bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of body temperature on the BOLD effect in murine SCC tumors†
Authors: Reijnders Koen , English Sean J. , Krishna Murali C. , Cook John A. , Sowers Anastasia L. , Mitchell James B. , Zhang Yantian
Published: January 2004

Changes in the blood oxygen level dependent (BOLD) enhancements in tumors (squamous cell carcinoma, (SCCVII)) implanted in mice maintained at core temperatures of 30°C or 37°C were measured using MRI and compared to tumor oxygen levels obtained using an oxygen‐sensitive Eppendorf electrode. Tumors were implanted in a hindleg of the mice intramuscularly. Tumor‐bearing mice were imaged by BOLD MRI, while first breathing air and then carbogen (95% O2, 5% CO2) for 15‐min intervals at a core temperature of 30°C. After an equilibration period, the identical regimen was conducted with the same animal maintained at 37°C. This procedure was repeated with additional mice starting at 37°C followed by imaging at 30°C. Likewise, oxygen electrode measurements of the tumor were determined at core temperatures of 30°C and 37°C. The Eppendorf measurements showed that tumors in animals maintained at 30°C were significantly more hypoxic than at 37°C. MRI studies demonstrated stronger BOLD enhancement at 30°C than at 37°C, suggesting significant changes in hypoxia and/or blood flow in tumors at these temperatures. The findings of the study stress the importance of maintaining normal core temperature when assessing tumor oxygen status using functional imaging modalities or oxygen‐sensitive electrodes. Magn Reson Med 51:389–393, 2004. Published 2004 Wiley‐Liss, Inc.
Steady‐state diffusion‐weighted imaging of in vivo knee cartilage
Authors: Miller Karla L. , Hargreaves Brian A. , Gold Garry E. , Pauly John M.
Published: January 2004

Diffusion‐weighted imaging (DWI) has strong potential as a diagnostic for early cartilage damage, with clinical impact for diseases such as osteoarthritis. However, in vivo DWI of cartilage has proven difficult with conventional methods due to the short T2. This work presents a 3D steady‐state DWI sequence that is able to image short‐T2 species with high SNR. When combined with 2D navigator correction of motion‐induced phase artifacts, this method enables high resolution in vivo DWI of cartilage. In vivo knee images in healthy subjects are presented with high SNR (SNR = 110) and submillimeter in‐plane resolution (0.5 × 0.7 × 3.0 mm3). A method for fitting the diffusion coefficient is presented which produces fits within 10% of literature values. This method should be applicable to other short‐T2 tissues, such as muscle, which are difficult to image using traditional DWI methods. Magn Reson Med 51:394–398, 2004. © 2004 Wiley‐Liss, Inc.
Active deep brain stimulation during MRI: A feasibility study
Authors: Georgi J.‐C. , Stippich C. , Tronnier V.M. , Heiland S.
Published: January 2004

The goal of this study was to evaluate the feasibility of active deep brain stimulation (DBS) during the application of standard clinical sequences for functional MRI (fMRI) in phantom measurements. During active DBS, we investigated induced voltage, temperature at the electrode tips and lead, forces on the electrode and lead, consequences of defective leads and loose connections, proper operation of the neurostimulator, and image quality. Sequences for diffusion‐ and perfusion‐weighted imaging, fMRI, and morphologic MRI were used. The DBS electrode and lead were placed in a NaCl solution‐filled phantom. The results indicate that there are severe potential hazards for patients. Strong heating, high induced voltage, and even sparking at defects in the connecting cable could be observed. However, it was demonstrated that under certain conditions, safe MR examinations during active DBS are feasible. Certain safety precautions are recommended in this report. Magn Reson Med 51:380–388, 2004. © 2004 Wiley‐Liss, Inc.
Enhancing measured diffusion anisotropy in gray matter by eliminating CSF contamination with FLAIR
Authors: Ma Xiangyang , Kadah Yasser M. , LaConte Stephen M. , Hu Xiaoping
Published: January 2004

In this work, the effect of fluid‐attenuated inversion recovery (FLAIR) on measured diffusion anisotropy was investigated in gray matter. DTI data were obtained with and without FLAIR in six normal volunteers. The application of FLAIR was experimentally demonstrated to lead to a consistent increase in fractional anisotropy (FA) in gray‐matter regions, which was attributed to suppressed partial volume effects from CSF. In addition to these experimental results, Monte Carlo simulations were performed to ascertain the effect of noise on the measured FA under the experimental conditions of this study. The experimentally observed effect of noise was corroborated by the simulation, indicating that the increase in the measured FA was not due to a noise‐related bias but to an actual increase in diffusion anisotropy. This enhanced measurement of diffusion anisotropy can be potentially used to differentiate directionally dependent structure and tracking fibers in gray matter. Magn Reson Med 51:423–427, 2004. © 2004 Wiley‐Liss, Inc.
Electrodiagnostic studies in the management and prognosis of neuromuscular disorders
Authors: Gilchrist James M. , Sachs George M.
Published: January 2004

