The Experts below are selected from a list of 96 Experts worldwide ranked by ideXlab platform
Oznur Sen - One of the best experts on this subject based on the ideXlab platform.
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The effects of different weaning modes on the endocrine stress response
Critical Care, 2003Co-Authors: Guniz Meyanci Koksal, Cem Sayilgan, Oznur SenAbstract:Introduction The aim of the present study was to investigate the effects of the stress response on plasma insulin, cortisol, glucose, and urinary Vanilmandelic Acid during weaning and after extubation, using pressure support (PS), continuous positive airway pressure (CPAP) and T-piece modes. Methods Sixty patients were randomly divided into three groups ( n = 20). The PS group received FiO_2 ≤ 0.4, PS ≤ 10 cmH_2O, and positive end expiratory pressure ≤ 5 cmH_2O for 2 hours. The CPAP group was given FiO_2 ≤ 0.4 and CPAP 5 ≤ cmH_2O for 2 hours. The T-piece group (group T) received 4 l/min oxygen via a T-piece for 2 hours. After 1 hour and 2 hours in their respective weaning modes, blood and urine samples were taken for insulin, cortisol, glucose and Vanilmandelic Acid measurements. Forty-eight hours after extubation, blood and urine samples were again taken. Results Plasma insulin was greater in group T than in the PS and CPAP groups ( P < 0.01 and P < 0.01). The plasma cortisol concentration was greater in group T than in group PS during weaning ( P < 0.05) and after extubation ( P < 0.05). Blood glucose concentrations were greater in group T than in the other groups (both P < 0.01) both during weaning and post extubation. Urine Vanilmandelic Acid was greater in group T than in the other groups during weaning and after extubation (both P < 0.001). Conclusion Weaning via the T-piece caused a greater stress response than the PS and CPAP modes.
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The effects of different weaning modes on the endocrine stress response.
Critical care (London England), 2003Co-Authors: Guniz Meyanci Koksal, Cem Sayilgan, Oznur SenAbstract:Introduction The aim of the present study was to investigate the effects of the stress response on plasma insulin, cortisol, glucose, and urinary Vanilmandelic Acid during weaning and after extubation, using pressure support (PS), continuous positive airway pressure (CPAP) and T-piece modes.
Neil W. Barnett - One of the best experts on this subject based on the ideXlab platform.
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A hybrid FIA/HPLC system incorporating monolithic column chromatography
Analytica Chimica Acta, 2007Co-Authors: Jacqui L. Adcock, Paul S. Francis, Kent M. Agg, Graham D. Marshall, Neil W. BarnettAbstract:We have combined the generation of solvent gradients using milliGAT pumps, chromatographic separations with monolithic columns and chemiluminescence detection in an instrument manifold that approaches the automation and separation efficiency of HPLC, whilst maintaining the positive attributes of flow injection analysis (FIA), such as manifold versatility, speed of analysis and portability. As preliminary demonstrations of this hybrid FIA/HPLC system, we have determined six opiate alkaloids (morphine, pseudomorphine, codeine, oripavine, ethylmorphine and thebaine) and four biogenic amines (Vanilmandelic Acid, serotonin, 5-hydroxyindole-3-acetic Acid and homovanillic Acid) in human urine, using tris(2,2'-bipyridyl)ruthenium(III) and Acidic potassium permanganate chemiluminescence detection.
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Determination of α,4-dihydroxy-3-methoxybenzeneacetic Acid (Vanilmandelic Acid) by flow injection analysis coupled with luminol–hexacyanoferrate(III) chemiluminescence detection
Analytical Communications, 1999Co-Authors: Neil W. Barnett, Paul S. Francis, Simon W. Lewis, Kieran F. LimAbstract:A simple and robust method for the determination of the clinically significant molecule Vanilmandelic Acid (α,4-dihydroxy-3-methoxybenzeneacetic Acid, 4-hydroxy-3-methoxymandelic Acid) using flow injection analysis with chemiluminescence detection is described. This compound was found to enhance the chemiluminescence from the reaction of luminol with hexacyanoferrate(III) in a basic medium. The calibration function obtained over the range from 2.5 × 10–8 to 1.0 × 10–6 mol dm–3 approximated to linearity (r2 = 0.9995) with the equation of best fit of y = 1.72 × 108x + 36.9, where y is the integrated signal (V s) and x is the concentration (mol dm–3). Precision (as measured by relative standard deviation) was 2.6% for 5 replicate analyses of a standard (2.5 × 10–7 mol dm–3) and the limit of detection (3σ) was 2 × 10–8 mol dm–3. Preliminary investigations revealed that the structurally similar homovanillic Acid inhibits the emission of chemiluminescence from the luminol–hexacyanoferrate(III) reaction and that the kinetics of light emission were different from those of the Vanilmandelic Acid enhanced reaction.
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determination of α 4 dihydroxy 3 methoxybenzeneacetic Acid Vanilmandelic Acid by flow injection analysis coupled with luminol hexacyanoferrate iii chemiluminescence detection
Analytical Communications, 1999Co-Authors: Neil W. Barnett, Paul S. Francis, Simon W. Lewis, Kieran F. LimAbstract:A simple and robust method for the determination of the clinically significant molecule Vanilmandelic Acid (α,4-dihydroxy-3-methoxybenzeneacetic Acid, 4-hydroxy-3-methoxymandelic Acid) using flow injection analysis with chemiluminescence detection is described. This compound was found to enhance the chemiluminescence from the reaction of luminol with hexacyanoferrate(III) in a basic medium. The calibration function obtained over the range from 2.5 × 10–8 to 1.0 × 10–6 mol dm–3 approximated to linearity (r2 = 0.9995) with the equation of best fit of y = 1.72 × 108x + 36.9, where y is the integrated signal (V s) and x is the concentration (mol dm–3). Precision (as measured by relative standard deviation) was 2.6% for 5 replicate analyses of a standard (2.5 × 10–7 mol dm–3) and the limit of detection (3σ) was 2 × 10–8 mol dm–3. Preliminary investigations revealed that the structurally similar homovanillic Acid inhibits the emission of chemiluminescence from the luminol–hexacyanoferrate(III) reaction and that the kinetics of light emission were different from those of the Vanilmandelic Acid enhanced reaction.
