bluuebunny/crossref_metadata_2025_split huggingface dataset:
Behavioral motor recovery in the 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine‐lesioned squirrel monkey (Saimiri sciureus): Changes in striatal dopamine and expression of tyrosine hydroxylase and dopamine transporter proteins
Authors: Petzinger Giselle M. , Fisher Beth , Hogg Elizabeth , Abernathy Avery , Arevalo Pablo , Nixon Kerry , Jakowec Michael W. 
Published: December 2005

AbstractThe neurotoxicant 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) provides an excellent opportunity to study repair and response to injury in the basal ganglia. Administration to mammals leads to the destruction of nigrostriatal dopaminergic neurons and depletion of striatal dopamine. In the squirrel monkey (Saimiri sciureus), MPTP‐lesioning results in parkinsonian motor symptoms including bradykinesia, postural instability, and rigidity. Over time animals display motor behavioral recovery. To better understand this mechanism we employed a lesioning regimen of two or six subcutaneous injections of MPTP (2.0 mg/kg, free‐base) to generate mild or moderate parkinsonism. Brain tissue was harvested at 6 weeks or 9 months after the last injection and analyzed for dopamine and its metabolites by high performance liquid chromatography (HPLC), and by immunohistochemical staining and Western immunoblotting for the expression of tyrosine hydroxylase (TH), dopamine transporter (DAT), and dopamine‐ and cAMP‐responsive protein phosphatase of 32 kDa (DARPP‐32), an effector molecule enriched in striatal medium spiny neurons. Several months after MPTP‐lesioning, when squirrel monkeys displayed full motor behavioral recovery, striatal dopamine levels remained low with a greater return in the ventral striatum. This finding is consistent with other reports using neurotoxicant‐lesioning models of the basal ganglia in rodents and other species of nonhuman primates. Elevated dopamine turnover ratio and decreased DAT expression appeared in early behavioral recovery at the 6‐week time point in both mild‐ and moderate‐parkinsonian monkeys. Tyrosine hydroxylase and DAT expression was increased in late stage recovery even within dopamine‐depleted regions and supports sprouting. Altered DARPP‐32 expression suggests a role of medium spiny neurons in recovery. © 2005 Wiley‐Liss, Inc.
Modulation of excitability as an early change leading to structural adaptation in the motor cortex
Authors: Manto Mario , Oulad ben Taib Nordeyn , Luft Andreas R. 
Published: December 2005

AbstractThe excitability of the motor cortex is a function of single cell excitability, synaptic strength, and the balance between excitatory cells and inhibitory cells. Sustained periods of sensory stimulation enhance the excitability in the motor cortex. This adaptation, which represents an early change in cortical network function effective in motor learning and recovery from a motor deficit, is followed by longer‐lasting changes, such as modifications in cortical somatotopy, and by structural plasticity. Interventions aiming at increasing excitability also positively affect learning processes. Recent studies highlight that the cerebellum, especially the interpositus nucleus, plays a key function in the adaptation of the motor cortex to repeated trains of peripheral stimulation. Interpositus neurons, which receive inputs from the sensorimotor cortex and the spinal cord, are involved in somesthetic reflex behaviors and assist the cerebral cortex in transforming sensory signals to motor‐oriented commands by acting via the cerebello‐thalamo‐cortical projections. Moreover, climbing fibers originating in the inferior olivary complex and innervating the nucleus interpositus mediate highly integrated sensorimotor information derived from spinal modules. The intermediate cerebellum allows the motor cortex to tune the gain of polysynaptic responses originating from the spinal cord after repetitive trains of peripheral stimulation, allowing an online calibration of cutaneo‐muscular responses. © 2005 Wiley‐Liss, Inc.
Radiographic classification of osteogenesis during bone distraction
Authors: Li Ru , Saleh Michael , Yang Lang , Coulton Les 
Published: December 2005

