bluuebunny/crossref_metadata_2025 huggingface dataset:
Early inhibition of nitric oxide production increases HSV‐1 intranasal infection
Authors: Gamba Gisela , Cavalieri Hernan , Courreges Maria C. , Massouh Ernesto J. , Benencia Fabian
Published: April 2004

Here, we studied the role of nitric oxide (NO) production during the first steps of the respiratory infection of BALB/c mice with herpes simplex virus type 1 (HSV‐1), strain F. Nitric oxide synthase II (NOS‐II) mRNA and protein were detected by reverse transcription (RT)‐PCR and dot blot, respectively in samples of lungs and turbinates early post‐infection (p.i.). Immunohistochemical analysis revealed pulmonar macrophages and PMN expressing NOS‐II in the lungs of infected animals. Animals intranasally treated with aminoguanidine (AG), a NOS inhibitor, during the first steps of infection, showed a dose‐dependent increase in pneumonitis compared to controls. Viral titres in turbinates, lungs, and brains were higher in AG treated mice. Finally, histopathology studies revealed a stronger inflammation in eyes, and lungs of these animals. Taken together, these results suggest a role of NO in controlling primary HSV intranasal infection. J. Med. Virol. 73:313–322, 2004. © 2004 Wiley‐Liss, Inc.
Cyclin‐dependent kinase 5 increases perikaryal neurofilament phosphorylation and inhibits neurofilament axonal transport in response to oxidative stress
Authors: Shea Thomas B. , Zheng Ya‐Li , Ortiz Daniela , Pant Harish C.
Published: April 2004

Cyclin‐dependent kinase 5 (cdk5) phosphorylates the high molecular weight neurofilament (NF) protein. Overexpression of cdk5 inhibits NF axonal transport and induces perikaryal accumulation of disordered phospho‐NF cables. Experimental and clinical motor neuron disease is characterized by oxidative stress, increased cdk5 activity, and accumulation of phospho‐NFs within perikarya or proximal axons. Because oxidative stress increases cdk5 activity in experimental motor neuron disease, we examined whether oxidative stress induced cdk5‐mediated NF phosphorylation. Treatment of cultured neuronal cells with hydrogen peroxide inhibited axonal transport of green fluorescent protein‐tagged NF subunits and induced perikaryal accumulation of NF phosphoepitopes normally confined to axons. These effects were prevented by treatment with the cdk5 inhibitor roscovitine or transfection with a construct expressing the endogenous cdk5 inhibitor peptide. These findings indicate that oxidative stress can compromise NF dynamics via hyperactivation of cdk5 and suggest that antioxidants may alleviate multiple aspects of neuropathology in motor neuron disease. © 2004 Wiley‐Liss, Inc.
Functional analysis of mouse 3‐phosphoglycerate dehydrogenase (Phgdh) gene promoter in developing brain
Authors: Shimizu Motohiro , Furuya Shigeki , Shinoda Yoko , Mitoma Junya , Okamura Tadashi , Miyoshi Ichiro , Kasai Noriyuki , Hirabayashi Yoshio , Suzuki Yasuo
Published: April 2004

D‐3‐Phosphoglycerate dehydrogenase (Phgdh; EC 1.1.1.95) is a necessary enzyme for de novo L‐serine biosynthesis via the phosphorylated pathway. Targeted disruption of the mouse Phgdh gene has been shown to result in embryonic lethality, accompanied by severe abnormalities in brain development. Phgdh is expressed exclusively by neuroepithelium and radial glia in developing brain and later mainly by astrocytes. To elucidate the molecular mechanism that regulates such cell‐type‐specific expression of Phgdh in developing brain, an upstream 3.5‐kilobase‐pair (kbp) region of the gene harboring the promoter was characterized in primary cultures and transgenic mice. Analysis of Phgdh 5′‐nested deletions in transfected cultures indicated that overall reporter luciferase levels were higher in glial cultures than those in neuronal cultures. Although basal promoter activity of the gene appeared to depend on an Sp1 binding sequence residing between –193 and –184 in both glial and neuronal cultures, an upstream 5′‐flanking region between –1,794 and –1,095 contributed to up‐regulation of Phgdh transcription in a glial‐cell‐specific manner. In the cerebral cortex of transgenic mouse embryos, the Phgdh promoter‐LacZ transgene DNA containing –1,794/+4 promoter sequences directed β‐galactosidase (β‐Gal) expression mainly to Phgdh‐positive neuroepithelium and radial glia. This glial preference diminished when β‐Gal expression was driven solely by the upstream 0.2‐kbp minimal promoter. However, glial preference of β‐Gal expression was restored by placing the 700‐base‐pair 5′‐DNA segment upstream of the minimal promoter. These observations suggest the presence of cis‐acting elements that confer the cell type specificity of Phgdh transcription in the distal promoter region. © 2004 Wiley‐Liss, Inc.
Diazoxide preconditioning protects against neuronal cell death by attenuation of oxidative stress upon glutamate stimulation
Authors: Nagy Krisztina , Kis Bela , Rajapakse Nishadi C. , Bari Ferenc , Busija David W.
Published: April 2004

