bluuebunny/crossref_metadata_2025_split huggingface dataset:
Matrix‐mediated gene transfer to brain cortex and dorsal root ganglion neurones by retrograde axonal transport after dorsal column lesion
Authors: Gonzalez Ana Maria , Berry Martin , Greenlees Lydia , Logan Ann , Baird Andrew 
Published: May 2006

AbstractBackgroundIn previous studies, we showed that the immobilisation of DNAs encoding basic fibroblast growth factor, neurotrophin‐3 and brain‐derived neurotrophic factor in a gene‐activated matrix (GAM) promotes sustained survival of axotomised retinal ganglion cells after optic nerve injury. Here, we evaluated if the immobilisation of DNAs in a GAM could be an effective approach to deliver genes to axotomised dorsal root ganglion (DRG) neurones after spinal cord injury and if the matrix component of the GAM would modulate the deposition of a dense scar at the injury site.MethodsWe evaluated the expression of the thymidine kinase (TK) reporter gene in brain cortex and DRG after a bilateral T8 dorsal column (DC) lesion using PCR, RT‐PCR and in situ hybridisation analyses. Collagen‐based GAMs were implanted at the lesion site and the cellular response to the GAM was assessed using cell‐specific markers.ResultsAt 1 week post‐injury, PCR analyses confirmed that DNATK was retrogradely transported from the DC lesion where the GAM was implanted to the brain cortex and to caudal DRG neurones, and RT‐PCR analyses showed expression of mRNATK. At 7 weeks post‐injury, DNATK was still be detected in the GAM and DRG. In situ hybridisation localised DNATK and mRNATK within fibroblasts, glia, endothelial and inflammatory cells invading the GAM and in DRG neurones. Interestingly, the presence of a GAM also reduced secondary cavitation and scar deposition at the lesion site.ConclusionsThese results establish that GAMs act as bridging scaffolds in DC lesions limiting cavitation and scarring and delivering genes both locally to injury‐reactive cells and distally to the cerebral cortex and to DRG neuronal somata through retrograde axonal transport. Copyright © 2006 John Wiley & Sons, Ltd.
Absence of synaptophysin near cortical neurons containing oligomer Aβ in Alzheimer's disease brain
Authors: Ishibashi Ken‐Ichi , Tomiyama Takami , Nishitsuji Kazuchika , Hara Mitsuhiro , Mori Hiroshi 
Published: May 2006

AbstractSoluble amyloid β protein (Aβ) oligomers have been considered recently to be responsible for the cognitive dysfunction that sets in prior to senile plaque formation in the Alzheimer's disease (AD) brain. By using the newly prepared antibody against oligomer Aβ, rather than fibrillar or monomer Aβ, we observed that oligomer Aβ in AD brains was localized as clusters ofdot‐likeimmunostains in the neurons in a manner different from that in senile plaques. The relationship of oligomer Aβ with synaptophysin, a synaptic molecular marker, was examined because oligomer Aβ is widely believed to be related to synaptic failure. We observed that immunostainings for synaptophysin were absent near neurons bearing clusters of oligomer Aβ. The present study provides morphological evidence to support the idea that accumulated oligomer Aβ, but not fibrillar Aβ, is closely associated with synaptic failure, which is the major cause of cognitive dysfunction. © 2006 Wiley‐Liss, Inc.
Cellular composition of long‐term human spinal cord‐ and forebrain‐derived neurosphere cultures
Authors: Piao Jing‐Hua , Odeberg Jenny , Samuelsson Eva‐Britt , Kjældgaard Anders , Falci Scott , Seiger Åke , Sundström Erik , Åkesson Elisabet 
Published: May 2006

