Sample records for aa uric acid

  1. Characterization of the radical-scavenging reaction of 2-O-substituted ascorbic acid derivatives, AA-2G, AA-2P, and AA-2S: a kinetic and stoichiometric study.

    PubMed

    Takebayashi, Jun; Tai, Akihiro; Gohda, Eiichi; Yamamoto, Itaru

    2006-04-01

    The aim of this study was to characterize the antioxidant activity of three ascorbic acid (AA) derivatives O-substituted at the C-2 position of AA: ascorbic acid 2-glucoside (AA-2G), ascorbic acid 2-phosphate (AA-2P), and ascorbic acid 2-sulfate (AA-2S). The radical-scavenging activities of these AA derivatives and some common low molecular-weight antioxidants such as uric acid or glutathione against 1,1-diphenyl-picrylhydrazyl (DPPH) radical, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS+), or galvinoxyl radical were kinetically and stoichiometrically evaluated under pH-controlled conditions. Those AA derivatives slowly and continuously reacted with DPPH radical and ABTS+, but not with galvinoxyl radical. They effectively reacted with DPPH radical under acidic conditions and with ABTS+ under neutral conditions. In contrast, AA immediately quenched all species of radicals tested at all pH values investigated. The reactivity of Trolox, a water-soluble vitamin E analogue, was comparable to that of AA in terms of kinetics and stoichiometrics. Uric acid and glutathione exhibited long-lasting radical-scavenging activity against these radicals under certain pH conditions. The radical-scavenging profiles of AA derivatives were closer to those of uric acid and glutathione rather than to that of AA. The number of radicals scavenged by one molecule of AA derivatives, uric acid, or glutathione was equal to or greater than that by AA or Trolox under the appropriate conditions. These data suggest the potential usage of AA derivatives as radical scavengers.

  2. Uric acid - urine

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003616.htm Uric acid urine test To use the sharing features on this page, please enable JavaScript. The uric acid urine test measures the level of uric acid ...

  3. Uric acid nephrolithiasis: An update.

    PubMed

    Cicerello, Elisa

    2018-04-01

    Uric acid nephrolithiasis appears to increase in prevalence. While a relationship between uric acid stones and low urinary pH has been for long known, additional association with various metabolic conditions and pathophysiological basis has recently been elucidated. Some conditions such as diabetes and metabolic syndrome disease, excessive dietary intake, and increased endogenous uric acid production and/or defect in ammoniagenesis are associated with low urinary pH. In addition, the phenomenon of global warming could result in an increase in areas with greater climate risk for uric acid stone formation. There are three therapeutic steps to be taken for management of uric acid stones: identification of urinary pH profiles, assessment of urinary volume status, and identification of disorders leading to excessive uric acid production. However, the most important factor for uric acid stone formation is acid urinary pH, which is a prerequisite for uric acid precipitation. This article reviews recent insights into the pathophysiology of uric acid stones and their management.

  4. Uric acid test (image)

    MedlinePlus

    Uric acid urine test is performed to check for the amount of uric acid in urine. Urine is collected over a 24 ... for testing. The most common reason for measuring uric acid levels is in the diagnosis or treatment of ...

  5. Crystallization of uric acid

    NASA Astrophysics Data System (ADS)

    Kalkura, S. Narayana; Vaidyan, V. K.; Kanakavel, M.; Ramasamy, P.

    1993-09-01

    Crystals of uric acid have been grown in tetra methoxy silane and silica gel medium. Small winged, transparent, platy crystals of uric acid of about 0.5x0.5x0.1 mm were grown and were found to be hydrated uric acid.

  6. Theobromine Inhibits Uric Acid Crystallization. A Potential Application in the Treatment of Uric Acid Nephrolithiasis

    PubMed Central

    Grases, Felix; Rodriguez, Adrian; Costa-Bauza, Antonia

    2014-01-01

    Purpose To assess the capacity of methylxanthines (caffeine, theophylline, theobromine and paraxanthine) to inhibit uric acid crystallization, and to evaluate their potential application in the treatment of uric acid nephrolithiasis. Materials and Methods The ability of methylxathines to inhibit uric acid nucleation was assayed turbidimetrically. Crystal morphology and its modification due to the effect of theobromine were evaluated by scanning electron microscopy (SEM). The ability of theobromine to inhibit uric acid crystal growth on calculi fragments resulting from extracorporeal shock wave lithotripsy (ESWL) was evaluated using a flow system. Results The turbidimetric assay showed that among the studied methylxanthines, theobromine could markedly inhibit uric acid nucleation. SEM images showed that the presence of theobromine resulted in thinner uric acid crystals. Furthermore, in a flow system theobromine blocked the regrowth of post-ESWL uric acid calculi fragments. Conclusions Theobromine, a natural dimethylxanthine present in high amounts in cocoa, acts as an inhibitor of nucleation and crystal growth of uric acid. Therefore, theobromine may be clinically useful in the treatment of uric acid nephrolithiasis. PMID:25333633

  7. Electrochemical Sensing of Dopamine, Uric Acid and Ascorbic Acid Using tRGO-TiO2 Nanocomposites.

    PubMed

    Rajamani, A R; Kannan, Rajesh; Krishnan, Sruthy; Ramakrishnan, S; Raj, S Mohan; Kumaresan, D; Kothurkar, Nikhil; Rangarajan, Murali

    2015-07-01

    This work reports a graphene-based nonenzymatic electrochemical sensing platform for the detection of dopamine (DA), uric acid (UA), and ascorbic acid (AA). Graphene oxide, synthesized by modified Hummers method, was thermally reduced in an induction furnace at 200 °C in an Ar-H2 atmosphere to obtain thermally reduced graphene oxide (tRGO). Nanocomposites of tRGO-TiO2 were obtained by a hydrothermal method, and were characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD). FTIR spectra showed Ti-O-C peaks, indicating covalent linkage between the TiO2 nanoparticles and the reduced graphene oxide sheets. Glassy carbon electrode (GCE) was modified with the nanocomposite (tRGO-TiO2-GCE), and the modified electrode could detect dopamine (DA: 1 to 1000 µM), uric acid (UA: 1 to 900 µM), and ascorbic acid (AA: 10 to 1000 µM) in each other's presence over wide ranges, with adequate separation in peak potentials. Differential pulse voltammetry experiments yielded linear responses with sensitivities of 133.18, 33.96, and 155.59 µA mM(-1) cm(-2) for DA, UA, and AA, respectively.

  8. Uric Acid, Hyperuricemia and Vascular Diseases

    PubMed Central

    Jin, Ming; Yang, Fan; Yang, Irene; Yin, Ying; Luo, Jin Jun; Wang, Hong; Yang, Xiao-Feng

    2011-01-01

    Uric acid is the product of purine metabolism. It is known that hyperuricemia, defined as high levels of blood uric acid, is the major etiological factor of gout. A number of epidemiological reports have increasingly linked hyperuricemia with cardiovascular and neurological diseases. Studies highlighting the pathogenic mechanisms of uric acid point to an inflammatory response as the primary mechanism for inducing gout and possibly contributing to uric acid's vascular effects. Monosodium urate (MSU) crystals induce an inflammatory reaction, which are recognized by Toll-like receptors (TLRs). These TLRs then activate NALP3 inflammasome. MSU also triggers neutrophil activation and further produces immune mediators, which lead to a proinflammatory response. In addition, soluble uric acid can also mediate the generation of free radicals and function as a pro-oxidant. This review summarizes the epidemiological studies of hyperuricemia and cardiovascular disease, takes a brief look at hyperuricemia and its role in neurological diseases, and highlights the studies of the advanced pathological mechanisms of uric acid and inflammation. PMID:22201767

  9. Uric Acid in Pregnancy: New Concepts.

    PubMed

    Moreno Santillan, Armando Alberto; Briones Garduño, Jesus Carlos; Diaz de Leon Ponce, Manuel Antonio

    2018-01-01

    The relationship between hyperuricemia and hypertensive disorders is well established; however, until today, the role of uric acid in the clinical course of severe preeclampsia has not been elucidated. Some recent studies suggest that at the time of presentation, subjects with severe preeclampsia frequently have significantly elevated serum uric acid levels, and that the degree of elevation correlates with the severity of the maternal syndrome and fetal morbimortality. In this chapter, we present our workgroup experience. In 2016, we designed a prospective, cross-sectional comparative study. A sample of 200 patients - 100 with severe preeclampsia and 100 with normotensive pregnancy - was obtained. Plasmatic uric acid levels were recorded in units of mg/dL as clinical variables and as laboratory and fetal growth data. We considered uric acid equal to or more than 6.0 mg/dL as the elevated level. To relate the significance of elevated uric acid levels with variables, chi-square tests and Mann-Whitney U test were applied. Any p value equal or <0.05 was accepted as significant. We found significant difference (p = 0.05) between serum uric acid levels among both groups. In comparison with the healthy patients, patients with severe preeclampsia and uric acid greater than 6 mg/dl presented significant differences in relation to fetal complications and maternal laboratory and clinical variables. Our conclusion is that values equal to or greater than 6 mg/dL of serum uric acid in patients with severe preeclampsia may be a valuable biomarker for preeclampsia and an association with the presence of adverse fetal and maternal effects. © 2018 S. Karger AG, Basel.

  10. Simultaneous determination of ascorbic acid, dopamine and uric acid based on tryptophan functionalized graphene.

    PubMed

    Lian, Qianwen; He, Zhifang; He, Qian; Luo, Ai; Yan, Kaiwang; Zhang, Dongxia; Lu, Xiaoquan; Zhou, Xibin

    2014-05-01

    A new type of tryptophan-functionalized graphene nanocomposite (Trp-GR) was synthesized by utilizing a facile ultrasonic method via π-π conjugate action between graphene (GR) and tryptophan (Trp) molecule. The material as prepared had well dispersivity in water and better conductivity than pure GR. The surface morphology of Trp-GR was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The electrochemical behaviors of ascorbic acid (AA), dopamine (DA), and uric acid (UA) were investigated by cyclic voltammetry (CV) on the surface of Trp-GR. The separation of the oxidation peak potentials for AA-DA, DA-UA and UA-AA was about 182 mV, 125 mV and 307 mV, which allowed simultaneously determining AA, DA, and UA. Differential pulse voltammetery (DPV) was used for the determination of AA, DA, and UA in their mixture. Under optimum conditions, the linear response ranges for the determination of AA, DA, and UA were 0.2-12.9 mM, 0.5-110 μM, and 10-1000 μM, with the detection limits (S/N=3) of 10.09 μM, 0.29 μM and 1.24 μM, respectively. Furthermore, the modified electrode was investigated for real sample analysis. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  11. Urine alkalization facilitates uric acid excretion

    PubMed Central

    2010-01-01

    Background Increase in the incidence of hyperuricemia associated with gout as well as hypertension, renal diseases and cardiovascular diseases has been a public health concern. We examined the possibility of facilitated excretion of uric acid by change in urine pH by managing food materials. Methods Within the framework of the Japanese government's health promotion program, we made recipes which consist of protein-rich and less vegetable-fruit food materials for H+-load (acid diet) and others composed of less protein but vegetable-fruit rich food materials (alkali diet). Healthy female students were enrolled in this consecutive 5-day study for each test. From whole-day collected urine, total volume, pH, organic acid, creatinine, uric acid and all cations (Na+,K+,Ca2+,Mg2+,NH4+) and anions (Cl-,SO42-,PO4-) necessary for the estimation of acid-base balance were measured. Results Urine pH reached a steady state 3 days after switching from ordinary daily diets to specified regimens. The amount of acid generated ([SO42-] +organic acid-gut alkai) were linearly related with those of the excretion of acid (titratable acidity+ [NH4+] - [HCO3-]), indicating that H+ in urine is generated by the metabolic degradation of food materials. Uric acid and excreted urine pH retained a linear relationship, where uric acid excretion increased from 302 mg/day at pH 5.9 to 413 mg/day at pH 6.5, despite the fact that the alkali diet contained a smaller purine load than the acid diet. Conclusion We conclude that alkalization of urine by eating nutritionally well-designed food is effective for removing uric acid from the body. PMID:20955624

  12. Uric acid and progression of chronic kidney disease.

    PubMed

    Weaver, Donald J

    2018-06-21

    The association between serum uric acid levels and human disease has garnered intense interest over the last decade including chronic kidney disease. Animal studies have provided evidence for a potential mechanistic role of uric acid in promoting progression of chronic kidney disease. Epidemiologic studies have also suggested an association between elevated serum uric acid levels and worsening renal function in the general population as well as in patients with chronic kidney disease. However, there is currently insufficient evidence to recommend the use of uric acid-lowering therapy to delay progression of chronic kidney disease in this patient population. Adequately powered, randomized, placebo-controlled trials are required to more precisely evaluate the risk and benefits of uric acid-lowering therapy in pediatric patients.

  13. Uric acid detection using uv-vis spectrometer

    NASA Astrophysics Data System (ADS)

    Norazmi, N.; Rasad, Z. R. Abdul; Mohamad, M.; Manap, H.

    2017-10-01

    The aim of this research is to detect uric acid (UA) concentration using Ultraviolet-Visible (UV-Vis) spectrometer in the Ultraviolet (UV) region. Absorption technique was proposed to detect different uric acid concentrations and its UV absorption wavelength. Current practices commonly take a lot of times or require complicated structures for the detection process. By this proposed spectroscopic technique, every concentration can be detected and interpreted into an absorbance value at a constant wavelength peak in the UV region. This is due to the chemical characteristics belong to the uric acid since it has a particular absorption cross-section, σ which can be calculated using Beer’s Lambert law formula. The detection performance was displayed using Spectrasuite sofware. It showed fast time response about 3 seconds. The experiment proved that the concentrations of uric acid were successfully detected using UV-Vis spectrometer at a constant absorption UV wavelength, 294.46 nm in a low time response. Even by an artificial sample of uric acid, it successfully displayed a close value as the ones reported with the use of the medical sample. It is applicable in the medical field and can be implemented in the future for earlier detection of abnormal concentration of uric acid.

  14. Recent advances on uric acid transporters

    PubMed Central

    Xu, Liuqing; Shi, Yingfeng; Zhuang, Shougang; Liu, Na

    2017-01-01

    Uric acid is the product of purine metabolism and its increased levels result in hyperuricemia. A number of epidemiological reports link hyperuricemia with multiple disorders, such as kidney diseases, cardiovascular diseases and diabetes. Recent studies also showed that expression and functional changes of urate transporters are associated with hyperuricemia. Uric acid transporters are divided into two categories: urate reabsorption transporters, including urate anion transporter 1 (URAT1), organic anion transporter 4 (OAT4) and glucose transporter 9 (GLUT9), and urate excretion transporetrs, including OAT1, OAT3, urate transporter (UAT), multidrug resistance protein 4 (MRP4/ABCC4), ABCG-2 and sodium-dependent phosphate transport protein. In the kidney, uric acid transporters decrease the reabsorption of urate and increase its secretion. These transporters’ dysfunction would lead to hyperuricemia. As the function of urate transporters is important to control the level of serum uric acid, studies on the functional role of uric acid transporter may provide a new strategy to treat hyperuricemia associated diseases, such as gout, chronic kidney disease, hyperlipidemia, hypertension, coronary heart disease, diabetes and other disorders. This review article summarizes the physiology of urate reabsorption and excretion transporters and highlights the recent advances on their roles in hyperuricemia and various diseases. PMID:29246027

  15. The simultaneous electrochemical detection of ascorbic acid, dopamine, and uric acid using graphene/size-selected Pt nanocomposites.

    PubMed

    Sun, Chia-Liang; Lee, Hsin-Hsien; Yang, Jen-Ming; Wu, Ching-Chou

    2011-04-15

    In this study, a graphene/Pt-modified glassy carbon (GC) electrode was created to simultaneously characterize ascorbic acid (AA), dopamine (DA), and uric acid (UA) levels via cyclic voltammetry (CV) and differential pulse voltammetry (DPV). During the preparation of the nanocomposite, size-selected Pt nanoparticles with a mean diameter of 1.7 nm were self-assembled onto the graphene surface. In the simultaneous detection of the three aforementioned analytes using CV, the electrochemical potential differences among the three detected peaks were 185 mV (AA to DA), 144 mV (DA to UA), and 329 mV (AA and UA), respectively. In comparison to the CV results of bare GC and graphene-modified GC electrodes, the large electrochemical potential difference that is achieved via the use of the graphene/Pt nanocomposites is essential to the distinguishing of these three analytes. An optimized adsorption of size-selected Pt colloidal nanoparticles onto the graphene surface results in a graphene/Pt nanocomposite that can provide a good platform for the routine analysis of AA, DA, and UA. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Serum uric acid levels are associated with homeostasis model assessment in obese nondiabetic patients: HOMA and uric acid.

    PubMed

    Elizalde-Barrera, Cesar I; Estrada-García, Teresa; Lozano-Nuevo, Jose J; Garro-Almendaro, Ana K; López-Saucedo, Catalina; Rubio-Guerra, Alberto F

    2017-10-01

    Hyperuricemia leads to insulin resistance, whereas insulin resistance decreases renal excretion of uric acid. The aim of this study was to evaluate whether there is a correlation between serum uric acid levels with homeostatic model assessment (HOMA) 1 in nondiabetic patients. We evaluated 88 nondiabetic patients, in whom uric acid levels were measured, in all of them HOMA of β-cell function (HOMA 1B) and HOMA of insulin resistance (HOMA 1IR) scores were performed. Uric acid and the HOMA 1 values were correlated using the Pearson coefficient. We did not find any correlation between uric acid levels with both HOMA 1B ( r = 0.102, p = 0.343), nor with HOMA 1IR ( r = 0.158, p = 0.117). When patients were analyzed by sex, we found a significant correlation with HOMA 1IR (0.278, p = 0.01), but not with HOMA 1B (0.138, p = 0.257) in women. We found a correlation with HOMA 1B in men ( r = 0.37, p = 0.044), but not with HOMA 1IR: 0.203, p = 0.283. The analysis performed based on body mass index did not show correlation in the patients with normal weight, (HOMA 1B r = 0.08, p = 0.5, HOMA 1IR = 0.034, p = 0.793), nor in the patients who were overweight (HOMA 1B: r = 0.05, p = 0.76, HOMA 1IR r = 0.145, p = 0.43). However, a significant correlation between uricemia with both HOMA 1B (0.559, p < 0.001), and HOMA 1IR (0.326, p < 0.05), was observed in obese patients. Our results suggest that serum uric acid levels seem to be associated with insulin resistance in women, and in obese patients, but not in nonobese men. Uric acid also modifies β-cell function in men and in obese patients.

  17. Regulation of uric acid metabolism and excretion.

    PubMed

    Maiuolo, Jessica; Oppedisano, Francesca; Gratteri, Santo; Muscoli, Carolina; Mollace, Vincenzo

    2016-06-15

    Purines perform many important functions in the cell, being the formation of the monomeric precursors of nucleic acids DNA and RNA the most relevant one. Purines which also contribute to modulate energy metabolism and signal transduction, are structural components of some coenzymes and have been shown to play important roles in the physiology of platelets, muscles and neurotransmission. All cells require a balanced quantity of purines for growth, proliferation and survival. Under physiological conditions the enzymes involved in the purine metabolism maintain in the cell a balanced ratio between their synthesis and degradation. In humans the final compound of purines catabolism is uric acid. All other mammals possess the enzyme uricase that converts uric acid to allantoin that is easily eliminated through urine. Overproduction of uric acid, generated from the metabolism of purines, has been proven to play emerging roles in human disease. In fact the increase of serum uric acid is inversely associated with disease severity and especially with cardiovascular disease states. This review describes the enzymatic pathways involved in the degradation of purines, getting into their structure and biochemistry until the uric acid formation. Copyright © 2015. Published by Elsevier Ireland Ltd.

  18. Uric Acid Levels in Normotensive Children of Hypertensive Parents.

    PubMed

    Yildirim, Ali; Keles, Fatma; Kosger, Pelin; Ozdemir, Gokmen; Ucar, Birsen; Kilic, Zubeyir

    2015-01-01

    This study evaluated uric acid concentrations in normotensive children of parents with hypertension. Eighty normotensive children from families with and without a history of essential hypertension were included. Concentrations of lipid parameters and uric acid were compared. Demographic and anthropometric characteristics were similar in the groups. Systolic and diastolic blood pressure were higher in the normotensive children of parents with hypertension without statistically significant difference (P > 0.05). Uric acid concentrations were higher in the normotensive children of parents with hypertension (4.61 versus 3.57 mg/dL, P < 0.01). Total cholesterol and triglyceride concentrations were similar in the two groups. Systolic and diastolic blood pressure were significantly higher in control children aged >10 years (P < 0.01). Uric acid levels were significantly higher in all children with more pronounced difference after age 10 of years (P < 0.001). Positive correlations were found between the level of serum uric acid and age, body weight, body mass index, and systolic and diastolic blood pressure in the normotensive children of parents. The higher uric acid levels in the normotensive children of hypertensive parents suggest that uric acid may be a predeterminant of hypertension. Monitoring of uric acid levels in these children may allow for prevention or earlier treatment of future hypertension.

  19. Uric Acid and Antioxidant Effects of Wine

    PubMed Central

    Boban, Mladen; Modun, Darko

    2010-01-01

    The aim of this article is to review the role of uric acid in the context of antioxidant effects of wine and its potential implication to human health. We described and discussed the mechanisms of increase in plasma antioxidant capacity after consumption of moderate amounts of wine. Because this effect is largely contributed by acute elevation in plasma uric acid, we paid special attention to wine constituents and metabolic processes that are likely to be involved in uric acid elevation. PMID:20162741

  20. Novel graphene flowers modified carbon fibers for simultaneous determination of ascorbic acid, dopamine and uric acid.

    PubMed

    Du, Jiao; Yue, Ruirui; Ren, Fangfang; Yao, Zhangquan; Jiang, Fengxing; Yang, Ping; Du, Yukou

    2014-03-15

    A novel and sensitive carbon fiber electrode (CFE) modified by graphene flowers was prepared and used to simultaneously determine ascorbic acid (AA), dopamine (DA) and uric acid (UA). SEM images showed that beautiful and layer-petal graphene flowers homogeneously bloomed on the surface of CFE. Moreover, sharp and obvious oxidation peaks were found at the obtained electrode when compared with CFE and glassy carbon electrode (GCE) for the oxidation of AA, DA and UA. Also, the linear calibration plots for AA, DA and UA were observed, respectively, in the ranges of 45.4-1489.23 μM, 0.7-45.21 μM and 3.78-183.87 μM in the individual detection of each component. By simultaneously changing the concentrations of AA, DA and UA, their oxidation peaks appeared at -0.05 V, 0.16 V and 2.6 V, and the good linear responses ranges were 73.52-2305.53 μM, 1.36-125.69 μM and 3.98-371.49 μM, respectively. In addition, the obtained electrode showed satisfactory results when applied to the determination of AA, DA and UA in urine and serum samples. © 2013 Elsevier B.V. All rights reserved.

  1. Parabanic acid is the singlet oxygen specific oxidation product of uric acid.

    PubMed

    Iida, Sayaka; Ohkubo, Yuki; Yamamoto, Yorihiro; Fujisawa, Akio

    2017-11-01

    Uric acid quenches singlet oxygen physically or reacts with it, but the oxidation product has not been previously characterized. The present study determined that the product is parabanic acid, which was confirmed by LC/TOFMS analysis. Parabanic acid was stable at acidic pH (<5.0), but hydrolyzed to oxaluric acid at neutral or alkaline pH. The total yields of parabanic acid and oxaluric acid based on consumed uric acid were ~100% in clean singlet oxygen production systems such as UVA irradiation of Rose Bengal and thermal decomposition of 3-(1,4-dihydro-1,4-epidioxy-4-methyl-1-naphthyl)propionic acid. However, the ratio of the amount of uric acid consumed to the total amount of singlet oxygen generated was less than 1/180, indicating that most of the singlet oxygen was physically quenched. The total yields of parabanic acid and oxaluric acid were high in the uric acid oxidation systems with hydrogen peroxide plus hypochlorite or peroxynitrite. They became less than a few percent in peroxyl radical-, hypochlorite- or peroxynitrite-induced oxidation of uric acid. These results suggest that parabanic acid could be an in vivo probe of singlet oxygen formation because of the wide distribution of uric acid in human tissues and extracellular spaces. In fact, sunlight exposure significantly increased human skin levels of parabanic acid.

  2. Uric acid stones increase the risk of chronic kidney disease.

    PubMed

    Li, Ching-Chia; Chien, Tsu-Ming; Wu, Wen-Jeng; Huang, Chun-Nung; Chou, Yii-Her

    2018-02-28

    The aim of this study was to compare the clinical characteristics of uric acid stones and their potential risk for chronic kidney disease (CKD). A total of 401 patients (196 with uric acid stone and 205 without) were enrolled from our database of patients with urolithiasis. We analyzed the clinical demographic features, stone location, urine chemistries, and renal function. There was a significant difference (p < 0.001) between the two groups in terms of age, with the higher mean age in the uric acid group. Patients with uric acid stones had much lower pH of urine (p < 0.001) and higher serum uric acid level (p = 0.002). Notably, those with uric acid stones had worse eGFR than those with non-uric acid stones. Multivariate analysis confirmed that age over 60 years (ORs = 9.19; 95% CI 3.5-24.3), female sex (ORs = 4.01; 95% CI 1.8-9.0), hyperuricemia (ORs = 8.47; 95% CI 1.6-43.5), and uric acid stone (OR = 2.86; 95% CI 1.2-6.7) were the independent predictors of poor prognoses in CKD. Therefore, an association exists between uric acid stones and higher prevalence of CKD. Patients with uric acid stones may need close monitoring of renal function during follow-up.

  3. Uric acid contributes greatly to hepatic antioxidant capacity besides protein.

    PubMed

    Mikami, T; Sorimachi, M

    2017-12-20

    Uric acid is the end-product of purine nucleotide metabolism and an increase in uric acid concentration in the body results in hyperuricemia, ultimately leading to gout. However, uric acid is a potent antioxidant and interacts with reactive oxygen species (ROS) to be non-enzymatically converted to allantoin. Uric acid accounts for approximately 60 % of antioxidant capacity in the plasma; however, its contribution to tissue antioxidant capacity is unknown. In this study, the contribution of uric acid to tissue antioxidant capacity and its conversion to allantoin by scavenging ROS in tissue were examined. The results showed that a decrease in hepatic uric acid content via allopurinol administration significantly reduced hepatic total-radical trapping antioxidant parameter (TRAP) content in protein-free cytosol. Additionally, treating protein-free cytosol with uricase led to a further reduction of hepatic TRAP content. Allantoin was also detected in the solution containing protein-free cytosol that reacted with ROS. These findings suggest that in the absence of protein, uric acid contributes greatly to antioxidant capacity in the liver, where uric acid is converted to allantoin by scavenging ROS.

  4. Functionalized-graphene modified graphite electrode for the selective determination of dopamine in presence of uric acid and ascorbic acid.

    PubMed

    Mallesha, Malledevaru; Manjunatha, Revanasiddappa; Nethravathi, C; Suresh, Gurukar Shivappa; Rajamathi, Michael; Melo, Jose Savio; Venkatesha, Thimmappa Venkatarangaiah

    2011-06-01

    Graphene is chemically synthesized by solvothermal reduction of colloidal dispersions of graphite oxide. Graphite electrode is modified with functionalized-graphene for electrochemical applications. Electrochemical characterization of functionalized-graphene modified graphite electrode (FGGE) is carried out by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The behavior of FGGE towards ascorbic acid (AA), dopamine (DA) and uric acid (UA) has been investigated by CV, differential pulse voltammetry (DPV) and chronoamperommetry (CA). The FGGE showed excellent catalytic activity towards electrochemical oxidation of AA, DA and UA compared to that of the bare graphite electrode. The electrochemical oxidation signals of AA, DA and UA are well separated into three distinct peaks with peak potential separation of 193mv, 172mv and 264mV between AA-DA, DA-UA and AA-UA respectively in CV studies and the corresponding peak potential separations in DPV mode are 204mv, 141mv and 345mv. The FGGE is successfully used for the simultaneous detection of AA, DA and UA in their ternary mixture and DA in serum and pharmaceutical samples. The excellent electrocatalytic behavior of FGGE may lead to new applications in electrochemical analysis. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Uric Acid Nephrolithiasis: A Systemic Metabolic Disorder

    PubMed Central

    Moe, Orson W.

    2014-01-01

    Uric acid nephrolithiasis is characteristically a manifestation of a systemic metabolic disorder. It has a prevalence of about 10% among all stone formers, the third most common type of kidney stone in the industrialized world. Uric acid stones form primarily due to an unduly acid urine; less deciding factors are hyperuricosuria and a low urine volume. The vast majority of uric acid stone formers have the metabolic syndrome, and not infrequently, clinical gout is present as well. A universal finding is a low baseline urine pH plus insufficient production of urinary ammonium buffer. Persons with gastrointestinal disorders, in particular chronic diarrhea or ostomies, and patients with malignancies with a large tumor mass and high cell turnover comprise a less common but nevertheless important subset. Pure uric acid stones are radiolucent but well visualized on renal ultrasound. A 24 h urine collection for stone risk analysis provides essential insight into the pathophysiology of stone formation and may guide therapy. Management includes a liberal fluid intake and dietary modification. Potassium citrate to alkalinize the urine to a goal pH between 6 and 6.5 is essential, as undissociated uric acid deprotonates into its much more soluble urate form. PMID:25045326

  6. Uric acid ameliorates indomethacin-induced enteropathy in mice through its antioxidant activity.

    PubMed

    Yasutake, Yuichi; Tomita, Kengo; Higashiyama, Masaaki; Furuhashi, Hirotaka; Shirakabe, Kazuhiko; Takajo, Takeshi; Maruta, Koji; Sato, Hirokazu; Narimatsu, Kazuyuki; Yoshikawa, Kenichi; Okada, Yoshikiyo; Kurihara, Chie; Watanabe, Chikako; Komoto, Shunsuke; Nagao, Shigeaki; Matsuo, Hirotaka; Miura, Soichiro; Hokari, Ryota

    2017-11-01

    Uric acid is excreted from blood into the intestinal lumen, yet the roles of uric acid in intestinal diseases remain to be elucidated. The study aimed to determine whether uric acid could reduce end points associated with nonsteroidal anti-inflammatory drug (NSAID)-induced enteropathy. A mouse model of NSAID-induced enteropathy was generated by administering indomethacin intraperitoneally to 8-week-old male C57BL/6 mice, and then vehicle or uric acid was administered orally. A group of mice treated with indomethacin was also concurrently administered inosinic acid, a uric acid precursor, and potassium oxonate, an inhibitor of uric acid metabolism, intraperitoneally. For in vitro analysis, Caco-2 cells treated with indomethacin were incubated in the presence or absence of uric acid. Oral administration of uric acid ameliorated NSAID-induced enteropathy in mice even though serum uric acid levels did not increase. Intraperitoneal administration of inosinic acid and potassium oxonate significantly elevated serum uric acid levels and ameliorated NSAID-induced enteropathy in mice. Both oral uric acid treatment and intraperitoneal treatment with inosinic acid and potassium oxonate significantly decreased lipid peroxidation in the ileum of mice with NSAID-induced enteropathy. Treatment with uric acid protected Caco-2 cells from indomethacin-induced oxidative stress, lipid peroxidation, and cytotoxicity. Uric acid within the intestinal lumen and in serum had a protective effect against NSAID-induced enteropathy in mice, through its antioxidant activity. Uric acid could be a promising therapeutic target for NSAID-induced enteropathy. © 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  7. An electrochemical sensor for simultaneous determination of ascorbic acid, dopamine, uric acid and tryptophan based on MWNTs bridged mesocellular graphene foam nanocomposite.

    PubMed

    Li, Huixiang; Wang, Yi; Ye, Daixin; Luo, Juan; Su, Biquan; Zhang, Song; Kong, Jilie

    2014-09-01

    A multi-walled carbon nanotubes (MWNTs) bridged mesocellular graphene foam (MGF) nanocomposite (MWNTs/MGF) modified glassy carbon electrode was fabricated and successfully used for simultaneous determination of ascorbic acid (AA), dopamine (DA), uric acid (UA) and tryptophan (TRP). Comparing with pure MGF, MWNTs or MWNTs/GS (graphene sheets), MWNTs/MGF displayed higher catalytic activity and selectivity toward the oxidation of AA, DA, UA and TRP. Under the optimal conditions, MWCNs/MGF/GCE can simultaneously detect AA, DA, UA and TRP with high selectivity and sensitivity. The detection limits were 18.28 µmol L(-1), 0.06 µmol L(-1), 0.93 µmol L(-1) and 0.87 µmol L(-1), respectively. Moreover, the modified electrode exhibited excellent stability and reproducibility. Copyright © 2014. Published by Elsevier B.V.

  8. Enhancement of renal excretion of uric acid during long-term thiazide therapy.

    PubMed

    Pak, C Y; Tolentino, R; Stewart, A; Galosy, R A

    1978-11-01

    The effect of thiazide (hydrochlorothiazide 100 mg per day orally in two divided doses for up to 3 years) on uric acid metabolism was examined in 21 patients with renal stones suffering from renal hypercalciuria or absorptive hypercalciuria. Serum concentration of uric acid increased during thiazide therapy in every patient. In 12 of 21 patients, there was a transient or persistent rise in urinary uric acid of more than 50 mg per day during treatment. The mean urinary uric acid produced by thiazide was positively correlated with the change in the renal clearance of uric acid. Thus, an increase in urinary uric acid was often associated with a rise in uric acid clearance. The results suggest that thiazide may either increase the production of uric acid or decrease the extrarenal disposal of uric acid, in some patients.

  9. Prevalence of renal uric acid stones in the adult.

    PubMed

    Trinchieri, Alberto; Montanari, Emanuele

    2017-12-01

    The aim of this study was to estimate uric acid renal stone prevalence rates of adults in different countries of the world. PubMed was searched for papers dealing with "urinary calculi and prevalence or composition" for the period from January 1996 to June 2016. Alternative searches were made to collect further information on specific topics. The prevalence rate of uric acid stones was computed by the general renal stone prevalence rate and the frequency of uric acid stones in each country. After the initial search, 2180 papers were extracted. Out of them, 79 papers were selected after the reading of the titles and of the abstracts. For ten countries, papers relating to both the renal stone prevalence in the general population and the frequency of uric stones were available. Additional search produced 13 papers that completed information on 11 more countries in 5 continents. Estimated prevalence rate of uric acid stones was >0.75% in Thailand, Pakistan, Saudi Arabia, Iran, South Africa (white population), United States and Australia; ranged 0.50-0.75% in Turkey, Israel, Italy, India (Southern), Spain, Taiwan, Germany, Brazil; and <0.50% in Tunisia, China, Korea, Japan, Caribe, South Africa (blacks), India (Northern). Climate and diet are major determinants of uric acid stone formation. A hot and dry climate increases fluid losses reducing urinary volume and urinary pH. A diet rich in meat protein causes low urinary pH and increased uric acid excretion. On the other hand, uric acid stone formation is frequently associated with obesity, metabolic syndrome and diabetes type 2 that are linked to dietary energy excess mainly from carbohydrate and saturated fat and also present with low urine pH values. An epidemic of uric acid stone formation could be if current nutritional trends will be maintained both in developed countries and in developing countries and the areas of greater climatic risk for the formation of uric acid stones will enlarge as result of the "global

  10. Efficacy of Vitamin C in Lowering Serum Uric Acid.

    PubMed

    Choudhury, M R; Haq, S M; Saleh, A A; Hakim, F; Azad, A K

    2016-10-01

    The objective of the study was to determine the efficacy of vitamin C in reducing serum uric acid (UA). This study was a double-blind placebo-controlled randomized trial conducted in the Department of Rheumatology, Bangabandhu Sheikh Mujib Medical University (BSMMU) Dhaka, Bangladesh from July 2007 and August 2008. Study participants were included from out patient department (OPD) of Rheumatology of BSMMU suffering from various Rheumatological problems other than gouty arthritis. All of the participants were non-smokers, non-alcoholics, and randomized to take either placebo or vitamin C (500 mg/day) for 12 weeks. A total of 98 subjects were enrolled in the study; 71 completed the trial, with 34 in the placebo group and 37 receiving vitamin C. Serum uric acid levels were not significantly reduced in the experimental group and they increased in the placebo group. In the vitamin C group, the mean change was -0.32mg/dl [95% confidence interval -0.73, 0.77], whereas in the placebo group, the mean change was +0.12mg/dl [95% confidence interval was -0.22, 0.47]. Subgroups were defined by sex, body mass index, and quartiles of baseline serum uric acid levels. In a subgroup analysis, vitamin C lowered serum uric acid significantly in those who had comparatively higher baseline uric acid levels. Although vitamin C did not lower serum uric acid significantly, participants with higher baseline serum uric acid levels experienced a significant uric acid lowering effect, but as the sample size was very small, it is difficult to draw any definitive conclusion.

  11. The Epidemiology of Uric Acid and Fructose

    PubMed Central

    Rho, Young Hee; Zhu, Yanyan; Choi, Hyon K.

    2011-01-01

    During the past few decades, the mean serum uric acid levels and the prevalence of hyperuricemia in the general population appear to have increased. Correspondingly, the prevalence and incidence of gout have doubled. Potential reasons behind these trends include the increasing prevalence of obesity and metabolic syndrome, western life-style factors, increased prevalence of medical conditions (e.g. renal conditions, hypertension, and cardiovascular disorders) and use of medications that increase uric acid levels (e.g. diuretics and low-dose aspirin). The substantial increase in sugar-sweetened soft drinks and associated fructose consumption has also coincided with the secular trend of hyperuricemia and gout. Recently, several large-scale epidemiologic studies have clarified a number of these long-suspected risk factors in relation with hyperuricemia and gout. Furthermore, recent studies have illuminated the substantial comorbidities of hyperuricemia and gout, particularly metabolic-cardiovascular-renal conditions. While many prospective studies have suggested an independent association between serum uric acid levels and the future risk of cardiovascular-metabolic morbidities and mortality, only a limited number of randomized clinical trials and observational studies have recently demonstrated that the use of allopurinol can be beneficial against these outcomes. As these data are scarce and the effects of allopurinol might not be limited to lowering serum uric acid levels, the potential causal role of uric acid on these outcomes remains to be clarified with further studies. PMID:22000647

  12. Portable electrochemical sensor based on 4-aminobenzoic acid-functionalized herringbone carbon nanotubes for the determination of ascorbic acid and uric acid in human fluids.

    PubMed

    Abellán-Llobregat, A; González-Gaitán, C; Vidal, L; Canals, A; Morallón, E

    2018-06-30

    A new portable electrochemical sensor based on 4-aminobenzoic acid-modified herringbone carbon nanotubes (hCNTs-4ABA/Au-IDA) has been developed for the simultaneous determination of ascorbic acid (AA) and uric acid (UA) in physiological fluids. AA and UA were quantified by chronoamperometry at 0.1 and 0.32 V, respectively, in phosphate buffer solution (PBS 0.25 M, pH 7.0). Significant results were obtained for the separate quantification of AA and UA, with a limit of detection (LOD) of 0.65 μM for both analytes, and sensitivities of (9.0 ± 0.4) A g -1 mM -1 and (8.8 ± 0.3) A g -1 mM -1 for AA and UA, respectively. Repeatability was studied at 50 μM for AA and UA, providing relative standard deviations (RSD) lower than 9%. Additions of glucose, dopamine and epinephrine did not interfere with the AA and UA determination. Furthermore, UA did not interfere with AA determination at 0.1 V, although AA additions increased the current recorded at 0.32 V. The method has been successfully applied to human urine, perspiration and serum samples, without significant matrix effects, which allows for the use of an external calibration and the analysis of all the matrices investigated. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Uric acid disrupts hypochlorous acid production and the bactericidal activity of HL-60 cells.

    PubMed

    Carvalho, Larissa A C; Lopes, João P P B; Kaihami, Gilberto H; Silva, Railmara P; Bruni-Cardoso, Alexandre; Baldini, Regina L; Meotti, Flavia C

    2018-06-01

    Uric acid is the end product of purine metabolism in humans and is an alternative physiological substrate for myeloperoxidase. Oxidation of uric acid by this enzyme generates uric acid free radical and urate hydroperoxide, a strong oxidant and potentially bactericide agent. In this study, we investigated whether the oxidation of uric acid and production of urate hydroperoxide would affect the killing activity of HL-60 cells differentiated into neutrophil-like cells (dHL-60) against a highly virulent strain (PA14) of the opportunistic pathogen Pseudomonas aeruginosa. While bacterial cell counts decrease due to dHL-60 killing, incubation with uric acid inhibits this activity, also decreasing the release of the inflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF- α). In a myeloperoxidase/Cl - /H 2 O 2 cell-free system, uric acid inhibited the production of HOCl and bacterial killing. Fluorescence microscopy showed that uric acid also decreased the levels of HOCl produced by dHL-60 cells, while significantly increased superoxide production. Uric acid did not alter the overall oxidative status of dHL-60 cells as measured by the ratio of reduced (GSH) and oxidized (GSSG) glutathione. Our data show that uric acid impairs the killing activity of dHL-60 cells likely by competing with chloride by myeloperoxidase catalysis, decreasing HOCl production. Despite diminishing HOCl, uric acid probably stimulates the formation of other oxidants, maintaining the overall oxidative status of the cells. Altogether, our results demonstrated that HOCl is, indeed, the main relevant oxidant against bacteria and deviation of myeloperoxidase activity to produce other oxidants hampers dHL-60 killing activity. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Low uric acid is a risk factor in mild cognitive impairment.

    PubMed

    Xue, LingLing; Liu, YongBing; Xue, HuiPing; Xue, Jin; Sun, KaiXuan; Wu, LinFeng; Hou, Ping

    2017-01-01

    Mild cognitive impairment (MCI) represents a transitional stage between normal aging and dementia. Uric acid is a water-soluble antioxidant found in the body. Many recent studies have found that uric acid plays an important role in cognitive impairment, although the effects of uric acid on MCI are not clear. The objective of this study was to explore the relationship between uric acid and MCI. Using a random sampling method, this study investigated 58 patients with MCI and 57 healthy elderly from January 2016 to November 2016. Demographic information was collected, the subjects were evaluated using the Mini Mental Status Examination (MMSE), and uric acid was measured in fasting venous blood. A total of 57 (49.6%) participants are healthy and 58 (50.4%) participants had MCI. The uric acid level was significantly lower in the patients with MCI (292.28±63.71 μmol/L) than in the normal controls (322.49±78.70 μmol/L; P <0.05). There were significant positive correlations between the MMSE scores, for each dimension and the total score, and uric acid level (all P <0.05). Multivariate logistic regression models illustrated that uric acid was a protective factor for MCI (odds ratio =0.999, 95% CI =0.987-0.999). A low uric acid level is a risk factor for MCI, and an appropriate increase in uric acid can be used to slow down the occurrence and development of MCI.

  15. Association Between Uric Acid and Metabolic Syndrome in Elderly Women.

    PubMed

    Wang, Hui-Juan; Shi, Lei-Zhi; Liu, Cun-Fei; Liu, Shi-Min; Shi, Song-Tao

    2018-01-01

    To investigate the relationship between uric acid and metabolic syndrome (MetS) in elderly women. A total of 468 women aged ≥60 years participating in a health examination were enrolled. The association between uric acid and MetS and its individual variables was evaluated by univariate and multivariate logistic regression models. A dose-response relationship was observed for the prevalence of MetS and uric acid quartiles. Subjects in the second, third and fourth quartile of uric acid had a 2.23-fold, 2.25-fold and 4.41-fold increased risk, respectively, of MetS than those in the first uric acid quartile (p for trend <0.001). Furthermore, each 1 mg/dl increment of serum uric acid level had a 1.38-fold increased risk of MetS (OR 1.38; 95% CI, 1.14-1.69; p=0.001). Our present study demonstrated that elevated uric acid was positively associated with the prevalence of MetS in elderly women. Further random control trials are needed to elucidate the effectiveness of treatment of hyperuricaemia in reducing the incidence of MetS in elderly women.

  16. [Percentage of uric acid calculus and its metabolic character in Dongjiang River valley].

    PubMed

    Chong, Hong-Heng; An, Geng

    2009-02-15

    To study the percentage of uric acid calculus in uroliths and its metabolic character in Dongjiang River valley. To analyze the chemical composition of 290 urinary stones by infrared (IR) spectroscopy and study the ratio changes of uric acid calculus. Uric acid calculus patients and healthy people were studied. Personal characteristics, dietary habits were collected. Conditional logistic regression was used for data analysis and studied the dietary risk factors of uric acid calculus. Patients with uric acid calculus, calcium oxalate and those without urinary calculus were undergone metabolic evaluation analysis. The results of uric acid calculus patients compared to another two groups to analysis the relations between the formation of uric acid calculus and metabolism factors. Uric acid calculi were found in 53 cases (18.3%). The multiple logistic regression analysis suggested that low daily water intake, eating more salted and animal food, less vegetable were very closely associated with uric acid calculus. Comparing to calcium oxalate patients, the urine volume, the value of pH, urine calcium, urine oxalic acid were lower, but uric acid was higher than it. The value of pH, urine oxalic acid and citric acid were lower than them, but uric acid and urine calcium were higher than none urinary calculus peoples. Blood potassium and magnesium were lower than them. The percentage of uric acid stones had obvious advanced. Less daily water intake, eating salted food, eating more animal food, less vegetables and daily orange juice intake, eating sea food are the mainly dietary risk factors to the formation of uric acid calculus. Urine volume, the value of pH, citric acid, urine calcium, urine uric acid and the blood natrium, potassium, magnesium, calcium, uric acid have significant influence to the information of uric acid stones.

  17. Uric acid in major depressive and anxiety disorders.

    PubMed

    Black, Catherine N; Bot, Mariska; Scheffer, Peter G; Snieder, Harold; Penninx, Brenda W J H

    2018-01-01

    Uric acid has neuroprotective effects, owing to its antioxidant properties. Lowered antioxidant capacity, causing increased oxidative stress, may be involved in affective disorders and might be altered by antidepressants. This study investigated the association of plasma uric acid, the greatest contributor to blood antioxidant capacity, with major depressive disorder (MDD) and anxiety disorders. Data were from the Netherlands Study of Depression and Anxiety including patients with current (N = 1648), remitted (N = 609) MDD and/or anxiety disorders (of which N = 710 antidepressant users) and 618 controls. Diagnoses were established with the Composite International Diagnostic Interview. Symptom severity was assessed with the Inventory of Depressive Symptoms-Self Report, Beck Anxiety Inventory and Fear Questionnaire. Uric acid was measured in plasma. Analyses were adjusted for sociodemographic, health and lifestyle variables. Plasma uric acid adjusted mean levels were lower in current MDD and/or anxiety disorder(s) (289μmol/l) compared to remitted disorders (298μmol/l, p < .001) and controls (299μmol/l, p < .001; Cohen's d .10). This finding was independent of antidepressant use. Depressive (β-.05, p = .0012), anxiety (β-.04, p = .009) and phobic (β-.03, p = .036) symptom severity, and symptom duration (β-.04, p = .009) were negatively associated with uric acid. Limitations include the lack of data on dietary intake which could be a potential confounding factor. From these cross-sectional findings, the association between uric acid and psychopathology cannot be inferred to be causal. This large scale study finds plasma uric acid levels are lower in current, but not remitted, MDD and/or anxiety disorders, according to a dose-response gradient. This suggests the involvement of decreased antioxidant status in affective disorders, and points to their potential as an avenue for treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Physiological functions and pathogenic potential of uric acid: A review.

    PubMed

    El Ridi, Rashika; Tallima, Hatem

    2017-09-01

    Uric acid is synthesized mainly in the liver, intestines and the vascular endothelium as the end product of an exogenous pool of purines, and endogenously from damaged, dying and dead cells, whereby nucleic acids, adenine and guanine, are degraded into uric acid. Mentioning uric acid generates dread because it is the established etiological agent of the severe, acute and chronic inflammatory arthritis, gout and is implicated in the initiation and progress of the metabolic syndrome. Yet, uric acid is the predominant anti-oxidant molecule in plasma and is necessary and sufficient for induction of type 2 immune responses. These properties may explain its protective potential in neurological and infectious diseases, mainly schistosomiasis. The pivotal protective potential of uric acid against blood-borne pathogens and neurological and autoimmune diseases is yet to be established.

  19. The hippocampal response to psychosocial stress varies with salivary uric acid level

    PubMed Central

    Goodman, Adam M.; Wheelock, Muriah D.; Harnett, Nathaniel G.; Mrug, Sylvie; Granger, Douglas A.; Knight, David C.

    2016-01-01

    Uric acid is a naturally occurring, endogenous compound that impacts mental health. In particular, uric acid levels are associated with emotion-related psychopathology (e.g., anxiety and depression). Therefore, understanding uric acid’s impact on the brain would provide valuable new knowledge regarding neural mechanisms that mediate the relationship between uric acid and mental health. Brain regions including the prefrontal cortex, amygdala, and hippocampus underlie stress reactivity and emotion regulation. Thus, uric acid may impact emotion by modifying the function of these brain regions. The present study used functional magnetic resonance imaging (fMRI) during a psychosocial stress task to investigate the relationship between baseline uric acid levels (in saliva) and brain function. Results demonstrate that activity within the bilateral hippocampal complex varied with uric acid concentrations. Specifically, activity within the hippocampus and surrounding cortex increased as a function of uric acid level. The current findings suggest that uric acid levels modulate stress-related hippocampal activity. Given that the hippocampus has been implicated in emotion regulation during psychosocial stress, the present findings offer a potential mechanism by which uric acid impacts mental health. PMID:27725214

  20. Uric Acid Secretion from Adipose Tissue and Its Increase in Obesity*

    PubMed Central

    Tsushima, Yu; Nishizawa, Hitoshi; Tochino, Yoshihiro; Nakatsuji, Hideaki; Sekimoto, Ryohei; Nagao, Hirofumi; Shirakura, Takashi; Kato, Kenta; Imaizumi, Keiichiro; Takahashi, Hiroyuki; Tamura, Mizuho; Maeda, Norikazu; Funahashi, Tohru; Shimomura, Iichiro

    2013-01-01

    Obesity is often accompanied by hyperuricemia. However, purine metabolism in various tissues, especially regarding uric acid production, has not been fully elucidated. Here we report, using mouse models, that adipose tissue could produce and secrete uric acid through xanthine oxidoreductase (XOR) and that the production was enhanced in obesity. Plasma uric acid was elevated in obese mice and attenuated by administration of the XOR inhibitor febuxostat. Adipose tissue was one of major organs that had abundant expression and activities of XOR, and adipose tissues in obese mice had higher XOR activities than those in control mice. 3T3-L1 and mouse primary mature adipocytes produced and secreted uric acid into culture medium. The secretion was inhibited by febuxostat in a dose-dependent manner or by gene knockdown of XOR. Surgical ischemia in adipose tissue increased local uric acid production and secretion via XOR, with a subsequent increase in circulating uric acid levels. Uric acid secretion from whole adipose tissue was increased in obese mice, and uric acid secretion from 3T3-L1 adipocytes was increased under hypoxia. Our results suggest that purine catabolism in adipose tissue could be enhanced in obesity. PMID:23913681

  1. Morphology-dependent Electrochemical Enhancements of Porous Carbon as Sensitive Determination Platform for Ascorbic Acid, Dopamine and Uric Acid

    NASA Astrophysics Data System (ADS)

    Cheng, Qin; Ji, Liudi; Wu, Kangbing; Zhang, Weikang

    2016-02-01

    Using starch as the carbon precursor and different-sized ZnO naoparticles as the hard template, a series of porous carbon materials for electrochemical sensing were prepared. Experiments of scanning electron microscopy, transmission electron microscopy and Nitrogen adsorption-desorption isotherms reveal that the particle size of ZnO has big impacts on the porous morphology and surface area of the resulting carbon materials. Through ultrasonic dispersion of porous carbon and subsequent solvent evaporation, different sensing interfaces were constructed on the surface of glassy carbon electrode (GCE). The electrochemical behaviors of ascorbic acid (AA), dopamine (DA) and uric acid (UA) were studied. On the surface of porous carbon materials, the accumulation efficiency and electron transfer ability of AA, DA and UA are improved, and consequently their oxidation signals enhance greatly. Moreover, the interface enhancement effects of porous carbon are also controlled by the particle size of hard template. The constructed porous carbon interface displays strong signal amplification ability and holds great promise in constructing a sensitive platform for the simultaneous determination of AA, DA and UA.

  2. Type 2 Diabetes and Uric Acid Nephrolithiasis

    NASA Astrophysics Data System (ADS)

    Maalouf, Naim M.

    2008-09-01

    Type 2 diabetes is associated with an increased propensity for uric acid nephrolithiasis. In individuals with diabetes, this increased risk is due to a lower urine pH that results from obesity, dietary factors, and impaired renal ammoniagenesis. The epidemiology and pathogenesis of uric acid stone disease in patients with diabetes are hereby reviewed, and potential molecular mechanisms are proposed.

  3. A novel and simple strategy for simultaneous determination of dopamine, uric acid and ascorbic acid based on the stacked graphene platelet nanofibers/ionic liquids/chitosan modified electrode.

    PubMed

    Niu, Xiuli; Yang, Wu; Guo, Hao; Ren, Jie; Yang, Fusheng; Gao, Jinzhang

    2012-09-15

    A promising electrochemical sensor for simultaneous determination of dopamine (DA), uric acid (UA) and ascorbic acid (AA) was fabricated based on the stacked graphene platelet nanofibers (SGNF)/ionic liquid (IL)/chitosan (CS) modified electrode. The SGNF/IL/CS modified electrode possessed excellent electrocatalytic activity towards the oxidation of DA, UA and AA with obvious reduction of over-potential and increased peak current, and the separations of oxidation peak potentials of DA-UA, DA-AA, and UA-AA were of 151, 213 and 364 mV, respectively. Under the optimum conditions, the linear range for the detection of DA, UA and AA were 0.05-240, 0.12-260, and 30-350 μM with the lowest detection limits of 0.05, 0.10 and 14.8 μM for DA, UA and AA, respectively. In addition, the electrochemical sensor showed high sensitivity, excellent selectivity, reproducibility and long-term stability. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Electronic structures and spectra of two antioxidants: uric acid and ascorbic acid

    NASA Astrophysics Data System (ADS)

    Shukla, M. K.; Mishra, P. C.

    1996-04-01

    Electronic absorption and fluorescence spectra of aqueous solutions of two well known antioxidants, uric acid and ascorbic acid (vitamin C), have been studied at different pH. The observed spectra have been interpreted in terms of neutral and anionic forms of the molecules with the help of molecular orbital calculations. The N 3 site of uric acid has been shown to be the most acidic. Fluorescence of uric acid seems to originate from an anion of the molecule in a wide pH range. Around pH 3, both the neutral and anionic forms of ascorbic acid appear to be present in aqueous solutions. In aqueous media, ascorbic acid appears to get converted easily to its dehydro form and this conversion does not seem to be reversible. An anion of dehydroascorbic acid seems to be formed on heating dehydroascorbic acid in aqueous solutions.

  5. Uric acid and chronic kidney disease: which is chasing which?

    PubMed Central

    Johnson, Richard J.; Nakagawa, Takahiko; Jalal, Diana; Sánchez-Lozada, Laura Gabriela; Kang, Duk-Hee; Ritz, Eberhard

    2013-01-01

    Serum uric acid is commonly elevated in subjects with chronic kidney disease (CKD), but was historically viewed as an issue of limited interest. Recently, uric acid has been resurrected as a potential contributory risk factor in the development and progression of CKD. Most studies documented that an elevated serum uric acid level independently predicts the development of CKD. Raising the uric acid level in rats can induce glomerular hypertension and renal disease as noted by the development of arteriolosclerosis, glomerular injury and tubulointerstitial fibrosis. Pilot studies suggest that lowering plasma uric acid concentrations may slow the progression of renal disease in subjects with CKD. While further clinical trials are necessary, uric acid is emerging as a potentially modifiable risk factor for CKD. Gout was considered a cause of CKD in the mid-nineteenth century [1], and, prior to the availability of therapies to lower the uric acid level, the development of end-stage renal disease was common in gouty patients. In their large series of gouty subjects Talbott and Terplan found that nearly 100% had variable degrees of CKD at autopsy (arteriolosclerosis, glomerulosclerosis and interstitial fibrosis) [2]. Additional studies showed that during life impaired renal function occurred in half of these subjects [3]. As many of these subjects had urate crystals in their tubules and interstitium, especially in the outer renal medulla, the disease became known as gouty nephropathy. The identity of this condition fell in question as the presence of these crystals may occur in subjects without renal disease; furthermore, the focal location of the crystals could not explain the diffuse renal scarring present. In addition, many subjects with gout also had coexistent conditions such as hypertension and vascular disease, leading some experts to suggest that the renal injury in gout was secondary to these latter conditions rather than to uric acid per se [4]. Indeed, gout was

  6. Anorexia nervosa and uric acid beyond gout: An idea worth researching.

    PubMed

    Simeunovic Ostojic, Mladena; Maas, Joyce

    2018-02-01

    Uric acid is best known for its role in gout-the most prevalent inflammatory arthritis in humans-that is also described as an unusual complication of anorexia nervosa (AN). However, beyond gout, uric acid could also be involved in the pathophysiology and psychopathology of AN, as it has many biological functions serving as a pro- and antioxidant, neuroprotector, neurostimulant, and activator of the immune response. Further, recent research suggests that uric acid could be a biomarker of mood dysfunction, personality traits, and behavioral patterns. This article discusses the hypothesis that uric acid in AN may not be a mere innocent bystander determined solely by AN behavior and its medical complications. In contrast, the relation between uric acid and AN may have evolutionary origin and may be reciprocal, where uric acid regulates some features and pathophysiological processes of AN, including weight and metabolism regulation, oxidative stress, immunity, mood, cognition, and (hyper)activity. © 2018 Wiley Periodicals, Inc.

  7. Does Altered Uric Acid Metabolism Contribute to Diabetic Kidney Disease Pathophysiology?

    PubMed

    Gul, Ambreen; Zager, Philip

    2018-03-01

    Multiple experimental and clinical studies have identified pathways by which uric acid may facilitate the development and progression of chronic kidney disease (CKD) in people with diabetes. However, it remains uncertain if the association of uric acid with CKD represents a pathogenic effect or merely reflects renal impairment. In contrast to many published reports, a recent Mendelian randomization study did not identify a causal link between uric acid and CKD in people with type 1 diabetes. Two recent multicenter randomized control trials, Preventing Early Renal Function Loss in Diabetes (PERL) and FEbuxostat versus placebo rAndomized controlled Trial regarding reduced renal function in patients with Hyperuricemia complicated by chRonic kidney disease stage 3 (FEATHER), were recently designed to assess if uric acid lowering slows progression of CKD. We review the evidence supporting a role for uric acid in the pathogenesis of CKD in people with diabetes and the putative benefits of uric acid lowering.

  8. Uric acid levels in patients with schizophrenia on clozapine monotherapy.

    PubMed

    Wysokiński, Adam; Kłoszewska, Iwona

    2015-08-01

    We tested the hypothesis that uric acid levels are higher in subjects with schizophrenia treated with clozapine than in healthy control and they correlate with anthropometric measurements, laboratory tests and results of bioimpedance analysis of body composition. Data for 24 subjects with schizophrenia treated with clozapine and 24 age- and sex-matched healthy volunteers was analyzed. There was no difference of fasting uric acid concentrations between clozapine and control groups (4.5 ± 1.4 vs. 4.3 ± 1.3 mg/dl, P = 0.87). Regarding the whole group, uric acid levels were significantly higher in men (5.2 ± 1.2 vs. 3.6 ± 0.9, P < 0.001). Uric acid levels correlated with weight (R = 0.58, P = 0.003), body mass index (BMI; R = 0.49, P = 0.01), abdominal circumference (R = 0.45, P = 0.03), waist circumference (R = 0.47, P = 0.02), waist-to-hip ratio (R = 0.42, P = 0.04), insulin (R = 0.50, P = 0.01), homoeostasis model assessment of insulin resistance 2 (HOMA2-IR; R = 0.49, P = 0.01), basal metabolic rate (R = 0.56, P = 0.004), lean body mass (R = 0.55, P = 0.005) and body water (R = 0.55, P = 0.005). There were no significant differences of uric acid levels for smoking status, impaired fasting glucose, abdominal obesity, obesity/overweight and dyslipidemia. Uric acid levels did not correlate with age, duration of clozapine treatment, clozapine dose, leg circumference, systolic blood pressure, diastolic blood pressure, total body fat, triglycerides, total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), homocysteine, corrected calcium, glucose and homoeostasis model assessment of insulin resistance 1 (HOMA1-IR). We did not find significant differences in blood uric acid levels between subjects with schizophrenia and controls. Association with weight, BMI, abdominal and waist circumferences, insulin levels and insulin resistance may support uric acid role as an important cardiovascular risk factor. Association with lean weight may explain

  9. Sensitive electrochemical sensors for simultaneous determination of ascorbic acid, dopamine, and uric acid based on Au@Pd-reduced graphene oxide nanocomposites

    NASA Astrophysics Data System (ADS)

    Jiang, Jingjing; Du, Xuezhong

    2014-09-01

    Sensitive electrochemical sensors were fabricated with reduced graphene oxide-supported Au@Pd (Au@Pd-RGO) nanocomposites by one-step synthesis for individual and simultaneous determination of ascorbic acid (AA), dopamine (DA), and uric acid (UA) with low detection limits and wide concentration ranges. From the Au@Pd-RGO-modified electrodes, well-separated oxidation peaks and enhanced peak currents of AA, DA, and UA were observed owing to the superior conductivity of RGO and the excellent catalytic activity of Au@Pd nanoparticles. For individual detection, the linear responses of AA, DA, and UA were in the concentration ranges of 0.1-1000, 0.01-100, and 0.02-500 μM with detection limits of 0.02, 0.002, and 0.005 μM (S/N = 3), respectively. For simultaneous detection by synchronous change of the concentrations of AA, DA, and UA, the linear response ranges were 1-800, 0.1-100, and 0.1-350 μM with detection limits of 0.28, 0.024, and 0.02 μM (S/N = 3), respectively. The fabricated sensors were further applied to the detection of AA, DA, and UA in urine samples. The Au@Pd-RGO nanocomposites have promising applications in highly sensitive and selective electrochemical sensing.Sensitive electrochemical sensors were fabricated with reduced graphene oxide-supported Au@Pd (Au@Pd-RGO) nanocomposites by one-step synthesis for individual and simultaneous determination of ascorbic acid (AA), dopamine (DA), and uric acid (UA) with low detection limits and wide concentration ranges. From the Au@Pd-RGO-modified electrodes, well-separated oxidation peaks and enhanced peak currents of AA, DA, and UA were observed owing to the superior conductivity of RGO and the excellent catalytic activity of Au@Pd nanoparticles. For individual detection, the linear responses of AA, DA, and UA were in the concentration ranges of 0.1-1000, 0.01-100, and 0.02-500 μM with detection limits of 0.02, 0.002, and 0.005 μM (S/N = 3), respectively. For simultaneous detection by synchronous change of the

  10. Overoxidized polyimidazole/graphene oxide copolymer modified electrode for the simultaneous determination of ascorbic acid, dopamine, uric acid, guanine and adenine.

    PubMed

    Liu, Xiaofang; Zhang, Ling; Wei, Shaping; Chen, Shihong; Ou, Xin; Lu, Qiyi

    2014-07-15

    In the present work, a novel strategy based on overoxidized polyimidazole (PImox) and graphene oxide (GO) copolymer modified electrode was proposed for the simultaneous determination of ascorbic acid (AA), dopamine (DA), uric acid (UA), guanine (G) and adenine (A). The copolymer was characterized by the scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). Due to the synergistic effects between PImox and GO, the proposed electrode exhibited excellent electrochemical catalytic activities and high selectivity and sensitivity toward the oxidation of AA, DA, UA, G and A. The peak separations between AA and DA, AA and UA, UA and G, and G and A were 140 mV, 200 mV, 380 mV and 300 mV, respectively. The linear response ranges for AA, DA, UA, G and A were 75-2275 μM, 12-278 μM, 3.6-249.6 μM, 3.3-103.3 μM and 9.6-215 μM, respectively, and corresponding detection limits were 18 μM, 0.63 μM, 0.59 μM, 0.48 μM and 1.28 μM. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Renal Transport of Uric Acid: Evolving Concepts and Uncertainties

    PubMed Central

    Bobulescu, Ion Alexandru; Moe, Orson W.

    2013-01-01

    In addition to its role as a metabolic waste product, uric acid has been proposed to be an important molecule with multiple functions in human physiology and pathophysiology and may be linked to human diseases beyond nephrolithiasis and gout. Uric acid homeostasis is determined by the balance between production, intestinal secretion, and renal excretion. The kidney is an important regulator of circulating uric acid levels, by reabsorbing around 90% of filtered urate, while being responsible for 60–70% of total body uric acid excretion. Defective renal handling of urate is a frequent pathophysiologic factor underpinning hyperuricemia and gout. In spite of tremendous advances over the past decade, the molecular mechanisms of renal urate transport are still incompletely understood. Many transport proteins are candidate participants in urate handling, with URAT1 and GLUT9 being the best characterized to date. Understanding these transporters is increasingly important for the practicing clinician as new research unveils their physiology, importance in drug action, and genetic association with uric acid levels in human populations. The future may see the introduction of new drugs that specifically act on individual renal urate transporters for the treatment of hyperuricemia and gout. PMID:23089270

  12. Molecularly imprinted titania nanoparticles for selective recognition and assay of uric acid

    NASA Astrophysics Data System (ADS)

    Mujahid, Adnan; Khan, Aimen Idrees; Afzal, Adeel; Hussain, Tajamal; Raza, Muhammad Hamid; Shah, Asma Tufail; uz Zaman, Waheed

    2015-06-01

    Molecularly imprinted titania nanoparticles are su ccessfully synthesized by sol-gel method for the selective recognition of uric acid. Atomic force microscopy is used to study the morphology of uric acid imprinted titania nanoparticles with diameter in the range of 100-150 nm. Scanning electron microscopy images of thick titania layer indicate the formation of fine network of titania nanoparticles with uniform distribution. Molecular imprinting of uric acid as well as its subsequent washing is confirmed by Fourier transformation infrared spectroscopy measurements. Uric acid rebinding studies reveal the recognition capability of imprinted particles in the range of 0.01-0.095 mmol, which is applicable in monitoring normal to elevated levels of uric acid in human blood. The optical shift (signal) of imprinted particles is six times higher in comparison with non-imprinted particles for the same concentration of uric acid. Imprinted titania particles have shown substantially reduced binding affinity toward interfering and structurally related substances, e.g. ascorbic acid and guanine. These results suggest the possible application of titania nanoparticles in uric acid recognition and quantification in blood serum.

  13. Uric acid and allopurinol aggravate absence epileptic activity in Wistar Albino Glaxo Rijswijk rats.

    PubMed

    Lakatos, Renáta Krisztina; Dobolyi, Árpád; Kovács, Zsolt

    2018-05-01

    Uric acid has a role in several physiological and pathophysiological processes. For example, uric acid may facilitate seizure generalization while reducing uric acid level may evoke anticonvulsant/antiepileptic effects. Allopurinol blocks the activity of xanthine oxidase, by which allopurinol inhibits catabolism of hypoxanthine to xanthine and uric acid and, as a consequence, decreases the level of uric acid. Although the modulation of serum uric acid level is a widely used strategy in the treatment of certain diseases, our knowledge regarding the effects of uric acid on epileptic activity is far from complete. Thus, the main aim of this study was the investigation of the effect of uric acid on absence epileptic seizures (spike-wave discharges: SWDs) in a model of human absence epilepsy, the Wistar Albino Glaxo/Rijswijk (WAG/Rij) rat. We investigated the influence of intraperitoneally (i.p.) injected uric acid (100 mg/kg and 200 mg/kg), allopurinol (50 mg/kg and 100 mg/kg), a cyclooxygenase 1 and 2 (COX-1 and COX-2) inhibitor indomethacin (10 mg/kg) and inosine (500 mg/kg) alone and the combined application of allopurinol (50 mg/kg) with uric acid (100 mg/kg) or inosine (500 mg/kg) as well as indomethacin (10 mg/kg) with uric acid (100 mg/kg) and inosine (500 mg/kg) with uric acid (100 mg/kg) on absence epileptic activity. We demonstrated that both uric acid and allopurinol alone significantly increased the number of SWDs whereas indomethacin abolished the uric acid-evoked increase in SWD number. Our results suggest that uric acid and allopurinol have proepileptic effects in WAG/Rij rats. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. 21 CFR 862.1775 - Uric acid test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Uric acid test system. 862.1775 Section 862.1775 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1775 Uric acid test system. (a) Identification. ...

  15. 21 CFR 862.1775 - Uric acid test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Uric acid test system. 862.1775 Section 862.1775 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1775 Uric acid test system. (a) Identification. ...

  16. 21 CFR 862.1775 - Uric acid test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Uric acid test system. 862.1775 Section 862.1775 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1775 Uric acid test system. (a) Identification. ...

  17. 21 CFR 862.1775 - Uric acid test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Uric acid test system. 862.1775 Section 862.1775 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1775 Uric acid test system. (a) Identification. ...

  18. 21 CFR 862.1775 - Uric acid test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Uric acid test system. 862.1775 Section 862.1775 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1775 Uric acid test system. (a) Identification. ...

  19. Association between serum uric acid levels and obesity among university students (China).

    PubMed

    Duan, Ying; Liang, Wei; Zhu, Lijun; Zhang, Ting; Wang, Linghong; Nie, Zhognhua; Chen, Yan; He, Lianping; Jin, Yuelong; Yao, Yingshui

    2015-06-01

    To evaluate the association between serum uric acid and obesity among university students who participated in routine health screening in 2013. In this cross-sectional study, 3529 subjects were analyzed. Obesity categories were classified by BMI levels references in China. And serum uric acid levels were classified by serum uric acid quartiles. Two-sample T-test and Wilcoxon Rank sum test were used to compare age, biochemical and anthropometric parameters of subjects of two genders. Rank correlation used to analyze relationship between serum uric acid and obesity. There were 1285 males (mean age, 19.8 ± 1.3 years) and 2244 females (mean age, 19.9 ± 1.3 years) in this study. Association between 2nd serum uric acid quartile and normal in male are significant and coefficient was 0.519. The 3rd serum uric acid quartile and normal in female was associated significantly (r = 0.173, p = 0.010). And associations between overweight and 3rd and 4th serum uric acid quartiles in female were significant (r = 0.128, p = 0.038 in 1st quartile and r = 0.282, p = 0.004 in 4th quartile). The 4th serum uric acid quartile and Obesity in two gender groups were significantly associated (r = 0.291, p = 0.000 in male and r = 0.484, p = 0.001 in female). High serum uric acid was positively associated with obesity in overweight and obesity group. However, the association was weak between two variables because serum uric acid influenced obesity with other related factors together. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  20. Association Between Serum Levels of Uric Acid and Blood Pressure Tracking in Childhood.

    PubMed

    Park, Bohyun; Lee, Hye Ah; Lee, Sung Hee; Park, Bo Mi; Park, Eun Ae; Kim, Hae Soon; Cho, Su Jin; Park, Hyesook

    2017-07-01

    Recent studies suggest that high levels of serum uric acid of very early life are a result of the in-utero environment and may lead to elevated blood pressure (BP) in adulthood. However, serum uric acid levels can change throughout life. We investigated the effect of serum uric acid levels in childhood on the BP tracking and analysed BP according to changes in serum uric acid levels in early life. A total of 449 children from the Ewha Birth and Growth Cohort study underwent at least 2 follow-up examinations. Data were collected across 3 check-up cycles. Serum uric acid levels, BP, and anthropometric characteristics were assessed at 3, 5, and 7 years of age. Children with a serum uric acid level higher than the median values had significantly increased systolic BP (SBP) and diastolic BP at 3 years of age. Baseline serum uric acid levels measured at 3 years of age, significantly affected subsequent BP in the sex and body mass index adjusted longitudinal data analysis (P < 0.05). Considering the changing pattern of serum uric acid over time, subjects with high uric acid levels at both 3 and 5 years of age had the highest SBP at 7 years of age. These findings suggest the importance of maintaining an adequate level of serum uric acids from the early life. Appropriate monitoring and intervention of uric acid levels in a high-risk group can reduce the risk of a future increased BP. © American Journal of Hypertension, Ltd 2017. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  1. Uric acid is linked to cardiometabolic risk factors in overweight and obese youths.

    PubMed

    Lurbe, Empar; Torro, María Isabel; Alvarez-Pitti, Julio; Redon, Josep; Borghi, Claudio; Redon, Pau

    2018-06-18

    Observational studies have indicated that high levels of serum uric acid are associated with the risk of cardiovascular disease. The aim of the present study is to investigate the association of uric acid with individual cardiometabolic risk factors, as well as their degree of clustering, in overweight and moderate obese youth. Three hundred and thirty-three Caucasians of both sexes (149 women), from 5-18 years of age from those who underwent an assessment of overweight/obesity. Anthropometric parameters, office and 24-h blood pressure measurements and metabolic profile, including HDL-cholesterol, triglycerides, insulin, HOMA index and uric acid were assessed. Uric acid was significantly higher in boys than in girls. A positive significant association between uric acid, and office, daytime and night-time SBP, insulin and triglycerides was observed. When boys and girls were grouped by sex-specific uric acid tertiles, a progressive increment was observed in BMI, BMI z-score and waist circumference as well as fasting insulin and HOMA index. In boys, this was also present in office and ambulatory SBP. Likewise, the number of abnormal metabolic risk factors also increases with the uric acid values and the higher the number of metabolic components the higher the uric acid values. Moreover, in a multiple regression analysis, uric acid was significantly related with male sex, waist circumference, both office and night-time SBP and birth weight. The present study found a positive association between uric acid and blood pressure, insulin and triglycerides. As uric acid levels increase there is a relevant clustering of metabolic risk factors, whereas elevated blood pressure is the risk factor less frequently present. Further studies need to assess the mechanistic link between uric acid and the cardiometabolic risk factors.

  2. Two-stage magnetic orientation of uric acid crystals as gout initiators

    NASA Astrophysics Data System (ADS)

    Takeuchi, Y.; Miyashita, Y.; Mizukawa, Y.; Iwasaka, M.

    2014-01-01

    The present study focuses on the magnetic behavior of uric acid crystals, which are responsible for gout. Under a sub-Tesla (T)-level magnetic field, rotational motion of the crystals, which were caused by diamagnetic torque, was observed. We used horizontal magnetic fields with a maximum magnitude of 500 mT generated by an electromagnet to observe the magnetic orientation of the uric acid microcrystals by a microscope. The uric acid crystals showed a perpendicular magnetic field orientation with a minimum threshold of 130 mT. We speculate that the distinct diamagnetic anisotropy in the uric acid crystals resulted in their rotational responses.

  3. High serum uric acid concentration predicts poor survival in patients with breast cancer.

    PubMed

    Yue, Cai-Feng; Feng, Pin-Ning; Yao, Zhen-Rong; Yu, Xue-Gao; Lin, Wen-Bin; Qian, Yuan-Min; Guo, Yun-Miao; Li, Lai-Sheng; Liu, Min

    2017-10-01

    Uric acid is a product of purine metabolism. Recently, uric acid has gained much attraction in cancer. In this study, we aim to investigate the clinicopathological and prognostic significance of serum uric acid concentration in breast cancer patients. A total of 443 female patients with histopathologically diagnosed breast cancer were included. After a mean follow-up time of 56months, survival was analysed using the Kaplan-Meier method. To further evaluate the prognostic significance of uric acid concentrations, univariate and multivariate Cox regression analyses were applied. Of the clinicopathological parameters, uric acid concentration was associated with age, body mass index, ER status and PR status. Univariate analysis identified that patients with increased uric acid concentration had a significantly inferior overall survival (HR 2.13, 95% CI 1.15-3.94, p=0.016). In multivariate analysis, we found that high uric acid concentration is an independent prognostic factor predicting death, but insufficient to predict local relapse or distant metastasis. Kaplan-Meier analysis indicated that high uric acid concentration is related to the poor overall survival (p=0.013). High uric acid concentration predicts poor survival in patients with breast cancer, and might serve as a potential marker for appropriate management of breast cancer patients. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Computed phase diagrams for the system: Sodium hydroxide-uric acid-hydrochloric acid-water

    NASA Astrophysics Data System (ADS)

    Brown, W. E.; Gregory, T. M.; Füredi-Milhofer, H.

    1987-07-01

    Renal stone formation is made complex by the variety of solid phases that are formed, by the number of components in the aqueous phase, and by the multiplicity of ionic dissociation and association processes that are involved. In the present work we apply phase diagrams calculated by the use of equilibrium constants from the ternary system sodium hydroxide-uric acid-water to simplify and make more rigorous the understanding of the factors governing dissolution and precipitation of uric acid (anhydrous and dihydrate) and sodium urate monohydrate. The system is then examined in terms of four components. Finally, procedures are described for fluids containing more than four components. The isotherms, singular points, and fields of supersaturation and undersaturation are shown in various forms of phase diagrams. This system has two notable features: (1) in the coordinates -log[H 2U] versus -log[NaOH], the solubility isotherms for anhydrous uric acid and uric acid dihydrate approximate straight lines with slopes equal to +1 over a wide range of concentrations. As a result, substantial quantities of sodium acid urate monohydrate can precipitate from solution or dissolve without changing the degree of saturation of uric acid significantly. (2) The solubility isotherm for NaHU·H 2O has a deltoid shape with the low-pH branch having a slope of infinity. As a result of the vertical slope of this isotherm, substantial quantities of uric acid can dissolve or precipitate without changing the degree of saturation of sodium acid urate monohydrate significantly. The H 2U-NaOH singular point has a pH of 6.87 at 310 K in the ternary system.

  5. Sensitive electrochemical sensors for simultaneous determination of ascorbic acid, dopamine, and uric acid based on Au@Pd-reduced graphene oxide nanocomposites.

    PubMed

    Jiang, Jingjing; Du, Xuezhong

    2014-10-07

    Sensitive electrochemical sensors were fabricated with reduced graphene oxide-supported Au@Pd (Au@Pd-RGO) nanocomposites by one-step synthesis for individual and simultaneous determination of ascorbic acid (AA), dopamine (DA), and uric acid (UA) with low detection limits and wide concentration ranges. From the Au@Pd-RGO-modified electrodes, well-separated oxidation peaks and enhanced peak currents of AA, DA, and UA were observed owing to the superior conductivity of RGO and the excellent catalytic activity of Au@Pd nanoparticles. For individual detection, the linear responses of AA, DA, and UA were in the concentration ranges of 0.1-1000, 0.01-100, and 0.02-500 μM with detection limits of 0.02, 0.002, and 0.005 μM (S/N = 3), respectively. For simultaneous detection by synchronous change of the concentrations of AA, DA, and UA, the linear response ranges were 1-800, 0.1-100, and 0.1-350 μM with detection limits of 0.28, 0.024, and 0.02 μM (S/N = 3), respectively. The fabricated sensors were further applied to the detection of AA, DA, and UA in urine samples. The Au@Pd-RGO nanocomposites have promising applications in highly sensitive and selective electrochemical sensing.

  6. Graphene-multiwall carbon nanotube-gold nanocluster composites modified electrode for the simultaneous determination of ascorbic acid, dopamine, and uric acid.

    PubMed

    Liu, Xiaofang; Wei, Shaping; Chen, Shihong; Yuan, Dehua; Zhang, Wen

    2014-08-01

    In this paper, graphene-multiwall carbon nanotube-gold nanocluster (GP-MWCNT-AuNC) composites were synthesized and used as modifier to fabricate a sensor for simultaneous detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA). The electrochemical behavior of the sensor was investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The combination of GP, MWCNTs, and AuNCs endowed the electrode with a large surface area, good catalytic activity, and high selectivity and sensitivity. The linear response range for simultaneous detection of AA, DA, and UA at the sensor were 120-1,701, 2-213, and 0.7-88.3 μM, correspondingly, and the detection limits were 40, 0.67, and 0.23 μM (S/N=3), respectively. The proposed method offers a promise for simple, rapid, selective, and cost-effective analysis of small biomolecules.

  7. Serum uric acid as prognostic marker of coronary heart disease (CHD).

    PubMed

    Purnima, Samudrala; El-Aal, Bahiga Galal Abd

    A substantial body of epidemiological and experimental evidence suggests the significance of serum uric acid as an important and independent risk factor of cardio vascular and renal diseases especially in patients with diabetes mellitus, hypertension. Hyperuricemia is a risk factor of coronary heart disease. Several studies showed positive association between hyperuricemia and CHD risk factors. To analyze the serum uric acid levels in patients with diabetes and hypertension, which helps in understanding its role as prognostic marker of coronary heart disease. The study was conducted in population of Wadi-Al Dawasir (K.S.A.) aged 20-80 years through random sampling from October 2012 to June 2013. It included 250 samples and the cases were categorized into diabetic and hypertensive. In the cases, purely hypertensive were 52, diabetic were 57 and mixed group included both diabetic and hypertensive patients 65. Fasting blood was collected to analyze lipid profile which included (total cholesterol, triglycerides, high density lipoprotein, low density lipoprotein) and serum uric acid in association with age and heredity was also studied. Patient demographics were recorded. The study revealed significant association of serum uric acid (p<0.014*) and total cholesterol (p<0.007**) triglycerides (p<0.009**) low density lipoprotein (p<0.044*) in hypertensive group. Serum uric acid levels in the mixed group patients with diabetes and hypertension reported serum uric acid (p<0.0037), total cholesterol (p<0.089+) proved to have increased risk of coronary heart disease. When compared to controls (non-diabetic p<0.529) and (non-hypertensive p<0.021*) with respect to serum uric acid levels show the magnitude of risk to coronary heart disease. With progressing age the association of lipid profile and serum uric acid reported (p<0.001**) in diabetics. Significant correlations were found between serum uric acid and risk factors for CHD. This is first study of its kind in this region

  8. Extra-Renal Elimination of Uric Acid via Intestinal Efflux Transporter BCRP/ABCG2

    PubMed Central

    Hosomi, Atsushi; Nakanishi, Takeo; Fujita, Takuya; Tamai, Ikumi

    2012-01-01

    Urinary excretion accounts for two-thirds of total elimination of uric acid and the remainder is excreted in feces. However, the mechanism of extra-renal elimination is poorly understood. In the present study, we aimed to clarify the mechanism and the extent of elimination of uric acid through liver and intestine using oxonate-treated rats and Caco-2 cells as a model of human intestinal epithelium. In oxonate-treated rats, significant amounts of externally administered and endogenous uric acid were recovered in the intestinal lumen, while biliary excretion was minimal. Accordingly, direct intestinal secretion was thought to be a substantial contributor to extra-renal elimination of uric acid. Since human efflux transporter BCRP/ABCG2 accepts uric acid as a substrate and genetic polymorphism causing a decrease of BCRP activity is known to be associated with hyperuricemia and gout, the contribution of rBcrp to intestinal secretion was examined. rBcrp was confirmed to transport uric acid in a membrane vesicle study, and intestinal regional differences of expression of rBcrp mRNA were well correlated with uric acid secretory activity into the intestinal lumen. Bcrp1 knockout mice exhibited significantly decreased intestinal secretion and an increased plasma concentration of uric acid. Furthermore, a Bcrp inhibitor, elacridar, caused a decrease of intestinal secretion of uric acid. In Caco-2 cells, uric acid showed a polarized flux from the basolateral to apical side, and this flux was almost abolished in the presence of elacridar. These results demonstrate that BCRP contributes at least in part to the intestinal excretion of uric acid as extra-renal elimination pathway in humans and rats. PMID:22348008

  9. Correlation of serum uric acid with heart rate variability in hypertension.

    PubMed

    Kunikullaya, K U; Purushottam, N; Prakash, V; Mohan, S; Chinnaswamy, R

    2015-01-01

    Autonomic dysfunction with dominant sympathetic tone is a common finding among hypertensives and prehypertensives. Uric acid is one of the independent predictors of hypertension. There are very few studies which have shown a relationship between the autonomic tone and uric acid generation pathway among prehypertensives and hypertensives. Aim of the study was to estimate and correlate serum uric acid levels with autonomic function as measured by heart rate variability (HRV) among prehypertensives and hypertensives. Cross-sectional study of three groups, prehypertensives, hypertensives and normotensives, classified according to Joint National Committee VII criteria, with 35 subjects in each group were included in this study. Serum uric acid levels were estimated by using colorimetric assay kit. HRV was analyzed after recording lead II Electrocardiogram using RMS Vagus HRV software (RMS, India). One-way ANOVA and Pearson's correlation was done using SPSS 18.0 software. Mean uric acid levels were 5.62±2.21mg/dL in normal subjects, 7.06±2.87mg/dL in prehypertensives and 9.77±2.04mg/dL in hypertensives. There was statistically significant negative correlation between uric acid and time domain parameters of HRV in the whole sample and among prehypertensives and positive correlation with low frequency power (LF) in ms(2) and n.u. Serum uric acid levels were high in prehypertensives and hypertensives as compared to normal subjects. Further, there was statistically significant correlation seen between uric acid levels and sympathetic domain parameters particularly among prehypertensives. Copyright © 2015 SEHLELHA. Published by Elsevier España, S.L.U. All rights reserved.

  10. Differentiation of uric acid versus non-uric acid kidney stones in the presence of iodine using dual-energy CT

    NASA Astrophysics Data System (ADS)

    Wang, J.; Qu, M.; Leng, S.; McCollough, C. H.

    2010-04-01

    In this study, the feasibility of differentiating uric acid from non-uric acid kidney stones in the presence of iodinated contrast material was evaluated using dual-energy CT (DECT). Iodine subtraction was accomplished with a commercial three material decomposition algorithm to create a virtual non-contrast (VNC) image set. VNC images were then used to segment stone regions from tissue background. The DE ratio of each stone was calculated using the CT images acquired at two different energies with DECT using the stone map generated from the VNC images. The performance of DE ratio-based stone differentiation was evaluated at five different iodine concentrations (21, 42, 63, 84 and 105 mg/ml). The DE ratio of stones in iodine solution was found larger than those obtained in non-iodine cases. This is mainly caused by the partial volume effect around the boundary between the stone and iodine solution. The overestimation of the DE ratio leads to substantial overlap between different stone types. To address the partial volume effect, an expectation-maximization (EM) approach was implemented to estimate the contribution of iodine and stone within each image pixel in their mixture area. The DE ratio of each stone was corrected to maximally remove the influence of iodine solutions. The separation of uric-acid and non-uric-acid stone was improved in the presence of iodine solution.

  11. Uric Acid: A Missing Link Between Hypertensive Pregnancy Disorders and Future Cardiovascular Disease?

    PubMed

    Weissgerber, Tracey L; Milic, Natasa M; Turner, Stephen T; Asad, Reem A; Mosley, Thomas H; Kardia, Sharon L R; Hanis, Craig L; Garovic, Vesna D

    2015-09-01

    To determine whether women who had a hypertensive pregnancy disorder (HPD) have elevated uric acid concentrations decades after pregnancy as compared with women who had normotensive pregnancies. The Genetic Epidemiology Network of Arteriopathy study measured uric acid concentrations in Hispanic (30%), non-Hispanic white (28%), and non-Hispanic black (42%) women (mean age, 60 ± 10 years). This cross-sectional study was conducted between July 1, 2000, and December 31, 2004. Hispanic participants were recruited from families with high rates of diabetes, whereas non-Hispanic participants were recruited from families with high rates of hypertension. This analysis compared uric acid concentrations in women with a history of normotensive (n = 1846) or hypertensive (n = 408) pregnancies by logistic regression. Women who had an HPD had higher uric acid concentrations (median, 5.7 mg/dL vs 5.3 mg/dL; P < .001) and were more likely to have uric acid concentrations above 5.5 mg/dL (54.4% vs 42.4%; P = .001) than were women who had normotensive pregnancies. These differences persisted after adjusting for traditional cardiovascular risk factors, comorbidities, and other factors that affect uric acid concentrations. A family-based subgroup analysis comparing uric acid concentrations in women who had an HPD (n = 308) and their parous sisters who had normotensive pregnancies (n = 250) gave similar results (median uric acid concentrations, 5.7 mg/dL vs 5.2 mg/dL, P = 0.02; proportion of women with uric acid concentrations > 5.5 mg/dL, 54.0% vs 40.3%, P < .001). Decades after pregnancy, women who had an HPD have higher uric acid concentrations. This effect does not appear to be explained by a familial predisposition to elevated uric acid concentrations. Copyright © 2015 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  12. Serum uric acid levels among Nigerians with essential hypertension.

    PubMed

    Emokpae, Abiodun M; Abdu, Aliyu

    2013-06-30

    There is an ongoing debate on the role of serum uric acid as an independent risk factor for hypertension and renal disease. This study determined the serum uric acid levels of Nigerians with essential hypertension and also evaluated the association between serum uric acid levels and blood pressure of these patients. A retrospective case-control study of three hundred and fifty one patients with essential hypertension seen at the hypertension clinic of Aminu Kano Teaching Hospital, Kano between January 2004 and December 2008. The control group comprised of one hundred apparently healthy non hypertensive subjects. The clinical characteristics including blood pressure measurement, serum uric acid, urea, creatinine, lipid profile and glucose were evaluated.The mean systolic and diastolic blood pressures of the male patients were 156mmHg and 101mmHg respectively, while those of the male controls were 120 ± 6.0 and 80 ± 5 respectively. The mean serum uric acid, fasting blood glucose, urea and creatinine were 483umol/L, 5.7mmol/L,6.61mmol/L, 93umol/l respectively compared to those of the male controls which were 326 ±10μmol/l, 5.0± 0.5mmol/l, 4.2± 0.12mmol/l, 5.16mmol/l ± 0.12 and 69±2.71μmol/l respectively. The mean systolic and diastolic blood pressures of the female patients were 158mmHg and 101mmHg, while those of the female controls were 101±2 and 62±9 respectively. The mean serum uric acid, fasting blood glucose, urea and creatinine of the female patients were 434umol/L, 5.3mmol/L 6.20mmol/L, and 88umol/L respectively while those for the female controls were 290±9μmol/l, 4.8±0.5mmol/l, 5.02±0.28 mmol/l, 62±0.36μmol/l respectively. Hyperuricaemia was observed in 59.3% of the male study patients and 62% of the female study patients. Serum uric acid correlated positively with both systolic blood pressure (r=0.192, p<0.001) and diastolic blood pressure (r=0.216; p<0.001). Hyperuricaemia is common among Nigerian patients with essential hypertension

  13. Uric acid lithiasis in the Sudan.

    PubMed

    Ibrahim, A; Zein, M; Beleil, O

    1977-08-01

    Fifty-seven per cent of Urinary Calculi in the Sudan contain Uric Acid, 20 per cent in the pure form and 37 per cent mixed with other constituents mainly calcium oxalate. The peak age presentation of urolithiasis is 30-40 years with more prediliction to males than females. An earlier study documented a high incidence of hyperuricaemia in Sudanese people. It is probable that "voluntary dehydration" and hyperuricaemia acting together may help in the formation of uric acid stones on the surface of which other crystals mainly calcium oxalate may be deposited to form the bigger calculi which are commonly encountered in this country.

  14. Uric acid in metabolic syndrome: From an innocent bystander to a central player

    PubMed Central

    Kanbay, Mehmet; Jensen, Thomas; Solak, Yalcin; Le, Myphuong; Roncal-Jimenez, Carlos; Rivard, Chris; Lanaspa, Miguel A.; Nakagawa, Takahiko; Johnson, Richard J.

    2016-01-01

    Uric acid, once viewed as an inert metabolic end-product of purine metabolism, has been recently incriminated in a number of chronic disease states, including hypertension, metabolic syndrome, diabetes, non-alcoholic fatty liver disease, and chronic kidney disease. Several experimental and clinical studies support a role for uric acid as a contributory causal factor in these conditions. Here we discuss some of the major mechanisms linking uric acid to metabolic and cardiovascular diseases. At this time the key to understanding the importance of uric acid in these diseases will be the conduct of large clinical trials in which the effect of lowering uric acid on hard clinical outcomes is assessed. Elevated uric acid may turn out to be one of the more important remediable risk factors for metabolic and cardiovascular diseases. PMID:26703429

  15. Uric acid in plants and microorganisms: Biological applications and genetics - A review.

    PubMed

    Hafez, Rehab M; Abdel-Rahman, Tahany M; Naguib, Rasha M

    2017-09-01

    Uric acid increased accumulation and/or reduced excretion in human bodies is closely related to pathogenesis of gout and hyperuricemia. It is highly affected by the high intake of food rich in purine. Uric acid is present in both higher plants and microorganisms with species dependent concentration. Urate-degrading enzymes are found both in plants and microorganisms but the mechanisms by which plant degrade uric acid was found to be different among them. Higher plants produce various metabolites which could inhibit xanthine oxidase and xanthine oxidoreductase, so prohibit the oxidation of hypoxanthine to xanthine then to uric acid in the purine metabolism. However, microorganisms produce group of degrading enzymes uricase, allantoinase, allantoicase and urease, which catalyze the degradation of uric acid to the ammonia. In humans, researchers found that several mutations caused a pseudogenization (silencing) of the uricase gene in ancestral apes which exist as an insoluble crystalloid in peroxisomes. This is in contrast to microorganisms in which uricases are soluble and exist either in cytoplasm or peroxisomes. Moreover, many recombinant uricases with higher activity than the wild type uricases could be induced successfully in many microorganisms. The present review deals with the occurrence of uric acid in plants and other organisms specially microorganisms in addition to the mechanisms by which plant extracts, metabolites and enzymes could reduce uric acid in blood. The genetic and genes encoding for uric acid in plants and microorganisms are also presented.