We examined the effects of diazoxide, the putative mitochondrial adenosine triphosphate‐sensitive potassium (mitoKATP) channel opener, against glutamate excitotoxicity in primary cultures of rat cortical neurons. Cells were treated with diazoxide for 24 hr and then exposed to 200 μM glutamate. Cell viability was measured 24 hr after glutamate exposure. We found that treatment 24 hr before glutamate exposure with 250 and 500 μM diazoxide but not with another mitoKATP channel opener, nicorandil, increased neuronal viability from 54 ± 2% to 84 ± 2% and 92 ± 3%, respectively (n = 25–40). These effects were not inhibited by the putative mitoKATP channel blocker 5‐hydroxydecanoic acid. Diazoxide application increased production of reactive oxygen species (ROS) and coapplication of M40401, a superoxide dismutase mimetic, prevented delayed preconditioning. The 24 hr preconditioned neurons showed significantly reduced ROS production upon glutamate stimulation compared to that in untreated cells. These results suggest that diazoxide induces delayed preconditioning in cultured cortical neurons via increased ROS production and attenuation of oxidative stress upon glutamate stimulation. © 2004 Wiley‐Liss, Inc.
17β‐estradiol attenuates glutamate‐induced apoptosis and preserves electrophysiologic function in primary cortical neurons
Authors: Sribnick Eric Anthony , Ray Swapan Kumar , Nowak Mark Walter , Li Li , Banik Naren Lal
Published: April 2004

Glutamate toxicity causes neuronal death in neurodegenerative diseases; hence, there is a need for therapeutic agents rendering functional neuroprotection. We tested the effects of 17β‐estradiol (estrogen) in rat primary cortical neurons after glutamate exposure. Wright staining and ApopTag assays indicated that 0.5 μM glutamate for 24 hr caused apoptosis. Glutamate‐induced apoptosis correlated with upregulation of calpain, a proapoptotic shift in the Bax:Bcl‐2 ratio, and increased activation of caspase‐3. Pretreatment with 10 nM estrogen prevented apoptosis, attenuated calpain upregulation, shifted the Bax:Bcl‐2 ratio toward survival, and decreased caspase‐3 activation. Single‐cell voltage‐clamp techniques were used to record whole‐cell currents associated with Na+ channels, N‐methyl‐D‐aspartate receptor channels, and kainate receptor channels. No significant differences were recorded in membrane capacitance at −70 mV in neurons treated with estrogen or estrogen plus glutamate, relative to controls. Notably, no changes in capacitance indicated that neurons treated with estrogen and glutamate did not experience apoptosis‐associated cell shrinkage. No membrane potential could be recorded in the neurons treated with glutamate due to apoptosis. All recorded currents were similar in amplitude and activation/inactivation kinetics in control neurons and neurons treated with estrogen plus glutamate. Estrogen thus preserved both neuronal viability and function in this in vitro glutamate toxicity model. © 2004 Wiley‐Liss, Inc.
Static and Dynamic Light Scattering of Polyelectrolyte/Surfactant Solutions: the Na‐Hyaluronate/(C10TAB) System
Authors: Villetti Marcos A. , Borsali Redouane , Crespo Janaina S. , Soldi Valdir , Fukada Kazuhiro
Published: April 2004

Summary: This work discusses the interactions between the anionic polyelectrolyte sodium hyaluronate (Na‐Hy) and the cationic surfactant decyltrimethylammonium bromide (C10TAB). Static and dynamic light scattering experiments were carried out in the single homogenous phases (region I: [C10TAB] < 0.040 M and region III: [C10TAB] > 0.350 M) in “salt‐free” and at different added salt concentrations (NaCl) in order to gain more understanding on the chain conformation and on the dynamics of polyelectrolyte/surfactant systems. In region I, the Na‐Hy “salt‐free” system exhibits the expected polyelectrolyte properties, i.e. the scattering intensity increases with the addition of surfactant or salt. As a consequence of this screening of the electrostatic interactions, a decrease in both the radius of gyration Rg and the second virial coefficient A2 is observed. This decrease is found more pronounced in the presence of surfactant C10TAB than in the case of added salt (Na‐Hy/NaCl). Consequently, the calculated apparent persistence length Lt, assuming a worm‐like chain at high ionic strength, is found about 58 Å in the case of surfactant and Lt = 71 Å in the case of added salt. This result demonstrates clearly that the binding of the surfactant to Na‐Hy is stronger than in the case of added salt and is at the origin of the phase separation that occurs at the concentration of C10TAB > 0.040 M. As far as the dynamic properties are concerned, the autocorrelation functions in “salt‐free” solutions measured in region I are better described by two relaxation modes (intermediate and slow) and by three relaxation modes (fast, intermediate and slow) in region III. The three relaxation modes reflect respectively the dynamics of free micelles (fast mode), association‐dissociation equilibrium of micelle‐like clusters (intermediate mode) and polymer‐micelles adsorption (slow mode). At high ionic strength (added salt) in region III, the micelle diameter increases (fast mode), the intermediate mode disappears and the polymer‐micelles adsorption diffusion coefficient increases due to the screening of the electrostatic interactions.

Phase diagram of Na‐Hy polyelectrolyte in C10TAB surfactant and NaCl salt.

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Phase diagram of Na‐Hy polyelectrolyte in C10TAB surfactant and NaCl salt.
Spherical MgCl2 Supported Iron Catalyst for Ethylene Polymerization: Effect of the Preparation Procedure on Catalyst Activity and the Morphology of Polyethylene Particles
Authors: Huang Rubin , Liu Dongbing , Wang Shibo , Mao Bingquan
Published: April 2004

Summary: A new procedure was developed to support [(ArNC(Me))2C5H3N]FeCl2 (Ar2,4,6‐trimethylphenyl) on spherical MgCl2 for ethylene polymerization. The resultant catalysts showed ten times higher activity of the corresponding catalyst in homogeneous catalysis. The morphologies of polyethylene particles strongly depended on supported catalyst preparation procedure and polymerization conditions. In addition, the GPC measurements showed bimodal polyethylene for the homogeneous polymerization while mono‐modal polyethylene of those supported catalysts.

EDX Line Scan analysis of the catalyst SMSIC‐1 regarding the aluminium and iron distribution in the volume (25 kV accelerating voltage, magnification 1 500).