AbstractIn vitro expanded neural precursor cells (NPCs) may provide a stable source for cell therapy. In search of the optimal cell source for spinal cord repair, we investigated influences of gestational age, regional heterogeneity, and long‐term in vitro propagation. The cellular content of neurosphere cultures prior to and after in vitro differentiation was studied by immunocytochemistry and flow cytometry. Human forebrain and spinal cord NPCs deriving from first‐trimester tissue were cultured as neurospheres in the presence of epidermal growth factor, basic fibroblast growth factor, and ciliary neurotrophic factor. Proteins characteristic for embryonic stem cells, i.e., Tra‐1‐60, Tra‐1‐81, and SSEA‐4, were present in ≈0.5% of the cells in donor tissues and neurospheres. The proportions of nestin‐ and proliferating cell nuclear antigen‐immunoreactive (IR) cells were also maintained, whereas the CD133‐IR population increased in vitro. Glial fibrillary acidic protein‐IR cells increased in number, and in contrast the fraction of β‐tubulin III‐IR cells decreased, at and beyond passage 5 in spinal cord but not forebrain cultures. However, dissociated and in vitro‐differentiated forebrain‐ and spinal cord‐derived neurospheres generated similar proportions of neurons, astrocytes, and oligodendrocytes. Gestational age of the donor tissue, which ranged from 4.5 to 12 weeks for forebrain and from 4.5 to 9.5 weeks for spinal cord, did not affect the proportion of cells with different phenotypes in culture. Thus, cellular composition of human neurosphere cultures differs as a result of long‐term in vitro propagation and regional heterogeneity of source tissue, despite expansion under equal culture conditions. This could in turn imply that human spinal cord and forebrain NPCs present different repair potentials in in vivo settings. © 2006 Wiley‐Liss, Inc.
Glutathione peroxidase 1 and glutathione are required to protect mouse astrocytes from iron‐mediated hydrogen peroxide toxicity
Authors: Liddell Jeff R. , Hoepken Hans H. , Crack Peter J. , Robinson Stephen R. , Dringen Ralf 
Published: May 2006

AbstractThe enzyme glutathione peroxidase 1 (GPx1) is involved in the cellular detoxification of peroxides. To test for the consequences of GPx deficiency in astrocytes, astrocyte‐rich primary cultures from wild‐type and GPx1‐deficient [GPx1(–/–)] mice were exposed to H2O2. In GPx1(–/–) astrocytes, the clearance rate of H2O2 was slower than in wild‐type cells. In contrast to GPx1‐deficient astrocytes, wild‐type cells exhibited, within 2 min of H2O2 application, a rapid and transient accumulation of cellular glutathione disulfide that amounted to 60% of total glutathione. The peroxide treatment did not affect the viability of wild‐type astrocytes, whereas 45% of the GPx1(–/–) cells died within 8 hr. However, the viability of both types of astrocytes was strongly compromised by lowering cellular glutathione content before peroxide application. In contrast, inactivation of catalase caused substantial cell death only in GPx1(–/–) cells but not in wild‐type astrocytes. The cell death observed was prevented by the iron chelators deferoxamine, 1,10‐phenathroline, or 2,2′‐dipyridyl, whereas preincubation with ferric ammonium citrate increased the toxicity of peroxide treatments. These results demonstrate that GPx1 contributes to the rapid clearance of H2O2 by mouse astrocytes and that both GPx1 and a high concentration of glutathione are required to protect these cells from iron‐dependent peroxide damage. © 2006 Wiley‐Liss, Inc.
Study of tryptophan metabolism via serotonin in cerebrospinal fluid of patients with noncommunicating hydrocephalus using a new endoscopic technique
Authors: Comai Stefano , Longatti Pierluigi , Perin Alessandro , Bertazzo Antonella , Ragazzi Eugenio , Costa Carlo V.L. , Allegri Graziella 
Published: May 2006