  16. Intestinal tract is an important organ for lowering serum uric acid in rats

    PubMed Central

    Gao, Zhiyi; Li, Yue; Gao, Tao; Duan, Jinlian; Yang, Rong; Dong, Xianxiang; Zhang, Lumei

    2017-01-01

    The kidney was recognized as a dominant organ for uric acid excretion. The main aim of the study demonstrated intestinal tract was an even more important organ for serum uric acid (SUA) lowering. Sprague-Dawley rats were treated normally or with antibiotics, uric acid, adenine, or inosine of the same molar dose orally or intraperitoneally for 5 days. Rat’s intestinal tract was equally divided into 20 segments except the cecum. Uric acid in serum and intestinal segment juice was assayed. Total RNA in the initial intestinal tract and at the end ileum was extracted and sequenced. Protein expression of xanthine dehydrogenase (XDH) and urate oxidase (UOX) was tested by Western blot analysis. The effect of oral UOX in lowering SUA was investigated in model rats treated with adenine and an inhibitor of uric oxidase for 5 days. SUA in the normal rats was 20.93±6.98 μg/ml, and total uric acid in the intestinal juice was 308.27±16.37 μg, which is two times more than the total SUA. The uric acid was very low in stomach juice, and attained maximum in the juice of the first segment (duodenum) and then declined all the way till the intestinal end. The level of uric acid in the initial intestinal tissue was very high, where XDH and most of the proteins associated with bicarbonate secretion were up-regulated. In addition, SUA was decreased by oral UOX in model rats. The results suggested that intestinal juice was an important pool for uric acid, and intestinal tract was an important organ for SUA lowering. The uric acid distribution was associated with uric acid synthesis and secretion in the upper intestinal tract, and reclamation in the lower. PMID:29267361

  17. Uric Acid Spherulites in the Reflector Layer of Firefly Light Organ

    PubMed Central

    Goh, King-Siang; Sheu, Hwo-Shuenn; Hua, Tzu-En; Kang, Mei-Hua; Li, Chia-Wei

    2013-01-01

    Background In firefly light organs, reflector layer is a specialized tissue which is believed to play a key role for increasing the bioluminescence intensity through reflection. However, the nature of this unique tissue remains elusive. In this report, we investigated the role, fine structure and nature of the reflector layer in the light organ of adult Luciola cerata. Principal Findings Our results indicated that the reflector layer is capable of reflecting bioluminescence, and contains abundant uric acid. Electron microscopy (EM) demonstrated that the cytosol of the reflector layer's cells is filled with densely packed spherical granules, which should be the uric acid granules. These granules are highly regular in size (∼700 nm in diameter), and exhibit a radial internal structure. X-ray diffraction (XRD) analyses revealed that an intense single peak pattern with a d-spacing value of 0.320 nm is specifically detected in the light organ, and is highly similar to the diffraction peak pattern and d-spacing value of needle-formed crystals of monosodium urate monohydrate. However, the molar ratio evaluation of uric acid to various cations (K+, Na+, Ca2+ and Mg2+) in the light organ deduced that only a few uric acid molecules were in the form of urate salts. Thus, non-salt uric acid should be the source of the diffraction signal detected in the light organ. Conclusions In the light organ, the intense single peak diffraction signal might come from a unique needle-like uric acid form, which is different from other known structures of non-salt uric acid form. The finding of a radial structure in the granules of reflector layer implies that the spherical uric acid granules might be formed by the radial arrangement of needle-formed packing matter. PMID:23441187

  18. Uric Acid Level and Elevated Blood Pressure in U.S. Adolescents

    PubMed Central

    Loeffler, Lauren F.; Navas-Acien, Ana; Brady, Tammy M.; Miller, Edgar R.; Fadrowski, Jeffrey J.

    2012-01-01

    Uric acid is associated with cardiovascular disease (CVD) and CVD risk factors in adults, including chronic kidney disease, coronary artery disease, stroke, diabetes, preeclampsia, and hypertension. We examined the association between uric acid and elevated blood pressure in a large, nationally representative cohort of U.S. adolescents, a population with a relatively low prevalence of CVD and CVD risk factors. Among 6,036 adolescents 12-17 years of age examined in the 1999-2006 National Health and Nutrition Examination Survey (NHANES) the mean age was 14.5 years, 17% were obese (body mass index [BMI] ≥95th percentile), and 3.3% had elevated blood pressure. Mean serum uric acid level was 5.0 mg/dL and 34% had a uric acid level ≥5.5 mg/dL. In analyses adjusted for age, sex, race/ethnicity and BMI percentile, the odds ratio of elevated blood pressure, defined as a systolic or diastolic blood pressure ≥95th percentile for age, sex and height, for each 0.1 mg/dL increase in uric acid level was 1.38 (95% confidence interval [CI], 1.16 to 1.65). Compared to <5.5 mg/dL, participants with a uric acid level ≥5.5 mg/dL had a 2.03 times higher odds of having elevated blood pressure (95% CI, 1.38 to 3.00). In conclusion, increasing levels of serum uric acid are associated with elevated blood pressure in healthy U.S. adolescents. Additional prospective studies and clinical trials are needed to determine if uric acid is merely a marker in a complex metabolic pathway, or causal of hypertension and thus a potential screening and therapeutic target. PMID:22353609

  19. Uric acid, an important antioxidant contributing to survival in termites

    PubMed Central

    Tasaki, Eisuke; Sakurai, Hiroki; Nitao, Masaru; Matsuura, Kenji; Iuchi, Yoshihito

    2017-01-01

    Reactive oxygen species (ROS) are generated spontaneously in all organisms and cause oxidative damage to biomolecules when present in excess. Accumulated oxidative damage accelerates aging; enhanced antioxidant capacity may be a positive factor for longevity. Recently, numerous studies of aging and longevity have been performed using short-lived animals, however, longevity mechanisms remain unknown. Here we show that a termite Reticulitermes speratus that is thought to be long-lived eusocial insect than other solitary insects uses large quantities of uric acid as an antioxidant against ROS. We demonstrated that the accumulation of uric acid considerably increases the free radical-scavenging activity and resistance against ultraviolet-induced oxidative stress in laboratory-maintained termites. In addition, we found that externally administered uric acid aided termite survival under highly oxidative conditions. The present data demonstrates that in addition to nutritional and metabolic roles, uric acid is an essential antioxidant for survival and contributes significantly to longevity. Uric acid also plays important roles in primates but causes gout when present in excess in humans. Further longevity studies of long-lived organisms may provide important breakthroughs with human health applications. PMID:28609463

  20. Uric acid as one of the important factors in multifactorial disorders--facts and controversies.

    PubMed

    Pasalic, Daria; Marinkovic, Natalija; Feher-Turkovic, Lana

    2012-01-01

    With considering serum concentration of the uric acid in humans we are observing hyperuricemia and possible gout development. Many epidemiological studies have shown the relationship between the uric acid and different disorders such are obesity, metabolic syndrome, hypertension and coronary artery disease. Clinicians and investigators recognized serum uric acid concentration as very important diagnostic and prognostic factor of many multifactorial disorders. This review presented few clinical conditions which are not directly related to uric acid, but the concentrations of uric acid might have a great impact in observing, monitoring, prognosis and therapy of such disorders. Uric acid is recognized as a marker of oxidative stress. Production of the uric acid includes enzyme xanthine oxidase which is involved in producing of radical-oxigen species (ROS). As by-products ROS have a significant role in the increased vascular oxidative stress and might be involved in atherogenesis. Uric acid may inhibit endothelial function by inhibition of nitric oxide-function under conditions of oxidative stress. Down regulation of nitric oxide and induction of endothelial dysfunction might also be involved in pathogenesis of hypertension. The most important and well evidenced is possible predictive role of uric acid in predicting short-term outcome (mortality) in acute myocardial infarction (AMI) patients and stroke. Nephrolithiasis of uric acid origin is significantly more common among patients with the metabolic syndrome and obesity. On contrary to this, uric acid also acts is an "antioxidant", a free radical scavenger and a chelator of transitional metal ions which are converted to poorly reactive forms.

  1. Uric acid is a main electron donor to peroxidases in human blood plasma.

    PubMed

    Padiglia, Alessandra; Medda, Rosaria; Longu, Silvia; Pedersen, Jens Z; Floris, Giovanni

    2002-11-01

    Peroxidases are widely distributed and have been isolated from many higher-order plants, animal tissues, yeast and microorganisms. During measurements of peroxidase activities in samples of human plasma, we noticed the presence of a compound in the plasma which was interfering with the peroxidase assay. In this paper we describe the purification and characterization of this factor, which was identified as uric acid. The procedure used to purify uric acid from plasma involved ultra-filtration of the plasma, heat denaturation, DEAE-cellulose chromatography, and high performance liquid chromatography. The lyophilized powder was tested for homogeneity using an HPLC apparatus and capillary electrophoresis. Genuine uric acid samples were used for comparison. The compound obtained by the above-reported purification procedure was identified as uric acid by spectrophotometric analysis through comparison with genuine uric acid samples. Spectrophotometric measurements indicated that uric acid was degraded by HRP in the presence of H2O2. The experimental procedures described above allowed us to isolate and identify uric acid as the component in human plasma that acts as a true substrate for peroxidases.

  2. Plasmodium falciparum-Derived Uric Acid Precipitates Induce Maturation of Dendritic Cells

    PubMed Central

    van de Hoef, Diana L.; Coppens, Isabelle; Holowka, Thomas; Ben Mamoun, Choukri; Branch, OraLee; Rodriguez, Ana

    2013-01-01

    Malaria is characterized by cyclical fevers and high levels of inflammation, and while an early inflammatory response contributes to parasite clearance, excessive and persistent inflammation can lead to severe forms of the disease. Here, we show that Plasmodium falciparum-infected erythrocytes contain uric acid precipitates in the cytoplasm of the parasitophorous vacuole, which are released when erythrocytes rupture. Uric acid precipitates are highly inflammatory molecules that are considered a danger signal for innate immunity and are the causative agent in gout. We determined that P. falciparum-derived uric acid precipitates induce maturation of human dendritic cells, increasing the expression of cell surface co-stimulatory molecules such as CD80 and CD86, while decreasing human leukocyte antigen-DR expression. In accordance with this, uric acid accounts for a significant proportion of the total stimulatory activity induced by parasite-infected erythrocytes. Moreover, the identification of uric acid precipitates in P. falciparum- and P. vivax-infected erythrocytes obtained directly from malaria patients underscores the in vivo and clinical relevance of our findings. Altogether, our data implicate uric acid precipitates as a potentially important contributor to the innate immune response to Plasmodium infection and may provide a novel target for adjunct therapies. PMID:23405174

  3. The utility of uric acid assay in dogs as an indicator of functional hepatic mass.

    PubMed

    Hill, J M; Leisewitz, A L; Goddard, A

    2011-06-01

    Uric acid was used as a test for liver disease before the advent of enzymology. Three old studies criticised uric acid as a test of liver function. Uric acid, as an end-product of purine metabolism in the liver, deserved re-evaluation as a liver function test. Serum totalbile acids are widely accepted as the most reliable liver function test. This study compared the ability of serum uric acid concentration to assess liver function with that of serum pre-prandial bile acids in dogs. In addition, due to the renal excretion of uric acid the 2 assays were also compared in a renal disease group. Using a control group of healthy dogs, a group of dogs with congenital vascular liver disease, a group of dogs with non-vascular parenchymal liver diseases and a renal disease group, the ability of uric acid and pre-prandial bile acids was compared to detect reduced functional hepatic mass overall and in the vascular or parenchymal liver disease groups separately. Sensitivities, specificities and predictive value parameters were calculated for each test. The medians of uric acid concentration did not differ significantly between any of the groups, whereas pre-prandial bile acids medians were significantly higher in the liver disease groups compared with the normal and renal disease group of dogs. The sensitivity of uric acid in detecting liver disease overall was 65% while the specificity of uric acid in detecting liver disease overall was 59%. The sensitivity and specificity of uric acid in detecting congenital vascular liver disease was 68% and 59%, respectively. The sensitivity and specificity of uric acid in detecting parenchymal liver disease was 63% and 60%, respectively. The overall positive and negative predictive values for uric acid in detecting liver disease were poor and the data in this study indicated uric acid to be an unreliable test of liver function. In dogs suffering from renal compromise serum uric acid concentrations may increase into the abnormal range due

  4. CTAB functionalized graphene oxide/multiwalled carbon nanotube composite modified electrode for the simultaneous determination of ascorbic acid, dopamine, uric acid and nitrite.

    PubMed

    Yang, Yu Jun; Li, Weikun

    2014-06-15

    We have developed hexadecyl trimethyl ammonium bromide (CTAB) functionalized graphene oxide (GO)/multiwalled carbon nanotubes (MWNTs) modified glassy carbon electrode (CTAB-GO/MWNT) as a novel system for the simultaneous determination of dopamine (DA), ascorbic acid (AA), uric acid (UA) and nitrite (NO2(-)). The combination of graphene oxide and MWNTs endow the biosensor with large surface area, good biological compatibility, electricity and stability, high selectivity and sensitivity. In the fourfold co-existence system, the linear calibration plots for AA, DA, UA and NO2(-) were obtained over the range of 5.0-300 μM, 5.0-500 μM, 3.0-60 μM and 5.0-800 μM with detection limits of 1.0 μM, 1.5 μM, 1.0 μM and 1.5 μM, respectively. In addition, the modified biosensor was applied to the determination of AA, DA, UA and NO2(-) in urine samples by using standard adding method with satisfactory results. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. The role of xanthine oxidoreductase and uric acid in metabolic syndrome.

    PubMed

    Battelli, Maria Giulia; Bortolotti, Massimo; Polito, Letizia; Bolognesi, Andrea

    2018-08-01

    Xanthine oxidoreductase (XOR) could contribute to the pathogenesis of metabolic syndrome through the oxidative stress and the inflammatory response induced by XOR-derived reactive oxygen species and uric acid. Hyperuricemia is strongly linked to hypertension, insulin resistance, obesity and hypertriglyceridemia. The serum level of XOR is correlated to triglyceride/high density lipoprotein cholesterol ratio, fasting glycemia, fasting insulinemia and insulin resistance index. Increased activity of endothelium-linked XOR may promote hypertension. In addition, XOR is implicated in pre-adipocyte differentiation and adipogenesis. XOR and uric acid play a role in cell transformation and proliferation as well as in the progression and metastatic process. Collected evidences confirm the contribution of XOR and uric acid in metabolic syndrome. However, in some circumstances XOR and uric acid may have anti-oxidant protective outcomes. The dual-face role of both XOR and uric acid explains the contradictory results obtained with XOR inhibitors and suggests caution in their therapeutic use. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  6. Reference Ranges for Serum Uric Acid among Healthy Assamese People

    PubMed Central

    Das, Madhumita; Borah, N. C.; Ghose, M.; Choudhury, N.

    2014-01-01

    This study was designed to establish reference ranges for serum uric acid among healthy adult Assamese population. Samples from 1470 aged 35–86 years were used to establish age and sex related reference range by the centile method (central 95 percentile) for serum uric acid level. There were 51% (n = 754) males and 49% (n = 716) females; 75.9% (n = 1115) of them were from urban area and the rest 24.1% (n = 355) were from the rural area. Majority of the population were nonvegetarian (98.6%, n = 1450) and only 1.4% (n = 20) were vegetarian. The mean age, weight, height, and uric acid of the studied group were 53.6 ± 11.3 years, 62.6 ± 10.5 kg, 160 ± 9.4 cm, and 5.5 ± 1.4 mg/dL, respectively. There is a statistically significant difference in the mean value of the abovementioned parameters between male and female. The observed reference range of uric acid in the population is 2.6–8.2 mg/dL which is wider than the current reference range used in the laboratory. Except gender (P < 0.0001), we did not find any significant relation of uric acid with other selected factors. PMID:24672726

  7. Uric acid concentrations are associated with insulin resistance and birthweight in normotensive pregnant women.

    PubMed

    Laughon, S Katherine; Catov, Janet; Roberts, James M

    2009-12-01

    We sought to investigate whether uric acid concentrations are increased in pregnant women with insulin resistance and to correlate both with fetal growth. Uric acid, glucose, and insulin were measured in plasma at 20.4 (+/-2.0) weeks' gestation in 263 women. The association between uric acid and insulin resistance, as estimated using the homeostasis model assessment (HOMA), was analyzed and related to birthweights. In 212 (80.6%) women who remained normotensive throughout pregnancy, HOMA increased 1.23 U per 1-mg/dL increase in uric acid (95% confidence interval, 1.07-1.42; P=.003). Infants born to normotensive women in the upper quartile of uric acid and lowest HOMA quartile weighed 435.6 g less than infants of women with highest uric acid and HOMA quartiles (P<.005). Increasing uric acid concentrations were associated with insulin resistance in midpregnancy. Hyperuricemia was associated with lower birthweight in normotensive women, and this effect was attenuated by insulin resistance.

  8. EFFECT OF URICOSURIC DRUG ADMINISTRATION ON URIC ACID LEVELS IN UNSTIMULATED PAROTID FLUID.

    DTIC Science & Technology

    Parotid fluid was collected twice daily without exogenous stimulation from 6 healthy young adult males, both before and during a 5-day period of...was found in parotid fluid uric acid concentration and uric acid secretion rate. The mean for serum uric acid decreased from 5.40 to 2.06 mg./100 ml...and parotid fluid uric acid concentration fell from 10.16 to 4.23 mg./100 ml. (morning samples) and 7.29 to 3.90 mg./100 ml. (afternoon samples). (Author)

  9. Association of serum uric acid level and blood pressure in type 2 diabetes mellitus

    NASA Astrophysics Data System (ADS)

    Savira, M.; Rusdiana; Syahputra, M.

    2018-03-01

    Uric acid is an end product of purine degradation in humans and primarily excreted through urine. In adulthood, concentrations rise steadily over time and vary with height, body weight, blood pressure, renal function, and alcohol intake. Uric acid is known as anti-oxidant, it has a beneficial role in diseases. Elevated serum uric acid associated with anincreased risk of cardiovascular disease. It has been found that elevated levels of uric acid associated with high risks of acomplication of type 2 diabetes mellitus and It has astrong association between elevated uric acid levels and obesity, metabolic syndrome, diabetes mellitus, hypertension, cardiovascular and renal disorders. The aim of the study analyzed the association between serum uric acid level and blood pressure in type 2 diabetes mellitus patients. This research is descriptive analytic research with a cross sectional design included 50 diabetic subjects aged over 40 years old. Subjects picked by consecutive sampling then we examined the weight, height, waist size, blood pressure, fasting blood sugar, and serum uric acid level. Statistical analysis using chi-square found that there was no significant association between serum uric acid level and systole and diastole pressure in type 2 diabetes mellitus patients (p>0.005).

  10. Serum Uric Acid Level as a Prognostic Marker in Patients With Acute Respiratory Distress Syndrome.

    PubMed

    Lee, Hyun Woo; Choi, Sun Mi; Lee, Jinwoo; Park, Young Sik; Lee, Chang-Hoon; Yim, Jae-Joon; Yoo, Chul-Gyu; Kim, Young Whan; Han, Sung Koo; Lee, Sang-Min

    2017-01-01

    Uric acid acts as both a pathogenic inflammatory mediator and an antioxidative agent. Several studies have shown that uric acid level correlates with the incidence, severity, and prognosis of pulmonary diseases. However, the association between uric acid level and acute respiratory distress syndrome (ARDS) has not been studied. This study was conducted to elucidate how serum uric acid level is related with clinical prognosis of ARDS. A retrospective cohort study with propensity score matching was conducted at a medical intensive care unit of a tertiary teaching hospital. The medical records of patients diagnosed with ARDS admitted from 2005 through 2011 were reviewed. Two hundred thirty-seven patients with ARDS met the inclusion criteria. Patients with a serum uric acid level <3.0 mg/dL were classified into the low uric acid group, and those with a level ≥3 mg/dL were classified into the normal to high uric acid group. We selected 40 patients in each group using propensity score matching. A higher percentage of patients in the low uric acid group experienced clinical improvement in ARDS. More patients died from sepsis in the normal to high uric acid group. Kaplan-Meier analysis showed that a low serum uric acid level was significantly associated with better survival rate. In patients with ARDS, a low serum uric acid level may be a prognostic marker of a low risk of in-hospital mortality.

  11. Characterization of the Complete Uric Acid Degradation Pathway in the Fungal Pathogen Cryptococcus neoformans

    PubMed Central

    Lee, I. Russel; Yang, Liting; Sebetso, Gaseene; Allen, Rebecca; Doan, Thi H. N.; Blundell, Ross; Lui, Edmund Y. L.; Morrow, Carl A.; Fraser, James A.

    2013-01-01

    Degradation of purines to uric acid is generally conserved among organisms, however, the end product of uric acid degradation varies from species to species depending on the presence of active catabolic enzymes. In humans, most higher primates and birds, the urate oxidase gene is non-functional and hence uric acid is not further broken down. Uric acid in human blood plasma serves as an antioxidant and an immune enhancer; conversely, excessive amounts cause the common affliction gout. In contrast, uric acid is completely degraded to ammonia in most fungi. Currently, relatively little is known about uric acid catabolism in the fungal pathogen Cryptococcus neoformans even though this yeast is commonly isolated from uric acid-rich pigeon guano. In addition, uric acid utilization enhances the production of the cryptococcal virulence factors capsule and urease, and may potentially modulate the host immune response during infection. Based on these important observations, we employed both Agrobacterium-mediated insertional mutagenesis and bioinformatics to predict all the uric acid catabolic enzyme-encoding genes in the H99 genome. The candidate C. neoformans uric acid catabolic genes identified were named: URO1 (urate oxidase), URO2 (HIU hydrolase), URO3 (OHCU decarboxylase), DAL1 (allantoinase), DAL2,3,3 (allantoicase-ureidoglycolate hydrolase fusion protein), and URE1 (urease). All six ORFs were then deleted via homologous recombination; assaying of the deletion mutants' ability to assimilate uric acid and its pathway intermediates as the sole nitrogen source validated their enzymatic functions. While Uro1, Uro2, Uro3, Dal1 and Dal2,3,3 were demonstrated to be dispensable for virulence, the significance of using a modified animal model system of cryptococcosis for improved mimicking of human pathogenicity is discussed. PMID:23667704

  12. Characterization of the complete uric acid degradation pathway in the fungal pathogen Cryptococcus neoformans.

    PubMed

    Lee, I Russel; Yang, Liting; Sebetso, Gaseene; Allen, Rebecca; Doan, Thi H N; Blundell, Ross; Lui, Edmund Y L; Morrow, Carl A; Fraser, James A

    2013-01-01

    Degradation of purines to uric acid is generally conserved among organisms, however, the end product of uric acid degradation varies from species to species depending on the presence of active catabolic enzymes. In humans, most higher primates and birds, the urate oxidase gene is non-functional and hence uric acid is not further broken down. Uric acid in human blood plasma serves as an antioxidant and an immune enhancer; conversely, excessive amounts cause the common affliction gout. In contrast, uric acid is completely degraded to ammonia in most fungi. Currently, relatively little is known about uric acid catabolism in the fungal pathogen Cryptococcus neoformans even though this yeast is commonly isolated from uric acid-rich pigeon guano. In addition, uric acid utilization enhances the production of the cryptococcal virulence factors capsule and urease, and may potentially modulate the host immune response during infection. Based on these important observations, we employed both Agrobacterium-mediated insertional mutagenesis and bioinformatics to predict all the uric acid catabolic enzyme-encoding genes in the H99 genome. The candidate C. neoformans uric acid catabolic genes identified were named: URO1 (urate oxidase), URO2 (HIU hydrolase), URO3 (OHCU decarboxylase), DAL1 (allantoinase), DAL2,3,3 (allantoicase-ureidoglycolate hydrolase fusion protein), and URE1 (urease). All six ORFs were then deleted via homologous recombination; assaying of the deletion mutants' ability to assimilate uric acid and its pathway intermediates as the sole nitrogen source validated their enzymatic functions. While Uro1, Uro2, Uro3, Dal1 and Dal2,3,3 were demonstrated to be dispensable for virulence, the significance of using a modified animal model system of cryptococcosis for improved mimicking of human pathogenicity is discussed.

  13. Uric acid promotes an acute inflammatory response to sterile cell death in mice

    PubMed Central

    Kono, Hajime; Chen, Chun-Jen; Ontiveros, Fernando; Rock, Kenneth L.

    2010-01-01

    Necrosis stimulates inflammation, and this response is medically relevant because it contributes to the pathogenesis of a number of diseases. It is thought that necrosis stimulates inflammation because dying cells release proinflammatory molecules that are recognized by the immune system. However, relatively little is known about the molecular identity of these molecules and their contribution to responses in vivo. Here, we investigated the role of uric acid in the inflammatory response to necrotic cells in mice. We found that dead cells not only released intracellular stores of uric acid but also produced it in large amounts postmortem as nucleic acids were degraded. Using newly developed Tg mice that have reduced levels of uric acid either intracellularly and/or extracellularly, we found that uric acid depletion substantially reduces the cell death–induced inflammatory response. Similar results were obtained with pharmacological treatments that reduced uric acid levels either by blocking its synthesis or hydrolyzing it in the extracellular fluids. Importantly, uric acid depletion selectively inhibited the inflammatory response to dying cells but not to microbial molecules or sterile irritant particles. Collectively, our data identify uric acid as a proinflammatory molecule released from dying cells that contributes significantly to the cell death–induced inflammatory responses in vivo. PMID:20501947

  14. Levels of uric acid in erectile dysfunction of different aetiology.

    PubMed

    Barassi, Alessandra; Corsi Romanelli, Massimiliano Marco; Pezzilli, Raffaele; Dozio, Elena; Damele, Clara Anna Linda; Vaccalluzzo, Liborio; Di Dario, Marco; Goi, Giancarlo; Papini, Nadia; Massaccesi, Luca; Colpi, Giovanni Maria; Melzi d'Eril, Gian Vico

    2018-01-12

    Erectile dysfunction is a common disease characterized by endothelial dysfunction. The aetiology of ED is often multifactorial but evidence is being accumulated in favor of the proper function of the vascular endothelium that is essential to achieving and maintaining penile erection. Uric acid itself causes endothelial dysfunction via decreased nitric oxide production. This study aims to evaluate the serum uric acid (SUA) levels in 180 ED patients, diagnosed with the International Index of Erectile Function-5 (IIEF-5) and 30 non-ED control. Serum uric acid was analyzed with a commercially available kit using ModularEVO (Roche, Monza, Italy). Within-assay and between-assay variations were 3.0% and 6.0%, respectively. Out of the ED patients, 85 were classified as arteriogenic (A-ED) and 95 as non-arteriogenic (NA-ED) with penile-echo-color-Doppler. Uric acid levels (median and range in mg/dL) in A-ED patients (5.8, 4.3-7.5) were significantly higher (p < .001) than in NA-ED patients (4.4, 2.6-5.9) and in control group (4.6, 3.1-7.2). There was a significant difference (p < .001) between uric acid levels in patients with mild A-ED (IIEF-5 16-20) and severe/complete A-ED (IIEF-5 ≤ 10) that were 5.4 (range 4.3-6.5) mg/dL and 6.8 (range 6.4-7.2) mg/dL, respectively. There was no difference between the levels of uric acid in patients with different degree of NA-ED. Our findings reveal that SUA is a marker of ED but only of ED of arteriogenic aetiology.

  15. Uric acid, an important screening tool to detect inborn errors of metabolism: a case series.

    PubMed

    Jasinge, Eresha; Kularatnam, Grace Angeline Malarnangai; Dilanthi, Hewa Warawitage; Vidanapathirana, Dinesha Maduri; Jayasena, Kandana Liyanage Subhashinie Priyadarshika Kapilani Menike; Chandrasiri, Nambage Dona Priyani Dhammika; Indika, Neluwa Liyanage Ruwan; Ratnayake, Pyara Dilani; Gunasekara, Vindya Nandani; Fairbanks, Lynette Dianne; Stiburkova, Blanka

    2017-09-06

    Uric acid is the metabolic end product of purine metabolism in humans. Altered serum and urine uric acid level (both above and below the reference ranges) is an indispensable marker in detecting rare inborn errors of metabolism. We describe different case scenarios of 4 Sri Lankan patients related to abnormal uric acid levels in blood and urine. CASE 1: A one-and-half-year-old boy was investigated for haematuria and a calculus in the bladder. Xanthine crystals were seen in microscopic examination of urine sediment. Low uric acid concentrations in serum and low urinary fractional excretion of uric acid associated with high urinary excretion of xanthine and hypoxanthine were compatible with xanthine oxidase deficiency. CASE 2: An 8-month-old boy presented with intractable seizures, feeding difficulties, screaming episodes, microcephaly, facial dysmorphism and severe neuro developmental delay. Low uric acid level in serum, low fractional excretion of uric acid and radiological findings were consistent with possible molybdenum cofactor deficiency. Diagnosis was confirmed by elevated levels of xanthine, hypoxanthine and sulfocysteine levels in urine. CASE 3: A 3-year-10-month-old boy presented with global developmental delay, failure to thrive, dystonia and self-destructive behaviour. High uric acid levels in serum, increased fractional excretion of uric acid and absent hypoxanthine-guanine phosphoribosyltransferase enzyme level confirmed the diagnosis of Lesch-Nyhan syndrome. CASE 4: A 9-year-old boy was investigated for lower abdominal pain, gross haematuria and right renal calculus. Low uric acid level in serum and increased fractional excretion of uric acid pointed towards hereditary renal hypouricaemia which was confirmed by genetic studies. Abnormal uric acid level in blood and urine is a valuable tool in screening for clinical conditions related to derangement of the nucleic acid metabolic pathway.

  16. Uric acid as one of the important factors in multifactorial disorders – facts and controversies

    PubMed Central

    Pasalic, Daria; Marinkovic, Natalija; Feher-Turkovic, Lana

    2012-01-01

    With considering serum concentration of the uric acid in humans we are observing hyperuricemia and possible gout development. Many epidemiological studies have shown the relationship between the uric acid and different disorders such are obesity, metabolic syndrome, hypertension and coronary artery disease. Clinicians and investigators recognized serum uric acid concentration as very important diagnostic and prognostic factor of many multifactorial disorders. This review presented few clinical conditions which are not directly related to uric acid, but the concentrations of uric acid might have a great impact in observing, monitoring, prognosis and therapy of such disorders. Uric acid is recognized as a marker of oxidative stress. Production of the uric acid includes enzyme xanthine oxidase which is involved in producing of radical-oxigen species (ROS). As by-products ROS have a significant role in the increased vascular oxidative stress and might be involved in atherogenesis. Uric acid may inhibit endothelial function by inhibition of nitric oxide-function under conditions of oxidative stress. Down regulation of nitric oxide and induction of endothelial dysfunction might also be involved in pathogenesis of hypertension. The most important and well evidenced is possible predictive role of uric acid in predicting short-term outcome (mortality) in acute myocardial infarction (AMI) patients and stroke. Nephrolithiasis of uric acid origin is significantly more common among patients with the metabolic syndrome and obesity. On contrary to this, uric acid also acts is an “antioxidant”, a free radical scavenger and a chelator of transitional metal ions which are converted to poorly reactive forms. PMID:22384520

  17. Uric acid association with pulsatile and steady components of central and peripheral blood pressures.

    PubMed

    Lepeytre, Fanny; Lavoie, Pierre-Luc; Troyanov, Stéphan; Madore, François; Agharazii, Mohsen; Goupil, Rémi

    2018-03-01

    Whether the cardiovascular risk attributed to elevated uric acid levels may be explained by changes in central and peripheral pulsatile and/or steady blood pressure (BP) components remains controversial. In a cross-sectional analysis of normotensive and untreated hypertensive participants of the CARTaGENE populational cohort, we examined the relationship between uric acid, and both pulsatile and steady components of peripheral and central BP, using sex-stratified linear regressions. Of the 20 004 participants, 10 161 individuals without antihypertensive or uric acid-lowering drugs had valid pulse wave analysis and serum uric acid levels. In multivariate analysis, pulsatile components of BP were not associated with uric acid levels, whereas steady components [mean BP (MBP), peripheral and central DBP] were all associated with higher levels of uric acid levels in women and men (all P < 0.001). Furthermore, there was a gradual increase of central SBP (cSBP), DBP and MBP from the lowest to the highest quintiles of uric acid levels but not for MBP-adjusted cSBP. Peripheral and cSBP, which are aggregate measures of pulsatile and steady BP, were also associated with uric acid levels in women (β = 0.063 and 0.072, respectively, both P < 0.001) and men (β = 0.043 and 0.051, both P ≤ 0.003). After further adjustments for MBP to account for the concomitant increase in steady component of BP, SBPs were no longer associated with uric acid levels. Serum uric acid levels appear to be associated with both central and peripheral steady but not pulsatile BP, regardless of sex.

  18. Genetics of Variation in Serum Uric Acid and Cardiovascular Risk Factors in Mexican Americans

    PubMed Central

    Voruganti, V. Saroja; Nath, Subrata D.; Cole, Shelley A.; Thameem, Farook; Jowett, Jeremy B.; Bauer, Richard; MacCluer, Jean W.; Blangero, John; Comuzzie, Anthony G.; Abboud, Hanna E.; Arar, Nedal H.

    2009-01-01

    Background: Elevated serum uric acid is associated with several cardiovascular disease (CVD) risk factors such as hypertension, inflammation, endothelial dysfunction, insulin resistance, dyslipidemia, and obesity. However, the role of uric acid as an independent risk factor for CVD is not yet clear. Objective: The aim of the study was to localize quantitative trait loci regulating variation in serum uric acid and also establish the relationship between serum uric acid and other CVD risk factors in Mexican Americans (n = 848; men = 310, women = 538) participating in the San Antonio Family Heart Study. Methods: Quantitative genetic analysis was conducted using variance components decomposition method, implemented in the software program SOLAR. Results: Mean ± sd of serum uric acid was 5.35 ± 1.38 mg/dl. Univariate genetic analysis showed serum uric acid and other CVD risk markers to be significantly heritable (P < 0.005). Bivariate analysis showed significant correlation of serum uric acid with body mass index, waist circumference, waist/hip ratio, total body fat, plasma insulin, serum triglycerides, high-density lipoprotein cholesterol, C-reactive protein, and granulocyte macrophage-colony stimulating factor (P < 0.05). A genome-wide scan for detecting quantitative trait loci regulating serum uric acid variation showed a significant logarithm of odds (LOD) score of 4.72 (empirical LOD score = 4.62; P < 0.00001) on chromosome 3p26. One LOD support interval contains 25 genes, of which an interesting candidate gene is chemokine receptor 2. Summary: There is a significant genetic component in the variation in serum uric acid and evidence of pleiotropy between serum uric acid and other cardiovascular risk factors. PMID:19001525

  19. Uric acid level and erectile dysfunction in patients with coronary artery disease.

    PubMed

    Solak, Yalcin; Akilli, Hakan; Kayrak, Mehmet; Aribas, Alpay; Gaipov, Abduzhappar; Turk, Suleyman; Perez-Pozo, Santos E; Covic, Adrian; McFann, Kim; Johnson, Richard J; Kanbay, Mehmet

    2014-01-01

    Erectile dysfunction (ED) is a frequent complaint of elderly subjects and is closely associated with endothelial dysfunction and cardiovascular disease (CVD). Uric acid is also associated with endothelial dysfunction, oxidative stress, and CVD, raising the hypothesis that an increased serum uric acid might predict ED in patients who are at risk for coronary artery disease (CAD). This study aims to evaluate the association of serum uric acid levels with presence and severity of ED in patients presenting with chest pain of presumed cardiac origin. This is a cross-sectional study of 312 adult male patients with suspected CAD who underwent exercise stress test (EST) for workup of chest pain and completed a sexual health inventory for men survey form to determine the presence and severity of ED. Routine serum biochemistry (and uric acid levels) were measured. Logistic regression analysis was used to assess risk factors for ED. The short version of the International Index of Erectile Function questionnaire diagnosed ED (cutoff score ≤ 21). Serum uric acid levels were determined. Patients with chest pain of suspected cardiac origin underwent an EST. One hundred forty-nine of 312 (47.7%) male subjects had ED by survey criteria. Patients with ED were older and had more frequent CAD, hypertension, diabetes and impaired renal function, and also had significantly higher levels of uric acid, fibrinogen, glucose, C-reactive protein, triglycerides compared with patients without ED. Uric acid levels were associated with ED by univariate analysis (odds ratio = 1.36, P = 0.002); however, this association was not observed in multivariate analysis adjusted for estimated glomerular filtration rate. Subjects presenting with chest pain of presumed cardiac origin are more likely to have ED if they have elevated uric acid levels. © 2013 International Society for Sexual Medicine.

  20. [Uric acid predicts type 2 diabetes mellitus in the general population].

    PubMed

    Cardona, Fernando; Rojo-Martínez, Gemma; de la Cruz Almaraz, María; Soriguer, Federico; García-Fuentes, Eduardo; Tinahones, Francisco José

    2009-02-01

    Abnormal uric acid levels are considered by some to be a risk factor for metabolic disorders, whereas others consider it to be just a marker. We therefore examined the association between plasma uric acid concentrations and the risk of type 2 diabetes mellitus. We undertook a prospective, 8-year study of 411 persons from the general population with no carbohydrate metabolism disorder at the start of the study evaluated by oral glucose overload. The following variables were measured at the beginning and end of the study: uric acid, triglycerides, cholesterol, high-density lipoprotein cholesterol, glucose and insulin in plasma, body mass index and waist-to-hip ratio. The participants were classified according to their plasma uric acid concentration, with a cut-off at the 33rd percentile (men, 291.45 and women, 208.18 micromol/l). Participants with plasma uric acid concentrations above the 33rd percentile at the start of the study had worse lipid and anthropometric profiles. These persons were at greater risk for carbohydrate disorder at the end of the 8- year follow-up study (relative risk, 1.73; 95% confidence interval, 1.04-2.8). No significant differences were found in age or in the remaining variables studied between these two groups. Increased uric acid levels in response to a possible chronic increase in oxidative stress may predict future disorders or complications such as type 2 diabetes in otherwise healthy persons.

  1. Biochemical and dietary factors of uric acid stone formation.

    PubMed

    Trinchieri, Alberto; Montanari, Emanuele

    2018-04-01

    The aim of this study was to compare the clinical characteristics of "pure" uric acid renal stone formers (UA-RSFs) with that of mixed uric acid/calcium oxalate stone formers (UC-RSFs) and to identify which urinary and dietary risk factors predispose to their formation. A total of 136 UA-RSFs and 115 UC-RSFs were extracted from our database of renal stone formers. A control group of 60 subjects without history of renal stones was considered for comparison. Data from serum chemistries, 24-h urine collections and 24-h dietary recalls were considered. UA-RSFs had a significantly (p = 0.001) higher body mass index (26.3 ± 3.6 kg/m 2 ) than UC-RSFs, whereas body mass index of UA-RSFs was higher but not significantly than in controls (24.6 ± 4.7) (p = 0.108). The mean urinary pH was significantly lower in UA-RSFs (5.57 ± 0.58) and UC-RSFs (5.71 ± 0.56) compared with controls (5.83 ± 0.29) (p = 0.007). No difference of daily urinary uric acid excretion was observed in the three groups (p = 0.902). Daily urinary calcium excretion was significantly (p = 0.018) higher in UC-RSFs (224 ± 149 mg/day) than UA-RSFs (179 ± 115) whereas no significant difference was observed with controls (181 ± 89). UA-RSFs tend to have a lower uric acid fractional excretion (0.083 ± 0.045% vs 0.107+/-0.165; p = 0.120) and had significantly higher serum uric acid (5.33 ± 1.66 vs 4.78 ± 1.44 mg/dl; p = 0.007) than UC-RSFs. The mean energy, carbohydrate and vitamin C intakes were higher in UA-SFs (1987 ± 683 kcal, 272 ± 91 g, 112 ± 72 mg) and UC-SFs (1836 ± 74 kcal, 265 ± 117, 140 ± 118) with respect to controls (1474 ± 601, 188 ± 84, 76 ± 53) (p = 0.000). UA-RSFs should be differentiated from UC-RSFs as they present lower urinary pH, lower uric acid fractional excretion and higher serum uric acid. On the contrary, patients with UC-RSFs show urinary risk factors

  2. Spectrophotometric determination of uric acid and some redeterminations of its solubility

    USGS Publications Warehouse

    Norton, D.R.; Plunkett, M.A.; Richards, F.A.

    1954-01-01

    The present study was initiated in order to develop a rapid and accurate method for the determination of uric acid in fresh, brackish, and sea water. It was found that the spectrophotometric determination of uric acid based upon its reaction with arsenophosphotungstic acid reagent in the presence of cyanide ion meets this objective. The absorbancy of the blue complex was measured at 890 m??. Slight variations from Beer's law were generally found. The results show the effects of pH, reaction time, concentration of reagents, and temperature upon color development and precipitate formation. Disodium dihydrogen ethylenediamine tetraacetate (Versene) was used as a buffering and complexirig agent. The results are significant in that they give the absorption spectrum of the blue complex and the effects of variables upon its absorbancy. Studies were made with the method to determine the stability of reagents and standard solutions and to determine the rate of bacterial decomposition of uric acid. Measurements of the solubility of uric acid are reported.

  3. Serum uric acid and target organ damage in essential hypertension

    PubMed Central

    Ofori, Sandra N; Odia, Osaretin J

    2014-01-01

    Background Hypertension is a major risk factor for cardiovascular mortality, as it acts through its effects on target organs, such as the heart and kidneys. Hyperuricemia increases cardiovascular risk in patients with hypertension. Objective To assess the relationship between serum uric acid and target organ damage (left ventricular hypertrophy and microalbuminuria) in untreated patients with essential hypertension. Patients and methods: A cross-sectional study was carried out in 130 (85 females, 45 males) newly diagnosed, untreated patients with essential hypertension. Sixty-five healthy age- and sex-matched non-hypertensive individuals served as controls for comparison. Left ventricular hypertrophy was evaluated by cardiac ultrasound scan, and microalbuminuria was assessed in an early morning midstream urine sample by immunoturbidimetry. Blood samples were collected for assessing uric acid levels. Results Mean serum uric acid was significantly higher among the patients with hypertension (379.7±109.2 μmol/L) than in the controls (296.9±89.8 μmol/L; P<0.001), and the prevalence of hyperuricemia was 46.9% among the hypertensive patients and 16.9% among the controls (P<0.001). Among the hypertensive patients, microalbuminuria was present in 54.1% of those with hyperuricemia and in 24.6% of those with normal uric acid levels (P=0.001). Similarly, left ventricular hypertrophy was more common in the hypertensive patients with hyperuricemia (70.5% versus 42.0%, respectively; P=0.001). There was a significant linear relationship between mean uric acid levels and the number of target organ damage (none versus one versus two: P=0.012). Conclusion These results indicate that serum uric acid is associated with target organ damage in patients with hypertension, even at the time of diagnosis; thus, it is a reliable marker of cardiovascular damage in our patient population. PMID:24833906

  4. Serum uric acid and target organ damage in essential hypertension.

    PubMed

    Ofori, Sandra N; Odia, Osaretin J

    2014-01-01

    Hypertension is a major risk factor for cardiovascular mortality, as it acts through its effects on target organs, such as the heart and kidneys. Hyperuricemia increases cardiovascular risk in patients with hypertension. To assess the relationship between serum uric acid and target organ damage (left ventricular hypertrophy and microalbuminuria) in untreated patients with essential hypertension. A cross-sectional study was carried out in 130 (85 females, 45 males) newly diagnosed, untreated patients with essential hypertension. Sixty-five healthy age- and sex-matched non-hypertensive individuals served as controls for comparison. Left ventricular hypertrophy was evaluated by cardiac ultrasound scan, and microalbuminuria was assessed in an early morning midstream urine sample by immunoturbidimetry. Blood samples were collected for assessing uric acid levels. Mean serum uric acid was significantly higher among the patients with hypertension (379.7±109.2 μmol/L) than in the controls (296.9±89.8 μmol/L; P<0.001), and the prevalence of hyperuricemia was 46.9% among the hypertensive patients and 16.9% among the controls (P<0.001). Among the hypertensive patients, microalbuminuria was present in 54.1% of those with hyperuricemia and in 24.6% of those with normal uric acid levels (P=0.001). Similarly, left ventricular hypertrophy was more common in the hypertensive patients with hyperuricemia (70.5% versus 42.0%, respectively; P=0.001). There was a significant linear relationship between mean uric acid levels and the number of target organ damage (none versus one versus two: P=0.012). These results indicate that serum uric acid is associated with target organ damage in patients with hypertension, even at the time of diagnosis; thus, it is a reliable marker of cardiovascular damage in our patient population.

  5. The relationship between uric acid and potassium in normal subjects.

    PubMed Central

    Kennedy, A C; Boddy, K; King, P C; Brennan, J; Anderson, J A; Buchanan, W W

    1978-01-01

    The serum uric acid concentration in normal healthy subjects has been studied in relation to sex, height, weight, lean body mass measured from total body potassium and predicted from the Hume-Weyers formula (1971), total body potassium, plasma potassium and urea, and packed cell volume. The strongest correlation was found with sex, but height, weight, total body potassium, lean body mass (measured and predicted) also correlated significantly with serum uric acid concentration. However, when the sex variable was removed, the other factors lost their significant correlation. Finally, total red blood cell and plasma volumes were predicted (Hume and Goldberg, 1964) and from these an estimate of total plasma uric acid, total plasma potassium, and total red blood cell potassium obtained. Measured total body potassium was found to correlate well with total plasma potassium and total red blood cell potassium independent of sex. Total plasma uric acid correlated well with measured total body potassium when both sexes were considered and when separated into male and female groups the males retained a significant correlation as did the female group. PMID:686865

  6. The Association of Albuminuria With Tubular Reabsorption of Uric Acid: Results From a General Population Cohort

    PubMed Central

    Scheven, Lieneke; Joosten, Michel M.; de Jong, Paul E.; Bakker, Stephan J. L.; Gansevoort, Ron T.

    2014-01-01

    Background Elevated albuminuria as well as an increased serum uric acid concentration is associated with poor cardiovascular outcome. We questioned whether these 2 variables (albuminuria and serum uric concentration) may be interrelated via tubular uric acid reabsorption. Methods and Results Included were 7688 participants of the PREVEND Study, an observational, general population‐based cohort study. Linear regression analyses were used to test associations of baseline albuminuria with baseline serum uric acid concentration and tubular uric acid reabsorption (calculated as [100−fractional uric acid excretion]%). Cox regression analyses were used to study the association of baseline serum uric acid and albuminuria with incident cardiovascular morbidity and mortality. In cross‐sectional analyses, albuminuria was associated positively with serum uric acid concentration, both crude and after adjustment for potential confounders (both P<0.001). Albuminuria was found to be associated positively with tubular uric acid reabsorption, again both crude and after adjustment for potential confounders (both P<0.001). In longitudinal analyses during a median follow‐up of 10.5 years, 702 cardiovascular events occurred. After adjusting for cardiovascular risk factors, both albuminuria and serum uric acid were associated with incident cardiovascular events (Hazard Ratios 1.09 [1.03 to 1.17], P=0.01 and 1.19 [1.09 to 1.30], P<0.001, respectively). A significant interaction between these variables was present (P<0.001), consistent with high serum uric acid being less predictive for cardiovascular morbidity and mortality in the presence of high albuminuria and vice versa. Conclusions Albuminuria is strongly associated with tubular uric acid reabsorption, and consequently with serum uric acid concentration. This phenomenon may explain in part why albuminuria is associated with cardiovascular outcome. PMID:24772520

  7. Regulation of xanthine dehydrogensase gene expression and uric acid production in human airway epithelial cells

    PubMed Central

    Huff, Ryan D.; Hsu, Alan C-Y.; Nichol, Kristy S.; Jones, Bernadette; Knight, Darryl A.; Wark, Peter A. B.; Hansbro, Philip M.

    2017-01-01

    Introduction The airway epithelium is a physical and immunological barrier that protects the pulmonary system from inhaled environmental insults. Uric acid has been detected in the respiratory tract and can function as an antioxidant or damage associated molecular pattern. We have demonstrated that human airway epithelial cells are a source of uric acid. Our hypothesis is that uric acid production by airway epithelial cells is induced by environmental stimuli associated with chronic respiratory diseases. We therefore examined how airway epithelial cells regulate uric acid production. Materials and methods Allergen and cigarette smoke mouse models were performed using house dust mite (HDM) and cigarette smoke exposure, respectively, with outcome measurements of lung uric acid levels. Primary human airway epithelial cells isolated from clinically diagnosed patients with asthma and chronic obstructive pulmonary disease (COPD) were grown in submerged cultures and compared to age-matched healthy controls for uric acid release. HBEC-6KT cells, a human airway epithelial cell line, were grown under submerged monolayer conditions for mechanistic and gene expression studies. Results HDM, but not cigarette smoke exposure, stimulated uric acid production in vivo and in vitro. Primary human airway epithelial cells from asthma, but not COPD patients, displayed elevated levels of extracellular uric acid in culture. In HBEC-6KT, production of uric acid was sensitive to the xanthine dehydrogenase (XDH) inhibitor, allopurinol, and the ATP Binding Cassette C4 (ABCC4) inhibitor, MK-571. Lastly, the pro-inflammatory cytokine combination of TNF-α and IFN-γ elevated extracellular uric acid levels and XDH gene expression in HBEC-6KT cells. Conclusions Our results suggest that the active production of uric acid from human airway epithelial cells may be intrinsically altered in asthma and be further induced by pro-inflammatory cytokines. PMID:28863172

  8. Relation between uric acid and metabolic syndrome in subjects with cardiometabolic risk

    PubMed Central

    da Silva, Hellen Abreu; Carraro, Júlia Cristina Cardoso; Bressan, Josefina; Hermsdorff, Helen Hermana Miranda

    2015-01-01

    Objective To identify possible relations between serum uric acid levels and metabolic syndrome and its components in a population with cardiometabolic risk. Methods This cross-sectional study included 80 subjects (46 women), with mean age of 48±16 years, seen at the Cardiovascular Health Program. Results The prevalence of hyperuricemia and metabolic syndrome was 6.3% and 47.1%, respectively. Uric acid level was significantly higher in individuals with metabolic syndrome (5.1±1.6mg/dL), as compared to those with no syndrome or with pre-syndrome (3.9±1.2 and 4.1±1.3mg/dL, respectively; p<0.05). The uric acid levels were significantly higher in men presenting abdominal obesity, and among women with abdominal obesity, lower HDL-c levels and higher blood pressure (p<0.05). Conclusion Uric acid concentrations were positively related to the occurrence of metabolic syndrome and its components, and there were differences between genders. Our results indicate serum uric acid as a potential biomarker for patients with cardiometabolic risk. PMID:26018145

  9. EDTA assisted synthesis of hydroxyapatite nanoparticles for electrochemical sensing of uric acid.

    PubMed

    Kanchana, P; Sekar, C

    2014-09-01

    Hydroxyapatite nanoparticles have been synthesized using EDTA as organic modifier by a simple microwave irradiation method and its application for the selective determination of uric acid (UA) has been demonstrated. Electrochemical behavior of uric acid at HA nanoparticle modified glassy carbon electrode (E-HA/GCE) has been investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), linear sweep voltammetry (LSV) and amperometry. The E-HA modified electrode exhibits efficient electrochemical activity towards uric acid sensing without requiring enzyme or electron mediator. Amperometry studies revealed that the fabricated electrode has excellent sensitivity for uric acid with the lowest detection limit of 142 nM over a wide concentration range from 1 × 10(-7) to 3 × 10(-5)M. Moreover, the studied E-HA modified GC electrode exhibits a good reproducibility and long-term stability and an admirable selectivity towards the determination of UA even in the presence of potential interferents. The analytical performance of this sensor was evaluated for the detection of uric acid in human urine and blood serum samples. Copyright © 2014. Published by Elsevier B.V.

  10. Simultaneous electrochemical detection of ascorbic acid, dopamine and uric acid based on graphene anchored with Pd-Pt nanoparticles.

    PubMed

    Yan, Jun; Liu, Shi; Zhang, Zhenqin; He, Guangwu; Zhou, Ping; Liang, Haiying; Tian, Lulu; Zhou, Xuemin; Jiang, Huijun

    2013-11-01

    Pd-Pt bimetallic nanoparticles anchored on functionalized reduced graphene oxide (RGO) nanomaterials were synthesized via a one-step in situ reduction process, in which Pt and Pd ions were first attached to poly(diallyldimethylammonium chloride) (PDDA) functionalized graphene oxide (GO) sheets, and then the encased metal ions and GO were subjected to simultaneous reduction by ethylene glycol. The as-prepared Pd3Pt1/PDDA-RGO nanocomposites were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and electrochemical methods. In addition, an electrochemical sensor based on the graphene nanocomposites was fabricated for the simultaneous detection of ascorbic acid (AA), dopamine (DA) and uric acid (UA) in their ternary mixture. Three well-separated voltammetric peaks along with remarkable increasing electro-oxidation currents were obtained in differential pulse voltammetry (DPV) measurements. Under the optimized conditions, there were linear relationships between the peak currents and the concentrations in the range of 40-1200 μM for AA, 4-200 μM for DA and 4-400 μM for UA, with the limit of detection (LOD) (based on S/N=3) of 0.61, 0.04 and 0.10 μM for AA, DA and UA, respectively. This improved electrochemical performance can be attributed to the synergistic effect of metallic nanoparticles and RGO and the combination of the bimetallic nanoparticles. Furthermore, the practical electroanalytical utility of the sensor was demonstrated by the determination of AA, DA and together with UA in human urine and blood serum samples with satisfactory results. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Uric Acid, Metabolic Syndrome and Atherosclerosis: The Chicken or the Egg, Which Comes First?

    PubMed

    De Pergola, Giovanni; Cortese, Francesca; Termine, Gaetano; Meliota, Giovanni; Carbonara, Rossella; Masiello, Michele; Cortese, Anna M; Silvestris, Francesco; Caccavo, Domenico; Ciccone, Marco Matteo

    2018-01-01

    A great debate in literature exists nowadays on the role of uric acid as a marker of cardiovascular and metabolic organ damage or a risk factor for cardiovascular and metabolic disease. The study aimed to determine the relationship among serum uric acid and metabolic syndrome and atherosclerosis, by means of carotid intima media-thickness, in a cohort of 811 otherwise healthy overweight/obese subjects, without overt atherosclerosis not using any kind of drug. Uric acid levels were positively related to male gender, waist circumference, BMI, systolic and diastolic pressure levels, fasting insulin, fasting glucose, HOMA-IR, triglycerides, total cholesterol, LDL cholesterol, the presence of metabolic syndrome and the number of the components of metabolic syndrome and negatively related to HDL cholesterol levels. No correlation was found between uric acid and carotid intima media thickness. At the multiple regression analysis, only waist circumference and triglycerides (positively) and HDL-cholesterol (negatively) maintained an independent association with uric acid as dependent variable, while age, female gender and uric acid showed a significant independent association with metabolic syndrome as dependent variable. Moreover, the analysis of the odd ratios showed that the risk of developing metabolic syndrome was consistent with uric acid levels ranging from 3 mg/dl to 8 mg/dl. The presence of metabolic syndrome does not seem to provide hyperuricemia. By contrast, higher serum uric acid level may predict the risk of metabolic syndrome. Moreover, our results suggest that uric acid cannot be considered a risk factor for early atherosclerosis, at least when assessed using carotid ultrasound. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  12. The effects of fasting in Ramadan. 1. Serum uric acid and lipid concentrations.

    PubMed

    Gumaa, K A; Mustafa, K Y; Mahmoud, N A; Gader, A M

    1978-11-01

    1. The changes in serum levels of uric acid and lipids during 1 month of starvation-refeeding were measured in sixteen male volunteers. 2. Uric acid levels increased linearly with the duration of the experiment. The increase was positively correlated with the increase in serum triglycerides but not with cholesterol or phospholipids. 3. Triglycerides increased at a faster rate than uric acid implying that the increase in uric acid was secondary to that of the lipid. 4. It was concluded that the purine and lipid synthetic pathways are linked through a common small-molecular-weight effector rather than through the sharing of a common enzyme.

  13. Association of serum uric acid with high-sensitivity C-reactive protein in postmenopausal women.

    PubMed

    Raeisi, A; Ostovar, A; Vahdat, K; Rezaei, P; Darabi, H; Moshtaghi, D; Nabipour, I

    2017-02-01

    To explore the independent correlation between serum uric acid and low-grade inflammation (measured by high-sensitivity C-reactive protein, hs-CRP) in postmenopausal women. A total of 378 healthy Iranian postmenopausal women were randomly selected in a population-based study. Circulating hs-CRP levels were measured by highly specific enzyme-linked immunosorbent assay method and an enzymatic calorimetric method was used to measure serum levels of uric acid. Pearson correlation coefficient, multiple linear regression and logistic regression models were used to analyze the association between uric acid and hs-CRP levels. A statistically significant correlation was seen between serum levels of uric acid and log-transformed circulating hs-CRP (r = 0.25, p < 0.001). After adjustment for age and cardiovascular risk factors (according to NCEP ATP III criteria), circulating hs-CRP levels were significantly associated with serum uric acid levels (β = 0.20, p < 0.001). After adjustment for age and cardiovascular risk factors, hs-CRP levels ≥3 mg/l were significantly associated with higher uric acid levels (odds ratio =1.52, 95% confidence interval 1.18-1.96). Higher serum uric acid levels were positively and independently associated with circulating hs-CRP in healthy postmenopausal women.

  14. Dietary Sodium Modifies Serum Uric Acid Concentrations in Humans.

    PubMed

    Todd, Alwyn S; Walker, Robert J; MacGinley, Robert J; Kelly, Jaimon; Merriman, Tony R; Major, Tanya J; Johnson, Richard J

    2017-11-06

    Subjects with hypertension are frequently obese or insulin resistant, both conditions in which hyperuricemia is common. Obese and insulin-resistant subjects are also known to have blood pressure that is more sensitive to changes in dietary sodium intake. Whether hyperuricemia is a resulting consequence, moderating or contributing factor to the development of hypertension has not been fully evaluated and very few studies have reported interactions between sodium intake and serum uric acid. We performed further analysis of our randomized controlled clinical trials (Australian New Zealand Clinical Trials Registry #12609000161224 and #12609000292279) designed to assess the effects of modifying sodium intake on concentrations of serum markers, including uric acid. Uric acid and other variables (including blood pressure, renin, and aldosterone) were measured at baseline and 4 weeks following the commencement of low (60 mmol/day), moderate (150 mmol/day), and high (200-250 mmol/day) dietary sodium intake. The median aldosterone-to-renin ratio was 1.90 [pg/ml]/[pg/ml] (range 0.10-11.04). Serum uric acid fell significantly in both the moderate and high interventions compared to the low sodium intervention. This pattern of response occurred when all subjects were analyzed, and when normotensive or hypertensive subjects were analyzed alone. Although previously reported in hypertensive subjects, these data provide evidence in normotensive subjects of an interaction between dietary sodium intake and serum uric acid. As this interaction is present in the absence of hypertension, it is possible it could play a role in hypertension development, and will need to be considered in future trials of dietary sodium intake. The trials were registered with the Australian and New Zealand Clinical Trials Registry as ACTRN12609000161224 and ACTRN1260. © American Journal of Hypertension, Ltd 2017. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  15. A causal role for uric acid in fructose-induced metabolic syndrome.

    PubMed

    Nakagawa, Takahiko; Hu, Hanbo; Zharikov, Sergey; Tuttle, Katherine R; Short, Robert A; Glushakova, Olena; Ouyang, Xiaosen; Feig, Daniel I; Block, Edward R; Herrera-Acosta, Jaime; Patel, Jawaharlal M; Johnson, Richard J

    2006-03-01

    The worldwide epidemic of metabolic syndrome correlates with an elevation in serum uric acid as well as a marked increase in total fructose intake (in the form of table sugar and high-fructose corn syrup). Fructose raises uric acid, and the latter inhibits nitric oxide bioavailability. Because insulin requires nitric oxide to stimulate glucose uptake, we hypothesized that fructose-induced hyperuricemia may have a pathogenic role in metabolic syndrome. Four sets of experiments were performed. First, pair-feeding studies showed that fructose, and not dextrose, induced features (hyperinsulinemia, hypertriglyceridemia, and hyperuricemia) of metabolic syndrome. Second, in rats receiving a high-fructose diet, the lowering of uric acid with either allopurinol (a xanthine oxidase inhibitor) or benzbromarone (a uricosuric agent) was able to prevent or reverse features of metabolic syndrome. In particular, the administration of allopurinol prophylactically prevented fructose-induced hyperinsulinemia (272.3 vs.160.8 pmol/l, P < 0.05), systolic hypertension (142 vs. 133 mmHg, P < 0.05), hypertriglyceridemia (233.7 vs. 65.4 mg/dl, P < 0.01), and weight gain (455 vs. 425 g, P < 0.05) at 8 wk. Neither allopurinol nor benzbromarone affected dietary intake of control diet in rats. Finally, uric acid dose dependently inhibited endothelial function as manifested by a reduced vasodilatory response of aortic artery rings to acetylcholine. These data provide the first evidence that uric acid may be a cause of metabolic syndrome, possibly due to its ability to inhibit endothelial function. Fructose may have a major role in the epidemic of metabolic syndrome and obesity due to its ability to raise uric acid.

  16. A comparison of uric acid levels in Black African vs Caucasian women from South Africa: the POWIRS study.

    PubMed

    Palmer, I M; Schutte, A E; Huisman, H W; Van Rooyen, J M; Schutte, R; Malan, L; Malan, N T

    2007-01-01

    Elevated levels of uric acid are often associated with cardiometabolic risk factors. The aim of this study was to determine whether uric acid levels differ between African and Caucasian women and whether uric acid is associated with cardiometabolic risk factors within the two ethnic groups. Women from African (N=102) and Caucasian (N=115) descent were recruited and their uric acid levels measured. Anthropometric measurements included height (stature), weight, and waist circumference. Correlations between uric acid and cardiometabolic variables within each ethnic group were also determined. African women had significantly lower levels of uric acid (P<.01) and significantly higher levels of blood pressure (P=.05) compared to the Caucasian women. There was a significant increase in blood pressure from the lower to higher uric acid tertiles in the African women. Uric acid strongly correlated with waist circumference in both ethnic groups. Despite their higher blood pressure, the African women had lower uric acid levels, yet they showed a significant increase in blood pressure from a low uric acid tertile to high uric acid tertile, which was not noticeable in the Caucasian women. A possible explanation is a lower waist circumference in African women compared to Caucasian women.

  17. Cichorium intybus L. promotes intestinal uric acid excretion by modulating ABCG2 in experimental hyperuricemia.

    PubMed

    Wang, Yu; Lin, Zhijian; Zhang, Bing; Nie, Anzheng; Bian, Meng

    2017-01-01

    Excessive production and/or reduced excretion of uric acid could lead to hyperuricemia, which could be a major cause of disability. Hyperuricemia has received increasing attention in the last few decades due to its global prevalence. Cichorium intybus L., commonly known as chicory, is a perennial herb of the asteraceae family. It was previously shown to exert potent hypouricemic effects linked with decreasing uric acid formation in the liver by down-regulating the activity of xanthine oxidase, and increasing uric acid excretion by up-regulating the renal OAT3 mRNA expression. The present study aimed to evaluate its extra-renal excretion and possible molecular mechanism underlying the transporter responsible for intestinal uric acid excretion in vivo. Chicory was administered intragastrically to hyperuricemic rats induced by drinking 10% fructose water. The uricosuric effect was evaluated by determining the serum uric acid level as well as the intestinal uric acid excretion by HPLC. The location and expression levels of ATP-binding cassette transporter, sub-family G, member 2 (ABCG2) in jejunum and ileum were analyzed. The administration of chicory decreased the serum uric acid level significantly and increased the intestinal uric acid excretion obviously in hyperuricemic rats induced by 10% fructose drinking. Staining showed that ABCG2 was expressed in the apical membrane of the epithelium and glands of the jejunum and ileum in rats. Further examination showed that chicory enhanced the mRNA and protein expressions of ABCG2 markedly in a dose-dependent manner in jejunum and ileum. These findings indicate that chicory increases uric acid excretion by intestines, which may be related to the stimulation of intestinal uric acid excretion via down-regulating the mRNA and protein expressions of ABCG2.

  18. Stable carbon and nitrogen isotope analysis of avian uric acid.

    PubMed

    Bird, Michael I; Tait, Elaine; Wurster, Christopher M; Furness, Robert W

    2008-11-01

    We report results obtained using a new technique developed to measure the stable-isotope composition of uric acid isolated from bird excreta (guano). Results from a diet-switch feeding trial using zebra finches suggest that the delta(13)C of uric acid in the guano equilibrates with the diet of the bird within 3 days of a change in diet, while the equilibration time for delta(15)N may be longer. The average carbon isotope discrimination between uric acid and food before the diet switch was +0.34 +/- 1 per thousand (1sigma) while after the diet switch this increased slightly to +0.83 +/- 0.7 per thousand (1sigma). Nitrogen isotope discrimination was +1.3 +/- 0.3 per thousand (1sigma) and +0.3 +/- 0.3 per thousand (1sigma) before and after the diet switch; however, it is possible that the nitrogen isotope values did not fully equilibrate with diet switch over the course of the experiment. Analyses of other chemical fractions of the guano (organic residue after uric acid extraction and non-uric acid organics solubilised during extraction) suggest a total range of up to 3 per thousand for both delta(13)C and delta(15)N values in individual components of a single bulk guano sample. The analysis of natural samples from a range of terrestrial and marine species demonstrates that the technique yields isotopic compositions consistent with the known diets of the birds. The results from natural samples further demonstrate that multiple samples from the same species collected from the same location yield similar results, while different species from the same location exhibit a range of isotopic compositions indicative of different dietary preferences. Given that many samples of guano can be rapidly collected without any requirement to capture specimens for invasive sampling, the stable-isotope analysis of uric acid offers a new, simple and potentially powerful tool for studying avian ecology and metabolism.

  19. Evaluation of serum uric acid levels in normal pregnant Nigerian women.

    PubMed

    Nwagha, U I; Ejezie, F E; Iyare, E E

    2009-03-01

    Hypertensive disorders in pregnancy are common in our environment. The aetiology is unknown and the prognostic indicators of the severity of maternal and fetal complications are variable. The level of uric acid, which is one of the prognostic indicators, is altered in normal pregnancy and as pregnancy advances. Base line values are thus extremely important to enable reasonable prognostic assessment in hypertensive pregnancies. To determine levels of serum uric acid during normal pregnancy in University of Nigeria Teaching Hospital (UNTH) Enugu. settings and methods: Sixty- five pregnant and 65 non-pregnant women with age range 20-38 years were recruited. The pregnant women were in their second and third trimesters, attending antenatal clinic at the University of Nigeria Teaching Hospital Enugu. Serum levels of uric acid were determined for the entire subjects. The serum uric acid levels were significantly lower in the pregnant women than in controls (P < 0.001). 0.15 +/- 0.03 mmol/L in the second trimester, 0.14 +/- 0.02 mmol/L in the third trimester and 0.29 +/- 0.04 mmoL for control. The low levels in pregnancy and as pregnancy progresses should be taken into consideration when monitoring hypertensive disorders in pregnancy using serum uric acid. Thus levels that are within normal for non pregnant population may indeed be an indication for intervention in pregnancies complicated by preeclampsia.

  20. Simultaneous determination of ascorbic acid, dopamine and uric acid by a novel electrochemical sensor based on N2/Ar RF plasma assisted graphene nanosheets/graphene nanoribbons.

    PubMed

    Jothi, Lavanya; Neogi, Sudarsan; Jaganathan, Saravana Kumar; Nageswaran, Gomathi

    2018-05-15

    A novel nitrogen/argon (N 2 /Ar) radio frequency (RF) plasma functionalized graphene nanosheet/graphene nanoribbon (GS/GNR) hybrid material (N 2 /Ar/GS/GNR) was developed for simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). Various nitrogen mites introduced into GS/GNR hybrid structure was evidenced by a detailed microscopic, spectroscopic and surface area analysis. Owing to the unique structure and properties originating from the enhanced surface area, nitrogen functional groups and defects introduced on both the basal and edges, N 2 /Ar/GS/GNR/GCE showed high electrocatalytic activity for the electrochemical oxidations of AA, DA, and UA with the respective lowest detection limits of 5.3, 2.5 and 5.7 nM and peak-to-peak separation potential (ΔE P ) (vs Ag/AgCl) in DPV of 220, 152 and 372 mV for AA/DA, DA/UA and AA/UA respectively. Moreover, the selectivity, stability, repeatability and excellent performance in real time application of the fabricated N 2 /Ar/GS/GNR/GCE electrode suggests that it can be considered as a potential electrode material for simultaneous detection of AA, DA, and UA. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Effect of uric acid on inflammatory COX-2 and ROS pathways in vascular smooth muscle cells.

    PubMed

    Oğuz, Nurgül; Kırça, Mustafa; Çetin, Arzu; Yeşilkaya, Akın

    2017-10-01

    Hyperuricemia is thought to play a role in cardiovascular diseases (CVD), including hypertension, coronary artery disease and atherosclerosis. However, exactly how uric acid contributes to these pathologies is unknown. An underlying mechanism of inflammatory diseases, such as atherosclerosis, includes enhanced production of cyclooxygenase-2 (COX-2) and superoxide anion. Here, we aimed to examine the effect of uric acid on inflammatory COX-2 and superoxide anion production and to determine the role of losartan. Primarily cultured vascular smooth muscle cells (VSMCs) were time and dose-dependently induced by uric acid and COX-2 and superoxide anion levels were measured. COX-2 levels were determined by ELISA, and superoxide anion was measured by the superoxide dismutase (SOD)-inhibitable reduction of ferricytochrome c method. Uric acid elevated COX-2 levels in a time-dependent manner. Angiotensin-II receptor blocker, losartan, diminished uric-acid-induced COX-2 elevation. Uric acid also increased superoxide anion level in VSMCs. Uric acid plays an important role in CVD pathogenesis by inducing inflammatory COX-2 and ROS pathways. This is the first study demonstrating losartan's ability to reduce uric-acid-induced COX-2 elevation.

  2. Thin layer chromatographic method for the detection of uric acid: collaborative study.

    PubMed

    Thrasher, J J; Abadie, A

    1978-07-01

    A collaborative study has been completed on an improved method for the detection and confirmation of uric acid from bird and insect excreta. The proposed method involves the lithium carbonate solubilization of the suspect excreta material, followed by butanol-methanol-water-acetic acid thin layer chromatography, and trisodium phosphate-phosphotungstic acid color development. The collaborative tests resulted in 100% detection of uric acid standard at the 50 ng level and 75% detection at the 20-25 ng level. No false positives were reported during tests of compounds similar to uric acid. The proposed method has been adopted official first action; the present official final action method, 44.161, will be retained for screening purposes.

  3. Uric acid inhibition of dipeptidyl peptidase IV in vitro is dependent on the intracellular formation of triuret.

    PubMed

    Mohandas, Rajesh; Sautina, Laura; Beem, Elaine; Schuler, Anna; Chan, Wai-Yan; Domsic, John; McKenna, Robert; Johnson, Richard J; Segal, Mark S

    2014-08-01

    Uric acid affects endothelial and adipose cell function and has been linked to diseases such as hypertension, metabolic syndrome, and cardiovascular disease. Interestingly uric acid has been shown to increase endothelial progenitor cell (EPC) mobilization, a potential mechanism to repair endothelial injury. Since EPC mobilization is dependent on activity of the enzyme CD26/dipeptidyl peptidase (DPP)IV, we examined the effect uric acid will have on CD26/DPPIV activity. Uric acid inhibited the CD26/DPPIV associated with human umbilical vein endothelial cells but not human recombinant (hr) CD26/DPPIV. However, triuret, a product of uric acid and peroxynitrite, could inhibit cell associated and hrCD26/DPPIV. Increasing or decreasing intracellular peroxynitrite levels enhanced or decreased the ability of uric acid to inhibit cell associated CD26/DPPIV, respectively. Finally, protein modeling demonstrates how triuret can act as a small molecule inhibitor of CD26/DPPIV activity. This is the first time that uric acid or a uric acid reaction product has been shown to affect enzymatic activity and suggests a novel avenue of research in the role of uric acid in the development of clinically important diseases. Published by Elsevier Inc.

  4. Exploration into Uric and Cardiovascular Disease: Uric Acid Right for heArt Health (URRAH) Project, A Study Protocol for a Retrospective Observational Study.

    PubMed

    Desideri, Giovambattista; Virdis, Agostino; Casiglia, Edoardo; Borghi, Claudio

    2018-06-01

    The relevance of cardiovascular role played by levels of serum uric acid is dramatically growing, especially as cardiovascular risk factor potentially able to exert either a direct deleterious impact or a synergic effect with other cardiovascular risk factors. At the present time, it still remains undefined the threshold level of serum uric acid able to contribute to the cardiovascular risk. Indeed, the available epidemiological case studies are not homogeneous, and some preliminary data suggest that the so-called "cardiovascular threshold limit" may substantially differ from that identified as a cut-off able to trigger the acute gout attack. In such scenario, there is the necessity to clarify and quantify this threshold value, to insert it in the stratification of risk algorithm scores and, in turn, to adopt proper prevention and correction strategies. The clarification of the relationship between circulating levels of uric acid and cardio-nephro-metabolic disorders in a broad sample representative of general population is critical to identify the threshold value of serum uric acid better discriminating the increased risk associated with uric acid. The Uric acid Right for heArt Health (URRAH) project has been designed to define, as primary objective, the level of uricemia above which the independent risk of cardiovascular disease may increase in a significantly manner in a general Italian population.

  5. Uric Acid: The Unknown Uremic Toxin.

    PubMed

    Treviño-Becerra, Alejandro

    2018-01-01

    This review brings together concepts of uric acid metabolism affecting renal parenchyma and its function and the current therapies to reduce hyperuricemia (HyU) and avoid renal disease progression. High uric acid plays an important role in several chronic diseases including kidney diseases such as lithiasis, gout nephropathy, and preeclampsia. In the last 30 years, it has been shown that reducing HyU with low protein and low purine diets in addition to allopurinol creates physiopathological conditions that produce a slight increase in the glomerular filtration rate (GFR). In recent years, in a new era of research in clinical, genetics, pharmacological, and epidemiologic fields, they have been moving forward to support the idea that reduction in HyU could benefit the chronic renal failure (CRF) patients (stage III-IV), thereby avoiding the drop of GFR for undefined mechanisms. There are several clinical trials in progress that show the HyU reducing to very low values and an increased GFR. In a young population, when treating HyU there is a reduction in high blood pressure. There are some reports showing that HyU could play a role in the diabetic nephropathy. Therefore, there have been some speculations that HyU treatment could stop the progression of CRF modifying the natural history of the diseases. So there will be new clinical trials with old and new medication and metabolic procedure to maintain a very low blood levels in the unknown uremic toxin know as uric acid which seems to be the toxin to the damage kidney. © 2018 S. Karger AG, Basel.

  6. Serum urea and uric acid concentration in pregnant women in sub-urban commercial community in Africa.

    PubMed

    Ahaneku, J E; Adinma, J I; Ahaneku, G I; Nwosu, B O; Nwofor, P C; Okoli, C C

    2009-06-01

    Serum uric acid and urea levels were determined in 27 pregnant and 17 non-pregnant black African women. Uric acid levels for the pregnant women were significantly raised, and the relationship between uric acid elevation and gestational proteinuric hypertension was discussed. In conclusion, we recommend that uric acid estimation should be included during routine antenatal clinics in normal pregnancy. That the use of uric acid levels should be encouraged for the diagnosis and management of gestational proteinuric hypertension in African pregnant women. The above recommendation will help to reduce prenatal morbidity and mortality in African pregnant women.

  7. Determinants of blood uric acid levels in a dyslipidemic Arab population.

    PubMed

    Al-Meshaweh, Ahoud F; Jafar, Yaqoub; Asem, Mohammad; Akanji, Abayomi O

    2012-01-01

    The objective of this study was to explore the relationships between circulating uric acid and lipid levels and components of the metabolic syndrome (MetS) in Arab dyslipidemic patients, a group already at high coronary artery disease risk. The medical records of 1,229 subjects (632 men, 597 women) referred for treatment of dyslipidemia and followed up for at least 12 months were reviewed. Serum levels of uric acid and lipids (total cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein) and other variables in the National Cholesterol Education Program ATP III criteria definition of MetS were assessed at initial presentation and every 4- 6 months, under specific lipid-lowering treatment (statins and/or fibrates), in each of the subjects. Their respective associations were explored by appropriate logistic regression techniques with control for confounding risk factors, including age, gender and body mass index. 306 subjects (24.9%) of the study population were hyperuricemic; they were more likely to be men, obese and diabetic. Also the serum uric acid level (mean ± SD) was greater in men with MetS compared with men without (377.0 ± 98.0 vs. 361.6 ± 83.1 μmol/l, p < 0.05), an observation not reproduced in women. Uric acid levels had significant associations with the presence of fasting hyperglycemia, hypertension and large waist circumference (WC) in men, but only with large WC in women. With statin treatment, uric acid levels decreased by 10% within 1 year of treatment; with fibrates, uric acid levels remained unchanged or slightly increased. The data showed that hyperuricemia is common in dyslipidemic patients in Kuwait, where its important determinants are male sex, obesity, diabetes and statin treatment. Copyright © 2011 S. Karger AG, Basel.

  8. The diurnal variation in urine acidification differs between normal individuals and uric acid stone formers

    PubMed Central

    Cameron, Mary Ann; Maalouf, Naim M.; Poindexter, John; Adams-Huet, Beverley; Sakhaee, Khashayar; Moe, Orson W.

    2012-01-01

    Many biologic functions follow circadian rhythms driven by internal and external cues that synchronize and coordinate organ physiology to diurnal changes in the environment and behavior. Urinary acid-base parameters follow diurnal patterns and it is thought these changes are due to periodic surges in gastric acid secretion. Abnormal urine pH is a risk factor for specific types of nephrolithiasis and uric acid stones are typical of excessively low urine pH. Here we placed 9 healthy volunteers and 10 uric acid stone formers on fixed metabolic diets to study the diurnal pattern of urinary acidification. All showed clear diurnal trends in urinary acidification but none of the patterns were affected by inhibitors of the gastric proton pump. Uric acid stone formers had similar patterns of change through the day but their urine pH was always lower compared to healthy volunteers. Uric acid stone formers excreted more acid (normalized to acid ingestion) with the excess excreted primarily as titratable acid rather than ammonium. Urine base excretion was also lower in uric acid stone formers (normalized to base ingestion) along with lower plasma bicarbonate concentrations during part of the day. Thus, increased net acid presentation to the kidney and the preferential use of buffers, other than ammonium, result in much higher concentrations of un-dissociated uric acid throughout the day and consequently an increased risk of uric acid stones. PMID:22297671

  9. Extended Gate Field-Effect Transistor Biosensors for Point-Of-Care Testing of Uric Acid.

    PubMed

    Guan, Weihua; Reed, Mark A

    2017-01-01

    An enzyme-free redox potential sensor using off-chip extended-gate field effect transistor (EGFET) with a ferrocenyl-alkanethiol modified gold electrode has been used to quantify uric acid concentration in human serum and urine. Hexacyanoferrate (II) and (III) ions are used as redox reagent. The potentiometric sensor measures the interface potential on the ferrocene immobilized gold electrode, which is modulated by the redox reaction between uric acid and hexacyanoferrate ions. The device shows a near Nernstian response to uric acid and is highly specific to uric acid in human serum and urine. The interference that comes from glucose, bilirubin, ascorbic acid, and hemoglobin is negligible in the normal concentration range of these interferents. The sensor also exhibits excellent long term reliability and is regenerative. This extended gate field effect transistor based sensor is promising for point-of-care detection of uric acid due to the small size, low cost, and low sample volume consumption.

  10. Uric Acid Induces Renal Inflammation via Activating Tubular NF-κB Signaling Pathway

    PubMed Central

    Zhou, Yang; Fang, Li; Jiang, Lei; Wen, Ping; Cao, Hongdi; He, Weichun; Dai, Chunsun; Yang, Junwei

    2012-01-01

    Inflammation is a pathologic feature of hyperuricemia in clinical settings. However, the underlying mechanism remains unknown. Here, infiltration of T cells and macrophages were significantly increased in hyperuricemia mice kidneys. This infiltration of inflammatory cells was accompanied by an up-regulation of TNF-α, MCP-1 and RANTES expression. Further, infiltration was largely located in tubular interstitial spaces, suggesting a role for tubular cells in hyperuricemia-induced inflammation. In cultured tubular epithelial cells (NRK-52E), uric acid, probably transported via urate transporter, induced TNF-α, MCP-1 and RANTES mRNA as well as RANTES protein expression. Culture media of NRK-52E cells incubated with uric acid showed a chemo-attractive ability to recruit macrophage. Moreover uric acid activated NF-κB signaling. The uric acid-induced up-regulation of RANTES was blocked by SN 50, a specific NF-κB inhibitor. Activation of NF-κB signaling was also observed in tubule of hyperuricemia mice. These results suggest that uric acid induces renal inflammation via activation of NF-κB signaling. PMID:22761883

  11. Circulating Levels of Uric Acid and Risk for Metabolic Syndrome.

    PubMed

    Rubio-Guerra, Alberto F; Morales-López, Herlinda; Garro-Almendaro, Ana K; Vargas-Ayala, German; Durán-Salgado, Montserrat B; Huerta-Ramírez, Saul; Lozano-Nuevo, Jose J

    2017-01-01

    Hyperuricemia leads to insulin resistance, whereas insulin resistance decreases renal excretion of uric acid, both mechanisms link elevated serum uric acid with metabolic syndrome. The aim of this study is to evaluate the probability for the development of metabolic syndrome in low-income young adults with hyperuricaemia. We evaluated 103 patients less than 40 years of age, from a low-income population, and without history of cardiovascular disease, in all of them the presence of metabolic syndrome was assessed in accordance with the International Diabetes Federation criteria. In all patients, fasting serum uric acid levels were measured; hyperuricaemia was defined as serum uric acid values 6.5 mg/dl in men and 5.1 mg/dl in women. Statistical analysis was performed with odds ratio. 83 of our patients (80.5%) suffered metabolic syndrome, the odds ratio for the presence of metabolic syndrome in patients with hyperuricaemia was 5.1 (p=0.002, I.C 1.8- 14.5). When patients were evaluated by gender a significantly association between hyperuricaemia and metabolic syndrome was found in women (odds ratio 3.6, p=0.048, C.I. 1.0-12.9), and men (odds ratio 10.2, p= 0.015, IC 1.5-13.2). When uric acid was correlated with the components of metabolic syndrome, we only found a positive correlation with waist circumference (r=0.483). Our results showed a significant association between hyperuricemia and metabolic syndrome in low-income young adults in Mexico. DR is associated with estimated risk of CVD in type 2 diabetic patients. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  12. Serum uric acid values in Tanzanian rural communities.

    PubMed

    Nhonoli, A M; Kihama, F

    1974-09-01

    Serum uric acid levels have been determined in random samples of 9-10% of a population of 3000 each in three rural areas of Tanzania. The levels in females are lower than in males. As far as age is concerned the levels in both sexes rise with age but the rate is slower in females resulting in a widening difference with increasing age. Above uric acid levels of 6 mg% the frequency occurrence of 'hyperuricaemia' is equal. The normal distribution of levels was 2.5-5.5 mg% in males and 2.0-4.5 mg% in females. Compared with results among different racial groups elsewhere these levels are lower.

  13. Peripartum cardiomyopathy is associated with increased uric acid concentrations: A population based study.

    PubMed

    Sagy, Iftach; Salman, Amjad Abu; Kezerle, Louise; Erez, Offer; Yoel, Idan; Barski, Leonid

    Peri-partum cardiomyopathy (PPCM) is a clinical heart failure that usually develops during the final stage of pregnancy or the first months following delivery. High maternal serum uric acid concentrations have been previous associated with heart failure and preeclampsia. 1) To explored the clinical characteristics of PPCM patients; and 2) to determine the association between maternal serum uric acid concentrations and PPCM. This is a retrospective population based case control study. Cases and controls were matched 1:4 (for gestational age, medical history of cardiac conditions and creatinine); conditional logistic regression was used to identify clinical parameters that were associated with PPCM. The prevalence of peripartum cardiomyopathy at our institution was 1-3832 deliveries (42/160,964). In a matched multivariate analysis high maternal serum uric acid concentrations were associated with PPCM (O.R 1.336, 95% C.I 1.003-1.778). Uric acid concentrations were higher within the Non-Jewish patients and mothers of male infant with PPCM in compare to those without PPCM (p value 0.003 and 0.01 respectively). PPCM patients had increased maternal serum uric acid concentrations. This observation aligns with previous report regarding the increased uric acid concentration in women with preeclampsia and congestive heart failure, suggestive of a common underlying mechanism that mediates the myocardial damage. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Uric acid demonstrates neuroprotective effect on Parkinson's disease mice through Nrf2-ARE signaling pathway.

    PubMed

    Huang, Ting-Ting; Hao, Dong-Lin; Wu, Bo-Na; Mao, Lun-Lin; Zhang, Jin

    2017-12-02

    Uric acid has neuroprotective effect on Parkinson's disease (PD) by inhibiting oxidative damage and neuronal cell death. Our previous study has shown that uric acid protected dopaminergic cell line damage through inhibiting accumulation of NF-E2-related factor 2 (Nrf2). This study aimed to investigate its in vivo neuroprotective effect. PD was induced by MPTP intraperitoneally injection for 7 d in male C57BL/6 mice. Mice were treated with either uric acid (intraperitoneally injection 250 mg/kg) or saline for a total of 13 d. We showed that uric acid improved behavioral performances and cognition of PD mice, increased TH-positive dopaminergic neurons and decreased GFAP-positive astrocytes in substantia nigra (SN). Uric acid increased mRNA and protein expressions of Nrf2 and three Nrf2-responsive genes, including γ-glutamate-cysteine ligase catalytic subunit (γ-GCLC), heme oxygenase-1 (HO-1) and NQO1. Uric acid significantly increased superoxide dismutase (SOD), CAT, glutathione (GSH) levels and decreased malondialdehyde (MDA) level in SN regions of MPTP-treated mice. Uric acid inhibited the hippocampal expression of IL-1β and decreased serum and hippocampus levels of interleukin-1β (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α). In conclusion, uric acid demonstrates neuroprotective properties for dopaminergic neurons in PD mice through modulation of neuroinflammation and oxidative stress. Copyright © 2017. Published by Elsevier Inc.

  15. Construction of uric acid biosensor based on biomimetic titanate nanotubes.

    PubMed

    Tao, Haisheng; Wang, Xuebin; Wang, Xizhang; Hu, Yemin; Ma, Yanwen; Lu, Yinong; Hu, Zheng

    2010-02-01

    A uric acid biosensor has been fabricated through the immobilization of uricase on glassy carbon electrode modified by biomimetic titanate nanotubes of high specific surface area synthesized by hydrothermal decomposition. The so-constructed biosensor presents a high affinity to uric acid with a small apparent Michaelis-Menten constant of only 0.66 mM. The biosensor exhibits fairly good electrochemical properties such as the high sensitivity of 184.3 microAcm(-2)mM(-1), the fast response of less than 2 s, as well as the wide linear range from 1 microM to 5 mM. These performances indicate that titanate nanotubes could provide a favorable microenvironment for uricase immobilization, stabilize its biological activity, and function as an efficient electron conducting tunnel to facilitate the electron transfer. This suggests an important potential of titanate nanotubes in uric acid biosensors.

  16. Uric Acid Excretion Predicts Increased Blood Pressure Among American Adolescents of African Descent.

    PubMed

    Mrug, Sylvie; Mrug, Michal; Morris, Anjana Madan; Reynolds, Nina; Patel, Anita; Hill, Danielle C; Feig, Daniel I

    2017-04-01

    Hyperuricemia predicts the incidence of hypertension in adults and its treatment has blood pressure (BP)-lowering effects in adolescents. To date, no studies have examined the predictive usage of hyperuricemia or urinary uric acid excretion on BP changes in adolescents. Mechanistic models suggest that uric acid impairs both endothelial function and vascular compliance, which would potentially exacerbate a myriad of hypertensive mechanisms, yet little is known about interaction of uric acid and other hypertension risk factors. The primary study was aimed at the effects of stress on BP in adolescents. A community sample of 84 low-income, urban adolescents (50% male, 95% African American, mean age = 13.36 ± 1 years) was recruited from public schools. Youth completed a 12-hour (overnight) urine collection at home and their BP was measured during rest and in response to acute psychosocial stress. Seventy-six of the adolescents participated in a follow-up visit at 1.5 years when their resting BP was reassessed. In this substudy, we assessed the relationship of renal urate excretion and BP reactivity. After adjusting for resting BP levels at baseline and other covariates, higher levels of uric acid excretion predicted greater BP reactivity to acute psychosocial stress and higher resting BP at 18 months. Urinary excretion of uric acid can serve as an alternative, noninvasive measure of serum uric acid levels that are predictive of BP changes. As hyperuricemia-associated hypertension is treatable, urban adolescents may benefit from routine screening for hyperuricemia or high uric acid excretion. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

  17. Effect and mechanism of dioscin from Dioscorea spongiosa on uric acid excretion in animal model of hyperuricemia.

    PubMed

    Zhang, Yi; Jin, Lijun; Liu, Jinchang; Wang, Wei; Yu, Haiyang; Li, Jian; Chen, Qian; Wang, Tao

    2018-03-25

    Dioscin, a spirostane glycoside, the rhizoma of Dioscorea septemloba (Diocoreacea) is used for diuresis, rheumatism, and joints pain. Given the poor solubility and stability of Dioscin, we proposed a hypothesis that Dioscin's metabolite(s) are the active substance(s) in vivo to contribute to the reducing effects on serum uric acid levels. The aim of this study is to identify the active metabolite(s) of Dioscin in vivo and to explore the mechanism of its antihyperuricemic activity. After oral administration of Dioscin in potassium oxonate (PO) induced hyperuricemia rats and adenine-PO induced hyperuricemia mice models, serum uric acid and creatinine levels, clearance of uric acid and creatinine, fractional excretion of uric acid, and renal pathological lesions were determined were used to evaluate the antihyperuricemic effects. Renal glucose transporter-9 (GLUT-9) and organic anion transporter-1 (OAT-1) expressions were analyzed by western blotting method. Renal uric acid excretion was evaluated using stably urate transporter-1 (URAT-1) transfected human epithelial kidney cell line. Intestinal uric acid excretion was evaluated by measuring the transcellular transport of uric acid in HCT116 cells. In hyperuricemia rats, both 25 and 50mg/kg of oral Dioscin decreased serum uric acid levels over 4h. In the hyperuricemia mice, two weeks treatment of Dioscin significantly decreased serum uric acid and creatinine levels, increased clearance of uric acid and creatinine, increased fractional excretion of uric acid, and reduced renal pathological lesions caused by hyperuricemia. In addition, renal GLUT -9 was significantly down-regulated and OAT-1 was up-regulated in Dioscin treated hyperuricemia mice. Dioscin's metabolite Tigogenin significantly inhibited uric acid re-absorption via URAT1 from 10 to 100μM. Diosgenin and Tigogenin increased uric acid excretion via ATP binding cassette subfamily G member 2 (ABCG2). Decreasing effect of Dioscin on serum uric acid level and

  18. Photoelectrocatalytic oxidation of glucose at a ruthenium complex modified titanium dioxide electrode promoted by uric acid and ascorbic acid for photoelectrochemical fuel cells

    NASA Astrophysics Data System (ADS)

    Lu, Shuo-Jian; Ji, Shi-Bo; Liu, Jun-Chen; Li, Hong; Li, Wei-Shan

    2015-01-01

    The simultaneous presence of uric acid (UA) and ascorbic acid (AA) is first found to largely promote the photoelectrocatalytic oxidation of glucose (GLU) at an indium-tin oxide (ITO) or TiO2 nanoparticles/ITO electrode modified with [Ru(tatp)3]2+ (tatp = 1,4,8,9-tetra-aza-triphenylene) possessing good redox activity and nanoparticle size distribution. A well-defined electrocatalytic peak for GLU oxidation is shown at 0.265 V (vs. SCE) under approximate physiological conditions upon incorporation of UA and AA. The [Ru(tatp)3]2+/ITO electrode exhibits attractive amperometric oxidation responses towards GLU, UA and AA, while controlled potentiostatically at 0.3 V, 0.7 V and 1.0 V, respectively, indicating high sensitivity and excellent reproducibility. On basis of the photoelectrocatalysis of [Ru(tatp)3]2+/TiO2/ITO anode, a GLU concentration-dependent photoelectrochemical fuel cell vs. SCE is elaborately assembled. The proposed free-enzyme photoelectrochemical fuel cell employing 0.1 M GLU associated with 0.01 M UA and 0.01 M AA as fuel shows open-circuit photovoltage of 0.608 V, short-circuit photocurrent density of 124.5 μA cm-2 and maximum power density of 21.75 μW cm-2 at 0.455 V, fill factor of 0.32 and photoenergy conversion efficiency of 36.65%, respectively.

  19. Association of high-sensitivity C-reactive protein and uric acid with the metabolic syndrome components.

    PubMed

    Sah, Santosh Kumar; Khatiwada, Saroj; Pandey, Sunil; Kc, Rajendra; Das, Binod Kumar Lal; Baral, Nirmal; Lamsal, Madhab

    2016-01-01

    Metabolic syndrome (MetS) has been found to be associated with inflammatory molecules. This study was conducted among 125 MetS patients at B P Koirala Institute of Health Sciences, Dharan, Nepal to find an association of high-sensitivity C-reactive protein (hs-CRP) and serum uric acid with MetS components. Anthropometric measurements, blood pressure, medical history and blood samples were taken. Estimation of hs-CRP, serum uric acid, blood glucose, triglyceride and high density lipoprotein (HDL) cholesterol was done. hs-CRP had positive correlation with blood glucose (r = 0.2, p = 0.026) and negative with HDL cholesterol (r = -0.361, p < 0.001). Serum uric acid had positive correlation with waist circumference (r = 0.178, p = 0.047). Patients with elevated hs-CRP and uric acid had higher waist circumference (p = 0.03), diastolic BP (p = 0.002) and lower HDL cholesterol (p = 0.004) than others. Elevated hs-CRP and high uric acid were individually associated with higher odds for low HDL cholesterol (7.992; 1.785-35.774, p = 0.002) and hyperglycemia (2.471; 1.111-5.495, p = 0.029) respectively. Combined rise of hs-CRP and uric acid was associated with severity of MetS (p < 0.001) and higher odds for hyperglycemia (8.036; 2.178-29.647, p = 0.001) as compared to individual rise of hs-CRP or uric acid. The present study demonstrates that hs-CRP and serum uric acid are associated with MetS components, and the combined rise of hs-CRP and uric acid is associated with the increase in severity of MetS.