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EDX Line Scan analysis of the catalyst SMSIC‐1 regarding the aluminium and iron distribution in the volume (25 kV accelerating voltage, magnification 1 500).
The movement disorder of Maurice Ravel
Authors: Cardoso Francisco
Published: April 2004

It has long been known that in the last years of his life Maurice Ravel (1875–1937) suffered from a progressive neurological illness. Despite several proposed diagnostic hypotheses, the precise nature of his illness remains elusive. © 2004 Movement Disorder Society
Rhythmic movement disorder and cyclic alternating pattern during sleep: A video‐polysomnographic study in a 9‐year‐old boy
Authors: Manni Raffaele , Terzaghi Michele , Sartori Ivana , Veggiotti Pierangelo , Parrino Liborio
Published: April 2004

We report on polysomnographic findings in a 9‐year‐old boy affected by rhythmic movement disorder. The subject's rhythmic movements were found to be intimately linked to unstable nonrapid eye movement N‐REM sleep, as shown by their close association with the A phases of the cyclic alternating pattern. We examine the complex interactions between arousal mechanisms and rhythmic movements occurring during sleep. © 2004 Movement Disorder Society
Deficits in rapid adjustments of movements according to task constraints in Parkinson's disease
Authors: Tunik Eugene , Adamovich Sergei V. , Poizner Howard , Feldman Anatol G.
Published: April 2004

The role of the basal ganglia in the adaptive control of movement was investigated by unexpectedly perturbing movements in 8 patients with Parkinson's disease (PD) tested off medication and in 6 aged‐matched healthy subjects. Subjects performed two movement components simultaneously and without visual feedback: touching the nose with the finger while leaning the trunk forward. Subjects wore a harness connected to an electromagnet, which was attached to a wall. The trunk movement was mechanically blocked in randomly selected trials by engaging the electromagnet. While healthy subjects performed the task equally well in both conditions, PD subjects' hand movements significantly deteriorated in trunk‐perturbed compared to trunk‐free trials. Deteriorated hand movements were characterized by segmented hand paths, unsmooth velocity profiles, and prolonged movement times. This finding indicated that the relatively local trunk perturbation had a global effect on the hand movement of PD subjects, necessitating them to reinitiate, after some delay, their arm movement in perturbed trials. Thus, the basal ganglia may be a critical node in brain networks mediating the flexibility of responses to altered motor states. © 2004 Movement Disorder Society
Multiscale analysis of thermoregulation in the human microvascular system
Authors: Deuflhard Peter , Hochmuth Reinhard
Published: April 2004

The bio‐heat transfer equation is a macroscopic model for describing the heat transfer in microvascular tissue. So far the derivation of the Helmholtz term arising in the bio‐heat transfer equation is not completely satisfactory. Here we use homogenization techniques to show that this term may be understood as asymptotic result of boundary value problems which provide a microscopic description for microvascular tissue. An appropriate scaling of so‐called heat transfer coefficients in Robin boundary conditions on tissue–blood boundaries is seen to play the crucial role. In view of a future application of our new mathematical model for treatment planning in hyperthermia, we derive asymptotic estimates for the first‐order corrector. Copyright © 2004 John Wiley & Sons, Ltd.
Advances in loading techniques to design multifrequency monopole antennas
Authors: Soler J. , González F.J. , Puente C. , Anguera J.
Published: April 2004

A top‐loading technique for monopole antennas which permits us to obtain a multiband performance from a wide set of antenna geometries is presented. Dual‐band and a triple‐band monopole antenna designs are described in detail, featuring both similar input impedances and radiation pattern across the different bands. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 434–437, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20162
Visualization and tracking of an inflatable balloon catheter using SSFP in a flow phantom and in the heart and great vessels of patients
Authors: Miquel Marc E. , Hegde Sanjeet , Muthurangu Vivek , Corcoran Benjamin J. , Keevil Stephen F. , Hill Derek L.G. , Razavi Reza S.
Published: April 2004

Passive catheter tracking involves direct interaction between the device and its surroundings, creating a local signal loss or enhancement of the image. Using only standard balloon catheters filled with CO2 and imaged with a steady‐state free precession sequence, it was possible to visualize and passively track catheters in a flow phantom and in the heart and great vessels of 20 patients without any additional image processing. The phantom work demonstrated that it was advantageous to sacrifice spatial resolution in order to increase temporal resolution. Frame rates greater than 10/sec were necessary for ease of catheter manipulation. Although only the tip of the catheter was visualized, this technique proved to be effective in patients undergoing cardiac catheterization. Magn Reson Med 51:988–995, 2004. © 2004 Wiley‐Liss, Inc.
Direct CSF injection of MnCl2 for dynamic manganese‐enhanced MRI
Authors: Liu Christina H. , D'Arceuil Helen E. , de Crespigny Alex J.
Published: April 2004

MnCl2 was injected intrathecally through the cisterna magna in rats, allowing infusion of divalent manganese ions (Mn++) into the CSF space and thence into the brain, without breaking the blood–brain barrier (BBB). Mn++ uptake and washout dynamics in the brain were measured by serial T1‐weighted MRI and EPI T1 and T2 mapping for up to 3 weeks after injection. Observations within the first 6 hr after injection demonstrated anterograde and bilateral distribution of the Mn++ within the CSF space, from the olfactory bulb and frontal cortex to the brain stem. Enhancement increased in most brain areas up to 4 days after injection, and then slowly decreased. Relaxation maps at each time point demonstrated higher concentrations of Mn in basal ganglia. Residual concentrations were still observable after 3 weeks in all brain regions. With the use of MnCl2 calibration phantoms, the maximum Mn concentration in the brain was estimated to be approximately 27 ± 16 μM, corresponding to changes in relaxation rates of 0.49 ± 0.30 s−1 for R1 and 3.9 ± 2.4 s−1 for R2. For comparison, an intrathecal GdDTPA injection was performed. This injection showed different distribution dynamics: it remained chiefly within the CSF spaces, and was largely washed out after 1 day. This method shows promise as a means of supplying Mn++ uniformly to the whole brain for a variety of chronic functional activation studies. Magn Reson Med 51:978–987, 2004. © 2004 Wiley‐Liss, Inc.
Assessment of human pulmonary function using oxygen‐enhancedT1imaging in patients with cystic fibrosis
Authors: Jakob Peter M. , Wang Tungte , Schultz Georg , Hebestreit Helge , Hebestreit Alexandra , Hahn Dietbert
Published: April 2004