AbstractSuccessful limb lengthening requires serial radiological evaluation of the progression of healing of the regenerate bone. However, there is no radiographic classification system that shows how the regenerate should progress during treatment in adults. The study aimed to address this need.A series of radiographs were studied from 92 patients (125 segments) who had undergone bone lengthening. A radiographic classification of osteogenesis was developed based on callus shape and radiographic features that occur between osteotomy and fixator removal.This classification system used both shape and type of feature to condense and record the radiographic information, but type of feature alone was sufficient to predict outcome. The concurrence and reproducibility of the classification system was tested by inter‐ and intra‐observer studies. The degree of consistent repetition and agreement between observers suggests that the classification system is reliable, reproducible, and therefore should be robust in use.This classification system provides an insight into osteogenesis; it allows the progress of the bone healing to be assessed against a successful pattern of healing. Hence, potential problems can be predicted and clinical changes made to improve outcome. The classification can be simplified to make it more appropriate for clinical use. © 2005 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:339–347, 2006
Oscillatory fluid flow regulates glycosaminoglycan production via an intracellular calcium pathway in meniscal cells
Authors: Eifler Robert L. , Blough Eric R. , Dehlin Jennifer M. , Haut Donahue Tammy L. 
Published: December 2005

AbstractMechanical loading in the form of oscillatory fluid flow‐induced shear stress was applied to meniscal cells while the biochemical response [intracellular calcium mobilization and sulfated glycosaminoglycan (GAG) production] was studied. Isolated rabbit meniscal cells were cultured onto microscope slides and placed in a parallel plate flow chamber. Cells were exposed to oscillating fluid flow‐induced shear stresses of 4 Pa for sulfated GAG studies and 0–6.5 Pa for calcium studies. The calcium response was monitored using a fluorescent probe and imaging techniques, sulfated GAG production was measured using the modified 1,9‐dimethylmethylene blue method, and thapsigargin was used to block intracellular calcium ([Ca2+]i) mobilization. A significant dose‐dependent relationship was found for the percentage of cells responding to oscillating fluid flow with an increase in [Ca2+]i versus shear stress level. The percentage of cells responding decreased linearly from 72% ± 17% at 6.5 Pa to 28% ± 7% at 2.0 Pa to 2% ± 1% for baseline no‐flow (0 Pa). No differences were found in the amplitude of the calcium response of responding cells for any shear stress level. Oscillating fluid flow‐induced shear stresses of 4 Pa produced a significantly greater amount of sulfated GAGs (253 ± 95 ng GAG/µg cell protein) compared to the no‐flow control (158 ± 86 ng/µg). The addition of thapsigargin to the media inhibited both the intracellular calcium response to oscillating fluid flow (less than 1.5% of the cells responded) and the increase in GAG production following oscillating fluid flow, which was returned to control levels (170 ± 72 ng/µg). These findings suggest that oscillatory fluid flow‐induced shear stress increases intracellular calcium levels and sulfated GAG production. Furthermore, they suggests that calcium may modulate the biochemical pathway that leads to sulfated GAG production. © 2005 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:375–384, 2006
Chondrocyte injection in distraction epiphysiolysis (rabbit model)
Authors: Ahn Jae I. , Erdin Robert A. , Smith Richard , Canale S. Terry , Hasty Karen A. 
Published: December 2005

AbstractThe purpose of this study was to determine if cultured chondrocytes could prevent premature closure of the physis after physeal distraction in a rabbit model. Epiphyseal distraction at the proximal tibial epiphysis was performed in 24 immature rabbits. Chondrocytes were harvested from the iliac apophysis. The animals were divided into three groups: A, epiphyseal distraction alone; B, injection of phosphate buffered saline (PBS) after epiphyseal distraction; and C, injection of cultured chondrocytes after epiphyseal distraction. After epiphyseal separation was noted radiographically, each animal was evaluated at routine intervals. At 2 to 4 weeks, significant tibial lengthening as compared to the contralateral tibia was noted in all three groups. At 10 weeks, lengthening was apparent only in group C; in groups A and B, the operated tibia was shorter than the unoperated one. Histologic examination at 4 weeks revealed partial bony bridge formation with cell clustering in the fibrocartilaginous matrix in groups A and B. In group C, the matrix showed a typical hyaline aspect with cells organized in columns at the injection site. The zone of hypertrophic chondrocytes was enlarged. It appears that the injected cells differentiated into hypertrophic chondrocytes and delayed premature physeal closure. At 10 weeks after distraction of the physis, the width of the physis was restored to 75% of normal, but disordered chondrocyte growth with cell clustering was present in the cell‐injected group. © 2005 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:355–365, 2006
Langerhans cell histiocytosis and human herpes virus 6 (HHV‐6), an analysis by real‐time polymerase chain reaction
Authors: Glotzbecker Michael P. , Dormans John P. , Pawel Bruce R. , Wills Brian P. , Joshi Yagnya , Elkan Michael , Hodinka Richard L. 
Published: December 2005

