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Background: Charcoal-based preparations have recently gained popularity, particularly in oral hygiene products such as tooth whitening dentifrices, owing to their abrasive and adsorptive properties. The present in vitro study evaluates the efficacy of a charcoal-based tooth whitening dentifrice compared with a non-charcoal-based whitening dentifrice in removing coffee stains on tooth surfaces. Methods: Thirty-three human extracted tooth specimens were randomly assigned to 1 of 3 study groups: Group 1 (charcoal-based whitening dentifrice [CBWD]), Group 2 (non-charcoal-based whitening dentifrice [NCBWD]), and Group 3 (distilled water [DW]). All tooth specimens were immersed in a prepared coffee extract for 4 weeks to facilitate staining and then mounted on blocks where they were brushed with an electric toothbrush daily for 8 seconds with 1 of the 2 allocated dentifrices or with DW for 4 weeks following staining. Spectrophotometric analysis was conducted using the CIELAB system to measure the L*, a*, and b* values at 3 time points: before staining, after staining, and following the brushing protocol. These values were used to calculate the colour change (ΔE) between time points. Results: Following the coffee staining, the tooth samples' whiteness (ΔL) decreased with the overall colour change (ΔE). Next, there was a significant improvement in the degree of tooth whiteness (ΔL) values following the brushing protocol in all 3 groups (p = 0.003), with the greatest improvement occurring in the CBWD group. However, the overall colour change (ΔE) was not significantly different between the groups. Conclusion: CBWD, NCBWD, and DW were effective in removing coffee stains from the tooth surface. However, the amount of colour change (ΔE) produced by CBWD was not significantly different from NCBWD or DW.
Introduction: Les préparations à base de charbon ont récemment gagné en popularité, en particulier dans les produits d'hygiène buccale comme les dentifrices blanchissants, en raison de leurs propriétés d'abrasion et d'adsorption. La présente étude in vitro évalue l'efficacité d'un dentifrice blanchissant à base de charbon par rapport à un dentifrice blanchissant sans charbon pour éliminer les taches de café sur la surface des dents. Méthodes: Trente-trois spécimens de dents humaines extraites ont été répartis aléatoirement dans 3 groupes d'étude : groupe 1 (dentifrice blanchissant à base de charbon [DBBC]), groupe 2 (dentifrice blanchissant sans charbon [DSC]) et groupe 3 (eau distillée [ED]). Tous les spécimens de dents ont été immergés dans une préparation de café pendant 4 semaines pour permettre la coloration, puis montés sur des blocs où ils ont été brossés quotidiennement à la brosse à dents électrique pendant 8 secondes avec l'un des deux dentifrices testés ou avec de l'eau distillée pour une période de 4 semaines après la coloration. Une analyse spectrophotométrique a été effectuée à l'aide du système CIELAB pour mesurer les valeurs L*, a* et b* à 3 moments précis : avant la coloration, après la coloration et après le protocole de brossage. Ces valeurs ont été utilisées pour calculer le changement de couleur (ΔE) entre les moments précis. Résultats: Après la coloration du café, la blancheur des échantillons de dents (ΔL) a diminué en raison du changement global de couleur (ΔE). Ensuite, il y a eu une amélioration significative du degré de blancheur des dents (ΔL) suivant le protocole de brossage dans les 3 groupes (p = 0,003), la plus grande amélioration ayant eu lieu dans le groupe DBBC. Toutefois, le changement global de couleur (ΔE) n'était pas significativement différent d'un groupe à l'autre. Conclusion: Les DBBC, DSC et l'ED se sont montrés efficaces pour éliminer les taches de café sur la surface des dents. Toutefois, le changement de couleur (ΔE) produit par le DBBC n'était pas significativement différent de celui produit par le DSC ou l'ED.
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Dentifrícios , Clareamento Dental , Descoloração de Dente , Humanos , Carvão Vegetal/uso terapêutico , Corantes , Dentifrícios/uso terapêutico , Dióxido de Silício , Fluoreto de Sódio , Coloração e Rotulagem , Clareamento Dental/métodos , Descoloração de Dente/tratamento farmacológico , Café/efeitos adversosRESUMO
It has been argued that the dopaminergic system is involved in the attribution of motivational value to reward predictive cues as well as prediction error. To evaluate, dopamine neurons were recorded from male rats performing a Pavlovian approach task containing cues that have both "predictive" and "incentive" properties. All animals learned the predictive nature of the cue (illuminated lever entry into cage), but some also found the cue to be attractive and were motivated toward it ("sign-trackers," STs). "Goal-trackers" (GTs) predominantly approached the location of reward receptacle. Rats were implanted with tetrodes for neural electrophysiological recordings in the ventral tegmental area. Cells were characterized by spike waveform shape and firing rate. Firing rates and magnitudes of responses in relation to Pavlovian behaviors, cue presentation, and reward delivery were assessed. We identified 103 dopamine and 141 nondopamine neurons. GTs and STs both showed responses to the initial lever presentation (CS1) and lever retraction (CS2). However, higher firing rates were sustained during the lever interaction period only in STs. Further, dopamine cells of STs showed a significantly higher proportion of cells responding to both CS1 and CS2. These are the first results to show that neurons from the VTA encode both predictive and incentive cues, support an important role for dopamine neurons in the attribution of incentive salience to reward-paired cues, and underscore the consequences of potential differences in motivational behavior between individuals.SIGNIFICANCE STATEMENT This project serves to determine whether dopamine neurons encode differences in cued approach behaviors and incentive salience. How neurons of the VTA affect signaling through the NAcc and subsequent dopamine release is still not well known. All cues that precede a reward are predictive in nature. Some, however, also have incentive value, in that they elicit approach toward them. We quantified the attribution of incentive salience through cue approach behavior and cue interaction, and the corresponding magnitude of VTA neural firing. We found dopamine neurons of the VTA encode strength of incentive salience of reward cues. This suggests that dopamine neurons specifically in the VTA encode motivation.
