bluuebunny/crossref_metadata_2025 huggingface dataset:
A pilot prospective study on closed loop controlled ventilation and oxygenation in ventilated children during the weaning phase
Authors: Jouvet Philippe , Eddington Allen , Payen Valérie , Bordessoule Alice , Emeriaud Guillaume , Gasco Ricardo Lopez , Wysocki Marc
Published: May 2012

Introduction

The present study is a pilot prospective safety evaluation of a new closed loop computerised protocol on ventilation and oxygenation in stable, spontaneously breathing children weighing more than 7 kg, during the weaning phase of mechanical ventilation.

Methods

Mechanically ventilated children ready to start the weaning process were ventilated for five periods of 60 minutes in the following order: pressure support ventilation, adaptive support ventilation (ASV), ASV plus a ventilation controller (ASV-CO2), ASV-CO2 plus an oxygenation controller (ASV-CO2-O2) and pressure support ventilation again. Based on breath-by-breath analysis, the percentage of time with normal ventilation as defined by a respiratory rate between 10 and 40 breaths/minute, tidal volume > 5 ml/kg predicted body weight and end-tidal CO2 between 25 and 55 mmHg was determined. The number of manipulations and changes on the ventilator were also recorded.

Results

Fifteen children, median aged 45 months, were investigated. No adverse event and no premature protocol termination were reported. ASV-CO2 and ASV-CO2-O2 kept the patients within normal ventilation for, respectively, 94% (91 to 96%) and 94% (87 to 96%) of the time. The tidal volume, respiratory rate, peak inspiratory airway pressure and minute ventilation were equivalent for all modalities, although there were more automatic setting changes in ASV-CO2 and ASV-CO2-O2. Positive end-expiratory pressure modifications by ASV-CO2-O2 require further investigation.

Conclusion

Over the short study period and in this specific population, ASV-CO2 and ASV-CO2-O2 were safe and kept the patient under normal ventilation most of the time. Further research is needed, especially for positive end-expiratory pressure modifications by ASV-CO2-O2.

Trial registration

ClinicalTrials.gov: NCT01095406
Determinants of mortality in non-neutropenic ICU patients with candidaemia
Authors: Marriott Deborah JE , Playford E Geoffrey , Chen Sharon , Slavin Monica , Nguyen Quoc , Ellis David , Sorrell Tania C ,   the Australian Candidaemia Study
Published: May 2012

Introduction

Candidaemia in critically-ill intensive care unit (ICU) patients is associated with high crude mortality. Determinants of mortality – particularly those amenable to potential modification – are incompletely defined.

Methods

A nationwide prospective clinical and microbiological cohort study of all episodes of ICU-acquired candidaemia occurring in non-neutropenic adults was undertaken in Australian ICUs between 2001 and 2004. Multivariate Cox regression analyses were performed to determine independently significant variables associated with mortality.

Results

183 episodes of ICU-acquired candidaemia occurred in 183 patients during the study period. Of the 179 with microbiological data, Candida albicans accounted for 111 (62%) episodes and Candida glabrata, 32 (18%). Outcome data were available for 173: crude hospital mortality at 30 days was 56%. Host factors (older age, ICU admission diagnosis, mechanical ventilation and ICU admission diagnosis) and failure to receive systemic antifungal therapy were significantly associated with mortality on multivariate analysis. Among the subset who received initial fluconazole therapy (n = 93), the crude mortality was 52%. Host factors (increasing age and haemodialysis receipt), but not organism- (Candida species, fluconazole MIC), pharmacokinetic- (fluconazole dose, time to initiation), or pharmacodynamic-related parameters (fluconazole dose:MIC ratio) were associated with mortality. Process of care measures advocated in recent guidelines were implemented inconsistently: follow-up blood cultures were obtained in 68% of patients, central venous catheters removed within five days in 80% and ophthalmological examination performed in 36%.

Conclusions

Crude mortality remains high in Australian ICU patients with candidaemia and is overwhelmingly related to host factors but not treatment variables (the time to initiation of antifungals or fluconazole pharmacokinetic and pharmacodynamic factors). The role and timing of early antifungal intervention in critically-ill ICU patients requires further investigation.
Dignifying the Guerrillero, Not the Assassin
Authors: Weld Kirsten A.
Published: May 2012

This article examines an understudied aspect of Guatemala's Cold War counter-insurgency campaign: the concerted effort to destroy the seeds of oppositional thinking by criminalizing any and all forms of dissent, both during wartime and since. It explores the lasting effects of this stigma on contemporary Guatemalan society and analyzes the work being done by a tenacious group of activists attempting to reverse that stigma in laboring to rescue and make use of a voluminous, recently discovered cache of once-secret police archives. By marshaling documentary evidence of crimes against humanity committed by state security forces, the activists and war survivors are toiling in the archives with an eye to the future: they hope to achieve not only criminal justice for the past, but also the broader reivindicación, or rehabilitation, of critical thinking and collective social action.
The Quest for a Legal Enemy
Authors: Blee Lisa
Published: May 2012

In 2004, the Washington Historical Court of Justice and Inquiry—a one-time, quasi-legal public history event—symbolically exonerated Nisqually Indian war leader Chief Leschi of the 147-year-old charge of murder. The judges determined that Leschi, who was captured following the 1855–56 Puget Sound War and indicted on criminal charges in territorial court, was a “legal enemy combatant” who had been unjustly denied the protections afforded to prisoners of war under international law. This article examines the Historical Court judges' decision in the context of the US War on Terror and detainment of so-called illegal enemy combatants. The Historical Court sought justice for Leschi by acknowledging his legal warrior status, but failed to interrogate the cultural assumptions that lead US officials to categorize certain enemies—in 1857 as well as 2004—as exceptional and outside of regular applications of law.
Police Museums in Latin America
Authors: Chazkel Amy
Published: May 2012

