bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prevention of strain‐related osteopenia in aseptic loosening of hip prostheses using perioperative bisphosphonate
Authors: Goodship Allen E. , Blunn Gordon W. , Green Jonathan , Coathup Melanie J. 
Published: November 2007

AbstractThe hypothesis tested in this study was that perioperative administration of the bisphosphonate zoledronate will reduce strain protection‐related calcar osteopenia and maintain functional integration of the femoral component in an ovine hemiarthroplasty model. Twelve sheep received a unilateral cemented hemiarthroplasty where six animals were given nine intravenous infusions of zoledronate (10 µg/kg) pre‐, peri‐, and postsurgery over 8 months. Control animals received physiological saline only. Implants remained in vivo for 9 months. Ground reaction force (GRF) was used to assess functional loading of the implanted limb, bone mineral density (BMD) was quantified using dual energy X‐ray absorptiometry (DEXA). Cortical bone area, thickness, and viable osteocytes were assessed histologically. No significant differences in GRF data between groups was identified. Results demonstrated a significant drop in BMD values in the control group (9.7%) when compared with the bisphosphonate‐treated group (3.2%) (p = 0.0159). Histological results showed that cortical area, thickness, and the percentage of lacunae with viable osteocytes was significantly greater in the bisphosphonate‐treated group when compared with control (p = 0.002, p = 0.001, p = 0.003, respectively). The administration of zoledronate reduced cortical osteopenia in the calcar region of the proximal femur and this therapy could be used as a preventive measure to combat strain protection osteopenia and its contribution to associated aseptic loosening in total hip replacement surgery. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:693–703, 2008
Optimizing CO2 normalizes pH and enhances chondrocyte viability during cold storage
Authors: Dontchos Brian N. , Coyle Christian H. , Izzo Nicholas J. , Didiano Deanna M. , Karpie John C. , Logar Alison , Chu Constance R. 
Published: November 2007

AbstractFresh osteochondral allografts are an important treatment option for the repair of full‐thickness articular cartilage defects. Viable chondrocytes within the transplanted tissue are considered important to maintaining matrix integrity. The purpose of this study is to determine whether an increase in pH decreases chondrocyte viability during cold storage and whether equilibration of Dulbecco's modified Eagle's medium (DMEM) in 5% CO2 normalizes pH and increases chondrocyte survival during storage at 4°C. Freshly isolated bovine articular chondrocytes cultured in alginate beads were stored for up to 5 days at 4°C or 37°C in DMEM exposed to ambient air or in DMEM equilibrated with 5% CO2. Chondrocyte viability was determined by flow cytometry. Physiologic pH was maintained when DMEM was equilibrated with 5% CO2, while pH increased in ambient air. After 5 days of storage at 4°C, chondrocyte necrosis was higher when stored in ambient air than if equilibrated with 5% CO2. No decrease in chondrocyte viability was observed with storage at 37°C. In addition, chondrocyte viability in bovine cartilage osteochondral cores was examined after storage for 14 days at 4°C in DMEM with and without HEPES, and with and without 5% CO2. Under these conditions, the superficial layer of chondrocytes was more viable when stored in DMEM with HEPES or DMEM equilibrated with 5% CO2 than when stored in DMEM in ambient air. This data shows that an increase in pH decreased bovine chondrocyte viability when refrigerated at 4°C in DMEM, and that optimization of CO2 normalized pH and improved chondrocyte viability during cold storage in DMEM. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:643–650, 2008
Deep vertical collagen fibrils play a significant role in mechanics of articular cartilage
Authors: Shirazi R. , Shirazi‐Adl A. 
Published: November 2007

AbstractThe primary orientation of collagen fibrils alters along the cartilage depth; being horizontal in the superficial zone, random in the transitional zone, and vertical in the deep zone. Commonly used confined and unconfined (when with no underlying bone) testing configurations cannot capture the mechanical role of deep vertical fibril network. To determine this role in cartilage mechanics, an axisymmetric nonlinear fibril‐reinforced poroelastic model of tibial cartilage plateaus was developed accounting for depth‐dependent properties and distinct fibril networks with physical material properties. Both creep and relaxation indentation models were analyzed which results were found equivalent in the transient period but diverged in post‐transient periods. Vertical fibrils played a significant role at the transient period in dramatically increasing the stiffness of the tissue and in protecting the solid matrix against large distortions and strains at the subchondral junction. This role, however, disappeared both with time and at loading rates slower than those expected in physiological activities such as walking. The vertical fibrils demonstrated a chevron‐type deformation pattern that was further accentuated with time in creep loading. Damages to deep vertical collagen fibril network or their firm anchorage to the bone, associated with bone bruises, for example, would weaken the transient stiffness and place the tissue at higher risk of failure particularly at the deep zone. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:608–615, 2008
Microcomputed tomography imaging in a rat model of delayed union/non‐union fracture
Authors: Dickson G.R. , Geddis C. , Fazzalari N. , Marsh D. , Parkinson I. 
Published: November 2007

