bluuebunny/crossref_metadata_2025_split huggingface dataset:
Androgen receptors in Dupuytren's contracture
Authors: Pagnotta A. , Specchia N. , Greco F. 
Published: October 2002

AbstractPalmar fascia tissue and cultured cells from patients with Dupuytren's contracture and from normal subjects were characterized and analyzed for androgen receptor expression. Androgen receptors have never been studied in Dupuytren's myofibroblasts and may have a role in its high male predominance. Surgical samples were collected from eight patients undergoing surgery for Dupuytren's contracture and from four patients with carpal tunnel syndrome, used as control tissue. Immunohistochemical analysis was performed on tissue samples and on cell cultures with anti‐androgen receptor, anti‐α‐smooth muscle actin, anti‐fibronectin, and anti‐type I and III collagen antibodies using the biotin–avidin peroxidase method as revelatory system. Immunostaining for androgen receptors in tissue samples and cultured cells revealed nuclear reaction in many Dupuytren's myofibroblasts, but in few fibroblasts of the normal palmar fascia. In a double‐labeling study, androgen receptors were seen to co‐localize with α‐actin in both cell cultures and tissue samples.We present the first evidence that the palmar fascia is a target tissue for androgen action and that the expression of androgen receptors in Dupuytren's contracture is considerably higher than in the normal palmar fascia. Further studies will need to evaluate whether the androgen‐responsive state of the tissue is related to the high incidence of Dupuytren's contracture in the male sex. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
The involvement of β1 integrin in the modulation by collagen of chondrocyte‐response to transforming growth factor‐β1
Authors: Lee Jin Woo , Qi Wen Ning , Scully Sean P. 
Published: October 2002

AbstractThe physiologic response of chondrocytes to maintenance of the matrix and response to injury likely involves signaling from multiple sources including soluble cytokines, mechanical stimulation, and signaling from the extracellular matrix. The signaling from the extracellular matrix may serve to effect cell differentiation and to modulate the response to cytokines. We have previously reported that type II collagen modulates the response of bovine articular chondrocytes to TGF‐β1. The molecular nature of the signaling mechanism has not been elucidated but presumably involves a similar mechanism by which the cell attaches to the surrounding matrix.An alginate bead culture system is utilized to which exogenous type II collagen is added. The inclusion of type II collagen results in an alteration of integrin expression with a down regulation of α2. The response of the chondrocyte to TGF‐β1 can be modulated by the inclusion of exogenous type II collagen. The modulation of DNA and proteoglycan synthesis was blocked by the treatment of anti‐β1 integrin antibody (4B4) or by cyclic RGD containing peptides. These events occur at concentrations that block cell adhesion to type II collagen. Linear RGD containing peptides and anti‐anchorin antibodies had no effect on the modulation by type II collagen.These results suggest that type II collagen binding by chondrocytes at least in part occurs through the β1 integrin. This binding results in modulation of the cell response to TGF‐β1. This modulation may serve to provide physiologic specificity to the cytokine‐signaling cascade. An understanding of the regulatory milieu of the chondrocyte may permit the stimulation of an intrinsic repair of articular cartilage in the future. A near term application of this understanding can be made to tissue engineering attempts at articular cartilage repair. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Changes in human knee ligament stiffness secondary to osteoarthritis
Authors: Fishkin Zair , Miller David , Ritter Christopher , Ziv Israel 
Published: October 2002