  20. Study of Serum Uric Acid Levels in Myocardial Infarction and Its Association With Killip Class.

    PubMed

    Mehrpooya, Maryam; Larti, Farnoosh; Nozari, Younes; Sattarzadeh-Badkoobeh, Roya; Zand Parsa, Amir Farhang; Zebardast, Jayran; Tavoosi, Anahita; Shahbazi, Fatemeh

    2017-02-01

    The present study aimed to compare the serum level of uric acid in patients with and without heart failure and also to determine the association between uric acid level and clinical status by Killip class in patients with STEMI. This case-control study was conducted on 50 consecutives as control group and 50 patients with acute heart failure, (20 patients had acute STEMI), who documented by both clinical conditions and echocardiography assessment. The mean plasma level of uric acid in the case group was 7.6±1.6 milligrams/deciliter (mg/dL) and in the control group was 4.5±1.5 respectively (P<0.001). These values in patients with STEMI was about 9.2±0.86, but in patients with acute heart failure in absence of STEMI was 6.5±1.04 (P<0.001). Moreover, there was significant difference among the level of uric acid and Killip classes (P<0.001). Also there was significant difference for uric acid level between HFrEF (HF with reduced EF) and severe LV systolic dysfunction (0.049). In STEMI patients with culprit LAD, mean uric acid was significantly higher than cases with culprit LCX [(9.7±0.98 versus 8.6±0.52 respectively) P=0.012]. Regarding  treatment plan in patients with STEMI, mean level of uric acid in those considered for CABG was significantly higher than who were considered for PCI, 9.9±0.82 versus 8.9±0.76 respectively, P=0.029. In STEMI patients with higher killip class, higher level of uric acid was seen. Also, the severity of LV systolic dysfunction was associated with higher level of uric acid.

  1. Genetic variation underlying renal uric acid excretion in Hispanic children: the Viva La Familia Study.

    PubMed

    Chittoor, Geetha; Haack, Karin; Mehta, Nitesh R; Laston, Sandra; Cole, Shelley A; Comuzzie, Anthony G; Butte, Nancy F; Voruganti, V Saroja

    2017-01-17

    Reduced renal excretion of uric acid plays a significant role in the development of hyperuricemia and gout in adults. Hyperuricemia has been associated with chronic kidney disease and cardiovascular disease in children and adults. There are limited genome-wide association studies associating genetic polymorphisms with renal urate excretion measures. Therefore, we investigated the genetic factors that influence the excretion of uric acid and related indices in 768 Hispanic children of the Viva La Familia Study. We performed a genome-wide association analysis for 24-h urinary excretion measures such as urinary uric acid/urinary creatinine ratio, uric acid clearance, fractional excretion of uric acid, and glomerular load of uric acid in SOLAR, while accounting for non-independence among family members. All renal urate excretion measures were significantly heritable (p <2 × 10 -6 ) and ranged from 0.41 to 0.74. Empirical threshold for genome-wide significance was set at p <1 × 10 -7 . We observed a strong association (p < 8 × 10 -8 ) of uric acid clearance with a single nucleotide polymorphism (SNP) in zinc finger protein 446 (ZNF446) (rs2033711 (A/G), MAF: 0.30). The minor allele (G) was associated with increased uric acid clearance. Also, we found suggestive associations of uric acid clearance with SNPs in ZNF324, ZNF584, and ZNF132 (in a 72 kb region of 19q13; p <1 × 10 -6 , MAFs: 0.28-0.31). For the first time, we showed the importance of 19q13 region in the regulation of renal urate excretion in Hispanic children. Our findings indicate differences in inherent genetic architecture and shared environmental risk factors between our cohort and other pediatric and adult populations.

  2. Association between Serum Uric Acid and Non-Alcoholic Fatty Liver Disease: A Meta-Analysis.

    PubMed

    Darmawan, Guntur; Hamijoyo, Laniyati; Hasan, Irsan

    2017-04-01

    non-alcoholic fatty liver disease (NAFLD) is known to be associated with some metabolic disorders. Recent studies suggested the role of uric acid in NAFLD through oxidative stress and inflammatory process. This study is aimed to evaluate the association between serum uric acid and NAFLD. a systematic literature review was conducted using Pubmed and Cochrane library. The quality of all studies was assessed using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE). All data were analyzed using REVIEW MANAGER 5.3. eleven studies from America and Asia involving 100,275 subjects were included. The pooled adjusted OR for NAFLD was 1.92 (95% CI: 1.66-2.23; p<0.00001). Subgroup analyses were done based on study design, gender, non-diabetic subjects, non-obese subjects. All subgroup analyses showed statistically significant adjusted OR and most of which having low to moderate heterogeneity. Two studies revealed relationship between increased serum uric acid levels and severity of NAFLD. No publication bias was observed. our study demonstrated association between serum uric acid level and NAFLD. This finding brings a new insight of uric acid in clinical practice. Increased in serum uric acid levels might serve as a trigger for physician to screen for NAFLD.

  3. Effects of Sodium Glucose Cotransporter-2 Inhibitors on Serum Uric Acid in Type 2 Diabetes Mellitus.

    PubMed

    Ahmadieh, Hala; Azar, Sami

    2017-09-01

    Hyperuricemia has been linked to metabolic syndrome, cardiovascular disease, and chronic kidney disease. Hyperuricemia and type 2 diabetes mellitus were inter-related, type 2 diabetes mellitus was more at risk of having a higher serum uric acid level, and also individuals with higher serum uric acid had higher risk of developing type 2 diabetes in the future. Insulin resistance seems to play an important role in the causal relationship between metabolic syndrome, type 2 diabetes, and hyperuricemia. Oral diabetic drugs that would have additional beneficial effects on reducing serum uric acid levels are of importance. Selective SGLT2 inhibitors were extensively studied in type 2 diabetes mellitus and were found to have improvement of glycemic control, in addition to their proven metabolic effects on weight and blood pressure. Additional beneficial effect of SGLT2 inhibitors on serum uric acid level reduction is investigated. Recently, data have been accumulating showing that they have additional beneficial effects on serum uric acid reduction. As for the postulated mechanism, serum uric acid decreased in SGLT2 inhibitor users as a result of the increase in the urinary excretion rate of uric acid, due to the inhibition of uric acid reabsorption mediated by the effect of the drug on the GLUT9 isoform 2, located at the collecting duct of the renal tubule.

  4. Activity and Stability of Biofilm Uricase of Lactobacillus plantarum for Uric Acid Biosensor

    NASA Astrophysics Data System (ADS)

    Iswantini, Dyah; Rachmatia, Rescy; Diana, Novita Rose; Nurhidayat, Novik; Akhiruddin; Saprudin, Deden

    2016-01-01

    Research of uric acid biosensor used a Lactobacillus plantarum was successfully conducted. Lactobacillus plantarum could produce uricase that could be used as uric acid biosensor. Therefore, lifetime of bacteria were quite short that caused the bacteria could not detect uric acid for a long time. To avoid this problem, development of biofilm for uric acid biosensor is important. Biofilms is a structured community of bacterial cells, stick together and are able to maintain a bacteria in an extreme environments. The purpose of present study was to determine and compare the activity of uricase produced by L. plantarum, deposited whithin biofilm and planktonic bacteria on glassy carbon electrode (GCEb & GCE), also to determine the stability of biofilm. The optimization process was conducted by using temperature, pH, and substrate concentration as the parameters. It showed that the activity of uricase within biofilm was able to increase the oxidation current. GCEb and GCE yielded the oxidation current in the amount of 47.24 μA and 23.04 μA, respectively, under the same condition. Results indicated that the optimum condition for uric acid biosensor using biofilm were pH 10, temperature of 40 oC, and uric acid concentration of 5 mM. The stability of GCEb decreased after 10 hours used, with decreasing percentage over 86.33%. This low stability probably caused by the unprotected active site of the enzyme that the enzyme is easier to experience the denaturation.

  5. [Advance in treatment of hyperuricemia by Chinese medicine based on uric acid transporterome].

    PubMed

    Zhou, Qi; Liu, Shu-min

    2015-11-01

    With the development of the quality of life, the morbidity of hyperuricemia is increasing year by year. At the same time, it appears that this disease attacks the young people currently. As the study of pathogenesis of hyperuricemia advanced, a series of uric acid transporters were found during this process. Meanwhile, the definition of transporterome was proposed. They were divided into three groups according to the functions: reabsorption proteins, excretion proteins and skeleton proteins. At moment, the drugs for hyperuricmia mainly include uric acid composition inhibitors and uric acid excretion promoters. Since the excretion of uric acid plays a leading role during the process of attack of hyperurecimia, it makes sense to explore Chinese medicines with clear mechanism targeting the transporterome. Therefore, this paper would focus on transporterome and summarize the mechanisms of Chinese medicines in treating hyperuricemia.

  6. Imprinted zeolite modified carbon paste electrode as a potentiometric sensor for uric acid

    NASA Astrophysics Data System (ADS)

    Khasanah, Miratul; Widati, Alfa Akustia; Fitri, Sarita Aulia

    2016-03-01

    Imprinted zeolite modified carbon paste electrode (carbon paste-IZ) has been developed and applied to determine uric acid by potentiometry. The imprinted zeolite (IZ) was synthesized by the mole ratio of uric acid/Si of 0.0306. The modified electrode was manufactured by mass ratio of carbon, IZ and solid paraffin was 40:25:35. The modified electrode had shown the measurement range of 10-5 M to 10-2 M with Nernst factor of 28.6 mV/decade, the detection limit of 5.86 × 10-6 M and the accuracy of 95.3 - 105.0%. Response time of the electrode for uric acid 10-5 M - 10-2 M was 25 - 44 s. The developed electrode showed the high selectivity toward uric acid in the urea matrix. Life time of the carbon paste-IZ electrode was 10 weeks.

  7. Biological Activities of Uric Acid in Infection Due to Enteropathogenic and Shiga-Toxigenic Escherichia coli

    PubMed Central

    Broome, Jacqueline E.; Lis, Agnieszka

    2016-01-01

    In previous work, we identified xanthine oxidase (XO) as an important enzyme in the interaction between the host and enteropathogenic Escherichia coli (EPEC) and Shiga-toxigenic E. coli (STEC). Many of the biological effects of XO were due to the hydrogen peroxide produced by the enzyme. We wondered, however, if uric acid generated by XO also had biological effects in the gastrointestinal tract. Uric acid triggered inflammatory responses in the gut, including increased submucosal edema and release of extracellular DNA from host cells. While uric acid alone was unable to trigger a chloride secretory response in intestinal monolayers, it did potentiate the secretory response to cyclic AMP agonists. Uric acid crystals were formed in vivo in the lumen of the gut in response to EPEC and STEC infections. While trying to visualize uric acid crystals formed during EPEC and STEC infections, we noticed that uric acid crystals became enmeshed in the neutrophilic extracellular traps (NETs) produced from host cells in response to bacteria in cultured cell systems and in the intestine in vivo. Uric acid levels in the gut lumen increased in response to exogenous DNA, and these increases were enhanced by the actions of DNase I. Interestingly, addition of DNase I reduced the numbers of EPEC bacteria recovered after a 20-h infection and protected against EPEC-induced histologic damage. PMID:26787720

  8. Suitable Concentrations of Uric Acid Can Reduce Cell Death in Models of OGD and Cerebral Ischemia-Reperfusion Injury.

    PubMed

    Zhang, Bin; Yang, Ning; Lin, Shao-Peng; Zhang, Feng

    2017-07-01

    Cerebral infarction (CI) is a common clinical cerebrovascular disease, and to explore the pathophysiological mechanisms and seek effective treatment means are the hotspot and difficult point in medical research nowadays. Numerous studies have confirmed that uric acid plays an important role in CI, but the mechanism has not yet been clarified. When treating HT22 and BV-2 cells with different concentrations of uric acid, uric acid below 450 μM does not have significant effect on cell viability, but uric acid more than 500 μM can significantly inhibit cell viability. After establishing models of OGD (oxygen-glucose deprivation) with HT22 and BV-2 cells, uric acid at a low concentration (50 μM) cannot improve cell viability and apoptosis, and Reactive oxygen species (ROS) levels during OGD/reoxygenation; a suitable concentration (300 μM) of uric acid can significantly improve cell viability and apoptosis, and reduce ROS production during OGD/reoxygenation; but a high concentration (1000 μM) of uric acid can further reduce cell viability and enhance ROS production. After establishing middle cerebral artery occlusion of male rats with suture method, damage and increase of ROS production in brain tissue could be seen, and after adding suitable concentration of uric acid, the degree of brain damage and ROS production was reduced. Therefore, different concentrations of uric acid should have different effect, and suitable concentrations of uric acid have neuroprotective effect, and this finding may provide guidance for study on the clinical curative effect of uric acid.

  9. Simultaneous determination of L-ascorbic acid, dopamine and uric acid with gold nanoparticles-β-cyclodextrin-graphene-modified electrode by square wave voltammetry.

    PubMed

    Tian, Xianqing; Cheng, Changming; Yuan, Hongyan; Du, Juan; Xiao, Dan; Xie, Shunping; Choi, Martin M F

    2012-05-15

    Graphene decorated with gold nanoparticles (AuNPs-β-CD-Gra) has been synthesized by in situ thermal reduction of graphene oxide and HAuCl(4) with β-cyclodextrin (β-CD) under alkaline condition. The AuNPs-β-CD-Gra product was well characterized by infrared spectroscopy, X-ray powder diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, and selected area electron diffraction. This material was used to fabricate an AuNPs-β-CD-Gra-modified glassy carbon electrode (GCE) which showed excellent electro-oxidation of l-ascorbic acid (AA), dopamine (DA) and uric acid (UA) in 0.10 M NaH(2)PO(4)-HCl buffer solution (pH 2.0) by square wave voltammetry (SWV). Three well-resolved oxidation peaks of AA and DA and UA were obtained. The AuNPs-β-CD-Gra/GCE exhibits linear responses to AA, DA and UA in the ranges 30-2000, 0.5-150 and 0.5-60 μM, respectively. The detection limits (based on S/N=3 and preconcentration time=3.0 min) for AA, DA and UA are 10, 0.15 and 0.21 μM, respectively. The AuNPs-β-CD-Gra/GCE has been successfully applied to determine UA in human urine with satisfactory results. Our work provides a simple, convenient and green route to synthesize AuNPs on Gra which is potentially useful in electroanalysis. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Uric acid priming in human monocytes is driven by the AKT–PRAS40 autophagy pathway

    PubMed Central

    Crişan, Tania O.; Cleophas, Maartje C. P.; Novakovic, Boris; Erler, Kathrin; van de Veerdonk, Frank L.; Stunnenberg, Hendrik G.; Netea, Mihai G.; Dinarello, Charles A.; Joosten, Leo A. B.

    2017-01-01

    Metabolic triggers are important inducers of the inflammatory processes in gout. Whereas the high serum urate levels observed in patients with gout predispose them to the formation of monosodium urate (MSU) crystals, soluble urate also primes for inflammatory signals in cells responding to gout-related stimuli, but also in other common metabolic diseases. In this study, we investigated the mechanisms through which uric acid selectively lowers human blood monocyte production of the natural inhibitor IL-1 receptor antagonist (IL-1Ra) and shifts production toward the highly inflammatory IL-1β. Monocytes from healthy volunteers were first primed with uric acid for 24 h and then subjected to stimulation with lipopolysaccharide (LPS) in the presence or absence of MSU. Transcriptomic analysis revealed broad inflammatory pathways associated with uric acid priming, with NF-κB and mammalian target of rapamycin (mTOR) signaling strongly increased. Functional validation did not identify NF-κB or AMP-activated protein kinase phosphorylation, but uric acid priming induced phosphorylation of AKT and proline-rich AKT substrate 40 kDa (PRAS 40), which in turn activated mTOR. Subsequently, Western blot for the autophagic structure LC3-I and LC3-II (microtubule-associated protein 1A/1B-light chain 3) fractions, as well as fluorescence microscopy of LC3-GFP–overexpressing HeLa cells, revealed lower autophagic activity in cells exposed to uric acid compared with control conditions. Interestingly, reactive oxygen species production was diminished by uric acid priming. Thus, the Akt–PRAS40 pathway is activated by uric acid, which inhibits autophagy and recapitulates the uric acid-induced proinflammatory cytokine phenotype. PMID:28484006

  11. Uric acid priming in human monocytes is driven by the AKT-PRAS40 autophagy pathway.

    PubMed

    Crişan, Tania O; Cleophas, Maartje C P; Novakovic, Boris; Erler, Kathrin; van de Veerdonk, Frank L; Stunnenberg, Hendrik G; Netea, Mihai G; Dinarello, Charles A; Joosten, Leo A B

    2017-05-23

    Metabolic triggers are important inducers of the inflammatory processes in gout. Whereas the high serum urate levels observed in patients with gout predispose them to the formation of monosodium urate (MSU) crystals, soluble urate also primes for inflammatory signals in cells responding to gout-related stimuli, but also in other common metabolic diseases. In this study, we investigated the mechanisms through which uric acid selectively lowers human blood monocyte production of the natural inhibitor IL-1 receptor antagonist (IL-1Ra) and shifts production toward the highly inflammatory IL-1β. Monocytes from healthy volunteers were first primed with uric acid for 24 h and then subjected to stimulation with lipopolysaccharide (LPS) in the presence or absence of MSU. Transcriptomic analysis revealed broad inflammatory pathways associated with uric acid priming, with NF-κB and mammalian target of rapamycin (mTOR) signaling strongly increased. Functional validation did not identify NF-κB or AMP-activated protein kinase phosphorylation, but uric acid priming induced phosphorylation of AKT and proline-rich AKT substrate 40 kDa (PRAS 40), which in turn activated mTOR. Subsequently, Western blot for the autophagic structure LC3-I and LC3-II (microtubule-associated protein 1A/1B-light chain 3) fractions, as well as fluorescence microscopy of LC3-GFP-overexpressing HeLa cells, revealed lower autophagic activity in cells exposed to uric acid compared with control conditions. Interestingly, reactive oxygen species production was diminished by uric acid priming. Thus, the Akt-PRAS40 pathway is activated by uric acid, which inhibits autophagy and recapitulates the uric acid-induced proinflammatory cytokine phenotype.

  12. Photothermal laser lithotripsy of uric acid calculi: clinical assessment of the effects of cyanide production

    NASA Astrophysics Data System (ADS)

    Teichman, Joel M. H.; Champion, Paolo C.; Glickman, Randolph D.; Wollin, Timothy A.; Denstedt, John D.

    1999-06-01

    The mechanism of holmium:YAG lithotripsy is photothermal. Holmium:YAG lithotripsy of uric acid calculi produces cyanide, which is a known, thermal decomposition produce of uric acid. we review our experience with holmium:YAG lithotripsy of uric acid to determine if there is any clinical evidence of cyanide toxicity. A retrospective analysis of all of our cases of holmium:YAG lithotripsy of uric acid calculi was done. Anesthetic and postoperative data were reviewed. A total of 18 patients with uric acid calculi were tread with holmium:YAG lithotripsy by urethroscopy (5), retrograde nephroscopy (2), percutaneous nephrolithotomy (5) or cystolithotripsy (6). Total holmium:YAG irradiation ranged from 1.2 to 331 kJ. No patient had evidence of increased end-tidal carbon dioxide, change sin electrocardiogram or significant decrease in postoperative serum bicarbonate. An 84 year old woman had decreased diastolic pressure of 30 mm Hg while under general anesthesia. No cyanide related neurologic, cardiac or respiratory complications were noted. These data suggest no significant cyanide toxicity from holmium:YAG lithotripsy or uric acid calculi in typical clinical settings. More specific studies in animals are warranted to characterize the risk.

  13. Correlation between Apgar score and urinary uric acid to creatinine ratio in perinatal asphyxia.

    PubMed

    Basu, Pallab; Som, Sabyasachi; Choudhuri, Nabendu; Das, Harendranath

    2008-10-01

    A randomized case control hospital based study was conducted over 12 months time on 31 asphyxiated and 31 normal newborn to see whether urinary uric acid can be used as a marker of perinatal asphyxia and can be correlated with the clinical diagnosis by Apgar score. Uric acid and creatinine were estimated in spot urine within 24 hours after birth in both cases and controls. A ratio between concentrations of uric acid to creatinine was estimated and compared between cases and controls. It was found that the ratios were significantly higher in cases than controls (3.1± 1.3 vs 0.96± 0.54; P < 0.001) and among asphyxia patients, a significant negative linear correlation was found between the uric acid to creatinine ratio and the Apgar score (r = -0.857, P < 0.001). So urinary uric acid to creatinine ratio can be used as an additional non-invasive dispace, easy and at the same time early biochemical marker of birth asphyxia which biochemically supports the clinical diagnosis and severity grading of asphyxia by Apgar score.

  14. GLUT9 influences uric acid concentration in patients with Lesch-Nyhan disease.

    PubMed

    Torres, Rosa J; Puig, Juan G

    2018-06-01

    Patients with deficient hypoxanthine-guanine phosphoribosyltransferase (HPRT) activity present hyperuricemia and/or hyperuricosuria, with a variable degree of neurological manifestations. Hyperuricemia in HPRT deficiency is due to uric acid overproduction and is frequently treated with allopurinol. Renal uric acid excretion is sharply increased in these patients. In recent years, several renal tubular urate transporter single nucleotide polymorphisms (SNPs), including those of the GLUT9, ABCG2 and URAT1 genes, have been described that influence the renal handling of uric acid and modulate serum urate levels. In the present study, we analyzed whether GLUT9, ABCG2 and URAT1 gene SNPs are able to influence uric acid levels and allopurinol response in patients with HPRT deficiency. Three SNPs, URAT1 rs11231825, GLUT9 rs16890979 and ABCG2 rs2231142, previously associated in our population with hyperuricemia and gout, were analyzed in 27 patients with HPRT deficiency treated with allopurinol for at least 5 years. Patients with HPRT deficiency having allele A of rs16890979 in the GLUT9 gene present with a lower serum urate concentration at diagnosis, before allopurinol treatment is instituted, and need lower allopurinol doses to maintain serum urate levels between 268 and 446 μmol/L (4.5 and 7.5 mg/dL). No relationship between rs2231142 in the ABCG2 gene or rs11231825 in the URAT1 gene and serum urate levels or allopurinol response was found in our patients with HPRT deficiency. GLUT9 SNPs influence the renal handling of uric acid and modulate serum urate levels and the response to treatment in patients with uric acid overproduction due to HPRT deficiency. © 2018 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.

  15. Conversion of Uric Acid into Ammonium in Oil-Degrading Marine Microbial Communities: a Possible Role of Halomonads.

    PubMed

    Gertler, Christoph; Bargiela, Rafael; Mapelli, Francesca; Han, Xifang; Chen, Jianwei; Hai, Tran; Amer, Ranya A; Mahjoubi, Mouna; Malkawi, Hanan; Magagnini, Mirko; Cherif, Ameur; Abdel-Fattah, Yasser R; Kalogerakis, Nicolas; Daffonchio, Daniele; Ferrer, Manuel; Golyshin, Peter N

    2015-10-01

    Uric acid is a promising hydrophobic nitrogen source for biostimulation of microbial activities in oil-impacted marine environments. This study investigated metabolic processes and microbial community changes in a series of microcosms using sediment from the Mediterranean and the Red Sea amended with ammonium and uric acid. Respiration, emulsification, ammonium and protein concentration measurements suggested a rapid production of ammonium from uric acid accompanied by the development of microbial communities containing hydrocarbonoclastic bacteria after 3 weeks of incubation. About 80 % of uric acid was converted to ammonium within the first few days of the experiment. Microbial population dynamics were investigated by Ribosomal Intergenic Spacer Analysis and Illumina sequencing as well as by culture-based techniques. Resulting data indicated that strains related to Halomonas spp. converted uric acid into ammonium, which stimulated growth of microbial consortia dominated by Alcanivorax spp. and Pseudomonas spp. Several strains of Halomonas spp. were isolated on uric acid as the sole carbon source showed location specificity. These results point towards a possible role of halomonads in the conversion of uric acid to ammonium utilized by hydrocarbonoclastic bacteria.

  16. Synthesis of positively charged CdTe quantum dots and detection for uric acid

    NASA Astrophysics Data System (ADS)

    Zhang, Tiliang; Sun, Xiangying; Liu, Bin

    2011-09-01

    The CdTe dots (QDs) coated with 2-Mercaptoethylamine was prepared in aqueous solution and characterized with fluorescence spectroscopy, UV-Vis absorption spectra, high-resolution transmission electron microscopy and infrared spectroscopy. When the λex = 350 nm, the fluorescence peak of positively charged CdTe quantum dots is at 592 nm. The uric acid is able to quench their fluorescence. Under optimum conditions, the change of fluorescence intensity is linearly proportional to the concentration of uric acid in the range 0.4000-3.600 μmol L -1, and the limit of detection calculated according to IUPAC definitions is 0.1030 μmol L -1. Compared with routine method, the present method determines uric acid in human serum with satisfactory results. The mechanism of this strategy is due to the interaction of the tautomeric keto/hydroxyl group of uric acid and the amino group coated at the CdTe QDs.

  17. Melatonin protects against uric acid-induced mitochondrial dysfunction, oxidative stress, and triglyceride accumulation in C2C12 myotubes.

    PubMed

    Maarman, Gerald J; Andrew, Brittany M; Blackhurst, Dee M; Ojuka, Edward O

    2017-04-01

    Excess uric acid has been shown to induce oxidative stress, triglyceride accumulation, and mitochondrial dysfunction in the liver and is an independent predictor of type-2 diabetes. Skeletal muscle plays a dominant role in type 2 diabetes and presents a large surface area to plasma uric acid. However, the effects of uric acid on skeletal muscle are underinvestigated. Our aim was therefore to characterize the effects of excessive uric acid on oxidative stress, triglyceride content, and mitochondrial function in skeletal muscle C 2 C 12 myotubes and assess how these are modulated by the antioxidant molecule melatonin. Differentiated C 2 C 12 myotubes were exposed to 750 µM uric acid or uric acid + 10 nM melatonin for 72 h. Compared with control, uric acid increased triglyceride content by ~237%, oxidative stress by 32%, and antioxidant capacity by 135%. Uric acid also reduced endogenous ROUTINE respiration, complex II-linked oxidative phosphorylation, and electron transfer system capacities. Melatonin counteracted the effects of uric acid without further altering antioxidant capacity. Our data demonstrate that excess uric acid has adverse effects on skeletal muscle similar to those previously reported in hepatocytes and suggest that melatonin at a low physiological concentration of 10 nM may be a possible therapy against some adverse effects of excess uric acid. NEW & NOTEWORTHY Few studies have investigated the effects of uric acid on skeletal muscle. This study shows that hyperuricemia induces mitochondrial dysfunction and triglyceride accumulation in skeletal muscle. The findings may explain why hyperuricemia is an independent predictor of diabetes. Copyright © 2017 the American Physiological Society.

  18. Heat Stress Nephropathy From Exercise-Induced Uric Acid Crystalluria: A Perspective on Mesoamerican Nephropathy.

    PubMed

    Roncal-Jimenez, Carlos; García-Trabanino, Ramón; Barregard, Lars; Lanaspa, Miguel A; Wesseling, Catharina; Harra, Tamara; Aragón, Aurora; Grases, Felix; Jarquin, Emmanuel R; González, Marvin A; Weiss, Ilana; Glaser, Jason; Sánchez-Lozada, Laura G; Johnson, Richard J

    2016-01-01

    Mesoamerican nephropathy (MeN), an epidemic in Central America, is a chronic kidney disease of unknown cause. In this article, we argue that MeN may be a uric acid disorder. Individuals at risk for developing the disease are primarily male workers exposed to heat stress and physical exertion that predisposes to recurrent water and volume depletion, often accompanied by urinary concentration and acidification. Uric acid is generated during heat stress, in part consequent to nucleotide release from muscles. We hypothesize that working in the sugarcane fields may result in cyclic uricosuria in which uric acid concentrations exceed solubility, leading to the formation of dihydrate urate crystals and local injury. Consistent with this hypothesis, we present pilot data documenting the common presence of urate crystals in the urine of sugarcane workers from El Salvador. High end-of-workday urinary uric acid concentrations were common in a pilot study, particularly if urine pH was corrected to 7. Hyperuricemia may induce glomerular hypertension, whereas the increased urinary uric acid may directly injure renal tubules. Thus, MeN may result from exercise and heat stress associated with dehydration-induced hyperuricemia and uricosuria. Increased hydration with water and salt, urinary alkalinization, reduction in sugary beverage intake, and inhibitors of uric acid synthesis should be tested for disease prevention. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  19. Uric Acid Levels Can Predict Metabolic Syndrome and Hypertension in Adolescents: A 10-Year Longitudinal Study.

    PubMed

    Sun, Hai-Lun; Pei, Dee; Lue, Ko-Huang; Chen, Yen-Lin

    2015-01-01

    The relationships between uric acid and chronic disease risk factors such as metabolic syndrome, type 2 diabetes mellitus, and hypertension have been studied in adults. However, whether these relationships exist in adolescents is unknown. We randomly selected 8,005 subjects who were between 10 to 15 years old at baseline. Measurements of uric acid were used to predict the future occurrence of metabolic syndrome, hypertension, and type 2 diabetes. In total, 5,748 adolescents were enrolled and followed for a median of 7.2 years. Using cutoff points of uric acid for males and females (7.3 and 6.2 mg/dl, respectively), a high level of uric acid was either the second or third best predictor for hypertension in both genders (hazard ratio: 2.920 for males, 5.222 for females; p<0.05). However, uric acid levels failed to predict type 2 diabetes mellitus, and only predicted metabolic syndrome in males (hazard ratio: 1.658; p<0.05). The same results were found in multivariate adjusted analysis. In conclusion, a high level of uric acid indicated a higher likelihood of developing hypertension in both genders and metabolic syndrome in males after 10 years of follow-up. However, uric acid levels did not affect the occurrence of type 2 diabetes in both genders.

  20. Uric acid, renal function and risk of hypoglycaemia in Chinese type 2 diabetes patients.

    PubMed

    Ren, Yanfeng; Ji, Linong; Mu, Yiming; Hong, Tianpei; Ji, Qiuhe; Guo, Lixin; Huang, Qin; Yang, Xilin

    2016-11-01

    This study aimed to explore independent associations between serum uric acid and hypoglycaemia, and whether mildly increased serum uric acid exacerbated the association between mild decline in estimated glomerular filtration rate (eGFR) and hypoglycaemia. A cross-sectional survey of 6713 inpatients with type 2 diabetes and eGFR ≥60 mL/min/1.73 m 2 and admitted to 81 tertiary care hospitals in China was conducted. Self-reported asymptotic hypoglycaemia with plasma glucose ≤3.9 mmol/L, hypoglycaemia episodes with symptoms in 1 month or hypoglycaemia that needed assistance from other people in 3 months before hospitalization was used to define hypoglycaemia. Binary logistic regression was used to estimate odds ratios of serum uric acid for hypoglycaemia. Three measures, that is, relative excess risk due to interaction (RERI), attributable proportion due to interaction and synergy index (S) were used to estimate the effect of mildly decreased eGFR on the association of serum uric acid with hypoglycaemia. Serum uric acid was associated with hypoglycaemia in an ordinal manner (P for trend <0.01) with an odds ratio of top quartile versus the lowest quartile up to 3.03 (95% confidence interval: 2.13-4.32). The odds ratio of serum uric acid levels ≥ versus <283 µmol/L (i.e. the median) was 1.98 (95% confidence interval:1.58-2.48). Serum uric acid levels ≥ versus <283 µmol/L greatly enhanced the association between mild decline in eGFR (eGFR < 90 mL/min/1.73 m 2 ) and hypoglycaemia from 0.94 (0.36-2.43) to 3.90 (2.55-5.95), with a significant additive interaction (P < 0.05 for RERI, AP and S). Mildly increased serum uric acid was associated with increased risk of hypoglycaemia and enhanced the association between mildly decreased eGFR and hypoglycaemia in type 2 diabetes. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  1. Serum uric acid level predicts adverse outcomes after myocardial revascularization or cardiac valve surgery.

    PubMed

    Lazzeroni, Davide; Bini, Matteo; Camaiora, Umberto; Castiglioni, Paolo; Moderato, Luca; Bosi, Davide; Geroldi, Simone; Ugolotti, Pietro T; Brambilla, Lorenzo; Brambilla, Valerio; Coruzzi, Paolo

    2018-01-01

    Background High levels of serum uric acid have been associated with adverse outcomes in cardiovascular diseases such as myocardial infarction and heart failure. The aim of the current study was to evaluate the prognostic role of serum uric acid levels in patients undergoing cardiac rehabilitation after myocardial revascularization and/or cardiac valve surgery. Design We performed an observational prospective cohort study. Methods The study included 1440 patients with available serum uric acid levels, prospectively followed for 50 ± 17 months. Mean age was 67 ± 11 years; 781 patients (54%) underwent myocardial revascularization, 474 (33%) cardiac valve surgery and 185 (13%) valve-plus-coronary artery by-pass graft surgery. The primary endpoints were overall and cardiovascular mortality while secondary end-points were combined major adverse cardiac and cerebrovascular events. Results Serum uric acid level mean values were 286 ± 95 µmol/l and elevated serum uric acid levels (≥360 µmol/l or 6 mg/dl) were found in 275 patients (19%). Overall mortality (hazard ratio = 2.1; 95% confidence interval: 1.5-3.0; p < 0.001), cardiovascular mortality (hazard ratio = 2.0; 95% confidence interval: 1.2-3.2; p = 0.004) and major adverse cardiac and cerebrovascular events rate (hazard ratio = 1.5; 95% confidence interval: 1.0-2.0; p = 0.019) were significantly higher in patients with elevated serum uric acid levels, even after adjustment for age, gender, arterial hypertension, diabetes, glomerular filtration rate, atrial fibrillation and medical therapy. Moreover, strong positive correlations between serum uric acid level and probability of overall mortality ( p < 0.001), cardiovascular mortality ( p < 0.001) and major adverse cardiac and cerebrovascular events ( p = 0.003) were found. Conclusions Serum uric acid levels predict mortality and adverse cardiovascular outcome in patients undergoing myocardial revascularization

  2. Uric Acid and the Risks of Kidney Failure and Death in Individuals With CKD.

    PubMed

    Srivastava, Anand; Kaze, Arnaud D; McMullan, Ciaran J; Isakova, Tamara; Waikar, Sushrut S

    2018-03-01

    Serum uric acid concentrations increase in chronic kidney disease (CKD) and may lead to tubular injury, endothelial dysfunction, oxidative stress, and intrarenal inflammation. Whether uric acid concentrations are associated with kidney failure and death in CKD is unknown. Prospective observational cohort study. 3,885 individuals with CKD stages 2 to 4 enrolled in the Chronic Renal Insufficiency Cohort (CRIC) between June 2003 and September 2008 and followed up through March 2013. Baseline uric acid concentrations. Kidney failure (initiation of dialysis therapy or transplantation) and all-cause mortality. During a median follow-up of 7.9 years, 885 participants progressed to kidney failure and 789 participants died. After adjustment for demographic, cardiovascular, and kidney-specific covariates, higher uric acid concentrations were independently associated with risk for kidney failure in participants with estimated glomerular filtration rates (eGFRs) ≥ 45mL/min/1.73m 2 (adjusted HR per 1-standard deviation greater baseline uric acid, 1.40; 95% CI, 1.12-1.75), but not in those with eGFRs<30mL/min/1.73m 2 . There was a nominally higher HR in participants with eGFRs of 30 to 44mL/min/1.73m 2 (adjusted HR, 1.13; 95% CI, 0.99-1.29), but this did not reach statistical significance. The relationship between uric acid concentration and all-cause mortality was J-shaped (P=0.007). Potential residual confounding through unavailable confounders; lack of follow-up measurements to adjust for changes in uric acid concentrations over time. Uric acid concentration is an independent risk factor for kidney failure in earlier stages of CKD and has a J-shaped relationship with all-cause mortality in CKD. Adequately powered randomized placebo-controlled trials in CKD are needed to test whether urate lowering may prove to be an effective approach to prevent complications and progression of CKD. Copyright © 2017 National Kidney Foundation, Inc. Published by Elsevier Inc. All

  3. Serum uric acid concentrations are directly associated with the presence of benign multiple sclerosis.

    PubMed

    Simental-Mendía, Esteban; Simental-Mendía, Luis E; Guerrero-Romero, Fernando

    2017-09-01

    It has been reported that patients with multiple sclerosis (MS) exhibit lower serum uric acid levels; however, the association between uric acid concentrations and benign MS (BMS) has not been assessed. Hence, the objective of the present study was to determine whether the serum concentrations of uric acid are associated with the presence of BMS. Men and non-pregnant women over 16 years of age with diagnosis of MS were enrolled in a cross-sectional study. Expanded Disability Status Scale score < 3, progression of disease ≤10 years, diabetes, renal or hepatic diseases, gout, malignancy, alcohol intake, and treatment with thiazide diuretics and/or acetylsalicylic acid were exclusion criteria. According to subtype of disease, the eligible patients were allocated into groups with BMS and other varieties of MS. A logistic regression analysis was conducted in order to evaluate the association between serum concentrations of uric acid and BMS. A total of 106 patients were included, 39 in the group with BMS and 67 in the group with other varieties of MS. The logistic regression analysis adjusted by age, sex, and disease duration showed that increased concentrations of uric acid, indeed within the physiological levels, are significantly associated with the presence of BMS (OR = 2.60; 95% CI: 1.55-4.38, p < 0.001). The results of the present study suggest that elevated concentrations of uric acid, indeed within the physiological range, are likely linked to the presence of BMS.

  4. Precipitation diagrams and solubility of uric acid dihydrate

    NASA Astrophysics Data System (ADS)

    Babić-Ivančić, V.; Füredi-Milhofer, H.; Brown, W. E.; Gregory, T. M.

    1987-07-01

    The solubility of uric acid dihydrate (UA·2H 2O) and the precipitation of UA·2H 2O and anhydrous uric acid (UA) from solutions containing sodium hydroxide and hydrochloric acid have been investigated. For the solubility studies, crystals of pure UA·2H 2O were prepared and equilibrated with water and with solutions of HCl or NaOH for 60 min or 20 h, respectively. The equilibrium pH (pH = 2-6.25) and uric acid concentration were determined. For the precipitation experiments, commercial UA was dissolved in NaOH in a 1:1.1 molar ratio and UA·2H 2O and/or UA were precipitated with hydrochloric acid. The precipitates and/or supernatants were examined 24 h after sample preparation. The results are represented in the form of tables, precipitation diagrams and "chemical potential" diagrams. Solubility measurements with 60 min equilibration times yielded the solubility products of UA·2H 2O, K sp(298 K) = (0.926 ± 0.025) × 10 -9mol2dm-6 and K sp(310 K) = (2.25 ± 0.05) × 10 -9mol2dm-6 and the first dissociation constants of uric acid, K 1(298 K) = (2.45 ± 0.07) × 10 -6moldm-3 and K 1(310 K) = (3.63 ± 0.08) × 10 -6moldm-3. Precipitation diagrams show that under the given experimental conditions, at 298 K, UA·2H 2O is stable for 24 h while at 310 K this was true only for precipitates formed from solutions of high supersaturations. At lower supersaturations, mixtures of UA·2H 2O and UA formed. Consequently, while the Ksp value determined from precipitation data obtained at 298 K (K sp = 1.04 × 10 -9mol2dm-6) was consistent with the respective solubility product, the 310 K precipitation boundary yielded an ion activity product, AP, the value of which fulfills the conditions Ksp(UA) < AP < Ksp (UA·2H 2O). Similar ion activity products were obtained from solubility measurements in pure water at 20 h equilibration time.

  5. Determination of uric acid level by polyaniline and poly (allylamine): Based biosensor

    PubMed Central

    Wathoni, Nasrul; Hasanah, Aliya Nur; Gozali, Dolih; Wahyuni, Yeni; Fauziah, Lia Layusa

    2014-01-01

    The uric acid biosensor has been much developed by immobilizing uricase enzyme into the membrane of conductive polymer and the membrane of polyelectrolyte such as polyaniline (PANI) and poly (allylamine) (PAA) respectively. The purpose of this research was to create a new amperometric uric acid biosensor by immobilization of uricase in combination between PANI and PAA membranes. The working electrode was Pt plate (0.5 mm). The auxiliary and the reference electrode were Pt wire 0.4 mm and Ag/AgCl respectively. Uricase, uric acid, PAA, pyrrole and glutaraldehyde were supplied from Sigma. All other chemical was obtained from Merck. The biosensor was created by immobilizing of uricase by a glutaraldehyde crosslinking procedure on PANI composite film on the surface of a platinum electrode while the polyelectrolyte layer of PAA were prepared via layer-by-layer assembly on the electrode, functioning as H2O2-selective film. Standard of deviation, coefficient of variation (CV) and coefficient of correlation (r) analysis were used in this study. The biosensor had a good linearity with a correlation coefficient of 0.993 and it could be used up to 27 times with the CV value of 3.97%. The presence of other compounds such as glucose and ascorbic acid gave 1.3 ± 1.13% and 3.27 ± 2.29% respectively on the interference effect toward the current response of uric acid biosensor. The polymer combination of PANI and PAA can be used as a selective matrix of uric acid biosensor. PMID:24696812

  6. U-Shaped Association Between Serum Uric Acid Level and Risk of Mortality: A Cohort Study.

    PubMed

    Cho, Sung Kweon; Chang, Yoosoo; Kim, Inah; Ryu, Seungho

    2018-04-25

    In addition to the controversy regarding the association of hyperuricemia with cardiovascular disease (CVD) mortality, few studies have examined the impact of a low uric acid level on mortality. We undertook the present study to evaluate the relationship between both low and high uric acid levels and the risk of all-cause and cause-specific mortality in a large sample of Korean adults over a full range of uric acid levels. A cohort study was performed in 375,163 South Korean men and women who underwent health check-ups from 2002 to 2012. Vital status and cause of death were ascertained from the national death records. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) for mortality outcomes were estimated using Cox proportional hazards regression analysis. During a total of 2,060,721.9 person-years of follow-up, 2,020 participants died, with 287 CVD deaths and 963 cancer deaths. Low and high uric acid levels were associated with increased all-cause, CVD, and cancer mortality. The multivariable-adjusted HRs for all-cause mortality in the lowest uric acid categories (<3.5 mg/dl for men and <2.5 mg/dl for women) compared with the sex-specific reference category were 1.58 (95% CI 1.18-2.10) and 1.80 (95% CI 1.10-2.93), respectively. Corresponding HRs in the highest uric acid categories (≥9.5 mg/dl for men and ≥8.5 mg/dl for women) were 2.39 (95% CI 1.57-3.66) and 3.77 (95% CI 1.17-12.17), respectively. In this large cohort study of men and women, both low and high uric acid levels were predictive of increased mortality, supporting a U-shaped association between serum uric acid levels and adverse health outcomes. © 2018, American College of Rheumatology.

  7. One-Step Electrochemical Fabrication of Reduced Graphene Oxide/Gold Nanoparticles Nanocomposite-Modified Electrode for Simultaneous Detection of Dopamine, Ascorbic Acid, and Uric Acid

    PubMed Central

    Lee, Chang-Seuk; Yu, Su Hwan; Kim, Tae Hyun

    2017-01-01

    Here, we introduce the preparation of the hybrid nanocomposite-modified electrode consisting of reduced graphene oxide (RGO) and gold nanoparticles (AuNPs) using the one-step electrochemical method, allowing for the simultaneous and individual detection of dopamine (DA), ascorbic acid (AA), and uric acid (UA). RGO/AuNPs nanocomposite was formed on a glassy carbon electrode by the co-reduction of GO and Au3+ using the potentiodynamic method. The RGO/AuNPs nanocomposite-modified electrode was produced by subjecting a mixed solution of GO and Au3+ to cyclic sweeping from −1.5 V to 0.8 V (vs. Ag/AgCl) at a scan rate 10 mV/s for 3 cycles. The modified electrode was characterized by scanning electron microscopy, Raman spectroscopy, contact angle measurement, electrochemical impedance spectroscopy, and cyclic voltammetry. Voltammetry results confirm that the RGO/AuNPs nanocomposite-modified electrode has high catalytic activity and good resolution for the detection of DA, AA, and UA. The RGO/AuNPs nanocomposite-modified electrode exhibits stable amperometric responses for DA, AA, and UA, respectively, and its detection limits were estimated to be 0.14, 9.5, and 25 μM. The modified electrode shows high selectivity towards the determination of DA, AA, or UA in the presence of potentially active bioelements. In addition, the resulting sensor exhibits many advantages such as fast amperometric response, excellent operational stability, and appropriate practicality. PMID:29301209

  8. Uric acid, lung function, physical capacity and exacerbation frequency in patients with COPD: a multi-dimensional approach.

    PubMed

    Kahnert, Kathrin; Alter, Peter; Welte, Tobias; Huber, Rudolf M; Behr, Jürgen; Biertz, Frank; Watz, Henrik; Bals, Robert; Vogelmeier, Claus F; Jörres, Rudolf A

    2018-06-04

    Recent investigations showed single associations between uric acid levels, functional parameters, exacerbations and mortality in COPD patients. The aim of this study was to describe the role of uric acid within the network of multiple relationships between function, exacerbation and comorbidities. We used baseline data from the German COPD cohort COSYCONET which were evaluated by standard multiple regression analyses as well as path analysis to quantify the network of relations between parameters, particularly uric acid. Data from 1966 patients were analyzed. Uric acid was significantly associated with reduced FEV 1 , reduced 6-MWD, higher burden of exacerbations (GOLD criteria) and cardiovascular comorbidities, in addition to risk factors such as BMI and packyears. These associations remained significant after taking into account their multiple interdependences. Compared to uric acid levels the diagnosis of hyperuricemia and its medication played a minor role. Within the limits of a cross-sectional approach, our results strongly suggest that uric acid is a biomarker of high impact in COPD and plays a genuine role for relevant outcomes such as physical capacity and exacerbations. These findings suggest that more attention should be paid to uric acid in the evaluation of COPD disease status.

  9. Facile synthesis of porous bimetallic alloyed PdAg nanoflowers supported on reduced graphene oxide for simultaneous detection of ascorbic acid, dopamine, and uric acid.

    PubMed

    Chen, Li-Xian; Zheng, Jie-Ning; Wang, Ai-Jun; Wu, Lan-Ju; Chen, Jian-Rong; Feng, Jiu-Ju

    2015-05-07

    Porous bimetallic alloyed palladium silver (PdAg) nanoflowers supported on reduced graphene oxide (PdAg NFs/rGO) were prepared via a facile and simple in situ reduction process, with the assistance of cetyltrimethylammonium bromide as a structure directing agent. The as-prepared nanocomposite modified glassy carbon electrode (PdAg NFs/rGO/GCE) showed enhanced catalytic currents and enlarged peak potential separations for the oxidation of ascorbic acid (AA), dopamine (DA), and uric acid (UA) as compared to those of PdAg/GCE, rGO/GCE, commercial Pd/C/GCE, and bare GCE. The as-developed sensor can selectively detect AA, DA, and UA with a good anti-interference ability, wide concentration ranges of 1.0 μM-2.1 mM, 0.4-96.0 μM, and 1.0-150.0 μM, respectively, together with low detection limits of 0.057, 0.048, and 0.081 μM (S/N = 3), respectively. For simultaneous detection of AA, DA, and UA, the linear current-concentration responses were observed from 1.0 μM-4.1 mM, 0.05-112.0 μM, and 3.0-186.0 μM, with the detection limits of 0.185, 0.017, and 0.654 μM (S/N = 3), respectively.

  10. Improvement of the uric acid determination by the carbonate method for serum and urine

    PubMed Central

    Eichhorn, F.; Zelmanowski, S.; Lew, E.; Rutenberg, A.; Fanias, B.

    1961-01-01

    An improved colorimetric procedure for determining uric acid by the carbonate method in serum and urine is described, using a 20% sodium carbonate solution with urea. Reliable results are also obtained in high concentrations of uric acid. PMID:13726059

  11. THE EFFECT OF RATE OF GLAND FUNCTION ON PAROTID FLUID URIC ACID LEVELS.

    DTIC Science & Technology

    Paired parotid fluid samples were collected without exogenous stimulation and at 5 different gustation-induced rates of flow. Enzymatic uric acid...diminished as flow rate increased. It is suggested that parotid fluid samples for uric acid analysis should be collected at flow rates of 0.7 ml./min. or more. (Author)

  12. Maternal serum uric acid level and maternal and neonatal complications in preeclamptic women: A cross-sectional study.

    PubMed

    Asgharnia, Maryam; Mirblouk, Fariba; Kazemi, Soudabeh; Pourmarzi, Davood; Mahdipour Keivani, Mina; Dalil Heirati, Seyedeh Fatemeh

    2017-09-01

    Preeclampsia is associated with maternal and neonatal complications. It has been indicated that increased uric acid might have a predictive role on preeclampsia. We aimed to investigate the relationship between the level of uric acid with maternal and neonatal complications in women with preeclampsia. In this cross-sectional study, 160 singleton preeclamptic women at more than 28 wk gestational age were included. Hemoglobin, hematocrit, platelet count, liver and uric acid tests, and maternal and neonatal complications were assessed. The severity of preeclampsia, placental abruption, preterm labor, thrombocytopenia, elevated alanine aminotransferase and aspartate aminotransferase (ALT and AST), HELLP syndrome, eclampsia and required hospitalization in the ICU was considered as the maternal complication. Fetal complications were: small for gestational age (SGA), intrauterine fetal death, hospitalization in the neonatal intensive care unit, and Apgar score <7 at five minutes. Of our participants, 38 women had severe preeclampsia (23.8%). The mean level of uric acid in women with severe preeclampsia was significantly higher than non-severe preeclampsia (p=0.031), also in those with an abnormal liver test (p=0.009). The mean level of uric acid in women with preterm delivery was significantly higher than women with term delivery (p=0.0001). Also, the level of uric acid had no effect on neonatal hospitalization in neonate invasive care unit. Based on logistic regression, the incidence of severe preeclampsia not affected by decreased or increased serum levels of uric acid. With higher level of uric acid in server preeclampsia we can expected more complications such as hepatic dysfunction and preterm delivery. Thus serum uric acid measurement can be helpful marker for severe preeclampsia.

  13. Selective and sensitive determination of uric acid in the presence of ascorbic acid and dopamine by PDDA functionalized graphene/graphite composite electrode.

    PubMed

    Yu, Yanyan; Chen, Zuanguang; Zhang, Beibei; Li, Xinchun; Pan, Jianbin

    2013-08-15

    In this work, a facile electrochemical sensor based on poly(diallyldimethylammonium chloride) (PDDA) functionalized graphene (PDDA-G) and graphite was fabricated. The composite electrode exhibited excellent selectivity and sensitivity towards uric acid (UA), owing to the electrocatalytic effect of graphene nanosheets and the electrostatic attractions between PDDA-G and UA. The anodic peak current of UA obtained by cyclic voltammetry (CV) increased over 10-fold compared with bare carbon paste electrode (CPE). And the reversibility of the oxidation process was improved significantly. Differential pulse voltammetry (DPV) was used to determine UA in the presence of ascorbic acid (AA) and dopamine (DA). It was found that all of oxidation peaks of three species could be well resolved, and the peak current of UA was much stronger than the other two components. More importantly, considerable-amount of AA and DA showed negligible interference to UA assay. The calibration curve for UA ranged from 0.5 to 20 μmol L(-1) with a correlation coefficient of 0.9934. The constructed sensor has been employed to quantitatively determine UA in urine samples. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. The effect of uric acid on outdoor copper and bronze.

    PubMed

    Bernardi, E; Bowden, D J; Brimblecombe, P; Kenneally, H; Morselli, L

    2009-03-15

    Bird droppings are often quoted as a decay agent for outdoor goods, in particular buildings and statues. Undoubtedly, they represent one of the major causes of aesthetic damage on outdoor materials, but the real chemical damage they are able to induce, in particular on metals, is not so well studied. This work focused on the short term role of uric acid, the main constituent of bird urine, with respect to copper, which make such an important contribution to architectural elements of buildings and outdoor sculpture. Preliminary results of laboratory tests and analyses on real exposed samples showed that uric acid chemically affects copper and bronzes: the surface of the metal is modified and copper urates formed. Also natural patina, formed on statues and roof, react with uric acid, even if it seems to afford some protection toward bird droppings. In general, experimental results confirm that the potential chemical damage by bird droppings is significant when considering external cultural heritage such as statues, metal monuments and buildings with historic copper roofs.

  15. Sugar, Uric Acid, and the Etiology of Diabetes and Obesity

    PubMed Central

    Johnson, Richard J.; Nakagawa, Takahiko; Sanchez-Lozada, L. Gabriela; Shafiu, Mohamed; Sundaram, Shikha; Le, Myphuong; Ishimoto, Takuji; Sautin, Yuri Y.; Lanaspa, Miguel A.

    2013-01-01

    The intake of added sugars, such as from table sugar (sucrose) and high-fructose corn syrup has increased dramatically in the last hundred years and correlates closely with the rise in obesity, metabolic syndrome, and diabetes. Fructose is a major component of added sugars and is distinct from other sugars in its ability to cause intracellular ATP depletion, nucleotide turnover, and the generation of uric acid. In this article, we revisit the hypothesis that it is this unique aspect of fructose metabolism that accounts for why fructose intake increases the risk for metabolic syndrome. Recent studies show that fructose-induced uric acid generation causes mitochondrial oxidative stress that stimulates fat accumulation independent of excessive caloric intake. These studies challenge the long-standing dogma that “a calorie is just a calorie” and suggest that the metabolic effects of food may matter as much as its energy content. The discovery that fructose-mediated generation of uric acid may have a causal role in diabetes and obesity provides new insights into pathogenesis and therapies for this important disease. PMID:24065788

  16. Direct electrodeposition of gold nanotube arrays of rough and porous wall by cyclic voltammetry and its applications of simultaneous determination of ascorbic acid and uric acid.

    PubMed

    Yang, Guangming; Li, Ling; Jiang, Jinhe; Yang, Yunhui

    2012-08-01

    Gold nanotube arrays of rough and porous wall has been synthesized by direct electrodeposition with cyclic voltammetry utilizing anodic aluminum oxide template (AAO) and polycarbonate membrane (PC) during short time (only 3 min and 2 min, respectively). The mechanism of the direct electrodeposition of gold nanotube arrays by cyclic voltammetry (CV) has been discussed. The morphological characterizations of the gold nanotube arrays have been investigated by scanning electron microscopy (SEM). A simultaneous determination of ascorbic acid (AA) and uric acid (UA) by differential pulse voltammetry (DPV) was constructed by attaching gold nanotube arrays (using AAO) onto the surface of a glassy carbon electrode (GCE). The electrochemical behavior of AA and UA at this modified electrode has been studied by CV and differential pulse voltammetry (DPV). The sensor offers an excellent response for AA and UA and the linear response range for AA and UA were 1.02×10(-7)-5.23×10(-4) mol L(-1) and 1.43×10(-7)-4.64×10(-4) mol L(-1), the detection limits were 1.12×10(-8) mol L(-1) and 2.24×10(-8) mol L(-1), respectively. This sensor shows good regeneration, stability and selectivity and has been used for the determination of AA and UA in real human urine and serum samples with satisfied results. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Serum Uric Acid Levels and Risk of Incident Hypertriglyceridemia: A Longitudinal Population-based Epidemiological Study.

    PubMed

    Zheng, Rongjiong; Ren, Ping; Chen, Qingmei; Yang, Tianmeng; Chen, Changxi; Mao, Yushan

    2017-09-01

    Hypertriglyceridemia is one of lipid metabolism abnormalities; however, it is still debatable whether serum uric acid is a cause or a consequence of hypertriglyceridemia. We performed the study to investigate the longitudinal association between serum uric acid levels and hypertriglyceridemia. The study included 4190 subjects without hypertriglyceridemia. The subjects had annual health examinations for 8 years to assess incident hyperglyceridemia, and the subjects were divided into groups based on the serum uric acid quartile. Cox regression models were used to analyze the risk factors of development hypertriglyceridemia. During follow-up, 1461 (34.9%) subjects developed hypertriglyceridemia over 8 years of follow-up. The cumulative incidence of hypertriglyceridemia was 28.2%, 29.1%, 36.9%, and 45.6% in quartile 1,2,3 and 4, respectively ( P for trend <0.001). Cox regression analyses indicated that serum uric acid levels were independently and positively associated with the risk of incident hypertriglyceridemia. Hypertriglyceridemia has become a serious public health problem. This longitudinal study demonstrates that high serum uric acid levels increase the risk of hypertriglyceridemia. © 2017 by the Association of Clinical Scientists, Inc.

  18. Serum uric acid in relation to endogenous reproductive hormones during the menstrual cycle: findings from the BioCycle study

    PubMed Central

    Mumford, Sunni L.; Dasharathy, Sonya S.; Pollack, Anna Z.; Perkins, Neil J.; Mattison, Donald R.; Cole, Stephen R.; Wactawski-Wende, Jean; Schisterman, Enrique F.

    2013-01-01

    STUDY QUESTION Do uric acid levels across the menstrual cycle show associations with endogenous estradiol (E2) and reproductive hormone concentrations in regularly menstruating women? SUMMARY ANSWER Mean uric acid concentrations were highest during the follicular phase, and were inversely associated with E2 and progesterone, and positively associated with FSH. WHAT IS KNOWN ALREADY E2 may decrease serum levels of uric acid in post-menopausal women; however, the interplay between endogenous reproductive hormones and uric acid levels among regularly menstruating women has not been elucidated. STUDY DESIGN, SIZE, DURATION The BioCycle study was a prospective cohort study conducted at the University at Buffalo research centre from 2005 to 2007, which followed healthy women for one (n = 9) or 2 (n = 250) menstrual cycle(s). PARTICIPANTS/MATERIALS, SETTING, METHODS Participants were healthy women aged 18–44 years. Hormones and uric acid were measured in serum eight times each cycle for up to two cycles. Marginal structural models with inverse probability of exposure weights were used to evaluate the associations between endogenous hormones and uric acid concentrations. MAIN RESULTS AND THE ROLE OF CHANCE Uric acid levels were observed to vary across the menstrual cycle, with the lowest levels observed during the luteal phase. Every log-unit increase in E2 was associated with a decrease in uric acid of 1.1% (β = −0.011; 95% confidence interval (CI): −0.019, −0.004; persistent-effects model), and for every log-unit increase in progesterone, uric acid decreased by ∼0.8% (β = −0.008; 95% CI: −0.012, −0.004; persistent-effects model). FSH was positively associated with uric acid concentrations, such that each log-unit increase was associated with a 1.6% increase in uric acid (β = 0.016; 95% CI: 0.005, 0.026; persistent-effects model). Progesterone and FSH were also associated with uric acid levels in acute-effects models. Of 509 cycles, 42 were anovulatory

  19. Uric acid and serum antioxidant capacity: a reaction to atherosclerosis?

    PubMed

    Nieto, F J; Iribarren, C; Gross, M D; Comstock, G W; Cutler, R G

    2000-01-01

    the evidence of a potential beneficial role of antioxidants in preventing atherosclerotic disease is not entirely consistent. to assess the longitudinal association of serum total antioxidant capacity and serum antioxidants with the presence of subclinical carotid atherosclerosis. Prospective case-control study nested within an historical cohort. Cases were 150 individuals with elevated carotid intimal-medial thickness measured by B-mode ultrasound at the first two examinations of the Atherosclerosis Risk in Communities Study (1987-92). Controls were 150 age-gender-matched individuals with low carotid intimal-medial thickness. Serum antioxidant vitamins, uric acid, and serum total antioxidant capacity were measured in frozen serum samples collected from the same individuals in 1974 (13-15 years prior to the determination of case-control status). Compared to controls, atherosclerosis cases had significantly higher levels of serum total antioxidant capacity in 1974 than controls. This difference was almost entirely explained by increased serum concentration of uric acid in cases. In contrast with cross-sectional results, uric acid serum concentration in 1974, was significantly higher in cases than in controls, even after adjusting for the main cardiovascular risk factors. Cases had significantly lower levels of alpha-carotene in the 1974 sera than controls, but no other differences in serum antioxidant vitamin concentrations were observed. The higher serum uric acid concentration seemed associated with elevated total serum antioxidant capacity among individuals with atherosclerosis. This finding is consistent with experimental evidence suggesting that hyperuricemia may be a compensatory mechanism to counteract oxidative damage related to atherosclerosis and aging in humans.

  20. The Effect of Lesinurad in Combination With Allopurinol on Serum Uric Acid Levels in Patients With Gout.

    PubMed

    Baumgartner, Scott; Yeh, Li-Tain; Shen, Zancong; Kerr, Bradley; Manhard, Kimberly; Quart, Barry

    2018-05-07

    The objective of the study was to evaluate the effect of lesinurad, a selective uric acid uptake inhibitor, alone and in combination with the xanthine oxidase inhibitor allopurinol, on serum uric acid and urinary urate excretion in patients with gout and hyperuricemia. A phase 1b, multicenter, open-label, multiple-dose study was carried out in patients with gout with serum uric acid ≥8 mg/dL following washout of urate-lowering therapy. Patients were treated with allopurinol 300 mg/day alone in week 1; lesinurad 400 or 600 mg/day was added in week 2, followed by lesinurad 400 or 600 mg/day alone in week 3. Serum uric acid and urine uric acid were evaluated each week. Safety was assessed throughout the study. Lesinurad 400 or 600 mg/day added to allopurinol 300 mg/day reduced serum uric acid by 60% and 72%, respectively, versus allopurinol alone (37%) or lesinurad 400 mg/day (44%) or 600 mg/day (47%) alone. A 100% response rate of serum uric acid <6 mg/dL was achieved by all combinations (serum uric acid <5 mg/dL by 50%-90%). Mean 24-hour urate excretion compared with baseline was -35% with allopurinol, +36% and +56.5% with lesinurad 400 mg/day and 600 mg/day, respectively, and -11.6% and -7.1% with the respective combination therapies. Treatments were well tolerated. In this phase 1 trial, lesinurad added to allopurinol resulted in greater serum uric acid reduction than did allopurinol or lesinurad monotherapy. © 2018, The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.

  1. Mid-gestational serum uric acid concentration effect on neonate birth weight and insulin resistance in pregnant women.

    PubMed

    Nasri, Khadijeh; Razavi, Maryamsadat; Rezvanfar, Mohammad Reza; Mashhadi, Esmat; Chehrei, Ali; Mohammadbeigi, Abolfazl

    2015-01-01

    To investigate the relationship between mid-gestational serum uric acid and birth weight in diabetic pregnant women with or without insulin resistance. In a prospective cohort study, fasting uric acid, blood glucose, and serum insulin were measured in 247 pregnant women between 20-22 weeks of gestational period. Insulin resistance was estimated using the homeostasis model assessment-insulin resistance (HOMA-IR). Stratification analysis and independent t-test was used to assess the association between uric acid and birth weights regarding to insulin resistance. The means of the mid-gestational serum uric acid concentrations were not significantly different in women with and without insulin resistance. But stratification analysis showed that there was a significant difference between uric acid concentration and macrosomic birth in diabetic women without insulin resistance. Higher mid - gestation serum uric acid concentration, even if it does not exceed the normal range, is accompanied by lower birth weight only in non-insulin resistance women. Insulin resistance could have a negative confounding effect on hyperuriemia and birth weight.

  2. Circulating uric acid levels and subsequent development of cancer in 493,281 individuals: findings from the AMORIS Study.

    PubMed

    Yiu, Andrew; Van Hemelrijck, Mieke; Garmo, Hans; Holmberg, Lars; Malmström, Håkan; Lambe, Mats; Hammar, Niklas; Walldius, Göran; Jungner, Ingmar; Wulaningsih, Wahyu

    2017-06-27

    Serum uric acid has been suggested to be associated with cancer risk. We aimed to study the association between serum uric acid and cancer incidence in a large Swedish cohort. A positive association was found between uric acid levels and overall cancer risk, and results were similar with adjustment for glucose, triglycerides and BMI. Hazard ratio (HR) for overall cancer for the 4th quartile of uric acid compared to the 1st was 1.08 (95% CI: 1.05-1.11) in men and 1.12 (1.09 - 1.16) in women. Site-specific analysis showed a positive association between uric acid and risk of colorectal, hepatobiliary, kidney, non-melanoma skin, and other cancers in men and of head and neck and other cancers in women. An inverse association was observed for pulmonary and central nervous system (CNS) cancers in men and breast, lymphatic and haematological, and CNS malignancies in women. We included 493,281 persons aged 20 years and older who had a measurement of serum uric acid and were cancer-free at baseline in the AMORIS study. Multivariable Cox proportional hazards regression was used to investigate sex-specific quartiles of serum uric acid in relation to cancer risk in men and women. Analysis was further adjusted for serum glucose, triglycerides and, where available, BMI. Site-specific analysis was performed for major cancers. Altered uric acid levels were associated with risk of overall and some specific cancers, further indicating the potential role of uric acid metabolism in carcinogenesis.

  3. Circulating uric acid levels and subsequent development of cancer in 493,281 individuals: findings from the AMORIS Study

    PubMed Central

    Yiu, Andrew; Van Hemelrijck, Mieke; Garmo, Hans; Holmberg, Lars; Malmström, Håkan; Lambe, Mats; Hammar, Niklas; Walldius, Göran; Jungner, Ingmar; Wulaningsih, Wahyu

    2017-01-01

    Objectives Serum uric acid has been suggested to be associated with cancer risk. We aimed to study the association between serum uric acid and cancer incidence in a large Swedish cohort. Results A positive association was found between uric acid levels and overall cancer risk, and results were similar with adjustment for glucose, triglycerides and BMI. Hazard ratio (HR) for overall cancer for the 4th quartile of uric acid compared to the 1st was 1.08 (95% CI: 1.05–1.11) in men and 1.12 (1.09 – 1.16) in women. Site-specific analysis showed a positive association between uric acid and risk of colorectal, hepatobiliary, kidney, non-melanoma skin, and other cancers in men and of head and neck and other cancers in women. An inverse association was observed for pulmonary and central nervous system (CNS) cancers in men and breast, lymphatic and haematological, and CNS malignancies in women. Materials and Methods We included 493,281 persons aged 20 years and older who had a measurement of serum uric acid and were cancer-free at baseline in the AMORIS study. Multivariable Cox proportional hazards regression was used to investigate sex-specific quartiles of serum uric acid in relation to cancer risk in men and women. Analysis was further adjusted for serum glucose, triglycerides and, where available, BMI. Site-specific analysis was performed for major cancers. Conclusions Altered uric acid levels were associated with risk of overall and some specific cancers, further indicating the potential role of uric acid metabolism in carcinogenesis. PMID:28418841

  4. The serum uric acid concentration is not causally linked to diabetic nephropathy in type 1 diabetes.

    PubMed

    Ahola, Aila J; Sandholm, Niina; Forsblom, Carol; Harjutsalo, Valma; Dahlström, Emma; Groop, Per-Henrik

    2017-05-01

    Previous studies have shown a relationship between uric acid concentration and progression of renal disease. Here we studied causality between the serum uric acid concentration and progression of diabetic nephropathy in 3895 individuals with type 1 diabetes in the FinnDiane Study. The renal status was assessed with the urinary albumin excretion rate and estimated glomerular filtration rate (eGFR) at baseline and at the end of the follow-up. Based on previous genomewide association studies on serum uric acid concentration, 23 single nucleotide polymorphisms (SNPs) with good imputation quality were selected for the SNP score. This score was used to assess the causality between serum uric acid and renal complications using a Mendelian randomization approach. At baseline, the serum uric acid concentration was higher with worsening renal status. In multivariable Cox regression analyses, baseline serum uric acid concentration was not independently associated with progression of diabetic nephropathy over a mean follow-up of 7 years. However, over the same period, baseline serum uric acid was independently associated with the decline in eGFR. In the cross-sectional logistic regression analyses, the SNP score was associated with the serum uric acid concentration. Nevertheless, the Mendelian randomization showed no causality between uric acid and diabetic nephropathy, eGFR categories, or eGFR as a continuous variable. Thus, our results suggest that the serum uric acid concentration is not causally related to diabetic nephropathy but is a downstream marker of kidney damage. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  5. Uric Acid Stimulates Fructokinase and Accelerates Fructose Metabolism in the Development of Fatty Liver

    PubMed Central

    Lanaspa, Miguel A.; Sanchez-Lozada, Laura G.; Cicerchi, Christina; Li, Nanxing; Roncal-Jimenez, Carlos A.; Ishimoto, Takuji; Le, Myphuong; Garcia, Gabriela E.; Thomas, Jeffrey B.; Rivard, Christopher J.; Andres-Hernando, Ana; Hunter, Brandi; Schreiner, George; Rodriguez-Iturbe, Bernardo; Sautin, Yuri Y.; Johnson, Richard J.

    2012-01-01

    Excessive dietary fructose intake may have an important role in the current epidemics of fatty liver, obesity and diabetes as its intake parallels the development of these syndromes and because it can induce features of metabolic syndrome. The effects of fructose to induce fatty liver, hypertriglyceridemia and insulin resistance, however, vary dramatically among individuals. The first step in fructose metabolism is mediated by fructokinase (KHK), which phosphorylates fructose to fructose-1-phosphate; intracellular uric acid is also generated as a consequence of the transient ATP depletion that occurs during this reaction. Here we show in human hepatocytes that uric acid up-regulates KHK expression thus leading to the amplification of the lipogenic effects of fructose. Inhibition of uric acid production markedly blocked fructose-induced triglyceride accumulation in hepatocytes in vitro and in vivo. The mechanism whereby uric acid stimulates KHK expression involves the activation of the transcription factor ChREBP, which, in turn, results in the transcriptional activation of KHK by binding to a specific sequence within its promoter. Since subjects sensitive to fructose often develop phenotypes associated with hyperuricemia, uric acid may be an underlying factor in sensitizing hepatocytes to fructose metabolism during the development of fatty liver. PMID:23112875

  6. Uric Acid Level Has a U-shaped Association with Clinical Outcomes in Patients with Vasospastic Angina.

    PubMed

    Gwag, Hye Bin; Yang, Jeong Hoon; Park, Taek Kyu; Song, Young Bin; Hahn, Joo Yong; Choi, Jin Ho; Lee, Sang Hoon; Gwon, Hyeon Cheol; Choi, Seung Hyuk

    2017-08-01

    No data are available on the association of serum uric acid and vasospastic angina (VSA) which has endothelial dysfunction as a possible pathophysiologic mechanism. Low uric acid level might cause adverse outcomes in VSA in connection with endothelial dysfunction. We enrolled 818 VSA patients whose uric acid level was measured at admission. Patients were categorized according to tertiles of uric acid level: group I, ≤ 4.8 mg/dL; group II, 4.9-5.9 mg/dL; and group III, ≥ 6.0 mg/dL. Primary outcome was major adverse cardiac events (MACEs), defined as a composite of cardiac death, acute myocardial infarction (MI), ischemic stroke, coronary revascularization, and rehospitalization for angina. Median follow-up duration was 49.2 months. Median uric acid values were 4.1 mg/dL for group I, 5.4 mg/dL for group II, and 6.7 mg/dL for group III. In the overall population, group II had a significantly lower incidence of MACE compared to group I (47 [17.1%] vs. 66 [24.6%]; hazard ratio [HR], 1.52; 95% confidence interval [CI], 1.02-2.26; P = 0.040) and a tendency of lower incidence of MACEs compared to Group III (47 [17.1%] vs. 62 [22.5%]; HR, 1.44; 95% CI, 0.98-2.13; P = 0.067). Among group I patients, those who received nitrates had a higher incidence of MACEs than those without nitrate therapy (P < 0.001). Low uric acid level was associated with adverse clinical outcomes, while high uric acid level had a trend toward an increase in it. Use of nitrate in patients with low uric acid level might have adverse effects on clinical outcomes of VSA. © 2017 The Korean Academy of Medical Sciences.

  7. Low Serum Levels of Uric Acid are Associated With Development of Poststroke Depression.

    PubMed

    Gu, Yingying; Han, Bin; Wang, Liping; Chang, Yaling; Zhu, Lin; Ren, Wenwei; Yan, Mengjiao; Zhang, Xiangyang; He, Jincai

    2015-11-01

    Poststroke depression (PSD) is a frequent complication of stroke that has been associated with poorer outcome of stroke patients. This study sought to examine the possible association between serum uric acid levels and the development of PSD.We recruited 196 patients with acute ischemic stroke and 100 healthy volunteers. Serum uric acid levels were tested by uricase-PAP method within 24 hr after admission. Neuropsychological evaluations were conducted at 3-month poststroke. The 17-item Hamilton Depression Scale was used to assess depressive symptoms. Diagnosis of PSD was made in accordance with DSM-IV criteria for depression. Multivariate analyses were conducted using logistic regression models.Fifty-six patients (28.6%) were diagnosed as having PSD at 3 months. PSD patients showed significantly lower levels of uric acid at baseline as compared to non-PSD patients (237.02 ± 43.43 vs 309.10 ± 67.44 μmol/L, t = -8.86, P < 0.001). In multivariate analyses, uric acid levels (≤239.0 and ≥328.1 μmol/L) were independently associated with the development of PSD (OR, 7.76; 95% confidence interval [CI], 2.56-23.47, P < 0.001 and OR, 0.05; 95% CI, 0.01-0.43, P = 0.01, respectively) after adjustment for possible variables.Serum uric acid levels at admission are found to be correlated with PSD and may predict its development at 3 months after stroke.

  8. Adverse effects of the classic antioxidant uric acid in adipocytes: NADPH oxidase-mediated oxidative/nitrosative stress.

    PubMed

    Sautin, Yuri Y; Nakagawa, Takahiko; Zharikov, Sergey; Johnson, Richard J

    2007-08-01

    Uric acid is considered a major antioxidant in human blood that may protect against aging and oxidative stress. Despite its proposed protective properties, elevated levels of uric acid are commonly associated with increased risk for cardiovascular disease and mortality. Furthermore, recent experimental studies suggest that uric acid may have a causal role in hypertension and metabolic syndrome. All these conditions are thought to be mediated by oxidative stress. In this study we demonstrate that differentiation of cultured mouse adipocytes is associated with increased production of reactive oxygen species (ROS) and uptake of uric acid. Soluble uric acid stimulated an increase in NADPH oxidase activity and ROS production in mature adipocytes but not in preadipocytes. The stimulation of NADPH oxidase-dependent ROS by uric acid resulted in activation of MAP kinases p38 and ERK1/2, a decrease in nitric oxide bioavailability, and an increase in protein nitrosylation and lipid oxidation. Collectively, our results suggest that hyperuricemia induces redox-dependent signaling and oxidative stress in adipocytes. Since oxidative stress in the adipose tissue has recently been recognized as a major cause of insulin resistance and cardiovascular disease, hyperuricemia-induced alterations in oxidative homeostasis in the adipose tissue might play an important role in these derangements.

  9. Do Uric Acid Deposits in Zooxanthellae Function as Eye-Spots?

    PubMed Central

    Yamashita, Hiroshi; Kobiyama, Atsushi; Koike, Kazuhiko

    2009-01-01

    The symbiosis between zooxanthellae (dinoflagellate genus Symbiodinium) and corals is a fundamental basis of tropical marine ecosystems. However the physiological interactions of the hosts and symbionts are poorly understood. Recently, intracellular crystalline deposits in Symbiodinium were revealed to be uric acid functioning for nutrient storage. This is the first exploration of these enigmatic crystalline materials that had previously been misidentified as oxalic acid, providing new insights into the nutritional strategies of Symbiodinium in oligotrophic tropical waters. However, we believe these deposits also function as eye-spots on the basis of light and electron microscopic observations of motile cells of cultured Symbiodinium. The cells possessed crystalline deposit clusters in rows with each row 100–150 nm thick corresponding to 1/4 the wavelength of light and making them suitable for maximum wave interference and reflection of light. Crystalline clusters in cells observed with a light microscope strongly refracted and polarized light, and reflected or absorbed short wavelength light. The facts that purines, including uric acid, have been identified as the main constituents of light reflectors in many organisms, and that the photoreceptor protein, opsin, was detected in our Symbiodinium strain, support the idea that uric acid deposits in Symbiodinium motile cells may function as a component of an eye-spot. PMID:19609449

  10. Do uric acid deposits in zooxanthellae function as eye-spots?

    PubMed

    Yamashita, Hiroshi; Kobiyama, Atsushi; Koike, Kazuhiko

    2009-07-17

    The symbiosis between zooxanthellae (dinoflagellate genus Symbiodinium) and corals is a fundamental basis of tropical marine ecosystems. However the physiological interactions of the hosts and symbionts are poorly understood. Recently, intracellular crystalline deposits in Symbiodinium were revealed to be uric acid functioning for nutrient storage. This is the first exploration of these enigmatic crystalline materials that had previously been misidentified as oxalic acid, providing new insights into the nutritional strategies of Symbiodinium in oligotrophic tropical waters. However, we believe these deposits also function as eye-spots on the basis of light and electron microscopic observations of motile cells of cultured Symbiodinium. The cells possessed crystalline deposit clusters in rows with each row 100-150 nm thick corresponding to 1/4 the wavelength of light and making them suitable for maximum wave interference and reflection of light. Crystalline clusters in cells observed with a light microscope strongly refracted and polarized light, and reflected or absorbed short wavelength light. The facts that purines, including uric acid, have been identified as the main constituents of light reflectors in many organisms, and that the photoreceptor protein, opsin, was detected in our Symbiodinium strain, support the idea that uric acid deposits in Symbiodinium motile cells may function as a component of an eye-spot.

  11. Taurine decreased uric acid levels in hyperuricemic rats and alleviated kidney injury.

    PubMed

    Feng, Ying; Sun, Fang; Gao, Yongchao; Yang, Jiancheng; Wu, Gaofeng; Lin, Shumei; Hu, Jianmin

    2017-07-29

    Hyperuricemia can lead to direct kidney damage. Taurine participates in several renal physiological processes and has been shown as a renoprotective agent. It has been reported that taurine could reduce uric acid levels in diabetic rats, but to date there was no research on the effects of taurine on hyperuricemic rats with kidney injury. In present study, hyperuricemic rat models were induced by intragastric administration of adenine and ethambutol hydrochloride for 10 days, and taurine (1% or 2%) were added in the drinking water 7 days in advance for consecutively 17 days. The results showed that taurine alleviated renal morphological and pathological changes as well as kidney dysfunction in hyperuricemic rats. Taurine could efficiently decrease the elevated xanthine oxidase activities in hyperuricemic rats, indicating its effect on the regulation of uric acid formation. The reabsorption and secretion of uric acid are dependent on a number of urate transporters. Expressions of three urate transporters were significantly down-regulated in hyperuricemic rats, while taurine prevented the decrease of mRNA and protein expression levels of these urate transporters. The results indicate that taurine might play a role in the regulation of renal uric acid excretion. Therefore, taurine could be a promising agent for the treatment of hyperuricemia. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. The role of uric acid in the pathogenesis of diabetic retinopathy based on notch pathway.

    PubMed

    Zhu, Dan-Dan; Wang, Yun-Zhi; Zou, Chen; She, Xin-Ping; Zheng, Zhi

    2018-06-19

    Uric acid has been proposed as an independent risk factor of diabetic retinopathy. Although Notch signaling was reported to be affected in the presence of high concentrations of uric acid or glucose, the underlying mechanisms of hyperuricemia through the Notch signaling pathway to promote the development of diabetic retinopathy remain unknown. We incubated human retinal endothelial cells (HRECs) with high glucose, high uric acid and high glucose plus high glucose respectively and evaluated the apoptosis rate in different treated cells by Tunel staining. We induced diabetic model by intraperitoneally streptozotocin. Then healthy rats and diabetic rats were given with adenine and oteracil potassium by gavage. Using automatic biochemical analyzer to detect blood glucose, uric acid, urea nitrogen, creatinine levels, to verify the success of modeling. The expression and mRNA levels of ICAM-1, IL-6, MCP-1, TNF-a, receptors Notch 1, ligands Dll 1, Dll 4, Jagged 1, Jagged 2 were detected by RT-PCR and Western-Blot. Notch1 siRNA was used to interfere Notch signaling pathway, the expression and mRNA levels of ICAM-1, IL-6, MCP-1 and TNF-α was detected by RT-PCR and Western blot respectively. In vitro models, the apoptosis of HRECs cells in high uric acid plus high glucose group was the most significant. In vitro and vivo models, detection of inflammatory cytokines revealed that the expression of inflammatory cytokines increased most significantly in high uric acid plus high glucose group. Notch signaling pathway activity was also increased most significantly in high uric acid plus high glucose group. After Notch 1 siRNA transfection in high glucose and high glucose plus uric acid group, the activity of Notch signaling pathway was successfully down-regulated. We found that the apoptosis of HRECs was significantly decreased in cells transfected with Notch 1 siRNA compared to the blank vector group, and the expression of inflammatory cytokines in cells was also significantly

  13. Uric Acid Level Has a J-Shaped Association with Arterial Stiffness in Korean Postmenopausal Women.

    PubMed

    Lee, Hyungbin; Jung, Young-Hyo; Kwon, Yu-Jin; Park, Byoungjin

    2017-11-01

    Uric acid has been reported to function both as an oxidant or antioxidant depending on the context. A previous study in the Korean population reported a positive linear association between serum uric acid level and arterial stiffness in men, but little is known about how serum uric acid level is related to the risk of increased arterial stiffness in Korean postmenopausal women. We performed a cross-sectional study of 293 subjects who participated in a health examination program run by the health promotion center of Gangnam Severance Hospital between October 2007 and July 2010. High brachial-ankle pulse wave velocity was defined as a brachial-ankle pulse wave velocity of more than 1,450 cm/s. The odds ratios (ORs) for high brachial-ankle pulse wave velocity were calculated using multivariate logistic regression analysis across uric acid quartiles after adjusting for other indicators of cardiovascular risk. The 293 postmenopausal women were divided into quartiles according to uric acid level. The mean brachial-ankle pulse wave velocity values of each quartile were as follows: Q1, 1,474 cm/s; Q2, 1,375 cm/s; Q3, 1,422 cm/s; Q4, 1,528 cm/s. The second quartile was designated as the control group based on mean brachial-ankle pulse wave velocity value. Multivariate adjusted ORs (95% confidence intervals) for brachial-ankle pulse wave velocity across the uric acid quartiles were 2.642 (Q1, 1.095-6.3373), 1.00, 4.305 (Q3, 1.798-10.307), and 4.375 (Q4, 1.923-9.949), after adjusting for confounding variables. Serum uric acid level has a J-shaped association with arterial stiffness in Korean postmenopausal women.

  14. Lower uric acid is associated with poor short-term outcome and a higher frequency of posterior arterial involvement in ischemic stroke.

    PubMed

    Liu, Hanxiang; Reynolds, Gavin P; Wang, Wenmin; Wei, Xianwen

    2018-06-01

    Uric acid has neuroprotective properties in experimental and clinical studies of neurodegenerative disease. It is, however, associated with increased risk of stroke, yet, despite some inconsistent findings, increasing evidence suggests it may also be related to improved stroke outcomes. We have determined whether there is an effect of plasma uric acid on the short-term outcome of stroke patients in a general hospital setting using the modified Rankin Scale (mRS). We also investigated the relationship of uric acid with other clinical correlates. Plasma uric acid was determined in 108 acute ischemic stroke patients and their mRS scores measured. Patients with a poor outcome (mRS > 2) had significantly lower uric acid than those with a better outcome; this remained after correcting for the effect of sex on uric acid concentrations. There was no significant association with other epidemiological factors or with cognitive function determined by Mini-Mental State Examination. An association between uric acid and the cerebral circulation was also found in which lower uric acid occurs with posterior artery involvement. These findings demonstrate in a naturalistic cohort of patients the association of uric acid with short-term disability following ischemic stroke. They also raise the question of whether uric acid may influence the regional brain involvement in stroke.

  15. High serum uric acid levels are a protective factor against unfavourable neurological functional outcome in patients with ischaemic stroke.

    PubMed

    Wang, Yu-Fang; Li, Jiao-Xing; Sun, Xun-Sha; Lai, Rong; Sheng, Wen-Li

    2018-05-01

    Objective We aimed to evaluate the association between serum uric acid levels at the onset and prognostic outcome in patients with acute ischaemic stroke. Methods We retrospectively analysed the outcomes of 1166 patients with ischaemic stroke who were hospitalized in our centre during August 2008 to November 2012. Correlations of serum uric acid levels and prognostic outcomes were analysed. Results Men had higher serum uric acid levels and better neurological functional outcomes compared with women. There was a strong negative correlation between serum uric acid levels and unfavourable neurological functional outcomes. Generalized estimated equation analysis showed that a higher serum uric acid level (>237 µmol/L) was a protective factor for neurological functional outcome in male, but not female, patients. Among five trial of ORG 10172 in acute stroke treatment classification subtypes, only patients with the large-artery atherosclerosis subtype had a significant protective effect of serum uric acid levels on neurological outcome. Conclusions Our study shows that high serum uric acid levels are a significant protective factor in men and in the large-artery atherosclerosis subtype in patients with ischaemic stroke. This is helpful for determining the prognostic value of serum uric acid levels for neurological outcome of acute ischaemic stroke.

  16. The systems biology of uric acid transporters: the role of remote sensing and signaling.

    PubMed

    Nigam, Sanjay K; Bhatnagar, Vibha

    2018-07-01

    Uric acid homeostasis in the body is mediated by a number of SLC and ABC transporters in the kidney and intestine, including several multispecific 'drug' transporters (e.g., OAT1, OAT3, and ABCG2). Optimization of uric acid levels can be viewed as a 'systems biology' problem. Here, we consider uric acid transporters from a systems physiology perspective using the framework of the 'Remote Sensing and Signaling Hypothesis.' This hypothesis explains how SLC and ABC 'drug' and other transporters mediate interorgan and interorganismal communication (e.g., gut microbiome and host) via small molecules (e.g., metabolites, antioxidants signaling molecules) through transporters expressed in tissues lining body fluid compartments (e.g., blood, urine, cerebrospinal fluid). The list of uric acid transporters includes: SLC2A9, ABCG2, URAT1 (SLC22A12), OAT1 (SLC22A6), OAT3 (SLC22A8), OAT4 (SLC22A11), OAT10 (SLC22A13), NPT1 (SLC17A1), NPT4 (SLC17A3), MRP2 (ABCC2), MRP4 (ABCC4). Normally, SLC2A9, - along with URAT1, OAT1 and OAT3, - appear to be the main transporters regulating renal urate handling, while ABCG2 appears to regulate intestinal transport. In chronic kidney disease (CKD), intestinal ABCG2 becomes much more important, suggesting remote organ communication between the injured kidney and the intestine. The remote sensing and signaling hypothesis provides a useful systems-level framework for understanding the complex interplay of uric acid transporters expressed in different tissues involved in optimizing uric acid levels under normal and diseased (e.g., CKD, gut microflora dysbiosis) conditions.

  17. Green synthesis of carbon dots from pork and application as nanosensors for uric acid detection

    NASA Astrophysics Data System (ADS)

    Zhao, Chunxi; Jiao, Yang; Hu, Feng; Yang, Yaling

    2018-02-01

    In this work, a green, simple, economical method was developed in the synthesis of fluorescent carbon dots using pork as carbon source. The as-prepared carbon dots exhibit exceptional advantages including high fluorescent quantum yield (17.3%) and satisfactory chemical stability. The fluorescence of carbon dots based nanosensor can be selectively and efficiently quenched by uric acid. This phenomenon was used to develop a fluorescent method for facile detection of uric acid within a linear range of 0.1-100 μM and 100-500 μM, with a detection limit of 0.05 μM (S/N = 3). Finally, the proposed method was successfully applied in the determination of uric acid in human serum and urine samples with satisfactory recoveries, which suggested that the new nanosensors have great prospect toward the detection of uric acid in human fluids.

  18. Association of Serum Uric Acid Levels with Leg Ischemia in Patients with Peripheral Arterial Disease after Treatment.

    PubMed

    Sotoda, Yoko; Hirooka, Shigeki; Orita, Hiroyuki; Wakabayashi, Ichiro

    2017-07-01

    We investigated the relationships of serum uric acid levels with the progression of atherosclerosis in patients with peripheral arterial disease (PAD) after treatment. Subjects were male patients diagnosed with PAD. Atherosclerosis at the common carotid artery was evaluated based on its intima-media thickness (IMT). Leg arterial flow was evaluated by measuring ankle-brachial index (ABI) and exercise-induced decrease in ABI. Among various risk factors including age, blood pressure, adiposity, estimated glomerular filtration rate, and blood lipid, blood glucose, uric acid, fibrinogen and C-reactive protein levels, only uric acid levels showed significant correlations with ABI [Pearson's correlation coefficient, -0.292 (p<0.01)] and leg exercise-induced decrease in ABI [Pearson's correlation coefficient, 0.236 (p< 0.05)]. However, there was no significant correlation between uric acid levels and maximum or mean IMT. Odds ratios of subjects with the 3rd tertile versus subjects with the 1st tertile for uric acid levels were significantly higher than the reference level of 1.00 for low ABI [4.44 (95% confidence interval, 1.45-13.65, p<0.01)] and for high % decrease in ABI after exercise [4.31 (95% confidence interval, 1.34-13.82, p<0.05)]. The associations of uric acid levels with the indicators of leg ischemia were also found after adjustment for age, history of revascularization therapy, diabetes, smoking, alcohol consumption, body mass index, triglyceride levels, and renal function. Uric acid levels are associated with the degree of leg ischemia in patients with PAD. Further interventional studies are needed to determine whether the correction of uric acid levels is effective in preventing the progression of PAD.

  19. Refrigeration is not necessary for measurement of uric acid in patients treated with rasburicase.

    PubMed

    Lindeman, Neal I; Melanson, Stacy E F; McDonnell, Anne; DeAngelo, Daniel J; Jarolim, Petr

    2013-05-01

    Rasburicase, used for hyperuricemia of tumor lysis syndrome, retains activity at room temperature (RT) in in vitro studies. Cold-temperature handling is recommended for uric acid measurements in patients receiving rasburicase: collection in prechilled tubes, transportation on ice, and 4°C centrifugation. We performed a prospective study of these requirements. A total of 65 pairs of blood samples were collected from 34 patients, 12-24 h after receiving rasburicase. The effect of temperature on uric acid concentration was tested on paired samples handled either at RT or when cold: centrifugation (18 sample pairs), collection tube (14 pairs), transportation (24 pairs), and nine pairs were retested after 1 h at RT. No significant temperature effect was seen on the uric acid measurements for any of the cold-handling steps: proportional, absolute biases were -1.4%, -0.06 mg/dL (centrifugation), -1.5%, +0.02 mg/dL (tube temperature), and -2.2%, -0.01 mg/dL (transportation). A 20% negative bias was seen in samples retested after 1 h at RT. Cold handling (prechilled tubes, iced transportation, 4°C centrifugation) was equivalent to RT for immediate measurement. An additional 1 h delay at RT led to a 20% decrease in uric acid. The cold handling measures required by the manufacturer are not necessary for uric acid testing of patients receiving rasburicase treatment, if testing is performed without delay.

  20. EFFECT OF DIETARY ANTIBIOTICS UPON COLIFORM BACTERIA AND LACTOBACILLI IN THE INTESTINAL TRACT OF URIC ACID-FED CHICKS.

    PubMed

    BARE, L N; WISEMAN, R F; ABBOTT, O J

    1964-02-01

    Bare, L. N. (University of Kentucky, Lexington), R. F. Wiseman, and O. J. Abbott. Effect of dietary antibiotics upon coliform bacteria and lactobacilli in the intestinal tract of uric acid-fed chicks. J. Bacteriol. 87:329-331. 1964.-Male chicks (1-day-old; Vantress X Arbor Acre) were fed a basal glucose-soybean oil meal diet, a 2% uric acid-containing diet with and without 5 mg/lb of zinc bacitracin and 20 mg/lb of procaine penicillin G, and one supplemented with the antibiotics only. After 4 weeks, the chicks receiving the uric acid without antibiotics showed a weight depression. The presence of antibiotics in the ration with the uric acid reversed this growth depression. Bacteriological and chemical analyses of the contents of the small intestine revealed an increase in numbers of uricolytic Aerobacter spp. and an increased degradation of uric acid in the tract of the "uric-antibiotic"-fed chicks. The counts of lactobacilli were always lowest in this group of chicks

  1. Uric acid predicts mortality and ischaemic stroke in subjects with diastolic dysfunction: the Tromsø Study 1994-2013.

    PubMed

    Norvik, Jon V; Schirmer, Henrik; Ytrehus, Kirsti; Storhaug, Hilde M; Jenssen, Trond G; Eriksen, Bjørn O; Mathiesen, Ellisiv B; Løchen, Maja-Lisa; Wilsgaard, Tom; Solbu, Marit D

    2017-05-01

    To investigate whether serum uric acid predicts adverse outcomes in persons with indices of diastolic dysfunction in a general population. We performed a prospective cohort study among 1460 women and 1480 men from 1994 to 2013. Endpoints were all-cause mortality, incident myocardial infarction, and incident ischaemic stroke. We stratified the analyses by echocardiographic markers of diastolic dysfunction, and uric acid was the independent variable of interest. Hazard ratios (HR) were estimated per 59 μmol/L increase in baseline uric acid. Multivariable adjusted Cox proportional hazards models showed that uric acid predicted all-cause mortality in subjects with E/A ratio <0.75 (HR 1.12, 95% confidence interval [CI] 1.00-1.25) or E/A ratio >1.5 (HR 1.51, 95% CI 1.09-2.09, P for interaction between E/A ratio category and uric acid = 0.02). Elevated uric acid increased mortality risk in persons with E-wave deceleration time <140 ms or >220 ms (HR 1.46, 95% CI 1.01-2.12 and HR 1.13, 95% CI 1.02-1.26, respectively; P for interaction = 0.04). Furthermore, in participants with isovolumetric relaxation time ≤60 ms, mortality risk was higher with increasing uric acid (HR 4.98, 95% CI 2.02-12.26, P for interaction = 0.004). Finally, elevated uric acid predicted ischaemic stroke in subjects with severely enlarged left atria (HR 1.62, 95% CI 1.03-2.53, P for interaction = 0.047). Increased uric acid was associated with higher all-cause mortality risk in subjects with echocardiographic indices of diastolic dysfunction, and with higher ischaemic stroke risk in persons with severely enlarged left atria.