AbstractWe aimed to develop a clinically relevant delayed union/non‐union fracture model to evaluate a cell therapy intervention repair strategy. Histology, three‐dimensional (3D) microcomputed tomography (micro‐CT) imaging and mechanical testing were utilized to develop an analytical protocol for qualitative and quantitative assessment of fracture repair. An open femoral diaphyseal osteotomy, combined with periosteal diathermy and endosteal excision, was held in compression by a four pin unilateral external fixator. Three delayed union/non‐union fracture groups established at 6 weeks—(a) a control group, (b) a cell therapy group, and (c) a group receiving phosphate‐buffered saline (PBS) injection alone—were examined subsequently at 8 and 14 weeks. The histological response was combined fibrous and cartilaginous non‐unions in groups A and B with fibrous non‐unions in group C. Mineralized callus volume/total volume percentage showed no statistically significant differences between groups. Endosteal calcified tissue volume/endosteal tissue volume, at the center of the fracture site, displayed statistically significant differences between 8 and 14 weeks for cell and PBS intervention groups but not for the control group. The percentage load to failure was significantly lower in the control and cell treatment groups than in the PBS alone group. High‐resolution micro‐CT imaging provides a powerful tool to augment characterization of repair in delayed union/non‐union fractures together with outcomes such as histology and mechanical strength measurement. Accurate, nondestructive, 3D identification of mineralization progression in repairing fractures is enabled in the presence or absence of intervention strategies. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:729–736, 2008
Bony impingement affects range of motion after total hip arthroplasty: A subject‐specific approach
Authors: Kessler Oliver , Patil Shantanu , Stefan Wirth , Mayr Eckart , Colwell Clifford W. , D'Lima Darryl D. 
Published: November 2007

AbstractHip range of motion after total hip arthroplasty has been shown to be dependent on prosthetic design and component placement. We hypothesized that bony anatomy would significantly affect range of motion. Computer models of a current generation hip arthroplasty design were virtually implanted in a model of pelvis and femur in various orientations ranging from 35° to 55° cup abduction, 0° to 30° cup anteversion, and 0° to 30° femoral anteversion. Four head sizes ranging from 22.2 to 32 mm and two neck sizes ranging from 10‐mm and 12‐mm diameter were tested. Range of motion was recorded as maximum flexion–extension, abduction–adduction, and axial rotation of the femur before any contact between prosthetic components or bone was detected. Bony impingement preceded component impingement in about 44% of all conditions tested, ranging from 66% in adduction to 22% in extension. Range of motion increased as head size increased. However, increasing head size also increased the propensity for bony impingement, which tended to reduce the beneficial effect of increased head size on range of motion. Reducing neck diameter had a greater effect on prosthetic impingement (mean, 3.5° increase in range of motion) compared to bone impingement (mean, 1.9°). This model allowed for a clinically relevant assessment of range of motion after total hip arthroplasty and may also be used with patient‐specific geometry [such as that obtained from preoperative computed tomography (CT) scans] for more accurate preoperative planning. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:443–452, 2008
Dynamic and static mechanical compression affects akt phosphorylation in porcine patellofemoral joint cartilage
Authors: Niehoff Anja , Offermann Michael , Dargel Jens , Schmidt Annette , Brüggemann Gert‐Peter , Bloch Wilhelm 
Published: November 2007

