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Selected AbstractsEffects of indomethacin on cerebral blood flow at rest and during hypercapnia: An arterial spin tagging study in humans,JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 6 2002Keith S. St. Lawrence PhD Abstract Purpose To investigate using an arterial spin tagging (AST) approach the effect of indomethacin on the cerebral blood flow (CBF) response to hypercapnia. Materials and Methods Subjects inhaled a gas mixture containing 6% CO2 for two 5-minute periods, which were separated by a 10-minute interval, in which subjects inhaled room air. In six subjects, indomethacin (i.v., 0.2 mg/kg) was infused in the normocapnic interval between the two hypercapnic periods. Results Indomethacin reduced normocapnic gray matter CBF by 36 ± 5% and reduced the CBF increase during hypercapnia from 43 ± 9% to 16 ± 5% in gray matter (P < 0.001) and from 48 ± 11% to 35 ± 9% in white matter (P < 0.025). Conclusion The results demonstrate that an AST approach can measure the effects of indomethacin on global CBF increases during hypercapnia and suggest that an AST approach could be used to investigate pharmacological effects on focal CBF increases during functional activation. J. Magn. Reson. Imaging 2002;15:628,635. Published 2002 Wiley-Liss, Inc. [source] Memory of children's faces by adults: Appearance does matter,APPLIED COGNITIVE PSYCHOLOGY, Issue 7 2009Vicki Silvers Gier Accurately detecting faces of children when their appearance has been altered is especially important in recognizing abducted or missing child. Face recognition studies have focussed on recognizing the adult perpetrator; however, there is lack of research on recognizing a child's face under different appearances. Two studies were conducted to determine what type of photos may increase recognition of missing children. In Experiment 1 participants were shown pictures of children's faces in a study phase in which their faces were either dirtied with negative affect or clean with positive affect, followed by a recognition phase. Accuracy and confidence were higher when the face at recognition was the same type as in the study phase. Experiment 2 replicated Experiment 1, adding four delay conditions: 10-minute interval (10-MI), 3, 6 or 12 week. Accuracy and confidence decreased over time and we again found a significant interaction between face at study and face at recognition. Copyright © 2008 John Wiley & Sons, Ltd. [source] Tissue Oxygenation Does Not Predict Central Venous Oxygenation in Emergency Department Patients With Severe Sepsis and Septic ShockACADEMIC EMERGENCY MEDICINE, Issue 4 2010Anthony M. Napoli MD Abstract Objectives:, This study sought to determine whether tissue oxygenation (StO2) could be used as a surrogate for central venous oxygenation (ScVO2) in early goal-directed therapy (EGDT). Methods:, The study enrolled a prospective convenience sample of patients aged ,18 years with sepsis and systolic blood pressure <90 mm Hg after 2 L of normal saline or lactate >4 mmol, who received a continuous central venous oximetry catheter. StO2 and ScVO2 were measured at 15-minute intervals. Data were analyzed using a random coefficients model, correlations, and Bland-Altman plots. Results:, There were 284 measurements in 40 patients. While a statistically significant relationship existed between StO2 and ScVO2 (F(1,37) = 10.23, p = 0.002), StO2 appears to systematically overestimate at lower ScVO2 and underestimate at higher ScVO2. This was reflected in the fixed effect slope of 0.49 (95% confidence interval [CI] = 0.266 to 0.720) and intercept of 34 (95% CI = 14.681 to 50.830), which were significantly different from 1 and 0, respectively. The initial point correlation (r = 0.5) was fair, but there was poor overall agreement (bias = 4.3, limits of agreement = ,20.8 to 29.4). Conclusions:, Correlation between StO2 and ScVO2 was fair. The two measures trend in the same direction, but clinical use of StO2 in lieu of ScVO2 is unsubstantiated due to large and systematic biases. However, these biases may reflect real physiologic states. Further research may investigate if these measures could be used in concert as prognostic indicators. ACADEMIC EMERGENCY MEDICINE 2010; 17:349,352 © 2010 by the Society for Academic Emergency Medicine [source] Effects of construction noise on behaviour of and exhibit use by Snow leopards Uncia uncia at Basel zooINTERNATIONAL ZOO YEARBOOK, Issue 1 2008C. E. SULSER Noise caused by human activities can cause stress in animals. We examined whether noise from construction sites affects the behaviour of and exhibit use by three Snow leopards Uncia uncia at Basel zoo. The behaviour and location of the animals were recorded at 1 minute intervals, using the instantaneous scan sampling method over a period of 216 hours (104 hours on noisy days and 112 hours on quiet days). The animals differed individually in their responses to the construction noise. On noisy days, the Snow leopards generally spent less time in locomotion and more time resting, but even on quiet days, resting was the predominant behaviour performed. Under noisy conditions, they increased social