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Sinais (Psicologia) , Motivação/fisiologia , Neurônios/fisiologia , Recompensa , Área Tegmentar Ventral/fisiologia , Animais , Comportamento Animal/fisiologia , Condicionamento Clássico/fisiologia , Neurônios Dopaminérgicos/fisiologia , Eletrodos Implantados , Fenômenos Eletrofisiológicos , Individualidade , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
Background: Unstable intra-articular proximal interphalangeal (PIP) joint fracture-dislocations present a difficult problem that requires congruous joint reduction and stable internal fixation or distraction. Though fractures with limited articular involvement may be treated successfully with less invasive procedures, fracture-dislocations with a volar shear component may benefit from joint reduction with subchondral support for maintenance of stability. The purpose of this article is to describe a volar transverse plate and screw technique and report the short-term postoperative results. Methods: Seventeen patients with volar shear PIP dorsal fracture-dislocations were treated with transverse plate and screw constructs at an average of 21 days (range, 2-52) after injury. Information on postoperative stability, range of motion at PIP and distal interphalangeal (DIP) joints, and radiographic outcomes and complications were retrospectively collected. Results: At a mean of 7.3 months post-operation (range, 1.5-24), there were no recurrent dislocations and an average PIP arc of 77.4° and DIP arc of 61.5°. Sixteen of 17 patients had radiographically concentric joints, with 1 patient showing slight radiographic dorsal subluxation not apparent clinically. Two of 17 patients (11.8%) had revision surgery for tenolysis and removal of hardware to improve range of motion at 4 and 9 months post-operation. Conclusions: In the setting of PIP dorsal fracture-dislocations with volar shear component >40% of the articular surface, the Seatbelt procedure allows for concentric joint and articular surface reduction with subchondral support for maintenance of stability. This volar transverse plating technique allows for highly functional range of motion without PIP dorsal subluxation clinically in the setting of comminution and delayed presentation.
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Traumatismos dos Dedos , Luxações Articulares , Adulto , Feminino , Traumatismos dos Dedos/diagnóstico por imagem , Traumatismos dos Dedos/cirurgia , Articulações dos Dedos/diagnóstico por imagem , Articulações dos Dedos/cirurgia , Fixação Interna de Fraturas , Humanos , Luxações Articulares/diagnóstico por imagem , Luxações Articulares/cirurgia , Masculino , Estudos RetrospectivosRESUMO
Some rats are especially prone to attribute incentive salience to a cue (conditioned stimulus, CS) paired with food reward (sign-trackers, STs), but the extent they do so varies as a function of the form of the CS. Other rats respond primarily to the predictive value of a cue (goal-trackers, GTs), regardless of its form. Sign-tracking is associated with greater cue-induced activation of mesolimbic structures than goal-tracking; however, it is unclear how the form of the CS itself influences activity in neural systems involved in incentive salience attribution. Thus, our goal was to determine how different cue modalities affect neural activity in the ventral pallidum (VP), which is known to encode incentive salience attribution, as rats performed a two-CS Pavlovian conditioned approach task in which both a lever-CS and a tone-CS predicted identical food reward. The lever-CS elicited sign-tracking in some rats (STs) and goal-tracking in others (GTs), whereas the tone-CS elicited only goal-tracking in all rats. The lever-CS elicited robust changes in neural activity (sustained tonic increases or decreases in firing) throughout the VP in STs, relative to GTs. These changes were not seen when STs were exposed to the tone-CS, and in GTs there were no differences in firing between the lever-CS and tone-CS. We conclude that neural activity throughout the VP encodes incentive signals and is especially responsive when a cue is of a form that promotes the attribution of incentive salience to it, especially in predisposed individuals.
