bluuebunny/crossref_metadata_2025 huggingface dataset:
Cx43 Hemichannels and Gap Junction Channels in Astrocytes Are Regulated Oppositely by Proinflammatory Cytokines Released from Activated Microglia
Authors: Retamal Mauricio A. , Froger Nicolas , Palacios-Prado Nicolas , Ezan Pascal , Sáez Pablo J. , Sáez Juan C. , Giaume Christian
Published: December 2007

Astrocytes have a role in maintaining normal neuronal functions, some of which depend on connexins, protein subunits of gap junction channels and hemichannels. Under inflammatory conditions, microglia release cytokines, including interleukin-1β and tumor necrosis factor-α, that reduce intercellular communication via gap junctions. Now, we demonstrate that either conditioned medium harvested from activated microglia or a mixture of these two cytokines enhances the cellular exchange with the extracellular milieu via Cx43 hemichannels. These changes in membrane permeability were not detected in astrocytes cultured from Cx43 knock-out mice and were abrogated by connexin hemichannel blockers, including La3+, mimetic peptides, and niflumic acid. Both the reduction in gap junctional communication and the increase in membrane permeability were mediated by a p38 mitogen-activated protein kinase-dependent pathway. However, the increase in membrane permeability, but not the gap junction inhibition, was rapidly reversed by the sulfhydryl reducing agent dithiothreitol, indicating that final regulatory mechanisms are different. Treatment with proinflammatory cytokines reduced the total and cell surface Cx43 levels, suggesting that the increase in membrane permeability was attributable to an increase in hemichannels activity. Indeed, unitary events of ∼220 pS corresponding to Cx43 hemichannels were much more frequent in astrocytes treated with microglia conditioned medium than under control conditions. Finally, the effect of cytokines enhanced the uptake and reduced the intercellular diffusion of glucose, which might explain changes in the metabolic status of astrocytes under inflammatory conditions. Accordingly, this opposite regulation may affect glucose trafficking and certainly will modify the metabolic status of astrocytes involved in brain inflammation.
Stepwise Morphological and Functional Maturation of Mechanotransduction in Rat Outer Hair Cells
Authors: Waguespack Jessica , Salles Felipe T. , Kachar Bechara , Ricci Anthony J.
Published: December 2007

Inner ear mechanosensory hair cells convert mechanical vibrations into electrical signals via the coordinated interaction of multiple proteins precisely positioned within the sensory hair bundle. Present work identifies the time course for the acquisition and maturation of mechanoelectric transduction (MET) in rat cochlea outer hair cells maintained in organotypic cultures. A spatiotemporal developmental progression was observed morphologically and functionally with basal cochlea maturation preceding apical cochlea by 2–3 d in all measured properties. The fraction of mechanosensitive cells increased rapidly, with a midpoint at postnatal day 0 for basal cells, and correlated with myosin IIIa immunoreactivity. MET current magnitude increased over several days. Adaptation lagged the onset of transduction by a day and matured more slowly, overlapping but preceding the rise in myosin Ic immunoreactivity. Less than ∼25% of myosin Ic expression was required for the mature adaptation response, suggesting multiple roles for this protein in hair bundle function. Directional sensitivity, lacking in immature responses, developed rapidly and correlated with the pruning of radial links and an increase in tenting of stereociliary tips. Morphological and electrophysiological data support a hypothesis in which key elements arrive independently at the site of MET, with a mature response occurring as membrane tension increases, likely by the increased tensioning of the tip link with the onset of adaptation. Organotypic cultures developed normal, tonotopically specific, MET response properties, suggesting that maturation was not influenced significantly by external factors such as innervation, endolymph, normal mechanical stimulation, or an intact organ of Corti.
TRPM8 Mechanism of Cold Allodynia after Chronic Nerve Injury
Authors: Xing Hong , Chen Meng , Ling Jennifer , Tan Weihong , Gu Jianguo G.
Published: December 2007

The cold- and menthol-sensitive receptor TRPM8 (transient receptor potential melastatin 8) has been suggested to play a role in cold allodynia, an intractable pain seen clinically. We studied how TRPM8 is involved in cold allodynia using rats with chronic constrictive nerve injury (CCI), a neuropathic pain model manifesting cold allodynia in hindlimbs. We found that cold allodynic response in the CCI animals was significantly attenuated by capsazepine, a blocker for both TRPM8 and TRPV1 (transient receptor potential vanilloid 1) receptors, but not by the selective TRPV1 antagonist I-RTX (5-iodoresiniferatoxin). In L5 dorsal root ganglion (DRG) sections of the CCI rats, immunostaining showed an increase in the percentage of TRPM8-immunoreactive neurons when compared with the sham group. Using the Ca2+-imaging technique and neurons acutely dissociated from the L5 DRGs, we found that CCI resulted in a significant increase in the percentage of menthol- and cold-sensitive neurons and also a substantial enhancement in the responsiveness of these neurons to both menthol and innocuous cold. These changes occurred in capsaicin-sensitive neurons, a subpopulation of nociceptive-like neurons. Using patch-clamp recordings, we found that membrane currents evoked by both menthol and innocuous cold were significantly enhanced in the CCI group compared with the sham group. By retrograde labeling afferent neurons that target hindlimb skin, we showed that the skin neurons expressed TRPM8 receptors, that the percentage of menthol-sensitive/cold-sensitive/capsaicin-sensitive neurons increased, and that the menthol- and cold-evoked responses were significantly enhanced in capsaicin-sensitive neurons after CCI. Together, the gain of TRPM8-mediated cold sensitivity on nociceptive afferent neurons provides a mechanism of cold allodynia.
Genetic Contributions to Long-Range Temporal Correlations in Ongoing Oscillations
Authors: Linkenkaer-Hansen Klaus , Smit Dirk J. A. , Barkil Andre , van Beijsterveldt Toos E. M. , Brussaard Arjen B. , Boomsma Dorret I. , van Ooyen Arjen , de Geus Eco J. C.
Published: December 2007