resting and decreased resting alone. Walking and social walking were also reduced on noisy days. Furthermore, the Snow leopards spent considerably more time in the remote off-exhibit enclosure under noisy conditions. Independent of background noise, they stayed more than half of the time in the caves and the forecourts of the outdoor enclosure. On quiet days, the Snow leopards used more sectors of their exhibit than on noisy days. The results indicate that the Snow leopards responded to construction noise by increasing the amount of time spent resting and by withdrawing to the remote parts of their exhibit. [source] Postprandial Hypotension in Long-Term Care Elderly Patients on Enteral FeedingJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 9 2006Emily Lubart MD OBJECTIVES: To examine the prevalence and nature of postprandial hypotension (PPH) in orally fed (OF), nasogastric tube (NGT)-fed, and percutaneous endoscopic gastrostomy (PEG)-fed older people. DESIGN: Prospective comparative study. SETTING: Nursing and skilled nursing wards of three geriatrics hospitals. PARTICIPANTS: Three groups (OF, PEG, NGT) of long-term care patients (50 in each cohort) were enrolled. MEASUREMENTS: Blood pressure (BP) and heart rate measurements were obtained just before lunch and at 15-minute intervals for 90 minutes after the completion of the meal. The meals were similar in caloric content and composition. RESULTS: PPH was evidenced in 64 (43%) patients. No significant intergroup (OF, PEG, NGT) differences were present. In 68% of PPH patients, the systolic BP (SBP) drop appeared within 30 minutes, and 70% reached their systolic nadir at 60 minutes. In 31%, the SBP drop was registered on only one measurement, whereas in 25%, the drop was detected on five to six measurements. All parameters were without notable intergroup differences. CONCLUSION: In enterally fed elderly patients (NGT or PEG), the rate and pattern of PPH are similar and not significantly different from that observed in OF patients. [source] A fractal forecasting model for financial time seriesJOURNAL OF FORECASTING, Issue 8 2004Gordon R. Richards Abstract Financial market time series exhibit high degrees of non-linear variability, and frequently have fractal properties. When the fractal dimension of a time series is non-integer, this is associated with two features: (1) inhomogeneity,extreme fluctuations at irregular intervals, and (2) scaling symmetries,proportionality relationships between fluctuations over different separation distances. In multivariate systems such as financial markets, fractality is stochastic rather than deterministic, and generally originates as a result of multiplicative interactions. Volatility diffusion models with multiple stochastic factors can generate fractal structures. In some cases, such as exchange rates, the underlying structural equation also gives rise to fractality. Fractal principles can be used to develop forecasting algorithms. The forecasting method that yields the best results here is the state transition-fitted residual scale ratio (ST-FRSR) model. A state transition model is used to predict the conditional probability of extreme events. Ratios of rates of change at proximate separation distances are used to parameterize the scaling symmetries. Forecasting experiments are run using intraday exchange rate futures contracts measured at 15-minute intervals. The overall forecast error is reduced on average by up to 7% and in one instance by nearly a quarter. However, the forecast error during the outlying events is reduced by 39% to 57%. The ST-FRSR reduces the predictive error primarily by capturing extreme fluctuations more accurately. Copyright © 2004 John Wiley & Sons, Ltd. [source] Effects of a Moderate Evening Alcohol Dose.ALCOHOLISM, Issue 8 2007I: Sleepiness Background: Few studies examining alcohol's effects consider prior sleep/wake history and circadian timing. We examined introspective and physiological sleepiness on nights with and without moderate alcohol consumption in well-rested young adults at a known circadian phase. Methods: Twenty-nine adults (males=9), ages 21 to 25 years (M=22.6, SD=1.2), spent 1 week on an at-home stabilized sleep schedule (8.5 or 9 hours), followed by 3 in-lab nights: adaptation, placebo, and alcohol. Alcohol (vodka; 0.54 g/kg for men; 0.49 g/kg for women) or placebo beverage was consumed over 30 minutes ending 1 hour before stabilized bedtime. In addition to baseline, 3 sleep latency tests (SLTs) occurred after alcohol/placebo ingestion (15, 16.5, and 18 hours after waking). Stanford Sleepiness Scales (SSS) and Visual Analog Scales (VAS) of sleepiness were completed before each SLT and approximately every 30 minutes. The Biphasic Alcohol Effects Scale (BAES) was administered a total of 4 times (baseline, 5, 60, and 90 minutes postalcohol/placebo). Subjects' circadian phase was determined from melatonin levels in saliva samples taken at approximately 30-minute intervals. Results: All sleepiness and sedation measures increased with time awake. Only SSS and BAES sedation measures showed higher levels of sleepiness and sedation after alcohol compared with placebo. The