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Prosencéfalo Basal/fisiologia , Condicionamento Clássico/fisiologia , Sinais (Psicologia) , Motivação/fisiologia , Recompensa , Animais , Comportamento Animal/fisiologia , Eletroencefalografia , Objetivos , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND: Accurate electrode placement is critical to the success of deep brain stimulation (DBS) surgery. Suboptimal targeting may arise from poor initial target localization, frame-based targeting error, or intraoperative brain shift. These uncertainties can make DBS surgery challenging. OBJECTIVE: To develop a computerized system to guide subthalamic nucleus (STN) DBS electrode localization and to estimate the trajectory of intraoperative microelectrode recording (MER) on magnetic resonance (MR) images algorithmically during DBS surgery. METHODS: Our method is based upon the relationship between the high-frequency band (HFB; 500-2000 Hz) signal from MER and voxel intensity on MR images. The HFB profile along an MER trajectory recorded during surgery is compared to voxel intensity profiles along many potential trajectories in the region of the surgically planned trajectory. From these comparisons of HFB recordings and potential trajectories, an estimate of the MER trajectory is calculated. This calculated trajectory is then compared to actual trajectory, as estimated by postoperative high-resolution computed tomography. RESULTS: We compared 20 planned, calculated, and actual trajectories in 13 patients who underwent STN DBS surgery. Targeting errors for our calculated trajectories (2.33 mm ± 0.2 mm) were significantly less than errors for surgically planned trajectories (2.83 mm ± 0.2 mm; P = .01), improving targeting prediction in 70% of individual cases (14/20). Moreover, in 4 of 4 initial MER trajectories that missed the STN, our method correctly indicated the required direction of targeting adjustment for the DBS lead to intersect the STN. CONCLUSION: A computer-based algorithm simultaneously utilizing MER and MR information potentially eases electrode localization during STN DBS surgery.
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Mapeamento Encefálico/métodos , Estimulação Encefálica Profunda/métodos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Núcleo Subtalâmico/diagnóstico por imagem , Idoso , Algoritmos , Mapeamento Encefálico/instrumentação , Eletrodos Implantados , Feminino , Humanos , Imageamento por Ressonância Magnética/instrumentação , Masculino , Microeletrodos , Pessoa de Meia-Idade , Núcleo Subtalâmico/fisiopatologiaRESUMO
HYPOTHESIS AND BACKGROUND: The classification and treatment of acromioclavicular (AC) joint dislocations remain controversial. The purpose of this study was to determine the interobserver and intraobserver reliability of the Rockwood classification system. We hypothesized poor interobserver and intraobserver reliability, limiting the role of the Rockwood classification system in determining severity of AC joint dislocations and accurately guiding treatment decisions. METHODS: We identified 200 patients with AC joint injuries using the International Classification of Diseases, Ninth Revision code 831.04. Fifty patients met inclusion criteria. Deidentified radiographs were compiled and presented to 6 fellowship-trained upper extremity orthopedic surgeons. The surgeons classified each patient into 1 of the 6 classification types described by Rockwood. A second review was performed several months later by 2 surgeons. A κ value was calculated to determine the interobserver and intraobserver reliability. RESULTS: The interobserver and intraobserver κ values were fair (κ = 0.278) and moderate (κ = 0.468), respectively. Interobserver results showed that 4 of the 50 radiographic images had a unanimous classification. Intraobserver results for the 2 surgeons showed that 18 of the 50 images were rated the same on second review by the first surgeon and 38 of the 50 images were rated the same on second review by the second surgeon. CONCLUSION: We found that the Rockwood classification system has limited interobserver and intraobserver reliability. We believe that unreliable classification may account for some of the inconsistent treatment outcomes among patients with similarly classified injuries. We suggest that a better classification system is needed to use radiographic imaging for diagnosis and treatment of AC joint dislocations.
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Articulação Acromioclavicular/lesões , Radiografia/métodos , Luxação do Ombro/classificação , Articulação Acromioclavicular/diagnóstico por imagem , Feminino , Humanos , Masculino , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Luxação do Ombro/diagnóstico por imagemRESUMO
BACKGROUND: Percutaneous techniques have been described for the treatment of nondisplaced scaphoid fractures, although less information has been reported about outcomes for unstable, displaced fractures. The aim of this study was to evaluate the union and complication rates following manual closed reduction and percutaneous screw placement for a consecutive series of unstable, displaced scaphoid fractures. METHODS: A total of 28 patients (average age, 27 years; 22 male/6 female) were treated for isolated unstable displaced scaphoid waist fractures. Closed reduction and percutaneous headless, compression screw fixation was successfully performed in 14 patients (average age, 32 years; 10 male/4 female), and the remaining 14 patients required open reduction. Patients who underwent percutaneous treatment were followed for radiographic fracture union and clinical outcomes. RESULTS: Thirteen of 14 fractures (93%) had clinical and radiographic evidence of bone union at an average of 2.8 months postoperatively. Average visual analog pain score at the time of union was 0.9. The average Quick Disability of the Arm, Shoulder, and Hand score at 2.5 years follow-up (range, 1.5-8.3 years) was 9.6 (range, 0.0-27.3). Complications included 1 case of nonunion and 1 case of intraoperative Kirschner wire breakage. CONCLUSIONS: Manual closed reduction followed by percutaneous headless, compression screw fixation was possible in 50% of patients who presented with acute unstable, displaced scaphoid fractures. This technique appears to be a safe and effective method when a manual reduction is possible, and it may offer a less invasive option when compared with a standard open technique.
