bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of muscle fatigue using dynamically embedded signals
Authors: Slack P S , Ma X-H
Published: March 2008

This paper explores a new method of analysing muscle fatigue within the muscles predominantly used during microsurgery. The captured electromyographic (EMG) data retrieved from these muscles are analysed for any defining patterns relating to muscle fatigue. The analysis consists of dynamically embedding the EMG signals from a single muscle channel into an embedded matrix. The muscle fatigue is determined by defining its entropy characterized by the singular values of the dynamically embedded (DE) matrix. The paper compares this new method with the traditional method of using mean frequency shifts in the EMG signal's power spectral density. Linear regressions are fitted to the results from both methods, and the coefficients of variation of both their slope and point of intercept are determined. It is shown that the complexity method is slightly more robust in that the coefficient of variation for the DE method has lower variability than the conventional method of mean frequency analysis.
The effect of glycosaminoglycan depletion on the friction and deformation of articular cartilage
Authors: Katta J , Stapleton T , Ingham E , Jin Z M , Fisher J
Published: March 2008

Glycosaminoglycans (GAGs) have been shown to be responsible for the interstitial fluid pressurization of articular cartilage and hence its compressive stiffness and load-bearing properties. Contradictory evidence has been presented in the literature on the effect of depleting GAGs on the friction properties of articular cartilage. The aim of this study was to investigate the effect of depleting GAGs on the friction and deformation characteristics of articular cartilage under different tribological conditions.

A pin-on-plate machine was utilized to measure the coefficient of friction of native and chondroitinase ABC (CaseABC)-treated articular cartilage under two different models: static (4 mm/s start-up velocity) and dynamic (4 mm/s sliding velocity; 4 mm stroke length) under a load of 25 N (0.4 MPa contact stress) and with phosphate-buffered saline as the lubricant. Indentation tests were carried out at 1 N and 2 N loads (0.14 MPa and 0.28 MPa contact stress levels) to study the deformation characteristics of both native and GAG-depleted cartilage samples.

CaseABC treatment rendered the cartilage tissue soft owing to the loss of compressive stiff-ness and a sulphated-sugar assay confirmed the loss of GAGs from the cartilage samples. CaseABC treatment significantly increased (by more than 50 per cent) the friction levels in the dynamic model ( p < 0.05) at higher loading times owing to the loss of biphasic lubrication. CaseABC treatment had no effect on friction in the static model in which the cartilage surfaces did not have an opportunity to recover fluid because of static loading unlike the cartilage tissue in the dynamic model, in which translation of the cartilage surfaces was involved, ensuring effective biphasic lubrication. Therefore the depletion of GAGs had a smaller effect on the coefficient of friction for the static model. Indentation tests showed that GAG-depleted cartilage samples had a lower elastic modulus and higher permeability than native tissue. These results corroborate the role of GAGs in the compressive and friction properties of articular cartilage and emphasize the need for developing strategies to control GAG loss from diseased articular cartilage tissue.
Closed-loop tracking control of a pendulum-driven cart-pole underactuated system
Authors: Yu H , Liu Y , Yang T
Published: March 2008

This paper investigates a new modelling and control issue: the tracking control problem of underactuated dynamic systems by using a special example – a pendulum-driven cart-pole system. A dynamic model of a pendulum-driven cart-pole system is firstly presented. Then, a six-step motion strategy of the pendulum-driven cart-pole system is proposed. After that, a desired profile of the pendulum joint velocity is developed based on the proposed six-step motion strategy. The desired joint position and acceleration can be computed using the desired joint velocity profile. A closed-loop control approach is proposed using the partial feedback linearization technique. Finally, extensive simulation studies are conducted to demonstrate the proposed approaches.
Dynamic Pricing and Lead-Time Quotation for a Multiclass Make-to-Order Queue
Authors: Çelik Sabri , Maglaras Costis
Published: March 2008

This paper considers a profit-maximizing make-to-order manufacturer that offers multiple products to a market of price and delay sensitive users, using a model that captures three aspects of particular interest: first, the joint use of dynamic pricing and lead-time quotation controls to manage demand; second, the presence of a dual sourcing mode that can expedite orders at a cost; and third, the interaction of the aforementioned demand controls with the operational decisions of sequencing and expediting that the firm must employ to optimize revenues and satisfy the quoted lead times. Using an approximating diffusion control problem we derive near-optimal dynamic pricing, lead-time quotation, sequencing, and expediting policies that provide structural insights and lead to practically implementable recommendations. A set of numerical results illustrates the value of joint pricing and lead-time control policies.
OR PRACTICE—The Dance of the Thirty-Ton Trucks: Dispatching and Scheduling in a Dynamic Environment
Authors: Durbin Martin , Hoffman Karla
Published: March 2008

We report on the application of operations research to a very complex scheduling and dispatching problem. Scheduling and dispatching are never easy, but the scheduling of concrete deliveries is particularly difficult for several reasons: (1) concrete is an extremely perishable product—it can solidify in the truck if offloading is delayed by a few hours; (2) customer orders are extremely unpredictable and volatile—orders are often canceled or drastically changed at the last minute; (3) the concrete company overbooks by as much as 20% to compensate for customer unpredictability; (4) many orders require synchronized deliveries by multiple trucks; (5) when a truck arrives at a customer site, the customer may not be ready for the delivery, or a storm may negate the ability to use the concrete; and (6) most of the travel takes place in highly congested urban areas, making travel times highly variable.

To assist the dispatchers, schedulers, and order takers at this company, we designed and implemented a decision-support tool consisting of both planning and execution tools. The modules determine whether new orders should be accepted, when drivers should arrive for work, the real-time assignment of drivers to delivery loads, the dispatching of these drivers to customers and back to plants, and the scheduling of the truck loadings at the plants.