Organized by the historian Amy Chazkel, who also provides the foreword, this forum gathers the work of three historians of Latin America who have written extensively on the social history of crime, prompting them to reflect on a ubiquitous but little studied public history institution: the police museum. Alejandra Bronfman, Lila Caimari, and Robert Buffington, specialists in Cuba, Argentina, and Mexico, respectively, guide us through a selection of five police museums: one in Havana that played a crucial role in legal medicine and developing ideas about race during Cuba's Republican period but no longer exists; one in Buenos Aires that was founded as part of the early twentieth-century wave of police reform and modernization; and two in Mexico City and one in Guadalajara that mushroomed in the context of the Mexican police's public image hemorrhage of recent decades. This forum is a critical examination of not only objects on display but also the deeper logic of the categorizing schemes used in each museum. The official history of crime presented to the public, epitomized by police museums, provides a fascinating counterpoint to the contemporary academic history of crime in Latin America, which is remarkably diverse but converges on its use of historical analysis to challenge normative understandings of the law and the illicit. Far from “calling the law into question,” unsurprisingly, police museums naturalize and dehistoricize the criminal law. Yet this forum points toward ways in which further research on police museums can shed new light on how the public encounters the most problematic and controversial manifestations of state power.
Institutional Memories
Authors: Buffington Robert M.
Published: May 2012

This essay argues that the troubled “birth” of the modern police museum in Mexico offers unique insights into the institutional uses of history as a means for fostering collective identities and social cohesion. Conventional history museums endeavor to produce sweeping historical narratives that reconstruct the forgotten past for a forgetful present—to invent traditions for societies no longer able to access the collective memories (rather than constructed histories) that characterized rural communities and urban neighborhoods in previous eras. In contrast, recent Mexican police museums seek to obliterate a too-well-remembered past that troubles the present and threatens to overwhelm official attempts to give birth to an unencumbered future. The genesis of the Mexican police museum thus opens an unexpected if disturbing window on the birth pangs of an institution—the public museum—whose conceptual stability we have taken too much for granted.
All Museums Are Sex Museums
Authors: Tyburczy Jennifer
Published: May 2012

This article elaborates on the themes and practices mobilized in the course Exhibiting Sexualities. The class begins with the premise that all museums are already sex museums and examines the museum context as a pivotal and highly influential site in the construction of modern sexual subjectivity. The article offers a brief history of the ways in which museums have structured ideas about sex from the birth of the modern museum in the nineteenth century to the present day. It incorporates a course syllabus and examples of the kinds of activities that students engage to analyze and create public sexuality exhibitions.
A cellular response linking eIF4AI activity to eIF4AII transcription
Authors: Galicia-Vázquez Gabriela , Cencic Regina , Robert Francis , Agenor Aouod Quang , Pelletier Jerry
Published: May 2012

The recruitment of ribosomes to eukaryotic cellular mRNAs requires the activity of two prototypic RNA helicases, eukaryotic initiation factor (eIF) 4AI and eIF4AII. The eIF4A isoforms are highly conserved, are thought to be functionally interchangeable, and are directed to the 5′ m7GpppN cap structure of mRNAs during translation initiation by virtue of their assembly into eIF4F, a heterotrimeric complex that also harbors the eIF4E cap binding protein and eIF4G scaffolding unit. During the course of RNA interference experiments aimed at investigating the respective roles of eIF4AI and eIF4AII in translation, we uncovered a cellular response pathway whereby suppression of eIF4AI increases transcription of the eIF4AII gene, leading to elevated eIF4AII mRNA and protein levels. Inhibition of eIF4AI suppresses protein synthesis, and although eIF4AII protein levels increase above and beyond what should be sufficient to compensate for the decrease in eIF4AI levels, there is no corresponding rescue of translation or of the block on cellular proliferation that occurs upon eIF4AI suppression. These results were phenocopied using the small molecule eIF4A inhibitor hippuristanol. Taken together, our results indicate that eIF4AI and eIF4AII expression appear linked and that the two protein isoforms exhibit functional differences.
A New Stochastic Derivative Estimator for Discontinuous Payoff Functions with Application to Financial Derivatives
Authors: Wang Yongqiang , Fu Michael C. , Marcus Steven I.
Published: May 2012

Motivated by infinitesimal perturbation analysis (IPA) and the likelihood ratio (LR) method, we derive a new unbiased stochastic derivative estimator for a class of discontinuous payoff functions that arise in many options pricing settings from finance. Our method includes IPA and the LR method as special cases and can be applied to functions of more general forms containing indicator functions. This new estimator can be computed from a single sample path or simulation, whereas existing estimators generally require additional simulations for the class of discontinuous payoff functions considered here. We apply this method to sensitivity analysis for European call options and American-style call options, and numerical experiments indicate that the estimator is computationally more efficient than other estimators.
Exact FCFS Matching Rates for Two Infinite Multitype Sequences
Authors: Adan Ivo , Weiss Gideon
Published: May 2012

Motivated by queues with multitype servers and multitype customers, we consider an infinite sequence of items of types 𝒞 = {c1,…,cI}, and another infinite sequence of items of types 𝒮 = {s1,…,sJ}, and a bipartite graph G of allowable matches between the types. We assume that the types of items in the two sequences are independent and identically distributed (i.i.d.) with given probability vectors α, β. Matching the two sequences on a first-come, first-served basis defines a unique infinite matching between the sequences. For (ci,sj) ∈ G we define the matching rate rci, sj as the long-term fraction of (ci, sj) matches in the infinite matching, if it exists. We describe this system by a multidimensional countable Markov chain, obtain conditions for ergodicity, and derive its stationary distribution, which is, most surprisingly, of product form. We show that if the chain is ergodic, then the matching rates exist almost surely, and we give a closed-form formula to calculate them. We point out the connection of this model to some queueing models.
Laminarly Orthogonal Excitation of Fast-Spiking and Low-Threshold-Spiking Interneurons in Mouse Motor Cortex
Authors: Apicella Alfonso J. , Wickersham Ian R. , Seung H. Sebastian , Shepherd Gordon M. G.
Published: May 2012

