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Sample records for plasma uric acid

  1. 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 ... testing. The most common reason for measuring uric acid levels is in the diagnosis or treatment of ...

  2. Uric Acid Test

    MedlinePlus

    ... limited. Home Visit Global Sites Search Help? Uric Acid Share this page: Was this page helpful? Also known as: Serum Urate; UA Formal name: Uric Acid Related tests: Synovial Fluid Analysis , Kidney Stone Analysis , ...

  3. Plasma urea, creatinine and uric acid concentrations in relation to feeding in peregrine falcons (Falco peregrinus).

    PubMed

    Lumeij, J T; Remple, J D

    1991-03-01

    Significant post-prandial increases in plasma uric acid and plasma urea concentrations were observed in peregrine falcons. Post-prandial uric acid concentrations were similar to those in birds suffering from hyperuricaemia and gout and were well above the theoretical limit of solubility of sodium urate in plasma. It is not clear why under normal circumstances no urate deposits occur in peregrine falcons (and probably other raptorial birds), which show hyperuricaemia for at least 12 h after ingesting a natural meal. It is important to evaluate renal function in peregrine falcons (and perhaps other birds) after a 24-h fast to avoid misinterpretation due to physiological food-induced elevated concentrations of nonprotein nitrogen substances.

  4. Uric acid - blood

    MedlinePlus

    ... High levels of uric acid can sometimes cause gout or kidney disease. You may have this test if you have had or are about to have certain types of chemotherapy. Rapid weight loss, which may occur with such treatments, can increase the amount of uric acid in ...

  5. Uric acid and hypertension.

    PubMed

    Feig, Daniel I

    2011-09-01

    A link between serum uric acid and the development of hypertension was first hypothesized in the 1870s. Although numerous epidemiologic studies in the 1980s and 1990s suggested an association, relatively little attention was paid to it until recently. Animal models have suggested a two-step pathogenesis by which uric acid initially activates the renin angiotensin system and suppresses nitric oxide, leading to uric acid-dependent increase in systemic vascular resistance, followed by a uric acid-mediated vasculopathy, involving renal afferent arterioles, resulting in a late sodium-sensitive hypertension. Initial clinical trials in young patients have supported these mechanisms in young patients but do not yet support pharmacologic reduction of serum uric acid as first-line therapy for hypertension.

  6. 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

  7. Association of uric acid, atherogenic index of plasma and albuminuria in diabetes mellitus

    PubMed Central

    Akbas, Emin Murat; Timuroglu, Aysu; Ozcicek, Adalet; Ozcicek, Fatih; Demirtas, Levent; Gungor, Adem; Akbas, Nergis

    2014-01-01

    Background: The associations of serum uric acid (UA), atherogenic index of plasma (AIP) and albuminuria with cardiovascular disease have been shown. Several studies focused on association of serum UA and dyslipidemia, serum UA and renal impairment, dyslipidemia and renal impairment. However, to date, in literature, there have been no studies demonstrating the relationship between these parameters in diabetic patients together. Aims: We aimed to investigate the association between serum UA, albuminuria and AIP in diabetic patients. Methods: This was a retrospective study involving data of 645 diabetic patients. The patients were separated into groups according to their serum uric acid and AIP levels. The quantitative urine albumin/creatinine ratio in morning spot urine samples were used for standard albuminuria determination. Serum uric acid levels under 6 mg/dL were considered as normal. AIP was calculated as the logarithmically transformed ratio of triglyceride to high density lipoprotein cholesterol. Results: AIP and albuminuria levels were high in high serum UA group compared to normal UA group. Uric acid and albuminuria tended to increase with increasing AIP. Correlation analysis showed that albuminuria, AIP and UA were significantly correlated with each other. Additionally, in binary logistic regression analysis, AIP was found to be independently associated with high UA levels. Conclusions: Present study reveals that serum UA, AIP and albuminuria are closely related. Physicians should be aware that patients with concomitant hyperuricemia, albuminuria and high AIP are at increased risk of developing cardiovascular disease. Our study confirms that there is a need for larger prospective studies to determine the mechanisms underlying the association of serum UA, AIP and albuminuria. PMID:25664100

  8. 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....1775 Uric acid test system. (a) Identification. A uric acid test system is a device intended to measure uric acid in serum, plasma, and urine. Measurements obtained by this device are used in the...

  9. 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....1775 Uric acid test system. (a) Identification. A uric acid test system is a device intended to measure uric acid in serum, plasma, and urine. Measurements obtained by this device are used in the...

  10. Comparison of plasma uric acid levels in five varieties of the domestic turkey, Meleagris gallopavo.

    PubMed

    Hartman, S; Taleb, S A; Geng, T; Gyenai, K; Guan, X; Smith, E

    2006-10-01

    Plasma uric acid (PUA) is a consensus physiological biomarker for many phenotypes in vertebrates because it is a reliable indicator for processes such as oxidative stress and tubular function. In birds, it is considered a major antioxidant and is also the primary endproduct of nitrogen metabolism. Despite this importance, knowledge of baseline levels of PUA in physiologically normal birds, including the turkey, Meleagris gallopavo, is limited. Here, we compared PUA levels in a total of 106 apparently normal male and female birds at 8 and 32 wk of age from 5 strains of the domestic turkey, including Bourbon Red, Narragansett, Blue Slate, Royal Palm, and Spanish Black. Though differences in PUA were not significant at 8 and 32 wk of age, BW, variety, and sex effects were highly significant. When adjusted for BW, female birds had, on average, a higher PUA per kilogram of BW than male birds. When adjusted for both sex and BW, Royal Palm birds had the lowest average PUA, and Blue Slate had the highest PUA. Results of these investigations represent the first comparative analysis of PUA in physiologically normal turkey varieties. They suggest that differences in basal plasma levels of uric acid in physiologically normal turkeys are influenced by sex, weight, and genetic background but may be independent of age.

  11. Uric acid transport and disease

    PubMed Central

    So, Alexander; Thorens, Bernard

    2010-01-01

    Uric acid is the metabolic end product of purine metabolism in humans. It has antioxidant properties that may be protective but can also be pro-oxidant, depending on its chemical microenvironment. Hyperuricemia predisposes to disease through the formation of urate crystals that cause gout, but hyperuricemia, independent of crystal formation, has also been linked with hypertension, atherosclerosis, insulin resistance, and diabetes. We discuss here the biology of urate metabolism and its role in disease. We also cover the genetics of urate transport, including URAT1, and recent studies identifying SLC2A9, which encodes the glucose transporter family isoform Glut9, as a major determinant of plasma uric acid levels and of gout development. PMID:20516647

  12. Uric acid protects erythrocytes from ozone-induced changes

    SciTech Connect

    Meadows, J.; Smith, R.C.

    1987-08-01

    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.

  13. Association of Renal Manifestations with Serum Uric Acid in Korean Adults with Normal Uric Acid Levels

    PubMed Central

    Jung, Dong-Hyuk; Lee, Yong-Jae; Lee, Hye-Ree; Lee, Jung-Hyun

    2010-01-01

    Several studies have reported that hyperuricemia is associated with the development of hypertension and cardiovascular disease. Increasing evidences also suggest that hyperuricemia may have a pathogenic role in the progression of renal disease. Paradoxically, uric acid is also widely accepted to have antioxidant activity in experimental studies. We aimed to investigate the association between glomerular filtration rate (GFR) and uric acid in healthy individuals with a normal serum level of uric acid. We examined renal function determined by GFR and uric acid in 3,376 subjects (1,896 men; 1,480 women; aged 20-80 yr) who underwent medical examinations at Gangnam Severance Hospital from November 2006 to June 2007. Determinants for renal function and uric acid levels were also investigated. In both men and women, GFR was negatively correlated with systolic and diastolic blood pressures, fasting plasma glucose, total cholesterol, uric acid, log transformed C reactive protein, and log transformed triglycerides. In multivariate regression analysis, total uric acid was found to be an independent factor associated with estimated GFR in both men and women. This result suggests that uric acid appears to contribute to renal impairment in subjects with normal serum level of uric acid. PMID:21165292

  14. Uric acid plasma level and urine pH in rats treated with ambroxol.

    PubMed

    Drewa, Tomasz; Wolski, Zbigniew; Gruszka, Marzena; Misterek, Bartosz; Lysik, Joanna

    2007-01-01

    It was a chance discovery that ambroxol parenteral administration led to urinary bladder stone formation in rats. This study was undertaken to examine the serum uric acid levels and urine pH in rats after ambroxol parenteral treatment. Ambroxol influence on the uric acid level was measured in 5 rats (Rattus sp.) treated with 60 mg/kg (dissolved in injection water, sc, daily) during 2 weeks. Ambroxol influence on urine pH was examined on 45 rats divided into 3 groups. Rats from the 1st and 2nd group received 30 and 60 mg/kg/24h ambroxol, respectively. Urine was collected once daily and measured with strip kit. All values were presented as the means with standard deviations. The Student t test was used to compare the means, p < 0.05 was considered as significant. Dynamics of pH changes was measured in 4 rats treated with 60 mg/kg/24h of ambroxol. Controls received 1 mL of injection water sc. Serum uric acid level increased up to 8.7 +/- 1.0 mg/dL vs. 5.7 +/- 1.0 mg/dL in control (p < 0.002). In the 1st and 2nd group urine pH increased up to 7.5 +/- 0.5 and 7.6 +/- 0.5 vs. 6.7 +/- 0.4 (p < 0.05). Ambroxol withdrawal resulted in sequential urine pH decrease. 11 days after interruption of ambroxol therapy pH reached the starting value. Urine pH changes and possible disturbances in uric acid metabolic pathway may influence on the stone formation in rats after ambroxol parenteral treatment. The influence of ambroxol on urinary tract GAG layer and the balance between xanthine and CaOx in the urine should be checked.