mean circadian phase was the same for assessments at both conditions. Conclusions: Alcohol did not increase physiological sleepiness compared with placebo nor was residual sedation evident under these conditions. We conclude that the effects on sleepiness of a moderate dose of alcohol are masked when sleep,wake homeostatic and circadian timing influences promote high levels of sleepiness. [source] A Work Sampling Study of Provider Activities in School-Based Health CentersJOURNAL OF SCHOOL HEALTH, Issue 6 2009Brian Mavis PhD ABSTRACT Background:, The purpose of this study was to describe provider activities in a convenience sample of School-Based Health Centers (SBHCs). The goal was to determine the relative proportion of time that clinic staff engaged in various patient care and non-patient care activities. Methods:, All provider staff at 4 urban SBHCs participated in this study; 2 were in elementary schools, 1 in a middle school, and 1 in a school with kindergarten through grade 8. The study examined provider activity from 6 days sampled at random from the school year. Participants were asked to document their activities in 15-minute intervals from 8:00 a.m. to 5:00 p.m. A structured recording form was used that included 35 activity categories. Results:, Overall, 1492 records were completed, accounting for 2708 coded activities. Almost half (48%) of all staff activities were coded as direct patient contact, with clinic operations the second largest category. Limited variations in activities were found across clinic sites and according to season. Conclusions:, A significant amount of provider activity was directed at the delivery of health care; direct patient care and clinic operations combined accounted for approximately 75% of clinic activity. Patient, classroom, and group education activities, as well as contacts with parents and school staff accounted for 20% of all clinic activity and represent important SBHC functions that other productivity measures such as billing data might not consistently track. Overall, the method was acceptable to professional staff as a means of tracking activity and was adaptable to meet their needs. [source] A Microdialysis Profile of Dynorphin A1,8 Release in the Rat Nucleus Accumbens Following Alcohol AdministrationALCOHOLISM, Issue 6 2006Peter W. Marinelli Background: Pharmacological studies have implicated the endogenous opioid system in mediating alcohol intake. Other evidence has shown that alcohol administration can influence endorphinergic and enkephalinergic activity, while very few studies have examined its effect on dynorphinergic systems. The aim of the present study was to investigate the effect of alcohol administration or a mechanical stressor on extracellular levels of dynorphin A1,8 in the rat nucleus accumbens,a brain region that plays a significant role in the processes underlying reinforcement and stress. Methods: Male Sprague,Dawley rats were implanted with a microdialysis probe aimed at the shell region of the nucleus accumbens. Artificial cerebrospinal fluid was pumped at a rate of 1.5 ,L/min in awake and freely moving animals and the dialysate was collected at 30-minute intervals. In one experiment, following a baseline period, rats were injected intraperitoneally with either physiological saline or 1 of 3 doses of alcohol, 0.8, 1.6, or 3.2 g ethanol/kg body weight. In a second experiment, following a baseline period, rats were applied a clothespin to the base of their tail for 20 minutes. The levels of dynorphin A1,8 in the dialysate were analyzed with solid-phase radioimmunoassay. Results: Relative to saline-treated controls, an alcohol dose of 1.6 and 3.2 g/kg caused a transient increase in the extracellular levels of dynorphin A1,8 in the first 30 minutes of alcohol administration. However, the effect resulting from the high 3.2 g/kg dose was far more pronounced and more significant than with the moderate dose. There was no effect of tail pinch on dynorphin A1,8 levels in the nucleus accumbens. Conclusions: In this experiment, a very high dose of alcohol was especially capable of stimulating dynorphin A1,8 release in the nucleus accumbens. Dynorphin release in the accumbens has been previously associated with aversive stimuli and may thus reflect a system underlying the aversive properties of high-dose alcohol administration. However, the lack of effect of tail-pinch stress in the present study suggests that dynorphin A1,8 is not released in response to all forms of stressful/aversive stimuli. [source] Descending thoracic aortic blood flow parameters during emergent surgery in anesthetized critically ill dogsJOURNAL OF VETERINARY EMERGENCY AND CRITICAL CARE, Issue 4 2002Richard J. Mills DVM Abstract Objective: To explore the potential value of transesophageally-determined descending thoracic aortic blood flow parameters in critically ill dogs undergoing surgery. Design: Observational case series. Setting: Private small animal referral hospital. Animals: Ten anesthetized critically ill dogs that underwent emergent surgery. Interventions: Placement of the ultrasonic transesophageal probe. Measurements and main results: Transesophageally-determined