The amplitude fluctuations of ongoing oscillations in the electroencephalographic (EEG) signal of the human brain show autocorrelations that decay slowly and remain significant at time scales up to tens of seconds. We call these long-range temporal correlations (LRTC). Abnormal LRTC have been observed in several brain pathologies, but it has remained unknown whether genetic factors influence the temporal correlation structure of ongoing oscillations. We recorded the ongoing EEG during eyes-closed rest in 390 monozygotic and dizygotic twins and investigated the temporal structure of ongoing oscillations in the alpha- and beta-frequency bands using detrended fluctuation analysis (DFA). The strength of LRTC was more highly correlated in monozygotic than in dizygotic twins. Statistical analysis attributed up to ∼60% of the variance in DFA to genetic factors, indicating a high heritability for the temporal structure of amplitude fluctuations in EEG oscillations. Importantly, the DFA and EEG power were uncorrelated. LRTC in ongoing oscillations are robust, heritable, and independent of power, suggesting that LRTC and oscillation power are governed by distinct biophysical mechanisms and serve different functions in the brain. We propose that the DFA method is an important complement to classical spectral analysis in fundamental and clinical research on ongoing oscillations.
A Mutation in the Cone-Specificpde6Gene Causes Rapid Cone Photoreceptor Degeneration in Zebrafish
Authors: Stearns George , Evangelista Meradelfa , Fadool James M. , Brockerhoff Susan E.
Published: December 2007

Photoreceptor degeneration is a common cause of inherited blindness worldwide. We have identified a blind zebrafish mutant with rapid degeneration of cone photoreceptors caused by a mutation in the cone phosphodiesterase c (pde6c) gene, a key regulatory component in cone phototransduction. Some rods also degenerate, primarily in areas with a low density of rods. Rod photoreceptors in areas of the retina that always have a high density of rods are protected from degeneration. Our findings demonstrate that, analogous to what happens to rod photoreceptors in therd1mouse model, loss of cone phosphodiesterase leads to rapid degeneration of cone photoreceptors. Furthermore, we propose that cell density plays a key role in determining whether rod photoreceptors degenerate as a secondary consequence to cone degeneration. Our zebrafish mutant serves as a model for developing therapeutic treatments for photoreceptor degeneration in humans.
The Neural Cost of the Auditory Perception of Language Switches: An Event-Related Functional Magnetic Resonance Imaging Study in Bilinguals
Authors: Abutalebi Jubin , Brambati Simona M. , Annoni Jean-Marie , Moro Andrea , Cappa Stefano F. , Perani Daniela
Published: December 2007

One of the most remarkable abilities of bilinguals is to produce and/or to perceive a switch from one language to the other without any apparent difficulty. However, several psycholinguistic studies indicate that producing, recognizing, and integrating a linguistic code different from the one in current use may entail a processing cost for the speaker/listener. Up to now, the underlying neural substrates of perceiving language switches are unknown. In the present study, we investigated the neural mechanisms of language switching during auditory perception in bilinguals. Event-related functional magnetic resonance imaging was performed in 12 early, highly proficient Italian/French bilinguals, who were more exposed to their second language. Subjects had to listen to narratives containing “switched passages” that could either respect (i.e., regular switches) or violate (i.e., irregular switches) the constituents of sentence structure. The results indicate that switching engages an extensive neural network, including bilateral prefrontal and temporal associative regions. Moreover, a clear dissociation is observed for the types of switches. Regular switches entail a pattern of brain activity closely related to lexical processing, whereas irregular switches engage brain structures involved in syntactic and phonological aspects of language processing. Noteworthy, when switching into the less-exposed language, we observed the selective engagement of subcortical structures and of the anterior cingulate cortex, putatively involved in cognitive and executive control. This suggests that switching into a less-exposed language requires controlled processing resources. This pattern of brain activity may constitute an important neural signature of language dominance in bilinguals.
Electrical Stimulation of Spared Corticospinal Axons Augments Connections with Ipsilateral Spinal Motor Circuits after Injury
Authors: Brus-Ramer Marcel , Carmel Jason B. , Chakrabarty Samit , Martin John H.
Published: December 2007

Activity-dependent competition shapes corticospinal (CS) axon outgrowth in the spinal cord during development. An important question in neural repair is whether activity can be used to promote outgrowth of CS axons in maturity. After injury, spared CS axons sprout and make new connections, but often not enough to restore function. We propose that electrically stimulating spared axons after injury will enhance sprouting and strengthen connections with spinal motor circuits. To study the effects of activity, we electrically stimulated CS tract axons in the medullary pyramid. To study the effects of injury, one pyramid was lesioned. We studied sparse ipsilateral CS projections of the intact pyramid as a model of the sparse connections preserved after CNS injury. We determined the capacity of CS axons to activate ipsilateral spinal motor circuits and traced their spinal projections. To understand the separate and combined contributions of injury and activity, we examined animals receiving stimulation only, injury only, and injury plus stimulation. Both stimulation and injury alone strengthened CS connectivity and increased outgrowth into the ipsilateral gray matter. Stimulation of spared axons after injury promoted outgrowth that reflected the sum of effects attributable to activity and injury alone. CS terminations were densest within the ventral motor territories of the cord, and connections in these animals were significantly stronger than after injury alone, indicating that activity augments injury-induced plasticity. We demonstrate that activity promotes plasticity in the mature CS system and that the interplay between activity and injury preferentially promotes connections with ventral spinal motor circuits.
Activin Acutely Sensitizes Dorsal Root Ganglion Neurons and Induces Hyperalgesia via PKC-Mediated Potentiation of Transient Receptor Potential Vanilloid I
Authors: Zhu Weiguo , Xu Pin , Cuascut Fernando X. , Hall Alison K. , Oxford Gerry S.
Published: December 2007

