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Potential Interference (potential + interference)
Selected AbstractsInduction Ovens and Electromagnetic Interference:PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 7p1 2003What is the Risk for Patients with Implanted Pacemakers? Electromagnetic fields may interfere with normal pacemaker function. Despite the introduction of modern pacemakers and bipolar lead systems, electromagnetic interference (EMI) still remains to be a concern during daily lives when patients are exposed to cellular phones, electronic security systems, and several household appliances. The aim of this study was to evaluate potential EMI risk of induction ovens, which are increasingly used in private households. The study included 40 consecutive patients (22 men, 18 women; age73 ± 11 years) with implanted DDD, VVI, VDD, and AAI pacemaker systems. The pacemakers were programmed to unipolar sensing and pacing. Sensitivity remained unchanged, if the measured sensing threshold was more than twice the programmed value; otherwise, it was set at half of the measured sensing threshold. Patients were placed in a sitting position at the closest possible distance of about 20 cm between two cooking pots and pacemaker bending the upper part of the body slightly over the induction oven. The energy was increased stepwise to the maximum. One pot was removed and placed again at the highest oven level. Potential interference was monitored continuously. The study showed no incidence of pacemaker malfunction during the entire test while the patients with intrinsic cardiac rhythms were exposed to the induction oven at varying energy strengths. Likewise, there was no external interference when the patients were paced at heart rates of 10,15 beats/min above their heart rates. The programmed parameters remained unchanged after the study. In conclusion, this study shows no EMI risk of an induction oven in patients with bipolar or right-sided unipolar pacemakers. (PACE 2003; 26[Pt. I]:1494,1497) [source] An integrated pneumatic tactile feedback actuator array for robotic surgeryTHE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY, Issue 1 2009Miguel L. Franco Abstract Background A pneumatically controlled balloon actuator array has been developed to provide tactile feedback to the fingers during robotic surgery. Methods The actuator and pneumatics were integrated onto a robotic surgical system. Potential interference of the inactive system was evaluated using a timed robotic peg transfer task. System performance was evaluated by measuring human perception of the thumb and index finger. Results No significant difference was found between performance with and without the inactive mounted actuator blocks. Subjects were able to determine inflation location with > 95% accuracy and five discrete inflation levels with both the index finger and thumb with accuracies of 94% and 92%. Temporal tests revealed that an 80 ms temporal separation was sufficient to detect balloon stimuli with high accuracy. Conclusions The mounted balloon actuators successfully transmitted tactile information to the index finger and thumb, while not hindering performance of robotic surgical movements. Copyright © 2008 John Wiley & Sons, Ltd. [source] Interaction between Anticonvulsants and Human Placental Carnitine TransporterEPILEPSIA, Issue 3 2004Shu-Pei Wu Summary: Purpose: To examine the inhibitory effect of anticonvulsants (AEDs) on carnitine transport by the human placental carnitine transporter. Methods: Uptake of radiolabeled carnitine by human placental brush-border membrane vesicles was measured in the absence and presence of tiagabine (TGB), vigabatrin (VGB), gabapentin (GBP), lamotrigine (LTG), topiramate (TPM), valproic acid (VPA), and phenytoin (PHT). The mechanism of the inhibitory action of TGB was determined. Results: Most of the AEDs inhibited placental carnitine transport. Kinetic analyses showed that TGB had the greatest inhibitory effect [50% inhibitory concentration (IC50, 190 ,M)], and the order of inhibitory potency was TGB > PHT > GBP > VPA > VGB, TPM > LTG. Further studies showed that TGB competitively inhibited carnitine uptake by the human placental carnitine transporter, suggesting that it may be a substrate for this carrier. Conclusions: Although the involvement of carnitine deficiency in