bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carbenoxolone and mefloquine suppress tremor in the harmaline mouse model of essential tremor
Authors: Martin Fredricka C. , Handforth Adrian 
Published: June 2006

AbstractExcessive olivo‐cerebellar synchrony is implicated in essential tremor. Because synchrony in some networks is mediated by gap junctions, we examined whether the gap junction blockers heptanol, octanol, carbenoxolone, and mefloquine suppress tremor in the mouse harmaline model, and performed an open‐treatment clinical study of mefloquine for essential tremor. Digitized motion was used to quantify tremor in mice administered harmaline, 20 mg/kg s.c. In mice the broad‐spectrum gap junction blockers heptanol, octanol (350 mg/kg i.p. each), and carbenoxolone (20 mg/kg) suppressed harmaline tremor. Mefloquine (50 mg/kg), which blocks gap junctions containing connexin 36, robustly suppressed harmaline tremor. Glycyrrhizic acid (related to carbenoxolone) and chloroquine (related to mefloquine), which do not block gap junctions, failed to suppress harmaline tremor in mice. Clinically, tremor was assessed with standard rating scales, and subjects asked to take 62.5, 125, and 250 mg mefloquine weekly for 12 weeks at each dose. None of the four human subjects showed a meaningful tremor reduction with mefloquine, likely because clinical levels were below those required for efficacy. In view of recent genetic evidence, the anti‐tremor mechanism of these compounds is uncertain but may represent a novel therapeutic target, possibly involving gap junctions other than those containing connexin 36. © 2006 Movement Disorder Society
Impaired bed mobility and disordered sleep in Parkinson's disease
Authors: Stack Emma L. , Ashburn Ann M. 
Published: June 2006

AbstractThe contribution of impaired mobility to disordered sleep in Parkinson's disease (PD) remains uncertain. We evaluated the sleep of 38 people with PD and observed their turning strategies. Most reported difficulty maintaining sleep and difficulty turning. Those who hip‐hitched rated themselves more disabled and those who sat up had more severe PD than those who used support. Using multiple strategies was associated with sleep disturbance. As the ability to turn deteriorates, we recommend patients identify the single strategy least disruptive to sleep. Research must address whether improving mobility improves sleep quality. © 2006 Movement Disorder Society
High‐intensity resistance training amplifies muscle hypertrophy and functional gains in persons with Parkinson's disease
Authors: Dibble Leland E. , Hale Tessa F. , Marcus Robin L. , Droge John , Gerber J. Parry , LaStayo Paul C. 
Published: June 2006

AbstractStrength deficits in persons with Parkinson's disease (PD) have been identified as a contributor to bradykinesia. However, there is little research that examines the effect of resistance training on muscle size, muscle force production, and mobility in persons with PD. The purpose of this exploratory study was to examine, in persons with PD, the changes in quadriceps muscle volume, muscle force production, and mobility as a result of a 12‐week high‐force eccentric resistance training program and to compare the effects to a standard‐care control. Nineteen individuals with idiopathic PD were recruited and consented to participate. Matched assignment for age and disease severity resulted in 10 participants in the eccentric group and 9 participants in the control group. All participants were tested prior to and following a 12‐week intervention period with testing and training conducted at standardized times in their medication cycle. The eccentric group performed high‐force quadriceps contractions on an eccentric ergometer 3 days a week for 12 weeks. The standard‐care group exercise program encompassed standard exercise management of PD. The outcome variables were quadriceps muscle volume, muscle force, and mobility measures (6‐minute walk, stair ascent/descent time). Each outcome variable was tested using separate one‐way analyses of covariance on the difference scores. Muscle volume, muscle force, and functional status improvements occurred in persons with PD as a result of high‐force eccentric resistance training. The eccentric group demonstrated significantly greater difference scores for muscle structure, stair descent, and 6‐minute walk (P< 0.05). Magnitude of effect size estimators for the eccentric group consistently exceeded those in the standard‐care group for all variables. To our knowledge, this is the first clinical trial to investigate and demonstrate the effects of eccentric resistance training on muscle hypertrophy, strength, and mobility in persons with PD. Additional research is needed to determine the anatomical and neurological mechanisms of the observed strength gains and mobility improvements. © 2006 Movement Disorder Society
The sequence effect and gait festination in Parkinson disease: Contributors to freezing of gait?
Authors: Iansek Robert , Huxham Frances , McGinley Jennifer 
Published: June 2006