Pain hypersensitivity is a cardinal sign of tissue damage, but how molecules from peripheral tissues affect sensory neuron physiology is incompletely understood. Previous studies have shown that activin A increases after peripheral injury and is sufficient to induce acute nociceptive behavior and increase pain peptides in sensory ganglia. This study was designed to test the possibility that the enhanced nociceptive responsiveness associated with activin involved sensitization of transient receptor potential vanilloid I (TRPV1) in primary sensory neurons. Activin receptors were found widely distributed among adult sensory neurons, including those that also express the capsaicin receptor. Whole-cell patch-clamp recording from sensory neurons showed that activin acutely sensitized capsaicin responses and depended on activin receptor kinase activity. Pharmacological studies revealed that the activin sensitization of capsaicin responses required PKCε signaling, but not PI3K (phosphoinositide 3-kinase), ERK (extracellular signal-regulated protein kinase), PKA, PKCα/β, or Src. Furthermore, activin administration caused acute thermal hyperalgesia in wild-type mice, but not in TRPV1-null mice. These data suggest that activin signals through its own receptor, involves PKCε signaling to sensitize the TRPV1 channel, and contributes to acute thermal hyperalgesia.
Synaptic Vesicle Mobility in Mouse Motor Nerve Terminals with and without Synapsin
Authors: Gaffield Michael A. , Betz William J.
Published: December 2007

We measured synaptic vesicle mobility using fluorescence recovery after photobleaching of FM 1-43 [N-(3-triethylammoniumpropyl)-4-(4-(dibutylamino)styryl) pyridinium dibromide] stained mouse motor nerve terminals obtained from wild-type (WT) and synapsin triple knock-out (TKO) mice at room temperature and physiological temperature. Vesicles were mobile in resting terminals at physiological temperature but virtually immobile at room temperature. Mobility was increased at both temperatures by blocking phosphatases with okadaic acid, decreased at physiological temperature by blocking kinases with staurosporine, and unaffected by disrupting actin filaments with latrunculin A or reducing intracellular calcium concentration with BAPTA-AM. Synapsin TKO mice showed reduced numbers of synaptic vesicles and reduced FM 1-43 staining intensity. Synaptic transmission, however, was indistinguishable from WT, as was synaptic vesicle mobility under all conditions tested. Thus, in TKO mice, and perhaps WT mice, a phospho-protein different from synapsin but otherwise of unknown identity is the primary regulator of synaptic vesicle mobility.
Quantifying Evidence for Candidate Gene Polymorphisms: Bayesian Analysis Combining Sequence-Specific and Quantitative Trait Loci Colocation Information
Authors: Ball Roderick D
Published: December 2007

We calculate posterior probabilities for candidate genes as a function of genomic location. Posterior probabilities for quantitative trait loci (QTL) presence in a small interval are calculated using a Bayesian model-selection approach based on the Bayesian information criterion (BIC) and used to combine QTL colocation information with sequence-specific evidence, e.g., from differential expression and/or association studies. Our method takes into account uncertainty in estimation of number and locations of QTL and estimated map position. Posterior probabilities for QTL presence were calculated for simulated data with n = 100, 300, and 1200 QTL progeny and compared with interval mapping and composite-interval mapping. Candidate genes that mapped to QTL regions had substantially larger posterior probabilities. Among candidates with a given Bayes factor, those that map near a QTL are more promising for further investigation with association studies and functional testing or for use in marker-aided selection. The BIC is shown to correspond very closely to Bayes factors for linear models with a nearly noninformative Zellner prior for the simulated QTL data with n ≥ 100. It is shown how to modify the BIC to use a subjective prior for the QTL effects.
The Role of Double-Stranded Break Repair in the Creation of Phenotypic Diversity at Cereal VRN1 Loci
Authors: Cockram James , Mackay Ian J , O'Sullivan Donal M
Published: December 2007

Nonhomologous repair of double-stranded breaks, although fundamental to the maintenance of genomic integrity in all eukaryotes, has received little attention as to its evolutionary consequences in the generation and selection of phenotypic diversity. Here we document the role of illegitimate recombination in the creation of novel alleles in VRN1 orthologs selected to confer adaptation to annual cropping systems in barley and wheat.
Subtelomeric Elements Influence But Do Not Determine Silencing Levels at Saccharomyces cerevisiae Telomeres
Authors: Mondoux Michelle A , Zakian Virginia A
Published: December 2007

In Saccharomyces cerevisiae, genes placed near telomeres are transcriptionally repressed (telomere position effect, TPE). Although telomeric DNA sequence is the same at all chromosome ends, the subtelomeric elements (STEs) and level of TPE vary from telomere to telomere. We tested whether STEs determine TPE levels. STEs contributed to TPE, as deleting the X element from the VI-R telomere modestly decreased silencing at this telomere. However, STEs were not the major determinant of TPE levels, as inserting the VI-R X element at the truncated VII-L telomere did not increase TPE. These data suggest that the TPE levels of individual telomeres are dependent on some aspect of chromosome context.
Extensive Allelic Variation in Gene Expression in Populus F1 Hybrids
Authors: Zhuang Yan , Adams Keith L
Published: December 2007

