487 research outputs found

    Urinary Bisphenol A and Hypertension in a Multiethnic Sample of US Adults

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    Background. Bisphenol A (BPA) is a common chemical used in the manufacture of polycarbonate plastics and epoxy resins, with >93% of US adults having detectable BPA levels in urine. Recent animal studies have suggested that BPA exposure may have a role in several mechanisms involved in the development of hypertension, including weight gain, insulin resistance, thyroid dysfunction, endothelial dysfunction, and oxidative stress. However, no previous human study has examined the association between markers of BPA exposure and hypertension. Methods. We examined urinary BPA levels in 1380 subjects from the National Health and Nutritional Examination Survey 2003-2004. Main outcome-of-interest was hypertension, defined as blood pressure-reducing medication use and/or blood pressures >140/90 mm of Hg (n = 580). Results. We observed a positive association between increasing levels of urinary BPA and hypertension independent of confounding factors such as age, gender, race/ethnicity, smoking, body mass index (BMI), diabetes mellitus and total serum cholesterol levels. Compared to tertile 1 (referent), the multivariate-adjusted odds ratio (95% confidence interval) of hypertension associated with tertile 3 was 1.50 (1.12−2.00); P-trend = 0.007. The association was consistently present in subgroup analyses by race/ethnicity, smoking status, BMI, and diabetes mellitus. Conclusions. Urinary BPA levels are associated with hypertension, independent of traditional risk factors

    Use of the viral 2A peptide for bicistronic expression in transgenic mice

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    <p>Abstract</p> <p>Background</p> <p>Transgenic animals are widely used in biomedical research and biotechnology. Multicistronic constructs, in which several proteins are encoded by a single messenger RNA, are commonly used in genetically engineered animals. This is currently done by using an internal ribosomal entry site to separate the different coding regions. 2A peptides result in the co-translational 'cleavage' of proteins and are an attractive alternative to the internal ribosomal entry site. They are more reliable than the internal ribosomal entry site and lead to expression of multiple cistrons at equimolar levels. They work in a wide variety of eukaryotic cells, but to date have not been demonstrated to function in transgenic mice in an inheritable manner.</p> <p>Results</p> <p>To test 2A function in transgenic mice and uncover any possible toxicity of widespread expression of the 2A peptide, we made a bicistronic reporter construct containing the coding sequence for a membrane localised red fluorescent protein (Myr-TdTomato) and a nuclear localised green fluorescent protein (H2B-GFP), separated by a 2A sequence. When this reporter is transfected into HeLa cells, the two fluorescent proteins correctly localise to mutually exclusive cellular compartments, demonstrating that the bicistronic construct is a reliable readout of 2A function. The two fluorescent proteins also correctly localise when the reporter is electroporated into chick neural tube cells. We made two independent transgenic mouse lines that express the bicistronic reporter ubiquitously. For both lines, transgenic mice are born in Mendelian frequencies and are found to be healthy and fertile. Myr-TdTomato and H2B-GFP segregate to mutually exclusive cellular compartments in all tissues examined from a broad range of developmental stages, ranging from embryo to adult. One transgenic line shows X-linked inheritance of the transgene and mosaic expression in females but uniform expression in males, indicating that the transgene has integrated into the X chromosome in this line.</p> <p>Conclusion</p> <p>The 2A peptide efficiently mediates co-translational cleavage in transgenic mice in which it has been inherited through the germ-line. Mice expressing it ubiquitously throughout development and into adulthood appear normal. It is therefore a viable tool for use in genetically engineered mice and represents a superior alternative to the widely used internal ribosomal entry site.</p

    Markers of Sleep Disordered Breathing and Diabetes Mellitus in a Multiethnic Sample of US Adults: Results from the National Health and Nutrition Examination Survey (2005–2008)

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    We examined gender and ethnic differences in the association between sleep disordered breathing (SDB) and diabetes among 6,522 participants aged ≥20 years from the National Health and Nutrition Examination Survey 2005–08. SDB severity was defined based on an additive summary score including sleep duration, snoring, snorting, and daytime sleepiness. We found that the summary SDB score was significantly associated with diabetes after adjusting for potential confounders in the whole population. Compared to those without any sleep disturbance, the multivariable odds ratio (OR) (95% confidence interval (CI)) of diabetes among those with ≥3 sleep disturbances was 2.04 (1.46–2.87). In sex-specific analyses, this association was significant only in women (OR (95% CI) = 3.68 (2.01–6.72)) but not in men (1.10 (0.59–2.04)), P-interaction = 0.01. However, there were no ethnic differences in this association, P-interaction = 0.7. In a nationally representative sample of US adults, SDB was independently associated with diabetes only in women, but not in men

