bluuebunny/crossref_metadata_2025_split huggingface dataset:
Static load magnitude is a risk factor in the development of cumulative low back disorder
Authors: Sbriccoli Paola , Solomonow Moshe , Zhou Bing‐He , Baratta Richard V. , Lu Yun , Zhu Meng‐Ping , Burger Evalina L. 
Published: January 2004

AbstractOccupations requiring frequent periods of static lumbar flexion are known epidemiologically to be risk factors for the development of cumulative low back disorder. The impact of the load magnitude sustained during a series of short static lumbar flexions followed by an equally long rest period on the development of a cumulative low back disorder was addressed in an in vivo feline model. Static loads of 20, 40, and 60 N were applied over 10 min of flexion followed by 10‐min rest sessions that were repeated six times (for a total of 2 h) while monitoring lumbar viscoelastic creep (laxity) and reflex electromyographic (EMG) activity from the multifidus muscles. Creep and EMG were also monitored over 7 h of rest following the six flexion–rest sessions. It was found that the creep developed in the 10‐min flexion periods did not recover completely during the following 10 min of rest, giving rise to a large cumulative creep at the end of the work–rest session. Muscle activity demonstrated spasms during the static flexion periods as well as initial and delayed hyperexcitability during the 7‐h rest period. Loads of 20 and 40 N did not result in delayed hyperexcitability, whereas loads of 60 N resulted in delayed hyperexcitability. Statistical analysis demonstrated that increased load significantly intensified the magnitude of the hyperexcitabilities (P < 0.05). Thus, repeated periods of static lumbar flexion were found to result in a transient neuromuscular disorder with an intensity directly related to the load magnitude, which should be considered a compounding risk factor. Muscle Nerve 29: 300–308, 2004
Somatosensory evoked potentials for the electrodiagnosis of meralgia paresthetica
Authors: Seror P. 
Published: January 2004

AbstractThe aim of this study was to evaluate the diagnostic utility of somatosensory evoked potential (SSEP) studies of the lateral femoral cutaneous nerve (LFCN) in assessing patients with meralgia paresthetica. Twenty‐one consecutive patients with unilateral meralgia paresthetica, as defined clinically (sensory impairment of lateral aspect of the thigh) and electrodiagnostically (abnormal sensory nerve conduction), and 21 control subjects were studied with two SSEP methods. SSEPs were elicited by stimulation of the LFCN below the anterior superior iliac spine (ASIS stimulation) and by cutaneous stimulation of the lateral aspect of the distal third of the thigh (thigh stimulation). Abnormalities were defined by the SSEP interside latency difference, interside amplitude ratio, or an absent response. The SSEP with ASIS stimulation had a sensitivity of 5% and a specificity of 95%, whereas with thigh stimulation it had a sensitivity of 52% and a specificity of 76%. Overall, SSEP after ASIS stimulation had no diagnostic value. Recording of the SSEP after thigh stimulation is recommended in obese patients only when sensory nerve conduction cannot be determined. Muscle Nerve 29: 309–312, 2004
Passive exercise and fetal spinal cord transplant both help to restore motoneuronal properties after spinal cord transection in rats
Authors: Beaumont Eric , Houlé John D. , Peterson Charlotte A. , Gardiner Phillip F. 
Published: January 2004

AbstractSpinal cord transection influences the properties of motoneurons and muscles below the lesion, but the effects of interventions that conserve muscle mass of the paralyzed limbs on these motoneuronal changes are unknown. We examined the electrophysiological properties of rat lumbar motoneurons following spinal cord transection, and the effects of two interventions shown previously to significantly attenuate the associated hindlimb muscle atrophy. Adult rats receiving a complete thoracic spinal cord transection (T‐10) were divided into three groups receiving: (1) no further treatment; (2) passive cycling exercise for 5 days/week; or (3) acute transplantation of fetal spinal cord tissue. Intracellular recording of motoneurons was carried out 4–5 weeks following transection. Transection led to a significant change in the rhythmic firing patterns of motoneurons in response to injected currents, as well as a decrease in the resting membrane potential and spike trigger level. Transplants of fetal tissue and cycling exercise each attenuated these changes, the latter having a stronger effect on maintenance of motoneuron properties, coinciding with the reported maintenance of structural and biochemical features of hindlimb muscles. The mechanisms by which these distinct treatments affect motoneuron properties remain to be uncovered, but these changes in motoneuron excitability are consistent with influences on ion conductances at or near the initial segment. The results may support a therapeutic role for passive limb manipulation and transplant of stem cells in slowing the deleterious responses of motoneurons to spinal cord injury, such that they remain more viable for subsequent alternative strategies. Muscle Nerve 29: 234–242, 2004
EMG and nerve conduction studies in children with congenital muscular dystrophy
Authors: Quijano‐Roy Susana , Renault Francis , Romero Norma , Guicheney Pascale , Fardeau Michel , Estournet Brigitte 
Published: January 2004