AbstractFestination and freezing of gait (FOG) are poorly understood gait disorders that cause disability and falls in people with Parkinson disease (PD). In PD, basal ganglia malfunction leads to motor set deficits (hypokinesia), while altered motor cue production leads to a sequence effect, whereby movements becomes progressively smaller as in festination. We suggest both factors may contribute to FOG. Disturbance of set maintenance by the basal ganglia in PD has previously been examined in gait, but limited systematic evaluation of the sequence effect exists. In this study, we investigated the step‐to‐step amplitude relationship in 10 PD subjects with clinical evidence of festination and FOG. Four conditions were examined: off levodopa, off with attentional strategies, off with visual cues, and on levodopa. Participants demonstrated a sequence effect (F = 6.24; P = 0.001), which was reversed only by use of visual cues. In contrast, medication, attentional strategies, and visual cues all improved hypokinesia. Variability was marked both within and between participants in all conditions. The variability of FOG is suggested to relate to a combination of factors, including the sequence effect and its variability, as well as the severity of hypokinesia and its response to medications. © 2006 Movement Disorder Society
Symptomatic treatment in the fragile X–associated tremor/ataxia syndrome
Authors: Hall Deborah A. , Berry‐Kravis Elizabeth , Hagerman Randi J. , Hagerman Paul J. , Rice Cathlin D. , Leehey Maureen A. 
Published: June 2006

AbstractThere is no established treatment for the neurological features of the recently discovered fragile X–associated tremor/ataxia syndrome (FXTAS). Fifty‐six patients with FXTAS completed a questionnaire to determine whether any medications had been effective for neurological symptoms. Of 11 subjects with definite FXTAS, 8 (70%) were on medications for their neurological symptoms, whereas most subjects with possible or probable FXTAS, 31 (70%) of 45 subjects, were not on medications. Although no therapy was uniformly effective for intention tremor, ataxia, Parkinsonism, memory loss, or anxiety, some subjects with intention tremor or Parkinsonism reported improvement with medications frequently used in other movement disorders. Overall, all 22 subjects on medications reported improvement in one or more symptoms. Lack of insight, recall bias, and cognitive impairment may have resulted in an underestimation of the beneficial effect of medical therapy. This study suggests that patients with FXTAS can derive improvement from medication treatment for some of their symptoms. © 2006 Movement Disorder Society
Excessive daytime sleepiness in patients with Parkinson's disease: A polysomnography study
Authors: Shpirer Isaac , Miniovitz Ala , Klein Colin , Goldstein Richard , Prokhorov Tatiana , Theitler Jack , Pollak Lea , Rabey Jose Martin 
Published: June 2006

AbstractTo investigate excessive daytime sleepiness (EDS) in patients with Parkinson's disease (PD), the reasons for which have not yet been clarified, polysomnography (PSG) and the Multiple Sleep Latency Test (MSLT) were performed in 46 patients with PD, and, in addition, PSG was performed in 30 healthy controls. Assessment included Epworth Sleepiness Score (ESS), Mini‐Mental State Examination (MMSE), and Hamilton Test (HT) for depression. Fifty percent of PD patients reported EDS (ESS, 10 ± 4.5 vs. 6.9 ± 3.7; P = 0.01). Compared with controls, PD patients as a group had lower sleep efficiency (65 ± 22 vs. 77 ± 14; P = 0.03), a longer Stage 2 (73 ± 12 vs. 67 ± 12; P = 0.03), and a shorter rapid eye movement stage (8 ± 8 vs. 17 ± 8; P < 0.001). Clinical data and sleep characteristics were similar in PD with/without EDS. Of interest, patients treated with clonazepam (CLNZ) had lower EDS than those without CLNZ (ESS, 7.9 ± 4.7 vs. 11.3 ± 4.0; P = 0.03). These patients suffered less periodic leg movement during sleep (2.1 ± 2.7 vs. 12.4 ± 28; P = 0.04), which might explain the finding. No correlation was found between ESS, MSLT, and all other clinical features analyzed. In PD patients, according to the data obtained, severity of EDS does not depend on any specific clinical factor and the etiology is probably multifactorial. Paradoxically, PD patients treated with CLNZ were less sleepy than patients not treated with CLNZ. © 2006 Movement Disorder Society
Special low‐protein foods ameliorate postprandial off in patients with advanced Parkinson's disease
Authors: Barichella Michela , Marczewska Agnieszka , De Notaris Roberta , Vairo Antonella , Baldo Cinzia , Mauri Andrea , Savardi Chiara , Pezzoli Gianni 
Published: June 2006