Prognosis remains a neglected aspect of modern medical care and research, behind diagnosis and treatment. The very term “electrodiagnosis” implies as much. Despite this, much has been published regarding the use and benefit of electrodiagnostic techniques in assessing prognosis and assisting in management of patients after the diagnosis has been established. This information is often hidden or otherwise not emphasized. This review summarizes the literature regarding the use of such techniques for prognosis and management of disorders of lower motor neurons, peripheral nerves, neuromuscular transmission, and muscle. Muscle Nerve 29: 165–190, 2004
Adult polyglucosan body disease: Case description of an expanding genetic and clinical syndrome
Authors: Klein Christopher J. , Boes Christopher J. , Chapin John E. , Lynch Christopher D. , Campeau Norbert G. , Dyck P. James B. , Dyck Peter J.
Published: January 2004

A non‐Jewish patient is described who had adult polyglucosan body disease (APBD) and glycogen branching enzyme (GBE) deficiency without GBE mutation. A heterozygous polymorphism (Val160Ile) was found, and also discovered in 1 of 50 normal individuals. Magnetic resonance imaging demonstrated increased T2 signal in the midbrain, medullary olives, dentate nuclei, cerebellar peduncles, and internal and external capsules, with vermian atrophy. Both muscle and nerve biopsy revealed perivascular inflammatory infiltrates. These findings expand the clinical and genetic spectrum of APBD. Factors other than mutation of the expressed GBE gene may cause enzyme deficiency and varied expression and development of APBD. Muscle Nerve 29: 323‐328, 2004
Loss‐of‐function phenotype of hereditary neuropathy with liability to pressure palsies
Authors: Li Jun , Krajewski Karen , Lewis Richard A. , Shy Michael E.
Published: January 2004

Hereditary neuropathy with liability to pressure palsies (HNPP) provides a human model to investigate the role of PMP22 in myelinated peripheral nerve, since the disease is caused by a deletion of one of the two PMP22 alleles. To systematically characterize the phenotype of HNPP, we prospectively evaluated the clinical features and electrophysiological findings in 17 genetically confirmed patients, 7 men and 10 women, ranging in age from 9 to 66 years (mean, 41 ± 13). Fifteen symptomatic patients presented with episodes of transient focal weakness or sensory loss that were usually related to particular activities causing nerve compression, including stretching or minor repetitive focal trauma. No patient sought medical attention for symptoms of a symmetric polyneuropathy. Neurological examinations were either normal or mildly abnormal. Neither focal slowing of nerve conduction studies, nor reduction in compound muscle action potential (CMAP) or sensory nerve action potential (SNAP) amplitudes consistently predicted the site of symptoms. We conclude that the majority of patients with HNPP present with transient, recurrent, focal symptoms of weakness or sensory loss in the distribution of individual nerves or plexus, and that a diffuse symmetric sensorimotor polyneuropathy is an unusual presentation of HNPP. These studies suggest that the function of PMP22, at least in part, is to stabilize myelin so that it will be protected from injuries resulting from repetitive, minor trauma. Muscle Nerve 29: 205–210, 2004
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

Occupations 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

The 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

Spinal 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

Motor 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

We 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

Oxidative 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

Threshold 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

We 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

This 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

In 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

The 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

This 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

Mammalian 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

Visual 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

Songbirds 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
Changes in retinal expression of neurotrophins and neurotrophin receptors induced by ocular hypertension
Authors: Rudzinski Marcelo , Wong Tak‐Pan , Uri Saragovi H.
Published: January 2004

