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Selected AbstractsEndocrine Function Is Altered in Chronic Migraine Patients with Medication-OveruseHEADACHE, Issue 4 2006Innocenzo Rainero MD Objective.,To evaluate the effects of analgesic overuse on endocrine function in patients with chronic migraine and medication-overuse headache (CM-MOH). Background.,Chronic migraine is frequently associated with an overuse of symptomatic medications. Drugs currently used in acute migraine attacks are associated with several endocrine effects. At present, the endocrine effects of medication overuse in chronic migraine patients are unknown. Methods.,Eighteen patients with CM-MOH, diagnosed according to the ICHD-II criteria, and 18 healthy controls received an intravenous administration of GHRH, hCRH, and TRH. Plasma concentrations of GH, TSH, ACTH, and cortisol were measured for a 90-minute period after administration of the specific releasing hormones. Results.,Hormonal basal concentrations were similar in both groups. GH response to GHRH was significantly reduced in patients with CM-MOH in comparison with controls. TRH induced a reduction of TSH concentrations only at the end of the test. After hCRH administration, ACTH and cortisol concentrations were significantly higher in cases than in controls. A significant correlation between duration of the disease and altered hormonal response was found. Conclusions.,Our study shows that both corticotropic and somatotropic functions are significantly impaired in CM-MOH patients and suggests a role for hormones in the development of chronic migraine. [source] Effect of an Electronic Control Device Exposure on a Methamphetamine-intoxicated Animal ModelACADEMIC EMERGENCY MEDICINE, Issue 4 2010Donald M. Dawes MD Abstract Objectives:, Because of the prevalence of methamphetamine abuse worldwide, it is not uncommon for subjects in law enforcement encounters to be methamphetamine-intoxicated. Methamphetamine has been present in arrest-related death cases in which an electronic control device (ECD) was used. The primary purpose of this study was to determine the cardiac effects of an ECD in a methamphetamine intoxication model. Methods:, Sixteen anesthetized Dorset sheep (26,78 kg) received 0.0 mg/kg (control animals, n = 4), 0.5 mg/kg (n = 4), 1.0 mg/kg (n = 4), or 1.5 mg/kg (n = 4) of methamphetamine hydrochloride as a slow intravenous (IV) bolus during continuous cardiac monitoring. The animals received the following exposures in sequence from a TASER X26 ECD beginning at 30 minutes after the administration of the drug: 1) 5-second continuous exposure, 2) 15-second intermittent exposure, 3) 30-second intermittent exposure, and 4) 40-second intermittent exposure. Darts were inserted at the sternal notch and the cardiac apex, to a depth of 9 mm. Cardiac motion was determined by thoracotomy (smaller animals, , 32 kg) or echocardiography (larger animals, > 68 kg). Data were analyzed using descriptive statistics and chi-square tests. Results:, Animals given methamphetamine demonstrated signs of methamphetamine toxicity with tachycardia, hypertension, and atrial and ventricular ectopy in the 30-minute period immediately after administration of the drug. Smaller animals (n = 8, , 32 kg, mean = 29.4 kg) had supraventricular dysrhythmias immediately after the ECD exposures. Larger animals (n = 8, > 68 kg, mean = 72.4) had only sinus tachycardia after the exposures. One of the smaller animals had frequent episodes of ventricular ectopy after two exposures, including runs of delayed onset, nonsustained six- to eight-beat unifocal and multifocal ventricular tachycardia that spontaneously resolved. This animal had significant ectopy prior to the exposures as well. Thoracotomy performed on three smaller animals demonstrated cardiac capture during ECD exposure consistent with previous animal studies. In the larger animals, none of the methamphetamine-intoxicated animals demonstrated cardiac capture. Two control sheep showed evidence of capture similar to the smaller animals. No ventricular fibrillation occurred after the exposure in any animal. Conclusions:, In smaller animals (32 kg or less), ECD exposure exacerbated atrial and ventricular irritability induced by methamphetamine intoxication, but this effect was not seen in larger, adult-sized animals. There were no episodes of ventricular fibrillation after exposure associated with ECD exposure in methamphetamine-intoxicated sheep. ACADEMIC EMERGENCY MEDICINE 2010; 17:436,443 © 2010 by the Society for Academic Emergency Medicine [source] Short-term prediction of the horizontal wind vector within a wake vortex warning systemMETEOROLOGICAL APPLICATIONS, Issue 1 2002Michael Frech A wake vortex warning system (WVWS) has been developed for Frankfurt Airport. This airport has two parallel runways which are separated by 518 m, a distance too short to