Hybridization between plant species can induce speciation as well as phenotypic novelty and heterosis. Hybrids also can show genome rearrangements and gene expression changes compared with their parents. Here we determined the allelic variation in gene expression in Populus trichocarpa × Populus deltoides F1 hybrids. Among 30 genes analyzed in four independently formed hybrids, 17 showed >1.5-fold expression biases for one of the two alleles, and there was monoallelic expression of one gene. Expression ratios of the alleles differed between leaves and stems for 10 genes. The results suggest differential regulation of the two parental alleles in the hybrids. To determine if the allelic expression biases were caused by hybridization we compared the ratios of species-specific transcripts between an F1 hybrid and its parents. Thirteen of 19 genes showed allelic expression ratios in the hybrid that were significantly different from the ratios of the parental species. The P. deltoides allele of one gene was silenced in the hybrid. Modes of gene regulation were inferred from the hybrid–parent comparisons. Cis-regulation was inferred for 6 genes, trans-regulation for 1 gene, and combined cis- and trans-regulation for 9 genes. The results from this study indicate that hybridization between plant species can have extensive effects on allelic expression patterns, some of which might lead to phenotypic changes.
Mapping Quantitative Trait Loci From a Single-Tail Sample of the Phenotype Distribution Including Survival Data
Authors: Sillanpää Mikko J , Hoti Fabian
Published: December 2007

A new effective Bayesian quantitative trait locus (QTL) mapping approach for the analysis of single-tail selected samples of the phenotype distribution is presented. The approach extends the affected-only tests to single-tail sampling with quantitative traits such as the log-normal survival time or censored/selected traits. A great benefit of the approach is that it enables the utilization of multiple-QTL models, is easy to incorporate into different data designs (experimental and outbred populations), and can potentially be extended to epistatic models. In inbred lines, the method exploits the fact that the parental mating type and the linkage phases (haplotypes) are known by definition. In outbred populations, two-generation data are needed, for example, selected offspring and one of the parents (the sires) in breeding material. The idea is to statistically (computationally) generate a fully complementary, maximally dissimilar, observation for each offspring in the sample. Bayesian data augmentation is then used to sample the space of possible trait values for the pseudoobservations. The benefits of the approach are illustrated using simulated data sets and a real data set on the survival of F2 mice following infection with Listeria monocytogenes.
Genomic Instability Within Centromeres of Interspecific Marsupial Hybrids
Authors: Metcalfe Cushla J , Bulazel Kira V , Ferreri Gianni C , Schroeder-Reiter Elizabeth , Wanner Gerhard , Rens Willem , Obergfell Craig , Eldridge Mark D B , O'Neill Rachel J
Published: December 2007

Several lines of evidence suggest that, within a lineage, particular genomic regions are subject to instability that can lead to specific types of chromosome rearrangements important in species incompatibility. Within family Macropodidae (kangaroos, wallabies, bettongs, and potoroos), which exhibit recent and extensive karyotypic evolution, rearrangements involve chiefly the centromere. We propose that centromeres are the primary target for destabilization in cases of genomic instability, such as interspecific hybridization, and participate in the formation of novel chromosome rearrangements. Here we use standard cytological staining, cross-species chromosome painting, DNA probe analyses, and scanning electron microscopy to examine four interspecific macropodid hybrids (Macropus rufogriseus × Macropus agilis). The parental complements share the same centric fusions relative to the presumed macropodid ancestral karyotype, but can be differentiated on the basis of heterochromatic content, M. rufogriseus having larger centromeres with large C-banding positive regions. All hybrids exhibited the same pattern of chromosomal instability and remodeling specifically within the centromeres derived from the maternal (M. rufogriseus) complement. This instability included amplification of a satellite repeat and a transposable element, changes in chromatin structure, and de novo whole-arm rearrangements. We discuss possible reasons and mechanisms for the centromeric instability and remodeling observed in all four macropodid hybrids.
Injuries in Bouldering: A Prospective Study
Authors: Josephsen Gary , Shinneman Scott , Tamayo-Sarver Joshua , Josephsen Kelly , Boulware David , Hunt Matthew , Pham Hoai
Published: December 2007

Objective

Bouldering is a type of rock climbing in which the climber ascends small boulders with pads and spotters in lieu of ropes, with an emphasis on ascending the most difficult surface possible. We sought to investigate the prevalence and incidence of injuries, and we hypothesized boulderers who enlisted preventative measures and those who bouldered indoors would have fewer injuries.

Methods

This cross-sectional cohort study assessed incidence and pattern of injury among indoor and outdoor boulderers over 1 year.

Results

Spotting other boulderers resulted in few injuries, but both climbing and falling were associated with diffuse injuries. Finger and ankle injuries were common. Traditional preventative measures were ineffective, and there were few differences between indoor and outdoor boulderers.

Conclusions

Bouldering outdoors has an increased risk of injury to the fingers. Preventative measures appear largely ineffective in reducing the number of injuries in both cohorts.
Cause of Death in Avalanche Fatalities
Authors: McIntosh Scott E. , Grissom Colin K. , Olivares Christopher R. , Kim Han S. , Tremper Bruce
Published: December 2007

Objective

Avalanches pose a life-threatening risk to participants of outdoor winter activities. Determining the causes of death in avalanche fatalities can aid rescue and resuscitation strategies and hopefully improve survival.

Methods

The study population included all avalanche fatalities in Utah from the 1989–90 to 2005–06 winter seasons. The Utah Avalanche Center and Medical Examiner records were reviewed to identify accident circumstances, autopsy findings, and causes of death.

Results

Fifty-six avalanche deaths were identified during the study period. Most deaths occurred while participating in recreational backcountry activities; 85.7% of deaths were due to asphyxiation, 8.9% were due to a combination of asphyxiation and trauma, and 5.4% were due to trauma alone. Head injuries were frequent in those killed solely by trauma.