In motor cortex, long-range output to subcortical motor circuits depends on excitatory and inhibitory inputs converging on projection neurons in layers 5A/B. How interneurons interconnect with these projection neurons, and whether these microcircuits are interneuron and/or projection specific, is unclear. We found that fast-spiking interneurons received strong intralaminar (horizontal) excitation from pyramidal neurons in layers 5A/B including corticostriatal and corticospinal neurons, implicating them in mediating disynaptic recurrent, feedforward, and feedback inhibition within and across the two projection classes. Low-threshold-spiking (LTS) interneurons were instead strongly excited by descending interlaminar (vertical) input from layer 2/3 pyramidal neurons, implicating them in mediating disynaptic feedforward inhibition to both projection classes. Furthermore, in a novel pattern, lower layer 2/3 preferentially excited interneurons in one layer (5A/LTS) and excitatory neurons in another (5B/corticospinal). Thus, these inhibitory microcircuits in mouse motor cortex follow an orderly arrangement that is laminarly orthogonalized by interneuron-specific, projection-nonspecific connectivity.
Intersection of Reward and Memory in Monkey Rhinal Cortex
Authors: Clark Andrew M. , Bouret Sebastien , Young Adrienne M. , Richmond Barry J.
Published: May 2012

In humans and other animals, the vigor with which a reward is pursued depends on its desirability, that is, on the reward's predicted value. Predicted value is generally context-dependent, varying according to the value of rewards obtained in the recent and distant past. Signals related to reward prediction and valuation are believed to be encoded in a circuit centered around midbrain dopamine neurons and their targets in the prefrontal cortex and basal ganglia. Notably absent from this hypothesized reward pathway are dopaminergic targets in the medial temporal lobe. Here we show that a key part of the medial temporal lobe memory system previously reported to be important for sensory mnemonic and perceptual processing, the rhinal cortex (Rh), is required for using memories of previous reward values to predict the value of forthcoming rewards. We tested monkeys with bilateral Rh lesions on a task in which reward size varied across blocks of uncued trials. In this experiment, the only cues for predicting current reward value are the sizes of rewards delivered in previous blocks. Unexpectedly, monkeys with Rh ablations, but not intact controls, were insensitive to differences in predicted reward, responding as if they expected all rewards to be of equal magnitude. Thus, it appears that Rh is critical for using memory of previous rewards to predict the value of forthcoming rewards. These results are in agreement with accumulating evidence that Rh is critical for establishing the relationships between temporally interleaved events, which is a key element of episodic memory.
Sleep Deprivation Is Associated with Attenuated Parametric Valuation and Control Signals in the Midbrain during Value-Based Decision Making
Authors: Menz Mareike M. , Büchel Christian , Peters Jan
Published: May 2012

Sleep deprivation (SD) has detrimental effects on cognition, but the affected psychological processes and underlying neural mechanisms are still essentially unclear. Here we combined functional magnetic resonance imaging and computational modeling to examine how SD alters neural representation of specific choice variables (subjective value and decision conflict) during reward-related decision making. Twenty-two human subjects underwent two functional neuroimaging sessions in counterbalanced order, once during rested wakefulness and once after 24 h of SD. Behaviorally, SD attenuated conflict-dependent slowing of response times, which was reflected in an attenuated conflict-induced decrease in drift rates in the drift diffusion model. Furthermore, SD increased overall choice stochasticity during risky choice. Model-based functional neuroimaging revealed attenuated parametric subjective value signals in the midbrain, parietal cortex, and ventromedial prefrontal cortex after SD. Conflict-related midbrain signals showed a similar downregulation. Findings are discussed with respect to changes in dopaminergic signaling associated with the sleep-deprived state.
PKC-2 Phosphorylation of UNC-18 Ser322 in AFD Neurons Regulates Temperature Dependency of Locomotion
Authors: Edwards Mark R. , Johnson James R. , Rankin Kimberley , Jenkins Rosalind E. , Maguire Carl , Morgan Alan , Burgoyne Robert D. , Barclay Jeff W.
Published: May 2012

Diacylglycerol (DAG)/protein kinase C (PKC) signaling plays an integral role in the regulation of neuronal function. This is certainly true inCaenorhabditis elegansand in particular for thermosensory signaling and behavior. Downstream molecular targets for transduction of this signaling cascade remain, however, virtually uncharacterized. We investigated whether PKC phosphorylation of Munc18-1, an essential protein in vesicle trafficking and exocytosis, was the downstream effector for DAG regulation of thermosensory behavior. We demonstrate here that theC. elegansortholog of Munc18-1, UNC-18, was phosphorylatedin vitroat Ser322. Transgenic rescue ofunc-18-null worms with Ser322 phosphomutants displayed altered thermosensitivity.C. elegansexpresses three DAG-regulated PKCs, and blocking UNC-18 Ser322 phosphorylation was phenocopied only by deletion of calcium-activated PKC-2. Expression of nonphosphorylatable UNC-18 S322A, either pan-neuronally or specifically in AFD thermosensory neurons, converted wild-type worms to apkc-2-null phenotype. These data demonstrate that an individual DAG-dependent thermosensory behavior of an organism is effected specifically by the downstream PKC-2 phosphorylation of UNC-18 on Ser322 in AFD neurons.
Pre-Cue Fronto-Occipital Alpha Phase and Distributed Cortical Oscillations Predict Failures of Cognitive Control
Authors: Hamm Jordan P. , Dyckman Kara A. , McDowell Jennifer E. , Clementz Brett A.
Published: May 2012