Open angle glaucoma is defined as a progressive and time‐dependent death of retinal ganglion cells concomitant with high intraocular pressure, leading to loss of visual field. Because neurotrophins are a family of growth factors that support neuronal survival, we hypothesized that quantitative and qualitative changes in neurotrophins or their receptors may take place early in ocular hypertension, preceding extensive cell death and clinical features of glaucoma. We present molecular, biochemical, and phenotypic evidence that significant neurotrophic changes occur in retina, which correlate temporally with retinal ganglion cell death. After 7 days of ocular hypertension there is a transient up‐regulation of retinal NGF, while its receptor TrkA is up‐regulated in a sustained fashion in retinal neurons. After 28 days of ocular hypertension there is sustained up‐regulation of retinal BDNF, but its receptor TrkB remains unchanged. Throughout, NT‐3 levels remain unchanged but there is an early and sustained increase of its receptor TrkC in Müller cells but not in retinal ganglion cells. These newly synthesized glial TrkC receptors are truncated, kinase‐dead isoforms. Expression of retinal p75 also increases late at day 28. Asymmetric up‐regulation of neurotrophins and neurotrophin receptors may preclude efficient neurotrophic rescue of RGCs from apoptosis. A possible rationale for therapeutic intervention with Trk receptor agonists and p75 receptor antagonists is proposed. © 2003 Wiley Periodicals, Inc. J Neurobiol 58: 341–354, 2004
Inducible transcript expressed by reactive epithelial cells at sites of olfactory sensory neuron proliferation
Authors: Stoss Thomas D. , Nickell Melissa D. , Hardin Debra , Derby Charles D. , McClintock Timothy S.
Published: January 2004

The continuous replacement of cells in the spiny lobster olfactory organ depends on proliferation of new cells at a specific site, the proximal proliferation zone (PPZ). Using representational difference analysis of cDNA, we identified transcripts enriched in the PPZ compared to the mature zone (MZ) of the organ. The 12 clones identified included four novel sequences, three exoskeletal proteins, a serine protease, two protease inhibitors, a putative growth factor, and a sequence named PET‐15 that has similarity to antimicrobial proteins of the crustin type. PET‐15 mRNA was only detected in epithelial cells. It was abundant in all epithelial cells of the PPZ, but was only detected in the MZ at sites of damage to the olfactory organ. PET‐15 mRNA was increased by types of damage that are known to induce proliferation of new olfactory sensory neurons in the olfactory organ. It increased in the PPZ after partial ablation of the olfactory organ and in the MZ after shaving of aesthetasc sensilla. These ipsilateral effects were mirrored by smaller increases in the undamaged contralateral olfactory organ. These contralateral effects are most parsimoniously explained by the action of a diffusible signal. Because epithelial cells are the source of proliferating progenitors in the olfactory organ, the same diffusible signal may stimulate increases in both cellular proliferation and PET‐15 mRNA. The uniformity of expression of PET‐15 in the PPZ epithelium suggests that the epithelial cells that give rise to new olfactory sensory neurons are a subset of cells that express PET‐15. © 2003 Wiley Periodicals, Inc. J Neurobiol 58: 355–368, 2004
Odor‐evoked responses in the olfactory center neurons in the terrestrial slug
Authors: Murakami Masayoshi , Watanabe Satoshi , Inoue Tsuyoshi , Kirino Yutaka
Published: January 2004

The procerebrum (PC) of the terrestrial mollusk Limax is a highly developed second‐order olfactory center consisting of two electrophysiologically distinct populations of neurons: nonbursting (NB) and bursting (B). NB neurons are by far the more numerous of the two cell types. They receive direct synaptic inputs from afferent fibers from the tentacle ganglion, the primary olfactory center, and also receive periodic inhibitory postsynaptic potentials (IPSPs) from B neurons. Odor‐evoked activity in the NB neurons was examined using perforated patch recordings. Stimulation of the superior tentacle with odorants resulted in inhibitory responses in 45% of NB neurons, while 11% of NB neurons showed an excitatory response. The specific response was reproducible in each neuron to the same odorant, suggesting the possibility that activity of NB neurons may encode odor identity. Analysis of the cycle‐averaged membrane potential of NB neurons revealed a correlation between the firing rate and the membrane potential at the plateau phase between IPSPs. Also, the firing rate of NB neurons was affected by the frequency of the IPSPs. These results indicate the existence of two distinct mechanisms for the regulation of NB neuron activity. © 2003 Wiley Periodicals, Inc. J Neurobiol 58: 369–378, 2004
TBX2/TBX3 transcriptional factor homologue controls olfactory adaptation in Caenorhabditis elegans
Authors: Miyahara Kohji , Suzuki Norio , Ishihara Takeshi , Tsuchiya Eiko , Katsura Isao
Published: January 2004