AbstractStiffness of the medial (MCL) and lateral (LCL) collateral ligaments was compared between a group of 10 patients undergoing total knee arthroplasty for varus degenerative osteoarthritis (OAP), a group of 10 osteoarthritic cadaveric knees (OAC), and a group of 10 non‐osteoarthritic cadaveric knees (NOA). A load‐elongation curve was obtained for the medial and lateral compartments of each knee using an instrumented Moreland spreader. A strain gage (SG) was attached to the spreader handle and strain was calibrated to load applied against the spread distance. In extension, medial compartment stiffness of the OAP, OAC, and NOA groups was 60.7 ± 16, 52.8 ± 9.3 and 21.4 ± 5.0 N/mm, respectively. Lateral compartment stiffness in extension was 29.2 ± 9.2, 33.3 ± 10.3 and 19.5 ± 5.3 N/mm, for OAP, OAC, and NOA, respectively. Differences in stiffness between the OAP and OAC groups were not statistically significant (p > 0.05). However, the osteoarthritic groups (OAP and OAC) demonstrated a statistically significantly (p < 0.05) increase in ligament stiffness when compared to the NOA group. Following knee arthroplasty, stiffer medial structures in extension may lead to flexion contracture and accelerated polyethylene wear. Adequate bone resection, in conjunction with soft tissue release may alleviate the threefold increase in stiffness observed in the medial compartment secondary to OA without jeopardizing joint stability. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Outcomes of surgical management of total HIP replacement in patients aged 65 years and older: cemented versus cementless femoral components and lateral or anterolateral versus posterior anatomical approach
Authors: Zimmerman Sheryl , Hawkes William G. , Hudson James I. , Magaziner Jay , Hebel J. Richard , Towheed Tanveer , Gardner James , Provenzano George , Kenzora John E. 
Published: October 2002

AbstractThis observational study compared the outcomes of 271 cases of hip osteoarthritis receiving primary total hip replacement (patients 65 years of age and older) from numerous surgeons in 12 Baltimore region hospitals from 1991–1993. The independent variables studied were: (a) totally non‐cemented prostheses (non‐cemented femoral component, non‐cemented acetabular component) versus hybrid prostheses (cemented femoral component, non‐cemented acetabular component), and (b) lateral or anterolateral surgical approach versus posterior surgical approach. Outcomes included complications during the initial hospitalization, hospital length of stay, hospital cost, readmission, and reported and/or observed physical, instrumental, neuromuscular and affective functioning and pain at 2, 6, and 12 months post surgery.Results indicated that, while the totally non‐cemented prosthesis was more costly, there were no statistically significant differences in clinical or functional outcomes between the non‐cemented and the hybrid prostheses up to 12 months post surgery. Also, while the posterior surgical approach was associated with a non‐statistically significant higher rate of dislocation, overall, there was improved function and reduced pain in the first 12 months post‐surgery associated with this approach. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Differential expression of neural cell adhesion molecule (NCAM) after tenotomy in rabbit skeletal muscle
Authors: Jamali Amir A. , Afshar Pouya , Abrams Reid A. , Lieber Richard L. 
Published: October 2002

AbstractTenotomy is a commonly encountered event in orthopaedic surgery. In 23 rabbit extensor digitorum longus (EDL) muscles, within 24 h after tenotomy, a marked drop in maximum force production occurred. This was not explainable based on architectural changes and histological examination using standard markers for muscle injury, i.e., haematoxylin and eosin morphology, developmental myosin heavy chain (MHC) immunolabeling, and quantitation of muscle fiber type percentage, area and distribution. The expression of neural cell adhesion molecule (NCAM), a glycoprotein expressed during muscle development was measured as a function of time in these muscles. NCAM expression was increased as early as one day after tenotomy with 2.2 ± 1.2% of the fibers showing positive expression. This expression level increased significantly to 15.4 ± 15.2% after 7 days and then subsided to 13.2 ± 10.6% 21 days after tenotomy. Two‐way analysis of variance demonstrated a significant effect of time and a significant time x tenotomy method interaction. These results suggest that tenotomy leads to possible changes in muscle‐nerve connections and/or excitation–contraction (EC) coupling. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
A retrospective analysis of two independent prospective cartilage repair studies: autogenous perichondrial grafting versus subchondral drilling 10 years post‐surgery
Authors: Bouwmeester Phianne S. J. M. , Kuijer Roel , Homminga George N. , Bulstra Sjoerd K. , Geesink Rudolph G. T. 
Published: October 2002

