Increase In Uric Acid Concentration Research Articles

Electrochemical detection of uric acid in human serum based on ultrasmall Ta2O5 nanoparticle anchored Pt atom with ultrahigh uricase and catalase activities.

The synthesis of ultrasmall Ta2O5 nanoparticle anchored Pt atom using aspartic acid-functionalized graphene quantum dot (Asp-GQD)is reported. The Asp-GQD was combined with tantalic acid and chloroplatinic acid to rapidly form water-soluble Ta-Asp-GQD and Pt-Asp-GQD complex. Followed by thermal annealing at 900 °C in N2 to obtain Ta2O5-Asp-GQD-Pt. The study shows that the introduction of Asp-GQD as a chelating agent and p-type semiconductor achieves to the formation of ultrasmall Ta2O5 nanoparticle, PN junction at the interface and Pt single atom anchored on the surface of Ta2O5 nanocrystals. The unique structure realizes ultrahigh uricase activity and catalase activities of Ta2O5-Asp-GQD-Pt. The Ta2O5-Asp-GQD-Pt was used as the bifunctional sensing material for the construction of an electrochemical uric acid sensor. The differential pulse voltammetric current at 0.45 V linearly increases with the increase of uric acid concentration in the range 0.001-5.00 mM with the detection limit of 0.41 μM (S/N = 3). The sensor exhibits a much better sensitivity compared with the reported methods for the detection of uric acid. The proposed analytical method has been applied tothe electrochemical detection of uric acid in human serum with a spiked recovery of 95-105%. The study also offers one way to design and synthesize multifunctional sensing materials with high catalytic activity.

Intravascular large B-cell lymphoma with isolated bone marrow involvement

Introduction. Intravascular large B-cell lymphoma is a rare variant of large B-cell, highly invasive extranodal tumors of the lymphatic system. The pathogenesis of the disease lies in the ability of tumor cells to penetrate into small vessels and capillaries of various organs. The clinical presentation is atypical for diffuse large B-cell lymphoma. In the relevant literature, information on the diagnosis and treatment of this pathology is extremely rare, therefore each publication makes a significant contribution to expanding the horizons of hematologists and morphologists.Aim – to present a case of diagnosing intravascular B-cell lymphoma.Main findings. A clinical case of a 78-year-old patient who fell ill acutely is presented. At the onset of the disease, febrile fever was noted. In the general blood test: hemoglobin – 104 g/L; erythrocytes – 3.0 × 1012/L; ESR – 24 mm/h; platelets – 112 × 109/L, leukocytes – 4.9 × 109/L, 4 % of cells with lymphoblast morphology were found in the leukocyte formula. Blood serum tests revealed: an increase in uric acid concentrations – up to 639 μmol/L, LDH – up to 1885 U/L, beta-2-microglobulin – up to 8.9 mmol/L, C-reactive protein – up to 0.6 g/L, a decrease in the concentration of total protein – up to 45 g/L, an increase in the concentration of aspartate aminotransferase – up to 48 units/L at normal concentrations of bilirubin and alanine aminotransferase.The histological and immunohistochemical picture, according to the study of bone biopsy, most corresponded to bone marrow damage by intravascular large B-cell lymphoma. Immunophenotyping was carried out – 15.7 % of blast cells with immunophenotype CD19+HLA/DR+CD24+CD37+CD20+CD10+IgM+ were detected. Cytogenetic studies revealed no karyotype abnormalities. The result of fluorescence in situ hybridization of the IGH locus (14q32) was normal. Based on the data obtained, the final clinical diagnosis was established: diffuse large B-cell lymphoma, stage IVB, intravascular variant with bone marrow involvement, aggressive course. The patient was prescribed the first line of therapy according to the R-CHOP scheme (rituximab, cyclophosphamide, vincristine, prednisolone). In the control study of the bone marrow, after the first course of therapy, the number of lymphoid elements was 3.6 %, laboratory parameters returned to normal.

Changes in Oxidative Status Biomarkers in Saliva and Serum in the Equine Gastric Ulcer Syndrome and Colic of Intestinal Aetiology: A Pilot Study.