For the real-time dispatching and order-taking decisions, optimization models are solved to within 1% of optimality every five minutes throughout the day. This nearly continuous reoptimization of the entire system allows quick reactions to changes. The modeling foundation is a time-space network with integer side constraints. We describe each of the models and explain how we handle imperfect data. We also detail how we overcome a variety of implementation issues.

The success of this project can be measured, most importantly, by the fact that the tool is being ported by the parent company, Florida Rock, to each of its other ready-mix concrete companies. Second, the corporation is sufficiently convinced of its importance that they have begun promoting this methodology as a “best practice” at the World of Concrete and ConAgg industry conventions.
TECHNICAL NOTE—Spatial Queueing Analysis of an Interdiction System to Protect Cities from a Nuclear Terrorist Attack
Authors: Atkinson Michael P. , Wein Lawrence M.
Published: March 2008

We formulate and analyze a spatial queueing model concerning a terrorist who is attempting to drive a nuclear or radiological weapon toward a target in a city center. In our model, imperfect radiation sensors form a circular wall around the periphery of the city, and vehicles setting off sensor alarms (representing a terrorist or a nuisance alarm) arrive randomly at the perimeter of a circle (representing the wall of sensors) and drive toward the center of the circle. Interdiction vehicles, one in each wedge of the circle, chase the alarm-generating vehicles. We derive an accurate mathematical expression for the mean damage inflicted by a terrorist in this system in terms of the arrival rate of alarm-generating vehicles and the number of interdiction vehicles. Our results suggest that detection-interdiction systems using current technology are capable of mitigating the damage from a nuclear weapon made of plutonium, but not one made of uranium or a radiological weapon.
Preventing Large Sojourn Times Using SMART Scheduling
Authors: Nuyens Misja , Wierman Adam , Zwart Bert
Published: March 2008

Recently, the so-called class of SMART scheduling policies has been introduced to formalize the common heuristic of “biasing toward small jobs.” We study the tail of the sojourn-time (response-time) distribution under both SMART policies and the foreground-background policy (FB) in the GI/GI/1 queue. We prove that these policies behave very well under heavy-tailed service times. Specifically, we show that the sojourn-time tail under all SMART policies and FB is similar to that of the service-time tail, up to a constant, which makes the SMART class superior to first-come-first-served (FCFS). In contrast, for light-tailed service times, we prove that the sojourn-time tail under FB and SMART is larger than that under FCFS. However, we show that the sojourn-time tail for a job of size y under FB and all SMART policies still outperforms FCFS as long as y is not too large.
Use of 5-HT1 Agonists in Pregnancy
Authors: Evans Emily W , Lorber Kristin C
Published: March 2008

OBJECTIVE:

To report and evaluate available data on the use of serotonin 5-HT1 agonists (triptans) during pregnancy.

DATA SOURCES:

A PubMed search, limited to English-language articles on human subjects, was conducted (1990–December 2007) using the search terms pregnancy, migraine, and the individual triptan drug names. In addition, the manufacturers of all 7 available triptans were contacted regarding the existence of a pregnancy registry for their drug(s) and the availability of registry reports.

STUDY SELECTION AND DATA EXTRACTION:

All retrospective and prospective studies reporting on pregnancy outcomes after the use of a triptan were included and critically evaluated. Data from all available manufacturer-sponsored pregnancy registries were also included.

DATA SYNTHESIS:

Safe and effective treatment of migraine during pregnancy is imperative. Data involving sumatriptan and, to a lesser extent, naratriptan and rizatriptan, exist primarily regarding exposure in the first trimester. These data show no significant differences in congenital malformations or poor pregnancy outcomes when compared with expected rates in the general population or with the observed rates in control subjects. There is very little information regarding exposure in middle and late pregnancy.

CONCLUSIONS:

Sumatriptan appears to be a safe treatment alternative for pregnant women who experience new-onset or worsened migraines in the first trimester. Further observation is needed prior to recommending its use in later trimesters. Based upon available data, the other agents in this class cannot be recommended for use during pregnancy at this time.
Enhanced Tau Phosphorylation in the Hippocampus of Mice Treated with 3,4-Methylenedioxymethamphetamine (“Ecstasy”)
Authors: Busceti Carla L. , Biagioni Francesca , Riozzi Barbara , Battaglia Giuseppe , Storto Marianna , Cinque Carlo , Molinaro Gemma , Gradini Roberto , Caricasole Andrea , Canudas Anna Maria , Bruno Valeria , Nicoletti Ferdinando , Fornai Francesco
Published: March 2008

3,4-Methylenedioxymethamphetamine (MDMA) (“Ecstasy”) produces neurotoxic effects, which result into an impairment of learning and memory and other neurological dysfunctions. We examined whether MDMA induces increases in tau protein phosphorylation, which are typically associated with Alzheimer's disease and other chronic neurodegenerative disorders. We injected mice with MDMA at cumulative doses of 10–50 mg/kg intraperitoneally, which are approximately equivalent to doses generally consumed by humans. MDMA enhanced the formation of reactive oxygen species and induced reactive gliosis in the hippocampus, without histological evidence of neuronal loss. An acute or 6 d treatment with MDMA increased tau protein phosphorylation in the hippocampus, revealed by both anti-phospho(Ser404)-tau and paired helical filament-1 antibodies. This increase was restricted to the CA2/CA3 subfields and lasted 1 and 7 d after acute and repeated MDMA treatment, respectively. Tau protein was phosphorylated as a result of two nonredundant mechanisms: (1) inhibition of the canonical Wnt (wingless-type MMTV integration site family) pathway, with ensuing activation of glycogen synthase kinase-3β; and (2) activation of type-5 cyclin-dependent kinase (Cdk5). MDMA induced the expression of the Wnt antagonist, Dickkopf-1, and the expression of the Cdk5-activating protein, p25. In addition, the increase in tau phosphorylation was attenuated by strategies that rescued the Wnt pathway or inhibited Cdk5. Finally, an impairment in hippocampus-dependent spatial learning was induced by doses of MDMA that increased tau phosphorylation, although the impairment outlasted this biochemical event. We conclude that tau hyperphosphorylation in the hippocampus may contribute to the impairment of learning and memory associated with MDMA abuse.
Zinc and 4-Hydroxy-2-Nonenal Mediate Lysosomal Membrane Permeabilization Induced by H2O2in Cultured Hippocampal Neurons
Authors: Hwang Jung Jin , Lee Sook-Jeong , Kim Tae-Youn , Cho Jae-Hyung , Koh Jae-Young
Published: March 2008