fetal anticonvulsant syndrome requires further evaluation, potential interference with placental carnitine transport by several AEDs was demonstrated. Despite the higher inhibitory potency of TGB, given the therapeutic unbound concentrations, the results for VPA and PHT are probably more clinically significant. [source] PRECLINICAL STUDY: Ecstasy-induced oxidative stress to adolescent rat brain mitochondria in vivo: influence of monoamine oxidase type AADDICTION BIOLOGY, Issue 2 2009Ema Alves ABSTRACT The administration of a neurotoxic dose of 3,4-methylenedioxymethamphetamine (MDMA; ,ecstasy') to the rat results in mitochondrial oxidative damage in the central nervous system, namely lipid and protein oxidation and mitochondrial DNA deletions with subsequent impairment of the correspondent protein expression. Although these toxic effects were shown to be prevented by monoamine oxidase B inhibition, the role of monoamine oxidase A (MAO-A) in MDMA-mediated mitochondrial damage remains to be evaluated. Thus, the aim of the present study was to clarify the potential interference of a specific inhibition of MAO-A by clorgyline, on the deleterious effects produced by a binge administration of a neurotoxic dose of MDMA (10 mg MDMA/kg of body weight, intraperitoneally, every 2 hours in a total of four administrations) to an adolescent rat model. The parameters evaluated were mitochondrial lipid peroxidation, protein carbonylation and expression of the respiratory chain protein subunits II of reduced nicotinamide adenine dinucleotide dehydrogenase (NDII) and I of cytochrome oxidase (COXI). Considering that hyperthermia has been shown to contribute to the neurotoxic effects of MDMA, another objective of the present study was to evaluate the body temperature changes mediated by MDMA with a MAO-A selective inhibition by clorgyline. The obtained results demonstrated that the administration of a neurotoxic binge dose of MDMA to an adolescent rat model previously treated with the specific MAO-A inhibitor, clorgyline, resulted in synergistic effects on serotonin- (5-HT) mediated behaviour and body temperature, provoking high mortality. Inhibition of MAO-A by clorgyline administration had no protective effect on MDMA-induced alterations on brain mitochondria (increased lipid peroxidation, protein carbonylation and decrease in the expression of the respiratory chain subunits NDII and COXI), although it aggravated MDMA-induced decrease in the expression of COXI. These results reinforce the notion that the concomitant use of MAO-A inhibitors and MDMA is counter indicated because of the resulting severe synergic toxicity. [source] A laser flash photolysis/IR diode laser absorption study of the reaction of chlorine atoms with selected alkanesINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 2 2002Hai-Bo Qian A high-resolution IR diode laser in conjunction with a Herriot multiple reflection flow-cell has been used to directly determine the rate coefficients for simple alkanes with Cl atoms at room temperature (298 K). The following results were obtained: k(Cl + n-butane) = (1.91 ± 0.10) × 10,10 cm3 molecule,1 s,1, k(Cl + n -pentane) = (2.46 ± 0.12) × 10,10 cm3 molecule,1 s,1, k(Cl + iso-pentane) = (1.94 ± 0.10) × 10,10 cm3 molecule,1 s,1, k(Cl + neopentane) = (1.01 ± 0.05) × 10,10 cm3 molecule,1 s,1, k(Cl + n -hexane) = (3.44 ± 0.17) × 10,10 cm3 molecule,1 s,1 where the error limits are ±1,. These values have been used in conjunction with our own previous measurements on Cl + ethane and literature values on Cl + propane and Cl + iso-butane to generate a structure activity relationship (SAR) for Cl atom abstraction reactions based on direct measurements. The resulting best fit parameters are kp = (2.61 ± 0.12) × 10,11 cm3 molecule,1 s,1, ks = (8.40 ± 0.60) × 10,11 cm3 molecule,1 s,1, kt = (5.90 ± 0.30) × 10,11 cm3 molecule,1 s,1, with f( CH2) = f ( CH2) = f (C) = f = 0.85 ± 0.06. Tests were carried out to investigate the potential interference from production of excited state HCl(v = 1) in the Cl + alkane reactions. There is some evidence for HCl(v = 1) production in the reaction of Cl with shape n -hexane. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 34: 86,94, 2002 [source] Effect of elevated concentration of alkaline phosphatase on cardiac troponin I assaysJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 4 2001Amitava Dasgupta Abstract Troponin I is the regulatory subunit of troponin complex associated with the actin thin filament within muscle cells. Cardiac troponin I (cTnI) is a good marker for diagnosis of myocardial damage. Several immunoassays are available for determination of cTnI in serum. The Stratus cTnI fluorometric enzyme immunoassay (Dade International) uses alkaline phosphatase (ALP) substrate. The microparticle enzyme immunoassay (MEIA) for cTnI (Abbott Laboratories) also uses ALP conjugate. On the other hand, the chemiluminescent assay (CLIA) for cTnI (Bayer Diagnostics) does not use ALP. ALP activity may frequently be elevated in serum of patients being evaluated for suspected myocardial infarction. Therefore, we studied the potential interference of ALP in cTnI assays. Serum pools were prepared from patients, and various concentrations of ALP solution were added to different aliquots. The cTnI concentrations were measured by the Stratus, MEIA, and CLIA assays. We observed no interference of ALP in the MEIA and CLIA assay for cTnI. On the other hand, we observed significant positive interference of ALP when cTnI concentrations were measured using the Stratus. J. Clin. Lab. Anal. 15:175,177, 2001. © 2001 Wiley-Liss, Inc. [source] Immunoglobulin-E Reactivity to a Glycosylated Food Allergen (Peanuts) Due to Interference With Cross-Reactive Carbohydrate Determinants in Heavy DrinkersALCOHOLISM, Issue 8 2009C. Vidal Background:, N-glycans in plant and invertebrate glycoproteins can induce extensive IgE cross-reactivity therefore limiting the specificity of in vitro allergy tests. IgE sensitization to N-glycans (cross-reactive carbohydrate determinants, CCDs) may be increased in heavy drinkers, who therefore show IgE reactivity to aeroallergens, latex, and Hymenoptera venoms. The peanut, a CCD-bearing allergen, is the leading cause of severe food allergic reactions in many populations. Aim of the study:, To investigate the potential interference of CCDs with determinations of IgE to peanuts in heavy drinkers. Methods:, We determined IgE to peanuts and IgE to a CCD marker (MUXF3, the N-glycan from bromelain) in 41 heavy drinkers admitted to the hospital and 54 healthy controls. None of the participants reported symptoms of peanut allergy. In cases with positive (,0.35 kU/l) IgE to peanuts, we performed inhibition assays with a neoglycoprotein consisting of MUXF3 molecules coupled to bovine serum albumin (MUXF3 -BSA) and a similar neoglycoprotein lacking xylose and fucose (MM-BSA). In the same cases, we screened for IgE to a panel of recombinant nonglycosylated peanut allergens. SDS-PAGE immunoblotting and inhibition assays were performed in selected cases. Results:, The prevalence of positive IgE to peanuts was 22 and 3.7% in heavy drinkers and healthy controls, respectively (p < 0.001). Peanut-IgE positivity was closely related to the presence of IgE to CCDs. In most (8/9) heavy drinkers with positive IgE to peanuts, reactivity was inhibited by preincubation with MUXF3 -BSA, but not with MM-BSA. IgE binding to multiple bands on immunoblotting studies was also inhibited by MUXF3 -BSA preincubation. IgE to nonglycosylated recombinant peanut allergens was uniformly negative. Conclusion:, Heavy drinking is associated with clinically asymptomatic IgE reactivity to peanuts, a relevant food allergen, in relation to CCD interference. [source] Diode laser hair removal does not interfere with botulinum toxin A treatment against axillary hyperhidrosisLASERS IN SURGERY AND MEDICINE, Issue 3 2010Anna Paul MD Abstract Background and Objective The possible interference of combined laser hair removal and Botulinum toxin A (BoNT/A) injections in the treatment of axillary hyperhidrosis has not previously been explored. In order to examine this potential interference, we assessed the effect of BoNT/A on axillary hyperhidrosis with and without concomitant diode laser axillary hair removal. Study Design/Materials and Methods In a prospective, double blind, randomized cross over trial, nine patients suffering from primary axillary hyperhidrosis were laser-treated on one randomly assigned axilla. One week later, both axillas were injected intradermally with BoNT/A (100,MU per axilla). During the same session, the previously untreated axilla was lasered. Axillary sweat rates (in g/5,minutes.) were determined