Prevalence of Gastroesophageal Reflux in Cats During Anesthesia and Effect of Omeprazole on Gastric pH.

BackgroundGastroesophageal reflux (GER) is poorly characterized in anesthetized cats, but can cause aspiration pneumonia, esophagitis, and esophageal stricture formation.ObjectiveTo determine whether pre-anesthetic orally administered omeprazole increases gastric and esophageal pH and increases serum gastrin concentrations in anesthetized cats, and to determine the prevalence of GER using combined multichannel impedance and pH monitoring.AnimalsTwenty-seven healthy cats undergoing elective dental procedures.MethodsProspective, double-masked, placebo-controlled, randomized clinical trial. Cats were randomized to receive 2 PO doses of omeprazole (1.45-2.20 mg/kg) or an empty gelatin capsule placebo 18-24 hours and 4 hours before anesthetic induction. Blood for measurement of serum gastrin concentration was collected during anesthetic induction. An esophageal pH/impedance catheter was utilized to continuously measure esophageal pH and detect GER throughout anesthesia.ResultsMean gastric pH in the cats that received omeprazole was 7.2 ± 0.4 (range, 6.6-7.8) and was significantly higher than the pH in cats that received the placebo 2.8 ± 1.0 (range, 1.3-4.1; P < .001). Omeprazole administration was not associated with a significant increase in serum gastrin concentration (P = .616). Nine of 27 cats (33.3%) had ≥1 episode of GER during anesthesia.Conclusions and clinical relevancePre-anesthetic administration of 2 PO doses of omeprazole at a dosage of 1.45-2.20 mg/kg in cats was associated with a significant increase in gastric and esophageal pH within 24 hours, but was not associated with a significant increase in serum gastrin concentration. Prevalence of reflux events in cats during anesthesia was similar to that of dogs during anesthesia

Observing Grasping Actions Directed to Emotion-Laden Objects: Effects upon Corticospinal Excitability

The motor system is recruited whenever one executes an action as well as when one observes the same action being executed by others. Although it is well established that emotion modulates the motor system, the effect of observing other individuals acting in an emotional context is particularly elusive. The main aim of this study was to investigate the effect induced by the observation of grasping directed to emotion-laden objects upon corticospinal excitability (CSE). Participants classified video-clips depicting the right-hand of an actor grasping emotion-laden objects. Twenty video-clips differing in terms of valence but balanced in arousal level were selected. Motor evoked potentials (MEPs) were then recorded from the first dorsal interosseous using transcranial magnetic stimulation (TMS) while the participants observed the selected emotional video-clips. During the video-clip presentation, TMS pulses were randomly applied at one of two different time points of grasping: (1) maximum grip aperture, and (2) object contact time. CSE was higher during the observation of grasping directed to unpleasant objects compared to pleasant ones. These results indicate that when someone observes an action of grasping directed to emotion-laden objects, the effect of the object valence promotes a specific modulation over the motor system.Fil: Nogueira Campos, Anaelli A.. Universidade Federal de Juiz de Fora; BrasilFil: Saunier, Ghislain. Universidade Federal do Pará; BrasilFil: Della Maggiore, Valeria Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: De Oliveira, Laura A. S.. Centro Universitário Augusto Motta; BrasilFil: Rodrigues, Erika C.. Centro Universitário Augusto Motta; BrasilFil: Vargas, Claudia D.. Universidade Federal do Rio de Janeiro; Brasi

Functional Imaging Reveals Movement Preparatory Activity in the Vegetative State

The vegetative state (VS) is characterized by the absence of awareness of self or the environment and preserved autonomic functions. The diagnosis relies critically on the lack of consistent signs of purposeful behavior in response to external stimulation. Yet, given that patients with disorders of consciousness often exhibit fragmented movement patterns, voluntary actions may go unnoticed. Here we designed a simple motor paradigm that could potentially detect signs of purposeful behavior in VS patients with mild to severe brain damage by examining the neural correlates of motor preparation in response to verbal commands. Twenty-four patients who met the diagnostic criteria for VS were recruited for this study. Eleven of these patients showing preserved auditory evoked potentials underwent functional magnetic resonance imaging (fMRI) to test for basic speech processing. Five of these patients, who showed word related activity, were included in a second fMRI study aimed at detecting functional changes in premotor cortex elicited by specific verbal instructions to move either their left or their right hand. Despite the lack of overt muscle activity, two patients out of five activated the dorsal premotor cortex contralateral to the instructed hand, consistent with movement preparation. Our results may reflect residual voluntary processing in these two patients. We believe that the identification of positive results with fMRI using this simple task, may complement the clinical assessment by helping attain a more precise diagnosis in patients with disorders of consciousness