Simple SummaryGastric ulcers and colic of intestinal aetiology (CIE) are highly prevalent diseases in domestic horses, with a negative impact on equine sport and breeding life. Therefore, the studies investigating possible biomarkers for their diagnosis or clarifying their pathophysiology are of high interest. Oxidative status changes have been reported in both diseases, but only in the blood. However, saliva may be a relevant source of oxidative status biomarkers not yet assessed in horses with interesting advantages, owing to its non-invasive collection. Hence, this study aimed to validate in both saliva and serum automated assays for the measurement of oxidative status biomarkers and assess them in horses suffering gastric ulcer diseases (squamous and/or glandular) and CIE, studying their possible relationship with their inflammatory and immunity status. It was found that horses with glandular mucosa ulcers showed higher levels of some antioxidant and oxidative biomarkers in saliva correlating with a marker of the immune system such as salivary adenosine deaminase. Horses suffering from CIE had increases in serum uric acid associated with their systemic inflammatory response and outcome of the disease. In conclusion, some oxidative status analytes can be automatically measured in horses’ saliva and serum and may potentially be assessed as biomarkers of gastric ulcers and CIE.Changes in the oxidative status of the blood of horses suffering from gastric ulcers and colic of intestinal aetiology (CIE) have been reported. However, saliva can also be a source of biomarkers of oxidative status. Therefore, this study aims to validate automated assays for the measurement of oxidative status biomarkers (ferric reducing ability of saliva/serum—FRAS/FRAP, cupric reducing antioxidant capacity—CUPRAC, the Trolox equivalent antioxidant capacity—TEAC, uric acid, and advanced oxidation protein products—AOPP) in the saliva and serum of horses, to assess their changes in the different ulcer gastric diseases (squamous—ESGD and glandular—EGGD) and CIE, and to evaluate their relationship with serum amyloid A (SAA), adenosine deaminase (ADA), and the systemic inflammatory response syndrome (SIRS) status. The assays showed a low imprecision and good linearity with enough sensitivity in both fluids. In EGGD, higher levels of FRAS, uric acid, and AOPP in saliva were observed compared to the healthy group, correlating with the salivary ADA levels. Horses with CIE showed increases in uric acid concentrations in serum associated with their SIRS status and outcome of the disease. In conclusion, analytes related to the oxidative status can be measured in the saliva and serum from horses by automated assays, and some of them can potentially be assessed as biomarkers in horses with gastric ulcers and CIE.

Multimode determination of uric acid based on porphyrinic MOFs thin films by electrochemical and photoelectrochemical methods

Uric acid (UA) is a significant biological substance for the disorders associated with alterations of the plasma urate concentration such as ketoacidosis, hyperuricemia, renal impairment, leukemia, Lesch-Nyhan syndrome and lactate excess, chronic nephritis, arthrolithiasis, etc. The development of UA ultra-sensitive determination technologies is an essential requirement due to its biological properties. Numerous determination technologies have been explored to analyze UA in various real samples. However, a rapid, easy-to-use, cost-effective and instrument-free biosensor for UA determination remains a great challenge. A facile electrochemical and photoelectrochemical (PEC) sensor was fabricated through metal organic frameworks (MOFs) which were synthesized based on Cu(NO3)2·3H2O and 5,10,15,20-tetrakis (4-carboxyphenyl) porphyrin (H2TCPP) by the environmentally-friendly solvothermal method. Cu-TCPP MOFs/GCE sensing platforms were applied in quantitative determination of UA through the different electrochemical technologies. The electrochemical signal responses of UA decreased regularly with the increase of UA concentration and the well-linear regression equations were established between the peak current intensity and UA concentrations in various electrochemical technologies.

Effects of gonadectomy on clinical-hematological, metabolic and hormone conditions of cockerels