AbstractProtein kinase B (Akt)–dependent signaling pathways induced by mechanical loading have been identified in a variety of tissue. However, there is no evidence for a potential regulation of Akt in cartilage mechanotransduction. This study was conducted in order to determine whether or not the Akt in chondrocytes is regulated by mechanical loading. Porcine patellofemoral joints were loaded in compression at 500 N for 150 s either dynamically at 12 Hz or 1 Hz or statically using a custom‐designed loading frame. Left‐sided knees served as intervention, right‐sided as unloaded control. Cartilage samples were harvested at different time points after mechanical loading and the phosphorylation of Akt was analyzed immunohistochemically. A downregulation of Akt phosphorylation was seen in cartilage 300 s after mechanical loading whereas Akt phosphorylation remained unchanged in unloaded specimens. In addition, regulation of Akt appeared to change with the frequency of loading, presenting different patterns in Akt phosphorylation with static and dynamic loading. Variations in Akt phosphorylation were detected through different zones of cartilage. Overall, our findings indicate that Akt signaling in porcine patellofemoral joint cartilage is dependent upon frequency of loading, cartilage zone, and the time interval between loading and cartilage harvest. It may be concluded that Akt plays a role in cartilage mechanotransduction. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:616–623, 2008
Altered osteoclast development and function in osteopontin deficient mice
Authors: Franzén Ahnders , Hultenby Kjell , Reinholt Finn P. , Önnerfjord Patrik , Heinegård Dick 
Published: November 2007

AbstractThe role of osteopontin in bone resorption was elucidated by studies of mice with knock out of the osteopontin gene generated by a different approach compared to previous models. Thus, a targeting vector with the promoter region as well as exons 1, 2, and 3 of the osteopontin gene was replaced by a loxP‐flanked Neo‐TK cassette, and this cassette was eliminated through transient expression of Cre recombinase. The recombined ES cells were used to create mice lacking expression of the osteopontin gene. Tissues from these mice were subjected structural and molecular analyses including morphometry and proteomics. The bone of the null mice contained no osteopontin but showed no significant alterations with regard to other bone proteins. The bone volume was normal in young null animals but in the lower metaphysis, the volume and number of osteoclasts were increased. Notably, the volume and length of the osteoclast ruffled border was several folds lower, indicating a lower resorptive capacity. The null mice did not develop the bone loss characteristic for osteoporosis demonstrated in old wild‐type female animals. This quantitative study demonstrates a bone phenotype in the osteopontin null mice of all ages. The data provides further evidence for a role of osteopontin in osteoclast activity. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:721–728, 2008
The quantitative and functional relation between insulin‐like growth factor‐I (IGF) and IGF‐binding proteins during human osteoarthritis
Authors: Morales Teresa I. 
Published: November 2007

AbstractA previous hypothesis stated that during osteoarthritis (OA) increased insulin‐like growth factor (IGF) binding proteins (IGFBPs) sequester IGFs and limit their access to the cell. The objective of this article was to test this by: (1) quantifying IGF and IGFBP‐3 as well as their ratios in human OA cartilages, and (2) measuring the metabolic responses of diseased cartilage to IGF‐I and its IGFBP‐insensitive analogs. Knee or hip OA cartilages were staged for OA by histology. Cartilage slices were either extracted for assays of IGF proteins, or maintained intact as organ cultures. Proteoglycan (PG) metabolism ± IGFs was measured by use of the 35S‐sulfate precursor. IGFBP‐3 (ng/mg protein) was weakly correlated with OA score by regression analysis (R2 = 0.122; p = 0.040; n = 35). IGF‐I (ng/mg protein) was constant across all OA groups (ANOVA; p = .428, n = 18) and the IGF‐I/IGFBP‐3 ratios were > 1 in most samples. All OA cartilages responded to hrIGF‐I by increasing PG synthesis [average 2.29‐fold ± 0.55 (±SD) at saturation, n = 12] irrespective of OA score. The des (1–3) IGF‐I analog (which lacks the three N‐terminal amino acids) had similar maximal effects (average 2.23‐fold stimulation ± 0.71, n = 10), but it was more effective in two out of three samples at suboptimal doses. The effect of hrIGF‐I, des (1–3) IGF‐I, or the B‐chain analog on degradation was minimal. In summary, catabolism was insensitive to IGF‐I, and this was probably not due to IGFBPs. By contrast, IGF‐I exerted a robust stimulation of anabolism at sufficiently high doses, even though IGFBPs could tone down the ligand effect at low doses. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:465–474, 2008
Does sentinel node biopsy improve the management of endometrial cancer? Data from 43 patients
Authors: Bats Anne‐Sophie , Clément Denys , Larousserie Florence , Le Frère‐Belda Marie‐Aude , Pierquet‐Ghazzar Nadia , Hignette Chantal , Lécuru Fabrice 
Published: November 2007