  2. Could be serum uric acid a risk factor for thrombosis and/or uveitis in Behcet's disease?

    PubMed

    Atıl, Avcı; Deniz, Avcı

    2018-01-01

    Introduction Serum uric acid level increases in many inflammatory conditions. Uric acid triggers the vascular inflammation and artery damage, which causes to an increased risk of endothelial dysfunction and atherosclerosis. It is not clear in the literature whether uric acid contributes to uveitis by similar mechanisms. We investigated whether uric acid level increases in Behcet's disease patients with thrombosis or anterior uveitis. Patients and methods We reviewed the medical records of 914 Behcet's disease. After screening for exclusion criteria, there were 50 Behcet's disease patients with thrombotic complication and as the control group 202 BD patients without any vascular complication were included to the study. In the Anterior uveitis group, there were 53 Behcet's disease patients. The Control group consisted of 39 Behçet's disease patients without eye findings. Results Mean uric acid value was 4.96 ± 1.06 mg/dl in Behcet's disease patients with thrombosis whereas 4.08 ± 0.94 mg/dl in controls, indicating a significant difference ( p < 0.001). There was no significant difference between the mean ages of the patients in both groups. The mean age of the BD group without eye findings was 39.31 ± 10.47 years and that of the Behcet's disease with Anterior Uveitis group was 37.72 ± 9.65 years ( p = 0.453). The mean serum UA in the BD group without eye findings was 4.21 ± 1.21 mg/dl, while in the BD with Anterior Uveitis group it was 4.57 ± 1.37 mg/dl ( p = 0.201). Conclusion The extent of increase in uric acid level was greater in Behcet's disease patients that have a thrombotic complication compared to those without thrombotic complication. Uric acid seems to play a role in the pathogenesis of thrombosis. It is concluded that the elevation of serum uric acid level in patients with anterior uveitis with Behcet's disease is not statistically significant.

  3. Uric acid is associated with inflammation, coronary microvascular dysfunction, and adverse outcomes in postmenopausal women

    PubMed Central

    Prasad, Megha; Matteson, Eric L.; Herrmann, Joerg; Gulati, Rajiv; Rihal, Charanjit S.; Lerman, Lilach O.; Lerman, Amir

    2016-01-01

    Uric acid is a risk factor for coronary artery disease (CAD) in postmenopausal women but the association with inflammation and coronary microvascular endothelial dysfunction (CED) is not well-defined. The aim of this study was to determine the relationship of serum uric acid (SUA), inflammatory markers and CED. In this prospective cohort study, serum uric acid, hsCRP levels, and neutrophil count were measured in 229 postmenopausal women who underwent diagnostic catheterization, were found to have no obstructive CAD and underwent coronary microvascular function testing, to measure coronary blood flow (CBF) response to intracoronary acetylcholine. The average age was 58 years (IQR 52, 66) years. Hypertension was present in 48%, type 2 diabetes mellitus in 5.6%, and hyperlipidemia in 61.8%. CED was diagnosed in 59% of postmenopausal women. Mean uric acid level was 4.7 ± 1.3 mg/dL. Postmenopausal women with CED had significantly higher SUA compared to patients without CED (4.9 ± 1.3 vs. 4.4 ± 1.3 mg/dL; p=0.02). There was a significant correlation between SUA and % change in CBF to acetylcholine (p=0.009), and this correlation persisted in multivariable analysis. SUA levels were significantly associated with increased neutrophil count (p=0.02) and hsCRP levels (p=0.006) among patients with CED, but not those without CED. Serum uric acid is associated with coronary microvascular endothelial dysfunction in postmenopausal women and may be related to inflammation. These findings link serum uric acid levels to early coronary atherosclerosis in postmenopausal women. PMID:27993955

  4. Impact of serum uric acid on incident hypertension in a worksite population of Japanese men.

    PubMed

    Kansui, Yasuo; Matsumura, Kiyoshi; Morinaga, Yuki; Inoue, Minako; Kiyohara, Kanako; Ohta, Yuko; Goto, Kenichi; Ohtsubo, Toshio; Ooboshi, Hiroaki; Kitazono, Takanari

    2018-07-01

    Higher levels of serum uric acid are associated with an increased risk of cardiovascular diseases, which may be confounded by comorbidities. We investigated the effects of serum uric acid on the risk of hypertension in Japanese men at a worksite. We evaluated a total of 2335 Japanese male workers without hypertension who ranged in age from 18 to 64 years at a worksite in 2009. These men were followed for 6 years from 2009 to 2015. During the follow-up period, 380 individuals developed hypertension. The odds ratio for the incident hypertension was estimated according to quartiles of serum uric acid levels of 5.1 or less, 5.2-5.8, 5.9-6.6, and at least 6.7 mg/dl. The multivariable-adjusted risk of incident hypertension was significantly higher in the highest serum uric acid quartile than in the lowest: odds ratio 1.00 (reference) for the lowest quartile, 1.34 (0.91-1.97) for the second quartile, 1.42 (0.97-2.06) for the third quartile, and 1.65 (1.14-2.40) for the highest quartile. In stratified analyses, the association between serum uric acid and incident hypertension was significant in the patients of aged below 45 years and without comorbidities, namely diabetes and low levels of high-density lipoprotein-cholesterol. Serum uric acid levels were associated with the future incidence of hypertension, and the association was observed in the younger individuals, those without diabetes, and those with preserved high-density lipoprotein cholesterol levels in a worksite population of Japanese men.

  5. Comparative semiempirical and ab initio study of the structural and chemical properties of uric acid and its anions

    NASA Astrophysics Data System (ADS)

    Altarsha, Muhannad; Monard, Gérald; Castro, Bertrand

    Semiempirical, density functional theory (DFT), and ab initio calculations have been performed to assess the relative stabilities of 15 possible tautomer forms of neutral uric acid, and of the different urate mono- and dianion forms. These methods have also been used to compute ionization potentials (IPs) for uric acid and its derived anions. Overall, we have found that semiempirical calculations, in particular PM3, perform well as compared with B3LYP or MP2 computations toward these different structural and chemical properties of uric acid: the triketo form of uric acid is the most stable tautomer form of neutral uric acid. Three other tautomer forms are relatively close in energy, within the range 2-6 kcal/mol above the triketo form, with a mean energy deviation of only 1.3 kcal/mol between PM3 and DFT or ab initio results; the monoanion form of uric acid obtained by abstracting one proton in position 3 (denoted UAN3-) is the most stable form among all four possible urate monoanions both in gas phase and in solution; the dianion form of uric acid obtained by abstracting two protons, respectively, in positions 3 and 9 of uric acid (denoted UAN3-N9-) is the most stable urate dianion form both in gas phase and in solution. However, these two most stable species do not have the lowest IPs in solution: among monoanions and dianions, respectively, the species with the lowest IPs are UAN7- and UAN7-N9-.

  6. Common genetic variants of the human UMOD gene are functional on transcription and predict plasma uric acid in two distinct populations

    PubMed Central

    Han, Jia; Liu, Ying; Rao, Fangwen; Nievergelt, Caroline M.; O’Connor, Daniel T.; Wang, Xingyu; Liu, Lisheng; Bu, Dingfang; Liang, Yu; Wang, Fang; Zhang, Luxia; Zhang, Hong; Chen, Yuqing; Wang, Haiyan

    2013-01-01

    Uromodulin (UMOD) genetic variants cause familial juvenile hyperuricemic nephropathy, characterized by hyperuricemia, decreased renal excretion of UMOD and uric acid; such findings suggest a role for UMOD in the regulation of plasma uric acid. We screened common variants across the UMOD locus in two populations, one from a community-based Chinese population, the other from California twins and siblings. Transcriptional activity of promoter variants was estimated in luciferase reporter plasmids transfected into HEK293 cells and mlMCD3 cells. By variance components in twin pairs, uric acid concentration and excretion were heritable traits. In the primary population from Beijing, we identified that carriers of haplotype GCC displayed higher plasma uric acid, and 3 UMOD promoter variants associated with plasma uric acid. UMOD promoter variants displayed reciprocal effects on urine uric acid excretion and plasma uric acid concentration, suggesting a primary effect on renal tubular handling of urate. These UMOD genetic marker-on-trait associations for uric acid were replicated in an independent American population sample. Site-directed mutagenesis at trait-associated UMOD promoter variants altered promoter activity in transfected luciferase reporter plasmids. These results suggest that UMOD promoter variants seem to initiate a cascade of transcriptional and biochemical changes influencing UMOD secretion, eventuating in elevation of plasma uric acid. PMID:23344472

  7. Serum uric acid level and its association with motor subtypes and non-motor symptoms in early Parkinson's disease: PALS study.

    PubMed

    Huang, Xinxin; Ng, Samuel Yong-Ern; Chia, Nicole Shuang-Yu; Acharyya, Sanchalika; Setiawan, Fiona; Lu, Z-H; Ng, Ebonne; Tay, Kay-Yaw; Au, Wing-Lok; Tan, Eng-King; Tan, Louis Chew-Seng

    2018-05-17

    Uric acid has been found to be potentially neuroprotective in Parkinson's disease (PD). We investigated the relationship between serum uric acid levels and both motor and non-motor features in a prospective early PD cohort study. Fasting serum uric acid levels were measured from 125 early PD patients. Demographic, clinical characteristics, motor and non-motor assessments were performed. Patients were categorized into three motor subtypes: tremor-dominant (TD), postural instability/gait difficulty (PIGD), and mixed. Non-motor symptoms were classified as present or absent based on the appropriate cut-offs for each non-motor instrument. Most patients had TD (n = 51, 40.8%) and mixed (n = 63, 50.4%) motor subtypes, while a minority had PIGD (n = 11, 8.8%) motor subtype. The mean serum uric acid levels were significantly different between the three motor subtypes (p = 0.0106), with the mixed subtype having the lowest serum uric acid levels. Using the TD subtype as reference, patients with higher serum uric acid levels were less likely to have the mixed (OR = 0.684; p = 0.0312) subtype as opposed to the TD subtype. Uric acid levels were not significantly different between the TD and PIGD subtypes. For non-motor symptoms, higher serum uric acid levels were significantly associated with less fatigue (OR = 0.693; p = 0.0408). Higher serum uric acid levels were associated with TD motor subtype and less fatigue in early PD, which could be related to its anti-oxidative properties. Uric acid could be an important biomarker for specific motor features and symptoms of fatigue in PD. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Anti-Salmonella and uric acid-preserving effect of pine bark tannin in composted poultry litter

    USDA-ARS?s Scientific Manuscript database

    Poultry litter contains appreciable amounts of uric acid which makes it a good crude protein supplement for ruminants, but the litter must be treated to kill bacterial pathogens. Presently, we examined the antimicrobial and uric acid-preserving activity of pine bark tannin during the early stage of...

  9. [Correlation between serum uric acid level and acute renal injury after coronary artery bypass grafting].

    PubMed

    Xu, D Q; Du, J; Zheng, Z; Tang, Y; Zou, L; Zhang, Y H; Zhang, H T

    2017-07-11

    Objective: To evaluate whether early postoperative serum uric acid level can predict postoperative acute renal injury (AKI) among patients undergoing coronary artery bypass grafting (CABG). Methods: The study retrospectively enrolled 1 306 patients undergoing CABG in Fuwai Hospital between September 2012 and December 2013. The patients were divided into 5 groups by the concentrations of serum uric acid measured on the morning of the first postoperative day, and uric acid categories were as follow: less than 195 μmol/L (Q1 group, 262 cases), 195-236 μmol/L (Q2 group, 263 cases), 237-280 μmol/L (Q3 group, 260 cases), 281-336 μmol/L (Q4 group, 261 cases), more than 336 μmol/L (Q5 group, 260 cases). The primary end points were AKI (RIFLE criteria), severe AKI (AKI≥stage Ⅰ), postoperative continuous renal replacement therapy (CRRT) requirement, in-hospital death, length of stay in hospital and intensive care unit(ICU). The area under the receiver-operating characteristic (ROC) curve (AUC) was used to determine the ability of the early postoperative serum uric acid level as a risk factor for postoperative AKI prediction. Results: Among the 1 306 patients enrolled in the study, AKI was found in 335 patients (25.65%). After adjusting for variables that were different between the 5 groups, the Q5 group had significantly higher risk of AKI, AKI≥ stage Ⅰ and the requirement of CRRT ( P <0.01). The ROC for the outcome of postoperative AKI had an AUC of 0.648 (95% CI: 0.612-0.683) when serum creatinine levels alone were used and 0.722 (95% CI: 0.688-0.755) when serum uric acid levels alone were used (both P <0.001). Early postoperative serum uric acid was a better predictor than serum creatinine( P <0.001). Conclusion: The serum uric acid concentration within 12 hours after operation is an independent predictor of postoperative AKI in patients undergoing CABG, which could be used to identify patients at high risk for AKI.

  10. Racial/Ethnic and Gender Differences in the Relationship between Uric Acid and Metabolic Syndrome in Adolescents: An Analysis of NHANES 1999–2006

    PubMed Central

    DeBoer, Mark D.; Dong, Lili; Gurka, Matthew J.

    2011-01-01

    Background Among adolescents uric acid is associated with insulin resistance, hypertension and the metabolic syndrome (MetS) and in adults high uric acid levels are an independent risk factor for cardiovascular disease and diabetes. Objective Determine whether the relationship of uric acid with MetS varies in adolescents by race/ethnicity and gender. Methods We used linear regression to evaluate associations between uric acid and other MetS-associated clinical and laboratory measures among 3,296 non-Hispanic-white, non-Hispanic-black and Hispanic adolescents age 12–19y participating in the National Health and Nutrition Evaluation Survey (1999–2006). Results Overall, non-Hispanic-white males and females had the highest uric acid levels among the three racial/ethnic groups. In each racial/ethnic group there were higher uric acid levels for those adolescents with vs. without MetS. However, the extent of the MetS-related increase in uric acid level varied by race and gender. Among males, MetS was associated with the greatest increases in uric acid among non-Hispanic whites. However, among females, the MetS-related increase in uric acid was greatest among non-whites. Non-Hispanic-white females exhibited the lowest degrees of correlation between levels of uric acid and MetS-associated variables. Uric acid levels did not correlate with insulin levels in non-Hispanic-white females. Conclusions These data suggest the relationship between uric acid and MetS varies by race/ethnicity and gender. In particular, non-Hispanic-white males exhibit a strong relationship and non-Hispanic-white females exhibit a relatively poor correlation between uric acid and MetS-related factors. These data may have implications for the use of uric acid as a marker of future risk among adolescents. PMID:22000606

  11. Effect of Uric Acid-Lowering Agents on Endothelial Function: A Randomized, Double-Blind, Placebo-Controlled Trial.

    PubMed

    Borgi, Lea; McMullan, Ciaran; Wohlhueter, Ann; Curhan, Gary C; Fisher, Naomi D; Forman, John P

    2017-02-01

    Higher levels of serum uric acid are independently associated with endothelial dysfunction, a mechanism for incident hypertension. Overweight/obese individuals are more prone to endothelial dysfunction than their lean counterparts. However, the effect of lowering serum uric acid on endothelial dysfunction in these individuals has not been examined thoroughly. In this randomized, double-blind, placebo-controlled trial of nonhypertensive, overweight, or obese individuals with higher serum uric acid (body mass index ≥25 kg/m 2 and serum uric acid ≥5.0 mg/dL), we assigned subjects to probenecid (500-1000 mg/d), allopurinol (300-600 mg/d), or matching placebo. The primary outcome was endothelium-dependent vasodilation measured by brachial artery ultrasound at baseline and 8 weeks. By the end of the trial, 47, 49, and 53 participants had been allocated to receive probenecid, allopurinol, and placebo, respectively. Mean serum uric acid levels significantly decreased in the probenecid (from 6.1 to 3.5 mg/dL) and allopurinol groups (from 6.1 to 2.9 mg/dL) but not in the placebo group (6.1 to 5.6 mg/dL). None of the interventions produced any significant change in endothelium-dependent vasodilation (probenecid, 7.4±5.1% at baseline and 8.3±5.1% at 8 weeks; allopurinol, 7.6±6.0% at baseline and 6.2±4.8% at 8 weeks; and placebo, 6.5±3.8% at baseline and 7.1±4.9% at 8 weeks). In this randomized, double-blind, placebo-controlled trial, uric acid lowering did not affect endothelial function in overweight or obese nonhypertensive individuals. These data do not support the hypothesis that uric acid is causally related to endothelial dysfunction, a potential mechanism for development of hypertension. © 2016 American Heart Association, Inc.

  12. Low antioxidant status of serum bilirubin, uric acid, albumin and creatinine in patients with myasthenia gravis.

    PubMed

    Yang, Dehao; Su, Zhongqian; Wu, Shengjie; Bi, Yong; Li, Xiang; Li, Jia; Lou, Kangliang; Zhang, Hongyu; Zhang, Xu

    2016-12-01

    Oxidative stress and low antioxidant status play a major role in the pathogenesis of inflammatory and autoimmune diseases. Myasthenia gravis (MG) is an autoimmune condition targeting the neuromuscular junction, and its antioxidant status is still controversial. Our study aimed to investigate the correlation between the clinical characteristics of MG and the serum antioxidant status of bilirubin (Tbil, Dbil and Ibil), uric acid, albumin and creatinine. We measured serum antioxidant molecule levels of bilirubin (Tbil, Dbil and Ibil), uric acid, albumin and creatinine in 380 individuals, including 166 MG and 214 healthy controls. We found that MG patients had significantly lower serum levels of bilirubin (Tbil, Dbil and Ibil), uric acid, albumin and creatinine than healthy controls, whether male or female. Moreover, it was also shown in our study that uric acid, albumin and creatinine levels in patients with MG were correlated with disease activity and classifications performed by the Myasthenia Gravis Foundation of America. Our findings demonstrated that serum levels of bilirubin (Tbil, Dbil and Ibil), uric acid, albumin and creatinine were reduced in patients with MG. This suggested an active oxidative process in MG patients who had low antioxidant status.

  13. Analysis of the binding interaction in uric acid - Human hemoglobin system by spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Makarska-Bialokoz, Magdalena

    2017-05-01

    The binding interaction between human hemoglobin and uric acid has been studied for the first time, by UV-vis absorption and steady-state, synchronous and three-dimensional fluorescence techniques. Characteristic effects observed for human hemoglobin intrinsic fluorescence during interaction with uric acid at neutral pH point at the formation of stacking non-covalent and non-fluorescent complexes. All the calculated parameters, the binding, fluorescence quenching and bimolecular quenching rate constants, as well as Förster resonance energy transfer parameters confirm the existence of static quenching. The results of synchronous fluorescence measurements indicate that the fluorescence quenching of human hemoglobin originates both from Trp and Tyr residues and that the addition of uric acid could significantly hinder the physiological functions of human hemoglobin.

  14. Identification of allantoin, uric acid, and indoxyl sulfate as biochemical indicators of filth in food packaging by LC.

    PubMed

    Carlson, M; Thompson, R D

    2001-01-01

    A liquid chromatographic (LC) method was developed for the determination of allantoin, uric acid, and indoxyl sulfate in mammalian urine contaminated packaging material including paper bagging, corrugated cardboard, grayboard, and burlap bagging. The procedure involves solvent extraction and isolation of the 3 analytes by reversed-phase LC with ultraviolet detection at 225 nm for allantoin and 286 nm for uric acid and indoxyl sulfate. The composition of authentic mammalian urine such as mouse, rat, cat, dog, and human were also determined with regard to the 3 compounds of interest. A linear concentration range of 0.11-20.4, 0.02-10.0, and 0.04-30.0 microg/mL was obtained for allantoin, uric acid, and indoxyl sulfate, respectively. Limits of detection (LOD) and quantitation (LOQ) were 0.0104 and 0.0345 microg/mL for allantoin; 0.0018 and 0.0060 microg/mL for uric acid; and 0.0049 and 0.0165 microg/mL for indoxyl sulfate, respectively. Interday relative standard deviation values for a mixture of standard allantoin, uric acid, and indoxyl sulfate (n = 5) were 0.97, 0.80, and 0.94%, respectively. Analyte composition for 5 types of authentic mammalian urine varied from 0.19-6.88 mg/mL allantoin; 0.08-0.57 mg/mL uric acid; and 0.03-0.78 mg/mL indoxyl sulfate. Analyte content for 8 samples including 2 samples each for paper, cardboard, grayboard, and burlap bagging each contaminated with mouse or rat urine ranged from uric acid; and 17.5 to 616 microg/gm indoxyl sulfate. Recoveries of allantoin, uric acid, and indoxyl sulfate from 11 fortified samples (4 types) for both mouse and rat urine ranged from 28.2 to 114.1 % for allantoin; 32.6 to 123.4% for uric acid; and 52.6 to 118.2% for indoxyl sulfate.

  15. Coffee, tea, and caffeine consumption and serum uric acid level: the third national health and nutrition examination survey.

    PubMed

    Choi, Hyon K; Curhan, Gary

    2007-06-15

    Coffee is one of the most widely consumed beverages in the world and may affect serum uric acid levels and risk of gout via various mechanisms. Our objective was to evaluate the relationship between coffee, tea, and caffeine intake and serum uric acid level in a nationally representative sample of men and women. Using data from 14,758 participants ages >/=20 years in the Third National Health and Nutrition Examination Survey (1988-1994), we examined the relationship between coffee, tea, and caffeine intake and serum uric acid level using linear regression. Additionally, we examined the relationship with hyperuricemia (serum uric acid >7.0 mg/dl among men and >5.7 mg/dl among women) using logistic regression. Intake was assessed by a food frequency questionnaire. Serum uric acid level decreased with increasing coffee intake. After adjusting for age and sex, serum uric acid level associated with coffee intake of 4 to 5 and >/=6 cups daily was lower than that associated with no intake by 0.26 mg/dl (95% confidence interval [95% CI] 0.11, 0.41) and 0.43 mg/dl (95% CI 0.23, 0.65; P for trend < 0.001), respectively. After adjusting for other covariates, the differences remained significant (P for trend < 0.001). Similarly, there was a modest inverse association between decaffeinated coffee intake and serum uric acid levels (multivariate P for trend 0.035). Total caffeine from coffee and other beverages and tea intake were not associated with serum uric acid levels (multivariate P for trend 0.15). The multivariate odds ratio for hyperuricemia in individuals with coffee intake >/=6 cups daily compared with those with no coffee use was 0.57 (95% CI 0.35, 0.94; P for trend 0.001). These findings from a nationally representative sample of US adults suggest that coffee consumption is associated with lower serum uric acid level and hyperuricemia frequency, but tea consumption is not. The inverse association with coffee appears to be via components of coffee other than caffeine.

  16. Urinary Urea, Uric Acid and Hippuric Acid as Potential Biomarkers in Multiple Sclerosis Patients.

    PubMed

    Atya, Hanaa B; Ali, Sahar A; Hegazy, Mohamed I; El Sharkawi, Fathia Z

    2018-04-01

    Urine is a proven source of metabolite biomarkers and has the potential to be a rapid, noninvasive, inexpensive, and efficient diagnostic tool for various human diseases. Despite these advantages, urine is an under-investigated source of biomarkers for multiple sclerosis (MS). The objective was to investigate the level of some urinary metabolites (urea, uric acid and hippuric acid) in patients with MS and correlate their levels to the severity of the disease, MS subtypes and MS treatment. The urine samples were collected from 73 MS patients-48 with RRMS and 25 with SPMS- and age matched 75 healthy controls. The values of urinary urea, uric acid and hippuric acid in MS patients were significantly decreased, and these metabolites in SPMS pattern showed significantly decrease than RRMS pattern. Also showed significant inverse correlation with expanded disability status scale and number of relapses. Accordingly, they may act as a potential urinary biomarkers for MS, and correlate to disease progression.

  17. Serum uric acid to creatinine ratio: A predictor of incident chronic kidney disease in type 2 diabetes mellitus patients with preserved kidney function.

    PubMed

    Gu, Liubao; Huang, Liji; Wu, Haidi; Lou, Qinglin; Bian, Rongwen

    2017-05-01

    Serum uric acid has shown to be a predictor of renal disease progression in most but not all studies. This study aims to test whether renal function-normalized serum uric acid is superior to serum uric acid as the predictor of incident chronic kidney disease in type 2 diabetes mellitus patients. In this study, 1339 type 2 diabetes mellitus patients with estimated glomerular filtration rate ⩾60 mL/min/1.73 m 2 and normouricemia were included. Renal function-normalized serum uric acid was calculated using serum uric acid/creatinine. Cox regression analysis was used to estimate the association between serum uric acid, renal function-normalized serum uric acid and incident chronic kidney disease. In total, 74 (5.53%) patients developed to chronic kidney disease 3 or greater during a median follow-up of 4 years, with older ages, longer diabetes duration and lower estimated glomerular filtration rate at baseline. The decline rate of estimated glomerular filtration rate was positively correlated with serum uric acid/creatinine ( r = 0.219, p < 0.001), but not serum uric acid ( r = 0.005, p = 0.858). Moreover, multivariate analysis revealed that serum uric acid was not an independent risk factor for incident chronic kidney disease ( p = 0.055), whereas serum uric acid to creatinine ratio was significantly associated with incident chronic kidney disease independently of potential confounders including baseline estimated glomerular filtration rate. serum uric acid to creatinine ratio might be a better predictor of incident chronic kidney disease in type 2 diabetes mellitus patients.

  18. Antioxidant status of serum bilirubin and uric acid in patients with polymyositis and dermatomyositis.

    PubMed

    Chen, Zhibo; Su, Zhongqian; Pang, Wanhui; Huang, Yuanyuan; Lin, Jie; Ding, Zhangna; Wu, Senmin; Xu, Shunyao; Quan, Weiwei; Zheng, Juzeng; Chen, Huale; Li, Zhengzheng; Li, Xiang; Li, Jia; Weng, Yiyun; Zhang, Xu

    2017-07-01

    Oxidative stress and variations in antioxidant status are implicated in the pathogenesis of inflammatory and autoimmune diseases. Polymyositis and dermatomyositis (PM/DM) are autoimmune diseases with inflammatory cells infiltrating into skeletal muscles, and the antioxidant status is still controversial. The aim of our study was to investigate the correlation between PM/DM and the antioxidant status of serum bilirubin (Tbil, Dbil and Ibil) and uric acid (UA). We measured serum concentrations of bilirubin (Tbil, Dbil and Ibil) and uric acid in 384 individuals, including 110 PM/DM patients and 274 healthy controls. We found that PM/DM patients had significantly lower serum concentrations of bilirubin (Tbil and Ibil) and uric acid than healthy controls, whether male or female. Also, after separately adjusting the covariances of age and gender, Tbil, Dbil, Ibil and UA were all relevant factors for PM/DM. Moreover, there were no significant differences in serum antioxidant molecule levels between PM and DM subgroups. Our study demonstrated the low serum levels of bilirubin and uric acid in patients with PM/DM. This suggested low antioxidant status in PM/DM patients with excessive oxidative stress.

  19. [Atorvastatin improves reflow after percutaneous coronary intervention in patients with acute ST-segment elevation myocardial infarction by decreasing serum uric acid level].

    PubMed

    Yan, Ling; Ye, Lu; Wang, Kun; Zhou, Jie; Zhu, Chunjia

    2016-05-25

    Objective: To investigate the effect of atorvastatin on reflow in patients with acute ST-segment elevation myocardial infarction (STEMI) after percutaneous coronary intervention (PCI) and its relation to serum uric acid levels. Methods: One hundred and fourteen STEMI patients undergoing primary PCI were enrolled and randomly divided into two groups:55 cases received oral atorvastatin 20 mg before PCI (routine dose group) and 59 cases received oral atorvastatin 80 mg before PCI (high dose group). According to the initial serum uric acid level, patients in two groups were further divided into normal uric acid subgroup and hyperuricemia subgroup. The changes of uric acid level and coronary artery blood flow after PCI were observed. Correlations between the decrease of uric acid, the dose of atorvastatin and the blood flow of coronary artery after PCI were analyzed. Results: Serum uric acid levels were decreased after treatment in both groups (all P <0.05), and patients with hyperuricemia showed more significant decrease in serum uric acid level ( P <0.05). Compared with the routine dose group, serum uric acid level in patients with hyperuricemia decreased more significantly in the high dose group ( P <0.05), but no significant difference was observed between patients with normal serum uric acid levels in two groups ( P >0.05). Among 114 patients, there were 19 cases without reflow after PCI (16.7%). In the routine dose group, there were 12 patients without reflow, in which 3 had normal uric acid and 9 had high uric acid levels ( P <0.01). In the high dose group, there were 7 patients without reflow, in which 2 had normal uric acid and 5 had high uric acid ( P <0.05). Logistic regression analysis showed that hyperuricemia was one of independent risk factors for no-reflow after PCI ( OR =1.01, 95% CI :1.01-1.11, P <0.01). The incidence of no-flow after PCI in the routine dose group was 21.8% (12/55), and that in the high dose group was 11.9% (7/59) ( P <0

  20. Preliminary Use of Uric Acid as a Biomarker for Wading Birds on Everglades Tree Islands, Florida, United States

    USGS Publications Warehouse

    Bates, Anne L.; Orem, William H.; Newman, Susan; Gawlik, Dale E.; Lerch, Harry E.; Corum, Margo D.; Van Winkle, Monica

    2010-01-01

    Concentrations of organic biomarkers and concentrations of phosphorus in soil cores can potentially be used as proxies for historic population densities of wading birds on tree islands in the Florida Everglades. This report focuses on establishing a link between the organic biomarker uric acid found in wading bird guano and the high phosphorus concentrations in tree island soils in the Florida Everglades. Uric acid was determined in soil core sections, in surface samples, and in bird guano by using a method of high-performance liquid chromatography-mass spectrometry (HPLC-MS) developed for this purpose. Preliminary results show an overall correlation between uric acid and total phosphorus in three soil cores, with a general trend of decreasing concentrations of both uric acid and phosphorus with depth. However, we have also found no uric acid in a soil core having high concentrations of phosphorus. We believe that this result may be explained by different geochemical circumstances at that site.

  1. Prevalence of hyperuricemia and relation of serum uric acid with cardiovascular risk factors in a developing country

    PubMed Central

    Conen, D; Wietlisbach, V; Bovet, P; Shamlaye, C; Riesen, W; Paccaud, F; Burnier, M

    2004-01-01

    Background The prevalence of hyperuricemia has rarely been investigated in developing countries. The purpose of the present study was to investigate the prevalence of hyperuricemia and the association between uric acid levels and the various cardiovascular risk factors in a developing country with high average blood pressures (the Seychelles, Indian Ocean, population mainly of African origin). Methods This cross-sectional health examination survey was based on a population random sample from the Seychelles. It included 1011 subjects aged 25 to 64 years. Blood pressure (BP), body mass index (BMI), waist circumference, waist-to-hip ratio, total and HDL cholesterol, serum triglycerides and serum uric acid were measured. Data were analyzed using scatterplot smoothing techniques and gender-specific linear regression models. Results The prevalence of a serum uric acid level >420 μmol/L in men was 35.2% and the prevalence of a serum uric acid level >360 μmol/L was 8.7% in women. Serum uric acid was strongly related to serum triglycerides in men as well as in women (r = 0.73 in men and r = 0.59 in women, p < 0.001). Uric acid levels were also significantly associated but to a lesser degree with age, BMI, blood pressure, alcohol and the use of antihypertensive therapy. In a regression model, triglycerides, age, BMI, antihypertensive therapy and alcohol consumption accounted for about 50% (R2) of the serum uric acid variations in men as well as in women. Conclusions This study shows that the prevalence of hyperuricemia can be high in a developing country such as the Seychelles. Besides alcohol consumption and the use of antihypertensive therapy, mainly diuretics, serum uric acid is markedly associated with parameters of the metabolic syndrome, in particular serum triglycerides. Considering the growing incidence of obesity and metabolic syndrome worldwide and the potential link between hyperuricemia and cardiovascular complications, more emphasis should be put on the

  2. Antioxidant status of bilirubin and uric acid in patients diagnosed with Plasmodium falciparum malaria in Douala.

    PubMed

    Bertrand, Kouam Eric; Mathieu, Ndomou; Inocent, Gouado; Honore, Fotso Kuate

    2008-06-15

    Oxidative stress and changes in antioxidant status have been implicated in the pathogenesis of malaria. To assess the antioxidant level ofbilirubin and uric acid associated with falciparum malaria infection, 60 untreated patients (30 men and 30 women) in Douala, Cameroon were screened for the study. Sixty five healthy individuals (29 men and 36 women) were used as controls. Total and conjugated bilirubin were calculated using Jendrassik-Grof method while uric acid was determined using Barham-Trinder method. It was observed that total and conjugated bilirubins were significantly (p < 0.001) higher in malaria patients (10.722 +/- 4.043 and 3.627 +/- 1.571 mg L(-1), respectively) when compared to control (6.830 +/- 2.436 and 1.777 +/- 0.729 mg L(-1)) and these bilirubin levels increased significantly with parasite count (p < 0.050). There was also significant increased (p = 0.021) of uric acid in malaria patients (56.262 +/- 13.963 mg L(-1)) compared to controls (49.838 +/- 15.419 mg L(-1)). No significant differences based on sex were observed on uric acid, parasite count, total and conjugated bilirubins in malaria patients. Positive correlations were obtained between parasite count and total bilirubin (r = 0.320, p < 0.050), conjugated bilirubin (r = 0.477, p < 0.001), uric acid (r = 0.060, p > 0.050) and between total and conjugated bilirubin (r = 0.729, p < 0.001). From this study, it has been hypothesized that the augmentation of plasma level ofbilirubin and uric acid could provide more protection against oxidative stress induced by malaria.

  3. Low serum uric acid concentration augments insulin effects on the prevalence of metabolic syndrome.

    PubMed

    Porchia, Leonardo M; Gonzalez-Mejia, M Elba; Torres-Rasgado, Enrique; Ruiz-Vivanco, Guadalupe; Pérez-Fuentes, Ricardo

    2018-05-01

    Insulin and uric acid were shown affect the prevalence of Metabolic Syndrome (MetS), but no studies examine their interaction. Therefore, we conducted this study to determine their biological interaction in subjects from central Mexico. 433 subjects were enrolled for a cross-sectional study. MetS was defined according to the Harmonizing Definition. Hyperuricemia was defined as ≥7.0 mg/dL in males and ≥5.8 mg/dL in females. Hyperinsulinemia was defined as ≥11.0 μU/mL. Pearson correlation coefficient (r) was calculated to determine the association between uric acid or insulin and MetS. Logistic regression was used to determine the risk (odds ratio) of developing MetS. Biological interactions were determined by the PROCESS Macro and Anderson's method. Insulin and uric acid levels were elevated in MetS positive group (p < .05) and correlated with the number of MetS components (r = 0.276 and r = 0.166, p < .001, respectively). The interaction between uric acid and insulin was associated with the number of MetS components (PROCESS Model 1, interaction coefficient = -0.009, 95%CI: -0.017 to -0.001, p = .036). Johnson-Neyman analysis suggests the interaction is lost when uric acid concentration increased >7.0 mg/dL. When the cohort was separated by hyperinsulinemia and hyperuricemia, there was a significant risk of developing MetS for subjects with hyperuricemia (odds ratio = 2.3; 95%CI: 1.1-4.8, p < .05), hyperinsulinemia (odds ratio = 3.1; 95%CI: 1.9-4.9, p < .05), or both (odds ratio = 7.4; 95%CI: 3.2-17.2, p < .05); however, there was no multiplicative or additive interaction. Here, we show that uric acid and insulin augments the prevalence of MetS; however, no biological interaction was determined for hyperuricemia and hyperinsulinemia. Copyright © 2017 Diabetes India. Published by Elsevier Ltd. All rights reserved.

  4. Association of serum uric acid with aortic stiffness and pressure in a Chinese workplace setting.

    PubMed

    Chen, Xin; Li, Yan; Sheng, Chang-Sheng; Huang, Qi-Fang; Zheng, Yang; Wang, Ji-Guang

    2010-04-01

    In the present analysis, we investigated the association of serum uric acid with aortic stiffness and pressure as measured by carotid-femoral pulse wave velocity (cf-PWV) and central systolic blood pressure (SBP), respectively. Our study was conducted in the framework of cardiovascular health examinations for the employees of a factory and their family members (ages 15-79 years). We performed arterial measurements using the SphygmoCor device. Hyperuricemia was defined as a serum uric acid concentration of at least 420 micromol/l in men and 360 micromol/l in women. The 940 study participants included 207 (22.0%) hypertensive patients, of whom 92 (9.8%) took antihypertensive medication. Men (n = 620), compared with women (n = 320), had significantly (P < or = 0.03) higher serum uric acid concentration (363 +/- 76 vs. 272 +/- 64 micromol/l), prevalence of hyperuricemia (17.9% vs. 7.5%), cf-PWV (7.41 vs. 7.16 m/s), and central SBP (114.4 vs. 108.8 mm Hg). Both before and after adjustment for age, serum uric acid was significantly (P < or = 0.02) and positively associated with cf-PWV and central SBP in all subjects and in men and women separately. After full adjustment for covariates, the association with cf-PWV remained statistically significant (P < or = 0.009) in all subjects and men, and with central SBP in all subjects only. Categorical analyses were confirmatory. In all subjects, patients with hyperuricemia had significantly (P = 0.03) higher cf-PWV (7.51 vs. 7.29 m/s) and central SBP (114.9 vs. 112.1 mm Hg) than those with normal serum uric acid. Serum uric acid was associated with aortic stiffness and pressure in a Chinese workplace setting, especially in men.

  5. Further characterization of photothermal breakdown products of uric acid stones following holmium:YAG laser lithotripsy

    NASA Astrophysics Data System (ADS)

    Glickman, Randolph D.; Weintraub, Susan T.; Kumar, Neeru; Corbin, Nicole S.; Lesani, Omid; Teichman, Joel M. H.

    2000-06-01

    Previously we found that Ho:YAG laser (2120 nm) lithotripsy of uric acid stones produced cyanide, a known thermal breakdown product of uric acid. We now report that alloxan, another thermal breakdown product, is also likely produced. Uric acid stones (approximately 98% pure) of human origin were placed in distilled water and subjected to one of the following experimental treatments: unexposed control, exposed to Ho:YAG laser, Nd:YAG laser, or mechanically crushed. Samples were then processed for HPLC analysis with UV detection. Peaks were identified by comparison to authentic standards. All samples contained uric acid, with retention time (RT) about 6 min. All of the laser-exposed samples contained a peak that eluted at 2.5 min, identical to the RT of authentic alloxan. Ho:YAG laser irradiation, however, produced a larger presumed alloxan peak than did the Nd:YAG laser. The peak at 2.5 min, as well as unidentified later-eluting peaks, were present in the laser-exposed, but not the unexposed or mechanically crushed, samples. These results confirm the thermal nature of lithotripsy performed with long-pulse IR lasers.

  6. Correlation between Serum Uric Acid Level and Microalbuminuria in Type-2 Diabetic Nephropathy

    PubMed Central

    Latif, Hina; Iqbal, Adil; Rathore, Rabia; Butt, Nasir Farooq

    2017-01-01

    Objective: To measure the correlation between microalbuminuria and serum uric acid level in Type-2 diabetic nephropathy. Methods: This cross-sectional study was done in department of Medicine, Mayo hospital Lahore from August 2014 to February 2015. A total of 200 patients with Type-2 diabetic nephropathy were enrolled in the study. Demographic data and contact details were obtained. Serum Uric acid and microalbuminuria by albumin to creatinine ratio (ACR) in random urine sample was measured at the time of inclusion of patients. All the information was collected through a pre-defined proforma. Pearson correlation coefficient and t-test were used to assess correlation and significance respectively. Results: Out of 200 cases, 29%(n=58) were between 16-40 years of age while 71%(n=142) were between 41-65 years of age, Mean ± SD was calculated as 48.1±10.26 years, 48.5%(n=97) were male and 51.5%(n=103) were females, Mean serum uric acid level was calculated as 6.99±1.01 mg/dL while microalbuminuria was calculated as 5.63±1.08 mg/mmol, r value was 0.0838 which is a positive correlation. Conclusion: The results of our study concluded that level of serum uric acid and microalbuminuria are significantly correlated to nephropathy in patients having Type-2 diabetes mellitus. PMID:29492061

  7. Electrochemical detection of uric acid via uricase-immobilized graphene oxide.

    PubMed

    Omar, Muhamad Nadzmi; Salleh, Abu Bakar; Lim, Hong Ngee; Ahmad Tajudin, Asilah

    2016-09-15

    Measurement of the uric acid level in the body can be improved by biosensing with respect to the accuracy, sensitivity and time consumption. This study has reported the immobilization of uricase onto graphene oxide (GO) and its function for electrochemical detection of uric acid. Through chemical modification of GO using 1-ethyl-3-(dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysulfosuccinimide (NHS) as cross-linking reagents, the enzyme activity of the immobilized uricase was much comparable to the free enzyme with 88% of the activity retained. The modified GO-uricase (GOU) was then subjected to electrocatalytic detection of uric acid (UA) via cyclic voltammetry (CV). For that reason, a glassy carbon electrode (GCE) was modified by adhering the GO along with the immobilized uricase to facilitate the redox reaction between the enzyme and the substrate. The modified GOU/GCE outperformed a bare electrode through the electrocatalytic activity with an amplified electrical signal for the detection of UA. The electrocatalytic response showed a linear dependence on the UA concentration ranging from 0.02 to 0.49 mM with a detection limit of 3.45 μM at 3σ/m. The resulting biosensor also exhibited a high selectivity towards UA in the presence of other interference as well as good reproducibility. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Fructose suppresses uric acid excretion to the intestinal lumen as a result of the induction of oxidative stress by NADPH oxidase activation.

    PubMed

    Kaneko, Chihiro; Ogura, Jiro; Sasaki, Shunichi; Okamoto, Keisuke; Kobayashi, Masaki; Kuwayama, Kaori; Narumi, Katsuya; Iseki, Ken

    2017-03-01

    A high intake of fructose increases the risk for hyperuricemia. It has been reported that long-term fructose consumption suppressed renal uric acid excretion and increased serum uric acid level. However, the effect of single administration of fructose on excretion of uric acid has not been clarified. We used male Wistar rats, which were orally administered fructose (5g/kg). Those rats were used in each experiment at 12h after administration. Single administration of fructose suppressed the function of ileal uric acid excretion and had no effect on the function of renal uric acid excretion. Breast cancer resistance protein (BCRP) predominantly contributes to intestinal excretion of uric acid as an active homodimer. Single administration of fructose decreased BCRP homodimer level in the ileum. Moreover, diphenyleneiodonium (DPI), an inhibitor of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox), recovered the suppression of the function of ileal uric acid excretion and the Bcrp homodimer level in the ileum of rats that received single administration of fructose. Single administration of fructose decreases in BCRP homodimer level, resulting in the suppression the function of ileal uric acid excretion. The suppression of the function of ileal uric acid excretion by single administration of fructose is caused by the activation of Nox. The results of our study provide a new insight into the mechanism of fructose-induced hyperuricemia. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Effect of Uric Acid Lowering on Renin-Angiotensin-System Activation and Ambulatory BP: A Randomized Controlled Trial

    PubMed Central

    Borgi, Lea; Fisher, Naomi; Curhan, Gary; Forman, John

    2017-01-01

    Background and objectives Higher serum uric acid levels, even within the reference range, are strongly associated with increased activity of the renin-angiotensin system (RAS) and risk of incident hypertension. However, the effect of lowering serum uric acid on RAS activity in humans is unknown, although the data that lowering serum uric acid can reduce BP are conflicting. Design, setting, participants, & measurements In a double-blind placebo-controlled trial conducted from 2011 to 2015, we randomly assigned 149 overweight or obese adults with serum uric acid ≥5.0 mg/dl to uric acid lowering with either probenecid or allopurinol, or to placebo. The primary endpoints were kidney-specific and systemic RAS activity. Secondary endpoints included mean 24-hour systolic BP, mean awake and asleep BP, and nocturnal dipping. Results Allopurinol and probenecid markedly lowered serum uric acid after 4 and 8 weeks compared with placebo (mean serum uric acid in allopurinol, probenecid, and placebo at 8 weeks was 2.9, 3.5, and 5.6 mg/dl, respectively). The change in kidney-specific RAS activity, measured as change in the median (interquartile range) renal plasma flow response to captopril (in ml/min per 1.73 m2) from baseline to 8 weeks, was −4 (−25 to 32) in the probenecid group (P=0.83), −4 (−16 to 9) in the allopurinol group (P=0.32), and 1 (−21 to 17) in the placebo group (P=0.96), with no significant treatment effect (P=0.77). Similarly, plasma renin activity and plasma angiotensin II levels did not significantly change with treatment. The change in mean (±SD) 24-hour systolic BPs from baseline to 8 weeks was −1.6±10.1 with probenecid (P=0.43), −0.4±6.1 with allopurinol (P=0.76), and 0.5±6.0 with placebo (P=0.65); there was no significant treatment effect (P=0.58). Adverse events occurred in 9%, 12%, and 2% of those given probenecid, allopurinol, or placebo, respectively. Conclusions In contrast to animal experiments and observational studies, this

  10. Effect of Uric Acid Lowering on Renin-Angiotensin-System Activation and Ambulatory BP: A Randomized Controlled Trial.

    PubMed

    McMullan, Ciaran J; Borgi, Lea; Fisher, Naomi; Curhan, Gary; Forman, John

    2017-05-08

    Higher serum uric acid levels, even within the reference range, are strongly associated with increased activity of the renin-angiotensin system (RAS) and risk of incident hypertension. However, the effect of lowering serum uric acid on RAS activity in humans is unknown, although the data that lowering serum uric acid can reduce BP are conflicting. In a double-blind placebo-controlled trial conducted from 2011 to 2015, we randomly assigned 149 overweight or obese adults with serum uric acid ≥5.0 mg/dl to uric acid lowering with either probenecid or allopurinol, or to placebo. The primary endpoints were kidney-specific and systemic RAS activity. Secondary endpoints included mean 24-hour systolic BP, mean awake and asleep BP, and nocturnal dipping. Allopurinol and probenecid markedly lowered serum uric acid after 4 and 8 weeks compared with placebo (mean serum uric acid in allopurinol, probenecid, and placebo at 8 weeks was 2.9, 3.5, and 5.6 mg/dl, respectively). The change in kidney-specific RAS activity, measured as change in the median (interquartile range) renal plasma flow response to captopril (in ml/min per 1.73 m 2 ) from baseline to 8 weeks, was -4 (-25 to 32) in the probenecid group ( P =0.83), -4 (-16 to 9) in the allopurinol group ( P =0.32), and 1 (-21 to 17) in the placebo group ( P =0.96), with no significant treatment effect ( P =0.77). Similarly, plasma renin activity and plasma angiotensin II levels did not significantly change with treatment. The change in mean (±SD) 24-hour systolic BPs from baseline to 8 weeks was -1.6±10.1 with probenecid ( P =0.43), -0.4±6.1 with allopurinol ( P =0.76), and 0.5±6.0 with placebo ( P =0.65); there was no significant treatment effect ( P =0.58). Adverse events occurred in 9%, 12%, and 2% of those given probenecid, allopurinol, or placebo, respectively. In contrast to animal experiments and observational studies, this randomized, placebo-controlled trial found that uric acid lowering had no effect on kidney

  11. Accurately Diagnosing Uric Acid Stones from Conventional Computerized Tomography Imaging: Development and Preliminary Assessment of a Pixel Mapping Software.

    PubMed

    Ganesan, Vishnu; De, Shubha; Shkumat, Nicholas; Marchini, Giovanni; Monga, Manoj

    2018-02-01

    Preoperative determination of uric acid stones from computerized tomography imaging would be of tremendous clinical use. We sought to design a software algorithm that could apply data from noncontrast computerized tomography to predict the presence of uric acid stones. Patients with pure uric acid and calcium oxalate stones were identified from our stone registry. Only stones greater than 4 mm which were clearly traceable from initial computerized tomography to final composition were included in analysis. A semiautomated computer algorithm was used to process image data. Average and maximum HU, eccentricity (deviation from a circle) and kurtosis (peakedness vs flatness) were automatically generated. These parameters were examined in several mathematical models to predict the presence of uric acid stones. A total of 100 patients, of whom 52 had calcium oxalate and 48 had uric acid stones, were included in the final analysis. Uric acid stones were significantly larger (12.2 vs 9.0 mm, p = 0.03) but calcium oxalate stones had higher mean attenuation (457 vs 315 HU, p = 0.001) and maximum attenuation (918 vs 553 HU, p <0.001). Kurtosis was significantly higher in each axis for calcium oxalate stones (each p <0.001). A composite algorithm using attenuation distribution pattern, average attenuation and stone size had overall 89% sensitivity, 91% specificity, 91% positive predictive value and 89% negative predictive value to predict uric acid stones. A combination of stone size, attenuation intensity and attenuation pattern from conventional computerized tomography can distinguish uric acid stones from calcium oxalate stones with high sensitivity and specificity. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  12. Potential mechanisms for low uric acid in Parkinson disease

    PubMed Central

    Young, Sarah; Rosen, Ami; Bernhard, Douglas; Millington, David; Factor, Stewart

    2018-01-01

    Several epidemiologic studies have described an association between low serum uric acid (UA) and Parkinson disease (PD). Uric acid is a known antioxidant, and one proposed mechanism of neurodegeneration in PD is oxidative damage of dopamine neurons. However, other complex metabolic pathways may contribute. The purpose of this study is to elucidate potential mechanisms of low serum UA in PD. Subjects who met diagnostic criteria for definite or probable PD (n = 20) and controls (n = 20) aged 55–80 years were recruited. Twenty-four hour urine samples were collected from all participants, and both uric acid and allantoin were measured and corrected for body mass index (BMI). Urinary metabolites were compared using a twoway ANOVA with diagnosis and sex as the explanatory variables. There were no significant differences between PD and controls for total UA (p = 0.60), UA corrected for BMI (p = 0.37), or in the interaction of diagnosis and sex on UA (p = 0.24). Similarly, there were no significant differences between PD and controls for allantoin (p = 0.47), allantoin corrected for BMI (p = 0.57), or in the interaction of diagnosis and sex on allantoin (p = 0.78). Allantoin/UA ratios also did not significantly differ by diagnosis (p = 0.99). Our results imply that low serum UA in PD may be due to an intrinsic mechanism that alters the homeostatic set point for serum UA in PD, and may contribute to relatively lower protection against oxidative damage. These findings provide indirect support for neuroprotection trials aimed at raising serum UA. PMID:26747026

  13. Effect of ethanol on metabolism of purine bases (hypoxanthine, xanthine, and uric acid).

    PubMed

    Yamamoto, Tetsuya; Moriwaki, Yuji; Takahashi, Sumio

    2005-06-01

    There are many factors that contribute to hyperuricemia, including obesity, insulin resistance, alcohol consumption, diuretic use, hypertension, renal insufficiency, genetic makeup, etc. Of these, alcohol (ethanol) is the most important. Ethanol enhances adenine nucleotide degradation and increases lactic acid level in blood, leading to hyperuricemia. In beer, purines also contribute to an increase in plasma uric acid. Although rare, dehydration and ketoacidosis (due to ethanol ingestion) are associated with the ethanol-induced increase in serum uric acid levels. Ethanol also increases the plasma concentrations and urinary excretion of hypoxanthine and xanthine via the acceleration of adenine nucleotide degradation and a possible weak inhibition of xanthine dehydrogenase activity. Since many factors such as the ALDH2*1 gene and ADH2*2 gene, daily drinking habits, exercise, and dehydration enhance the increase in plasma concentration of uric acid induced by ethanol, it is important to pay attention to these factors, as well as ingested ethanol volume, type of alcoholic beverage, and the administration of anti-hyperuricemic agents, to prevent and treat ethanol-induced hyperuricemia.

  14. [The role of uric acid in the insulin resistance in children and adolescents with obesity].

    PubMed

    de Miranda, Josiane Aparecida; Almeida, Guilherme Gomide; Martins, Raissa Isabelle Leão; Cunha, Mariana Botrel; Belo, Vanessa Almeida; dos Santos, José Eduardo Tanus; Mourão-Júnior, Carlos Alberto; Lanna, Carla Márcia Moreira

    2015-12-01

    To investigate the association between serum uric acid levels and insulin resistance in children and adolescents with obesity. Cross-sectional study with 245 children and adolescents (134 obese and 111 controls), aged 8 to 18 years. The anthropometric variables (weight, height and waist circumference), blood pressure and biochemical parameters were collected. The clinical characteristics of the groups were analyzed by t-test or chi-square test. To evaluate the association between uric acid levels and insulin resistance the Pearson's test and logistic regression were applied. The prevalence of insulin resistance was 26.9%. The anthropometric variables, systolic and diastolic blood pressure and biochemical variables were significantly higher in the obese group (p<0.001), except for the high-density-lipoprotein cholesterol. There was a positive and significant correlation between anthropometric variables and uric acid with HOMA-IR in the obese and in the control groups, which was higher in the obese group and in the total sample. The logistic regression model that included age, gender and obesity, showed an odds ratio of uric acid as a variable associated with insulin resistance of 1.91 (95%CI 1.40 to 2.62; p<-0.001). The increase in serum uric acid showed a positive statistical correlation with insulin resistance and it is associated with and increased risk of insulin resistance in obese children and adolescents. Copyright © 2015 Sociedade de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

  15. Photoresponsive surface molecularly imprinted polymer on ZnO nanorods for uric acid detection in physiological fluids.

    PubMed

    Tang, Qian; Li, Zai-Yong; Wei, Yu-Bo; Yang, Xia; Liu, Lan-Tao; Gong, Cheng-Bin; Ma, Xue-Bing; Lam, Michael Hon-Wah; Chow, Cheuk-Fai

    2016-09-01

    A photoresponsive surface molecularly imprinted polymer for uric acid in physiological fluids was fabricated through a facile and effective method using bio-safe and biocompatible ZnO nanorods as a support. The strategy was carried out by introducing double bonds on the surface of the ZnO nanorods with 3-methacryloxypropyltrimethoxysilane. The surface molecularly imprinted polymer on ZnO nanorods was then prepared by surface polymerization using uric acid as template, water-soluble 5-[(4-(methacryloyloxy)phenyl)diazenyl]isophthalic acid as functional monomer, and triethanolamine trimethacryl ester as cross-linker. The surface molecularly imprinted polymer on ZnO nanorods showed good photoresponsive properties, high recognition ability, and fast binding kinetics toward uric acid, with a dissociation constant of 3.22×10(-5)M in aqueous NaH2PO4 buffer at pH=7.0 and a maximal adsorption capacity of 1.45μmolg(-1). Upon alternate irradiation at 365 and 440nm, the surface molecularly imprinted polymer on ZnO nanorods can quantitatively uptake and release uric acid. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Correlation of retinal nerve fibre layer and macular thickness with serum uric acid among type 2 diabetes mellitus.

    PubMed

    Vinuthinee-Naidu, Munisamy-Naidu; Zunaina, Embong; Azreen-Redzal, Anuar; Nyi-Nyi, Naing

    2017-06-14

    Uric acid is a final breakdown product of purine catabolism in humans. It's a potent antioxidant and can also act as a pro-oxidant that induces oxidative stress on the vascular endothelial cells, thus mediating progression of diabetic related diseases. Various epidemiological and experimental evidence suggest that uric acid has a role in the etiology of type 2 diabetes mellitus. We conducted a cross-sectional study to evaluate the correlation of retinal nerve fibre layer (RNFL) and macular thickness with serum uric acid in type 2 diabetic patients. A cross-sectional study was conducted in the Eye Clinic, Hospital Universiti Sains Malaysia, Kelantan between the period of August 2013 till July 2015 involving type 2 diabetes mellitus patients with no diabetic retinopathy and with non-proliferative diabetic retinopathy (NPDR). An evaluation for RNFL and macular thickness was measured using Spectralis Heidelberg optical coherence tomography. Six ml of venous blood was taken for the measurement of serum uric acid and glycosylated haemoglobin (HbA1 C ). A total of 180 diabetic patients were recruited (90 patients with no diabetic retinopathy and 90 patients with NPDR) into the study. The mean level of serum uric acid for both the groups was within normal range and there was no significance difference between the two groups. Based on gender, both male and female gender showed significantly higher level of mean serum uric acid in no diabetic retinopathy group (p = 0.004 respectively). The mean serum uric acid was significantly higher in patient with HbA1 C  < 6.5% (p < 0.031). Patients with NPDR have thicker RNFL and macular thickness compared to patients with no diabetic retinopathy. However, only the RNFL thickness of the temporal quadrant and the macular thickness of the superior outer, inferior outer and temporal outer subfields were statistically significant (p = 0.038, p = 0.004, 0.033 and <0.001 respectively). There was poor correlation between RNFL and

  17. Serum uric acid levels and mortality in the Japanese population: the Yamagata (Takahata) study.

    PubMed

    Kamei, Keita; Konta, Tsuneo; Ichikawa, Kazunobu; Sato, Hiroko; Suzuki, Natsuko; Kabasawa, Asami; Suzuki, Kazuko; Hirayama, Atsushi; Shibata, Yoko; Watanabe, Tetsu; Kato, Takeo; Ueno, Yoshiyuki; Kayama, Takamasa; Kubota, Isao

    2016-12-01

    Serum uric acid level is regulated by gender, dietary habit, genetic predisposition, and renal function, and is associated with the development of renal and cardiovascular diseases. This study prospectively investigated the association between serum uric acid levels and mortality in a community-based population. Three thousand four hundred and eighty-seven subjects regardless of the antihyperuricemic medication (45 % male; mean age 62 years old) from the Takahata town in Japan participated in this study and were followed up for 8 years (median 7.5 years). We examined the association between serum uric acid levels at baseline and the all-cause and cardiovascular mortality, respectively, in this population. One hundred seventy-nine subjects died during the follow-up period, with 49 deaths attributed to cardiovascular causes. Kaplan-Meier analysis revealed that the all-cause mortality was significantly higher along with the increase in serum uric acid levels at baseline among female (Log-rank P < 0.01), but not male subjects (P = 0.97). Cox-proportional hazard model analysis with adjustment for possible confounders including age, renal function, and comorbidities revealed that hyperuricemia (uric acid ≥7.0 mg/dL) was an independent risk factor for all-cause and cardiovascular mortality, respectively, in female [hazard ratio (HR) 5.92, 95 % confidence interval (CI) 2.10-14.6 for all-cause mortality, and HR 10.7, 95 % CI 1.76-50.2 for cardiovascular mortality], but not male subjects. Hyperuricemia was an independent risk for all-cause and cardiovascular mortality in female, but not among the male subjects in a community-based population.

  18. Electrochemical Co-Reduction Synthesis of AuPt Bimetallic Nanoparticles-Graphene Nanocomposites for Selective Detection of Dopamine in the Presence of Ascorbic Acid and Uric Acid

    PubMed Central

    Zhao, Zongya; Zhang, Mingming; Chen, Xiang; Li, Youjun; Wang, Jue

    2015-01-01

    In this paper, AuPt bimetallic nanoparticles-graphene nanocomposites were obtained by electrochemical co-reduction of graphene oxide (GO), HAuCl4 and H2PtCl6. The as-prepared AuPt bimetallic nanoparticles-graphene nanocomposites were characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and other electrochemical methods. The morphology and composition of the nanocomposite could be easily controlled by adjusting the HAuCl4/H2PtCl6 concentration ratio. The electrochemical experiments showed that when the concentration ratio of HAuCl4/H2PtCl6 was 1:1, the obtained AuPt bimetallic nanoparticles-graphene nanocomposite (denoted as Au1Pt1NPs-GR) possessed the highest electrocatalytic activity toward dopamine (DA). As such, Au1Pt1NPs-GR nanocomposites were used to detect DA in the presence of ascorbic acid (AA) and uric acid (UA) using the differential pulse voltammetry (DPV) technique and on the modified electrode, there were three separate DPV oxidation peaks with the peak potential separations of 177 mV, 130 mV and 307 mV for DA and AA, DA and UA, AA and UA, respectively. The linear range of the constructed DA sensor was from 1.6 μM to 39.7 μM with a detection limit of 0.1 μM (S/N = 3). The obtained DA sensor with good stability, high reproducibility and excellent selectivity made it possible to detect DA in human urine samples. PMID:26184200

  19. Electrochemical Co-Reduction Synthesis of AuPt Bimetallic Nanoparticles-Graphene Nanocomposites for Selective Detection of Dopamine in the Presence of Ascorbic Acid and Uric Acid.

    PubMed

    Zhao, Zongya; Zhang, Mingming; Chen, Xiang; Li, Youjun; Wang, Jue

    2015-07-09

    In this paper, AuPt bimetallic nanoparticles-graphene nanocomposites were obtained by electrochemical co-reduction of graphene oxide (GO), HAuCl4 and H2PtCl6. The as-prepared AuPt bimetallic nanoparticles-graphene nanocomposites were characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and other electrochemical methods. The morphology and composition of the nanocomposite could be easily controlled by adjusting the HAuCl4/H2PtCl6 concentration ratio. The electrochemical experiments showed that when the concentration ratio of HAuCl4/H2PtCl6 was 1:1, the obtained AuPt bimetallic nanoparticles-graphene nanocomposite (denoted as Au1Pt1NPs-GR) possessed the highest electrocatalytic activity toward dopamine (DA). As such, Au1Pt1NPs-GR nanocomposites were used to detect DA in the presence of ascorbic acid (AA) and uric acid (UA) using the differential pulse voltammetry (DPV) technique and on the modified electrode, there were three separate DPV oxidation peaks with the peak potential separations of 177 mV, 130 mV and 307 mV for DA and AA, DA and UA, AA and UA, respectively. The linear range of the constructed DA sensor was from 1.6 μM to 39.7 μM with a detection limit of 0.1 μM (S/N = 3). The obtained DA sensor with good stability, high reproducibility and excellent selectivity made it possible to detect DA in human urine samples.

  20. Effects of Lowering Glycemic Index of Dietary Carbohydrate on Plasma Uric Acid: The OmniCarb Randomized Clinical Trial

    PubMed Central

    Juraschek, Stephen P; McAdams-Demarco, Mara; Gelber, Allan C; Sacks, Frank M.; Appel, Lawrence J; White, Karen; Miller, Edgar R

    2017-01-01

    Objective The effects of carbohydrates on plasma uric acid levels are controversial. We determined the individual and combined effects of carbohydrate quality (glycemic index, GI) and quantity (proportion of total daily energy, %carb) on uric acid. Methods We conducted a randomized, crossover feeding trial in overweight or obese adults without cardiovascular disease (N=163). Participants were fed each of four diets over 5-week periods separated by 2-week washout periods. Body weight was kept constant. The four diets were: high GI (GI ≥65) with high %carb (58% kcal), low GI (GI ≤45) with low %carb (40% kcal), low GI with high %carb; and high GI with low %carb. Plasma uric acid was measured at baseline and after each feeding period for comparison between the 4 diets. Results Study participants were 52% women and 50% non-Hispanic black with a mean age of 52.6 years and a mean uric acid of 4.7 (SD, 1.2) mg/dL. Reducing GI lowered uric acid when the %carb was low (−0.24 mg/dL; P <0.001) or high (−0.17 mg/dL; P <0.001). Reducing the %carb marginally increased uric acid only when GI was high (P = 0.05). The combined effect of lowering GI and increasing the %carb was −0.27 mg/dL (P <0.001). This effect was observed even after adjustment for concurrent changes in kidney function, insulin sensitivity, and products of glycolysis. Conclusions Reducing GI lowers uric acid. Future studies should examine whether reducing GI can prevent gout onset or flares. TRIAL REGISTRATION clinicaltrials.gov, Identifier: NCT00608049 PMID:26636424

  1. Uric acid therapy improves the outcomes of stroke patients treated with intravenous tissue plasminogen activator and mechanical thrombectomy.

    PubMed

    Chamorro, Ángel; Amaro, Sergio; Castellanos, Mar; Gomis, Meritxell; Urra, Xabier; Blasco, Jordi; Arenillas, Juan F; Román, Luis S; Muñoz, Roberto; Macho, Juan; Cánovas, David; Marti-Fabregas, Joan; Leira, Enrique C; Planas, Anna M

    2017-06-01

    Background Numerous neuroprotective drugs have failed to show benefit in the treatment of acute ischemic stroke, making the search for new treatments imperative. Uric acid is an endogenous antioxidant making it a drug candidate to improve stroke outcomes. Aim To report the effects of uric acid therapy in stroke patients receiving intravenous thrombolysis and mechanical thrombectomy. Methods Forty-five patients with proximal vessel occlusions enrolled in the URICO-ICTUS trial received intravenous recombinant tissue plasminogen activator within 4.5 h after stroke onset and randomized to intravenous 1000 mg uric acid or placebo (NCT00860366). These patients also received mechanical thrombectomy because a brain computed tomogaphy angiography confirmed the lack of proximal recanalization at the end of systemic thrombolysis. The primary outcome was good functional outcome at 90 days (modified Rankin Score 0-2). Safety outcomes included mortality, symptomatic intracerebral bleeding, and gout attacks. Results The rate of successful revascularization was >80% in the uric acid and the placebo groups but good functional outcome was observed in 16 out of 24 (67%) patients treated with uric acid and 10 out of 21 (48%) treated with placebo (adjusted Odds Ratio, 6.12 (95% CI 1.08-34.56)). Mortality was observed in two out of 24 (8.3%) patients treated with uric acid and one out of 21 (4.8%) treated with placebo (adjusted Odds Ratio, 3.74 (95% CI 0.06-226.29)). Symptomatic cerebral bleeding and gout attacks were similar in both groups. Conclusions Uric acid therapy was safe and improved stroke outcomes in stroke patients receiving intravenous thrombolysis followed by thrombectomy. Validation of this simple strategy in a larger trial is urgent.

  2. Determination of glucose and uric acid with bienzyme colorimetry on microfluidic paper-based analysis devices.

    PubMed

    Chen, Xi; Chen, Jin; Wang, Fubin; Xiang, Xia; Luo, Ming; Ji, Xinghu; He, Zhike

    2012-05-15

    In this work, we first employ a drying method combining with the bienzyme colorimetric detection of glucose and uric acid on microfluidic paper-based analysis devices (μPADs). The channels of 3D μPADs are also designed by us to get better results. The color results are recorded by both Gel Documentation systems and a common camera. By using Gel Documentation systems, the limits of detection (LOD) of glucose and uric acid are 3.81 × 10(-5)M and 4.31 × 10(-5)M, respectively one order of magnitude lower than that of the reported methods on μPADs. By using a common camera, the limits of detection (LOD) of glucose and uric acid are 2.13 × 10(-4)M and 2.87 × 10(-4)M, respectively. Furthermore, the effects of detection conditions have been investigated and discussed comprehensively. Human serum samples are detected with satisfactory results, which are comparable with the clinical testing results. A low-cost, simple and rapid colorimetric method for the simultaneous detection of glucose and uric acid on the μPADs has been developed with enhanced sensitivity. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Surface modification of pitch-based spherical activated carbon by CVD of NH 3 to improve its adsorption to uric acid

    NASA Astrophysics Data System (ADS)

    Liu, Chaojun; Liang, Xiaoyi; Liu, Xiaojun; Wang, Qin; Zhan, Liang; Zhang, Rui; Qiao, Wenming; Ling, Licheng

    2008-08-01

    Surface chemistry of pitch-based spherical activated carbon (PSAC) was modified by chemical vapor deposition of NH 3 (NH 3-CVD) to improve the adsorption properties of uric acid. The texture and surface chemistry of PSAC were studied by N 2 adsorption, pH PZC (point of zero charge), acid-base titration and X-ray photoelectron spectroscopy (XPS). NH 3-CVD has a limited effect on carbon textural characteristics but it significantly changed the surface chemical properties, resulting in positive effects on uric acid adsorption. After modification by NH 3-CVD, large numbers of nitrogen-containing groups (especially valley-N and center-N) are introduced on the surface of PSAC, which is responsible for the increase of pH PZC, surface basicity and uric acid adsorption capacity. Pseudo-second-order kinetic model can be used to describe the dynamic adsorption of uric acid on PSAC, and the thermodynamic parameters show that the adsorption of uric acid on PSAC is spontaneous, endothermic and irreversible process in nature.

  4. Serum Uric Acid level in the severity of Congestive Heart Failure (CHF)

    PubMed Central

    khan, Adnan; Shah, Mohammad Hassan; khan, Sarbiland; Shamim, Umama; Arshad, Sanan

    2017-01-01

    Background and Objective: It has been observed that in a clinical condition like hypoxemia there is an increase in the serum Uric acid level. The objective of our study was to find out the relationship between serum uric acid levels in the severity of Heart failure. Methods: We analyze 285 patients with a diagnosis of Congestive heart failure admitted in Lady Reading Hospital Peshawar from March 1st to August 2016. Age group of patients was 17- 67 years. New York Health Association (NYHA) scoring were used to access the severity of Congestive Heart Failure. Serum UA level >7.0 mg/dl was considered high. Results: Total 285 patients with CHF were analyzed with a mean age of 54±2.8 years in which males were 65.96% and 34.03% were female. 40% were in class II of New York Health Association (NYHA), 32.63% in class III and 25.61% in class IV and 1.75% were in class I. Out of 285, 59.29% met the definition of hyperuricemia. In which 83.43% were male and 16.57% were female. Most of the Hyperuricemic patients 62.13% were in age group of 51- 60 years, with a mean age of 57±4.5 years. We found a significant correlation between uric acid level and BNP (p= <0.001), and use of diuretics (p=<0.001). 34.93% of the Hyperuricemic CHF patients were in NYHA III and NYHA IV whose SUA was above 8 mg/dl as compared to 31.57% Hyperuricemic CHF patients whose SUA was below 8 mg/dl. Conclusion: High serum Uric acid was observed in 59.29% of patients with CHF. The observed significant correlation between UA level and some established prognostic markers in these patients may indicate that serum UA could provide additional prognostic information in this population. SUA as a marker can be measured anywhere at a low cost to help identify high-risk patients with CHF. Lowing uric acid is expected to be a new approach for prevention and therapy of HF. PMID:28523032

  5. The Krebs Uric Acid Cycle: A Forgotten Krebs Cycle.

    PubMed

    Salway, Jack G

    2018-05-25

    Hans Kornberg wrote a paper entitled 'Krebs and his trinity of cycles' commenting that every school biology student knows of the Krebs cycle, but few know that Krebs discovered two other cycles. These are (i) the ornithine cycle (urea cycle), (ii) the citric acid cycle (tricarboxylic acid or TCA cycle), and (iii) the glyoxylate cycle that was described by Krebs and Kornberg. Ironically, Kornberg, codiscoverer of the 'glyoxylate cycle', overlooked a fourth Krebs cycle - (iv) the uric acid cycle. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Effects of uric acid-lowering therapy on the progression of chronic kidney disease: a systematic review and meta-analysis.

    PubMed

    Liu, Xuemei; Zhai, Tingting; Ma, Ruixia; Luo, Congjuan; Wang, Huifang; Liu, Liqiu

    2018-11-01

    Whether uric acid levels were associated with the progression of chronic kidney disease (CKD) remained controversial. This meta-analysis was aimed to assess the effect of lowering serum uric acid therapy on the progression of CKD to clarify the role of uric acid in the progression of CKD indirectly. Pubmed, Embase, the Cochrane library, CBM were searched for randomized controlled trials (RCTs) that assessed the efficiency of lowering serum uric acid therapy on the progression of CKD without language restriction. Summary estimates of weighted mean differences (WMDs) and relative risk (RR) were obtained by using random-effect or fixed-effect models. Sensitivity analyses were performed to identify the source of heterogeneity. A total of 12 randomized controlled trials with 832 CKD participants were included in the analysis. Pooled estimate for eGFR was in favor of lowering serum uric acid therapy with a mean difference (MD) of 3.88 ml/min/1.73 m 2 , 95% CI 1.26-6.49 ml/min/1.73 m 2 , p = .004 and this was consistent with results for serum creatinine. The risk of worsening of kidney function or ESRD or death was significantly decreased in the treatment group compared to the control group (RR 0.39, 95% CI 0.28-0.52, p< .01). Uric acid-lowering therapy may be effective in retarding the progression of CKD. Further randomized controlled trials should be performed to confirm the effect of lowering serum uric acid therapy on the progression of CKD.

  7. Zurampic Protects Pancreatic β-Cells from High Uric Acid Induced-Damage by Inhibiting URAT1 and Inactivating the ROS/AMPK/ERK Pathways.

    PubMed

    Xin, Ying; Wang, Kun; Jia, Zhaotong; Xu, Tao; Xu, Qiang; Zhang, Chao; Liu, Jia; Chen, Rui; Du, Zhongcai; Sun, Jianjing

    2018-05-25

    Zurampic is a US FDA approved drug for treatment of gout. However, the influence of Zurampic on pancreatic β-cells remains unclear. The study aimed to evaluate the effects of Zurampic on high uric acid-induced damage of pancreatic β-cells and the possible underlying mechanisms. INS-1 cells and primary rat islets were stimulated with Zurampic and the mRNA expression of urate transporter 1 (URAT1) was assessed by qRT-PCR. Cells were stimulated with uric acid or uric acid plus Zurampic, and cell viability, apoptosis and ROS release were measured by MTT and flow cytometry assays. Western blot analysis was performed to evaluate the expressions of active Caspase-3 and phosphorylation of AMPK and ERK. Finally, cells were stimulated with uric acid or uric acid plus Zurampic at low/high level of glucose (2.8/16.7 mM glucose), and the insulin release was assessed by ELISA. mRNA expression of URAT1 was decreased by Zurampic in a dose-dependent manner. Uric acid decreased cell viability, promoted cell apoptosis and induced ROS release. Uric acid-induced alterations could be reversed by Zurampic. Activation of Caspase-3 and phosphorylation of AMPK and ERK were enhanced by uric acid, and the enhancements were reversed by Zurampic. Decreased phosphorylation of AMPK and ERK, induced by Zurampic, was further reduced by adding inhibitor of AMPK or ERK. Besides, uric acid inhibited high glucose-induced insulin secretion and the inhibition was rescued by Zurampic. Zurampic has a protective effect on pancreatic β-cells against uric acid induced-damage by inhibiting URAT1 and inactivating the ROS/AMPK/ERK pathway. © 2018 The Author(s). Published by S. Karger AG, Basel.

  8. Serum uric acid levels contribute to new renal damage in systemic lupus erythematosus patients.

    PubMed

    Reátegui-Sokolova, C; Ugarte-Gil, Manuel F; Gamboa-Cárdenas, Rocío V; Zevallos, Francisco; Cucho-Venegas, Jorge M; Alfaro-Lozano, José L; Medina, Mariela; Rodriguez-Bellido, Zoila; Pastor-Asurza, Cesar A; Alarcón, Graciela S; Perich-Campos, Risto A

    2017-04-01

    This study aims to determine whether uric acid levels contribute to new renal damage in systemic lupus erythematosus (SLE) patients. This prospective study was conducted in consecutive patients seen since 2012. Patients had a baseline visit and follow-up visits every 6 months. Patients with ≥2 visits were included; those with end-stage renal disease (regardless of dialysis or transplantation) were excluded. Renal damage was ascertained using the SLICC/ACR damage index (SDI). Univariable and multivariable Cox-regression models were performed to determine the risk of new renal damage. Uric acid was included as a continuous and dichotomous (per receiving operating characteristic curve) variable. Multivariable models were adjusted for age at diagnosis, disease duration, socioeconomic status, SLEDAI, SDI, serum creatinine, baseline use of prednisone, antimalarials, and immunosuppressive drugs. One hundred and eighty-six patients were evaluated; their mean (SD) age at diagnosis was 36.8 (13.7) years; nearly all patients were mestizo. Disease duration was 7.7 (6.8) years. Follow-up time was 2.3 (1.1) years. The SLEDAI was 5.2 (4.3) and the SDI 0.8 (1.1). Uric acid levels were 4.5 (1.3) mg/dl. During follow-up, 16 (8.6%) patients developed at least one new point in the renal domain of the SDI. In multivariable analyses, uric acid levels (continuous and dichotomous) at baseline predicted the development of new renal damage (HR 3.21 (1.39-7.42), p 0.006; HR 18.28 (2.80-119.48), p 0.002; respectively). Higher uric acid levels contribute to the development of new renal damage in SLE patients independent of other well-known risk factors for such occurrence.

  9. Albumin, bilirubin, uric acid and cancer risk: results from a prospective population-based study.

    PubMed

    Kühn, Tilman; Sookthai, Disorn; Graf, Mirja E; Schübel, Ruth; Freisling, Heinz; Johnson, Theron; Katzke, Verena; Kaaks, Rudolf

    2017-11-07

    It has long been proposed that albumin, bilirubin and uric acid may inhibit cancer development due to their anti-oxidative properties. However, there is a lack of population-based studies on blood levels of these molecules and cancer risk. Associations between pre-diagnostic serum albumin, bilirubin and uric acid and the risks of common cancers as well as cancer death in the EPIC-Heidelberg cohort were evaluated by multivariable Cox regression analyses. A case-cohort sample including a random subcohort (n=2739) and all incident cases of breast (n=627), prostate (n=554), colorectal (n=256), and lung cancer (n=195) as well as cancer death (n=761) that occurred between baseline (1994-1998) and 2009 was used. Albumin levels were inversely associated with breast cancer risk (hazard ratio Quartile 4 vs Quartile 1 (95% CI): 0.71 (0.51, 0.99), P linear trend =0.004) and overall cancer mortality (HR Q4 vs Q1 (95% CI): 0.64 (0.48, 0.86), P linear trend <0.001) after multivariable adjustment. Uric acid levels were also inversely associated with breast cancer risk (HR Q4 vs Q1 (95% CI): 0.72 (0.53, 0.99), P linear trend =0.043) and cancer mortality (HR Q4 vs Q1 (95% CI): 0.75 (0.58, 0.98), P linear trend =0.09). There were no significant associations between albumin or uric acid and prostate, lung and colorectal cancer. Serum bilirubin was not associated with any cancer end point. The present findings indicate that higher levels of albumin and uric acid are related to lower risks of breast cancer and cancer mortality. Further studies are needed to assess whether the observed associations are causal.

  10. The association of vitamin C, alcohol, coffee, tea, milk and yogurt with uric acid and gout.

    PubMed

    Towiwat, Patapong; Li, Zhan-Guo

    2015-06-01

    About 2500 years ago, gout was observed by Hippocrates and many people suffered severe pain and deformity. Lifestyle and diet play a significant role in gout and serum uric acid levels. Epidemiological and research studies have supported this evidence. Many recommendations and guidelines from different parts of the world mention the impact of diet on gout. Recently, new research has shown associations between vitamin C, alcohol, coffee, tea, milk and yogurt with uric acid and the risk of gout. Our review summarizes recently published research regarding dietary impact on the risk of gout and serum uric acid levels. © 2015 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  11. Uric acid is released in the brain during seizure activity and increases severity of seizures in a mouse model for acute limbic seizures.

    PubMed

    Thyrion, Lisa; Raedt, Robrecht; Portelli, Jeanelle; Van Loo, Pieter; Wadman, Wytse J; Glorieux, Griet; Lambrecht, Bart N; Janssens, Sophie; Vonck, Kristl; Boon, Paul

    2016-03-01

    Recent evidence points at an important role of endogenous cell-damage induced pro-inflammatory molecules in the generation of epileptic seizures. Uric acid, under the form of monosodium urate crystals, has shown to have pro-inflammatory properties in the body, but less is known about its role in seizure generation. This study aimed to unravel the contribution of uric acid to seizure generation in a mouse model for acute limbic seizures. We measured extracellular levels of uric acid in the brain and modulated them using complementary pharmacological and genetic tools. Local extracellular uric acid levels increased three to four times during acute limbic seizures and peaked between 50 and 100 min after kainic acid infusion. Manipulating uric acid levels through administration of allopurinol or knock-out of urate oxidase significantly altered the number of generalized seizures, decreasing and increasing them by a twofold respectively. Taken together, our results consistently show that uric acid is released during limbic seizures and suggest that uric acid facilitates seizure generalization. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Double injection/single detection asymmetric flow injection manifold for spectrophotometric determination of ascorbic acid and uric acid: Selection the optimal conditions by MCDM approach based on different criteria weighting methods.

    PubMed

    Boroumand, Samira; Chamjangali, Mansour Arab; Bagherian, Ghadamali

    2017-03-05

    A simple and sensitive double injection/single detector flow injection analysis (FIA) method is proposed for the simultaneous kinetic determination of ascorbic acid (AA) and uric acid (UA). This method is based upon the difference between the rates of the AA and UA reactions with Fe 3+ in the presence of 1, 10-phenanthroline (phen). The absorbance of Fe 2+ /1, 10-phenanthroline (Fe-phen) complex obtained as the product was measured spectrophotometrically at 510nm. To reach a good accuracy in the differential kinetic determination via the mathematical manipulations of the transient signals, different criteria were considered in the selection of the optimum conditions. The multi criteria decision making (MCDM) approach was applied for the selection of the optimum conditions. The importance weights of the evaluation criteria were determined using the analytic hierarchy process, entropy method, and compromised weighting (CW). The experimental conditions (alternatives) were ranked by the technique for order preference by similarity to an ideal solution. Under the selected optimum conditions, the obtained analytical signals were linear in the ranges of 0.50-5.00 and 0.50-4.00mgL -1 for AA and UA, respectively. The 3σ detection limits were 0.07mgL -1 for AA and 0.12mgL -1 for UA. The relative standard deviations for four replicate determinations of AA and UA were 2.03% and 3.30% respectively. The method was also applied for the analysis of analytes in the blood serum, Vitamine C tablets, and tap water with satisfactory results. Copyright © 2016. Published by Elsevier B.V.

  13. Double injection/single detection asymmetric flow injection manifold for spectrophotometric determination of ascorbic acid and uric acid: Selection the optimal conditions by MCDM approach based on different criteria weighting methods

    NASA Astrophysics Data System (ADS)

    Boroumand, Samira; Chamjangali, Mansour Arab; Bagherian, Ghadamali

    2017-03-01

    A simple and sensitive double injection/single detector flow injection analysis (FIA) method is proposed for the simultaneous kinetic determination of ascorbic acid (AA) and uric acid (UA). This method is based upon the difference between the rates of the AA and UA reactions with Fe3 + in the presence of 1, 10-phenanthroline (phen). The absorbance of Fe2 +/1, 10-phenanthroline (Fe-phen) complex obtained as the product was measured spectrophotometrically at 510 nm. To reach a good accuracy in the differential kinetic determination via the mathematical manipulations of the transient signals, different criteria were considered in the selection of the optimum conditions. The multi criteria decision making (MCDM) approach was applied for the selection of the optimum conditions. The importance weights of the evaluation criteria were determined using the analytic hierarchy process, entropy method, and compromised weighting (CW). The experimental conditions (alternatives) were ranked by the technique for order preference by similarity to an ideal solution. Under the selected optimum conditions, the obtained analytical signals were linear in the ranges of 0.50-5.00 and 0.50-4.00 mg L- 1 for AA and UA, respectively. The 3σ detection limits were 0.07 mg L- 1 for AA and 0.12 mg L- 1 for UA. The relative standard deviations for four replicate determinations of AA and UA were 2.03% and 3.30% respectively. The method was also applied for the analysis of analytes in the blood serum, Vitamine C tablets, and tap water with satisfactory results.

  14. Serum uric acid concentrations in meat eaters, fish eaters, vegetarians and vegans: a cross-sectional analysis in the EPIC-Oxford cohort.

    PubMed

    Schmidt, Julie A; Crowe, Francesca L; Appleby, Paul N; Key, Timothy J; Travis, Ruth C

    2013-01-01

    Circulating concentrations of uric acid may be affected by dietary components such as meat, fish and dairy products, but only a few studies have compared uric acid concentrations among individuals who exclude some or all of these foods from their diet. The aim of this study was to investigate differences in serum uric acid concentrations between meat eaters, fish eaters, vegetarians and vegans. A sample of 670 men and 1,023 women (424 meat eaters, 425 fish eaters, 422 vegetarians and 422 vegans, matched on age and sex) from the European Prospective Investigation into Cancer and Nutrition Oxford cohort were included in this cross-sectional analysis. Diet was assessed using a semi-quantitative food frequency questionnaire and serum concentrations of uric acid were measured. Mean concentrations of uric acid by diet group were calculated after adjusting for age, body mass index, calcium and alcohol intake. In both men and women, serum uric acid concentrations differed significantly by diet group (p<0.0001 and p = 0.01, respectively). The differences between diet groups were most pronounced in men; vegans had the highest concentration (340, 95% confidence interval 329-351 µmol/l), followed by meat eaters (315, 306-324 µmol/l), fish eaters (309, 300-318 µmol/l) and vegetarians (303, 294-312 µmol/l). In women, serum uric acid concentrations were slightly higher in vegans (241, 234-247 µmol/l) than in meat eaters (237, 231-242 µmol/l) and lower in vegetarians (230, 224-236 µmol/l) and fish eaters (227, 221-233 µmol/l). Individuals consuming a vegan diet had the highest serum concentrations of uric acid compared to meat eaters, fish eaters and vegetarians, especially in men. Vegetarians and individuals who eat fish but not meat had the lowest concentrations of serum uric acid.

  15. Serum uric acid and renal function in patients with type 1 diabetes: a nationwide study in Brazil.

    PubMed

    Pizarro, Marcela Haas; Santos, Deborah Conte; Barros, Bianca Senger Vasconcelos; de Melo, Laura Gomes Nunes; Gomes, Marilia Brito

    2018-01-01

    Diabetes nephropathy is a microvascular complication associated with high morbidity and mortality in patients with type 1 diabetes, and its pathogenesis is not fully understood. Our aim was to evaluate the association between levels of serum uric acid and renal function assessed by glomerular filtration rate (GFR) and albuminuria in patients with type 1 diabetes. This is a multicenter, cross-sectional, observational study with 1686 patients, conducted between August 2011 and August 2014 in 14 public clinics from ten Brazilian cities. Renal function was estimated by CKD-EPI (adults) and by Schwartz (adolescents). We analyzed 1686 patients, aged 30.1 ± 12.0, with 15.4 ± 9.3 years of duration of diabetes; 55.8% were female and 54.0% were Caucasians. Serum uric acid was related to renal function, with a mean of 4.8 ± 1.4 (in the normal renal function group) vs 5.2 ± 2.0 (GFR ≥ 60 ml/min and albuminuria) vs 6.5 ± 2.6 mg/dl (GFR < 60 ml/min). In the pooled group, multivariate analysis showed an inverse correlation between serum uric acid and GFR (r = - 0.316, p < 0.001) with a decrease of 4.11 ml/min in the GFR for every increase of 1 mg/dl in serum uric acid. Considering only patients with normal renal function (n = 1170), a decrease of 2.04 ml/min in the GFR for every increase of 1 mg/dl in Serum uric acid was noted using multivariate analysis. Patients with higher levels of serum uric acid have worse renal function, independently of HbA1c or duration of diabetes, which persisted even in patients with normal renal function. Further prospective studies are necessary to establish if patients with higher serum uric acid may have an elevated risk for developing chronic kidney disease.

  16. Uric acid levels may be a biological marker for the differentiation of unipolar and bipolar disorder: the role of affective temperament.

    PubMed

    Kesebir, Sermin; Tatlıdil Yaylacı, Elif; Süner, Ozgür; Gültekin, Bülent Kadri

    2014-08-01

    The aim of this study was to investigate whether uric acid levels are different between patients with remission period of bipolar disorder type I (BD) and patients with remission period of major depressive disorder (MDD). For this aim 41 patients diagnosed with BD and 30 patients diagnosed with recurrent MDD according to DSM-IV who were in remission period for at least 8 weeks were evaluated consecutively. The median age and gender distribution of the two groups were similar. Subjects with comorbid psychiatric diagnosis and/or severe medical illnesses were excluded. Affective temperament was evaluated with TEMPS-A (Temperament Evaluation of Memphis, Pisa, Paris and San Diego Autoquestionnaire). Plasma uric acid levels were recorded in mg/dl. The uric acid levels of BD patients were found higher than patients with MDD and healthy controls. Additionally uric acid levels of MDD patients were lower than patients with BD and healthy subjects (F=4.183, p=0.039). A moderate correlation between hyperthymic and irritable temperament scores and uric acid levels was detected in both patient groups and in healthy controls. A negative correlation was observed between depressive temperament and uric acid levels only in MDD group. The measurements of temperament were estimated depending on the patient׳s statement. The medications that patients used were not controlled. There is a purinergic dysfunction not only in BD but also in MDD patients. High uric acid levels are associated with hyperthymic and irritable temperament scores whereas low uric acid levels are associated with depressive temperament scores. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. A double blind placebo controlled randomized trial of the effect of acute uric acid changes on inflammatory markers in humans: A pilot study

    PubMed Central

    Milaneschi, Yuri; Zhang, Yongqing; Becker, Kevin G.; Zukley, Linda; Ferrucci, Luigi

    2017-01-01

    Uric acid has been linked with increased risk of chronic disease such as cardiovascular disease and this association has been attributed to a pro-inflammatory effect. Indeed, observational studies have shown that high uric acid is associated with high level of pro-inflammatory cytokines in the blood. However, whether high uric acid directly affects inflammation or rather represents a parallel defensive antioxidant mechanism in response to pathology that causes inflammation is unknown. To determine whether acute increase or decrease uric acid levels affects inflammation in healthy individuals, a randomized, placebo-controlled, double blind clinical study of uric acid or rasburicase with 20 healthy volunteers in each treatment-placebo group was conducted at the National Institute on Aging (NIA) Clinical Research Unit (CRU) at Harbor Hospital in Baltimore, MD. Change in inflammatory response was assessed by administering an oral lipid tolerance before and after the treatment of uric acid, rasburicase and placebo. Following uric acid administration, there was an accentuated increase in IL-6 during the oral lipid tolerance test (P<0.001). No significant differences were observed after lowering of uric acid with rasburicase. No side effects were reported throughout the trial. In health individuals, acute increase in uric acid results in an increased IL-6 response when challenged with lipid load. Such effect of amplification of inflammatory response may explain the higher risk of chronic diseases observed in subclinical hyperuricemia in observational studies. Trial Registration: ClinicalTrials.gov NCT01323335 PMID:28786993

  18. [Association between urinary polycyclic aromatic hydrocarbon metabolites and elevated serum uric acid levels in coke oven workers].

    PubMed

    Deng, Siyun; Deng, Qifei; Hu, Die; Li, Jun; Zhu, Xiaoyan; Guo, Huan; Wu, Tangchun

    2014-06-01

    To analyze the relationship between metabolites of polycyclic aromatic hydrocarbons (PAHs) and serum uric acid levels in coke oven workers and to provide new clues to the pathogenic mechanism of PAHs. A total of 1302 coke oven workers were divided into four groups, namely control group and low-, intermediate-, and high-dose exposure groups. The concentrations of ambient PAHs at each workplace were determined by high-performance liquid chromatography. The detailed information on the occupational history and health of workers was collected by questionnaire survey and physical examination, and so were their blood and urine samples. Serum uric acid and creatinine levels were measured using a Hitachi 7020 automatic biochemical analyzer. Ten urinary PAH metabolites were detected by gas chromatography-mass spectrometry. Serum uric acid levels were the highest in the high-dose exposure group, followed by the intermediate- and low-dose exposure groups, and were the lowest in the control group. There were significant correlations between serum uric acid levels and the quartiles of 1-hydroxynaphthalene and 1-hydroxyphenanthrene (P < 0.05). After adjustment for PAH metabolite-related relationship, only urinary 1-hydroxyphenanthrene was significantly correlated with serum uric acid levels (P = 0.001). After adjustment for confounding factors and using the 1st quartile of 1-hydroxyphenanthrene as a reference, the odds ratio for hyperuricemia in subjects with the 2nd, 3rd, and 4th quartiles of 1-hydroxyphenanthrene were 1.55, 1.57, and 2.35, respectively. Urinary 1-hydroxyphenanthrene is associated with a dose-response increase in serum uric acid levels in coke oven workers, and exposure to phenanthrene in PAHs may be a risk factor for hyperuricemia.