AbstractPatients with Langerhans cell histiocytosis (LCH) usually present to orthopedic surgeons because this disease most commonly affects bone. The pathogenesis of LCH is unknown, although roles for environmental, infectious, immunologic, and genetic causes have been postulated. More specifically, there is limited data suggesting that human herpes virus 6 (HHV‐6) may be a potential etiologic agent. Frozen biopsy material was obtained from 13 patients with LCH and 20 patients without the disease. After ensuring histologic adequacy of the material, the tissue was tested for HHV‐6 by qualitative and quantitative real‐time TaqMan PCR. Four of 13 patients with LCH had evidence of HHV‐6 DNA in their tissue while 7 of 20 control patients tested positive for HHV‐6 genome. Viral loads are reported for the positive patients; no statistical difference was observed in the presence or quantity of HHV‐6 DNA found in either population, suggesting that the prevalence of HHV‐6 in the tissue of LCH patients is the same as that found in tissue from individuals without disease. © 2005 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:313–320, 2006
T2 relaxation time and delayed gadolinium‐enhanced MRI of cartilage (dGEMRIC) of human patellar cartilage at 1.5 T and 9.4 T: Relationships with tissue mechanical properties
Authors: Lammentausta E. , Kiviranta P. , Nissi M.J. , Laasanen M.S. , Kiviranta I. , Nieminen M.T. , Jurvelin J.S. 
Published: December 2005

AbstractQuantitative magnetic resonance imaging (MRI) techniques have been developed for noninvasive assessment of the structure of articular cartilage. T2 relaxation time is sensitive to the integrity and orientation of the collagen network, while T1 relaxation time in presence of Gd‐DTPA2− (dGEMRIC) reflects the proteoglycan content of cartilage. In the present study, human patellar cartilage samples were investigated in vitro to determine the ability of MRI parameters to reveal topographical variations and to predict mechanical properties of cartilage at two different field strengths. T2 and dGEMRIC measurements at 1.5 T and 9.4 T were correlated with the static and dynamic compressive moduli at six anatomical locations of the patellar surface. Statistically significant linear correlations were observed between MRI and mechanical parameters at both field strengths, especially between T2 and Young's modulus. No significant difference was found between the T2 measurements at different field strengths in predicting mechanical properties of the tissue. Topographical variation of T2 values at both field strengths was similar to that of Young's moduli. The current results demonstrate the feasibility of quantitative MRI, particularly T2 mapping, to reflect the mechanical properties of human patellar cartilage at both field strengths. © 2005 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:366–374, 2006
Influence of polyethylene creep behavior on wear in total hip arthroplasty
Authors: Penmetsa Janaki R. , Laz Peter J. , Petrella Anthony J. , Rullkoetter Paul J. 
Published: December 2005

AbstractAfter total hip arthroplasty (THA), polyethylene acetabular liner creep occurs quickly and serves to increases head–liner contact area and decrease contact pressures. What effect these early changes in contact mechanics will have on the wear behavior of the articulation remains unclear, and hence, selection or modification of polyethylene materials for optimal creep and wear performance is impossible. The objective of this study was to determine the influence of polyethylene creep behavior on volumetric wear and linear creep and wear penetration during simulated gait loading conditions. A finite element model of THA articulation was developed, and simultaneous numerical creep and wear simulation was performed to 10 million gait cycles with three levels of polyethylene creep behavior. Long‐term volumetric wear and penetration were surprisingly unaffected by the polyethylene creep behavior due to the competing decrease in contact pressures coupled with increased contact area. In addition, variation in contact mechanics with the creep levels studied was only noteworthy in the initial postoperative period; after 1 million gait cycles, peak contact pressures and areas were within 13% regardless of the creep material behavior selected. Femoral head size had considerable impact on wear and penetration, while liner thickness primarily affected only early penetration. These results suggest that polyethylene creep behavior plays a major role in early penetration, but has little influence on the more important long‐term volumetric wear. © 2005 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:422–427, 2006
A robot‐assisted study of intrinsic muscle regulation on proximal interphalangeal joint stiffness by varying metacarpophalangeal joint position
Authors: Li Zong‐Ming , Davis Gregg , Gustafson Norm P. , Goitz Robert J. 
Published: December 2005