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Parafusos Ósseos , Redução Fechada/métodos , Fixação Interna de Fraturas , Consolidação da Fratura , Fraturas Ósseas/cirurgia , Osso Escafoide/cirurgia , Adulto , Avaliação da Deficiência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Redução Aberta , Estudos Retrospectivos , Osso Escafoide/lesões , Escala Visual Analógica , Adulto JovemRESUMO
This paper explores the challenges of resolving conflicting feelings around talking with a child about their terminal prognosis. When children are left out of such conversations it is usually done with good intent, with a parent wishing to protect their child from anxiety or loss of hope. There is however growing evidence that sensitive, timely, age appropriate information from those with whom children have a good relationship is helpful both for the child and their family. There is no evidence that involving children in sensitive and timely discussions creates significant problems, rather that withholding information may lead to confusion, frustration, distress and anger. The authors discuss ways in which families can be supported to have these significant conversations with their children.
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Atitude Frente a Morte , Comunicação , Cuidados Paliativos/psicologia , Relações Pais-Filho , Pais/psicologia , Doente Terminal/psicologia , Revelação da Verdade , Adolescente , Criança , Feminino , Humanos , MasculinoRESUMO
PURPOSE: Among patients who undergo surgical treatment of terrible triad elbow injuries (TTEI), we hypothesized that those who received perioperative glucocorticoid (GC) therapy would have improved postoperative pain and range of motion (ROM) and a similar complication rate compared with patients who did not receive GC therapy. METHODS: We retrospectively identified 26 patients who underwent surgical treatment of TTEI from 2009 to 2015. Thirteen patients received a single intraoperative dose of 10 mg intravenous dexamethasone followed with a 6-day oral methylprednisolone taper course (GC group), and 13 did not (control group). After surgery, patients were placed in an orthosis at 90° flexion with the forearm in pronation for 2 weeks, after which ROM was initiated. Patients were seen in clinic at 2, 6, 12, and 24 weeks after surgery, at which time numeric pain scale scores and ROM data were collected and any complications were noted. RESULTS: Compared with the control group, the GC group had a greater flexion-extension arc of motion at 24 weeks (132.5° vs 105.5°); significant differences were not found at earlier time points. Supination measurements were significantly greater for the GC group at every time point with a difference at final follow-up of 23.2° (61.0° vs. 84.2°). There were 5 complications in the control group (35.8%), 3 of which required additional surgery, and 3 complications in the GC group (23.1%), 1 of which required another surgery. No postoperative infections were found in either group. CONCLUSIONS: Perioperative glucocorticoid administration is associated with improved ROM after surgical treatment of TTEI. Flexion-extension, pronosupination arc of motion, and overall supination were significantly improved. Postoperative pain scores and complication rates were similar between GC and control groups. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.
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Dexametasona/administração & dosagem , Articulação do Cotovelo/cirurgia , Glucocorticoides/administração & dosagem , Luxações Articulares/cirurgia , Metilprednisolona/administração & dosagem , Fraturas do Rádio/cirurgia , Amplitude de Movimento Articular/efeitos dos fármacos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Estudos Retrospectivos , Resultado do Tratamento , Lesões no CotoveloRESUMO
Continental shelf sediments are globally important for biogeochemical activity. Quantification of shelf-scale stocks and fluxes of carbon and nutrients requires the extrapolation of observations made at limited points in space and time. The procedure for selecting exemplar sites to form the basis of this up-scaling is discussed in relation to a UK-funded research programme investigating biogeochemistry in shelf seas. A three-step selection process is proposed in which (1) a target area representative of UK shelf sediment heterogeneity is selected, (2) the target area is assessed for spatial heterogeneity in sediment and habitat type, bed and water column structure and hydrodynamic forcing, and (3) study sites are selected within this target area encompassing the range of spatial heterogeneity required to address key scientific questions regarding shelf scale biogeochemistry, and minimise confounding variables. This led to the selection of four sites within the Celtic Sea that are significantly different in terms of their sediment, bed structure, and macrofaunal, meiofaunal and microbial community structures and diversity, but have minimal variations in water depth, tidal and wave magnitudes and directions, temperature and salinity. They form the basis of a research cruise programme of observation, sampling and experimentation encompassing the spring bloom cycle. Typical variation in key biogeochemical, sediment, biological and hydrodynamic parameters over a pre to post bloom period are presented, with a discussion of anthropogenic influences in the region. This methodology ensures the best likelihood of site-specific work being useful for up-scaling activities, increasing our understanding of benthic biogeochemistry at the UK-shelf scale.
