[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.

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

[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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

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.

[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 is associated with the severity of PH and higher uric acid level serves as an important predictor for poor clinical outcome of PH patients.

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

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.

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.

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.

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.

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.

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.

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.

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.

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

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 to its renal route of excretion.

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 ...

Gout

MedlinePlus

... much uric acid Your body has a hard time getting rid of uric acid When uric acid builds up in the fluid around the joints (synovial fluid), uric acid crystals form. These crystals cause the joint to become ...

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.

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.

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 macular thickness with serum uric acid in both the groups. Serum uric acid showed a poor correlation with RNFL and macular thickness among type 2 diabetic patients.

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.

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 evolving prevalence of hyperuricemia in developing countries. PMID:15043756

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.

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.

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.

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.

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.

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.

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.

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.

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 ...

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 enhancing effect on urate excretion were confirmed in hyperuricemia animal models. Tigogenin, a metabolite of Dioscin, was identified as an active substance with antihyperuricemic activity in vivo, through inhibition of URAT1 and promotion of ABCG2. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

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

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

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.

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.

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.

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.

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.

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.

A biohybrid hydrogel for the urate-responsive release of urate oxidase.

PubMed

Geraths, Christian; Daoud-El Baba, Marie; Charpin-El Hamri, Ghislaine; Weber, Wilfried

2013-10-10

Functional biomaterials that detect and correct pathological parameters hold high promises for biomedical application. In this study we describe a biohybrid hydrogel that detects elevated concentrations of uric acid and responds by dissolution and the release of uric acid-degrading urate oxidase. This material was synthesized by incorporating PEG-stabilized urate oxidase into a polyacrylamide hydrogel that was crosslinked by the uric acid-sensitive interaction between the uric acid transcription factor HucR and its operator hucO. We characterize the uric acid responsiveness of the material and demonstrate that it can effectively be applied to counteract flares of uric acid in a mouse model. This approach might be a first step towards a biomedical device autonomously managing uric acid burst associated to gouty arthritis and the tumor lysis syndrome. © 2013.

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sorensen, L.B.

Studies were made of the total amount of uric acid in the human body and the turnover rate. Uric acid labeled with C/sup 14/ was used as a tracer. A comparison of the amount of uric acid turned over per day with the amount excreted in the urine made it clear that a considerable part of uric acid ie eliminated by some other route than through the kidney. Results are reported from studies on the extrarenal excretion of uric acid. (C.H.)

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.

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.

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.

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.

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).

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.

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

[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 <0.01). Conclusion: High dose atorvastatin can decrease serum uric acid levels and improve reflow after PCI in patients with STEMI.

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

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

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 decreased. Our study reported that high uric acid can promote the inflammation of the retina and increase the activity of Notch signaling pathway on the basis of high glucose. Hyperuricemia promotes the development of diabetic retinopathy by increasing the activity of Notch signaling pathway. Notch signaling pathway is a potential therapeutic target for diabetic retinopathy. Copyright © 2018. Published by Elsevier Inc.

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

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.

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.

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 (8.3%). Higher uric acid levels were associated with increased odds of anovulation (odds ratio 2.39, 95% CI: 1.25, 4.56). LIMITATIONS, REASONS FOR CAUTION The change in uric acid levels among this cohort of healthy women was modest, and analysis was limited to two menstrual cycles. The women in this study were healthy and regularly menstruating, and as such there were few women with high uric acid levels and anovulatory cycles. WIDER IMPLICATIONS OF THE FINDINGS These findings demonstrate the importance of taking menstrual cycle phase into account when measuring uric acid in premenopausal women, and confirm the hypothesized beneficial lowering effects of endogenous E2 on uric acid levels. These findings suggest that there could be an underlying association affecting both sporadic anovulation and high uric acid levels among young, regularly menstruating women. Further studies are needed to confirm these findings and elucidate the connection between uric acid and reproductive and later cardiovascular health. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (contract # HHSN275200403394C). No competing interests declared. PMID:23562957

Genetics Home Reference: renal hypouricemia

MedlinePlus

... disorder that results in a reduced amount of uric acid in the blood. Uric acid is a byproduct of certain normal chemical reactions ... molecules called free radicals. However, having too much uric acid in the body is toxic, so excess uric ...

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.

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.

Hyperuricemia Causes Pancreatic β-Cell Death and Dysfunction through NF-κB Signaling Pathway

PubMed Central

Jia, Lu; Xing, Jing; Ding, Ying; Shen, Yachen; Shi, Xuhui; Ren, Wei; Wan, Meng; Guo, Jianjin; Zheng, Shujing; Liu, Yun; Liang, Xiubin; Su, Dongming

2013-01-01

Accumulating clinical evidence suggests that hyperuricemia is associated with an increased risk of type 2 diabetes. However, it is still unclear whether elevated levels of uric acid can cause direct injury of pancreatic β-cells. In this study, we examined the effects of uric acid on β-cell viability and function. Uric acid solution or normal saline was administered intraperitoneally to mice daily for 4 weeks. Uric acid-treated mice exhibited significantly impaired glucose tolerance and lower insulin levels in response to glucose challenge than did control mice. However, there were no significant differences in insulin sensitivity between the two groups. In comparison to the islets in control mice, the islets in the uric acid–treated mice were markedly smaller in size and contained less insulin. Treatment of β-cells in vitro with uric acid activated the NF-κB signaling pathway through IκBα phosphorylation, resulting in upregulated inducible nitric oxide synthase (iNOS) expression and excessive nitric oxide (NO) production. Uric acid treatment also increased apoptosis and downregulated Bcl-2 expression in Min6 cells. In addition, a reduction in insulin secretion under glucose challenge was observed in the uric acid–treated mouse islets. These deleterious effects of uric acid on pancreatic β-cells were attenuated by benzbromarone, an inhibitor of uric acid transporters, NOS inhibitor L-NMMA, and Bay 11–7082, an NF-κB inhibitor. Further investigation indicated that uric acid suppressed levels of MafA protein through enhancing its degradation. Collectively, our data suggested that an elevated level of uric acid causes β-cell injury via the NF-κB-iNOS-NO signaling axis. PMID:24205181

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peden, D.B.; Swiersz, M.; Ohkubo, K.

Uric acid, an important scavenger of ozone, has been identified as the major low molecular weight antioxidant in baseline and cholinergically induced nasal secretions. The purpose of this study was to determine the specific tissue source of uric acid in airway secretions. The secretion of uric acid is increased by cholinergic stimulation and correlates closely with the secretion of lactoferrin (a nasal glandular protein), suggesting that submucosal glands are involved. Indeed, nasal turbinate tissue was found to contain uric acid. However, careful analysis of nasal turbinate tissue failed to reveal the presence of xanthine oxidase, the enzyme responsible for uricmore » acid synthesis. These data suggest that uric acid might be taken up secondarily by glands from plasma. This possibility was strengthened by the observation that lowering the plasma urate level with probenecid concomitantly lowered urate secretion. These findings are consistent with the hypotheses that the principal source of uric acid in nasal secretions is plasma and that uric acid is taken up, concentrated, and secreted by nasal glands.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meadows, J.; Smith, R.C.

Uric acid effectively reduced hemolysis and methemoglobin formation in bovine and swine erythrocytes bubbled with ozone in vitro. In bovine erythrocytes, formation of thiobarbituric acid-reactive material was inhibited by uric acid, but there was little immediate protection for the swine cells. Antioxidant protection was due to preferential degradation of the uric acid by ozone. These results provide evidence to support the hypothesis that in plasma, uric acid can provide antioxidant protection for erythrocytes.

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)

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.

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

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.

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

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.

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meadows, J.; Smith, R.C.

Uric acid has been proposed to be an important antioxidant and free radical scavenger in humans. Of the purine and pyrimidine compounds examined in this study, uric acid showed the greatest susceptibility to ozone-induced degradation. The parent compounds, purine and pyrimidine, were more resistant to ozonation than were the nucleobases. When the degradation of OH-substituted purines was examined, it was found that the more OH groups on the purine ring, the more readily the purine was degraded. Urea and allantoin were identified as degradation products of uric acid. The relative rates of nucleobase degradation in the presence and absence ofmore » uric acid were compared. Uric acid protected thymine, guanine, and uracil from degradation by ozone. In this system uric acid was found to protect the nucleobases as effectively as reduced glutathione.« less

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.

Allopurinol

MedlinePlus

... is used to treat gout, high levels of uric acid in the body caused by certain cancer medications, ... inhibitors. It works by reducing the production of uric acid in the body. High levels of uric acid ...

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

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

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.

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.

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.

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.

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.

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.

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.

Imaging birefringent crystals using micro optical coherence tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Sharma, Gargi; Singh, Kanwarpal; Gardecki, Joseph A.; Tearney, Guillermo J.

2017-02-01

Background: Uric acid crystals have recently been identified as a possible therapeutic target for coronary artery disease. Being subcellular in size, it is difficult to identify these crystals in situ. Micro optical coherence tomography (Micro-OCT) allows one to image subcellular structures with 1-micron resolution. Even though Micro-OCT should be capable of resolving urate crystals, it's difficult to differentiate these structures from other scattering particles within tissue. In this work we developed a novel polarization sensitive micro OCT (ps-Micro-OCT) system for identification of uric acid crystals. Methods: A spectrometer based ps-Micro-OCT system was developed using a broadband light source. The broadband input light was divided into reference and sample signals using a beam splitter. The reference signal was further divided into two polarized signals with different polarization states. Reflected reference and sample signals were combined and sent to a spectrometer that recorded the interference signal. Results: To test the performance of system, a mirror was used as sample and a quarter wave-plate was placed in the sample path. The measured quarter wave-plate angle values matched closely to actual angle values. Next we prepared uric acid crystals in our lab and imaged them using this system.We were able to image and identify these crystals based on polarization measurements. Conclusion: In this work we imaged and identified uric acid crystals using a newly developed ps-Micro-OCT system. The proposed technique will enable imaging uric acid crystals in coronary artery.

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.

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.

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

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.

Sweetened beverages intake, hyperuricemia and metabolic syndrome: the Mexico City Diabetes Study.

PubMed

López-Molina, Rubén; Parra-Cabrera, Socorro; López-Ridaura, Ruy; González-Villalpando, María E; Ferrannini, Ele; González-Villalpando, Clicerio

2013-12-01

OBJECTIVE. To determine prevalence of hyperuricemia and its relation with intake of sweetened beverages (SB) and metabolic syndrome (MS) in low income urban Mexican population. MATERIALS AND METHODS. A cross-sectional analysis of The Mexico City Diabetes Study, a prospective population-based investigation (1 173 participants) was performed. We used logistic regression, adjusted by pertinent variables. We determined prevalence of hyperuricemia and explored associations of uric acid levels with MS and intake of SB. RESULTS. Prevalence of hyperuricemia was 26.5 and 19.8% in males and females respectively. In an adjusted multivariate model, body mass index, waist circumference, and triglyceride were higher as uric acid quartiles increased (p<0.005-0.001). The odds ratio for MS was 1.48 for 3rd uric acid quartile and 2.03 for 4th quartile. Higher consumption of SB was associated with higher uric acid levels (p<0.001). CONCLUSION. Prevalence of hyperuricemia is high. Potential association with intake of SB, resulting in metabolic alterations should be considered.

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.

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.

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 warming".

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.

Gout

MedlinePlus

... red, hot and stiff joints. Gout happens when uric acid builds up in your body. Uric acid comes from the breakdown of substances called purines. ... liver, dried beans and peas, and anchovies. Normally, uric acid dissolves in the blood. It passes through the ...

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.

Untersuchungen zum Harnsäuremetabolismus von Littorina littorea (Gastropoda)

NASA Astrophysics Data System (ADS)

Heil, K. P.; Eichelberg, D.

1983-12-01

Periwinkles, as typical inhabitants of sea-shores, are subjected to extreme changes of environmental conditions, which affect their excretion. In Littorina littorea uric acid, urea and ammonium were detected particularly in the kidney, but the only metabolite excreted was ammonium. Only the concentration of uric acid was dependent on the availability of water; decreasing periods of submersion during low tide and raised salinities caused a higher concentration of uric acid, while increasing periods of submersion and lowered salinities effected the opposite. Transfer of periwinkles within their intertidal habitat and laboratory experiments to test the effect of salinity showed that the concentration of uric acid in the kidney is adaptable. The dependence of uric acid concentration in the kidney on environmental conditions and the ammoniotelic excretion of L. littorea are discussed with regard to its particular living conditions. It is suggested that uric acid serves as nitrogen depot and has a particular function in osmoregulation.

Is a pre-analytical process for urinalysis required?

PubMed

Petit, Morgane; Beaudeux, Jean-Louis; Majoux, Sandrine; Hennequin, Carole

2017-10-01

For the reliable urinary measurement of calcium, phosphate and uric acid, a pre-analytical process by adding acid or base to urine samples at laboratory is recommended in order to dissolve precipitated solutes. Several studies on different kind of samples and analysers have previously shown that a such pre-analytical treatment is useless. The objective was to study the necessity of pre-analytical treatment of urine on samples collected using the V-Monovette ® (Sarstedt) system and measured on the analyser Architect C16000 (Abbott Diagnostics). Sixty urinary samples of hospitalized patients were selected (n=30 for calcium and phosphate, and n=30 for uric acid). After acidification of urine samples for measurement of calcium and phosphate, and alkalinisation for measurement of uric acid respectively, differences between results before and after the pre-analytical treatment were compared to acceptable limits recommended by the French society of clinical biology (SFBC). No difference in concentration between before and after pre-analytical treatment of urine samples exceeded acceptable limits from SFBC for measurement of calcium and uric acid. For phosphate, only one sample exceeded these acceptable limits, showing a result paradoxically lower after acidification. In conclusion, in agreement with previous study, our results show that acidification or alkalinisation of urine samples from 24 h urines or from urination is not a pre-analytical necessity for measurement of calcium, phosphate and uric acid.

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.

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.

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.

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.

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-.

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.

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

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

Impact of Hyperuricemia on Long-term Outcomes of Kidney Transplantation: Analysis of the FAVORIT Study.

PubMed

Kalil, Roberto S; Carpenter, Myra A; Ivanova, Anastasia; Gravens-Mueller, Lisa; John, Alin A; Weir, Matthew R; Pesavento, Todd; Bostom, Andrew G; Pfeffer, Marc A; Hunsicker, Lawrence G

2017-12-01

Elevated uric acid concentration is associated with higher rates of cardiovascular (CV) morbidity and mortality in the general population. It is not known whether hyperuricemia increases the risk for CV death or transplant failure in kidney transplant recipients. Post hoc cohort analysis of the FAVORIT Study, a randomized controlled trial that examined the effect of homocysteine-lowering vitamins on CV disease in kidney transplantation. Adult recipients of kidney transplants in the United States, Canada, or Brazil participating in the FAVORIT Study, with hyperhomocysteinemia, stable kidney function, and no known history of CV disease. Uric acid concentration. The primary end point was a composite of CV events. Secondary end points were all-cause mortality and transplant failure. Risk factors included in statistical models were age, sex, race, country, treatment assignment, smoking history, body mass index, presence of diabetes mellitus, history of CV disease, blood pressure, estimated glomerular filtration rate (eGFR), donor type, transplant vintage, lipid concentrations, albumin-creatinine ratio, and uric acid concentration. Cox proportional hazards models were fit to examine the association of uric acid concentration with study end points after risk adjustment. 3,512 of 4,110 FAVORIT participants with baseline uric acid concentrations were studied. Median follow-up was 3.9 (IQR, 3.0-5.3) years. 503 patients had a primary CV event, 401 died, and 287 had transplant failure. In unadjusted analyses, uric acid concentration was significantly related to each outcome. Uric acid concentration was also strongly associated with eGFR. The relationship between uric acid concentration and study end points was no longer significant in fully adjusted multivariable models (P=0.5 for CV events; P=0.09 for death, and P=0.1 for transplant failure). Unknown use of uric acid-lowering agents among study participants. Following kidney transplantation, uric acid concentrations are not independently associated with CV events, mortality, or transplant failure. The strong association between uric acid concentrations with traditional risk factors and eGFR is a possible explanation. Copyright © 2017 National Kidney Foundation, Inc. All rights reserved.

Glucosamine: Can It Worsen Gout Symptoms?

MedlinePlus

... in joints. Gout is caused by deposits of uric acid crystals in a joint. Uric acid is a waste product formed from the breakdown ... contain purines, it isn't likely to increase uric acid levels or aggravate gout symptoms. Likewise, there's no ...

Methylated purines in urinary stones.

PubMed

Safranow, Krzysztof; Machoy, Zygmunt

2005-08-01

The aim of the study was to measure the content of methylated purines that appear as admixtures in uric acid stones. We analyzed urinary calculi from 48 residents of Western Pomerania who underwent surgery at the urology ward in Szczecin. Stone samples were dissolved in 0.1 mol/L NaOH. Extracts were diluted in 50 mmol/L KH(2)PO(4) and analyzed by reversed-phase HPLC with ultraviolet detection and use of a gradient of methanol concentration and pH. Uric acid was the main component of 9 stones. All 9 showed admixtures of 9 other purine derivatives: endogenous purine breakdown products (xanthine, hypoxanthine, and 2,8-dihydroxyadenine) and exogenous methyl derivatives of uric acid and xanthine (1-, 3-, and 7-methyluric acid; 1,3-dimethyluric acid; and 3- and 7-methylxanthine). Amounts of these purine derivatives ranged from the limit of detection to 12 mg/g of stone weight and showed a strong positive correlation (Spearman rank correlation coefficients, 0.63-0.94) with the uric acid content of the samples. The main methylated purine in the stones was 1-methyluric acid. Urinary purines at concentrations below their saturation limits may coprecipitate in samples supersaturated with uric acid and appear as admixtures in urinary stones. The amount of each purine depends on its average urinary excretion, similarity to the chemical structure of uric acid, and concentration of the latter in the stone. These findings suggest that purines in stones represent a substitutional solid solution with uric acid as solvent. Methylxanthines, which are ubiquitous components of the diet, drugs, and uric acid calculi, may be involved in the pathogenesis of urolithiasis.

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.

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

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.

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.

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

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

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.

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.

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.

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

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.

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.

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.

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.

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.

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

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

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

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.

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.

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 removed from the textbooks as a cause of CKD, and the common association of hyperuricemia with CKD was solely attributed to the retention of serum uric acid that is known to occur as the glomerular filtration rate falls. Renewed interest in uric acid as a cause of CKD occurred when it was realized that invalid assumptions had been made in the arguments to dismiss uric acid as a risk factor for CKD [5]. The greatest assumption was that the mechanism by which uric acid would cause kidney disease would be via the precipitation as crystals in the kidney, similar to the way it causes gout. However, when laboratory animals with CKD were made hyperuricemic, the renal disease progressed rapidly despite an absence of crystals in the kidney [6]. Since this seminal study, there has been a renewed interest in the potential role uric acid may have in both acute and CKD. We briefly review some of the major advances that have occurred in this field in the last 15 years. PMID:23543594

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.

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

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.

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.

Stone heterogeneity index on single-energy noncontrast computed tomography can be a positive predictor of urinary stone composition

PubMed Central

Lee, Jong Soo; Cho, Kang Su; Lee, Seung Hwan; Yoon, Young Eun; Kang, Dong Hyuk; Jeong, Won Sik; Jung, Hae Do; Kwon, Jong Kyou

2018-01-01

The aim of this study was to investigate the correlation between stone composition and single-energy noncontrast computed tomography (NCCT) parameters, including stone heterogeneity index (SHI) and mean stone density (MSD), in patients with urinary calculi. We retrospectively reviewed medical records of 255 patients who underwent operations or procedures for urinary stones or had spontaneous stone passage between December 2014 and October 2015. Among these, 214 patients with urinary calculi who underwent NCCT and stone composition analyses were included in the study. Maximal stone length (MSL), mean stone density (MSD), and stone heterogeneity index (SHI) were determined on pretreatment NCCT. The mean MSD (454.68±177.80 HU) and SHI (115.82±96.31 HU) of uric acid stones were lower than those of all other types. Based on post hoc tests, MSD was lower for uric acid stones than for the other types (vs. CaOx: P<0.001; vs. infection stones: P<0.001). SHI was lower for uric acid stones than for the other types (vs. CaOx: P<0.001; vs. infection stones: P<0.001) Receiver operating characteristic curves of uric acid stones for MSD and SHI demonstrated that SHI (cut-off value: 140.4 HU) was superior to MSD (cut-off value: 572.3 HU) in predicting uric acid stones (P<0.001). PMID:29649219

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.

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.

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

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 of K.S.A., which helps the community to understand the role of serum uric acid in coronary heart disease, justifies the objective of research in taking preventive measures to combat the deleterious effect of coronary heart disease. Prevention and early detection of elevated uric acid in both hypertensive and diabetic patients could serve as effective investigative tool in reducing coronary heart disease. Copyright © 2016 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.

Coevolution of URAT1 and Uricase during Primate Evolution: Implications for Serum Urate Homeostasis and Gout

PubMed Central

Tan, Philip K.; Farrar, Jennifer E.; Gaucher, Eric A.; Miner, Jeffrey N.