AbstractMotor and sensory nerve conduction velocities (NCVs) and needle electromyography (EMG) results were reviewed in 26 children with different types of congenital muscular dystrophy (CMD), including patients with mutations in the genesLAMA2,FKRP, andCOL6A2. In every patient, at least one EMG examination detected myopathic changes that were predominant in proximal muscles, although EMG performed at birth was normal in two patients. Brief bursts of high‐frequency repetitive discharges were electrically elicited in four patients. Uniformly slowed motor NCVs without signs of denervation were observed in seven patients: five merosin‐deficient, one merosin‐positive, and one with unavailable merosin status. The merosin‐deficient neuropathy also involved sensory nerves in three patients and worsened with age in two. In conclusion, myopathic EMG changes were typical and early findings in all types of CMD. An associated neuropathy was detected in most patients with merosin‐deficient CMD, and also in a child with normal merosin expression. Muscle Nerve 29: 292–299, 2004
Muscle pathology in 57 patients with myotonic dystrophy type 2
Authors: Schoser Benedikt G.H. , Schneider‐Gold Christiane , Kress Wolfram , Goebel Hans‐Hilmar , Reilich Peter , Koch Manuela C. , Pongratz Dieter E. , Toyka Klaus V. , Lochmüller Hanns , Ricker Kenneth 
Published: January 2004

AbstractWe evaluated muscle biopsies from 57 patients with genetically confirmed myotonic dystrophy type 2/proximal myotonic myopathy (DM2/PROMM). Light microscopy showed myopathic together with “denervation‐like” changes in almost all biopsies obtained from four different muscles: increased fiber size variation, internal nuclei, small angulated fibers, pyknotic nuclear clumps, and predominant type 2 fiber atrophy. Quantitative morphometry in 18 biopsies that were immunostained for myosin heavy chain confirmed a predominance of nonselective type 2 fiber atrophy. These histological changes were similar in all patients regardless of the site of biopsy, the predominant clinical symptoms and signs, and the clinical course. It is likely that, in a number of undiagnosed patients, DM2 is the underlying disorder. With a better understanding of the histopathological pattern in DM2, biopsies from patients with undiagnosed neuromuscular disorders can now be reevaluated. Muscle Nerve 29: 275–281, 2004
Overexpression of semicarbazide‐sensitive amine oxidase in human myopathies
Authors: Olivé Montse , Unzeta Mercè , Moreno Dolores , Ferrer Isidro 
Published: January 2004

AbstractOxidative stress has been implicated in the pathogenesis of several muscle diseases. Semicarbazide‐sensitive amine oxidase (SSAO) metabolizes oxidative deamination of primary aromatic and aliphatic amines. In the oxidative reactions, amine substrates are converted into the aldehyde, followed by the production of ammonia and H2O2. Although normal levels in muscle are very low, SSAO is expressed in almost all mammalian tissues. In this study, we examined the possible implication of SSAO as an additional source of oxidative stress in the pathogenesis of muscle disorders. The expression of SSAO was examined immunohistochemically in muscle biopsy specimens from patients with inclusion‐body myositis (IBM; n = 5), desmin‐related myopathy (DRM; n = 3), dermatomyositis (n = 3), granulomatous (sarcoid) myopathy (n = 2), muscle denervation–reinnervation (n = 3), and rhabdomyolysis (n = 2), as well as from control subjects (n = 3). Strong SSAO immunoreactivity was present in vacuolated and nonvacuolated fibers in IBM, in abnormal fibers in DRM, and in degenerating and regenerating fibers in dermatomyositis and rhabdomyolysis. In addition, SSAO overexpression was observed in muscle fibers adjacent to granulomas in sarcoid myopathy. These results suggest that SSAO is a source of oxidative stress in diseased human skeletal muscle and that it contributes to oxidative stress‐induced damage in various inflammatory and other myopathies. Alternatively, the expression of SSAO in muscle fibers may be a consequence of muscle fiber injury. Muscle Nerve 29: 261–266, 2004
Excitability properties of human median axons measured at the motor point
Authors: Kuwabara Satoshi , Bostock Hugh , Ogawara Kazue , Sung Jia‐Ying , Misawa Sonoko , Kitano Yukiko , Mizobuchi Keiko , Lin Cindy S.‐Y. , Hattori Takamichi 
Published: January 2004