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Results from a 1D setup of the European Regional Seas Ecosystem Model (ERSEM) biogeochemical model were compared with new observations collected under the UK Shelf Seas Biogeochemistry (SSB) programme to assess model performance and clarify elements of shelf-sea benthic biogeochemistry and carbon cycling. Observations from two contrasting sites (muddy and sandy) in the Celtic Sea in otherwise comparable hydrographic conditions were considered, with the focus on the benthic system. A standard model parameterisation with site-specific light and nutrient adjustments was used, along with modifications to the within-seabed diffusivity to accommodate the modelling of permeable (sandy) sediments. Differences between modelled and observed quantities of organic carbon in the bed were interpreted to suggest that a large part (>90%) of the observed benthic organic carbon is biologically relatively inactive. Evidence on the rate at which this inactive fraction is produced will constitute important information to quantify offshore carbon sequestration. Total oxygen uptake and oxic layer depths were within the range of the measured values. Modelled depth average pore water concentrations of ammonium, phosphate and silicate were typically 5-20% of observed values at the muddy site due to an underestimate of concentrations associated with the deeper sediment layers. Model agreement for these nutrients was better at the sandy site, which had lower pore water concentrations, especially deeper in the sediment. Comparison of pore water nitrate with observations had added uncertainty, as the results from process studies at the sites indicated the dominance of the anammox pathway for nitrogen removal; a pathway that is not included in the model. Macrofaunal biomasses were overestimated, although a model run with increased macrofaunal background mortality rates decreased macrofaunal biomass and improved agreement with observations. The decrease in macrofaunal biomass was compensated by an increase in meiofaunal biomass such that total oxygen demand remained within the observed range. The permeable sediment modification reproduced some of the observed behaviour of oxygen penetration depth at the sandy site. It is suggested that future development in ERSEM benthic modelling should focus on: (1) mixing and degradation rates of benthic organic matter, (2) validation of benthic faunal biomass against large scale spatial datasets, (3) incorporation of anammox in the benthic nitrogen cycle, and (4) further developments to represent permeable sediment processes.
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We investigated the potential of deep brain stimulation (DBS) in the central nucleus of the amygdala (CeA) in rats to modulate functional reward mechanisms. The CeA is the major output of the amygdala with direct connections to the hypothalamus and gustatory brainstem, and indirect connections with the nucleus accumbens. Further, the CeA has been shown to be involved in learning, emotional integration, reward processing, and regulation of feeding. We hypothesized that DBS, which is used to treat movement disorders and other brain dysfunctions, might block reward motivation. In rats performing a lever-pressing task to obtain sugar pellet rewards, we stimulated the CeA and control structures, and compared stimulation parameters. During CeA stimulation, animals stopped working for rewards and rejected freely available rewards. Taste reactivity testing during DBS exposed aversive reactions to normally liked sucrose tastes and even more aversive taste reactions to normally disliked quinine tastes. Interestingly, given the opportunity, animals implanted in the CeA would self-stimulate with 500 ms trains of stimulation at the same frequency and current parameters as continuous stimulation that would stop reward acquisition. Neural recordings during DBS showed that CeA neurons were still active and uncovered inhibitory-excitatory patterns after each stimulus pulse indicating possible entrainment of the neural firing with DBS. In summary, DBS modulation of CeA may effectively usurp normal neural activity patterns to create an 'information lesion' that not only decreased motivational 'wanting' of food rewards, but also blocked 'liking' of rewards.
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Comportamento Animal/fisiologia , Núcleo Central da Amígdala/fisiologia , Estimulação Encefálica Profunda , Preferências Alimentares/fisiologia , Motivação/fisiologia , Recompensa , Animais , Comportamento Alimentar/fisiologia , Alimentos , Masculino , Núcleo Accumbens/fisiologia , Ratos Sprague-DawleyRESUMO
UNLABELLED: There is considerable individual variation in the extent to which reward cues are attributed with incentive salience. For example, a food-predictive conditioned stimulus (CS; an illuminated lever) becomes attractive, eliciting approach toward it only in some rats ("sign trackers," STs), whereas others ("goal trackers," GTs) approach the food cup during the CS period. The purpose of this study was to determine how individual differences in Pavlovian approach responses are represented in neural firing patterns in the major output structure of the mesolimbic system, the ventral pallidum (VP). Single-unit in vivo electrophysiology was used to record neural activity in the caudal VP during the performance of ST and GT conditioned responses. All rats showed neural responses to both cue onset and reward delivery but, during the CS period, STs showed greater neural activity than GTs both in terms of the percentage of responsive neurons and the magnitude of the change in neural activity. Furthermore, neural activity was positively correlated with the degree of attraction to the cue. Given that the CS had equal predictive value in STs and GTs, we conclude that neural activity in the VP largely reflects the degree to which the CS was attributed with incentive salience. SIGNIFICANCE STATEMENT: Cues associated with reward can acquire motivational properties (i.e., incentive salience) that cause them to have a powerful influence on desire and motivated behavior. There are individual differences in sensitivity to reward-paired cues, with some individuals attaching greater motivational value to cues than others. Here, we investigated the neural activity associated with these individual differences in incentive salience. We found that cue-evoked neural firing in the ventral pallidum (VP) reflected the strength of incentive motivation, with the greatest neural responses occurring in individuals that demonstrated the strongest attraction to the cue. This suggests that the VP plays an important role in the process by which cues gain control over motivation and behavior.