Gonadectomy (caponization) of cockerels is an important way of increasing their productivity, improving the quality and taste properties of the meat, and obtaining dietary products. The objective of the study was the influence of gonadectomy of cockerels on their clinical condition, morphological composition of blood, hemoglobin content and anabolism in the tissues, their productivity and chemical content of the muscles. In the experiment, we used 30 Adler silver cockerels aged 4 weeks, which were divided into two groups: control (intact) and experimental (gonadectomized) according to the analogue principle, with 15 individuals in each. The experiment lasted for 185 days, including the main period of 175 days. We determined that the body temperature of cockerels after gonadectomy increased as early as days one and three. In the blood of gonadectomized cockerels, the number of leukocytes decreased by 36.3%, thrombocytes – by 24.7%, while hemoglobin concentration, numbers of heterophils, eosinophils, basophils, monocytes and lymphocytes did not change compared with the intact individuals. On days 20 and 185 of the experiment, the concentration of testosterone in the blood plasma of gonadectomized cockerels was lower respectively by 57.1% and 53.1%, whereas no differences were found prior to gonadectomy and on the third day of the experiment. We determined increase in uric acid concentration and decrease in the level of ionizing calcium in blood plasma of gonadectomized cockerels compared with intact individuals, while the content of cortisol, glucose, total protein, triglycerides, cholesterol, total calcium and inorganic phosphorus, and also activities of alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase did not change. Live weight of gonadectomized cockerels in the period from 45 to 105 days of the raising did not change, and was higher by 10.4–17.0% from day 115 to 145, and further remained not different from the control. Thoracic muscles of gonadectomized cockerels contained 1.8 times more fat, while the levels of moisture, dry matter, protein and ash in thoracic and thigh muscles did not change. The conducted studies have revealed the effect of gonadectomy of roosters on clinical-hematological parameters, metabolic processes, productivity of birds and chemical composition of muscles and may be used to improve the production of chicken meat with high dietary and taste properties.

Molecularly imprinted electrochemical sensor based on electrode modified by functionalized carbon nanotube for selective detection of uric acid

In this study, we have developed a novel biomimetic electrochemical sensor sensitized with functionalized carbon nanotubes using a molecularly imprinted film as a recognition element for the rapid detection of uric acid. Using K 3 [Fe(CN) 6 ] as a probe, uric acid imprinted films on electrodes are characterized by voltammetry measurements and electrochemical impedance spectroscopy. The optimizations of experimental steps are conducted by cyclic voltammetry and differential pulse voltammetry. When the imprinted sensor is immersed in the solution containing a certain concentration of uric acid and incubated for a period of time, the oxidation peak current of K 3 [Fe(CN) 6 ] decreases with the increase of uric acid concentration. Under optimal conditions, the peak current of K 3 [Fe(CN) 6 ] has a good linear relationship with uric acid concentration at range from 0.1 μM to 3.3 μM with the detection limit of 0.03 μM. The proposed sensor shows high selectivity for rapid detection of uric acid in human serum samples.

The effect of cryotherapy on the reduction of pain levels in gout arthritis patients in Jambi city

Background: Gouty arthritis is a disease caused by metabolic disorders with an increase in uric acid concentration which causes local joint pain. The management of gouty arthritis with pharmacological therapy usually uses several conventional drugs. The high prevalence of chronic pain experienced by sufferers has made the patient undergo non-pharmacological therapy with cold compresses (cryotherapy) to be more appropriate for joints with signs of inflammation such as redness and swelling that occur in patients with rheumatoid arthritis. Ice (ice packs) and ice water in the treatment of injuries and treatment modalities commonly used in the management of pain and injuries.Methods: This study used a quasi-experiment design with a two-group pre-test and post-test design approach. This study was conducted on patients with gout arthritis at PSTW Budi Luhur Jambi city with 16 respondent and control groups respectively. Data analysis in this study used univariate and bivariate using the independent t-test.Results: The results showed the average decreased levels of pain in patients with gouty arthritis in the control group without treatment pretest 3:50 whereas for the average posttest 3:19 and the average value decreased levels of pain in patients with gouty arthritis in the intervention group before performed cryotherapy 3:38 while for the average after treatment is 1.38, the statistical test p value is 0.000Conclusions: The influence cryotherapy to decrease rate gout arthritis pain in patients PSTW Budi Luhur in the city of Jambi.

Uric acid alterations by consumption of gluten-free bakery products in relation to cardiovascular and metabolic syndrome risk factors.