Cognitive control is required for correct performance on antisaccade tasks, including the ability to inhibit an externally driven ocular motor response (a saccade to a peripheral stimulus) in favor of an internally driven ocular motor goal (a saccade directed away from a peripheral stimulus). Healthy humans occasionally produce errors during antisaccade tasks, but the mechanisms associated with such failures of cognitive control are uncertain. Most research on cognitive control failures focuses on poststimulus processing, although a growing body of literature highlights a role of intrinsic brain activity in perceptual and cognitive performance. The current investigation used dense array electroencephalography and distributed source analyses to examine brain oscillations across a wide frequency bandwidth in the period before antisaccade cue onset. Results highlight four important aspects of ongoing and preparatory brain activations that differentiate error from correct antisaccade trials: (1) ongoing oscillatory beta (20–30 Hz) power in anterior cingulate before trial initiation (lower for error trials); (2) instantaneous phase of ongoing alpha/theta (7 Hz) in frontal and occipital cortices immediately before trial initiation (opposite between trial types); (3) gamma power (35–60 Hz) in posterior parietal cortex 100 ms before cue onset (greater for error trials); and (4) phase locking of alpha (5–12 Hz) in parietal and occipital cortices immediately before cue onset (lower for error trials). These findings extend recently reported effects of pre-trial alpha phase on perception to cognitive control processes and help identify the cortical generators of such phase effects.
Brain-Derived Neurotrophic Factor Val66Met Polymorphism Affects Resting Regional Cerebral Blood Flow and Functional Connectivity Differentially in Women Versus Men
Authors: Wei Shau-Ming , Eisenberg Daniel P. , Kohn Philip D. , Kippenhan Jonathan S. , Kolachana Bhaskar S. , Weinberger Daniel R. , Berman Karen F.
Published: May 2012

The human Val66Met single nucleotide polymorphism in the brain-derived neurotrophic factor (BDNF) gene impacts BDNF signaling at the cellular level. At the neural-systems level, it is associated with differences in prefrontal cortex (PFC) and hippocampal function during performance of cognitive and affective tasks. Because the impact of this variant on basal prefrontal and hippocampal activity is not known but may be relevant to understanding the function of this gene in health and disease, we studied 94 healthy individuals with H215O PET to assess regional cerebral blood flow (rCBF) during rest and tested for between-genotype differences. Because BDNF and gonadal steroid hormones conjointly influence neuronal growth, survival, and plasticity in hippocampus and PFC, we also tested for sex × genotype interactions. Finally, in light of the known impact of BDNF on plasticity and dendritic arborization, we complimented direct rCBF comparisons with connectivity analyses to determine how activity in hippocampal and prefrontal regions showing between-genotype group differences covaries with rCBF in other nodes throughout the brain in a genotype- or sex-dependent manner. Compared with Val homozygotes, Met carriers had higher rCBF in prefrontal (BA25 extending into BA10) and hippocampal/parahippocampal regions. Moreover, there were significant sex × genotype interactions in regions (including frontal, parahippocampal, and lateral temporal cortex) in which Val homozygotes showed higher rCBF in females than males, but Met carriers showed the opposite relationship. Functional connectivity analysis demonstrated that correlations of BA25, hippocampus, and parahippocampus with frontal and temporal networks were positive for Val homozygotes and negative for Met carriers. In addition, sex × genotype analysis of functional connectivity revealed that genotype affected directionality of the inter-regional correlations differentially in men versus women. Our data indicate thatBDNFallelic variation and sex interactively affect basal prefrontal and hippocampal function.
Adult Neurogenesis Is Associated with the Maintenance of a Stereotyped, Learned Motor Behavior
Authors: Pytte Carolyn L. , George Shanu , Korman Shoshana , David Eva , Bogdan Diane , Kirn John R.
Published: May 2012

Adult neurogenesis is thought to provide neural plasticity used in forming and storing new memories. Here we show a novel relationship between numbers of new neurons and the stability of a previously learned motor pattern. In the adult zebra finch, new projection neurons are added to the nucleus HVC and become part of the motor pathway for producing learned song. However, new song learning occurs only in juveniles and the behavioral impact of adding new neurons to HVC throughout life is unclear. We report that song changes after deafening are inversely correlated with the number of new neurons added to HVC, suggesting that adult neurogenesis in this context may contribute to behavioral stability. More broadly, we propose that new neuron function may depend on the site of integration and can vary as widely as promoting, or restricting, behavioral plasticity.
Egr-1 Induces DARPP-32 Expression in Striatal Medium Spiny Neurons via a Conserved Intragenic Element
Authors: Keilani Serene , Chandwani Samira , Dolios Georgia , Bogush Alexey , Beck Heike , Hatzopoulos Antonis K. , Rao Gadiparthi N. , Thomas Elizabeth A. , Wang Rong , Ehrlich Michelle E.
Published: May 2012