AbstractObjectivesTo map sentinel lymph nodes (SLNs) detected by intracervical injection in patients with endometrial cancer and to determine the prevalence of node micrometastases.MethodsRadionuclide and blue dye injections were used for SLN detection in 43 patients with clinical stage I endometrial cancer. Lymphoscintigraphy was done before surgery. Intraoperatively, the pelvic and para‐aortic territories were examined for blue and/or radioactive nodes. Pelvic lymphadenectomy was performed with or without para‐aortic lymphadenectomy. SLNs stained with hematoxylin‐eosin‐saffron were examined and, when negative, evaluated using step sectioning and immunohistochemistry.ResultsFeasibility was 100%. No adverse effects occurred. SLNs were identified in 30 patients (69.8%), usually in an interiliac location (28/30 patients, 93.3%). SLNs were found only in the common iliac chain in 1 (3%) patient and in both the common iliac chain and promontory area in another (3%). No patients had para‐aortic SLNs or SLNs confined to the promontory. Node metastases were identified in eight patients and were confined to SLNs in six. In 2 (2/30, 6%) patients, SLNs contained micrometastases. No false‐negatives occurred.ConclusionsIntracervical injection of radionuclide and blue dye chiefly revealed pelvic SLNs. The prevalence of micrometastases was within the expected range. Comparisons with peritumoral injection are needed. J. Surg. Oncol. 2008;97:141–145. © 2007 Wiley‐Liss, Inc.
No mortality after 150 consecutive pancreatoduodenctomies with duct‐to‐mucosa pancreaticogastrostomy
Authors: Murakami Yoshiaki , Uemura Kenichiro , Hayashidani Yasuo , Sudo Takeshi , Hashimoto Yasushi , Nakagawa Naoya , Ohge Hiroki , Sueda Taijiro 
Published: November 2007

AbstractBackground and ObjectivesThe mortality rate after pancreatoduodenectomy (PD) remains 0–5% at major surgical centers with the major cause of operative death being a leak at the pancreaticojejunal anastomosis. The aim of this retrospective study was to evaluate the safety of duct‐to‐mucosa pancreaticogastrostomy (PG) at a single institute.MethodsOne hundred fifty consecutive patients with pancreato‐biliary diseases undergoing duct‐to‐mucosa PG following PD between 1995 and 2005 were evaluated. One hundred forty patients underwent a pylorus‐preserving PD and 10 patients underwent a conventional PD (Whipple operation). External drainage of pancreatic juice was performed in 77 cases.ResultsThe mean operating time was 378 min and the mean blood loss was 1,640 ml. Blood transfusion was not required in 97 patients (65%). The morbidity rate was 50% (75/150), but the mortality rate was 0%. Pancreatic fistulae occurred in 11 patients (7%). Gender, age, operative procedure, portal vein resection, external drainage of the pancreatic juice, operative time, blood loss and blood transfusion did not affect the rate of pancreatic fistula. The rate of pancreatic fistulae tended to be lower in pancreatic carcinoma (3%) than non‐pancreatic carcinoma (11%).ConclusionsDuct‐to‐mucosa PG is a safe procedure for reconstruction following PD. J. Surg. Oncol. 2008;97:205–209. © 2007 Wiley‐Liss, Inc.
Papillary thyroid microcarcinoma: Prognostic factors and treatment
Authors: Besic Nikola , Pilko Gasper , Petric Rok , Hocevar Marko , Zgajnar Janez 
Published: November 2007

AbstractBackground and ObjectivesWithin the group of patients with papillary thyroid microcarcinoma (PTMC), the prognostic factors have not been well defined and the optimal treatment has not been proved. The aim of this study was to find out the factors associated with the tumor recurrence in the patients with PTMC.MethodsA total of 228 patients with PTMC (189 females, 39 males; age 14–85 years, median 46 years) were treated at our Institute between 1975 and 2006. The data on patients' gender, age, extent of disease, pathomorphological characteristics, therapy, locoregional control, disease‐free survival and disease‐specific survival were collected. Statistical correlation between possible prognostic factors and the duration of disease‐free interval was analyzed by univariate and Cox's multivariate survival analysis.ResultsThe tumor diameter ranged from 0.1 to 10 mm (mean 6.1 mm). The median length of observation was 84 months (range 1–385). During the follow‐up period, the recurrence was diagnosed in 7 patients (6 locoregional and 1 distant). Multivariate analysis showed that tumor size and lymph node metastases were independent prognostic factors for disease‐free interval.ConclusionsLonger disease‐free interval was found in the patients with a tumor diameter ≤6 mm and without lymph‐node metastases. J. Surg. Oncol. 2008;97:221–225. © 2007 Wiley‐Liss, Inc.
Experimental and quantum‐chemical studies of 1H, 13C and 15N NMR coordination shifts in Pd(II) and Pt(II) chloride complexes with quinoline, isoquinoline, and 2,2′‐biquinoline
Authors: Pazderski Leszek , Toušek Jaromír , Sitkowski Jerzy , Kozerski Lech , Szłyk Edward 
Published: November 2007