Serum uric acid (UA) levels are one of the determinants of the cardiovascular disease and metabolic syndrome but none of criteria for that syndrome include serum UA. Consumption of bakery products (with or without gluten) is associated with an increasing prevalence of overweight/obesity and hyperuricemia frequently occurs in subjects with overweight and obesity. The aim of the study was to find out how 6-weeks consumption of gluten-free bakery products can affect risk factors for cardiovascular disease and metabolic syndrome, and especially uric acid levels. The group was composed of 27 female volunteers consuming gluten-free bakery products during 6-week period. The biochemical parameters levels were measured by Biolis 24i Premium, the anthropometric parameters by InBody 720 and blood pressure by OMRON Microlife. We found a non-significant increase in total cholesterol and decrease in triglycerides, in the case of LDL cholesterol a significant reduction in values and increase of HDL cholesterol. Glucose level increased significantly, but uric acid has not changed significantly. We found the highest total cholesterol, triglyceride, and LDL concentrations in the third UA quartile. The highest glucose concentrations were found in the lower UA quartiles, while the lowest in the highest quartiles. Linear increases in UA concentrations were not observed in any of the parameters. Evaluation of the anthropometric parameters showed that while values of BMI, VFA, fat mass and waist circumference were the highest at the beginning of the study in the second quartile, after intervention the highest values were shifted to the third quartile. Due to the consumption of gluten-free bakery products the risk values of the monitored parameters shifted to higher UA quartiles.

Production, nitrogenous compounds in manure and serum chemistry of laying hens provided multi-species (Lactobacillus spp.) probiotics

Context A practical, low-cost suggestion for industry to reduce ammonia (NH3) in layer houses is use of Lactobacillus species (L. rhamnosus, L. paracasei and L. plantarum) in drinking water or feed. Thus, we investigated their short-term (8 weeks) use in young layers. Aim A combination of species of Lactobacillus (L. rhamnosus, L. paracasei and L. plantarum at 1.0 × 1012 CFU/kg feed) was provided for laying hens in order to investigate effects on production, nitrogenous compounds in manure, serum chemistry and uric acid in the liver. Method Ninety-six White Leghorns (32 weeks old) were randomly assigned to a control diet (commercial feed) or a diet containing commercial feed + probiotics (g/kg feed: L. rhamnosus 1.667, L. paracasei 0.667 and L. plantarum 0.740) and fed for an additional 8 weeks. Key results No significant major effects were observed among diets on bodyweight, feed intake, egg production or feed conversion ratio. Numerical reductions were noted for feed intake (10%) and feed conversion ratio (9%) at Week 2 for layers receiving probiotics as compared to the control. Ammonia, ammonium-nitrogen (N), total Kjeldahl N and total N in manure were not changed significantly by probiotics, nor did probiotics significantly affect the serum profile (ammonia, uric acid, total protein, albumin and creatine kinase) or uric acid in the liver. There was a numerical but non-significant increase in creatine kinase (11%) after 8 weeks in serum of hens receiving probiotics; likewise, there was a non-significant 8% increase in uric acid concentration in the liver of hens receiving probiotics at the end of the experimental period. Conclusion The probiotics (L. rhamnosus, L. paracasei and L. plantarum at 1.0 × 1012 CFU/kg feed) used in this study did not significantly reduce N-containing compounds in manure of 32–40-week-old layers. Implications Age, different types of layers (and broilers) and mode of administration or concentration of probiotics play important roles in outcomes. Extensive collaborative studies are needed to provide definitive answers for use of probiotics in layer (as well as broiler) feed for reduction of N-containing compounds in poultry houses.

Impact of Alpha-Lipoic Acid Chronic Discontinuous Treatment in Cardiometabolic Disorders and Oxidative Stress Induced by Fructose Intake in Rats.

