bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel method for isolating Schwann cells using the extracellular domain of Necl1
Authors: Spiegel Ivo , Peles Elior 
Published: July 2009

AbstractMyelinating cocultures of Schwann cells and dorsal root ganglion neurons are a powerful experimental system for probing the molecular mechanisms of axon–Schwann cell interaction. The isolation of a pure population of myelination‐competent Schwann cells is a prerequisite for this experimental system. We describe here a protocol for a FACS‐based isolation of Schwann cells utilizing a specific affinity reagent (Necl1‐Fc) and the use of these isolated cells in myelinating cocultures. An advantage of the myelinating coculture system is that Schwann cells and the neurons can be genetically manipulated before they are cocultured. We further show that our method allows the isolation of virally transduced Schwann cells in a single purification step. This protocol for the FACS‐based isolation of myelination‐competent Schwann cells by Necl1‐Fc and the use of these cells in myelinating cocultures should significantly facilitate future studies aimed at delineation of the molecular mechanisms of axon–Schwann cell interactions and myelination. © 2009 Wiley‐Liss, Inc.
Effect of exogenous IGF‐1 on chondrocyte apoptosis in a rabbit intraarticular osteotomy model
Authors: Higgins Thomas F. , Johnson Brian D. 
Published: July 2009

AbstractInsulin‐like growth factor‐1 (IGF‐1) has been shown to protect chondrocytes from apoptosis in vitro. IGF‐1 expression may also assist in maintaining a fully differentiated chondrocyte phenotype. Theoretically, posttraumatic administration of IGF‐1 may inhibit chondrocyte apoptosis. This study is to determine if administration of IGF‐1 after fracture inhibits apoptosis in vivo. Twenty‐four mature female New Zealand white rabbits were randomized to control and IGF‐1 groups. All subjects underwent standardized medial femoral condyle fracture and repair. Fibrin clot was administered in all subjects, with 25 mcg/ml IGF‐1 in the clot in half the subjects. Half of the animals in each group were sacrificed at 2 weeks and half at 4 weeks, specimens were fixed and underwent TUNEL staining. Two‐week controls showed significantly higher rate of apoptosis than 2‐week IGF‐1 subjects (21 ± 6 vs. 12 ± 6, p = 0.04). Likewise, 4‐week controls showed significantly higher rate of apoptosis than 2‐week IGF‐1 subjects (23 ± 7 vs. 10 ± 2, p = 0.01). There was no significant administration difference between 2‐week control and 4‐week control subjects, or between 2‐week IGF‐1 and 4‐week IGF‐1 subjects. Intraarticular IGF‐1 at the time of fracture repair appears to inhibit chondrocyte apoptosis in vivo, as judged by TUNEL staining, in this animal model. If administration of IGF‐1 inhibits human chondrocyte apoptosis in vivo, this may lead to interventions that may reduce posttraumatic arthritis after fracture. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:125–130, 2010
k‐t PCA: Temporally constrained k‐t BLAST reconstruction using principal component analysis
Authors: Pedersen Henrik , Kozerke Sebastian , Ringgaard Steffen , Nehrke Kay , Kim Won Yong 
Published: July 2009

AbstractThe k‐t broad‐use linear acquisition speed‐up technique (BLAST) has become widespread for reducing image acquisition time in dynamic MRI. In its basic form k‐t BLAST speeds up the data acquisition by undersampling k‐space over time (referred to as k‐t space). The resulting aliasing is resolved in the Fourier reciprocal x‐f space (x = spatial position, f = temporal frequency) using an adaptive filter derived from a low‐resolution estimate of the signal covariance. However, this filtering process tends to increase the reconstruction error or lower the achievable acceleration factor. This is problematic in applications exhibiting a broad range of temporal frequencies such as free‐breathing myocardial perfusion imaging. We show that temporal basis functions calculated by subjecting the training data to principal component analysis (PCA) can be used to constrain the reconstruction such that the temporal resolution is improved. The presented method is called k‐t PCA. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
High dynamic‐range magnetic resonance spectroscopy (MRS) time‐domain signal analysis
Authors: Hutton William C. , Bretthorst G. Larry , Garbow Joel R. , Ackerman Joseph J.H. 
Published: July 2009