AbstractBackground: Experimental data indicate that perichondrial grafting to restore articular cartilage defects will result in repair with hyaline‐like cartilage. In contrast, debridement and drilling results in repair with fibro‐cartilage. In this retrospective study the longterm clinical results of both procedures were compared to evaluate the theoretical benefit of repair with hyaline‐like tissue.Methods: From two independent studies patients were selected with a cartilage defect in their knee. The selection was performed using strict inclusion criteria published elsewhere [Bouwmeester et al. Int. Orthop. 21 (1997) 313]. The patients were treated with either a perichondrium transplantation (PT group, n = 14) or with an ‘open’ debridement and drilling procedure (DD group, n = 11). The results of both procedures after 10–11 years were evaluated using the Hospital for Special Surgery Knee Score (HSSS), X‐ray examination, clinical examination and visual analogue scales (VAS) for pain during walking and at rest.Results: Both procedures resulted in a general improvement compared to the situation before the operation. After an average of 10 years in the PT group there were three failures, in the DD group none, success rates were 78% and 100%, respectively. When comparing the successful PT patients with the DD patients, there were no differences in HSSS and VAS data. Both groups showed an equal number of irregular operation surface sites on X‐ray (PT 9/11 versus DD 8/10).Conclusions: This study shows that clinically at 10 years follow‐up no difference was observed between debridement and drilling and perichondrium transplantation for treatment of an isolated cartilage defect. This raises questions about ongoing research to develop methods in order to improve the results of debridement and drilling as therapy for an isolated cartilage defect in a young patient (⩽ 40 years). © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Spinal degenerative disk disease (DDD) in female macaque monkeys: epidemiology and comparison with women
Authors: Kramer Patricia Ann , Newell‐Morris Laura L. , Simkin Peter A. 
Published: October 2002

AbstractSpinal degenerative disk disease (DDD) in a radiographic, cross‐sectional sample of 192 female macaque monkeys, approximately 5–30 years old, is described. The presence and extent of disk space narrowing (DSN) and anterior osteophytosis were assessed with reference to age, average lifetime body mass, and distribution within the thoracolumbar spine. Age was a strong correlate of disk narrowing and osteophytosis, with early signs appearing at equivalent ages in both species and increasing in prevalence thereafter. Macaques showed a far greater prevalence of DDD, especially in the oldest age group, than has been reported in the human data. Body mass was associated with disk narrowing in the macaque, but not with osteophytosis. The two species differed little in the pattern of distribution of DDD along the spine. Our results suggest that bipedality is not the singular, or even the most important, biomechanical factor in the development of human DDD. Rather, others shared postural regimes, e.g., sitting, may be responsible for the onset and progression of DDD in both species. The macaque model could substantially add to the under‐standing and, potentially, treatment of this oftentimes debilitating condition. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Human knee and ankle cartilage explants: Catabolic differences
Authors: Eger Wolfgang , Schumacher Barbara L. , Mollenhauer Jürgen , Kuettner Klaus E. , Cole Ada A. 
Published: October 2002