  19. Effect of losartan combined with amlodipine or with a thiazide on uric acid levels in hypertensive patients.

    PubMed

    Rubio-Guerra, Alberto F; Garro-Almendaro, Ana K; Elizalde-Barrera, Cesar I; Suarez-Cuenca, Juan A; Duran-Salgado, Montserrat B

    2017-02-01

    Hyperuricemia leads to endothelial dysfunction and insulin resistance, and has been associated with diseases such as hypertension. Antihypertensive drugs modify serum uric acid levels, however, few data are available about their combinations on uricemia. In this study we evaluate the effect of two combinations of losartan, with amlodipine or with hydrochlorothiazide, on serum uric acid levels in hypertensive patients. A total of 60 hypertensive patients were randomized in two groups; group LA received losartan/amlodipine (100/5 mg) once a day, whereas LH group received losartan hydrochlorothiazide (100/12.5 mg) once a day for 3 months. In both groups serum uric acid levels were measured at the beginning and end of the study. Patients were evaluated monthly for blood pressure (BP) and adverse events. Statistical analysis was performed with a two-way analysis of variance (ANOVA) for repeated measures. All patients experienced a significant reduction of BP to the same extent (LA 155/94 to 123/79, LH 157/92 to 124/78 mmHg, p > 0.05). In the LA group, serum uric acid decreased from 6.5 ± 1.6 to 4.6 ± 1.3 mg/ml ( p = 0.0001), whereas in the LH group there was a nonsignificant increase from 5.82 ± 1.4 to 5.85 ± 1.5 mg/ml, ( p = 0.936). When both groups were compared, we found a significant reduction ( p < 0.00013) on serum uric acid levels in the LA group. Both combinations decrease BP values to the same extent, however, LA combination showed a reduction on serum uric acid levels, which may contribute to a reduction in the metabolic risk in hypertensive patients.

  20. Xanthine oxidase and uric acid as independent predictors of albuminuria in patients with diabetes mellitus type 2.

    PubMed

    Klisic, Aleksandra; Kocic, Gordana; Kavaric, Nebojsa; Jovanovic, Milovan; Stanisic, Verica; Ninic, Ana

    2018-05-01

    Xanthine oxidase (XO) is an important enzyme responsible for conversion of purine bases to uric acid and represents the major source of reactive oxygen species (ROS) production in circulation. Since pathophysiological mechanism of the relationship between XO activity and urinary albumin excretion (UAE) rate is not well elucidated, we aimed to investigate this association in patients with diabetes mellitus type 2 (DM2). In addition, we wanted to examine whether uric acid itself plays an independent role in albuminuria onset and progression, or it is only mediated through XO activity. A total of 83 patients with DM2 (of them 56.6% females) were included in this cross-sectional study. Anthropometric, biochemical parameters and blood pressure were obtained. Multivariate logistic regression analysis showed that uric acid and XO were the independent predictors for albuminuria onset in patients with DM2 [odds ratio (OR) 1.015, 95% CI (1.008-1.028), p = 0.026 and OR 1.015, 95% CI (1.006-1.026), p = 0.040, respectively]. Rise in uric acid for 1 µmol/L enhanced the probability for albuminuria by 1.5%. Also, elevation in XO activity for 1 U/L increased the probability for albuminuria for 1.5%. A total of 66.7% of variation in UAE could be explained with this Model. Both XO and uric acid are independently associated with albuminuria in diabetes. Better understanding of pathophysiological relationship between oxidative stress and albuminuria could lead to discoveries of best pharmacological treatment of XO- and/or uric acid-induced ROS, in order to prevent albuminuria onset and progression.

  1. Higher Serum Uric Acid May Contribute to Cerebral Infarction in Patients with Type 2 Diabetes Mellitus: a Meta-Analysis.

    PubMed

    Du, Lei; Ma, Jianhua; Zhang, Xiaoning

    2017-01-01

    Higher levels of serum uric acid tend to increase the diabetes-related complications. We performed a meta-analysis to investigate whether the higher serum uric acid levels were associated with cerebral infarction in type 2 diabetes patients. We searched for relevant studies in the PubMed, Embase, China National Knowledge Infrastructure, China BioMedicine, and VIP database until August 2015. All observational studies comparing serum uric acid levels in type 2 diabetic patients with and without cerebral infarction were included. We calculated the ratio of means (RoM) of serum uric acid by mean cerebral infarction /mean diabetic control from the individual studies and then pooled RoM and its 95 % confidence intervals (CI). A total of 23 eligible studies were identified. Pooled estimates indicated that type 2 diabetes patients with cerebral infarction were associated with 29 % (RoM 1.29; 95 % CI 1.26-1.31) higher serum uric acid levels than those without cerebral infarction in a random effect model. Subgroup analyses based on gender indicated that RoM was 1.23 (95 % CI 1.09-1.38) for men and 1.12 (95 % CI 0.98-1.27) for women. This meta-analysis suggests that higher serum uric acid levels may contribute to cerebral infarction in patients with type 2 diabetes.

  2. Urinary excretion of uric acid is negatively associated with albuminuria in patients with chronic kidney disease: a cross-sectional study.

    PubMed

    Li, Fengqin; Guo, Hui; Zou, Jianan; Chen, Weijun; Lu, Yijun; Zhang, Xiaoli; Fu, Chensheng; Xiao, Jing; Ye, Zhibin

    2018-04-24

    Increasing evidence has shown that albuminuria is related to serum uric acid. Little is known about whether this association may be interrelated via renal handling of uric acid. Therefore, we aim to study urinary uric acid excretion and its association with albuminuria in patients with chronic kidney disease (CKD). A cross-sectional study of 200 Chinese CKD patients recruited from department of nephrology of Huadong hospital was conducted. Levels of 24 h urinary excretion of uric acid (24-h Uur), fractional excretion of uric acid (FEur) and uric acid clearance rate (Cur) according to gender, CKD stages, hypertension and albuminuria status were compared by a multivariate analysis. Pearson and Spearman correlation and multiple regression analyses were used to study the correlation of 24-h Uur, FEur and Cur with urinary albumin to creatinine ratio (UACR). The multivariate analysis showed that 24-h Uur and Cur were lower and FEur was higher in the hypertension group, stage 3-5 CKD and macro-albuminuria group (UACR> 30 mg/mmol) than those in the normotensive group, stage 1 CKD group and the normo-albuminuria group (UACR< 3 mg/mmol) (all P < 0.05). Moreover, males had higher 24-h Uur and lower FEur than females (both P < 0.05). Multiple linear regression analysis showed that UACR was negatively associated with 24-h Uur and Cur (P = 0.021, P = 0.007, respectively), but not with FEur (P = 0.759), after adjusting for multiple confounding factors. Our findings suggested that urinary excretion of uric acid is negatively associated with albuminuria in patients with CKD. This phenomenon may help to explain the association between albuminuria and serum uric acid.

  3. Serum uric acid concentrations and SLC2A9 genetic variation in Hispanic children: the Viva La Familia Study1234

    PubMed Central

    Voruganti, V Saroja; Laston, Sandra; Haack, Karin; Mehta, Nitesh R; Cole, Shelley A; Butte, Nancy F; Comuzzie, Anthony G

    2015-01-01

    Background: Elevated concentrations of serum uric acid are associated with increased risk of gout and renal and cardiovascular diseases. Genetic studies in adults have consistently identified associations of solute carrier family 2, member 9 (SLC2A9), polymorphisms with variation in serum uric acid. However, it is not known whether the association of serum uric acid with SLC2A9 polymorphisms manifests in children. Objective: The aim was to investigate whether variation in serum uric acid is under genetic influence and whether the association with SLC2A9 polymorphisms generalizes to Hispanic children of the Viva La Familia Study. Design: We conducted a genomewide association study with 1.1 million genetic markers in 815 children. Results: We found serum uric acid to be significantly heritable [h2 ± SD = 0.45 ± 0.08, P = 5.8 × 10−11] and associated with SLC2A9 variants (P values between 10−16 and 10−7). Several of the significantly associated polymorphisms were previously identified in studies in adults. We also found positive genetic correlations between serum uric acid and BMI z score (ρG = 0.45, P = 0.002), percentage of body fat (ρG = 0.28, P = 0.04), fat mass (ρG = 0.34, P = 0.02), waist circumference (ρG = 0.42, P = 0.003), and waist-to-height ratio (ρG = 0.46, P = 0.001). Conclusions: Our results show that variation in serum uric acid in Hispanic children is under considerable genetic influence and is associated with obesity-related phenotypes. As in adults, genetic variation in SLC2A9 is associated with serum uric acid concentrations, an important biomarker of renal and cardiovascular disease risk, in Hispanic children. PMID:25833971

  4. Association between serum uric acid, metabolic syndrome and microalbuminuria in previously untreated essential hypertensive patients.

    PubMed

    Rodilla, Enrique; Pérez-Lahiguera, Francisco; Costa, José A; González, Carmen; Miralles, Amparo; Moral, Desamparados; Pascual, José María

    2009-01-17

    The aim of the study was to assess the association of serum uric acid levels with microalbuminuria -urinary albumin excretion (UAE)> or = 30mg/24h-. Cross-sectional study in 429 (220 women) hypertensive, non diabetic, never treated patients (mean age: 47 years) with glomerular filtration rate > or =60ml/min/1.73m(2). The prevalence of microalbuminuria was 20.5%; 18% had hyperuricemia and 47% fulfilled the criteria for metabolic syndrome (MS). Baseline UAE correlated in the unvaried analysis to diastolic blood pressure, waist circumference, high-density lipoprotein cholesterol and uric acid. In multiple linear regression models, only MS (beta=0.113; p=0.03), and serum uric acid values (beta=0.04; p=0.05) were independently associated with logUAE, after adjustment for age and sex. Hyperuricemia (serum uric acid level > or =7.0mg/dl for men and > or =6.5mg/dl for women; odds ratio=2.18; 95% confidence interval, 1.21-3.92; p=0.010), and MS (odds ratio=2.16; 95% confidence interval, 1.32-3.53; p=0.002) were independently associated with a higher risk of microalbuminuria in multiple logistic regression analyses. The prevalence of microalbuminuria was 45.8% in patients with coexistent MS and hyperuricemia, as compared to 13.6% in hypertensive patients without it (p<0.001). In patients with concomitant MS and hyperuricemia the probability of being microalbuminuric was 3.7 times higher than in patients without those factors. Serum uric acid level is associated with microalbuminuria. Coexistence of MS and hyperuricemia in hypertensive patients increases almost 4 times the odds of being microalbuminuric.

  5. Serum uric acid and the risk of mortality during 23 years follow-up in the Scottish Heart Health Extended Cohort Study.

    PubMed

    Juraschek, Stephen P; Tunstall-Pedoe, Hugh; Woodward, Mark

    2014-04-01

    Elevated uric acid is a prevalent condition with controversial health consequences. Observational studies disagree with regard to the relationship of uric acid with mortality, and with factors modifying this relationship. We examined the association of serum uric acid with mortality in 15,083 participants in the Scottish Heart Health Extended Cohort (SHHEC) Study. Serum uric acid was measured at study enrollment. Death was ascertained using both the Scottish death register and record linkage. During a median follow-up of 23 years, there were 3980 deaths. In Cox proportional hazards models with sexes combined, those in the highest fifth of uric acid had significantly greater mortality (HR 1.18, 95% CI: 1.06, 1.31) compared with the second fifth, after adjustment for traditional cardiovascular risk factors. This relationship was modified by sex (P-interaction=0.002) with adjusted HRs of 1.69 (95% CI: 1.40, 2.04) and 0.99 (95% CI: 0.86, 1.14) in women and men, respectively. Compared with the second fifth, the highest fifth of uric acid was most associated with kidney-related death (HR: 2.08, 95% CI: 1.31, 3.32). Elevated uric acid is associated with earlier mortality, especially in women. Future studies should evaluate mechanisms for these interactions and explore the strong association with renal-related mortality. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  6. Serum Uric Acid and the Risk of Mortality During 23 Years Follow-up in the Scottish Heart Health Extended Cohort Study

    PubMed Central

    Juraschek, Stephen P.; Tunstall-Pedoe, Hugh; Woodward, Mark

    2017-01-01

    Background Elevated uric acid is a prevalent condition with controversial health consequences. Observational studies disagree with regard to the relationship of uric acid with mortality, and with factors modifying this relationship. Objective We examined the association of serum uric acid with mortality in 15,083 participants in the Scottish Heart Health Extended Cohort (SHHEC) Study. Methods Serum uric acid measured at study enrollment. Death was ascertained using both the Scottish death register and record linkage. Results During a median follow-up of 23 years, there were 3,980 deaths. In Cox proportional hazards models with sexes combined, those in the highest fifth of uric acid had significantly greater mortality (HR 1.18, 95% CI: 1.06, 1.31) compared with the second fifth, after adjustment for traditional cardiovascular risk factors. This relationship was modified by sex (P-interaction = 0.002) with adjusted HRs of 1.69 (95% CI: 1.40, 2.04) and 0.99 (95% CI: 0.86, 1.14) in women and men, respectively. Compared with the second fifth, the highest fifth of uric acid was most associated with kidney-related death (HR: 2.08, 95% CI: 1.31, 3.32). Conclusion Elevated uric acid is associated with earlier mortality, especially in women. Future studies should evaluate mechanisms for these interactions and explore the strong association with renal-related mortality. PMID:24534458

  7. Lessons from comparative physiology: could uric acid represent a physiologic alarm signal gone awry in western society?

    PubMed Central

    Sautin, Yuri Y.; Oliver, William J.; Roncal, Carlos; Mu, Wei; Sanchez-Lozada, L. Gabriela; Rodriguez-Iturbe, Bernardo; Nakagawa, Takahiko; Benner, Steven A.

    2009-01-01

    Uric acid has historically been viewed as a purine metabolic waste product excreted by the kidney and gut that is relatively unimportant other than its penchant to crystallize in joints to cause the disease gout. In recent years, however, there has been the realization that uric acid is not biologically inert but may have a wide range of actions, including being both a pro- and anti-oxidant, a neurostimulant, and an inducer of inflammation and activator of the innate immune response. In this paper, we present the hypothesis that uric acid has a key role in the foraging response associated with starvation and fasting. We further suggest that there is a complex interplay between fructose, uric acid and vitamin C, with fructose and uric acid stimulating the foraging response and vitamin C countering this response. Finally, we suggest that the mutations in ascorbate synthesis and uricase that characterized early primate evolution were likely in response to the need to stimulate the foraging “survival” response and might have inadvertently had a role in accelerating the development of bipedal locomotion and intellectual development. Unfortunately, due to marked changes in the diet, resulting in dramatic increases in fructose- and purine-rich foods, these identical genotypic changes may be largely responsible for the epidemic of obesity, diabetes and cardiovascular disease in today’s society. PMID:18649082

  8. A double signal amplification platform for ultrasensitive and simultaneous detection of ascorbic acid, dopamine, uric acid and acetaminophen based on a nanocomposite of ferrocene thiolate stabilized Fe₃O₄@Au nanoparticles with graphene sheet.

    PubMed

    Liu, Meiling; Chen, Qiong; Lai, Cailang; Zhang, Youyu; Deng, Jianhui; Li, Haitao; Yao, Shouzhuo

    2013-10-15

    A double signal amplification platform for ultrasensitive and simultaneous detection of ascorbic acid (AA), dopamine (DA), uric acid (UA) and acetaminophen (AC) was fabricated by a nanocomposite of ferrocene thiolate stabilized Fe₃O₄@Au nanoparticles with graphene sheet. The platform was constructed by coating a newly synthesized phenylethynyl ferrocene thiolate (Fc-SAc) modified Fe₃O₄@Au NPs coupling with graphene sheet/chitosan (GS-chitosan) on a glassy carbon electrode (GCE) surface. The Fe₃O₄@Au-S-Fc/GS-chitosan modified GCE exhibits a synergistic catalytic and amplification effect toward AA, DA, UA and AC oxidation. The oxidation peak currents of the four compounds on the electrode were linearly dependent on AA, DA, UA and AC concentrations in the ranges of 4-400 μM, 0.5-50 μM, 1-300 μM and 0.3-250 μM in the individual detection of each component, respectively. By simultaneously changing the concentrations of AA, DA, UA and AC, their electrochemical oxidation peaks appeared at -0.03, 0.15, 0.24 and 0.35 V, and good linear current responses were obtained in the concentration ranges of 6-350, 0.5-50, 1-90 and 0.4-32 μM with the detection limits of 1, 0.1, 0.2 and 0.05 μM (S/N=3), respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Electrodeposited reduced graphene oxide incorporating polymerization of l-lysine on electrode surface and its application in simultaneous electrochemical determination of ascorbic acid, dopamine and uric acid.

    PubMed

    Zhang, Dongdong; Li, Lingzhi; Ma, Weina; Chen, Xia; Zhang, Yanmin

    2017-01-01

    This paper demonstrates a novel strategy for the construction of a graphene hybrid composites film, which was fabricated by electrodeposited reduced graphene oxide (ERGO) incorporating polymerization of l-lysine (PLL) onto glassy carbon electrode (GCE). Here we show that graphene films can be prepared on electrodes directly from GO dispersions by one-step electrodeposition technique based on electropolymerized PLL as a positively charged polymer interface to adsorb negatively charged GO nanosheets through electrostatic attraction. The thickness of graphene film can be easily controlled by using the electrodeposition technique, a distinct advantage over previously developed methods. The electrochemically reduced process of GO and electropolymerization of l-lysine were investigated by cyclic voltammetry with a wide potential range. The surface morphology of the modified electrode was characterized by scanning electron microscopy. The ERGO/PLL/GCE shows conducive to electron transfer kinetics for Fe(CN) 6 3- /Fe(CN) 6 4- redox probes, compared with bare GCE, PLL/GCE and ERGO/GCE. The electrochemical behaviors of ascorbic acid (AA), dopamine (DA) and uric acid (UA) at ERGO/PLL/GCE were investigated by cyclic voltammetry, and the results suggest that the modified electrode exhibits enhanced electrocatalytic activity toward these important molecules. Under physiological condition and in the co-existence system of AA, DA and UA, the ERGO/PLL/GCE showed linear voltammetric responses in the concentration of 100μM-1200μM for AA, 2.0μM-60μM for DA and 20μM-200μM for UA, and with the detection limits (S/N=3) of 2.0μM, 0.10μM and 0.15μM for AA, DA and UA, respectively. The developed method has been applied to simultaneous determination of AA, DA and UA in human urine with satisfactory recoveries of 104.2%, 95.4% and 99.9%, respectively. This work demonstrates that the attractive features of ERGO/PLL provide promising applications in simultaneous determination of AA, DA

  10. Pulse radiolytic study of the oxidation reactions of uric acid in presence of bovine serum albumin. Evidence of possible complex formation in the transient state

    NASA Astrophysics Data System (ADS)

    Adhikari, S.; Joshi, R.; Gopinathan, C.

    1997-01-01

    The pulse radiolytic and spectrophotometric study of uric acid in presence of bovine serum albumin (BSA) has been carried out. In the spectrophotometric study there is no evidence for ground state interaction between BSA and uric acid. The oxidation reactions of uric acid in presence and absence of BSA employing CCl 3OO and Br radicals have been carried out. In a composition of equal concentration of uric acid and BSA, the CCl 3OO and Br radicals produce a transient absorption spectrum which show two peaks at 330 and 360 nm. The peak at 360 nm is ascribed due to weak complex formation between semioxidised BSA and uric acid radicals. The rate constant of CCl 3OO . radical with uric acid increases with the increase in BSA concentration which is explained as protection of BSA by uric acid from radical attack. The Br radical attacks uric acid and BSA in a manner similar to CCl 3OO radical. The bimolecular rate constants for the reaction of Br radical with BSA and uric acid have been found as 2.9 × 10 10 dm 3 mol -1 s -1 and 6.33 × 10 9 dm 3 mol -1 s -, respectively.

  11. Serum uric acid level is an independent risk factor for presence of calcium in coronary arteries: an observational case-controlled study.

    PubMed

    Atar, Aslı Inci; Yılmaz, Omer Cağlar; Akın, Kayıhan; Selçoki, Yusuf; Er, Okan; Eryonucu, Beyhan

    2013-03-01

    A link between uric acid levels and cardiovascular diseases has been previously reported. Coronary artery calcium score (CACS) is a marker of atherosclerotic disease and a predictor of cardiovascular events. We sought to determine if serum uric acid level is an independent risk factor for the presence of calcium in coronary arteries. Four hundred and forty-two patients who were evaluated in the cardiology outpatient clinic for suspected coronary heart disease with a low-moderate risk for coronary artery disease were included in this observational case-controlled study. Serum uric acid levels were measured with colorimetric methods. CACS were performed using a 64-slice CT scanner. Patients were divided to 3 groups according to their CACS value (Group 1: CACS=0, Group 2: CACS 1-100, Group 3: CACS>100). The demographical characteristics and laboratory findings of 3 groups were similar, except age, fasting glucose levels and serum uric acid levels. Serum uric acid levels were found to increase significantly with increasing CACS (p=0.001). Patients were grouped according to presence CAC (CACS=0 and CACS≥1) and in the multiple regression analysis, age (OR, 1.11, 95% CI, 1.07-1.16), smoking (OR, 3.83, 95% CI, 2.06-7.09), serum uric acid levels (OR, 1.26, 95% CI, 1.04-1.54) and average 10-year total risk of Framingham risk score (OR, 1.13, 95% CI, 1.04-1.09) appeared as independent factors predictive of presence of CAC (p<0.05). Serum uric acid level is an independent risk factor for presence of coronary calcium. Moreover, increasing levels of serum uric acid are associated with increasing CACS.

  12. Uric acid levels in plasma and urine in rats chronically exposed to inorganic As (III) and As(V).

    PubMed

    Jauge, P; Del-Razo, L M

    1985-07-01

    The effect of inorganic arsenic (III) and arsenic (V) on renal excretion and plasma levels of uric acid was examined in rats. Oral administration of 1200 micrograms As/kg/day for 6 weeks diminished uric acid levels in plasma by 67.1% and 26.5% of control after the administration of As(III) and As(V), respectively. Renal excretion of uric acid was significantly reduced during the first 3 weeks following As (III) administration, with a subsequent increase to approach control values at the end of the treatment. When As(V) was administered, the diminution in renal excretion was significant at 6 weeks.

  13. Electrocatalytic simultaneous determination of ascorbic acid, uric acid and L-Cysteine in real samples using quercetin silver nanoparticles-graphene nanosheets modified glassy carbon electrode

    NASA Astrophysics Data System (ADS)

    Zare, Hamid R.; Jahangiri-Dehaghani, Fahime; Shekari, Zahra; Benvidi, Ali

    2016-07-01

    By immobilizing of quercetin at the surface of a glassy carbon electrode modified with silver nanoparticles and graphene nanosheets (Q-AgNPs-GNs-GCE) a new sensor has been fabricated. The cyclic voltammogram of Q-AgNPs-GNs-GCE shows a stable redox couple with surface confined characteristics. Q-AgNPs-GNs-GCE demonstrated a high catalytic activity for L-Cysteine (L-Cys) oxidation. Results indicated that L-Cys peak potential at Q-AgNPs-GNs-GCE shifted to less positive values compared to GNs-GCE or AgNPs-GCE. Also, the kinetic parameters such as the electron transfer coefficient,, and the heterogeneous electron transfer rate constant, k‧, for the oxidation of L-Cys at the Q-AgNPs-GNs-GCE surface were estimated. In differential pulse voltammetric determination, the detection limit of L-Cys was obtained 0.28 μM, and the calibration plots were linear within two ranges of 0.9-12.4 μM and 12.4-538.5 μM of L-Cys. Also, the proposed modified electrode is used for the simultaneous determinations of ascorbic acid (AA), uric acid (UA), and L-Cys. Finally, this study has demonstrated the practical analytical utility of the sensor for determination of AA in vitamin C tablet, L-Cys in a milk sample and UA in a human urine sample.

  14. Acute effect of fructose intake from sugar-sweetened beverages on plasma uric acid: a randomised controlled trial.

    PubMed

    Carran, E L; White, S J; Reynolds, A N; Haszard, J J; Venn, B J

    2016-09-01

    Excessive fructose intake has been linked to hyperuricaemia. Our aim was to test whether 355 and 600 ml of commercial sugar-sweetened soft drinks would acutely raise plasma uric acid. Forty-one participants were randomised to a control group or an intervention group. The control group consumed 600 ml of fructose and 600 ml of glucose beverages. The soft drink group consumed 355 and 600 ml of beverages in random order. The control beverages were matched for fructose content with 600 ml of soft drink (26.7 g). Blood samples were collected at baseline, 30 and 60 min and analysed for plasma uric acid. Plasma uric acid concentrations were 13 (95% confidence interval: (CI): 3, 23) and 17 μmol/l (95% CI: 6, 28) higher 30 and 60 min after consumption of 600 ml of soft drink compared with the glucose control. The corresponding values for the fructose beverage were 22 (95% CI: 16, 29) and 23 μmol/l (95% CI: 14, 33). There was no significant difference in the increase in uric acid following the 600-ml soft drink compared with the fructose control at 30 min (6 μmol/l; 95% CI: -4, 15) or 60 min (5 μmol/l; 95% CI: -7, 17). There was no difference in the uric-acid-raising effect between the 355 and 600 ml volumes at 30 min (-1 μmol/l; 95% CI: -9, 6) or 60 min (-5 μmol/l; 95% CI: -10, 1). Small and transient increases in plasma uric acid are likely after consumption of sucrose-sweetened commercially available single-serve soft drinks in volumes as small as 355 ml.

  15. D-tagatose, a stereoisomer of D-fructose, increases blood uric acid concentration.

    PubMed

    Buemann, B; Toubro, S; Holst, J J; Rehfeld, J F; Bibby, B M; Astrup, A

    2000-08-01

    D-Fructose has been found to increase uric acid production by accelerating the degradation of purine nucleotides, probably due to hepatocellular depletion of inorganic phosphate (Pi) by an accumulation of ketohexose-1-phosphate. The hyperuricemic effect of D-tagatose, a stereoisomer of D-fructose, may be greater than that of D-fructose, as the subsequent degradation of D-tagatose-1-phosphate is slower than the degradation of D-fructose-1-phosphate. We tested the effect of 30 g oral D-tagatose versus D-fructose on plasma uric acid and other metabolic parameters in 8 male subjects by a double-blind crossover design. Both the peak concentration and 4-hour area under the curve (AUC) of serum uric acid were significantly higher after D-tagatose compared with either 30 g D-fructose or plain water. The decline in serum Pi concentration was greater at 50 minutes after D-tagatose versus D-fructose. The thermogenic and lactacidemic responses to D-tagatose were blunted compared with D-fructose. D-Tagatose attenuated the glycemic and insulinemic responses to a meal that was consumed 255 minutes after its administration. Moreover, both fructose and D-tagatose increased plasma concentrations of cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1). The metabolic effects of D-tagatose occurred despite its putative poor absorption.

  16. Serum Uric Acid Concentrations in Meat Eaters, Fish Eaters, Vegetarians and Vegans: A Cross-Sectional Analysis in the EPIC-Oxford Cohort

    PubMed Central

    Schmidt, Julie A.; Crowe, Francesca L.; Appleby, Paul N.; Key, Timothy J.; Travis, Ruth C.

    2013-01-01

    Introduction Circulating concentrations of uric acid may be affected by dietary components such as meat, fish and dairy products, but only a few studies have compared uric acid concentrations among individuals who exclude some or all of these foods from their diet. The aim of this study was to investigate differences in serum uric acid concentrations between meat eaters, fish eaters, vegetarians and vegans. Subjects and Methods A sample of 670 men and 1,023 women (424 meat eaters, 425 fish eaters, 422 vegetarians and 422 vegans, matched on age and sex) from the European Prospective Investigation into Cancer and Nutrition Oxford cohort were included in this cross-sectional analysis. Diet was assessed using a semi-quantitative food frequency questionnaire and serum concentrations of uric acid were measured. Mean concentrations of uric acid by diet group were calculated after adjusting for age, body mass index, calcium and alcohol intake. Results In both men and women, serum uric acid concentrations differed significantly by diet group (p<0.0001 and p = 0.01, respectively). The differences between diet groups were most pronounced in men; vegans had the highest concentration (340, 95% confidence interval 329–351 µmol/l), followed by meat eaters (315, 306–324 µmol/l), fish eaters (309, 300–318 µmol/l) and vegetarians (303, 294–312 µmol/l). In women, serum uric acid concentrations were slightly higher in vegans (241, 234–247 µmol/l) than in meat eaters (237, 231–242 µmol/l) and lower in vegetarians (230, 224–236 µmol/l) and fish eaters (227, 221–233 µmol/l). Conclusion Individuals consuming a vegan diet had the highest serum concentrations of uric acid compared to meat eaters, fish eaters and vegetarians, especially in men. Vegetarians and individuals who eat fish but not meat had the lowest concentrations of serum uric acid. PMID:23418557

  17. Serum Uric Acid Level Predicts Progression of IgA Nephropathy in Females but Not in Males

    PubMed Central

    Shoji, Tatsuya; Shinzawa, Maki; Hasuike, Yukiko; Nagatoya, Katsuyuki; Yamauchi, Atsushi; Hayashi, Terumasa; Kuragano, Takayuki; Moriyama, Toshiki; Isaka, Yoshitaka; Nakanishi, Takeshi

    2016-01-01

    Background Immunoglobulin A nephropathy (IgAN) is one of most common forms of glomerulonephritis. At this point, the clinical impact of hyperuricemia on IgAN is not clear. The aim of the present study was to explore the clinical impact of hyperuricemia on the progression of IgAN. Study Design Multicenter retrospective cohort study. Setting & Participants 935 IgAN patients who were diagnosed by kidney biopsy at Osaka University Hospital, Osaka General Hospital, and Osaka Rosai Hospital. were included in this study. Predictor Uric acid levels at renal biopsy. Outcomes The outcome of interest was the time from the kidney biopsy to the time when a 50% increase in the baseline serum creatinine level was observed, which was defined as "progression". Measurements The baseline characteristics according to the kidney biopsy at the time of diagnosis were collected from the medical records, and included age, gender, body mass index, hypertension, diabetes (use of antidiabetic drugs), serum levels of creatinine, urinary protein, smoking status, RAAS blockers and steroid therapy. Results An elevated serum uric acid level was an independent risk factor for progression in female patients (per 1.0 mg/dL, multivariate-adjusted incident rate ratio 1.33 [95% confidence interval 1.07, 1.64], P = 0.008) but not in male patients (1.02 [0.81, 1.29], P = 0.855). To control a confounding effect of renal function on an association between serum uric acid level and progression in female patients, age- and serum creatinine-matched and propensity score-matched analyses were performed, and these results also supported the effect by uric acid on kidney disease progression independent of basal kidney function. Limitations A cohort analyzed retorospectively. Conclusions This study revealed that an elevated uric acid level was an independent risk factor for ESKD in female IgAN patients. Therefore, uric acid might be a treatable target in female IgAN patients. PMID:27560997

  18. Serum Uric Acid and Renal Transplantation Outcomes: At Least 3-Year Post-transplant Retrospective Multivariate Analysis

    PubMed Central

    Zhang, Kun; Gao, Baoshan; Wang, Yuantao; Wang, Gang; Wang, Weigang; Zhu, Yaxiang; Yao, Liyu; Gu, Yiming; Chen, Mo; Zhou, Honglan; Fu, Yaowen

    2015-01-01

    Since the association of serum uric acid and kidney transplant graft outcome remains disputable, we sought to evaluate the predictive value of uric acid level for graft survival/function and the factors could affect uric acid as time varies. A consecutive cohort of five hundred and seventy three recipients transplanted during January 2008 to December 2011 were recruited. Data and laboratory values of our interest were collected at 1, 3, 6, 12, 24 and 36 months post-transplant for analysis. Cox proportional hazard model, and multiple regression equation were built to adjust for the possible confounding variables and meet our goals as appropriate. The current cohort study lasts for 41.86 ± 15.49 months. Uric acid level is proven to be negatively associated with eGFR at different time point after adjustment for age, body mass index and male gender (standardized β ranges from -0.15 to -0.30 with all P<0.001).Males with low eGFR but high level of TG were on CSA, diuretics and RAS inhibitors and experienced at least one episode of acute rejection and diabetic issue were associated with a higher mean uric acid level. Hyperuricemia was significantly an independent predictor of pure graft failure (hazard ratio=4.01, 95% CI: 1.25-12.91, P=0.02) after adjustment. But it was no longer an independent risk factor for graft loss after adjustment. Interestingly, higher triglyceride level can make incidence of graft loss (hazard ratio=1.442, for each unit increase millimoles per liter 95% CI: 1.008-2.061, P=0.045) and death (hazard ratio=1.717, 95% CI: 1.105-2.665, P=0.016) more likely. The results of our study suggest that post-transplant elevated serum uric acid level is an independent predictor of long-term graft survival and graft function. Together with the high TG level impact on poor outcomes, further investigations for therapeutic effect are needed. PMID:26208103

  19. Periodic variation in bile acids controls circadian changes in uric acid via regulation of xanthine oxidase by the orphan nuclear receptor PPARα.

    PubMed

    Kanemitsu, Takumi; Tsurudome, Yuya; Kusunose, Naoki; Oda, Masayuki; Matsunaga, Naoya; Koyanagi, Satoru; Ohdo, Shigehiro

    2017-12-29

    Xanthine oxidase (XOD), also known as xanthine dehydrogenase, is a rate-limiting enzyme in purine nucleotide degradation, which produces uric acid. Uric acid concentrations in the blood and liver exhibit circadian oscillations in both humans and rodents; however, the underlying mechanisms remain unclear. Here, we demonstrate that XOD expression and enzymatic activity exhibit circadian oscillations in the mouse liver. We found that the orphan nuclear receptor peroxisome proliferator-activated receptor-α (PPARα) transcriptionally activated the mouse XOD gene and that bile acids suppressed XOD transactivation. The synthesis of bile acids is known to be under the control of the circadian clock, and we observed that the time-dependent accumulation of bile acids in hepatic cells interfered with the recruitment of the co-transcriptional activator p300 to PPARα, thereby repressing XOD expression. This time-dependent suppression of PPARα-mediated transactivation by bile acids caused an oscillation in the hepatic expression of XOD, which, in turn, led to circadian alterations in uric acid production. Finally, we also demonstrated that the anti-hyperuricemic effect of the XOD inhibitor febuxostat was enhanced by administering it at the time of day before hepatic XOD activity increased. These results suggest an underlying mechanism for the circadian alterations in uric acid production and also underscore the importance of selecting an appropriate time of day for administering XOD inhibitors. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Quantification of urinary uric acid in the presence of thymol and thimerosal by high-performance liquid chromatography

    NASA Technical Reports Server (NTRS)

    Chen, Y.; Pietrzyk, R. A.; Whitson, P. A.

    1997-01-01

    A high-performance liquid chromatographic method was developed as an alternative to automated enzymatic analysis of uric acid in human urine preserved with thymol and/or thimerosal. Uric acid (tR = 10 min) and creatinine (tR = 5 min) were separated and quantified during isocratic elution (0.025 M acetate buffer, pH 4.5) from a mu Bondapak C18 column. The uric-acid peak was identified chemically by incubating urine samples with uricase. The thymol/thimerosal peak appeared at 31 min during the washing step and did not interfere with the analysis. We validated the high-performance liquid chromatographic method for linearity, precision and accuracy, and the results were found to be excellent.

  1. Serum lipid, uric acid and glucose levels in urban black males doing manual or clerical work.

    PubMed

    Botha, J L; Irwig, L M; Joffe, B I; Mendelsohn, D; Seftel, H C

    1981-08-15

    Serum lipid, uric acid and glucose levels were measured in four groups of Black male factory workers 1 hour after an oral glucose load. These groups comprised non-obese manual, obese manual, non-obese clerical and obese clerical workers. Obese men had significantly higher serum uric acid, total cholesterol and triglyceride levels and lower high=density lipoprotein (HDL) cholesterol levels than non-obese men. Serum glucose and low-density lipoprotein (LDL) cholesterol values were also higher in obese than in non-obese men, but the differences were not significant. Clerical workers had higher levels than manual workers for most of the biochemical variables measured, but only in the case of uric acid was the difference significant. Possible reasons for the fact that the effect of occupation on the variables was slight are briefly discussed.

  2. Wearable salivary uric acid mouthguard biosensor with integrated wireless electronics.

    PubMed

    Kim, Jayoung; Imani, Somayeh; de Araujo, William R; Warchall, Julian; Valdés-Ramírez, Gabriela; Paixão, Thiago R L C; Mercier, Patrick P; Wang, Joseph

    2015-12-15

    This article demonstrates an instrumented mouthguard capable of non-invasively monitoring salivary uric acid (SUA) levels. The enzyme (uricase)-modified screen printed electrode system has been integrated onto a mouthguard platform along with anatomically-miniaturized instrumentation electronics featuring a potentiostat, microcontroller, and a Bluetooth Low Energy (BLE) transceiver. Unlike RFID-based biosensing systems, which require large proximal power sources, the developed platform enables real-time wireless transmission of the sensed information to standard smartphones, laptops, and other consumer electronics for on-demand processing, diagnostics, or storage. The mouthguard biosensor system offers high sensitivity, selectivity, and stability towards uric acid detection in human saliva, covering the concentration ranges for both healthy people and hyperuricemia patients. The new wireless mouthguard biosensor system is able to monitor SUA level in real-time and continuous fashion, and can be readily expanded to an array of sensors for different analytes to enable an attractive wearable monitoring system for diverse health and fitness applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Wearable salivary uric acid mouthguard biosensor with integrated wireless electronics

    PubMed Central

    Kim, Jayoung; Imani, Somayeh; de Araujo, William R.; Warchall, Julian; Valdés-Ramírez, Gabriela; Paixão, Thiago R.L.C.; Mercier, Patrick P.; Wang, Joseph

    2016-01-01

    This article demonstrates an instrumented mouthguard capable of non-invasively monitoring salivary uric acid (SUA) levels. The enzyme (uricase)-modified screen printed electrode system has been integrated onto a mouthguard platform along with anatomically-miniaturized instrumentation electronics featuring a potentiostat, microcontroller, and a Bluetooth Low Energy (BLE) transceiver. Unlike RFID-based biosensing systems, which require large proximal power sources, the developed platform enables real-time wireless transmission of the sensed information to standard smartphones, laptops, and other consumer electronics for on-demand processing, diagnostics, or storage. The mouthguard biosensor system offers high sensitivity, selectivity, and stability towards uric acid detection in human saliva, covering the concentration ranges for both healthy people and hyperuricemia patients. The new wireless mouthguard biosensor system is able to monitor SUA level in real-time and continuous fashion, and can be readily expanded to an array of sensors for different analytes to enable an attractive wearable monitoring system for diverse health and fitness applications. PMID:26276541

  4. Electrochemical detection of nanomolar dopamine in the presence of neurophysiological concentration of ascorbic acid and uric acid using charge-coated carbon nanotubes via facile and green preparation.

    PubMed

    Oh, Jeong-Wook; Yoon, Yeo Woon; Heo, Jihye; Yu, Joonhee; Kim, Hasuck; Kim, Tae Hyun

    2016-01-15

    Negatively charged multi-walled carbon nanotubes (MWCNTs) were prepared using simple sonication technique with non-toxic citric acid (CA) for the electrochemical detection of dopamine (DA). CA/MWCNTs were placed on glassy carbon (GC) electrodes by drop-casting method and then electrochemical determinations of DA were performed in the presence of highly concentrated ascorbic acid (AA). For the comparison of the charge effect on MWCNTs surface, positively charged polyethyleneimine (PEI)/MWCNT/GC electrode and pristine MWCNT/GC electrode were also prepared. Contrary to conventional GC electrode, all three types of MWCNT modified electrodes (CA/MWCNT/GC, PEI/MWCNT/GC, and pristine MWCNT/GC) can discriminate ~μM of DA from 1mM AA using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) due to the inherent electrocatalytic effect of MWCNTs. Compared to positively charged PEI/MWCNT/GC and pristine MWCNT/GC electrodes, negatively charged CA/MWCNT/GC electrode remarkably enhanced the electrochemical sensitivity and selectivity of DA, showing the linear relationship between DPV signal and DA concentration in the range of 10-1000nM even in the presence of ~10(5) times concentrated AA, which is attributed to the synergistic effect of the electrostatic interaction between cationic DA molecules and negatively charged MWCNTs and the inherent electrocatalytic property of MWCNT. As a result, the limit of detection (LOD) of DA for CA/MWCNT/GC electrode was 4.2nM, which is 5.2 and 16.5 times better than those for MWCNT/GC electrode and PEI/MWCNT/GC electrode even in the presence of 1mM AA. This LOD value for DA at CA/MWCNT/GC electrode is one of the lowest values compared to the previous reports and is low enough for the early diagnosis of neurological disorder in the presence of physiological AA concentration (~0.5mM). In addition, the high selectivity and sensitivity of DA at CA/MWCNT/GC electrode were well kept even in the presence of both 1mM AA and 10μM uric acid

  5. The xanthine oxidase inhibitor Febuxostat reduces tissue uric acid content and inhibits injury-induced inflammation in the liver and lung

    PubMed Central

    Kataoka, Hiroshi; Yang, Ke; Rock, Kenneth L.

    2014-01-01

    Necrotic cell death in vivo induces a robust neutrophilic inflammatory response and the resulting inflammation can cause further tissue damage and disease. Dying cells induce this inflammation by releasing pro-inflammatory intracellular components, one of which is uric acid. Cells contain high levels of intracellular uric acid, which is produced when purines are oxidized by the enzyme xanthine oxidase. Here we test whether a non-nucleoside xanthine oxidase inhibitor, Febuxostat (FBX), can reduce intracellular uric acid levels and inhibit cell death-induced inflammation in two different murine tissue injury models; acid-induced acute lung injury and acetaminophen liver injury. Infiltration of inflammatory cells induced by acid injection into lungs or peritoneal administration of acetaminophen was evaluated by quantification with flow cytometry and tissue myeloperoxidase activity in the presence or absence of FBX treatment. Uric acid levels in serum and tissue were measured before giving the stimuli and during inflammation. The impact of FBX treatment on the peritoneal inflammation caused by the microbial stimulus, zymosan, was also analyzed to see whether FBX had a broad anti-inflammatory effect. We found that FBX reduced uric acid levels in acid-injured lung tissue and inhibited acute pulmonary inflammation triggered by lung injury. Similarly, FBX reduced uric acid levels in the liver and inhibited inflammation in response to acetaminophen-induced hepatic injury. In contrast, FBX did not reduce inflammation to zymosan, and therefore is not acting as a general anti-inflammatory agent. These results point to the potential of using agents like FBX to treat cell death-induced inflammation. PMID:25449036

  6. Usefulness of dual-energy computed tomography with and without dedicated software in identifying uric acid kidney stones.

    PubMed

    Salvador, R; Luque, M P; Ciudin, A; Paño, B; Buñesch, L; Sebastia, C; Nicolau, C

    2016-01-01

    To prospectively evaluate the usefulness of dual-energy computed tomography (DECT) with and without dedicated software in identifying uric acid kidney stones in vivo. We studied 65 kidney stones in 63 patients. All stones were analyzed in vivo by DECT and ex vivo by spectrophotometry. We evaluated the diagnostic performance in identifying uric acid stones with DECT by analyzing the radiologic densities with dedicated software and without using it (through manual measurements) as well as by analyzing the attenuation ratios of the stones in both energies with and without the dedicated software. The six uric acid stones included were correctly identified by evaluating the attenuation ratios with a cutoff of 1.21, both with the dedicated software and without it, yielding perfect diagnostic performance without false positives or false negatives. The study of the attenuations of the stones obtained the following values on the receiver operating characteristic curves in the classification of the uric acid stones: 0.92 for the measurements done with the software and 0.89 for the manual measurements; a cutoff of 538 HU yielded 84% (42/50) diagnostic accuracy for the software and 83.1% (54/65) for the manual measurements. DECT enabled the uric acid stones to be identified correctly through the calculation of the ratio of the attenuations in the two energies. The results obtained with the dedicated software were similar to those obtained manually. Copyright © 2015 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  7. Associations between serum uric acid levels and the incidence of nonfatal stroke: a nationwide community-based cohort study.

    PubMed

    Kamei, Keita; Konta, Tsuneo; Hirayama, Atsushi; Ichikawa, Kazunobu; Kubota, Isao; Fujimoto, Shouichi; Iseki, Kunitoshi; Moriyama, Toshiki; Yamagata, Kunihiro; Tsuruya, Kazuhiko; Narita, Ichiei; Kondo, Masahide; Shibagaki, Yugo; Kasahara, Masato; Asahi, Koichi; Watanabe, Tsuyoshi

    2017-06-01

    Hyperuricemia is an established risk factor for cardiovascular events and mortality. This study investigated the association between serum uric acid and the incidence of nonfatal stroke in a Japanese community-based population. We used a nationwide database of 155,322 subjects (aged 40-73, male 39 %) who participated in the annual "Specific Health Check and Guidance in Japan" checkup from 2008 to 2010. We examined the relationship between the quintiles of serum uric acid levels at baseline and the incidence of nonfatal stroke during a 2-year study period using self-reported data. The crude incidence of nonfatal stroke was significantly associated with serum uric acid levels at baseline, showing the lowest values in subjects with the 3rd quintile (Q3: men, 5.0-5.6; women, 3.8-4.3) of uric acid levels (mg/dL) and the highest values in subjects with the highest quintile (Q5: men ≥7.1, women ≥5.5) both in men and women (P < 0.05). In multivariate-adjusted logistic regression analysis, the odds ratio (OR) of the Q5 group was significantly higher than for the Q3 group in both men and women [men: OR 1.26, 95 % confidence interval (CI) 1.04-1.54, women: OR 1.24, 95 % CI 1.00-1.48]. In the subgroup analysis, the OR of the Q5 group of uric acid levels for incident stroke was high, irrespective of characteristics such as age, sex, and renal function. This study has shown that serum uric acid is independently associated with the incidence of nonfatal stroke in the general Japanese population.

  8. Phase transition and epitaxies between hydrated orthorhombic and anhydrous monoclinic uric acid crystals

    NASA Astrophysics Data System (ADS)

    Boistelle, R.; Rinaudo, C.

    1981-05-01

    Anhydrous monoclinic and hydrated orthorhombic uric acid crystals can be nucleated and grown from pure water solutions either separately or together with epitaxial relationships. When crystals of one modification exist in the solution they can act as nucleation substrate for the crystals of the other modification. In both cases the new phase grows epitaxially on the substrate; the mutual orientations are the same but the contact planes are different. In addition, the anhydrous modification grows into the hydrated one which undergoes a phase transition by a dissolution-recrystallization process. It is likely that the same processes occur in human stones made up of uric acids.

  9. Simultaneous and sensitive determination of ascorbic acid, dopamine, uric acid, and tryptophan with silver nanoparticles-decorated reduced graphene oxide modified electrode.

    PubMed

    Kaur, Balwinder; Pandiyan, Thangarasu; Satpati, Biswarup; Srivastava, Rajendra

    2013-11-01

    In this paper, we report the synthesis of silver nanoparticle-decorated reduced graphene oxide composite (AgNPs/rGO) by heating the mixture of graphene oxide and silver nitrate aqueous solution in the presence of sodium hydroxide. This material was characterized by means of X-ray diffraction, UV-vis spectroscopy, and transmission electron microscopy. AgNPs/rGO based electrochemical sensor was fabricated for the simultaneous determination of ascorbic acid, dopamine, uric acid, and tryptophan. Electrochemical studies were carried out by using cyclic voltammetry, linear sweep voltammetry, and chronoamperometry. AgNPs/rGO modified electrode exhibited excellent electrocatalytic activity, stability, sensitivity, and selectivity with well-separated oxidation peaks toward ascorbic acid, dopamine, uric acid, and tryptophan in the simultaneous determination of their quaternary mixture. The analytical performance of this material as a chemical sensor was demonstrated for the determination of ascorbic acid and dopamine in commercial pharmaceutical samples such as vitamin C tablets and dopamine injections, respectively. The applicability of this sensor was also extended in the determination of uric acid in human urine samples. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Uric acid causes kidney injury through inducing fibroblast expansion, Endothelin-1 expression, and inflammation.

    PubMed

    Romi, Muhammad Mansyur; Arfian, Nur; Tranggono, Untung; Setyaningsih, Wiwit Ananda Wahyu; Sari, Dwi Cahyani Ratna

    2017-10-31

    Uric acid (UA) plays important roles in inducing renal inflammation, intra-renal vasoconstriction and renal damage. Endothelin-1 (ET-1) is a well-known profibrotic factor in the kidney and is associated with fibroblast expansion. We examined the role of hyperuricemia conditions in causing elevation of ET-1 expression and kidney injury. Hyperuricemia was induced in mice using daily intraperitoneal injection of uric acid 125 mg/Kg body weight. An NaCl injection was used in control mice. Mice were euthanized on days-7 (UA7) and 14 (UA14). We also added allopurinol groups (UAL7 and UAL14) with supplementation of allopurinol 50 mg/Kg body weight orally. Uric acid and creatinine serum were measured from blood serum. Periodic Acid Schiff (PAS) and Sirius Red staining were done for glomerulosclerosis, tubular injury and fibrosis quantification. mRNA expression examination was performed for nephrin, podocin, preproEndothelin-1 (ppET-1), MCP-1 and ICAM-1. PDGFRβ immunostaining was done for quantification of fibroblast, while α-SMA immunostaining was done for localizing myofibroblast. Western blot analysis was conducted to quantify TGF-β1, α-SMA and Endothelin A Receptor (ETAR) protein expression. Uric acid and creatinine levels were elevated after 7 and 14 days and followed by significant increase of glomerulosclerosis and tubular injury score in the uric acid group (p < 0.05 vs. control). Both UA7 and UA14 groups had higher fibrosis, tubular injury and glomerulosclerosis with significant increase of fibroblast cell number compared with control. RT-PCR revealed down-regulation of nephrin and podocin expression (p < 0.05 vs. control), and up-regulation of MCP-1, ET-1 and ICAM-1 expression (p < 0.05 vs. control). Western blot revealed higher expression of TGF-β1 and α-SMA protein expression. Determination of allopurinol attenuated kidney injury was based on reduction of fibroblast cell number, inflammation mediators and ppET-1 expression with reduction of TGF

  11. [Serum uric acid is associated with disease severity and an important predictor for clinical outcome in patients with pulmonary hypertension].

    PubMed

    Luo, D L; Zhang, C J; Huang, Y G; Huang, T; Li, H Z

    2017-06-24

    Objective: The growing body of literature showed a link between uric acid and pulmonary hypertension (PH), but the impact of hyperuremia on outcome of patients with PH has not been well defined. Therefore, the present study was performed to analyze the impact of uric acid on outcome of PH patients. Methods: One hundred seventy-three PH patients (112 females, mean age 38 years old), who were hospitalized in our department between January 2010 and December 2015, were included in our study, the PH diagnosis was made based on right heart catheterization examination result (mean pulmonary artery pressure≥25 mmHg(1 mmHg=0.133 kPa)). PH patients were divided into mild to moderate PH group (Rp/Rs≤0.6, n =97) and severe PH group (Rp/Rs>0.6, n =76). Fifty-one patients (33 females, mean age 45 years old) without PH based on right heart catheterization were included as control subjects. All participants were followed up for a median of 24 months(6-71 months). Clinical endpoints were defined as cardiogenic death or heart-and-lung transplantation. Results: Uric acid was positively correlated with pulmonary vascular resistance( r =0.398, P <0.01), systemic vascular resistance( r =0.244, P <0.01) and mean right atrial pressure ( r =0.26, P <0.01), and was negatively correlated with cardiac index( r =-0.278, P <0.01)and mixed venous oxygen saturation ( r =-0.322, P <0.01)in PH patients. Serum uric acid level was significantly higher in patients with severe PH than in patients with mild-to-moderate PH and the control subjects (both P <0.05). According to the receiver operating characteristic curve (ROC), 425.5 μmol/L was found to be the best cut-off value of serum uric acid level to predict the outcome of PH patients (sensitivity 50%, specificity 72%). During follow-up, patients with higher level of uric acid (>425.5 μmol/L) were linked with poorer clinical outcome compared to patients with uric acid <425.5 μmol/L( P =0.027). Conclusion: Our findings suggests that uric acid

  12. Randomized controlled trial of febuxostat versus allopurinol or placebo in individuals with higher urinary uric acid excretion and calcium stones.

    PubMed

    Goldfarb, David S; MacDonald, Patricia A; Gunawardhana, Lhanoo; Chefo, Solomon; McLean, Lachy

    2013-11-01

    Higher urinary uric acid excretion is a suspected risk factor for calcium oxalate stone formation. Febuxostat, a xanthine oxidoreductase inhibitor, is effective in lowering serum urate concentration and urinary uric acid excretion in healthy volunteers and people with gout. This work studied whether febuxostat, compared with allopurinol and placebo, would reduce 24-hour urinary uric acid excretion and prevent stone growth or new stone formation. In this 6-month, double-blind, multicenter, randomized controlled trial, hyperuricosuric participants with a recent history of calcium stones and one or more radio-opaque calcium stone ≥ 3 mm (as seen by multidetector computed tomography) received daily febuxostat at 80 mg, allopurinol at 300 mg, or placebo. The primary end point was percent change from baseline to month 6 in 24-hour urinary uric acid. Secondary end points included percent change from baseline to month 6 in size of index stone and change from baseline in the mean number of stones and 24-hour creatinine clearance. Of 99 enrolled participants, 86 participants completed the study. Febuxostat led to significantly greater reduction in 24-hour urinary uric acid (-58.6%) than either allopurinol (-36.4%; P=0.003) or placebo (-12.7%; P<0.001). Percent change from baseline in the size of the largest calcium stone was not different with febuxostat compared with allopurinol or placebo. There was no change in stone size, stone number, or renal function. No new safety concerns were noted for either drug. Febuxostat (80 mg) lowered 24-hour urinary uric acid significantly more than allopurinol (300 mg) in stone formers with higher urinary uric acid excretion after 6 months of treatment. There was no change in stone size or number over the 6-month period.

  13. Relationship between serum uric acid and mortality among hemodialysis patients: Retrospective analysis of Korean end-stage renal disease registry data

    PubMed Central

    Kim, Chang Seong; Jin, Dong-Chan; Yun, Young Cheol; Bae, Eun Hui; Ma, Seong Kwon; Kim, Soo Wan

    2017-01-01

    Background It is thought that hyperuricemia might lower the risk of mortality among hemodialysis patients, unlike in the general population, but the evidence is controversial. The aim of the current study was to evaluate the impact of serum uric acid level on the long-term clinical outcomes of hemodialysis patients in Korea. Methods Retrospective analysis was performed on data from the End-Stage Renal Disease Registry of the Korean Society of Nephrology. This included data for 7,333 patients (mean age, 61 ± 14 years; 61% male) who received hemodialysis from January 2001 through April 2015. Initial laboratory data were used in the analysis. Results The mean serum uric acid level in this study was 7.1 ± 1.7 mg/dL. Body mass index, normalized protein catabolic rate, albumin, and cholesterol were positively correlated with serum uric acid level after controlling for age and sex. After controlling for demographic data, comorbidities, and residual renal function, a higher uric acid level was independently associated with a significantly lower all-cause mortality (hazard ratio [HR], 0.90 per 1 mg/dL increase in uric acid level; 95% confidence interval [CI], 0.83–0.97; P = 0.008), but not cardiovascular mortality (HR, 0.90; 95% CI, 0.80–1.01; P = 0.078). Comparing uric acid levels in the highest and lowest quintiles, the HR for all-cause mortality was 0.65 (95% CI, 0.42–0.99; P = 0.046). Conclusion Hyperuricemia was strongly associated with a lower risk of all-cause mortality, but there seems to be no significant association between serum uric acid level and cardiovascular mortality among Korean hemodialysis patients with end-stage renal disease. PMID:29285429

  14. Serum uric acid concentrations and SLC2A9 genetic variation in Hispanic children: The Viva La Familia Study

    USDA-ARS?s Scientific Manuscript database

    Elevated concentrations of serum uric acid are associated with increased risk of gout and renal and cardiovascular diseases. Genetic studies in adults have consistently identified associations of solute carrier family 2, member 9 (SLC2A9), polymorphisms with variation in serum uric acid. However, it...

  15. Treatment with Uric Acid Reduces Infarct and Improves Neurologic Function in Female Mice After Transient Cerebral Ischemia.

    PubMed

    Dhanesha, Nirav; Vázquez-Rosa, Edwin; Cintrón-Pérez, Coral J; Thedens, Daniel; Kort, Alexa J; Chuong, Vicky; Rivera-Dompenciel, Adriana M; Chauhan, Anil K; Leira, Enrique C; Pieper, Andrew A

    2018-05-01

    Exogenous administration of uric acid, a naturally occurring antioxidant that scavenges reactive oxygen species in vasculature, has shown protective efficacy in both rodent models of stroke and human stroke patients in Spain as an adjuvant treatment to mechanical thrombectomy. Before clinical trials can be initiated in the United States, however, confirmation of efficacy in alternative preclinical models is required in accordance with stroke therapy academic industry roundtable-RIGOR criteria. To date, preclinical efficacy has only been established in the acute setting in male rodents. To address this need, we subjected 7- to 9-week old ovariectomized female mice to filament-induced right middle cerebral artery ischemia and reperfusion, an established preclinical model of mechanical thrombectomy. Fidelity of the procedure was monitored by laser Doppler flowmetry. A separate lab randomly assigned animals to vehicle versus uric acid infusion, which was initiated immediately after 45 minutes of reperfusion. Poststroke analysis of infarction size and neurologic function were conducted by investigators blind to treatment group, with a 7-day primary endpoint and a 3-day intermediary analysis at 1and. Infarct size and neurologic function at 7 days poststroke were significantly improved in uric acid-treated animals, relative to vehicle. Efficacy of uric acid in preclinical models of stroke is now expanded to include female mice analyzed at a later time point than has been investigated previously. These results support stroke therapy academic industry roundtable-RIGOR driven determination of the suitability of acute administration of uric acid as an adjuvant to mechanical thrombectomy in clinical trials for patients with stroke. Published by Elsevier Inc.

  16. [Clinical characteristics and renal uric acid excretion in early-onset gout patients].

    PubMed

    Li, Q H; Liang, J J; Chen, L X; Mo, Y Q; Wei, X N; Zheng, D H; Dai, L

    2018-03-01

    Objective: To investigate clinical characteristics and renal uric acid excretion in early-onset gout patients. Methods: Consecutive inpatients with primary gout were recruited between 2013 and 2017. The patients with gout onset younger than 30 were defined as early-onset group while the others were enrolled as control group. Clinical characteristics and uric acid (UA) indicators were compared between two groups. Results: Among 202 recruited patients, the early-onset group included 36 patients (17.8%). Compared with control group, the early-onset group presented more patients with obesity [13 patients (36.1%) vs. 22 patients (13.3%), P< 0.05], significantly higher serum UA level [(634±124)μmol/L vs.(527±169)μmol/L] and glomerular load of UA[(7.2±2.8)mg·min(-1)·1.73m(-2) vs. (4.4±2.2)mg·min(-1)·1.73m(-2)] and estimated glomerular filtration rate (GFR) [(83±21)ml·min(-1)·1.73m(-2) vs. (67±21)ml·min(-1)·1.73m(-2)] (all P< 0.05), lower fractional excretion of UA [4.4% (3.4%,6.1%) vs. 7.2% (5.2%,9.6%), P< 0.05], whereas 24h urinary UA excretion was comparable [(2 788±882)μmol/1.73m(2) vs. (2 645±1 140)μmol/1.73m(2), P= 0.274]. Subgroup analysis of patients without chronic kidney disease showed significantly lower fractional excretion of UA in the early-onset group [4.5%(3.3%,6.1%) vs. 6.7% (5.1%,8.7%), P< 0.05]. Logistic regression analysis showed that obesity ( OR= 3.25) and fractional excretion of UA less than 7% ( OR= 9.01, all P< 0.05) were risk factors of gout early onset. Conclusion: The gout patients with early-onset younger than 30 present high serum and glomerular load of uric acid which might be due to obesity and relative under-excretion of renal uric acid.

  17. NCCN-IPI score-independent prognostic potential of pretreatment uric acid levels for clinical outcome of diffuse large B-cell lymphoma patients

    PubMed Central

    Prochazka, Katharina T; Melchardt, Thomas; Posch, Florian; Schlick, Konstantin; Deutsch, Alexander; Beham-Schmid, Christine; Weiss, Lukas; Gary, Thomas; Neureiter, Daniel; Klieser, Eckhard; Greil, Richard; Neumeister, Peter; Egle, Alexander; Pichler, Martin

    2016-01-01

    Background: Blood-based parameters are gaining increasing interest as potential prognostic biomarkers in patients with diffuse large B-cell lymphoma (DLBCL). The aim of this study was to comprehensively evaluate the prognostic significance of pretreatment plasma uric acid levels in patients with newly diagnosed DLBCL. Methods: The clinical course of 539 DLBCL patients, diagnosed and treated between 2004 and 2013 at two Austrian high-volume centres with rituximab-based immunochemotherapy was evaluated retrospectively. The prognostic influence of uric acid on overall survival (OS) and progression-free survival (PFS) were studied including multi-state modelling, and analysis of conditional survival. Results: Five-year OS and PFS were 50.4% (95% CI: 39.2–60.6) and 44.0% (33.4–54.0) in patients with uric acid levels above the 75th percentile of the uric acid distribution (Q3, cut-off: 6.8 mg dl−1), and 66.2% (60.4–71.5) and 59.6% (53.7–65.0%) in patients with lower levels (log-rank P=0.002 and P=0.0045, respectively). In univariable time-to-event analysis, elevated uric acid levels were associated with a worse PFS (hazard ratio (HR) per 1 log increase in uric acid 1.47, 95% CI: 1.10–1.97, P=0.009) and a worse OS (HR=1.60, 95% CI: 1.16–2.19, P=0.004). These associations prevailed upon multivariable adjustment for the NCCN-IPI score. Uric acid levels significantly improved the predictive performance of the R-IPI and NCCN-IPI scores, and in multi-state analysis, it emerged as a highly significant predictor of an increased risk of death without developing recurrence (transition-HR=4.47, 95% CI: 2.17–9.23, P<0.0001). Conclusions: We demonstrate that elevated uric acid levels predict poor long-term outcomes in DLBCL patients beyond the NCCN-IPI risk index. PMID:27764838

  18. Relationship between Uric Acid Level and Achievement Motivation. Final Report.

    ERIC Educational Resources Information Center

    Mueller, Ernst F.; French, John R. P., Jr.

    In an investigation of the relationship of uric acid (a metabolic end product) to achievement, this study hypothesized that a person's serum urate level (a factor often associated with gout) is positively related to achievement need as well as indicators of actual achievement. (Speed of promotion and number of yearly publications were chosen as…

  19. Association between Serum Uric Acid Level and Carotid Atherosclerosis in Chinese Individuals Aged 75 Years or Older: A Hospital-Based Case-Control Study.

    PubMed

    Feng, L; Hua, C; Sun, H; Qin, L-Y; Niu, P-P; Guo, Z-N; Yang, Y

    2018-01-01

    To investigate the association between serum uric acid level and the presence and progression of carotid atherosclerosis in Chinese individuals aged 75 years or older. Case-control study. In a teaching hospital. Five hundred and sixty-four elderlies (75 years or above) who underwent general health screening in our hospital were enrolled. The detailed carotid ultrasound results, physical examination information, medical history, and laboratory test results including serum uric acid level were recorded, these data were used to analyze the relationship between serum uric acid level and carotid atherosclerosis. Then, subjects who underwent the second carotid ultrasound 1.5-2 years later were further identified to analyzed the relationship between serum uric acid and the progression of carotid atherosclerosis. A total of 564 subjects were included, carotid plaque was found in 482 (85.5%) individuals. Logistic regression showed that subjects with elevated serum uric acid (expressed per 1 standard deviation change) had significantly higher incidence of carotid plaque (odds ratio, 1.37; 95% confidence interval, 1.07-1.75; P= 0.012) after controlling for other factors. A total of 236 subjects underwent the follow-up carotid ultrasound. Linear regression showed that serum uric acid level (expressed per 1 standard deviation change; 1 standard deviation = 95.5 μmol/L) was significantly associated with percentage of change of plaque score (P = 0.008). Multivariable linear regression showed that 1 standard deviation increase in serum uric acid levels was expected to increase 0.448% of plaque score (P = 0.023). The elevated serum uric acid level may be independently and significantly associated with the presence and progression of carotid atherosclerosis in Chinese individuals aged 75 years or older.

  20. Urea, Uric Acid, Prolactin and fT4 Concentrations in Aqueous Humor of Keratoconus Patients.

    PubMed

    Stachon, Tanja; Stachon, Axel; Hartmann, Ulrike; Seitz, Berthold; Langenbucher, Achim; Szentmáry, Nóra

    2017-06-01

    Keratoconus is a noninflammatory disease of the cornea associated with progressive thinning and conical shape. Metabolic alterations in the urea cycle, with changes in collagen fibril stability, oxidative stress, thyroid hormones and prolactin with regulatory effect on biosynthesis and biomechanical stability of corneal stroma, may all play a role in keratoconus etiology. Our purpose was to determine urea, uric acid, prolactin and free thyroxin (fT4) concentrations in human aqueous humor (hAH) of keratoconus and cataract patients. hAH was collected from 100 keratoconus (penetrating keratoplasty) (41.9 ± 14.9 years, 69 males) and 100 cataract patients (cataract surgery) (71.2 ± 12.4 years, 58 males). Urea, uric acid, prolactin and fT4 concentrations were measured by Siemens clinical chemistry or immunoassay system. For statistical analysis, a generalized linear model (GLM) was used. Urea concentration was 11.88 ± 3.03 mg/dl in keratoconus and 16.44 ± 6.40 mg/dl in cataract patients, uric acid 2.04 ± 0.59 mg/dl in keratoconus and 2.18 ± 0.73 mg/dl in cataract groups. Prolactin concentration was 3.18 ± 0.34 ng/ml in keratoconus and 3.33 ± 0.32 ng/ml in cataract patients, fT4 20.57 ± 4.76 pmol/l in KC and 19.06 ± 3.86 pmol/l in cataract group. Urea concentration was effected through gender (p = 0.039), age (p = 0.001) and diagnosis (p = 0.025). Uric acid concentration was not effected through any of the analyzed parameters (p > 0.056). Prolactin and fT4 concentration were effected only through diagnosis (p = 0.009 and p = 0.006). Urea and prolactin concentrations are decreased, fT4 concentration is increased in aqueous humor of keratoconus patients, and uric acid concentration remains unchanged. Urea concentration in aqueous humor is also increased in older and male patients. Therefore, metabolic disorder and hormonal balance may both have an impact on keratoconus development. Further studies are necessary to assess the specific impact.

  1. Effects of Uric Acid on the Alterations of White Matter Connectivity in Patients with Major Depression.

    PubMed

    Sohn, Hoyoung; Kwon, Min-Soo; Lee, Sun-Woo; Oh, Jongsoo; Kim, Min-Kyoung; Lee, Sang-Hyuk; Lee, Kang Soo; Kim, Borah

    2018-06-07

    Uric acid is a non-enzymatic antioxidant associated with depression. Despite its known protective role in other brain disorders, little is known about its influence on the structural characteristics of brains of patients with major depressive disorder (MDD). This study explored the association between uric acid and characteristics of white matter (WM) in patients with MDD. A total of 32 patients with MDD and 23 healthy controls (HCs) were examined. All participants were scored based on the Beck Depression Inventory and Beck Anxiety Inventory at baseline. All patients were also rated with the Hamilton Depression Rating Scale. We collected blood samples from all participants immediately after their enrollment and before the initiation of antidepressants in case of patients. Tract-based spatial statistics were used for all imaging analyses. Lower fractional anisotropy (FA) and higher radial diffusivity (RD) values were found in the MDD group than in the HC group. Voxelwise correlation analysis revealed that the serum uric acid levels positively correlated with the FA and negatively with the RD in WM regions that previously showed significant group differences in the MDD group. The correlated areas were located in the left anterior corona radiata, left frontal lobe WM, and left anterior cingulate cortex WM. The present study suggests a significant association between altered WM connectivity and serum uric acid levels in patients with MDD, possibly through demyelination.

  2. Very fast electrophoretic determination of creatinine and uric acid in human urine using a combination of two capillaries with different internal diameters.

    PubMed

    Pavlíček, Václav; Tůma, Petr; Matějčková, Jana; Samcová, Eva

    2014-04-01

    A capillary system formed by combining 25 and 100 μm id capillaries was used in the short-end injection mode to determine creatinine and uric acid in human urine. The separation was performed at an electric field intensity of 2.3 kV/cm. Creatinine was determined in a BGE with a composition of 20 mM citric acid/NaOH (pH 3.0), and uric acid was determined in 20 mM MES/NaOH (pH 6.0). Under these conditions, migration times of 12.2 s for creatinine and 8.6 s for uric acid were achieved. The LOD value is 2.4 mg/L for creatinine and 0.9 mg/L for uric acid; the RSD for the migration time varies in the range 0.7-1.1% (intra day) to 1.0-7.5% (inter day); RSDs for the peak areas equalled 3.4-4.0% (intra day) and 4.3-4.7% (inter day). The determined creatinine values in seven urine samples vary in the range 221-1394 mg/L for creatinine and 87-615 mg/L for uric acid. t-Test did not reveal any statistically significant difference between the developed CE methodologies and reference methods - Jaffé reaction for creatinine and enzymatic uricase test for uric acid. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Long-term effects of L- and N-type calcium channel blocker on uric acid levels and left atrial volume in hypertensive patients.

    PubMed

    Masaki, Mitsuru; Mano, Toshiaki; Eguchi, Akiyo; Fujiwara, Shohei; Sugahara, Masataka; Hirotani, Shinichi; Tsujino, Takeshi; Komamura, Kazuo; Koshiba, Masahiro; Masuyama, Tohru

    2016-11-01

    Left ventricular (LV) diastolic dysfunction is associated with hypertension and hyperuricemia. However, it is not clear whether the L- and N-type calcium channel blocker will improve LV diastolic dysfunction through the reduction of uric acid. The aim of this study was to investigate the effects of anti-hypertensive therapy, the L- and N-type calcium channel blocker, cilnidipine or the L-type calcium channel blocker, amlodipine, on left atrial reverse remodeling and uric acid in hypertensive patients. We studied 62 patients with untreated hypertension, randomly assigned to cilnidipine or amlodipine for 48 weeks. LV diastolic function was assessed with the left atrial volume index (LAVI), mitral early diastolic wave (E), tissue Doppler early diastolic velocity (E') and the ratio (E/E'). Serum uric acid levels were measured before and after treatment. After treatment, systolic and diastolic blood pressures equally dropped in both groups. LAVI, E/E', heart rate and uric acid levels decreased at 48 weeks in the cilnidipine group but not in the amlodipine group. The % change from baseline to 48 weeks in LAVI, E wave, E/E' and uric acid levels were significantly lower in the cilnidipine group than in the amlodipine group. Larger %-drop in uric acid levels were associated with larger %-reduction of LAVI (p < 0.01). L- and N-type calcium channel blocker but not L-type calcium channel blocker may improve LV diastolic function in hypertensive patients, at least partially through the decrease in uric acid levels.

  4. Colloidal silver nanoparticles prepared by UV-light induced citrate reduction technique for the quantitative detection of uric acid

    NASA Astrophysics Data System (ADS)

    Maity, Anupam; Panda, Sovan Kumar

    2018-04-01

    Reddish-yellow color colloid consisting of silver nanoparticles (Ag NPs) has been synthesized by reducing aqueous AgNO3 solution by photo-induced citrate reduction technique under UV light. As prepared colloid exhibits single and intense plasmonic absorption peak in the violet region of the visible spectra with the peak centered at 405 nm. The NPs are fine and spherical with diameter ranging from 5 to 10 nm. These colloidal NPs have been used for the quantitative detection of uric acid by UV-VIS spectroscopy. A linear red shifting of the characteristics Plasmonic absorption peak of Ag NPs is observed with uric acid concentration. Uric acid can be detected by UV-VIS spectroscopy down to 5 nM limit using the prepared colloid.

  5. Does the serum uric acid level have any relation to arterial stiffness or blood pressure in adults with congenital renal agenesis and/or hypoplasia?

    PubMed

    Yazici, Raziye; Guney, İbrahim; Altintepe, Lutfullah; Yazici, Mehmet

    2017-01-01

    The relationship between serum uric acid and arterial stiffness or blood pressure is not clear. The serum uric acid level and its association with cardiovascular risk is not well known in patients with reduced renal mass. We aimed to investigate the relation between serum uric acid levels and arterial stiffness and also blood pressure in patients with congenital renal agenesis and/or hypoplasia. In this single center, cross-sectional study, a total of 55 patients (39 (% 70.9) with unilateral small kidney and 16 (%29.1) with renal agenesis) were included. The median age was 35 (21-50) years. The study population was divided into tertiles of serum uric acid (according to 2.40-3.96, 3.97-5.10, and 5.11-9.80 mg/dl cut-off values of serum uric acid levels). Official and 24-h ambulatory non-invasive blood pressures of all patients were measured. The arterial stiffness was assessed by pulse wave velocity (PWV). PWV values were increased from first to third tertile (5.5 ± 0.6, 5.7 ± 0.8, 6.1 ± 0.7, respectively), but this gradual increase between tertiles did not reach significance. Linear regression analyses showed a positive correlation between serum uric acid levels and PWV (β = 0.40, p = 0.010), but no correlation was found between uric acid and daytime systolic blood pressure (β = 0.24, p = 0.345). In congenital renal agenesis/hypoplasia, the serum uric acid level was positively correlated with arterial stiffness, but there was no correlation with blood pressure.

  6. The association between serum uric acid and the incidence of prediabetes and type 2 diabetes mellitus: The Rotterdam Study.

    PubMed

    van der Schaft, Niels; Brahimaj, Adela; Wen, Ke-Xin; Franco, Oscar H; Dehghan, Abbas

    2017-01-01

    Limited evidence is available about the association between serum uric acid and sub-stages of the spectrum from normoglycaemia to type 2 diabetes mellitus. We aimed to investigate the association between serum uric acid and risk of prediabetes and type 2 diabetes mellitus. Eligible participants of the Rotterdam Study (n = 8,367) were classified into mutually exclusive subgroups of normoglycaemia (n = 7,030) and prediabetes (n = 1,337) at baseline. These subgroups were followed up for incident prediabetes (n = 1,071) and incident type 2 diabetes mellitus (n = 407), respectively. We used Cox proportional hazard models to determine hazard ratios (HRs) for incident prediabetes among individuals with normoglycaemia and incident type 2 diabetes mellitus among individuals with prediabetes. The mean duration of follow-up was 7.5 years for incident prediabetes and 7.2 years for incident type 2 diabetes mellitus. A standard deviation increment in serum uric acid was significantly associated with incident prediabetes among individuals with normoglycaemia (HR 1.10, 95% confidence interval (CI) 1.01; 1.18), but not with incident type 2 diabetes mellitus among individuals with prediabetes (HR 1.07, 95% CI 0.94; 1.21). Exclusion of individuals who used diuretics or individuals with hypertension did not change our results. Serum uric acid was significantly associated with incident prediabetes among normoglycaemic women (HR 1.13, 95% CI 1.02; 1.25) but not among normoglycaemic men (HR 1.08, 95% CI 0.96; 1.21). In contrast, serum uric acid was significantly associated with incident type 2 diabetes mellitus among prediabetic men (HR 1.23, 95% CI 1.01; 1.48) but not among prediabetic women (HR 1.00, 95% CI 0.84; 1.19). Our findings agree with the notion that serum uric acid is more closely related to early-phase mechanisms in the development of type 2 diabetes mellitus than late-phase mechanisms.

  7. Serum uric acid level as a cardio-cerebrovascular event risk factor in middle-aged and non-obese Chinese men.

    PubMed

    Li, Zhi-Jun; Yi, Chen-Ju; Li, Jing; Tang, Na

    2017-04-11

    The role of uric acid as a risk factor for cardio-cerebrovascular diseases is controversial. In this study, we aimed to investigate the relationship between serum uric acid level and the risk of cardio-cerebrovascular events in middle-aged and non-obese Chinese men. We included 3152 participants from the health examination center of Tongji Hospital from June 2007 to June 2010. Clinical examination and medical records were collected at the annual health examination. The hazard ratios (HRs) of uric acid for cardio-cerebrovascular events were calculated by Cox proportional hazards models. Generalized additive model and threshold effect analysis were used to explore the non-linear relationship between serum uric acid level and the incidence of cardio-cerebrovascular event. The mean follow-up time was 52 months. When the participants were classified into four groups by the serum acid quarter (Q1-Q4), the HRs (95% CI) of Q2-Q4 for cardio-cerebrovascular events were 1.26 (0.83, 1.92), 1.97 (1.33, 2.91) and 2.05 (1.40, 3.01), respectively, compared with the reference (Q1). The actual incidence and conditional incidence of cardio-cerebrovascular events in the high serum acid group were higher than those in the low serum acid group, which were stratified by the turning point (sUA = 372 μmol/L). We also showed a strong prognostic accuracy of the multiple variable-based score in 3 years and 5 years, with area under the receiver operating characteristic (ROC) curve of 0.790 (0.756-0.823) and 0.777 (0.749-0.804), respectively. Serum uric acid level is a strong risk factor for cardio-cerebrovascular events.

  8. Glassy carbon electrodes sequentially modified by cysteamine-capped gold nanoparticles and poly(amidoamine) dendrimers generation 4.5 for detecting uric acid in human serum without ascorbic acid interference.

    PubMed

    Ramírez-Segovia, A S; Banda-Alemán, J A; Gutiérrez-Granados, S; Rodríguez, A; Rodríguez, F J; Godínez, Luis A; Bustos, E; Manríquez, J

    2014-02-17

    Glassy carbon electrodes (GCE) were sequentially modified by cysteamine-capped gold nanoparticles (AuNp@cysteamine) and PAMAM dendrimers generation 4.5 bearing 128-COOH peripheral groups (GCE/AuNp@cysteamine/PAMAM), in order to explore their capabilities as electrochemical detectors of uric acid (UA) in human serum samples at pH 2. The results showed that concentrations of UA detected by cyclic voltammetry with GCE/AuNp@cysteamine/PAMAM were comparable (deviation <±10%; limits of detection (LOD) and quantification (LOQ) were 1.7×10(-4) and 5.8×10(-4) mg dL(-1), respectively) to those concentrations obtained using the uricase-based enzymatic-colorimetric method. It was also observed that the presence of dendrimers in the GCE/AuNp@cysteamine/PAMAM system minimizes ascorbic acid (AA) interference during UA oxidation, thus improving the electrocatalytic activity of the gold nanoparticles. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Low sensitivity for the metabolic syndrome to detect uric acid elevations in females and non-Hispanic-black male adolescents: an analysis of NHANES 1999-2006.

    PubMed

    DeBoer, Mark D; Gurka, Matthew J

    2012-02-01

    Uric acid is tightly linked to the metabolic syndrome (MetS) and among adults higher uric acid levels are associated with future risk for diabetes, cardiovascular disease, hypertension and renal disease. Evaluate the sensitivity of MetS to identify adolescents with elevated uric acid levels on a race/ethnicity and gender-specific basis. We evaluated 3296 male and female adolescents 12-19 y participating in the National Health and Nutrition Evaluation Survey 1999-06, comprised of 67.6% non-Hispanic whites, 15.1% non-Hispanic blacks, and 17.3% Hispanics. We used a definition of MetS modified for use in adolescents and evaluated the sensitivity of a diagnosis of MetS to identify individuals with uric acid elevations (approximately the 95th percentile of uric acid by gender among normal-weight adolescents). When used as a screening test to identify individuals with uric acid elevations MetS performed more poorly among females (18.0%) than among males (37.0%) (p<0.001). Among males, MetS exhibited a lower sensitivity among non-Hispanic blacks (17.8%) compared to Hispanics (45.9%) (p<0.01) and non-Hispanic whites (37.4%) (p<0.05). There were no race/ethnicity differences in detecting elevated uric acid levels among females (non-Hispanic-white 15.5%, non-Hispanic-black 19.4%, Hispanic 26.5%, p>0.05). Current criteria to diagnose MetS exhibit racial/ethnic and gender differences in the ability to identify adolescents with elevated uric acid levels, performing poorly among non-Hispanic-black males and among females. Given emerging data regarding the ability of uric acid elevations for predicting future disease, these data may have implications regarding the use of MetS as a marker of risk among all gender and racial/ethnic groups. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  10. Investigation on uric acid biosensor model for enzyme layer thickness for the application of arthritis disease diagnosis.

    PubMed

    Parthasarathy, P; Vivekanandan, S

    2018-12-01

    Uric acid biosensors for arthritis disease has been developed for the specific selection of uricase enzyme film thickness coated over the TiO 2 -CeO 2 nano-composite matrix is modelled mathematically. This model is purely based on R-diffusion conditions with irreversible first-order catalytic reactions. By arithmetical method, the impact of the thickness of enzyme layer on the current response of the biosensor was explored. This article displays a structure for choice of the enzyme layer thickness, guaranteeing the adequately stable sensitivity of a biosensor in a required extent of the maximal enzymatic rate. The numerical outcomes showed subjective and sensible quantitative information for oxidation current due to uric acid also shows the maximum change in the biosensor current response due to the change in membrane thickness, which will be more suitable for uric acid biosensor for the application of arthritis disease diagnosis.

  11. Association between blood pressure and magnesium and uric acid levels in indigenous Argentinean children at high altitude.

    PubMed

    Hirschler, Valeria; González, Claudio; Maccallini, Gustavo; Molinari, Claudia; Castano, Luis

    2017-07-08

    To determine the association between nontraditional risk factors such as magnesium and uric acid with blood pressure (BP) in Indigenous children. A total of 263 school-aged indigenous children living at high altitude were enrolled in a cross-sectional study in November 2011. Prehypertension (preHTN) and hypertension (HTN) were defined by systolic and/or diastolic BP ≥ 90th to <95th percentile or ≥95th percentile respectively, according to age, sex, and height. The prevalence of preHTN and HTN was 13.7 and 8.3%, respectively. Low magnesium levels were identified in 21.7% (57/263): 28.1% (16/57) of the children with low magnesium levels had preHTN versus 9.7% (20/206) with normal magnesium values. Furthermore, 21.8% (12/57) of the children with low magnesium levels had HTN versus 4.5% (20/206) with normal magnesium values. There was a significant association between mean arterial pressure and magnesium (r = -026), uric acid (r = 0.20), phosphorus (r = -0.17), z-BMI (r = 0.22), potassium (r = -0.10), HOMA-IR (r = 0.17), calcium (r = -0.10), and sodium (r = -0.13). Multiple linear regression analysis showed that mean arterial pressure was associated significantly and directly with BMI, age, gender, and uric acid; and inversely with magnesium, adjusted for sodium, calcium, phosphorus, potassium, and HOMA-IR (R 2  = 0.43). Furthermore, multiple logistic regression analyses showed that magnesium (OR = 0.015) and uric acid (OR = 2.95) were significantly associated with preHTN. Similar results were obtained when preHTN was replaced by HTN. Our results indicate that HTN was associated inversely with magnesium and positively with uric acid in indigenous school children. © 2017 Wiley Periodicals, Inc.

  12. Acupuncture for serum uric acid in patients with asymptomatic hyperuricemia: A randomized, double-blind, placebo-controlled trial.

    PubMed

    Huang, Yingjuan; Meng, Jun; Sun, Baoguo; Xiang, Ting; Zhou, Xin; Xu, Biyu; Wu, Yingzi; Chen, Zexiong; Zhang, Shijun

    2017-04-01

    Hyperuricemia (HUA) is the most common disease associated with cardiovascular disease, metabolic syndrome, hypertension, and kidney disease. The objective of the current study was to evaluate the preliminary efficacy, mechanism, and safety of acupuncture on serum uric acid in patients with asymptomatic HUA. A randomized, placebo-controlled trial among 123 patients with asymptomatic HUA was conducted. The acupoints used in the acupuncture group were bilateral Five Shu in Spleen Meridian. Each participant received the intervention once daily for 10 consecutive days. The sham group received the same treatment duration on the same acupoints by the Park Sham Device. All patients underwent measurements of serum or urine creatinine, uric acid, serum lipid profiles, fasting plasma glucose, HbA1c, xanthine oxidase (XOD) and urate-anion exchanger (URAT-1). At the end of the intervention, the individuals in the acupuncture group were found to have significantly less levels of serum uric acid than those in the sham group [(453±65 vs. 528±81) μmol/L, p<0.01]. Acupuncture was effective on increasing the urine uric acid level, urine pH value and 24-hour urine volume than the sham treatment (p<0.05 for all). Interestingly, acupuncture significantly decreased the level of URAT-1 (p<0.01) but not XOD than that of the sham intervention. The adverse events were that 3 patients experienced severe pain. Acupuncture on Five Shu in Spleen Meridian appeared to be safe and efficacious for decreasing serum uric acid in a Chinese HUA patient population. The mechanism might be associated with the decrease level of enzyme URAT-1. ChiCTR-TRC-13004122. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Uric acid in aortic dissection: A meta-analysis.

    PubMed

    Li, Xiaodong; Jiang, Shanshan; He, Jiaan; Li, Nan; Fan, Yichuan; Zhao, Xingzhi; Hu, Xinhua

    2018-06-04

    Studies on the serum uric acid levels in patients with aortic dissection have yielded conflicting results. To compare the difference in serum uric acid (SUA) levels between aortic dissection patients and controls by meta-analysis. Electronic literature search was conducted in PubMed, Embase, CKNI, CBM, Wanfang, and VIP databases until January 31, 2018. All observational studies that investigated SUA levels in aortic dissection patients and controls were included. Weighted mean difference (WMD) with 95% confidence intervals (CI) was used to summarize the difference in SUA levels between aortic dissection and control group. A total of seven case-control studies involving 1197 patients and 1193 controls were included. Pooled analysis showed that SUA levels were significantly higher in aortic dissection patients compared with those in the controls (WMD 58.22 μmol/L; 95% CI 26.71-89.73) in a random effect model. No significant difference (WMD 9.94 μmol/L; 95% CI -17.89-37.76) was observed in SUA levels between Stanford type A and Stanford type B aortic dissection. This meta-analysis provides evidence that SUA levels are significantly higher among patients with aortic dissection than those in controls. Elevated SUA levels may contribute to the pathogenesis of aortic dissection. Further large clinical studies to investigate whether SUA levels are an independently risk factor for aortic dissection are warranted. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Bimetallic-organic framework derived porous Co3O4/Fe3O4/C-loaded g-C3N4 nanocomposites as non-enzymic electrocatalysis oxidization toward ascorbic acid, dopamine acid, and uric acid

    NASA Astrophysics Data System (ADS)

    Hu, Bin; Liu, Yongkang; Wang, Zhuo-Wei; Song, Yingpan; Wang, Minghua; Zhang, Zhihong; Liu, Chun-Sen

    2018-05-01

    We report on the synthesis of Co- and Fe-based bimetallic nanocatalysts embedded in mesoporous carbon and g-C3N4 nanosheets (denoted as Co3O4/Fe3O4/mC@g-C3N4) for selectively simultaneous determination of ascorbic acid (AA), dopamine acid (DA), and uric acid (UA). These electrocatalysts consisting of bimetallic Co-Fe alloy nanoparticles encapsulated in N-doped carbon matrix were prepared via pyrolysis of Co/Fe-MOFs after grinding with high amounts of melamine. Chemical/crystal structures suggest high contents of mesoporous carbon in calcinated Co3O4/Fe3O4/mC nanocomposites, which exhibited enhanced electrocatalytic activity toward small biomolecules. The intrinsic performances of Co/Fe-MOFs with large specific surface area and regular nodes in the two-dimensional nanostructured g-C3N4 nanosheets endowed the as-prepared series of Co3O4/Fe3O4/mC@g-C3N4 nanocomposites with remarkable electrocatalytic activities and high adsorption ability toward oxidation of AA, DA, and UA. The developed biosensors also showed long-term stability and high selectivity for targeted analytes, with satisfactory results on actual samples in human urine. The results indicate that the as-synthesized Co3O4/Fe3O4/mC@g-C3N4 nanostructure exhibits good electrocatalytic activity and potential applications in clinical diagnosis and biosensing.

  15. 3-D periodic mesoporous nickel oxide for nonenzymatic uric acid sensors with improved sensitivity

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Cao, Yang; Chen, Yong; Zhou, Yang; Huang, Qingyou

    2015-12-01

    3-D periodic mesoporous nickel oxide (NiO) particles with crystalline walls have been synthesized through the microwave-assisted hard template route toward the KIT-6 silica. It was investigated as a nonenzymatic amperometric sensor for the detection of uric acid. 3-D periodic nickel oxide matrix has been obtained by the hard template route from the KIT-6 silica template. The crystalline nickel oxide belonged to the Ia3d space group, and its structure was characterized by X-ray diffraction (XRD), N2 adsorption-desorption, and transmission electron microscopy (TEM). The analysis results showed that the microwave-assisted mesoporous NiO materials were more appropriate to be electrochemical sensors than the traditional mesoporous NiO. Cyclic voltammetry (CV) revealed that 3-D periodic NiO exhibited a direct electrocatalytic activity for the oxidation of uric acid in sodium hydroxide solution. The enzyme-less amperometric sensor used in the detection of uric acid with detection limit of 0.005 μM (S/N = 3) over wide linear detection ranges up to 0.374 mM and with a high sensitivity of 756.26 μA mM-1 cm-2, and a possible mechanism was also given in the paper.

  16. Tubular urate transporter gene polymorphisms differentiate patients with gout who have normal and decreased urinary uric acid excretion.

    PubMed

    Torres, Rosa J; de Miguel, Eugenio; Bailén, Rebeca; Banegas, José R; Puig, Juan G

    2014-09-01

    Primary gout has been associated with single-nucleotide polymorphisms (SNP) in several tubular urate transporter genes. No study has assessed the association of reabsorption and secretion urate transporter gene SNP with gout in a single cohort of documented primary patients with gout carefully subclassified as normoexcretors or underexcretors. Three reabsorption SNP (SLC22A12/URAT1, SLC2A9/GLUT9, and SLC22A11/OAT4) and 2 secretion transporter SNP (SLC17A1/NPT1 and ABCG2/BRCP) were studied in 104 patients with primary gout and in 300 control subjects. The patients were subclassified into normoexcretors and underexcretors according to their serum and 24-h urinary uric acid levels under strict conditions of dietary control. Compared with control subjects, patients with gout showed different allele distributions of the 5 SNP analyzed. However, the diagnosis of underexcretor was only positively associated with the presence of the T allele of URAT1 rs11231825, the G allele of GLUT9 rs16890979, and the A allele of ABCG2 rs2231142. The association of the A allele of ABCG2 rs2231142 in normoexcretors was 10 times higher than in underexcretors. The C allele of NPT1 rs1165196 was only significantly associated with gout in patients with normal uric acid excretion. Gout with uric acid underexcretion is associated with transporter gene SNP related mainly to tubular reabsorption, whereas uric acid normoexcretion is associated only with tubular secretion SNP. This finding supports the concept of distinctive mechanisms to account for hyperuricemia in patients with gout with reduced or normal uric acid excretion.

  17. Uric acid stimulates proliferative pathways in vascular smooth muscle cells through the activation of p38 MAPK, p44/42 MAPK and PDGFRβ.

    PubMed

    Kırça, M; Oğuz, N; Çetin, A; Uzuner, F; Yeşilkaya, A

    2017-04-01

    Hyperuricemia and angiotensin II (Ang II) may have a pathogenetic role in the development of hypertension and atherosclerosis as well as cardiovascular disease (CVD) and its prognosis. The purpose of this study was to investigate whether uric acid can induce proliferative pathways of vascular smooth muscle cell (VSMC) that are thought to be responsible for the development of CVD. The phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK), p44/42 mitogen-activated protein kinase (p44/42 MAPK) and platelet-derived growth factor receptor β (PDGFRβ) was measured by Elisa and Western blot techniques to determine the activation of proliferative pathways in primary cultured VSMCs from rat aorta. Results demonstrated that uric acid can stimulate p38 MAPK, p44/42 MAPK and PDGFRβ phosphorylation in a time- and concentration-dependent manner. Furthermore, treatment of VSMCs with the angiotensin II type I receptor (AT1R) inhibitor losartan suppressed p38 MAPK and p44/42 MAPK induction by uric acid. The stimulatory effect of uric acid on p38 MAPK was higher compared to that of Ang II. The results of this study show for the first time that uric acid-induced PDGFRβ phosphorylation plays a crucial role in the development of CVDs and that elevated uric acid levels could be a potential therapeutical target in CVD patients.

  18. Single Zno Nanowire-Based Biofet Sensors for Ultrasensitive, Label-Free and Real-Time Detection of Uric Acid

    NASA Astrophysics Data System (ADS)

    Lin, Pei; Liu, Xi; Yan, Xiaoqin; Kang, Zhuo; Lei, Yang; Zhao, Yanguang

    2012-08-01

    Qualitative and quantitative detection of biological and chemical species is crucial in many areas, ranging from clinical diagnosis to homeland security. Due to the advantages of ultrahigh sensitivity, label-free, fast readout and easy fabrication over the traditional detection systems, semiconductor nanowire based electronic devices have emerged as a potential platform. In this paper, we fabricated a single ZnO nanowire-based bioFET sensor for the detection of low and high concentration uric acid solution at the same time. The addition of uric acid with the concentrations from 1 pM to 0.5 mM resulted in the electrical conductance changes of up to 227 nS, and the response time turns out to be in the order of millisecond. The ZnO NW biosensor could easily detect as low as 1 pM of the uric acid with 14.7 nS of conductance increase, which implied that the sensitivity of the biosensor can be below the 1pM concentration.

  19. Effect of fenofibrate on uric acid and gout in type 2 diabetes: a post-hoc analysis of the randomised, controlled FIELD study.