AbstractProtein intake interferes with levodopa therapy. Patients with advanced Parkinson's disease (PD) should restrict daily protein intake and shift protein intake to the evening. For further reduction of protein intake in the first part of the day, special low‐protein products (LPP) should be used instead of normal food products at breakfast and lunch. We studied the efficacy of LPP on postprandial off periods, in PD patients on levodopa therapy. The methods included a randomized, cross‐over, single‐blind, pilot clinical trial comparing a 2‐month balanced diet with a 2‐month LPP diet in 18 PD patients with motor fluctuations. The off phases were significantly shorter after LPP diet than after balanced diet (postprandial off, 49 ± 73 min vs. 79 ± 72 min and total off, 164 ± 148 min vs. 271 ± 174 min, both P < 0.0001). Moreover, a reduction in total off time during LPP diet (3.3 ± 2.7 hr vs. 4.7 ± 3.3 hr, P < 0.0001), occurred also in the 9 patients who did not experience subjective benefit. No significant changes in hematological and biochemical variables or body composition were recorded; a slight reduction in body weight (mean, −1.8%) was observed. Consumption of LPP in the first part of the day ameliorates off periods in PD patients, but additional studies including pharmacokinetics are needed. © 2006 Movement Disorder Society
Chemical exposures and Parkinson's disease: A population‐based case–control study
Authors: Frigerio Roberta , Sanft Kevin R. , Grossardt Brandon R. , Peterson Brett J. , Elbaz Alexis , Bower James H. , Ahlskog J. Eric , De Andrade Mariza , Maraganore Demetrius M. , Rocca Walter A. 
Published: June 2006

AbstractThe putative association between pesticide exposures and Parkinson's disease (PD) remains controversial. We identified all subjects who developed PD in Olmsted County, Minnesota, from 1976 through 1995, and matched them by age (± 1 year) and sex to general population controls. We assessed exposures to chemical products by means of telephone interview with cases, controls, or their proxies (149 cases; 129 controls). Exposure to pesticides related or unrelated to farming was associated with PD in men (odds ratio, 2.4; 95% confidence interval, 1.1–5.4; P = 0.04). The association remained significant after adjustment for education or smoking. Analyses for the other six categories of industrial and household chemicals were all nonsignificant. This population‐based study suggests a link between pesticides use and PD that is restricted to men. Pesticides may interact with other genetic or nongenetic factors that are different in men and women. © 2006 Movement Disorder Society
Factors influencing flip angle mapping in MRI: RF pulse shape, slice‐select gradients, off‐resonance excitation, and B0 inhomogeneities
Authors: Wang Jinghua , Mao Weihua , Qiu Maolin , Smith Michael B. , Constable R. Todd 
Published: June 2006

AbstractTo understand the various effects that influence actual flip angles, and correct for these effects, it is important to precisely quantify the MRI parameters (such as T1, T2, and perfusion). In this paper actual flip angle maps are calculated using a conventional gradient‐echo (GRE) sequence with different radiofrequency (RF) pulse shapes (Gaussian, sinc, and truncated‐sinc), slice‐selection gradients, off‐resonance excitations, and B0 field inhomogeneities. The experimental results demonstrate that RF pulse shapes significantly affect the flip angle distribution and calibration factors. Off‐resonance RF excitations, B0 nonuniformities, and slice‐selection gradients can lead to degradations in the signal intensities of the images used to map the flip angle, and potentially introduce a bias and increased variance in the measured flip angles. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Measurement of short and ultrashort T2 components using progressive binomial RF saturation
Authors: Ropele Stefan , Enzinger Christian , Seifert Thomas , Fazekas Franz 
Published: June 2006