Lysosomal membrane permeabilization (LMP) is implicated in cancer cell death. However, its role and mechanism of action in neuronal death remain to be established. In the present study, we investigate the function of cellular zinc in oxidative stress-induced LMP using hippocampal neurons. Live-cell confocal microscopy with FluoZin-3 fluorescence showed that H2O2exposure induced vesicles containing labile zinc in hippocampal neurons. Double staining with LysoTracker or MitoTracker disclosed that the majority of the zinc-containing vesicles were lysosomes and not mitochondria. H2O2additionally augmented the 4-hydroxy-2-nonenal (HNE) adduct level in lysosomes. Intracellular zinc chelation with TPEN [tetrakis(2-pyridylmethyl)ethylenediamine] completely blocked both HNE accumulation and neuronal death. Interestingly, within 1 h after the onset of H2O2exposure, some of zinc-loaded vesicles lost their zinc signals. Consistent with the characteristics of LMP, a lysosomal enzyme, cathepsin D, was released into the cytosol, and cathepsin inhibitors partially rescued neuronal death. We further examined the possibility that HNE or zinc mediates H2O2-triggered LMP. Similar to H2O2, exposure to HNE or zinc triggered lysosomal zinc accumulation and LMP. Moreover, isolated lysosomes underwent LMP when exposed to HNE or zinc, but not H2O2, supporting the direct mediation of LMP by HNE and/or zinc. The appearance of zinc-containing vesicles and the increases in levels of cathepsin D and HNE, were also observed in hippocampal neurons of rats after kainate seizures. Thus, under oxidative stress, neuronal lysosomes accumulate zinc and HNE, and eventually undergo LMP, which may constitute a key mechanism of oxidative neuronal death.
Competition between Calcium-Activated K+Channels Determines Cholinergic Action on Firing Properties of Basolateral Amygdala Projection Neurons
Authors: Power John M. , Sah Pankaj
Published: March 2008

Acetylcholine (ACh) is an important modulator of learning, memory, and synaptic plasticity in the basolateral amygdala (BLA) and other brain regions. Activation of muscarinic acetylcholine receptors (mAChRs) suppresses a variety of potassium currents, including sIAHP, the calcium-activated potassium conductance primarily responsible for the slow afterhyperpolarization (AHP) that follows a train of action potentials. Muscarinic stimulation also produces inositol 1,4,5-trisphosphate (IP3), releasing calcium from intracellular stores. Here, we show using whole-cell patch-clamp recordings and high-speed fluorescence imaging that focal application of mAChR agonists evokes large rises in cytosolic calcium in the soma and proximal dendrites in rat BLA projection neurons that are often associated with activation of an outward current that hyperpolarizes the cell. This hyperpolarization results from activation of small conductance calcium-activated potassium (SK) channels, secondary to the release of calcium from intracellular stores. Unlike bath application of cholinergic agonists, which always suppressed the AHP, focal application of ACh often evoked a paradoxical enhancement of the AHP and spike-frequency adaptation. This enhancement was correlated with amplification of the action potential-evoked calcium response and resulted from the activation of SK channels. When SK channels were blocked, cholinergic stimulation always reduced the AHP and spike-frequency adaptation. Conversely, suppression of the sIAHPby the β-adrenoreceptor agonist, isoprenaline, potentiated the cholinergic enhancement of the AHP. These results suggest that competition between cholinergic suppression of the sIAHPand cholinergic activation of the SK channels shapes the AHP and spike-frequency adaptation.
Downregulation of the CB1Cannabinoid Receptor and Related Molecular Elements of the Endocannabinoid System in Epileptic Human Hippocampus
Authors: Ludányi Anikó , Erőss Loránd , Czirják Sándor , Vajda János , Halász Péter , Watanabe Masahiko , Palkovits Miklós , Maglóczky Zsófia , Freund Tamás F. , Katona István
Published: March 2008

Endocannabinoid signaling is a key regulator of synaptic neurotransmission throughout the brain. Compelling evidence shows that its perturbation leads to development of epileptic seizures, thus indicating that endocannabinoids play an intrinsic protective role in suppressing pathologic neuronal excitability. To elucidate whether long-term reorganization of endocannabinoid signaling occurs in epileptic patients, we performed comparative expression profiling along with quantitative electron microscopic analysis in control (postmortem samples from subjects with no signs of neurological disorders) and epileptic (surgically removed from patients with intractable temporal lobe epilepsy) hippocampal tissue. Quantitative PCR measurements revealed that CB1cannabinoid receptor mRNA was downregulated to one-third of its control value in epileptic hippocampus. Likewise, the cannabinoid receptor-interacting protein-1a mRNA was decreased, whereas 1b isoform levels were unaltered. Expression of diacylglycerol lipase-α, an enzyme responsible for 2-arachidonoylglycerol synthesis, was also reduced by ∼60%, whereas its related β isoform levels were unchanged. Expression level ofN-acyl-phosphatidylethanolamine-hydrolyzing phospholipase D and fatty acid amide hydrolase, metabolic enzymes of anandamide, and 2-arachidonoylglycerol's degrading enzyme monoacylglycerol lipase did not change. The density of CB1immunolabeling was also decreased in epileptic hippocampus, predominantly in the dentate gyrus, where quantitative electron microscopic analysis did not reveal changes in the ratio of CB1-positive GABAergic boutons, but uncovered robust reduction in the fraction of CB1-positive glutamatergic axon terminals. These findings show that a neuroprotective machinery involving endocannabinoids is impaired in epileptic human hippocampus and imply that downregulation of CB1receptors and related molecular components of the endocannabinoid system may facilitate the deleterious effects of increased network excitability.
Bounded Integration in Parietal Cortex Underlies Decisions Even When Viewing Duration Is Dictated by the Environment
Authors: Kiani Roozbeh , Hanks Timothy D. , Shadlen Michael N.
Published: March 2008