    PubMed

    Waldman, Boris; Ansquer, Jean-Claude; Sullivan, David R; Jenkins, Alicia J; McGill, Neil; Buizen, Luke; Davis, Timothy M E; Best, James D; Li, Liping; Feher, Michael D; Foucher, Christelle; Kesaniemi, Y Antero; Flack, Jeffrey; d'Emden, Michael C; Scott, Russell S; Hedley, John; Gebski, Val; Keech, Anthony C

    2018-04-01

    Gout is a painful disorder and is common in type 2 diabetes. Fenofibrate lowers uric acid and reduces gout attacks in small, short-term studies. Whether fenofibrate produces sustained reductions in uric acid and gout attacks is unknown. In the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) trial, participants aged 50-75 years with type 2 diabetes were randomly assigned to receive either co-micronised fenofibrate 200 mg once per day or matching placebo for a median of 5 years follow-up. We did a post-hoc analysis of recorded on-study gout attacks and plasma uric acid concentrations according to treatment allocation. The outcomes of this analysis were change in uric acid concentrations and risk of on-study gout attacks. The FIELD study is registered with ISRCTN, number ISRCTN64783481. Between Feb 23, 1998, and Nov 3, 2000, 9795 patients were randomly assigned to fenofibrate (n=4895) or placebo (n=4900) in the FIELD study. Uric acid concentrations fell by 20·2% (95% CI 19·9-20·5) during the 6-week active fenofibrate run-in period immediately pre-randomisation (a reduction of 0·06 mmol/L or 1 mg/dL) and remained -20·1% (18·5-21·7, p<0·0001) lower in patients taking fenofibrate than in those on placebo in a random subset re-measured at 1 year. With placebo allocation, there were 151 (3%) first gout events over 5 years, compared with 81 (2%) among those allocated fenofibrate (HR with treatment 0·54, 95% CI 0·41-0·70; p<0·0001). In the placebo group, the cumulative proportion of patients with first gout events was 7·7% in patients with baseline uric acid concentration higher than 0·36 mmol/L and 13·9% in those with baseline uric acid concentration higher than 0·42 mmol/L, compared with 3·4% and 5·7%, respectively, in the fenofibrate group. Risk reductions were similar among men and women and those with dyslipidaemia, on diuretics, and with elevated uric acid concentrations. For participants with elevated baseline uric acid concentrations

  20. The association between serum uric acid and the incidence of prediabetes and type 2 diabetes mellitus: The Rotterdam Study

    PubMed Central

    van der Schaft, Niels; Brahimaj, Adela; Wen, Ke-xin; Franco, Oscar H.

    2017-01-01

    Background Limited evidence is available about the association between serum uric acid and sub-stages of the spectrum from normoglycaemia to type 2 diabetes mellitus. We aimed to investigate the association between serum uric acid and risk of prediabetes and type 2 diabetes mellitus. Methods Eligible participants of the Rotterdam Study (n = 8,367) were classified into mutually exclusive subgroups of normoglycaemia (n = 7,030) and prediabetes (n = 1,337) at baseline. These subgroups were followed up for incident prediabetes (n = 1,071) and incident type 2 diabetes mellitus (n = 407), respectively. We used Cox proportional hazard models to determine hazard ratios (HRs) for incident prediabetes among individuals with normoglycaemia and incident type 2 diabetes mellitus among individuals with prediabetes. Results The mean duration of follow-up was 7.5 years for incident prediabetes and 7.2 years for incident type 2 diabetes mellitus. A standard deviation increment in serum uric acid was significantly associated with incident prediabetes among individuals with normoglycaemia (HR 1.10, 95% confidence interval (CI) 1.01; 1.18), but not with incident type 2 diabetes mellitus among individuals with prediabetes (HR 1.07, 95% CI 0.94; 1.21). Exclusion of individuals who used diuretics or individuals with hypertension did not change our results. Serum uric acid was significantly associated with incident prediabetes among normoglycaemic women (HR 1.13, 95% CI 1.02; 1.25) but not among normoglycaemic men (HR 1.08, 95% CI 0.96; 1.21). In contrast, serum uric acid was significantly associated with incident type 2 diabetes mellitus among prediabetic men (HR 1.23, 95% CI 1.01; 1.48) but not among prediabetic women (HR 1.00, 95% CI 0.84; 1.19). Conclusions Our findings agree with the notion that serum uric acid is more closely related to early-phase mechanisms in the development of type 2 diabetes mellitus than late-phase mechanisms. PMID:28632742

  1. Elevated serum uric acid levels are independent risk factors for diabetic foot ulcer in female Chinese patients with type 2 diabetes.

    PubMed

    Ye, Xiao; Cao, Ying; Gao, Fang; Yang, Qunying; Zhang, Qian; Fu, Xiajun; Li, Jimin; Xue, Yaoming

    2014-01-01

    To investigate the relationship between elevated serum uric acid levels and the presence of diabetic foot ulcer (DFU) in Chinese patients with type 2 diabetes (T2D). A retrospective study was performed on 829 outpatients with T2D (478 men, 351 women) who visited the Diabetes Clinic (Nanfang Hospital, Southern Medical University) from January 2007 to December 2009. Information regarding their clinical history, anthropometric measurements, and laboratory data were collected. Potential confounding variables with P < 0.10 were adjusted for in multivariate logistic regression analysis. In univariate analyses, there was a significant difference in serum uric acid levels between female patients with and without DFU (370 ± 128 vs. 313 ± 107 μmol/L, respectively; P < 0.05), but not between male patients with and without DFU (317 ± 100 vs. 348 ± 111 μmol/L, respectively; P = 0.643). The prevalence of DFU among quintiles of uric acid levels (from 1-20% to 80-100%) was 5.3%, 3.9%, 7.7%, 5.5%, and 16.7%, respectively. Using uric acid level as a continuous variable, the multivariate-adjusted odds ratio for diabetic foot ulcer in female patients was 1.004 (95% confidence interval 1.001-1.008; P < 0.05). Elevated uric acid levels are a significant and independent risk factor for diabetic foot ulcer in female Chinese patients with T2D. Whether serum uric acid is involved in the pathogenesis of DFU in female patients remains to be investigated. © 2013 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

  2. Very unusual "needle- and pencil-like" uric acid crystals in the urine unmasked by infrared spectroscopy investigation.

    PubMed

    Baroni, S; Garigali, G; Primiano, A; Gervasoni, J; Fogazzi, G B

    2018-04-01

    In this paper we describe a case with very unusual "needle- and pencil-like" crystals, partly similar to those reported by other investigators, who considered them as due to uric acid. Quite importantly, infrared spectroscopy investigation which, to our knowledge, we have been the first to perform on this type of crystals, confirmed their nature as uric acid structures. This case demonstrates that the planet of urinary crystals still has several unknown facets and still deserves exploration. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Flower-like ZnO decorated polyaniline/reduced graphene oxide nanocomposites for simultaneous determination of dopamine and uric acid.

    PubMed

    Ghanbari, Kh; Moloudi, M

    2016-11-01

    A novel sensor was fabricated by electrochemical deposition of ZnO flower-like/polyaniline nanofiber/reduced graphene oxide nanocomposite (ZnO/PANI/RGO) on glassy carbon electrode (GCE) for direct detection of dopamine (DA) and uric acid (UA) in the presence of fixed concentration of ascorbic acid (AA). Surface morphology and characterization of the modified electrodes were confirmed by field emission scanning microscopy (FE-SEM), X-ray diffraction (XRD), Raman and FT-IR spectroscopies. For individual detection, the linear responses were in the two concentration ranges of 0.001-1 μM and 1-1000 μM with detection limit 0.8 nM (S/N = 3) for DA, and also 0.1-100 μM and 100-1000 μM with detection limit 0.042 μM (S/N = 3) for UA. Simultaneous determination of these species in their mixture solution showed the linear responses in the two concentration ranges of 0.1-90 μM and 90-1000 μM with detection limit 0.017 μM (S/N = 3) for DA and also showed two linear range of 0.5-90 μM and 100-1000 μM with detection limit 0.12 μM (S/N = 3) for UA, with coexistence of 1000 μM AA. The applicability of sensor for the analysis of DA, and UA in dopamine injection solution, human serum and human urine samples was successfully demonstrated. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Hypothesis: Could Excessive Fructose Intake and Uric Acid Cause Type 2 Diabetes?

    PubMed Central

    Johnson, Richard J.; Perez-Pozo, Santos E.; Sautin, Yuri Y.; Manitius, Jacek; Sanchez-Lozada, Laura Gabriela; Feig, Daniel I.; Shafiu, Mohamed; Segal, Mark; Glassock, Richard J.; Shimada, Michiko; Roncal, Carlos; Nakagawa, Takahiko

    2009-01-01

    We propose that excessive fructose intake (>50 g/d) may be one of the underlying etiologies of metabolic syndrome and type 2 diabetes. The primary sources of fructose are sugar (sucrose) and high fructose corn syrup. First, fructose intake correlates closely with the rate of diabetes worldwide. Second, unlike other sugars, the ingestion of excessive fructose induces features of metabolic syndrome in both laboratory animals and humans. Third, fructose appears to mediate the metabolic syndrome in part by raising uric acid, and there are now extensive experimental and clinical data supporting uric acid in the pathogenesis of metabolic syndrome. Fourth, environmental and genetic considerations provide a potential explanation of why certain groups might be more susceptible to developing diabetes. Finally, we discuss the counterarguments associated with the hypothesis and a potential explanation for these findings. If diabetes might result from excessive intake of fructose, then simple public health measures could have a major impact on improving the overall health of our populace. PMID:19151107

  5. Effects of acute and repeated oral doses of D-tagatose on plasma uric acid in normal and diabetic humans.

    PubMed

    Saunders, J P; Donner, T W; Sadler, J H; Levin, G V; Makris, N G

    1999-04-01

    D-tagatose, a stereoisomer of D-fructose, is a naturally occurring ketohexose proposed for use as a low-calorie bulk sweetener. Ingested D-tagatose appears to be poorly absorbed. The absorbed portion is metabolized in the liver by a pathway similar to that of D-fructose. The main purpose of this study was to determine if acute or repeated oral doses of D-tagatose would cause elevations in plasma uric acid (as is seen with fructose) in normal humans and Type 2 diabetics. In addition, effects of subchronic D-tagatose ingestion on fasting plasma phosphorus, magnesium, lipids, and glucose homeostasis were studied. Eight normal subjects and eight subjects with Type 2 diabetes participated in this two-phase study. Each group was comprised of four males and four females. In the first phase, all subjects were given separate 75 g 3-h oral glucose and D-tagatose tolerance tests. Uric acid, phosphorus, and magnesium were determined in blood samples collected from each subject at 0, 30, 60, 120, and 180 min after dose. In the 8-week phase of the study, the normals were randomly placed into two groups which received 75 g of either D-tagatose or sucrose (25 g with each meal) daily for 8 weeks. The diabetics were randomized into two groups which received either 75 g D-tagatose or no supplements of sugar daily for 8 weeks. Uric acid, phosphorus, magnesium, lipids, glycosylated hemoglobin, glucose, and insulin were determined in fasting blood plasma of all subjects at baseline (time zero) and biweekly over the 8 weeks. The 8-week test did not demonstrate an increase in fasting plasma uric acid in response to the daily intake of D-tagatose. However, a transient increase of plasma uric acid levels was observed after single doses of 75 g of D-tagatose in the tolerance test. Plasma uric acid levels were found to rise and peak at 60 min after such dosing. No clinical relevance was attributed to this treatment-related effect because excursions of plasma uric acid levels above the normal

  6. Evaluation of Salivary Uric Acid and pH in Human Immunodeficiency Virus Infected Patients: A Historical Cohort Study.

    PubMed

    Ahmadi-Motamayel, Fatemeh; Amjad, Samaneh Vaziri; Goodarzi, Mohammad Taghi; Poorolajal, Jalal

    2018-01-01

    Antioxidants protect the body against cellular damage. Saliva has immunological, enzymatic and antioxidant defense systems. Uric acid is the main and predominant salivary antioxidant. The aim of this study was to evaluate salivary uric acid levels and pH in HIV-infected patients in the west of Iran. HIV-infected patients were selected from behavioral advisory centers of Hamadan and Kermanshah Provinces, west of Iran. Saliva was collected between 8 and10 in the morning. Five mL of whole unstimulated saliva was collected in 5 minutes by spitting into sterilized Falcon tubes based on Navazesh method; pH was measured with a pH meter and uric acid was assessed with spectrophotometric method. Data were analyzed with STATA 12. Salivary pH in the HIV-positive group was lower (6.99±0.46) than the healthy controls (7.14±1.03) but the difference was not statistically significant (P=380). Uric acid concentrations in HIV-infected patients (2.94±2.14) were significantly lower in comparison to the healthy controls (5.21±2.30). The results showed a statistically significant decrease in the case group (P=0.001). Mean age and DMFT index of the case group were higher than the control group. Uric acid, the main antioxidant of saliva, was significantly lower in HIVinfected individuals; pH also was lower in these patients. HIV can alter salivary antioxidant status, which can influence patients' oral health status. Diet with antioxidant properties might be helpful in these patients. More research is necessary to discover true antioxidant and salivary changes and their relation with HIV consequences in future. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  7. Deproteinizing methods evaluated for determination of uric acid in serum by reversed-phase liquid chromatography with ultraviolet detection.

    PubMed

    Sakuma, R; Nishina, T; Kitamura, M

    1987-08-01

    We evaluated six deproteinizing methods for determination of uric acid in serum by "high-performance" liquid chromatography with ultraviolet detection: those involving zinc hydroxide, sodium tungstate, trichloroacetic acid, perchloric acid, acetonitrile, and centrifugal ultrafiltration (with Amicon MPS-1 devices). We used a Toyosoda ODS-120A reversed-phase column. The mobile phase was sodium phosphate buffer (40 mmol/L, pH 2.2) containing 20 mL of methanol per liter. Absorbance of the eluate was monitored at 284 nm. The precipitation method with perchloric acid gave high recoveries of uric acid and good precision, and results agreed with those by the uricase-catalase method of Kageyama (Clin Chim Acta 1971;31:421-6).

  8. Uric acid promotes vascular stiffness, maladaptive inflammatory responses and proteinuria in western diet fed mice.

    PubMed

    Aroor, Annayya R; Jia, Guanghong; Habibi, Javad; Sun, Zhe; Ramirez-Perez, Francisco I; Brady, Barron; Chen, Dongqing; Martinez-Lemus, Luis A; Manrique, Camila; Nistala, Ravi; Whaley-Connell, Adam T; Demarco, Vincent G; Meininger, Gerald A; Sowers, James R

    2017-09-01

    Aortic vascular stiffness has been implicated in the development of cardiovascular disease (CVD) and chronic kidney disease (CKD) in obese individuals. However, the mechanism promoting these adverse effects are unclear. In this context, promotion of obesity through consumption of a western diet (WD) high in fat and fructose leads to excess circulating uric acid. There is accumulating data implicating elevated uric acid in the promotion of CVD and CKD. Accordingly, we hypothesized that xanthine oxidase(XO) inhibition with allopurinol would prevent a rise in vascular stiffness and proteinuria in a translationally relevant model of WD-induced obesity. Four-week-old C57BL6/J male mice were fed a WD with excess fat (46%) and fructose (17.5%) with or without allopurinol (125mg/L in drinking water) for 16weeks. Aortic endothelial and extracellular matrix/vascular smooth muscle stiffness was evaluated by atomic force microscopy. Aortic XO activity, 3-nitrotyrosine (3-NT) and aortic endothelial sodium channel (EnNaC) expression were evaluated along with aortic expression of inflammatory markers. In the kidney, expression of toll like receptor 4 (TLR4) and fibronectin were assessed along with evaluation of proteinuria. XO inhibition significantly attenuated WD-induced increases in plasma uric acid, vascular XO activity and oxidative stress, in concert with reductions in proteinuria. Further, XO inhibition prevented WD-induced increases in aortic EnNaC expression and associated endothelial and subendothelial stiffness. XO inhibition also reduced vascular pro-inflammatory and maladaptive immune responses induced by consumption of a WD. XO inhibition also decreased WD-induced increases in renal TLR4 and fibronectin that associated proteinuria. Consumption of a WD leads to elevations in plasma uric acid, increased vascular XO activity, oxidative stress, vascular stiffness, and proteinuria all of which are attenuated with allopurinol administration. Copyright © 2017 Elsevier Inc

  9. A simple and sensitive fluorescence based biosensor for the determination of uric acid using H2O2-sensitive quantum dots/dual enzymes.

    PubMed

    Azmi, Nur Ellina; Ramli, Noor Izaanin; Abdullah, Jaafar; Abdul Hamid, Mohammad Azmi; Sidek, Hamidah; Abd Rahman, Samsulida; Ariffin, Nurhayati; Yusof, Nor Azah

    2015-05-15

    A novel optical detection system consisting of combination of uricase/HRP-CdS quantum dots (QDs) for the determination of uric acid in urine sample is described. The QDs was used as an indicator to reveal fluorescence property of the system resulting from enzymatic reaction of uricase and HRP (horseradish peroxidase), which is involved in oxidizing uric acid to allaintoin and hydrogen peroxide. The hydrogen peroxide produced was able to quench the QDs fluorescence, which was proportional to uric acid concentration. The system demonstrated sufficient activity of uricase and HRP at a ratio of 5U:5U and pH 7.0. The linearity of the system toward uric acid was in the concentration range of 125-1000 µM with detection limit of 125 µM. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Design and synthesis of a novel lanthanide fluorescent probe (TbIII-dtpa-bis(2,6-diaminopurine)) and its application to the detection of uric acid in urine sample.

    PubMed

    Yang, Fan; Yu, Zhiyue; Li, Xinyi; Ren, Peipei; Liu, Guanhong; Song, Youtao; Wang, Jun

    2018-06-03

    In this study, a novel fluorescent probe, Tb III -dtpa-bis(2,6-diaminopurine) (Tb-dtpa-bdap), is designed based on the principle of complementary base pairing and synthesized for uric acid detection. The synthesized fluorescent probe is characterized by 1 H NMR, 13 C NMR, infra-red (IR) spectrum and ultraviolet-visible (UV-vis) spectra. It is found that the fluorescence of Tb-dtpa-bdap solution can be quenched obviously in the presence of uric acid. The affecting factors, including solution acidity, uric acid concentration and interfering substances, on the detection of uric acid using this probe are examined. Under optimized conditions, the fluorescence intensities of Tb-dtpa-bdap solution towards different uric acid concentrations show a linear response in the range from 1.00 × 10 -5  mol·L -1 to 5.00 × 10 -5  mol·L -1 with a linear correlation coefficient (R 2 ) of 0.9877. And the obtained limit of detection (LOD) is about 5.80 × 10 -6  mol·L -1 , which is lower than the level of uric acid in actual urine. The mechanism on the detection of uric acid by using Tb-dtpa-bdap is inferred from the experimental results. The facts demonstrate that the proposed fluorescent probe can be successfully applied for the determination of uric acid in human urine samples. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Serum uric acid level as an independent component of the metabolic syndrome in type 2 diabetic blacks.

    PubMed

    Akande, A A; Jimoh, A K; Akinyinka, O A; Olarinoye, G O

    2007-06-01

    No consensus has been achieved on the components included in the definition of Metabolic Syndrome (MS). Uric acid and Gamma glutamyl transpeptidase are however newer markers not included in previous studies. This study was carried out to determine the prevalence of MS in Diabetes Mellitus, the correlation between hyperuricaemia and MS as well as make a case for the inclusion of serum Uric acid level as a new marker for MS. Fasting venous sample from the cubital vein of 77 females and 44 males diagnosed NIDDM patients for enzymatic determination of serum lipids, glucose and uric acid using QCA kits. The demographic records were obtained from the folders. Metabolic syndrome was diagnosed using the WHO criteria. The prevalence of the new component hyperuricaemia among the study subjects was 10.7%. Thirty-eight (31.6%) of the subjects who had high blood pressure, hypertriglyceridemia, low HDL-C and BMI > 30 kg/m2 diagnostic of MS also had hyperuricaemia as against the 29 (23.9%) subjects who hadMS only. About 23.7% of the 38 subjects who had MS and hyperuricaemia had serum uric acid values above 0.38 mmol/l recommended as the cut off value. There was a significant correlation (r = 0.301, p < 0.01) between serum uric acid level, BMI, total cholesterol, LDL-C and HDL-C/TC, among the female subjects while the male subjects showed significant correlation (p < 0.05) between their BMI and serum HDL-C level only. There was a significant difference (p < 0.001) in the CHD risk ratio between the male and the female MS subjects. The correlation between hyperuricaemia and other components of MS as demonstrated in this study may suggest a common etiological factor between the MS components as suggested in other studies. Insulin resistance has been implicated as a common denominator. Thus a further investigation in this direction would be needed.

  12. SGLT2 inhibitor lowers serum uric acid through alteration of uric acid transport activity in renal tubule by increased glycosuria

    PubMed Central

    Chino, Yukihiro; Samukawa, Yoshishige; Sakai, Soichi; Nakai, Yasuhiro; Yamaguchi, Jun-ichi; Nakanishi, Takeo; Tamai, Ikumi

    2014-01-01

    Sodium glucose cotransporter 2 (SGLT2) inhibitors have been reported to lower the serum uric acid (SUA) level. To elucidate the mechanism responsible for this reduction, SUA and the urinary excretion rate of uric acid (UEUA) were analysed after the oral administration of luseogliflozin, a SGLT2 inhibitor, to healthy subjects. After dosing, SUA decreased, and a negative correlation was observed between the SUA level and the UEUA, suggesting that SUA decreased as a result of the increase in the UEUA. The increase in UEUA was correlated with an increase in urinary d-glucose excretion, but not with the plasma luseogliflozin concentration. Additionally, in vitro transport experiments showed that luseogliflozin had no direct effect on the transporters involved in renal UA reabsorption. To explain that the increase in UEUA is likely due to glycosuria, the study focused on the facilitative glucose transporter 9 isoform 2 (GLUT9ΔN, SLC2A9b), which is expressed at the apical membrane of the kidney tubular cells and transports both UA and d-glucose. It was observed that the efflux of [14C]UA in Xenopus oocytes expressing the GLUT9 isoform 2 was trans-stimulated by 10 mm d-glucose, a high concentration of glucose that existed under SGLT2 inhibition. On the other hand, the uptake of [14C]UA by oocytes was cis-inhibited by 100 mm d-glucose, a concentration assumed to exist in collecting ducts. In conclusion, it was demonstrated that the UEUA could potentially be increased by luseogliflozin-induced glycosuria, with alterations of UA transport activity because of urinary glucose. PMID:25044127

  13. Graphene-carbon nanotube composite aerogel for selective detection of uric acid

    NASA Astrophysics Data System (ADS)

    Zhang, Feifei; Tang, Jie; Wang, Zonghua; Qin, Lu-Chang

    2013-12-01

    Graphene and single-walled carbon nanotube (SWNT) composite aerogel has been prepared by hydrothermal synthesis. The restacking of graphene is effectively reduced by SWNTs inserted in between graphene layers in order to make available more active sites and reactive surface area. Electrochemical experiments show that the graphene-SWNT composite electrode has superior catalytic performance in selective detection of uric acid (UA).

  14. Patients with gout differ from healthy subjects in renal response to changes in serum uric acid.

    PubMed

    Liu, Sha; Perez-Ruiz, Fernando; Miner, Jeffrey N

    2017-03-01

    Our objectives were to determine whether a change in serum uric acid (sUA) resulted in a corresponding change in the fractional excretion of uric acid (FEUA) and whether the renal response was different in patients with gout versus healthy subjects. FEUA was calculated from previously published studies and four new phase I studies in healthy subjects and/or patients with gout before and after treatment to lower or raise sUA. Treatments included xanthine oxidase inhibitors to lower sUA as well as infusion of uric acid and provision of a high-purine diet to raise sUA. Plots were created of FEUA versus sUA before and after treatment. For the phase I studies, percent change in FEUA per mg/dL change in sUA was calculated separately for healthy subjects and patients with gout, and compared using Student's t test. Analysis of previously published data and the new phase I clinical data indicates that changing sUA by a non-renal mechanism leads to a change in FEUA. The magnitude of change is greater in subjects with higher baseline FEUA versus patients with gout. Healthy subjects excrete more urate than do patients with gout at physiological urate-filtered load; this difference disappears when the urate-filtered load is decreased to ∼5000mg/24hours. These observations are consistent with a less saturated urate reabsorption system in patients with gout versus healthy subjects, resulting in elevated retention of uric acid. Further investigation could lead to the discovery of mechanisms responsible for the etiology of hyperuricemia/gout. Copyright © 2016 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

  15. Evolutionary context for the association of γ-globin, serum uric acid, and hypertension in African Americans.

    PubMed

    Shriner, Daniel; Kumkhaek, Chutima; Doumatey, Ayo P; Chen, Guanjie; Bentley, Amy R; Charles, Bashira A; Zhou, Jie; Adeyemo, Adebowale; Rodgers, Griffin P; Rotimi, Charles N

    2015-11-05

    Hyperuricemia and associated cardio-metabolic disorders are more prevalent in African Americans than in European Americans. We used genome-wide admixture mapping and association testing to identify loci with ancestry effects on serum uric acid levels. We analyzed 1,976 African Americans from Washington, D.C, including 1,322 individuals from 328 pedigrees and 654 unrelated individuals, enrolled in the Howard University Family Study. We performed admixture mapping and genome-wide association testing using ~800 k autosomal single-nucleotide polymorphisms (SNPs). We performed fine mapping by dense genotyping. We assessed functionality by a combination of bioinformatic annotation, reporter gene assays, and gel shift experiments. We also analyzed 12,641 individuals enrolled in the National Health and Nutrition Examination Survey. We detected a genome-wide significant locus on chromosome 11p15.4 at which serum uric acid levels increased with increasing African ancestry, independent of kidney function. Fine-mapping identified two independent signals in the β-globin locus. The ancestral allele at SNP rs2855126, located upstream of the hemoglobin, gamma A gene HBG1, was associated with increased serum uric acid levels and higher expression of a reporter gene relative to the derived allele. Hyperuricemia was associated with increased risk of hypertension in 3,767 African Americans (Odds Ratio = 2.48, p = 2.71 × 10(-19)). Given that increased expression of γ-globin leads to increased levels of fetal hemoglobin which confers protection against malaria, we hypothesize that evolution in Africa of protection against malaria may have occurred at the cost of increased serum uric acid levels, contributing to the high rates of hyperuricemia and associated cardio-metabolic disorders observed in African Americans.

  16. Evaluation of uric acid levels, thyroid function, and anthropometric parameters in Japanese children with Down syndrome.

    PubMed

    Niegawa, Tomomi; Takitani, Kimitaka; Takaya, Ryuzo; Ishiro, Manabu; Kuroyanagi, Yuichi; Okasora, Keisuke; Minami, Yukako; Matsuda, Takuya; Tamai, Hiroshi

    2017-09-01

    Down syndrome, caused by trisomy 21, is characterized by congenital abnormalities as well as mental retardation. From the neonatal stage through adolescence, patients with Down syndrome often have several complications. Thus, it is important to attain knowledge of the prevalence of these comorbidities in children with Down syndrome. We, therefore, evaluated the biochemical data, thyroid function, and anthropometric parameters, and analyzed the association among them in Japanese children and early adolescents with Down syndrome. There was no difference in the prevalence of obesity and overweight between boys and girls. The level of uric acid was higher in boys than in girls. Moreover, the prevalence of hyperuricemia was also higher in boys than in girls (approximately 32% and 10%, respectively). The prevalence of subclinical hypothyroidism in children with Down syndrome was approximately 20%, with no significant sex differences. The levels of uric acid and dehydroepiandrosterone-sulfate were positively associated with age, while the levels of thyroid-stimulating hormone and free thyroxine had a negative association with age. Overall, children with Down syndrome, exhibit a higher incidence of hyperuricemia. Therefore, uric acid levels, as well as thyroid function, from childhood to early adulthood should be monitored in this patient cohort.

  17. Fructose containing sugars do not raise blood pressure or uric acid at normal levels of human consumption.

    PubMed

    Angelopoulos, Theodore J; Lowndes, Joshua; Sinnett, Stephanie; Rippe, James M

    2015-02-01

    The impact of fructose, commonly consumed with sugars by humans, on blood pressure and uric acid has yet to be defined. A total of 267 weight-stable participants drank sugar-sweetened milk every day for 10 weeks as part of their usual, mixed-nutrient diet. Groups 1 and 2 had 9% estimated caloric intake from fructose or glucose, respectively, added to milk. Groups 3 and 4 had 18% of estimated caloric intake from high fructose corn syrup or sucrose, respectively, added to the milk. Blood pressure and uric acid were determined prior to and after the 10-week intervention. There was no effect of sugar type on either blood pressure or uric acid (interaction P>.05), and a significant time effect for blood pressure was noted (P<.05). The authors conclude that 10 weeks of consumption of fructose at the 50th percentile level, whether consumed as pure fructose or with fructose-glucose-containing sugars, does not promote hyperuricemia or increase blood pressure. © 2014 Wiley Periodicals, Inc.

  18. The impact of serum uric acid reduction on renal function and blood pressure in chronic kidney disease patients with hyperuricemia.

    PubMed

    Tsuji, Takayuki; Ohishi, Kazuhisa; Takeda, Asumi; Goto, Daiki; Sato, Taichi; Ohashi, Naro; Fujigaki, Yoshihide; Kato, Akihiko; Yasuda, Hideo

    2018-04-26

    Febuxostat is tolerable in chronic kidney disease (CKD) patients with hyperuricemia. However, the long-term effect of lowering uric acid with febuxostat on renal function and blood pressure has not been elucidated. This was a 2 years retrospective observational study. 86 CKD patients with hyperuricemia who continued with allopurinol (allopurinol group, n = 30), switched from allopurinol to febuxostat (switched group, n = 25), or were newly prescribed febuxostat (febuxostat group, n = 31) were included in this study. Serum uric acid, estimated glomerular filtration rate (eGFR), blood pressure, and urinary protein were analyzed. Moreover, the impact of serum uric acid reduction on renal function and blood pressure was assessed. Serum uric acid in the switched and febuxostat groups was significantly reduced at 6 months (switched group; 8.49 ± 1.32-7.19 ± 1.14 mg/dL, p < 0.0001, febuxostat group; 9.43 ± 1.63-6.31 ± 0.90 mg/dL, p < 0.0001). In the allopurinol group, serum uric acid was increased (6.86 ± 0.87-7.10 ± 0.85 mg/dL, p = 0.0213). eGFR was significantly increased (35.2 ± 12.8-37.3 ± 13.9 mL/min/1.73 m 2 , p = 0.0232), while mean arterial pressure (93.1 ± 10.8-88.2 ± 9.5 mmHg, p = 0.0039) was significantly decreased at 6 months in the febuxostat group, resulting in the retention of eGFR for 2 years. The impact of serum uric acid reduction might have beneficial effects on CKD progression and blood pressure. However, a large prospective study is needed to determine the long-term efficacy of febuxostat therapy in CKD patients with hyperuricemia.

  19. Safety and efficacy of uric acid in patients with acute stroke (URICO-ICTUS): a randomised, double-blind phase 2b/3 trial.

    PubMed

    Chamorro, Angel; Amaro, Sergio; Castellanos, Mar; Segura, Tomás; Arenillas, Juan; Martí-Fábregas, Joan; Gállego, Jaime; Krupinski, Jurek; Gomis, Meritxell; Cánovas, David; Carné, Xavier; Deulofeu, Ramón; Román, Luis San; Oleaga, Laura; Torres, Ferran; Planas, Anna M

    2014-05-01

    Uric acid is an antioxidant with neuroprotective effects in experimental models of stroke. We assessed whether uric acid therapy would improve functional outcomes at 90 days in patients with acute ischaemic stroke. URICO-ICTUS was a randomised, double-blind, placebo-controlled, phase 2b/3 trial that recruited patients with acute ischaemic stroke admitted to ten Spanish stroke centres. Patients were included if they were aged 18 years or older, had received alteplase within 4·5 h of symptom onset, and had an eligible National Institutes of Health Stroke Scale (NIHSS) score (>6 and ≤25) and premorbid (assessed by anamnesis) modified Rankin Scale (mRS) score (≤2). Patients were randomly allocated (1:1) to receive uric acid 1000 mg or placebo (both infused intravenously in 90 min during the infusion of alteplase), stratified by centre and baseline stroke severity. The primary outcome was the proportion of patients with excellent outcome (ie, an mRS score of 0-1, or 2 if premorbid score was 2) at 90 days, analysed in the target population (all randomly assigned patients who had been correctly diagnosed with ischaemic stroke and had begun study medication). The study is registered with ClinicalTrials.gov, number NCT00860366. Between July 1, 2011, and April 30, 2013, we randomly assigned 421 patients, of whom 411 (98%) were included in the target population (211 received uric acid and 200 received placebo). 83 (39%) patients who received uric acid and 66 (33%) patients who received placebo had an excellent outcome (adjusted risk ratio 1·23 [95% CI 0·96-1·56]; p=0·099). No clinically relevant or statistically significant differences were reported between groups with respect to death (28 [13%] patients who received uric acid vs 31 [16%] who received placebo), symptomatic intracerebral haemorrhage (nine [4%] vs six [3%]), and gouty arthritis (one [<1%] vs four [2%]). 516 adverse events occurred in the uric acid group and 532 in the placebo group, of which 61 (12

  20. [Association of blood uric acid with other cardiovascular risk factors in the male working population in Valencia].

    PubMed

    Corella, D; Silla, J; Ordovás, J M; Sabater, A; Ruiz de la Fuente, S; Portolés, O; González, J I; Saiz, C

    1999-12-01

    Serum uric acid has been reported to be a risk factor for cardiovascular disease (CVD). The objective of the present work was to determine the prevalence of hyperuricemia in a large size sample of a healthy male population, as well as the association between uric acid and other cardiovascular risk factors. A cross-sectional study was conducted in a randomly selected sample of 1,564 healthy men in Valencia (Spain), aged 20-67 years, working in the automobile industry. Serum values of uric acid, cholesterol, and glucose were obtained, as well as blood pressure and body mass index measurements. An assessment was made of socio-economic data, drug therapy, and smoking. The overall prevalence of hyperuricemia was 5.10%; it increased with age. A marked increase (p < 0.01) of hyperuricemic individuals was observed with increased prevalence of other cardiovascular risk factors (from 1.8% with hyperuricemia alone up to 28% among individuals with four simultaneous risk factors). By means of a multivariate logistic regression analysis, the OR of hyperuricemia associated with each factor were calculated: increased serum glucose was the variable with a stronger association (OR: 2.69; 95%CI: 1.21-5.99), obesity ranking next (OR: 2.50; 95%CI: 1.42-4.49). Statistically significant associations were also observed for increased serum cholesterol, increased blood pressure, and smoking. The prevalence of hyperuricemia varies with the simultaneous presence of other classical cardiovascular risk factors. Even in this healthy mediterranean population, uric acid is significantly associated with several components in the plurimetabolic syndrome.

  1. Association of three genetic loci with uric acid concentration and risk of gout: a genome-wide association study.

    PubMed

    Dehghan, Abbas; Köttgen, Anna; Yang, Qiong; Hwang, Shih-Jen; Kao, Wh Linda; Rivadeneira, Fernando; Boerwinkle, Eric; Levy, Daniel; Hofman, Albert; Astor, Brad C; Benjamin, Emelia J; van Duijn, Cornelia M; Witteman, Jacqueline C; Coresh, Josef; Fox, Caroline S

    2008-12-06

    Hyperuricaemia, a highly heritable trait, is a key risk factor for gout. We aimed to identify novel genes associated with serum uric acid concentration and gout. Genome-wide association studies were done for serum uric acid in 7699 participants in the Framingham cohort and in 4148 participants in the Rotterdam cohort. Genome-wide significant single nucleotide polymorphisms (SNPs) were replicated in white (n=11 024) and black (n=3843) individuals who took part in the study of Atherosclerosis Risk in Communities (ARIC). The SNPs that reached genome-wide significant association with uric acid in either the Framingham cohort (p<5.0 x 10(-8)) or the Rotterdam cohort (p<1.0 x 10(-7)) were evaluated with gout. The results obtained in white participants were combined using meta-analysis. Three loci in the Framingham cohort and two in the Rotterdam cohort showed genome-wide association with uric acid. Top SNPs in each locus were: missense rs16890979 in SLC2A9 (p=7.0 x 10(-168) and 2.9 x 10(-18) for white and black participants, respectively); missense rs2231142 in ABCG2 (p=2.5 x 10(-60) and 9.8 x 10(-4)), and rs1165205 in SLC17A3 (p=3.3 x 10(-26) and 0.33). All SNPs were direction-consistent with gout in white participants: rs16890979 (OR 0.59 per T allele, 95% CI 0.52-0.68, p=7.0 x 10(-14)), rs2231142 (1.74, 1.51-1.99, p=3.3 x 10(-15)), and rs1165205 (0.85, 0.77-0.94, p=0.002). In black participants of the ARIC study, rs2231142 was direction-consistent with gout (1.71, 1.06-2.77, p=0.028). An additive genetic risk score of high-risk alleles at the three loci showed graded associations with uric acid (272-351 mumol/L in the Framingham cohort, 269-386 mumol/L in the Rotterdam cohort, and 303-426 mumol/L in white participants of the ARIC study) and gout (frequency 2-13% in the Framingham cohort, 2-8% in the Rotterdam cohort, and 1-18% in white participants in the ARIC study). We identified three genetic loci associated with uric acid concentration and gout. A score based on

  2. Population pharmacokinetics and exposure-uric acid analyses after single and multiple doses of ABT-639, a calcium channel blocker, in healthy volunteers.

    PubMed

    An, Guohua; Liu, Wei; Duan, W Rachel; Nothaft, Wolfram; Awni, Walid; Dutta, Sandeep

    2015-03-01

    ABT-639 is a selective T-type calcium channel blocker with efficacy in a wide range of preclinical models of nociceptive and neuropathic pain. In the current first-in-human (FIH) study, the pharmacokinetics, tolerability, and safety of ABT-639 after single- (up to 170 mg) and multiple doses (up to 160 mg BID) were evaluated in healthy volunteers in a randomized, double-blinded, placebo-controlled manner. ABT-639 demonstrated acceptable safety and pharmacokinetic profiles in human. Results from assessment of the routine laboratory variables showed an unexpected statistically significant and clinically relevant decrease in blood uric acid with the increase in ABT-639 dose, which is possibly due to inhibition in URAT1 transporter. Pharmacokinetic/pharmacodynamic models were constructed to characterize the relationship between ABT-639 exposure and uric acid response. The final model was a mechanism-based indirect response pharmacodynamic model with the stimulation of uric acid elimination by ABT-639. The model estimated K in values in males and females were 10.2 and 7.13 μmol/h, respectively. The model estimated K out was 0.033 1/h. ABT-639 concentration that can produce 50% stimulation in uric acid elimination was estimated to be 8,070 ng/mL. Based on the final model, further simulations were conducted to predict the effect of ABT-639 on uric acid in gout patients. The simulation results indicated that, if the urate-lowering response to ABT-639 in gout patients is similar to that in healthy subjects, ABT-639 BID doses of 140 mg or higher would be expected to provide clinically meaningful lowering of blood uric acid levels below the 380 μmol/L solubility limit of monosodium urate.

  3. Serum creatinine and uric acid levels in pregnant urban African and Caucasian women.

    PubMed

    Nduka, N; Ekeke, G I

    1986-12-01

    Serum creatinine and uric acid concentrations were determined for 117 pregnant urban African women and 109 pregnant Caucasian women covering the three trimesters of pregnancy. The creatinine levels for Caucasians rose as pregnancy progressed, exceeding the normal adult level, while that for Africans rose only slightly and only during the last trimester of pregnancy. A similar observation was made for uric acid levels except that the rise in Africans commenced earlier than it did for creatinine, commencing from about the second trimester. Also, the levels in both groups of people remained within the normal adult range. The increased levels of these non-protein nitrogen compounds during pregnancy was attributable to increased metabolism associated with the condition. The difference observed between the Caucasians and Africans was attributed to the better protein nutritional status of the former. It is suggested that the creatinine "curve" especially for the Caucasians could be utilized in the monitoring of foetal well-being.

  4. Association and prognostic value of serum Cystatin C, IL-18 and Uric acid in urological patients with acute kidney injury.

    PubMed

    Choudhary, Arpan; Basu, Supriya; Dey, Sujit K; Rout, Jayanta K; Das, Ranjit K; Dey, Ranjan K

    2018-07-01

    To assess the role of serum Cystatin C, IL-18 and Uric acid in acute kidney injury (AKI) in urological patients, along with their prognostic significance. Prospective observational study included 61 cases, admitted in urology ward with baseline serum creatinine ≤1.5 mg/dL. All patients had at least one or more predisposing factors for AKI. Daily urine output and creatinine level were checked. Serum levels of biomarkers were measured at baseline and postoperatively after 24 h. Development of AKI and its outcome were analysed. Thirty nine patients (63.9%) developed AKI in the study. Patients with AKI were found to have a greater percentage rise of Cystatin C (118.7% v/s 81.8%, p = 0.005), IL-18 (59.0% v/s 25.5%, p = 0.004) and Uric acid (34.3% v/s 19.2%, p = 0.008) after 24 h. Absolute Uric acid level at day 1 was also significantly associated with AKI (5.18 ± 0.91 v/s 4.45 ± 0.86, p = 0.003). Risk stratification of AKI was poor for all biomarkers. Area under curve for Cystatin C, IL-18 and Uric acid was 0.715, 0.696 and 0.734 respectively. Renal function after 3 months, had a positive correlation with baseline creatinine and baseline Cystatin C levels (r = 0.56 & 0.39). Postoperative serum Cystatin C, IL-18 and Uric acid after 24 h were significantly associated with AKI. Baseline Cystatin C had moderate capability to predict short term renal function. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. THE PREDICTIVE VALUE OF SERUM URIC ACID FOR THE OCCURRENCE, SEVERITY AND OUTCOMES OF PRE-ECLAMPSIA AMONG PARTURIENTS AT NNEWI, NIGERIA.

    PubMed

    Osakwe, Chukwudi Richmond; Ikpeze, Okechukwu C; Ezebialu, Ifeanyi Uzoma; Osakwe, Joy Oluchi; Mbadugha, Norah Nwadiogo

    2015-01-01

    To determine the predictive value of serum uric acid for preeclampsia, its severity and pregnancy outcome. This is a cohort study that was performed on normal pregnant women attending antenatal clinic at Nnamdi Azikiwe University Teaching Hospital Nnewi Nigeria. Serum uric acid was determined in 200 women attending antenatal clinic between the gestational ages of 14 and 26 weeks. The women were followed up at 2 weekly intervals until 36 weeks and weekly thereafter until delivery. Women who developed pre-eclampsia or eclampsia were identified. Pregnancy outcomes were determined as well as fetal and placental weights. The data was analised with SPSS version 16.0. The chi square was used for test of significance. The positive and negative predictive values were determined. A total of 200 normal pregnant women were recruited for the study. Nine of them were lost to follow up. Subsequently, 10.5% of the women developed preeclampsia. The positive and negative predictive values of serum uric acid for preeclampsia were 78.9% and 97.1%, respectively. Serum uric acid was found to be a useful predictor of the occurrence of preeclampsia and its severity.

  6. Association of serum uric acid and risk of hypertension in adults: a prospective study of Kailuan Corporation cohort.

    PubMed

    Cui, Liu-Fu; Shi, Hui-Jing; Wu, Shou-Ling; Shu, Rong; Liu, Na; Wang, Guan-Ying; Zhou, Bin; Sun, Kai; Yu, Ping; Wang, Jian; Song, Hai-Cheng; Yang, Wen-Hao; Wang, Jie-Rui; Han, Yi-Xuan; Mu, Rong

    2017-05-01

    Whether hyperuricemia is an independent risk factor for hypertension in adults is still under debate. To determine the association between serum uric acid and risk of hypertension in the Chinese population, we conducted a prospective study using the "Kailuan Corporation cohort." A total of 39,233 adult subjects with available data on serum uric acid were enrolled from 2006 to 2007. Subjects with established hypertension were excluded and were then grouped based on the gender and baseline quartile serum uric acid into F1-4 for women and M1-4 for men with F1 and M1 being the lowest quartiles. Incidence of newly described primary hypertension was reevaluated in 2010-2011. The median (interquantile range) baseline uric acid (UA) was 290 (243-344) μmol/L in men and 230 (194-274) μmol/L in women. During a 4-year follow-up period, 12,844 subjects (31.31 %) were newly diagnosed with hypertension. The incidence of hypertension was 14.36, 16.57, 19.06, and 22.35 % in F1 to F4 and 33.64, 33.97, 36.54, and 40.74 % in M1 to M4, respectively. Multiple logistic regression analysis showed that the odds ratios (ORs) of incident hypertension were 1.17 [95 % confidence interval (CI) 1.00-1.37, P = 0.055], 1.24 (95 % CI 1.06-1.45, P = 0.009), and 1.20 (95 % CI 1.02-1.41, P = 0.027) in F2 to F4 compared to the F1 and 0.98 (95 % CI 0.91-1.05, P = 0.534), 1.05 (95 % CI 0.98-1.13, P = 0.190), and 1.13 (95 % CI 1.05-1.22, P = 0.002) in M2 to M4 compared to the M1. Elevated level of serum uric acid is associated with an increased risk of hypertension in adults.

  7. Association of uric acid levels with components of metabolic syndrome and non-alcoholic fatty liver disease in overweight or obese children and adolescents.

    PubMed

    Cardoso, Anajás S; Gonzaga, Nathalia C; Medeiros, Carla C M; Carvalho, Danielle F de

    2013-01-01

    To investigate the association between serum uric acid concentration according to the presence or absence of non-alcoholic fatty liver disease (NAFLD) and/or metabolic syndrome (MS) in overweight or obese children and adolescents. This was a cross-sectional study conducted from April of 2009 to March of 2010, including 129 children and adolescents treated at the Center for Childhood Obesity. Anthropometric data, blood pressure measurements, and laboratory test results were obtained, and NAFLD diagnosis was made by ultrasound. The diagnosis of MS was made using the criteria of the National Cholesterol Education Program/Adult Treatment Panel III, adapted to age range. The chi-squared test or or Fisher's test were used to evaluate the association of uric acid with the groups, with a 95% confidence interval. One-way analysis of variance (ANOVA) was used for comparison of means. Multiple logistic regression was used for adjustment of variables. The data were analyzed with the Statistical Package for Social Sciences (SPSS), release 17. High levels of uric acid were significantly associated with adolescence, MS, and systolic blood pressure. The highest quartile of uric acid showed significantly higher values of body mass index, waist circumference, systolic blood pressure, diastolic blood pressure, triglycerides, total cholesterol, and homeostatic model assessment index (HOMA-IR), and lower mean values of HDL cholesterol. In the final model, only age range and the presence of MS remained associated with uric acid levels. High levels of uric acid were associated with MS and adolescence, which was not observed with NAFLD. Copyright © 2013 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  8. Immbolization of uricase enzyme in Langmuir and Langmuir-Blodgett films of fatty acids: possible use as a uric acid sensor.

    PubMed

    Zanon, Nathaly C M; Oliveira, Osvaldo N; Caseli, Luciano

    2012-05-01

    Preserving the enzyme structure in solid films is key for producing various bioelectronic devices, including biosensors, which has normally been performed with nanostructured films that allow for control of molecular architectures. In this paper, we investigate the adsorption of uricase onto Langmuir monolayers of stearic acid (SA), and their transfer to solid supports as Langmuir-Blodgett (LB) films. Structuring of the enzyme in β-sheets was preserved in the form of 1-layer LB film, which was corroborated with a higher catalytic activity than for other uricase-containing LB film architectures where the β-sheets structuring was not preserved. The optimized architecture was also used to detect uric acid within a range covering typical concentrations in the human blood. The approach presented here not only allows for an optimized catalytic activity toward uric acid but also permits one to explain why some film architectures exhibit a superior performance. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. The Urinary Uric Acid/Creatinine Ratio is An Adjuvant Marker for Perinatal Asphyxia

    PubMed Central

    Bhongir, Aparna Varma; Yakama, Akhil Varma Venkata; Saha, Subhajit; Radia, Sejal B.; Pabbati, Jayalakshmi

    2015-01-01

    Objective To assess the urinary uric acid/creatinine ratio (UA/Cr) in relation to Apgar score and cord blood gas analysis in identification of perinatal asphyxia and to define the cutoff values. Design case control study. Setting The newborns admitted in the department of pediatrics and NICU of Mediciti Institute of Medical Science, Ghanpur, Medchal mandal, Telangana from May-July 2011 were enrolled. Participants/patients The study was conducted on 31 (18 males, 13 females) controls and 18 (12males, 6 females) asphyxiated neonates. Outcome Measure(s) 5ml of arterial cord blood of newborn collected at the time of birth and spot urine samples were collected within 24-72 hours of life. Cord blood gas analysis were done immediately and Urinary uric acid was measured by modified Uricase method, urinary creatinine by modified kinetic Jaffe's reaction. Results The mean urinary uric acid and creatinine ratio (2.58± 0.48 vs 1.89 ± 0.59) is significantly higher in Asphyxiated group than in the control group. The umbilical cord blood pH had significant positive correlation with 1st minute Apgar score (r= 0.41, p=0.003), 5th minute Apgar (r= 0.44, p=0.002), while urinary UA/Cr ratio had significant negative correlation with cord blood pH (r= -0.63, p=0.002). Urinary UA/Cr ratio with criterion of >2.43 had 80% sensitivity, 87.5% specificity with AUC of 0.84 (p=0.003) had a better predictive value. Conclusions Urinary UA/Cr ratio is easy, non-invasive, painless and economical adjuvant parameter with better predictive value for diagnosing perinatal asphyxia with simple diagnostic equipment. PMID:26998526

  10. The Urinary Uric Acid/Creatinine Ratio is An Adjuvant Marker for Perinatal Asphyxia.

    PubMed

    Bhongir, Aparna Varma; Yakama, Akhil Varma Venkata; Saha, Subhajit; Radia, Sejal B; Pabbati, Jayalakshmi

    2015-09-01

    To assess the urinary uric acid/creatinine ratio (UA/Cr) in relation to Apgar score and cord blood gas analysis in identification of perinatal asphyxia and to define the cutoff values. case control study. The newborns admitted in the department of pediatrics and NICU of Mediciti Institute of Medical Science, Ghanpur, Medchal mandal, Telangana from May-July 2011 were enrolled. The study was conducted on 31 (18 males, 13 females) controls and 18 (12males, 6 females) asphyxiated neonates. 5ml of arterial cord blood of newborn collected at the time of birth and spot urine samples were collected within 24-72 hours of life. Cord blood gas analysis were done immediately and Urinary uric acid was measured by modified Uricase method, urinary creatinine by modified kinetic Jaffe's reaction. The mean urinary uric acid and creatinine ratio (2.58± 0.48 vs 1.89 ± 0.59) is significantly higher in Asphyxiated group than in the control group. The umbilical cord blood pH had significant positive correlation with 1 st minute Apgar score (r= 0.41, p=0.003), 5 th minute Apgar (r= 0.44, p=0.002), while urinary UA/Cr ratio had significant negative correlation with cord blood pH (r= -0.63, p=0.002). Urinary UA/Cr ratio with criterion of >2.43 had 80% sensitivity, 87.5% specificity with AUC of 0.84 (p=0.003) had a better predictive value. Urinary UA/Cr ratio is easy, non-invasive, painless and economical adjuvant parameter with better predictive value for diagnosing perinatal asphyxia with simple diagnostic equipment.

  11. Evaluation of uric acid levels, thyroid function, and anthropometric parameters in Japanese children with Down syndrome

    PubMed Central

    Niegawa, Tomomi; Takitani, Kimitaka; Takaya, Ryuzo; Ishiro, Manabu; Kuroyanagi, Yuichi; Okasora, Keisuke; Minami, Yukako; Matsuda, Takuya; Tamai, Hiroshi

    2017-01-01

    Down syndrome, caused by trisomy 21, is characterized by congenital abnormalities as well as mental retardation. From the neonatal stage through adolescence, patients with Down syndrome often have several complications. Thus, it is important to attain knowledge of the prevalence of these comorbidities in children with Down syndrome. We, therefore, evaluated the biochemical data, thyroid function, and anthropometric parameters, and analyzed the association among them in Japanese children and early adolescents with Down syndrome. There was no difference in the prevalence of obesity and overweight between boys and girls. The level of uric acid was higher in boys than in girls. Moreover, the prevalence of hyperuricemia was also higher in boys than in girls (approximately 32% and 10%, respectively). The prevalence of subclinical hypothyroidism in children with Down syndrome was approximately 20%, with no significant sex differences. The levels of uric acid and dehydroepiandrosterone-sulfate were positively associated with age, while the levels of thyroid-stimulating hormone and free thyroxine had a negative association with age. Overall, children with Down syndrome, exhibit a higher incidence of hyperuricemia. Therefore, uric acid levels, as well as thyroid function, from childhood to early adulthood should be monitored in this patient cohort. PMID:28955133

  12. Simultaneous Detection of Dopamine and Uric Acid Using a Poly(l-lysine)/Graphene Oxide Modified Electrode

    PubMed Central

    Zhang, Yuehua; Lei, Wu; Xu, Yujuan; Xia, Xifeng; Hao, Qingli

    2016-01-01

    A novel, simple and selective electrochemical method was investigated for the simultaneous detection of dopamine (DA) and uric acid (UA) on a poly(l-lysine)/graphene oxide (GO) modified glassy carbon electrode (PLL/GO/GCE) by differential pulse voltammetry (DPV). The electrochemically prepared PLL/GO sensory platform toward the oxidation of UA and DA exhibited several advantages, including high effective surface area, more active sites and enhanced electrochemical activity. Compared to the PLL-modified GCE (PLL/GCE), GO-modified GCE and bare GCE, the PLL/GO/GCE exhibited an increase in the anodic potential difference and a remarkable enhancement in the current responses for both UA and DA. For the simultaneous detection of DA and UA, the detection limits of 0.021 and 0.074 μM were obtained, while 0.031 and 0.018 μM were obtained as the detection limits for the selective detection of UA and DA, using DPV in the linear concentration ranges of 0.5 to 20.0 and 0.5 to 35 μM, respectively. In addition, the PLL/GO/GCE demonstrated good reproducibility, long-term stability, excellent selectivity and negligible interference of ascorbic acid (AA). The proposed modified electrode was successfully implemented in the simultaneous detection of DA and UA in human blood serum, urine and dopamine hydrochloride injection with satisfactory results. PMID:28335305

  13. ZIF-67 derived porous Co3O4 hollow nanopolyhedron functionalized solution-gated graphene transistors for simultaneous detection of glucose and uric acid in tears.

    PubMed

    Xiong, Can; Zhang, Tengfei; Kong, Weiyu; Zhang, Zhixiang; Qu, Hao; Chen, Wei; Wang, Yanbo; Luo, Linbao; Zheng, Lei

    2018-03-15

    Biomarkers in tears have attracted much attention in daily healthcare sensing and monitoring. Here, highly sensitive sensors for simultaneous detection of glucose and uric acid are successfully constructed based on solution-gated graphene transistors (SGGTs) with two separate Au gate electrodes, modified with GOx-CHIT and BSA-CHIT respectively. The sensitivity of the SGGT is dramatically improved by co-modifying the Au gate with ZIF-67 derived porous Co 3 O 4 hollow nanopolyhedrons. The sensing mechanism for glucose sensor is attributed to the reaction of H 2 O 2 generated by the oxidation of glucose near the gate, while the sensing mechanism for uric acid is due to the direct electro-oxidation of uric acid molecules on the gate. The optimized glucose and uric acid sensors show the detection limits both down to 100nM, far beyond the sensitivity required for non-invasive detection of glucose and uric acid in tears. The glucose and uric acid in real tear samples was quantitatively detected at 323.2 ± 16.1μM and 98.5 ± 16.3μM by using the functionalized SGGT device. Due to the low-cost, high-biocompatibility and easy-fabrication features of the ZIF-67 derived porous Co 3 O 4 hollow nanopolyhedron, they provide excellent electrocatalytic nanomaterials for enhancing sensitivity of SGGTs for a broad range of disease-related biomarkers. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. A Potentiometric Indirect Uric Acid Sensor Based on ZnO Nanoflakes and Immobilized Uricase

    PubMed Central

    Usman Ali, Syed M.; Ibupoto, Zafar Hussain; Kashif, Muhammad; Hashim, Uda; Willander, Magnus

    2012-01-01

    In the present work zinc oxide nanoflakes (ZnO-NF) structures with a wall thickness around 50 to 100 nm were synthesized on a gold coated glass substrate using a low temperature hydrothermal method. The enzyme uricase was electrostatically immobilized in conjunction with Nafion membrane on the surface of well oriented ZnO-NFs, resulting in a sensitive, selective, stable and reproducible uric acid sensor. The electrochemical response of the ZnO-NF-based sensor vs. a Ag/AgCl reference electrode was found to be linear over a relatively wide logarithmic concentration range (500 nM to 1.5 mM). In addition, the ZnO-NF structures demonstrate vast surface area that allow high enzyme loading which results provided a higher sensitivity. The proposed ZnO-NF array-based sensor exhibited a high sensitivity of ∼66 mV/ decade in test electrolyte solutions of uric acid, with fast response time. The sensor response was unaffected by normal concentrations of common interferents such as ascorbic acid, glucose, and urea. PMID:22736977

  15. Inhibition of free radical-induced erythrocyte hemolysis by 2-O-substituted ascorbic acid derivatives.

    PubMed

    Takebayashi, Jun; Kaji, Hiroaki; Ichiyama, Kenji; Makino, Kazutaka; Gohda, Eiichi; Yamamoto, Itaru; Tai, Akihiro

    2007-10-15

    Inhibitory effects of 2-O-substituted ascorbic acid derivatives, ascorbic acid 2-glucoside (AA-2G), ascorbic acid 2-phosphate (AA-2P), and ascorbic acid 2-sulfate (AA-2S), on 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative hemolysis of sheep erythrocytes were studied and were compared with those of ascorbic acid (AA) and other antioxidants. The order of the inhibition efficiency was AA-2S> or =Trolox=uric acid> or =AA-2P> or =AA-2G=AA>glutathione. Although the reactivity of the AA derivatives against AAPH-derived peroxyl radical (ROO(*)) was much lower than that of AA, the derivatives exerted equal or more potent protective effects on AAPH-induced hemolysis and membrane protein oxidation. In addition, the AA derivatives were found to react per se with ROO(*), not via AA as an intermediate. These findings suggest that secondary reactions between the AA derivative radical and ROO(*) play a part in hemolysis inhibition. Delayed addition of the AA derivatives after AAPH-induced oxidation of erythrocytes had already proceeded showed weaker inhibition of hemolysis compared to that of AA. These results suggest that the AA derivatives per se act as biologically effective antioxidants under moderate oxidative stress and that AA-2G and AA-2P may be able to act under severe oxidative stress after enzymatic conversion to AA in vivo.

  16. Serum Uric Acid Levels and Diabetic Peripheral Neuropathy in Type 2 Diabetes: a Systematic Review and Meta-analysis.

    PubMed

    Yu, Shuai; Chen, Ying; Hou, Xu; Xu, Donghua; Che, Kui; Li, Changgui; Yan, Shengli; Wang, Yangang; Wang, Bin

    2016-03-01

    Previous studies suggested a possible association between serum uric acid levels and peripheral neuropathy in patients with type 2 diabetes, but no definite evidence was available. A systematic review and meta-analysis of relevant studies were performed to comprehensively estimate the association. Pubmed, Web of Science, Embase, and China Biology Medicine (CBM) databases were searched for eligible studies. Study-specific data were combined using random-effect or fixed-effect models of meta-analysis according to between-study heterogeneity. Twelve studies were finally included into the meta-analysis, which involved a total of 1388 type 2 diabetic patients with peripheral neuropathy and 4746 patients without peripheral neuropathy. Meta-analysis showed that there were obvious increased serum uric acid levels in diabetic patients with peripheral neuropathy (weighted mean difference [WMD] = 50.03 μmol/L, 95% confidence interval [95%CI] 22.14-77.93, P = 0.0004). Hyperuricemia was also significantly associated with increased risk of peripheral neuropathy in patients with type 2 diabetes (risk ratio [RR] = 2.83, 95%CI 2.13-3.76, P < 0.00001). Meta-analysis of two studies with adjusted risk estimates showed that hyperuricemia was independently associated with increased risk of peripheral neuropathy in type 2 diabetic patients (RR = 1.95, 95%CI 1.23-3.11, P = 0.005). Type 2 diabetic patients with peripheral neuropathy have obvious increased serum uric acid levels, and hyperuricemia is associated with increased risk of peripheral neuropathy. Further prospective cohort studies are needed to validate the impact of serum uric acid levels on peripheral neuropathy risk.

  17. A novel screen-printed microfluidic paper-based electrochemical device for detection of glucose and uric acid in urine.

    PubMed

    Yao, Yong; Zhang, Chunsun

    2016-10-01

    A novel screen-printed microfluidic paper-based analytical device with all-carbon electrode-enabled electrochemical assay (SP-ACE-EC-μPAD) has been developed. The fabrication of these devices involved wax screen-printing, which was simple, low-cost and energy-efficient. The working, counter and reference electrodes were screen-printed using carbon ink on the patterned paper devices. Different wax screen-printing processes were examined and optimized, which led to an improved method with a shorter heating time (~5 s) and a lower heating temperature (75 °C). Different printing screens were examined, with a 300-mesh polyester screen yielding the highest quality wax screen-prints. The carbon electrodes were screen-printed on the μPADs and then examined using cyclic voltammetry. The analytical performance of the SP-ACE-EC-μPADs for the detection of glucose and uric acid in standard solutions was investigated. The results were reproducible, with a linear relationship [R(2) = 0.9987 (glucose) or 0.9997 (uric acid)] within the concentration range of interest, and with detection limits as low as 0.35 mM (glucose) and 0.08 mM (uric acid). To determine the clinical utility of the μPADs, chronoamperometry was used to analyze glucose and uric acid in real urine samples using the standard addition method. Our devices were able to detect the analytes of interest in complex real-world biological samples, and have the potential for use in a wide variety of applications.

  18. The rs2231142 variant of the ABCG2 gene is associated with uric acid levels and gout among Japanese people.

    PubMed

    Yamagishi, Kazumasa; Tanigawa, Takeshi; Kitamura, Akihiko; Köttgen, Anna; Folsom, Aaron R; Iso, Hiroyasu

    2010-08-01

    Recent genome-wide association and functional studies have shown that the ABCG2 gene encodes for a urate transporter, and a common causal ABCG2 variant, rs2231142, leads to elevated uric acid levels and prevalent gout among Whites and Blacks. We examined whether this finding is observed in a Japanese population, since Asians have a high reported prevalence of the T-risk allele. A total of 3923 Japanese people from the Circulatory Risk in Communities Study aged 40-90 years were genotyped for rs2231142. Associations of the rs2231142 variant with serum uric acid levels and prevalence of gout and hyperuricaemia were examined. The frequency of the T-risk allele was 31% in this Japanese sample. Multivariable adjusted mean uric acid levels were 7-9 micromol/l higher for TG and TT than GG carriers (P-additive = 0.0006). The multivariable-adjusted odds ratio (OR) of prevalent gout was 1.37 (95% CI 0.68, 2.76) for TG and 4.37 (95% CI 1.98, 9.62) for TT compared with the GG carriers (P-additive = 0.001). When evaluating the combined outcome of hyperuricaemia and gout, the respective ORs were 1.40 (95% CI 1.04, 1.87) for TG and 1.88 (95% CI 1.23, 2.89) for TT carriers. The population attributable risk was 29% for gout and 19% for gout and/or hyperuricaemia. The association of the causal ABCG2 rs2231142 variant with uric acid levels and gout was confirmed in a sample of Japanese ancestry. Our study emphasizes the importance of this common causal variant in a population with a high risk allele frequency, especially as more Japanese adopt a Western lifestyle with a concomitant increase in mean serum uric acid levels.

  19. Uric acid as a danger signal in gout and its comorbidities

    PubMed Central

    Rock, Kenneth L.; Kataoka, Hiroshi; Lai, Jiann-Jyh

    2013-01-01

    Uric acid is a waste product of purine catabolism. This molecule comes to clinical attention when it nucleates to form crystals of monosodium urate (MSU) in joints or other tissues and thereby causes the inflammatory disease of gout. Patients with gout also frequently suffer from a number of co-morbid conditions including hypertension, diabetes mellitus and cardiovascular disease. Why MSU crystals trigger inflammation and are associated with comorbidities of gout has been unclear, but recent studies provide new insights these issues. Rather than simply being a waste product, uric acid could serve a pathophysiological role as a local alarm signal that alerts the immune system to cell injury and helps to trigger both innate and adaptive immune responses. The inflammatory component of these immune responses is caused when urate crystals trigger both inflammasome-dependent and independent pathways to generate the proinflammatory cytokine IL-1. The resulting bioactive IL-1 stimulates the inflammation of gout and might contribute to the development of other comorbidities. Surprisingly, the same mechanisms underlie the inflammatory response to a number of irritant particles, many of which also cause disease. These new insights help to explain the pathogenesis of gout and point to potential new therapeutic targets for this and other sterile inflammatory diseases. PMID:22945591

  20. Second trimester amniotic fluid glucose, uric acid, phosphate, potassium, and sodium concentrations in relation to maternal pre-pregnancy BMI and birth weight centiles.

    PubMed

    Fotiou, Maria; Michaelidou, Alexandra Maria; Athanasiadis, Apostolos P; Menexes, Georgios; Symeonidou, Maria; Koulourida, Vasiliki; Ganidou, Maria; Theodoridis, Theodoros D; Tarlatzis, Basil C

    2015-05-01

    To study the evolution profile of amniotic fluid (AF) glucose, uric acid, phosphate, potassium, and sodium, in the second trimester of pregnancy, and explore the possible relations between the concentration of these components and maternal, as well as neonatal characteristics. AF of 52 pregnant women was analyzed using an automatic multichannel analyzer. Maternal age, pre-pregnancy Body Mass Index (BMI), inter-pregnancy intervals, and smoking status were derived from questionnaires. Information on pregnancy and delivery was collected from medical records. Uric acid increased (r = 0.423, p < 0.01), while phosphate and glucose concentrations decreased during the period of 16-26th week of pregnancy (r = -0.590, p < 0.001 and r = -0.314, p < 0.05, respectively). Maternal pre-pregnancy BMI was significantly correlated with AF uric acid concentration (r = 0.460, p < 0.01) and marginally with AF glucose (r = 0.274, p = 0.052) and sodium (r = 0.254, p = 0.070) levels. Multiple linear regression indicated that mid-trimester AF uric acid and phosphate levels were significantly related to birth weight centiles (R(2)( )= 0.345, p < 0.05). Our results suggest that: (a) AF phosphate levels reflect gestational age to a satisfactory extent, (b) maternal pre-pregnancy BMI is significantly correlated with AF uric acid concentration, and (c) in appropriate for gestational age infants, AF phosphate and uric acid levels may serve as potential biomarkers of birth weight centiles. Further studies on AF composition may help to unravel the biochemical pathways underlying fetal development and could offer insight on the potential impact of maternal nutritional management on fetal growth regulation.

  1. Uric acid induces hepatic steatosis by generation of mitochondrial oxidative stress: potential role in fructose-dependent and -independent fatty liver.

    PubMed

    Lanaspa, Miguel A; Sanchez-Lozada, Laura G; Choi, Yea-Jin; Cicerchi, Christina; Kanbay, Mehmet; Roncal-Jimenez, Carlos A; Ishimoto, Takuji; Li, Nanxing; Marek, George; Duranay, Murat; Schreiner, George; Rodriguez-Iturbe, Bernardo; Nakagawa, Takahiko; Kang, Duk-Hee; Sautin, Yuri Y; Johnson, Richard J

    2012-11-23

    Uric acid is an independent risk factor in fructose-induced fatty liver, but whether it is a marker or a cause remains unknown. Hepatocytes exposed to uric acid developed mitochondrial dysfunction and increased de novo lipogenesis, and its blockade prevented fructose-induced lipogenesis. Rather than a consequence, uric acid induces fatty liver Hyperuricemic people are more prone to develop fructose-induced fatty liver. Metabolic syndrome represents a collection of abnormalities that includes fatty liver, and it currently affects one-third of the United States population and has become a major health concern worldwide. Fructose intake, primarily from added sugars in soft drinks, can induce fatty liver in animals and is epidemiologically associated with nonalcoholic fatty liver disease in humans. Fructose is considered lipogenic due to its ability to generate triglycerides as a direct consequence of the metabolism of the fructose molecule. Here, we show that fructose also stimulates triglyceride synthesis via a purine-degrading pathway that is triggered from the rapid phosphorylation of fructose by fructokinase. Generated AMP enters into the purine degradation pathway through the activation of AMP deaminase resulting in uric acid production and the generation of mitochondrial oxidants. Mitochondrial oxidative stress results in the inhibition of aconitase in the Krebs cycle, resulting in the accumulation of citrate and the stimulation of ATP citrate lyase and fatty-acid synthase leading to de novo lipogeneis. These studies provide new insights into the pathogenesis of hepatic fat accumulation under normal and diseased states.

  2. Changes in sodium and uric acid concentrations in plasma during the menstrual cycle.

    PubMed

    Mira, M; Stewart, P M; Gebski, V; Llewellyn-Jones, D; Abraham, S F

    1984-03-01

    Hormonal changes during the menstrual cycle are well documented, but many other biochemical variables have not been studied. We find that in the luteal phase of the menstrual cycle the concentrations of sodium and uric acid are significantly lower. The changes may be of significance for the determination of the normal reference interval.

  3. First versus second trimester mean platelet volume and uric acid for prediction of preeclampsia in women at moderate and low risk.

    PubMed

    Rezk, Mohamed; Gaber, Wael; Shaheen, Abdelhamid; Nofal, Ahmed; Emara, Mahmoud; Gamal, Awni; Badr, Hassan

    2018-06-12

    To determine if second trimester mean platelet volume (MPV) and serum uric acid are reasonable predictors of preeclampsia (PE) or not, in patients at moderate and low risk. This prospective study was conducted on 9522 women at low or moderate risk for developing PE who underwent dual measurements of MPV and serum uric acid at late first trimester (10-12 weeks) and at second trimester (18-20 weeks) and subsequently divided into two groups; PE group (n = 286) who later developed PE and non-PE group (n = 9236). Test validity of MPV and serum uric acid was the primary outcome measure. Data were collected and analyzed. Second trimester MPV is a good predictor for development of PE at a cutoff value of 9.55 fL with area under the curve (AUC) of 0.86, sensitivity of 95.2%, specificity of 66.7%, positive predictive value (PPV) of 87%, negative predictive value (NPV) of 85.7%, and accuracy of 86.7%. Second trimester serum uric acid is a good predictor for development of PE at a cutoff value of 7.35 mg/dL, with AUC of 0.85, sensitivity of 95.2%, specificity of 55.6%, PPV of 83.3%, NPV of 83.3%, and accuracy of 83.3%. Combination of both tests has a sensitivity of 100%, specificity of 22.2%, PPV of 75%, NPV of 100%, and accuracy of 76.7%. Second trimester MPV and serum uric acid alone or in combination could be used as a useful biochemical markers for prediction of PE based on their validity, simplicity, and availability.

  4. Effects of Eurycoma longifolia provision on blood sugar level, cholesterols, and uric acid of Etawa Crossbreed Goat

    NASA Astrophysics Data System (ADS)

    Pratomo, Hurip

    2018-05-01

    Previous research on male white rat with provision of Eurycoma longifolia until the 3rd days has increased significantly on the formation of final spermatid from spermatozoon, and testosterone, and increase activity of pituitary cell producing the LH hormone. However, these researches yet studied on possibility of side effects caused by provision of Eurycoma longifolia for 6 days on male EC goat. The research aims to measure the effect of Eurycoma longifolia on the levels of: 1). Blood sugar, 2). Cholesterols, and 3). Uric acid of Male Etawa Crossbreed (EC) goat. This research was conducted through two treatment groups, namely : 1). Control group (provision of aquadest) for 1 day, 3 days, and 6 days, 2) Eurycoma longifolia group with a dose of 90 mg/kg body weight (bb) for 1 day, 3 days, and 6 days. Measurements on the sugar blood, cholesterol and uric acid level were conducted in the 1st, 2nd and 6th days. The obtained data were analyzed using Duncan test with confidence level by 95% (α=0,05) comparing the sugar blood, cholesterol and uric acid measured from the control group in the 1st, 3rd and 6th days with the same compound level measured from the Eurycoma longifolia treatment group in the 1st, 3rd and 6th days. The result obtained there were no significant changes on the sugar blood, cholesterol and uric acid levels between all Eurycoma longifolia treatment groups compared to the control group in the 1st, 3rd and 6th days. Thus, the Eurycoma longifolia provision until in the 6th day did not provide any negative side effects and can be applied in the Etawa crossbreed goat farm.

  5. Association of lead exposure, serum uric acid and parameters of renal function in Nigerian lead-exposed workers.

    PubMed

    Alasia, D D; Emem-Chioma, P C; Wokoma, F S

    2010-10-01

    The presence of hyperuricemia and renal function impairment, especially in the absence of urate stone formation is strongly suggestive of lead nephropathy. The evaluation of this association is essential in areas where lead exposure is still prevalent and uncontrolled. To determine the relationship between serum uric acid and renal function indices in lead-exposed workers. A cross-sectional study of 190 adults with occupational lead exposure and 80 adults (comparison group), matched for age and sex was performed in Port Harcourt, South-south Nigeria. Blood lead was used as the biomarker of lead exposure while serum urea, serum creatinine, urine albumin (using urine albumin:creatinine ratio), estimated glomerular filtration rate (GFR) and serum uric acid were the renal function indices measured. Occupationally lead-exposed subjects had a significantly (p = 0.008) higher mean±SD blood lead levels (50.37±24.58 μg/dL) than the comparison group (41.40±26.85). The mean±SD serum urea (8.6±2.3 mg/dL), creatinine (1.0±0.2 mg/dL) and serum uric acid (4.6±1.2 mg/dL) were significantly (p < 0.01) higher in the study subjects than the comparison group (7.6±2.4, 0.9±0.2, and 3.9±1.1 mg/dL, respectively). The mean±SD creatinine clearance was significantly (p = 0.002) lower in the study subjects than the comparison group (98.9±21.3 vs. 108.2±25.2 mL/min/1.72 m2). Serum uric acid level correlated positively with serum creatinine (r = 0.134) and negatively with GFR (r = -0.151). People with occupational lead exposure are at risk of developing hyperuricemia and renal impairment.

  6. Real-time in vivo uric acid biosensor system for biophysical monitoring of birds.

    PubMed

    Gumus, A; Lee, S; Karlsson, K; Gabrielson, R; Winkler, D W; Erickson, D

    2014-02-21

    Research on birds has long played an important role in ecological investigations, as birds are relatively easily observed, and their high metabolic rates and diurnal habits make them quite evidently responsive to changes in their environments. A mechanistic understanding of such avian responses requires a better understanding of how variation in physiological state conditions avian behavior and integrates the effects of recent environmental changes. There is a great need for sensor systems that will allow free-flying birds to interact with their environment and make unconstrained decisions about their spatial location at the same time that their physiological state is being monitored in real time. We have developed a miniature needle-based enzymatic sensor system suitable for continuous real-time amperometric monitoring of uric acid levels in unconstrained live birds. The sensor system was constructed with Pt/Ir wire and Ag/AgCl paste. Uricase enzyme was immobilized on a 0.7 mm sensing cavity of Nafion/cellulose inner membrane to minimize the influences of background interferents. The sensor response was linear from 0.05 to 0.6 mM uric acid, which spans the normal physiological range for most avian species. We developed a two-electrode potentiostat system that drives the biosensor, reads the output current, and wirelessly transmits the data. In addition to extensive characterization of the sensor and system, we also demonstrate autonomous operation of the system by collecting in vivo extracellular uric acid measurements on a domestic chicken. The results confirm our needle-type sensor system's potential for real-time monitoring of birds' physiological state. Successful application of the sensor in migratory birds could open up a new era of studying both the physiological preparation for migration and the consequences of sustained avian flight.

  7. Random urine uric acid to creatinine and prediction of perinatal asphyxia: a meta-analysis.

    PubMed

    Bellos, Ioannis; Fitrou, Georgia; Pergialiotis, Vasilios; Perrea, Despina N; Papantoniou, Nikolaos; Daskalakis, Georgios

    2018-05-15

    The purpose of the present review is to evaluate whether urine uric acid to creatinine ratio is increased in perinatal asphyxia and hypoxic-ischemic encephalopathy (HIE), as well as to assess its predictive accuracy in the disease. We used the Medline (1966-2017), Scopus (2004-2017), Clinicaltrials.gov (2008-2017), Embase (1980-2017), Cochrane Central Register of Controlled Trials CENTRAL (1999-2017), and Google Scholar (2004-2017) databases in our primary search along with the reference lists of electronically retrieved full-text papers. The hierarchical summary receiver operating characteristic (HSROC) model was used for the meta-analysis of diagnostic accuracy. Fourteen studies were finally included in the present review, that investigated 1226 neonates. Urinary uric acid to creatinine ratio was significantly higher in neonates with perinatal asphyxia than in healthy controls (mean differences (MD): 1.43 95%CI [1.17, 1.69]). Specifically, the mean difference for Sarnat stage 1 was 0.70 (95%CI [0.28, 1.13]), for stage 2 1.41 (95%CI [0.99, 1.84]), and for stage 3 2.71 (95%CI [2.08, 3.35]). The estimated sensitivity for the summary point was 0.90 (95%CI (0.82-0.95)), the specificity was 0.88 (95%CI (0.73-0.95)) and the diagnostic odds ratio was calculated at 63.62 (95%CI (17.08-236.96)). Urinary uric acid to creatinine ratio is a rapid and an easily detected biomarker that may help physicians identify neonates at risk of developing perinatal asphyxia and HIE. However, large-scale prospective studies are still needed to determine its value in predicting mortality, as well as short- and long-term adverse neurological outcomes.

  8. Effect of losartan versus candesartan on uric acid, renal function, and fibrinogen in patients with hypertension and hyperuricemia associated with diuretics.

    PubMed

    Rayner, Brian L; Trinder, Yvonne A; Baines, Donette; Isaacs, Sedick; Opie, Lionel H

    2006-02-01

    Hyperuricemia may counter benefits of blood pressure (BP) reduction, although this is controversial. We examined the effects of candesartan and losartan on uric acid, creatinine, and fibrinogen. Patients with hypertension and serum uric acid > or = 0.42 mmol/L (7 mg/dL) associated with diuretics were randomized to receive losartan 50 to 100 mg or candesartan 8 to 16 mg for 24 weeks. At randomization and after 24 weeks, systolic and diastolic BP, serum uric acid, creatinine, and fibrinogen were measured. A total of 59 patients were entered into the study (30 in the losartan and 29 in the candesartan group). Mean systolic and diastolic BP were reduced in the candesartan group, from 156 mm Hg at baseline to 132 mm Hg at 24 weeks, and from 90.9 to 80.8 mm Hg respectively, P < .0001), and in the losartan group from 150.3 to 132 mm Hg and from 89.6 to 77.6 respectively, P < 0001). Overall mean values of fibrinogen levels were again reduced from 4.39 g/L at baseline to 4.01 g/L at 24 weeks (P < .02). Mean values of serum uric acid in the losartan and candesartan groups were similar at baseline (0.44 and 0.46 mmol/L, respectively), but they were lower in the losartan group after 24 weeks (0.39 and 0.48 mmol/L, P = .01). Twelve patients (44%) in the candesartan group had a 10% increase in serum creatinine compared with four patients (14.2%) in the losartan group (P < .02). Candesartan and losartan lowered BP, but only losartan reduced uric acid. The lowering of fibrinogen in both groups may explain the reduction in stroke with angiotensin receptor blockers. The effect of persistent hyperuricemia on renal function requires further study.

  9. Uric acid and cardiovascular disease.

    PubMed

    Ndrepepa, Gjin

    2018-05-24

    Uric acid (UA) is an end product of purine metabolism in humans and great apes. UA acts as an antioxidant and it accounts for 50% of the total antioxidant capacity of biological fluids in humans. When present in cytoplasm of the cells or in acidic/hydrophobic milieu in atherosclerotic plaques, UA converts into a pro-oxidant agent and promotes oxidative stress and through this mechanism participates in the pathophysiology of human disease including cardiovascular disease (CVD). Most epidemiological studies but not all of them suggested the existence of an association between elevated serum UA level and CVD, including coronary heart disease (CHD), stroke, congestive heart failure, arterial hypertension and atrial fibrillation as well as an increased risk for mortality due to CVD in general population and subjects with confirmed CHD. Evidence available also suggests an association between elevated UA and traditional cardiovascular risk factors, metabolic syndrome, insulin resistance, obesity, non-alcoholic fatty liver disease and chronic kidney disease. Experimental and clinical studies have evidenced several mechanisms through which elevated UA level exerts deleterious effects on cardiovascular health including increased oxidative stress, reduced availability of nitric oxide and endothelial dysfunction, promotion of local and systemic inflammation, vasoconstriction and proliferation of vascular smooth muscle cells, insulin resistance and metabolic dysregulation. Although the causality in the relationship between UA and CVD remains unproven, UA may be pathogenic and participate in the pathophysiology of CVD by serving as a bridging mechanism mediating (enabling) or potentiating the deleterious effects of cardiovascular risk factors on vascular tissue and myocardium. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Comparison of the effects of metoprolol or carvedilol on serum gamma-glutamyltransferase and uric acid levels among patients with acute coronary syndrome without ST segment elevation.

    PubMed

    Aşkın, Lütfü; Karakelleoğlu, Şule; Değirmenci, Hüsnü; Demirelli, Selami; Şimşek, Ziya; Taş, Muhammed Hakan; Topçu, Selim; Lazoğlu, Zakir

    2016-01-01

    Serum gamma-glutamyltransferase (GGT) and uric acid levels measured in patients with acute coronary syndrome without ST segment elevation (NSTEMI) are important in diagnosis and in predicting the prognosis of the disease. There is a limited number of clinical studies investigating the effects of beta-blockers on GGT and uric acid levels in these patients. In our study, we aimed to investigate the effects of beta-blocker therapy on GGT and uric acid levels. We conducted a randomized, prospective clinical study. Hundred patients with NSTEMI were included in this study, and they were divided into two groups. Fifty patients were administered metoprolol succinate treatment (1 x 50 mg), whereas the remaining 50 patients were administered carvedilol treatment (2 x 12.5 mg). Thereafter, all of the patients underwent coronary angiography. Blood samples were taken at the time of admission, at the 1st month, and 3rd month to detect GGT and uric acid levels. There was no statistically significant difference among the metoprolol or carvedilol groups in terms of the GGT levels measured at the baseline, 1st month, and 3rd month (p=0.904 and p=0.573, respectively). In addition, there was no statistically significant difference among the metoprolol or carvedilol groups in terms of uric acid levels measured at the baseline, 1st month, and 3rd month (p=0.601 and p=0.601, respectively). We found that GGT and uric acid levels did not show any change compared to the baseline values, with metoprolol and carvedilol treatment initiated in the early period in patients with NSTEMI.

  11. Genetic variation underlying renal uric acid excretion in Hispanic children: The Viva La Familia Study

    USDA-ARS?s Scientific Manuscript database

    Reduced renal excretion of uric acid plays a significant role in the development of hyperuricemia and gout in adults. Hyperuricemia has been associated with chronic kidney disease and cardiovascular disease in children and adults. There are limited genome-wide association studies associating genetic...

  12. Clinical implications of eicosapentaenoic acid/arachidonic acid ratio (EPA/AA) in adult patients with congenital heart disease.

    PubMed

    Kanoh, Miki; Inai, Kei; Shinohara, Tokuko; Tomimatsu, Hirofumi; Nakanishi, Toshio

    2017-12-01

    Recent studies showed that a low ratio between the levels of eicosapentaenoic acid and those of arachidonic acid (EPA/AA) is associated with higher incidence of coronary artery disease and poor prognosis of heart failure, arrhythmia, and cardiac sudden death. However, the clinical implications of EPA/AA in adult patients with congenital heart disease remain unclear. We aimed to assess the prognostic value of EPA/AA regarding cardiac events in adult patients with congenital heart disease. We measured the serum levels of eicosapentaenoic acid and arachidonic acid in 130 adult patients (median age, 31 years) stratified into two groups according to their EPA/AA (low, ≤0.22; high, >0.22). We prospectively analyzed the association between EPA/AA and incidence of cardiac events during a mean observation period of 15 months, expressed in terms of hazard ratio (HR) with 95% confidence interval (95% CI). In the subgroup of patients with biventricular circulation (2VC) (n = 76), we analyzed the same clinical endpoints. In our study population, EPA/AA was not associated with the incidence of arrhythmic events (HR, 1.52; 95% CI, 0.82-2.85; p = 0.19), but low EPA/AA was a predictor of heart failure hospitalization (HR, 2.83; 95% CI, 1.35-6.30; p < 0.01). Among patients with 2VC, an EPA/AA of ≤0.25 was associated with a significantly higher risk of arrhythmic events (HR, 2.55; 95% CI, 1.11-6.41; p = 0.03) and heart failure hospitalization (HR, 5.20; 95% CI, 1.78-18.1; p < 0.01). EPA/AA represents a useful predictor of cardiac events in adult patients with congenital heart disease.

  13. The effect of coffee, tea, and caffeine consumption on serum uric acid and the risk of hyperuricemia in Korean Multi-Rural Communities Cohort.

    PubMed

    Bae, Jisuk; Park, Pil Sook; Chun, Byung-Yeol; Choi, Bo Youl; Kim, Mi Kyung; Shin, Min-Ho; Lee, Young-Hoon; Shin, Dong Hoon; Kim, Seong-Kyu

    2015-02-01

    Caffeine, a commonly consumed food constituent, is known to exert beneficial physiological effects in humans. There is a lack of comprehensive population data for the effects of caffeine intake on urate metabolism. Therefore, the aim of this study was to determine whether coffee, tea, and caffeine intake influences serum uric acid and the risk of hyperuricemia in the Korean Multi-Rural Communities Cohort. We enrolled 9,400 participants in this study. An assessment of various dietary intake amounts of substances such as coffee and tea was performed using a food frequency questionnaire. The content of caffeine was calculated from coffee (74 mg/cup) and tea (15 mg/cup) intake information from the past year. Multivariate logistic regression models, multiple linear regression models, and analysis of covariance were applied to identify any association of dietary intake with serum uric acid levels or the risk of hyperuricemia. No trends for coffee, tea, or caffeine intake were found according to each quintile with serum uric acid in males, although there were weak, marginally significant trends between the content of coffee and caffeine intake and serum uric acid level in females (p = 0.07 for both). Tea intake in males and caffeine intake in females were significantly different between non-hyperuricemia and hyperuricemia (p = 0.04 and p = 0.04, respectively). In addition, a significant association of serum uric acid level with tea intake in males (β = 0.0006, p = 0.02) and with tea intake and caffeine intake in females (β = 0.0003, p = 0.04 and β = 0.0006, p = 0.02, respectively) was observed. There was no effect of coffee, tea, or caffeine intake on the risk of hyperuricemia in either males or females. This study suggests that caffeine consumption might have an effect on serum uric acid in females. However, coffee, tea, and caffeine intake amounts were not associated with the risk of hyperuricemia.

  14. Association between serum uric acid, high sensitive C-reactive protein and pro-oxidant-antioxidant balance in patients with metabolic syndrome.

    PubMed

    Ahmadnezhad, Mahsa; Arefhosseini, Seyed Rafie; Parizadeh, Mohammad Reza; Tavallaie, Shima; Tayefi, Maryam; Darroudi, Susan; Ghazizadeh, Hamideh; Moohebati, Mohsen; Ebrahimi, Mahmoud; Heidari-Bakavoli, Alireza; Azarpajouh, Mahmoud Reza; Ferns, Gordon A; Mogharebzadeh, Vahid; Ghayour-Mobarhan, Majid

    2018-05-01

    There is persuasive evidence that oxidative stress and inflammation are features of the metabolic syndrome (MetS). We have investigated the relationship between serum pro-oxidant-antioxidant balance (PAB), serum uric acid, and high sensitive C-reactive protein (hs-CRP) in 7,208 participants from the MASHAD study cohort, who were categorized as having MetS, or not, using International Diabetes Foundation (IDF) criteria. Serum hs-CRP was measured by Polyethylene glycol (PEG)-enhanced immunoturbidimetry method using an Alycon analyzer (ABBOTT, Chicago, IL, USA). A colorimetric method was used to determine serum PAB. Serum PAB values were significantly higher in the individuals with MetS compared to those without (P < 0.001). Furthermore, there was a step-wise increase in mean serum PAB concentrations as the number of components of the MetS increased. The combination of features of MetS had different association with serum PAB and hs-CRP. Multiple linear regression analysis showed that body mass index (BMI, B = 2.04, P < 0.001), physical activity level (PAL, B = 18.728, P = 0.001), serum uric acid (B = -1.545, P = 0.003), and serum C-reactive protein (B = 0.663, P < 0.001) were associated with serum PAB in individuals with MetS. Multiple logistic regression analysis showed that serum PAB (B = 0.002, P < 0.001, CI = 1.001-1.003), serum C-reactive protein (B = 0.007, P < 0.015, CI = 1.001-1.013), and serum uric acid (B = 0.207, P < 0.001, CI = 1.186-1.277) were all significantly associated with MetS. Serum PAB was strongly associated with serum uric acid and serum hs-CRP. Moreover, serum PAB as well as serum uric acid and serum hs-CRP were independently associated with MetS. Individual features of MetS were also associated with serum hs-CRP and PAB. © 2018 BioFactors, 44(3):263-271, 2018. © 2018 International Union of Biochemistry and Molecular Biology.

  15. Uric Acid Is a Strong Risk Marker for Developing Hypertension From Prehypertension: A 5-Year Japanese Cohort Study.

    PubMed

    Kuwabara, Masanari; Hisatome, Ichiro; Niwa, Koichiro; Hara, Shigeko; Roncal-Jimenez, Carlos A; Bjornstad, Petter; Nakagawa, Takahiko; Andres-Hernando, Ana; Sato, Yuka; Jensen, Thomas; Garcia, Gabriela; Rodriguez-Iturbe, Bernardo; Ohno, Minoru; Lanaspa, Miguel A; Johnson, Richard J

    2018-01-01

    Prehypertension frequently progresses to hypertension, a condition associated with high morbidity and mortality from cardiovascular diseases and stroke. However, the risk factors for developing hypertension from prehypertension remain poorly understood. We conducted a retrospective cohort study using the data from 3584 prehypertensive Japanese adults (52.1±11.0 years, 2081 men) found to be prehypertensive in 2004 and reexamined in 2009. We calculated the cumulative incidences of hypertension over 5 years, examined risk factors, and calculated odds ratios (ORs) for developing hypertension after adjustments for age, sex, body mass index, smoking and drinking habits, baseline systolic and diastolic blood pressure, pulse rate, diabetes mellitus, dyslipidemia, chronic kidney disease, and serum uric acid levels. The additional analysis evaluated whether serum uric acid (hyperuricemia) constituted an independent risk factor for developing hypertension. The cumulative incidence of hypertension from prehypertension over 5 years was 25.3%. There were no significant differences between women and men (24.4% versus 26.0%; P =0.28). The cumulative incidence of hypertension in subjects with hyperuricemia (n=726) was significantly higher than those without hyperuricemia (n=2858; 30.7% versus 24.0%; P <0.001). After multivariable adjustments, the risk factors for developing hypertension from prehypertension were age (OR, 1.023; P <0.001), female sex (OR, 1.595; P <0.001), higher body mass index (OR, 1.051; P <0.001), higher baseline systolic (OR, 1.072; P <0.001) and diastolic blood pressure (OR, 1.085; P <0.001), and higher serum uric acid (OR, 1.149; P <0.001). Increased serum uric acid is a strong risk marker for developing hypertension from prehypertension. Further studies are needed to determine whether treatment of hyperuricemia in prehypertensive subjects could impede the onset of hypertension. © 2017 American Heart Association, Inc.

  16. Sensitive colorimetric assay for uric acid and glucose detection based on multilayer-modified paper with smartphone as signal readout.

    PubMed

    Wang, Xu; Li, Fang; Cai, Ziqi; Liu, Kaifan; Li, Jing; Zhang, Boyang; He, Jianbo

    2018-04-01

    In this work, a multilayer-modified paper-based colorimetric sensing platform with improved color uniformity and intensity was developed for the sensitive and selective determination of uric acid and glucose with smartphone as signal readout. In detail, chitosan, different kinds of chromogenic reagents, and horseradish peroxidase (HRP) combined with a specific oxidase, e.g., uricase or glucose oxidase (GOD), were immoblized onto the paper substrate to form a multilayer-modified test paper. Hydrogen peroxide produced by the oxidases (uricase or GOD) reacts with the substrates (uric acid or glucose), and could oxidize the co-immoblized chromogenic reagents to form colored products with HRP as catalyst. A simple strategy by placing the test paper on top of a light-emitting diode lamp was adopted to efficiently prevent influence from the external light. The color images were recorded by the smartphone camera, and then the gray values of the color images were calculated for quantitative analysis. The developed method provided a wide linear response from 0.01 to 1.0 mM for uric acid detection and from 0.02 to 4.0 mM for glucose detection, with a limit of detection (LOD) as low as 0.003 and 0.014 mM, respectively, which was much lower than for previously reported paper-based colorimetric assays. The proposed assays were successfully applied to uric acid and glucose detection in real serum samples. Furthermore, the enhanced analytical performance of the proposed method allowed the non-invasive detection of glucose levels in tear samples, which holds great potential for point-of-care analysis. Graphical abstract ᅟ.

  17. Effect of vitamin C supplementation on lipid profile, serum uric acid, and ascorbic acid in children on hemodialysis.