Insulin resistance (IR) and cardiometabolic disorders are the main consequences of today’s alimentary behavior. This study evaluates the effects of a chronic-discontinuous treatment with alpha-lipoic acid (AL), an antioxidant substance that improves glycemic control associated with diabetes mellitus, on metabolic disorders and plasma oxidative stress induced by fructose intake, in rats. Sprague-Dawley rats (48 animals) were randomized into two series (n = 24): rats fed with standard chow or with standard chow supplemented with 60% fructose. In each of the two series, for 2 weeks/month over 12 weeks, a group of rats (n = 12) was intraperitoneally injected with NaCl 0.9%, and a second group (n = 12) received AL 50 mg/kg/day. Body weight, glycemia, and systolic blood pressure were monitored throughout the study. After 12 weeks, IR, plasma lipoproteins, uric acid, transaminase activities, and oxidative stress markers were assessed. The high fructose-enriched diet induced cardiometabolic disorders (hypertension, hyperglycemia, IR and dyslipidemia), an increase in uric acid concentration, transaminase activities and C-reactive protein level. This diet also enhanced plasma products of lipid and protein oxidation, homocysteine level, and decreased GSH/GSSG ratio. In this field, there is evidence to indicate that oxidative stress plays an important role in the etiology of diabetic complications. AL discontinuous treatment prevents the metabolic disorders induced by fructose intake, reduced plasma lipid and protein oxidation-products, and restored the GHS/GSSG ratio. Our study proves a promising potential of the chronic-discontinuous treatment of AL and highlights the pleiotropic effects of this antioxidant substance in metabolic disorders such as diabetes.

Ischaemia-induced muscle metabolic abnormalities are poorly alleviated by endurance training in a mouse model of sickle cell disease.

What is the central question of this study? The aim of this study was to evaluate the potential beneficial effects of endurance training during an ischaemia-reperfusion protocol in a mouse model of sickle cell disease (SCD). What is the main finding and its importance? Endurance training did not reverse the metabolic defects induced by a simulated vaso-occlusive crisis in SCD mice, with regard to intramuscular acidosis, mitochondrial dysfunction or anatomical properties. Our results suggest that endurance training would reduce the number of vaso-occlusive crises rather than the complications related to vaso-occlusive crises. The aim of this study was to investigate whether endurance training could limit the abnormalities described in a mouse model of sickle cell disease (SCD) in response to an ischaemia-reperfusion (I/R) protocol. Ten sedentary (HbSS-SED) and nine endurance-trained (HbSS-END) SCD mice were submitted to a standardized protocol of I/R of the leg, during which ATP, phosphocreatine and inorganic phosphate concentrations and intramuscular pH were measured using magnetic resonance spectroscopy. Forty-eight hours later, skeletal muscles were harvested. Oxidative stress markers were then measured. Although the time course of protons accumulation was slightly different between trained and sedentary mice (P<0.05), the extent of acidosis was similar at the end of the ischaemic period. The initial rate of phosphocreatine resynthesis measured at blood flow restoration, illustrating mitochondrial function, was not altered in trained mice compared with sedentary mice. Although several oxidative stress markers were not different between groups (P>0.05), the I/R-related increase of uric acid concentration observed in sedentary SCD mice (P<0.05) was not present in the trained group. The spleen weight, generally used as a marker of the severity of the disease, was not different between groups (P>0.05). In conclusion, endurance training did not limit the metabolic consequences of an I/R protocol in skeletal muscle of SCD mice, suggesting that the reduction in the severity of the disease previously demonstrated in the basal state would be attributable to a reduction of the occurrence of vaso-occlusive crises rather than a decrease of the deleterious effects of vaso-occlusive crises.

Analysis of NT-proBNP and uric acid due to left ventricle hypertrophy in the patients of aortic valve disease.

Objective:To evaluate the concentration of N terminal proBNP (NT-proBNP) and partially the serum uric acid in the severe condition of aortic valve dysfunction for assessment of left ventricle hypertrophy.Methods:The study was conducted in the signal transduction lab department of biochemistry Quaid-I-Azam University, Islamabad from September 2013 to February 2017. NT-proBNP and serum uric acid were measured in one hundred patients of aortic valve dysfunction. The patients were divided into three main groups: 1) Aortic stenosis, 2) Aortic regurgitation, and 3) Aortic stenosis with Aortic regurgitation. The results were compared between disease and controls groups.Results:High level of plasma NT-proBNP was detected in all the three disease groups of aortic valve (stenosis, p<0.001), (regurgitation, p<0.001) and (stenosis with regurgitation, p<0.001). In addition, non-significantly increased level of serum uric acid was also observed in left ventricle hypertrophy in all the three respective disease groups of aortic valve.Conclusion:Increased secretion of NT-proBNP during cardiac remodeling can be related to the severity of left ventricle hypertrophy due to aortic valve abnormality in all the disease groups of severe stenosis, severe regurgitation, and combine disease condition of severe stenosis and severe regurgitation. However, non-significant increase in uric acid concentration is also identified which may be due to one of the factors involved in left ventricle hypertrophy in all the three disease groups of aortic valve. The interaction of uric acid with NT-proBNP during cardiac remolding due to aortic valve dysfunction is still not clear.