Decisions about sensory stimuli are often based on an accumulation of evidence in time. When subjects control stimulus duration, the decision terminates when the accumulated evidence reaches a criterion level. Under many natural circumstances and in many laboratory settings, the environment, rather than the subject, controls the stimulus duration. In these settings, it is generally assumed that subjects commit to a choice at the end of the stimulus stream. Indeed, failure to benefit from the full stream of information is interpreted as a sign of imperfect accumulation or memory leak. Contrary to these assumptions, we show that monkeys performing a direction discrimination task commit to a choice when the accumulated evidence reaches a threshold level (or bound), sometimes long before the end of stimulus. This bounded accumulation of evidence is reflected in the activity of neurons in the lateral intraparietal cortex. Thus, the readout of visual cortex embraces a termination rule to limit processing even when potentially useful information is available.
Structural Correlates of Efficient GABAergic Transmission in the Basal Ganglia–Thalamus Pathway
Authors: Bodor Ágnes L. , Giber Kristóf , Rovó Zita , Ulbert István , Acsády László
Published: March 2008

Giant inhibitory terminals with multiple synapses, the counterparts of excitatory “detonator” or “driver” terminals, have not been described in the forebrain. Using three-dimensional reconstructions of electron microscopic images, we quantitatively characterize a GABAergic pathway that establishes synaptic contacts exclusively via multiple synapses. Axon terminals of the nigrothalamic pathway formed, on average, 8.5 synapses on large-diameter dendrites and somata of relay cells in the ventromedial nucleus of the rat thalamus. All synapses of a given terminal converged on a single postsynaptic element. The vast majority of the synapses established by a single terminal were not separated by astrocytic processes. Nigrothalamic terminals in the macaque monkey showed the same ultrastructural features both in qualitative and quantitative terms (the median number of synapse per target was also 8.5). The individual synapses were closely spaced in both species. The nearest-neighbor synaptic distances were 169 nm in the rat and 178 nm in the monkey. The average number of synapses within 0.75 μm from any given synapse was 3.8 in the rat and 3.5 in the monkey. The arrangement of synapses described in this study creates favorable conditions for intersynaptic spillover of GABA among the multiple synapses of a single bouton, which can result in larger charge transfer. This could explain faithful and efficient GABAergic signal transmission in the nigrothalamic pathway in the healthy condition and during Parkinson's disease. In addition, our structural data suggest that the rodent nigrothalamic pathway can be a valid model of the primate condition, when the mechanism of GABAergic transmission is studied.
Methylprednisolone Protects Oligodendrocytes But Not Neurons after Spinal Cord Injury
Authors: Lee Jin-Moo , Yan Ping , Xiao Qingli , Chen Shawei , Lee Kuang-Yung , Hsu Chung Y. , Xu Jan
Published: March 2008

Methylprednisolone (MP) is used to treat a variety of neurological disorders involving white matter injury, including multiple sclerosis, acute disseminated encephalomyelitis, and spinal cord injury (SCI). Although its mechanism of action has been attributed to anti-inflammatory or antioxidant properties, we examined the possibility that MP may have direct neuroprotective activities. Neurons and oligodendrocytes treated with AMPA or staurosporine died within 24 h after treatment. MP attenuated oligodendrocyte death in a dose-dependent manner; however, neurons were not rescued by the same doses of MP. This protective effect was reversed by the glucocorticoid receptor (GR) antagonist (11, 17)-11-[4-(dimethylamino)phenyl]-17-hydroxy-17-(1-propynyl)estra-4,9-dien-3-one (RU486) and small interfering RNA directed against GR, suggesting a receptor-dependent mechanism. MP reversed AMPA-induced decreases in the expression of anti-apoptotic Bcl-xL, caspase-3 activation, and DNA laddering, suggesting anti-apoptotic activity in oligodendrocytes. To examine whether MP demonstrated this selective protectionin vivo, neuronal and oligodendrocyte survival was assessed in rats subjected to spinal cord injury (SCI); groups of rats were treated with or without MP in the presence or absence of RU486. Eight days after SCI, MP significantly increased oligodendrocytes (CC-1-immunoreactive cells) after SCI, but neuronal (neuronal-specific nuclear protein-immunoreactive cells) number remained unchanged; RU486 reversed this protective effect. MP also inhibited SCI-induced decreases in Bcl-xLand caspase-3 activation. Consistent with these findings, the volume of demyelination, assessed by Luxol fast blue staining, was attenuated by MP and reversed by RU486. These results suggest that MP selectively inhibits oligodendrocyte but not neuronal cell death via a receptor-mediated action and may be a mechanism for its limited protective effect after SCI.
Orexin Signaling Mediates the Antidepressant-Like Effect of Calorie Restriction
Authors: Lutter Michael , Krishnan Vaishnav , Russo Scott J. , Jung Saendy , McClung Colleen A. , Nestler Eric J.
Published: March 2008