Conclusions

Most avalanche deaths in Utah result from asphyxia. Therefore, most victims are alive in the postavalanche period and have the potential for live recovery. Rescue strategies that employ rapid recovery as well as techniques that prolong survival while buried provide the best means of improving outcome.
Corpus Callosum Index: A practical method for long-term follow-up in multiple sclerosis
Authors: Figueira Fernando Faria Andrade , Santos Valeria Silva dos , Figueira Gustavo Medeiros Andrade , Silva Ângela Correa Marques da
Published: December 2007

Rather than acute inflammation, long-standing multiple sclerosis (MS) course is hallmarked by relentless axonal loss and brain atrophy, both with subtle clinical expression and scarcely visible on conventional MRI studies. Brain atrophy imaging has sophisticated methodological requirements, not always practical and accessible to most centers. Corpus callosum (CC) is a major inter-hemispheric white matter bundle, grossly affected by long term MS and easily assessed by MRI. To determine whether a practical imaging method can reliably follow presumed axonal loss in patients with progressive MS, we designed a 5-year prospective open label study, enrolling 128 consecutive patients (75 relapsing-remitting (RR) and 53 secondary-progressive (SP)), on regular immunomodulatory therapy compared to control group, formed by 23 patients with MRI considered normal. On a conventional best mid-saggital T1W, CC index (CCI) was obtained by measuring anterior, medium and posterior segments of CC, normalized to its greatest anteroposterior diameter using an orthogonal semi-automated linear system. CCI was measured at baseline and at least once yearly. Results were plotted intra-individually; baseline values were used as reference. At baseline, CCI was able to distinguish SP patients from RR and controls, and on follow-up, despite some overlap, demonstrated a progressive reduction from baseline on both RR and SP groups compared to controls. From the third year on, difference between SP and RR patients reached statistical significance, which did not correlated with disability measured by EDSS. So, a corpus callosum index proved practical and feasible to longitudinally demonstrate morphometric callosal changes with potential to be used as a tool for long-term follow-up, mostly in SP patients.
Motor learning processes: an electrophysiologic perspective
Authors: Velasques Bruna , Ferreira Camila , Teixeira Silmar Silva , Furtado Vernon , Mendes Elizabeth , Basile Luis , Cagy Mauricio , Piedade Roberto , Ribeiro Pedro
Published: December 2007

The goal of the present study was to investigate electrophysiologic, qEEG, changes when individuals were exposed to a motor task. Subjects’ brain electrical activity was analyzed before and after the typewriting training task. For the neurophysiological variable asymmetry, a paired t-test was performed to compare each moment, pre and post-task, in the beta bands. The findings showed a change for the qEEG variable in each scalp site, F3/F4; C3/C4 and P3/P4. These results suggest an adaptation of pre-frontal, sensory-motor and parietal cortex, as a consequence of the typewriting training.
Pure neural leprosy: steroids prevent neuropathy progression
Authors: Jardim Márcia R. , Illarramendi Ximena , Nascimento Osvaldo J.M. , Nery Jose Augusto C. , Sales Anna M. , Sampaio Elizabeth P. , Sarno Euzenir N.
Published: December 2007

Multidrug therapy (MDT), with rifampicin, dapsone, and clofazimine, treats leprosy infection but is insufficient in arresting or preventing the nerve damage that causes impairments and disabilities. This case-series study evaluates the benefits of the combined use of steroids and MDT in preventing nerve damage in patients with pure neural leprosy (PNL). In addition to MDT, 24 patients (88% male aged 20-79 years, median=41) received a daily morning dose of 60 mg prednisone (PDN) that was gradually reduced by 10 mg during each of the following 5 months. PNL was clinically diagnosed and confirmed by nerve histopathology or PCR. A low prevalence (8.3%) of reaction was observed after release from treatment. However, most of the clinical parameters showed significant improvement; and a reduction of nerve conduction block was observed in 42% of the patients. The administration of full-dose PDN improved the clinical and electrophysiological condition of the PNL patients, contributing to the prevention of further neurological damage.
Ultrastructural study of the lateral ventricle choroid plexus in experimental hydrocephalus in Wistar rats
Authors: Tirapelli Daniela Pretti da Cunha , Lopes Luiza da Silva , Lachat João José , Colli Benedicto Oscar , Tirapelli Luís Fernando
Published: December 2007

Hydrocephalus is one of the most frequent and complex neurological diseases characterized by the abnormal buildup of cerebrospinal fluid (CSF) in the ventricles of the brain, due to an altered CSF dynamics. To detect possible ultrastructural alterations of the lateral ventricles choroid plexus (responsible for the CSF production), rats seven days after birth were submitted to an intracisternal injection of 20% kaolim (hydrated aluminum silicate) for the hydrocephalus induction. Twenty-eight or 35 days after injection, injected animals and respective controls were processed for observation under a transmission electron microscopy. Alterations found: presence of concentric cell membrane fragments, larger number of primary and secondary lysossomes, vacuoles, and cytoplasmic vesicles, and an enlargement of the intercellular space and between the basolateral interdigitation of the choroid epithelium. The alterations observed are probably associated to an increase of the ventricular pressure, inducing morpho-functional effects on the choroid plexus integrity.
Basal encephalocele associated with morning glory syndrome: case report
Authors: Minotto Ivanete , Abdala Nitamar , Miachon Adriana Aparecida Siviero , Spinola e Castro Angela Maria , Imamura Paulo , Nogueira Roberto Gomes
Published: December 2007