  15. Effects of acute creatine supplementation on iron homeostasis and uric acid-based antioxidant capacity of plasma after wingate test

    PubMed Central

    2012-01-01

    Background Dietary creatine has been largely used as an ergogenic aid to improve strength and athletic performance, especially in short-term and high energy-demanding anaerobic exercise. Recent findings have also suggested a possible antioxidant role for creatine in muscle tissues during exercise. Here we evaluate the effects of a 1-week regimen of 20 g/day creatine supplementation on the plasma antioxidant capacity, free and heme iron content, and uric acid and lipid peroxidation levels of young subjects (23.1 ± 5.8 years old) immediately before and 5 and 60 min after the exhaustive Wingate test. Results Maximum anaerobic power was improved by acute creatine supplementation (10.5 %), but it was accompanied by a 2.4-fold increase in pro-oxidant free iron ions in the plasma. However, potential iron-driven oxidative insult was adequately counterbalanced by proportional increases in antioxidant ferric-reducing activity in plasma (FRAP), leading to unaltered lipid peroxidation levels. Interestingly, the FRAP index, found to be highly dependent on uric acid levels in the placebo group, also had an additional contribution from other circulating metabolites in creatine-fed subjects. Conclusions Our data suggest that acute creatine supplementation improved the anaerobic performance of athletes and limited short-term oxidative insults, since creatine-induced iron overload was efficiently circumvented by acquired FRAP capacity attributed to: overproduction of uric acid in energy-depleted muscles (as an end-product of purine metabolism and a powerful iron chelating agent) and inherent antioxidant activity of creatine. PMID:22691230

  16. Fructose and uric acid in diabetic nephropathy.

    PubMed

    Bjornstad, Petter; Lanaspa, Miguel A; Ishimoto, Takuji; Kosugi, Tomoki; Kume, Shinji; Jalal, Diana; Maahs, David M; Snell-Bergeon, Janet K; Johnson, Richard J; Nakagawa, Takahiko

    2015-09-01

    Clinical studies have reported associations between serum uric acid levels and the development of diabetic nephropathy, but the underlying mechanisms remain elusive. There is evidence from animal studies that blocking uric acid production protects the kidney from tubulointerstitial injury, which may suggest a causal role for uric acid in the development of diabetic tubular injury. In turn, when fructose, which is endogenously produced in diabetes via the polyol pathway, is metabolised, uric acid is generated from a side-chain reaction driven by ATP depletion and purine nucleotide turnover. For this reason, uric acid derived from endogenous fructose could cause tubulointerstitial injury in diabetes. Accordingly, our research group recently demonstrated that blocking fructose metabolism in a diabetic mouse model mitigated the development of tubulointerstitial injury by lowering tubular uric acid production. In this review we discuss the relationship between uric acid and fructose as a novel mechanism for the development of diabetic tubular injury. PMID:26049401

  17. Fructose and uric acid in diabetic nephropathy

    PubMed Central

    Bjornstad, Petter; Lanaspa, Miguel A.; Ishimoto, Takuji; Kosugi, Tomoki; Kume, Shinji; Jalal, Diana; Maahs, David M.; Snell-Bergeon, Janet K.; Johnson, Richard J.

    2016-01-01

    Clinical studies have reported associations between serum uric acid levels and the development of diabetic nephropathy, but the underlying mechanisms remain elusive. There is evidence from animal studies that blocking uric acid production protects the kidney from tubulointerstitial injury, which may suggest a causal role for uric acid in the development of diabetic tubular injury. In turn, when fructose, which is endogenously produced in diabetes via the polyol pathway, is metabolised, uric acid is generated from a side-chain reaction driven by ATP depletion and purine nucleotide turnover. For this reason, uric acid derived from endogenous fructose could cause tubulointerstitial injury in diabetes. Accordingly, our research group recently demonstrated that blocking fructose metabolism in a diabetic mouse model mitigated the development of tubulointerstitial injury by lowering tubular uric acid production. In this review we discuss the relationship between uric acid and fructose as a novel mechanism for the development of diabetic tubular injury. PMID:26049401

  18. Elevated levels of plasma uric acid and its relation to hypertension in arsenic-endemic human individuals in Bangladesh

    SciTech Connect

    Huda, Nazmul; Hossain, Shakhawoat; Rahman, Mashiur; Karim, Md. Rezaul; Islam, Khairul; Mamun, Abdullah Al; Hossain, Md. Imam; Mohanto, Nayan Chandra; Alam, Shahnur; Aktar, Sharmin; Arefin, Afroza; Ali, Nurshad; Salam, Kazi Abdus; Aziz, Abdul; Saud, Zahangir Alam; Miyataka, Hideki; Himeno, Seiichiro; Hossain, Khaled

    2014-11-15

    Blood uric acid has been recognized as a putative marker for cardiovascular diseases (CVDs). CVDs are the major causes of arsenic-related morbidity and mortality. However, the association of arsenic exposure with plasma uric acid (PUA) levels in relation to CVDs has not yet been explored. This study for the first time demonstrated the associations of arsenic exposure with PUA levels and its relationship with hypertension. A total of 483 subjects, 322 from arsenic-endemic and 161 from non-endemic areas in Bangladesh were recruited as study subjects. Arsenic concentrations in the drinking water, hair and nails of the study subjects were measured by inductively coupled plasma mass spectroscopy. PUA levels were measured using a colorimetric method. We found that PUA levels were significantly (p < 0.001) higher in males and females living in arsenic-endemic areas than those in non-endemic area. Arsenic exposure (water, hair and nail arsenic) levels showed significant positive correlations with PUA levels. In multiple regression analyses, arsenic exposure levels were found to be the most significant contributors on PUA levels among the other variables that included age, body mass index, blood urea nitrogen, and smoking. There were dose–response relationships between arsenic exposure and PUA levels. Furthermore, diastolic and systolic blood pressure showed significant positive correlations with PUA levels. Finally, the average PUA levels were significantly higher in the hypertensive group than those in the normotensive group in both males and females living in arsenic-endemic areas. These results suggest that arsenic exposure-related elevation of PUA levels may be implicated in arsenic-induced CVDs. - Highlights: • PUA levels were higher in arsenic-endemic subjects than in non-endemic subjects. • Drinking water, hair and nail arsenic showed significant associations with PUA levels. • Drinking water, hair and nail arsenic showed dose–response relationships with

  19. 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.

  20. 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

  1. 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

  2. Corticosterone, cortisol, triglycerides, aspartate aminotransferase and uric acid plasma concentrations during foie gras production in male mule ducks (Anas platyrhynchos × Cairina moschata).

    PubMed

    Flament, A; Delleur, V; Poulipoulis, A; Marlier, D

    2012-01-01

    1. Corticosterone, cortisol, triglycerides, aspartate aminotransferase (AST) and uric acid (UA) plasma concentration were measured at 8 (7 days after group housing), 12 (after 7 days of force feeding) and 13 weeks of age (at slaughter after 12 days of force feeding), and 45 min after an adrenocorticotrophic hormone (ACTH) stimulation test at 8 weeks of age in 12 male mule ducks in an on-farm experiment. 2. No significant increase of corticosterone was found during the force-feeding period compared with the concentration after housing. 3. Comparison of corticosterone and cortisol values indicates that cortisol can be considered as a reliable acute stress indicator in future routine examinations. 4. Plasma concentrations of triglycerides and aspartate aminotransferase increased progressively from pre-force feeding period to slaughtering. 5. Plasma concentrations of uric acid increased from the start at 8 weeks of age to the mid-force feeding period but no difference was noticed between the mid-force feeding period and slaughtering. 6. It is concluded that acute stress induced by force-feeding is similar at the beginning and end of the commercial production of foie gras.

  3. Plasma Uric Acid Levels Correlate with Inflammation and Disease Severity in Malian Children with Plasmodium falciparum Malaria

    PubMed Central

    Lopera-Mesa, Tatiana M.; Mita-Mendoza, Neida K.; van de Hoef, Diana L.; Doumbia, Saibou; Konaté, Drissa; Doumbouya, Mory; Gu, Wenjuan; Traoré, Karim; Diakité, Seidina A. S.; Remaley, Alan T.; Anderson, Jennifer M.; Rodriguez, Ana; Fay, Michael P.; Long, Carole A.; Diakité, Mahamadou; Fairhurst, Rick M.

    2012-01-01

    Background Plasmodium falciparum elicits host inflammatory responses that cause the symptoms and severe manifestations of malaria. One proposed mechanism involves formation of immunostimulatory uric acid (UA) precipitates, which are released from sequestered schizonts into microvessels. Another involves hypoxanthine and xanthine, which accumulate in parasitized red blood cells (RBCs) and may be converted by plasma xanthine oxidase to UA at schizont rupture. These two forms of ‘parasite-derived’ UA stimulate immune cells to produce inflammatory cytokines in vitro. Methods and Findings We measured plasma levels of soluble UA and inflammatory cytokines and chemokines (IL-6, IL-10, sTNFRII, MCP-1, IL-8, TNFα, IP-10, IFNγ, GM-CSF, IL-1β) in 470 Malian children presenting with uncomplicated malaria (UM), non-cerebral severe malaria (NCSM) or cerebral malaria (CM). UA levels were elevated in children with NCSM (median 5.74 mg/dl, 1.21-fold increase, 95% CI 1.09–1.35, n = 23, p = 0.0007) and CM (median 5.69 mg/dl, 1.19-fold increase, 95% CI 0.97–1.41, n = 9, p = 0.0890) compared to those with UM (median 4.60 mg/dl, n = 438). In children with UM, parasite density and plasma creatinine levels correlated with UA levels. These UA levels correlated with the levels of seven cytokines [IL-6 (r = 0.259, p<0.00001), IL-10 (r = 0.242, p<0.00001), sTNFRII (r = 0.221, p<0.00001), MCP-1 (r = 0.220, p<0.00001), IL-8 (r = 0.147, p = 0.002), TNFα (r = 0.132, p = 0.006) and IP-10 (r = 0.120, p = 0.012)]. In 39 children, UA levels were 1.49-fold (95% CI 1.34–1.65; p<0.0001) higher during their malaria episode [geometric mean titer (GMT) 4.67 mg/dl] than when they were previously healthy and aparasitemic (GMT 3.14 mg/dl). Conclusions Elevated UA levels may contribute to the pathogenesis of P. falciparum malaria by activating immune cells to produce inflammatory cytokines. While this study cannot identify the cause of

  4. Peroxynitrite-mediated formation of free radicals in human plasma: EPR detection of ascorbyl, albumin-thiyl and uric acid-derived free radicals.