2016-01-01

Uric acid is the highly insoluble end-product of purine metabolism in humans. Serum levels exceeding the solubility threshold can trigger formation of urate crystals resulting in gouty arthritis. Uric acid is primarily excreted through the kidneys with 90% reabsorbed back into the bloodstream through the uric acid transporter URAT1. This reabsorption process is essential for the high serum uric acid levels found in humans. We discovered that URAT1 proteins from humans and baboons have higher affinity for uric acid compared with transporters from rats and mice. This difference in transport kinetics of URAT1 orthologs, along with inability of modern apes to oxidize uric acid due to loss of the uricase enzyme, prompted us to ask whether these events occurred concomitantly during primate evolution. Ancestral URAT1 sequences were computationally inferred and ancient transporters were resurrected and assayed, revealing that affinity for uric acid was increased during the evolution of primates. This molecular fine-tuning occurred between the origins of simians and their diversification into New- and Old-World monkey and ape lineages. Remarkably, it was driven in large-part by only a few amino acid replacements within the transporter. This alteration in primate URAT1 coincided with changes in uricase that greatly diminished the enzymatic activity and took place 27–77 Ma. These results suggest that the modifications to URAT1 transporters were potentially adaptive and that maintaining more constant, high levels of serum uric acid may have provided an advantage to our primate ancestors. PMID:27352852

Urate oxidase knockdown decreases oxidative stress in a murine hepatic cell line

USDA-ARS?s Scientific Manuscript database

Humans, birds, and some primates do not express the uric acid degrading enzyme urate oxidase (UOX) and, as a result, have plasma uric acid concentrations higher than UOX expressing animals. Although high uric acid concentrations are suggested to increase the antioxidant defense system and provide a...

The genetics of hyperuricaemia and gout.

PubMed

Reginato, Anthony M; Mount, David B; Yang, Irene; Choi, Hyon K

2012-10-01

Gout is a common and very painful inflammatory arthritis caused by hyperuricaemia. This review provides an update on the genetics of hyperuricaemia and gout, including findings from genome-wide association studies. Most of the genes that associated with serum uric acid levels or gout are involved in the renal urate-transport system. For example, the urate transporter genes SLC2A9, ABCG2 and SLC22A12 modulate serum uric acid levels and gout risk. The net balance between renal urate absorption and secretion is a major determinant of serum uric acid concentration and loss-of-function mutations in SLC2A9 and SLC22A12 cause hereditary hypouricaemia due to reduced urate absorption and unopposed urate secretion. However, the variance in serum uric acid explained by genetic variants is small and their clinical utility for gout risk prediction seems limited because serum uric acid levels effectively predict gout risk. Urate-associated genes and genetically determined serum uric acid levels were largely unassociated with cardiovascular-metabolic outcomes, challenging the hypothesis of a causal role of serum uric acid in the development of cardiovascular disease. Strong pharmacogenetic associations between HLA-B*5801 alleles and severe allopurinol-hypersensitivity reactions were shown in Asian and European populations. Genetic testing for HLA-B*5801 alleles could be used to predict these potentially fatal adverse effects.

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.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Struck, W.A.; Elving, P.J.

Alloxan is the dominant product of the chemical oxidation of uric acid under strongly acid conditions; allantoin is the corresponding product for less acidic to alkaline conditions; separate reaction paths have generally been postulated to account for this difference. A study of the electrolytic oxidation of uric acid indicates the presence of a common path which eventually diverges to produce both alloxan and allantoin in comparable amounts, Uric acid gives a well- defined anodic voltammetric wave at a graphite electrode. When uric acid is electrolytically oxidized in diIute acetic acid at large graphite electrodes, 2.2 Faradays are passed, and 0,25more » mole CO/sub 2/, 0.25 mole of a precursor of allantoin, 0.75 mole urea, 0,3 mole parabanic acid and 0.3 mole alloxan simultaneously appear per mole of uric acid oxidized. At any stage during electrolysis, the sum of the moles of allantoin precursor and urea equals the moles of uric acid oxidized. This material balance and the stability of the allantoin precursor indicate that the production of urea is associated with the pathway(s) that produce alloxan and parabanic acid. These and other facts indicate a mechanism whereby uric acid is oxidized in a 2e process to a primary short-lived intermediate, which undergoes three simultaneous transformations: (1) hydrolysis to the allantoin precursor, (2) hydrolysis to alloxan and urea, and (3) further oxidation and hydrolysis leading to parabanic acid and urea. The non- stoichiometric amount of CO/sub 2/ produced and the non-integral number of electrons involved are accounted for by the formation of parabanic acid. The primary oxidation intermediate ultimately produces both allantoin and alloxan, suggesting that this intermediate may be common to all uric acid oxidations and that the ultimate product heretofore considered to be typified by either allantoin or alloxan (but not both) is most likely controlled by experimental conditions. (auth)« less

[The hyperiricosuria as an indicator of derangement of biologic functions of endoecology and adaptation, biologic reactions of excretion, inflammation and arterial tension].

PubMed

Titov, V N; Oshchepkova, E V; Dmitriev, V A; Gushchina, O V; Shiriaeva, Iu K; Iashin, A Ia

2012-04-01

During millions years in all animals allantoine (oxidized by uricase uric acid) was catabolite of purines and ascorbic acid was an acceptor of active forms of oxygen. The proximal tubules of nephron reabsorbed the trace amounts of uric acid Then during phylogenesis the primates had a mutation of ascorbic acid gen minus. Later on occurred a second spontaneous mutation and uricase gen minus and uric acid became catabolites of purines. In absence of ascorbic acid synthesis ions of urates became a major capturers of active forms of oxygen and all uric acid as before underwent the reabsorption. Later the carriers were formed which began in epithelium of proximal tubules to secrete all uric acid into urine. At every incident of "littering" of intercellular medium with endogenic flogogens (impairment of biologic function of endoecology) under compensatory development of biologic reaction of inflammation the need in inactivation of active forms of oxygen increases. Hence later on in phylogenesis one more stage was formed--post secretory reabsorption of uric acid In the biologic reaction of inflammation epithelium of proximal tubules initiates retentional hyperiricosuria. The general antioxidant activity of human blood plasma in 60% is presented by urates' ions. The excretion of uric acid includes 4 stages: filtration, full reabsorption, secretion and post secretory reabsorption. In phylogenesis these stages formed in sequence. The mild hyperiricosuria is most frequently considered as a non-specific indicator of activation of biologic reaction of inflammation. The productive hyperiricosuria develops more infrequently under surplus of meat food and cytolysis syndrome (intensification of cell loss in vivo). Under concentration of uric acid more than 400 mkmol/l part of urates circulates in intercellular medium in the form of crystals. The microcrystals of uric acid (biologic "litter") initiate the syndrome of systemic inflammatory response as an endogenic flogogen--initiator of inflammation. The uric acid in the form of ion-capturers of active forms of oxygen is involved into in the formation of syndrome of compensatory anti-inflammatory defense. It may be assumed that simultaneously with post-secretory reabsorption of ions of urates in proximal tubules of nephron occurs intensification of philogenetically late post-secretory reabsorption of ions of sodium and activation of of biologic reaction of hydrodynamic and hydraulic pressure in local pool of intravascular medium i.e. arterial tension. The uric acid simultaneously participates in realization of biologic function of endoecology and adaptation, biologic reactions of excretion, inflammation and arterial tension.

Anemia Causes Hypoglycemia in Intensive Care Unit Patients Due to Error in Single-Channel Glucometers: Methods of Reducing Patient Risk

DTIC Science & Technology

2010-01-01

hematocrit, low oxygen tension, acetaminophen, uric acid , ascorbic acid , maltose, galactose, xy- lose, lactose, operator inexperience, age of strips, heat...Biomedical, Waltham, MA) that corrects for the effects of anemia, low oxygen tension, acetaminophen, uric acid , ascorbic acid , maltose, galactose, xylose, and...resulted in inappropriately high glucometer values (data not shown). The effects of interfering substances (acetaminophen, uric acid , ascorbic acid

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.

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 why men have higher levels of uric acid than women.

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.

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.

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.

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.

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...

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

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

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

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.

Coevolution of URAT1 and Uricase during Primate Evolution: Implications for Serum Urate Homeostasis and Gout.

PubMed

Tan, Philip K; Farrar, Jennifer E; Gaucher, Eric A; Miner, Jeffrey N

2016-09-01

Uric acid is the highly insoluble end-product of purine metabolism in humans. Serum levels exceeding the solubility threshold can trigger formation of urate crystals resulting in gouty arthritis. Uric acid is primarily excreted through the kidneys with 90% reabsorbed back into the bloodstream through the uric acid transporter URAT1. This reabsorption process is essential for the high serum uric acid levels found in humans. We discovered that URAT1 proteins from humans and baboons have higher affinity for uric acid compared with transporters from rats and mice. This difference in transport kinetics of URAT1 orthologs, along with inability of modern apes to oxidize uric acid due to loss of the uricase enzyme, prompted us to ask whether these events occurred concomitantly during primate evolution. Ancestral URAT1 sequences were computationally inferred and ancient transporters were resurrected and assayed, revealing that affinity for uric acid was increased during the evolution of primates. This molecular fine-tuning occurred between the origins of simians and their diversification into New- and Old-World monkey and ape lineages. Remarkably, it was driven in large-part by only a few amino acid replacements within the transporter. This alteration in primate URAT1 coincided with changes in uricase that greatly diminished the enzymatic activity and took place 27-77 Ma. These results suggest that the modifications to URAT1 transporters were potentially adaptive and that maintaining more constant, high levels of serum uric acid may have provided an advantage to our primate ancestors. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

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.

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.

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

Von Gierke disease

MedlinePlus

... liver or kidney Blood sugar test Genetic testing Lactic acid blood test Triglyceride level Uric acid blood ... sugar and high levels of lactate (produced from lactic acid), blood fats (lipids), and uric acid.

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.

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.

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

The genetics of hyperuricaemia and gout

PubMed Central

Reginato, Anthony M.; Mount, David B.; Yang, Irene; Choi, Hyon K.

2013-01-01

Gout is a common and very painful inflammatory arthritis caused by hyperuricaemia. This Review provides an update on the genetics of hyperuricaemia and gout, including findings from genome-wide association studies. Most of the genes that associated with serum uric acid levels or gout are involved in the renal urate-transport system. For example, the urate transporter genes SLC2A9, ABCG2 and SLC22A12 modulate serum uric acid levels and gout risk. The net balance between renal urate absorption and secretion is a major determinant of serum uric acid concentration and loss-of-function mutations in SLC2A9 and SLC22A12 cause hereditary hypouricaemia due to reduced urate absorption and unopposed urate secretion. However, the variance in serum uric acid explained by genetic variants is small and their clinical utility for gout risk prediction seems limited because serum uric acid levels effectively predict gout risk. Urate-associated genes and genetically determined serum uric acid levels were largely unassociated with cardiovascular–metabolic outcomes, challenging the hypothesis of a causal role of serum uric acid in the development of cardiovascular disease. Strong pharmacogenetic associations between HLA-B*5801 alleles and severe allopurinol-hypersensitivity reactions were shown in Asian and European populations. Genetic testing for HLA-B*5801 alleles could be used to predict these potentially fatal adverse effects. PMID:22945592

[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.

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.

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.

Homozygous SLC2A9 Mutations Cause Severe Renal Hypouricemia

PubMed Central

Gray, Nicola K.; Campbell, Susan; Shu, Xinhua; Sawyer, Lindsay; Richardson, William; Rechavi, Gideon; Amariglio, Ninette; Ganon, Liat; Sela, Ben-Ami; Bahat, Hilla; Goldman, Michael; Weissgarten, Joshua; Millar, Michael R.; Wright, Alan F.; Holtzman, Eliezer J.

2010-01-01

Hereditary hypouricemia may result from mutations in the renal tubular uric acid transporter URAT1. Whether mutation of other uric acid transporters produces a similar phenotype is unknown. We studied two families who had severe hereditary hypouricemia and did not have a URAT1 defect. We performed a genome-wide homozygosity screen and linkage analysis and identified the candidate gene SLC2A9, which encodes the glucose transporter 9 (GLUT9). Both families had homozygous SLC2A9 mutations: A missense mutation (L75R) in six affected members of one family and a 36-kb deletion, resulting in a truncated protein, in the other. In vitro, the L75R mutation dramatically impaired transport of uric acid. The mean concentration of serum uric acid of seven homozygous individuals was 0.17 ± 0.2 mg/dl, and all had a fractional excretion of uric acid >150%. Three individuals had nephrolithiasis, and three had a history of exercise-induced acute renal failure. In conclusion, homozygous loss-of-function mutations of GLUT9 cause a total defect of uric acid absorption, leading to severe renal hypouricemia complicated by nephrolithiasis and exercise-induced acute renal failure. In addition to clarifying renal handling of uric acid, our findings may provide a better understanding of the pathophysiology of acute renal failure, nephrolithiasis, hyperuricemia, and gout. PMID:19926891

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

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)

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.

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. ...

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. ...

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. ...

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. ...

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...

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. ...

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.

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.

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.

Nephrocalcinosis

MedlinePlus

... Blood tests to check levels of calcium, phosphate, uric acid, and parathyroid hormone Urinalysis to see crystals and ... to measure acidity and levels of calcium, sodium, uric acid, oxalate, and citrate

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.

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

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

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.

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.

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.

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.

Phosphorescent inner filter effect-based sensing of xanthine oxidase and its inhibitors with Mn-doped ZnS quantum dots.

PubMed

Tang, Dandan; Zhang, Jinyi; Zhou, Rongxin; Xie, Ya-Ni; Hou, Xiandeng; Xu, Kailai; Wu, Peng

2018-05-10

Overexpression and crystallization of uric acid have been recognized as the course of hyperuricemia and gout, which is produced via xanthine oxidase (XOD)-catalyzed oxidation of xanthine. Therefore, the medicinal therapy of hyperuricemia and gout is majorly based on the inhibition of the XOD enzymatic pathway. The spectroscopic nature of xanthine and uric acid, namely both absorption (near the ultraviolet region) and emission (non-fluorescent) characteristics, hinders optical assay development for XOD analysis. Therefore, the state-of-the-art analysis of XOD and the screening of XOD inhibitors are majorly based on chromatography. Here, we found the near ultraviolet absorption of uric acid overlapped well with the absorption of a large bandgap semiconductor quantum dots, ZnS. On the other hand, the intrinsic weak fluorescence of ZnS QDs can be substantially improved via transition metal ion doping. Therefore, herein, we developed an inner filter effect-based assay for XOD analysis and inhibitor screening with Mn-doped ZnS QDs. The phosphorescence of Mn-doped ZnS QDs could be quenched by uric acid generated from xanthine catabolism by XOD, leading to the phosphorescence turn-off detection of XOD with a limit of detection (3σ) of 0.02 U L-1. Furthermore, the existence of XOD inhibitors could inhibit the XOD enzymatic reaction, resulting in weakened phosphorescence quenching. Therefore, the proposed assay could also be explored for the facile screening analysis of XOD inhibitors, which is important for the potential medicinal therapy of hyperuricemia and gout.

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

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.

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

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

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.

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.

Ceruloplasmin and Hypoferremia: Studies in Burn and Non-Burn Trauma Patients

DTIC Science & Technology

2015-03-06

Minneapolis, MN, USA). Serum uric acid concentrations were determined by standard clinical chemistry assay. Glutathione peroxidase activity was...Although serum total antioxidant potential was lower than control values throughout, glutathione peroxidase activity and uric acid levels were within...2 reducing potential and uric acid concentrations in 10 thermally injured subjects. Data expressed as mean ± SE. Dotted lines denote the upper and

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.

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 and/or cardiac valve surgery even after the adjustment for age, gender, arterial hypertension, diabetes, glomerular filtration rate and medical therapy.

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.

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 rights reserved.

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.

Clinical Investigation Program Report.

DTIC Science & Technology

1981-10-01

Resident Surgical Instructional Experience. (T) 41 1979 Routine Use of Serum Uric Acid Levels at 36 Weeks Gestation as Screening Test for Preeclampsia as...Title: Routine Use of Serum Uric Acid Levels at 36 Weeks Gestation as Screening Test for Preeclampsia as an Aid to Further Management. Start Date: Jan 80...Knight, MC Key Words: Serum Uric Acid Preeclampsia Ac,-uulative MEDCASE -rEst Accumulative Periodic Jan 81 Cost: OMA Cost: I Revie , Results Continue

Annual Research Progress Report, Fiscal Year 1980,

DTIC Science & Technology

1980-10-01

Uric Acid Levels at 36 Weeks Gestation as 45 Screening Test for Preeclampsia as an Aid to Further Manage- ment. (0) DEPARTMENT OF PSYCHIATRY...Investigators: CPT Ellis M. Knight, MC Key Words: Serum Uric Acid Preeclampsia Accumulative MEDCASE Est Accumulative Periodic Ap-roved for continuation...Cost: 0 OMA Cost: 0 Review Results Study Objective: To demonstrate that: A. Serum uric acid level is a simple specific screening test for preeclampsia

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

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

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.

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.

A Novel Multi-Epitope Vaccine Based on Urate Transporter 1 Alleviates Streptozotocin-Induced Diabetes by Producing Anti-URAT1 Antibody and an Immunomodulatory Effect in C57BL/6J Mice.

PubMed

Ma, Yanjie; Cao, Huimin; Li, Zhixin; Fang, Jinzhi; Wei, Xiaomin; Cheng, Peng; Jiao, Rui; Liu, Xiaoran; Li, Ya; Xing, Yun; Tang, Jiali; Jin, Liang; Li, Taiming

2017-10-16

Hyperuricemia (HUA) is related to diabetes. Uric acid-induced inflammation and oxidative stress are risk factors for diabetes and its complications. Human urate transporter 1 (URAT1) regulates the renal tubular reabsorption of uric acid. IA-2(5)-P2-1, a potent immunogenic carrier designed by our laboratory, can induce high-titer specific antibodies when it carries a B cell epitope, such as B cell epitopes of DPP4 (Dipeptidyl peptidase-4), xanthine oxidase. In this report, we describe a novel multi-epitope vaccine composing a peptide of URAT1, an anti-diabetic B epitope of insulinoma antigen-2(IA-2) and a Th2 epitope (P2:IPALDSLTPANED) of P277 peptide in human heat shock protein 60 (HSP60). Immunization with the multi-epitope vaccine in streptozotocin-induced diabetes C57BL/6J mice successfully induced specific anti-URAT1 antibody, which inhibited URAT1 action and uric acid reabsorption, and increased pancreatic insulin level with a lower insulitis incidence. Vaccination with U-IA-2(5)-P2-1 (UIP-1) significantly reduced blood glucose and uric acid level, increased Th2 cytokines interleukin (IL)-10 and IL-4, and regulated immune reactions through a balanced Th1/Th2 ratio. These results demonstrate that the URAT1-based multi-epitope peptide vaccine may be a suitable therapeutic approach for diabetes and its complications.

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.

Temporal Relationship Between Hyperuricemia and Insulin Resistance and Its Impact on Future Risk of Hypertension.

PubMed

Han, Tianshu; Lan, Li; Qu, Rongge; Xu, Qian; Jiang, Ruyue; Na, Lixin; Sun, Changhao

2017-10-01

Although hyperuricemia and insulin resistance significantly correlated, their temporal sequence and how the sequence influence on future risk of hypertension are largely unknown. This study assessed temporal relationship between uric acid and insulin resistance and its impact on future risk of hypertension by examining a longitudinal cohort including 8543 subjects aged 20 to 74 years from China, with an average follow-up of 5.3 years. Measurements of fasting uric acid, as well as fasting and 2-hour serum glucose and insulin, were obtained at baseline and follow-up. Indicators of hepatic and peripheral insulin resistance were calculated. Cross-lagged panel and mediation analysis were used to examine the temporal relationship between uric acid and insulin resistance and its impact on follow-up hypertension. After adjusting for covariates, the cross-lagged path coefficients ( β 1 values) from baseline uric acid to follow-up insulin resistance indices were significantly greater than path coefficients ( β 2 values) from baseline insulin resistance indices to follow-up uric acid ( β 1 =0.110 versus β 2 =0.017; P <0.001, for hepatic insulin resistance; β 1 =-0.208 versus β 2 =-0.021; P <0.001, for peripheral insulin resistance). The path coefficients from baseline uric acid to follow-up insulin resistance indices in the hypertensive group were significantly greater than that in the normotensive group ( P <0.001 for the difference of β 1 values in the 2 groups). Insulin resistance partially mediated the effect of uric acid on subsequent hypertension, and the mediation effect of peripheral insulin resistance was significantly greater than that of hepatic insulin resistance (31.3% versus 13.2%; P <0.001, for the difference of mediation effects). These findings provide evidence that higher uric acid levels probably precede insulin resistance, and peripheral insulin resistance likely plays a more important role in the development of hypertension than hepatic insulin resistance does. © 2017 American Heart Association, Inc.

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.

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 randomized, placebo-controlled trial found that uric acid lowering had no effect on kidney-specific or systemic RAS activity after 8 weeks or on mean systolic BP. These data do not support the hypothesis that higher levels of uric acid are a reversible risk factor for increased BP. PMID:28320765

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-specific or systemic RAS activity after 8 weeks or on mean systolic BP. These data do not support the hypothesis that higher levels of uric acid are a reversible risk factor for increased BP. Copyright © 2017 by the American Society of Nephrology.

Essential trace elements and antioxidant status in relation to severity of HIV in Nigerian patients.