Effect of indoor nitrogen dioxide on lung function in urban environment

Background: High levels of indoor NO2 are associated with increased asthma symptoms and decreased expiratory peak flows in children. We investigated the association of exposure to domestic indoor NO2, objectively measured in winter and spring, with respiratory symptoms and lung function in a sample of adolescents from a southern Mediterranean area. Methods: From a large school population sample (n=2150) participating in an epidemiological survey in the urban area of the City of Palermo (southern Italy), a sub-sample of 303 adolescents was selected which furnished an enriched sample for cases of current asthma. All subjects were evaluated by a health questionnaire, skin prick tests and spirometry. One-week indoor NO2 monitoring of their homes was performed by diffusive sampling during spring and again during winter. Results: We found that about 25% of subjects were exposed to indoor NO2 levels higher than the 40μg/m3 World Health Organization limit, during both spring and winter. Moreover, subjects exposed to the highest indoor NO2 concentrations had increased frequency of current asthma (p=0.005), wheeze episodes in the last 12 months (p<0.001), chronic phlegm (p=0.013), and rhinoconjunctivitis (p=0.008). Finally, subjects with a personal history of wheeze ever had poorer respiratory function (FEF25-75%, p=0.01) when exposed to higher indoor NO2 concentrations. Conclusions: Home exposure to high indoor NO2 levels frequently occurs in adolescents living in a southern Mediterranean urban area and is significantly associated with the risks for increased frequency of both respiratory symptoms and reduced lung function

Forward estimation of movement state in posterior parietal cortex

During goal-directed movements, primates are able to rapidly and accurately control an online trajectory despite substantial delay times incurred in the sensorimotor control loop. To address the problem of large delays, it has been proposed that the brain uses an internal forward model of the arm to estimate current and upcoming states of a movement, which are more useful for rapid online control. To study online control mechanisms in the posterior parietal cortex (PPC), we recorded from single neurons while monkeys performed a joystick task. Neurons encoded the static target direction and the dynamic movement angle of the cursor. The dynamic encoding properties of many movement angle neurons reflected a forward estimate of the state of the cursor that is neither directly available from passive sensory feedback nor compatible with outgoing motor commands and is consistent with PPC serving as a forward model for online sensorimotor control. In addition, we found that the space–time tuning functions of these neurons were largely separable in the angle–time plane, suggesting that they mostly encode straight and approximately instantaneous trajectories

fMRI Supports the Sensorimotor Theory of Motor Resonance

The neural mechanisms mediating the activation of the motor system during action observation, also known as motor resonance, are of major interest to the field of motor control. It has been proposed that motor resonance develops in infants through Hebbian plasticity of pathways connecting sensory and motor regions that fire simultaneously during imitation or self movement observation. A fundamental problem when testing this theory in adults is that most experimental paradigms involve actions that have been overpracticed throughout life. Here, we directly tested the sensorimotor theory of motor resonance by creating new visuomotor representations using abstract stimuli (motor symbols) and identifying the neural networks recruited through fMRI. We predicted that the network recruited during action observation and execution would overlap with that recruited during observation of new motor symbols. Our results indicate that a network consisting of premotor and posterior parietal cortex, the supplementary motor area, the inferior frontal gyrus and cerebellum was activated both by new motor symbols and by direct observation of the corresponding action. This tight spatial overlap underscores the importance of sensorimotor learning for motor resonance and further indicates that the physical characteristics of the perceived stimulus are irrelevant to the evoked response in the observer

Perceiving What Is Reachable Depends on Motor Representations: Evidence from a Transcranial Magnetic Stimulation Study

Background: Visually determining what is reachable in peripersonal space requires information about the egocentric location of objects but also information about the possibilities of action with the body, which are context dependent. The aim of the present study was to test the role of motor representations in the visual perception of peripersonal space. Methodology: Seven healthy participants underwent a TMS study while performing a right-left decision (control) task or perceptually judging whether a visual target was reachable or not with their right hand. An actual grasping movement task was also included. Single pulse TMS was delivered 80 % of the trials on the left motor and premotor cortex and on a control site (the temporo-occipital area), at 90 % of the resting motor threshold and at different SOA conditions (50ms, 100ms, 200ms or 300ms). Principal Findings: Results showed a facilitation effect of the TMS on reaction times in all tasks, whatever the site stimulated and until 200ms after stimulus presentation. However, the facilitation effect was on average 34ms lower when stimulating the motor cortex in the perceptual judgement task, especially for stimuli located at the boundary of peripersonal space. Conclusion: This study provides the first evidence that brain motor area participate in the visual determination of what is reachable. We discuss how motor representations may feed the perceptual system with information about possibl

Visuomotor adaptive improvement and aftereffects are impaired differentially following cerebellar lesions in SCA and PICA territory