During periods of reduced food availability, animals must respond with behavioral adaptations that promote survival. Despite the fact that many psychiatric syndromes include disordered eating patterns as a component of the illness, little is known about the neurobiology underlying behavioral changes induced by short-term calorie restriction. Presently, we demonstrate that 10 d of calorie restriction, corresponding to a 20–25% weight loss, causes a marked antidepressant-like response in two rodent models of depression and that this response is dependent on the hypothalamic neuropeptide orexin (hypocretin). Wild-type mice, but not mice lacking orexin, show longer latency to immobility and less total immobility in the forced swim test after calorie restriction. In the social defeat model of chronic stress, calorie restriction reverses the behavioral deficits seen in wild-type mice but not in orexin knock-out mice. Additionally, chronic social defeat stress induces a prolonged reduction in the expression of prepro-orexin mRNA via epigenetic modification of the orexin gene promoter, whereas calorie restriction enhances the activation of orexin cells after social defeat. Together, these data indicate that orexin plays an essential role in mediating reduced depression-like symptoms induced by calorie restriction.
Chagas disease as a mechanistic model for testing a novel hypothesis
Authors: Mosovich Serge A. , Mady Charles , Lopes Neuza , Ianni Barbara , Dias João Carlos Pinto , Correia Dalmo , Farkouh Michael E.
Published: March 2008

The association between depression and cardiovascular disease is well documented. Nevertheless, the process through which they are linked remains unknown, as does the direction of this relationship. Studies have suggested both that depression is a risk factor for heart disease and that heart disease is a risk factor for depression. A number of studies have established that a relationship exists between depression and inflammation, with alterations in the levels of inflammatory markers (IL-1, IL-6, TNF-alpha and others). Depressive symptoms have also been identified in many diseases characterized by inflammatory processes e.g. rheumatoid arthritis, bronchial asthma, diabetes, tuberculosis and cardiovascular diseases. In this brief viewpoint, we explain and propose how to use Chagas disease, a disorder characterized by inflammatory processes and leading to cardiovascular and autonomic problems, as a model for studying the directionality of the relationship between heart disease and depression.
Perfil epidemiológico do trauma de face dos pacientes atendidos no pronto socorro de um hospital público
Authors: Macedo Jefferson Lessa Soares de , Camargo Larissa Macedo de , Almeida Pedro Fragoso de , Rosa Simone Corrêa
Published: March 2008

OBJETIVO: Avaliar os dados epidemiológicos e a localização dos traumas de face de pacientes atendidos no Hospital Regional da Asa Norte (HRAN), Brasília, Distrito Federal. MÉTODO: Trata-se de um estudo retrospectivo, realizado no pronto socorro do HRAN-DF, visando avaliar o perfil epidemiológico dos pacientes atendidos pela equipe da Unidade de Cirurgia Plástica vítimas de trauma de face no período de 1 de janeiro a 31 dezembro de 2004. RESULTADOS: O estudo compreendeu 711 pacientes, destacando-se o sexo masculino (72,8%). Quanto à causa, predominou a agressão física, seguida por acidente com veículos/motos. As quedas foram a causa predominante das lesões em crianças, mas verificou-se a participação cada vez maior da agressão física como mecanismo de trauma facial com o aumento da idade. A relação de homem:mulher foi de 3:1. A faixa etária mais atingida foi de 21 a 30 anos, representando 35,3% dos pacientes. As fraturas foram encontradas em 24,9% das lesões faciais. O nariz foi o local mais acometido nas fraturas de face (76,8%). CONCLUSÃO: A violência interpessoal foi a principal causa de trauma de face. A queda da própria altura mostrou-se como importante mecanismo de trauma nos extremos de idade.
Embolização pré operatória de tumores renais com microparticulas esféricas de tecnologia nacional. (Spherus®-First line Brasil)
Authors: Espinosa Gaudencio , Miranda Luiz Carlos de , Matias Valentim Altino de Chantal , Fonseca Jose Luis Telles da , Chagas Vera Lucia Antunes , Rocha Fabrício Lazzarin Domingos
Published: March 2008

Os autores relatam pela primeira vez utilização de uma nova partícula para embolização, constituída de um núcleo de acetato de polivinil revestido por polivinil-álcool, de forma esférica (Spherus®-First Line Brasil), como preparo pré-operatório em três pacientes portadores de neoplasia renal, na intenção de diminuir o tamanho do tumor e prevenir complicações hemorrágicas durante o ato operatório. Estas novas partículas foram projetadas e elaboradas nos laboratórios da COPPE/UFRJ. A embolização intra-arterial pré-operatória com estas novas partículas ocasionou acentuada isquemia em todo o tecido tumoral facilitando o procedimento cirúrgico.
A matemática escolar, o aluno e o professor: paradoxos aparentes e polarizações em discussão
Authors: Santos Vinício de Macedo
Published: March 2008

Neste artigo são caracterizadas e discutidas questões que estão no centro das preocupações e ações do professor de matemática como concepções de conhecimento matemático, de ensino e aprendizagem, a relação entre conteúdo e metodologia de ensino, entre trabalho individual e coletivo etc. Essas questões têm marcado as atividades de formar professores e de ensinar matemática, assumindo um caráter de dualidades irreconciliáveis ou de paradoxos aparentes com implicações sobre o ensino e a aprendizagem. Considera-se reducionismo indesejável atribuir importância a um dos pólos, desqualificando o outro, ou adotar uma posição multipolar sem que se explicite e compreenda o problema epistemológico subjacente a possíveis antagonismos. Por em questão alguns dos mitos enraizados no nosso ideário de professores pode significar um exercício de reflexão que nos esclareça sobre dificuldades instauradas no ensino de matemática e indique meios para saná-las.
Histologic evaluation of rats' liver after Croton cajucara Benth (sacaca) administration
Authors: Graim Jair Francisco de Santana , Lopes Filho Gaspar de Jesus , Brito Marcus Vinicius Henriques , Matos Lia Tavares de Moura Brasil
Published: March 2008