PubMed

Olaniyi, J A; Arinola, O G

2007-01-01

This study was designed to determine the plasma levels of some antioxidants and trace elements in three severity groups of HIV patients compared with non-HIV-infected controls. The plasma levels of antioxidants (total antioxidant, albumin, bilirubin and uric acid) and trace elements (Mg, Fe, Zn, Mn, Cu, Cr, Cd and Se) were estimated spectrophotometrically in controls and patients with CD4 counts of <200; 200-499 and > or =500 cells/microl. Uric acid and Zn were significantly higher, while vitamin E and all the trace elements (except Zn) were significantly lower in HIV-infected patients compared to healthy controls. The highest level of uric acid was observed in those with CD4 counts of <200 cells/microl. All the trace elements (except Zn) were higher in HIV subjects with a CD4 count of 200-499 cells/microl compared to >500 cells/microl. Only uric acid and Zn showed significant correlation with CD4 count. Based on the results of this study, we recommend routine assessment and appropriate supplementation of antioxidants/trace elements in HIV subjects. This supplementation is hoped to strengthen the immune system and reduce the adverse consequences of HIV- related oxidative stress. Copyright 2007 S. Karger AG, Basel.

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.

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.

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 despite taking allopurinol at study entry, there was no heterogeneity of the treatment effect of fenofibrate on gout risk. Taking account of all gout events, fenofibrate treatment halved the risk (HR 0·48, 95% CI 0·37-0·60; p<0·0001) compared with placebo. Fenofibrate lowered uric acid concentrations by 20%, and almost halved first on-study gout events over 5 years of treatment. Fenofibrate could be a useful adjunct for preventing gout in diabetes. None. Copyright © 2018 Elsevier Ltd. All rights reserved.

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.

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.

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.

Factors influencing insulin resistance in relation to atherogenicity in mood disorders, the metabolic syndrome and tobacco use disorder.

PubMed

Bortolasci, Chiara Cristina; Vargas, Heber Odebrecht; Vargas Nunes, Sandra Odebrecht; de Melo, Luiz Gustavo Piccoli; de Castro, Márcia Regina Pizzo; Moreira, Estefania Gastaldello; Dodd, Seetal; Barbosa, Décio Sabbatini; Berk, Michael; Maes, Michael

2015-07-01

This study examines the effects of malondialdehyde (MDA) and uric acid on insulin resistance and atherogenicity in subjects with and without mood disorders, the metabolic syndrome (MetS) and tobacco use disorder (TUD). We included 314 subjects with depression and bipolar depression, with and without the MetS and TUD and computed insulin resistance using the updated homeostasis model assessment (HOMA2IR) and atherogenicity using the atherogenic index of plasma (AIP), that is log10 (triglycerides/high density lipoprotein (HDL) cholesterol. HOMA2IR is correlated with body mass index (BMI) and uric acid levels, but not with mood disorders and TUD, while the AIP is positively associated with BMI, mood disorders, TUD, uric acid, MDA and male sex. Uric acid is positively associated with insulin and triglycerides and negatively with HDL cholesterol. MDA is positively associated with triglyceride levels. Comorbid mood disorders and TUD further increase AIP but not insulin resistance. Glucose is positively associated with increasing age, male gender and BMI. The results show that mood disorders, TUD and BMI together with elevated levels of uric acid and MDA independently contribute to increased atherogenic potential, while BMI and uric acid are risk factors for insulin resistance. The findings show that mood disorders and TUD are closely related to an increased atherogenic potential but not to insulin resistance or the MetS. Increased uric acid is a highly significant risk factor for insulin resistance and increased atherogenic potential. MDA, a marker of lipid peroxidation, further contributes to different aspects of the atherogenic potential. Mood disorders and TUD increase triglyceride levels, lower HDL cholesterol and are strongly associated with the atherogenic, but not insulin resistance, component of the MetS. Copyright © 2015 Elsevier B.V. All rights reserved.

[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.

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.

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.

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.

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.

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.

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.

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.

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

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.

Pharmacokinetics and Metabolism of Allopurinol Riboside,

DTIC Science & Technology

1991-05-01

total bilirubin, alkaline phosphatase. uric acid , arnd was 28 years; the age range was from 18 to 48 years. chemical and microscopic urinalyses... uric acid , hy- tions, the mean retention times relative to N-acetlp- pIoxanthine, xanthine, allopurinol, oxypurinol, and al- aminophenol 128.5 + 1.5...there was a decrease in serum uric acid levels to less to 10%), and nilopurinol (0% to 2%), Oxvpudwl~i aixt than 4.2 mig/dl (normal level 4,2 to 8,8

Investigation of Crimean-Congo Hemorrhagic Fever and Hemorrhagic Fever with Renal Syndrome in Greece

DTIC Science & Technology

1993-12-20

collect a 24-h urine sample, wich was sent to the laboratory for total protein excretion, electrolytes, uric acid , 3 and creatinine measurements. On...electrolytes, uric acid , total protein, and globulins was also obtained. Urinary comcentrating ability was studied using the protocol of Gyory et al., in...Electrolytes in sera and urine were determined by flame photometry, and creatinine by the method of Hare. Urice acid was determined by a uricase method

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.

Oral Fructose Absorption in Obese Children with Non-Alcoholic Fatty Liver Disease

PubMed Central

Sullivan, Jillian S; Le, MyPhuong T; Pan, Zhaoxing; Rivard, Christopher; Love-Osborne, Kathryn; Robbins, Kristen; Johnson, Richard J; Sokol, Ronald J; Sundaram, Shikha S

2014-01-01

Background Fructose intake is associated with NAFLD (Non-Alcoholic Fatty Liver Disease) development. Objective To measure fructose absorption/metabolism in pediatric NAFLD compared to obese and lean controls. Methods Children with histologically proven NAFLD, and obese and lean controls received oral fructose (1 gm/kg ideal body weight). Serum glucose, insulin, uric acid, and fructose, urine uric acid, urine fructose, and breath hydrogen levels were measured at baseline and multiple points until 360 minutes after fructose ingestion. Results Nine NAFLD (89% Hispanic, mean age 14.3 years, mean BMI 35.3 kg/m2), 6 Obese Controls (67% Hispanic, mean age 12.7 years, mean BMI 31.0 kg/m2), and 9 Lean Controls (44% Hispanic, mean age 14.3 years, mean BMI 19.4 kg/m2) were enrolled. Following fructose ingestion, NAFLD vs. Lean Controls had elevated serum glucose, insulin, and uric acid (p<0.05), higher urine uric acid (p=0.001) but lower fructose excretion (p=0.002) and lower breath hydrogen 180-min AUC (p=0.04). NAFLD vs. Obese Controls had similar post-fructose serum glucose, insulin, urine uric acid, and breath hydrogen, but elevated serum uric acid (p<0.05) and lower urine fructose excretion (p=0.02). Conclusions Children with NAFLD absorb and metabolize fructose more effectively than lean subjects, associated with an exacerbated metabolic profile following fructose ingestion. PMID:24961681

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

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

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

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.

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.

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.

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.

Febuxostat

MedlinePlus

... Gout is a type of arthritis in which uric acid, a naturally occurring substance in the body, builds ... inhibitors. It works by decreasing the amount of uric acid that is made in the body. Febuxostat is ...

Rasburicase Injection

MedlinePlus

... injection is used to treat high levels of uric acid (a natural substance that builds up in the ... medications called enzymes. It works by breaking down uric acid so that the body can eliminate it.

Lesinurad

MedlinePlus

... oxidase inhibitor to treat hyperuricemia (high levels of uric acid) in people with gout (sudden attacks of redness, ... is in a class of medications called selective uric acid reabsorption inhibitors. It works by helping the kidneys ...

Pegloticase Injection

MedlinePlus

... by abnormally high levels of a substance called uric acid in the blood) in adults who cannot take ... is in a class of medications called PEGylated uric acid specific enzymes. It works by decreasing the amount ...

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.

[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.

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 genes with a putative role in renal urate handling showed a substantial risk for gout.

The feasibility of using microwave-induced thermoacoustic tomography for detection and evaluation of renal calculi.

PubMed

Cao, Caijun; Nie, Liming; Lou, Cunguang; Xing, Da

2010-09-07

Imaging of renal calculi is important for patients who suffered a urinary calculus prior to treatment. The available imaging techniques include plain x-ray, ultrasound scan, intravenous urogram, computed tomography, etc. However, the visualization of a uric acid calculus (radiolucent calculi) is difficult and often impossible by the above imaging methods. In this paper, a new detection method based on microwave-induced thermoacoustic tomography was developed to detect the renal calculi. Thermoacoustic images of calcium oxalate and uric acid calculus were compared with their x-ray images. The microwave absorption differences among the calcium oxalate calculus, uric acid calculus and normal kidney tissue could be evaluated by the amplitude of the thermoacoustic signals. The calculi hidden in the swine kidney were clearly imaged with excellent contrast and resolution in the three orthogonal thermoacoustic images. The results indicate that thermoacoustic imaging may be developed as a complementary method for detecting renal calculi, and its low cost and effective feature shows high potential for clinical applications.

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.

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

New β-Cyclodextrin Entrapped in Polyethyleneimine Film-Modified Electrodes for Pharmaceutical Compounds Determination

PubMed Central

Fritea, Luminţa; Tertiş, Mihaela; Cristea, Cecilia; Săndulescu, Robert

2013-01-01

The electrochemical behavior of ascorbic acid and uric acid on glassy carbon bare electrodes and ones modified with β-cyclodextrin entrapped in polyethyleneimine film has been investigated using square wave voltammetry. The electrode modification was achieved in order to separate the voltammetric peaks of ascorbic acid and uric acid when present in the same solution. On the modified electrodes the potential of the oxidation peak of the ascorbic acid was shifted to more negative values by over 0.3 V, while in the case of uric acid, the negative potential shift was about 0.15 V compared to the bare glassy carbon electrode. When the two compounds were found together in the solution, on the bare electrode only a single broad signal was observed, while on the modified electrode the peak potentials of these two compounds were separated by 0.4 V. When the uric acid concentration remained constant, the peak intensity of the ascorbic acid is increased linearly with the concentration (r2 = 0.996) and when the ascorbic acid concentration remains constant, the peak intensity of the uric acid increased linearly with the concentration (r2 = 0.992). FTIR measurements supported the formation of inclusion complexes. In order to characterize the modification of the electrodes microscopic studies were performed. The modified electrodes were successfully employed for the determination of ascorbic acid in pharmaceutical formulations with a detection limit of 0.22 μM. PMID:24287544

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.

[Identification and quantitation of purine derivatives in urinary calculi as markers of abnormal purine metabolism by using high-performance liquid chromatography (HPLC)].

PubMed

Safranow, K

2000-01-01

The objective of this study was to develop a practical method for the analysis of purine derivatives in urinary calculi using high-performance liquid chromatography (HPLC). The method presented herein includes extraction of purine derivatives from urinary stones, followed by chromatography on a reversed-phase column with UV detection. A simpler isocratic method was applied to quantitate 6 purines known to be components of urinary stones, namely uric acid, xanthine, hypoxanthine, 2,8-dihydroxyadenine, oxypurinol and allopurinol. Gradient method separated 10 additional peaks representing methyl derivatives of uric acid or xanthine (1-, 3-, 7-, and 9-methyluric acid, 1,3-,1,7-, and 3,7-dimethyluric acid, and 1-, 3-, and 7-methylxanthine) (Fig. 1). Detection limits for individual compounds ranged from 25 to 140 micrograms purine per g stone weight and precision (RSD%) was 0.5-2.4%. Both methods were next used to analyze purine derivatives in urinary calculi from 48 residents of Western Pomerania. Uric acid was the main component of 9 stones. All of the uric acid stones showed admixtures of 9 other purine derivatives: natural metabolites (hypoxanthine, xanthine, 2,8-dihydroxyadenine) and methyl derivatives of uric acid (1-,3-, and 7-methyluric acid, 1,3-dimethyluric acid, 3-, and 7-methylxanthine) originating from the metabolism of exogenous methylxanthines (caffeine, theophylline and theobromine) (Tab. 1,2). Methyl derivatives of uric acid and xanthine, with a maximal content in stones of 1.7%, have hitherto not been considered constituents of urinary calculi. Statistical analysis of the results revealed strong positive correlations between the level of uric acid and of other purine derivatives in stones (Fig. 2). Correlations were also found between levels of some purines and inorganic compounds (Tab. 3). The sensitivity and specificity of HPLC with UV detection satisfy the requirements of a reference method for the analysis of purines in urinary stones. Isocratic separation is simpler in terms of technique and equipment, and therefore more suitable for hospital laboratories. Examination of purine derivatives in stones may be very helpful for the diagnosis of abnormal purine metabolism and urolithiasis, particularly in dihydroxyadeninuria, xanthinuria and during treatment with allopurinol. Gradient separation requiring more sophisticated instrument seems useful for research purposes when the content of methyl derivatives of purines must be known. The present results indicate that urinary purines at concentrations lower than saturation point may nevertheless coprecipitate with oversaturated uric acid and appear as admixtures in urinary stones. The content of a purine derivative in stone depends on its average urinary excretion in the general population, similarity to the chemical structure of uric acid, and content of the latter in stone. These findings suggest that purines in stones represent a solid solution with uric acid as solvent. It is also plausible that methylxanthines, ubiquitous components of the diet and drugs, are involved in the pathogenesis of urolithiasis. Interpretation of results and practical significance of the determination of purine derivatives in stones is discussed, and future studies to assess the clinical importance of endo- and exogenous purine derivatives in urinary calculi are suggested.

Lesch-Nyhan syndrome

MedlinePlus

... recycle purines. Without it, abnormally high levels of uric acid build up in the body. ... Too much uric acid can cause gout-like swelling in some of the joints. In some cases, kidney and bladder stones develop. ...

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.

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.

Recent insights into the pathogenesis of hyperuricaemia and gout.

PubMed

Riches, Philip L; Wright, Alan F; Ralston, Stuart H

2009-10-15

Gout is a common rheumatic disease in humans which is characterized by elevation in serum uric acid levels, and deposition of uric acid crystals in the joint. Hyperuricaemia is the primary risk factor for the development of gout and primates have uniquely high levels of serum uric acid due to missense mutations in the uricase gene. Levels of serum uric acid are known to be highly heritable, and mutations in genes which encode enzymes in the purine salvage pathway have long been recognized as rare causes of gout. Until recently, however, little has been known about the genetic determinants of urate metabolism and susceptibility to gout in the general population. Over recent months, a series of large scale genome wide association studies have been performed which have shed new light on the genes which regulate serum uric acid levels and susceptibility to gout. Most of these genes seem to be involved in regulating the renal excretion of uric acid which underscores the importance of reduced urate excretion as opposed to increased endogenous production as a cause of gout. Further work will now be required to investigate the mechanisms by which these genetic variants regulate urate excretion and serum urate levels. However, it seems likely that the genes so far identified will represent new molecular targets for the design of drugs to enhance urate excretion and the genetic variants that predispose to gout might be of value as genetic markers of susceptibility to gout.

A comparative study of efficacy and safety of febuxostat and allopurinol in pyrazinamide-induced hyperuricemic tubercular patients.

PubMed

Pichholiya, Meenu; Yadav, Arvind Kumar; Luhadia, S K; Tahashildar, Jameela; Aseri, M L

2016-01-01

To compare the efficacy and safety of febuxostat and allopurinol in pyrazinamide (PZA)-induced hyperuricemia in patients taking antitubercular therapy (ATT). This randomized controlled study was conducted at a tertiary care teaching institute of Rajasthan in all the sputum-positive tubercular patients aged between 18 and 65 years of either sex. Serum uric acid level was monitored at 0 th , 2 nd , 4 th , 6 th , and 8 th week of ATT. Patients whose uric acid level was found to be increased at 2 nd week were finally recruited in the study. Ninety patients who developed hyperuricemia due to ATT were divided randomly into three groups (Group A - febuxostat, Group B - allopurinol, and Group C - control) of thirty patients each. Mean serum uric acid levels were calculated at all the weeks in all the groups, and serum uric acid levels were compared by applying student's t -test and ANOVA. Mean serum uric acid level decreased from 10.698 mg/dl (at 2 nd week) to 7.846 mg/dl (at 8 th week) in Group A and from 11.34 mg/dl (at 2 nd week) to 7.280 mg/dl (at 8 th week) in Group B. Numbers of adverse events encountered across both the treatment groups were same with both the drugs. Allopurinol and febuxostat were equally efficacious in lowering PZA induced raised serum uric acid level in tubercular patients, and it was possible to continue ATT without withdrawing PZA.

[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.

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.

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%) and 67 (13%), respectively, were serious adverse events (p=0·703). The addition of uric acid to thrombolytic therapy did not increase the proportion of patients who achieved excellent outcome after stroke compared with placebo, but it did not lead to any safety concerns. Institute of Health Carlos III of the Spanish Ministry of Health and Fundación Doctor Melchor Colet. Copyright © 2014 Elsevier Ltd. All rights reserved.

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 and there is an association between serum uric acid level and blood pressure. Further studies on the pathophysiologic significance of hyperuricaemia in these patients are recommended.

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-β1 and α-SMA protein expression. UA induced glomerulosclerosis, tubular injury and renal fibrosis with reduction of podocyte function and inflammatory mediator elevation. ET-1 and fibroblast expansion might modulate hyperuricemia induced renal fibrosis.

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.

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.

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.

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).

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

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.

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

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.

Effects of Febuxostat on Oxidative Stress.

PubMed

Fukui, Toshiki; Maruyama, Mie; Yamauchi, Kazuhiro; Yoshitaka, Sumie; Yasuda, Tadashi; Abe, Youichi

2015-07-01

We previously examined factors that affect the measured derivatives of reactive oxygen metabolites (d-ROMs), an indicator of reactive oxygen species production, and biological antioxidant potential (BAP), an indicator of antioxidant capacity, in typical health checkup examinees and reported the usefulness of measuring both indicators simultaneously. In addition, a positive correlation reportedly exists between d-ROMs and the visceral fat area measured by using computed tomography. A recent study of the relationship between uric acid levels and various obesity-related factors found that visceral fat was the factor most strongly related to uric acid levels. Uric acid is itself a potent endogenous antioxidant, but because reactive oxygen species are produced during uric acid generation, it is suggested that uric acid may have opposing effects. The objective of this study was to analyze the effect of febuxostat, a novel xanthine oxidase inhibitor, on oxidative stress. Study subjects were 43 hyperuricemia outpatients receiving care in the internal medicine department of our institution. The subjects were divided into a new administration group (29 patients) and a switched administration group (14 patients); the latter were allopurinol-treated patients with hyperuricemia who were switched to febuxostat. In addition to measuring the patients' uric acid and creatinine levels and estimated glomerular filtration rate before and after treatment, their d-ROMs and BAP as well as the BAP/d-ROMs ratio were also measured. Both groups exhibited significant decreases in uric acid levels, as well as significant decreases in d-ROMs and BAP. No significant changes were observed in the BAP/dROMs ratio or renal function, including creatinine levels and estimated glomerular filtration rate. Febuxostat could significantly reduce d-ROMs. However, BAP levels were also significantly reduced concurrently. No changes were observed in the BAP/d-ROMs ratios. This regulatory mechanism is believed to have counteracted changes in the in vivo oxidative stress balance caused by febuxostat administration. Copyright © 2015 Elsevier HS Journals, Inc. All rights reserved.

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.

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

Carotid intima-media thickness, dietary intake, and cardiovascular phenotypes in adolescents: relation to metabolic syndrome.

PubMed

Croymans, Daniel M; Sanchez, Albert; Barth, Jacques D; Roberts, Christian K

2010-04-01

Little is known about the interrelationships between metabolic syndrome (MS), uric acid, and early carotid atherosclerosis with diet in adolescents. We investigated associations among diet, carotid intima-media thickness (cIMT), MS, uric acid, and other cardiovascular risk factors in adolescents. Two hundred forty-nine adolescents from 3 high schools in Central California-a predominately Hispanic (n = 119, 16.1 +/- 0.9 years old, 94% Hispanic), a mixed-ethnicity (n = 94, 15.7 +/- 1.2 years old), and a Seventh-day Adventist (SDA) (n = 33, 17.0 +/- 1.3 years old) high school-were assessed for cIMT, blood lipids, uric acid, blood glucose, systolic and diastolic blood pressure, body mass index (BMI), and dietary intake. Compared with SDA adolescents, the predominately Hispanic and mixed-ethnicity high school adolescents exhibited higher low-density lipoprotein and BMI percentile, whereas adolescents from the SDA and mixed-ethnicity high schools exhibited lower uric acid and fasting glucose levels than those from the Hispanic high school. After adjusting for age and sex, cIMT was only correlated with systolic blood pressure percentile (r = 0.16, P < .01). Controlling for age, levels of uric acid were correlated with BMI percentile (males: r = 0.59, P < .001; females: r = 0.24, P < .01), low-density lipoprotein (males: r = 0.40, P < .001; females: r = 0.20, P < .01), and total cholesterol in males (r = 0.38, P < .001). Despite no significant differences in the high school frequency of MS risk factors, 59% of adolescents had one or more MS risk factors. A relationship was noted between the number of MS risk factors and uric acid (P < .002). Most of the adolescents presented MS risk factors independent of ethnicity or a purportedly healthier lifestyle (SDA). Uric acid association with MS and its risk factors suggests its potentially heightened importance for the assessment of adolescent cardiovascular health. Published by Elsevier Inc.

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.

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.

Chemical composition and binary mixture of human urinary stones using FT-Raman spectroscopy method.