AbstractThe prevalence of osteoarthritis (OA) is lower in some joints, i.e., the ankle, than in the knee. We have compared the cartilages from these two joints of the same limb in adult donors (matched pairs). Our data to date suggest that there are metabolic, biochemical and biomechanical differences between the cartilages of the two joints. The current study has focused on extending the metabolic studies comparing the response of chondrocytes to Interleukin‐1β (IL‐1β) and osteogenic protein 1 (OP‐1) by analyzing changes in sulfate incorporation into glycosaminoglycans (GAGs) as a measure of proteoglycan (PG) synthesis. Human adult chondrocytes from normal knees (tibiofemoral) and ankles (talocrural) joints cultured as explants both responded to IL‐1β after 72 h by decreasing PG synthesis; however, the IC50 for the knee chondrocytes was 6.2 pg/ml, while that for the ankle was 35 pg/ml. When the explants were incubated for 72 h with IL‐1β and allowed to rebound without IL‐1β, synthesis of PG was significantly elevated by ankle chondrocytes within five days; knee chondrocytes were unable to significantly increase synthesis even after eight days. However, in both knee and ankle, application of OP‐1 enhanced PG synthesis in the rebound phase. In response to IL‐1, an upregulation of proteinase activity was detectable by an increase in the neoepitopes proteolytically‐generated by both aggrecanase and matrix metalloproteinases (MMPs), in the deep zone of the knee cartilage. Stromelysin and collagenase were upregulated as well. The data emerging from these studies confirm that the ankle is less responsive to catabolic stimulation and more responsive to anabolic stimulation following IL‐1 removal. These differences in metabolic activity between the cartilages of the two joints could in part help to explain their differences in susceptibility to OA. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
ACL transection influences mRNA levels for collagen type I and TNF‐α in MCL scar
Authors: Majima Tokifumi , Lo Ian K. Y. , Randle John A. , Marchuk Linda L. , Shrive Nigel G. , Frank Cyril B. , Hart David A. 
Published: October 2002

AbstractTo assess the mRNA expression of extracellular matrix genes which might correlate with or contribute to mechanically weaker medial collateral ligament (MCL) scars in the ACL‐deficient rabbit knee joint compared to those in anterior cruciate ligament (ACL) intact knee joints, a bilateral MCL injury was induced in 10 skeletally mature female NZW rabbits. As part of the same surgical procedure, the ACL was transected in one of the knees while the contralateral knee had a sham procedure. The side having the combined MCL and ACL injury was randomly assigned. After six weeks, the rabbits were euthanized. Histological assessments were performed on samples of the MCL scars from each operated knee (n = 3 animals) and mRNA levels for collagen type I, III, V, decorin, biglycan, lumican, fibromodulin, TGF‐β, IL‐1, TNF‐α, MMP‐1, MMP‐1, MMP‐13, and a housekeeping gene (GAPDH) were assessed using semiquantitative RT‐PCR on RNA isolated from the MCL scar tissue of the remaining animals (n = 7 animals). Levels of mRNA for each gene were normalized using the corresponding GAPDH value. Results showed that the total RNA yield (per mg wet weight) in the MCL scar of the ACL‐deficient knee was significantly greater than that in the MCL scar from the ACL‐intact knee. Collagen type I mRNA levels were significantly lower and mRNA levels for TNF‐α were significantly greater in the scars of ACL‐deficient knees compared to scars from ACL‐intact joints. There were no significant differences between ACL‐deficient and ACL‐intact knees with respect to MCL scar mRNA levels for the remaining genes assessed. Histologically, the “flaw” area, which has been shown to correlate with mechanical properties in previous studies, was significantly greater in MCL scars from ACL‐deficient knees than in the ACL‐intact MCL scars. The mean number of cells/mm2 in MCL scars from ACL‐deficient knees was significantly greater than in MCL scars from ACL‐intact knees. The present study suggests that MCL scar cell metabolism is differentially influenced by the combined injury environment. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Measurement of anterior–posterior knee laxity: a comparison of three techniques
Authors: Fleming Braden C. , Brattbakk Bjarne , Peura Glenn D. , Badger Gary J. , Beynnon Bruce D. 
Published: October 2002