PURPOSE: To evaluate the hepatic effect of Croton cajucara Benth (sacaca) herbal extract in rats. METHODS: 60 Wistar rats (Rattus novergicus albinus) were used, weighing between 250 and 350 g. The animals were distributed randomically in 2 groups: GS - animals which received daily 0,1 ml/ 100 g of sacaca herbal extract through gavage, and GA -animals which received daily 0,1 ml/100g of distilled water through gavage. These were distributed in 3 subgroups with 10 animals, according to theirs euthanasia dates, which were 14th, 28th and 56th day of treatment. RESULTS: Architectural alterations were not observed, however when it was analyzed the presence or absence of necrosis, it was observed in 50% of GS28 subgroup and 90% of subgroup. In 50% of the animals from GS28 subgroup and 90% of GS56 subgroup was observed vast degeneration areas and zonal necrosis, regarding center-lobular veins alterations, there were no alterations in any of the groups CONCLUSION: The Croton cajucara Benth (sacaca) herbal extract in this experiment caused degeneration and hepatic necrosis, suggesting dose-dependent action.
Hemodynamics alterations during orthotopic liver experimental transplantation in pigs
Authors: Torres Orlando Jorge Martins , Pantoja Patrícia Brandão , Barbosa Erica Sampaio , Barros Cristiany de Almeida , Servin Elizabeth Teixeira Noguera , Servin Santiago Cirilo Noguera
Published: March 2008

PURPOSE: To describe the hemodynamics alterations during orthotopic liver transplantation in pigs. METHODS: In the period from April 2004 to December 2005, forty-four female Landrace pigs, weighting between 32 and 38 Kg were undergone to orthotopic liver transplantation. The animals were divided into two groups, donor and recipient pairs, which received whole liver grafts. The surgical procedure was divided into four parts: harvested, back-table, hepatectomy of the recipient and implantation. We analyze heart rate, blood gas, mean systemic arterial pressure (MAP-mmHg), central venous pressure, pH, Na-, K+, Cl-, Ca+ and urinary output. RESULTS: The mean anhepatic time was 69 min, cold ischemia was 252.2 min and back-table was 56.6 min. Blood pressure and heart rate dropped significantly during anhepatic phase and after revascularization. Blood gas and electrolytes alterations were observed during anhepatic and reperfusion phases. Although alterations were noted during these phases, the hemodynamic status was recovered and stabilized in the end of the surgery. CONCLUSIONS: Simplified technique of liver transplant was achieved and description of hemodynamic alterations was possible in pigs.
The protective effect of methylene blue in lungs, small bowel and kidney after intestinal ischemia and reperfusion
Authors: Greca Fernando Hintz , Gonçalves Neuza Maria Ferraz de Mello , Souza Filho Zacarias Alves de , Noronha Lúcia de , Silva Ruy Fernando Kuenzer Caetano da , Rubin Michel Risnic
Published: March 2008

PURPOSE: To study the role of methylene blue as an inhibitor of superoxide production by xanthine oxidase. METHODS: Thirty-two Wistar rats were divided into 2 groups of 16 animals: the control group and the experimental group. All were submitted to a laparotomy for the occlusion of the cranial mesenteric artery during 60 minutes. The reperfusion was confirmed by the pulsation of the artery after the release of the temporary ligature and color change of the intestines. In the animals of the control group, 2 ml of saline were injected in the peritoneal cavity and in the animals of the experimental group, 2 ml of methylene blue were injected in the peritoneal cavity. After reperfusion for 4 hours, the animals were then sacrificed. The lungs were excised from all 32 rats. Simultaneously, the small intestine and kidneys were ressected in 20 animals (10 from the control group and 10 from the experimental group). Samples of the organs were taken to evaluate the action of xanthine-oxidase, for histopathology studies and for characterization of the edema. RESULTS: In the animals of the experimental group, the inflammatory lesion as well as the edema in the lung was greater than in the control group. The intestinal and renal lesions were similar in both groups, but the lung damage was superior to that observed in the intestines and kidneys. . CONCLUSION: Despite similar action of the xanthine oxidase in the control and the experimental group, after intestinal ischemia and reperfusion, the protective effect of methylene blue was observed only in the lungs of the experimental group.
Biomechanical evaluation of microbial cellulose (Zoogloea sp.) and expanded polytetrafluoroethylene membranes as implants in repair of produced abdominal wall defects in rats
Authors: Falcão Suyiene Cordeiro , Coelho Antônio Roberto de Barros , Evêncio Neto Joaquim
Published: March 2008

PURPOSE: To evaluate the Load of Rupture of implants of membranes of microbial cellulose (Zoogloea sp.) and extended polytetrafuoroethylene in sharp defects of abdominal wall of rats. METHODS: Sixty Wistar male rats, with a mean weight of 437,7g ± 40,9, anesthetized by a mixture of ketamine (5mg/100g) and xylazine (2mg/100g), were submitted to a rectangular (2x3cm) excision of the abdominal wall, including fascia, muscle and peritoneum, and treated with membranes of microbial cellulose (MC) (MC Group- 30 animals) or extended polytetrafluoroethylene (ePTFE) (ePTFE Group- 30 animals). Each group was subdivided in 14th POD, 28th POD and 60th POD Subgroups. Under anesthesia, animals were submitted to euthanasia at 14th POD, 28th POD and 60th POD for evaluation of Load of Rupture. RESULTS: Load of Rupture levels were significantly elevated (p<0, 05) among 14th, 28th and 60th postoperative days from each Group. When compared between groups, values of Load of Rupture were significantly larger (p<0, 05) in ePTFE Group than in MC Group. CONCLUSION: Resistance to strength at implant/host interface was more pronounced in PTFEe Group than in MC Group.
Agenda 21 nacional e indicadores de desenvolvimento sustentável: contexto brasileiro
Authors: Malheiros Tadeu Fabricio , Phlippi Jr. Arlindo , Coutinho Sonia Maria Viggiani
Published: March 2008