DARPP-32 (dopamine and adenosine 3′, 5′-cyclic monophosphate cAMP-regulated phosphoprotein, 32 kDa) is a striatal-enriched protein that mediates signaling by dopamine and other first messengers in the medium spiny neurons. The transcriptional mechanisms that regulate striatal DARPP-32 expression remain enigmatic and are a subject of much interest in the efforts to induce a striatal phenotype in stem cells. We report the identification and characterization of a conserved region, also known as H10, in intron IV of the gene that codes for DARPP-32 (Ppp1r1b). This DNA sequence forms multiunit complexes with nuclear proteins from adult and embryonic striata of mice and rats. Purification of proteins from these complexes identified early growth response-1 (Egr-1). The interaction between Egr-1 and H10 was confirmedin vitroandin vivoby super-shift and chromatin immunoprecipitation assays, respectively. Importantly, brain-derived neurotrophic factor (BDNF), a known inducer of DARPP-32 and Egr-1 expression, enhanced Egr-1 binding to H10in vitro. Moreover, overexpression of Egr-1 in primary striatal neurons induced the expression of DARPP-32, whereas a dominant-negative Egr-1 blocked DARPP-32 induction by BDNF. Together, this study identifies Egr-1 as a transcriptional activator of thePpp1r1bgene and provides insight into the molecular mechanisms that regulate medium spiny neuron maturation.
PMCA2 via PSD-95 Controls Calcium Signaling by α7-Containing Nicotinic Acetylcholine Receptors on Aspiny Interneurons
Authors: Gómez-Varela David , Schmidt Manuela , Schoellerman Jeff , Peters Eric C. , Berg Darwin K.
Published: May 2012

Local control of calcium concentration within neurons is critical for signaling and regulation of synaptic communication in neural circuits. How local control can be achieved in the absence of physical compartmentalization is poorly understood. Challenging examples are provided by nicotinic acetylcholine receptors that contain α7 nicotinic receptor subunits (α7-nAChRs). These receptors are highly permeable to calcium and are concentrated on aspiny dendrites of interneurons, which lack obvious physical compartments for constraining calcium diffusion. Using functional proteomics on rat brain, we show that α7-nAChRs are associated with plasma membrane calcium-ATPase pump isoform 2 (PMCA2). Analysis of α7-nAChR function in hippocampal interneurons in culture shows that PMCA2 activity limits the duration of calcium elevations produced by the receptors. Unexpectedly, PMCA2 inhibition triggers rapid calcium-dependent loss of α7-nAChR clusters. This extreme regulatory response is mediated by CaMKII, involves proteasome activity, depends on the second intracellular loop of α7-nAChR subunits, and is specific in that it does not alter two other classes of calcium-permeable ionotropic receptors on the same neurons. A critical link is provided by the scaffold protein PSD-95 (postsynaptic density-95), which is associated with α7-nAChRs and constrains their mobility as revealed by single-particle tracking on neurons. The PSD-95 link is required for PMCA2-mediated removal of α7-nAChR clusters. This three-component combination of PMCA2, PSD-95, and α7-nAChR offers a novel mechanism for tight control of calcium dynamics in neurons.
Equivalent Representation of Real and Illusory Contours in Macaque V4
Authors: Pan Yanxia , Chen Minggui , Yin Jiapeng , An Xu , Zhang Xian , Lu Yiliang , Gong Hongliang , Li Wu , Wang Wei
Published: May 2012

The cortical processing of illusory contours provides a unique window for exploring the brain mechanisms underlying visual perception. Previous electrophysiological single-cell recordings demonstrate that a subgroup of cells in macaque V1 and V2 signal the presence of illusory contours, whereas recent human brain imaging studies reveal higher-order visual cortices playing a central role in illusory figure processing. It seems that the processing of illusory contours/figures may engage multiple cortical interactions between hierarchically organized processing stages in the ventral visual pathway of primates. However, it is not yet known in which brain areas illusory contours are represented in the same manner as real contours at both the population and single-cell levels. Here, by combining intrinsic optical imaging in anesthetized rhesus macaques with single-cell recordings in awake ones, we found a complete overlap of orientation domains in visual cortical area V4 for processing real and illusory contours. In contrast, the orientation domains mapped in early visual areas V1 and V2 mainly encoded the local physical stimulus features inducing the subjective perception of global illusory contours. Our results indicate that real and illusory contours are encoded equivalently by the same functional domains in V4, suggesting that V4 is a key cortical locus for integration of local features into global contours.
PGC-1α Negatively Regulates Extrasynaptic NMDAR Activity and Excitotoxicity
Authors: Puddifoot Clare , Martel Marc-Andre , Soriano Francesc X. , Camacho Alberto , Vidal-Puig Antonio , Wyllie David J. A. , Hardingham Giles E.
Published: May 2012

Underexpression of the transcriptional coactivator PGC-1α is causally linked to certain neurodegenerative disorders, including Huntington's Disease (HD). HD pathoprogression is also associated with aberrant NMDAR activity, in particular an imbalance between synaptic versus extrasynaptic (NMDAREX) activity. Here we show that PGC-1α controls NMDAREXactivity in neurons and that its suppression contributes to mutant Huntingtin (mHtt)-induced increases in NMDAREXactivity and vulnerability to excitotoxic insults.

We found that knock-down of endogenous PGC-1α increased NMDAREXactivity and vulnerability to excitotoxic insults in rat cortical neurons. In contrast, exogenous expression of PGC-1α resulted in a neuroprotective reduction of NMDAREXcurrents without affecting synaptic NMDAR activity. Since HD models are associated with mHtt-mediated suppression of PGC-1α expression, as well as increased NMDAREXactivity, we investigated whether these two events were linked. Expression of mHtt (148Q) resulted in a selective increase in NMDAREXactivity, compared with wild-type Htt (18Q), and increased vulnerability to NMDA excitotoxicity. Importantly, we observed that the effects of mHtt and PGC-1α knockdown on NMDAREXactivity and vulnerability to excitotoxicity were nonadditive and occluded each other, consistent with a common mechanism. Moreover, exogenous expression of PGC-1α reversed mtHtt-mediated increases in NMDAREXactivity and protected neurons against excitotoxic cell death. The link between mHtt, PGC-1α, and NMDAR activity was also confirmed in rat striatal neurons. Thus, targeting levels of PGC-1α expression may help reduce aberrant NMDAREXactivity in disorders where PGC-1α is underexpressed.
From Mutineers to Volunteers
Authors: Ching Leo T. S.
Published: May 2012