descending thoracic aortic blood flow, stroke volume, blood velocity, blood acceleration, left ventricular ejection time interval, and heart rate parameters were recorded every minute. Systolic and mean arterial blood pressures were non-invasively determined and recorded at 1,5 minute intervals. The anesthetist and surgeon were blinded to the descending thoracic aortic blood flow parameters. All dogs received fluid challenges as part of their management, and 2 dogs received dopamine. The variability of the descending thoracic aortic blood flow parameters within each dog was greater than has been reported in non-critically ill anesthetized dogs. Consistent trends in descending thoracic aortic blood flow parameters after fluid challenges were not found. An escalating dopamine infusion was, however, accompanied by increasing aortic blood flow, stroke volume, acceleration, and peak velocity. Conclusions: Descending thoracic aortic blood flow parameters may eventually be useful for evaluating the responses to and suggesting the need for cardiovascular interventions during emergent surgeries in anesthetized critically ill canine patients. For this to occur, more experience with this technology will be required. [source] Reliability of a new ultrasonic cardiac output monitor in recipients of living donor liver transplantation,,§¶LIVER TRANSPLANTATION, Issue 7 2008Bai-Chuan Su The ultrasonic cardiac output monitor (USCOM) is a new Doppler device for noninvasive hemodynamic monitoring. The aim of this prospective nonrandomized study was to test the feasibility, perioperative reliability, and clinical applicability of using USCOM as an alternative to pulmonary artery catheterization in recipients of living donor liver transplantation. Thirteen patients scheduled to receive living donor liver transplants were initially recruited. Three were subsequently excluded prior to the commencement of surgery because of technical difficulties in obtaining diagnostic-quality images with USCOM. Ten patients proceeded to be studied. Cardiac output measurements by thermodilution and USCOM were compared at 30-minute intervals throughout the procedure and at 10 specific procedural reference points during the surgery when hemodynamic changes were most likely to be observed. The data were analyzed with Lin's concordance coefficient and Bland-Altman analysis. Two hundred ninety paired cardiac output values were obtained from the 10 patients. The concordance between both methods was excellent in 8 patients and satisfactory in 2. Bland-Altman analysis of all data produced a mean bias of , 0.02 L/minute for USCOM, and the 95% limits of agreement were ,1.06 to +1.10 L/minute. Further analysis of the 10 reference time points showed minimal bias and high levels of agreement between the methods. We conclude that USCOM provides an accurate and noninvasive method for cardiac output measurement during liver transplantation. It may therefore represent an alternative to pulmonary artery catheter placement with consequent reduction in patient's risk and morbidity associated with catheterization. Liver Transpl 14:1029,1037, 2008. © 2008 AASLD. [source] Metabolic changes in the liver graft monitored continuously with microdialysis during liver transplantation in a pig modelLIVER TRANSPLANTATION, Issue 5 2002Grzegorz Nowak MD Microdialysis provides the opportunity to continuously monitor metabolic changes in tissue. The aim of the study is to monitor metabolic changes in the liver graft over time during transplantation in a pig model. Fourteen littermate female pigs with a body weight of 30 to 34 kg were used for seven orthotopic liver transplantations. Intrahepatic implantation of a microdialysis catheter into the liver graft was performed in the donor. Microdialysis samples were collected at 20-minute intervals during the donor operation, cold preservation, and for 7 hours after reperfusion in the recipient. Glucose, lactate, pyruvate, and glycerol concentrations were measured. After cold perfusion, glucose, lactate, and glycerol levels increased, whereas pyruvate levels decreased rapidly. During cold storage, glucose and glycerol levels increased, whereas lactate levels remained stable and pyruvate levels were undetectable. During implantation of the liver graft, glucose, lactate, and glycerol levels showed an accelerated increase. After portal reperfusion, glucose, lactate, and glycerol levels continued to increase for another 40 to 60 minutes, after which they decreased and finally settled at normal levels. At this time, pyruvate levels increased, with a peak within 2 hours after reperfusion, and then decreased to normal levels. Calculated lactate-pyruvate ratio increased after cold perfusion and remained stable during cold storage. During rewarming, it showed an accelerated increase, but after reperfusion, it decreased rapidly. Rewarming and reperfusion are most harmful to the liver, reflected by an accelerated increase in glucose and glycerol levels and lactate-pyruvate ratio. High intrahepatic glucose levels during ischemia appear to be a liver-specific event, which may represent glycogen degradation in injured hepatocytes. [source] | ||||||||||