Although transcriptional factors are known to play important roles in synaptic plasticity, their role in olfactory adaptation has not been studied well. Here we report that Ce‐TBX‐2, the TBX2/TBX3 transcriptional factor homologue of the nematode Caenorhabditis elegans, is involved in olfactory adaptation. Two missense hypomorphic mutations in this gene confer abnormality in adaptation, but not chemotaxis, to all the odorants sensed by AWC olfactory neurons. The Ce‐tbx‐2 gene is expressed in AWB, AWC, ASJ, and many pharyngeal neurons, but expression in AWC neurons is sufficient for normal adaptation. Unexpectedly, the protein product is localized mostly in cytoplasm. The AWC neurons in the mutants retain their characteristic morphology and many marker gene expressions, suggesting that the mutants are abnormal in neural functions rather than neuronal differentiation. The results of this study imply that some of the mammalian T‐box family proteins, which play central roles in embryonic development, may also control functions like neural plasticity in differentiated neurons. © 2003 Wiley Periodicals, Inc. J Neurobiol 58: 392–402, 2004
Identification of a proctolin preprohormone gene (Proct) of Drosophila melanogaster: Expression and predicted prohormone processing
Authors: Taylor Christine A. M. , Winther Åsa M. E. , Siviter Richard J. , Shirras Alan D. , Isaac R. Elwyn , Nässel Dick R.
Published: January 2004

Proctolin was the first insect neuropeptide to be sequenced and has been the subject of many physiological and pharmacological studies in insects and crustaceans. We have identified a Drosophila gene (CG7105, Proct) encoding a precursor protein containing the neuropeptide proctolin (RYLPT). In situ hybridization with a riboprobe to the Proct gene revealed a distribution of transcript in neurons of the larval central nervous system (CNS) matching that seen with antiserum to proctolin. An antiserum raised to a sequence in the precursor downstream of proctolin labeled the same neurons as those seen with the antiproctolin antisera. The predicted protein encoded by Proct has a single copy of the RYLPT sequence that directly follows the predicted signal peptidase cleavage point and precedes a consensus recognition site for a furinlike processing endoprotease. Ectopic expression of Proct in the CNS and midgut via the GAL4‐UAS system, using an Actin5C‐GAL4 driver, confirmed that the predicted preproproctolin can be processed to generate immunoreactive proctolin peptide. Pupae over‐expressing Proct displayed a 14% increase in heart rate, providing evidence in support of a cardioacceleratory endocrine function for proctolin in Drosophila. The distribution of proctolin suggests roles as a neuromodulator in motoneurons and interneurons, and as a neurohormone that could be released from brain neurosecretory cells with terminations in the ring gland. © 2003 Wiley Periodicals, Inc. J Neurobiol 58: 379–391, 2004
Regulation of dendritic length and branching by semaphorin 3A
Authors: Fenstermaker Vivian , Chen Yachi , Ghosh Anirvan , Yuste Rafael
Published: January 2004

The molecular mechanisms that control dendritic development are still unclear. Semaphorin 3A, a class III semaphorin, has been shown to regulate the radial orientation of pyramidal neurons in the developing neocortex. Here, we investigate the effects of Sema3A on the development of dendritic topology. Neocortical slices from Sema3A null mutant mice were cultured and neurons were transfected with GFP, reconstructed, and compared with neurons from wild‐type and heterozygote littermates. We also added exogenous Sema3A to cultured wild‐type neocortical slices to further test its effects on dendritic development. We document reductions in dendritic length and branching in Sema3A null mice and increases in dendritic length and branching after the addition of exogenous Sema3A to wild‐type neurons. We conclude that Sema3A is necessary for the elaboration of second and third order dendritic branches in pyramidal neurons. © 2003 Wiley Periodicals, Inc. J Neurobiol 58: 403–412, 2004
V Fenstermaker, Y Chen, A Ghosh, R Yuste. Regulation of dendritic length and branching by Semaphorin 3A, Journal of Neurobiology (2004) 58(3) 403–412
Authors: Fenstermaker Vivian , Chen Yachi , Ghosh Anirvan , Yuste Rafael
Published: January 2004

The original article to which this Erratum refers was published in Journal of Neurobiology (2004) 58(3) 403–412
Partition of unity enrichment for bimaterial interface cracks
Authors: Sukumar N. , Huang Z. Y. , Prévost J.‐H. , Suo Z.
Published: January 2004

Partition of unity enrichment techniques are developed for bimaterial interface cracks. A discontinuous function and the two‐dimensional near‐tip asymptotic displacement functions are added to the finite element approximation using the framework of partition of unity. This enables the domain to be modelled by finite elements without explicitly meshing the crack surfaces. The crack‐tip enrichment functions are chosen as those that span the asymptotic displacement fields for an interfacial crack. The concept of partition of unity facilitates the incorporation of the oscillatory nature of the singularity within a conforming finite element approximation. The mixed‐mode (complex) stress intensity factors for bimaterial interfacial cracks are numerically evaluated using the domain form of the interaction integral. Good agreement between the numerical results and the reference solutions for benchmark interfacial crack problems is realized. Copyright © 2004 John Wiley & Sons, Ltd.
Evaporative light scattering detection of pyrrolizidine alkaloids
Authors: Schaneberg Brian T. , Molyneux Russell J. , Khan Ikhlas A.
Published: January 2004