    Bisphenol A and Metabolic Syndrome: Results from NHANES

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    Background. Bisphenol A (BPA) is detected in the urine of 95% of US adults. Recent evidence from population-based studies suggests that BPA is associated with individual components for metabolic syndrome (MetS). However, no previous study has examined the direct association between BPA and MetS. Methods. We examined 2,104 participants from the National Health and Nutrition Examination Survey 2003–2008. The main outcome was the presence of MetS (). Results. Increasing levels of urinary BPA were positively associated with MetS, independent of confounders such as age, gender, race/ethnicity, smoking, alcohol intake, physical activity, and urinary creatinine. Compared to tertile 1 (referent), the multivariable adjusted odds ratio (95% confidence interval) of MetS in tertile 3 was 1.51 (1.07–2.12); -trend was 0.02. Conclusions. Urinary BPA levels are positively associated with MetS, in a representative sample of US adults and independent of traditional risk factors for MetS. Future, prospective studies are needed to confirm our findings

    INTER CARRIER INTERFERENCE AND SIGNAL TO INTERFERENCE RATIO OF VARIOUS PULSE SHAPING FUNCTIONS USED IN OFDM SYSTEM WITH CARRIER FREQUENCY OFFSET

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    Orthogonal Frequency Division Multiplexing (OFDM) is the important modulation of choice for fourthgeneration broadband multimedia wireless systems. This paper is focused on the problem of reducing the intercarrierinterference (ICI) and signal to noise ratio in the transmission over OFDM using various pulse shaping methods. Here we have performed a detailed performance comparison of various pulse shaping functions used in OFDM System with Carrier Frequency Offset. They appear to be suitable for transmission in OFDM systems with carrier frequency offset. The results obtained by analysis show that the performance improvement over conventional pulse shapes, are significant for reducing average intercarrier-interference (ICI) power and increased ratio of average signal power to average ICI power (SIR)

    Analysis of docosanol using GC/MS: Method development, validation, and application to ex vivo human skin permeation studies

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    Docosanol is the only US Food and Drug Administration (FDA) approved over-the-counter topical product for treating recurrent oral-facial herpes simplex labialis. Validated analytical methods for docosanol are required to demonstrate the bioequivalence of docosanol topical products. A gas chromatography/selected ion monitoring mode mass spectrometry (GC/SIM-MS) method was developed and validated for docosanol determination in biological samples. Docosanol and isopropyl palmitate (internal standard) were separated on a high-polarity GC capillary column with (88% cyanopropy)aryl-polysiloxane employed as the stationary phase. The ions of m/z 83 and 256 were selected to monitor docosanol and isopropyl palmitate, respectively; the total run time was 20 min. The GC/SIM-MS method was validated in accordance with US FDA guidelines, and the results met the US FDA acceptance criteria. The docosanol calibration standards were linear in the 100–10000 ng/mL concentration range (R2\u3e0.994). The recoveries for docosanol from the receptor fluid and skin homogenates were \u3e93.2% and \u3e95.8%, respectively. The validated method was successfully applied to analyze ex vivo human cadaver skin permeation samples. On applying Abreva® cream tube and Abreva® cream pump, the amount of docosanol that penetrated human cadaver skin at 48 h was 21.5 ± 7.01 and 24.0 ± 6.95 ng/mg, respectively. Accordingly, we concluded that the validated GC/SIM-MS was sensitive, specific, and suitable for quantifying docosanol as a quality control tool. This method can be used for routine analysis as a cost-effective alternative to other techniques

    Selection of effective bio-​antagonistic bacteria for biological control of tomato wilt caused by Fusarium oxysporum F. sp. lycopersici

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    Bacteria from the rhizoplane soil and surrounding soil of healthy and Fusarium oxysporum diseased tomato plants of district regions of Karnataka were collected. The best bacterial strains, based on their ability to control development of Fusarium oxysporum isolate, were identified as BS1, BS5 and BS18. All bacterial isolates resulted effective for the in vitro control of growth of Fusarium oxysporum, where the control mechanisms used by the bacteria do not involve the secretion of fungal cell wall hydrolytic enzymes. On the other hand, all bacteria grew well in conditions similar to those that can be found at the field level (considering pH, salinity, Fe3+ and temp.) and showed a good capacity of tomato root colonization. These results suggest that Pseudomonas fluorescens isolates studied have an excellent potential to be used as biocontrol agents of Fusarium oxysporum in tomato greenhouses at the field level

    Biological Control of F. Oxysporum F. Sp. Lycopersici Causing Wilt of Tomato by Pseudomonas Fluorescens

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    Abstract- Pseudomonas fluorescens is one of the major fungal biocontrol agents found in the soil and the rhizosphere of various crop systems. Ten isolates of P.fluorescens were isolated from rhizosphere soil samples collected from various tomato-growing fields and evaluated for their efficacy in increasing seed quality variables of tomato and in inhibiting the mycelial growth of Fusarium oxysporum. Pseudomonas isolate 2 produced effective results and was selected and mass multiplied. Talc and sodium alginate formulations of mass multiplied using different agents were prepared and evaluated for their effects against fusarium wilt under greenhouse conditions. Fresh cultures of Pf2 isolate was found to increase seedling emergence and reduce fusarium wilt disease incidence when compared to the control and the formulations
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