Respondendo às crescentes pressões da sociedade civil organizada para implementação de diretrizes estabelecidas nos instrumentos de comprometimento internacionais voltadas à promoção do desenvolvimento sustentável, estados nacionais vêm elaborando suas estratégias e planos de desenvolvimento sustentável. Esforços também vêm sendo dispensados na proposição de indicadores para acompanhar resultados e impactos na implementação de políticas. Em 2002, o Brasil aprovou sua Agenda 21, elaborada por meio de processo participativo, que é uma experiência significativa num contexto de grande diversidade social, ambiental e econômica, embora o Governo brasileiro não tenha ainda um sistema consolidado de monitoramento e avaliação da Agenda 21 brasileira. Seguindo orientação e incentivo da Comissão de Desenvolvimento Sustentável das Nações Unidas, o IBGE (Instituto Brasileiro de Geografia e Estatística) publicou em 2002 os Indicadores de Desenvolvimento Sustentável - Brasil 2002. Apesar de ambos os esforços terem se desenvolvido em momentos concomitantes e possuírem como foco a mesma temática - desenvolvimento sustentável do Brasil - a não priorização da integração desses processos gerou lacunas no conjunto de indicadores, enfraquecendo oportunidade de se criar condições para a avaliação e a revisão da implementação do plano nacional de desenvolvimento sustentável e das agendas 21 locais. Esse é o foco deste documento, ao apresentar uma análise integrada sobre a elaboração da Agenda 21 brasileira, entendida como um Plano Nacional Estratégico para o Desenvolvimento Sustentável, e a construção dos Indicadores de Desenvolvimento Sustentável do Brasil, propostos pelo IBGE, apresentando pontos positivos, avanços, oportunidades, lacunas e perspectivas.
Mãe, cuidadora e trabalhadora: as múltiplas identidades de mães que trabalham
Authors: Almeida Leila Sanches de
Published: March 2008

Nas últimas décadas, muitas mulheres da camada média brasileira assumiram simultaneamente os papéis de trabalhadora e mãe, funções habituais à maioria das mães trabalhadoras da camada popular. Este estudo, fundamentado na Rede de Significações, investigou os sentidos construídos sobre maternidade, cuidados infantis e trabalho por quatro trabalhadoras da camada média e seis grupos de mães trabalhadoras da camada popular. Foram realizadas entrevistas e grupos-focais. As mulheres atribuíram exclusivamente à mãe a função de educar e cuidar dos filhos. Elas encontram dificuldade em integrar os papéis de mãe e trabalhadora. O trabalho assume diferentes sentidos nas duas camadas sociais.
Dermatologia na pele negra
Authors: Alchorne Mauricio Mota de Avelar , Abreu Marilda Aparecida Milanez Morgado de
Published: March 2008

Este estudo aborda a dermatologia na pele negra. Inicialmente, discute os conceitos de raça e etnia, assim como os critérios de classificação da população brasileira, indicando as regiões em que a população negra se concentra. A seguir, faz breve explanação sobre os sistemas de classificação da cor da pele e descreve particularidades estruturais, biológicas e funcionais da epiderme, derme e anexos cutâneos que diferenciam as peles clara e escura. Posteriormente, mostra algumas alterações fisiológicas comumente observadas na pele, nas unhas e nas mucosas dos indivíduos negros. Aponta, também, alguns padrões de reações e modificações da cor das lesões, decorrentes da hiperpigmentação cutânea, que determinam aspectos inusitados às dermatoses, dificultando seu reconhecimento. Finalmente, destaca algumas doenças em especial, enfatizando particularidades inerentes ao padrão das lesões e à freqüência de algumas dermatoses na pele negra. Nesse contexto, a intenção foi fornecer dados para auxiliar o dermatologista a se familiarizar com as diferentes nuanças que as doenças podem adquirir na pele mais pigmentada.
Impacto na qualidade de vida em pacientes com hanseníase: correlação do Dermatology Life Quality Index com diversas variáveis relacionadas à doença
Authors: Martins Bruna Dacier Lobato , Torres Fernanda Nogueira , Oliveira Maria Leide Wand-Del-Rey de
Published: March 2008

FUNDAMENTOS: A hanseníase é doença infectocontagiosa crônica causada pelo Micobacterium leprae. Caracteriza-se por acometimento dermatoneurológico, variando em espectro entre dois pólos estáveis. Apesar de curável, ainda representa relevante problema de saúde pública, sendo o Brasil o segundo país mais endêmico do mundo. Sua maior morbidade associa-se aos estados reacionais e ao acometimento neural, podendo causar incapacidades físicas permanentes que comprometem significativamente a qualidade de vida dos pacientes, com auto-estigmatização e vergonha. OBJETIVO: Avaliar o grau de comprometimento da qualidade de vida nos pacientes com hanseníase. MÉTODOS: Estudo observacional com correlação entre variáveis clínicas de gravidade da doença e questionário de avaliação da qualidade de vida: Dermatology Life Quality Index. RESULTADOS: Dos 40 pacientes avaliados, a maioria apresentou comprometimento da qualidade de vida de grave a muito grave segundo score obtido no Dermatology Life Quality Index. As variáveis analisadas individualmente também mostraram correlação de gravidade com o número de pontos obtido. CONCLUSÃO: A hanseníase causa sofrimento que ultrapassa a dor e o mal-estar estritamente vinculados ao prejuízo físico, com grande impacto social e psicológico, justificando tanto avanços para abordagem multidisciplinar ao paciente quanto a necessidade de ações de saúde que visem ao controle da doença.
Síndrome dos cabelos impenteáveis (pili canaliculi): variabilidade clínica em 12 membros de uma família
Authors: Cunha Filho Roberto Rheingantz da , Almeida Jr Hiram Larangeira de , Rocha Nara Moreira , Castro Luis Antônio Suita de
Published: March 2008