    PubMed Central

    Vásquez-Vivar, J; Santos, A M; Junqueira, V B; Augusto, O

    1996-01-01

    Formation of peroxynitrite by the fast reaction between nitric oxide and superoxide anion may represent a critical control point in cells producing both species, leading to either down-regulation of the physiological effects of superoxide anion and nitric oxide by forming an inert product, nitrate, or to potentiation of their toxic effects by oxidation of nearby molecules by peroxynitrite. (The term peroxynitrite is used to refer to the sum of all possible forms of peroxynitrite anion and peroxynitrous acid unless otherwise specified.) In this report we demonstrate that, in spite of all the antioxidant defences present in human plasma, its interaction with peroxynitrite leads to generation of free radical intermediates such as (i) the ascorbyl radical, detected by direct EPR, (ii) the albumin-thiyl radical, detected by spin-trapping experiments with both N-tert-butyl-alpha-phenylnitrone and 5,5-dimethyl-1-pyrroline N-oxide (DMPO), and (iii) a uric acid-derived free radical, detected as the DMPO radical adduct in plasma whose thiol groups were previously blocked with 5,5-dithiobis-(2-nitrobenzoic acid). The identity of the latter adduct was confirmed by parallel experiments demonstrating that it is not detectable in plasma pretreated with uricase, whereas it is formed in incubations of peroxynitrite with uric acid. Peroxynitrite-mediated oxidations were also followed by oxygen consumption and ascorbate and plasma-thiol depletion. Our results support the view that peroxynitrite-mediated one-electron oxidation of biomolecules may be an important event in its cytotoxic mechanism. In addition, the data have methodological implications by providing support for the use of EPR methodologies for monitoring both free radical reactions and ascorbate concentrations in biological fluids. PMID:8615782

  5. Uric acid in the etiology of psoriasis.

    PubMed

    Goldman, M

    1981-01-01

    The potential etiologic relationship between uric acid in its microcrystalline monosodium urate form and psoriasis was examined by 1) substantiating the reported correlation between hyperuricemia and psoriasis using the phosphotungstate method; 2) examining psoriatic tissue samples for the presence of urates under a microscope using polarized light and a compensator; 3) attempting to induce psoriasis-like symptoms in laboratory animals with purine-to-uric acid metabolism by increasing serum uric acid level; and 4) observing psoriasis-hyperuricemic patients following treatment for their hyperuricemia with Allopurinol. As expected, both men and women psoriatics had higher uric acid levels than did their counterparts in a control group. Monosodium urate crystals were found in samples from psoriatic plaques by both methods used. They were clustered particularly around sweat pores and Munro abscesses, but were found only occasionally in epidermal tissue taken from nonpsoriatics. Psoriasis-like symptoms were induced in laboratory animals (the South American boa, Constrictor constrictor) when they were fed doses of uric acid. Patients with psoriasis and hyperuricemia showed marked improvement in psoriasis when treated for their hyperuricemia. Psoriasis, like gout, may be, at least partly, a result of disorder of purine metabolism and monosodium urate crystals may be responsible for the cell proliferation that is characteristic of psoriatic plaques. Monosodium urate crystals were found by the author to be strikingly segmented. This structure may result in ease of fragmentation, thus increasing the difficulty in identifying urates in any tissue.

  6. 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

  7. Delayed uric Acid accumulation in plasma provides additional anti-oxidant protection against iron-triggered oxidative stress after a wingate test.

    PubMed

    Souza-Junior, Tp; Lorenço-Lima, L; Ganini, D; Vardaris, Cv; Polotow, Tg; Barros, Mp

    2014-12-01

    Reactive oxygen species are produced during anaerobic exercise mostly by Fe ions released into plasma and endothelial/muscle xanthine oxidase activation that generates uric acid (UA) as the endpoint metabolite. Paradoxically, UA is considered a major antioxidant by virtue of being able to chelate pro-oxidative iron ions. This work aimed to evaluate the relationship between UA and plasma markers of oxidative stress following the exhaustive Wingate test. Plasma samples of 17 male undergraduate students were collected before, 5 and 60 min after maximal anaerobic effort for the measurement of total iron, haem iron, UA, ferric-reducing antioxidant activity in plasma (FRAP), and malondialdehyde (MDA, biomarker of lipoperoxidation). Iron and FRAP showed similar kinetics in plasma, demonstrating an adequate pro-/antioxidant balance immediately after exercise and during the recovery period (5-60 min). Slight variations of haem iron concentrations did not support a relevant contribution of rhabdomyolysis or haemolysis for iron overload following exercise. UA concentration did not vary immediately after exercise but rather increased 29% during the recovery period. Unaltered MDA levels were concomitantly measured. We propose that delayed UA accumulation in plasma is an auxiliary antioxidant response to post-exercise (iron-mediated) oxidative stress, and the high correlation between total UA and FRAP in plasma (R-Square = 0.636; p = 0.00582) supports this hypothesis. PMID:25435669

  8. DELAYED URIC ACID ACCUMULATION IN PLASMA PROVIDES ADDITIONAL ANTI-OXIDANT PROTECTION AGAINST IRON-TRIGGERED OXIDATIVE STRESS AFTER A WINGATE TEST

    PubMed Central

    Souza-Junior, TP; Lorenço-Lima, L; Ganini, D; Vardaris, CV; Polotow, TG

    2014-01-01

    Reactive oxygen species are produced during anaerobic exercise mostly by Fe ions released into plasma and endothelial/muscle xanthine oxidase activation that generates uric acid (UA) as the endpoint metabolite. Paradoxically, UA is considered a major antioxidant by virtue of being able to chelate pro-oxidative iron ions. This work aimed to evaluate the relationship between UA and plasma markers of oxidative stress following the exhaustive Wingate test. Plasma samples of 17 male undergraduate students were collected before, 5 and 60 min after maximal anaerobic effort for the measurement of total iron, haem iron, UA, ferric-reducing antioxidant activity in plasma (FRAP), and malondialdehyde (MDA, biomarker of lipoperoxidation). Iron and FRAP showed similar kinetics in plasma, demonstrating an adequate pro-/antioxidant balance immediately after exercise and during the recovery period (5–60 min). Slight variations of haem iron concentrations did not support a relevant contribution of rhabdomyolysis or haemolysis for iron overload following exercise. UA concentration did not vary immediately after exercise but rather increased 29% during the recovery period. Unaltered MDA levels were concomitantly measured. We propose that delayed UA accumulation in plasma is an auxiliary antioxidant response to post-exercise (iron-mediated) oxidative stress, and the high correlation between total UA and FRAP in plasma (R-Square = 0.636; p = 0.00582) supports this hypothesis. PMID:25435669

  9. The seasonal glucocorticoid response of male Rufous-winged Sparrows to acute stress correlates with changes in plasma uric acid, but neither glucose nor testosterone.

    PubMed

    Deviche, Pierre; Valle, Shelley; Gao, Sisi; Davies, Scott; Bittner, Stephanie; Carpentier, Elodie

    2016-09-01

    We sought to clarify functional relationships between baseline and acute stress-induced changes in plasma levels of the stress hormone corticosterone (CORT) and the reproductive hormone testosterone (T), and those of two main metabolites, uric acid (UA) and glucose (GLU). Acute stress in vertebrates generally stimulates the secretion of glucocorticoids, which in birds is primarily CORT. This stimulation is thought to promote behavioral and metabolic changes, including increased glycemia. However, limited information in free-ranging birds supports the view that acutely elevated plasma CORT stimulates glycemia. Acute stress also often decreases the secretion of reproductive hormones (e.g., T in males), but the role of CORT in this decrease and the contribution of T to the regulation of plasma GLU remain poorly understood. We measured initial (pre-stress) and acute stress-induced plasma CORT and T as well as GLU in adult male Rufous-winged Sparrows, Peucaea carpalis, sampled during the pre-breeding, breeding, post-breeding molt, and non-breeding stages. Stress increased plasma CORT and the magnitude of this increase did not differ across life history stages. The stress-induced elevation of plasma CORT was consistently associated with decreased plasma UA, suggesting a role for CORT in the regulation of plasma UA during stress. During stress plasma GLU either increased (pre-breeding), did not change (breeding), or decreased (molt and non-breeding), and plasma T either decreased (pre-breeding and breeding) or did not change (molt and non-breeding). These data provide only partial support to the hypothesis that CORT secretion during acute stress exerts a hyperglycemic action or is responsible for the observed decrease in plasma T taking place at certain life history stages. They also do not support the hypothesis that rapid changes in plasma T influence glycemia. PMID:27292791

  10. [Uric acid, kidney disease and nephrolithiasis].

    PubMed

    Kim, Min Jeong; Hopfer, Helmut; Mayr, Michael

    2016-01-01

    Different types of kidney disease are known to be associated with hyperuricemia. The underlying pathophysiologic mechanisms strongly vary, and different ways of therapeutic approach are therefore required. In tumor lysis syndrome, a rapid, excessive increase of serum uric acid level can cause an acute renal failure. For chronic urate nephropathy, on the other hand, constantly elevated serum uric acid level for a longer period seems to be important. Being still controversial as a disease entity however, the aetiology for putative chronic urate nephropathy might be in fact chronic lead intoxication, as suggested by quite an amount of association data. In terms of uric acid nephrolithiasis, the major risk factor is a urinary acidification defect with persistently acidic urine pH, and not necessarily hyperuricemia or hyperuricosuria. Evidence suggests that metabolic diseases with increased insulin resistance are strongly associated with urinary acidification defect. Patients with uric acid kidney stones should therefore be thoroughly evaluated for such metabolic diseases and in a positive case adequately treated.

  11. [Uric acid, kidney disease and nephrolithiasis].

    PubMed

    Kim, Min Jeong; Hopfer, Helmut; Mayr, Michael

    2016-01-01

    Different types of kidney disease are known to be associated with hyperuricemia. The underlying pathophysiologic mechanisms strongly vary, and different ways of therapeutic approach are therefore required. In tumor lysis syndrome, a rapid, excessive increase of serum uric acid level can cause an acute renal failure. For chronic urate nephropathy, on the other hand, constantly elevated serum uric acid level for a longer period seems to be important. Being still controversial as a disease entity however, the aetiology for putative chronic urate nephropathy might be in fact chronic lead intoxication, as suggested by quite an amount of association data. In terms of uric acid nephrolithiasis, the major risk factor is a urinary acidification defect with persistently acidic urine pH, and not necessarily hyperuricemia or hyperuricosuria. Evidence suggests that metabolic diseases with increased insulin resistance are strongly associated with urinary acidification defect. Patients with uric acid kidney stones should therefore be thoroughly evaluated for such metabolic diseases and in a positive case adequately treated. PMID:27008449

  12. 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...) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1775 Uric acid test system. (a) Identification. A uric acid test system is a device intended to...

  13. 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...) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1775 Uric acid test system. (a) Identification. A uric acid test system is a device intended to...