PubMed

Selvaraju, R; Raja, A; Thiruppathi, G

2013-10-01

In the present study the human urinary stones were observed in their different chemical compositions of calcium oxalate monohydrate, calcium oxalate dihydrate, calcium phosphate, struvite (magnesium ammonium phosphate), uric acid, cystine, oxammite (ammonium oxalate monohydrate), natroxalate (sodium oxalate), glushinkite (magnesium oxalate dihydrate) and moolooite (copper oxalate) were analyzed using Fourier Transform-Raman (FT-Raman) spectroscopy. For the quantitative analysis, various human urinary stone samples are used for ratios calculation of binary mixtures compositions such as COM/COD, HAP/COD, HAP/COD, Uric acid/COM, uric acid/COD and uric acid/HAP. The calibration curve is used for further analysis of binary mixture of human urinary stones. For the binary mixture calculation the various intensities bands at 1462 cm(-1) (I(COM)), 1473 cm(-1) (I(COD)), 961 cm(-1) (I(HAP)) and 1282 cm(-1) (I(UA)) were used. Copyright © 2013 Elsevier B.V. All rights reserved.

Common Variants in LRP2 and COMT Genes Affect the Susceptibility of Gout in a Chinese Population

PubMed Central

Zhou, Jingru; Qian, Qiaoxia; Ma, Yanyun; He, Hongjun; Ji, Hengdong; Yang, Yajun; Wang, Xiaofeng; Xu, Xia; Pang, Yafei; Zou, Hejian; Jin, Li; Wang, Jiucun

2015-01-01

Gout is a common inflammation disease resulting from an increase in serum uric acid. Nearly 70% of uric acid is excreted via the kidneys. To date, evidence for an association between genetic loci and gout is absent, equivocal or not replicated. Our study aims to test variants in two genes abundantly expressed in the kidney, LRP2 and COMT, for their association with uric acid and gout. In total, 1318 Chinese individuals were genotyped for rs2544390 in LRP2 and rs4680 in COMT. These LRP2 and COMT gene polymorphisms showed no significant effect on uric acid (P = 0.204 and 0.188, separately); however, rs2544390 in LRP2 did influence uric acid levels in individuals with BMI ≥ 25 (P = 0.009). In addition, the allele frequency distributions of the two loci showed a significant difference between gout patients and healthy controls. A missense variation in rs4680 (G > A) decreased the risk of gout (OR = 0.77, P = 0.015), whereas the T allele of rs2544390 was associated with gout pathogenesis risk (OR = 1.26, P = 0.020). The present study provides the first evidence for an association between COMT and gout. Rs2544390 in LRP2 only influenced uric acid levels in individuals with BMI ≥ 25, which might explain the discrepant results among previous studies. In addition, we are the first to identify the association between LRP2 and gout in a Chinese population and to confirm this association in Asians. PMID:26147675

Common Variants in LRP2 and COMT Genes Affect the Susceptibility of Gout in a Chinese Population.

PubMed

Dong, Zheng; Zhao, Dongbao; Yang, Chengde; Zhou, Jingru; Qian, Qiaoxia; Ma, Yanyun; He, Hongjun; Ji, Hengdong; Yang, Yajun; Wang, Xiaofeng; Xu, Xia; Pang, Yafei; Zou, Hejian; Jin, Li; Wang, Jiucun

2015-01-01

Gout is a common inflammation disease resulting from an increase in serum uric acid. Nearly 70% of uric acid is excreted via the kidneys. To date, evidence for an association between genetic loci and gout is absent, equivocal or not replicated. Our study aims to test variants in two genes abundantly expressed in the kidney, LRP2 and COMT, for their association with uric acid and gout. In total, 1318 Chinese individuals were genotyped for rs2544390 in LRP2 and rs4680 in COMT. These LRP2 and COMT gene polymorphisms showed no significant effect on uric acid (P = 0.204 and 0.188, separately); however, rs2544390 in LRP2 did influence uric acid levels in individuals with BMI ≥ 25 (P = 0.009). In addition, the allele frequency distributions of the two loci showed a significant difference between gout patients and healthy controls. A missense variation in rs4680 (G > A) decreased the risk of gout (OR = 0.77, P = 0.015), whereas the T allele of rs2544390 was associated with gout pathogenesis risk (OR = 1.26, P = 0.020). The present study provides the first evidence for an association between COMT and gout. Rs2544390 in LRP2 only influenced uric acid levels in individuals with BMI ≥ 25, which might explain the discrepant results among previous studies. In addition, we are the first to identify the association between LRP2 and gout in a Chinese population and to confirm this association in Asians.

A comparative study of efficacy and safety of febuxostat and allopurinol in pyrazinamide-induced hyperuricemic tubercular patients

PubMed Central

Pichholiya, Meenu; Yadav, Arvind Kumar; Luhadia, S. K.; Tahashildar, Jameela; Aseri, M. L.

2016-01-01

Objectives: To compare the efficacy and safety of febuxostat and allopurinol in pyrazinamide (PZA)-induced hyperuricemia in patients taking antitubercular therapy (ATT). Methods: This randomized controlled study was conducted at a tertiary care teaching institute of Rajasthan in all the sputum-positive tubercular patients aged between 18 and 65 years of either sex. Serum uric acid level was monitored at 0th, 2nd, 4th, 6th, and 8th week of ATT. Patients whose uric acid level was found to be increased at 2nd week were finally recruited in the study. Ninety patients who developed hyperuricemia due to ATT were divided randomly into three groups (Group A - febuxostat, Group B - allopurinol, and Group C - control) of thirty patients each. Mean serum uric acid levels were calculated at all the weeks in all the groups, and serum uric acid levels were compared by applying student's t-test and ANOVA. Results: Mean serum uric acid level decreased from 10.698 mg/dl (at 2nd week) to 7.846 mg/dl (at 8th week) in Group A and from 11.34 mg/dl (at 2nd week) to 7.280 mg/dl (at 8th week) in Group B. Numbers of adverse events encountered across both the treatment groups were same with both the drugs. Conclusion: Allopurinol and febuxostat were equally efficacious in lowering PZA induced raised serum uric acid level in tubercular patients, and it was possible to continue ATT without withdrawing PZA. PMID:27721537

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.

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.

Delineation of the Caffeine C-8 Oxidation Pathway in Pseudomonas sp. Strain CBB1 via Characterization of a New Trimethyluric Acid Monooxygenase and Genes Involved in Trimethyluric Acid Metabolism

PubMed Central

Mohanty, Sujit Kumar; Yu, Chi-Li; Das, Shuvendu; Louie, Tai Man; Gakhar, Lokesh

2012-01-01

The molecular basis of the ability of bacteria to live on caffeine via the C-8 oxidation pathway is unknown. The first step of this pathway, caffeine to trimethyluric acid (TMU), has been attributed to poorly characterized caffeine oxidases and a novel quinone-dependent caffeine dehydrogenase. Here, we report the detailed characterization of the second enzyme, a novel NADH-dependent trimethyluric acid monooxygenase (TmuM), a flavoprotein that catalyzes the conversion of TMU to 1,3,7-trimethyl-5-hydroxyisourate (TM-HIU). This product spontaneously decomposes to racemic 3,6,8-trimethylallantoin (TMA). TmuM prefers trimethyluric acids and, to a lesser extent, dimethyluric acids as substrates, but it exhibits no activity on uric acid. Homology models of TmuM against uric acid oxidase HpxO (which catalyzes uric acid to 5-hydroxyisourate) reveal a much bigger and hydrophobic cavity to accommodate the larger substrates. Genes involved in the caffeine C-8 oxidation pathway are located in a 25.2-kb genomic DNA fragment of CBB1, including cdhABC (coding for caffeine dehydrogenase) and tmuM (coding for TmuM). Comparison of this gene cluster to the uric acid-metabolizing gene cluster and pathway of Klebsiella pneumoniae revealed two major open reading frames coding for the conversion of TM-HIU to S-(+)-trimethylallantoin [S-(+)-TMA]. The first one, designated tmuH, codes for a putative TM-HIU hydrolase, which catalyzes the conversion of TM-HIU to 3,6,8-trimethyl-2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (TM-OHCU). The second one, designated tmuD, codes for a putative TM-OHCU decarboxylase which catalyzes the conversion of TM-OHCU to S-(+)-TMA. Based on a combination of enzymology and gene-analysis, a new degradative pathway for caffeine has been proposed via TMU, TM-HIU, TM-OHCU to S-(+)-TMA. PMID:22609920

Xanthine Oxidase Induces Foam Cell Formation through LOX-1 and NLRP3 Activation.

PubMed

Dai, Yao; Cao, Yongxiang; Zhang, Zhigao; Vallurupalli, Srikanth; Mehta, Jawahar L

2017-02-01

Xanthine oxidase catalyzes the oxidation of xanthine to uric acid. This process generates excessive reactive oxygen species (ROS) that play an important role in atherogenesis. Recent studies show that LRR and PYD domains-containing protein 3 (NLRP3), a component of the inflammasome, may be involved in the formation of foam cells, a hallmark of atherosclerosis. This study was designed to study the role of various scavenger receptors and NLRP3 inflammasome in xanthine oxidase and uric acid-induced foam cell formation. Human vascular smooth muscle cells (VSMCs) and THP-1 macrophages were treated with xanthine oxidase or uric acid. Xanthine oxidase treatment (of both VSMCs and THP-1 cells) resulted in foam cell formation in concert with generation of ROS and expression of cluster of differentiation 36 (CD36) and oxidized low density lipoprotein (lectin-like) receptor 1 (LOX-1), but not of scavenger receptor A (SRA). Uric acid treatment resulted in foam cell formation, ROS generation and expression of CD36, but not of LOX-1 or SRA. Further, treatment of cells with xanthine oxidase, but not uric acid, activated NLRP3 and its downstream pro-inflammatory signals- caspase-1, interleukin (IL)-1β and IL-18. Blockade of LOX-1 or NLRP3 inflammasome with specific siRNAs reduced xanthine oxidase-induced foam cell formation, ROS generation and activation of NLRP3 and downstream signals. Xanthine oxidase induces foam cell formation in large part through activation of LOX-1 - NLRP3 pathway in both VSMCs and THP-1 cells, but uric acid-induced foam cell formation is exclusively through CD36 pathway. Further, LOX-1 activation is upstream of NLRP3 activation. Graphical Abstract Steps in the formation of foam cells in response to xanthine oxidase and uric acid. Xanthine oxidase stimulates LOX-1 expression on the cell membrane of macrophages and vascular smooth muscle cells (VSMCs) and increases generation of ROS, which activate NLRP3 inflammasome and downstream pro-inflammatory mediators such as Caspase-1, IL-1β and IL-18. Xanthine oxidase also induces CD36 expression. Activation of both LOX-1 and CD36 (LOX-1> > CD36) participates in the transformation of macrophages and VSMCs into foam cells. Uric acid formed from xanthine-xanthine oxidase interaction stimulates CD36 expression and triggers foam cell formation independent of NLRP3 activation.

Preclinical Evaluation to Specifically Target Ovarian Cancer with Folic Acid conjugated Nanoceria

DTIC Science & Technology

2013-06-01

function (creatinine; urea ; albumin, uric acid ) in plasma collected, showed no significant difference in the untreated and treated mice. All values were...Transaminase), AST (Aspartate Transaminase), Albumin, Creatinine, urea and uric acid . groups (Fig 9). These data show that FA-NCe treatment...Specifically Target Ovarian Cancer with Folic Acid conjugated Nanoceria. PRINCIPAL INVESTIGATOR: Ramandeep Rattan, PhD CONTRACTING ORGANIZATION

Identification, Characterisation and Clinical Development of the New Generation of Breast Cancer Susceptibility Alleles

DTIC Science & Technology

2010-03-01

amino acid substitution in this gene has been associated with uric acid nephrolithiasis (32). Recent GWAS have identified another variant within this...Identification of a novel gene and a common variant associated with uric acid nephrolithiasis in a Sardinian genetic isolate. Am J Hum Genet 72

Hyperuricaemia and preeclampsia: is there a pathogenic link?

PubMed

Schackis, R C

2004-01-01

A hypothesis, based on animal studies and human observational studies, was developed proposing a direct pathogenic link between hyperuricemia and preeclampsia. Epidemiological characteristics of preeclampsia such as its uniqueness to humans and an increased incidence of preeclampsia in multiple pregnancies, increased body mass index, renal and hypertensive disease all have uric acid as their common denominator. Animal studies have linked hyperuricaemia to hypertensive, cardiovascular and renal disease. The aim of the study was to determine whether lowering the serum uric acid levels in preeclampsia would affect biochemical parameters and hypertensive control. A randomized, double-blind, placebo controlled study. A tertiary referral center. Forty women with preeclampsia between 26 and 32 weeks gestation. Probenecid 250 mg twice daily for seven days. Renal function and haematological parameters, hypertensive control. In the Probenecid group, there was a significant drop in the serum uric acid levels. Lower uric acid levels in the Probenecid group had no significant effect on blood pressure. Patients in the Probenecid group had a significantly lower serum creatinine value at the end of the study when compared to patients in the placebo group. Other renal function parameters (creatinine clearance, urea, 24 h urinary protein excretion) did not show any significant difference between the two groups. Platelet count differed between the two groups with the platelet count being significantly higher in the Probenecid group at the end of the study. The significant improvement in the platelet count in the Probenecid group warrants further study.

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.

Contribution of the blood glucose level in perinatal asphyxia.

PubMed

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

2009-07-01

This is a comparative study between 60 asphyxiated newborns (cases) and 60 normal neonates (controls) in respect of their plasma glucose and uric acid levels and also their clinical and neurological status. The mean plasma glucose level was significantly lower (35.1 +/- 11.4 mg/dl vs. 56.9 +/- 5.5 mg/dl; P < 0.001) and the mean serum uric acid level was higher (8.0 +/- 1.2 mg/dl vs. 4.5 +/- 0.83 mg/dl; P < 0.001) in the asphyxiated group when compared to the controls. Within the perinatal asphyxia group, the plasma glucose level and Apgar scores showed a significant positive linear correlation (r = 0.740, P < 0.001), whereas a significant negative linear correlation was observed between the glucose level and different stages of hypoxic ischemic encephalopathy (HIE) (r = -0.875, P < 0.001). Although a strong positive linear correlation was found between uric acid and HIE stages (r = 0.734, P < or = 0.001), the linear correlation between uric acid and Apgar scores (r = -0.885, P < 0.001) and uric acid and the plasma glucose level (r = -0.725, P < 0.001) were found to be significantly negative among the cases. The severity of encephalopathy and cellular damage varies with the severity of hypoglycemia.

Metabolic Interactions of Purine Derivatives with Human ABC Transporter ABCG2: Genetic Testing to Assess Gout Risk.

PubMed

Ishikawa, Toshihisa; Aw, Wanping; Kaneko, Kiyoko

2013-11-04

In mammals, excess purine nucleosides are removed from the body by breakdown in the liver and excretion from the kidneys. Uric acid is the end product of purine metabolism in humans. Two-thirds of uric acid in the human body is normally excreted through the kidney, whereas one-third undergoes uricolysis (decomposition of uric acid) in the gut. Elevated serum uric acid levels result in gout and could be a risk factor for cardiovascular disease and diabetes. Recent studies have shown that human ATP-binding cassette transporter ABCG2 plays a role of renal excretion of uric acid. Two non-synonymous single nucleotide polymorphisms (SNPs), i.e., 421C>A (major) and 376C>T (minor), in the ABCG2 gene result in impaired transport activity, owing to ubiquitination-mediated proteosomal degradation and truncation of ABCG2, respectively. These genetic polymorphisms are associated with hyperuricemia and gout. Allele frequencies of those SNPs are significantly higher in Asian populations than they are in African and Caucasian populations. A rapid and isothermal genotyping method has been developed to detect the SNP 421C>A, where one drop of peripheral blood is sufficient for the detection. Development of simple genotyping methods would serve to improve prevention and early therapeutic intervention for high-risk individuals in personalized healthcare.

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.

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 more similar to those for calcium oxalate stones. The dietary approach in patients forming uric acid stones should be reconsidered with more attention to the quantity and quality of carbohydrate intake.

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.

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.

Use of multiple colorimetric indicators for paper-based microfluidic devices.

PubMed

Dungchai, Wijitar; Chailapakul, Orawon; Henry, Charles S

2010-08-03

We report here the use of multiple indicators for a single analyte for paper-based microfluidic devices (microPAD) in an effort to improve the ability to visually discriminate between analyte concentrations. In existing microPADs, a single dye system is used for the measurement of a single analyte. In our approach, devices are designed to simultaneously quantify analytes using multiple indicators for each analyte improving the accuracy of the assay. The use of multiple indicators for a single analyte allows for different indicator colors to be generated at different analyte concentration ranges as well as increasing the ability to better visually discriminate colors. The principle of our devices is based on the oxidation of indicators by hydrogen peroxide produced by oxidase enzymes specific for each analyte. Each indicator reacts at different peroxide concentrations and therefore analyte concentrations, giving an extended range of operation. To demonstrate the utility of our approach, the mixture of 4-aminoantipyrine and 3,5-dichloro-2-hydroxy-benzenesulfonic acid, o-dianisidine dihydrochloride, potassium iodide, acid black, and acid yellow were chosen as the indicators for simultaneous semi-quantitative measurement of glucose, lactate, and uric acid on a microPAD. Our approach was successfully applied to quantify glucose (0.5-20 mM), lactate (1-25 mM), and uric acid (0.1-7 mM) in clinically relevant ranges. The determination of glucose, lactate, and uric acid in control serum and urine samples was also performed to demonstrate the applicability of this device for biological sample analysis. Finally results for the multi-indicator and single indicator system were compared using untrained readers to demonstrate the improvements in accuracy achieved with the new system. 2010 Elsevier B.V. All rights reserved.

Sulfinpyrazone

MedlinePlus

... arthritis. It works by lowering the amount of uric acid in your blood, preventing gout attacks. The drug ... Sulfinpyrazone helps your body get rid of uric acid through your urine. This process may cause kidney stones. To help prevent kidney stones, be sure to drink 10 to 12 glasses (8 ...

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.

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.

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.

Correlation of metabolic syndrome with urinary stone composition.

PubMed

Cho, Sung Tae; Jung, Seung Il; Myung, Soon Chul; Kim, Tae Hyoung

2013-02-01

To determine the correlation between metabolic syndrome and the distribution of stone components in patients with urolithiasis. Between January 2007 and December 2010, renal or ureteral stones were collected from 712 patients (432 males, 280 females) who underwent surgical intervention at three hospitals in South Korea. Metabolic syndrome was defined according to the latest definition of the International Diabetes Federation, using ethnicity- and sex-specific cut-off values for central obesity. Patients were assessed by factors used in metabolic syndrome. All urinary stones were analyzed using infrared spectrophotometry and categorized according to their main component. The patients' mean age was 55.9 years (range 19-93 years). Of the 712 patients, 347 (48.7%; 205 males, 142 females) had a diagnosis of metabolic syndrome. Calcium oxalate (71.5%), uric acid (15.3%), carbonate apatite (8.0%) and struvite (4.1%) calculi were found as the main stone components. Overall, the proportion of uric acid calculi was markedly higher in patients with rather than without metabolic syndrome (19.6 vs 11.2%; P=0.002). However, the proportion of calcium oxalate, carbonate apatite and struvite calculi did not differ between the two groups. The multivariable-adjusted odds ratio for uric acid calculi according to the metabolic syndrome components indicated that the presence of metabolic syndrome was associated with a 93% increased odds ratio of uric acid calculi compared with the absence of metabolic syndrome. Impaired fasting glucose and hypertriglyceridemia were independent risk factors for uric acid calculi. Metabolic syndrome is associated with a significantly increased risk of uric acid calculi development, especially those with impaired fasting glucose and hypertriglyceridemia. © 2012 The Japanese Urological Association.

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.

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.

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.

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

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.

Animal urine as painting materials in African rock art revealed by cluster ToF-SIMS mass spectrometry imaging.

PubMed

Mazel, Vincent; Richardin, Pascale; Touboul, David; Brunelle, Alain; Richard, Caroline; Laval, Eric; Walter, Philippe; Laprévote, Olivier

2010-08-01

The rock art site at the village of Songo in Mali is a very important Dogon ritual place where, since the end of the nineteenth century until today, takes place the ceremony of circumcision. During these ceremonies, paintings are performed on the walls of the shelter with mainly three colors: red, black and white. Ethnological literature mentions the use of animal urine of different species such as birds, lizards or snakes as a white pigment. Urine of these animals is mainly composed of uric acid or urate salts. In this article, time-of-flight secondary ion mass spectrometry (ToF-SIMS) is used to compare uric acid, snake urine and a sample of a white pigment of a Dogon painting coming from the rock art site of Songo. ToF-SIMS measurements in both positive and negative ion modes on reference compounds and snake urine proved useful for the study of uric acid and urate salts. This method enables to identify unambiguously these compounds owing to the detection in negative ion mode of the ion corresponding to the deprotonated molecule ([M-H](-) at m/z 167.01) and its fragment ions. Moreover, the mass spectra obtained in positive ion mode permit to differentiate uric acid and urate salts on the basis of specific ions. Applying this method to the Dogon white pigments sample, we show that the sample is entirely composed of uric acid. This proves for the first time, that animal urine was used as a pigment by the Dogon. The presence of uric acid instead of urate salts as normally expected in animal urine could be explained by the preparation of the pigment for its application on the stone. Copyright 2010 John Wiley & Sons, Ltd.

Effect of Chemicals on the Cell Membrane Transport of Nucleosides.

DTIC Science & Technology

1983-08-01

hypoxanthine in the external buffer and the efflux mte is decreased by uric acid in tne buffer. Perfluorodecanoic acid ( PFDA ), adenine, or xanthlne...uric acid in the buffer. Perfluorodecanoic acid ( PFDA ), Sadenine, or xanthine in the external buffer have no direct effect on the rate of AP efflux, in...observed that perfluorooctanoic acid ( PFOA ) produces a transient weight N loss, but no mortality in young rats. By contrast, the treatment of rats with

Plasma chemistry in booted eagle (Hieraaetus pennatus) during breeding season.