This chapter examines the most deprived and marginalized population in the Japanese colonial hierarchy, the Taiwanese aborigines. The insertion of the aborigines has two important implications: (1) it points to the irreducibly uneven development in colonial society; and (2) the particular modes of production of the aborigines required the Japanese colonial authority to employ a more authoritarian rule with the aborigine population than with the Chinese–Taiwanese population in the plains. The 1930 Musha uprising constituted a historical event that signaled an unprecedented resistance by the colonized which deeply shook Japanese rule. After it, people encountered a visible shift in the representations of aborigines that were current in colonial culture.
“Into the Muddy Stream”
Authors: Ching Leo T. S.
Published: May 2012

The reconstitution of consciousness offers a more historical and thus critical alternative in conceptualizing colonial violence than the politics of identity. The Orphan of Asia exhibits the symptom of channeling political impossibility into a personalized struggle over identity. It presents a parable of Taiwan's gradual “coming into being” with the intensification of colonial rule and its disillusion with Chinese nationalism. It also became indicative of the historical moment when the intensifying Pacific war had precluded any revolutionary or reformist corrective to Japanese colonialism, and when China and Chinese nationalism no longer provided a clear and viable alternative to Taiwan's emancipation.
Promoting Network Formation in Nanorod-filled Binary Blends
Authors: Yan Li-Tang , Maresov Egor , Hayward Ryan C. , Emrick Todd , Russell Thomas P. , Balazs Anna C.
Published: May 2012

Using a hybrid computational approach, we introduce A-like nanorods into a phaseseparating AB blend, which has 45/55 composition. In the absence of the rods, the minority A phase forms droplets in the matrix of B. With the addition of N = 670 rods that interact solely through a short range repulsive interaction (mimicking the steric stabilization provided by a coating of A ligands), the mixture retains this droplet morphology. When, however, we add an effective attraction between the sterically stabilized rods, the nanoparticles form extensive networks in the A phase, which can form a continuous phase. In addition to altering the morphology of the mixture, the attractive interaction influences the rate of domain growth. In particular, at early times, the mutually attractive rods increase the growth rate of the domains in the early stage. At late times, the domain growth crosses over to a slow growth regime. Our findings demonstrate that the morphology and coarsening of a rod-filled blend can be controlled by varying the rod-rod interaction and hence, provides guidelines for tailoring the electrical and mechanical properties of the nanocomposites.
Cuatro especies nuevas del grupo de especies Drosophila mesophragmatica (Diptera, Drosophilidae) de los Andes ecuatorianos
Authors: Céspedes Diego , Rafael Violeta
Published: May 2012

Se describen cuatro especies nuevas del grupo Drosophila mesophragmatica. Las nuevas especies fueron descubiertas en los páramos y remanentes de bosque andino de los Andes ecuatorianos. Las capturas fueron realizadas desde los 2200 hasta los 4000 m de altitud. Las especies nuevas son: D. cashapamba sp. nov., D. chorlavi sp. nov., D. rucux sp. nov. y D. yanayuyu sp. nov. Con las cuatro especies nuevas descubiertas, el número de especies dentro del grupo D. mesophragmatica se incrementa a 17. Los miembros del grupo están distribuidos principalmente en los Andes sudamericanos.
Estudo da morbimortalidade em pacientes com trauma pancreático
Authors: Fonseca Neto Olival Cirilo Lucena da , Anunciação Carlos Eduardo Caiado , Miranda Antônio Lopes de
Published: May 2012

RACIONAL: A lesão pancreática é pouco freqüente após traumas abdominais fechados ou penetrantes, e tem sido relatada entre 0,2 a 12% dos traumas abdominais fechados graves e em cinco a 7% dos traumas penetrantes. A maioria das lesões pancreáticas ocorre em homens jovens e está associada a alta incidência de lesões a órgãos adjacentes e estruturas vasculares importantes. OBJETIVO: Avaliar a morbimortalidade dos pacientes com trauma pancreático, o manuseio aplicado a esses pacientes e sua evolução. MÉTODOS: Estudo prospectivo realizado em pacientes admitidos em unidade de trauma. Treze adultos (> 13 anos) foram estratificados em graves e não-graves de acordo com critérios clínicos no momento da identificação do início do quadro e de acordo com os critérios de Baltazar (A, B, C, D e E). O tipo de trauma externo (aberto ou fechado), a classificação do trauma pancreático, números de órgãos acometidos pelo trauma, número de reoperações, o tipo de suporte nutricional e o tempo de permanência hospitalar também foram analisados. A presença de síndrome compartimental abdominal e a necessidade de fechamento temporário foram estudados e comparados com a morbimortalidade nos pacientes. RESULTADOS: Todos os pacientes eram do sexo masculino com a idade média de 28,6 anos (13 a 60 anos) e apresentaram pancreatite traumática no pós-operatório. Em sete, o ferimento era penetrante por projétil de arma de fogo; em três, abdominal fechado; em dois, por arma branca; em um, grande queimado (> 50% da área corporal). Quanto à classificação do trauma, os graus I e II ocorreram em 38,46; o grau III,15,38 % e o grau IV, 7,7 % . Foram realizadas drenagens da loja pancreática, hemostasia da lesão e pancreatectomia distal com esplenectomia associado à drenagem cavitária Foram classificados como não-grave, oito pacientes. Dentro dos critérios de Baltazar a predominância foi o grau D e C (quatro pacientes, cada). Não houve grau A e apenas um foi E. Apenas três pacientes não foram reoperados (média de 1,7 cirurgias por paciente). Em 46,15%, ocorreu hipertensão intra-abdominal sendo necessário colocação de bolsa de Bogotá. O tempo de internamento variou de 30 à 365 dias (média = 53,4 dias). Ocorreu apenas um óbito. CONCLUSÃO: A pancreatite traumática é de elevada morbimortalidade, e uma das complicações mais importantes relacionada ao trauma pancreático, sendo o seu diagnóstico precoce junto com o acompanhamento multidisciplinar intensivo, o fator que poderá interferir favoravelmente na evolução desses pacientes.
Gasometria arterial e inflamação pulmonar de ratos com diferentes tempos de sepse abdominal
Authors: Rocha Sérgio Luiz , Souza Geórgia Rubiane Meira do Rosário de , Abujamra Karla Bueno , Ostrowski Marco Antônio Beuting , Souza Monique Carolina Meira do Rosário de
Published: May 2012