operate them independently because wake vortices may be advected to the adjacent runway. The objective of the WVWS is to enable operation with reduced separation between two aircraft approaching the parallel runways during appropriate wind conditions. The WVWS applies a statistical persistence model to predict the crosswind within a 20-minute period. One of the main problems identified in the old WVWS is discontinuity between successive forecasts. These forecast breakdowns were not acceptable to air traffic controllers. At least part of the problem was related to the fact that the forecast was solely based on the prediction of crosswind. A new method is developed on the basis of 523 days of sonic anemometer measurements at Frankfurt Airport. It is demonstrated that the prediction of the horizontal wind vector avoids these difficulties and significantly improves the system's performance. Copyright © 2002 Royal Meteorological Society. [source] Use of a plant-derived enzyme template for the production of the green-note volatile hexanalBIOTECHNOLOGY & BIOENGINEERING, Issue 3 2003Frank Schade Abstract Hexanal is a key organoleptic element of green-note that is found in both fragrances and flavors. We report a novel process for the production of hexanal using immobilized enzyme templates extracted from different plant sources in combination with hollow-fiber ultrafiltration for in situ separation. Enzyme templates, known to be responsible for the synthesis of hexanal from linoleic acid (18:2), were isolated from naturally enriched tissues including carnation petals, strawberry and tomato leaves. These templates were immobilized in an alginate matrix and used as a biocatalyst in a packed-bed bioreactor. Continuous product recovery was achieved using a hollow-fiber ultrafiltration unit. The effects of pH, reaction temperature, and substrate and enzyme concentrations were studied and their effects on hexanal generation identified and optimized. Utilizing optimized conditions, hexanal production 112-fold higher than endogenous steady-state levels in a corresponding amount of plant tissue could be achieved over a 30-minute period. Based on the reactor studies, product inhibition also appears to be an important factor for bioreactor-based hexanal production. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 84: 265,273, 2003. [source] Blood Pressure Response to the ImpedanceThreshold Device in Hypotensive Emergency Department PatientsACADEMIC EMERGENCY MEDICINE, Issue 2008Samuel Luber Background:, An impedance threshold device (ITD) has been found to enhance circulation during CPR by increasing cardiac preload. Additionally, in the spontaneously breathing patient, the ITD has been found to create a small degree of inspiratory resistance (-6 cm H2O at flow rate of 20L/min). Hypothesis: We sought to determine the effects of the ITD on awake patients with hypotension presenting to the emergency department. We hypothesized that the ITD would improve blood pressure when compared to standard therapy. The main outcome measure was the systolic blood pressure (SBP) change during 10 minutes of ITD use. Methods:, A convenience sample of patients with SBPs <95 mmHg were randomized in double-blind fashion to active or sham ITDs. Patients were enrolled if they were between the ages of 18 and 70 and their hypotension was felt to be due to non-traumatic blood loss or dehydration by the treating physician. Patients were excluded if they were experiencing shortness of breath, chest pain, failed the abbreviated mini-mental status exam, or had predefined cardiac/pulmonary history criteria. After consent and baseline measurements, patients spontaneously breathed through a mouthpiece attached to an active or sham ITD for a 10 minute period during which vital signs and patient status were recorded. Results:, 12 patients were enrolled (5 randomized to the active device, 7 to the sham device). Mean baseline SBPs were similar between groups with the active and sham devices having baseline SBPs of 84.5 mmHg (SD 5.45) and 83.67 mmHg (SD 10.02), respectively. The active ITD produced a statistically significant (p = 0.03) increase in SBP of 13.0 mmHg (SD 4.69) compared to the sham ITD, 2.33 mmHg (SD 0.58). Conclusions:, In spontaneously breathing hypotensive ED patients, the ITD was well-tolerated and increased the SBP. If these results are validated with a larger sample, the ITD may be a useful adjunct in the treatment of hypotension due to volume loss in the ED. [source] 4364: Direct intra-arterial (ophthalmic artery) chemotherapy with melphalan for advanced intraocular retinoblastoma: the Italian experienceACTA OPHTHALMOLOGICA, Issue 2010T HADJISTILIANOU Purpose To report the preliminary results of the conservative treatment of advanced retinoblastoma (Stage Va e Vb) obtained with the melphalan protocol (direct intraarterial-ophthalmic artery infusion ). Methods 33 children (35 eyes) with advanced retinoblastoma who were eligible for enucleation were entered in phase two of one center open study-approved protocol of ophthalmic artery infusion of Melphalan to avoid enucleation (Italian Melphalan protocol, approved by the Ethic Commettee , University Hospital of Siena). Two cases have been treated bilaterally. 