bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stem–cement porosity may explain early loosening of cemented femoral hip components: Experimental–computational in vitro study
Authors: Mann Kenneth A. , Damron Leatha A. , Miller Mark A. , Race Amos , Clarke Michael T. , Cleary Richard J. 
Published: December 2006

AbstractA combination of laboratory experiment and computational simulation was performed to assess the role of interface porosity on stem migration. The early motion of in vitro prepared cemented femoral components was measured during application of cyclic stair climbing loads. Following testing, transverse sections were obtained and the distribution of pores at the stem–cement interface was determined. Finite element models of cemented stem constructs were developed and a scheme was implemented to randomly assign pores to the stem–cement interface. For a series of 14 in vitro prepared components, pore fractions at the stem–cement interface ranged from 23% to 67%. The majority of pores at the stem–cement interface were less than 1 mm in length with a mean length of 1.27 ± 2.7 mm and thickness of 0.12 ± 0.11 mm. For stems with large pore fractions, pores tended to coalesce in longer extended gaps over the stem surface. Finite element and experimental models both revealed strong positive correlations (r2 = 0.55–0.72; p < 0.0001) between stem–cement pore fraction and stem internal rotation, suggesting that the presence and extent of pores could explain the early motion of the stems. There was an increased volume of cement at risk of fatigue failure with increasing stem migration. Pore fractions greater than 30% resulted in large increases in stem internal rotation, suggesting that attempts to maintain surface porosity at or below this level may be desirable to minimize the risk of clinical loosening. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Assessment of brain iron and neuronal integrity in patients with Parkinson's disease using novel MRI contrasts
Authors: Michaeli Shalom , öz Gülin , Sorce Dennis J. , Garwood Michael , Ugurbil Kamil , Majestic Stacy , Tuite Paul 
Published: December 2006

AbstractPostmortem demonstration of increased iron in the substantia nigra (SN) is a well‐appreciated finding in Parkinson's disease (PD). Iron facilitates generation of free radicals, which are thought to play a role in dopamine neuronal loss. To date, however, magnetic resonance imaging (MRI) has failed to show significant in vivo differences in SN iron levels in subjects with PD versus control subjects. This finding may be due to the limitations in tissue contrasts achievable with conventional T1‐ and T2‐weighted MRI sequences that have been used. With the recent development of novel rotating frame transverse (T2ρ) and longitudinal (T1ρ) relaxation MRI methods that appear to be sensitive to iron and neuronal loss, respectively, we embarked on a study of 8 individuals with PD (Hoehn & Yahr, Stage II) and 8 age‐matched control subjects. Using these techniques with a 4T MRI magnet, we assessed iron deposits and neuronal integrity in the SN. First, T2ρ MRI, which is reflective of iron‐related dynamic dephasing mechanisms (e.g., chemical exchange and diffusion in the locally different magnetic susceptibilities), demonstrated a statistically significant difference between the PD and control group, while routine T2 MRI did not. Second, T1ρ measurements, which appear to reflect upon neuronal count, indicated neuronal loss in the SN in PD. We show here that sub‐millimeter resolution T1ρ and T2ρ MRI relaxation methods can provide a noninvasive measure of iron content as well as evidence of neuronal loss in the midbrain of patients with PD. © 2006 Movement Disorder Society
R1514Q substitution in Lrrk2 is not a pathogenic Parkinson's disease mutation
Authors: Nichols William C. , Marek Diane K. , Pauciulo Michael W. , Pankratz Nathan , Halter Cheryl A. , Rudolph Alice , Shults Clifford W. , Wojcieszek Joanne , Foroud Tatiana 
Published: December 2006

AbstractMutations in LRRK2 were first reported as causing Parkinson's disease (PD) in late 2004. Since then, approximately a dozen LRRK2 substitutions have been identified that are believed to be pathogenic mutations. The substitution of adenine for guanine at nucleotide 4541 (4541G>A) in LRRK2 was recently reported. This substitution resulted in the replacement of an arginine at position 1514 with a glutamine (R1514Q). Although this substitution was not found in a large cohort of controls, its pathogenicity could not be verified. We have now genotyped the R1514Q substitution in a sample of 954 PD patients from 429 multiplex PD families. This substitution was identified in 1.8% of the PD patients; however, the majority of the PD sibships segregating this substitution were discordant for this putative mutation. In addition, the R1514Q substitution was detected in 1.4% of neurologically evaluated, control individuals. These data suggest that the R1514Q variant is not a pathogenic LRRK2 mutation. We believe it is imperative that the causative nature of any newly identified genetic variant be determined before it is included in any panel for diagnostic testing. © 2006 Movement Disorder Society
Joubert syndrome surviving to adulthood associated with a progressive movement disorder
Authors: Gunzler Steven A. , Stoessl A. Jon , Egan Robert A. , Weleber Richard G. , Wang Paul , Nutt John G. 
Published: December 2006