by gravimetry and compared at rest, during mental exercise, and during physical exercise. Additionally, subjective outcome measures were assessed by a visual analogue scale, Dermatology Life Quality Index, and Global Clinical Impression score. Results No differences were found regarding the effect of BoNT/A on previously laser-treated and laser co-treated sides over time course for any of the outcome parameters. Sweat production was reduced 3 weeks after BoNT/A treatment by 93.5% at rest, 96.5% during mental exercise, and 67% during physical exercise. Conclusions Concomitant laser hair removal does not interfere with BoNT/A treatment on axillary hyperhidrosis. Lasers Surg. Med. 42:211,214, 2010. © 2010 Wiley-Liss, Inc. [source] Adsorptive Stripping Voltammetric Determination of Trace Uranium with a Bismuth-Film Electrode Based on the U(VI),U(V) Reduction Step of the Uranium-Cupferron ComplexELECTROANALYSIS, Issue 3 2006Georgia Kefala Abstract This work reports the use of adsorptive stripping voltammetry (AdSV) for the determination of uranium on a preplated rotating-disk bismuth-film electrode (BiFE). The principle of the method relied on the complexation of U(VI) ions with cupferron and the subsequent adsorptive accumulation of the complex on the surface of the BiFE. The uranium in the accumulated complex was then reduced by means of a cathodic voltammetric scan while the analytically useful U(VI),U(V) reduction signal was monitored. The experimental variables as well as potential interferences were investigated and the figures of merit of the method were established. Using the selected conditions, the 3, limit of detection for uranium was 0.1,,g L,1 at a preconcentration time of 480,s and the relative standard deviation was 4.7% at the 5,,g L,1 level for a preconcentration time of 120,s (n=8). The accuracy of the method was established by analyzing a reference sea water sample. [source] Trace Determination of Chromium by Square-Wave Adsorptive Stripping Voltammetry on Bismuth Film ElectrodesELECTROANALYSIS, Issue 21 2004Eleni Chatzitheodorou Abstract This works reports the use of adsorptive stripping voltammetry (AdSV) for the trace determination of chromium on a rotating-disk bismuth-film electrode (BFE). During the reductive accumulation step, all the chromium species in the sample were reduced to Cr(III) which was complexed with cupferron and the complex was accumulated by adsorption on the surface of a preplated BFE. The stripping step was carried out by using a square-wave (SW) potential-time voltammetric signal. Electrochemical cleaning of the bismuth film was employed, enabling the same bismuth film to be used for a series of measurements in the presence of dissolved oxygen. The experimental variables as well as potential interferences were investigated and the figures of merit of the method were established. Using the selected conditions, the 3, limit of detection for chromium was 100,ng L,1 (for 120,s of preconcentration) and the relative standard deviation was 3.6% at the 2,,g L,1 level (n=8). Finally, the method was applied to the determination of chromium in real samples with satisfactory results. [source] Managing oral anticoagulation therapy: improving clinical outcomes.JOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 6 2008A review Summary Many physicians are reluctant to prescribe oral anticoagulation therapy (OAT) because of the fear of haemorrhagic complications. Changes in patient health, lifestyle or diet and other drugs can alter the effectiveness of oral anticoagulants. These potential interferences, added to the fact that each individual has a different reaction to these drugs, requires that therapy is monitored regularly. This article aims to review those strategies which help to achieve optimal anticoagulation control and improve the outcomes of OAT. Relevant articles were identified through a search of MEDLINE and included publications reporting on intensity of anticoagulation, the initiation of therapy and the role of pharmacogenetics, the transition from primary to secondary care, management by specialized clinics using decision support software and home-testing. Implementation of these strategies would increase the use of oral anticoagulants by physicians and offers the potential to improve patient safety and reduce adverse events. [source] | |||||||||||||