AbstractBy a recent minimally invasive neuroendoscopic technique, the cerebral ventricles have been reached in a quick, reliable, and harmless way, making possible the study of cerebrospinal fluid (CSF) of the lateral ventricles and, above all, the CSF adjacent to the walls of the third ventricle. Tryptophan, 5‐hydroxytryptophan, serotonin (5‐HT), and 5‐hydroxyindoleacetic acid (5‐HIAA) were measured in CSF by HPLC equipment. Twenty‐six patients affected with noncommunicating hydrocephalus were enrolled in the study and, as controls, 28 subjects not suffering from any neurological disease. The concentrations of tryptophan were higher in right ventricular CSF than in lumbar CSF (P < 0.01). 5‐HT was detectable in the CSF of the right ventricle of hydrocephalic patients. 5‐HIAA was higher in right ventricular CSF than in cisternal and lumbar CSF (P < 0.01), both in controls and in hydrocephalic patients. However, there was a higher concentration of 5‐HIAA in right ventricular (P < 0.05) and cisternal (P < 0.01) CSF in hydrocephalic patients in comparison with controls. In the CSF samples withdrawn during neuroendoscopy, 5‐HT presented the highest concentrations in the pineal recess. The highest amounts of 5‐HIAA were found in the choroid plexus, third and right ventricles, pituitary recess, and aqueduct, and the lowest in pineal recess, subarachnoid space, infundibulum, and interpeduncolar cistern. These results provide new insight into the fate of tryptophan and its metabolites via serotonin in the CSF and suggest the feasibility of the new neuroendoscopic technique for brain metabolic studies. © 2006 Wiley‐Liss, Inc.
Distributions of long dry spells in the iberian peninsula, years 1951–1990
Authors: Lana X. , Martínez M. D. , Burgueño A. , Serra C. , Martín‐Vide J. , Gómez L. 
Published: May 2006

AbstractStatistical distributions of annual extreme and long dry spells for the Iberian Peninsula are investigated by using a daily database compiled from 43 rain gauges, with the recording period extending from 1951 to 1990 and with a minor lack of data. Dry spell lengths are derived for three different daily rainfall thresholds of 0.1, 1.0 and 5.0 mm/day. On one hand, the generalised extreme value (GEV) and generalised Pareto (GP) distributions are considered for modelling the series of annual extreme (AE) dry spells. On the other hand, both theoretical distributions are assumed for the partial duration (PD) series, which are derived from the dry spell lengths exceeding the 95th percentile. In both cases, a robust estimation of the three parameters of the GEV and GP distributions is obtained by L‐moments. The fit between empirical and theoretical distributions is evaluated by using the 95% confidence bands of the Kolmogorov–Smirnov test and the L‐skewness‐kurtosis distance. Even though AE spells are quite well fitted by the GEV model, the GP distribution is a better option for some rain gauges. The PD series are usually better fitted by the GP distribution, only a few cases being better modelled by the GEV distribution. The basis for climatic drought risk assessment in the Iberian Peninsula is then established for dry spell lengths associated with return periods of 2, 5, 10, 25 and 50 years and accurately reviewed by comparing with results deduced from the AE and PD sampling strategies. As a general feature, both the spatial distribution of the statistical parameters and the dry spell lengths for the different return periods depict a north to south gradient. Some local deviations of this behaviour could be due to the vicinity to the Mediterranean Sea and the Atlantic Ocean. Copyright © 2006 Royal Meteorological Society
Broadband Dielectric Spectroscopy Studies of Hyperbranched Polyglycerols
Authors: Garcia‐Bernabé Abel , Díaz‐Calleja Ricardo , Haag Rainer 
Published: May 2006

AbstractSummary: The broadband dielectric spectroscopy of three hyperbranched polyglycerols with different molecular weights has been studied. All of the hyperbranched polyglycerols exhibited three relaxation processes, one related to glass transition (α relaxation) and two sub‐glass processes (β and γ relaxations). The relaxations were analyzed in terms of the Havriliak‐Negami equation. The two sub‐glass processes collapse with α relaxation in different scenarios at high temperatures and only a broad and apparently symmetric relaxation peak is observed. Within this temperature range, two clearly different tendencies were observed at the low and high extremes of the temperature range.
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Strained Diphosphines Built upon a Calix[4]arene Skeleton. Synthesis of a Highly Active Norbornene Polymerization Catalyst
Authors: Lejeune Manuel , Jeunesse Catherine , Matt Dominique , Sémeril David , Peruch Frédéric , Toupet Loïc , Lutz Pierre J. 
Published: May 2006