    PubMed

    El Mashad, Ghada Mohamed; ElSayed, Hanan M; Nosair, Nahla A

    2016-01-01

    Children with end-stage renal disease (ESRD) suffer from dyslipidemia and hyperuricemia that might play a causal role in the progression of cardiovascular disease (CVD). The aim of the study is to assess the effects of Vitamin C supplementation on uric acid, ascorbic acid, and serum lipid levels among children on hemodialysis (HD). This prospective study was conducted in the pediatric nephrology unit at Menoufia University Hospital. The study included a total of 60 children with ESRD on maintenance HD therapy. They were divided into two groups: Group I (supplemented group, n = 30) received intravenous Vitamin C supplementation and Group II (control, n = 30) received placebo (intravenous saline) for three months. The results are shown as a mean ± standard deviation. Statistical evaluation was performed by SPSS software (version 11.5) using paired t-test. After supplementation with Vitamin C, the serum Vitamin C and high-density lipoprotein levels increased significantly with a significant reduction in the levels of serum uric acid, cholesterol, low-density lipoproteins, and triglyceride at the end of the study period. No significant changes were observed in the control group. Vitamin C can serve as a useful urate lowering medicine in HD patients to avoid complications of hyperuricemia. Furthermore, it had favorable effects on the lipid profile. This improvement can be considered as a preventive strategy in the progression of CVD in HD patients. Vitamin C supplementation improves ascorbic acid deficiency in these patients.

  18. Distribution of Serum Uric Acid in Black Africans and Its Association With Cardiovascular Risk Factors.

    PubMed

    Moulin, Stephanie R; Baldo, Marcelo P; Souza, Juliana B; Luchi, Weverton M; Capingana, Daniel P; Magalhães, Pedro; Mill, José G

    2017-01-01

    Hyperuricemia is associated with cardiovascular disease and its prevalence is unknown in black Africans. This study reports hyperuricemia distribution and its association with cardiovascular risk factors in a selected Angolan population. A cross-sectional study in 585 black Africans was performed. Hyperuricemia was defined as uric acid >7.0 mg/dL in men or >5.7 mg/dL in women. Overall prevalence was 25%. Hyperuricemia was associated with hypertension (odds ratio [OR], 2.20; confidence interval [CI], 95% 1.41-3.47), high waist circumference (OR, 1.67; CI, 95% 1.05-2.65), and metabolic syndrome (OR, 1.66; CI, 95% 1.07-2.57). Compared to those with uric acid levels in the first quartile, individuals in the fourth quartile showed higher body mass index, waist circumference, systolic blood pressure, and plasma levels of creatinine and triglycerides. Hypertension, high waist circumference, and metabolic syndrome were the major cardiovascular risk factors associated with hyperuricemia. ©2016 Wiley Periodicals, Inc.

  19. Serum uric acid concentration is associated with early changes of glomerular filtration rate in patients with diabetes type 1 without increased albumin excretion.

    PubMed

    Spaleniak, Sebastian; Korzeniewska-Dyl, Irmina; Moczulski, Dariusz

    2014-10-01

    The early loss of renal function in patients with type 1 diabetes may begin before proteinuria. Only 30% of patients with diabetes manifest overt proteinuria. According to the previous studies, increased urinary albumin excretion, which is considered a classic marker of progression of diabetic kidney disease, can regress to normal urine albumin excretion. The current studies conducted in patients with type 1 diabetes without increased urine albumin excretion showed that the uric acid concentration was an independent factor for the development of diabetic kidney disease. The aim of study was to assess the impact of uric acid concentration and to identify risk factors of the early glomerular filtration loss in patients with type 1 diabetes and normal urinary albumin excretion. 147 patients (61 women and 86 men) with type 1 diabetes without increased urine albumin excretion were analysed. GFR (gromerular filtration rate) was estimated based on the serum cystatin C concentration. Centile charts were used to determine the variation of uric acid concentration depending on GFR and gender. The mean value of the filtration rate for the study group was 117 ml/min/m2. The uric acid level above 90th percentile in relation to GFR was diagnosed in 8.2% of women and 0% of men, between 90th and 50th percentile in 44.3 % of women and 5.8% of men and below 50th percentile in 47.5% of women and 94.2% of men. Contrary to men in women higher serum acid concentration was strongly associated with higher glomerular filtration rate. Hyperfiltraion was diagnosed in 15 of women and 19 of men. The high normal uric acid concentration in women with type 1 diabetes might play a crucial role in development of hyperfiltration.

  20. The relationship between training status, blood pressure and uric acid in adults and elderly.

    PubMed

    Trapé, Atila Alexandre; Jacomini, André Mourão; Muniz, Jaqueline Jóice; Sertorio, Jonas Tadeu Cau; Tanus-Santos, José Eduardo; do Amaral, Sandra Lia; Zago, Anderson Saranz

    2013-06-21

    Hypertension can be generated by a great number of mechanisms including elevated uric acid (UA) that contribute to the anion superoxide production. However, physical exercise is recommended to prevent and/or control high blood pressure (BP). The purpose of this study was to investigate the relationship between BP and UA and whether this relationship may be mediated by the functional fitness index. All participants (n = 123) performed the following tests: indirect maximal oxygen uptake (VO2max), AAHPERD Functional Fitness Battery Test to determine the general fitness functional index (GFFI), systolic and diastolic blood pressure (SBP and DBP), body mass index (BMI) and blood sample collection to evaluate the total-cholesterol (CHOL), LDL-cholesterol (LDL-c), HDL-cholesterol (HDL-c), triglycerides (TG), uric acid (UA), nitrite (NO2) and thiobarbituric acid reactive substances (T-BARS). After the physical, hemodynamic and metabolic evaluations, all participants were allocated into three groups according to their GFFI: G1 (regular), G2 (good) and G3 (very good). Baseline blood pressure was higher in G1 when compared to G3 (+12% and +11%, for SBP and DBP, respectively, p<0.05) and the subjects who had higher values of BP also presented higher values of UA. Although UA was not different among GFFI groups, it presented a significant correlation with GFFI and VO2max. Also, nitrite concentration was elevated in G3 compared to G1 (140±29 μM vs 111±29 μM, for G3 and G1, respectively, p<0.0001). As far as the lipid profile, participants in G3 presented better values of CHOL and TG when compared to those in G1. Taking together the findings that subjects with higher BP had elevated values of UA and lower values of nitrite, it can be suggested that the relationship between blood pressure and the oxidative stress produced by uric acid may be mediated by training status.

  1. Uric acid and transforming growth factor in fructose-induced production of reactive oxygen species in skeletal muscle

    PubMed Central

    Maarman, Gerald J.; Ojuka, Edward

    2016-01-01

    The consumption of fructose, a major constituent of the modern diet, has raised increasing concern about the effects of fructose on health. Research suggests that excessive intake of fructose (>50 g/d) causes hyperuricemia, insulin resistance, mitochondrial dysfunction, de novo lipogenesis by the liver, and increased production of reactive oxygen species (ROS) in muscle. In a number of tissues, uric acid has been shown to stimulate the production of ROS via activation of transforming growth factor β1 and NADPH (nicotinamide adenine dinucleotide phosphate) oxidase 4. The role of uric acid in fructose-induced production of ROS in skeletal muscle, however, has not been investigated. This review examines the evidence for fructose-induced production of ROS in skeletal muscle, highlights proposed mechanisms, and identifies gaps in current knowledge. PMID:26946251

  2. Hypertension in Children: Role of Obesity, Simple Carbohydrates, and Uric Acid

    PubMed Central

    Orlando, Antonina; Cazzaniga, Emanuela; Giussani, Marco; Palestini, Paola; Genovesi, Simonetta

    2018-01-01

    Over the past 60 years there has been a dramatic increase in the prevalence of overweight in children and adolescents, ranging from 4% in 1975 to 18% in 2016. Recent estimates indicate that overweight or obese children and adolescents are more than 340 million. Obesity is often associated with hypertension, which is an important cardiovascular risk factor. Recent studies show that the presence of hypertension is a frequent finding in the pediatric age. Hypertensive children easily become hypertensive adults. This phenomenon contributes to increasing cardiovascular risk in adulthood. Primary hypertension is a growing problem especially in children and adolescents of western countries, largely because of its association with the ongoing obesity epidemic. Recently, it has been hypothesized that a dietary link between obesity and elevated blood pressure (BP) values could be simple carbohydrate consumption, particularly fructose, both in adults and in children. Excessive intake of fructose leads to increased serum uric acid (SUA) and high SUA values are independently associated with the presence of hypertension and weaken the efficacy of lifestyle modifications in children. The present review intends to provide an update of existing data regarding the relationship between BP, simple carbohydrates (particularly fructose), and uric acid in pediatric age. In addition, we analyze the national policies that have been carried out over the last few years, in order to identify the best practices to limit the socio-economic impact of the effects of excessive sugar consumption in children. PMID:29774210

  3. A Synthetic Uric Acid Analog Accelerates Cutaneous Wound Healing in Mice

    PubMed Central

    Chan, Sic L.; Arumugam, Thiruma V.; Baharani, Akanksha; Tang, Sung-Chun; Yu, Qian-Sheng; Holloway, Harold W.; Wheeler, Ross; Poosala, Suresh; Greig, Nigel H.; Mattson, Mark P.

    2010-01-01

    Wound healing is a complex process involving intrinsic dermal and epidermal cells, and infiltrating macrophages and leukocytes. Excessive oxidative stress and associated inflammatory processes can impair wound healing, and antioxidants have been reported to improve wound healing in animal models and human subjects. Uric acid (UA) is an efficient free radical scavenger, but has a very low solubility and poor tissue penetrability. We recently developed novel UA analogs with increased solubility and excellent free radical-scavenging properties and demonstrated their ability to protect neural cells against oxidative damage. Here we show that the uric acid analog (6, 8 dithio-UA, but not equimolar concentrations of UA or 1, 7 dimethyl-UA) modified the behaviors of cultured vascular endothelial cells, keratinocytes and fibroblasts in ways consistent with enhancement of the wound healing functions of all three cell types. We further show that 6, 8 dithio-UA significantly accelerates the wound healing process when applied topically (once daily) to full-thickness wounds in mice. Levels of Cu/Zn superoxide dismutase were increased in wound tissue from mice treated with 6, 8 dithio-UA compared to vehicle-treated mice, suggesting that the UA analog enhances endogenous cellular antioxidant defenses. These results support an adverse role for oxidative stress in wound healing and tissue repair, and provide a rationale for the development of UA analogs in the treatment of wounds and for modulation of angiogenesis in other pathological conditions. PMID:20386608

  4. Hypertension in Children: Role of Obesity, Simple Carbohydrates, and Uric Acid.

    PubMed

    Orlando, Antonina; Cazzaniga, Emanuela; Giussani, Marco; Palestini, Paola; Genovesi, Simonetta

    2018-01-01

    Over the past 60 years there has been a dramatic increase in the prevalence of overweight in children and adolescents, ranging from 4% in 1975 to 18% in 2016. Recent estimates indicate that overweight or obese children and adolescents are more than 340 million. Obesity is often associated with hypertension, which is an important cardiovascular risk factor. Recent studies show that the presence of hypertension is a frequent finding in the pediatric age. Hypertensive children easily become hypertensive adults. This phenomenon contributes to increasing cardiovascular risk in adulthood. Primary hypertension is a growing problem especially in children and adolescents of western countries, largely because of its association with the ongoing obesity epidemic. Recently, it has been hypothesized that a dietary link between obesity and elevated blood pressure (BP) values could be simple carbohydrate consumption, particularly fructose, both in adults and in children. Excessive intake of fructose leads to increased serum uric acid (SUA) and high SUA values are independently associated with the presence of hypertension and weaken the efficacy of lifestyle modifications in children. The present review intends to provide an update of existing data regarding the relationship between BP, simple carbohydrates (particularly fructose), and uric acid in pediatric age. In addition, we analyze the national policies that have been carried out over the last few years, in order to identify the best practices to limit the socio-economic impact of the effects of excessive sugar consumption in children.

  5. Serum uric acid levels in patients with Parkinson's disease: A meta-analysis.

    PubMed

    Wen, Min; Zhou, Bo; Chen, Yun-Hua; Ma, Zhao-Lei; Gou, Yun; Zhang, Chun-Lin; Yu, Wen-Feng; Jiao, Ling

    2017-01-01

    Lower serum uric acid (UA) levels have been reported as a risk factor in Parkinson's disease (PD). However, the results have been inconsistent so far. The aim of the present study was to clarify the potential relationship of uric acid with PD. Comprehensive electronic search in pubmed, web of science, and the Cochrane Library database to find original articles about the association between PD and serum uric acid levels published before Dec 2015. Literature quality assessment was performed with the Newcastle-Ottawa Scale. Random-effects model was used to estimate the standardized mean differences (SMDs) with 95% confidence intervals (CIs). Heterogeneity across studies was assessed using I2 and H2 statistics. Sensitivity analyses to assess the influence of individual studies on the pooled estimate. Publication bias was investigated using funnel plots and Egger's regression test. Analyses were performed by using Review Manager 5.3 and Stata 11.0. Thirteen studies with a total of 4646 participants (2379 PD patients and 2267 controls) were included in this meta-analysis. The current results showed that the serum UA levels in PD patients were significantly lower compared to sex and age-matched healthy controls (SMD: -0.49, 95% CI: [-0.67, -0.30], Z = 5.20, P < 0.001) and these results showed no geographic regional (Asia: SMD = -0.65, 95% CI [-0.84, -0.46], Z = 6.75, p <0.001; Non-Asia: SMD = -0.25, 95% CI [-0.43, -0.07], Z = 2.70, p = 0.007) and sex differences (women: SMD = -0.53, 95% CI [-0.70, -0.35], z = 5.98, p <0.001; men: SMD = -0.66, 95% CI [-0.87, -0.44], z = 6.03, p <0.001). Serum UA levels in middle-late stage PD patients with higher H&Y scales were significantly lower than early stage PD patients with lower H&Y scales (SMD = 0.63, 95% CI [0.36,0.89], z = 4.64, p <0.001). Our study showed that the serum UA levels are significantly lower in PD and the level is further decreased as the disease progresses. Thus it might be a potential biomarker to indicate the

  6. Serum levels of uric acid and diabetes mellitus influence survival after surgery for primary hyperparathyroidism: a prospective cohort study.

    PubMed

    Bergenfelz, Anders; Bladström, Anna; Their, Mark; Nordenström, Erik; Valdemarsson, Stig; Westerdahl, Johan

    2007-07-01

    Primary hyperparathyroidism (pHPT) is associated with an increased mortality attributable to cardiovascular disease (CVD), suggested to be alleviated by surgery. The exact mechanism of the beneficial influence of parathyroidectomy on survival is unknown. Furthermore, studies suggest that there is no increased mortality compared to the mortality rate in the general population during recent years. This study therefore investigated relative survival (RS), as well overall mortality associated with the clinical and biochemical variables in patients undergoing operation for sporadic pHPT. Furthermore, the influence of surgery on biochemical variables associated with pHPT was analyzed. A group of 323 patients with sporadic pHPT operated between September 1989 and July 2003 were followed from surgery over a 10-year period. The median and mean follow-up time was 69 and 70 months, respectively (range: 1-120 months). Relative survival (RS) was calculated, and the impact of clinical and biochemical variables on overall death were evaluated. Postoperatively, serum levels of triglycerides and uric acid decreased. Glucose levels and glomerular filtration rate remained unchanged. A decreased RS was evident during the latter part of the 10 year follow-up period. In the multivariate Cox-analysis, diabetes mellitus (hazard ratio [HR] = 2.8, 95%; confidence interval [CI] 1.2-6.7), and the combination of an increased level of serum uric acid and cardiovascular disease (CVD) (HR = 8.6, 95%; CI 1.5-49.7) was associated with a higher mortality. The increased risk of death was evident for patients with persistently increased levels of uric acid postoperatively (HR = 4.8, 95%; CI = 1.4-16.01). Patients undergoing operation for pHPT had a decreased RS during a 10-year follow-up compared to the general population. This decrease in RS is associated with diabetes mellitus and increased levels of uric acid pre-and postoperatively.

  7. Serum Uric Acid, Hyperuricemia and Body Mass Index in Children and Adolescents with Intellectual Disabilities

    ERIC Educational Resources Information Center

    Lin, Jin-Ding; Lin, Pei-Ying; Lin, Lan-Ping; Hsu, Shang-Wei; Yen, Chia-Feng; Fang, Wen-Hui; Wu, Sheng-Ru; Chien, Wu-Chien; Loh, Ching-Hui; Chu, Cordia M.

    2009-01-01

    The aims of the preset study were to describe the profile of serum uric acid, the prevalence of hyperuricemia and its risk factors among children and adolescents with intellectual disabilities. We conducted a cross-sectional study of 941 children and adolescents with intellectual disabilities (aged 4-18 years) who participated in annual health…

  8. Uric acid but not apple polyphenols is responsible for the rise of plasma antioxidant activity after apple juice consumption in healthy subjects.

    PubMed

    Godycki-Cwirko, Maciek; Krol, Maciej; Krol, Bogusław; Zwolinska, Anna; Kolodziejczyk, Krzysztof; Kasielski, Marek; Padula, Gianluca; Grebowski, Jacek; Grębocki, Jacek; Kazmierska, Paulina; Kazimierska, Paulina; Miatkowski, Marcin; Markowski, Jarosław; Nowak, Dariusz

    2010-08-01

    To determine whether (1) rapid consumption of 1 L of apple juice increases blood antioxidant capacity, measured as ferric-reducing ability of plasma (FRAP) and serum 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, and (2) apple polyphenols or fructose-induced elevation of plasma uric acid contributes to post-juice increase of blood antioxidant activity. The study involved 12 (mean age 32 ± 5 years, mean body weight 73 ± 7 kg) healthy nonsmoking subjects. Tested subjects consumed 1 L of clear apple juice and then FRAP; serum DPPH-scavenging activity, serum uric acid, and total plasma phenolics and quercetin levels were measured just before juice ingestion and 1, 2.5, and 4 hours after ingestion. This was repeated 3 times with 4-day intervals, but volunteers drank either 1 L of clear apple juice without polyphenols (placebo), or 1 L of cloudy apple juice (positive control), or 1 L of water (negative control) at the time. All juices had similar content of sugars (i.e., saccharose, glucose, and fructose) and precisely defined composition of phenolics and antioxidant activity. Consumption of all 3 juices transiently increased FRAP and serum DPPH-scavenging activity, with peak values at 1 hour post-juice ingestion. This was paralleled by the rise of serum uric acid, but no significant changes in plasma total phenolics and quercetin levels were observed after all dietary interventions. At the same time, no substantial differences were found between juices (especially between clear apple juice and clear apple juice without polyphenols) concerning the measured variables. A strong significant correlation was noted instead between serum uric acid and plasma antioxidant activity at all analyzed time points, before and after juice ingestion. Plasma total phenolics and quercetin levels were not associated with FRAP and serum DPPH radical-scavenging activity. We have demonstrated that rapid consumption of apple juice increased plasma antioxidant activity in

  9. The antioxidant capacity of erythrocyte concentrates is increased during the first week of storage and correlated with the uric acid level.

    PubMed

    Bardyn, M; Maye, S; Lesch, A; Delobel, J; Tissot, J-D; Cortés-Salazar, F; Tacchini, P; Lion, N; Girault, H H; Prudent, M

    2017-10-01

    Red blood cells (RBCs) suffer from lesions during cold storage, depending in part on their ability to counterbalance oxidative stress by activating their antioxidant defence. The aim of this study was to monitor the antioxidant power (AOP) in erythrocyte concentrates (ECs) during cold storage. Six ECs were prepared in saline-adenine-glucose-mannitol (SAGM) additive solution and followed during 43 days. The AOP was quantified electrochemically using disposable electrode strips and compared with results obtained from a colorimetric assay. Haematological data, data on haemolysis and the extracellular concentration of uric acid were also recorded. Additionally, a kinetic model was developed to extract quantitative kinetic data on the AOP behaviour. The AOP of total ECs and their extracellular samples attained a maximum after 1 week of storage prior to decaying and reaching a plateau, as shown by the electrochemical measurements. The observed trend was confirmed with a colorimetric assay. Uric acid had a major contribution to the extracellular AOP. Interestingly, the AOP and uric acid levels were linked to the sex of the donors. The marked increase in AOP during the first week of storage suggests that RBCs are impacted early by the modification of their environment. The AOP behaviour reflects the changes in metabolism activity following the adjustment of the extracellular uric acid level. Knowing the origin, interdonor variability and the effects of the AOP on the RBCs could be beneficial for the storage quality, which will have to be further studied. © 2017 International Society of Blood Transfusion.

  10. Validation of a multi-analyte HPLC-DAD method for determination of uric acid, creatinine, homovanillic acid, niacinamide, hippuric acid, indole-3-acetic acid and 2-methylhippuric acid in human urine.

    PubMed

    Remane, Daniela; Grunwald, Soeren; Hoeke, Henrike; Mueller, Andrea; Roeder, Stefan; von Bergen, Martin; Wissenbach, Dirk K

    2015-08-15

    During the last decades exposure sciences and epidemiological studies attracts more attention to unravel the mechanisms for the development of chronic diseases. According to this an existing HPLC-DAD method for determination of creatinine in urine samples was expended for seven analytes and validated. Creatinine, uric acid, homovanillic acid, niacinamide, hippuric acid, indole-3-acetic acid, and 2-methylhippuric acid were separated by gradient elution (formate buffer/methanol) using an Eclipse Plus C18 Rapid Resolution column (4.6mm×100mm). No interfering signals were detected in mobile phase. After injection of blank urine samples signals for the endogenous compounds but no interferences were detected. All analytes were linear in the selected calibration range and a non weighted calibration model was chosen. Bias, intra-day and inter-day precision for all analytes were below 20% for quality control (QC) low and below 10% for QC medium and high. The limits of quantification in mobile phase were in line with reported reference values but had to be adjusted in urine for homovanillic acid (45mg/L), niacinamide 58.5(mg/L), and indole-3-acetic acid (63mg/L). Comparison of creatinine data obtained by the existing method with those of the developed method showing differences from -120mg/L to +110mg/L with a mean of differences of 29.0mg/L for 50 authentic urine samples. Analyzing 50 authentic urine samples, uric acid, creatinine, hippuric acid, and 2-methylhippuric acid were detected in (nearly) all samples. However, homovanillic acid was detected in 40%, niacinamide in 4% and indole-3-acetic acid was never detected within the selected samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Electrocatalytic oxidation and voltammetric determination of ciprofloxacin employing poly(alizarin red)/graphene composite film in the presence of ascorbic acid, uric acid and dopamine.

    PubMed

    Zhang, Xin; Wei, Youli; Ding, Yaping

    2014-07-04

    A glassy carbon electrode modified with poly(alizarin red)/electrodeposited graphene (PAR/EGR) composite film was prepared and applied to detect ciprofloxacin (CPFX) in the presence of ascorbic, uric acid and dopamine. The morphology and interface property of PAR/EGR films were examined by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The electrocatalytic oxidation of CPFX on AR/EGR was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The linearity ranged from 4 × 10(-8) to 1.2 × 10(-4) M with a detection limit (S/N=3) of 0.01 μM. The modified electrode could be applied to the individual determination of CPFX as well as the simultaneous determination of CPFX, ascorbic acid, uric acid and dopamine. This method proved to be a simple, selective and rapid way to determine CPFX in pharmaceutical preparation and biological media. Copyright © 2014. Published by Elsevier B.V.

  12. Bilateral uric acid nephrolithiasis and ureteral hypertrophy in a free-ranging river otter (Lontra canadensis)

    USGS Publications Warehouse

    Grove, Robert A.; Bildfell, Rob; Henny, Charles J.; Buhler, D.R.

    2003-01-01

    We report the first case of uric acid nephrolithiasis in a free-ranging river otter (Lontra canadensis). A 7 yr old male river otter collected from the Skagit River of western Washington (USA) had bilateral nephrolithiasis and severely enlarged ureters (one of 305 examined [0.33%]). The uroliths were 97% uric acid and 3% protein. Microscopic changes in the kidney were confined to expansion of renal calyces, minor loss of medullary tissue, and multifocal atrophy of the cortical tubules. No inflammation was observed in either kidney or the ureters. The ureters were enlarged due to marked hypertrophy of smooth muscle plus dilation of the lumen. Fusion of the major calyces into a single ureteral lumen was several cm distal to that of two adult male otters used as histopathologic control specimens. This case report is part of a large contaminant study of river otters collected from Oregon and Washington. It is important to understand diseases and lesions of the otter as part of our overall evaluation of this population.

  13. [Risk control of traditional Chinese medicines containing aristolochis acids (AAs) based on influencing factors of content of AAs].

    PubMed

    Tian, Jing-Zhuo; Liang, Ai-Hua; Liu, Jing; Zhang, Bo-Li

    2017-12-01

    Aristolochic acids (AAs) widely exist in such plants as Aristolochia and Asarum. The renal toxicity of AAs as well as its carcinogenicity to urinary system have been widely known. In 2003 and 2004, China prohibited the use of Aristolochiae Radix, Aristolochiae Manshuriensis Caulis and Aristolochiae Fangchi Radix, and required administering other AAs-containing medicines in accordance with the regulations for prescription drugs. In this paper, we retrieved literatures on the content determination of AAs in recent 10 years in China. It suggested that the AAs content is lower in Asarum herb, especially in its roots and rhizomes, and most of which do not show detectable amount of AA-I. Some of traditional Chinese medicines show fairly small amount of detectable AA-I. The AAs content in Aristolochia herb (including Fructus Aristolochiae, kaempfer dutchmanspipe root) is relatively high; however, there are fewer literatures for studying the content determination of AAs in Chinese patent medicines. There were many factors affecting AAs content, including the parts used, origins, processing methods, extraction process. It suggested that we should pay attention to the toxicity of Chinese medicines containing AAs and use these decoction pieces and traditional Chinese medicines cautiously. In addition, basic studies for the origins, processing methods and extraction process of Chinese patent medicines containing AAs, as well as supervision and detection of AAs content in traditional Chinese medicinal materials, decoction pieces and Chinese patent medicines shall be strengthened for reducing medication risk and guaranteeing clinical medication safety. Copyright© by the Chinese Pharmaceutical Association.

  14. Successful Diabetic Control as Measured by Hemoglobin A1c is Associated with Lower Urine Risk Factors for Uric Acid Calculi.

    PubMed

    Maciolek, Kimberly A; Penniston, Kristina L; Jhagroo, R Allan; Best, Sara L

    2018-06-13

    To examine the association of glycemic control, including strict glycemic control, with 24-hour (24-h) urine risk factors for uric acid and calcium calculi. With IRB approval, we identified 183 stone formers (SFs) with 459 24-h urine collections. Hemoglobin A1c (HgbA1c) measures were obtained within 3 months of the urine collection. Collections were separated into normoglycemic (NG, HgbA1c<6.5) and hyperglycemic (HG, HgbA1c≥6.5) cohorts; 24-h urine parameters were compared. The NG cohort was further divided into patients with and without a history of diabetes type 2 (DM). Variables were analyzed using chi squared, Welch's t-test and multivariate linear regression to adjust for clustering, BMI, age, gender, thiazide and potassium citrate use. Patients in the HG group were older with higher BMI. Multivariate analysis of the total study population revealed that hyperglycemia correlated with lower pH, higher uric acid relative saturation (RS), lower brushite RS and higher citrate. NG SFs with and without a history of DM had similar risk factors for uric acid stone formation. Among NG SFs, those with DM had higher urine calcium (UCa) and calcium oxalate RS than those without DM. However, this difference may be related to other factors since neither parameter correlated with DM on multivariate regression (p>0.05). Successful glycemic control may be associated with reduced urinary risk factors for uric acid stone formation. Patients with well controlled DM had equivalent risk factors to those without DM. Glycemic control should be considered a target of the multidisciplinary medical management of stone disease.

  15. Study of photo-oxidative reactivity of sunscreening agents based on photo-oxidation of uric acid by kinetic Monte Carlo simulation.

    PubMed

    Moradmand Jalali, Hamed; Bashiri, Hadis; Rasa, Hossein

    2015-05-01

    In the present study, the mechanism of free radical production by light-reflective agents in sunscreens (TiO2, ZnO and ZrO2) was obtained by applying kinetic Monte Carlo simulation. The values of the rate constants for each step of the suggested mechanism have been obtained by simulation. The effect of the initial concentration of mineral oxides and uric acid on the rate of uric acid photo-oxidation by irradiation of some sun care agents has been studied. The kinetic Monte Carlo simulation results agree qualitatively with the existing experimental data for the production of free radicals by sun care agents. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Uric acid and transforming growth factor in fructose-induced production of reactive oxygen species in skeletal muscle.

    PubMed

    Madlala, Hlengiwe P; Maarman, Gerald J; Ojuka, Edward

    2016-04-01

    The consumption of fructose, a major constituent of the modern diet, has raised increasing concern about the effects of fructose on health. Research suggests that excessive intake of fructose (>50 g/d) causes hyperuricemia, insulin resistance, mitochondrial dysfunction, de novo lipogenesis by the liver, and increased production of reactive oxygen species (ROS) in muscle. In a number of tissues, uric acid has been shown to stimulate the production of ROS via activation of transforming growth factor β1 and NADPH (nicotinamide adenine dinucleotide phosphate) oxidase 4. The role of uric acid in fructose-induced production of ROS in skeletal muscle, however, has not been investigated. This review examines the evidence for fructose-induced production of ROS in skeletal muscle, highlights proposed mechanisms, and identifies gaps in current knowledge. © The Author(s) 2016. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  17. Assessment of urinary inhibitor or promoter activity in uric acid nephrolithiasis

    PubMed Central

    Doizi, Steeve; Rodgers, Kathy; Poindexter, John; Sakhaee, Khashayar; Maalouf, Naim M.

    2017-01-01

    Purpose To assess the presence of a reduced inhibitor activity or an increased promoter activity in urine of idiopathic uric acid stone formers (IUASF) compared to non-stone formers (NSF) independent of urinary pH. Methods 30 IUASF, 9 obese NSF and 12 lean NSF collected 24-hour urine under metabolic diet. Three urine aliquots per subject were used to assess spontaneous nucleation (SN, de novo crystal formation), crystal growth (CG) using a 0.1 mg/mL seed of anhydrous uric acid (UA) and steady state (SS) of UA solubility using a 5 mg/mL seed of UA (assessing maximum amount of UA dissolvable in urine). All experiments were conducted for 6 hours at a constant pH of 5.0. UA concentration was measured in filtered aliquots at 0, 3 and 6 hours. Results At baseline, 24-hour urinary pH was significantly lower and UA saturation significantly higher in IUASF. No significant SN occurred and a similar SS UA concentration was reached in the three groups. IUASF and lean NSF displayed a similar decrease in UA concentration during CG, while obese NSF started with higher UA concentration and consequently displayed higher magnitude of decrease in UA concentration for CG. Conclusions This study suggests that there is no significant difference between IUASF and NSF in terms of promoter or inhibitor activity in whole urine against UA stone formation when urine pH is maintained constant. The findings suggest that UA stone formation is dictated by a high urinary saturation with respect to UA, driven primarily by a low urine pH. PMID:26723865

  18. Metabolic syndrome and uric acid nephrolithiasis: insulin resistance in focus.

    PubMed

    Spatola, Leonardo; Ferraro, Pietro Manuel; Gambaro, Giovanni; Badalamenti, Salvatore; Dauriz, Marco

    2018-06-01

    Uric acid nephrolithiasis (UAN) is an increasingly common disease in ethnically diverse populations and constitutes about 10% of all kidney stones. Metabolic syndrome and diabetes mellitus are accounted among the major risk factors for UAN, together with environmental exposure, individual lifestyle habits and genetic predisposition. The development and overt manifestation of UAN appears to stem on the background of insulin resistance, which acts at the kidney level by reducing urinary pH, thus hampering the ability of the kidney to generate renal ammonium in response to an acid load. Unduly acidic urinary pH and overt UAN are both considered renal manifestations of insulin resistance. The mechanisms underlying increased endogenous acid production and/or defective ammonium excretion are yet to be completely understood. Although the development of UAN and, more in general, of kidney stones largely recognizes modifiable individual determining factors, the rising prevalence of diabetes, obesity and accompanying metabolic disorders calls for the identification of novel therapeutic approaches and intervention targets. This review aims at providing an updated picture of existing evidence on the relationship between insulin resistance and UAN in the context of metabolic syndrome and in light of the most recent advancements in our understanding of its genetic signature. Copyright © 2018. Published by Elsevier Inc.

  19. The occurence of uric acids and the growth morphology of the anhydrous monoclinic modification : C 5H 4N 4O 3

    NASA Astrophysics Data System (ADS)

    Rinaudo, C.; Boistelle, R.

    1980-07-01

    Anhydrous and hydrated uric acid crystals which frequently occur in human urolithiasis have been grown from pure aqueous solutions at 25 and 37°C. The appearance domain of either modification is given as a function of initial uric acid concentration at pH values ranging from 3.0 to 5.5. The present paper mostly deals with the anhydrous phase and it is shown that its experimental and theoretical growth morphologies are in agreement, the crystals exhibiting the {100}, {210}, {121}, {001} and {201} forms. Crystal habit depends on supersaturation; {100} has always the largest extension at low supersaturation {121} develops to the detriment of {210}, {001} and {201}.

  20. Serum uric acid and progression of diabetic nephropathy in type 1 diabetes.

    PubMed

    Pilemann-Lyberg, S; Lindhardt, M; Persson, Frederik; Andersen, S; Rossing, P

    2018-05-01

    Uric acid (UA) is a risk factor for CKD. We evaluated UA in relation to change in GFR in patients with type 1 diabetes. Post hoc analysis of a trial of losartan in diabetic nephropathy, mean follow-up 3 years (IQR 1.5-3.5). UA was measured at baseline. Primary end-point was change in measured GFR. UA was tested in a linear regression model adjusted for known progression factors (gender, HbA 1c , systolic blood pressure, cholesterol, baseline GFR and baseline urinary albumin excretion rate (UAER)). Baseline UA was 0.339 mmol/l (SD ±0.107), GFR 87 ml/min/1.73 m 2 (±23), geometric mean UAER 1023 mg/24 h (IQR, 631 - 1995). Mean rate of decline in GFR was 4.6 (3.7) ml/min/year. In the upper quartile of baseline UA the mean decline in GFR from baseline to the end of the study was 6.2 (4.9) ml/min/1.73 m 2 and 4.1 (3.1) ml/min/1.73 m 2 in the three lower quartiles of UA, (p = 0.088). In a linear model including baseline covariates (UAER, GFR, total cholesterol, HDL cholesterol) UA was associated with decline in GFR (r 2  = 0.45, p < 0.001). Uric acid was weakly associated with decline in GFR in type 1 diabetic patients with overt nephropathy. Copyright © 2018. Published by Elsevier Inc.

  1. Analysis of the relationship of leptin, high-sensitivity C-reactive protein, adiponectin, insulin, and uric acid to metabolic syndrome in lean, overweight, and obese young females.

    PubMed

    Abdullah, Abdul Ridha; Hasan, Haydar A; Raigangar, Veena L

    2009-02-01

    Over the last decade there has been a steady rise in obesity and co-morbidity, but little is known about the rate of metabolic dysfunction among young adults in the United Arab Emirates. Various factors have been implicated as biomarkers of metabolic syndrome. The objective of this study was to analyze the relationships of leptin, C-reactive protein (CRP), adiponectin, insulin, and uric acid to the metabolic syndrome components in lean, overweight, and obese young females. This was a cross-sectional study of 69 apparently healthy young females, who were classified according to their body mass index (BMI) (kg/m(2)) into three groups: lean (25 and <30), and obese (>or=30). Estimated biomarkers were: leptin, insulin, adiponectin, high-sensitivity [hs]-CRP, uric acid, blood sugar, high-density lipoprotein (HDL), low-density lipoprotein (LDL), total cholesterol, and triglycerides (TG). Anthropometric measures, blood pressure, and homeostasis model assessment-insulin resistance (HOMA-IR) were also measured. Serum leptin, hs-CRP, insulin, and uric acid increased significantly (p < 0.01) with increased BMI. Only one significant correlation (p < 0.05) between the biomarkers and the metabolic syndrome components was found in lean subjects (leptin vs. waist circumference r = 0.48) as opposed to six in the obese group (hs-CRP vs. waist circumference and systolic blood pressure [SBP], r = 0.45 and r = -0.41, respectively; insulin vs. diastolic blood pressure [DBP], r = 0.47; adiponectin vs. blood sugar, r = -0.44; and uric acid vs. waist circumference and TG, r = 0.5 and r = 0.51, respectively). Estimation of the levels of studied biomarkers could be an important tool for early detection of metabolic syndrome before the appearance of its frank components. Uric acid seems to be the most reliable biomarker to identify obese subjects with metabolic syndrome.

  2. Waist circumference, body mass index, serum uric acid, blood sugar, and triglyceride levels are important risk factors for abnormal liver function tests in the Taiwanese population.

    PubMed

    Hsieh, Meng-Hsuan; Lin, Wen-Yi; Chien, Hsu-Han; Chien, Li-Ho; Huang, Chao-Kuan; Yang, Jeng-Fu; Chang, Ning-Chia; Huang, Chung-Feng; Wang, Chao-Ling; Chuang, Wan-Long; Yu, Ming-Lung; Dai, Chia-Yen; Ho, Chi-Kung

    2012-09-01

    Several studies have found that metabolic syndrome and uric acid level are related to abnormal liver function test results. The aim of this study was to explore the associations of risk factors [including blood pressure, blood sugar, total cholesterol, triglyceride, uric acid, waist circumference and body mass index (BMI) measurements] with abnormal liver function in the Taiwanese population.In total, 11,411 Taiwanese adults were enrolled in this study. Blood pressure was assessed according to the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure criteria, fasting blood sugar level according to the Bureau of Health Promotion, Department of Health, R.O.C., criteria, total cholesterol and triglyceride levels according to the Third Report of the National Cholesterol Education Program Adult Treatment Panel III criteria, BMI according to the Asia-Pacific criteria, and waist circumference according to the Revised Diagnostic Criteria of Metabolic Syndrome in Taiwan. The prevalence of a past history of hypertension and diabetes mellitus was 17.7% and 6.5%, respectively, and the rates of abnormal measurements of blood pressure, BMI, waist circumference, fasting blood sugar, triglyceride, total cholesterol, uric acid (male/female), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were 76.2%, 67.6%, 40.0%, 28.6%, 30.6%, 57.3%, 37.9%/21.9%, 14.6% and 21.3%, respectively. Multivariate analysis showed that waist circumference, BMI, serum uric acid, blood sugar, and triglyceride levels were related to abnormal AST and ALT (p<0.05), but the odds ratio for waist circumference was larger than that for BMI. In conclusion, waist circumference, BMI, serum uric acid, blood sugar, and triglyceride levels are important risk factors for abnormal AST and ALT readings in Taiwanese adults. Waist circumference might be a better indicator of risk of abnormal liver function than BMI. Copyright © 2012

  3. Serum uric acid concentrations in a Xhosa community in the Transkei of Southern Africa.

    PubMed

    Beighton, P; Daynes, G; Soskolne, C L

    1976-02-01

    Serum uric acid (SUA) concentrations were measured in specimens obtained from 479 respondents aged 15 and over during an epidemiological survey of bone and joint conditions in a tribal Xhosa community living in the Transkei, Southern Africa. Population SUA levels in the Xhosa were significantly lower than those previously observed in South Africa Negro groups in rural and urban environments. This finding agrees with the observations that population SUA concentrations tend to rise with increasing complexity of life style.

  4. Mildly abnormal general movement quality in infants is associated with higher Mead acid and lower arachidonic acid and shows a U-shaped relation with the DHA/AA ratio.

    PubMed

    van Goor, S A; Schaafsma, A; Erwich, J J H M; Dijck-Brouwer, D A J; Muskiet, F A J

    2010-01-01

    We showed that docosahexaenoic acid (DHA) supplementation during pregnancy and lactation was associated with more mildly abnormal (MA) general movements (GMs) in the infants. Since this finding was unexpected and inter-individual DHA intakes are highly variable, we explored the relationship between GM quality and erythrocyte DHA, arachidonic acid (AA), DHA/AA and Mead acid in 57 infants of this trial. MA GMs were inversely related to AA, associated with Mead acid, and associated with DHA/AA in a U-shaped manner. These relationships may indicate dependence of newborn AA status on synthesis from linoleic acid. This becomes restricted during the intrauterine period by abundant de novo synthesis of oleic and Mead acids from glucose, consistent with reduced insulin sensitivity during the third trimester. The descending part of the U-shaped relation between MA GMs and DHA/AA probably indicates DHA shortage next to AA shortage. The ascending part may reflect a different developmental trajectory that is not necessarily unfavorable. Copyright 2009 Elsevier Ltd. All rights reserved.

  5. Uric acid-dependent inhibition of AMP kinase induces hepatic glucose production in diabetes and starvation: evolutionary implications of the uricase loss in hominids

    PubMed Central

    Cicerchi, Christina; Li, Nanxing; Kratzer, James; Garcia, Gabriela; Roncal-Jimenez, Carlos A.; Tanabe, Katsuyuki; Hunter, Brandi; Rivard, Christopher J.; Sautin, Yuri Y.; Gaucher, Eric A.; Johnson, Richard J.; Lanaspa, Miguel A.

    2014-01-01

    Reduced AMP kinase (AMPK) activity has been shown to play a key deleterious role in increased hepatic gluconeogenesis in diabetes, but the mechanism whereby this occurs remains unclear. In this article, we document that another AMP-dependent enzyme, AMP deaminase (AMPD) is activated in the liver of diabetic mice, which parallels with a significant reduction in AMPK activity and a significant increase in intracellular glucose accumulation in human HepG2 cells. AMPD activation is induced by a reduction in intracellular phosphate levels, which is characteristic of insulin resistance and diabetic states. Increased gluconeogenesis is mediated by reduced TORC2 phosphorylation at Ser171 by AMPK in these cells, as well as by the up-regulation of the rate-limiting enzymes PEPCK and G6Pc. The mechanism whereby AMPD controls AMPK activation depends on the production of a specific AMP downstream metabolite through AMPD, uric acid. In this regard, humans have higher uric acid levels than most mammals due to a mutation in uricase, the enzyme involved in uric acid degradation in most mammals, that developed during a period of famine in Europe 1.5 × 107 yr ago. Here, working with resurrected ancestral uricases obtained from early hominids, we show that their expression on HepG2 cells is enough to blunt gluconeogenesis in parallel with an up-regulation of AMPK activity. These studies identify a key role AMPD and uric acid in mediating hepatic gluconeogenesis in the diabetic state, via a mechanism involving AMPK down-regulation and overexpression of PEPCK and G6Pc. The uricase mutation in the Miocene likely provided a survival advantage to help maintain glucose levels under conditions of near starvation, but today likely has a role in the pathogenesis of diabetes.—Cicerchi, C., Li, N., Kratzer, J., Garcia, G., Roncal-Jimenez, C. A., Tanabe, K., Hunter, B., Rivard, C. J., Sautin, Y. Y., Gaucher, E. A., Johnson, R. J., Lanaspa, M. A. Uric acid-dependent inhibition of AMP kinase

  6. Serum uric acid level and cardiovascular risks in hemodialysis patients: an Algerian cohort study.

    PubMed

    Gouri, Adel; Dekaken, Aoulia; Bentorki, Ahmed Aimen; Touaref, Amel; Yekhlef, Amina; Sekkache, Fouzia; Kouicem, Nabila

    2013-09-01

    Elevated Serum Uric Acid (SUA) was usually associated with an increased risk of cardiovascular events and mortality in general population. However, there are few reports concerning the clinical impact and the pathogenic role of Uric Acid (UA) in Hemodialysis (HD) patients. The aim of the study was to investigate the relationship between SUA and various Cardiovascular (CV) risk factors in HD patients. This retrospective; observational cohort study includes 45 HD patients with a mean age of 51.26+/-15.21 years. The differences of the CV risk factors between the patients according to their SUA levels were investigated. Age, Cardiovascular Diseases (CVD), increased creatinine, Fasting Blood Glucose (FBG), Corrected Calcium (cCa), Phosphate (P), cCa x P product and LDL cholesterol levels were associated with lower SUA levels, whereas higher SUA level was associated with Diabetes Mellitus (DM), hypertension and increased triglycerides level (p<0.01). In multiple regression analysis, history of diabetes (beta= 0.360, p<0.05), reduced corrected serum calcium (cCa) (beta = -1.456, p<0.01) and Phosphate (P) levels (beta= -1.752, p<0.01) were predictive of an increased SUA concentration. Despite from what has been demonstrated in the general population and DM patients, a lower SUA level in HD patients was associated with higher cardiovascular risk factors and high co-morbidity burden. Moreover, higher SUA concentrations may be cardioprotective in dialysis patients.

  7. Enhancing the peroxidase-like activity of ficin via heme binding and colorimetric detection for uric acid.

    PubMed

    Pan, Yadi; Yang, Yufang; Pang, Yanjiao; Shi, Ying; Long, Yijuan; Zheng, Huzhi

    2018-08-01

    Ficin, a classical sulfhydryl protease, was found to possess intrinsic peroxidase-like activity. In this paper, we have put forward a novel strategy to improving the peroxidase-like activity of ficin through binding heme. Heme-ficin complexes were successfully obtained by simple one-step syntheticism. The results demonstrated that the catalytic activity and efficiency of heme-ficin complexes were about 1.7 times and 3 times higher than those of native ficin, respectively. Taking advantages of the high peroxidase-like activity, the heme-ficin complexes were used for colorimetric determination of uric acid with a low detection limit of 0.25 μM. Based on the excellent selectivity and sensitivity, we detected the concentration of uric acid in human serum successfully. On the basis of these findings, the heme-ficin complexes are promising for wide applications in various fields. Thus we not only optimized the peroxidase-like activity of the ficin, but also established a new strategy for development of artificial enzyme mimics by mimicking the architecture of the active site in horseradish peroxidase. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Serum uric acid concentrations in a Xhosa community in the Transkei of Southern Africa.

    PubMed Central

    Beighton, P; Daynes, G; Soskolne, C L

    1976-01-01

    Serum uric acid (SUA) concentrations were measured in specimens obtained from 479 respondents aged 15 and over during an epidemiological survey of bone and joint conditions in a tribal Xhosa community living in the Transkei, Southern Africa. Population SUA levels in the Xhosa were significantly lower than those previously observed in South Africa Negro groups in rural and urban environments. This finding agrees with the observations that population SUA concentrations tend to rise with increasing complexity of life style. PMID:1275585

  9. Can urinary excretion rate of malondialdehyde, uric acid and protein predict the severity and impending death in perinatal asphyxia?

    PubMed

    Banupriya, C; Ratnakar; Doureradjou, P; Mondal, N; Vishnu, Bhat; Koner, B C

    2008-08-01

    Perinatal asphyxia (PA) associated with multi-organ damage is a leading cause of neonatal mortality and morbidity. We evaluated if urinary malondialdehyde:creatinine (UMDA:Cr), uric acid:creatinine (UUA:Cr) and protein:creatinine (UP:Cr) vary with the severity of PA and if these parameters can predict the impending death in PA. Study included 20 asphyxiated and 20 healthy newborn males. Hypoxic-ischemic encephalopathy (HIE) staging, APGAR (activity, pulse, grimace, appearance and respiration) score and urinary protein, uric acid, creatinine and MDA were evaluated. UMDA:Cr, UUA:Cr and UP:Cr were significantly higher and correlated with APGAR and HIE in PA. By regression analysis also, urinary parameters were found to have significant association with HIE stage and APGAR in PA. Receiver operating characteristics (ROC) curve of UP:Cr, UUA:Cr and UMDA:Cr showed area under curve of 0.896 (p=0.003), 0.859 (p=0.008) and 0.849 (p=0.010) with cut-off value of 9.04 mg, 2.34 mg and 3.49 microg/mg of creatinine respectively that can optimally predict the impending death in PA. SDS-PAGE of unconcentrated urine detected both high (73 kDa and 68 kDa) and low molecular weight proteins (52 kDa, 47 kDa, 25 kDa and 20 kDa) in PA but not in controls. Urinary excretion rate of uric acid, MDA and proteins is higher and has potential to act as biochemical markers for severity evaluation and death prediction in PA.

  10. Development of luminol-N-hydroxyphthalimide chemiluminescence system for highly selective and sensitive detection of superoxide dismutase, uric acid and Co2.

    PubMed

    Saqib, Muhammad; Qi, Liming; Hui, Pan; Nsabimana, Anaclet; Halawa, Mohamed Ibrahim; Zhang, Wei; Xu, Guobao

    2018-01-15

    N-hydroxyphthalimide (NHPI), a well known reagent in organic synthesis and biochemical applications, has been developed as a stable and efficient chemiluminescence coreactant for the first time. It reacts with luminol much faster than N-hydroxysuccinimide, eliminating the need of a prereaction coil used in N-hydroxysuccinimide system. Without using prereaction coil, the chemiluminescence peak intensities of luminol-NHPI system are about 102 and 26 times greater than that of luminol-N-hydroxysuccinimide system and classical luminol-hydrogen peroxide system, respectively. The luminol-NHPI system achieves the highly sensitive detection of luminol (LOD = 70pM) and NHPI (LOD = 910nM). Based on their excellent quenching efficiencies, superoxide dismutase and uric acid are sensitively detected with LODs of 3ng/mL and 10pM, respectively. Co 2+ is also detected a LOD of 30pM by its remarkable enhancing effect. Noteworthily, our method is at least 4 orders of magnitude more sensitive than previously reported uric acid detection methods, and can detect uric acid in human urine and Co 2+ in tap and lake water real samples with excellent recoveries in the range of 96.35-102.70%. This luminol-NHPI system can be an important candidate for biochemical, clinical and environmental analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Effect of uric acid on mitochondrial function and oxidative stress in hepatocytes.

    PubMed

    Yang, Y; Zhou, Y; Cheng, S; Sun, J L; Yao, H; Ma, L

    2016-06-24

    Here, we investigated the effect of uric acid (UA) on hepatocyte mitochondria. Hepatocytes cultured in vitro were treated with varying concentrations of UA. The change in apoptotic activity was detected by flow cytometry. The DNA damage index 8-hydroxy-deoxy-guanosine (8-OHdG) and mitochondrial function indices succinate dehydrogenase (SDH), cytochrome C oxidase (CCO), and adenosine triphosphate (ATP) were detected by enzyme assays. Reactive oxygen species (ROS) accumulation was confirmed by a dichloro-dihydro-fluorescein diacetate assay. We observed an increase in apoptotic activity, ROS accumulation, and 8-OHdG activity in hepatocytes treated with UA for extended periods, indicating DNA damage; specifically, we observed a significant increase in these activities 48, 72, and 96 h after UA addition, compared to those observed at 24 h (P < 0.05). Cells treated with 30 mg/dL UA for 96 h showed a peak in apoptotic activity. We also observed a significant decrease in ATP, SDH, and CCO activities with the increase in uric acid concentration over time. Cells treated with 30 mg/dL UA for 96 h showed the highest ATP levels, while SDH and CCO activities at 48, 72, and 96 h post-UA treatment were significantly lower than those at 24 h (P < 0.01). Moreover, cells treated with 30 mg/dL UA showed a 0.02 ± 0.02 and 0.15 ± 0.01 mmol/ mg/min decrease in SDH and CCO levels after 72 h. Therefore, we concluded that high concentrations of UA may induce oxidative stress in hepatocyte mitochondria, increasing ROS production and ultimately resulting in mitochondrial damage.

  12. Diclofenac toxicity in Gyps vulture is associated with decreased uric acid excretion and not renal portal vasoconstriction.

    PubMed

    Naidoo, V; Swan, G E

    2009-04-01

    Diclofenac (DF), a non-steroidal anti-inflammatory drug (NSAID), is largely regarded as one of the most devastating environmental toxicant in recent times, after accidental exposure via their food-chain lead to massive mortalities in three vulture species on the Asian subcontinent. Although the use of diclofenac was recently banned on the Indian subcontinent, following the favourable safety profile of meloxicam, its mechanism of toxicity remains unknown. In an attempt to establish this mechanism, we test three hypotheses using models established from either the domestic chicken (Gallus domesticus) or the African White-backed vulture (Gyps africanus). We demonstrate that both DF and meloxicam are toxic to renal tubular epithelial (RTE) cells following 12 h of exposure, due to an increase in production of reactive oxygen species (ROS), which could be temporarily ameliorated by pre-incubation with uric acid (UA). When cultures were incubated with either drug for only 2 h, meloxicam showed no toxicity in contrast to diclofenac. In both cases no increase in ROS production was evident. In addition, diclofenac decreased the transport of uric acid, by interfering with the p-amino-hippuric acid (PAH) channel. We conclude that vulture susceptibility to diclofenac results from a combination of an increased ROS, interference with UA transport and the duration of exposure.

  13. Development and Validation of a Simple High Performance Liquid Chromatography/UV Method for Simultaneous Determination of Urinary Uric Acid, Hypoxanthine, and Creatinine in Human Urine.

    PubMed

    Wijemanne, Nimanthi; Soysa, Preethi; Wijesundara, Sulochana; Perera, Hemamali

    2018-01-01

    Uric acid and hypoxanthine are produced in the catabolism of purine. Abnormal urinary levels of these products are associated with many diseases and therefore it is necessary to have a simple and rapid method to detect them. Hence, we report a simple reverse phase high performance liquid chromatography (HPLC/UV) technique, developed and validated for simultaneous analysis of uric acid, hypoxanthine, and creatinine in human urine. Urine was diluted appropriately and eluted with C-18 column 100 mm × 4.6 mm with a C-18 precolumn 25 mm × 4.6 mm in series. Potassium phosphate buffer (20 mM, pH 7.25) at a flow rate of 0.40 mL/min was employed as the solvent and peaks were detected at 235 nm. Tyrosine was used as the internal standard. The experimental conditions offered a good separation of analytes without interference of endogenous substances. The calibration curves were linear for all test compounds with a regression coefficient, r 2 > 0.99. Uric acid, creatinine, tyrosine, and hypoxanthine were eluted at 5.2, 6.1, 7.2, and 8.3 min, respectively. Intraday and interday variability were less than 4.6% for all the analytes investigated and the recovery ranged from 98 to 102%. The proposed HPLC procedure is a simple, rapid, and low cost method with high accuracy with minimum use of organic solvents. This method was successfully applied for the determination of creatinine, hypoxanthine, and uric acid in human urine.

  14. Association of Functional Polymorphism rs2231142 (Q141K) in the ABCG2 Gene With Serum Uric Acid and Gout in 4 US Populations

    PubMed Central

    Zhang, Lili; Spencer, Kylee L.; Voruganti, V. Saroja; Jorgensen, Neal W.; Fornage, Myriam; Best, Lyle G.; Brown-Gentry, Kristin D.; Cole, Shelley A.; Crawford, Dana C.; Deelman, Ewa; Franceschini, Nora; Gaffo, Angelo L.; Glenn, Kimberly R.; Heiss, Gerardo; Jenny, Nancy S.; Kottgen, Anna; Li, Qiong; Liu, Kiang; Matise, Tara C.; North, Kari E.; Umans, Jason G.; Kao, W. H. Linda

    2013-01-01

    A loss-of-function mutation (Q141K, rs2231142) in the ATP-binding cassette, subfamily G, member 2 gene (ABCG2) has been shown to be associated with serum uric acid levels and gout in Asians, Europeans, and European and African Americans; however, less is known about these associations in other populations. Rs2231142 was genotyped in 22,734 European Americans, 9,720 African Americans, 3,849 Mexican Americans, and 3,550 American Indians in the Population Architecture using Genomics and Epidemiology (PAGE) Study (2008–2012). Rs2231142 was significantly associated with serum uric acid levels (P = 2.37 × 10−67, P = 3.98 × 10−5, P = 6.97 × 10−9, and P = 5.33 × 10−4 in European Americans, African Americans, Mexican Americans, and American Indians, respectively) and gout (P = 2.83 × 10−10, P = 0.01, and P = 0.01 in European Americans, African Americans, and Mexican Americans, respectively). Overall, the T allele was associated with a 0.24-mg/dL increase in serum uric acid level (P = 1.37 × 10−80) and a 1.75-fold increase in the odds of gout (P = 1.09 × 10−12). The association between rs2231142 and serum uric acid was significantly stronger in men, postmenopausal women, and hormone therapy users compared with their counterparts. The association with gout was also significantly stronger in men than in women. These results highlight a possible role of sex hormones in the regulation of ABCG2 urate transporter and its potential implications for the prevention, diagnosis, and treatment of hyperuricemia and gout. PMID:23552988

  15. Uric acid: A Danger Signal from the RNA World that may have a role in the Epidemic of Obesity, Metabolic Syndrome and CardioRenal Disease: Evolutionary Considerations

    PubMed Central

    Johnson, Richard J; Lanaspa, Miguel A; Gaucher, Eric A

    2011-01-01

    All humans are uricase knockouts; we lost the uricase gene due to a mutation that occurred in the mid Miocene approximately 15 million years ago. The consequence of being a uricase knockout is that we have higher serum uric acid levels that are less regulatable and can be readily influenced by diet. This increases our risk for gout and kidney stones, but there is also increasing evidence that uric acid increases our risk for hypertension, kidney disease, obesity and diabetes. This raises the question of why this mutation occurred. In this paper we review current hypotheses. We suggest that uric acid is a danger and survival signal carried over from the RNA world. The mutation of uricase that occurred during the food shortage and global cooling that occurred in the Miocene resulted in a survival advantage for early primates, particularly in Europe. Today, the loss of uricase functions as a thrifty gene, increasing our risk for obesity and cardiorenal disease. PMID:22000645

  16. The validity, stability, and utility of measuring uric acid in saliva.

    PubMed

    Riis, Jenna L; Bryce, Crystal I; Matin, Marla J; Stebbins, John L; Kornienko, Olga; Huisstede, Lauren van; Granger, Douglas A

    2018-06-06

    Serum uric acid (UA) is associated with many health conditions, including kidney, cardiovascular, and metabolic disorders. We examined the validity and stability of salivary UA as a noninvasive measure of serum UA. Using serum and salivary UA data from healthy adults (n = 99), we examined the UA serum-saliva correlation, and UA associations with adiponectin and C-reactive protein. Using longitudinal data from young adults (n = 182), we examined salivary UA stability. We found robust positive serum-saliva correlations for UA. UA and adiponectin were inversely related in serum and saliva. Salivary UA was relatively stable; 62-66% of variance could be attributed to a latent trait-like component. Salivary UA may be an important biomarker indexing health and disease risk.

  17. Uric acid versus non-uric acid urinary stones: differentiation with single energy CT texture analysis.

    PubMed

    Zhang, G-M-Y; Sun, H; Shi, B; Xu, M; Xue, H-D; Jin, Z-Y

    2018-05-21

    To evaluate the accuracy of computed tomography (CT) texture analysis (TA) to differentiate uric acid (UA) stones from non-UA stones on unenhanced CT in patients with urinary calculi with ex vivo Fourier transform infrared spectroscopy (FTIR) as the reference standard. Fourteen patients with 18 UA stones and 31 patients with 32 non-UA stones were included. All the patients had preoperative CT evaluation and subsequent surgical removal of the stones. CTTA was performed on CT images using commercially available research software. Each texture feature was evaluated using the non-parametric Mann-Whitney test. Receiver operating characteristic (ROC) curves were created and the area under the ROC curve (AUC) was calculated for texture parameters that were significantly different. The features were used to train support vector machine (SVM) classifiers. Diagnostic accuracy was evaluated. Compared to non-UA stones, UA stones had significantly lower mean, standard deviation and mean of positive pixels but higher kurtosis (p<0.001) on both unfiltered and filtered texture scales. There were no significant differences in entropy or skewness between UA and non-UA stones. The average SVM accuracy of texture features for differentiating UA from non-UA stones ranged from 88% to 92% (after 10-fold cross validation). A model incorporating standard deviation, skewness, and kurtosis from unfiltered texture scale images resulted in an AUC of 0.965±00.029 with a sensitivity of 94.4% and specificity of 93.7%. CTTA can be used to accurately differentiate UA stones from non-UA stones in vivo using unenhanced CT images. Copyright © 2018 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  18. Uric acid lowering to prevent kidney function loss in diabetes: the preventing early renal function loss (PERL) allopurinol study.

    PubMed

    Maahs, David M; Caramori, Luiza; Cherney, David Z I; Galecki, Andrzej T; Gao, Chuanyun; Jalal, Diana; Perkins, Bruce A; Pop-Busui, Rodica; Rossing, Peter; Mauer, Michael; Doria, Alessandro

    2013-08-01

    Diabetic kidney disease causes significant morbidity and mortality among people with type 1 diabetes (T1D). Intensive glucose and blood pressure control have thus far failed to adequately curb this problem and therefore a major need for novel treatment approaches exists. Multiple observations link serum uric acid levels to kidney disease development and progression in diabetes and strongly argue that uric acid lowering should be tested as one such novel intervention. A pilot of such a trial, using allopurinol, is currently being conducted by the Preventing Early Renal Function Loss (PERL) Consortium. Although the PERL trial targets T1D individuals at highest risk of kidney function decline, the use of allopurinol as a renoprotective agent may also be relevant to a larger segment of the population with diabetes. As allopurinol is inexpensive and safe, it could be cost-effective even for relatively low-risk patients, pending the completion of appropriate trials at earlier stages.

  19. Performance of AA5052 alloy anode in alkaline ethylene glycol electrolyte with dicarboxylic acids additives for aluminium-air batteries

    NASA Astrophysics Data System (ADS)

    Wang, DaPeng; Zhang, DaQuan; Lee, KangYong; Gao, LiXin

    2015-11-01

    Dicarboxylic acid compounds, i.e. succinic acid (SUA), adipic acid (ADA) and sebacic acid (SEA), are used as electrolyte additives in the alkaline ethylene glycol solution for AA5052 aluminium-air batteries. It shows that the addition of dicarboxylic acids lowers the hydrogen gas evolution rate of commercial AA5052 aluminium alloy anode. AA5052 aluminium alloy has wide potential window for electrochemical activity and better discharge performance in alkaline ethylene glycol solution containing dicarboxylic acid additives. ADA has the best inhibition effect for the self-corrosion of AA5052 anode among the three dicarboxylic acid additives. Fourier transform infrared spectroscopy (FT-IR) reveals that dicarboxylic acids and aluminium ions can form coordination complexes. Quantum chemical calculations shows that ADA has a smaller energy gap (ΔE, the energy difference between the lowest unoccupied orbital and the highest occupied orbital), indicating that ADA has the strongest interaction with aluminium ions.

  20. High Normal Uric Acid Levels Are Associated with an Increased Risk of Diabetes in Lean, Normoglycemic Healthy Women.

    PubMed

    Shani, Michal; Vinker, Shlomo; Dinour, Dganit; Leiba, Merav; Twig, Gilad; Holtzman, Eliezer J; Leiba, Adi

    2016-10-01

    The risk associated with serum uric acid (SUA) levels within the normal range is unknown, especially among lean and apparently healthy adults. Evaluating whether high-normal SUA levels, 6.8 mg/dL and below, are associated with an increased diabetes risk, compared with low-normal SUA. This was a cohort study with 10 years of followup involving all clinics of the largest nationally distributed Health Maintenance Organization in Israel. Participants included 469,947 examinees, 40-70 years old at baseline, who had their SUA measured during 2002. We excluded examinees who had hyperuricemia (SUA > 6.8 mg/dL), impaired fasting glucose, overweight or obesity and chronic cardiovascular or renal disorders. The final cohort was composed of 30 302 participants. Participants were followed up to a new diagnosis of diabetes during the study period. Odds ratio of developing diabetes among participants with high-normal baseline SUA were compared with low-normal (2 ≤ uric acid < 3 and 3 ≤ uric acid < 4 in women and men, respectively). In a logistic regression model adjusted for age, body mass index, socioeconomic status, smoking, baseline estimated glomerular filtration rate, and baseline glucose, SUA levels of 4-5 mg/dL for women were associated with 61% increased risk for incident diabetes (95% confidence interval, 1.1-2.3). At the highest normal levels for women (SUA, 5-6 mg/dL) the odds ratio was 2.7 (1.8-4.0), whereas men had comparable diabetes risk at values of 6-6.8 mg/dL (hazard ratio, 1.35; 95% confidence interval, 0.9-2.1). SUA levels within the normal range are associated with an increased risk for new-onset diabetes among healthy lean women when compared with those with low-normal values.

  1. Serum uric acid level and cardiovascular risks in hemodialysis patients: an Algerian cohort study.

    PubMed

    Gouri, Adel; Dekaken, Aoulia; Bentorki, Ahmed Aimen; Touaref, Amel; Yakhlef, Amina; Kouicem, Nabila

    2014-01-01

    Elevated serum uric acid (SUA) was usually associated with an increased risk of cardiovascular events and mortality in the general population. However, there are few reports concerning the clinical impact and the pathogenic role of uric acid (UA) in hemodialysis (HD) patients. The aim of the study was to investigate the relationship between SUA and various cardiovascular (CV) risk factors in HD patients. This retrospective, observational cohort study includes 45 HD patients with a mean age of 51.26 +/- 15.21 years. The differences of the CV risk factors between the patients according to their SUA levels were investigated. Age, cardiovascular diseases (CVD), increased creatinine, fasting blood glucose (FBG), corrected calcium (cCa), phosphate (P), cCa x P product, and LDL cholesterol levels were associated with lower SUA levels, whereas a higher SUA level was associated with diabetes mellitus (DM), hypertension, and increased triglycerides level (p < 0.01). In multiple regression analysis, history of diabetes (beta = 0.360, p < 0.05), reduced corrected serum calcium (cCa) (beta = -1.456, p < 0.01), and phosphate (P) levels (beta = -1.752, p < 0.01) were predictive of an increased SUA concentration. Despite what has been demonstrated in the general population and DM patients, a lower SUA level in HD patients was associated with higher cardiovascular risk factors and high co-morbidity burden. Moreover, higher SUA concentrations may be cardioprotective in dialysis patients.

  2. Serum Uric Acid, Kidney Function and Acute Ischemic Stroke Outcomes in Elderly Patients: A Single-Cohort, Perspective Study

    PubMed Central

    Falsetti, Lorenzo; Capeci, William; Tarquinio, Nicola; Viticchi, Giovanna; Silvestrini, Mauro; Catozzo, Vania; Fioranelli, Agnese; Buratti, Laura; Pellegrini, Francesco

    2017-01-01

    Chronic kidney disease and hyperuricemia have been associated to an increased risk and a worse prognosis in acute ischemic stroke. Several mechanisms, including platelet dysfunction, coagulation disorders, endothelial dysfunction, inflammation, and an increased risk of atrial fibrillation could be implicated. The role of serum uric acid in this setting is still object of debate. We enrolled all the consecutive patients admitted to our department for acute ischemic stroke. Cox regression analysis was used to evaluate the risk of in-hospital death considering serum uric acid levels and all the comorbidities. In the overall sample, hyperuricemia was independently associated to an increased risk of in-hospital mortality. This effect was stronger in patients with chronic kidney disease while, in the group of patients with normal renal function, the relationship between hyperuricemia and increased stroke mortality was not confirmed. Hyperuricemia could be associated to higher in-hospital mortality for ischemic stroke among elderly patients when affected by kidney disease. Survival does not seem to be affected by hyperuricemia in patients with normal kidney function. PMID:28461885

  3. Health status of elderly based on daily activities living, cholesterol and uric acid profile in Medan city

    NASA Astrophysics Data System (ADS)

    Amelia, R.; Harahap, J.; Wahyuni, A. S.; Pratama, A.

    2018-03-01

    Health problems in the elderly come from declining body cells, so the function and body endurance decreased along with increased risk factors for diseases. This study aimed to determine the elderly health status in Public Health Center of Tuntungan Medan. Health status includes measurement of daily activities living (DAL),and health parameter include blood pressure, blood sugar level (BSL), cholesterol level and uric acid level. The study design was descriptive with cross-sectional approach. The study population was the entire elderly population residing in the service area of public health center of Tuntungan Medan (55 subjects). The elderly who had a reasonable level of independence were 47 subjects (85.5%), the majority of elderly were in the category of hypertension stage I (20 subjects; 36.4%) with a mean systolic blood pressure level was 143mmHg. Most of them have BSL that exceeded the standard limit (42 subjects; 76.4%) with BSL mean value was 177mg/dL.Uric acid levels were in the high category (34 subjects; 61.98%) with a mean value of 7.0mm/dL, and most of them have normal cholesterol (43 subjects; 78.2%).

  4. Antioxidative phytochemicals from Rhododendron oldhamii Maxim. leaf extracts reduce serum uric acid levels in potassium oxonate-induced hyperuricemic mice.

    PubMed

    Tung, Yu-Tang; Lin, Lei-Chen; Liu, Ya-Ling; Ho, Shang-Tse; Lin, Chi-Yang; Chuang, Hsiao-Li; Chiu, Chien-Chao; Huang, Chi-Chang; Wu, Jyh-Horng

    2015-12-01

    Some of the genus Rhododendron was used in traditional medicine for arthritis, acute and chronic bronchitis, asthma, pain, inflammation, rheumatism, hypertension and metabolic diseases and many species of the genus Rhododendron contain a large number of phenolic compounds and antioxidant properties that could be developed into pharmaceutical products. In this study, the antioxidative phytochemicals of Rhododendron oldhamii Maxim. leaves were detected by an online HPLC-DPPH method. In addition, the anti-hyperuricemic effect of the active phytochemicals from R. oldhamii leaf extracts was investigated using potassium oxonate (PO)-induced acute hyperuricemia. Six phytochemicals, including (2R, 3R)-epicatechin (1), (2R, 3R)-taxifolin (2), (2R, 3R)-astilbin (3), hyposide (4), guaijaverin (5), and quercitrin (6), were isolated using the developed screening method. Of these, compounds 3, 4, 5, and 6 were found to be major bioactive phytochemicals, and their contents were determined to be 130.8 ± 10.9, 105.5 ± 8.5, 104.1 ± 4.7, and 108.6 ± 4.0 mg per gram of EtOAc fraction, respectively. In addition, the four major bioactive phytochemicals at the same dosage (100 mmol/kg) were administered to the abdominal cavity of potassium oxonate (PO)-induced hyperuricemic mice, and the serum uric acid level was measured after 3 h of administration. H&E staining showed that PO-induced kidney injury caused renal tubular epithelium nuclear condensation in the cortex areas or the appearance of numerous hyaline casts in the medulla areas; treatment with 100 mmol/kg of EtOAc fraction, (2R, 3R)-astilbin, hyposide, guaijaverin, and quercitrin significantly reduced kidney injury. In addition, the serum uric acid level was significantly suppressed by 54.1, 35.1, 56.3, 56.3, and 53.2 %, respectively, by the administrations of 100 mmol/kg EtOAc fraction and the derived major phytochemicals, (2R, 3R)-astilbin, hyposide, guaijaverin, and quercitrin, compared to the PO group. The administration

  5. Uric Acid Induces Hepatic Steatosis by Generation of Mitochondrial Oxidative Stress

    PubMed Central

    Lanaspa, Miguel A.; Sanchez-Lozada, Laura G.; Choi, Yea-Jin; Cicerchi, Christina; Kanbay, Mehmet; Roncal-Jimenez, Carlos A.; Ishimoto, Takuji; Li, Nanxing; Marek, George; Duranay, Murat; Schreiner, George; Rodriguez-Iturbe, Bernardo; Nakagawa, Takahiko; Kang, Duk-Hee; Sautin, Yuri Y.; Johnson, Richard J.

    2012-01-01

    Metabolic syndrome represents a collection of abnormalities that includes fatty liver, and it currently affects one-third of the United States population and has become a major health concern worldwide. Fructose intake, primarily from added sugars in soft drinks, can induce fatty liver in animals and is epidemiologically associated with nonalcoholic fatty liver disease in humans. Fructose is considered lipogenic due to its ability to generate triglycerides as a direct consequence of the metabolism of the fructose molecule. Here, we show that fructose also stimulates triglyceride synthesis via a purine-degrading pathway that is triggered from the rapid phosphorylation of fructose by fructokinase. Generated AMP enters into the purine degradation pathway through the activation of AMP deaminase resulting in uric acid production and the generation of mitochondrial oxidants. Mitochondrial oxidative stress results in the inhibition of aconitase in the Krebs cycle, resulting in the accumulation of citrate and the stimulation of ATP citrate lyase and fatty-acid synthase leading to de novo lipogeneis. These studies provide new insights into the pathogenesis of hepatic fat accumulation under normal and diseased states. PMID:23035112

  6. Urinary Uric Acid/Creatinine Ratio - A Marker For Perinatal Asphyxia.

    PubMed

    Patel, Kinjal Prahaladbhai; Makadia, Mayur Goradhanbhai; Patel, Vishwal Indravardan; Nilayangode, Haridas Neelakandan; Nimbalkar, Somashekhar Marutirao

    2017-01-01

    Perinatal hypoxia is one of the leading causes of perinatal mortality in developing countries. Both apgar score and arterial blood pH predict the neonatal mortality in asphyxia. Apgar score alone does not predict neurologic outcome and as it is influenced by various factors. This study was conducted to evaluate the utility and sensitivity of urinary uric acid to creatinine ratio (UA/Cr ratio) in asphyxia diagnosis, compared to invasive Arterial Blood Gas (ABG) analysis. To assess the urinary uric acid/creatinine ratio as an additional marker for perinatal asphyxia compared with ABG analysis in apgar score monitoring. The present case control study was conducted at a teaching hospital in Central Gujarat. Data of 40 healthy newborns and 40 asphyxiated newborns were collected. In absence of regional estimates, a sample of size 39 was required to attain a power of 80% at 5% alpha (type I error) considering a moderate effect size of 0.65. (UA/Cr) ratio was measured from the spot urine sample collected during 24-72 hours of birth. Statistical analysis was performed by Independent t-test, Pearson's correlation coefficient (r) and Receiver Operating Characteristic (ROC) plots. The mean (UA/Cr ratio) (2.75±0.18 vs 1.78±0.23) is significantly higher in asphyxiated group than in the control group (p<0.0001). Urinary UA/Cr ratio had negative correlation with blood pH (r= -0.27, p=0.18), which was not significant (p>0.05). Urinary UA/Cr ratio with criterion of >2.3 had 100% sensitivity, 100% specificity with AUC of 1 (p<0.0001) had a better predictive value. Apgar score is usually reduced in neonates with congenital anomalies and premature neonates. Hence, it is preferable that the clinical diagnosis of asphyxia by apgar scores be supported by other investigations so that early decision can be taken about the level of care the baby needs. pH, lactates and base deficits change with establishment of respiration following resuscitation. However, pH, lactate, base deficit

  7. Urinary Uric Acid/Creatinine Ratio - A Marker For Perinatal Asphyxia

    PubMed Central

    Patel, Kinjal Prahaladbhai; Makadia, Mayur Goradhanbhai; Patel, Vishwal Indravardan; Nilayangode, Haridas Neelakandan

    2017-01-01

    Background Perinatal hypoxia is one of the leading causes of perinatal mortality in developing countries. Both apgar score and arterial blood pH predict the neonatal mortality in asphyxia. Apgar score alone does not predict neurologic outcome and as it is influenced by various factors. This study was conducted to evaluate the utility and sensitivity of urinary uric acid to creatinine ratio (UA/Cr ratio) in asphyxia diagnosis, compared to invasive Arterial Blood Gas (ABG) analysis. Aim To assess the urinary uric acid/creatinine ratio as an additional marker for perinatal asphyxia compared with ABG analysis in apgar score monitoring. Materials and Methods The present case control study was conducted at a teaching hospital in Central Gujarat. Data of 40 healthy newborns and 40 asphyxiated newborns were collected. In absence of regional estimates, a sample of size 39 was required to attain a power of 80% at 5% alpha (type I error) considering a moderate effect size of 0.65. (UA/Cr) ratio was measured from the spot urine sample collected during 24-72 hours of birth. Statistical analysis was performed by Independent t-test, Pearson’s correlation coefficient (r) and Receiver Operating Characteristic (ROC) plots. Results The mean (UA/Cr ratio) (2.75±0.18 vs 1.78±0.23) is significantly higher in asphyxiated group than in the control group (p<0.0001). Urinary UA/Cr ratio had negative correlation with blood pH (r= -0.27, p=0.18), which was not significant (p>0.05). Urinary UA/Cr ratio with criterion of >2.3 had 100% sensitivity, 100% specificity with AUC of 1 (p<0.0001) had a better predictive value. Conclusions Apgar score is usually reduced in neonates with congenital anomalies and premature neonates. Hence, it is preferable that the clinical diagnosis of asphyxia by apgar scores be supported by other investigations so that early decision can be taken about the level of care the baby needs. pH, lactates and base deficits change with establishment of respiration

  8. Serum uric acid, protein intake and mortality in hemodialysis patients.

    PubMed

    Park, Christina; Obi, Yoshitsugu; Streja, Elani; Rhee, Connie M; Catabay, Christina J; Vaziri, Nosratola D; Kovesdy, Csaba P; Kalantar-Zadeh, Kamyar

    2017-10-01

    The association between serum uric acid (SUA) and mortality has been conflicting among studies using hemodialysis (HD) patients. Given the close link between purine and protein in foods, we hypothesized that normalized protein catabolic rate (nPCR), a dietary protein intake surrogate, modifies the SUA-mortality association in the HD population. We identified 4298 patients who initiated HD and had one or more SUA measurement in a contemporary cohort of HD patients over 5 years (1 January 2007-31 December 2011), and examined survival probability according to the first uric acid measurement, adjusting for dialysis vintage, case-mix and malnutrition-inflammation complex-related variables. Mean SUA concentration was 6.6 ± 1.8 mg/dL. There was a consistent association of higher SUA with better nutritional status and lower all-cause mortality irrespective of adjusted models (Ptrend < 0.001). In the case-mix adjusted model, the highest SUA category (≥8.0 mg/dL) compared with the reference group (>6.0-7.0 mg/dL) showed no significant mortality risk [hazard ratio (HR) 0.90, 95% confidence interval (CI) 0.72-1.13], while the lowest category (<5.0 mg/dL) was associated with higher mortality (HR 1.42, 95% CI 1.16-1.72). The hypouricemia-mortality association was significantly modified by nPCR (Pinteraction = 0.001). Mortality risk of low SUA (<5.0 mg/dL) persisted among patients with low nPCR (<0.9 g/kg/day; HR 1.73, 95% CI 1.42-2.10) but not with high nPCR (≥0.9 g/kg/day; HR 0.99, 95% CI 0.74-1.33). SUA may be a nutritional marker in HD patients. Contrary to the general population, low but not high SUA is associated with higher all-cause mortality in HD patients, especially in those with low protein intake. Nutritional features of SUA warrant additional studies. © The Author 2017. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  9. Uric acid upregulates the adiponectin-adiponectin receptor 1 pathway in renal proximal tubule epithelial cells

    PubMed Central

    Yang, Qingmei; Fu, Chensheng; Xiao, Jing; Ye, Zhibin

    2018-01-01

    Adiponectin (APN) is a protein hormone that is primarily derived from adipocytes. It can also be secreted by renal cells. Hypoadiponectinemia has been documented in patients with hyperuricemia, however, whether soluble uric acid (SUA) regulates the expression of APN and APN receptor 1 (AdipoR1) in renal proximal tubule epithelial cells (PTECs) remains to be elucidated. The present study investigated the expression of APN and AdipoR1 in cultured PTECs that were exposed to SUA through immunofluorescence and western blot analysis. In addition, Sprague-Dawley rats with oxonic acid-induced hyperuricemia (HUA) with or without febuxostat treatment were employed as an animal model to measure 24 h urine protein, serum creatinine, urea nitrogen, uric acid and homeostasis model assessment of insulin resistance. Renal pathology was evaluated using hematoxylin and eosin and immunohistochemical staining. APN and AdipoR1 expression in the renal cortex were evaluated by western blotting. The results demonstrated that, in PTECs, the expression of APN and AdipoR1 was constant and increased upon SUA exposure. Similar observations were made within the proximal renal tubules of rats, and the oxonic acid-induced increases in APN and AdipoR1 were offset by febuxostat treatment. Furthermore, SUA-treated PTECs exhibited an increase in the expression of NLR family pyrin domain-containing (NLRP) 3, which was dose-dependent. NLRP3 expression was also significantly increased in the renal cortex of HUA rats compared with control and febuxostat-treated rats. In conclusion, SUA enhanced the expression of APN and AdipoR1 in PTECs, which was associated with an increase in NLRP3 expression. The APN-AdipoR1 pathway was demonstrated to have an important role in in vitro and in vivo models of renal proximal tubule inflammatory injury. Therefore, this pathway may be a potential therapy target in urate nephropathy. PMID:29359786

  10. Serum Uric Acid Levels were Dynamically Coupled with Hemoglobin A1c in the Development of Type 2 Diabetes

    NASA Astrophysics Data System (ADS)

    Wei, Fengjiang; Chang, Baocheng; Yang, Xilin; Wang, Yaogang; Chen, Liming; Li, Wei-Dong

    2016-06-01

    The aim of the study was to decipher the relationship between serum uric acid (SUA) and glycated hemoglobin A1c (HbA1c) or fasting plasma glucose (FPG) in both type 2 diabetes mellitus (T2DM) patients and normal subjects. A total of 2,250 unrelated T2DM patients and 4,420 Han Chinese subjects from a physical examination population were recruited for this study. In T2DM patients SUA levels were negatively correlated with HbA1c (rs = -0.109, P = 0.000) and 2 h plasma glucose levels (rs = -0.178, P = 0.000). In the physical examination population, SUA levels were inversely correlated with HbA1c (rs = -0.175, P = 0.000) and FPG (rs = -0.131, P = 0.009) in T2DM patients but positively correlated with HbA1c (rs = 0.040, P = 0.012) and FPG (rs = 0.084, P = 0.000) in normal-glucose subjects. Multivariate analyses showed that HbA1c was significantly negatively associated with HUA both in T2DM patients (OR = 0.872, 95% CI: 0.790~0.963) and in the physical examination T2DM patients (OR = 0.722, 95% CI: 0.539~0.968). Genetic association studies in T2DM patients showed that alleles of two glucose-uric acid transporter genes, ABCG2 and SLC2A9 were significantly associated with SUA levels (P < 0.05). SUA level is inversely correlated with HbA1c in T2DM patients but positively correlated with HbA1c in normal-glucose subjects. The reverse transporting of uric acid and glucose in renal tubules might be accounted for these associations.

  11. The association between elevated serum uric acid level and an increased risk of renal function decline in a health checkup cohort in China.

    PubMed

    Cao, Xia; Wu, Liuxin; Chen, Zhiheng

    2018-03-01

    To investigate whether an elevated serum uric acid (SUA) level is an independent risk factor for rapid decline in renal function or new-onset chronic kidney disease (CKD) in a Chinese health checkup population. A cohort study of 6495 Chinese individuals who underwent health checkups with normal estimated glomerular filtration rate (eGFR) at baseline was carried out from May 2011 to April 2016. Examinations included a questionnaire, physical measurements, and blood sampling. The gender-specific quartiles of blood uric acid were used to present baseline descriptive data. Rapid decline of renal function was defined as eGFR loss of > 3 mL/min/1.73 m 2 /year. New-onset CKD was defined as follow-up eGFR < 60 mL/min/1.73 m 2 or positive proteinuria. Multivariable logistic regression was used to assess the relationship between serum uric acid and the following outcomes: rapid decline of renal function, incident CKD, and combined renal outcomes. During mean follow-up of 52.8 months, 1608 (24.8%) individuals reached combined renal events. Rapid decline in renal function developed in 1506 (23.2%) individuals, and incident CKD was documented in 372 (5.7%) individuals. In a multivariate model adjusted for age, BMI, diabetes, hypertension, alcohol drinking, SBP, total cholesterol, and eGFR, the odds ratio for rapid decline of renal function increased across quartiles of serum uric acid level, reaching a 1.32 (95% CI 1.02-2.97) for the top quartile compared to the lowest quartile (P for trend < 0.001). Meanwhile, higher SUA was also associated with incident CKD in all models. Furthermore, an increased risk of reaching renal outcomes across increasing quartiles of SUA levels appeared to be similar among subgroups stratified according to age, eGFR, and SBP (P < 0.05 in all). These findings suggest that higher SUA may predict progressive renal damage and dysfunction in a health checkup population in China.

  12. Are There Any Promising Biochemical Correlates of Achievement Behavior and Motivation? The Evidence for Serum Uric Acid and Serum Cholesterol

    ERIC Educational Resources Information Center

    Kasl, Stanislav V.

    1974-01-01

    This review examines the available evidence in support of the argument that serum uric acid (SUA) possesses considerable promise as an indicator of one type of biochemical influence on achievement behavior. The evidence arguing for further research into the role of serum cholesterol in achievement behavior is also examined. (Author/JR)

  13. Effects of feeding reduced crude protein diets on growth performance, nitrogen excretion, and plasma uric acid concentration of broiler chicks during the starter period.

    PubMed

    Kriseldi, R; Tillman, P B; Jiang, Z; Dozier, W A

    2018-05-01

    An experiment (2 trials) was conducted to determine the effects of feeding reduced crude protein (CP) diets to Ross × Ross 708 male broilers while maintaining adequate essential amino acid (AA) concentrations on growth performance, nitrogen excretion, and plasma uric acid (UA) concentration during the starter period. In trial 1, 11 dietary treatments were fed from 1 to 18 d of age containing 1.20% digestible Lys. Diet 1 (23.2% CP) was formulated with DL-Met, L-Lys, and L-Thr to contain 1.70 total Gly + Ser to digestible Lys ratio whereas diets 2 (23.4% CP) to 11 were formulated with additional Gly to contain 1.90 total Gly + Ser to digestible Lys ratio. Free AA were added sequentially in the order of limitation (L-Val, L-Ile, L-Arg, L-Trp, L-His, L-Phe, and L-Leu) from diets 3 to 10 to decrease CP content from 22.6 to 18.8%, respectively. In diet 11, L-Gln was added to increase the CP content to 23.4%. Feed conversion of broilers fed diet 2 was lower (P < 0.05) than those consuming diets 6 to 11 from 1 to 17 d of age. Nitrogen excretion (mg/b/d) decreased (P < 0.001) by 14.1% when broilers were fed diet 4 compared with birds fed diet 2 from 15 to 16 d of age. Broilers fed diet 4 had lower (P = 0.011) plasma UA concentration than birds fed diet 2 at 18 d of age. In trial 2, 8 dietary treatments containing 1.25% digestible Lys and 1.70 total Gly + Ser to digestible Lys ratio were fed from 1 to 21 d of age. Diet 1 (24.0% CP) was supplemented with DL-Met, L-Lys, and L-Thr. Free AA (L-Val, Gly, L-Ile, L-Arg, L-Trp, L-His, and L-Phe) were sequentially supplemented in the order of limitation to decrease CP content in diets 2 to 8 from 23.8 to 20.3%. Broilers fed diet 1 had higher (P < 0.05) body weight gain and lower (P < 0.05) feed conversion when compared with diet 7 or 8. Plasma UA concentration of broiler provided diets 4 to 8 was lower (P < 0.05) compared with diet 1 at 21 d of age. Placing a minimum on dietary CP percentage may not be necessary when proper AA

  14. G-protein beta3 subunit gene variant is unlikely to have a significant influence on serum uric acid level in Japanese workers.

    PubMed

    Suwazono, Yasushi; Kobayashi, Etsuko; Uetani, Mirei; Miura, Katsuyuki; Morikawa, Yuko; Ishizaki, Masao; Kido, Teruhiko; Nakagawa, Hideaki; Nogawa, Koji

    2006-06-01

    The C825T variant of the G-protein beta3 subunit (GNB3) gene has attracted renewed attention as a candidate gene for obesity, hypertension and hyperuricemia. The main role of G-protein is to translate signals from the cell surface into a cellular response. The 825T allele is associated with a splice variant of GNB3 protein and enhanced G-protein activation. We examined the relationship between this variant and the risk of hyperuricemia in Japanese workers. The study subjects were 1,452 men and 1,169 women selected from 3,834 men and 2,591 women in 1997. On the basis of common clinical criteria, hyperuricemia I was defined as serum uric acid >or= 7.0 mg/dl in men and 6.0 mg/dl in women or taking antihyperuricemic medication. The hyperuricemia I group consisted of 186 men and 20 women and its control of 1,266 men and 1,149 women. Hyperuricemia II was defined as serum uric acid > 5.7 mg/dl (median) in men and 3.9 mg/dl (median) in women or taking antihyperuricemic medication. The hyperuricemic II group consisted of 684 men and 570 women and its control of 768 men and 599 women. To replicate previous significant results in young Caucasian men, we selected these criteria because the authors of the study in young Caucasian men adopted the median in their subjects as a cut-off. The statistical power was estimated as 99% based on the significant results in Caucasians. Genotype and allele distributions in men and women with hyperuricemia I and II were not significantly different from those in the corresponding control groups. Logistic regression analysis on hyperuricemia I and II, and multiple regression on serum uric acid level demonstrated no significant effect of the C825T genotype. Despite the sufficient statistical power, this study could not demonstrate the significant influence of C825T on hyperuricemia or serum uric acid. The targeting of this polymorphism is unlikely to be beneficial in the prevention of hyperuricemia in the general Japanese population.

  15. Correlation Between C-reactive Protein and Non-enzymatic Antioxidants (Albumin, Ferritin, Uric Acid and Bilirubin) in Hemodialysis Patients.

    PubMed

    Beciragic, Amela; Resic, Halima; Prohic, Nejra; Karamehic, Jasenko; Smajlovic, Ajdin; Masnic, Fahrudin; Ajanovic, Selma; Coric, Aida

    2015-04-01

    Increased levels of C-Reactive Protein are found in 30-60% on hemodialysis patients and it is closely associated with the progression of atherosclerosis, cardiovascular morbidity and mortality. Non enzymatic antioxidants are antioxidants which primarily retain potentially dangerous ions of iron and copper in their inactive form and thereby prevent its participation in the production of free radicals. The aim of the study was to examine the relationship of CRP and non enzymatic antioxidants (albumin, ferritin, uric acid and bilirubin) i.e. examine the importance of CRP as a serum biomarker in assessing the condition of inflammation and its relationship to antioxidant protection in patients on hemodialysis. The study was cross-sectional, clinical, comparative and descriptive. The study involved 100 patients (non diabetic) on chronic hemodialysis. The control group consisted of 50 subjects without subjective and objective indicators of chronic renal disease. In all patients, the concentration of CRP as well as concentrations of non enzymatic antioxidants were determined. In the group of hemodialysis patients 60% were men and 40% women. The average age of hemodialysis patients was 54.13 ± 11.8 years and the average age of the control group 41.72 ± 9.8 years. The average duration of hemodialysis treatment was 91.42 ± 76.2 months. In the group of hemodialysis patients statistically significant, negative linear correlation was determined between the concentration of CRP in and albumin concentration (rho = -0.251, p = 0.012) as well as negative, statistics insignificant, linear correlation between serum CRP and the concentration of uric acid (r = -0.077, p = 0.448). Furthermore, the positive, linear correlation was determined between serum CRP and ferritin (r = 0.159, p = 0.114) and positive linear correlation between CRP and total serum bilirubin (r = 0.121, p = 0.230). In the control group was determined a statistically significant, positive, linear correlation

  16. Creatinine, urea, uric acid, water and electrolytes renal handling in the healthy oldest old

    PubMed Central

    Musso, Carlos Guido; Álvarez Gregori, Joaquín; Jauregui, José Ricardo; Macías Núñez, Juan Florencio

    2012-01-01

    Renal physiology in the healthy oldest old has the following characteristics, in comparison with the renal physiology in the young: a reduced creatinine clearance, tubular pattern of creatinine back-filtration, preserved proximal tubule sodium reabsorption and uric acid secretion, reduced sodium reabsorption in the thick ascending loop of Henle, reduced free water clearance, increased urea excretion, presence of medulla hypotonicity, reduced urinary dilution and concentration capabilities, and finally a reduced collecting tubules response to furosemide which expresses a reduced potassium excretion in this segment due to a sort of aldosterone resistance. All physiological changes of the aged kidney are the same in both genders. PMID:24175249

  17. Simultaneous determination of plasma creatinine, uric acid, kynurenine and tryptophan by high-performance liquid chromatography: method validation and in application to the assessment of renal function.

    PubMed

    Zhao, Jianxing

    2015-03-01

    A high-performance liquid chromatography with ultraviolet detection method has been developed for the simultaneous determination of a set of reliable markers of renal function, including creatinine, uric acid, kynurenine and tryptophan in plasma. Separation was achieved by an Agilent HC-C18 (2) analytical column. Gradient elution and programmed wavelength detection allowed the method to be used to analyze these compounds by just one injection. The total run time was 25 min with all peaks of interest being eluted within 13 min. Good linear responses were found with correlation coefficient >0.999 for all analytes within the concentration range of the relevant levels. The recovery was: creatinine, 101 ± 1%; uric acid, 94.9 ± 3.7%; kynurenine, 100 ± 2%; and tryptophan, 92.6 ± 2.9%. Coefficients of variation within-run and between-run of all analytes were ≤2.4%. The limit of detection of the method was: creatinine, 0.1 µmol/L; uric acid, 0.05 µmol/L; kynurenine, 0.02 µmol/L; and tryptophan, 1 µmol/L. The developed method could be employed as a useful tool for the detection of chronic kidney disease, even at an early stage. Copyright © 2014 John Wiley & Sons, Ltd.

  18. Antioxidant capacity of BO-653, 2,3-dihydro-5-hydroxy-4,6-di-tert-butyl-2,2-dipentylbenzofuran, and uric acid as evaluated by ORAC method and inhibition of lipid peroxidation.

    PubMed

    Niki, Etsuo; Fukuhara, Akiko; Omata, Yo; Saito, Yoshiro; Yoshida, Yasukazu

    2008-04-01

    The role of radical-scavenging antioxidant against oxidative stress has received much attention. The antioxidant capacity has been assessed by various methods. Above all, oxygen radical absorbance capacity (ORAC) has been frequently employed [Prior et.al., J. Agric. Food Chem.2005, 53, 4290]. In the present study, the antioxidant capacity of 2,3-dihydro-5-hydroxy-4,6-di-tert-butyl-2,2-dipentylbenzofuran (BO-653) and uric acid was assessed by ORAC method using pyranine as a reference probe and compared with that against lipid peroxidation of human plasma. It was found that BO-653 was assessed to be much less potent than uric acid by ORAC method, whereas BO-653 exerted much higher antioxidant activity than uric acid against plasma lipid peroxidation. The reason for such discrepancy is discussed. The results suggest that ORAC method is suitable for the assessment of free radical scavenging capacity, but not for the assessment of antioxidant capacity against lipid peroxidation in plasma.