AbstractA new magnetic resonance (MR) method for measuring T2 relaxation times in tissues is proposed. The method is based on a T2 selective saturation period followed by sampling of the remaining longitudinal magnetization. Saturation of the longitudinal magnetization is accomplished by a single binomial RF pulse of zeroth order with a constant flip angle. The T2 selectivity is controlled by the RF pulse duration. A full T2 spectrum can be obtained by performing a series of measurements with varying RF pulse duration. On a conventional 1.5 T system this approach allows detection of T2 components as short as several hundred microseconds. A major limitation is the method's susceptibility to resonance offsets. At typical offsets of 0.1–0.2 ppm the sensitivity of the method is limited to a T2 range below 20 ms, which corresponds to an RF pulse duration shorter than 50 ms. The new method was used to acquire T2 spectra from the liver of pigs in vitro on a conventional 1.5 T system. We observed a short T2 component around 17 ms and an ultrashort T2 component in the range of 0.9–1.1 ms. Numerical simulations and in vitro measurements suggest that resonance offsets have effects that require further investigation. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Resolution and SNR effects on carotid plaque classification
Authors: Ronen Raphael R. , Clarke Sharon E. , Hammond Robert R. , Rutt Brian K. 
Published: June 2006

AbstractMulticontrast‐weighted MRI, which is increasingly being used in combination with automatic classification algorithms, has the potential to become a powerful tool for assessing plaque composition. The current literature, however, does not address the relationship between imaging conditions and segmentation viability well. In this study 13 carotid endarterectomy samples were imaged with a 156‐μm in‐plane resolution and high signal‐to‐noise ratio (SNR) using proton density (PD), T1, T2, and diffusion weightings. The maximum likelihood (ML) algorithm was used to classify plaque components, with sets of three contrast weighting intensities used as features. The resolution and SNR of the images were then degraded. Classification accuracy was found to be independent of in‐plane resolution between 156 μm and 1250 μm, but dependent on SNR. Accuracy decreased less than 10% for degradation in SNR down to 25% of original values, and decreased sharply thereafter. The robustness of automatic classifiers makes them applicable to a wide range of imaging conditions, including standard in vivo carotid imaging scenarios. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Approximate dynamic programming methods for an inventory allocation problem under uncertainty
Authors: Topaloglu Huseyin , Kunnumkal Sumit 
Published: June 2006

AbstractWe propose two approximate dynamic programming methods to optimize the distribution operations of a company manufacturing a certain product at multiple production plants and shipping it to different customer locations for sale. We begin by formulating the problem as a dynamic program. Our first approximate dynamic programming method uses a linear approximation of the value function and computes the parameters of this approximation by using the linear programming representation of the dynamic program. Our second method relaxes the constraints that link the decisions for different production plants. Consequently, the dynamic program decomposes by the production plants. Computational experiments show that the proposed methods are computationally attractive, and in particular, the second method performs significantly better than standard benchmarks. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006
Stress intensity factor computation using the method of fundamental solutions: mixed‐mode problems
Authors: Berger J. R. , Karageorghis Andreas , Martin P. A. 
Published: June 2006

AbstractThe method of fundamental solutions is applied to the computation of stress intensity factors in linear elastic fracture mechanics. The displacements are approximated by linear combinations of the fundamental solutions of the Cauchy–Navier equations of elasticity and the leading terms for the displacement near the crack tip. Two algorithms are developed, one using a single domain and one using domain decomposition. Numerical results are given. Copyright © 2006 John Wiley & Sons, Ltd.
Molecular simulation of the glass transition and proton conductivity of 2,2′‐benzidinedisulfonic acid and 4,4′‐diaminodiphenylether‐2,2′‐disulfonic acid‐based copolyimides as polyelectrolytes for fuel cell applications
Authors: Hu Naiping , Chen Rongrong , Hsu Andrew 
Published: June 2006