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Prosencéfalo Basal/fisiologia , Sinais (Psicologia) , Motivação/fisiologia , Rede Nervosa/fisiologia , Plasticidade Neuronal/fisiologia , Recompensa , Potenciais de Ação/fisiologia , Animais , Atenção/fisiologia , Individualidade , Masculino , Ratos , Análise e Desempenho de TarefasRESUMO
The hedonic value of a sweet food reward, or how much a taste is 'liked', has been suggested to be encoded by neuronal firing in the posterior ventral pallidum (VP). Hedonic impact can be altered by psychological manipulations, such as taste aversion conditioning, which can make an initially pleasant sweet taste become perceived as disgusting. Pairing nausea-inducing LiCl injection as a Pavlovian unconditioned stimulus (UCS) with a novel taste that is normally palatable as the predictive conditioned stimulus (CS+) suffices to induce a learned taste aversion that changes orofacial 'liking' responses to that sweet taste (e.g., lateral tongue protrusions) to 'disgust' reactions (e.g., gapes) in rats. We used two different sweet tastes of similar initial palatability (a sucrose solution and a polycose/saccharin solution, CS ± assignment was counterbalanced across groups) to produce a discriminative conditioned aversion. Only one of those tastes (arbitrarily assigned and designated as CS+) was associatively paired with LiCl injections as UCS to form a conditioned aversion. The other taste (CS-) was paired with mere vehicle injections to remain relatively palatable as a control sweet taste. We recorded the neural activity in VP in response to each taste, before and after aversion training. We found that the safe and positively hedonic taste always elicited excitatory increases in firing rate of VP neurons. By contrast, aversion learning reversed the VP response to the 'disgusting' CS+ taste from initial excitation into a conditioned decrease in neuronal firing rate after training. Such neuronal coding of hedonic impact by VP circuitry may contribute both to normal pleasure and disgust, and disruptions of VP coding could result in affective disorders, addictions and eating disorders.
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Aprendizagem por Associação/fisiologia , Aprendizagem da Esquiva/fisiologia , Prosencéfalo Basal/fisiologia , Condicionamento Clássico/fisiologia , Neurônios/fisiologia , Percepção Gustatória/fisiologia , Potenciais de Ação/fisiologia , Animais , Cateteres de Demora , Sacarose Alimentar/administração & dosagem , Eletrodos Implantados , Glucanos/administração & dosagem , Cloreto de Lítio , Masculino , Atividade Motora , Náusea , Ratos Sprague-Dawley , Recompensa , Sacarina/administração & dosagemRESUMO
BACKGROUND: Informed consent is required for both standard cancer treatments and experimental cancer treatments in a clinical trial. Effective and sensitive physician-patient communication about informed consent is difficult to achieve. Our aim was to train doctors in clear, collaborative and ethical communication about informed consent and evaluate the impact of training on doctor behaviour, stress and satisfaction. PARTICIPANTS AND METHODS: Participants were 21 oncologists from 10 Australian/New Zealand (ANZ) centres and 41 oncologists from 10 Swiss/German/Austrian (SGA) centres. Oncologists were randomized to participate in a 1-day workshop or not. Patients were recruited before and after the training. Doctors were asked to submit 1-2 audiotaped consultations before and after training. Doctors completed outcome measures before and after completing the post-training cohort recruitment. RESULTS: Ninety-five consultation interactions were audiotaped. Doctors strongly endorsed the training. ANZ intervention doctors demonstrated a significant increase in collaborative communication (P = 0.03). There was no effect of training on other doctor behaviours. Trained doctors did not demonstrate reduced stress and burnout. Patient outcomes are presented elsewhere. CONCLUSIONS: Training can improve some aspects of the process of obtaining informed consent. Methods to increase the impact of training are required and may include longer training and more intensive follow-up.