The basal encephaloceles refer to rare entities and they correspond to herniation of brain tissue through defects of skull along the cribiform plate or the sphenoid bone. A rare morning glory syndrome, with characteristic retinal defect has been reported in association with basal encephaloceles. Hypophysis hormonal deficiencies may occur. We accounted for a pituitary dwarfism with delayed diagnosed transsphenoidal encephalocele associated with morning glory syndrome, showing the alterations found in retinography, computed tomography and magnetic resonance imaging.
Bilateral ptosis and supranuclear downgaze paralysis
Authors: Maranhão-Filho Péricles , Campos João Carlos S. , Lima Marco A.
Published: December 2007

The purpose of this article is to highlight an uncommon combination of supranuclear downward gaze paralysis with bilateral eyelid ptosis in a 53-years-old man with a radiation induced midbrain tumor and to discuss the aspects regarding the centers and pathways that mediate supranuclear vertical gaze movements.
Cerebellar degeneration and immune thrombocytopenic purpura associated with human immunodefi ciency virus infection (HIV)
Authors: Godeiro-Júnior Clécio de Oliveira , Felício André Carvalho , Barsottini Orlando Graziani Povoas , Gabbai Alberto Alain
Published: December 2007

Cerebellar disorders associated with HIV infection are usually caused by opportunistic infections, central nervous system lymphoma, and toxic effects of medicines, nutritional and metabolic disorders, and cerebrovascular disease. We present an unusual association of cerebellar degeneration and immune thrombocytopenic purpura in a 28-years-old woman HIV infected. An autoimmune aetiology is likely.
Endovascular treatment of a basilar artery dissecting aneurysm
Authors: Patroclo Cristiane Borges , Puglia Jr Paulo , Leite Claudia da Costa , Yamamoto Fabio Iuji , Ciríaco Jovana Gobbi Marchesi , Scaff Milberto , Conforto Adriana Bastos
Published: December 2007

Basilar artery (BA) dissecting aneurysms pose difficulties to treatment because both bleeding and thrombosis can happen in the same patient, clinical course is unpredictable and high morbidity is usual. We report the case of a 37-year-old woman with a BA aneurysm probably caused by arterial dissection, presenting embolic and hemorrhagic complications. The aneurysm was submitted to endovascular treatment with stenting and coil embolization. Clinical and radiological results were excellent and no complications were observed, suggesting that BA stenting and coil embolization may be a safe and effective treatment for this condition.
Endovascular treatment of a basilar artery dissecting aneurysm
Authors: Forcelini Cassiano Mateus , Rotta Francisco Tellechea , Posenato Naiana , Rovani Joana Stella , Crusius Paulo Sérgio , Mallmann Adroaldo Baseggio , Seibert Cláudio Albano , Crusius Marcelo Ughini , Carazzo Charles , Crusius Cassiano Ughini , Goellner Eduardo , Ragnini Jean , Wayhs Sâmia Yasin
Published: December 2007

Fasciculations are symptoms present in a broad spectrum of conditions, ranging from normal manifestations to motor neuron diseases. They also represent the main picture of benign fasciculation syndrome. We report a case of such syndrome: a 48-years-old woman complaining about fasciculations for three decades who remained with the symptoms even after the compensation of a disclosed hyperthyroidism. The introduction of gabapentin rendered control of her fasciculations. The available data in the literature about the therapeutic approaches for fasciculations are revised, as long as the rare reports of evolution from patients with "benign" fasciculations to cases of amyotrophic lateral sclerosis, underlining the importance of following the patients with fasciculations.
Cerebral abscess caused by Serratia marcescens in a premature neonate
Authors: Hirooka Tatiana Mattos , Fontes Ricardo Braganca de Vasconcellos , Diniz Edna Maria , Pinto Fernando Campos , Matushita Hamilton
Published: December 2007

BACKGROUND: Cerebral abscesses are extremely rare in neonates. Serratia marcescens is an unusual cause of sepsis and neurological spread is especially ominous. PURPOSE: To report the case of a 34-week neonate who developed this rare condition and to discuss diagnostic and therapeutic measures. CASE REPRT: A 34-week male neonate sequentially developed respiratory distress syndrome, early sepsis and necrotizing enterocolitis; later cultures revealed S. marcescens. After deterioration, a cerebral abscess became evident, which revealed S. marcescens. Clinical improvement ensued after high-dose amikacin and meropenem. CONCLUSION: Clinical signs are often non-specific. Proper diagnostic measures, neurosurgical consultation and aggressive antibiotic therapy are essential for these high-risk neonates.
Pyridoxine-dependent epilepsy initially responsive to phenobarbital
Authors: Lin Jaime , Lin Katia , Masruha Marcelo Rodrigues , Vilanova Luiz Celso Pereira
Published: December 2007

Pyridoxine-dependent epilepsy is a rare autossomal recessive disorder characterized by recurrent seizures that are not controlled by anticonvulsant medications but remits after administration of pyridoxine. We report on a 30 day-old girl who presented with seizures during the first day of life, initially responsive to anticonvulsant therapy, which remitted within two weeks. Seizures were characterized as multifocal myoclonic jerks of upper and lower limbs associated with buccal-lingual oral movements and eyelid blinking. Laboratory and neuroimaging studies were normal. Electroencephalographic record demonstrated a abnormal background activity with high-voltage epileptic discharges and a burst-suppression pattern. The seizures ceased after oral administration of pyridoxine, but recurred after withdrawal, confirming the diagnosis.
Horner's syndrome after blunt cervical and chest trauma: case report
Authors: Paiva Wellingson Silva , Amorim Robson Luis Oliveira De , Tavares Wagner Malago , Alho Eduardo Joaquim Lopes , Ping Jeng Brasil , Figueiredo Eberval Gadelha
Published: December 2007