Indirect qualitative MRI of pulmonary function is feasible using the paramagnetic effects of oxygen physically dissolved in blood. In this study, a more quantitative oxygen‐enhanced pulmonary function test based on the slope of a plot ofR1vs. oxygen concentration—the oxygen transfer function (OTF)—was developed and tested in a pool of five healthy volunteers and five patients with cystic fibrosis (CF). The lungT1relaxation rate,R1, under normoxic conditions (room air, 21% O2), and the response to various hyperoxic conditions (40%–100% O2) were studied. LungT1in healthy volunteers showed a relatively homogeneous distribution while they breathed room air, and a homogeneous decrease under hyperoxic conditions. LungT1in CF patients showed an inhomogeneous distribution while they breathed room air, and the observed lungT1decrease under hyperoxia depended on the actual state of the diseased lung tissue. In the selected group of CF patients, areas with reduced OTF also showed reduced perfusion, as confirmed by qualitative contrast‐enhanced MR pulmonary perfusion imaging. The results demonstrate that this completely noninvasive oxygen‐enhanced pulmonary function test has potential for clinical applications in the serial diagnosis of lung diseases such as CF. Magn Reson Med 51:1009–1016, 2004. © 2004 Wiley‐Liss, Inc.
Quantifying arbitrary magnetic susceptibility distributions with MR
Authors: Li Lin , Leigh John S.
Published: April 2004

Magnetic susceptibility, as a physical property of materials, plays important roles in many physical, chemical, engineering, and medical applications. Its quantification becomes of significant interest when MRI becomes a commonly used technique in biomedical applications. A general method is presented here for quantifying arbitrary magnetic susceptibility distributions in a localized region on the basis of first principles of magnetic induction field distributions in space. A proof of the concept was demonstrated by computer simulations. The study establishes the methodological basis for quantitative magnetic susceptibility imaging with MR. Magn Reson Med 51:1077–1082, 2004. © 2004 Wiley‐Liss, Inc.
Human imaging of phosphorus in cortical and trabecular bone in vivo
Authors: Robson Matthew D. , Gatehouse Peter D. , Bydder Graeme M. , Neubauer Stefan
Published: April 2004

Phosphorus was imaged in vivo in human cortical and trabecular bone and the T1 and T were measured. An ultrashort TE (UTE) pulse sequence (TE = 70 μm) was used with half pulse excitation and radial mapping of k‐space from the center out. T was measured using multiple echo times and T1 was measured both by saturation recovery and by a method using different RF pulse amplitudes. Seven normal subjects (32–85 years) were examined. Phosphorus was imaged, with a true in‐plane resolution of 2.9 × 2.9 mm and a signal‐to‐noise ratio (SNR) of 19:1, in both cortical and trabecular bone. The mean T value was 207 ± 12 μs, and the mean T1 value was 8.6 ± 3.0 sec. Images and measurements were obtained in realistic times on a clinical MR system. This may provide a new approach to characterizing disease of bone. Magn Reson Med 51:888–892, 2004. © 2004 Wiley‐Liss, Inc.
Selection of the optimum b factor for diffusion‐weighted magnetic resonance imaging assessment of ischemic stroke
Authors: Kingsley Peter B. , Monahan W. Gordon
Published: April 2004

The purpose of this study was to determine the diffusion sensitivity factor b that optimizes the contrast‐to‐noise ratio (CNR) for both diffusion‐weighted signal intensity and the apparent diffusion coefficient (ADCNR) when evaluating ischemic stroke by diffusion‐weighted MRI. The relative contrast, noise levels, CNR, and ADCNR were calculated for typical ADC values in human brain, 780 μm2/s in adults and 1200 μm2/s in neonates in normal tissue, 20–40% less in acute and subacute stroke, and 50% more in chronic stroke. The optimum b factor depends strongly on the ADC, whether TE is fixed or varies with the b factor, whether CNR or ADCNR is measured, and anisotropy. The optimum b factor in adults is 1000 s/mm2 in acute and chronic stroke, and 1200 s/mm2 in subacute stroke. The optimum values are about 200 s/mm2 lower in neonates than in adults. The CNR and ADCNR are within 10% of the optimum over at least a 2‐fold range of b factors, from 68–136% of the optimum b factor. If a single b factor is to be used for all situations, a diffusion b factor of 1000 s/mm2 is recommended. Magn Reson Med 51:996–1001, 2004. © 2004 Wiley‐Liss, Inc.
Magnetization tagging decay to measure long‐range 3He diffusion in healthy and emphysematous canine lungs
Authors: Woods Jason C. , Yablonskiy Dmitriy A. , Chino Kimiaki , Tanoli Tariq S.K. , Cooper Joel D. , Conradi Mark S.
Published: April 2004