A reverse‐phase high‐performance liquid chromatography method utilizing evaporative light scattering detection (ELSD) has been developed for the simultaneous detection of hepatotoxic pyrrolizidine alkaloids with and without chromophores, namely, riddelliine, riddelliineN‐oxide, senecionine, senecionineN‐oxide, seneciphylline, retrorsine, integerrimine, lasiocarpine and heliotrine. Pyrrolizidine alkaloids were detected in ﬁve plant extracts (Senecio spartioides,S. douglasii var. longilobus,S. jacobaea,S. intergerrimus var. exaltatusandSymphytum ofﬁcinale). The detection of heliotrine (which does not contain a chromophore) was much improved by ELSD compared with photodiode array detection. Copyright © 2004 John Wiley & Sons, Ltd.
Quantiﬁcation of allergenic urushiols in extracts of Ginkgo biloba leaves, in simple one‐step extracts and reﬁned manufactured material (EGb 761)
Authors: Schötz Karl
Published: January 2004

Extracts of leaves of Ginkgo biloba (family Ginkgoaceae), widely used in the treatment of peripheral and cerebral circulatory disorders as well as for dementia of different aetiology, contain long chain alkylphenols (with allergenic, cytotoxic, mutagenic and tumour‐promoting properties) together with the extremely potent allergens, the urushiols. Such hazardous compounds can be present only in very low concentrations in phyto‐pharmaceutical preparations and hence, for the purposes of drug safety, techniques must be available for the identiﬁcation and quantiﬁcation of these allergens at extremely low levels in reﬁned manufactured materials. GC‐MS analysis of samples collected at various stages during the production process of a standardised extract of G. biloba (EGb 761) demonstrated that all alkylphenols present in the primary acetone extracts were removed in parallel with the same efﬁciency irrespective of their aromatic substitution pattern. Furthermore, in the ﬁnal product the content of urushiols was generally below the detection limit of 0.03 ppm. Therefore, it is concluded that demonstrating the absence of the predominant, and easily quantiﬁable, ginkgolic acids provides a reliable means for the control of pharmaceutical quality of the ﬁnal product. Copyright © 2004 John Wiley & Sons, Ltd.
HPLC‐PAD‐APCI/MS assay of phenylpropanoids in cereals
Authors: Bily Antoine C. , Burt Andrew J. , Ramputh Al‐Idrissi , Livesey John , Regnault‐Roger Catherine , Philogène Bernard R. , Arnason John T.
Published: January 2004

A new, rapid HPLC‐PAD‐APCI/MS assay has been developed in order to measure accurately the amount of p‐coumaric, E‐ and Z‐ferulic acid and the dehydrodimers of ferulic acid in cereal grain. In the positive ionisation mode, MS patterns gave additional information for the identiﬁcation of the dimers. The time required and the quantities of solvents employed in the developed analytical method are much lower than those involved in previously available assays of these compounds, thus making the method suitable for the screening of cereal genotypes. Application of the method to accessions of maize, wheat and sorghum showed that E‐ferulic was the most abundant phenylpropanoid, whilst the major dimer was 8‐O‐4′ dehydrodimer of ferulic acid followed by the 5–5′ and then the 8–5′ forms. Maize grains, especially of the Mexican landraces, contained the highest levels of these dimers. Copyright © 2004 John Wiley & Sons, Ltd.
Quantitative determination of Aconitum alkaloids in blood and urine samples by high‐performance liquid chromatography
Authors: Wang Zhao Hong , Guo Dean , He Yi , Hu Chunhua , Zhang Jizong
Published: January 2004

An HPLC method has been developed for the simultaneous determination of the toxic Aconitum alkaloids, aconitine, mesaconitine and hypaconitine in blood and urine samples. The samples were initially subjected to solid phase extraction using Oasis® MCX cartridges, and the alkaloids were separated on an XTerra™ RP18 column, gradient‐eluted with acetonitrile: ammonium hydrogen carbonate buffer. Calibration curves were linear in the range 2.75–550 ng for aconitine and hypaconitine, and 3–600 ng for mesaconitine: the limit of detection was 0.1 ng (signal‐to‐noise ratio of 3) for each alkaloid. The described analysis proved to be sensitive, rapid and economical, and will be applied in the identiﬁcation and determination of these alkaloids in forensic and therapeutic drug monitoring. Copyright © 2004 John Wiley & Sons, Ltd.