AbstractA 48‐year‐old man presented with a progressive gait disorder. He had longstanding ataxia, oculomotor apraxia, motor delay, and cognitive impairment, diagnosed as cerebral palsy. Physical examination revealed ataxia, oculomotor apraxia, extrapyramidal signs, and a wide‐based, shuffling gait. Magnetic resonance imaging showed vermian aplasia, consistent with Joubert syndrome. Positron emission tomography scan revealed normal fluorodopa uptake, but elevated raclopride binding, compatible with dopamine deficiency. This case demonstrates that a patient with Joubert syndrome may survive into adulthood and present as a chronic neurologic disorder with subacute extrapyramidal signs. © 2006 Movement Disorder Society
Health‐related quality of life in sporadic adult‐onset ataxia
Authors: Abele Michael , Klockgether Thomas 
Published: December 2006

AbstractDespite progressive disability in sporadic adult‐onset ataxia (SAOA), little is known about patients' assessment of their ataxic disorder and its impact on health‐related quality of life (Hr‐QoL). This study investigated Hr‐QoL by means of the following self‐administered scales: Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, Beck Depression Inventory (BDI), and the Medical Outcome Study Short Form (SF‐36). Twenty‐two unselected ataxia patients were included. Sleep‐related complaints were found in 9 (41%) of 22 and symptoms of depression in 6 (38%) of 16 patients. Compared to a large german control group, SAOA patients had lower scores in all SF‐36 dimensions except for bodily pain. The greatest impairment was found in the domain physical functioning, followed by the domains social functioning and role limitations (emotional problems). There was a significant negative correlation of all nonmotor SF‐36 dimensions with the BDI score. Walking aid dependency was significantly correlated with poorer health status perception in several motor and nonmotor domains. In addition, impaired sleep quality was correlated with an impaired general health perception and with bodily pain. The study demonstrates a great impact of SAOA on Hr‐QoL. Adequate treatment of depression, motor disability, and impaired sleep quality is essential to improve Hr‐QoL in ataxic patients. © 2006 Movement Disorder Society
Hypomyelinating leukoencephalopathy with paroxysmal tonic upgaze and absence of psychomotor development
Authors: Blumkin Lubov , Lev Dorit , Watemberg Nathan , Lerman‐Sagie Tally 
Published: December 2006

AbstractHypomyelinating leukoencephalopathies are characterized by a substantial and permanent deficit in myelin deposition in the brain. Although our knowledge and understanding of the etiology of white matter diseases has progressively increased, many cases with this disorder remain undiagnosed, despite extensive evaluations. Recently, new disease entities have been defined by combining magnetic resonance imaging pattern recognition and clinical features. We describe a 1‐year‐old Ashkenazi Jewish girl with a hypomyelinating leukoencephalopathy, who presented in the neonatal period with episodes of sustained paroxysmal tonic upward gaze, roving eye movements, pendular nystagmus, and severe hypotonia, with the later appearance of pyramidal and extrapyramidal signs and no development. In addition, she has dysmorphic signs. This clinical picture is not consistent with any of the previously described hypomyelinating leukoencephalopathies and may represent a new entity. © 2006 Movement Disorder Society
A double‐blind placebo‐controlled trial of zonisamide (zonegran) in the treatment of essential tremor
Authors: Zesiewicz Theresa A. , Ward Christopher L. , Hauser Robert A. , Sanchez‐Ramos Juan , Staffetti Joseph F. , Sullivan Kelly L. 
Published: December 2006