  14. Lower uric Acid linked with cognitive dysfunction in the elderly.

    PubMed

    Méndez-Hernández, Edna; Salas-Pacheco, José; Ruano-Calderón, Luis; Téllez-Valencia, Alfredo; Cisneros-Martínez, Jorge; Barraza-Salas, Marcelo; Arias-Carrión, Oscar

    2015-01-01

    Uric acid has been associated as a risk factor for cardiovascular disease. Recently, however, there is growing evidence that uric acid plays a role as antioxidant in the brain. In cognitive dysfunction, vascular and oxidative stress mechanisms play a role, but the link remains unknown. Therefore, we investigated the link between serum uric acid-levels and cognitive function in 62 elderly subjects. The statistical analysis was adjusted to age, sex and cardiovascular risk factors. Here, we found that lower serum uric acid levels are linked to cognitive dysfunction. In a Mexican population, higher levels of uric acid are associated with a decreased risk of dementia. PMID:25925000

  15. Extra-renal elimination of uric acid via intestinal efflux transporter BCRP/ABCG2.

    PubMed

    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.

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

    PubMed Central

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

    2013-01-01

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

  17. [Outpatient care in uric acid disorders].

    PubMed

    Schwenke, R; Altus, R E; Kirschner, I

    1979-08-15

    In 35 patients with uricopathy (arthritis urica, essential hyperuricaemia) the serum uric acid values, consumption of alcohol, overweight, hypertension and liver enzyma under dietary and medicamentous therapy (allopurinol) were investigated. Here during an observation lasting 12--48 months allopurinol proved as a well tolerable uricostatic drug which was sufficiently effective also with a considerable exogenic purine application. We only insufficiently succeeded in influencing overweight and alcohol consumption as well as hypertension by rheumatic dispensary care and family doctor.

  18. [Uric acid and kidneys – Physiological and pathophysiological aspects].

    PubMed

    Kim, Min Jeong; Mayr, Michael

    2016-01-01

    Kidneys play a critical role in the excretion of uric acid. Improved knowledge of the renal tubular uric acid transport mechanisms helps to better understand, why hyper- or hypouricemia can develop without the external influence of purine intake. Besides the genetic mutations, several drugs and specific medical conditions can significantly influence the tubular excretion of uric acid and thus the serum uric acid level. It seems evident that the renal function per se has a relevant impact on the uric acid excretion. It is however not clear, whether uric acid has a causal role in the development of chronic kidney disease and if so, to what extent. In order to better understand the impact of hyper- and hypouricemia and especially their clinical relevance, further researches on the renal tubular physio- and pathophysiology and also high quality intervention studies are required.

  19. Uric acid excretion predicts increased aggression in urban adolescents.

    PubMed

    Mrug, Sylvie; Mrug, Michal

    2016-09-01

    Elevated levels of uric acid have been linked with impulsive and disinhibited behavior in clinical and community populations of adults, but no studies have examined uric acid in relation to adolescent aggression. This study examined the prospective role of uric acid in aggressive behavior among urban, low income adolescents, and whether this relationship varies by gender. A total of 84 adolescents (M age 13.36years; 50% male; 95% African American) self-reported on their physical aggression at baseline and 1.5years later. At baseline, the youth also completed a 12-h (overnight) urine collection at home which was used to measure uric acid excretion. After adjusting for baseline aggression and age, greater uric acid excretion predicted more frequent aggressive behavior at follow up, with no significant gender differences. The results suggest that lowering uric acid levels may help reduce youth aggression. PMID:27180134

  20. [Uric acid and kidneys – Physiological and pathophysiological aspects].

    PubMed

    Kim, Min Jeong; Mayr, Michael

    2016-01-01

    Kidneys play a critical role in the excretion of uric acid. Improved knowledge of the renal tubular uric acid transport mechanisms helps to better understand, why hyper- or hypouricemia can develop without the external influence of purine intake. Besides the genetic mutations, several drugs and specific medical conditions can significantly influence the tubular excretion of uric acid and thus the serum uric acid level. It seems evident that the renal function per se has a relevant impact on the uric acid excretion. It is however not clear, whether uric acid has a causal role in the development of chronic kidney disease and if so, to what extent. In order to better understand the impact of hyper- and hypouricemia and especially their clinical relevance, further researches on the renal tubular physio- and pathophysiology and also high quality intervention studies are required. PMID:27008450

  1. [Serum uric acid levels and risk of developing preeclampsia].

    PubMed

    Corominas, Ana I; Balconi, Silvia M; Palermo, Mario; Maskin, Bernardo; Damiano, Alicia E

    2014-01-01

    It is well known that preeclampsia is associated to high uric acid levels, but the clinical assessment of this relationship is still under consideration. Our research was to evaluate if periodic doses of uric acid during pregnancy might help to identify a high risk group prior to the onset of preeclampsia. We conducted a retrospective investigation in 79 primary gestates with normal blood pressure and 79 women with preeclampsia who were assisted at Hospital Nacional Posadas during 2010. Serum uric acid levels, creatininemia, uremia, and proteinuria data from the clinical records of the pregnant women were considered. Uric acid levels were similar in both groups during the first half of gestation. However, as of the 20th week, uric acid increased 1.5-times in preeclamptic women with no changes in creatinine and urea, confirming that these patients had no renal complications. Furthermore, we noted that higher levels of uric acid correlated with low birth weight. We also observed that pregnant women with a family history of hypertension were more likely to develop this condition. Moreover, we did not find a direct relationship with the fetal sex or the appearance of clinical symptoms. The analytical evidence suggests that changes in uric acid concentrations may be due to metabolic alterations at the initial stages of preeclampsia. Therefore, we propose that monitoring levels of uric acid during pregnancy might contribute to the early control of this condition.

  2. Serum Uric Acid Level among Acute Stroke Patients.

    PubMed

    Mohsin, M; Das, S N; Haque, M F; Shikha, S S; Bhuiyan, A S; Saha, P L; Das, B R; Chowdhury, M; Jahan, M K; Rahman, M M

    2016-04-01

    Stroke is one of the leading causes of death and disability in developed as well as developing countries like Bangladesh. Elevated serum uric acid levels may predict an increased risk for cerebro-vascular (CV) events including stroke. Aim of the study was to measure the serum uric acid level among stroke patients and determine the relationship between serum uric acid level and stroke. This descriptive, cross-sectional study was carried out in Department of Medicine, Mymensingh Medical College Hospital, Mymensingh, Bangladesh to measure serum uric acid level among 102 stroke patients in a period of one year by using non-probability sampling procedure. Finally, collected data were analyzed using SPSS software Version 17.0. It was observed that the mean age of patients was 60.87±8.05 years, of them 80(78.43%) patients were male and the rest 22(21.57%) were female. About 66(64.70%) of respondents were in age group 60 years and above, while 36(35.30%) were in age group 59 years and below. At least 23(22.55%) of stroke patients had elevated serum uric acid with a mean serum uric acid level of 5.18mg/dl and standard deviation 1.26mg/dl. About 23(27.38%) patients in ischemic stroke had elevated serum uric acid whereas 18(100%) patients in hemorrhagic stroke had normal uric acid level. Uric acid level was elevated in ischemic stroke than haemorrhagic stroke patients (p<0.001). High uric acid level may be considered as a risk factor in patients with acute ischemic stroke. PMID:27277350

  3. Acute consumption of organic and conventional tropical grape juices (Vitis labrusca L.) increases antioxidants in plasma and erythrocytes, but not glucose and uric acid levels, in healthy individuals.

    PubMed

    Toaldo, Isabela Maia; Cruz, Fernanda Alves; da Silva, Edson Luiz; Bordignon-Luiz, Marilde T

    2016-08-01

    Bioactive polyphenols in grapes are influenced by grape variety and cultivation conditions. The Vitis labrusca L. varieties are cultivated in tropical regions and used for grape juice production. We hypothesized that polyphenols from tropical grape juices would beneficially affect redox homeostasis in humans. Therefore, the effects of acute consumption of organic and conventional grape juices from V labrusca L. on antioxidants biomarkers were investigated in healthy individuals. In a controlled, randomized, crossover, intervention trial, 24 individuals were assigned to drink 400 mL of conventional juice, organic juice, or water. Each intervention was followed by a 14-day washout period. Blood samples were obtained before and 1 hour after acute intake and analyzed for erythrocyte reduced glutathione, serum total antioxidant capacity, antioxidant enzymes in erythrocytes, and glucose and uric acid in serum. The ingestion of both grape juices resulted in elevated levels of reduced glutathione (P< .001) and serum total antioxidant capacity (P< .05) and increased activity of catalase (P< .001), superoxide dismutase (P< .001), and glutathione peroxidase (P< .05) compared with the control intervention, with no significant differences between grape juices (P< .05). The intake of juices did not affect significantly the concentrations of glucose or uric acid. Grape juice polyphenols were associated with increased antioxidants, and the chemical differences between organic and conventional juices were not predictive of the observed responses. The results suggest a bioactive potential of V labrusca L. juices to improve redox homeostasis, which is involved in defense against oxidative stress in humans. PMID:27440535

  4. Acute consumption of organic and conventional tropical grape juices (Vitis labrusca L.) increases antioxidants in plasma and erythrocytes, but not glucose and uric acid levels, in healthy individuals.

    PubMed

    Toaldo, Isabela Maia; Cruz, Fernanda Alves; da Silva, Edson Luiz; Bordignon-Luiz, Marilde T

    2016-08-01

    Bioactive polyphenols in grapes are influenced by grape variety and cultivation conditions. The Vitis labrusca L. varieties are cultivated in tropical regions and used for grape juice production. We hypothesized that polyphenols from tropical grape juices would beneficially affect redox homeostasis in humans. Therefore, the effects of acute consumption of organic and conventional grape juices from V labrusca L. on antioxidants biomarkers were investigated in healthy individuals. In a controlled, randomized, crossover, intervention trial, 24 individuals were assigned to drink 400 mL of conventional juice, organic juice, or water. Each intervention was followed by a 14-day washout period. Blood samples were obtained before and 1 hour after acute intake and analyzed for erythrocyte reduced glutathione, serum total antioxidant capacity, antioxidant enzymes in erythrocytes, and glucose and uric acid in serum. The ingestion of both grape juices resulted in elevated levels of reduced glutathione (P< .001) and serum total antioxidant capacity (P< .05) and increased activity of catalase (P< .001), superoxide dismutase (P< .001), and glutathione peroxidase (P< .05) compared with the control intervention, with no significant differences between grape juices (P< .05). The intake of juices did not affect significantly the concentrations of glucose or uric acid. Grape juice polyphenols were associated with increased antioxidants, and the chemical differences between organic and conventional juices were not predictive of the observed responses. The results suggest a bioactive potential of V labrusca L. juices to improve redox homeostasis, which is involved in defense against oxidative stress in humans.