RACIONAL: Sepse é a principal causa de morbi-mortalidade nas vítimas de trauma e em pacientes cirúrgico e apesar de toda tecnologia e terapêutica disponível não há diminuição nestas estatísticas. OBJETIVOS: Avaliar as repercussões ácido-básicas e o grau de injúria pulmonar decorrentes de sepse abdominal em ratos após seis e 24 horas de peritonite fecal através da ligadura e punção do ceco. MÉTODOS: Foram utilizados 40 ratos Wistar, machos, adultos. A amostra foi dividida aleatoriamente em quatro grupos: grupo A (sham/6 h - n=5) submetidos à laparotomia mediana infra-umbilical sem nenhuma outra intervenção; grupo B (sham/24h - n=5) submetidos à laparotomia mediana infra-umbilical sem nenhuma outra intervenção; grupo C (LPC/6 h - n=15) submetidos à ligadura e punção do ceco e grupo D (LPC/24h - n=15) submetidos à ligadura e punção do ceco. Após seis ou 24 horas, conforme o grupo em estudo, os animais foram novamente anestesiados e submetidos as seguintes análises: observação clínica de sinais de sepse, laparotomia através do mesmo acesso anterior e realização de cultura do líquido peritoneal e punção cardíaca para obtenção de amostra sangüínea suficiente para gasometria arterial, hematócrito e leucometria. Procedeu-se eutanásia e os pulmões retirados para análise de edema pulmonar e o infiltrado inflamatório. RESULTADOS: Ocorreram quatro óbitos no grupo D. Verificou-se, em todos os grupos, a presença de acidose mista. Comparando os grupos experimento 6h versus controle 6h foram encontradas duas variáveis significativas - HCO3 (p=0,0015) e BE (p=0,0015) -, demonstrando acidose metabólica mais grave no grupo experimento. Nos grupos controle também se confirmou acidose mista, devido às alterações das variáveis HCO3 (p=0,0079), PO2 (p=0,0079) e SO2 (p=0,0079). A correlação entre o grau de comprometimento pulmonar e o estado metabólico confirma a existência de resposta inflamatória sistêmica evidenciada por aumento de neutrófilos e hemorragia alveolar difusa nos pulmões do rato séptico. CONCLUSÃO: O modelo de LPC foi método eficaz para indução de sepse. A laparotomia e a manipulação de alças intestinais são fatores desencadeantes de acidose mista em ratos, comprovado pelos resultados da gasometria, que demonstrou ser método confiável na detecção de alterações no metabolismo ácido-básico dos ratos estudados.
Qualidade de vida do paciente submetido à Microcirurgia Endoscópica Transanal (TEM)
Authors: Moraes Roberto da Silveira , Zanchet Marcos Vinícius , Sobottka Wagner Herbert , Lima João Henrique Felício de , Morgenstern Glauco Afonso , Malafaia Osvaldo , Buess Gerhard , Coelho Júlio Cezar Uili
Published: May 2012

RACIONAL: A Microcirurgia Endoscópica Transanal (TEM) é procedimento minimamente invasivo para o tratamento de tumores retais selecionados. Atualmente, existe crescente interesse médico na medida quantitativa da qualidade de vida. OBJETIVO: Avaliar a qualidade de vida dos pacientes submetidos a TEM no Serviço de Cirurgia do Aparelho Digestivo no Hospital de Clínicas da Universidade Federal do Paraná. MÉTODOS: Trata-se de um estudo observacional prospectivo e de coorte da avaliação da qualidade de vida após TEM. Trinta e quatro pacientes responderam a um questionário composto de 14 questões, abordando aspectos pós-operatórios e laborais. Dirigiam-se elas para levantar dados principalmente sobre: o consentimento informado; a dor experimentada após a operação; a capacidade de o paciente caminhar no período pós-operatório; o período para retorno às atividades habituais; a satisfação com a ausência de cicatriz pós-operatória; a incontinência no pós-operatório; se recomendaria a operação a um familiar ou conhecido. RESULTADOS: Todos os 34 pacientes relataram ter sido adequadamente informados sobre o procedimento. Ausência de dor pós-operatória foi observada em 82,5% e todos se mostraram capazes de deambular no 1º dia do pós-operatório. O retorno às atividades habituais deu-se em média sete dias após o procedimento. Somente cinco pacientes (14,70%) apresentaram incontinência fecal transitória, não maior que uma semana. Três pacientes (8,82%) necessitaram de re-internação, sendo dois por tumores residuais e outro por recidiva tumoral. Dois pacientes (5,88%) referiram modificação temporária na vida sexual após a cirurgia e 97,05% indicariam a TEM a um familiar ou amigo. O período médio de internação foi de três dias. CONCLUSÃO: Os pacientes apresentaram boa evolução, com pouca dor pós-operatória, curto período de internação e baixo índice de complicações, mostrando satisfação e adequada qualidade de vida com a TEM.
Cicatrização de feridas
Authors: Campos Antonio Carlos Ligocki , Borges-Branco Alessandra , Groth Anne Karoline
Published: May 2012