AbstractThreshold tracking was used to measure excitability indices (strength–duration properties, threshold electrotonus, and the current‐threshold relationship) at the motor point of the abductor pollicis brevis, and the results were compared with those of the median nerve at the wrist. Using an accelerometer placed at the thumb tip, movement‐related potentials were recorded as target responses. When stimulating at the same site, excitability measurements were no different, and their variability no greater, when the target responses were movements rather than muscle action potentials. Motor point stimulation resulted in significantly shorter strength–duration time‐constant and higher rheobase than wrist stimulation. In addition, the technique of latent addition showed that a slow component was much smaller at the motor point than at the wrist. In threshold electrotonus, threshold changes in response to depolarizing and hyperpolarizing conditioning currents were significantly smaller at the motor point than at the wrist. The differences in strength–duration time‐constant and latent addition suggest that persistent Na+ current at the resting potential is smaller at the motor point. The differences in threshold electrotonus may depend in part on altered fiber geometry but suggest that inward and possibly outward rectification are increased distally. Motor point excitability testing may provide new insights into the pathophysiology of the nerve terminals in a variety of peripheral neuropathies and motor neuron disorders. Muscle Nerve 29: 227–233, 2004
Transthyretin amyloidosis presenting with multifocal demyelinating mononeuropathies
Authors: Briemberg Hannah R. , Amato Anthony A. 
Published: January 2004

AbstractWe describe a patient with transthyretin amyloidosis who presented with multifocal mononeuropathies with features of demyelination on nerve conduction studies, a constellation of findings not previously described in amyloid polyneuropathy. Genetic testing revealed a valine122isoleucine mutation in the coding region of the transthyretin gene, a mutation that generally presents with late‐onset cardiac amyloidosis. Our patient was also unusual in that she was 34 years old at the time of presentation and had no cardiac involvement. Muscle Nerve 29: 318–322, 2004
Consolidation analysis of a cross‐anisotropic homogeneous elastic soil using a finite layer numerical method
Authors: Mei Guo‐Xiong , Yin Jian‐Hua , Zai Jin‐Min , Yin Zong‐Ze , Ding Xiao‐Li , Zhu Guo‐Fu , Chu Lok Man 
Published: January 2004

AbstractThis paper presents a finite layer procedure for Biot's consolidation analysis of layered soils using a cross‐anisotropic elastic constitutive model. The program is first verified using published results. Then, using this program, the influences of cross‐anisotropy on the immediate settlement, the final settlement, and the consolidation behaviour are investigated by changing one model parameter at one time. The results obtained using the cross‐anisotropic elastic model are compared with results using an isotropic elastic model. It is found that the cross‐anisotropy has very large influences on the immediate settlement, the final settlement, and the consolidation behaviour. Curves or tables of the immediate settlement coefficients, the final settlement coefficients, and the average degree of consolidation are obtained and presented in the paper. These curves or tables can be easily used to estimate the immediate settlement, the final settlement, and the consolidation settlement of a cross‐anisotropic soil. Copyright © 2004 John Wiley & Sons, Ltd.
A cyclic viscoelastic–viscoplastic constitutive model for clay and liquefaction analysis of multi‐layered ground
Authors: Oka Fusao , Kodaka Takeshi , Kim Yong‐Seong 
Published: January 2004

