The effect of supplementary antioxidant therapy in patients who report hypersensitivity to electricity: a randomized controlled trial.
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CONTEXT: Hypersensitivity to electricity is a proposed environmental illness of unknown etiology. Patients report a variety of symptoms that they relate to electric equipment. The afflicted individuals suffer from ill health. Many interventions have been tried but, to date, there is no one specific treatment that has been proven superior to other remedial actions. In general, there is a lack of controlled prospective studies. OBJECTIVE: To test the hypothesis that antioxidant therapy reduces symptoms and improves health in patients reporting hypersensitivity to electricity. DESIGN: Randomized, double-blind, crossover, placebo-controlled study. SETTING: Patients referred to the Environmental Illness Research Centre, Stockholm County Council. PATIENTS: Sixteen patients reporting hypersensitivity to electricity. INTERVENTION: Antioxidant supplementation (vitamins C and E, selenium). MAIN OUTCOME MEASURES: Self-reported symptoms and reported degree of hypersensitivity to electricity, serum levels of uric acid and diphenylpycrylhydrazyl (DPPH). RESULTS: The results indicated no significant differences in reported symptoms, reported hypersensitivity to electricity, or oxidative status in serum between periods of antioxidant and placebo treatments. Serum levels of DPPH and uric acid showed no correlation with the reported degree of symptoms or hypersensitivity to electricity. CONCLUSIONS: The study did not show any beneficial effect of antioxidant supplementation for patients reporting hypersensitivity to electricity. The results do not support the hypothesis that oxidative stress is a major contributor to ill health in patients who report hypersensitivity to electricity. (+info)
Filtration of native and glycated beta2-microglobulin by charged and neutral dialysis membranes.
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BACKGROUND: It has been postulated that protein glycation and formation of advanced glycation end products (AGE) are among toxic factors in chronic uremia, whether the renal disease is of diabetic or nondiabetic origin. In this setting, AGE-modified beta2-microglobulin (beta2m) may favor dialysis beta2m-related dialysis amyloidosis. Consequently, efficient removal of modified beta2m by highly permeable dialysis membranes is as important as removal of native beta2m to postpone the development of dialysis amyloidosis. METHODS: To define the role of dialysis membrane surface electronegativity on plasma protein transfer, an in vitro model was used to test the interactions of native and glycated beta2m with various highly permeable dialysis membranes. An experimental circuit with minidialyzers was used. The neutral high-flux polysulfone membrane (PS), the electronegative polymethylmetacrylate membrane (PMMA), the electronegative AN69 membrane and a modified AN69 membrane, the surface of which was neutralized with polyethyleneimine (AN69-PEI), were tested using both native beta2m and the more acidic glycated beta2m. Protein mass transfer and binding to the membrane were measured. RESULTS: Mass transfer of glycated beta2m was significantly decreased through all membranes tested when compared with native beta2m. This result was due to the increased molecular weight of beta2m, which became less permeable to porous membranes, whereas adsorption of both native and glycated beta2m to membranes, due to ionic interactions, decreased similarly with AN69 and AN69-PEI, but remained unchanged with PS and PMMA. Moreover, surface neutralization of AN69 membrane did not alter its core binding capacity, since beta2m absorption accounted for 98 and 97% and glycated beta2m for 83.7 and 81.4% of the protein removed with AN69 and AN69-PEI, respectively. CONCLUSION: Clearance of glycated beta2m through highly permeable neutral and negatively charged membranes was lower than that of native beta2m, reflecting a decreased sieving coefficient for the neoformed higher molecular weight and conformationally altered molecule. The binding capacity of the neutral PS was roughly half that of the charged membranes. Neutralizing surface electronegativity of the AN69 membrane with PEI did not alter its binding capacity. These results suggest that it would be useful for dialysis protocols to include comparative studies of both serum native and modified beta2m in order to prevent beta2m-amyloidosis. (+info)
Effects of electric and magnetic fields from high-power lines on female urinary excretion of 6-sulfatoxymelatonin.
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In 1998, the authors studied the effect of residential exposure to electric and magnetic fields from high-power lines on female urinary excretion of 6-sulfatoxymelatonin (6-OHMS) in the Quebec city, Canada, metropolitan area. A sample of 221 women living near a 735-kV line was compared with 195 women the same age living away from any power lines. Participants provided morning urine samples on 2 consecutive days and wore a magnetic dosimeter for 36 consecutive hours to measure personal magnetic exposure. The indoor electric field was assessed by spot measurements. After adjustment for other factors associated with low melatonin secretion, such as medication use or light exposure, nighttime concentration of 6-OHMS was similar in the two groups. When either 24-hour or sleep-time exposure to magnetic field or electric field measurements was used, no exposure-effect relation was evident. However, the trend of decreasing 6-OHMS concentration with age was more pronounced for women living near the lines, as was a lower 6-OHMS concentration in women with high body mass index. Chronic residential exposure to magnetic fields from high-power lines may accentuate the decrease in melatonin secretion observed in some vulnerable subgroups of the population. (+info)
Do electric patient beds reduce the risk of lower back disorders in nurses?