PubMed

Casado, Eva; Balbontin, Javier; Ferrer, Miguel

2002-02-01

Most studies that have examined raptor plasma chemistry have been conducted on birds living in captivity. In this study, we describe typical plasma chemistry values indicators of body condition in free-living Booted Eagles, Hieraaetus pennatus, from Doñana National Park (Spain). Values are compared with those of other raptors. Mean concentrations of creatinine, uric acid and urea were lower in adults than in nestlings, while glucose, DAT and AAT were lower in nestlings than in adults. Interactions of age/sex affected plasma mean levels of creatine kinase, glucose, AAT, uric acid and urea. Adult females showed significantly lower levels of creatine kinase, uric acid and urea than adult males and nestlings. Adult males had significantly higher levels of AAT than the other groups. The lowest levels of glucose and the highest levels of uric acid were found in nestling females. We think the differences in blood parameters can be explained by differences in size of species, of individuals (because of both body condition and sexual dimorphism) and diet.

Hyperuricemia in the inhabitants of the Marshall Islands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, W.H.; Harper, J.A.; Heotis, P.M.

1984-06-01

Annual medical examinations are conducted by Brookhaven National Laboratory (BNL) for a population of Marshallese who were accidentally exposed to radioactive fallout in 1954, for a comparison population, and for all inhabitants of the atolls of Rongelap and Utirik. Disease surveillance includes analysis of serum samples. Elevated serum uric acid (SUA) levels are common along Pacific populations, and modifying environmental factors have been investigated as a cause for this finding. The authors have studied SUA levels of people living in the Marshall Islands, and have found elevated values similar to those reported for other Micronesian populations. The nearly Gaussian distributionmore » of individual serum uric acid values for men, and for women less than or equal to45 years of age, indicates that the elevation is due to a regularized increase in serum uric acid rather than to a subpopulation that has pathologic hyperuricemia. The higher serum uric acid levels appear, therefore, to be normal for the Marshallese, a conclusion supported by the infrequency of clinical gout in the population tested.« less

Xanthine oxidoreductase and its inhibitors: relevance for gout.

PubMed

Day, Richard O; Kamel, Bishoy; Kannangara, Diluk R W; Williams, Kenneth M; Graham, Garry G

2016-12-01

Xanthine oxidoreductase (XOR) is the rate-limiting enzyme in purine catabolism and converts hypoxanthine to xanthine, and xanthine into uric acid. When concentrations of uric acid exceed its biochemical saturation point, crystals of uric acid, in the form of monosodium urate, emerge and can predispose an individual to gout, the commonest form of inflammatory arthritis in men aged over 40 years. XOR inhibitors are primarily used in the treatment of gout, reducing the formation of uric acid and thereby, preventing the formation of monosodium urate crystals. Allopurinol is established as first-line therapy for gout; a newer alternative, febuxostat, is used in patients unable to tolerate allopurinol. This review provides an overview of gout, a detailed analysis of the structure and function of XOR, discussion on the pharmacokinetics and pharmacodynamics of XOR inhibitors-allopurinol and febuxostat, and the relevance of XOR in common comorbidities of gout. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

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.

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.

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.

The value of fixed rasburicase dosing versus weight-based dosing in the treatment and prevention of tumor lysis syndrome.

PubMed

Boutin, Alyssa; Blackman, Alison; O'Sullivan, David M; Forcello, Nicholas

2018-01-01

Background Rasburicase is a recombinant urate oxidase enzyme used for the treatment and prevention of tumor lysis syndrome. Our objective was to assess the efficacy of indication-based, low-dose rasburicase administration compared to the Food and Drug Administration-approved weight-based dosing. Methods This was a retrospective cohort study utilizing data from a tertiary medical center including patients admitted from 2012 to 2016, who received at least one dose of rasburicase. The primary outcome was achieving a uric acid level less than 7.5 mg/dl after a single dose of rasburicase in the preprotocol (Food and Drug Administration-approved weight-based dosing) and postprotocol (indication-based, low-dose) groups. Secondary outcomes included the change in uric acid levels between the pre- and postprotocol groups, adherence to the new institutional protocol, need for repeat rasburicase doses, and a cost analysis. Results Sixty-four patients received at least one dose of rasburicase between 1 January 2012 and 1 December 2016. Twenty-seven (79.4%) doses in the preprotocol group and 28 (82.4%) doses in the postprotocol group successfully achieved a uric acid level less than 7.5 mg/dl after a single dose of rasburicase (p=1.000). The average total monthly cost of rasburicase was reduced by 59.9% after adoption of the new protocol. Conclusions Indication-based, low-dose rasburicase displayed significantly more value when compared to weight-based dosing as shown by achieving cost savings without compromising clinical efficacy.

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.

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.

Management of gout in a South Auckland general practice.

PubMed

Reaves, Esther; Arroll, Bruce

2014-03-01

In New Zealand, the highest prevalence of gout is in Maori and Pacific people. Counties Manukau District Health Board (CMDHB) has the highest Maori and Pacific population of any New Zealand District Health Board. A CMDHB study found that a high proportion of patients with gout were also at increased risk of cardiovascular disease. The primary objective was to examine whether the control of gout had changed over time at one clinic. The secondary objective was to assess the management of cardiovascular risk factors in patients with gout at that clinic. The mean serum uric acid level of patients with gout in the practice had risen in comparison with a similar audit carried out in March 2009. This indicates that the control of gout for patients at the practice has worsened over time. Many patients had not had an annual serum uric acid test. A repeat uric acid level was scheduled for all patients with gout in the practice, with follow-up appointments to be arranged if the result was abnormal. Gout is often suboptimally managed. Serum uric acid levels may only be tested when a patient presents with an acute attack of gout. Consideration should be given to a minimum of annual serum uric acid levels. Appropriate management of modifiable cardiovascular risk factors in this particular cohort is important and should be a particular focus of care.

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

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.

Impact of dual energy characterization of urinary calculus on management.

PubMed

Habashy, David; Xia, Ryan; Ridley, William; Chan, Lewis; Ridley, Lloyd

2016-10-01

Dual energy CT (DECT) is a recent technique that is increasingly being used to differentiate between calcium and uric acid urinary tract calculi. The aim of this study is to determine if urinary calculi composition analysis determined by DECT scanning results in a change of patient management. All patients presenting with symptoms of renal colic, who had not previously undergone DECT scanning underwent DECT KUB. DECT data of all patients between September 2013 and July 2015 were reviewed. Urinary calculi composition based on dual energy characterization was cross-matched with patient management and outcome. A total of 585 DECT KUB were performed. 393/585 (67%) DECT scans revealed urinary tract calculi. After excluding those with isolated bladder or small asymptomatic renal stones, 303 patients were found to have symptomatic stone(s) as an explanation for their presentation. Of these 303 patients, there were 273 (90.1%) calcium calculi, 19 (6.3%) uric acid calculi and 11 (3.4%) mixed calculi. Of those with uric acid calculi, 15 were commenced on dissolution therapy. Twelve of those commenced on dissolution therapy had a successful outcome, avoiding need for surgical intervention (lithotripsy or stone retrieval). Three patients failed dissolution therapy and required operative intervention for definitive management of the stone. Predicting urinary tract calculi composition by DECT plays an important role in identifying patients who may be managed with dissolution therapy. Identification of uric acid stone composition altered management in 15 of 303 (5.0%) patients, and was successful in 12, thereby avoiding surgery and its attendant risks. © 2016 The Royal Australian and New Zealand College of Radiologists.

Urinary stone composition in Israel: current status and variation with age and sex--a bicenter study.

PubMed

Usman, Kalba D; Golan, Shay; Abdin, Tamer; Livne, Pinhas M; Pode, Dov; Duvdevani, Mordechai; Lifshitz, David

2013-12-01

The epidemiologic data regarding stone composition in Israel are based on anachronistic methods of stone analysis. Historically, Israel was noted for an unusually high percentage of uric acid stones. The aim of the study was to describe the current stone composition distribution in Israel, using modern techniques of urinary stone analysis. Age and sex correlations were investigated. In a bicenter study, using infrared spectroscopy and X-ray diffraction, stones from five hundred and thirty eight (538) patients were analyzed and demographic data recorded. The study cohort included 401 men (74.5%) and 137 women (25.5%) with a male to female ratio of 2.9:1 and a median age of 48 years (range 2-85 years). While calcium oxalate monohydrate was the predominant component in both sexes, it was lower in female patients (77.3% vs 65%). The rate of infection stones (struvite+carbonate apatite) was significantly higher in women (35.7% vs 10.2%). Uric acid stones were found in only 14.5% of the patients and increased with age. Conversely, the rate of calcium oxalate dihydrate decreased with age. Modern techniques of urinary stone analysis showed that the most frequent stone component in Israel is calcium oxalate monohydrate. In contrast to earlier reports and in accordance with reports from other countries, the overall frequency of uric acid is 14.5%. With age, the frequency of uric acid increases reaching 21% in persons >60 years old. A significant sex difference was noted in the distribution of calcium oxalate stones and infection stones. The classic 3:1 ratio was maintained, however.

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 range were small and were of short duration. Consistent with earlier observations on fructose, the increase of plasma uric acid was associated with a slight decrease of plasma phosphorus and a slight increase of magnesium. The daily ingestion of D-tagatose for 8 weeks had no effect on fasting plasma magnesium, phosphorus, cholesterol, triglycerides, glycosylated hemoglobin, glucose, and insulin levels. The ingestion of three 25-g doses per day for a period of 8 weeks resulted in varying amounts of flatulence in seven of the eight subjects, and some degree of diarrhea in six subjects. D-tagatose holds promise as a sweetener with no adverse clinical effects observed in these studies. Copyright 1999 Academic Press.

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...

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%).

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.

Characterization of Mesoamerican Nephropathy in a Kidney Failure Hotspot in Nicaragua.

PubMed

Kupferman, Joseph; Amador, Juan José; Lynch, Katherine E; Laws, Rebecca L; López-Pilarte, Damaris; Ramírez-Rubio, Oriana; Kaufman, James S; Lau, Jorge Luis; Weiner, Daniel E; Robles, Ninoska Violeta; Verma, Karina P; Scammell, Madeleine K; McClean, Michael D; Brooks, Daniel R; Friedman, David J

2016-11-01

Mesoamerican nephropathy (MeN) is a kidney disease of unknown cause that mainly affects working-age men in Central America. Despite being a major cause of morbidity and mortality in this region, its clinical characteristics have not been well defined. Cross-sectional family-based study. 266 members of 24 families with high chronic kidney disease (CKD) burdens in a MeN hotspot in Northwestern Nicaragua. We compared clinical and biochemical characteristics of affected individuals first with their unaffected relatives and then with NHANES (National Health and Nutrition Examination Survey) participants with CKD in order to reveal identifying features of MeN. CKD defined as serum creatinine level ≥ 1.5mg/dL in men and ≥1.4mg/dL in women. Clinical and biochemical parameters, including serum sodium, potassium, bicarbonate, calcium, magnesium, phosphorus, and uric acid. Hyperuricemia, in many cases severe, was common among patients with MeN. Uric acid levels in patients with MeN were higher than those in NHANES participants (mean, 9.6 vs 7.4mg/dL for men in each group) despite more frequent use of uric acid-lowering medications in Nicaraguan individuals (71.7% vs 11.2%). In multivariable linear mixed-effects regression analysis, uric acid levels were 2.0mg/dL (95% CI, 1.0-3.0; P<0.001) higher in patients with MeN compared with their NHANES counterparts after adjusting for age, estimated glomerular filtration rate, and uric acid-lowering therapies. In contrast to prior reports, hyponatremia and hypokalemia were not common. CKD defined by single serum creatinine measurement; population likely not representative of full MeN phenotype spectrum across Central America; major differences between MeN and NHANES groups in important characteristics such as age, ancestry, and recruitment method. Hyperuricemia out of proportion to the degree of decreased kidney function was common among Nicaraguan patients with MeN. Our results suggest that rather than being solely a consequence of CKD, hyperuricemia may play a role in MeN pathogenesis, a hypothesis that deserves further study. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

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.

Effects of nitro-treatment on Salmonella, E. coli and nitrogen metabolism during composting of 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 whose gut microbes transform the nitrogen in uric acid into high quality microbial protein. However, poultry litter must be treated to kill bacterial pathogens before feeding. Pres...

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.

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.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ingebretsen, O.C.; Borgen, J.; Farstad, M.

A reversed-phase liquid-chromatographic procedure is presented for quantitation or uric acid in human serum, with absorbance measured at 292 nm. The mobile phase was sodium acetate (35 mmol/L, pH 5.0)/acetonitrile (9/1 by vol). Complete precipitation of serum proteins was obtained by mixing serum (50-500 microL) with an equal volume of acetonitrile, and the precipitate was removed by centrifugation. Aliquots (20 microL) of the supernate were injected directly into the liquid chromatograph, which was adjusted so that the absorbance reading of the uric acid peak was as high as possible. Routinely, a full-scale deflection of 1.28 absorbance units was used. Themore » within-run precision (CV) was 0.6% for a serum uric acid concentration of 227 mumol/L and day-to-day precision over a 15-day period was 0.8% for uric acid of 345 mumol/L. No interferences from related compounds were observed. Researchers compared results by this method with those by kinetic and equilibrium adaptations of uricase methods. The method reported is simple, and can be used in a fully automatic liquid-chromatographic system.« less

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

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

Urinary and plasma purine derivatives in fed and fasted llamas (Lama glama and L. guanacoe).

PubMed

Bakker, M L; Chen, X B; Kyle, D J; Orskov, E R; Bourke, D A

1996-02-01

The changes in urinary and plasma purine derivatives in response to fasting and level of feeding in llamas were examines. In one experiment, four llamas were gradually deprived of feed within 3 days and then fasted for 6 days. Daily urinary excretion of purine derivatives decreased with feed intake and leveled on the last 3 days of fasting at 177 +/- 26 mumol/kg W0.75. Allantoin and uric acid comprised 71% and 15% of total purine derivatives, respectively, in both fed and fasted states, but hypoxanthine plus xanthine increased from 9% to 36%. Plasma concentration of allantoin declined with feed intake reduction, but those of uric acid (217 mumol/l) and hypoxanthine plus xanthine (27 mumol/l) remained relatively unchanged. Concentration of uric acid was higher than that of allantoin, probably due to a high reabsorption of uric acid in renal tubules, which was measured as over 90%. In a second experiment, the four llamas were fed at 860 and 1740 g dry matter/d in a crossover design. Urinary total purine derivatives excretion responded to feed intake (10.4 vs 14.4 mmol/d), although the observed differences did not reach significance. Compared with some ruminant species, it appears that the llama resembles sheep regarding the magnitude of urinary purine derivatives excretion but is unique in maintaining a high concentration of uric acid in plasma, which could be part of the llama's adaptation to their environment.

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.

Studying the Role for CD4+ T Cell Subsets in Human Lupus

DTIC Science & Technology

2013-07-01

heterogeneous, ranging from self- originating uric acid , calcium pyrophosphate crystals, choles- terol crystals, ATP, and glucose to environment-derived...Tardivel, and J. Tschopp. 2006. Gout- associated uric acid crystals activate the NALP3 inflammasome. Nature 440: 237–241. 44. Napirei, M., H. Karsunky, B...patterns (PAMPs) commonly found in microorganisms (1, 2). Different classes of PRRs have been identified. These receptors include TLRs, retinoic acid

Can a dual-energy computed tomography predict unsuitable stone components for extracorporeal shock wave lithotripsy?

PubMed

Ahn, Sung Hoon; Oh, Tae Hoon; Seo, Ill Young

2015-09-01

To assess the potential of dual-energy computed tomography (DECT) to identify urinary stone components, particularly uric acid and calcium oxalate monohydrate, which are unsuitable for extracorporeal shock wave lithotripsy (ESWL). This clinical study included 246 patients who underwent removal of urinary stones and an analysis of stone components between November 2009 and August 2013. All patients received preoperative DECT using two energy values (80 kVp and 140 kVp). Hounsfield units (HU) were measured and matched to the stone component. Significant differences in HU values were observed between uric acid and nonuric acid stones at the 80 and 140 kVp energy values (p<0.001). All uric acid stones were red on color-coded DECT images, whereas 96.3% of the nonuric acid stones were blue. Patients with calcium oxalate stones were divided into two groups according to the amount of monohydrate (calcium oxalate monohydrate group: monohydrate≥90%, calcium oxalate dihydrate group: monohydrate<90%). Significant differences in HU values were detected between the two groups at both energy values (p<0.001). DECT improved the characterization of urinary stone components and was a useful method for identifying uric acid and calcium oxalate monohydrate stones, which are unsuitable for ESWL.

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.

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. Published by Elsevier B.V.

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.

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.

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.

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.

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 healthy subjects; this was caused by the fructose-induced rise of serum uric acid levels, but was not due to the presence of antioxidant polyphenols in juice. Thus, short-term consumption of apple juice seems not to be the effective dietary intervention to augment plasma antioxidant activity due to the concomitant possibility for uric acid to be a risk factor for several diseases, as verified by other authors.

Seasonal variations in urinary risk factors among patients with nephrolithiasis

NASA Technical Reports Server (NTRS)

Hill, K.; Poindexter, J.; Pak, C. Y.

1991-01-01

Twenty-four hour urine specimens from 5,677 stone-forming patients throughout the United States were analyzed for seasonal variations in urinary risk factors for nephrolithiasis. Determinations were performed for urine volume, pH, calcium, oxalate, phosphorus, sodium, magnesium, citrate, sulfate, uric acid, and the relative supersaturation (RS) of calcium oxalate, brushite, monosodium urate, and uric acid. Criteria for significant seasonal variation included a significant difference in monthly means of risk factors, seasonal grouping of the data by the Student-Newman-Keuls multiple range test, consistent year-to-year trends and a physiologically significant range. Minimum urine volume of 1.54 +/- 0.70 SD L/day occurred in October while a maximum urine volume of 1.76 +/- 0.78 SD L/day was observed during February. Minimum urine pH of 5.94 +/- 0.64 SD was observed during July and August while a maximum pH of 6.18 +/- 0.61 SD was observed during February. Daily urinary excretion of sodium was lowest during August, 158 +/- 74 SD mEq/day and highest during February 177 +/- 70 SD mEq/day. The RS of brushite and uric acid were found to display significant pH-dependent seasonal variation with a maximum RS of uric acid 2.26 +/- 1.98 SD in June and a low of 1.48 +/- 1.30 SD in February. Maximum RS of brushite 2.75 +/- 2.58 was observed during February. Minimum RS of brushite 1.93 +/- 1.70 SD was observed in June. Phosphorus excretion displayed seasonal variation about a spring-fall axis with a maximum value 1042 +/- 373 SD mg/day in April and a minimum value of 895 +/- 289 SD mg/day. Urine volume, sodium, and pH were significantly lower during the summer (June, July, August) than in the winter (December, January, February). The RS of uric acid was higher, but that of brushite and monosodium urate was lower in the summer than in the winter. The seasonal changes observed in urine volume, pH, sodium, and the RS of brushite and uric acid are consistent with summertime sweating and increased physical activity. Seasonal variations in phosphorus excretion are probably dietary in origin. The summertime was characterized by an increased propensity for the crystallization of uric acid but not of calcium oxalate or calcium phosphate.

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.

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.

Iterative outlier removal: A method for identifying outliers in laboratory recalibration studies

PubMed Central

Parrinello, Christina M.; Grams, Morgan E.; Sang, Yingying; Couper, David; Wruck, Lisa M.; Li, Danni; Eckfeldt, John H.; Selvin, Elizabeth; Coresh, Josef

2016-01-01

Background Extreme values that arise for any reason, including through non-laboratory measurement procedure-related processes (inadequate mixing, evaporation, mislabeling), lead to outliers and inflate errors in recalibration studies. We present an approach termed iterative outlier removal (IOR) for identifying such outliers. Methods We previously identified substantial laboratory drift in uric acid measurements in the Atherosclerosis Risk in Communities (ARIC) Study over time. Serum uric acid was originally measured in 1990–92 on a Coulter DACOS instrument using an uricase-based measurement procedure. To recalibrate previous measured concentrations to a newer enzymatic colorimetric measurement procedure, uric acid was re-measured in 200 participants from stored plasma in 2011–13 on a Beckman Olympus 480 autoanalyzer. To conduct IOR, we excluded data points >3 standard deviations (SDs) from the mean difference. We continued this process using the resulting data until no outliers remained. Results IOR detected more outliers and yielded greater precision in simulation. The original mean difference (SD) in uric acid was 1.25 (0.62) mg/dL. After four iterations, 9 outliers were excluded, and the mean difference (SD) was 1.23 (0.45) mg/dL. Conducting only one round of outlier removal (standard approach) would have excluded 4 outliers (mean difference [SD] = 1.22 [0.51] mg/dL). Applying the recalibration (derived from Deming regression) from each approach to the original measurements, the prevalence of hyperuricemia (>7 mg/dL) was 28.5% before IOR and 8.5% after IOR. Conclusion IOR is a useful method for removal of extreme outliers irrelevant to recalibrating laboratory measurements, and identifies more extraneous outliers than the standard approach. PMID:27197675

Urinary pH as a Risk Factor for Stone Type

NASA Astrophysics Data System (ADS)

Sakhaee, Khashayar

2007-04-01

A high urinary pH is main risk factor for the calcium phosphate stone formation; however, its pathophysiologic mechanism has not been fully understood. The introduction of Topiramate in the treatment of various neurological disorders has been complicated by metabolic acidosis, significant hypocitraturia, elevated urinary pH, and calcium phosphate stone formation. This model provides a probe to investigate the pathophysiologic mechanism of calcium phosphate stone formation and perhaps to develop appropriate countermeasures in the future. On the other hand an unduly acidic urine predisposes one to uric acid nephrolithiasis. Our recent investigation linking low urinary pH, and defective renal ammoniagenesis to insulin resistance provides new knowledge to unfold the pathophysiology of uric acid nephrolithiasis. The metabolic profile leading to uric acid stone may emerge as one of the components of metabolic syndrome.