Abstract1H, 13C, and 15N NMR studies of platinide(II) (M = Pd, Pt) chloride complexes with quinolines (L = quinoline–quin, or isoquinoline–isoquin; LL = 2,2′‐biquinoline–bquin), having the general formulae trans‐/cis‐[ML2Cl2] and [M(LL)Cl2], were performed and the respective chemical shifts (δ1H, δ13C, δ15N) reported. 1H coordination shifts of various signs and magnitudes (Δ1Hcoord = δ1Hcomplex − δ1Hligand) are discussed in relation to the changes of diamagnetic contribution to the relevant 1H shielding constants. The comparison to the literature data for similar complexes containing auxiliary ligands other than chlorides exhibited a large dependence of δ1H parameters on electron density variations and ring‐current effects (inductive and anisotropic phenomena). The influence of deviations from planarity, concerning either MN2Cl2 chromophores or azine ring systems, revealed by the known X‐ray structures of [Pd(bquin)Cl2] and [Pt(bquin)Cl2], is discussed in respect to 1H NMR spectra. 15N coordination shifts (Δ15Ncoord = δ15Ncomplex − δ15Nligand) of ca. 78–100 ppm (to lower frequency) are attributed mainly to the decrease of the absolute value of paramagnetic contribution in the relevant 15N shielding constants, this phenomenon being noticeably dependent on the type of a platinide metal and coordination sphere geometry. The absolute magnitude of Δ15Ncoord parameter increased by ca 15 ppm upon Pd(II) → Pt(II) replacement but decreased by ca. 15 ppm following trans → cis transition. Experimental 1H, 13C, 15N NMR chemical shifts are compared to those quantum‐chemically calculated by B3LYP/LanL2DZ + 6–31G**//B3LYP/LanL2DZ + 6–31G*, both in vacuo and in CHCl3 or DMF solution. Copyright © 2007 John Wiley & Sons, Ltd.
SELOVS: Brain MRSI localization based on highly selective T1‐ and B1‐insensitive outer‐volume suppression at 3T
Authors: Henning Anke , Schär Michael , Schulte Rolf F. , Wilm Bertram , Pruessmann Klaas P. , Boesiger Peter 
Published: November 2007

AbstractIn vivo, high‐field MR spectroscopic imaging (MRSI) profits from signal‐to‐noise ratio (SNR) gain and increased spectral resolution. However, bandwidth limitations of slice‐selective excitation and refocusing pulses lead to strong chemical‐shift displacement at high field strength when using conventional MRSI localization based on PRESS. Consequential metabolic information, particularly of border regions such as cortical brain tissue, is distorted. In addition, lipid contamination remains a major confound. To address these problems it is proposed to abandon PRESS selection and rely on a novel scheme of highly selective T1‐ and B1‐insensitive outer‐volume suppression in combination with slice‐selective spin‐echo acquisition for brain MRSI. Multiple cycles of overlapping suppression slabs are applied with flip angles optimized to account for tissue‐dependent T1 relaxation times and band crossings. Broadband frequency modulated saturation pulses with polynomial phase‐response are utilized in order to minimize chemical‐shift displacement. Efficacy of the outer‐volume suppression sequence was simulated and evaluated in vitro and in vivo. Brain MRSI localization at 3T was significantly improved and reliable suppression of short‐range lipid contamination enabled, leading to substantial enhancement of spectral quality, particularly in cortical tissue. Hence, the new method holds potential to expand the applicability of high‐field MRSI to the entire brain. Magn Reson Med, 2007. © 2007 Wiley‐Liss, Inc.