AbstractMedical therapy for essential tremor (ET), a common movement disorder, is often inadequate. We performed a double‐blind placebo‐controlled randomized trial to evaluate the efficacy and tolerability of zonisamide (ZNS), an antiepileptic agent, in treating ET. Twenty patients (mean age, 60 ± 15 years) with ET were randomized to receive ZNS or placebo. ZNS was initiated at a dosage of 100 mg/day and escalated to 200 mg/day at day 14. Patients were evaluated by accelerometry and the Fahn–Tolosa–Marin (FTM) rating scale at baseline and days 14 and 28, as well as the Clinical Global Impression (CGI‐C) scale at day 28. At endpoint, subjects assigned to ZNS were taking a mean dosage of 160 ± 50 mg/day. There were no significant improvements in the FTM total score or its subsections. Tremor amplitude as assessed by accelerometry significantly improved in the ZNS group compared to the placebo group at endpoint relative to baseline (−0.50 ± 0.72 vs. 0.30 ± 0.79 m/s2; P = 0.03). On the CGI‐C, 60% (n = 6) of patients in the ZNS group felt that their tremor was unchanged, while the remaining patients felt that their tremor was “minimally improved.” Thirty percent (n = 3) of patients taking ZNS discontinued the study due to side effects (fatigue, headache, paresthesias) while taking 100 mg per day. ZNS did not provide significant improvements in clinical rating scales at study endpoint compared to placebo and was only modestly well tolerated. ZNS was effective in reducing tremor amplitude as measured by accelerometry. © 2006 Movement Disorder Society
NMR structure of the peptidyl transferase RNA inhibitor antibiotic amicetin
Authors: Shammas Christos , Donarski James A , Ramesh Vasudevan 
Published: December 2006

AbstractIn this communication, we report the solution state NMR structure determination of the peptidyl transferase RNA inhibitor antibiotic amicetin. We have successfully characterised the NMR spectrum of amicetin using a range of homo‐ and heteronuclear NMR techniques. Using experimental ROE‐based distance and 1H1H scalar coupling derived dihedral angle geometrical constraints as input into the three‐dimensional structure determination protocol, we have generated an energy‐minimised average structure of the antibiotic. Amicetin adopts a stable well‐folded conformation in solution, mediated by a network of hydrogen bonds caused by proton donor and acceptor groups at either end of the molecule. The NMR structure of amicetin shows that the cytosine moiety occupies the critical turn position within the fold, which may be structurally significant for interaction with peptidyl transferase ribosomal RNA. The structure is distinctly different from the published X‐ray crystal structure of amicetin in which it adopts a linear, extended chain‐like conformation with a number of intermolecular hydrogen bonds. In addition to structure, we have probed the dynamics of amicetin in solution and have observed retarded exchange of the amide proton involved in folding. We have also characterised the ionisation properties of amicetin by carrying out NMR pH titration and measuring the pKa of the primary and tertiary amino groups, 7.27 and 7.52, respectively, which are in agreement with the reported values in literature. Solving the NMR structure of amicetin provides a valuable opportunity to determine the structure of its complex with RNA in solution state. Copyright © 2006 John Wiley & Sons, Ltd.
Propagation of a shear band in sandstone
Authors: Riedel J. J. , Labuz J. F. 
Published: December 2006

AbstractClosed‐loop, servo‐controlled experiments were conducted to investigate the development of a shear band in Berea sandstone at various confining pressures. The tests were performed with the University of Minnesota Plane‐Strain Apparatus, which was designed to allow the shear band to develop in an unrestricted manner. Measured load and displacements provided estimates of the stress and deformation states whereby dilatancy and friction were evaluated prior to localization. Experiments were stopped at various stages of shear‐band development within the strain‐softening regime. The specimens displayed a progression of deformation from inception, where the shear band was characterized by a high density of intragranular microcracks and crushed grains, to the tip where the intragranular microcracks were significantly less dense and separated by intact grains. Decreased slip deformation towards the tip of the shear band indicated that localization developed and propagated in plane. Thin‐section microscopy showed porosity increase within the shear band was 3–4 grain diameters wide. Increased porosity did not extend beyond the tip of the shear band. A cohesive zone model of shear fracture, used to examine the stress field near the tip, showed similarities to principal compressive stress orientations interpreted from intragranular microcracks. Thus, propagation of the shear band could be associated with in‐plane mode II fracture. Copyright © 2006 John Wiley & Sons, Ltd.
Detrusor overactivity and urge urinary incontinence following trans obturator versus midurethral slings
Authors: Botros Sylvia M. , Miller Jay‐James R. , Goldberg Roger P. , Gandhi Sanjay , Akl Mohammed , Beaumont Jennifer L. , Sand Peter K. 
Published: December 2006