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.

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…

Oxidative Stress Increases the Blood Brain Barrier Permeability Resulting in Increased Incidence of Brain Metastasis in BRCA Mutation Carriers

DTIC Science & Technology

2012-02-01

to HBMEC showed increase in ROS levels as compared to control, and this increased in ROS formation was abrogated by the antioxidant uric acid , UA...in HBMEC permeability was observed by ROS and these changes were inhibited in the presence of UA antioxidant, uric acid , indicating the involvement

Oxidative Stress Increases the Blood Brain Barrier Permeability Resulting in Increased Incidence of Brain Metastasis in BRCA Mutation Carriers

DTIC Science & Technology

2014-08-01

increase in ROS levels as compared to control, and this increased in ROS formation was abrogated by the antioxidant uric acid , UA (Table 1). Table 1...presence of UA antioxidant, uric acid , indicating the involvement of ROS in loss of the HBMEC integrity. The functional changes paralleled enhanced

Catalase deficiency may complicate urate oxidase (rasburicase) therapy.

PubMed

Góth, László; Bigler, N William

2007-09-01

Patients with low (inherited and acquired) catalase activities who are treated with infusion of uric acid oxidase because they are at risk of tumour lysis syndrome may experience very high concentrations of hydrogen peroxide. They may suffer from methemoglobinaemia and haemolytic anaemia which may be attributed either to deficiency of glucose-6-phosphate dehydrogenase or to other unknown circumstances. Data have not been reported from catalase deficient patients who were treated with uric acid oxidase. It may be hypothesized that their decreased blood catalase could lead to the increased concentration of hydrogen peroxide which may cause haemolysis and formation of methemoglobin. Blood catalase activity should be measured for patients at risk of tumour lysis syndrome prior to uric acid oxidase treatment.

Benign positional vertigo and hyperuricaemia.

PubMed

Adam, A M

2005-07-01

To find out if there is any association between serum uric acid level and positional vertigo. A prospective, case controlled study. A private neurological clinic. All patients presenting with vertigo. Ninety patients were seen in this period with 78 males and 19 females. Mean age was 47 +/- 3 years (at 95% confidence level) with a standard deviation of 12.4. Their mean uric acid level was 442 +/- 16 (at 95% confidence level) with a standard deviation of 79.6 umol/l as compared to 291 +/- 17 (at 95% confidence level) with a standard deviation of 79.7 umol/l in the control group. The P-value was less than 0.001. That there is a significant association between high uric acid and benign positional vertigo.

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}.

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.

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.

A Therapeutic Uricase with Reduced Immunogenicity Risk and Improved Development Properties.

PubMed

Nyborg, Andrew C; Ward, Chris; Zacco, Anna; Chacko, Benoy; Grinberg, Luba; Geoghegan, James C; Bean, Ryan; Wendeler, Michaela; Bartnik, Frank; O'Connor, Ellen; Gruia, Flaviu; Iyer, Vidyashankara; Feng, Hui; Roy, Varnika; Berge, Mark; Miner, Jeffrey N; Wilson, David M; Zhou, Dongmei; Nicholson, Simone; Wilker, Clynn; Wu, Chi Y; Wilson, Susan; Jermutus, Lutz; Wu, Herren; Owen, David A; Osbourn, Jane; Coats, Steven; Baca, Manuel

2016-01-01

Humans and higher primates are unique in that they lack uricase, the enzyme capable of oxidizing uric acid. As a consequence of this enzyme deficiency, humans have high serum uric acid levels. In some people, uric acid levels rise above the solubility limit resulting in crystallization in joints, acute inflammation in response to those crystals causes severe pain; a condition known as gout. Treatment for severe gout includes injection of non-human uricase to reduce serum uric acid levels. Krystexxa® is a hyper-PEGylated pig-baboon chimeric uricase indicated for chronic refractory gout that induces an immunogenic response in 91% of treated patients, including infusion reactions (26%) and anaphylaxis (6.5%). These properties limit its use and effectiveness. An innovative approach has been used to develop a therapeutic uricase with improved properties such as: soluble expression, neutral pH solubility, high E. coli expression level, thermal stability, and excellent activity. More than 200 diverse uricase sequences were aligned to guide protein engineering and reduce putative sequence liabilities. A single uricase lead candidate was identified, which showed low potential for immunogenicity in >200 human donor samples selected to represent diverse HLA haplotypes. Cysteines were engineered into the lead sequence for site specific PEGylation and studies demonstrated >95% PEGylation efficiency. PEGylated uricase retains enzymatic activity in vitro at neutral pH, in human serum and in vivo (rats and canines) and has an extended half-life. In canines, an 85% reduction in serum uric acid levels was observed with a single subcutaneous injection. This PEGylated, non-immunogenic uricase has the potential to provide meaningful benefits to patients with gout.

Losartan vs. amlodipine treatment in elderly oncologic hypertensive patients: a randomized clinical trial.

PubMed

Motta, Massimo; Russo, Cristina; Vacante, Marco; Liardo, Rocco Luca Emanuele; Reitano, Francesca; Cammalleri, Lisa; Costanzo, Mario; Benfatto, Giuseppe; Frazzetto, Paola; Mondati, Enrico; Malaguarnera, Michele; Pennisi, Giovanni

2011-01-01

Elderly neoplastic patients frequently may show hypertension and hyperuricemia, before and after chemotherapeutic treatments. The purpose of this study was to evaluate the efficacy of losartan which is an antihypertensive drug with uricosuric properties vs. amlodipine in hypertensive neoplastic elderly patients. This was an open-labeled, randomized, comparative trial. The study was performed as a 30-day study. Seventy patients with cancer were randomly assigned to receive losartan or amlodipine. Blood pressure (BP), blood urea nitrogen (BUN) levels, creatinine, serum and urinary uric acid, creatinine and uric acid clearance were determined before and after chemotherapy. One day after chemotherapy in losartan group vs. amlodipine group we observed a significant difference in urinary uric acid (p<0.001) of 18 mg/24 h vs. 40 mg/24 h. Thirty days after chemotherapy we observed a significant difference in azotemia of 0.0 mg/dl vs. 3.8 mg/dl (p<0.001), serum uric acid of 0.05 mg/dl vs. 0.49 mg/dl (p<0.001), urinary uric acid (p<0.001) of 23 mg/24 h vs. 0.0 mg/24 h, GFR of 2 ml/min/1.73 m(2) vs. -8 ml/min/1.73 m(2) (p<0.05) and systolic BP (SBP) of 3.6 mmHg vs. 0.8 mmHg (p<0.05). The findings of the present study support the effective role of losartan compared to amlodipine in treating hypertension and hyperuricemia in elderly patients under chemotherapeutic treatment. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Clinical and metabolic evaluation of patients with history of renal calculi in Qazvin, Iran.

PubMed

Charkhchian, Maliheh; Samani, Simin; Merat, Ehsan

2015-12-01

Nephrolithiasis is a common clinical disorder with significant health and economic burden. We conducted this study to evaluate clinical and metabolic parameters in adult patients with history of renal calculi. A total of 213 patients with history of nephrolithiasis participated in this study. Evaluation included the measurement of serum calcium, uric acid, parathormone, renal function tests, urinalysis, and urinary tests for cystinuria. Also, parameters such as volume, creatinine, calcium, uric acid, citrate, and oxalate levels were measured on 24-h urine. All patients underwent urinary tract system sonography. Of total patients, 52% were males and 48% females. The mean age was 45.16 ± 13.16 years. Also, 51.2% of subjects had positive family history of nephrolithiasis. The mean body mass index was (26.8 ± 4.2) kg/m(2). The mean 24-h urine biochemical profiles were volume (1,748 ± 860 ml), Ca (183 ± 115), uric acid (544 ± 220), citrate (490 ± 351), and oxalate (17.1 ± 15.3) mg/day; urine calcium to creatinine ratio (0.15 ± 0.10) mg/mg, and urine calcium to weight ratio (2.4 ± 1.7) mg/kg. While there were weak positive correlations between the body mass index and urinary calcium (r = 0.101, P < 0.001) and uric acid (r = 0.200, P < 0.001), a weak negative correlation with urine pH (r = -0.104, P < 0.001) was found. Urine calcium, uric acid, and oxalate excretion were low in our patients while urine citrate was relatively high. Higher BMI maybe a risk factor for nephrolithiasis.

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.

[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.

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.

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.

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

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.

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.

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…

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)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meadows, J.; Smith, R.C.; Reeves, J.

Aqueous preparations of linolenic acid, bovine serum albumin, and bovine erythrocyte membrane fragments were bubbled with ozone in the presence or absence of uric acid. Ozonation of the membrane fragments or the bovine serum albumin did not result in protein degradation. After 15 min of ozonation, the absorbance of the thiobarbituric acid-reactive material increased by 0.34 in the linolenic acid preparation and by 0.08 in the suspension of membrane fragments. In the presence of uric acid, these changes in absorbance were reduced to 0.14 for the fatty acid and to 0.01 for the membrane fragments. This result indicates that uricmore » acid protects lipids from ozone-induced oxidation.« less

ARISTOLOCHIA BRACTEOLATE RETZ. ATTENUATES HYPERURICEMIA IN A METABOLIC ARTHRITIS RAT MODEL.

PubMed

Li, Yun-Peng; Wu, Shuang; Ran, Afou; Xu, Da-Yong; Wei, Jing-Mei; Zhao, Zi-Long

2017-01-01

The leaves of Aristolochia bracteolata Retz. has been documented in the folk medicine literature for its anti-arthritic activity. The target of the research envisaged was to elucidate the activity of A. bracteolata extract on hyperuricemic condition in arthritis rat model. Dried and powdered plant leaves were extracted using ether and chloroform. Potassium oxonate was injected intra-articularly to produce arthritis. The hyperuricemic effect, of A. bracteolate was analyzed by studying levels of uric acid in serum as well as in urine of arthritis induced rats. Effects of plant extracts were also studied on BUN (blood urea nitrogen) levels and fraction of uric acid excreted. Results indicate that administration of A. bracteolata presented substantial change in uric acid concentration, augmented by potassium oxonate administration in rats. The reduction in levels of uric acid levels was nearly same as allopurinol. The investigation also revealed that the primary plant extract has nephroprotective effect by enhancing the production of Prostaglandin E 2 and Interleukin-1. Histological studies of rat kidney slices indicated the safety of the present plant extract. The crude extract of A. bracteolate can be used to reduce hyperuricemia in metabolic arthritis produced in rat model, without inducing any potential damaging effects.

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.

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.

Kidney stones: Composition, frequency and relation to metabolic diagnosis.

PubMed

Spivacow, Francisco R; Del Valle, Elisa E; Lores, Ernesto; Rey, Paula G

Nephrolithiasis is one of the most frequent urologic diseases. The aim of this paper is to study the composition and frequency of 8854 patient kidney stones and in a subset of them their metabolic risk factors to be related to their type of calculi. Physicochemical and crystallographic methods were used to assess kidney stone composition. In a subset of 715 patients, we performed an ambulatory metabolic protocol with diagnostic purposes. From the total sample 79% of stones were made of calcium salts (oxalate and phosphate), followed by uric acid stones in 16.5%, calcium salts and uric acid in 2%, other salts in 1.9% and cystine in 0.6%. Male to female ratio was almost three times higher in calcium salts and other types of stones, reaching a marked male predominance in uric acid stones, M/F 18.8 /1.0. The major risk factors for calcium stones are idiopathic hypercalciuria, followed by unduly acidic urine pH and hyperuricosuria. In uric acid stones unduly acidic urine pH and less commonly hyperuricosuria are the most frequent biochemical diagnosis. Our results show that analysis of kidney stones composition and the corresponding metabolic diagnosis may provide a scientific basis for the best management and prevention of kidney stone formation, as well as it may help us to study the mechanisms of urine stone formation.

Urate synthesis and oxidative stress in phenytoin hepatotoxicity: the role of antioxidant vitamins.

PubMed

Ekaidem, Itemobong S; Usoh, Itoro F; Akpanabiatu, Monday I; Uboh, Friday E; Akpan, Henry D

2014-11-01

Phenytoin is known to induce microsomal enzymes including xanthine oxidase which catalyzes uric acid synthesis with superoxides as byproducts, thus contributing to the oxidative stress of phenytoin hepatotoxicity. To investigate the role of antioxidant vitamins in ameliorating phenytoin induced hepatic changes through possible actions on xanthine oxidase activities as measured by urate concentration. Growing albino rats of Wistar strain were randomly divided into 8 groups of 7 rats each. Group 2, 3, 4, 5, 6, 7 and 8 were treated with phenytoin alone, phenytoin + folic acid, phenytoin + vitamin E, phenytoin + vitamin E + vitamin C, phenytoin + vitamin C, phenytoin + folic acid + vitamin E and phenytoin + vitamin E + vitamin C + folic acid respectively while animals in group 1 were given normal saline to serve as control. Serum concentrations of uric acid, albumin, total protein and the activities of aspartate and alanine aminotransferases (AST and ALT) and catalase were measured spectrophotometrically using appropriate commercial reagent kits. Result showed that administration of phenytoin alone caused significant (p < 0.05) increase in serum levels of globulin, uric acid, AST and ALT activities while the levels of albumin and catalase were reduced significantly (p < 0.05). Supplementation of phenytoin treatment with vitamins resulted in various degrees of protection. However, the elevated level of uric acid in serum was not significantly (p < 0.05) affected by any of the vitamins used and there was no significant correlation between the activities of aminotransferases and uric acid concentration in the vitamin treated animals as was observed between aminotransferases and catalase. The findings in this study suggest that antioxidant vitamins were able to ameliorate phenytoin hepatotoxic effects by improving oxidant radicals removal in the animals but would not inhibit further generation of the superoxides by xanthine oxidase activity and that xanthine oxidase may contribute significantly to the oxidative stress of phenytoin therapy.

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.

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.

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.

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.

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.

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.

Short chain nitrocompounds as a treatment of layer hen manure and litter; effects on in vitro survivability of Salmonella, generic E. coli, and nitrogen metabolism

USDA-ARS?s Scientific Manuscript database

Layer hen manure and litter contain appreciable amounts of uric acid, which makes these good crude protein sources for ruminants. Rumen microbial populations can upgrade the nitrogen in uric acid into high quality microbial protein of nutritional value to the host. Layer hen manure and litter can ...

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).

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.

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

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.

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 induces hepatic glucose production in diabetes and starvation: Evolutionary implications of the uricase loss in hominids. PMID:24755741

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.

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

A Therapeutic Uricase with Reduced Immunogenicity Risk and Improved Development Properties

PubMed Central

Nyborg, Andrew C.; Ward, Chris; Zacco, Anna; Grinberg, Luba; Geoghegan, James C.; Bean, Ryan; Wendeler, Michaela; Bartnik, Frank; O’Connor, Ellen; Gruia, Flaviu; Iyer, Vidyashankara; Feng, Hui; Roy, Varnika; Berge, Mark; Miner, Jeffrey N.; Wilson, David M.; Zhou, Dongmei; Nicholson, Simone; Wilker, Clynn; Wu, Chi Y.; Wilson, Susan; Jermutus, Lutz; Wu, Herren; Owen, David A.; Osbourn, Jane; Coats, Steven; Baca, Manuel

2016-01-01

Humans and higher primates are unique in that they lack uricase, the enzyme capable of oxidizing uric acid. As a consequence of this enzyme deficiency, humans have high serum uric acid levels. In some people, uric acid levels rise above the solubility limit resulting in crystallization in joints, acute inflammation in response to those crystals causes severe pain; a condition known as gout. Treatment for severe gout includes injection of non-human uricase to reduce serum uric acid levels. Krystexxa® is a hyper-PEGylated pig-baboon chimeric uricase indicated for chronic refractory gout that induces an immunogenic response in 91% of treated patients, including infusion reactions (26%) and anaphylaxis (6.5%). These properties limit its use and effectiveness. An innovative approach has been used to develop a therapeutic uricase with improved properties such as: soluble expression, neutral pH solubility, high E. coli expression level, thermal stability, and excellent activity. More than 200 diverse uricase sequences were aligned to guide protein engineering and reduce putative sequence liabilities. A single uricase lead candidate was identified, which showed low potential for immunogenicity in >200 human donor samples selected to represent diverse HLA haplotypes. Cysteines were engineered into the lead sequence for site specific PEGylation and studies demonstrated >95% PEGylation efficiency. PEGylated uricase retains enzymatic activity in vitro at neutral pH, in human serum and in vivo (rats and canines) and has an extended half-life. In canines, an 85% reduction in serum uric acid levels was observed with a single subcutaneous injection. This PEGylated, non-immunogenic uricase has the potential to provide meaningful benefits to patients with gout. PMID:28002433

Activity of xanthine oxidase in plasma correlates with indices of insulin resistance and liver dysfunction in Japanese patients with type 2 diabetes mellitus and metabolic syndrome: A pilot exploratory study.

PubMed

Sunagawa, Sumito; Shirakura, Takashi; Hokama, Noboru; Kozuka, Chisayo; Yonamine, Masato; Namba, Toyotaka; Morishima, Satoko; Nakachi, Sawako; Nishi, Yukiko; Ikema, Tomomi; Okamoto, Shiki; Matsui, Chieko; Hase, Naoki; Tamura, Mizuho; Shimabukuro, Michio; Masuzaki, Hiroaki

2018-06-03

There is a controversy whether hyperuricemia is an independent risk for cardiometabolic diseases. Serum level of uric acid is affected by a wide variety of factors involved in its production and excretion. On the other hand, evidence has accumulated that locally and systemically activated xanthine oxidase (XO), a rate limiting enzyme for production of uric acid, is linked to metabolic derangement in humans and rodents. We therefore explored the clinical implication of plasma XO activity in patients with type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS). We enrolled 60 patients with T2DM and MetS. MetS was defined according to the 2005 International Diabetes Federation guidelines. Plasma XO activity was measured by highly sensitive fluorometric assay measuring the conversion of pterin to isoxanthopterin, and explored associations between the value of plasma XO activity and metabolic parameters. Value of plasma XO activity was correlated with indices of insulin resistance and level of circulating liver transaminases. On the other hand, level of serum uric acid was not correlated with indices of insulin resistance. The value of plasma XO activity was not correlated with serum uric acid level. Plasma XO activity correlates with indices of insulin resistance and liver dysfunction in Japanese patients with T2DM and MetS. Through assessing the plasma XO activity, patients demonstrating normal level of serum uric acid with higher activity of XO can be screened, thereby possibly providing a clue to uncover metabolic risks in T2DM and MetS. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Effects of oral D-tagatose, a stereoisomer of D-fructose, on liver metabolism in man as examined by 31P-magnetic resonance spectroscopy.

PubMed

Buemann, B; Gesmar, H; Astrup, A; Quistorff, B

2000-10-01

D-tagatose, which is a stereoisomer of D-fructose, is phosphorylated to D-tagatose-1-phosphate by fructokinase in the liver. Because of a slow degradation rate of D-tagatose-1-phosphate, this substance may accumulate, and ingested D-tagatose may therefore cause a longer lasting reduction in inorganic phosphate (Pi) and adenosine triphosphate (ATP) levels in the liver compared with D-fructose. Similar to what is seen in patients with hereditary fructose intolerance, this may increase purine nucleotide degradation and thereby increase uric acid production. The effect of 30 g D-tagatose or D-fructose administered orally on ketohexose-1-phosphates, ATP, and Pi levels in the liver was studied by 31P-magnetic resonance spectroscopy (PMRS) in 5 young male volunteers. Blood and urine were collected to detect a possible increased uric acid production. A peak at 5.2 ppm assigned as D-tagatose-1-phosphate equivalent to about 1 mmol/L was found in the spectrum within 30 minutes after D-tagatose was administered in all subjects. Concomitantly, ATP was reduced by about 12% (P < .05). Both effects had vanished after 150 minutes. Serum uric acid concentration was increased by 17% 50 minutes after D-tagatose (P < .05) and did not reach baseline level when the experiment was terminated 230 minutes after the load. Although renal fractional extraction of uric acid decreased by approximately 12%, this could not explain the acute hyperuricemic effect of D-tagatose. No changes in 31PMRS spectra or serum uric acid concentration were found after D-fructose. These results suggest that a moderate intake of D-tagatose may affect liver metabolism by phosphate trapping despite the fact that the sugar may only be incompletely absorbed in the gut.

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.

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

Hyperferritinemia increases the risk of hyperuricemia in HFE-hereditary hemochromatosis.