INTRODUÇÃO: A cicatrização de feridas consiste em perfeita e coordenada cascata de eventos que culminam com a reconstituição tecidual. O processo cicatricial é comum a todas as feridas, independe do agente que a causou. O processo de cicatrização é dividido didaticamente em três fases: inflamatória, proliferação ou granulação e remodelamento ou maturação. O colágeno é a proteína mais abundante no corpo humano e também é o principal componente da matriz extracelular dos tecidos. Estrutura-se numa rede densa e dinâmica resultante da sua constante deposição e reabsorção. O tecido cicatricial é resultado da interação entre sua síntese, fixação e degradação. Existem várias maneiras de avaliar a cicatrização das feridas. Os métodos mais utilizados atualmente são a tensiometria, a densitometria e morfometria do colágeno, a imunoistoquímica e, mais recentemente, a dosagem de fatores de crescimento. MÉTODOS: Foram revisadas todas as dissertações de mestrado e teses de doutorado realizadas na linha de pesquisa "Cicatrização de órgãos e tecidos" do programa de Pós-Graduação em Clínica Cirúrgica da Universidade Federal do Paraná. Foi realizada, também, revisão atualizada da literatura internacional no Pubmed e nacional. CONCLUSÃO: A cicatrização é um processo complexo, que começou a ser entendido em maior amplitude nos últimos anos. Recentes pesquisas têm sido direcionadas para atuar na modulação da cicatrização a nível molecular, na tentativa de evitar completamente cicatrizes patológicas.
Adenocarcinoma gástrico tipo difuso de Lauren: disseminação linfática exuberante em paciente jovem
Authors: Nery Roberto , Batista Thales Paulo , Carvalho Estela K. B.
Published: May 2012

RACIONAL: O câncer gástrico continua sendo relevante causa oncológica de morte em todo o mundo, com a grande maioria dos casos ocidentais sendo diagnosticados em fase tumoral avançada. O adenocarcinoma representa a quase totalidade dos casos, com pior prognóstico no tipo difuso de Lauren, o qual acomete mais freqüentemente pacientes jovens. OBJETIVO: Relatar um caso de adenocarcinoma difuso em jovem de 20 anos, no qual a disseminação ocorreu de forma agressiva, disseminada e peculiar. RELATO DO CASO: Agricultor de 20 anos, admitido com plenitude gástrica, dor abdominal e vômitos pós-prandiais, com adenomegalia generalizada de consistência endurecida e indolor, mais evidente, pelo tamanho, na região epigástrica, sub-mandibular e cutânea. Endoscopia digestiva alta demonstrou lesão antral úlcero-infiltrativa com extensas áreas de necrose obstruindo completamente o piloro. Tomografia abdominal mostrou tumoração mal delimitada, estendendo-se ao hipocôndrio direito, epigástrio e comprometendo a segunda porção do duodeno. Estudo anatomopatológico mostrou tratar-se de adenocarcinoma pouco diferenciado com padrão em células de anel de sinete. Foi submetido à gastrojejunostomia paliativa. CONCLUSÃO: O adenocarcinoma gástrico pode apresentar-se com comprometimento linfonodal exuberante e sistêmico de grande porte principalmente em baixa idade produzindo adenomegalias volumosas possibilitando somente tratamento paliativo quando diagnosticado.
Colangiopancreatografia endoscópica retrógrada (CPRE) intraoperatória como alternativa no tratamento de coledocolitíase
Authors: Ettinger Júnior Eric , Amaral Paulo Cezar Galvão do , Ázaro Filho Euler , Fortes Marcos Fraga , Cangussu Heron Crusoé , Fahel Edvaldo
Published: May 2012

RACIONAL: O tratamento da coledocolitíase continua controverso, podendo ser realizado por pancreatocolangiografia retrógrada endoscópica pré-operatória seguida de videolaparocolecistectomia ou por videolaparocolecistectomia com exploração de vias biliares. Há relato na literatura de taxa de insucesso da pancreatocolangiografia retrógrada endoscópica pré-operatória em torno de 6%. OBJETIVO: Apresentar caso de uma paciente que necessitou da realização de CPRE intra-operatória para resolução de coledocolitíase tratada sem êxito por CPRE. RELATO DO CASO: Paciente de 45 anos, admitida na emergência com quadro de dor abdominal em epigástrio e hipocôndrio direito. A ultra-sonografia da admissão evidenciou coledocolitíase, sendo ela encaminhada para pancreatocolangiografia retrógrada endoscópica pré-operatória onde não houve sucesso na cateterização da papila. Foi optado então pela realização de videolaparocolecistectomia com exploração de via biliar por pancreatocolangiografia retrógrada endoscópica pré-operatória intra-operatoria com a cateterização da papila direcionada por fio guia passado pelo ducto cístico. Foi realizada duodenoscopia com captura do fio guia que serviu para a passagem do papilótomo dando seqüência à pancreatocolangiografia retrógrada endoscópica pré-operatória e retirada dos cálculos. A paciente evoluiu satisfatoriamente tendo alta no 2º dia do pós-operatório. CONCLUSÃO: A abordagem da coledocolitíase por pancreatocolangiografia retrógrada endoscópica intra-operatória seguida de videolaparocolecistectomia, mostrou-se segura e eficaz.