  19. Association of Serum Uric Acid Levels in Psoriasis

    PubMed Central

    Li, Xin; Miao, Xiao; Wang, Hongshen; Wang, Yifei; Li, Fulun; Yang, Qiong; Cui, Rutao; Li, Bin

    2016-01-01

    Abstract High levels of serum uric acid (SUAC) are frequently detected in patients with psoriasis. However, the relationship between psoriasis and hyperuricemia remains unknown. Here we conducted a meta-analysis to identify the SUAC levels in subjects with psoriasis and to determine whether there is an associated risk between psoriasis and hyperuricemia. A comprehensive search of the literature from January 1980 to November 2014 across 7 databases (MEDLINE, Embase, Cochrane Central Register, and 4 Chinese databases) was conducted to determine whether there is an associated risk between psoriasis and hyperuricemia. Among the 170 identified reports, 14 observational studies were included in this meta-analysis. We found a significant higher SUAC level (MD 0.68, 95% CI 0.26–1.09; P = 0.002) in patients with psoriasis in Western Europe, but no significant differences were found between the East Asia and India subgroup (MD 1.22, 95% CI –0.13–2.56; P = 0.08) or the Middle East subgroup (MD 0.48, 95% CI –0.49–1.44; P = 0.33). Similar results were obtained from the meta-analysis of SUAC levels in subjects with severe psoriasis. Our meta-analysis showed that the correlation between psoriasis and hyperuricemia was either ethnicity- or region-dependent and that patients with psoriasis in Western Europe were more likely to have hyperuricemia. PMID:27175702

  20. Uric acid and dehydration in children with gastroenteritis.

    PubMed

    Kuge, Rie; Morikawa, Yoshihiko; Hasegawa, Yukihiro

    2017-11-01

    Clinical assessment of dehydration in children with acute gastroenteritis (AGE) is crucial for treatment. The gold standard for assessment is acute weight loss. Dehydration severity, as determined by weight loss, significantly correlates with serum urea nitrogen (UN) in children with AGE. The disadvantage of using serum UN as a marker of dehydration severity, however, is that the level can be affected by nutrition. Serum uric acid (UA) theoretically could serve as an alternative in this regard, but there have been no reports on the direct relationship between serum UA and weight loss. The aim of this study was therefore to assess the relationship between serum UA and weight loss in patients with AGE. This was a prospective observational study of children 1-71 months of age admitted to Tokyo Metropolitan Children's Medical Center with AGE between 1 December 2010 and 31 March 2015. Patients with symptoms of AGE ≥ 8 days, chronic disease, or incomplete data were excluded from the study. Pre-post-rehydration weight change was used as an alternative, gold standard marker for the assessment of dehydration severity. The study participants consisted of 97 children. Serum UA correlated significantly with weight change, and increased significantly along with dehydration severity. Serum UA can be considered as an adjunct to the clinical assessment of dehydration in children with AGE. © 2017 Japan Pediatric Society.

  1. Liver zonation in children with non-alcoholic fatty liver disease: Associations with dietary fructose and uric acid concentrations.

    PubMed

    Nobili, Valerio; Mosca, Antonella; De Vito, Rita; Raponi, Massimiliano; Scorletti, Eleonora; Byrne, Christopher D

    2018-06-01

    As dietary components are delivered directly to the periportal zone of the liver lobule, there is the potential for greater injury in this zone (zone 1) compared to the perivenous zone (zone 3). We investigated the associations between dietary fructose consumption and uric acid concentrations and differential zonal injury in periportal and perivenous zones. A total of 271 children's histological images were scored in 5 periportal and 5 perivenous zones for steatosis, ballooning, inflammation and fibrosis severity. Dietary fructose consumption (g/d) was assessed and uric acid measured in serum. Logistic regression was undertaken to test associations between both high fructose consumption and hyperuricaemia, and histological disease in periportal and perivenous zones. Children with a mean age of 12.5 years were included in the study. Inflammation (mean ± SD) was increased in the periportal vs perivenous zones (0.78 ± 0.43 vs 0.41 ± 0.48, P = .041). There were non-significant trends towards greater steatosis, ballooning and fibrosis in the periportal zone. In the fully adjusted models, high fructose intake was associated with disease in both zones. Example for periportal and perivenous zones, respectively, steatosis 1.56 (1.12, 2.49) and 1.21 (1.09, 2.73); inflammation 4.29 (2.31, 5.88) and 3.69 (2.14, 4.56); and fibrosis 2.72 (1.43, 3.76) and 1.96 (1.24, 2.37). Hyperuricaemia (uric acid ≥5.9 mg/dL) was associated with inflammation in the periportal zone 1.71 (1.17, 2.35); and was associated with steatosis and fibrosis in both zones; for example, for periportal and perivenous zones, respectively, steatosis 2.98 (1.65, 3.23) and 1.14 (1.05, 1.99); and fibrosis, 2.65 (1.35, 2.99) and 1.31 (1.13, 2.17). High fructose consumption is associated with disease severity in both lobular zones and hyperuricaemia may be associated with more severe disease in the periportal zone. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Sex-specific associations of serum uric acid with metabolic syndrome in Chinese rural population: The RuralDiab study.

    PubMed

    Zhang, Honglei; Li, Yuqian; Mao, Zhenxing; Liu, Xiaotian; Zhang, Xia; Yang, Kaili; Liu, Ruihua; Qian, Xinling; Zhang, Haiqing; Jiang, Jingjing; Zhang, Gongyuan; Wang, Chongjian

    2018-05-01

    We explored the association between serum uric acid (SUA) and metabolic syndrome (MetS) in Chinese rural adults. A total of 16,577 subjects (6354 men and 10,223 women) were from the RuralDiab study. SUA concentration was measured by the enzymatic colorimetric method. A meta-analysis including 12 eligible studies focused on SUA and MetS was preformed to confirm the findings of the cross-sectional study. After adjustment for age, educational level, and other covariates, the odds ratio (ORs) for MetS increased smoothly with the increasing SUA concentration in both sexes (P for no-linear trend > 0.05). The adjusted ORs of MetS comparing the fourth and firstly quartiles were 3.11 [95% CI: 2.58-3.74] in men and 3.64 [95% CI: 3.22-4.11] in women (P trend  < 0.001). In continuous analysis, each 1 mg/dl increment in SUA concentration was significantly associated with a 41% increased risk of MetS in men and 62% in women. The meta-analysis validated the positive association between SUA and MetS (pooled OR: Men, 1.80 [95% CI: 1.57-2.07]; Women, 2.46 [95% CI: 1.95-3.12]). SUA concentration was positively with the prevalence of MetS in Chinese rural population, and more studies are needed to explore the mechanisms of the relationship. WHAT IS ALREADY KNOWN ON THIS TOPIC?: Previous studies have explored the association between serum uric acid and metabolic syndrome, but evidence on the strength and consistency of the association remains uncertain and limited, especially in rural population. In addition, the epidemiological research and meta-analysis on the association have not been reported. WHAT DOES THIS STUDY ADD?: The results of this study showed that serum uric acid was significantly associated with metabolic syndrome and its components in Chinese rural population. Furthermore, the findings demonstrated that the significant associations varied across sex. In addition, the results of epidemiological research were similar with the meta-analysis, which demonstrates

  3. Spectroscopic analyses and studies on respective interaction of cyanuric acid and uric acid with bovine serum albumin and melamine

    NASA Astrophysics Data System (ADS)

    Chen, Dandan; Wu, Qiong; Wang, Jun; Wang, Qi; Qiao, Heng

    2015-01-01

    In this work, the fluorescence quenching was used to study the interaction of cyanuric acid (CYA) and uric acid (UA) with bovine serum albumin (BSA) at two different temperatures (283 K and 310 K). The bimolecular quenching constant (Kq), apparent quenching constant (Ksv), effective binding constant (KA) and corresponding dissociation constant (KD), binding site number (n) and binding distance (r) were calculated by adopting Stern-Volmer, Lineweaver-Burk, Double logarithm and overlap integral equations. The results show that CYA and UA are both able to obviously bind to BSA, but the binding strength order is BSA + CYA < BSA + UA. And then, the interactions of CYA and UA with melamine (MEL) under the same conditions were also studied by using similar methods. The results indicates that both CYA and UA can bind together closely with melamine (MEL). It is wished that these research results would facilitate the understanding the formation of kidney stones and gout in the body after ingesting excess MEL.

  4. Effects of Parsley (Petroselinum crispum) and its Flavonol Constituents, Kaempferol and Quercetin, on Serum Uric Acid Levels, Biomarkers of Oxidative Stress and Liver Xanthine Oxidoreductase Aactivity inOxonate-Induced Hyperuricemic Rats.

    PubMed

    Haidari, Fatemeh; Keshavarz, Seid Ali; Mohammad Shahi, Majid; Mahboob, Soltan-Ali; Rashidi, Mohammad-Reza

    2011-01-01

    Increased serum uric acid is known to be a major risk related to the development of several oxidative stress diseases. The aim of this study was to investigate the effect of parsley, quercetin and kaempferol on serum uric acid levels, liver xanthine oxidoreductase activity and two non-invasive biomarkers of oxidative stress (total antioxidant capacity and malondialdehyde concentration) in normal and oxonate-induced hyperuricemic rats. A total of 60 male Wistar rats were randomly divided into ten equal groups; including 5 normal groups (vehicle, parsley, quercetin, kaempferol and allopurinol) and 5 hyperuricemic groups (vehicle, parsley, quercetin, kaempferol and allopurinol). Parsley (5 g/Kg), quercetin (5 mg/Kg), kaempferol (5 mg/Kg) and allopurinol (5 mg/Kg) were administrated to the corresponding groups by oral gavage once a day for 2 weeks. The results showed that parsley and its flavonol did not cause any significant reduction in the serum uric acid levels in normal rats, but significantly reduced the serum uric acid levels of hyperuricemic rats in a time-dependent manner. All treatments significantly inhibited liver xanthine oxidoreductase activity. Parsley, kaempferol and quercetin treatment led also to a significant increase in total antioxidant capacity and decrease in malondialdehyde concentration in hyperuricemic rats. Although the hypouricemic effect of allopurinol was much higher than that of parsley and its flavonol constituents, it could not significantly change oxidative stress biomarkers. These features of parsley and its flavonols make them as a possible alternative for allopurinol, or at least in combination therapy to minimize the side effects of allopurinol to treat hyperuricemia and oxidative stress diseases.

  5. Effects of Parsley (Petroselinum crispum) and its Flavonol Constituents, Kaempferol and Quercetin, on Serum Uric Acid Levels, Biomarkers of Oxidative Stress and Liver Xanthine Oxidoreductase Aactivity inOxonate-Induced Hyperuricemic Rats

    PubMed Central

    Haidari, Fatemeh; Keshavarz, Seid Ali; Mohammad Shahi, Majid; Mahboob, Soltan-Ali; Rashidi, Mohammad-Reza

    2011-01-01

    Increased serum uric acid is known to be a major risk related to the development of several oxidative stress diseases. The aim of this study was to investigate the effect of parsley, quercetin and kaempferol on serum uric acid levels, liver xanthine oxidoreductase activity and two non-invasive biomarkers of oxidative stress (total antioxidant capacity and malondialdehyde concentration) in normal and oxonate-induced hyperuricemic rats. A total of 60 male Wistar rats were randomly divided into ten equal groups; including 5 normal groups (vehicle, parsley, quercetin, kaempferol and allopurinol) and 5 hyperuricemic groups (vehicle, parsley, quercetin, kaempferol and allopurinol). Parsley (5 g/Kg), quercetin (5 mg/Kg), kaempferol (5 mg/Kg) and allopurinol (5 mg/Kg) were administrated to the corresponding groups by oral gavage once a day for 2 weeks. The results showed that parsley and its flavonol did not cause any significant reduction in the serum uric acid levels in normal rats, but significantly reduced the serum uric acid levels of hyperuricemic rats in a time-dependent manner. All treatments significantly inhibited liver xanthine oxidoreductase activity. Parsley, kaempferol and quercetin treatment led also to a significant increase in total antioxidant capacity and decrease in malondialdehyde concentration in hyperuricemic rats. Although the hypouricemic effect of allopurinol was much higher than that of parsley and its flavonol constituents, it could not significantly change oxidative stress biomarkers. These features of parsley and its flavonols make them as a possible alternative for allopurinol, or at least in combination therapy to minimize the side effects of allopurinol to treat hyperuricemia and oxidative stress diseases. PMID:24250417

  6. AA-PMe, a novel asiatic acid derivative, induces apoptosis and suppresses proliferation, migration, and invasion of gastric cancer cells.

    PubMed

    Jing, Yue; Wang, Gang; Ge, Ying; Xu, Minjie; Tang, Shuainan; Gong, Zhunan

    2016-01-01

    Asiatic acid (AA; 2α,3β,23-trihydroxyurs-12-ene-28-oic acid) is widely used for medicinal purposes in many Asian countries due to its various bioactivities. A series of AA derivatives has been synthesized in attempts to improve its therapeutic potencies. Herein we investigated the anti-tumor activities of N-(2α,3β,23-acetoxyurs-12-en-28-oyl)-l-proline methyl ester (AA-PMe), a novel AA derivative. AA-PMe exhibited a stronger anti-cancer activity than its parent compound AA. AA-PMe inhibited the proliferation of SGC7901 and HGC27 human gastric cancer cells in a dose-dependent manner but had no significant toxicity in human gastric mucosa epithelial cells (GES-1). AA-PMe induced cell cycle arrest in G0/G1 phase and blocked G1-S transition, which correlated well with marked decreases in levels of cyclin D1, cyclin-dependent kinase CKD4, and phosphorylated retinoblastoma protein, and increase in cyclin-dependent kinase inhibitor P15. Further, AA-PMe induced apoptosis of human gastric cancer cells by affecting Bcl-2, Bax, c-Myc, and caspase-3. Moreover, AA-PMe suppressed the migration and invasion of human gastric cancer cells (SGC7901 and HGC27) cells by downregulating the expression of MMP-2 and MMP-9. Overall, this study investigated the potential anti-cancer activities of AA-PMe including inducing apoptosis and suppressing proliferation, migration and invasion of gastric cancer cells, as well as the underlying mechanisms, suggesting that AA-PMe is a promising anti-cancer drug candidate in gastric cancer therapy.

  7. Facile electrochemical pretreatment of multiwalled carbon nanotube - Polydimethylsiloxane paste electrode for enhanced detection of dopamine and uric acid

    NASA Astrophysics Data System (ADS)

    Buenaventura, Angelo Gabriel E.; Yago, Allan Christopher C.

    2018-05-01

    A facile electrochemical pretreatment via anodization was done on Carbon Paste Electrodes (CPEs) composed of Multiwalled Carbon Nanotubes (MWCNTs) and Polydimethylsiloxane (PDMS) binder to produce `anodized' CPEs (ACPE). Cyclic Voltammetry (CV) technique was used to anodize the CPEs. The anodization step, performed in various solutions (0.2 M NaOH(aq), 0.06 M BR Buffer at pH 7.0, and 0.2 M HNO3(aq)), were found to enhance the electrochemical properties of the ACPEs compared to non-anodized CPE. Electrochemical Impedance Spectroscopy (EIS) measurements revealed a significantly lower charge transfer resistance (Rct) for the ACPEs (4.01-6.25 kΩ) as compared to CPE (25.9 kΩ). Comparison of the reversibility analysis for Fe(CN)63-/4- redox couple showed that the ACPEs have peak current ratio (Ia/Ic) at range of 0.97-1.10 while 1.92 for the CPE; this result indicated better electrochemical reversible behaviors for Fe(CN)63-/4- redox couple using the ACPEs. CV Anodization process was further optimized by varying solution and CV parameters (i.e. pH, composition, number of cycles, and potential range), and the resulting optimized ACPE was used for enhanced detection of Dopamine (DA) and Uric Acid (UA) in the presence of excess Ascorbic Acid (AA). Employing Differential Pulse Voltammetry technique, enhanced voltammetric signal for DA and significant peak separation between DA and UA was obtained. The anodic peak currents for the oxidation of DA and UA appeared at 0.263V and 0.414 V, respectively, and it was observed to be linearly increasing with increasing concentrations of biomolecules (25-100 µM). The detection limit was determined to be 3.86 µM for DA and 5.61 µM for UA. This study showed a quick and cost-effective pretreatment for CPEs based on MWCNT-PDMS composite which lead to significant enhancement on its electrochemical properties.

  8. Prognostic impact of elevated serum uric acid levels on long-term outcomes in patients with chronic heart failure: A post-hoc analysis of the GISSI-HF (Gruppo Italiano per lo Studio della Sopravvivenza nella Insufficienza Cardiaca-Heart Failure) trial.

    PubMed

    Mantovani, Alessandro; Targher, Giovanni; Temporelli, Pier Luigi; Lucci, Donata; Gonzini, Lucio; Nicolosi, Gian Luigi; Marchioli, Roberto; Tognoni, Gianni; Latini, Roberto; Cosmi, Franco; Tavazzi, Luigi; Maggioni, Aldo Pietro

    2018-06-01

    The prognostic impact of hyperuricemia on long-term clinical outcomes in patients with chronic heart failure (HF) has been investigated in observational registries and clinical trials, but the results have been often inconclusive. We examined the prognostic impact of elevated serum uric acid levels on long-term clinical outcomes in the GISSI-HF (Gruppo Italiano per lo Studio della Sopravvivenza nella Insufficienza Cardiaca-Heart Failure) trial. CLINICALTRIALS. NCT00336336. We assessed the rates of all-cause death, cardiovascular death, cardiovascular hospitalization and the composite of all-cause death or cardiovascular hospitalization over a median follow-up of 3.9 years among 6683 ambulatory patients with chronic HF. Patients in the 3rd serum uric acid tertile (>7.2 mg/dl) had a nearly 1.8-fold increased risk of both all-cause death and cardiovascular death, and a nearly 1.5-fold increased risk of cardiovascular hospitalization and of the composite endpoint compared to those in the 1st uric acid tertile (<5.7 mg/dl). Beyond serum uric acid ≥ 7 mg/dl the risk of outcomes increased sharply and linearly. The significant association between elevated serum uric acid levels and adverse outcomes persisted after adjustment for multiple established cardiovascular risk factors, HF etiology, left ventricular ejection fraction, medication use and other potential confounders, with an adjusted hazard ratio of 1.37 (95% CI 1.22-1.55) for all-cause death, 1.48 (1.29-1.69) for cardiovascular death, 1.19 (1.09-1.30) for cardiovascular hospitalization and 1.21 (1.11-1.31) for the composite endpoint, respectively. Elevated serum uric acid levels are independently associated with poor long-term survival and increased risk of cardiovascular hospitalization in patients with chronic HF. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. AA-PMe, a novel asiatic acid derivative, induces apoptosis and suppresses proliferation, migration, and invasion of gastric cancer cells

    PubMed Central

    Jing, Yue; Wang, Gang; Ge, Ying; Xu, Minjie; Tang, Shuainan; Gong, Zhunan

    2016-01-01

    Asiatic acid (AA; 2α,3β,23-trihydroxyurs-12-ene-28-oic acid) is widely used for medicinal purposes in many Asian countries due to its various bioactivities. A series of AA derivatives has been synthesized in attempts to improve its therapeutic potencies. Herein we investigated the anti-tumor activities of N-(2α,3β,23-acetoxyurs-12-en-28-oyl)-l-proline methyl ester (AA-PMe), a novel AA derivative. AA-PMe exhibited a stronger anti-cancer activity than its parent compound AA. AA-PMe inhibited the proliferation of SGC7901 and HGC27 human gastric cancer cells in a dose-dependent manner but had no significant toxicity in human gastric mucosa epithelial cells (GES-1). AA-PMe induced cell cycle arrest in G0/G1 phase and blocked G1-S transition, which correlated well with marked decreases in levels of cyclin D1, cyclin-dependent kinase CKD4, and phosphorylated retinoblastoma protein, and increase in cyclin-dependent kinase inhibitor P15. Further, AA-PMe induced apoptosis of human gastric cancer cells by affecting Bcl-2, Bax, c-Myc, and caspase-3. Moreover, AA-PMe suppressed the migration and invasion of human gastric cancer cells (SGC7901 and HGC27) cells by downregulating the expression of MMP-2 and MMP-9. Overall, this study investigated the potential anti-cancer activities of AA-PMe including inducing apoptosis and suppressing proliferation, migration and invasion of gastric cancer cells, as well as the underlying mechanisms, suggesting that AA-PMe is a promising anti-cancer drug candidate in gastric cancer therapy. PMID:27073325

  10. Sensitive detection of dopamine via leucodopaminechrome on polyacrylic acid-coated ceria nanorods

    NASA Astrophysics Data System (ADS)

    Sheng, Weiqin; Zheng, Liang; Liu, Yan; Zhao, Xueqin; Weng, Jian; Zhang, Yang

    2017-09-01

    The major hurdle in detection of dopamine (DA) by electro-analysis is the presence of physiological interferents with a similar oxidation potential of DA. The conventional method is to enlarge the difference of their oxidation potentials. Here, we report an unconventional method to detect DA via leucodopaminechrome on CeO2 nanorods. Leucodopaminechrome is produced from the cyclization of dopamine-quinone, a product of two-electron oxidation of DA. Thus, its concentration is proportional to the DA concentration. Determining DA is demonstrated by measuring the reduction current of leucodopaminechrome on CeO2 nanorods. CeO2 nanorods demonstrate high electrocatalytic activity for reduction of leucodopaminechrome with a low potential at -0.27 V. The low detection potential of leucodopaminechrome can avoid the interference from ascorbic acid (AA) and uric acid (UA). Therefore, detecting DA via leucodopaminechrome is an effective method to avoid interference from AA and UA, and the suggested biosensor also displays good reproducibility and stability.

  11. The effect of depurinized milk draught diet on rat serum uric acid, lipid status and haematological parameters.

    PubMed

    Kocic, G; Pavlovic, R; Nikolic, G; Stojanovic, D; Jevtovic, T; Sokolovic, D; Cencic, A; Stojanovic, S; Jelic, M; Zivanovic, S

    2012-08-01

    Hyperuricaemia and gout are closely related, but hyperuricaemia is an independent risk factor for endothelial damage, autoinflammation and haemodynamic abnormalities. Milk, generally known as a 'purine-free diet', is an essential protein source for patients suffering from hyperuricaemia and gout. As milk still contains different purine ribonucleotides, the new product, depurinized milk, almost free of purine nucleotides and uric acid, was produced. The potential effect of depurinized milk diet on serum uric acid (SUA) level, lipid parameters and blood haematological parameters was explored in rats after 72 h and 15 days, in relation to standard laboratory chow or the untreated milk diet. The beneficial effect on SUA was achieved when depurinized milk draught was given instead of standard chow for 72 h [28.39 ± 4.76 μm; p < 0.001 vs. standard diet (STD) 47.6 ± 6.12, vs. untreated milk diet 31.55 ± 8.50; p < 0.05] or as a supplement for STD for 15 days experiment (35.38 ± 6.40 μm; p < 0.05 vs. STD only 48.05 ± 4.32; vs. untreated milk + STD 46.02 ± 9.48). Depurinized milk diet significantly decreased the low density lipoproteins/high density lipoproteins (LDL/HDL) ratio (p < 0.001), triglycerides (p < 0.05) and leucocyte count (p < 0.001), while both milk draughts enhanced haemoglobin concentration (p < 0.01). In conclusion, considering the detrimental effect of persisting hyperuricaemia, the depurinized milk draught may meet the demand of healthy dairy product for population under hyperuricaemic risk. © 2011 Blackwell Verlag GmbH.

  12. Suppressive effect of viscous dietary fiber on elevations of uric acid in serum and urine induced by dietary RNA in rats is associated with strength of viscosity.

    PubMed

    Koguchi, Takashi; Nakajima, Hisao; Koguchi, Hiromi; Wada, Masahiro; Yamamoto, Yuji; Innami, Satoshi; Maekawa, Akio; Tadokoro, Tadahiro

    2003-10-01

    This study was performed to clarify how dietary fiber (DF) with different viscosities would be associated with dietary RNA metabolism. Male Wistar strain rats, four weeks old, were fed diets containing a 3% (w/w) yeast RNA and a 5% (w/w) viscous DF for five days. Viscosity of DF samples used, in order of strength, were xanthan gum (XG) > guar gum (GG) > locust bean gum (LBG) > karaya gum (KG) > pectin (PE) = arabic gum (AG) > CM-cellulose (CMC) = inulin (IN). The serum uric acid concentration in the viscous DF groups significantly decreased as compared with that in the cellulose (CL) group. The urinary excretions of uric acid and allantoin in the respective groups given AG, GG, IN, KG, PE, and XG were significantly suppressed as compared with those in the CL group. The fecal RNA excretion was markedly increased in the IN, KG, PE, and XG groups in comparison to the CL group. The DF with high viscosity significantly suppressed RNA digestion by RNase A and decreased uptakes of 14C-labeled adenosine and adenosine 5'-monophosphate (5'-AMP) in rat jejunum. The results reveal that the suppressive effect of DF on elevation of serum uric acid concentration induced by dietary RNA in rats is associated with the strength of DF viscosity. The mechanism by which this is accomplished is suggested to be attributed to the inhibitions of digestion for dietary RNA and/or absorption of the hydrolyzed compounds.

  13. Dual-energy dual-source CT with additional spectral filtration can improve the differentiation of non-uric acid renal stones: An ex vivo phantom study

    PubMed Central

    Qu, Mingliang; Ramirez Giraldo, Juan C.; Leng, Shuai; Williams, James C.; Vrtiska, Terri J.; Lieske, John C.; McCollough, Cynthia H.

    2014-01-01

    Purpose To determine the ex vivo ability of dual-energy, dual-source computed tomography (DE-DSCT) with additional tin filtration to differentiate between five groups of human renal stone types. Methods Forty-three renal stones of ten types were categorized into five primary groups based on effective atomic numbers, which were calculated as the weighted average of the atomic numbers of constituent atoms. Stones were embedded in porcine kidneys and placed in a 35cm water phantom. DE-DSCT scans were performed with and without tin filtration at 80/140kV. The CT number ratio [CTR=CT(low)/CT(high)] was calculated on a volumetric voxel-by-voxel basis for each stone. Statistical analysis was performed and receiver operating characteristic (ROC) curves were plotted to compare the difference in CTR with and without tin filtration, and to measure the discrimination between stone groups. Results CTR of non-uric acid stones increased on average by 0.17 (range 0.03–0.36) with tin filtration. The CTR values for non-uric acid stone groups were not significantly different (p>0.05) between any of the two adjacent groups without tin filtration. Use of the additional tin filtration on the high-energy x-ray tube significantly improved the separation of non-uric acid stone types by CTR (p<0.05). The area under the ROC curve increased from 0.78–0.84 without fin filtration to 0.89–0.95 with tin filtration. Conclusion Our results demonstrated better separation between different stone types when additional tin filtration was used on DE-DSCT. The increased spectral separation allowed a 5-group stone classification scheme. Some overlapping between particular stone types still exists, including brushite and calcium oxalate. PMID:21606290

  14. Variation of amino acid sequences of serum amyloid a (SAA) and immunohistochemical analysis of amyloid a (AA) in Japanese domestic cats.

    PubMed

    Tei, Meina; Uchida, Kazuyuki; Chambers, James K; Watanabe, Ken-Ichi; Tamamoto, Takashi; Ohno, Koichi; Nakayama, Hiroyuki

    2018-02-02

    Amyloid A (AA) amyloidosis, a fatal systemic amyloid disease, occurs secondary to chronic inflammatory conditions in humans. Although persistently elevated serum amyloid A (SAA) levels are required for its pathogenesis, not all individuals with chronic inflammation necessarily develop AA amyloidosis. Furthermore, many diseases in cats are associated with the elevated production of SAA, whereas only a small number actually develop AA amyloidosis. We hypothesized that a genetic mutation in the SAA gene may strongly contribute to the pathogenesis of feline AA amyloidosis. In the present study, genomic DNA from four Japanese domestic cats (JDCs) with AA amyloidosis and from five without amyloidosis was analyzed using polymerase chain reaction (PCR) amplification and direct sequencing. We identified the novel variation combination of 45R-51A in the deduced amino acid sequences of four JDCs with amyloidosis and five without. However, there was no relationship between amino acid variations and the distribution of AA amyloid deposits, indicating that differences in SAA sequences do not contribute to the pathogenesis of AA amyloidosis. Immunohistochemical analysis using antisera against the three different parts of the feline SAA protein-i.e., the N-terminal, central, and C-terminal regions-revealed that feline AA contained the C-terminus, unlike human AA. These results indicate that the cleavage and degradation of the C-terminus are not essential for amyloid fibril formation in JDCs.

  15. Fructose Intake, Serum Uric Acid, and Cardiometabolic Disorders: A Critical Review.

    PubMed

    Caliceti, Cristiana; Calabria, Donato; Roda, Aldo; Cicero, Arrigo F G

    2017-04-18

    There is a direct relationship between fructose intake and serum levels of uric acid (UA), which is the final product of purine metabolism. Recent preclinical and clinical evidence suggests that chronic hyperuricemia is an independent risk factor for hypertension, metabolic syndrome, and cardiovascular disease. It is probably also an independent risk factor for chronic kidney disease, Type 2 diabetes, and cognitive decline. These relationships have been observed for high serum UA levels (>5.5 mg/dL in women and >6 mg/dL in men), but also for normal to high serum UA levels (5-6 mg/dL). In this regard, blood UA levels are much higher in industrialized countries than in the rest of the world. Xanthine-oxidase inhibitors can reduce UA and seem to minimize its negative effects on vascular health. Other dietary and pathophysiological factors are also related to UA production. However, the role of fructose-derived UA in the pathogenesis of cardiometabolic disorders has not yet been fully clarified. Here, we critically review recent research on the biochemistry of UA production, the relationship between fructose intake and UA production, and how this relationship is linked to cardiometabolic disorders.

  16. Eicosapentaenoic acid to arachidonic acid (EPA/AA) ratio as an associated factor of high risk plaque on coronary computed tomography in patients without coronary artery disease.

    PubMed

    Nagahara, Yasuomi; Motoyama, Sadako; Sarai, Masayoshi; Ito, Hajime; Kawai, Hideki; Takakuwa, Yoko; Miyagi, Meiko; Shibata, Daisuke; Takahashi, Hiroshi; Naruse, Hiroyuki; Ishii, Junichi; Ozaki, Yukio

    2016-07-01

    Coronary computed tomography angiography (CCTA)-verified high risk plaque (HRP) characteristics including positive remodeling and low attenuation plaque have been associated with acute coronary syndromes. Several studies reported that the n-3 polyunsaturated fatty acids have been associated with cardiovascular events. However, the relationship between serum eicosapentaenoic acid to arachidonic acid (EPA/AA) ratio and CCTA-verified HRP in patients without known coronary artery disease (CAD) is unclear. We aimed at investigating the relation between EPA/AA and CCTA-verified HRP in patients without known CAD. We included 193 patients undergoing CCTA without known CAD (65.5 ± 12.0 years, 55.0% male). No patient has been treated with EPA. The relation of coronary risk factors, lipid profile, high-sensitivity C-reactive protein, coronary artery calcification score (CACS), number of vessel disease, plaque burden, and EPA/AA with the presence of HRP was evaluated by logistic regression analysis. Incremental value of EPA/AA to predict HRP was also analyzed by C-index, NRI, and IDI. A Cox proportional hazards model was used to estimate the time to cardiovascular event. HRP was observed in 37 (19%) patients. Multivariable logistic regression analysis revealed that current smoking (OR 2.58; p=0.046), number of vessel disease (OR 1.87; p=0.031), and EPA/AA ratio (OR 0.65; p=0.0006) were independent associated factors of HRP on CCTA. Although the addition of EPA/AA to the baseline model did not significantly improve C-index, both NRI (0.60, p=0.0049) and IDI (0.054, p=0.0072) were significantly improved. Patients with HRP had significantly higher rate of events compared with patients without HRP (14% vs. 3%, Logrank p=0.0004). On multivariable Cox hazard analysis, baseline EPA/AA ratio was an independent predictor (HR 0.57, p=0.047). Low EPA/AA was an associated factor of HRP on CCTA in patients without CAD. In addition to conventional coronary risk factors and CACS, EPA/AA

  17. Attenuating the mortality risk of high serum uric acid: the role of physical activity underused.

    PubMed

    Chen, Jiunn-Horng; Wen, Chi Pang; Wu, Shiuan Bei; Lan, Joung-Liang; Tsai, Min Kuang; Tai, Ya-Ping; Lee, June Han; Hsu, Chih Cheng; Tsao, Chwen Keng; Wai, Jackson Pui Man; Chiang, Po Huang; Pan, Wen Han; Hsiung, Chao Agnes

    2015-11-01

    High serum uric acid (sUA) has been associated with increased mortality risks, but its clinical treatment varied with potential side effects. The role of physical activity has received limited attention. A cohort, consisting of 467 976 adults, who went through a standard health screening programme, with questionnaire and fasting blood samples, was successively recruited between 1996 and 2008. High sUA is defined as uric acid above 7.0 mg/dL. Leisure time physical activity level was self-reported, with fully active defined as those with 30 min per day for at least 5 days a week. National death file identified 12 228 deaths with a median follow-up of 8.5 years. Cox proportional model was used to analyse HRs, and 12 variables were controlled, including medical history, life style and risk factors. High sUA constituted one quarter of the cohort (25.6%). Their all-cause mortality was significantly increased [HR: 1.22 (1.15-1.29)], with much of the increase contributed to by the inactive (HR: 1.27 (1.17-1.37)), relative to the reference group with sUA level of 5-6 mg/dL. When they were fully active, mortality risks did not increase, but decreased by 11% (HR: 0.89 (0.82-0.97)), reflecting the benefits of being active was able to overcome the adverse effects of high sUA. Given the same high sUA, a 4-6 years difference in life expectancy was found between the active and the inactive. Physical activity is a valuable alternative to pharmacotherapy in its ability to reduce the increases in mortality risks from high sUA. By being fully active, exercise can extend life span by 4-6 years, a level greater than the 1-4 years of life-shortening effect from high sUA. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  18. Endogenous and Uric Acid-Induced Activation of NLRP3 Inflammasome in Pregnant Women with Preeclampsia.

    PubMed

    Matias, Mariana Leticia; Romão, Mariana; Weel, Ingrid Cristina; Ribeiro, Vanessa Rocha; Nunes, Priscila Rezeck; Borges, Vera Therezinha; Araújo, João Pessoa; Peraçoli, José Carlos; de Oliveira, Leandro; Peraçoli, Maria Terezinha

    2015-01-01

    Preeclampsia (PE) is a specific syndrome of pregnancy, characterized by hypertension and proteinuria. This pathology is associated with hyperuricemia and elevated serum levels of inflammatory cytokines. Uric acid crystals may activate an intracellular complex called inflammasome, which is important for processing and release of inflammatory cytokines. This study investigated the state of monocyte activation, both endogenous and stimulated with monosodium urate (MSU), by gene expression of NLRP1 and NLRP3 receptors as well as their association with inflammatory cytokines expression. Monocytes were obtained from peripheral blood of 23 preeclamptic pregnant women, 23 normotensive pregnant women (NT) and 23 healthy non-pregnant women (NP). Inflammasome activation was evaluated by the gene expression of NLRP1, NLRP3, caspase-1, IL-1β, IL-18 and TNF-α by RT-qPCR in unstimulated monocytes (endogenous expression), or after cell stimulation with MSU (stimulated expression). The concentration of cytokines was assessed by ELISA. In preeclamptic pregnant women, gene expression of NLRP1, NLRP3, caspase-1, IL-1β and TNF-α by monocytes stimulated or not with MSU was significantly higher than in NT and NP groups. Stimulation of monocytes from preeclamptic and non-pregnant women with MSU induced increased gene expression of NLRP3, caspase-1 and TNF-α in relation to the endogenous expression in these groups, while this was not observed in the NT group. The cytokine determination showed that monocytes from women with PE produced higher endogenous levels of IL-1β, IL-18 and TNF-α compared to the other groups, while the stimulus with MSU led to higher production of these cytokines in preeclamptic group than in the NT group. In conclusion, the results showed increased basal gene expression of NLRP1 and NLRP3 receptors in monocytes from PE group. These cells stimulation with MSU demonstrates that uric acid plays a role in NLRP3 inflammasome activation, suggesting the participation

  19. Serum uric acid levels are associated with lupus nephritis in patients with normal renal function.

    PubMed

    Calich, Ana Luisa; Borba, Eduardo Ferreira; Ugolini-Lopes, Michelle Remião; da Rocha, Luiza Fuoco; Bonfá, Eloisa; Fuller, Ricardo

    2018-05-01

    Uric acid has been recognised as a potential marker of endothelial dysfunction and kidney disease but there are scarce data about its importance in systemic lupus erythematosus (SLE) nephritis. This study aimed to evaluate serum uric acid (UA) levels in lupus nephritis (LN), by comparing SLE patients with normal renal function, with and without nephritis. Forty-six female SLE patients were consecutively selected and divided in two groups according to renal activity at the evaluation: presence of a recently diagnosed lupus nephritis (LN+, n = 18) and absence of lupus nephritis (LN-, n = 28). Age-matched healthy women were selected (CONTROL, n = 28). Patients with gout, creatinine clearance lower than 80 ml/min and use of drugs that interfere in UA were excluded. Laboratory and clinical data were analysed by appropriate tests. A multivariate analysis was performed, and a receiver operating characteristic (ROC) curve was plotted, and the area under the curve was calculated to assess the diagnostic strength of UA in LN. The mean age was similar among LN+, LN- and CONTROL groups (32.44 ± 6.09 vs. 30.68 ± 5.36 vs. 30.86 ± 5.00 years, p = 0.52). UA was significantly higher in LN+ compared to LN- (5.54 ± 1.67 vs. 3.65 ± 1.090 mg/dL, p < 0.001) and CONTROL (5.54 ± 1.67 vs. 3.92 ± 0.95 mg/dL p < 0.001). Multivariate analysis confirmed that high UA was an independent variable related to LN (p < 0.001). The cut-off value for UA using the ROC curve was 4.47 mg/dL (AUC 0.86, p = 0.00004, CI 95% 0.75-0.96). Lupus nephritis was associated with higher UA. Hyperuricemia as a predictor of renal damage in SLE needs to be evaluated in further studies.

  20. Association between serum uric acid and metabolic syndrome components in prepubertal obese children (Tanner Stage I) from Nuevo León, Mexico - a preliminary study.

    PubMed

    Perez, Elizabeth Solis; Medina, Mario Alberto González; Lomeli, Manuel Lopez-Cabanillas; González, Verónica Tijerina; Pérez, Jesús Zacarías Villarreal; Lavalle González, Fernando J; Imrhan, Victorine; Juma, Shanil; Vijayagopal, Parakat; Boonme, Kittipong; Prasad, Chandan

    2017-01-01

    Metabolic syndrome (MetS) is a major risk factor for cardiovascular disease and diabetes. Previous studies in obese children demonstrating a positive association between serum uric acid (sUA) and components of MetS are confounded by lack of uniformity in age and pubertal status of children. Therefore, we have examined the role of sUA in MetS and its components in pre-pubertal children (Tanner Stage I, age ≤ 9 years). Pre-pubertal obese children (32 boys, 27 girls, age 6-9 years) were recruited from Nuevo Leon, Mexico. For comparison, an equal number of children with normal body mass index (BMI) in the same age range (22 Boys, 39 girls, age 6-9 years) were also recruited from the same community. Presence of MetS and its components was defined according to the criteria of International Diabetes Federation. Fasting blood was analyzed for lipids, glucose, insulin, and uric acid. Among the obese children, sUA was positively associated with insulin resistance and hypertriglyceridemia and negatively associated with high density lipoprotein-cholesterol (HDLc). Subjects were three times more likely to have a MetS diagnosis per one unit (md/dL) difference in sUA. Of the 59 obese pre-pubertal children, 20 were classified as having MetS defined by the presence of abdominal obesity and two or more of other components described under methods. Of these, 57.1% (20/61) had sUA between 5.1 and 7.1 mg/dl. The findings of this study clearly indicate a positive relationship between uric acid and MetS and its components in pre-pubertal obese children with Tanner stage I and ≤9 years of age.

  1. Urinary calculi composed of uric acid, cystine, and mineral salts: differentiation with dual-energy CT at a radiation dose comparable to that of intravenous pyelography.

    PubMed

    Thomas, Christoph; Heuschmid, Martin; Schilling, David; Ketelsen, Dominik; Tsiflikas, Ilias; Stenzl, Arnulf; Claussen, Claus D; Schlemmer, Heinz-Peter

    2010-11-01

    To retrospectively evaluate radiation dose, image quality, and the ability to differentiate urinary calculi of differing compositions by using low-dose dual-energy computed tomography (CT). The institutional review board approved this retrospective study; informed consent was waived. A low-dose dual-energy CT protocol (tube voltage and reference effective tube current-time product, 140 kV and 23 mAs and 80 kV and 105 mAs; collimation, 64 × 0.6 mm; pitch, 0.7) for the detection of urinary calculi was implemented into routine clinical care. All patients (n = 112) who were examined with this protocol from July 2008 to August 2009 were included. The composition of urinary calculi was assessed by using commercially available postprocessing software and was compared with results of the reference standard (ex vivo infrared spectroscopy) in 40 patients for whom the reference standard was available. Effective doses were calculated. Image quality was rated subjectively and objectively and was correlated with patient size expressed as body cross-sectional area at the level of acquisition by using Spearman correlation coefficients. One calcified concrement in the distal ureter of an obese patient was mistakenly interpreted as mixed calcified and uric acid. One struvite calculus was falsely interpreted as cystine. All other uric acid, cystine, and calcium-containing calculi were correctly identified by using dual-energy CT. The mean radiation dose was 2.7 mSv. The average image quality was rated as acceptable, with a decrease in image quality in larger patients. Low-dose unenhanced dual-source dual-energy CT can help differentiate between calcified, uric acid, and cystine calculi at a radiation dose comparable to that of conventional intravenous pyelography. Because of decreased image quality in obese patients, only nonobese patients should be examined with this protocol. © RSNA, 2010.

  2. Dietary, anthropometric, and biochemical determinants of uric acid in free-living adults

    PubMed Central

    2013-01-01

    Background High plasma uric acid (UA) is a prerequisite for gout and is also associated with the metabolic syndrome and its components and consequently risk factors for cardiovascular diseases. Hence, the management of UA serum concentrations would be essential for the treatment and/or prevention of human diseases and, to that end, it is necessary to know what the main factors that control the uricemia increase. The aim of this study was to evaluate the main factors associated with higher uricemia values analyzing diet, body composition and biochemical markers. Methods 415 both gender individuals aged 21 to 82 years who participated in a lifestyle modification project were studied. Anthropometric evaluation consisted of weight and height measurements with later BMI estimation. Waist circumference was also measured. The muscle mass (Muscle Mass Index – MMI) and fat percentage were measured by bioimpedance. Dietary intake was estimated by 24-hour recalls with later quantification of the servings on the Brazilian food pyramid and the Healthy Eating Index. Uric acid, glucose, triglycerides (TG), total cholesterol, urea, creatinine, gamma-GT, albumin and calcium and HDL-c were quantified in serum by the dry-chemistry method. LDL-c was estimated by the Friedewald equation and ultrasensitive C-reactive protein (CRP) by the immunochemiluminiscence method. Statistical analysis was performed by the SAS software package, version 9.1. Linear regression (odds ratio) was performed with a 95% confidence interval (CI) in order to observe the odds ratio for presenting UA above the last quartile (♂UA > 6.5 mg/dL and ♀ UA > 5 mg/dL). The level of significance adopted was lower than 5%. Results Individuals with BMI ≥ 25 kg/m2 OR = 2.28(1.13-4.6) and lower MMI OR = 13.4 (5.21-34.56) showed greater chances of high UA levels even after all adjustments (gender, age, CRP, gamma-gt, LDL, creatinine, urea, albumin, HDL-c, TG, arterial hypertension and glucose). As

  3. [Effect of oral administration of ascorbic acid on insulin sensitivity and lipid profile in obese individuals].

    PubMed

    Martínez-Abundis, E; Pascoe-González, S; González-Ortiz, M; Mora-Martínez, J M; Cabrera-Pivaral, C E

    2001-01-01

    The aim of this study was to identify the effect of an oral ascorbic acid (AA) supplement on lipid profile and insulin sensitivity in obese people. A randomized double-blind clinical trial placebo controlled was performed in 16 obese male volunteers [body mass index (BMI) 30-40 kg/m2]. Eight received orally 1 g of AA daily for four weeks and the other eight volunteers received placebo by the same scheme and period of time. Before and after the pharmacological intervention were measured total cholesterol, high-density-lipoprotein (HDL) cholesterol, triglycerides, glucose, creatinine and uric acid. Low-density-lipoprotein (LDL) cholesterol and very-low-density-lipoprotein (VLDL) triglycerides were calculated using formulas. In order to assess insulin sensitivity before and after the intervention, the steady-state glucose (SSG) was calculated from the insulin suppression test modified with octreotide. There were not significant differences in clinical characteristics between both groups. Basal metabolic profile and SSG were similar between both groups. There were not significant differences in both groups between before and after the intervention in metabolic profile and insulin sensitivity. AA did not modify the lipid profile nor insulin sensitivity in the group of obese people studied.

  4. Sol-gel thin-film based mesoporous silica and carbon nanotubes for the determination of dopamine, uric acid and paracetamol in urine.

    PubMed

    Canevari, Thiago C; Raymundo-Pereira, Paulo A; Landers, Richard; Benvenutti, Edilson V; Machado, Sérgio A S

    2013-11-15

    This work describes the preparation, characterization and application of a hybrid material composed of disordered mesoporous silica (SiO2) modified with multiwalled carbon nanotubes (MWCNTs), obtained by the sol-gel process using HF as the catalyst. This hybrid material was characterized by N2 adsorption-desorption isotherms, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission microscopy (HR-TEM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). This new hybrid material was used for the construction of a thin film on a glassy carbon electrode. The modified electrode using this material was designated SiO2/MWCNT/GCE. The electrocatalytic properties of the electrode toward dopamine, uric acid and paracetamol oxidation were studied by differential pulse voltammetry. Well-defined and separated oxidation peaks were observed in phosphate buffer solution at pH 7.0, in contrast with the ill-defined peaks observed with unmodified glassy carbon electrodes. The electrode had high sensitivity for the determination of dopamine, uric acid and paracetamol, with the limits of detection obtained using statistical methods, at 0.014, 0.068 and 0.098 µmol L(-1), respectively. The electrode presented some important advantages, including enhanced physical rigidity, surface renewability by polishing and high sensitivity, allowing the simultaneous determination of these three analytes in a human urine sample. Crown Copyright © 2013 Published by Elsevier B.V. All rights reserved.

  5. Uric acid levels are associated with endothelial dysfunction and severity of coronary atherosclerosis during a first episode of acute coronary syndrome.

    PubMed

    Gaubert, Mélanie; Marlinge, Marion; Alessandrini, Marine; Laine, Marc; Bonello, Laurent; Fromonot, Julien; Cautela, Jennifer; Thuny, Franck; Barraud, Jeremie; Mottola, Giovanna; Rossi, Pascal; Fenouillet, Emmanuel; Ruf, Jean; Guieu, Régis; Paganelli, Franck

    2018-06-01

    The role of serum uric acid in coronary artery disease has been extensively investigated. It was suggested that serum uric acid level (SUA) is an independent predictor of endothelial dysfunction and related to coronary artery lesions. However, the relationship between SUA and severity of coronary atherosclerosis evaluated via endothelial dysfunction using peripheral arterial tone (PAT) and the reactive hyperhemia index (RHI) has not been investigated during a first episode of acute coronary syndrome (ACS). The aim of our study was to address this point. We prospectively enrolled 80 patients with a first episode of ACS in a single-center observational study. All patients underwent coronary angiography, evaluation of endothelial function via the RHI, and SUA measurement. The severity of the coronary artery lesion was assessed angiographically, and patients were classified in three groups based on the extent of disease and Gensini and SYNTAX scores. Endothelial function was considered abnormal if RHI < 1.67. We identified a linear correlation between SUA and RHI (R 2  = 0.66 P < 0.001). In multivariable analyses, SUA remained associated with RHI, even after adjustment for traditional cardiovascular risk factors and renal function. SUA was associated with severity of coronary artery disease. SUA is associated with severity of coronary atherosclerosis in patients with asymptomatic hyperuricemia. This inexpensive, readily measured biological parameter may be useful to monitor ACS patients.

  6. Pure hemozoin is inflammatory in vivo and activates the NALP3 inflammasome via release of uric acid

    PubMed Central

    Griffith, Jason W.; Sun, Tiffany; McIntosh, Michael T.; Bucala, Richard

    2013-01-01

    The role of pro-inflammatory cytokine production in the pathogenesis of malaria is well established, but the identification of the parasite products that initiate inflammation is not complete. Hemozoin is a crystalline metabolite of hemoglobin digestion that is released during malaria infection. In the present study, we characterized the immunostimulatory activity of pure synthetic hemozoin (sHz) in vitro and in vivo. Stimulation of naïve murine macrophages with sHz results in the MyD88-independent activation of NF-κB and ERK, and the release of the chemokine MCP-1; these responses are augmented by IFN-γ. In macrophages pre-stimulated with IFN-γ, sHz also results in a MyD88-dependent release of TNF-α. Endothelial cells, which encounter hemozoin after schizont rupture, respond to sHz by releasing IL-6 and the chemokines MCP-1 and IL-8. In vivo, the introduction of sHz into the peritoneal cavity produces an inflammatory response characterized by neutrophil recruitment and the production of MCP-1, KC, IL-6, IL-1α and IL-1β. MCP-1 and KC are produced independently of MyD88, TLR 2/4 and 9, and components of the inflammasome, however neutrophil recruitment, the localized production of IL-1β, and the increase in circulating IL-6 require MyD88 signaling, the IL-1R pathway and the inflammasome components ICE, ASC and NALP3. Of note, inflammasome activation by sHz is reduced by allopurinol, which is an inhibitor of uric acid synthesis. This data suggests that uric acid is released during malaria infection and may serve to augment the initial host response to hemozoin via activation of the NALP3 inflammasome. PMID:19783673

  7. Electrochemical detection of dopamine using porphyrin-functionalized graphene.

    PubMed

    Wu, Li; Feng, Lingyan; Ren, Jinsong; Qu, Xiaogang

    2012-04-15

    A new type of porphyrin-functionalized graphene was synthesized and used for highly selective and sensitive detection of dopamine (DA). The aromatic π-π stacking and electrostatic attraction between positively-charged dopamine and negatively-charged porphyrin-modified graphene can accelerate the electron transfer whereas weakening ascorbic acid (AA) and uric acid (UA) oxidation on the porphyrin-functionalized graphene-modified electrode. Differential pulse voltammetry was used for electrochemical detection, the separation of the oxidation peak potentials for AA-DA, DA-UA and UA-AA is about 188 mV, 144 mV and 332 mV, which allows selectively determining DA. The detection limit of DA can be as low as 0.01 μM. More importantly, the sensor we presented can detect DA in the presence of large excess of ascorbic acid and uric acid. With good sensitivity and selectivity, the present method was applied to the determination of DA in real hydrochloride injection sample, human urine and serum samples, respectively, and the results was satisfactory. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Role of combined use of potassium citrate and tamsulosin in the management of uric acid distal ureteral calculi.

    PubMed

    El-Gamal, Osama; El-Bendary, Mohamed; Ragab, Maged; Rasheed, Mohamed

    2012-06-01

    In this article, we investigated the effect of the combined use of tamsulosin and potassium citrate (Uralyt-U(®)) for the treatment of uric acid stones in the distal ureter. The study was designed as a prospective, double blind randomized controlled trial. A total of 191 adult patients with radiolucent distal ureteral calculi were recruited. We included patients with solitary stones ≥5 mm with mild or moderate hydronephrosis and a normal contralateral tract. The patients were randomized into four equal groups (the placebo, tamsulosin, Uralyt-U(®), and the combined treatment groups). The patients were treated for a maximum duration of 4 weeks or until stone expulsion. The stone size in all groups ranged from 5 to 11 mm (7.69 ± 1.7 mm). The total expulsion rate of the stones was significantly lower in the control group (26.1%) compared with that of any of the other three groups (68.8, 58.7, and 84.8% respectively) (P < 0.05). Meanwhile, the difference between the Uralyt-U(®) group and the combined treatment group was also statistically significant (P < 0.05). When we studied the patients with stones >8 mm as a separate subgroup to find the effect of the used drugs on the relatively large stones, we detected that the expulsion rate of these stones was significantly higher in the patients who received the combined treatment in comparison with any of the other three groups (P < 0.05). In conclusion, the use of urinary alkalization with tamsulosin can increase the frequency of spontaneous passage of distal ureteral uric acid stones especially those of 8-11 mm.

  9. A multiple free-radical scavenging (MULTIS) study on the antioxidant capacity of a neuroprotective drug, edaravone as compared with uric acid, glutathione, and trolox.

    PubMed

    Kamogawa, Erisa; Sueishi, Yoshimi

    2014-03-01

    Edaravone (3-methyl-1-phenyl-2-pyrazoline-5-one) is a neuroprotective drug that has been used for brain ischemia injury treatment. Because its activity is speculated to be due to free radical scavenging activity, we carried out a quantitative determination of edaravone's free radical scavenging activity against multiple free radical species. Electron spin resonance (ESR) spin trapping-based multiple free-radical scavenging (MULTIS) method was employed, where target free radicals were hydroxyl radical, superoxide anion, alkoxyl radical, alkylperoxyl radical, methyl radical, and singlet oxygen. Edaravone showed relatively high scavenging abilities against hydroxyl radical (scavenging rate constant k=2.98×10(11) M(-1) s(-1)), singlet oxygen (k=2.75×10(7) M(-1) s(-1)), and methyl radical (k=3.00×10(7) M(-1) s(-1)). Overall, edaravone's scavenging activity against multiple free radical species is as robust as other known potent antioxidant such as uric acid, glutathione, and trolox. A radar chart illustration of the MULTIS activity relative to uric acid, glutathione, and trolox indicates that edaravone has a high and balanced antioxidant activity with low specificity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Traditional Uighur Medicine Karapxa decoction, inhibits liver xanthine oxidase and reduces serum uric acid concentrations in hyperuricemic mice and scavenges free radicals in vitro.

    PubMed

    Amat, Nurmuhammat; Umar, Anwar; Hoxur, Parida; Anaydulla, Mihrigul; Imam, Guzalnur; Aziz, Ranagul; Upur, Halmurat; Kijjoa, Anake; Moore, Nicholas

    2015-04-25

    Karapxa decoction (KD) is a Traditional Uighur Medicine used for hepatitis, cholecystitis, gastralgia, oedema, gout and arthralgia. Because of its purported effect in gout, its effects were tested in hyperuricemic mice models induced by yeast extract paste or potassium oxonate, as well as its capacity to scavenge free radicals in vitro. Hyperuricemia was induced in mice by yeast extract paste or potassium oxonate. KD was given orally for 14 days at 200, 400 and 800 mg/kg/day, with Allopurinol 10 mg/kg/day as positive control. Serum uric acid (UA), and liver xanthine oxidase activity (XO) were measured. Scavenging activity of KD on 1, 1-diphenyl-2-picrylhydrazyl radicals (DPP•), nitric oxide (•NO), superoxide (O2•-), efficiency against lipid peroxidation, and XO inhibition were determined in vitro. KD inhibited liver XO activity and reduced serum uric acid in hyperuricemic mice. KD also showed noticeable antioxidant activity, scavenging free radicals (DPP•, •NO and O2•-). It was effective against lipid peroxidation and inhibited XO in vitro. This study supports the traditional use of Karapxa decoction to treat hyperuricemia and gout.

  11. 40 CFR Appendix A to Subpart Aa of... - Applicability of General Provisions (40 CFR Part 63, Subpart A) to Subpart AA

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (40 CFR Part 63, Subpart A) to Subpart AA A Appendix A to Subpart AA of Part 63 Protection of... Hazardous Air Pollutants From Phosphoric Acid Manufacturing Plants Pt. 63, Subpt. AA, App. A Appendix A to Subpart AA of Part 63—Applicability of General Provisions (40 CFR Part 63, Subpart A) to Subpart AA 40 CFR...

  12. 40 CFR Appendix A to Subpart Aa of... - Applicability of General Provisions (40 CFR Part 63, Subpart A) to Subpart AA

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (40 CFR Part 63, Subpart A) to Subpart AA A Appendix A to Subpart AA of Part 63 Protection of... Hazardous Air Pollutants From Phosphoric Acid Manufacturing Plants Pt. 63, Subpt. AA, App. A Appendix A to Subpart AA of Part 63—Applicability of General Provisions (40 CFR Part 63, Subpart A) to Subpart AA 40 CFR...

  13. Mechanism and kinetics of electrochemical degradation of uric acid using conductive-diamond anodes.

    PubMed

    Dbira, Sondos; Bensalah, Nasr; Bedoui, Ahmed

    2016-12-01

    Uric acid (UA) is one of the principal effluents of urine wastewaters, widely used in agriculture as fertilizer, which is potentially dangerous and biorefractory. Hence, the degradation of UA (2,6,8-trihydroxy purine) in aqueous solution of pH 3.0 has been studied by conductive-diamond electrochemical oxidation. Hydroxyl radicals formed from water oxidation at the surface of boron-doped diamond anodes were the main oxidizing agents. Effects of current density and supporting electrolyte on the degradation rate and process efficiency are assessed. Results show that the increase of current density from 20 to 60 mA cm(-2) leads to a decrease in the efficiency of the electrochemical process. In addition, the best degradation occurred in the presence of NaCl as conductive electrolyte. Interestingly, an almost total mineralization of 50 ppm UA was obtained when anodic oxidation was performed at low current densities (20 mA cm(-2)) and in the presence of NaCl. This result confirmed that the electrolysis using diamond anodes is a very interesting technology for the treatment of UA. The identification of UA transformation products was performed by high-performance liquid chromatography (HPLC). HPLC analysis of treated solutions revealed that oxalic acid and urea were the two intermediates found. Oxalic acid was the most persistent product. Based on detected intermediates and bibliographic research, a mechanism of UA mineralization by anodic oxidation has been proposed. Ionic chromatography analysis confirmed the release of [Formula: see text] and [Formula: see text] ions during UA mineralization.

  14. Serum Uric Acid and Risk for Acute Kidney Injury Following Contrast.

    PubMed

    Kanbay, Mehmet; Solak, Yalcin; Afsar, Baris; Nistor, Ionut; Aslan, Gamze; Çağlayan, Ozlem Hilal; Aykanat, Asli; Donciu, Mihaela-Dora; Lanaspa, Miguel A; Ejaz, Ahsan A; Johnson, Richard J; Covic, Adrian

    2017-02-01

    Contrast-induced acute kidney injury (CI-AKI) is a common cause of hospital-acquired acute kidney injury (AKI). We evaluated the evidence that uric acid (UA) plays a pathogenic role in CI-AKI. Ten studies were eligible for inclusion for meta-analysis. Hyperuricemia predicted risk for cases with AKI in prospective cohort studies. Higher levels of serum UA (SUA), as defined by the authors, were associated with a 2-fold increased risk to develop AKI (pooled odds ratio 2.03; 95% confidence interval [CI] 1.48-2.78). Significant heterogeneity was found in cohort studies ( P = .001, I 2 = 85.7%). In 2 clinical trials, lowering of SUA with saline hydration was significantly associated with reduced risk for AKI compared with saline hydration alone or saline hydration with N-acetyl cysteine. An analysis of 2 randomized controlled trials found that allopurinol with saline hydration had a significant protective effect on renal function (assessed by serum creatinine values) compared with hydration alone (mean difference: -0.52 mg/dL; 95% CI: -0.81 to -0.22). Hyperuricemia independently predicts CI-AKI. Two clinical trials suggest lowering SUA may prevent CI-AKI. The mechanism by which UA induces CI-AKI is likely related to acute uricosuria.

  15. Vibrational spectra for uric acid and its D- and 15N-substituted analogues. Assignments for its normal modes from ab initio 3-21G force field.

    NASA Astrophysics Data System (ADS)

    Majoube, M.; Vergoten, G.

    1993-03-01

    FTR, Raman, FTIR spectra are obtained for polycrystalline uric acid and seven of its D-and 15N-substituted analogues. Assignments are given from a normal coordinate analysis carried out using a 3-21G ab initio force field. These are discussed by considering observed and calculated frequencies and D- and 15N-isotopic shifts.

  16. Cu nanoparticles incorporated polypyrrole modified GCE for sensitive simultaneous determination of dopamine and uric acid.

    PubMed

    Ulubay, Sükriye; Dursun, Zekerya

    2010-01-15

    Cu nanoparticles have been electrochemically incorporated polypyrrole film that was used for modification of the glassy carbon electrode surface. The performance of the electrode has been characterized by cyclic voltammetry and atomic force microscopy. The electrode has shown high electrocatalytic activity towards the oxidation of dopamine (DA) and uric acid (UA) simultaneously in a phosphate buffer solution (pH 7.00). The electrocatalytic oxidation currents of UA and DA were found linearly related to concentration over the range 1x10(-9) to 1x10(-5)M for UA and 1x10(-9) to 1x10(-7)M for DA using DPVs method. The detection limits were determined as 8x10(-10)M (s/n=3) for UA and 8.5x10(-10)M (s/n=3) for DA at a signal-to-noise ratio of 3.

  17. Biochemical and structural characterization of Klebsiella pneumoniae oxamate amidohydrolase in the uric acid degradation pathway

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hicks, Katherine A.; Ealick, Steven E.

    HpxW from the ubiquitous pathogenKlebsiella pneumoniaeis involved in a novel uric acid degradation pathway downstream from the formation of oxalurate. Specifically, HpxW is an oxamate amidohydrolase which catalyzes the conversion of oxamate to oxalate and is a member of the Ntn-hydrolase superfamily. HpxW is autoprocessed from an inactive precursor to form a heterodimer, resulting in a 35.5 kDa α subunit and a 20 kDa β subunit. Here, the structure of HpxW is presented and the substrate complex is modeled. In addition, the steady-state kinetics of this enzyme and two active-site variants were characterized. These structural and biochemical studies provide furthermore » insight into this class of enzymes and allow a mechanism for catalysis consistent with other members of the Ntn-hydrolase superfamily to be proposed.« less

  18. Self-powered implantable electronic-skin for in situ analysis of urea/uric-acid in body fluids and the potential applications in real-time kidney-disease diagnosis.

    PubMed

    Yang, Wenyan; Han, Wuxiao; Gao, Huiling; Zhang, Linlin; Wang, Shuai; Xing, Lili; Zhang, Yan; Xue, Xinyu

    2018-01-25

    As the concentration of different biomarkers in human body fluids are an important parameter of chronic disease, wearable biosensors for in situ analysis of body fluids with high sensitivity, real-time detection, flexibility and biocompatibility have significant potential therapeutic applications. In this paper, a flexible self-powered implantable electronic-skin (e-skin) for in situ body fluids analysis (urea/uric-acid) as a real-time kidney-disease diagnoser has been proposed based on the piezo-enzymatic-reaction coupling process of ZnO nanowire arrays. It can convert the mechanical energy of body movements into a piezoelectric impulse, and the outputting piezoelectric signal contains the urea/uric-acid concentration information in body fluids. This piezoelectric-biosensing process does not need an external electricity supply or battery. The e-skin was implanted under the abdominal skin of a mouse and provided in situ analysis of the kidney-disease parameters. These results provide a new approach for developing a self-powered in situ body fluids-analysis technique for chronic-disease diagnosis.

  19. A rapid microwave synthesis of nitrogen-sulfur co-doped carbon nanodots as highly sensitive and selective fluorescence probes for ascorbic acid.

    PubMed

    Duan, Junxia; Yu, Jie; Feng, Suling; Su, Li

    2016-06-01

    A ultrafast one-step microwave-assisted method was developed for the synthesis of nitrogen-sulfur co-doped carbon nanodots (N,S-CDs) by using ethylenediamine as the carbon source and sulfamic acid as the surface passivation reagent. The morphology and the properties of N,S-CDs were explored by a series of techniques, such as high-resolution transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, UV-vis absorption and fluorescence spectroscopy. The prepared N,S-CDs exhibit bright blue photoluminescence with a high fluorescence quantum yield (FLQY) up to 28%, and high stability and excellent water solubility. A N,S-CDs-based fluorescent probe was developed for sensitive detection ascorbic acid (AA) in the presence of Cu(2+), based on the mechanism that AA reduces Cu(2+) to Cu(+), then Cu(+) quenches the fluorescence of N,S-CDs through electron or energy transfer due to the interaction between Cu(+) and thiol ligand on the N,S-CDs surface. The observed linear response concentration range was from 0.057 to 4.0μM to AA with a detection limit as low as 18nM. The probe exhibited a highly selective response toward AA even in the presence of possible interfering substances, such as uric acid and citric acid. Moreover, these promising features made the sensing system used for the analysis of human serum and urine samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Detection Of Uric Acid Based On Multi-Walled Carbon Nanotubes Polymerized With A Layer Of Molecularly Imprinted PMAA

    NASA Astrophysics Data System (ADS)

    Chen, Po-Yen; Lin, Chia-Yu; Ho, Kuo-Chuan

    2009-05-01

    A molecularly imprinted poly-metharylic acid (PMAA), polymerizing on the surface of multi-walled carbon nanotube (MWCNT), was synthesized. The MWCNT was modified by a layer of carboxylic acid and reacted with EDC and NHS to activate the carboxylic acid, which was prepared for the purpose of bonding allyl amine and getting an unsaturated side chain (-C=C). The resultant structure is abbreviated as MWCNTs-CH=CH2. It is well known that the vinyl group side chain provides good attachment between the MWCNTs and the molecularly imprinted polymer (MIP). The MIP based on PMAA was polymerized on the surface of MWCNTs-CH=CH2 with the addition of uric acid (UA). The non-imprinted polymer (NIP) was polymerized without adding UA. The adsorbed amount of UA approached the equilibrium value upon 60 min adsorption. The adsorption isotherm was obtained by immersing 10 mg of MIP or NIP in 5 mL aqueous solution containing different concentrations of UA. The adsorbed amounts were measured via a UV-Vis spectrometer at a wavelength of 292 nm. From the adsorption isotherm, it is seen that the MIP particles possess a good imprinting efficiency of about 4.41.

  1. Bardoxolone methyl (BARD) ameliorates aristolochic acid (AA)-induced acute kidney injury through Nrf2 pathway.

    PubMed

    Wu, Juan; Liu, Xinhui; Fan, Jinjin; Chen, Wenfang; Wang, Juan; Zeng, Youjia; Feng, Xiaorang; Yu, Xueqing; Yang, Xiao

    2014-04-06

    Bardoxolone methyl (BARD) is an antioxidant modulator that acts through induction of the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway. This study aimed to investigate the role of BARD in protecting kidneys from aristolochic acid (AA)-induced acute kidney injury (AKI). Male C57BL/6 mice received intraperitoneal (i.p.) injections of aristolochic acid I (AAI) (5mg/kg/day) for 5 days to produce acute AA nephropathy (AAN) model. BARD (10mg/kg/day, i.p.) was applied for 7 consecutive days, starting 2 days prior to AAI administration. The mice in the AA group showed AKI as evidenced by worsening kidney function evaluated by blood urea nitrogen (BUN) and serum creatinine (SCr) levels, and severe tubulointerstitial injury marked by massive tubule necrosis in kidney tissues. BARD significantly reduced BUN and SCr levels which were elevated by AAI. Additionally, AAI-induced histopathological renal damage was ameliorated by BARD. Furthermore, the expression of Nrf2 was reduced, and its repressor Kelch-like ECH-associated protein 1 (Keap1) was increased significantly, whereas heme oxygenase-1 (HO-1) was upregulated and NAD(P)H quinone oxidoreductase-1 (NQO1) was barely increased in the cytoplasm of tubules in kidneys after treatment with AAI. BARD significantly upregulated renal Nrf2, NQO1 and HO-1 expression and downregulated Keap1 expression compared with those in the AA group. Moreover, it was found that Nrf2 was expressed both in the cytoplasm and nuclear of glomeruli and tubules, whereas NQO1 and HO-1 were localized in the cytoplasm of tubules only. In conclusion, AA-induced acute renal injury was associated with impaired Nrf2 activation and expression of its downstream target genes in renal tissues. BARD prevented renal damage induced by AAI, and this renoprotective effect may be exerted by activating the Nrf2 signaling pathway and increasing expression of the downstream target genes. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. A novel third generation uric acid biosensor using uricase electro-activated with ferrocene on a Nafion coated glassy carbon electrode.

    PubMed

    Ghosh, Tanushree; Sarkar, Priyabrata; Turner, Anthony P F

    2015-04-01

    A new uric acid biosensor was constructed using ferrocene (Fc) induced electro-activated uricase (UOx) deposited within Nafion (Naf) on glassy carbon electrode (GCE). Electro-activation of UOx was successfully achieved by cyclic voltammetry through the electrostatic interaction of Fc with Trp residues within the hydrophobic pockets in UOx. The Naf/UOx/Fc composite was characterised by AFM, FTIR and EDX to ensure proper immobilisation. The interaction of Fc with the enzyme was analysed by Trp fluorescence spectroscopy and the α-helicity of the protein was measured by CD spectropolarimetry. The charge transfer resistance (Rct), calculated from electrochemical impedance spectroscopy, for the modified sensor was lowered (1.39 kΩ) and the enzyme efficiency was enhanced by more than two fold as a result of Fc incorporation. Cyclic voltammetry, differential pulse voltammetry and amperometry all demonstrated the excellent response of the Naf/UOx/Fc/GCE biosensor to uric acid. The sensor system generated a linear response over a range of 500 nM to 600 μM UA, with a sensitivity and limit of detection of 1.78 μA μM(-1) and 230 nM, respectively. The heterogeneous rate constant (ks) for UA oxidation was much higher for Naf/UOx/Fc/GCE (1.0 × 10(-4) cm s(-1)) than for Naf/UOx/GCE (8.2 × 10(-5) cm s(-1)). Real samples, i.e. human blood, were tested for serum UA and the sensor yielded accurate results at a 95% confidence limit. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Renal function in children suffering from sickle cell disease: challenge of early detection in highly resource-scarce settings.

    PubMed

    Aloni, Michel Ntetani; Ngiyulu, René Makwala; Gini-Ehungu, Jean-Lambert; Nsibu, Célestin Ndosimao; Ekila, Mathilde Bothale; Lepira, François Bompeka; Nseka, Nazaire Mangani

    2014-01-01

    The prevalence of Sickle cell disease is extremely high in Democratic Republic of Congo. Despite this high prevalence of the disease, data on renal abnormalities in children are rare. The study proposed to assess blood pressure, glomerular function, urea and uric acid levels in 65 steady state Congolese children with homozygous sickle cell disease and 67 normal controls. In Hb-SS group, blood pressure level tended to be lower than Hb-AA groups but there was no statistically significant difference (p>0.05) between the two groups. The absolute values for GFR corrected for BSA were significantly higher in Hb-SS group compared to Hb-AA group (130.5±34.1 ml/min/1.73 m2 vs 113.7±24.5 ml/min/1.73 m2; p = 0.004). Children with Hb-SS were more likely to hyperfiltrate (30.8% of subjects) than children with Hb-AA (6.1% of subjects). Proteinuria was found in 4 (6.2%) children with Hb-SS. Uric acid level was significantly increased in children with Hb-SS compared to corresponding values in control group (4.4±1.3 mg/dl vs 3.5±1.1 mg/dl; p<0.001). Urea level was significantly decreased compared to corresponding values in Hb-AA group (15.3±8.3 mg/dl vs 22.9±10.1 mg/dl; p<0.001). Hyperfiltration, low creatinine, lower urea and high uric acid are more common in children with sickle cell disease than in normal controls.

  4. Bioenergetic Approaches and Inflammation of MPTP Toxicity

    DTIC Science & Technology

    2009-09-01

    published. We also showed that a number ofspecific metabolites were altered including 8-hydroxy-2- deoxyguanosine and reduced uric acid . We have now shown...3- nitropropionic acid -induced neurotoxicity. J Neurochem 2005;94:995-1004 Cleren C, Starkov AA, Calingasan NY, Lorenzo BJ, Chen J, Beal MF

  5. Complete Occlusion of a Subcutaneous Pyelovesical Bypass Graft (Detour® System) Caused by Uric Acid Stone Formation.

    PubMed

    Wilhelm, Konrad; Schultze-Seemann, Wolfgang; Miernik, Arkadiusz

    2017-01-01

    Subcutaneous pyelovesical bypass graft (SPBG) is a urinary diversion treatment option for ureteral obstruction. Initially its use was limited to palliative care patients. However, the indication profile has been extended to selected patients with benign conditions causing ureteral obstruction and hydronephrosis. Occlusion of SPBGs is rarely reported and mostly related to infections. We describe the clinical case of a patient with SPBG after iatrogenic ureteral stricture who was not suitable for other reconstructive treatment forms due to distinct retroperitoneal scarring after multiple previous surgeries. Several months after the SPBG insertion, the patient developed complete occlusion of the system with uric acid stone material. Sufficient endoscopic intervention was not feasible. After forced chemolitholysis, the stone mass could be completely dissolved. Since then the patient has remained symptom-free. © 2014 S. Karger AG, Basel.

  6. The effect of high-fructose corn syrup consumption on triglycerides and uric acid.

    PubMed

    Angelopoulos, Theodore J; Lowndes, Joshua; Zukley, Linda; Melanson, Kathleen J; Nguyen, Von; Huffman, Anik; Rippe, James M

    2009-06-01

    Rates of overweight and obesity have been on a steady rise for decades, and the problems society faces from this and associated metabolic diseases are many. As a result, the need to understand the contributing factors is great. A very compelling case can be made that excess sugar consumption has played a significant role. In addition, fructose, as a component of the vast majority of caloric sweeteners, is seen to be particularly insidious. Evidence shows that fructose bypasses many of the body's satiating signals, thus potentially promoting overconsumption of energy, weight gain, and the development on insulin resistance. It has also been shown to increase uric acid levels, which in turn promotes many of the abnormalities seen in the metabolic syndrome including hypertriglyceridemia. However, the main source of fructose in the diet is high-fructose corn syrup (HFCS), an artificially manufactured disaccharide that is only 55% fructose. This review highlights the fact that limited data are available about the metabolic effects of HFCS compared with other caloric sweeteners. The data suggest that HFCS yields similar metabolic responses to other caloric sweeteners such as sucrose.

  7. Serum uric acid concentrations and fructose consumption are independently associated with NASH in children and adolescents.

    PubMed

    Mosca, Antonella; Nobili, Valerio; De Vito, Rita; Crudele, Annalisa; Scorletti, Eleonora; Villani, Alberto; Alisi, Anna; Byrne, Christopher D

    2017-05-01

    Recent research has suggested that dietary fructose intake may increase serum uric acid (UA) concentrations. Both UA concentration and fructose consumption maybe also increase in NAFLD. It is not known whether dietary fructose consumption and UA concentration are independently associated with non-alcoholic steatohepatitis (NASH). Our aim was to investigate the factors associated with NASH in children and adolescents with proven NAFLD, and to test whether UA concentrations and fructose consumption are independently associated with NASH. Obese children with NAFLD were studied (n=271). NASH was diagnosed by a NAFLD activity score ⩾5 and the fatty liver inhibition of progression (FLIP) algorithm. Fructose consumption (g/day) was assessed by food frequency questionnaire, and UA (mg/dl) was measured in serum. Binary logistic regression with adjustment for covariates and potential confounders was undertaken to test factors independently associated with NASH. NASH occurred in 37.6% of patients. Hyperuricaemia (UA ⩾5.9mg/dl) was present in 47% of patients with NASH compared with 29.7% of non-NASH patients (p=0.003). Both UA concentration (OR=2.488, 95% CI: 1.87-2.83, p=0.004) and fructose consumption (OR=1.612, 95% CI 1.25-1.86, p=0.001) were independently associated with NASH, after adjustment for multiple (and all) measured confounders. Fructose consumption was independently associated with hyperuricaemia (OR=2.021, 95% CI: 1.66-2.78, p=0.01). These data were confirmed using the FLIP algorithm. Both dietary fructose consumption and serum UA concentrations are independently associated with NASH. Fructose consumption was the only factor independently associated with serum UA concentration. Currently, it is not known whether dietary fructose consumption and uric acid (UA) concentration are linked with non-alcoholic steatohepatitis (NASH) in children and adolescents. Our aim was to test whether UA concentrations and fructose consumption are independently associated with

  8. Electrochemical detection of uric acid using ruthenium-dioxide-coated carbon nanotube directly grown onto Si wafer

    NASA Astrophysics Data System (ADS)

    Shih, Yi-Ting; Lee, Kuei-Yi; Lin, Chung-Kuang

    2015-12-01

    Carbon nanotubes (CNTs) directly grown onto a Si substrate by thermal chemical vapor deposition were used in uric acid (UA) detection. The process is simple and formation is easy without the need for additional chemical treatments. However, CNTs lack selectivity and sensitivity to UA. To enhance the electrochemical analysis, ruthenium oxide was used as a catalytic mediator in the modification of electrodes. The electrochemical results show that RuO2 nanostructures coated onto CNTs can strengthen the UA signal. The peak currents of RuO2 nanostructures coated onto CNTs linearly increase with increasing UA concentration, meaning that they can work as electrodes for UA detection. The lowest detection limit and highest sensitivity were 55 nM and 4.36 µA/µM, respectively. Moreover, the characteristics of RuO2 nanostructures coated onto CNTs were examined by scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy.

  9. Uric acid and the cardiovascular profile of African and Caucasian men.

    PubMed

    Palmer, I M; Schutte, A E; Huisman, H W

    2010-10-01

    The African population is considered a high-risk group for the development of hypertension, and identifying risk factors are therefore essential in preventive actions against cardiovascular disease (CVD). Elevated levels of uric acid (UA) are often associated with CVD. Our first aim was to establish possible ethnic differences in UA levels between African and Caucasian men. Our second aim was to determine any associations between UA levels and cardio-metabolic variables, and also how these correlates differ between the two groups. African (N=87) and Caucasian (N=121) men participated in this cross-sectional study. Our results have shown that African men had significantly lower (353±87.7 vs 401±98.2; P<0.01) UA levels compared with Caucasian men. Waist circumference and triglycerides correlated strongly with UA in both ethnic groups. This was confirmed with a forward stepwise multiple regression analysis. After adjustment for confounders, the correlation between UA and triglycerides remained significant only in the Caucasians (r=0.29; P=0.02), whereas only the African men showed an independent correlation between UA and total peripheral resistance (TPR) (r=0.23; P=0.04). TPR increased significantly across UA tertiles only in the African men (P=0.01 vs P=0.96). In conclusion, despite their lower UA levels, Africans showed an independent relationship between UA and vascular resistance, indicating a possible explanation for their high prevalence of hypertension.

  10. Simultaneous determination of dopamine and uric acid using layer-by-layer graphene and chitosan assembled multilayer films.

    PubMed

    Weng, Xuexiang; Cao, Qingxue; Liang, Lixin; Chen, Jianrong; You, Chunping; Ruan, Yongmin; Lin, Hongjun; Wu, Lanju

    2013-12-15

    Multilayer films containing graphene (Gr) and chitosan (CS) were prepared on glassy carbon electrodes with layer-by-layer (LBL) assembly technique. After being characterized with cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM), the electrochemical sensor based on the resulted films was developed to simultaneously determine dopamine (DA) and uric acid (UA). The LBL assembled electrode showed excellent electrocatalytic activity towards the oxidation of DA and UA. In addition, the self-assembly electrode possessed an excellent sensing performance for detection of DA and UA with a linear range from 0.1 μM to 140 µM and from 1.0 µM to 125 µM with the detection limit as low as 0.05 µM and 0.1 µM based on S/N=3, respectively. © 2013 Elsevier B.V. All rights reserved.

  11. Elevated levels of plasma uric acid and its relation to hypertension in arsenic-endemic human individuals in Bangladesh

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Huda, Nazmul; Department of Medicine, Rajshahi Medical College, Rajshahi 6000; Hossain, Shakhawoat

    Blood uric acid has been recognized as a putative marker for cardiovascular diseases (CVDs). CVDs are the major causes of arsenic-related morbidity and mortality. However, the association of arsenic exposure with plasma uric acid (PUA) levels in relation to CVDs has not yet been explored. This study for the first time demonstrated the associations of arsenic exposure with PUA levels and its relationship with hypertension. A total of 483 subjects, 322 from arsenic-endemic and 161 from non-endemic areas in Bangladesh were recruited as study subjects. Arsenic concentrations in the drinking water, hair and nails of the study subjects were measuredmore » by inductively coupled plasma mass spectroscopy. PUA levels were measured using a colorimetric method. We found that PUA levels were significantly (p < 0.001) higher in males and females living in arsenic-endemic areas than those in non-endemic area. Arsenic exposure (water, hair and nail arsenic) levels showed significant positive correlations with PUA levels. In multiple regression analyses, arsenic exposure levels were found to be the most significant contributors on PUA levels among the other variables that included age, body mass index, blood urea nitrogen, and smoking. There were dose–response relationships between arsenic exposure and PUA levels. Furthermore, diastolic and systolic blood pressure showed significant positive correlations with PUA levels. Finally, the average PUA levels were significantly higher in the hypertensive group than those in the normotensive group in both males and females living in arsenic-endemic areas. These results suggest that arsenic exposure-related elevation of PUA levels may be implicated in arsenic-induced CVDs. - Highlights: • PUA levels were higher in arsenic-endemic subjects than in non-endemic subjects. • Drinking water, hair and nail arsenic showed significant associations with PUA levels. • Drinking water, hair and nail arsenic showed dose

  12. Rationale and design of a multicenter randomized study for evaluating vascular function under uric acid control using the xanthine oxidase inhibitor, febuxostat: the PRIZE study.

    PubMed

    Oyama, Jun-Ichi; Tanaka, Atsushi; Sato, Yasunori; Tomiyama, Hirofumi; Sata, Masataka; Ishizu, Tomoko; Taguchi, Isao; Kuroyanagi, Takanori; Teragawa, Hiroki; Ishizaka, Nobukazu; Kanzaki, Yumiko; Ohishi, Mitsuru; Eguchi, Kazuo; Higashi, Yukihito; Yamada, Hirotsugu; Maemura, Koji; Ako, Junya; Bando, Yasuko K; Ueda, Shinichiro; Inoue, Teruo; Murohara, Toyoaki; Node, Koichi

    2016-06-18

    Xanthine oxidase inhibitors are anti-hyperuricemic drugs that decrease serum uric acid levels by inhibiting its synthesis. Xanthine oxidase is also recognized as a pivotal enzyme in the production of oxidative stress. Excess oxidative stress induces endothelial dysfunction and inflammatory reactions in vascular systems, leading to atherosclerosis. Many experimental studies have suggested that xanthine oxidase inhibitors have anti-atherosclerotic effects by decreasing in vitro and in vivo oxidative stress. However, there is only limited evidence on the clinical implications of xanthine oxidase inhibitors on atherosclerotic cardiovascular disease in patients with hyperuricemia. We designed the PRIZE study to evaluate the effects of febuxostat on a surrogate marker of cardiovascular disease risk, ultrasonography-based intima-media thickness of the carotid artery in patients with hyperuricemia. The study is a multicenter, prospective, randomized, open-label and blinded-endpoint evaluation (PROBE) design. A total of 500 patients with asymptomatic hyperuricemia (uric acid >7.0 mg/dL) and carotid intima-media thickness ≥1.1 mm will be randomized centrally to receive either febuxostat (10-60 mg/day) or non-pharmacological treatment. Randomization is carried out using the dynamic allocation method stratified according to age (<65, ≥65 year), gender, presence or absence of diabetes mellitus, serum uric acid (<8.0, ≥8.0 mg/dL), and carotid intima-media thickness (<1.3, ≥1.3 mm). In addition to administering the study drug, we will also direct lifestyle modification in all participants, including advice on control of body weight, sleep, exercise and healthy diet. Carotid intima-media thickness will be evaluated using ultrasonography performed by skilled technicians at a central laboratory. Follow-up will be continued for 24 months. The primary endpoint is percentage change in mean intima-media thickness of the common carotid artery 24 months after baseline, measured by

  13. Emerging role of rasburicase in the management of increased plasma uric acid levels in patients with hematologic malignancies

    PubMed Central

    Kennedy, LeAnne D; Koontz, Susannah; Rao, Kamakshi

    2011-01-01

    Tumor lysis syndrome (TLS) is defined as a group of metabolic derangements that result from the massive and abrupt release of cellular components into the bloodstream after rapid lysis of tumor cells. Breakdown of released materials leads to a number of electrolyte abnormalities, including elevated uric acid concentrations in the blood (hyperuricemia), which carries potentially serious consequences. The diagnosis, prevention, and management of TLS is complicated by variability in definitions, differences in risk factors based on patient- and tumor-specific characteristics, and practitioner preferences in terms of pharmaceutical management strategies. The best prevention and management option for a particular patient depends on the patient’s baseline risk for TLS development, the severity of symptoms in the event of TLS development, practical management considerations, and financial implications of treatment. PMID:22287858

  14. Association Between Metabolic Syndrome and the Serum Uric Acid: a Cohort Study.

    PubMed

    Ren, Ping; Gao, Mengna

    2018-05-01

    Metabolic syndrome (MS) consists of a cluster of metabolic diseases, and the association between serum uric acid (SUA) and MS has recently been reported in several studies; however, whether SUA is a susceptibility or risk biomarker for the development of MS among Chinese adults is unclear. This study was designed to investigate the relationship between SUA and MS. This study involved 4,988 subjects who were followed up for 9 years. Cox regression model was used to analyze the risk factors of MS. Of the 4,988 subjects, 1,192 subjects developed MS over 9 years of follow-up. The overall 9-year cumulative incidence of MS was 23.9%, ranging from 16.6% in quartile 1 to 35.1% in quartile 4 (p for trend < 0.001). Cox regression analyses indicated that SUA was significantly associated with incident MS (HR comparing quartile 2, 3, and 4 vs. quartile 1, 1.11, 1.33, and 1.78, respectively; p < 0.001) after adjusting for multiple associated parameters. In receiver operating characteristic curve analysis, the cutoff levels for SUA to predict incident MS were 350 μmol/L and 268 μmol/L in males and females, respectively. The results of this study demonstrated that high SUA concentrations may increase the risk of MS among Chinese adults.

  15. Phytic acid/graphene oxide nanocomposites modified electrode for electrochemical sensing of dopamine.

    PubMed

    Wang, Donglei; Xu, Fei; Hu, Jiajie; Lin, Meng

    2017-02-01

    An electrochemical sensor for determining dopamine was developed by modifying phytic acid/graphene oxide (PA/GO) nanocomposites onto a glassy carbon electrode (GCE). PA functionalized GO was prepared by an ultra-sonication method. Subsequently, the PA/GO nanocomposites were drop-casted on a glassy carbon substrate. The structural feature of the PA/GO modified GCE was confirmed by attenuated total reflection infrared (ATR-IR) spectroscopy. The proposed electrochemical sensor was applied to detect various concentrations of DA by differential pulse voltammetry (DPV). The PA/GO/GCE was considered to be highly sensitive to DA in the range of 0.05-10μM. In addition, the PA/GO/GCE demonstrated high electrochemical selectivity toward DA in the presence of ascorbic acid (AA) and uric acid (UA). The prepared electrochemical DA sensor was applied for detection of DA in dopamine hydrochloride injection and spiked samples of human urine with satisfactory results. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Acid-base metabolism: implications for kidney stones formation.

    PubMed

    Hess, Bernhard

    2006-04-01

    The physiology and pathophysiology of renal H+ ion excretion and urinary buffer systems are reviewed. The main focus is on the two major conditions related to acid-base metabolism that cause kidney stone formation, i.e., distal renal tubular acidosis (dRTA) and abnormally low urine pH with subsequent uric acid stone formation. Both the entities can be seen on the background of disturbances of the major urinary buffer system, NH3+ <--> NH4+. On the one hand, reduced distal tubular secretion of H+ ions results in an abnormally high urinary pH and either incomplete or complete dRTA. On the other hand, reduced production/availability of NH4+ is the cause of an abnormally low urinary pH, which predisposes to uric acid stone formation. Most recent research indicates that the latter abnormality may be a renal manifestation of the increasingly prevalent metabolic syndrome. Despite opposite deviations from normal urinary pH values, both the dRTA and uric acid stone formation due to low urinary pH require the same treatment, i.e., alkali. In the dRTA, alkali is needed for improving the body's buffer capacity, whereas the goal of alkali treatment in uric acid stone formers is to increase the urinary pH to 6.2-6.8 in order to minimize uric acid crystallization.

  17. Development of anodic titania nanotubes for application in high sensitivity amperometric glucose and uric acid biosensors.

    PubMed

    Lee, Hsiang-Ching; Zhang, Li-Fan; Lin, Jyh-Ling; Chin, Yuan-Lung; Sun, Tai-Ping

    2013-10-21

    The purpose of this study was to develop novel nanoscale biosensors using titania nanotubes (TNTs) made by anodization. Titania nanotubes were produced on pure titanium sheets by anodization at room temperature. In this research, the electrolyte composition ethylene glycol 250 mL/NH4F 1.5 g/DI water 20 mL was found to produce the best titania nanotubes array films for application in amperometric biosensors. The amperometric results exhibit an excellent linearity for uric acid (UA) concentrations in the range between 2 and 14 mg/dL, with 23.3 (µA·cm-2)·(mg/dL)-1 UA sensitivity, and a correlation coefficient of 0.993. The glucose biosensor presented a good linear relationship in the lower glucose concentration range between 50 and 125 mg/dL, and the corresponding sensitivity was approximately 249.6 (µA·cm-2)·(100 mg/dL)-1 glucose, with a correlation coefficient of 0.973.

  18. Development of Anodic Titania Nanotubes for Application in High Sensitivity Amperometric Glucose and Uric Acid Biosensors

    PubMed Central

    Lee, Hsiang-Ching; Zhang, Li-Fan; Lin, Jyh-Ling; Chin, Yuan-Lung; Sun, Tai-Ping

    2013-01-01

    The purpose of this study was to develop novel nanoscale biosensors using titania nanotubes (TNTs) made by anodization. Titania nanotubes were produced on pure titanium sheets by anodization at room temperature. In this research, the electrolyte composition ethylene glycol 250 mL/NH4F 1.5 g/DI water 20 mL was found to produce the best titania nanotubes array films for application in amperometric biosensors. The amperometric results exhibit an excellent linearity for uric acid (UA) concentrations in the range between 2 and 14 mg/dL, with 23.3 (μA·cm−2)·(mg/dL)−1 UA sensitivity, and a correlation coefficient of 0.993. The glucose biosensor presented a good linear relationship in the lower glucose concentration range between 50 and 125 mg/dL, and the corresponding sensitivity was approximately 249.6 (μA·cm−2)·(100 mg/dL)−1 glucose, with a correlation coefficient of 0.973. PMID:24152934

  19. Low serum uric acid levels in chronic insomnia patients: A case-control study.

    PubMed

    Zhao, Kai; Luan, Xiaoqian; Liu, Zhihua; Zhu, Zhuoying; Chen, Huijun; Shen, Huiping; Cai, Yan; Qiu, Huihua; Wang, Qiongzhang; Gu, Yingying; Zhu, Lin; He, Jincai

    2017-09-14

    Recent studies have demonstrated the presence of oxidative stress in insomnia patients. Uric acid (UA) is regarded as one of the most important antioxidants that may attenuate oxidative stress. The aim of our study was to investigate whether there is an alteration of serum UA levels in chronic insomnia patients. The association between sleep quality and serum UA in chronic insomnia patients was also investigated. We recruited 300 chronic insomnia patients and 300 age- and gender-matched normal controls. The uricase-PAP method was used to measure the concentration of UA both in patient and normal control subjects. The Pittsburgh Sleep Quality Index (PSQI) was used to assess the sleep quality of chronic insomniac participants. As a result, significantly lower serum UA levels were observed in patients with chronic insomnia when compared with normal control subjects (279.56±65.80 vs. 299.10±61.17μmol/L, t=-3.991, p<0.001). Low serum UA levels were correlated with high PSQI scores in multiple linear regression models (β=-0.322, p<0.001). Our results suggested that low serum UA levels were associated with the presence and severity of chronic insomnia. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Serum uric acid in top-level alpine skiers over four consecutive competitive seasons.

    PubMed

    Lombardi, Giovanni; Colombini, Alessandra; Ricci, Cristian; Freschi, Marco; Lippi, Giuseppe; Banfi, Giuseppe

    2010-05-02

    Uric acid (UA), a major plasmatic antioxidant is an intracellular scavenger, especially during metabolic stress. UA serum concentration could be important for evaluating oxidant stress and the correspondent response in sportsmen, who are prone to the risk of oxidant increase and related cell and tissue damage. Blood was collected from 10 male and 8 female alpine skiers from the Italian National Team (current age range, 26-33 and 24-28 years, respectively) over an entire season. The analyses were performed using an uricase-based enzymatic method. Mean UA values were 3.8 mg/dl in females and 4.8 mg/dl in males: a significant difference between genders was maintained across all four competitive seasons. No differences emerged within either gender during each season nor between different intra-seasonal or inter-seasonal blood drawings in individual athletes. Our results suggest that serum UA in top-level athletes is a stable parameter. High-intensity workload caused serum UA changes lower than biological variability both within the competitive season or between different seasons. Serum UA increased immediately after exercise, but the resting concentration was not influenced by sports activity. The data of our study showed that this parameter is not useful for marking high physical demand or overtraining. Copyright 2010 Elsevier B.V. All rights reserved.