PubMed

Flais, Jérémy; Bardou-Jacquet, Edouard; Deugnier, Yves; Coiffier, Guillaume; Perdriger, Aleth; Chalès, Gérard; Ropert, Martine; Loréal, Olivier; Guggenbuhl, Pascal

2017-05-01

Hyperuricemia is becoming increasingly frequent in the population, and is known to be sometimes the cause of gout. The impact of uric acid is still not clearly understood, however. The iron metabolism may interact with the uric acid metabolism. The aim of this study was to examine the relationship between the serum uric acid and serum ferritin levels in a cohort of hemochromatosis patients who were homozygous for the HFE p.Cys282Tyr mutation. 738 patients with the HFE gene mutation Cys282Tyr in the homozygous state were included in the study. The variables measured during the initial evaluation were compared in univariate analysis by Student's t test. In multivariate analysis, linear stepwise regression was used. In the group of hyperuricemic patients, ferritinemia was significantly higher than in the group of non-hyperuricemic patients (1576.7±1387.4μg/l vs. 1095.63±1319.24μg/l, P<0.005). With multivariate analysis, only ferritin and BMI independently explained the uricemia (R 2 =0.258) after adjustment for age, glycemia and CRP. The correlation between uricemia and log(ferritin) with partial regression correlation coefficients was 0.307 (P<0.01). The increase in uricemia is associated with the increase in ferritin in a population of patients who were homozygous for the HFE gene mutation p.Cys282Tyr and this independently of factors commonly associated with hyperuricemia. The increase in uric acid associated with hyperferritinemia, could be a response to the visceral toxicity of excess non-transferrin bound iron linked to oxidative stress via the antioxidant properties of uric acid. Copyright © 2016 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

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.

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.

Uricaemia as a cardiovascular events risk factor in hypertension: the role of interval training programme in its downregulation.

PubMed

Lamina, Sikiru; Okoye, Chuba G

2011-01-01

Elevated serum uric acid is considered to be positively associated with cardiovascular event risk factor in hypertension. Also, the positive role of exercise in the management of Hypertension has been well and long established. However the relationship between serum uric acid (SUA) level and hypertensive management particularly in non pharmacological technique is ambiguous and unclear. Therefore the purpose of the present study was to determine the effect of interval training programme on serum uric acid level and cardiovascular parameters in male subjects with hypertension. Two hundred and forty five male patients with mild to moderate (systolic blood pressure [SBP] between 140-180 and diastolic blood pressure [DBP] between 90-109 mmHg) essential hypertension were age matched and grouped into interval and control groups. The interval (n = 140; 58.90 +/- 7.35 years) group involved in an 8 weeks interval training (60-79% HR max reserve) programme of between 45 minutes to 60 minutes at a work/rest ratio of 1:1 of 6 minutes each, while age-matched controls hypertensive (n = 105; 58.27 +/- 6.24 years) group remain sedentary during this period. Cardiovascular parameters (SBP, DBP and VO2max) and serum uric acid were assessed. Students' t and Pearson correlation tests were used in data analysis. Findings of the study revealed significant effect of interval training programme on VO2max, SBP, DBP and serum uric acid level at p < 0.05. Also there was significant correlation between changes VO2max and changes in SUA, SBP and DBP. It was concluded that interval training programme is an effective non-pharmacological means of downregulation of SUA.

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.

Hyperuricemia, Type 2 Diabetes Mellitus, and Hypertension: an Emerging Association.

PubMed

Mortada, Ibrahim

2017-09-01

Uric acid is the final oxidation product of purine metabolism in circulation and has been associated with the occurrence of gout and kidney stones. Type 2 diabetes mellitus and hypertension are two important public health challenges, and both are linked to increased risk of cardiovascular events. Hyperuricemia has recently emerged as an independent risk factor in the development of type 2 diabetes mellitus and hypertension through several proposed mechanisms. Few clinical trials investigated the use of uric acid lowering agents in the management of these two disease entities; however, their results provided encouraging evidence to a potential role for these agents in fighting disease burden. Larger randomized controlled trials are therefore warranted to establish the role of uric acid as a promising target for novel therapeutic interventions in the management of type 2 diabetes mellitus and hypertension.

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

Lab-on-a-bird: biophysical monitoring of flying birds.

PubMed

Gumus, Abdurrahman; Lee, Seoho; Ahsan, Syed S; Karlsson, Kolbeinn; Gabrielson, Richard; Guglielmo, Christopher G; Winkler, David W; Erickson, David

2015-01-01

The metabolism of birds is finely tuned to their activities and environments, and thus research on avian systems can play an important role in understanding organismal responses to environmental changes. At present, however, the physiological monitoring of bird metabolism is limited by the inability to take real-time measurements of key metabolites during flight. In this study, we present an implantable biosensor system that can be used for continuous monitoring of uric acid levels of birds during various activities including flight. The system consists of a needle-type enzymatic biosensor for the amperometric detection of uric acid in interstitial fluids. A lightweight two-electrode potentiostat system drives the biosensor, reads the corresponding output current and wirelessly transfers the data or records to flash memory. We show how the device can be used to monitor, in real time, the effects of short-term flight and rest cycles on the uric acid levels of pigeons. In addition, we demonstrate that our device has the ability to measure uric acid level increase in homing pigeons while they fly freely. Successful application of the sensor in migratory birds could open up a new way of studying birds in flight which would lead to a better understanding of the ecology and biology of avian movements.

The ygeW encoded protein from Escherichia coli is a knotted ancestral catabolic transcarbamylase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Yongdong; Jin, Zhongmin; Yu, Xiaolin

Purine degradation plays an essential role in nitrogen metabolism in most organisms. Uric acid is the final product of purine catabolism in humans, anthropoid apes, birds, uricotelic reptiles, and almost all insects. Elevated levels of uric acid in blood (hyperuricemia) cause human diseases such as gout, kidney stones, and renal failure. Although no enzyme has been identified that further degrades uric acid in humans, it can be oxidized to produce allantoin by free-radical attack. Indeed, elevated levels of allantoin are found in patients with rheumatoid arthritis, chronic lung disease, bacterial meningitis, and noninsulin-dependent diabetes mellitus. In other mammals, some insectsmore » and gastropods, uric acid is enzymatically degraded to the more soluble allantoin through the sequential action of three enzymes: urate oxidase, 5-hydroxyisourate (HIU) hydrolase and 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU) decarboxylase. Therefore, an elective treatment for acute hyperuricemia is the administration of urate oxidase. Many organisms, including plants, some fungi and several bacteria, are able to catabolize allantoin to release nitrogen, carbon, and energy. In Arabidopsis thaliana and Eschrichia coli, S-allantoin has recently been shown to be degraded to glycolate and urea by four enzymes: allantoinase, allantoate amidohydrolase, ureidoglycine aminohydrolase, and ureidoglycolate amidohydrolase.« less

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

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.

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.

Gout and arrhythmias: In search for causation beyond association.

PubMed

Giannopoulos, Georgios; Angelidis, Christos; Deftereos, Spyridon

2018-06-13

Gout is a systemic disease, characterized by the formation and deposition of crystals in tissues (mainly in and around the joints) of individuals with elevated serum uric acid levels. Lately, a considerable number of reports relating elevated uric acid and/or gout with rhythm disorders, such as atrial fibrillation, have been published. This review summarizes evidence linking common arrhythmias and hyperuricemia/gout and discusses questions or controversies that surround it. Overall, existing evidence may not be overwhelming, but strongly suggests a positive correlation between uric acid levels and common rhythm disorders. Needless to say that such a link - as a univariate association between the two - is to be expected, given the extensive overlap of risk factors and comorbidities of hyperuricemia/gout and arrhythmias. However, the observed associations seem to persist - in most studies - after extensive adjustment for potential confounders. Still, multivariable analyses of epidemiologically collected data cannot substitute for proof coming from basic and clinical studies. There is obviously a need for further basic research to establish a causal relationship between uric acid effects and arrhythmias, as well as translational studies and clinical trials to investigate the therapeutic implications of such a relationship. Simply put, we are fairly certain that there is association, but proof of causation is what we are still in want of. Copyright © 2018. Published by Elsevier Inc.

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.

Management of gout by UK rheumatologists: a British Society for Rheumatology national audit.

PubMed

Roddy, Edward; Packham, Jon; Obrenovic, Karen; Rivett, Ali; Ledingham, Joanna M

2018-05-01

To assess the concordance of gout management by UK rheumatologists with evidence-based best-practice recommendations. Data were collected on patients newly referred to UK rheumatology out-patient departments over an 8-week period. Baseline data included demographics, method of diagnosis, clinical features, comorbidities, urate-lowering therapy (ULT), prophylaxis and blood tests. Twelve months later, the most recent serum uric acid level was collected. Management was compared with audit standards derived from the 2006 EULAR recommendations, 2007 British Society for Rheumatology/British Health Professionals in Rheumatology guideline and the National Institute for Health and Care Excellence febuxostat technology appraisal. Data were collected for 434 patients from 91 rheumatology departments (mean age 59.8 years, 82% male). Diagnosis was crystal-proven in 13%. Of 106 taking a diuretic, this was reduced/stopped in 29%. ULT was continued/initiated in 76% of those with one or more indication for ULT. One hundred and fifty-eight patients started allopurinol: the starting dose was most commonly 100 mg daily (82%); in those with estimated glomerular filtration rate <60 ml/min the highest starting dose was 100 mg daily. Of 199 who started ULT, prophylaxis was co-prescribed for 94%. Fifty patients started a uricosuric or febuxostat: 84% had taken allopurinol previously. Of 44 commenced on febuxostat, 18% had a history of heart disease. By 12 months, serum uric acid levels ⩽360 and <300 μmol/l were achieved by 45 and 25%, respectively. Gout management by UK rheumatologists concords well with guidelines for most audit standards. However, fewer than half of patients achieved a target serum uric level over 12 months. Rheumatologists should help ensure that ULT is optimized to achieve target serum uric acid levels to benefit patients.

Comparison of avian biochemical test results with Abaxis VetScan and Hitachi 911 analyzers.

PubMed

Greenacre, Cheryl B; Flatland, Bente; Souza, Marcy J; Fry, Michael M

2008-12-01

To compare results of clinical biochemical analysis using an Abaxis VetScan bench-top analyzer with reagents specifically marketed for avian use and a Hitachi 911 analyzer, plasma (both methods) and whole blood (VetScan method) samples from 20 clinically healthy Hispaniolan Amazon parrots (Amazona ventralis) were analyzed. Correlation between methods was very high (r = 0.9-1.0) for aspartate aminotransferase (AST), calcium, glucose, and uric acid; high (r = 0.7-0.89) for creatine kinase (CK), phosphorus, potassium, and total protein; moderate (r = 0.5-0.69) for globulin; and low (r = 0.3-0.49) for albumin and sodium. VetScan analyzer results for globulin, sodium, and uric acid had a constant negative bias (values below those from the Hitachi method). Based on difference plot analysis, results for AST, calcium, CK, and glucose are comparable. Because 16 of 20 values fell below the lower detection limit of the VetScan analyzer, bile acid data were excluded from analysis. By using a relatively small sample size (0.1 ml whole blood or plasma), the VetScan analyzer offers rapid in-house results, compact size, and ease of operation. For 4 of the most clinically relevant biochemical analytes used in avian medicine (AST, calcium, CK, glucose), it offers reliable values. For an additional 4 analytes (phosphorous, potassium, total protein, uric acid), establishing analyzer-specific reference intervals is recommended. Neither the VetScan nor the Hitachi method is recommended to assess albumin and globulin concentrations.

A Randomized Controlled Trial of the Effects of Febuxostat Therapy on Adipokines and Markers of Kidney Fibrosis in Asymptomatic Hyperuricemic Patients With Diabetic Nephropathy

PubMed Central

Beddhu, Srinivasan; Filipowicz, Rebecca; Wang, Bin; Wei, Guo; Chen, Xiaorui; Roy, Abinash C.; DuVall, Scott L.; Farrukh, Hanadi; Habib, Arsalan N.; Bjordahl, Terrence; Simmons, Debra L.; Munger, Mark; Stoddard, Greg; Kohan, Donald E.; Greene, Tom; Huang, Yufeng

2016-01-01

Background: In observational studies, higher uric acid levels are associated with metabolic syndrome, diabetes, and kidney disease. Objective: The objective of this study is to examine whether reduction of plasma uric acid with febuxostat, a xanthine oxido reductase inhibitor, impacts adipose tissue oxidative stress, adipokines, and markers of systemic inflammation or kidney fibrosis. Design: This was a double-blinded randomized controlled trial. Setting: Academic university setting was used. Patients: Overweight or obese adults with hyperuricemia and type 2 diabetic nephropathy were included. Measurements: Adipose tissue thiobarbituric acid reducing substances (TBARS) and adiponectin concentrations and urinary transforming growth factor–β (TGF-β) were primary endpoints. Plasma C-reactive protein, high molecular weight–adiponectin, interleukin–6, tumor necrosis factor–α, and TBARS and albuminuria were among predefined secondary endpoints. Methods: Participants were randomly assigned to febuxostat (n = 40) or matching placebo (n = 40) and followed for 24 weeks. Results: Baseline plasma uric acid levels were 426 ± 83 µmol/L; 95% completed the study. Estimated glomerular filtration rate (eGFR) declined from 54 ± 17 mL/min/1.73 m2 at baseline to 51 ± 17 mL/min/1.73 m2 at 24 weeks (P = .05). In separate mixed-effects models, compared with placebo, febuxostat reduced uric acid by 50% (P < .001) but had no significant effects on subcutaneous adipose tissue TBARS (−7.4%, 95% confidence interval [CI], 57.4%-101.4%) or adiponectin (6.7%, 95% CI, 26.0%-53.8%) levels or urinary TGF-β/creatinine ratio (18.0%, 95% CI, 10.0%-54.8%) or secondary endpoints. Limitations: Relatively modest sample size and short duration of follow-up. Conclusions: In this population with progressive diabetic nephropathy, febuxostat effectively reduced plasma uric acid. However, no detectable effects were observed for the prespecified primary or secondary endpoints. Trial Registration: The study was registered in clinicaltrials.gov (NCT01350388). PMID:28270924

Plasma chemistry references values in psittaciformes.

PubMed

Lumeij, J T; Overduin, L M

1990-04-01

Reference values for 17 plasma chemical variables in African greys. Amazons, cockatoos and macaws were established for use in avian clinical practice. The inner limits are given for the percentiles P(2.5) and P(97.5) with a probability of 90%. The following variables were studied: urea, creatinine, uric acid, urea/uric acid ratio, osmolality, sodium, potassium, calcium, glucose, aspartate aminotransferase, alanine aminotransferase, gamma glutamyltransferase, lactate dehydrogenase, creatine kinase, bile acids, total protein, albumin/globulin ratio. Differences between methods used and values found in this study and those reported previously are discussed.

Biomarkers to Assess Possible Biological Effects on Reproductive Potential, Immune Function, and Energetic Fitness of Bottlenose Dolphins Exposed to Sounds Consistent with Naval Sonars

DTIC Science & Technology

2011-09-30

creatinine, calcium, ALK.phos, AST(SGOT), ALT(SGPT), total bilirubin, total protein and albumin); iron, LDH; phosphate; and uric acid . For liver function...assays AST, ALT, total bilirubin, and uric acid are most relevant, whereas for kidney function, BUN and creatinine are of particular interest. For...formic acid (for analysis in the positive ion mode) and in methanol:water 4:1 with 10 mM ammonium acetate (for the negative ion mode). FT-ICR mass

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

Prevalence of peripheral artery disease (PAD) and factors associated: An epidemiological analysis from the population-based Screening PRE-diabetes and type 2 DIAbetes (SPREDIA-2) study.

PubMed

Cornejo Del Río, V; Mostaza, J; Lahoz, C; Sánchez-Arroyo, V; Sabín, C; López, S; Patrón, P; Fernández-García, P; Fernández-Puntero, B; Vicent, D; Montesano-Sánchez, L; García-Iglesias, F; González-Alegre, T; Estirado, E; Laguna, F; de Burgos-Lunar, C; Gómez-Campelo, P; Abanades-Herranz, J C; de Miguel-Yanes, J M; Salinero-Fort, M A

2017-01-01

To describe the prevalence of Peripheral Artery Disease (PAD) in a random population sample and to evaluate its relationship with Mediterranean diet and with other potential cardiovascular risk factors such as serum uric acid and pulse pressure in individuals ranged 45 to 74 years. Cross-sectional analysis of 1568 subjects (mean age 6.5 years, 43% males), randomly selected from the population. A fasting blood sample was obtained to determine glucose, lipids, and HbA1C levels. An oral glucose tolerance test was performed in non-diabetic subjects. PAD was evaluated by ankle-brachial index and/or having a prior diagnosis. PAD prevalence was 3.81% (95% CI, 2.97-4.87) for all participants. In men, PAD prevalence was significantly higher than in women [5.17% (95% CI, 3.74-7.11) vs. 2.78% (95% CI, 1.89-4.07); p = 0.014]. Serum uric acid in the upper quartile was associated with the highest odds ratio (OR) of PAD (for uric acid > 6.1 mg/dl, OR = 4.31; 95% CI, 1.49-12.44). The remaining variables more strongly associated with PAD were: Heart rate >90 bpm (OR = 4.16; 95%CI, 1.62-10.65), pulse pressure in the upper quartile (≥ 54 mmHg) (OR = 3.82; 95%CI, 1.50-9.71), adherence to Mediterranean diet (OR = 2.73; 95% CI, 1.48-5.04), and former smoker status (OR = 2.04; 95%CI, 1.00-4.16). Our results show the existence of a low prevalence of peripheral artery disease in a population aged 45-74 years. Serum uric acid, pulse pressure and heart rate >90 bpm were strongly associated with peripheral artery disease. The direct association between Mediterranean diet and peripheral artery disease that we have found should be evaluated through a follow-up study under clinical practice conditions.

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

Comparative Analysis of Serum (Anti)oxidative Status Parameters in Healthy Persons

PubMed Central

Jansen, Eugène HJM; Ruskovska, Tatjana

2013-01-01

Five antioxidant and two oxidative stress assays were applied to serum samples of 43 healthy males. The antioxidant tests showed different inter-assay correlations. A very good correlation of 0.807 was observed between the ferric reducing ability of plasma (FRAP) and total antioxidant status (TAS) assay and also a fair correlation of 0.501 between the biological antioxidant potential (BAP) and TAS assay. There was no statistically significant correlation between the BAP and FRAP assay. The anti-oxidant assays have a high correlation with uric acid, especially the TAS (0.922) and FRAP assay (0.869). The BAP assay has a much lower and no statistically significant correlation with uric acid (0.302), which makes BAP more suitable for the antioxidant status. The total thiol assay showed no statistically significant correlation with uric acid (0.114). The total thiol assay, which is based on a completely different principle, showed a good and statistically significant correlation with the BAP assay (0.510) and also to the TAS assay, but to a lower and not significant extent (0.279) and not with the FRAP assay (−0.008). The oxy-adsorbent test (OXY) assay has no correlation with any of the other assays tested. The oxidative stress assays, reactive oxygen metabolites (ROM) and total oxidant status (TOS), based on a different principle, do not show a statistically significant correlation with the serum samples in this study. Both assays showed a negative, but not significant, correlation with the antioxidant assays. In conclusion, the ROM, TOS, BAP and TTP assays are based on different principles and will have an additional value when a combination of these assays will be applied in large-scale population studies. PMID:23507749

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.

Japan Report, Science and Technology.

DTIC Science & Technology

1987-05-06

Figure 17. Microcapsule Type Enzyme Immobilized Membrane Such metabolites as creatinine, uric acid , and vitamin B12 are relatively easily adsorbed by...WEST EUROPE ivory AFRICA (SUB-SAHARA) tan SCIENCE $ TECHNOLOGY gray WORLDWIDES pewter The changes that are of interest to readers of this report...condition and that they are unstable in strong acids , strong bases, organic solvents, and heat. Ordinarily, an enzyme docks with a substrate in an

Efficacy and safety of febuxostat in the treatment of hyperuricemia in stable kidney transplant recipients

PubMed Central

Sofue, Tadashi; Inui, Masashi; Hara, Taiga; Nishijima, Yoko; Moriwaki, Kumiko; Hayashida, Yushi; Ueda, Nobufumi; Nishiyama, Akira; Kakehi, Yoshiyuki; Kohno, Masakazu

2014-01-01

Background Post-transplant hyperuricemia (PTHU), defined as serum uric acid concentration ≥7.0 mg/dL or need for treatment with allopurinol or benzbromarone, reduces long-term allograft survival in kidney transplant recipients. Febuxostat, a new nonpurine selective xanthine oxidase inhibitor, is well tolerated in patients with moderate renal impairment. However, its efficacy and safety in kidney recipients with PTHU is unclear. We therefore assessed the efficacy and safety of febuxostat in stable kidney transplant recipients with PTHU. Methods Of 93 stable adult kidney transplant recipients, 51 were diagnosed with PTHU (PTHU group) and 42 were not (NPTHU group). Of the 51 patients with PTHU, 26 were treated with febuxostat (FX group) and 25 were not (NFX group), at the discretion of each attending physician. One-year changes in serum uric acid concentrations, rates of achievement of target uric acid (<6.0 mg/dL), estimated glomerular filtration rates in allografts, and adverse events were retrospectively analyzed in the FX, NFX, and NPTHU groups. Results The FX group showed significantly greater decreases in serum uric acid (−2.0±1.1 mg/dL versus 0.0±0.8 mg/dL per year, P<0.01) and tended to show a higher rate of achieving target uric acid levels (50% versus 24%; odds ratio 3.17 [95% confidence interval 0.96–10.5], P=0.08) than the NFX group. Although baseline allograft estimated glomerular filtration rates tended to be lower in the FX group than in the NFX group (40±14 mL/min/1.73 m2 versus 47±19 mL/min/1.73 m2), changes in allograft estimated glomerular filtration rate were similar (+1.0±4.9 mL/min/1.73 m2 versus −0.2±6.9 mL/min/1.73 m2 per year, P=0.50). None of the patients in the FX group experienced any severe adverse effects, such as pancytopenia or attacks of gout, throughout the entire study period. Nephrologists were more likely than urologists to start febuxostat in kidney transplant recipients with PTHU (69% versus 8%). Conclusion Treatment with febuxostat sufficiently lowered uric acid levels without severe adverse effects in stable kidney transplant recipients with PTHU. PMID:24600205

Efficacy and safety of febuxostat in the treatment of hyperuricemia in stable kidney transplant recipients.