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Participação do Paciente , Seleção de Pacientes , Relações Médico-Paciente , Neoplasias da Mama/terapia , Competência Clínica , Comunicação , Educação , Educação Médica Continuada , Feminino , Humanos , Consentimento Livre e Esclarecido/psicologia , Masculino , Pessoa de Meia-Idade , Encaminhamento e Consulta , Gravação em FitaRESUMO
PURPOSE: To evaluate union and complication rates associated with the use of 2 headless compression screws and bone grafting for the treatment of scaphoid nonunions. METHODS: A total of 19 patients (18 male and 1 female) at an average age of 21 years were treated with open reduction and internal fixation with 2 cannulated, headless, compression screws for scaphoid nonunions. Bone grafting techniques included corticocancellous autograft from the iliac crest in 14 patients, capsular-based vascularized distal radius graft in 3, and medial femoral condyle free vascularized bone graft in 2. Patients were treated an average 19 months after the injury. Fracture nonunions were at the waist (n = 12), proximal third (n = 5), or distal third (n = 2) of the scaphoid. Dorsal (n = 7) and volar (n = 12) surgical approaches were used. RESULTS: All fractures had clinical and radiographic evidence of bone union at an average of 3.6 months. Postoperative computed tomography scans were available in 13 patients and showed union without evidence of screw penetration of the scaphoid cortex. No complications occurred in this series, and no revision procedures have been necessary. CONCLUSIONS: Our results indicate that the use of 2 headless compression screws for the treatment of scaphoid nonunions is safe and effective. A variety of bone grafting techniques can be used with this technique. The use of 2 compression screws may provide superior biomechanical stability and ultimately improve outcomes measured with future long-term comparative studies. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.
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Parafusos Ósseos , Transplante Ósseo/métodos , Fixação Interna de Fraturas/instrumentação , Fraturas não Consolidadas/cirurgia , Osso Escafoide/lesões , Osso Escafoide/cirurgia , Adulto , Artroscopia/métodos , Estudos de Coortes , Terapia Combinada/métodos , Desenho de Equipamento , Feminino , Seguimentos , Fixação Interna de Fraturas/métodos , Consolidação da Fratura/fisiologia , Fraturas não Consolidadas/diagnóstico por imagem , Humanos , Escala de Gravidade do Ferimento , Masculino , Medição da Dor , Estudos Retrospectivos , Medição de Risco , Osso Escafoide/diagnóstico por imagem , Fatores de Tempo , Tomografia Computadorizada por Raios X/métodos , Resultado do Tratamento , Adulto JovemRESUMO
Anhedonia, or the inability to experience positive feelings is a hallmark of depression. However, few animal models have relied on decreased positive affect as an index of susceptibility to depression. Rats emit frequency-modulated ultrasonic vocalizations (USVs), designated as "positive" calls in the 50-kHz range. USVs have been associated with pharmacological activation of motivational reward circuits. Here we utilized selectively-bred rats differing in "emotionality" to ask whether there are associated differences in USVs. Rats bred based on locomotor response to novelty and classified as bred High Responders (bHRs) or bred Low Responders (bLRs) exhibit inborn differences in response to environmental cues, stress responsiveness, and depression-like behavior. These animals also exhibit differences in anxiety-like behavior, which are reversed by exposure to environmental complexity (EC). Finally, these animals exhibit unique profiles of responsiveness to rewarding stimuli accompanied with distinct patterns of dopamine regulation. We investigated whether acute and chronic environmental manipulations impacted USVs in bHRs and bLRs. We found that, relative to bLRs, bHRs emitted significantly more 50-kHz USVs. However, if a bLR is accompanied by another bLR, there is a significant increase in 50-kHZ USVs emitted by this phenotype. bHRs emitted increases in 50-kHZ UVSs upon first exposure to EC, whereas bLRs showed a similar increase only after repeated exposure. bLRs' increase in positive affect after chronic EC was coupled with significant positive correlations between corticosterone levels and c-fos mRNA in the accumbens. Conversely, a decline in the rate of positive calls in bHRs after chronic EC was associated with a negative correlation between corticosterone and accumbens c-fos mRNA. These studies demonstrate that inborn differences in emotionality interact with the environment to influence positive affect and underscore the potential interaction between glucocorticoids and the mesolimbic reward circuitry in modulating 50-kHz calls.