Horner‘s syndrome is the triad of miosis, ptosis, and anhidrosis, resulting from disruption of the sympathetic pathways. This article describes an uncommon case of Horner‘s syndrome in a 22-year-old man after blunt trauma to the neck and chest without carotid artery dissection. The patient was brought to the emergency service after motorcycle fall. Neurologic examination revealed a patient presenting the score 15 at Glasgow Coma Scale. The left eyelid was 1-2 mm lower than the right. Carotid Doppler and angiotomography were undertaken and revealed no abnormalities of the carotid artery. CT disclosed a mediastinal hematoma extending to the left apex, compressing the left sympathetic chain. The understanding of this clinical entity may help the surgeon to make a better differential diagnosis in trauma patients in whom prompt diagnosis is critical to stablish the correct treatment.
Modelagem neurocomputacional do circuito tálamo-cortical: implicações para compreensão do transtorno de défi cit de atenção e hiperatividade
Authors: Madureira Daniele Q.M. , Carvalho Luis Alfredo V. de , Cheniaux Elie
Published: December 2007

CONTEXTO: A desatenção no transtorno de déficit de atenção e hiperatividade (TDAH) é principalmente associada à hipoatividade dopaminérgica mesocortical. Contudo, variações dopaminérgicas mesotalâmicas também afetam o controle da atenção e, possivelmente, originam alterações atencionais no TDAH. OBJETIVO: Elaboração de um modelo neurocomputacional a partir do conhecimento do funcionamento bioquímico dos sistemas dopaminérgicos mesocortical e mesotalâmico, a fim de investigar a influência dos níveis de dopamina na via mesotalâmica sobre o circuito tálamo-cortical e suas implicações nos sintomas de desatenção do TDAH. MÉTODO: Através de um conjunto de equações modelamos propriedades fisiológicas de neurônios talâmicos. A seguir, simulamos computacionalmente o comportamento do circuito tálamo-cortical variando os níveis de dopamina nas vias mesotalâmica e mesocortical. RESULTADOS: Em relação à via mesotalâmica, a hipoatividade dopaminérgica dificulta o deslocamento do foco de atenção, e a hiperatividade dopaminérgica acarreta desfocalização atencional. Quando tais situações são acompanhadas de hipoatividade dopaminérgica mesocortical, surge uma incapacidade em perceber estímulos, devido à competição sem vencedores entre regiões talâmicas pouco ativadas. A desatenção no TDAH também se origina em desequilíbrios dopaminérgicos na via mesotalâmica, que levam à focalização excessiva ou à desfocalização da atenção. CONCLUSÃO: O nosso experimento in silico sugere que no TDAH a desatenção relaciona-se com alterações dopaminérgicas, que não se restringem à via mesocortical.
Glioblastoma pediátrico: estudo clínico patológico de 12 casos com imunoistoquímica para proteína p53
Authors: Pope Leonora Zozula Blind , Serapião Maria José , Serapião Carlos José , Oliveira Maria Marcelina Silva Teive , Benites Filho Paulo Roberto , Gugelmin Elizabeth Scheneider , Bleggi-Torres Luiz Fernando
Published: December 2007

Glioblastoma é um dos tumores primários mais letais do sistema nervoso central (SNC). Apesar dos significativos progressos, há poucas análises em crianças. Com o objetivo de avaliar localização, idade, sexo, sobrevida e imunoistoquímica para proteína p53, foram coletados casos de glioblastomas pediátricos do "Banco de Tumores do SNC de Curitiba", durante 1987-2003 e do Hospital Municipal Jesus, Rio de Janeiro, de 1970 a 1988. Doze preencheram os critérios de inclusão. A idade variou até 12 anos (média 7), sendo sete do sexo feminino e cinco do masculino. A sobrevida média foi 7,9 meses. Localizavam-se em hemisférios cerebrais (58,4%), mesencéfalo e tronco (33,3%) e um no cerebelo. A imunoistoquímica demonstrou p53 positivo em 9 (75%). Em conclusão, glioblastoma tem comportamento semelhante entre crianças e adultos, sendo nestas menos freqüentes. Acomete hemisférios cerebrais com maior freqüência que estruturas infratentoriais, mostrando alta sensitividade com a imunomarcação para proteína p53, sendo nestes casos mais agressivos, com menor sobrevida.
Anatomia microcirúrgica do hipocampo na Amígdalo-hipocampectomia seletiva sob a perspectiva da técnica de Niemeyer e método pré-operatório para maximizar a corticotomia
Authors: Isolan Gustavo Rassier , Azambuja Ney , Paglioli Neto Eliseu , Paglioli Eduardo
Published: December 2007

O conhecimento da anatomia microcirúrgica do hipocampo tem importância fundamental na cirurgia da epilepsia do lobo temporal. Uma das técnicas mais utilizadas na cirurgia da epilepsia é a técnica de Niemeyer. OBJETIVO: Descrever em detalhes a anatomia do hipocampo e mostrar uma técnica na qual pontos de referências anatômicos pré-operatórios visualizados na RNM são usados para guiar a corticotomia. MÉTODO: Foram utilizados 20 hemisférios cerebrais e 8 cadáveres para dissecções anatômicas microcirúrgicas do lobo temporal e hipocampo para identificação e descrição das principais estruturas do hipocampo. Foram estudados prospectivamente 32 pacientes com epilepsia do lobo temporal refratários ao tratamento clínico submetidos a amígdalo-hipocampectomia seletiva pela técnica de Niemeyer três parâmetros anatômicos foram mensurados na RNM pré operatória e transferidos para o ato cirúrgico. RESULTADOS: O hipocampo foi dividido em cabeça, corpo e cauda e sua anatomia microcirúrgica descrita em detalhes. As medidas adquiridas são apresentadas e discutidas. CONCLUSÃO: A complexa anatomia do hipocampo pode ser entendida de uma forma tridimensional durante dissecções microcirúrgicas. As medidas pré-operatórias mostraram-se guias anatômicos úteis para corticotomia na técnica de Niemeyer.
Prevalência do transtorno do déficit de atenção e hiperatividade e suas comorbidades em uma amostra de escolares
Authors: Pastura Giuseppe , Mattos Paulo , Araújo Alexandra Prufer de Queiroz Campos
Published: December 2007