Spatial modulation (tagging) of the longitudinal magnetization allows diffusive displacements to be measured over times approximately as long as T1 and over correspondingly long distances. Magnetization tagging is used here with hyperpolarized 3He gas in canine lungs with unilateral elastase‐induced emphysema. A new scheme for analyzing images subsequent to tagging determines the spatially‐resolved fractional modulation and its decay rate, using a sliding window. The diffusivity so determined over seconds and centimeter lengths, Dsec, is smaller in all cases than the diffusivity measured over milliseconds and hundreds of microns, Dmsec (in healthy lungs, this ratio is about 0.1). While Dmsec is sensitive to lung microstructure on the alveolar level, Dsec reflects airway connectivity and provides new information on lung structure. The results show substantial increases in Dsec in the lungs of four dogs with clear evidence of emphysema. For these dogs, the fractional increase in long‐range diffusivity Dsec in the emphysematous lungs was greater than that in short‐range diffusivity Dmsec. Magn Reson Med 51:1002–1008, 2004. © 2004 Wiley‐Liss, Inc.
Improved route for the visualization of stem cells labeled with a Gd‐/Eu‐Chelate as dual (MRI and fluorescence) agent
Authors: Crich Simonetta Geninatti , Biancone Luigi , Cantaluppi Vincenzo , Duò Debora , Esposito G. , Russo Simona , Camussi Giovanni , Aime Silvio
Published: April 2004

A simple labeling procedure of stem/progenitor cells based on the use of Gd‐HPDO3A and Eu‐HPDO3A, respectively, is described. The Gd‐chelate acts as T1‐agent for MRI visualization, whereas the corresponding Eu‐chelate acts as reporter in fluorescence microscopy. Owing to their substantial chemical equivalence, the two chelates are equally internalized in EPCs (endothelial progenitor cells), thus allowing their visualization by both techniques. The lanthanide chelates are entrapped in endosomic vesicles and the labeled cells retain biological activity with preservation of viability and pro‐angiogenesis capacity. Hyperintense spots in MR have been observed for Gd‐labeled EPCs injected under mice kidney capsule or grafted on a subcutaneous Matrigel plug up to 14 days after transplantation. Magn Reson Med 51:938–944, 2004. © 2004 Wiley‐Liss, Inc.
Quantitative t1ρ NMR spectroscopy of rat cerebral metabolites in vivo: Effects of global ischemia
Authors: Kettunen Mikko I. , Gröhn Olli H.J. , Kauppinen Risto A.
Published: April 2004

The NMR relaxation times (T1ρ, T2, and T1) of water, N‐acetylaspartate (NAA), creatine (Cr), choline‐containing compounds (Cho), and lactate (Lac) were quantified in rat brain at 4.7 T. In control animals, the cerebral T1ρ figures, as determined with a spin‐lock field of 1.0 G, were 575 ± 30 ms, 380 ± 19 ms, 705 ± 53 ms, and 90 ± 1 ms for NAA, Cr, Cho, and water, respectively. The T1ρ figures were 62–103% longer than their respective T2 values determined by a multiecho method. In global (ischemic) ischemia, T1ρ of NAA declined by 34%, that of Cr and Cho did not change, and that of water increased by 10%. The T1ρ of lactate in ischemic brain was 367 ± 44 ms. Similar patterns of changes were observed in the multiecho T2 of these cerebral metabolites. The T1 of water and NAA changed in a fashion similar to that of T1ρ and T2. These results show differential responses in metabolite and water T1ρ relaxation times following ischemia, and indicate that metabolite T1ρ and T2 relaxation times behave similarly in the ischemic brain. The contributions of dipolar and nondipolar effects on T1ρ relaxation in vivo are discussed in this work. Magn Reson Med 51:875–880, 2004. © 2004 Wiley‐Liss, Inc.
Is muscle spindle proprioceptive function spared in muscular dystrophies? A muscle tendon vibration study
Authors: Ribot‐Ciscar Edith , Tréfouret Sylvie , Aimonetti Jean‐Marc , Attarian Shahram , Pouget Jean , Roll Jean‐Pierre
Published: April 2004

Muscular dystrophies (MDs) are characterized by the degeneration of skeletal muscle fibers. The aim of the present study was to determine whether the intrafusal fibers of muscle spindles are also affected in MD. The functional integrity of muscle spindles was tested by analyzing their involvement in the perception of body segment movements and in the control of posture. Twenty MD patients (4 with dystrophinopathy, 5 with myotonic dystrophies, 5 with fascioscapulohumeral MD, and 6 with limb‐girdle dystrophies) and 10 healthy subjects participated in the study. The MD patients perceived passive movements and experienced illusory movements similar to those perceived by healthy subjects in terms of their direction and velocity. Vibratory stimulation applied to the neck and ankle muscle tendons induced postural responses in MD patients with spatial and temporal characteristics similar to those produced by healthy subjects. These results suggest that the proprioceptive function of muscle spindles is spared in muscular dystrophies. Muscle Nerve 29: 861–866, 2004
Reliability of quantitative motor unit action potential parameters
Authors: Takehara Itaru , Chu Jennifer , Li Tung‐Chou , Schwartz Ira
Published: April 2004

We evaluated the test–retest reliability (reproducibility) of motor unit action potential (MUAP) parameters in multi‐MUAP analysis over time. Reproducibility studies are not available for needle quantitative electromyography (QEMG) performed by the same examiner. Fourteen consecutive individuals (10 men and 4 women) had repeat QEMG at 3 hours after the first examination, and seven (5 men and 2 women) had a repeat QEMG after 4–10 days. The intraclass correlation coefficient (ICC) was 87–97% with same‐day testing and 52–81% with different‐day testing. Size index and firing rate were the most reproducible, suggesting use in follow‐up multi‐MUAP studies. Muscle Nerve 30: 111–113, 2004
Painful peripheral neuropathy and its nonsurgical treatment
Authors: Wolfe Gil I. , Trivedi Jaya R.
Published: April 2004