AbstractIn the absence of water signal suppression, the proton magnetic resonance spectroscopy (1H MRS) in vivo water resonance signal‐to‐noise ratio (SNR) is orders of magnitude larger than the SNR of all the other resonances. In this case, because the high‐SNR water resonance dominates the data, it is difficult to obtain reliable parameter estimates for the low SNR resonances. Herein, a new model is described that offers a solution to this problem. In this model, the time‐domain signal for the low SNR resonances is represented as the conventional sum of exponentially decaying complex sinusoids. However, the time‐domain signal for the high SNR water resonance is assumed to be a complex sinusoid whose amplitude is slowly varying from pure exponential decay and whose phase is slowly varying from a constant frequency. Thus, the water resonance has only an instantaneous amplitude and frequency. The water signal is neither filtered nor subtracted from the data. Instead, Bayesian probability theory is used to simultaneously estimate the frequencies, decay‐rate constants, and amplitudes for all the low SNR resonances, along with the water resonance's time‐dependent amplitude and phase. While computationally intensive, this approach models all of the resonances, including the water and the metabolites of interest, to within the noise level. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
CSF protein biomarkers for proximal axonal damage improve prognostic accuracy in the acute phase of Guillain‐Barré syndrome
Authors: Petzold A. , Brettschneider J. , Jin K. , Keir G. , Murray N.M.F. , Hirsch N.P. , Itoyama Y. , Reilly M.M. , Takeda A. , Tumani H. 
Published: July 2009

AbstractEarly predictors of prognosis in Guillain‐Barré syndrome (GBS) are needed to identify patients who are likely to make a poor recovery and to guide therapeutic decision‐making in the acute phase. Here we investigate whether axonal protein biomarkers released into the cerebrospinal fluid (CSF) following proximal axonal damage improve the early prognostic accuracy in GBS. A prospective multicenter study including 132 patients (38 GBS, 38 neurological controls, 42 headaches, 14 chronic inflammatory demyelinating neuropathy). CSF levels of axonal [neurofilament (NfH) and tau] and glial (S100B and glial fibrillary acidic protein) protein biomarkers were measured on admission. Nerve conduction studies were performed at the time of lumbar puncture and patients were classified according to neurophysiological criteria. Outcome was assessed on the Hughes functional score (F‐score). Poor outcome was defined as the inability to walk independently (F‐score ≥3). High NfH levels (>0.73 ng/ml) predicted poor outcome (P = 0.01) with an odds ratio of 7.3 and correlated with the outcome F‐score (R = 0.51, P < 0.01), as did hTau levels (R = 0.47, P < 0.01). Patients with poor outcome had significantly higher CSF NfH (median 1.78 ng/ml) when compared to those with good outcome (0.03 ng/ml) or all of the control groups (neurological controls 0.18 ng/ml, headaches 0.06 ng/ml, chronic inflammatory demyelinating neuropathy 0.05 ng/ml). Except for age (P < 0.05) and need for ventilatory support (P < 0.05), none of the other features reliably predicted outcome. Improved prognostic accuracy in the acute phase of GBS seems possible using CSF NfH levels. Muscle Nerve 40: 42–49, 2009
Fiber density of the motor units recruited at high and low force output
Authors: Lukács Miklós , Vécsei László , Beniczky Sándor 
Published: July 2009

AbstractMotor units (MUs) are recruited according to the size principle. At low force output, macro‐motor unit potentials (macro‐MUPs) with small amplitude and area are recorded; MUs with large electrical size fire at high force output. Our objective was to elucidate whether this difference is caused by a higher fiber density (FD) of the MUs recruited at high force output. We measured the FD and respectively the amplitude and the area of the macro‐MUPs via single‐fiber macro electromyography (EMG) recorded at low and high force output in 48 healthy subjects. The macro‐MUPs were significantly larger at high force output than at low force. The FD did not differ at the two force levels. Our findings suggest that the larger electrical size of the high recruitment threshold MUs is due not to a higher FD, but to a larger territory. FD is a robust EMG parameter, independent of the level of the force output. Muscle Nerve 40: 112–114, 2009
Motor unit number estimation in the rat tail using a modified multipoint stimulation technique
Authors: Kasselman Lora J. , Shefner Jeremy M. , Rutkove Seward B. 
Published: July 2009