AbstractIn order to estimate viscous effect of clay in the wide range of low to high level of strain, a cyclic viscoelastic–viscoplastic constitutive model for clay is proposed. First, we confirm the performance of the proposed model by simulating the cyclic undrained triaxial tests to determine the cyclic strength and deformation characteristics of a natural marine clay. Then, the proposed model is incorporated into an effective stress based liquefaction analysis method to estimate the effect of an intermediate clay layer on the behaviour of liquefiable sand layers.The seismic response against foreshocks, main shock as well as aftershocks of 1995 Hyogoken Nambu Earthquake is analysed in the present study. The difference of shear strength characteristics of the alluvial clay layer is one of the reasons why Port Island has a higher liquefaction potential than that of Rokko Island. The proposed model gives a good description of the damping characteristics of clay layer during large earthquakes. Acceleration responses in both clay layer and liquefiable sand layer just above it are damped due to viscous effect of clay. In the case of main shock and the following aftershocks that occurred within less than 9 days after main event, acceleration responses near ground surface are de‐amplified due to the developed excess pore water pressure, while responses near ground surface are amplified before and long after the main event. Using the viscoelastic–viscoplastic model for clay layer, time history of acceleration response in upper liquefiable sand layer can be well calculated, in particular in the range of microtremor process after the main seismic motion. Copyright © 2004 John Wiley & Sons, Ltd.
Stability analysis of rock slopes with a modified Hoek–Brown failure criterion
Authors: Yang Xiao‐Li , Li Liang , Yin Jian‐Hua 
Published: January 2004

AbstractThe original Hoek–Brown (HB) failure criterion was used to analyse the stability of rock slopes. For highly fractured rock, the original HB failure criterion has been modified, but its effect on the stability of rock slopes has not been studied. Within the framework of the kinematical approach of limit analysis, this paper computes the rigorous upper bounds of stability factors of homogeneous rock slopes with the modified HB failure criterion under the plane strain condition, by employing a ‘generalized tangential’ technique. In such technique, instead of using the modified HB failure criterion, a series of linear failure surfaces tangent to the actual non‐linear failure surface are utilized to derive the upper bound solutions, incorporating a new parameter n ranging from 0.5 to 0.65. The numerical results are compared with other published solutions for the case of n=0.5. The effects of the n on the stability factors of rock slopes are discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Advective transport from a penny‐shaped crack in a porous medium and an associated uniqueness theorem
Authors: Selvadurai A. P. S. 
Published: January 2004

AbstractThis paper examines the problem of the advective transport of a contaminant from sources in the shape of either a penny‐shaped crack or an elongated needle‐shaped cavity located in a porous medium of infinite extent. The advective transport is induced by Darcy flow in the porous medium, where the internal boundary is maintained at a constant potential. The paper presents an approximate analytical solution to this problem, which is deduced from a formulation that models a cavity in the shape of either an oblate or a prolate spheroid. The results also represent one of the few spatially three‐dimensional exact analytical solutions for the, albeit linear, hyperbolic problem governing the contaminant transport problem. The paper also presents a canonical proof of uniqueness for advective contaminant transport problems associated with media of infinite extent. Copyright © 2004 John Wiley & Sons, Ltd.
Odorant receptor expression in the mouse cerebral cortex
Authors: Otaki Joji M. , Yamamoto Haruhiko , Firestein Stuart 
Published: January 2004

AbstractMammalian odorant receptors have been known to be involved not only in odorant detection but also in neuronal development of olfactory sensory neurons. We have examined a possibility of odorant receptor expression in nonolfactory neurons in the mouse. Mouse odorant receptors (M71, C6, and OR3), two of which were already shown to be functionally activated by odorants in heterologous systems, were detected by polymerase chain reactions (PCRs) from the cerebral cortex but not from other brain tissues. Degenerate PCR further suggested that other odorant receptors were also expressed in the mouse cerebral cortex. One of these receptors showed high sequence‐match with a putative chick odorant receptor OR7 transiently expressed in the notochord during development. In situ hybridization detected signals for M71 and C6 receptors in the layer II cortical pyramidal neurons located in the occipital pole. In the M71‐IRES‐tauLacZ mouse, in which M71 expression was genetically marked with tauLacZ, X‐gal staining signals were mostly localized in the layer II neurons in the occipital pole, being consistent with the in situ hybridization result. Fluorescent immunohistochemistry using anti‐β‐galactosidase antibody further detected the tauLacZ signals in the same cells. X‐gal staining began at P3, peaked at P8, and continued to adults, although signals gradually decreased. These data showed that at least a few odorant receptors are expressed not only in olfactory sensory neurons but also in pyramidal neurons in the cerebral cortex, possibly playing an important role either in chemical detection of exogenous or endogenous ligands or in a developmental process such as axon guidance and target recognition. © 2003 Wiley Periodicals, Inc. J Neurobiol 58:315–327, 2004
Presynaptic protein kinase C controls maturation and branch dynamics of developing retinotectal arbors: Possible role in activity‐driven sharpening
Authors: Schmidt John T. , Fleming Matthew R. , Leu Byunghee 
Published: January 2004