Treatment of neuropathic pain is the primary focus of management for many patients with painful peripheral neuropathy. Antidepressants and anticonvulsants are the two pharmacological classes most widely studied and represent first‐line agents in the management of neuropathic pain. The number of pharmacological agents that have demonstrated effectiveness for neuropathic pain continues to expand. In the current review, we summarize data from randomized, controlled pharmacological trials in painful peripheral neuropathies. Although neuropathic pain management remains challenging because the response to therapy varies considerably between patients, and pain relief is rarely complete, a majority of patients can benefit from monotherapy using a well‐chosen agent or polypharmacy that combines medications with different mechanisms of action. Muscle Nerve 30: 3–19, 2004
Whiplash: Pathophysiology, diagnosis, treatment, and prognosis
Authors: Rodriquez Arthur A. , Barr Karen P. , Burns Stephen P.
Published: April 2004

We have reviewed the literature relevant to pathophysiology, diagnosis, treatment, and prognosis of whiplash‐associated disorder (WAD) since 1995 and provided a brief summary of literature pertaining to forces action on the head and neck during a motor vehicle accident. The scope of the current review is confined to the Quebec guidelines for WAD grades 1–3 but excludes grade 4 (neck complaints and fracture or dislocation). After excluding papers without scientific data and single case reports or case series with fewer than 20 patients, articles were reviewed for methodological quality. The diagnosis remains clinical. No imaging, physiological, or psychological study provides specific diagnostic criteria. In the acute period up to 2 weeks, soft collars or rest and work‐leave do not shorten the duration of neck pain. Sick leave is reduced by high‐dose methylprednisolone given within 8 h of injury, but confirmatory studies examining the cost–benefit relationship are needed. In the first 6 months, active as opposed to passive treatment results in improved outcomes. Specific exercise strategies have not been studied. For those with symptoms lasting more than 6 months, percutaneous radio‐frequency neurotomy can provide pain relief for many months in those responding to blind local anesthetic facet blocks. Intra‐articular corticosteroids are ineffective. Uncontrolled trials suggest that multimodal rehabilitation programs result in improved overall function. The overall prognosis for recovery has varied considerably across studies. Such variability is likely due to differences in case identification methods and whether outcome is assessed in terms of symptoms or the receipt of financial compensation for injury. The impact on prognosis of both collision‐ and patient‐related factors is also reviewed. Muscle Nerve 29: 768–781, 2004
Cavitation of rubber particles in high‐impact polystyrene: Effects of crosslinking by γ‐irradiation
Authors: Bucknall C.B. , Soares V.L.P.
Published: April 2004

Tensile tests on high‐impact polystyrene (HIPS) show that a 60 Mrad dose of γ‐radiation raises the yield stress from 11.5 to 19.8 MPa, and the flow stress from 10.0 to 19.6 MPa, while reducing the elongation at break from 50 to 4%. Similar reductions in fracture resistance are observed in irradiated Charpy impact specimens. The Tg of the rubber phase shifts from −70 to −57 °C, and its estimated shear modulus increases from 0.1 to 0.5 MPa. It is concluded that the observed changes in mechanical properties are due almost entirely to crosslinking of the polybutadiene. This not only inhibits cavitation and fibrillation in the rubbery membranes of the “salami” particles, thereby delaying yield, but also makes the fibrillated membranes more resistant to further dilatation, so that rates of craze thickening in the polystyrene matrix are reduced. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2168–2180, 2004
Co‐operative functions between nuclear factors NFκB and CCAT/enhancer‐binding protein‐β (C/EBP‐β) regulate the IL‐6 promoter in autocrine human prostate cancer cells
Authors: Xiao Weihua , Hodge David R. , Wang Lihua , Yang Xiaoyi , Zhang Xiaohu , Farrar William L.
Published: April 2004

BACKGROUND

IL‐6 is a growth and survival factor for prostate cancer cells through autocrine pathways. Here, we have systematically examined the transcriptional regulation mechanisms of IL‐6 in autocrine prostate cancer cells.

METHODS

RT‐PCR and immunohistochemical staining were used to determine IL‐6 production in the cells. Serial mutant IL‐6 promoter luciferase reporters were generated and their transcriptional activities were examined. The transcription factors involved in IL‐6 regulation were identified with super‐shift EMSA. Overexpression of NFκB p65 and C/EBP‐β, and blockade of NFκB with IκBα or CAPE were performed to demonstrate the cooperation between NFκB p65 and C/EBP‐β in activation of IL‐6.

RESULTS

Transcription factor regulatory sites IL6‐NFκB, IL6‐C/EBP, IL6‐CREB, and IL6‐AP1, are responsive to constitutively activated IL‐6 production in autocrine prostate cancer cell lines. Among these sites, IL6‐AP1 and IL6‐C/EBP appear most important, while IL6‐NFκB shows the least effect for IL‐6 promoter activity as determined by mutant IL‐6 promoter luciferase reporter assay. Nevertheless, nuclear factor NFκB is activated and required. Such activation is minimally dependent upon the IL6‐NFκB site, occurring through cooperation with other transcription factors that bind the IL‐6 promoter. Cooperation between NFκB p65 and C/EBP‐β did not require a functional IL6‐NFκB binding site.

CONCLUSIONS

These data support a unique role for NFκB p65 as the primary trigger in autocrine production of IL‐6 in prostate cancer cells. Furthermore, we describe a novel transcriptional activation mechanism for NFκB that is independent of its regulatory binding site, occurring through cooperation with other transcription factors that facilitate the neighboring regulatory site. © 2004 Wiley‐Liss, Inc.
Amyloid β‐peptide interactions with neuronal and glial cell plasma membrane: binding sites and implications for Alzheimer's disease
Authors: Verdier Yann , Zarándi Márta , Penke Botond
Published: April 2004

The extracellular accumulation of amyloid‐beta (Aβ) in neuritic plaques is one of the characteristic hallmarks of Alzheimer's disease (AD), a progressive dementing neurodegenerative disorder of the elderly. By virtue of its structure, Aβ is able to bind to a variety of biomolecules, including lipids, proteins and proteoglycans. The binding of the various forms of Aβ (soluble or fibrillar) to plasma membranes has been studied with regard to the direct toxicity of Aβ to neurons, and the activation of a local inflammation phase involving microglia.