Assuntos
Afeto , Depressão/psicologia , Modelos Animais de Doenças , Meio Ambiente , Individualidade , Estresse Psicológico/metabolismo , Animais , Ansiedade/psicologia , Comportamento Animal , Corticosterona/metabolismo , Depressão/metabolismo , Comportamento Exploratório , Genes fos/genética , Locomoção , Masculino , Núcleo Accumbens/metabolismo , RNA Mensageiro , Ratos , Ratos Sprague-Dawley , Recompensa , Estresse Psicológico/psicologia , UltrassomRESUMO
BACKGROUND: Despite advances in the treatment of childhood cancer, some children continue to die from their disease. This study aimed to assess the impact of specialist paediatric palliative care services (SPPCSs) on the number of hospital admissions in children who subsequently died from cancer in Yorkshire, UK. METHODS: An extract of patients aged 0-19 years from the Yorkshire Specialist Register of Cancer in Children and Young People (YSRCCYP) diagnosed from 1990 to 2009 were linked to inpatient hospital episodes data and a SPPCS database. Deaths were included if they occurred before 31 August 2011. Differences in hospital admission patterns were assessed using negative binomial regression and presented as incidence rate ratios (IRRs). RESULTS: Of 2508 children on the YSRCCYP, 657 (26%) had died by the censoring date. A total of 211 children had been referred to the local SPPCS, of whom 182 (86%) had subsequently died. Referral to SPPCS was associated with a significant reduction in the rate of planned hospital admissions (IRR=0.60, 95% CI 0.43-0.85). Central nervous system tumours showed significant decreases for all planned and emergency admissions compared with all other diagnostic groups. CONCLUSION: Referral to SPPCS significantly reduced the number of planned hospital admissions for children and young people with cancer before their death, which are often integral to paediatric oncology treatment regimens. Overall, our findings show that SPPCS have a role in reducing hospital admissions during end of life care of paediatric cancer patients with potential personal, social and economic benefits.
Assuntos
Hospitalização/estatística & dados numéricos , Neoplasias/terapia , Cuidados Paliativos , Admissão do Paciente/estatística & dados numéricos , Encaminhamento e Consulta , Especialização/estatística & dados numéricos , Assistência Terminal , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Masculino , Prognóstico , Adulto JovemRESUMO
Data from preclinical and clinical studies have implicated the norepinephrine system in the development and maintenance of post-traumatic stress disorder. The primary source of norepinephrine in the forebrain is the locus coeruleus (LC); however, LC activity cannot be directly measured in humans, and previous research has often relied upon peripheral measures of norepinephrine to infer changes in central LC-norepinephrine function. To directly assess LC-norepinephrine function, we measured single-unit activity of LC neurons in a validated rat model of post-traumatic stress disorder - single prolonged stress (SPS). We also examined tyrosine hydroxylase mRNA levels in the LC of SPS and control rats as an index of norepinephrine utilisation. For electrophysiological recordings, 92 LC neurons were identified from 19 rats (SPS, 12; control, 7), and spontaneous and evoked responses to a noxious event (paw compression) were recorded. Baseline and restraint stress-evoked tyrosine hydroxylase mRNA expression levels were measured in SPS and control rats (n = 16 per group) in a separate experiment. SPS rats showed lower spontaneous activity but higher evoked responses, leading to an enhanced signal-to-noise ratio of LC neurons, accompanied by impaired recovery from post-stimulus inhibition. In concert, tyrosine hydroxylase mRNA expression in the LC of SPS rats tended to be lower at baseline, but was exaggerated following restraint stress. These data demonstrate persistent changes in LC function following stress/trauma in a rat model of post-traumatic stress, as measured by differences in both the electrophysiological properties of LC neurons and tyrosine hydroxylase mRNA transcription.
Assuntos
Locus Cerúleo/metabolismo , Norepinefrina/metabolismo , Estresse Psicológico/fisiopatologia , Potenciais de Ação , Animais , Locus Cerúleo/citologia , Locus Cerúleo/fisiopatologia , Masculino , Inibição Neural , Neurônios/metabolismo , Neurônios/fisiologia , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Restrição Física , Transtornos de Estresse Pós-Traumáticos/metabolismo , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Estresse Psicológico/metabolismo , Transcrição Gênica , Tirosina 3-Mono-Oxigenase/genética , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
PURPOSE: Children undergoing chemotherapeutic treatment of malignancies have up to a 9 % incidence of osteonecrosis. The purpose of this article is to determine the time from initiation of chemotherapy to the onset of symptoms and the diagnosis of osteonecrosis of the femoral head in this patient population. METHODS: A retrospective review of the records of 18 patients (29 hips) under 21 years of age with both a diagnosis of osteonecrosis of the femoral head and childhood onset malignancy was undertaken to determine the time from initiation of chemotherapy to the onset of symptoms and diagnosis of osteonecrosis of the femoral head. RESULTS: Mean time from initiation of chemotherapy to the onset of pain was 18.8 months (8.0-49.1). The mean time from development of pain to diagnosis of osteonecrosis was 3.9 months (-13.1 to 25). The mean overall time from initiation of chemotherapy to diagnosis of osteonecrosis was 22.7 months (9.0-54.1). 11/18 patients had bilateral disease. 16/18 patients (21/29 hips) had already progressed to stage 4 osteonecrosis at the time of diagnosis. CONCLUSIONS: There was a high incidence of stage 4 or greater osteonecrosis at the time of diagnosis. Providers caring for these patients should be aware of the potential for osteonecrosis, and the need for prompt diagnosis and referral to an orthopedic surgeon. Screening with advanced imaging studies may be warranted for children undergoing chemotherapeutic regimens for childhood malignancy to prevent delay in the diagnosis and management of this process so that joint preservation therapies remain an option.