AbstractAimsTo compare the rates of resolution of detrusor overactivity (DO) and subjective urge urinary incontinence (UUI) as well as de novo DO and UUI between the Monarc, TVT, and SPARC midurethral sling procedures.MethodsTwo hundred and seventy‐six subjects with urodynamic stress or mixed urinary incontinence underwent retropubic midurethral slings (TVT, N = 99; SPARC, N = 52) or transobturator slings (Monarc, N = 125). All evaluable subjects had a routine office evaluation, subjective assessment of UUI, and multichannel urodynamic testing pre‐ and 3 months postoperatively. Comparisons were made using Student's t‐test, ANOVA, McNemar's test, and Chi‐Square test where appropriate. Multivariate logistic regression was performed to detect possible confounding factors such as sling type, and differences in concomitant surgical procedures.ResultsDe novo subjective UUI differed significantly between the Monarc and the other two slings (33% TVT vs. 8% Monarc vs. 17% SPARC, P = 0.04). Fourteen to Sixteen percents of patients with preoperative UUI who underwent TVT or SPARC had worsening of their UUI symptoms while only 6% of the Monarc group did (P = 0.02). There was no difference in rates of resolution of DO among the three groups (40% vs. 48% vs. 32%, P = 0.39) or de novo DO (32% vs. 22% vs. 22%, P = 0.64) at 3 months.ConclusionsPatients who undergo transobturator procedures have significantly lower rates of de novo UUI than those who undergo midurethral sling procedures. Rates of resolution of DO, UUI, and de novo DO do not differ between groups. Neurourol. Urodynam. © 2006 Wiley‐Liss, Inc.
2‐DE profiling of GDNF overexpression‐related proteome changes in differentiating ST14A rat progenitor cells
Authors: Hoffrogge Raimund , Beyer Susanne , Hübner Rayk , Mikkat Stefan , Mix Eilhard , Scharf Christian , Schmitz Ulf , Pauleweit Stefan , Berth Matthias , Zubrzycki Igor Z. , Christoph Hilmar , Pahnke Jens , Wolkenhauer Olaf , Uhrmacher Adelinde , Völker Uwe , Rolfs Arndt 
Published: December 2006

AbstractTargeted differentiation of neural progenitor cells (NPCs) is a challenge for treatment of neurodegenerative diseases by cell replacement therapy and cell signalling manipulation. Here, we applied a proteome profiling approach to the rat striatal progenitor model cell line ST14A in order to elucidate cellular differentiation processes. Native cells and cells transfected with the glial cell line‐derived neurotrophic factor (GDNF) gene were investigated at the proliferative state and at seven time points up to 72 h after induction of differentiation. 2‐DE combined with MALDI‐MS was used to create a reference 2‐DE‐map of 652 spots of which 164 were identified and assigned to 155 unique proteins. For identification of protein expression changes during cell differentiation, spot patterns of triplicate gels were matched to the 2‐DE‐map. Besides proteins that display expression changes in native cells, we also noted 43 protein‐spots that were differentially regulated by GDNF overexpression in more than four time points of the experiment. The expression patterns of putative differentiation markers such as annexin 5 (ANXA5), glucosidase II beta subunit (GLU2B), phosphatidylethanolamine‐binding protein 1 (PEBP1), myosin regulatory light chain 2‐A (MLRA), NASCENT polypeptide‐associated complex alpha (NACA), elongation factor 2 (EF2), peroxiredoxin‐1 (PRDX1) and proliferating cell nuclear antigen (PCNA) were verified by Western blotting. The results reflect the large rearrangements of the proteome during the differentiation process of NPCs and their strong modification by neurotrophic factors like GDNF.
Proteomic analysis of glutamate‐induced toxicity in HT22 cells
Authors: Lee Youra , Park Hye‐won , Park Sung Goo , Cho Sayeon , Myung Pyung Keun , Park Byoung Chul , Lee Do Hee 
Published: December 2006