AbstractSummary: The complexes cis‐P,P′‐(η5‐cylopentadienyl)‐{5,17‐dibromo‐11,23‐bis(diphenylphosphino)‐25,26,27,28‐tetrapropoxy‐calix[4]arene}nickel(II) tetrafluoroborate (1) and dibromo‐{5,17‐dibromo‐11,23‐bis(diphenylphosphino)‐25,26,27,28‐tetrapropoxycalix[4]arene}nickel(II) (2), both of which contain a constrained chelating diphosphine, were evaluated for the polymerization of norbornene. Combined with methylaluminoxane, they result in remarkably active systems for the production of high‐molar‐mass vinyl‐type polynorbornene. Turnover frequencies of up to 7.5 × 105 mol(NBE) · mol(Ni)−1 · h−1 are observed. A plausible explanation for their high performances relies on a periodic P–Ni–P bite angle enlargement that temporarily increases the steric hindrance about the catalytic centre, which in turn favours the insertion steps.Molecular structure of 2.imageMolecular structure of 2.
Thermoresponsive Polymeric Nanoemulsions
Authors: Koňák Čestmír , Hrubý Martin 
Published: May 2006

AbstractSummary:Solutions of poly(N‐isopropylacrylamide) (PNIPA) with added sodium dodecyl sulfate (SDS) were investigated by light scattering methods at temperatures of 15–40 °C. The formation of well‐defined nanoparticles of PNIPA was observed on heating at low SDS additions. The effects of PNIPA and SDS concentrations and the molecular weight of PNIPA on nanoparticle parameters were investigated. An interpretation based on stabilization of PNIPA nuclei by SDS was suggested.The proposed mechanism of nanoparticle formation.imageThe proposed mechanism of nanoparticle formation.
Expectation and the placebo effect in Parkinson's disease patients with subthalamic nucleus deep brain stimulation
Authors: Mercado Rodrigo , Constantoyannis Constantine , Mandat Tomasz , Kumar Ajit , Schulzer Michael , Stoessl A. Jon , Honey Christopher R. 
Published: May 2006

AbstractTo determine whether the degree to which a patient with Parkinson's disease expects therapeutic benefit from subthalamic nucleus–deep brain stimulation (STN‐DBS) influences the magnitude of his or her improved motor response, 10 patients with idiopathic Parkinson's and bilateral STN‐DBS were tested after a 12‐hour period off medication and stimulation. Four consecutive UPDRS III scores were performed in the following conditions: (a) stimulation OFF, patient aware; (b) stimulation OFF, patient blind; (c) stimulation ON, patient aware; and (d) stimulation ON, patient blind. Statistical significance (P = 0.0001) was observed when comparing main effect ON versus OFF (mean ON: 32.55; mean OFF: 49.15). When the stimulation was OFF, patients aware of this condition had higher UPDRS motor scores than when they were blinded (mean: 50.7 vs. 47.6). With the stimulation ON, UPDRS motor scores were lower when the patients were aware of the stimulation compared with when they were blinded (mean: 30.6 vs. 34.5). The interaction between these levels was significant (P = 0.049). This variation was important for bradykinesia and was not significant for tremor and rigidity. The authors conclude that the information about the condition of the stimulation enhanced the final clinical effect in opposite directions. The results presented support the role of expectation and placebo effects in STN‐DBS in Parkinson's disease patients. © 2006 Movement Disorder Society
Two cases of ischemia associated with subthalamic nucleus stimulator implantation for advanced Parkinson's disease
Authors: Novak Kevin E. , Nenonene Emmanuel K. , Bernstein Lawrence P. , Vergenz Sandra , Medalle Gina , Prager Jordan M. , Eller Theodore W. , Cozzens Jeffrey W. , Rezak Michael 
Published: May 2006