The binding of Aβ to membrane lipids facilitates Aβ fibrillation, which in turn disturbs the structure and function of the membranes, such as membrane fluidity or the formation of ion channels.

A subset of membrane proteins binds Aβ. The serpin‐enzyme complex receptor (SEC‐R) and the insulin receptor can bind the monomeric form of Aβ. The α7nicotinic acetylcholine receptor (α7nAChR), integrins, RAGE (receptor for advanced glycosylation end‐products) and FPRL1 (formyl peptide receptor‐like 1) are able to bind the monomeric and fibrillar forms of Aβ. In addition, APP (amyloid precursor protein), the NMDA‐R (N‐methyl‐D‐aspartate receptor), the P75 neurotrophin receptor (P75NTR), the CLAC‐P/collagen type XXV (collagen‐like Alzheimer amyloid plaque component precursor/collagen XXV), the scavenger receptors A, BI (SR‐A, SR‐BI) and CD36, a complex involving CD36, α6β1–integrin and CD47 have been reported to bind the fibrillar form of Aβ.

Heparan sulfate proteoglycans have also been described as cell‐surface binding sites for Aβ. The various effects of Aβ binding to these membrane molecules are discussed. Copyright © 2004 European Peptide Society and John Wiley & Sons, Ltd.
Suicidal ideation and attempts in adolescents: associations with depression and six domains of self‐esteem
Authors: Wild Lauren G. , Flisher Alan J. , Lombard Carl
Published: April 2004

This study aimed to disentangle the influence of depression and self‐esteem on suicidal behaviour in adolescence. Grades 8 and 11 students in Cape Town, South Africa (n=939) completed questionnaires assessing suicidal ideation and behaviour, depression, and self‐esteem with respect to family, peers, school, sports/athletics, body image and global self‐worth. Data were analysed using a series of multinomial logistic regression models adjusted for gender, grade, race and the sampling strategy. Results indicated that depression and low self‐esteem in the family context were independently associated with suicide ideation and attempts. Moreover, low family self‐esteem significantly differentiated suicide attempters from ideators. Screening for depression and low self‐esteem in the family context is discussed as a possible strategy for helping to identify adolescents at risk for suicide attempts.
Cholesterol perturbing agents inhibit NMDA‐dependent calcium influx in rat hippocampal primary culture
Authors: Frank Claudio , Giammarioli Anna Maria , Pepponi Rita , Fiorentini Carla , Rufini Stefano
Published: April 2004

The present study was carried out to investigate the potential involvement of cholesterol‐rich membrane microdomains in the mobilization of calcium induced by NMDA‐receptors (NMDA‐R). We herein provide evidence that agents interfering with plasma membrane cholesterol (namely, filipin and methyl‐β‐cyclodextrin (Cdex)) inhibit the NMDA‐stimulated influx of calcium in hippocampal cells in culture. Filipin‐treated cells maintained their morphology and were able to respond with a calcium influx to high K+ challenge, whereas Cdex altered both cellular parameters. These results suggest that the NMDA‐R can be located in cholesterol‐rich membrane microdomains or alternatively that the mechanisms coupling their dynamics in the post‐synaptic membrane are dependent on the integrity of the microdomains.
Proton pumping mechanism and catalytic cycle of cytochrome c oxidase: Coulomb pump model with kinetic gating
Authors: Popović Dragan M. , Stuchebrukhov Alexei A.
Published: April 2004

Using electrostatic calculations, we have examined the dependence of the protonation state of cytochrome c oxidase from bovine heart on its redox state. Based on these calculations, we propose a possible scheme of redox‐linked proton pumping. The scheme involves His291 – one of the ligands of the CuB redox center – which plays the role of the proton loading site (PLS) of the pump. The mechanism of pumping is based on ET reaction between two hemes of the enzyme, which is coupled to a transfer of two protons. Upon ET, the first proton (fast reaction) is transferred to the PLS (His291), while subsequent transfer of the second “chemical” proton to the binuclear center (slow reaction) is accompanied by the ejection of the first (pumped) proton. Within the proposed model, we discuss the catalytic cycle of the enzyme.
Evidence of finely tuned expression of DNA polymerase β in vivo using transgenic mice
Authors: Bergoglio Valérie , Fréchet Mathilde , Philippe Magali , Bieth Anne , Mercier Pascale , Morello Dominique , Lacroix-Tricki Magali , Delsol Georges , Hoffmann Jean-Sébastien , Cazaux Christophe
Published: April 2004

DNA polymerase β (Pol β) is an error‐prone repair DNA polymerase that has been shown to create genetic instability and tumorigenesis when overexpressed by only 2‐fold in cells, suggesting that a rigorous regulation of its expression may be essential in vivo. To address this question, we have generated mice which express a transgene (Tg) bearing the Pol β cDNA under the control of the ubiquitous promoter of the mouse H‐2K gene from the major histocompatibility complex. These mice express the Tg only in thymus, an organ which normally contains the most abundant endogenous Pol β mRNA and protein, supporting the idea of a tight regulation of Pol β in vivo. Furthermore, we found no tumor incidence, suggesting that the single Pol β overexpression event is not sufficient to initiate tumorigenesis in vivo.
Generic manufacturing strategies and plant performance
Authors: Devaraj Sarv , Hollingworth David G , Schroeder Roger G
Published: April 2004