  5. An Increase Incidence in Uric Acid Nephrolithiasis: Changing Patterns

    PubMed Central

    Kumari, Asha; Mittal, Pawan; Kumar, Rajender; Goel, Richa; Bansal, Piyush; Kumar, Himanshu Devender; Bhutani, Jaikrit

    2016-01-01

    Introduction Nephrolithiasis is a complex disease affecting all age groups globally. As the causative factors for nephrolithiasis rises significantly, its incidence, prevalence and recurrence continues to baffle clinicians and patients. Aim To study the prevalence of different types of renal stones extracted by Percutaneous Nephrolithotomy (PCNL) and open surgical procedures. Materials and Methods Renal stones from 50 patients were retrieved by Percutaneous Nephrolithotomy (PCNL), Ureterorenoscopy (URS) and open surgical techniques for qualitative tests for detection of calcium, oxalate, uric acid, phosphate, ammonium ion, carbonate, cystine and xanthine. Results Three patients had stone removed by open surgery and rest had undergone PCNL. Nine of the stones were pure of calcium oxalate, 9 were of pure uric acid and 32 were mixed stones. Forty one stones had calcium. Among the mixed stones, oxalate was present in 25 samples (39 of total), uric acid was seen in 17 (25 of total stones), phosphate was present in 23 (23 of total) and carbonate was present in 4 stones (4 of total). Only 1 patient had triple phosphate stone. 12 were of staghorn appearance of which 6 were of struvite type, 6 were pure uric acid and remaining were mixed oxalate-phosphate stones. Conclusion Our study, though in a small number of hospital based patients, found much higher prevalence of uric acid stones and mixed stones than reported by previous hospital based studies in north India (oxalate stones~90%, uric acid~1% and mixed stones~3%). Biochemical analysis of renal stones is warranted in all cases. PMID:27630833

  6. An Increase Incidence in Uric Acid Nephrolithiasis: Changing Patterns

    PubMed Central

    Kumari, Asha; Mittal, Pawan; Kumar, Rajender; Goel, Richa; Bansal, Piyush; Kumar, Himanshu Devender; Bhutani, Jaikrit

    2016-01-01

    Introduction Nephrolithiasis is a complex disease affecting all age groups globally. As the causative factors for nephrolithiasis rises significantly, its incidence, prevalence and recurrence continues to baffle clinicians and patients. Aim To study the prevalence of different types of renal stones extracted by Percutaneous Nephrolithotomy (PCNL) and open surgical procedures. Materials and Methods Renal stones from 50 patients were retrieved by Percutaneous Nephrolithotomy (PCNL), Ureterorenoscopy (URS) and open surgical techniques for qualitative tests for detection of calcium, oxalate, uric acid, phosphate, ammonium ion, carbonate, cystine and xanthine. Results Three patients had stone removed by open surgery and rest had undergone PCNL. Nine of the stones were pure of calcium oxalate, 9 were of pure uric acid and 32 were mixed stones. Forty one stones had calcium. Among the mixed stones, oxalate was present in 25 samples (39 of total), uric acid was seen in 17 (25 of total stones), phosphate was present in 23 (23 of total) and carbonate was present in 4 stones (4 of total). Only 1 patient had triple phosphate stone. 12 were of staghorn appearance of which 6 were of struvite type, 6 were pure uric acid and remaining were mixed oxalate-phosphate stones. Conclusion Our study, though in a small number of hospital based patients, found much higher prevalence of uric acid stones and mixed stones than reported by previous hospital based studies in north India (oxalate stones~90%, uric acid~1% and mixed stones~3%). Biochemical analysis of renal stones is warranted in all cases.

  7. 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.

  8. Liver Enzymes and Uric acid in Acute Heart Failure

    PubMed Central

    Vakilian, Farveh; Rafighdoost, Abbas Ali; Rafighdoost, Amir Hossein; Amin, Ahmad; Salehi, Maryam

    2015-01-01

    Background: Acute heart failure (AHF) is defined as the new onset or recurrence of gradual or rapidly worsening signs and symptoms of heart failure, requiring urgent or emergent therapy. Objectives: This study attempts to assess the association of liver function tests (LFT) and uric acid level with in hospital outcome and echocardiography parameters, in patients with acute decompensated heart failure. Patients and Methods: A total of 100 patients (aged 16 - 90 years, 60% men) admitted with AHF were enrolled. LFTs and uric acid levels were assessed on first day and before discharge, and patients were followed for 3 months. Results: In-hospital outcomes were considered. Mean Left Ventricular Ejection Fraction (LVEF) was 35% (20 - 45%). Mean Uric acid level was 8.4 mg/dL, significantly higher than chronic HF and normal groups (P < 0.02). Elevated liver enzymes were seen in 52% patients, mostly (87%) in transaminases. Liver enzymes were decreased in 85% patients before discharge. LFT and uric acid levels were inversely and significantly correlated with LVEF on echocardiography (P = 0.02), but not with diastolic parameters. Although there was no significant correlation between uric acid level and in-hospital mortality, risk of intubation and rehospitalization in 3 months, enzyme levels increased in these groups. Increased aspartate transaminase (AST level) was associated with inotrope infusion in AHF patients (42 vs. 82 mg/dL, P = 0.03). Conclusions: Abnormal transaminases and uric acid levels are seen in AHF patients. Increased AST levels may be a predictor of the need for inotrope during hospital course in these patients. PMID:26528447

  9. The relationship between uric acid and its oxidative product allantoin: a potential indicator for the evaluation of oxidative stress in birds.

    PubMed

    Tsahar, Ella; Arad, Zeev; Izhaki, Ido; Guglielmo, Christopher G

    2006-09-01

    Uric acid is the main nitrogenous waste product in birds but it is also known to be a potent antioxidant. Hominoid primates and birds lack the enzyme urate oxidase, which oxidizes uric acid to allantoin. Consequently, the presence of allantoin in their plasma results from non-enzymatic oxidation. In humans, the allantoin to uric acid ratio in plasma increases during oxidative stress, thus this ratio has been suggested to be an in vivo marker for oxidative stress in humans. We measured the concentrations of uric acid and allantoin in the plasma and ureteral urine of white-crowned sparrows (Zonotrichia leucophrys gambelii) at rest, immediately after 30 min of exercise in a hop/hover wheel, and after 1 h of recovery. The plasma allantoin concentration and the allantoin to uric acid ratio did not increase during exercise but we found a positive relationship between the concentrations of uric acid and allantoin in the plasma and in the ureteral urine in the three activity phases. In the plasma, the slope of the regression describing the above positive relationships was significantly higher immediately after activity. We suggest that the slope indicates the rate of uric acid oxidation and that during activity this rate increases as a result of higher production of free radicals. The present study demonstrates that allantoin is present in the plasma and in the ureteral urine of white-crowned sparrows and therefore might be useful as an indicator of oxidative stress in birds.

  10. 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…

  11. Sugar, uric acid, and the etiology of diabetes and obesity.

    PubMed

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

    2013-10-01

    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.

  12. Sugar, uric acid, and the etiology of diabetes and obesity.

    PubMed

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

    2013-10-01

    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

  13. 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.

  14. Uric Acid as a Target of Therapy in CKD

    PubMed Central

    Jalal, Diana I.; Chonchol, Michel; Chen, Wei; Targher, Giovanni

    2012-01-01

    The prevalence of chronic kidney disease (CKD) has risen and will continue to rise in the United States and worldwide. This is alarming considering that CKD remains an irreversible condition and patients who progress to chronic kidney failure suffer reduced quality of life and high mortality rates. As such, it is imperative to identify modifiable risk factors to develop strategies to slow CKD progression. One such factor is hyperuricemia. Recent observational studies have associated hyperuricemia with kidney disease. In addition, hyperuricemia is largely prevalent in patients with CKD. Data from experimental studies have revealed several potential mechanisms by which hyperuricemia may contribute to the development and progression of CKD. In this manuscript we offer a critical review of the experimental evidence linking hyperuricemia to CKD, we highlight the gaps in our knowledge on the topic as it stands today, and we review the observational and interventional studies that have examined the potential nephro-protective effect of lowering uric acid in CKD patients . While uric acid may also be linked to cardiovascular disease and mortality in patients with CKD, this review will focus only on uric acid as a potential therapeutic target to prevent kidney disease onset and progression. PMID:23058478

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

    PubMed Central

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

    2013-01-01

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

  16. Uric acid: a modulator of prostate cells and activin sensitivity.

    PubMed

    Sangkop, Febbie; Singh, Geeta; Rodrigues, Ely; Gold, Elspeth; Bahn, Andrew

    2016-03-01

    Elevated serum uric acid (SUA) or urate is associated with inflammation and gout. Recent evidence has linked urate to cancers, but little is known about urate effects in prostate cancer. Activins are inflammatory cytokines and negative growth regulators in the prostate. A hallmark of prostate cancer progression is activin insensitivity; however, mechanisms underlying this are unclear. We propose that elevated SUA is associated with prostate cancer counteracting the growth inhibitory effects of activins. The expression of activins A and B, urate transporter GLUT9 and tissue urate levels were examined in human prostate disease. Intracellular and secreted urate and GLUT9 expression were assessed in human prostate cancer cell lines. Furthermore, the effects of urate and probenecid, a known urate transport inhibitor, were determined in combination with activin A. Activin A expression was increased in low-grade prostate cancer, whereas activin B expression was reduced in high-grade prostate cancer. Intracellular urate levels decreased in all prostate pathologies, while GLUT9 expression decreased in benign prostatic hyperplasia, prostatitis and high-grade prostate cancer. Activin responsive LNCaP cells had higher intracellular and lower secreted urate levels than activin-insensitive PC3 cells. GLUT9 expression in prostate cancer cells was progressively lower than in prostate epithelial cells. Elevated extracellular urate was growth promoting in vitro, which was abolished by the gout medication probenecid, and it antagonized the growth inhibitory effects of activins. This study shows for the first time that a change in plasma or intracellular urate levels, possibly involving GLUT9 and a urate efflux transporter, has an impact on prostate cancer cell growth, and that lowering SUA levels in prostate cancer is likely to be therapeutically beneficial. PMID:26910779

  17. 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

  18. Caecal decomposition of uric acid in captive and free ranging willow ptarmigan (Lagopus lagopus lagopus).

    PubMed

    Mortensen, A; Tindall, A R

    1981-02-01

    Urine entering the caeca of birds contains significant amounts of uric acid. The discovery of great numbers of bacteria utilizing uric acid in the caeca has encouraged the discussion about nitrogen recycling in birds. In this work caecal decomposition of uric acid in wild and captive willow ptarmigan has been investigated using radioactively labelled uric acid injected directly into one of the caeca. The appearance of radioactive CO2 in the expired air was taken as an indication of uric acid breakdown. The decomposition occurred at a rate corresponding to a half-life of 26 min (11-36 min). The results are in accordance with the previously reported observations of huge numbers of uric acid utilizing bacteria in the caeca of a variety of birds, and also with the nitrogen recycling theory. However, no conclusion concerning the nitrogen recycling can be drawn. PMID:7282388

  19. [Clinical value of the sequential study of the uric acid in CSF in patients with cerebral diseases: Part I. Brain tumor and the effect of irradiation].