AbstractVisual activity refines developing retinotectal maps and shapes individual retinal arbors via an NMDA receptor‐dependent mechanism. As retinal axons grow into tectum, they slow markedly and emit many transient side branches behind the tip, assuming a “bottlebrush” morphology. Some branches are stabilized and branch further, giving rise to a compact arbor. The dynamic rate of branch addition and deletion is increased twofold when MK801 is used to block NMDA receptors, as if this prevents release of a stabilizing signal such as arachidonic acid (AA) from the postsynaptic neuron. In optic tract, AA mediates NCAM and L1 stimulation of axon growth by activating presynaptic protein kinase C (PKC) to phosphorylate GAP‐43 and stabilize F‐actin, and, if present in tectum, this growth control pathway could be modulated by postsynaptic activation. To test for the effects on arbor morphology of blocking PKC or AA release, we examined DiO‐labeled retinal axons of larval zebrafish with time‐lapse videomicroscopy. Bath application of the selective PKC inhibitor bisindolylmaleimide from 2 or 3 days onward doubled the rate at which side branches were added and deleted, as seen with MK801, and also prevented maturation of the arbor so that it retained a “bottlebrush” morphology. In order to selectively block the PKC being transported to retinal terminals, we injected the irreversible inhibitor calphostin C into the eye from which the ganglion cells were labeled, and this produced both effects seen with bath application. In contrast, there were no effects of control injections, which included Ringers into the same eye and the same dose into the opposite eye (actually much closer to the tectum of interest), to rule out the possibility that the inhibitor leaked from the eye to act on tectal cells. For comparison, we examined arbors treated with the NMDA blocker MK801 at half‐hour time‐lapse intervals, and detected the twofold rise in rates of branch addition and deletion previously reported in Xenopus larvae, but not the structural effect seen with the PKC inhibitors. In addition, we could produce both effects seen with PKC inhibitors by using RHC80267 to block AA release from DAG lipase, indicating that AA is the main drive for PKC activation. Thus, the results show a distinct role of AA and presynaptic PKC in both maturation of arbor structure and in the dynamic control of branching. The effects on branch dynamics were present regardless of the level of maturity of arbor structure. The fact that they mimicked those of MK801 suggests that presynaptic PKC may be involved in the NMDA receptor‐driven stabilization of developing retinal arbors. © 2003 Wiley Periodicals, Inc. J Neurobiol 58: 328–340, 2004
Estrogen contributes to seasonal plasticity of the adult avian song control system
Authors: Soma Kiran K. , Tramontin Anthony D. , Featherstone Joy , Brenowitz Eliot A. 
Published: January 2004

AbstractSongbirds show dramatic neural plasticity as adults, including large‐scale anatomical changes in discrete brain regions (“song control nuclei”) controlling the production of singing behavior. The volumes of several song control nuclei are much larger in the breeding season than in the nonbreeding season, and these seasonal neural changes are regulated by plasma testosterone (T) levels. In many cases, the effects of T on the central nervous system are mediated by neural conversion to estradiol (E2) by the enzyme aromatase. The forebrain of male songbirds expresses very high levels of aromatase, in some cases adjacent to song control nuclei. We examined the effects of aromatase inhibition and estrogen treatment on song nuclei size using wild male songbirds in both the breeding and nonbreeding seasons. In breeding males, aromatase inhibition caused the volume of a telencephalic song control nucleus (HVC) to decrease, and this effect was partially rescued by concurrent estrogen replacement. In nonbreeding males, estradiol treatment caused HVC to grow to maximal spring size within 2 weeks. Overall, these data suggest that aromatization of T is an important mediator of song control system plasticity, and that estradiol has neurotrophic effects in adult male songbirds. This study demonstrates that estrogen can affect adult neural plasticity on a gross anatomical scale and is the first examination of estrogen effects on the brain of a wild animal. © 2003 Wiley Periodicals, Inc. J Neurobiol 58: 413–422, 2004