The aim of the present study was to elucidate the contribution of the superior and posterior inferior cerebellum to adaptive improvement and aftereffects in a visuomotor adaptation task. Nine patients with ischemic lesions within the territory of the posterior inferior cerebellar artery (PICA), six patients with ischemic lesions within the territory of the superior cerebellar artery (SCA) and 17 age-matched controls participated. All subjects performed center-out reaching movements under 60° rotation of visual feedback. For the assessment of aftereffects, we tested retention of adaptation and de-adaptation under 0° visual rotation. From this data we also quantified five measures of motor performance. Cerebellar lesion-symptom mapping was performed using magnetic resonance imaging subtraction analysis. Adaptive improvement during 60° rotation was significantly degraded in PICA patients and even more in SCA patients. Subtraction analysis revealed that posterior (Crus I) as well as anterior cerebellar regions (lobule V) showed a common overlap related to deficits in adaptive improvement. However, for aftereffect measures as well as for motor performance variables only SCA patients, but not PICA patients showed significant differences to control subjects. Subtraction analysis showed that affection of lobules V and VI were more common in patients with impaired retention and de-adaptation, respectively. Data shows that areas both within the superior and posterior inferior cerebellum are involved in adaptive improvement. However, only the superior cerebellum including lobules V and VI appears to be important for aftereffects and therefore true adaptive ability

Geographical information system and environmental epidemiology: a cross-sectional spatial analysis of the effects of traffic-related air pollution on population respiratory health

<p>Abstract</p> <p>Background</p> <p>Traffic-related air pollution is a potential risk factor for human respiratory health. A Geographical Information System (GIS) approach was used to examine whether distance from a main road (the Tosco-Romagnola road) affected respiratory health status.</p> <p>Methods</p> <p>We used data collected during an epidemiological survey performed in the Pisa-Cascina area (central Italy) in the period 1991-93. A total of 2841 subjects participated in the survey and filled out a standardized questionnaire on health status, socio-demographic information, and personal habits. A variable proportion of subjects performed lung function and allergy tests. Highly exposed subjects were defined as those living within 100 m of the main road, moderately exposed as those living between 100 and 250 m from the road, and unexposed as those living between 250 and 800 m from the road. Statistical analyses were conducted to compare the risks for respiratory symptoms and diseases between exposed and unexposed. All analyses were stratified by gender.</p> <p>Results</p> <p>The study comprised 2062 subjects: mean age was 45.9 years for men and 48.9 years for women. Compared to subjects living between 250 m and 800 m from the main road, subjects living within 100 m of the main road had increased adjusted risks for persistent wheeze (OR = 1.76, 95% CI = 1.08-2.87), COPD diagnosis (OR = 1.80, 95% CI = 1.03-3.08), and reduced FEV₁/FVC ratio (OR = 2.07, 95% CI = 1.11-3.87) among males, and for dyspnea (OR = 1.61, 95% CI = 1.13-2.27), positivity to skin prick test (OR = 1.83, 95% CI = 1.11-3.00), asthma diagnosis (OR = 1.68, 95% CI = 0.97-2.88) and attacks of shortness of breath with wheeze (OR = 1.67, 95% CI = 0.98-2.84) among females.</p> <p>Conclusion</p> <p>This study points out the potential effects of traffic-related air pollution on respiratory health status, including lung function impairment. It also highlights the added value of GIS in environmental health research.</p

Reduction in Learning Rates Associated with Anterograde Interference Results from Interactions between Different Timescales in Motor Adaptation

Prior experiences can influence future actions. These experiences can not only drive adaptive changes in motor output, but they can also modulate the rate at which these adaptive changes occur. Here we studied anterograde interference in motor adaptation – the ability of a previously learned motor task (Task A) to reduce the rate of subsequently learning a different (and usually opposite) motor task (Task B). We examined the formation of the motor system's capacity for anterograde interference in the adaptive control of human reaching-arm movements by determining the amount of interference after varying durations of exposure to Task A (13, 41, 112, 230, and 369 trials). We found that the amount of anterograde interference observed in the learning of Task B increased with the duration of Task A. However, this increase did not continue indefinitely; instead, the interference reached asymptote after 15–40 trials of Task A. Interestingly, we found that a recently proposed multi-rate model of motor adaptation, composed of two distinct but interacting adaptive processes, predicts several key features of the interference patterns we observed. Specifically, this computational model (without any free parameters) predicts the initial growth and leveling off of anterograde interference that we describe, as well as the asymptotic amount of interference that we observe experimentally (R2 = 0.91). Understanding the mechanisms underlying anterograde interference in motor adaptation may enable the development of improved training and rehabilitation paradigms that mitigate unwanted interference