15 eyes were first diagnosis and 18 were relapses following chemo and/or radiotherapy. In two cases has not been possible to conclude the procedure due to haemodynamic problems. Results The ophthalmic artery was successfully cannulated in 35 eyes (total, 121 procedures). In 2 attempts was impossible to successfully conclude the procedure due to hemodynamic problems. Cannulation of the ophthalmic artery was performed by a femoral artery approach using microcatheters (magic 1.5) while the children were under general anesthesia and anticoagulated. Melphalan was infused into the artery over a 30-minute period (dose of 3-7 mg according to the age and size of the globe). Local and systemic toxicity have been evaluated and documented. Conclusion 33 children (35 eyes) with advanced retinoblastoma (Stage Va and Vb Reese classification) were eligible for the Melphalan Italian Protocol. The 78.7% of treated eyes is in complete remission. Superselective chemotherapy delivered through the ophthalmic artery can avoid enucleation, primary radiation or abuse of systemic chemotherapy. [source] Determination of the Effect of In Vitro Time, Temperature, and Tourniquet Use on Whole Blood Venous Point-of-care Lactate ConcentrationsACADEMIC EMERGENCY MEDICINE, Issue 7 2007Alan E. Jones MD Objectives:The authors sought to determine the effect of in vitro time, temperature, and removable tourniquet use on changes in venous point-of-care lactate concentrations. Methods:This was a prospective randomized trial on healthy volunteers. Subjects were randomized to one of three groups: group 1 had venous lactate concentrations measured on blood drawn without a tourniquet and the sample placed in ice (,1°C), group 2 had lactate concentrations measured on blood drawn without a tourniquet and the sample left at 23°C, and group 3 had lactate concentrations measured on blood drawn with a tourniquet placed 5 minutes before venipuncture and the sample placed in ice (,1°C). Lactate concentrations were measured on a point-of-care device at time 0, 3, 6, 9, 12, and 15 minutes in all three groups. Mean lactate concentrations were analyzed using a two-way repeated-measures analysis of variance. Results:Eighty subjects were randomized, with complete data available in 63 (21 per group). Over the 15-minute period, lactate concentrations [source] Two-thumb vs Two-finger Chest Compression in an Infant Model of Prolonged Cardiopulmonary ResuscitationACADEMIC EMERGENCY MEDICINE, Issue 10 2000Michele L. Dorfsman MD Abstract. Objective: Previous experiments in the authors swine lab have shown that cardiopulmonary resuscitation (CPR) using two-thumb chest compression with a thoracic squeeze (TT) produces higher blood and perfusion pressures when compared with the American Heart Association (AHA)-recommended two-finger (TF) technique. Previous studies were of short duration (1-2 minutes). The hypothesis was that TT would be superior to TF during prolonged CPR in an infant model. Methods: This was a prospective, randomized crossover experiment in a laboratory setting. Twenty-one AHA-certified rescuers performed basic CPR for two 10-minute periods, one with TT and the other with TF. Trials were separated by 2-14 days, and the order was randomly assigned. The experimental circuit consisted of a modified manikin with a fixed-volume arterial system attached to a neonatal monitor via an arterial pressure transducer. The arterial circuit was composed of a 50-mL bag of normal saline solution (air removed) attached to the manikin chest plate and connected to the transducer with a 20-gauge intravenous catheter and tubing. Rescuers were blinded to the arterial pressure tracing. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were recorded in mm Hg, and pulse pressures (PPs) were calculated. Data were analyzed with two-way repeated-measures analysis of variance. Sphericity assumed modeling, with Greenhouse-Geisser and Huynh-Feldt adjustments, was applied. Results: Marginal means for TT SBP (68.9), DBP (17.6), MAP (35.3), and PP (51.4) were higher than for TF SBP (44.8), DBP (12.5), MAP (23.3), and PP (32.2). All four pressures were significantly different between the two techniques (p , 0.001). Conclusion: In this infant CPR model, TT chest compression produced higher MAP, SBP, DBP, and PP when compared with TF chest compression during a clinically relevant duration of prolonged CPR. [source] The Effect of In Vivo Mechanical Loading on Estrogen Receptor , Expression in Rat Ulnar