AbstractThe glass transition temperatures (Tgs) and proton conductivities of polyimides synthesized from naphthalene‐1,4,5,8‐tetracarboxylic dianhydride (NTDA), 2,2′‐benzidinedisulfonic acid (BDSA), 4,4′‐diaminodiphenylether‐2,2′‐disulfonic acid (ODADS), and non‐sulfonated diamine monomers have been predicted using molecular dynamics simulations. The specific volumes for two dry and four hydrated NTDA‐based polyimides were plotted versus temperatures above and below Tgs to obtain the glass transition temperatures. The simulation results suggest that the ODADS‐based polyimide membranes exhibit lower Tgs and thus better mechanical properties than the BDSA‐based polyimides, which may be attributed to the high mobility of backbones of ODADS as supported by the vectorial autocorrelation function (VACF) results of this study. In addition, comparison of the simulated Tgs for the dry and hydrated ODADS‐based polyimides has shown that water content in polyimides can affect their Tgs. The proton conductivities of a representative polyimide in both dry and hydrated conditions have been obtained from molecular dynamics simulations of the proton and hydronium ion diffusion. The simulated conductivity for the hydrated NTDA‐ODADS/BAPB cell is in reasonable agreement with the experimental value obtained from the AC impedance method. The relationship between the chemical composition, chain flexibility, and the glass transition and proton conduction of these NTDA‐based polyimides was explored on the basis of VACF and pair correlation function analysis. Copyright © 2006 Society of Chemical Industry
Chemical and electrochemical synthesis of conducting graft copolymer of acrylonitrile with aniline
Authors: Hosseini S Hossein , Dabiri M , Ashrafi M 
Published: June 2006

AbstractA new conducting copolymer, polyacrylonitrile‐graft‐polyaniline (PAN‐g‐PANi), has been prepared by chemical and electrochemical methods from a precursor polymer. Poly[acrylonitrile‐co‐(acrylimine phenylenediamine)] (PAN‐co‐PAIPD) was synthesized chemically by reacting PAN with sodium 1,4‐phenylenediamine salt. PAN‐g‐PANi was synthesized chemically using ammonium peroxydisulfate as the oxidant and p‐toluenesulfonic acid in dimethylsulfoxide solution and adding aniline to oxidized PAN‐co‐PAIPD. Electrochemical polymerization was carried out by spin coating PAN‐co‐PAIPD on the surface of a Pt electrode, then the growth of the graft copolymer (PAN‐g‐PANi) in the presence of fresh aniline and acidic solution. The structures of the graft copolymer and PAN‐co‐PAIPD were characterized using UV‐visible, Fourier transform infrared, and 1H and 13C NMR spectroscopies. The thermal properties of PAN‐g‐PANi were studied using thermogravimetric analysis and differential scanning calorimetry. Scanning electron microscopy (SEM) images showed that the morphology of PAN‐g‐PANi copolymer films was homogeneous. Electrical conductivity of the copolymer was studied using the four‐probe method, which gave a conductivity of 4.5 × 10−3 S cm−1 with 51.4% PANi. SEM and electrical conductivity measurements supported the formation of the graft copolymer. Copyright © 2006 Society of Chemical Industry
Morphologies and properties of epoxy resin/layered silicate–silica nanocomposites
Authors: Jia Qingming , Zheng Maosheng , Cheng Jun , Chen Hongxiang 
Published: June 2006

AbstractA new nanofiller containing layered organo‐modified montmorillonite (oMMT) and spherical silica (SiO2) was prepared by an in situ deposition method and coupling agent modification. Fourier transform infrared spectrometry, X‐ray diffraction and transmission electron microscopy show that there are interactions between oMMT and SiO2, and the spherical SiO2 particles are self‐assembled on the edge of oMMT layers, forming a novel layered–spherical nanostructure. An epoxy resin (EP)/oMMT–SiO2 nanocomposite was obtained by adding oMMT–SiO2 to EP matrix. Morphologies and mechanical and thermal properties of the new ternary nanocomposite were investigated. For purposes of comparison, the corresponding binary nanocomposites, i.e., EP modified with either oMMT or SiO2, were also tested. The results for the mechanical properties show that oMMT obviously improves the strength of EP, and SiO2 enhances the toughness of EP, but oMMT–SiO2 exhibits a synergistic effect on toughening and reinforcing of EP. The toughening and reinforcing mechanism is explained by scanning electron microscopy. In addition, the thermal resistance of EP/oMMT–SiO2 is better than that of EP/SiO2, but it is worse than that of EP/oMMT. Copyright © 2006 Society of Chemical Industry
Retracted: Preparation and characterization of nitrile rubber/poly(vinyl chloride)/organoclay nanocomposites
Authors: Shokri Ahmad Ali 
Published: June 2006

AbstractRetracted: A. Shokri. Preparation and characterization of nitrile rubber/poly (vinyl chloride)/organoclay nanocomposites, Polymer International. [DOI: 10.1002/pi.2076].
The above article, published online in EarlyView on 13 June 2006, has been retracted for legal reasons.