Developing Paper Based Diagnostic Technique to Detect Uric Acid in Urine.

Urinary or serum uric acid concentration is an indicator of chronic kidney condition. An increase in uric acid concentration may indicate renal dysfunction. Reliable instantaneous detection of uric acid without requiring sophisticated laboratory and analytical instrumentation, such as: chromatographic and spectrophotometric methods, would be invaluable for patients with renal complication. This paper reports the early development of a simple, low-cost, instantaneous and user-friendly paper based diagnostic device (PAD) for the qualitative and quantitative detection of uric acid in urine. A colorimetric detection technique was developed based on the intensity of Prussian blue color formation on paper in presence of uric acid; the reaction rate of corresponding chemical reactions on paper surface was also studied. Based on the colorimetric signal produced on paper surface, a calibration curve was developed to detect unknown concentration of uric acid in urine. The effect of temperature on formation of color signal on paper surface was also analyzed. In this study, estimation of urinary uric acid using MATLAB coding on a windows platform was demonstrated as the use of software application and digital diagnostics. This paper-based technique is faster and less expensive compared to traditional detection techniques. The paper-based diagnostic can be integrated with a camera of smart phone, tablet computer or laptop and an image processing application (using windows/android/IOS platform) as a part of digital diagnostics. Therefore, with proper calibration, the paper-based technique can be compatible and economical to the sophisticated detection techniques used to detect urinary uric acid.

Uric acid contributes greatly to hepatic antioxidant capacity besides protein.

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.

Serum uric acid concentration is associated with hypertensive retinopathy in hypertensive chinese adults

BackgroundThis cross sectional investigation included 12,966 subjects with hypertension, a cohort of the China Stroke Primary Prevention Trial (CSPPT), a randomized, multicenter clinical trial. This study aimed to explore the correlation between serum uric acid (SUA) concentration and hypertensive retinopathy in hypertensive adults.MethodsDiagnosis of hypertensive retinopathy was determined by non-mydriatic fundus photography and classified with Keith-Wagener-Barker (KWB) system. The correlation of SUA levels with hypertensive retinopathy prevalence and severity was assessed by statistical analysis.Results9848 (75.95%) subjects were diagnosed with hypertensive retinopathy with the following retinopathy grade distribution: grade 1: 58.80%, grade 2: 14.81%, and grade 3–4: 2.34%. SUA levels were significantly associated with hypertensive retinopathy prevalence. Patients with hypertensive retinopathy had higher SUA levels than those without hypertensive retinopathy. Patients in the highest uric acid quartile had an odds ratio for hypertensive retinopathy of 1.21 compared to patients in the lowest uric acid quartile (OR = 1.21, 95% CI: 1.05–1.40, P = 0.008). When compared to the non-hyperuricemia group, those in the hyperuricemia group had an odds ratio for hypertensive retinopathy of 1.18(OR = 1.18, 95% CI: 1.05–1.33, P = 0.004). Every 1 mg/dl increase in uric acid concentration was significantly associated with a 6% higher odds of hypertensive retinopathy (OR = 1.06, 95% CI: 1.02–1.10, P = 0.002).ConclusionsThe prevalence of hypertensive retinopathy was high (75.95%) among hypertensives in our patients cohort. In addition, SUA concentration was significantly associated with hypertensive retinopathy.

Prenatal Earthquake Exposure and Midlife Uric Acid Levels Among Chinese Adults.