    PubMed

    Ueda, T; Wakisaka, S; Kinoshita, K; Adachi, H

    1984-03-01

    Uric acid is the end product of the purine metabolism in the human and is mainly excreted to the urine. The studies on cerebrospinal fluid (CSF) uric acid in patients with various neurological diseases were reported in the literature. In the present study the authors discussed the clinical value of the sequential study of the CSF uric acid content in patients with brain tumors. CSF was investigated for uric acid in 23 controls and 30 cases of brain tumor. The results were as follows: The mean value and standard deviation of the uric acid in CSF in controls was 0.23 +/- 0.13 mg/dl. The uric acid in CSF increased in patients with malignant brain tumor (0.49 +/- 0.22 mg/dl, p less than 0.005), but was in normal range in patients with benign brain tumor (0.32 +/- 0.13 mg/dl, 0.10 less than p less than 0.25). There was no significant correlation between CSF uric acid and CSF protein contents. Uric acid in the lumbar CSF was approximately 4 times higher than in the ventricular CSF in patients with brain tumor. The CSF uric acid had progressively increased during irradiation to the whole brain. The factors contributing to increase of the uric acid in CSF were thought to be increased permeability of blood-CSF barrier, global damage of brain tissue, increased nucleic acid catabolism in the central nervous system (CNS) for example in tumor, inflammation or immunoreaction, increased of xanthine, hypoxanthine or xanthine oxidase activity in the CNS, directly increased of plasma components into the CSF due to such as subarachnoid hemorrhage, intraventricular hemorrhage, bleeding in the tumor or surgical operation, dysfunction of the CSF dynamics.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. 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.

  1. 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.

  2. Serum uric acid may not be involved in the development of preeclampsia.

    PubMed

    Chen, Q; Lau, S; Tong, M; Wei, J; Shen, F; Zhao, J; Zhao, M

    2016-02-01

    Higher serum levels of uric acid are associated with preeclampsia and may signal an early change in preeclampsia. However there is less evidence suggesting there is a meaningful association between uric acid and the development of preeclampsia. A total of 877 women with preeclampsia at presentation and 580 normotensive pregnancies were retrospectively recruited from January 2009 to May 2014. In addition, 5556 pregnant women were also prospectively recruited from September 2012 to December 2013. Retrospective serum levels of uric acid were obtained from women with preeclampsia at the time of presentation (n=877), and serum levels of uric acid in the first, second and third trimester were prospectively collected in women who later developed preeclampsia (n=78), as well as those who did not (n=5478). The serum levels of uric acid were significantly increased in women with preeclampsia at presentation from retrospective samples and this increase correlated with the time of onset and the severity of preeclampsia. However, in prospective samples, serum levels of uric acid were not increased in the first and second trimesters in women who later developed preeclampsia compared with those who did not. The serum level of uric acid in the first and second trimesters in women who developed preeclampsia was not different. Our results demonstrate that the serum levels of uric acid were only increased after the presentation of clinical symptoms of preeclampsia. Therefore, it is likely that uric acid is not involved in the development of preeclampsia and cannot be an early prediction biomarker of this disease.

  3. Potential mechanisms for low uric acid in Parkinson disease.

    PubMed

    Sampat, Radhika; Young, Sarah; Rosen, Ami; Bernhard, Douglas; Millington, David; Factor, Stewart; Jinnah, H A

    2016-04-01

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

  4. 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

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

    PubMed Central

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

    2015-01-01

    Objective To determine whether women who had a hypertensive pregnancy disorder (HPD) have elevated uric acid concentrations decades after pregnancy, when compared to women who had normotensive pregnancies. Patients and Methods The Genetic Epidemiology Network of Arteriopathy study measured uric acid concentrations in Hispanic (30%), non-Hispanic white (28%), and non-Hispanic black (42%) women (60 ± 10 years of age). This cross-sectional study was conducted between July 1, 2000 and December 31, 2004. Hispanic participants were recruited from families with high rates of diabetes, whereas non-Hispanic participants were recruited from families with high rates of hypertension. This analysis compared uric acid concentrations in women with a history of normotensive (n=1,846) or hypertensive (n=408) pregnancies by logistic regression. Results Women who had a HPD had higher uric acid concentrations (Median: 5.7 vs. 5.3 mg/dL, P<.001) and were more likely to have uric acid concentrations above 5.5 mg/dl (54.4% vs. 42.4%, P=.001) than women who had normotensive pregnancies. These differences persisted after adjusting for traditional cardiovascular risk factors, co-morbidities and other factors that affect uric acid concentrations. A family-based subgroup analysis comparing uric acid concentrations in women who had a HPD (n=308) and their parous sisters who had normotensive pregnancies (n=250) gave similar results (Median uric acid concentrations: 5.7 vs. 5.2 mg/dl, P=0.02; Proportion of women with uric acid >5.5 mg/dl: 54.0% vs. 40.3%, P<.001). Conclusion Decades after pregnancy, women who had a HPD have higher uric acid concentrations. This effect does not appear to be explained by a familial predisposition to elevated uric acid concentrations. PMID:26260220

  6. Perfluoroalkyl chemicals and elevated serum uric acid in US adults

    PubMed Central

    Shankar, Anoop; Xiao, Jie; Ducatman, Alan

    2011-01-01

    Background: Perfluoroalkyl chemicals, including perfluorooctanoic acid and perfluorooctane sulfonate, are man-made chemicals that have been detected in the blood of over 98% of the US population. Serum uric acid is a novel biomarker, even mild elevations of which has been implicated in the development of hypertension, diabetes mellitus, cardiovascular disease, and chronic kidney disease. We examined the relationship of serum perfluoroalkyl chemicals, including perfluorooctanoic acid and perfluorooctane sulfonate, and elevated uric acid levels in a representative sample of US adults. Methods: We examined 3883 participants from the 1999–2000 and 2003–2006 National Health and Nutritional Examination Surveys, a representative, multiethnic population-based survey of noninstitutionalized US adults. Serum perfluorooctanoic acid and perfluorooctane sulfonate were analyzed as quartiles. The main outcome was hyperuricemia. Results: We found that serum levels of perfluoroalkyl chemicals, including perfluorooctanoic acid and perfluorooctane sulfonate, were positively associated with hyperuricemia. This association appeared to be independent of confounders such as age, gender, race-ethnicity, body mass index, diabetes, hypertension, and serum cholesterol. Compared with subjects in quartile 1 (referent), the multivariate odds ratio for hyperuricemia among subjects in quartile 4 was 1.97 (95% confidence interval 1.44–2.70, P < 0.0001) for perfluorooctanoic acid and 1.48% (95% confidence interval 0.99–2.22, P = 0.0433) for perfluorooctane sulfonate. This observed association persisted in subgroup analysis by gender and body mass index. Conclusion: Our results demonstrate that elevated levels of perfluoroalkyl chemicals are associated with hyperuricemia even at low perfluoroalkyl chemical exposure levels as seen in the US general population. PMID:22003309

  7. 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

  8. 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.

  9. Xanthine oxidase-mediated denitrosation of N-nitroso-tryptophan by superoxide and uric acid.

    PubMed

    Viles, Kimberley; Mathai, Clinton; Jourd'heuil, Frances L; Jourd'heuil, David

    2013-01-15

    Recent studies indicate the formation of protein nitrosamines in vivo and tryptophan residues in proteins might represent important targets of nitrosative and oxidative stress. In the present work, we examined the mechanism by which xanthine oxidase (XO) denitrosates N-nitroso Trp residues and determined the applicability of the reactions involved to the detection of nitrosated Trp residues by tri-iodide-based chemiluminescence. We found that - in addition to superoxide - denitrosation of N-acetyl-nitroso Trp (NANT) by hypoxanthine and XO occurred via the intermediacy of uric acid. Zero-order dependence of NANT decay rate with uric acid was achieved with increasing concentrations of uric acid (k(0)∼6.0×10(-4)s(-1)) and generated nitric oxide. In contrast, S-nitrosoglutathione and nitrosyl-myoglobin were stable in the presence of uric acid. NANT decomposition by uric acid could be reproducibly measured using the tri-iodide-based chemiluminescence assay in the presence of excess nitrite upon pre-treatment with acidified sulfanilamide. N-nitrosated albumin was sensitive to uric acid-induced decomposition only after proteolytic degradation. In conclusion, XO decomposes nitrosated Trp through superoxide and uric acid pathways and in the case of uric acid generates free nitric oxide. Site-specificity of this reaction may possibly be used in combination with the tri-iodide-based chemiluminescence assay to discern between nitrosated Trp, S-nitrosothiols, and nitrosylated heme proteins. PMID:23099296

  10. The role of uric acid in the pathogenesis of hypertension in the young.

    PubMed

    Feig, Daniel I

    2012-06-01

    Uric acid has been suspected to be a risk factor for hypertension since the 1870s. Numerous epidemiological studies demonstrate an association between uric acid and both incident and prevalent hypertension in diverse populations. Studies in elderly patients have had more variable results, raising the possibility that uric acid may be more significant to hypertension in the young. Animal models support a two-phase mechanism for the development of hyperuricemic hypertension. Initially, uric acid induces vasoconstriction by activation of the renin-angiotensin system and reduction of circulating nitric oxide, which can be reversed by lowering uric acid. Over time, uric acid uptake into vascular smooth muscle cells causes cellular proliferation and secondary arteriolosclerosis that impairs pressure natriuresis, causing sodium-sensitive hypertension. Consistent with the animal model data, small clinical trials performed in adolescents with newly diagnosed essential hypertension demonstrate that at least in certain young patients, reduction of serum uric acid can mitigate blood pressure elevation. While more research is clearly necessary, the available data suggest that uric acid is likely causative in some cases of early-onset hypertension.