AbstractMotor unit number estimation (MUNE) of the rodent hindlimb has been used mainly for following the progression of motor neuron disorders. By performing MUNE in the tail, however, progression of axonal neuropathy could also be assessed, as both proximal and distal regions would be available for study. In this investigation, three raters performed a modified multipoint stimulation MUNE technique in the tails of 14 healthy adult rats. The technique was straightforward to perform, with a relatively narrow range of motor unit number estimates of 40 ± 16 (standard deviation) for the proximal tail and 21 ± 11 for the distal tail. Intrarater reliability coefficients were 0.31 (P = 0.033) and 0.32 (P = 0.028) for the proximal and distal tail, respectively. Interrater reliability coefficients were 0.22 (P = 0.086) and 0.44 (P = 0.004). These reliability assessments, along with the relatively low motor unit estimates and narrow range of values, support the idea that rat tail MUNE may have utility in the evaluation of rodent models of neuromuscular disease, including length‐dependent neuropathy. Muscle Nerve 40: 115–121, 2009
Torque‐based triggering improves stimulus timing precision in activation tests
Authors: Krishnan Chandramouli , Allen Eric J. , Williams Glenn N. 
Published: July 2009

AbstractThe aim of this study was to assess whether automated torque‐based stimulator triggering could improve precision in delivering stimuli near peak torque during voluntary activation tests. The quadriceps activation test was used as a test model in 11 volunteers. Automated torque‐based triggering reduced stimulus delivery timing errors by 75% when compared with conventional automated time‐based triggering. Torque‐based stimulator triggering is recommended as an alternative to automated time‐based triggering in voluntary activation tests, as it improves stimulus timing precision and thereby reduces measurement error. Muscle Nerve 40: 130–133, 2009
Thymic carcinoma in myasthenia gravis developing years after thymectomy
Authors: Katzberg Hans D. , Miller Robert G. , Katz Jonathan 
Published: July 2009

AbstractWe report two patients with myasthenia gravis (MG) who underwent thymectomy but developed thymic carcinoma years after the initial surgery. In one patient, the initial thymic pathology was normal, whereas the other had an encapsulated benign thymoma that was found only on pathological assessment. These cases demonstrate that MG may occur as part of a “new” paraneoplastic syndrome even after thymectomy. The late appearance of metastatic thymoma raises questions about monitoring for these patients. Muscle Nerve 40: 137–138, 2009
Median nerve ultrasonography in carpal tunnel syndrome: Findings from two laboratories
Authors: Hobson‐Webb Lisa D. , Padua Luca 
Published: July 2009

AbstractUltrasonographic (US) enlargement of the median nerve at the wrist is known to be consistent with carpal tunnel syndrome (CTS), although the effects of different measurement techniques, equipment, and patient populations remain unknown. The purpose of this study was to examine the similarities and differences of US findings in CTS between two electromyography (EMG) laboratories. In 2006 and 2007, US measurements of the median nerve were recorded independently and statistically analyzed in patients with CTS at two EMG laboratories (Duke University, Durham, NC, USA, and Università Cattolica del Sacro Cuore, Rome, Italy). Patient age, median nerve area in the forearm, and neurophysiologic score did not differ significantly between the two laboratories. The North Carolina group had a larger median nerve area at the wrist and wrist‐to‐forearm ratio than the Italian group, although both were elevated in reference to established values for the diagnosis of CTS. Median nerve US is less susceptible to differences between laboratories than previously thought, permitting greater generalization of findings. Muscle Nerve 40: 94–97, 2009
Determination of the best electrode position for recording of the diaphragm compound muscle action potential
Authors: Dionne Annie , Parkes Anthony , Engler Beata , Watson Bradley V. , Nicolle Michael W. 
Published: July 2009

AbstractTo determine the optimal recording site for phrenic nerve conduction studies, six different recording techniques were compared in 11 healthy volunteers (22 phrenic nerves). The mean diaphragm compound muscle action potential (CMAP) amplitude, side‐to‐side difference, and the number of studies with a false‐positive result (CMAP amplitude <0.30 mV) were compared for each technique. The largest amplitude (0.65 ± 0.23 mV, range 0.30–1.2 mV) with good right–left agreement (mean difference 0.15 mV) and no false positives was obtained using technique 1, where the G1 electrode was positioned 5 cm above the xiphoid process and G2 16 cm from G1 along the costal margin. This was also the easiest technique to perform. It does not require rib counting, which may be difficult and inaccurate, especially in overweight patients. At least one false positive occurred with each of the remaining five techniques. Muscle Nerve 40: 37–41, 2009
Diagnostic nerve ultrasound in Charcot–Marie–Tooth disease type 1B
Authors: Cartwright Michael S. , Brown Martin E. , Eulitt Patrick , Walker Francis O. , Lawson Victoria H. , Caress James B. 
Published: July 2009