To test whether prenatal exposure to earthquake (as a surrogate for acute prenatal stress) could have unfavorable effects on uric acid levels later in life. We included 536 individuals who had been prenatally exposed to the Tangshan earthquake in 1976, and 536 sex- and age-matched individuals without that exposure. Serum uric acid concentrations were measured based on fasting blood samples, which were repeatedly collected in 2006, 2008, and 2010. Mean uric acid concentrations in 2010 and the increasing rate from 2006 to 2010 were compared between the 2 groups, after adjustment for age, sex, body mass index, serum concentrations of glucose, triglycerides, C-reactive protein level, estimated glomerular filtration rate, and other potential confounders. We also used multiple logistic regression to estimate the risk of hyperuricemia (>416 μmole/liter in men or >357 μmole/liter in women) in 2010 by calculating the odds ratios (ORs) and 95% confidence intervals (95% CIs) after adjustment for the previously mentioned covariates. Participants with prenatal exposure to the earthquake had higher concentrations of serum uric acid (adjusted means 315 μmole/liter versus 296 μmole/liter; P = 0.001) and a higher likelihood of having hyperuricemia (multivariate adjusted OR 1.70 [95% CI 1.09-2.66]) in 2010 relative to those without the exposure. Prenatal exposure to the earthquake was consistently significantly associated with a faster increase in uric acid concentration from 2006 to 2010 (P < 0.001). Prenatal exposure to the earthquake was associated with higher serum uric acid and higher odds of hyperuricemia in early adulthood.

Metabolic Effects of Replacing Sugar-Sweetened Beverages with Artificially-Sweetened Beverages in Overweight Subjects with or without Hepatic Steatosis: A Randomized Control Clinical Trial.

Objective: Addition of fructose to the diet of normal weight and overweight subjects can increase postprandial plasma triglyceride and uric acid concentration. We, therefore, assessed whether replacing sugar-sweetened beverages (SSB) with artificially-sweetened beverages (ASB) in the diet of overweight and obese subjects would decrease these parameters. Methods: Twenty-six participants of the REDUCS study, which assessed the effects of replacing SSB by ASB over 12 weeks on intra-hepatocellular lipid concentration, were included in this sub-analysis. All were studied after a four-week run-in period during which they consumed their usual diet and SSBs, and after a 12-week intervention in which they were randomly assigned to replace their SSBs with ASBs (ASB arm) or to continue their usual diet and SSBs (control arm, CTRL). At the end of run-in (week 4) and again at the end of intervention (week 16), they took part in an 8.5 h metabolic investigation during which their plasma glucose, insulin, glucagon, lactate, triglyceride (TG), non-esterified fatty acids (NEFA), and uric acid concentrations were measured over a 30 min fasting period (−30–0 min), then every 2 h over 480 min. with ingestion of standard breakfast at time 0 min and a standard lunch at time 240 min. Breakfast and lunch were consumed together with a 3.3 dL SSB at week 4 and with either an ASB (ASB arm) or a SSB (CTRL arm) at week 16. After analyzing the whole group, a secondary analysis was performed on 14 subjects with hepatic steatosis (seven randomized to ASB, seven to CTRL) and 12 subjects without hepatic steatosis (six randomized to ASB and six to CTRL). Results: Ingestion of meals increased plasma glucose, insulin, glucagon, lactate, and TG concentrations and decreased NEFA concentrations, but with no significant difference of integrated postprandial responses between week 4 and week 16 in both ASB and CTRL, except for a slightly decreased glucagon response in ASB. There was, however, no significant postprandial increase in uric acid concentration in both arms. In the secondary analysis, replacing SSBs with ASBs did not significantly change postprandial TG and uric acid concentrations irrespective of the presence or not of hepatic steatosis, Conclusions: In overweight, high SSB consumers, replacing SSBs with ASBs during 12 weeks did not significantly alter post-prandial TG and uric acid concentration, in spite of the lower energy and fructose content of the meals. These effects were globally the same in subjects without and with hepatic steatosis.

Effect of uric acid on mitochondrial function and oxidative stress in hepatocytes.