  11. Teneligliptin Decreases Uric Acid Levels by Reducing Xanthine Dehydrogenase Expression in White Adipose Tissue of Male Wistar Rats

    PubMed Central

    2016-01-01

    We investigated the effects of teneligliptin on uric acid metabolism in male Wistar rats and 3T3-L1 adipocytes. The rats were fed with a normal chow diet (NCD) or a 60% high-fat diet (HFD) with or without teneligliptin for 4 weeks. The plasma uric acid level was not significantly different between the control and teneligliptin groups under the NCD condition. However, the plasma uric acid level was significantly decreased in the HFD-fed teneligliptin treated rats compared to the HFD-fed control rats. The expression levels of xanthine dehydrogenase (Xdh) mRNA in liver and epididymal adipose tissue of NCD-fed rats were not altered by teneligliptin treatment. On the other hand, Xdh expression was reduced significantly in the epididymal adipose tissue of the HFD-fed teneligliptin treated rats compared with that of HFD-fed control rats, whereas Xdh expression in liver did not change significantly in either group. Furthermore, teneligliptin significantly decreased Xdh expression in 3T3-L1 adipocytes. DPP-4 treatment significantly increased Xdh expression in 3T3-L1 adipocytes. With DPP-4 pretreatment, teneligliptin significantly decreased Xdh mRNA expression compared to the DPP-4-treated 3T3-L1 adipocytes. In conclusion, our studies suggest that teneligliptin reduces uric acid levels by suppressing Xdh expression in epididymal adipose tissue of obese subjects.

  12. Teneligliptin Decreases Uric Acid Levels by Reducing Xanthine Dehydrogenase Expression in White Adipose Tissue of Male Wistar Rats

    PubMed Central

    2016-01-01

    We investigated the effects of teneligliptin on uric acid metabolism in male Wistar rats and 3T3-L1 adipocytes. The rats were fed with a normal chow diet (NCD) or a 60% high-fat diet (HFD) with or without teneligliptin for 4 weeks. The plasma uric acid level was not significantly different between the control and teneligliptin groups under the NCD condition. However, the plasma uric acid level was significantly decreased in the HFD-fed teneligliptin treated rats compared to the HFD-fed control rats. The expression levels of xanthine dehydrogenase (Xdh) mRNA in liver and epididymal adipose tissue of NCD-fed rats were not altered by teneligliptin treatment. On the other hand, Xdh expression was reduced significantly in the epididymal adipose tissue of the HFD-fed teneligliptin treated rats compared with that of HFD-fed control rats, whereas Xdh expression in liver did not change significantly in either group. Furthermore, teneligliptin significantly decreased Xdh expression in 3T3-L1 adipocytes. DPP-4 treatment significantly increased Xdh expression in 3T3-L1 adipocytes. With DPP-4 pretreatment, teneligliptin significantly decreased Xdh mRNA expression compared to the DPP-4-treated 3T3-L1 adipocytes. In conclusion, our studies suggest that teneligliptin reduces uric acid levels by suppressing Xdh expression in epididymal adipose tissue of obese subjects. PMID:27652270

  13. Teneligliptin Decreases Uric Acid Levels by Reducing Xanthine Dehydrogenase Expression in White Adipose Tissue of Male Wistar Rats.

    PubMed

    Moriya, Chihiro; Satoh, Hiroaki

    2016-01-01

    We investigated the effects of teneligliptin on uric acid metabolism in male Wistar rats and 3T3-L1 adipocytes. The rats were fed with a normal chow diet (NCD) or a 60% high-fat diet (HFD) with or without teneligliptin for 4 weeks. The plasma uric acid level was not significantly different between the control and teneligliptin groups under the NCD condition. However, the plasma uric acid level was significantly decreased in the HFD-fed teneligliptin treated rats compared to the HFD-fed control rats. The expression levels of xanthine dehydrogenase (Xdh) mRNA in liver and epididymal adipose tissue of NCD-fed rats were not altered by teneligliptin treatment. On the other hand, Xdh expression was reduced significantly in the epididymal adipose tissue of the HFD-fed teneligliptin treated rats compared with that of HFD-fed control rats, whereas Xdh expression in liver did not change significantly in either group. Furthermore, teneligliptin significantly decreased Xdh expression in 3T3-L1 adipocytes. DPP-4 treatment significantly increased Xdh expression in 3T3-L1 adipocytes. With DPP-4 pretreatment, teneligliptin significantly decreased Xdh mRNA expression compared to the DPP-4-treated 3T3-L1 adipocytes. In conclusion, our studies suggest that teneligliptin reduces uric acid levels by suppressing Xdh expression in epididymal adipose tissue of obese subjects. PMID:27652270

  14. Stored wheat insect infestation related to uric acid as determined by liquid chromatography.

    PubMed

    Wehling, R L; Wetzel, D L; Pedersen, J R

    1984-01-01

    Liquid chromatography is used to measure the uric acid content of wheat internally infested by various growth stages of granary weevil (Sitophilus granarius), rice weevil (Sitophilus oryzae), and lesser grain borer (Ryzopertha dominica). Good correlation exists between numbers of insects and uric acid content of grain infested by a given stage of an internally infesting stored product insect, with correlation coefficients ranging from 0.970 to 0.998. Uric acid content of infested grain increases as the insect life cycle progresses, with granary weevil producing the greatest quantities of uric acid followed in order by rice weevil and lesser grain borer. A detection limit for the analytical procedure of less than 1.0 ppm uric acid allows detection of infestation levels as low as one kernel per 100 g grain for late instar granary weevil larvae. This limit is sufficiently sensitive to detect levels of infestation that may be commonly encountered in commerce.

  15. Luteolin prevents uric acid-induced pancreatic β-cell dysfunction

    PubMed Central

    Ding, Ying; Shi, Xuhui; Shuai, Xuanyu; Xu, Yuemei; Liu, Yun; Liang, Xiubin; Wei, Dong; Su, Dongming

    2014-01-01

    Abstract Elevated uric acid causes direct injury to pancreatic β-cells. In this study, we examined the effects of luteolin, an important antioxidant, on uric acid-induced β-cell dysfunction. We first evaluated the effect of luteolin on nitric oxide (NO) formation in uric acid-stimulated Min6 cells using the Griess method. Next, we performed transient transfection and reporter assays to measure transcriptional activity of nuclear factor (NF)-κB. Western blotting assays were also performed to assess the effect of luteolin on the expression of MafA and inducible NO synthase (iNOS) in uric acid-treated cells. Finally, we evaluated the effect of luteolin on uric acid-induced inhibition of glucose-stimulated insulin secretion (GSIS) in Min6 cells and freshly isolated mouse pancreatic islets. We found that luteolin significantly inhibited uric acid-induced NO production, which was well correlated with reduced expression of iNOS mRNA and protein. Furthermore, decreased activity of NF-κB was implicated in inhibition by luteolin of increased iNOS expression induced by uric acid. Besides, luteolin significantly increased MafA expression in Min6 cells exposed to uric acid, which was reversed by overexpression of iNOS. Moreover, luteolin prevented uric acid-induced inhibition of GSIS in both Min6 cells and mouse islets. In conclusion, luteolin protects pancreatic β-cells from uric acid-induced dysfunction and may confer benefit on the protection of pancreatic β-cells in hyperuricemia-associated diabetes. PMID:25050113

  16. Phytochemicals from Tradescantia albiflora Kunth Extracts Reduce Serum Uric Acid Levels in Oxonate-induced Rats

    PubMed Central

    Wang, Wen-Ling; Sheu, Shi-Yuan; Huang, Wen-Dar; Chuang, Ya-Ling; Tseng, Han-Chun; Hwang, Tzann-Shun; Fu, Yuan-Tsung; Kuo, Yueh-Hsiung; Yao, Chun-Hsu; Kuo, Tzong-Fu

    2016-01-01

    Background: Tradescantia albiflora (TA) Kunth (Commelinaceae) has been used for treating gout and hyperuricemia as folklore remedies in Taiwan. Therefore, it is worthwhile to study the effect of TA extracts on lowering uric acid activity. The hypouricemic effects of TA extracts on potassium oxonate (PO)-induced acute hyperuricemia were investigated for the first time. Materials and Methods: All treatments at the same volume (1 ml) were orally administered to the abdominal cavity of PO-induced hyperuricemic rats. One milliliter of TA extract in n-hexane (HE), ethyl acetate (EA), n-butanol (BuOH), and water fractions has 0.28, 0.21, 0.28, and 1.03 mg TA, respectively; and the plasma uric acid (PUA) level was measured for a consecutive 4 h after administration. Results: All four fractions' extracts derived from TA were observed to significantly reduce PUA compared with the PO group. The EA-soluble fraction (TA-EA) exhibited the best xanthine oxidase (XO) inhibitory activity. Following column chromatography, 12 phytochemicals were isolated and identified from the EA fraction. The IC50 values of isolated phytochemicals indicated that bracteanolide A (AR11) showed the remarkable XO inhibitory effect (IC50 value of 76.4 μg/ml). These findings showed that the in vivo hypouricemic effect in hyperuricemic rats was consistent with in vitro XO inhibitory activity, indicating that TA extracts and derived phytochemicals could be potential candidates as hypouricemic agents. SUMMARY Tradescantia albiflora extracts possess in vivo hypouricemic action in hyperuricemic ratsT. albiflora extracts exhibited strong inhibitory activity against xanthine oxidase (XO)Butenolide may play an important role in XO inhibitionThe extract bracteanolide A was demonstrated potent XO inhibitory activity in vitro. Abbreviations used: TA: Tradescantia albiflora, PO: potassium oxonate, HE: n-hexane, EA: ethyl acetate, BuOH: n-butanol, PUA: plasma uric acid, XO: xanthine oxidase, MeOH: methanol, IP

  17. Altered Serum Uric Acid Level in Lichen Planus Patients

    PubMed Central

    Chakraborti, Goutam; Biswas, Rabindranath; Chakraborti, Sandip; Sen, Pradyot Kumar

    2014-01-01

    Background: Lichen planus (LP) is a common disorder whose etiopathogenesis is not clear. Recently, it has been suggested that increased reactive oxygen species (ROS) play important roles in the underlying mechanism of LP. Objectives: The principal aim of this study was to evaluate serum uric acid (UA) levels as a measure of the antioxidant defense status in LP patients. Methods: Serum UA levels were determined in 58 LP patients and 61 controls. Results: Serum UA levels were significantly decreased in patients with respect to controls. Moreover, serum UA level was decreased according to increasing duration of disease. Conclusions: The results of our study suggest that LP is associated with decrease of UA levels in serum. UA may be a potential, useful biomarker of antioxidant status in LP for elaboration of treatment strategy and monitoring. PMID:25484383

  18. 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.