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The aim of this study was to compare the probability estimates of lower back disorder (LBD) for a nurse performing a range of simulated patient care activities involving manual and electric patient beds. Studies of simulated patient care involving patient beds were undertaken using electrically powered and manually operated patient beds. The estimated probabilities of back injury, as calculated by the Lumbar Motion Monitor (LMM), between the two beds were compared statistically. A statistically significant reduction in LBD probability was observed in those functions that were completely achieved by the electrical mechanism. No significant difference in risk was observed in the patient care activities involving manipulating the patient in and around the bed that are more typical of 'heavy' orthopaedic nursing care in a busy acute ward environment. A potential for increased patient independence was observed during this trial. The LMM recorded no real risk reduction between situations involving electric or manual patient beds in those actions typically required of nurses in an acute orthopaedic ward caring for a disabled patient. (+info)
Effect of weak electric current on reducing oral bacteria in vitro.
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The ions generated by weak electric current may be used for removal of dental plaque. Also, it has been judged from changes in the viable bacterial cell count and the amount of adenosine triphosphate (ATP) in the saliva that the passage of such a current also has a bactericidal effect on the oral microflora. We confirmed in vitro that 0.5 and 1.0 mA currents that passed for 10 min through phosphate buffered saline containing salivary bacteria were effective in killing the bacteria. (+info)
Photoelectric properties and detection of the aromatic carcinogens benza[a]pyrene and dimethylbenzanthracene.
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The absolute photoelectron quantum yield spectra for benzo[a]pyrene and dimethylbenzanthracene are presented in the wavelength range 180--230 nm. These polycyclic aromatic carcinogens have photoelectron quantum yields of approximately 2 x 10(-3) electrons per incident photon at 180 nm. The quantum yields fall off quickly and monotonically at wavelengths longer than 210 nm (5.9 eV). Threshold values for benzo[a]pyrene and dimethylbenzanthracene are 5.25 +/- 0.06 cV and 5.27 +/- 0.04 eV, respectively. The photoelectron quantum yields of benzo[a]pyrene and dimethylbenzanthracene are several orders of magnitude greater than typical components of biological membranes (amino acids, phospholipids, and polysaccharides). Preliminary micrographs of benzo[a]pyrene and dimethylbenzanthracene sublimed onto poly(L-lysine) and onto dimyristoyl phosphatidylcholine demonstrate the high contrast of small crystallites of carcinogens against a background of membrane components. These results and calculations involving relative contrast factors suggest that the distribution of these carcinogens in biological membranes can be determined by using photoelectron microscopy. (+info)
Initial energy setting, outcome and efficiency in direct current cardioversion of atrial fibrillation and flutter.
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OBJECTIVES: The purpose of this study was to design a more efficient protocol for the electrical cardioversion of atrial arrhythmias. BACKGROUND: Guidelines for electrical cardioversion of atrial arrhythmias recommend starting with low energy shocks, which are often ineffective. METHODS: We recorded the sequence of shocks in 1,838 attempts at cardioversion for atrial fibrillation (AF) and 678 attempts at cardioversion for atrial flutter. These data were used to calculate the probability of success for each shock of a standard series and the probability of success with a single shock at each intensity. In 150 cases, a rhythm strip with the time of each shock allowed us to calculate the time expended on unsuccessful shocks. RESULTS: We analyzed the effects of 5,152 shocks delivered to patients for AF and 1,238 shocks delivered to patients for atrial flutter. The probability of success on the first shock in AF of > 30 days duration was 5.5% at < 200 J, 35% at 200 J and 56% at 360 J. In atrial flutter, an initial 100 J shock worked in 68%. In AF of >30 days duration, shocks of < 200 J had a 6.1% probability of success; this fell to 2.2% with a duration >180 days. In those with AF for >180 days, the initial use of a 360 J shock was associated with the eventual use of less electrical energy than with an initial shock of < or =100 J (581 +/- 316 J vs. 758 +/- 433 J, p < 0.01, Mann-Whitney U test). CONCLUSIONS: An initial energy setting of > or =360 J can achieve cardioversion of AF more efficiently in patients than traditional protocols, particularly with AF of longer duration. (+info)
Hydrogen production. Green algae as a source of energy.
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Hydrogen gas is thought to be the ideal fuel for a world in which air pollution has been alleviated, global warming has been arrested, and the environment has been protected in an economically sustainable manner. Hydrogen and electricity could team to provide attractive options in transportation and power generation. Interconversion between these two forms of energy suggests on-site utilization of hydrogen to generate electricity, with the electrical power grid serving in energy transportation, distribution utilization, and hydrogen regeneration as needed. A challenging problem in establishing H(2) as a source of energy for the future is the renewable and environmentally friendly generation of large quantities of H(2) gas. Thus, processes that are presently conceptual in nature, or at a developmental stage in the laboratory, need to be encouraged, tested for feasibility, and otherwise applied toward commercialization. (+info)