Here, we investigated the effect of uric acid (UA) on hepatocyte mitochondria. Hepatocytes cultured in vitro were treated with varying concentrations of UA. The change in apoptotic activity was detected by flow cytometry. The DNA damage index 8-hydroxy-deoxy-guanosine (8-OHdG) and mitochondrial function indices succinate dehydrogenase (SDH), cytochrome C oxidase (CCO), and adenosine triphosphate (ATP) were detected by enzyme assays. Reactive oxygen species (ROS) accumulation was confirmed by a dichloro-dihydro-fluorescein diacetate assay. We observed an increase in apoptotic activity, ROS accumulation, and 8-OHdG activity in hepatocytes treated with UA for extended periods, indicating DNA damage; specifically, we observed a significant increase in these activities 48, 72, and 96 h after UA addition, compared to those observed at 24 h (P < 0.05). Cells treated with 30 mg/dL UA for 96 h showed a peak in apoptotic activity. We also observed a significant decrease in ATP, SDH, and CCO activities with the increase in uric acid concentration over time. Cells treated with 30 mg/dL UA for 96 h showed the highest ATP levels, while SDH and CCO activities at 48, 72, and 96 h post-UA treatment were significantly lower than those at 24 h (P < 0.01). Moreover, cells treated with 30 mg/dL UA showed a 0.02 ± 0.02 and 0.15 ± 0.01 mmol/ mg/min decrease in SDH and CCO levels after 72 h. Therefore, we concluded that high concentrations of UA may induce oxidative stress in hepatocyte mitochondria, increasing ROS production and ultimately resulting in mitochondrial damage.

Relationship between Uric Acid and Endothelial Function in Hypertensive Patients with Metabolic Syndrome

Aim: To investigate the association between uric acid (UA) and endothelial function in Chinese hypertensive patients with Metabolic Syndrome (MS). Methods: 615 hypertensive patients were enrolled, all hypertensives were divided into two groups: hypertensives with MS (MS group, n=239) and hypertensives without MS (NMS group, n=376). 87 age- and sex-matched normotensives served as controls (NC group). Flow-mediated (endothelium-dependent) dilatations (FMD), nitroglycerin-induced (endothelium-independent) dilatation (EID) in the brachial artery were assessed by highresolution ultrasonography. UA was detected by urease indophenol. Results: A trend of increase in UA concentration was found among NC, NMS and MS group ((323.77 ± 104.49) μmol/l vs. (353.63 ± 92.83) μmol/l vs. (390.90 ± 101.42) μmol/l, p<0.001). There was a significant difference in FMD (control: (12.03 ± 4.51)% vs. NMS:(8.98 ± 4.32)% vs. MS:(8.23 ± 4.58)%, p<0.001) among groups. After stratification of gender, lower FMD was only seen in male hypertensives with MS accompanied by hyperuricemia <60 years old ((9.98 ± 5.78)% vs (7.12 ± 4.49)%, p<0.05); Pearson correlation analysis showed that the FMD was negatively correlated with UA (r=-0.314, p<0.01); Finally, logistic regression analysis showed that a 50 μmol/L increase in UA levels carried a 41.1% higher risk for endothelial dysfunction in this cohort. Conclusions: A higher UA level is related to poorer endothelial function in hypertensives with MS. Increased UA can be used as an alternative indicator for monitoring endothelial function and preventing vascular damage in male hypertensives with MS aged less than 60 years old.

Uridine--an indicator of post-exercise uric acid concentration and blood pressure.

Studies have shown that uridine concentration in plasma may be an indicator of uric acid production in patients with gout. It has been also postulated that uridine takes part in blood pressure regulation. Since physical exercise is an effective tool in treatment and prevention of cardio-vascular diseases that are often accompanied by hyperuricemia and hypertension, it seemed advisable to attempt to evaluate the relationship between oxypurine concentrations (Hyp, Xan and UA) and that of Urd and BP after physical exercise in healthy subjects. Sixty healthy men (17.2+/-1.71 years, BMI 23.2+/-2.31 kg m(-2), VO(2max) 54.7+/-6.48 ml kg(-1) min(-1)) took part in the study. The subjects performed a single maximal physical exercise on a bicycle ergometer. Blood for analyses was sampled three times: immediately before exercise, immediately after exercise, and in the 30th min of rest. Concentrations of uridine and hypoxanthine, xanthine and uric acid were determined in whole blood using high-performance liquid chromatography. We have shown in this study that the maximal exercise-induced increase of uridine concentration correlates with the post-exercise increase of uric acid concentration and systolic blood pressure. The results of our study show a relationship between uridine concentration in blood and uric acid concentration and blood pressure. We have been the first to demonstrate that a maximal exercise-induced increase in uridine concentration is correlated with the post-exercise and recovery-continued increase of uric acid concentration in healthy subjects. Thus, it appears that uridine may be an indicator of post-exercise hyperuricemia and blood pressure.