AbstractIn the present study, we have investigated the proteome changes associated with glutamate‐induced HT22 cell death, a model system to study oxidative stress‐mediated toxicity. Among a number of HT22 proteins exhibiting altered expression, several molecular chaperones demonstrated substantial changes. For example, the levels of Hsp90 and Hsp70 decreased as cell death progressed whereas that of Hsp60 increased dramatically. Interestingly, cytosolic Hsp60 increased more prominently than mitochondrial Hsp60. Concomitantly, the accumulation of poly‐ubiquitylated proteins and differential regulation of the peptidase activities and the subunits of 26S proteasomes were observed in glutamate‐treated HT22 cells. Our findings that the molecular chaperones and the ubiquitin‐proteasome system undergo changes during glutamate‐induced HT22 cell death may suggest the importance of a protein quality control system in oxidative damage‐mediated toxicity.
Ab initio calculations of the gas‐phase elimination kinetics of ethyl oxamate, ethyl oxanilate, and ethyl N,N‐dimethyl oxamate
Authors: Mora Jose R. , Loroño Marcos , Cordova Tania , Chuchani Gabriel 
Published: December 2006

AbstractTheoretical studies of the gas‐phase elimination kinetics of title compounds were performed by using “ab initio” methods at MP2/6‐31G, MP2/6‐31G(d,p) and ONIOM [MP2/6‐31G (d,p) // MP2/6‐31G]. Ethyl Oxamate and ethyl oxanilate undergo a rapid decarbonylation to give the corresponding carbamates. These intermediates proceed to a parallel decomposition to give the corresponding unstable carbamic acid and ethylene through six‐membered cyclic transition state (path 1) and isocyanate and ethanol through a four‐membered cyclic transition state (path 2). Ethyl N,N‐dimethyloxamate elimination reaction yields in one step, through a six‐membered cyclic transition state, dimethyl oxamic acid and ethylene gas. The calculated bond orders, NBO charges and synchronicity indicate that these reactions are concerted and slightly asynchronous. The estimated kinetic and thermodynamic parameters are in good agreement with the reported experimental values. Copyright © 2006 John Wiley & Sons, Ltd.
Substituted polyacetylenes
Authors: Masuda Toshio 
Published: December 2006

AbstractThis article reviews the chemistry of substituted polyacetylenes developed by our research group, more specifically, development of polymerization catalyst, synthesis of new polymers, elucidation of their structure, investigation of their properties, and development of their functions. The main features are as follows: a number of catalysts based on group 5, 6, and 9 transition metals (Nb, Ta, Mo, W, and Rh) have been developed, which include living polymerization catalysts. By using these catalysts, many new substituted polyacetylenes have been synthesized, whose molecular weights are very high (Mw = 104−106). Most of the polymers are soluble in many common solvents and stable enough in the air unlike polyacetylene. Some of these polymers exhibit interesting functions including high gas permeability and photoelectronic properties. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 165–180, 2007
X‐ray photoelectron and carbon Kα emission measurements and calculations of O‐, CO‐, N‐, and S‐containing substances
Authors: Shimada Shingo , Hiroi Toshiyuki , Ida Tomonori , Mizuno Motohiro , Endo Kazunaka , Kurmaev Ernst Z. , Moewes Alexander 
Published: December 2006

AbstractX‐ray fluorescence measurements for O‐containing [polyethylene oxide, polyvinyl alcohol, polyvinyl methyl ether], CO‐containing [polyvinyl methyl ketone, polyethylene terephthalate], N‐containing [poly‐4‐vinylpyridine (P4VP), polyaniline oligomer (PAO)], and S‐containing [polyphenylene sulfide] substances are presented. Carbon Kα X‐ray emission spectra (XES) and X‐ray photoelectron spectra (XPS) are compared with our DFT calculations performed with the Amsterdam density functional (ADF) program. The combined analysis of valence XPS and carbon Kα XES allows us to determine the individual contributions from pσ‐ and pπ‐bonding molecular orbitals of the polymers. The ΔSCF calculations yield the accurate C1s core‐electron binding energies (CEBEs) for all carbon sites of the organic compound. We calculate all CEBEs of the model molecules using the ΔEKS approach. Our simulated C1s photoelectron and C Kα emission spectra are in good agreement with our measurements. We also obtain WD (work function and the other energies) values for the polymers and PAO from the difference between calculated (gas‐phase) and measured (solid) CEBE values. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 162–172, 2007