Guniz Meyanci Koksal - One of the best experts on this subject based on the ideXlab platform.
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The effects of different weaning modes on the endocrine stress response
Critical Care, 2003Co-Authors: Guniz Meyanci Koksal, Cem Sayilgan, Oznur SenAbstract:Introduction The aim of the present study was to investigate the effects of the stress response on plasma insulin, cortisol, glucose, and urinary Vanilmandelic Acid during weaning and after extubation, using pressure support (PS), continuous positive airway pressure (CPAP) and T-piece modes. Methods Sixty patients were randomly divided into three groups ( n = 20). The PS group received FiO_2 ≤ 0.4, PS ≤ 10 cmH_2O, and positive end expiratory pressure ≤ 5 cmH_2O for 2 hours. The CPAP group was given FiO_2 ≤ 0.4 and CPAP 5 ≤ cmH_2O for 2 hours. The T-piece group (group T) received 4 l/min oxygen via a T-piece for 2 hours. After 1 hour and 2 hours in their respective weaning modes, blood and urine samples were taken for insulin, cortisol, glucose and Vanilmandelic Acid measurements. Forty-eight hours after extubation, blood and urine samples were again taken. Results Plasma insulin was greater in group T than in the PS and CPAP groups ( P < 0.01 and P < 0.01). The plasma cortisol concentration was greater in group T than in group PS during weaning ( P < 0.05) and after extubation ( P < 0.05). Blood glucose concentrations were greater in group T than in the other groups (both P < 0.01) both during weaning and post extubation. Urine Vanilmandelic Acid was greater in group T than in the other groups during weaning and after extubation (both P < 0.001). Conclusion Weaning via the T-piece caused a greater stress response than the PS and CPAP modes.
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The effects of different weaning modes on the endocrine stress response.
Critical care (London England), 2003Co-Authors: Guniz Meyanci Koksal, Cem Sayilgan, Oznur SenAbstract:Introduction The aim of the present study was to investigate the effects of the stress response on plasma insulin, cortisol, glucose, and urinary Vanilmandelic Acid during weaning and after extubation, using pressure support (PS), continuous positive airway pressure (CPAP) and T-piece modes.
Kenji Iwasaki - One of the best experts on this subject based on the ideXlab platform.
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Rapid and simple analysis of urinary Vanilmandelic Acid by high-performance liquid chromatography with electrochemical detection.
Industrial health, 1999Co-Authors: Takeshi Sasaki, Tatsuo Oka, Naomi Hisanaga, Kenji IwasakiAbstract:We examined an analytical method for urinary Vanilmandelic Acid (VMA) by high-performance liquid chromatography with electrochemical detection from the viewpoint of practical analysis and application. The sample pretreatment in our method is only the dilution of urine samples with citrate buffer. The calibration curve for VMA was linear within the range 0.2 to 20 ng. The detection limit was 50 pg at a signal-to-noise ratio of 3 and the coefficients of variation were 2.30-4.30%. Variations in the urinary levels of VMA, noradrenaline (NA) and adrenaline (Ad) during and after exercise were investigated for 5 males (mean +/- SD, 42.4 +/- 4.3 years of age). The high levels of urinary NA and Ad during 1 hr exercise rapidly decreased after exercise, whereas urinary VMA increased after exercise rather than during exercise and decreased later. The correlation of the urinary levels of VMA and NA for 71 salesman (mean +/- SD, 40.6 +/- 11.7 years of age) in a field study was significantly positive (r = 0.426, p < 0.001). These results suggest that urinary VMA mostly reflects NA, but the excretion rate of VMA is slower than that of NA.
Sadanobu Kagamimori - One of the best experts on this subject based on the ideXlab platform.
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Job strain does not relate to morning level Vanilmandelic Acid in Japanese civil servants.
Journal of epidemiology, 2002Co-Authors: Ali Nasermoaddeli, Michikazu Sekine, Shimako Hamanishi, Sadanobu KagamimoriAbstract:Epidemiologic and clinical studies have related acute and, less frequently, chronic life stress to cardiovascular diseases. In addition, animal models suggest that chronic psychological stress could cause atherosclerosis, probably by increasing sympathetic activation. In this cross-sectional study we evaluated the association between job strain, as one of the markers of workplace stress, and the urinary excretion of Vanilmandelic Acid (VMA) upon awakening as a sympathoadrenal activity marker in the morning. Subjects were 936 male and 823 female civil servants working in departments related to the municipality of a city in Toyama Prefecture, Japan, in the spring of 2001. VMA was measured by high-performance liquid chromatography. We found that there was an age dependent increase in the level of VMA and females had higher VMA levels than males. Males who were current smokers had significantly lower VMA levels than nonsmokers after adjusting for age. Job strain level did not relate to VMA concentration in urine after adjusting for age and smoking status both in men and women. In addition, working and sleeping hours as predictor variables were also not associated with urinary VMA levels upon awakening in the morning. In conclusion, it seems that job strain does not independently relate to the sympathoadrenal activity, but the interaction between job strain and other variables such as personal characteristics and environmental factors and their relation with sympathoadrenal activity should further be explored.
