 Nm. Intervertebral motions were calculated using stereophotogrammetry and presented in the form of load‐displacement curves, each containing three rotations and three translations at one intervertebral level. Average ± SD flexion, extension, axial rotation, and lateral bending ranges of motion to one side were 2.7 ± 1.3°, 2.4 ± 1.3°, 1.8 ± 0.7°, and 3.5 ± 1.1°, respectively, at level T11–T12. The same ranges of motion at T12‐L1 were 2.9 ± 1.4°, 3.9 ± 1.4°, 1.2 ± 0.7°, and 3.7 ± 1.1°, respectively. The extension and axial rotation ranges of motion at level T11–T12 were found to be significantly different than the same motions at T12‐L1. The different geometry in the facet joints explains these observed differences in the mechanical behavior of T11–T12 and T12‐L1.
Immunohistochemical localization of β1‐integrins in anterior cruciate and medial collateral ligaments of human and rabbit
Authors: Gesink Dirk S. , Pacheco Hector O. , Kuiper Scott D. , Schreck Paul J. , Amiel David , Akeson Wayne H. , Woods Jr. Virgil L. 
Published: February 2005

AbstractThe integrins are a family of adhesion‐mediating cell surface receptors that play critical roles in cell‐extracellular matrix interactions and have been shown to be important in the healing response in several tissues. We have studied integrin expression in normal human and rabbit anterior cruciate (ACL) and medial collateral (MCL) ligaments of the knee as a preamble to studies of β1‐integrin expression in healing ligaments. Histologic sections of human and rabbit ACL and MCL were probed for integrin expression utilizing integrin‐specific monoclonal antibodies (mAbs) followed by immunoperoxidase detection. Staining of human specimens with mAbs revealed the presence of β1‐, α1‐, and α5‐integrin chains on the tissue fibroblasts of both ACL and MCL, while staining of rabbit specimens with rabbit integrin‐reactive monoclonals revealed the presence of β1‐ and α5‐integrin on these ligaments. Equivalent amounts of the integrins studied were present on normal ACL and MCL. We conclude that the rabbit is an appropriate model for analyzing the expression and functional role of integrins in ligament wound healing.
[99mTc]Diphosphonate uptake and hemodynamics in experimental arthritis: Effect of naproxen in the canine carrageenan injection model
Authors: Hansen Ebbe Stender , He Shu‐Zheng , Søballe Kjeld , Kjølseth Dorthe , Henriksen Tine Brink , Hjortdal Vibeke Elisabeth , Bünger Cody 
Published: February 2005

AbstractThe impact of naproxen treatment on juxta‐articular hemodynamics and bone metabolism in experimental juvenile arthritis was studied in the articular carrageenan injection model. Unilateral gonarthritis was induced for 12 weeks in eight dogs receiving naproxen (dosage, 2 mg/kg) and eight controls. Regional blood flow was assessed by the microsphere method, plasma volume by the distribution space of [125I]fibrinogen, and bone metabolism by the 2‐h uptake of [99mTc]diphosphonate ([99mTc]DPD). Synovial effusion was less prominent with naproxen treatment as judged by joint fluid volume and pressure. Naproxen reduced the arthritic capsular hyperemia, almost normalized a severe blood flow increase in patella and both juxta‐articular epiphyses, ameliorated an expansion of plasma volume in the patella and the distal femoral epiphysis, and normalized an increased [99mTc]DPD uptake in subchondral femoral bone and the tibial cortex. Significantly increased arteriovenous shunting in the arthritic extremity was unaffected by naproxen. The study suggests that long‐term cyclooxygenase inhibition offers protection against hemodynamic and metabolic changes in juxta‐articular bone secondary to synovial inflammation.