AbstractThe tightness of intrinsic hand muscles is a common cause of finger joint stiffness. The purposes of this study were to develop a robot‐assisted methodology to obtain torque–angle data of a finger joint, and to investigate the regulation of the intrinsic muscles on finger joint stiffness. Our robot system features the integration of a low payload robot arm, a controller, and a force/torque transducer. The system provided highly reproducible torque–angle curves. Torque–angle data of the proximal interphalangeal joint with the metacarpophalangeal joint at 0 and 60 degrees were obtained from eight asymptomatic hands. The torque–angle curve shifted with the position of the metacarpophalangeal joint. As the metacarpophalangeal joint flexion angle changed from 60 to 0 degrees, the equilibrium of the proximal interphalangeal joint increased more than 20 degrees, and joint stiffness increased more than 50%. The dependence of the stiffness of the proximal interphalangeal joint on metacarpophalangeal joint position supports the regulatory role of the intrinsic muscles on finger joint mechanics. This regulatory mechanics is likely amplified in hands with intrinsic muscle tightness, justifying the commonly used Bunnell Intrinsic Tightness Test. © 2005 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:407–415, 2006
Changes in gene expression and protein distribution at different stages of mechanically induced disc degeneration—an in vivo study on the New Zealand white rabbit
Authors: Omlor Georg W. , Lorenz Helga , Engelleiter Karl , Richter Wiltrud , Carstens Claus , Kroeber Markus W. , Guehring Thorsten 
Published: December 2005

AbstractThe objective of the study was to improve the biological understanding of degenerative disc disease using a rabbit model in which different stages of disc degeneration are induced by variation of the duration of loading with an external compression‐device applying 2.4 MPa. Gene expression and protein distribution were analyzed in controls and after 1, 28, and 56 days of hyperphysiologic loading. To evaluate extracellular matrix genes, quantitative real‐time reverse‐transcriptase polymerase chain reaction was applied for collagen I, collagen II, biglycan, decorin, fibromodulin, fibronectin, aggrecan, and osteonectin. As representatives of catabolic, anticatabolic, and anabolic factors, matrix metalloproteinase‐13 (MMP‐13), tissue inhibitor of matrix metalloproteinase‐1 (TIMP‐1), and bone morphogenetic protein‐2 (BMP‐2) were chosen. To evaluate protein distribution, immunohistochemistry was performed for collagen I, collagen II, and BMP‐2/4. Matrix gene expression was characterized by two major developments: collagen I and II, biglycan, and decorin showed early elevation followed by later downregulation to control levels, whereas fibromodulin, fibronectin, aggrecan, and osteonectin showed continuous upregulation or remained at similar levels. Induction of MMP‐13 gene expression was found in degenerated discs. TIMP‐1 and BMP‐2 were elevated immediately after hyperphysiologic loading and presented highest levels in the 56‐day group. Immunohistochemistry showed less collagen II and BMP‐2/4 positive cells after compression. In conclusion, elevated matrix gene expression represents an early cellular response to hyperphysiologic loading. As degeneration progresses, some matrix genes increase upregulation, whereas others start downregulation. Continuous upregulation of catabolic, anticatabolic, and anabolic factors indicates their important role in the degeneration process. © 2005 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:385–392, 2006
Ablative versus non‐ablative treatment of perioral rhytides. A randomized controlled trial with long‐term blinded clinical evaluations and non‐invasive measurements
Authors: Hedelund L. , Bjerring P. , Egekvist H. , Haedersdal M. 
Published: January 2006