PubMed

Sofue, Tadashi; Inui, Masashi; Hara, Taiga; Nishijima, Yoko; Moriwaki, Kumiko; Hayashida, Yushi; Ueda, Nobufumi; Nishiyama, Akira; Kakehi, Yoshiyuki; Kohno, Masakazu

2014-01-01

Post-transplant hyperuricemia (PTHU), defined as serum uric acid concentration ≥7.0 mg/dL or need for treatment with allopurinol or benzbromarone, reduces long-term allograft survival in kidney transplant recipients. Febuxostat, a new nonpurine selective xanthine oxidase inhibitor, is well tolerated in patients with moderate renal impairment. However, its efficacy and safety in kidney recipients with PTHU is unclear. We therefore assessed the efficacy and safety of febuxostat in stable kidney transplant recipients with PTHU. Of 93 stable adult kidney transplant recipients, 51 were diagnosed with PTHU (PTHU group) and 42 were not (NPTHU group). Of the 51 patients with PTHU, 26 were treated with febuxostat (FX group) and 25 were not (NFX group), at the discretion of each attending physician. One-year changes in serum uric acid concentrations, rates of achievement of target uric acid (<6.0 mg/dL), estimated glomerular filtration rates in allografts, and adverse events were retrospectively analyzed in the FX, NFX, and NPTHU groups. The FX group showed significantly greater decreases in serum uric acid (-2.0±1.1 mg/dL versus 0.0±0.8 mg/dL per year, P<0.01) and tended to show a higher rate of achieving target uric acid levels (50% versus 24%; odds ratio 3.17 [95% confidence interval 0.96-10.5], P=0.08) than the NFX group. Although baseline allograft estimated glomerular filtration rates tended to be lower in the FX group than in the NFX group (40±14 mL/min/1.73 m(2) versus 47±19 mL/min/1.73 m(2)), changes in allograft estimated glomerular filtration rate were similar (+1.0±4.9 mL/min/1.73 m(2) versus -0.2±6.9 mL/min/1.73 m(2) per year, P=0.50). None of the patients in the FX group experienced any severe adverse effects, such as pancytopenia or attacks of gout, throughout the entire study period. Nephrologists were more likely than urologists to start febuxostat in kidney transplant recipients with PTHU (69% versus 8%). Treatment with febuxostat sufficiently lowered uric acid levels without severe adverse effects in stable kidney transplant recipients with PTHU.

Clinical Investigation Program Report Control Symbol MED 300.

DTIC Science & Technology

1982-10-01

Preeclampsia as an Aid to Further Management. (C) (PR) 41 1961 Use of C-Reactive Protein in Prediction of ARD Prog- nosiS, (C) (PR) 42 1981 The Assessment...37 Status: Completed * Title: Routine Use of Serum Uric Acid Levels at 36 Weeks Gestation as Screening Test for Preeclampsia as an Aid to Further...nvestigators: .amily Pr-&ctiU. CPT Ellis M. Knight, MC Key Words: Serum Uric Acid Preeclampsia Accumulative MZDCASI Eat Accumulative Periodic Mar 82 Cost: ]A

Autosomal dominant tubulointerstitial kidney disease caused by uromodulin mutations: seek and you will find.

PubMed

Raffler, Gabriele; Zitt, Emanuel; Sprenger-Mähr, Hannelore; Nagel, Mato; Lhotta, Karl

2016-04-01

Uromodulin (UMOD)-associated kidney disease belongs to the group of autosomal dominant interstitial kidney diseases and is caused by mutations in the UMOD gene. Affected patients present with hyperuricemia, gout, and progressive renal failure. The disease is thought to be very rare but is probably underdiagnosed. Two index patients from two families with tubulointerstitial nephropathy and hyperuricemia were examined, including blood and urine chemistry, ultrasound, and mutation analysis of the UMOD gene. In addition, other available family members were studied. In a 46-year-old female patient with a fractional excretion of uric acid of 3 %, analysis of the UMOD gene revealed a p.W202S missense mutation. The same mutation was found in her 72-year-old father, who suffers from gout and end-stage renal disease. The second index patient was a 47-year-old female with chronic kidney disease and gout for more than 10 years. Her fractional uric acid excretion was 3.5 %. Genetic analysis identified a novel p.H250Q UMOD mutation that was also present in her 12-year-old son, who had normal renal function and uric acid levels. In patients suffering from chronic tubulointerstitial nephropathy, hyperuricemia, and a low fractional excretion of uric acid mutation, analysis of the UMOD gene should be performed to diagnose UMOD-associated kidney disease.

Fourier transform infrared spectroscopy for analysis of kidney stones.

PubMed

Khan, Aysha Habib; Imran, Sheharbano; Talati, Jamsheer; Jafri, Lena

2018-01-01

To compare the results of a chemical method of kidney stone analysis with the results of Fourier transform infrared (FT-IR) spectroscopy. Kidney stones collected between June and October 2015 were simultaneously analyzed by chemical and FT-IR methods. Kidney stones (n=449) were collected from patients from 1 to 81 years old. Most stones were from adults, with only 11.5% from children (aged 3-16 years) and 1.5% from children aged <2 years. The male to female ratio was 4.6. In adults, the calcium oxalate stone type, calcium oxalate monohydrate (COM, n=224), was the most common crystal, followed by uric acid and calcium oxalate dihydrate (COD, n=83). In children, the most frequently occurring type was predominantly COD (n=21), followed by COM (n=11), ammonium urate (n=10), carbonate apatite (n=6), uric acid (n=4), and cystine (n=1). Core composition in 22 stones showed ammonium urate (n=2), COM (n=2), and carbonate apatite (n=1) in five stones, while uric acid crystals were detected (n=13) by FT-IR. While chemical analysis identified 3 stones as uric acid and the rest as calcium oxalate only. Agreement between the two methods was moderate, with a kappa statistic of 0.57 (95% confidence interval, 0.5-0.64). Disagreement was noted in the analysis of 77 stones. FT-IR analysis of kidney stones can overcome many limitations associated with chemical analysis.

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.

Vapor-phase deposition of polymers as a simple and versatile technique to generate paper-based microfluidic platforms for bioassay applications.

PubMed

Demirel, Gokhan; Babur, Esra

2014-05-21

Given their simplicity and functionality, paper-based microfluidic systems are considered to be ideal and promising bioassay platforms for use in less developed countries or in point-of-care services. Although a series of innovative techniques have recently been demonstrated for the fabrication of such platforms, development of simple, inexpensive and versatile new strategies are still needed in order to reach their full potential. In this communication, we describe a simple yet facile approach to fabricate paper-based sensor platforms with a desired design through a vapor-phase polymer deposition technique. We also show that the fabricated platforms could be readily employed for the detection of various biological target molecules including glucose, protein, ALP, ALT, and uric acid. The limit of detection for each target molecule was calculated to be 25 mg dL(-1) for glucose, 1.04 g L(-1) for protein, 7.81 unit per L for ALP, 1.6 nmol L(-1) for ALT, and 0.13 mmol L(-1) for uric acid.

Simultaneous determination of 16 purine derivatives in urinary calculi by gradient reversed-phase high-performance liquid chromatography with UV detection.

PubMed

Safranow, Krzysztof; Machoy, Zygmunt

2005-05-25

A reversed-phase high-performance liquid chromatography (HPLC) method with ultraviolet detection has been developed for the analysis of purines in urinary calculi. The method using gradient of methanol concentration and pH was able to separate 16 compounds: uric acid, 2,8-dihydroxyadenine, xanthine, hypoxanthine, allopurinol and oxypurinol as well as 10 methyl derivatives of uric acid or xanthine (1-, 3-, 7- and 9-methyluric acid, 1,3-, 1,7- and 3,7-dimethyluric acid, 1-, 3- and 7-methylxanthine). Limits of detection for individual compounds ranged from 0.006 to 0.035 mg purine/g of the stone weight and precision (CV%) was 0.5-2.4%. The method enabled us to detect in human uric acid stones admixtures of nine other purine derivatives: natural metabolites (hypoxanthine, xanthine, 2,8-dihydroxyadenine) and methylated purines (1-, 3- and 7-methyluric acid, 1,3-dimethyluric acid, 3- and 7-methylxanthine) originating from the metabolism of methylxanthines (caffeine, theophylline and theobromine). The method allows simultaneous quantitation of all known purine constituents of urinary stones, including methylated purines, and may be used as a reference one for diagnosing disorders of purine metabolism and research on the pathogenesis of urolithiasis.

Relative Supersaturation of 24-Hour Urine and Likelihood of Kidney Stones.

PubMed

Prochaska, Megan; Taylor, Eric; Ferraro, Pietro Manuel; Curhan, Gary

2018-05-01

The relative supersaturation of calcium oxalate, calcium phosphate and uric acid is used clinically in kidney stone prevention. The magnitude of the association between relative supersaturation and stone risk requires further quantification. We performed a cross-sectional study using 24-hour urine collections from the NHS (Nurses' Health Study) I and II, and HPFS (Health Professionals Follow-up Study) cohorts to quantify the association between the relative supersaturation of calcium oxalate, calcium phosphate and uric acid, and the likelihood of stone formation. The OR of being a stone former was 5.85 (95% CI 3.40-10.04) in NHS I, 6.38 (95% CI 3.72-11.0) in NHS II and 6.95 (95% CI 3.56-13.6) in HPFS for the highest category of calcium oxalate relative supersaturation compared with less than 1.0. The OR of being a stone former was 1.86 (95% CI 0.94-3.71) in NHS I, 4.37 (95% CI 2.68-7.10) in NHS II and 3.59 (95% CI 2.04-6.31) in HPFS for the highest category of calcium phosphate relative supersaturation compared with less than 1.0. For uric acid relative supersaturation the OR of being a stone former was 4.30 (95% CI 2.34-7.90) in NHS I and 2.74 (95% CI 1.71-4.40) in NHS II for the highest relative supersaturation category compared with less than 1.0. In HPFS the uric acid relative supersaturation was not significantly associated with the likelihood of stone formation. The likelihood of being a stone former increases with higher relative supersaturation of calcium oxalate and calcium phosphate in men and women, and with higher relative supersaturation of uric acid in women. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

[Comparative efficacy of nitrofurans in children and adolescents with pyelonephritis in presence of crystalluria].

PubMed

Aver'anova, N I; Balueva, L G; Ivanova, N V

2013-01-01

To evaluate the efficacy of nitrofurans in children and adolescents with pyelonephritis in the presence of crystalluria. The study included 50 patients aged 4-14 years with chronic pyelonephritis in the presence of dysmetabolism. The patients underwent general blood test, general urinalysis with an urocytogram, bacteriological examination of urine, biochemical test of serum (uric acid, calcium, phosphorus, magnesium, urea, and creatinine) and 24-hour urinary excretion (uric acid, oxalates, calcium, phosphorus, and magnesium) at hospital admission and over time. The treatment regimen for Group 1 patients after antibiotic therapy involved furamag, Group 2 received furagin. The drugs were used in a dosage of 2 mg/kg/day in 2 divided doses for 14 days. Complaints, major clinical manifestations, crystalluria patterns, and a number of laboratory findings were analyzed over time. The urinary sediment showed leukocyturia and bacteriuria in all the patients, oxaluria in 70% of the patients, uraturia in 10%, and mixed crystalluria in 20%. The main etiological agent of pyelonephritis was Escherichia coli (48.4%). Increased serum uric acid concentrations were revealed in 14% of the patients. Daily urine tests revealed hyperoxaluria, hyperuricosuria, and hypercalciuria in 86, 18, and 8% of the patients, respectively; urinary magnesium excretion was reduced in 86%. After treatment, Group 1 patients showed a more marked therapeutic effect in terms of a number of indicators (leukocyturia, crystalluria, uricosuria, magnesuria). The results of the study showed that the antibacterial therapy involving antibiotics and nitrofurans for an exacerbation of chronic pyelonephritis in the presence of crystalluria not only provides an anti-inflammatory effect, but also leads to reductions in the level of crystalluria and the urinary content of uric acid and calcium. There was a significantly marked reduction in crystalluria, serum uric acid, and urinary oxalates and calcium in the children taking furamag. Out of nitrofurans, furamag may be recommended as the drug of choice to treat urinary tract infections in the presence of crystalluria.

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.

Febuxostat for treating allopurinol-resistant hyperuricemia in patients with chronic kidney disease.

PubMed

Sakai, Yukinao; Otsuka, Tomoyuki; Ohno, Dai; Murasawa, Tsuneo; Sato, Naoki; Tsuruoka, Shuichi

2014-03-01

Availability of the novel xanthine oxidase inhibitor febuxostat, which has multiple excretion pathways, enables investigation of the significance of serum uric acid control on renal function in patients with chronic kidney disease (CKD). This was an exploratory, retrospective, observational study conducted at a single Japanese center. Serum uric acid concentrations and serum creatinine levels in the 6 months before and after the start of febuxostat treatment were collected for CKD patients switched from allopurinol after failing to achieve serum uric acid concentrations ≤6.0 mg/dL. Evaluable data were available for 60 patients, 67% of whom had advanced CKD (eGFR <30 mL/min/1.73 m2). Mean dose of febuxostat was 15.9 (± 8) mg/day. Mean serum uric acid concentration decreased from 8.4 (±1.4) mg/dL at baseline to 6.2 (±1.2) mg/dL at 6 months; 47.5% of patients achieved a level ≤6.0 mg/dL. The change from baseline in eGFR was positive at all time points during febuxostat treatment and the increase of 2.3 (±5.6) mL/min/1.73 m2 at 6 months was significant (p = 0.0027). Whereas the eGFR slope was negative during allopurinol treatment, it became positive after the switch to febuxostat. The change in eGFR slope before and after febuxostat treatment was significant for all patients (p < 0.01), for male patients (p < 0.05), and for patients with a baseline eGFR of <15 mL/min/1.73 m2 (p < 0.05). In patients with CKD, febuxostat reduces serum uric acid concentrations effectively and may suppress the progressive decline in renal function.

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. All rights reserved.

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.

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.

Enhancing Activity and Stability of Uricase from Lactobacillus plantarum by Zeolite immobilization

NASA Astrophysics Data System (ADS)

Iswantini, D.; Nurhidayat, N.; Sarah

2017-03-01

Lactobacillus plantarum has been known be able to produce uricase for uric acid biosensor. Durability and stability of L. plantarum in generating uricase enzyme was low. Hence, we tried to enhance its durability and stability by immobilizing it onto activated 250 mg zeolite at room temperature using 100 μL L.plantarum suspension and 2.87 mM uric acid, while Michaelis-Menten constant (KM) and Vmax were obtained at 6.7431 mM and 0.9171 µA consecutively, and the linearity range was 0.1-3.3 mM (R2 = 0.9667). Limit of detection (LOD) and limit of quantification (LOQ) value of the measurement were 0.4827 mM and 1.6092 mM respectively. Biosensor stability treatment was carried out in two different treatments, using the same electrode and using disposable electrode. The disposable electrode stability showed better result based on repeated measurements, but stability was still need improvement.

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.

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

A urolith of biogenic dolomite - another clue in the dolomite mystery

NASA Astrophysics Data System (ADS)

Mansfield, Charles F.

1980-06-01

A male Dalmatian, Canis familiaris, produced uroliths of almost pure dolomite, 3-8 mm across, in his urinary bladder in less than 8 months at 38°C and about 1 atm. The X-ray diffractogram identified the predominant mineral as dolomite, and the sharp (01.5) peak showed it is ordered dolomite, not the disordered form, protodolomite. Geochemically and biologically plausible causes include (1) renal, respiratory, or metabolic alkalosis, (2) infection by urease-producing (urea-splitting) fungi or bacteria and (3) infection by uric acid-fermenting bacteria. Hematological, bacteriological, urological and geochemical considerations most strongly implicate infection by either anaerobic, urease-producing bacteria or anaerobic, uric acid-fermenting bacteria. The physical and chemical conditions of this urinary system more closely approximate modern and inferred ancient carbonate depositional settings than most previous laboratory experiments, especially in terms of temperature, pressure, total salinity and, possibly, biota. The presence of urease-producing and/or uric acid-fermenting bacteria in urea- and/or acid-containing sediment, such as fecal pellets and algal mats, could promote formation of authigenic dolomite or other carbonates.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takigami, S.; Maeda, Y.; Nakamura, Y.

The diffusive permeability of potassium chloride, urea, and uric acid through cellophanes grafted with acrylamide, acrylic acid, styrene, and N-vinyl-2-pyrrolidone by ..gamma..-ray irradiation was studied. The diffusive permeability coefficients of the permeants through the grafted cellophanes were increased with increase in hydration of the grafted membranes, except for the permeation of potassium chloride through cellophanes grafted with acrylic acid. The permeation of potassium chloride, urea, and uric acid through the various grafted cellophanes is explained by the free volume concept of homogeneously water-swollen membranes. However, the behavior of the permeation of potassium chloride through cellophane grafted with acrylic acid deviatedmore » from that of nonionic membranes because of the contribution of the electrical interaction between electrolyte and charge of the membrane. 4 figures, 3 tables.« less

Hyperuricemia Is a Risk Factor for the Onset of Impaired Fasting Glucose in Men with a High Plasma Glucose Level: A Community-Based Study

PubMed Central

Miyake, Teruki; Kumagi, Teru; Furukawa, Shinya; Hirooka, Masashi; Kawasaki, Keitarou; Koizumi, Mitsuhito; Todo, Yasuhiko; Yamamoto, Shin; Abe, Masanori; Kitai, Kohichiro; Matsuura, Bunzo; Hiasa, Yoichi

2014-01-01

Background It is not clear whether elevated uric acid is a risk factor for the onset of impaired fasting glucose after stratifying by baseline fasting plasma glucose levels. We conducted a community-based retrospective longitudinal cohort study to clarify the relationship between uric acid levels and the onset of impaired fasting glucose, according to baseline fasting plasma glucose levels. Methods We enrolled 6,403 persons (3,194 men and 3,209 women), each of whom was 18–80 years old and had >2 annual check-ups during 2003–2010. After excluding persons who had fasting plasma glucose levels ≥6.11 mM and/or were currently taking anti-diabetic agents, the remaining 5,924 subjects were classified into quartiles according to baseline fasting plasma glucose levels. The onset of impaired fasting glucose was defined as fasting plasma glucose ≥6.11 mM during the observation period. Results In the quartile groups, 0.9%, 2.1%, 3.4%, and 20.2% of the men developed impaired fasting glucose, respectively, and 0.1%, 0.3%, 0.5%, and 5.6% of the women developed impaired fasting glucose, respectively (P trend <0.001). After adjusting for age, body mass index, systolic blood pressure, triacylglycerols, high density lipoprotein-cholesterol, creatinine, fatty liver, family history of diabetes, alcohol consumption, and current smoking, uric acid levels were positively associated with onset of impaired fasting glucose in men with highest-quartile fasting plasma glucose levels (adjusted hazard ratio, 1.003; 95% confidence interval, 1.0001–1.005, P = 0.041). Conclusions Among men with high fasting plasma glucose, hyperuricemia may be independently associated with an elevated risk of developing impaired fasting glucose. PMID:25237894

Colorimetric and fluorometric determination of uric acid based on the use of nitrogen-doped carbon quantum dots and silver triangular nanoprisms.

PubMed

Wang, Yanying; Yang, Yan; Liu, Wei; Ding, Fang; Zhao, Qingbiao; Zou, Ping; Wang, Xianxiang; Rao, Hanbing

2018-05-04

A dual-read detection system is described for non-enzymatic and non-aggregation based analysis of uric acid (UA). Silver triangular nanoprisms (AgTNPs) were used as colorimetric probes, while the reduction in the fluorescence of nitrogen-doped carbon quantum dots (N-CQDs) served as the fluorometric readout. The absorption band of the AgTNPs overlaps the emission band of N-CQDs (with a peak at 440 nm). Therefore, fluorescence is reduced owing to an inner filter effect. The AgTNPs are etched if exposed to H 2 O 2 , and round nanodiscs are formed. In the presence of UA, etching of the AgTNPs is suppressed because the facets of the AgTNPs are coated with UA. The absorbance, best measured at 683 nm, increases with the concentration of the pre-added UA. The colorimetric assay works in the 0.1-45 μM UA concentration range, and the fluorometric assay between 1 and 42 μM of UA. The respective detection limits are 50 and 200 nM, respectively. The probe can be used for direct visualization of UA. The method was successfully applied to the determination of UA in urine samples. Graphical abstract The fluorescence of nitrogen-doped carbon quantum dots (N-CQDs) is quenched by AgTNPs (silver triangular nanoprisms). As the AgTNPs are etched by H 2 O 2 , fluorescence recovers in the system after H 2 O 2 is added, and also undergoes a color change. Uric acid (UA) protects the AgTNPs from etching because the facets of the AgTNPs are coated with UA. The fluorescence of N-CQDs decreases. Thus, a dual-read probe is developed for determination of UA.

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.