AbstractUltrasound is emerging as a useful tool for evaluation of neuromuscular conditions, because it can provide high‐resolution anatomic information to complement electrodiagnostic data. There have been few studies in which ultrasound was used to assess the peripheral nerves of individuals with Charcot–Marie–Tooth (CMT) disease and none involving CMT type 1B. In this study we compared nerve cross‐sectional area in individuals from a single large family with CMT 1B with normal, healthy controls. We also assessed for cranial nerve enlargement in those with CMT 1B with cranial neuropathies compared to those with CMT 1B without cranial neuropathies. Individuals with CMT 1B have significantly larger median and vagus nerves than healthy controls, but no difference was seen in cranial nerve size between those with versus those without cranial neuropathies. This is the first study to characterize the ultrasonographic findings in the peripheral nerves of individuals with CMT 1B. Muscle Nerve 40: 98–102, 2009
Atrogin‐1, MuRF1, and FoXO, as well as phosphorylated GSK‐3β and 4E‐BP1 are reduced in skeletal muscle of chronic spinal cord–injured patients
Authors: Léger Bertrand , Senese Rosalba , Al‐Khodairy Abdul W. , Dériaz Olivier , Gobelet Charles , Giacobino Jean‐Paul , Russell Aaron P. 
Published: July 2009

AbstractChronic complete spinal cord injury (SCI) is associated with severe skeletal muscle atrophy as well several atrophy and physical‐inactivity–related comorbidity factors such as diabetes, obesity, lipid disorders, and cardiovascular diseases. Intracellular mechanisms associated with chronic complete SCI‐related muscle atrophy are not well understood, and thus their characterization may assist with developing strategies to reduce the risk of comorbidity factors. Therefore, the aim of this study was to determine whether there was an increase in catabolic signaling targets, such as atrogin‐1, muscle ring finger‐1 (MuRF1), forkhead transcription factor (FoXO), and myostatin, and decreases in anabolic signaling targets, such as insulin‐like growth factor (IGF), v‐akt murine thymoma viral oncogene (Akt), glycogen synthase kinase‐β (GSK‐3β), mammalian target of rapamycin (mTOR), eukaryotic initiation factor 4E binding protein 1 (4E‐BP1), and p70s6kinase in chronic complete SCI patients. In SCI patients, when compared with controls, there was a significant reduction in mRNA levels of atrogin‐1 (59%; P < 0.05), MuRF1 (55%; P < 0.05), and myostatin (46%; P < 0.01), and in protein levels of FoXO1 (72%; P < 0.05), FoXO3a (60%; P < 0.05), and atrogin‐1 (36%; P < 0.05). Decreases in the protein levels of IGF‐1 (48%; P < 0.001) and phosphorylated GSK‐3β (54%; P < 0.05), 4E‐BP1 (48%; P < 0.05), and p70s6kinase (60%; P = 0.1) were also observed, the latter three in an Akt‐ and mTOR‐independent manner. Reductions in atrogin‐1, MuRF1, FoXO, and myostatin suggest the existence of an internal mechanism aimed at reducing further loss of muscle proteins during chronic SCI. The downregulation of signaling proteins that regulate anabolism, such as IGF, GSK‐3β, and 4E‐BP1, would reduce the ability to increase protein synthesis rates. Muscle Nerve 40: 69–78, 2009
Correlation between isometric force and intramuscular pressure in rabbit tibialis anterior muscle with an intact anterior compartment
Authors: Winters Taylor M. , Sepulveda Genaro S. , Cottler Patrick S. , Kaufman Kenton R. , Lieber Richard L. , Ward Samuel R. 
Published: July 2009

AbstractTo determine the degree to which intramuscular pressure (IMP) and muscle force are correlated in an intact compartment, a custom pressure transducer was inserted into the rabbit tibialis anterior (TA) while activating the muscle via the peroneal nerve and measuring TA muscle force distal to the ankle retinaculum. In general, IMP was more variable compared with muscle force throughout the entire isometric length–tension relationship. In contrast to results obtained on isolated TA muscles, IMP–force relations with the compartment intact were not significantly different between the ascending and descending limbs of the length–tension curve. Specifically, average relative pressure–force coefficients of determination (r2) were 0.76 ± 0.11 for the active ascending limb and 0.98 ± 0.01 for the active descending limb. These data demonstrate that muscle force and IMP are fairly well correlated under isometric conditions and that this relationship is not improved by measuring IMP in an intact environment. Muscle Nerve 40: 79–85, 2009
“Dropped head syndrome” caused by Lambert–Eaton myasthenic syndrome
Authors: Ueda T. , Kanda F. , Kobessho H. , Hamaguchi H. , Motomura M. 
Published: July 2009