AbstractBackground and ObjectiveTo compare efficacy and side effects of CO2 laser resurfacing and intense pulsed light (IPL) rejuvenation for treatment of perioral rhytides.MethodsTwenty‐seven female subjects with perioral rhytides (class I–III) were randomly treated with either CO2 laser or IPL (three monthly treatments). Efficacy was evaluated by patient self‐assessments and blinded photographs up to 12 months postoperatively. Side effects were assessed clinically. Non‐invasive measurements included: trans epidermal water loss (TEWL), skin reflectance, skin elasticity, and ultrasound.ResultsCO2 laser resurfacing resulted in higher degrees of patient satisfaction and clinical rhytide reduction compared to IPL rejuvenation up to 12 months postoperatively (patient evaluations, P < 0.05) (observer evaluations, P < 0.008). Laser‐induced side effects included erythema, dyspigmentation, and milia whereas no side effects were observed after IPL rejuvenation. Non‐invasive measurements showed a significant higher reduction of the subepidermal low‐echogenic band in CO2 laser treated areas versus IPL treated areas (12 months postoperatively, P < 0.001). Skin elasticity (expressed as Young's modulus) increased in both groups (P = ns). One month postoperatively a significant increase in TEWL values (P < 0.009) and skin redness% (P < 0.02) was found in CO2 laser treated patients versus IPL treated patients. No significant differences were seen in skin pigmentation% during the observation period.ConclusionCO2 laser resurfacing induces a significantly higher degree of clinical rhytide reduction followed by considerably more side effects compared to IPL rejuvenation in a homogeneous group of patients. Lasers Surg. Med. 38:129–136, 2006. © 2006 Wiley‐Liss, Inc.
Antioxidant agents transiently inhibit aneuploidy progression in Li‐Fraumeni cell strains
Authors: Kraniak Janice M. , Abrams Judith , Nowak James E. , Tainsky Michael A. 
Published: December 2005

AbstractCultured human fibroblasts from patients with the Li‐Fraumeni syndrome (LFS) containing heterozygous germline p53 mutations develop genomic instability, loss of the wild‐type p53 allele, and immortalize at a low frequency. Since genomic instability and phenotypic change are observed in presenescent cells without specific exposure to mutagens, we hypothesized that reactive oxygen species (ROS) produced during normal cell metabolism coupled with deficient p53 dependent DNA damage repair pathways make a significant contribution to immortalization related parameters. To test this hypothesis, three LFS cell strains (MDAH087, MDAH041, and MDAH172) were exposed to five compounds with demonstrated antioxidant properties for ≥85% of their proliferative lifetimes. Agent effectiveness was evaluated every five passages during subculturing by analyzing aberrant chromosome number, anchorage independent growth (AIG), and p16 expression. Cytogenetic analysis revealed that of the five antioxidants tested, only oltipraz was significantly effective in transiently delaying a shift to hyperdiploidy in all three cell strains. However, treated populations were not different from untreated controls when measured in the last 10% of their lifetimes. Additionally, no differences were observed in AIG and p16 expression in antioxidant treated or untreated control populations. Epidemiological studies, in vitro and in vivo experimentation and some clinical trials have suggested that antioxidants may inhibit the progression of cancer and other mutation related diseases. This data, however, does not support the hypothesis that the antioxidants tested have chemopreventive potential in cancers that develop genomic instability due to loss of p53. © 2005 Wiley‐Liss, Inc.
Microsatellite instability in multiple nonfamilial malignancies
Authors: Niv Eva , Bomstein Yonit , Bernheim Joelle , Lishner Michael 
Published: December 2005

AbstractDevelopment of multiple tumors of different histopathologic types may suggest a profound generalized genetic defect, such as malfunction of DNA mismatch repair (MMR) mechanism. Defects in this mechanism are best reflected in microsatellite instability (MSI). We aimed to determine the role of MSI in a group of patients with dual malignancies and compared the data with that of patients with a single malignancy. Fifty patients were enrolled in the study, of whom 16 patients developed both solid and hematologic nonfamilial malignancies, 18 patients developed a single matched hematologic malignancy, and 16 a single matched solid malignancy. Five microsatellite markers were replicated by polymerase chain reaction (PCR) after DNA extraction from paraffin‐embedded tissue blocks and analyzed by the GeneScan Analysis Software. The MSI‐high phenotype was defined as instability in at least 40% of the examined loci. A higher prevalence of MSI‐high phenotype was found in patients with dual malignancies (31.3%) compared with patients with single hematologic (5.6%) or solid malignancy (6.3%) (P = 0.0498 and 0.07, respectively). In conclusion, defects in DNA MMR mechanism may have an important role in the development of multiple sporadic nonfamilial malignancies. © 2005 Wiley‐Liss, Inc.