Pili canaliculi é alteração capilar rara, geralmente herdada de forma autossômica dominante, caracterizada por cabelos arrepiados, pertencendo ao espectro dos cabelos impenteáveis. Poucos estudos encontram ou explicitam sua variabilidade clínica. Uma família com 12 indivíduos afetados foi estudada, e o acometimento do couro cabeludo demonstrou grande variabilidade, desde cabelos arrepiados, difíceis de pentear, hipotricose leve ou intensa, até atriquia adquirida. O exame de microscopia óptica de cortes transversais dos cabelos, a estereomicroscopia e a microscopia eletrônica de varredura confirmaram o diagnóstico, demonstrando canais na superfície dos cabelos.
Os efeitos dos aparelhos funcionais sobre a dimensão transversal da maxila e mandíbula
Authors: Araújo Adriano Marotta , Buschang Peter H.
Published: March 2008

Enquanto os efeitos dos aparelhos ortopédicos funcionais sobre as dimensões ântero-posterior e vertical vêm sendo amplamente estudados, o efeito sobre a dimensão transversal é um campo limitado e pouco explorado. A presença de escudos vestibulares, a pressão muscular, tração periostal e o reposicionamento lingual são alguns dos tópicos que podem influenciar o crescimento transversal da maxila e mandíbula. Vários estudos mostram uma alteração transversal dos arcos dentários, como resposta da terapia com o aparelho funcional. Baseado em uma revisão sistemática da literatura esse trabalho teve como objetivo: 1) avaliar os mecanismo de ação dos aparelhos e a influência sobre a dimensão transversal e 2) resumir os efeitos clínicos de diferentes aparelhos funcionais sobre a dimensão transversal.
Avaliação da angulação e inclinação dos elementos dentários em pacientes adultos jovens portadores de fissura transforame incisivo bilateral
Authors: Reis Andréia Caixeta , Capelozza Filho Leopoldino , Ozawa Terumi Okada , Cavassan Arlete de Oliveira
Published: March 2008

OBJETIVO: desse trabalho foi avaliar e mensurar o posicionamento dentário (angulação e inclinação) em pacientes com fissura transforame incisivo bilateral, no intuito de determinar características comuns a esses pacientes. METODOLOGIA: Para tanto, foram selecionados aleatoriamente, a partir do arquivo do Hospital de Reabilitação de Anomalias Craniofaciais da Universidade de São Paulo (HRAC-USP), trinta pares de modelos de gesso dos arcos dentários de pacientes operados, portadores deste tipo de fissura e em estágio de dentadura permanente, com idades entre 12 e 27 anos. Os modelos foram preparados e as medidas realizadas, baseando-se na metodologia proposta por Andrews¹. RESULTADOS: Os resultados obtidos foram: 1. Angulação - no arco superior, valores positivos (angulação positiva), com tendência crescente progressiva, de molares para caninos e para os incisivos, valores negativos (contra-angulação). No arco inferior, valores positivos decrescentes de molares para pré-molares e negativos em toda a região anterior; 2. Inclinação - valores negativos, correspondentes a inclinação palatina ou lingual, para todos os dentes da amostra. CONCLUSÕES: Conclui-se que os caninos e incisivos superiores foram os dentes mais afetados pela presença da fissura; o arco inferior manteve valores mais uniformes, devido à menor interferência da fissura; inclinações negativas em todo o arco inferior e apinhamentos anteriores freqüentes sugerem a compensação inferior à maxila atrésica.
Relação do zinco e cobre plasmáticos com componentes nutricionais e desempenho de leitões: uma meta-análise
Authors: Hauschild Luciano , Lovatto Paulo Alberto , Carvalho Amanda d'Ávila , Andretta Ines , Lehnen Cheila Roberta
Published: March 2008

Foi realizada uma meta-análise para estudar a relação do zinco (Zn) e cobre (Cu) plasmáticos com os nutrientes da dieta e ganho de peso em leitões. A base de dados contemplou 18 publicações. As variáveis nutricionais consideradas na análise foram ingestões de PB, lisina, Ca, P, Cu e Zn. Foram realizadas análises de regressão por intermédio de modelos mistos. O Zn plasmático foi influenciado pelo P, Zn ingeridos e Cu plasmático. O P ingerido e Cu plasmático afetaram negativamente o Zn plasmático. A análise de regressão mostrou que, para cada grama de P total ingerido/kg PV0,6, houve redução de 0,043 mg/L de Zn plasmático. O Cu plasmático foi influenciado pelo Ca, P, Cu e o Zn ingerido. O Ca e Zn ingerido afetaram negativamente o Cu plasmático. O ganho de peso foi influenciado pela PB, Ca, lisina e Cu ingeridos e o Zn plasmático. O Zn ingerido apresentou efeito negativo no metabolismo do Cu, mas o Zn plasmático teve influência positiva no ganho de peso. Neste estudo de meta-análise, identificaram-se alguns fatores de origem dietética, como o P e Ca, que influenciam negativamente a absorção e o metabolismo de Zn e Cu em leitões.