AbstractSeveral non‐invasive techniques have been developed to assess anterior–posterior (A–P) laxity of the knee, however, their accuracy remains unclear. Roentgen Stereophotogrammetry Analysis (RSA) is a three‐dimensional motion analysis method that has been shown to be an accurate tool for evaluating joint kinematics. Thus, RSA provides a means that can be used to evaluate other less invasive techniques. The objectives of this study were to compare A–P laxity values as measured using the KT‐1000 Knee Arthrometer, planar stress radiography and RSA, and to determine if they detect similar changes in A–P laxity over time in 15 subjects following anterior cruciate ligament reconstruction with patellar tendon autografts. The A–P laxity values of the injured knee were measured immediately following surgery and at their 3‐, 6‐, and 12‐month follow‐up visits. A–P laxity was defined as the A–P translation of the tibia relative to the femur that occurred between the posterior and anterior shear load limits of −90 to +130 N, respectively. The values of A–P laxity across all time points were 11.4 ± 3.0, 10.2 ± 3.3, and 6.9 ± 3.0 mm (mean ± standard deviation) for the KT‐1000, planar stress radiography and the RSA methods, respectively. These values were significantly different from each other (p < 0.001). The two‐dimensional analyses techniques (planar stress radiography and the KT‐1000) consistently over‐estimated the true laxity values that were obtained using the three‐dimensional RSA technique. Significant increases in A–P laxity values over time were also detected with the KT‐1000 (p = 0.04) and the RSA technique (p = 0.04). However, this increase was not evident when using planar stress radiography (p = 0.89). This study determined that the KT‐1000 and RSA document temporal changes in A–P laxity following ACL reconstruction that were not documented by planar stress radiography. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Preliminary report on the biocompatibility of a moldable, resorbable, composite bone graft consisting of calcium phosphate cement and poly(lactide‐co‐glycolide) microspheres
Authors: Simon Carl G. , Khatri Chetan A. , Wight Scott A. , Wang Francis W. 
Published: October 2002

AbstractWe have assessed the biocompatibility of a new composite bone graft consisting of calcium phosphate cement (CPC) and poly(lactide‐co‐glycolide) (PLGA) microspheres (approximate diameter of 0.18–0.36 mm) using cell culture techniques. CPC powder is mixed with PLGA microspheres and water to yield a workable paste that could be sculpted to fit the contours of a wound. The cement then hardens into a matrix of hydroxyapatite microcrystals containing PLGA microspheres. The rationale for this design is that the microspheres will initially stabilize the graft but can then degrade to leave behind macropores for colonization by osteoblasts. The CPC matrix could then be resorbed and replaced with new bone. In the present study, osteoblast‐like cells (MC3T3‐E1 cells) were seeded onto graft specimens and evaluated with fluorescence microscopy, environmental scanning electron microscopy and the Wst‐1 assay (an enzymatic assay for mitochondrial dehydrogenase activity). Cells were able to adhere, attain a normal morphology, proliferate and remain viable when cultured on the new composite graft (CPC–PLGA) or on a control graft (CPC alone). These results suggest that our new cement consisting of CPC and PLGA microspheres is biocompatible. This is the first time that a ‘polymer‐in‐mineral’ (PLGA microspheres dispersed in a CPC matrix) cement has been formulated that is moldable, resorbable and that can form macropores after the cement has set. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Immunohistological analysis of transglutaminase factor XIIIA expression in mouse embryonic growth plate
Authors: Nurminskaya M. V. , Linsenmayer T. F. 
Published: October 2002

AbstractPreviously we demonstrated the expression of Factor XIIIA (FXIIIA), a coagulation transglutaminase, in avian embryonic growth plate. To explore whether FXIIIA is also expressed by chondrocytes of the mammalian cartilage anlagen of bones, we analyzed the mouse embryonic growth plate by immunostaining using anti‐FXIIIA antibodies developed against human and chicken proteins. We revealed the expression of FXIIIA in the epiphyseal growth plate, where FXIIIA appears first intracellularly in the zone of proliferation/maturation, and remains intra‐ and extracellularly throughout the hypertrophic zone. Externalization of FXIIIA occurs before mineralization. Transglutaminase activity was assayed in organ cultures using rhodamine‐labeled synthetic substrate Pro–Val–Lys–Gly. Enzymatic activity shows a restricted distribution in cartilage and correlates with FXIIIA expression pattern, suggesting that cartilagenous transglutaminase activity is due, at least partially, to the FXIIIA isoform. We conclude, that coagulation factor FXIIIA is expressed by chondrocytes of embryonic mouse long bone cartilages in a strictly regulated pattern, which correlates with chondrocyte differentiation and matrix mineralization. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.