Osteocytes,,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 9 2002P. J. Ehrlich Abstract The presence of estrogen receptor , (ER,) in osteocytes was identified immunocytochemically in transverse sections from 560 to 860 ,m distal to the midshaft of normal neonatal and adult male and female rat ulnas (n = 3 of each) and from adult male rat ulnas that had been exposed to 10 days of in vivo daily 10-minute periods of cyclic loading producing peak strains of either ,3000 (n = 3) or ,4000 microstrain (n = 5). Each animal ambulated normally between loading periods, and its contralateral ulna was used as a control. In animals in which limbs were subject to normal locomotor loading alone, 14 ±1.2% SEM of all osteocytes in each bone section were ER, positive. There was no influence of either gender (p = 0.725) or age (p = 0.577) and no interaction between them (p = 0.658). In bones in which normal locomotion was supplemented by short periods of artificial loading, fewer osteocytes expressed ER, (7.5 ± 0.91% SEM) than in contralateral control limbs, which received locomotor loading alone (14 ± 1.68% SEM; p = 0.01; median difference, 6.43; 95% CI, 2.60, 10.25). The distribution of osteocytes expressing ER, was uniform across all sections and thus did not reflect local peak strain magnitude. This suggests that osteocytes respond to strain as a population, rather than as individual strain-responsive cells. These data are consistent with the hypothesis that ER, is involved in bone cells' responses to mechanical strain. High strains appear to decrease ER, expression. In osteoporotic bone, the high strains assumed to accompany postmenopausal bone loss may reduce ER, levels and therefore impair the capacity for appropriate adaptive remodeling. [source] Fluctuation in Autonomic Tone is a Major Determinant of Sustained Atrial Arrhythmias in Patients with Focal Ectopy Originating from the Pulmonary VeinsJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2001MARC ZIMMERMANN M.D. Autonomic Variations in Focal AF. Introduction: This study was designed to analyze dynamic changes in autonomic tone preceding the onset of sustained atrial arrhythmias in patients with focal atrial fibrillation (AF) to determine why patients with frequent discharge from the arrhythmogenic foci develop sustained AF. Methods and Results: Holter tapes from 13 patients (10 men and 3 women; mean age 53 ± 5 years) with paroxysmal "lone" AF (mean 18 ± 13 episodes per week) and a proven focal origin (pulmonary veins in all cases) were analyzed. A total of 38 episodes of sustained AF (> 30 min) were recorded and submitted to frequency-domain heart rate variability analysis. Six periods were studied using repeated measures analysis of variance: the 24,hour period, the hour preceding AF, and the 20 minutes before AF divided into four 5,minute periods. A significant increase in high-frequency (HF, HF-NU) components was observed during the 20 minutes preceding AF (P = 0.003 and 0.002, respectively), together with a progressive decrease in normalized low-frequency (LF-NU) components (P = 0.035). An increase in LF/HF ratio followed by a linear decrease starting 15 minutes before sustained AF also was observed, indicating fluctuations in autonomic tone, with a primary increase in adrenergic drive followed by a marked modulation toward vagal predominance immediately before AF onset. Conclusion: In patients with focal ectopy originating from the pulmonary veins, sustained episodes of atrial arrhythmias are mainly dependent on variations of autonomic tone, with a significant shift toward vagal predominance before AF onset. [source] When a graph is poorer than 100 words: A comparison of computerised natural language generation, human generated descriptions and graphical displays in neonatal intensive careAPPLIED COGNITIVE PSYCHOLOGY, Issue 1 2010Marian van der Meulen Volunteer staff from a Neonatal Intensive Care Unit (NICU) were presented with sets of anonymised physiological data recorded over approximately 45,minute periods from former patients. Staff were asked to select medical/nursing actions appropriate for each of the patients whose data were displayed. Data were shown in one of three conditions (a) as multiple line graphs similar to those commonly shown on the ward, or as textual descriptions generated by (b) expert medical/nursing staff or (c) computerised natural language generation (NLG). An overall advantage was found for the human generated text, but NLG resulted in decisions that were at least as good as those for the graphical displays with which staff were familiar. It is suggested that NLG might offer a viable automated approach to removing noise and artefacts in real, complex and dynamic data sets, thereby reducing visual complexity and mental workload, and enhancing decision-making particularly for inexperienced staff. Copyright © 2008 John Wiley & Sons, Ltd. [source] | ||||||||||