AbstractDeep brain stimulation is generally a safe and effective method of alleviating motor impairment in advanced‐stage Parkinson's disease patients. However, adverse events of surgery have been noted, such as hemorrhage, infection, seizures, and device failure. In this report, we describe 2 cases of the unusual adverse event of ischemia associated with subthalamic nucleus stimulator implantation. We present the intraoperative neurological symptoms, microelectrode recording data, imaging findings, and other correlated events. In the first case, the clinical effects of ischemia were evident intraoperatively and coincided with silence during microelectrode recording from the ischemic region. In the second case, the timing of the ischemic event could not be determined precisely but also was associated with a difficult mapping. Subcortical ischemia may be an underrecognized event that confounds neurophysiological mapping of deep brain structures and affects clinical outcomes. © 2006 Movement Disorder Society
Striatal dopa and glucose metabolism in PD patients with freezing of gait
Authors: Bartels Anna L. , de Jong Bauke M. , Giladi Nir , Schaafsma Joanna D. , Maguire R. Paul , Veenma Lammy , Pruim Jan , Balash Yacov , Youdim Moussa B.H. , Leenders Klaus L. 
Published: May 2006

AbstractIn Parkinson's disease (PD), freezing suggests sudden and transient blocks of motor behavior during initiating or continuous repetitive movements. Its underlying pathophysiology remains unclear. The objective of this study is to compare striatal dopamine metabolism and cerebral glucose metabolism between PD patients with and without freezing of gait (FOG). A total of 10 PD patients with FOG at off and 7 PD patients without FOG underwent brain positron emission tomography with 18[F]‐6‐fluoro‐levodopa (FDOPA) and 18[F]‐fluordesoxyglucose (FDG). Striatum decarboxylase activity was expressed by metabolic influx constants of the striatum related to the occipital lobe (Kocc). FDG uptake in caudate and putamen was normalized to global FDG uptake. Region of interest (ROI) analysis of striatal regions was used, as well as voxel‐based analysis by statistical parametric mapping (SPM). ROI analysis did not reveal differences in striatal FDOPA and FDG uptake between the groups. SPM showed lower putaminal FDOPA uptake (P = 0.05 uncorrected) with increased FDG uptake (P = 0.01 uncorrected) in freezing PD, whereas caudate uptake of the two tracers was reduced. Freezing‐related cortical FDG decrease was found in (right) parietal regions. In conclusion, in freezing PD, caudate uptake of FDG and FDOPA was reduced, whereas putamen FDOPA decrease was associated with FDG increase. Right hemisphere circuitry seemed to be more affected in freezing patients. © 2006 Movement Disorder Society
Boundary value problem for theN‐dimensional time periodic Vlasov–Poisson system
Authors: Bostan M. 
Published: May 2006

AbstractIn this work, we study the existence of time periodic weak solution for theN‐dimensional Vlasov–Poisson system with boundary conditions. We start by constructing time periodic solutions with compact support in momentum and bounded electric field for a regularized system. Then, thea prioriestimates follow by computations involving the conservation laws of mass, momentum and energy. One of the key point is to impose a geometric hypothesis on the domain: we suppose that its boundary is strictly star‐shaped with respect to some point of the domain. These results apply for both classical or relativistic case and for systems with several species of particles. Copyright © 2006 John Wiley & Sons, Ltd.
Predictive value of initial urodynamic pattern on urinary continence in patients with myelomeningocele
Authors: Kessler Thomas M. , Lackner Jakob , Kiss Gustav , Rehder Peter , Madersbacher Helmut 
Published: May 2006