AbstractA 67‐year‐old man was admitted with a 2‐year history of dropped head. Neurological examination revealed ptosis, dysarthria, neck weakness, hyporeflexia of all limbs, and autonomic failure. Electrophysiologic study showed a 400% increment response to high‐rate repetitive nerve stimulation. Serum anti‐P/Q‐voltage‐gated calcium channel antibody was positive, confirming the diagnosis of Lambert–Eaton myasthenic syndrome (LEMS). His symptoms and electrophysiological abnormalities improved with oral prednisolone following plasmapheresis. This is the first report of LEMS as a cause of dropped head syndrome. Muscle Nerve 40: 134–136, 2009
Enzyme replacement therapy in adult‐onset glycogenosis II: Is quantitative muscle MRI helpful?
Authors: Pichiecchio A. , Poloni G.U. , Ravaglia S. , Ponzio M. , Germani G. , Maranzana D. , Costa A. , Repetto A. , Tavazzi E. , Danesino C. , Moglia A. , Bastianello S. 
Published: July 2009

AbstractAlthough it has been shown that muscle magnetic resonance imaging (MRI) improves the phenotypic characterization of patients with neuromuscular disorders and allows accurate quantification of muscle and adipose tissue distribution, to date quantitative MRI has not been used to assess the therapeutic response in clinical trials of neuromuscular diseases. We discuss quantitative MRI findings after a 6‐month course of enzyme replacement therapy administered to nine patients with adult‐onset glycogenosis II. Muscle Nerve 40: 122–125, 2009
Serum creatine kinase levels in spinobulbar muscular atrophy and amyotrophic lateral sclerosis
Authors: Chahin Nizar , Sorenson Eric J. 
Published: July 2009

AbstractWe compared serum creatine kinase (CK) levels between spinobulbar muscular atrophy (SBMA) and amyotrophic lateral sclerosis (ALS) and reviewed available histochemical studies of frozen sections of muscle biopsies. CK levels and the frequency of patients with elevated CK levels were significantly higher in the SBMA group when compared with the ALS group. CK levels occasionally approached values up to 8 times the upper limit of normal in the SBMA group. In addition to the chronic neurogenic changes in the muscle biopsy, all SBMA patients showed one or more myopathic changes. Increased numbers of markedly hypertrophic fibers were consistently seen in all patients. It is not clear whether the elevated CK level is directly related to the increased number of hypertrophic fibers or to other myopathic features. Based on these findings, we recommend genetic testing for SBMA in cases of male patients with motor neuron disease who present with a significantly elevated serum creatine kinase level, even when other characteristic clinical features of SBMA are absent. Muscle Nerve 40: 126–129, 2009
Increased sensitivity to a nondepolarizing muscle relaxant in a patient with acquired neuromyotonia
Authors: Ginsburg Greg , Forde Ryan , Martyn Jeevendra A.J. , Eikermann Matthias 
Published: July 2009

AbstractNeuromyotonia is a disorder of hyperexcitability of the peripheral nerve. It has electromyographic features of spontaneous, continuous, irregularly occurring doublets, or multiplets of motor unit potential discharges. Neuromyotonia is characterized by both myokymic and neuromyotonic discharges. To our knowledge, this is the first report in the literature to assess the sensitivity of skeletal muscle to a nondepolarizing muscle relaxant drug, rocuronium, in a woman with acquired neuromyotonia. She had a past medical history notable for prolonged postoperative paralysis following anesthesia. The patient showed increased sensitivity to the neuromuscular effects of rocuronium. This increase in sensitivity may be explained by downregulation of acetylcholine receptors in response to chronic high agonist (acetylcholine) concentrations. If patients with neuromyotonia receive anesthesia, we recommend that smaller doses of a nondepolarizing muscle relaxant be administered, accompanied by monitoring of neuromuscular function, so as to provide optimal muscle relaxation while avoiding overdose and prolonged postoperative recovery. Muscle Nerve 40: 139–142, 2009