This study examines the effects of the fit between generic manufacturing strategies (GMS) and manufacturing objectives upon strategically relevant plant level performance outcomes (e.g. cost‐efficiency, quality, delivery, flexibility, and innovation). The proposition that plants with generic manufacturing strategies that are consistent (fit) with operational objectives will experience relatively higher levels of performance than others is tested using data from multiple countries and industries. A simultaneous estimation analysis revealed significant relationships between generic manufacturing strategies and plant performance, when accounting for operational objectives and while controlling for country, industry, and size effects.
Bilateral Chylothorax after Neck Dissection
Authors: Busquets José M. , Rullan Pedro J. , Trinidad‐Pinedo Juan
Published: April 2004

Chylous fistula is a well‐recognized complication of neck dissection, occurring in 1% to 2% of cases.1 Cardiopulmonary complications, on the other hand, are rare. Bilateral chylothorax is an extremely rare occurrence following neck dissection. Severe respiratory, metabolic, and immunologic derangements can occur secondary to chylothorax. We report a case of bilateral chylothorax after neck dissection and cervical thoracic duct ligation.
Nonrhinologic Headache in a Tertiary Rhinology Practice
Authors: Perry Brian F. , Login Ivan S. , Kountakis Stilianos E.
Published: April 2004

OBJECTIVE

Our goal was to determine the etiology of headache in patients who were referred for sinus evaluation but were found to have no evidence of rhinosinusitis on computed tomography (CT) of the sinuses and on endoscopic examination.

METHODS

Data were collected prospectively from 100 patients with headache but with normal sinus CT and endoscopic examination. Headache and 20‐Item Sino‐Nasal Outcomes Test (SNOT‐20) scores of patients with the chief complaint of headache and who requested further neurologic evaluation (group I) were compared with the scores of patients who did not list headache as a significant symptom (group II) and with the scores of patients without headache (group III).

RESULTS

The most common neurologic diagnosis for group I patients (n = 36) was migraine headaches (58%). These patients also had higher mean SNOT‐20 scores (24 ± 3.3) compared to group II patients with mild headache (14.6 ± 2.3) or group III patients without headache (12.4 ± 2.1).

CONCLUSION

Migraine was the most common type of headache in patients with normal sinus CT treated for presumed rhinosinusitis as the cause of the headache. Patients with headache as their chief complaint that required further neurologic evaluation had overall higher SNOT‐20 scores than nonheadache patients, indicating greater disability of their overall quality of life index. (Otolaryngol Head Neck Surg 2004;130:449‐52.)
Radiologic and Histological Evaluation of Otogenic Sliced Cartilage Grafts at the Tip of the Chin of Rabbits: An Experimental Study
Authors: Akbas Hayati , Karacaoglan Naci , Eroglu Lutfi , Uysal Ata , Incesu Lutfi , Kandemir Bedri
Published: April 2004

OBJECTIVES

Cartilage grafts have been commonly used in plastic and reconstructive surgery applications for many different goals, such as auricular reconstruction and rhinoplasty. The use of autologous cartilage is ideal for many reasons. An attempt was made to produce an experimental animal model to test the efficacy of otogenic Surgicel‐wrapped sliced cartilage.

METHODS

In this experimental study, cartilage grafts were harvested from rabbits' ears. These grafts were cut in pieces of 0.5 mm to 1 mm using a no. 11 blade. This cartilage mass was wrapped in one layer of Surgicel (oxidized regenerated cellulose) and inserted in the chin of the rabbits. MR analyses were made at 1 week and 6 months and histological analyses were made at 6 months.

RESULTS

Cartilage grafts maintained approximately 80% of their dimensions in MRI. The proportion of necrosis was between 30% and 50% and the proportion of resorption was approximately 20% in the histological studies.
Recycled metasomatized lithosphere as the origin of the Enriched Mantle II (EM2) end‐member: Evidence from the Samoan Volcanic Chain
Authors: Workman R. K. , Hart S. R. , Jackson M. , Regelous M. , Farley K. A. , Blusztajn J. , Kurz M. , Staudigel H.
Published: April 2004

An in‐depth Sr‐Nd‐Pb‐He‐Os isotope and trace element study of the EMII‐defining Samoan hot spot lavas leads to a new working hypothesis for the origin of this high 87Sr/86Sr mantle end‐member. Systematics of the Samoan fingerprint include (1) increasing 206Pb/204Pb with time ‐ from 18.6 at the older, western volcanoes to 19.4 at the present‐day hot spot center, Vailulu'u Seamount, (2) en‐echelon arrays in 206Pb/204Pb – 208Pb/204Pb space which correspond to the two topographic lineaments of the 375 km long volcanic chain – this is much like the Kea and Loa Trends in Hawai'i, (3) the highest 87Sr/86Sr (0.7089) of all oceanic basalts, (4) an asymptotic decrease in 3He/4He from 24 RA [Farley et al., 1992] to the MORB value of 8 RA with increasing 87Sr/86Sr, and (5) mixing among four components which are best described as the “enriched mantle”, the depleted FOZO mantle, the (even more depleted) MORB Mantle, and a mild HIMU (high 238U/204Pb) mantle component. A theoretical, “pure” EMII lava composition has been calculated and indicates an extremely smooth trace element pattern of this end‐member mantle reservoir. The standard recycling model (of ocean crust/sediment) fails as an explanation for producing Samoan EM2, due to these smooth spidergrams for EM2 lavas, low 187Os/188Os ratios and high 3He/4He (>8 RA). Instead, the origin of EM2 has been modeled with the ancient formation of metasomatised oceanic lithosphere, followed by storage in the deep mantle and return to the surface in the Samoan plume.