AbstractAimsTo investigate whether the initial urodynamic pattern may predict urinary continence and the need for adjunctive incontinence surgery in patients with myelomeningocele.Patients and MethodsOne hundred and twenty‐three patients with myelomeningocele were included in our retrospective study. The patients were divided based on the urodynamic pattern at initial evaluation into four categories: overactive detrusor with overactive (spastic) sphincter (group 1, n = 43), overactive detrusor with underactive/acontractile sphincter (group 2, n = 37), underactive/acontractile detrusor with overactive (spastic) sphincter (group 3, n = 8), and underactive/acontractile detrusor with underactive/acontractile sphincter (group 4, n = 35). Urinary continence status at the last follow‐up and the need for adjunctive incontinence surgery were compared between the four groups.ResultsMean follow‐up was 10 years and mean age at the last follow‐up 17 years. A socially acceptable continence status (continent or socially dry) was achieved in 74% and was significantly different among the four groups (P = 0.023): 86% and 87% of the patients in group 1 and 3 became continent or socially dry, but only 57% and 74% of those in group 2 and 4, respectively. Although none of the patients in group 3 underwent adjunctive incontinence surgery compared to about 25% in the other groups, statistically the difference was not significant (P = 0.48).ConclusionsThe initial urodynamic pattern is very useful in counseling families by predicting urinary continence in patients with myelomeningocele. The chances of becoming continent or at least socially dry are best for patients with overactive (spastic) sphincter. Neurourol. Urodynam. 25:361–367, 2006. © 2006 Wiley‐Liss, Inc.
Dopaminergic mechanisms controlling urethral function in rats
Authors: Ogawa Teruyuki , Seki Satoshi , Masuda Hitoshi , Igawa Yasuhiko , Nishizawa Osamu , Kuno Sadako , Chancellor Michael B. , de Groat William C. , Yoshimura Naoki 
Published: May 2006

AbstractAimsTo investigate the role of dopamine receptor subtypes in the control of urethral activity.MethodsSimultaneous recordings of intravesical and urethral perfusion pressure (UPP) were performed in rats under urethane anesthesia. Changes in coordinated activity of the bladder and urethral sphincter were examined following intravenous (i.v.), intrathecal (i.t.), or intracerebroventricular (i.c.v.) administration of dopamine D1‐ and D2‐like receptor agonists (SKF38393 and quinpirole, respectively) and antagonists (SCH23390 and remoxipride, respectively).ResultsQuinpirole (0.03, 0.1, and 0.3 mg/kg i.v.) dose‐dependently decreased baseline urethral pressure to 45.33 ± 5.8, 33.7 ± 3.3 (P < 0.05, n = 6), and 27.7 ± 3.3 cm H2O (P < 0.05, n = 5) from the control value (46.0 ± 4.0 cm H2O), respectively. i.c.v. injection of quinpirole (1 µg) decreased baseline urethral pressure to 33.6 ± 5.0 cm H2O (P < 0.05, n = 4) from the control value (51.4 ± 4.9 cm H2O) in contrast to the insignificant effects of i.t. administration of the drug (3 µg). The decrement of baseline pressure induced by quinpirole (0.1 mg/kg i.v.) was suppressed by α‐bungarotoxin (BGT), a neuromuscular blocking agent. SCH23390 (1 and 3 mg/kg, i.v.) dose‐dependently decreased the frequency of high frequency oscillation (HFO) of the urethral sphincter. SKF38393 or remoxipride did not have significant effects on any parameters of bladder and urethral activity.ConclusionsThese results indicate that activation of D2‐like dopamine receptors at a supraspinal site can suppress activity of the striated muscle urethral sphincter. Thus, decreased urethral resistance induced by D2 dopamine receptor activation might aggravate urge incontinence symptoms often seen in patients with Parkinson's disease (PD). Neurourol. Urodynam. © 2006 Wiley‐Liss, Inc.