O transtorno do déficit de atenção e hiperatividade (TDAH) é comum em crianças na idade escolar e freqüentemente apresenta-se em comorbidade com outros distúrbios psiquiátricos. No Brasil, há escassez de estudos em amostras não-clínicas. OBJETIVO: Calcular a prevalência deste transtorno e suas comorbidades numa amostra de escolares. MÉTODO: Estudo observacional analítico seccional realizado numa amostra de escolares do Colégio de Aplicação da Universidade Federal do Rio de Janeiro. Utilizou-se questionário de triagem seguido por entrevista clínica estruturada com os pais de crianças suspeitas de serem portadores do transtorno. RESULTADOS: A prevalência encontrada para o TDAH foi 8,6%. As comorbidades deste transtorno se mostraram presentes em 58% dos casos, sendo transtorno opositivo-desafiador, encontrado em 38,5% dos casos, o mais prevalente. CONCLUSÃO: A prevalência do TDAH e suas comorbidades na amostra estudada é semelhante àquela observada na literatura internacional.
Alterações na banda alfa do eletrencefalograma durante imagética motora visual e cinestésica
Authors: Stecklow Marcus Vinicius , Infantosi Antonio Fernando Catelli , Cagy Maurício
Published: December 2007

Foi investigada a contribuição em potência na vizinhança do pico da banda alfa (BPA) do EEG durante imagética motora (IM). Sinais EEG (derivações occipitais e parietais) foram adquiridos em sujeitos destros (18-40 anos), durante repouso (ESP) e IM nas modalidades cinestésica (IMC) e visual (IMV), sendo 15 atletas de voleibol e 15 não-atletas. O Revised Movement Imagery Questionnaire não indicou diferenças entre grupos ou modalidades de IM; todavia os atletas imaginaram-se melhor que os não-atletas. Para ambos os grupos, a potência em BPA resultou menor em IM do que em ESP, sendo mais reduzida em IMC. Ativação cortical similar ocorreu em ambos os hemisférios de não-atletas e mais pronunciada no hemisfério esquerdo de atletas, principalmente durante IMC. Tais resultados sugerem que IM reduz a atividade de alfa de acordo com o conhecimento real da tarefa e a modalidade de IM.
Ensaios comparativos de cultivares de trigo em diferentes regiões paulistas no biênio 1979/80
Authors: Felício João Carlos , Ferreira Filho Antonio Wilson Penteado , Castro Jairo Lopes de , Barros Benedito de Camargo
Published: December 2007

Visando estudar o comportamento de cultivares de trigo recomendados para solos com ou sem alumínio nocivo na camada arável, juntamente com outros cultivares comerciais, foram realizados vários ensaios nas regiões tritícolas paulistas no biênio 1979/80. Nos experimentos em solos com alumínio, somente 'IAC-21' e 'BR-4' apresentaram produções médias superiores à testemunha 'BH-1146', enquanto nos solos sem alumínio os cultivares Tucano, Anahuac, El Pato, Mitacoré, Aracatu, Sema 220, MR 74042 e MR 74501 alcançaram as melhores médias de produção. Entre os cultivares comerciais testados, IAC-13, INIA-66, Itapua-5, PAT-24, IAC-17, IAC-5, BH-1146 e Tobari-66 revelaram as melhores produções, variando de acordo com a região. De maneira geral, em condições de campo, os cultivares PAT-24, IAC-13, INIA-66, CNT-8, Alondra, MR-74044, MR 74501 e Sparrow "S" apresentaram os menores índices de infecção de Puccinia graminis f. sp. tritici. Com relação à ferrugem da folha (P. recondita), os cultivares IAPAR-1 (Mitacoré), IAPAR-3 (Aracatu), Alondra e CNT-8 tiveram os mais baixos índices de infecção.
Nitrogênio na adubação química do cafeeiro: doses e parcelamentos do nitrocálcio
Authors: Cervellini Genésio da Silva , Toledo Sérgio Vasco de , Reis Antonio Junqueira , Rocha Túlio Ribeiro
Published: December 2007

Nitrocálcio nas quantidades de 60, 120, 180 e 240 gramas de N por cafeeiro e por ano foi aplicado em parcelamentos diferentes, de acordo com os tratamentos e em três locais com início em 1973/74: Centro Experimental de Campinas, Estação Experimental de Mococa e Estação Experimental de Ribeirão Preto. Foram estudados os efeitos das quantidades crescentes e avaliadas as conveniências do parcelamento das doses de N aplicadas. Os acréscimos de produção com a elevação dessas doses foram bastante grandes até 120g, passando, a partir dessa quantidade, a aumentos menores. Os efeitos residuais do sulfato de amônio, Nitrocálcio, uréia e salitre-do-chile aplicados quatro anos antes do início do experimento ainda afetaram as produções, passados dez anos das últimas aplicações, reduzindo-as mais para as correspondentes ao salitre-do-chile e uréia. Os parcelamentos utilizados não favoreceram dados consistentes para conclusões, devendo seu estudo ter continuidade em novas séries de ensaios.