  19. Uric acid deposits and estivation in the invasive apple-snail, Pomacea canaliculata.

    PubMed

    Giraud-Billoud, Maximiliano; Abud, María A; Cueto, Juan A; Vega, Israel A; Castro-Vazquez, Alfredo

    2011-04-01

    The physiological ability to estivate is relevant for the maintenance of population size in the invasive Pomacea canaliculata. However, tissue reoxygenation during arousal from estivation poses the problem of acute oxidative stress. Uric acid is a potent antioxidant in several systems and it is stored in specialized tissues of P. canaliculata. Changes in tissue concentration of thiobarbituric acid reactive substances (TBARS), uric acid and allantoin were measured during estivation and arousal in P. canaliculata. Both TBARS and uric acid increased two-fold during 45 days estivation, probably as a consequence of concomitant oxyradical production during uric acid synthesis by xanthine oxidase. However, after arousal was induced, uric acid and TBARS dropped to or near baseline levels within 20 min and remained low up to 24h after arousal induction, while the urate oxidation product allantoin continuously rose to a maximum at 24h after induction, indicating the participation of uric acid as an antioxidant during reoxygenation. Neither uric acid nor allantoin was detected in the excreta during this 24h period. Urate oxidase activity was also found in organs of active snails, but activity shut down during estivation and only a partial and sustained recovery was observed in the midgut gland.

  20. 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

  1. Preterm Birth is Associated with Higher Uric Acid Levels in Adolescents

    PubMed Central

    Washburn, Lisa K.; Nixon, Patricia A.; Russell, Gregory B.; Snively, Beverly M.; O’Shea, T. Michael

    2015-01-01

    Objective To compare serum uric acid levels in adolescents born prematurely and adolescents born at term and to assess the correlation between serum uric acid and blood pressure in those born prematurely. Study design In this observational cohort study, 124 adolescents born prematurely and 44 adolescents born at term were studied at 14 years of age. Multivariate analyses were used to describe the relationship of premature birth to serum uric acid, while adjusting for confounding variables. Pearson correlation was used to describe the relationship between uric acid and systolic blood pressure among those born prematurely. Results Adjusting for race, sex, maternal hypertension and fetal growth, preterm adolescents had higher serum uric acid levels than adolescents born at term [adjusted mean difference (95% confidence interval: 0.46 (0.10, 0.81) mg/dL, 27.4 (6, 48.2) μmol/L, p=0.012]. Among those born prematurely, uric acid was positively correlated with systolic blood pressure [Pearson correlation coefficient: 0.29 (0.12, 0.44; p= 0.0013). Conclusions Serum uric acid levels are higher in adolescents born prematurely than in those born at term and this difference could contribute to higher blood pressure among individuals born prematurely. PMID:25868431

  2. 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.

  3. 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. PMID:26082349

  4. 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.

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

    PubMed

    Zhou, Qi; Liu, Shu-min

    2015-11-01

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

  6. Associations among Lead Dose Biomarkers, Uric Acid, and Renal Function in Korean Lead Workers

    PubMed Central

    Weaver, Virginia M.; Jaar, Bernard G.; Schwartz, Brian S.; Todd, Andrew C.; Ahn, Kyu-Dong; Lee, Sung-Soo; Wen, Jiayu; Parsons, Patrick J.; Lee, Byung-Kook

    2005-01-01

    Recent research suggests that both uric acid and lead may be nephrotoxic at lower levels than previously recognized. We analyzed data from 803 current and former lead workers to determine whether lead biomarkers were associated with uric acid and whether previously reported associations between lead dose and renal outcomes were altered after adjustment for uric acid. Outcomes included uric acid, blood urea nitrogen, serum creatinine, measured and calculated creatinine clearances, and urinary N-acetyl-β-d-glucosaminidase (NAG) and retinol-binding protein. Mean (± SD) uric acid, tibia lead, and blood lead levels were 4.8 ± 1.2 mg/dL, 37.2 ± 40.4 μg/g bone mineral, and 32.0 ± 15.0 μg/dL, respectively. None of the lead measures (tibia, blood, and dimercaptosuccinic-acid–chelatable lead) was associated with uric acid, after adjustment for age, sex, body mass index, and alcohol use. However, when we examined effect modification by age on these relations, both blood and tibia lead were significantly associated (β= 0.0111, p < 0.01 and β= 0.0036, p = 0.04, respectively) in participants in the oldest age tertile. These associations decreased after adjustment for blood pressure and renal function, although blood lead remained significantly associated with uric acid (β= 0.0156, p = 0.01) when the population was restricted to the oldest tertile of workers with serum creatinine greater than the median (0.86 mg/dL). Next, in models of renal function in all workers, uric acid was significantly (p < 0.05) associated with all renal outcomes except NAG. Finally, in the oldest tertile of workers, associations between lead dose and NAG were unchanged, but fewer associations between the lead biomarkers and the clinical renal outcomes remained significant (p ≤0.05) after adjustment for uric acid. In conclusion, our data suggest that older workers comprise a susceptible population for increased uric acid due to lead. Uric acid may be one, but not the only, mechanism for

  7. A new approach for noninvasive transdermal determination of blood uric acid levels

    PubMed Central

    Ching, Congo Tak-Shing; Yong, Kok-Khun; Yao, Yan-Dong; Shen, Huan-Ting; Hsieh, Shiu-Man; Jheng, Deng-Yun; Sun, Tai-Ping; Shieh, Hsiu-Li

    2014-01-01

    The aims of this study were to investigate the most effective combination of physical forces from laser, electroporation, and reverse iontophoresis for noninvasive transdermal extraction of uric acid, and to develop a highly sensitive uric acid biosensor (UAB) for quantifying the uric acid extracted. It is believed that the combination of these physical forces has additional benefits for extraction of molecules other than uric acid from human skin. A diffusion cell with porcine skin was used to investigate the most effective combination of these physical forces. UABs coated with ZnO2 nanoparticles and constructed in an array configuration were developed in this study. The results showed that a combination of laser (0.7 W), electroporation (100 V/cm2), and reverse iontophoresis (0.5 mA/cm2) was the most effective and significantly enhanced transdermal extraction of uric acid. A custom-designed UAB coated with ZnO2 nanoparticles and constructed in a 1×3 array configuration (UAB-1×3-ZnO2) demonstrated enough sensitivity (9.4 μA/mM) for quantifying uric acid extracted by the combined physical forces of laser, electroporation, and RI. A good linear relationship (R2=0.894) was demonstrated to exist between the concentration of uric acid (0.2–0.8 mM) inside the diffusion cell and the current response of the UAB-1×3-ZnO2. In conclusion, a new approach to noninvasive transdermal extraction and quantification of uric acid has been established. PMID:25061289

  8. Uric acid promotes left ventricular diastolic dysfunction in mice fed a Western diet.

    PubMed

    Jia, Guanghong; Habibi, Javad; Bostick, Brian P; Ma, Lixin; DeMarco, Vincent G; Aroor, Annayya R; Hayden, Melvin R; Whaley-Connell, Adam T; Sowers, James R

    2015-03-01

    The rising obesity rates parallel increased consumption of a Western diet, high in fat and fructose, which is associated with increased uric acid. Population-based data support that elevated serum uric acids are associated with left ventricular hypertrophy and diastolic dysfunction. However, the mechanism by which excess uric acid promotes these maladaptive cardiac effects has not been explored. In assessing the role of Western diet-induced increases in uric acid, we hypothesized that reductions in uric acid would prevent Western diet-induced development of cardiomyocyte hypertrophy, cardiac stiffness, and impaired diastolic relaxation by reducing growth and profibrotic signaling pathways. Four-weeks-old C57BL6/J male mice were fed excess fat (46%) and fructose (17.5%) with or without allopurinol (125 mg/L), a xanthine oxidase inhibitor, for 16 weeks. The Western diet-induced increases in serum uric acid along with increases in cardiac tissue xanthine oxidase activity temporally related to increases in body weight, fat mass, and insulin resistance without changes in blood pressure. The Western diet induced cardiomyocte hypertrophy, myocardial oxidative stress, interstitial fibrosis, and impaired diastolic relaxation. Further, the Western diet enhanced activation of the S6 kinase-1 growth pathway and the profibrotic transforming growth factor-β1/Smad2/3 signaling pathway and macrophage proinflammatory polarization. All results improved with allopurinol treatment, which lowered cardiac xanthine oxidase as well as serum uric acid levels. These findings support the notion that increased production of uric acid with intake of a Western diet promotes cardiomyocyte hypertrophy, inflammation, and oxidative stress that lead to myocardial fibrosis and associated impaired diastolic relaxation.

  9. 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

  10. A new approach for noninvasive transdermal determination of blood uric acid levels.

    PubMed

    Ching, Congo Tak-Shing; Yong, Kok-Khun; Yao, Yan-Dong; Shen, Huan-Ting; Hsieh, Shiu-Man; Jheng, Deng-Yun; Sun, Tai-Ping; Shieh, Hsiu-Li

    2014-01-01

    The aims of this study were to investigate the most effective combination of physical forces from laser, electroporation, and reverse iontophoresis for noninvasive transdermal extraction of uric acid, and to develop a highly sensitive uric acid biosensor (UAB) for quantifying the uric acid extracted. It is believed that the combination of these physical forces has additional benefits for extraction of molecules other than uric acid from human skin. A diffusion cell with porcine skin was used to investigate the most effective combination of these physical forces. UABs coated with ZnO₂ nanoparticles and constructed in an array configuration were developed in this study. The results showed that a combination of laser (0.7 W), electroporation (100 V/cm(2)), and reverse iontophoresis (0.5 mA/cm(2)) was the most effective and significantly enhanced transdermal extraction of uric acid. A custom-designed UAB coated with ZnO₂ nanoparticles and constructed in a 1×3 array configuration (UAB-1×3-ZnO₂) demonstrated enough sensitivity (9.4 μA/mM) for quantifying uric acid extracted by the combined physical forces of laser, electroporation, and RI. A good linear relationship (R(2)=0.894) was demonstrated to exist between the concentration of uric acid (0.2-0.8 mM) inside the diffusion cell and the current response of the UAB-1×3-ZnO₂. In conclusion, a new approach to noninvasive transdermal extraction and quantification of uric acid has been established.

  11. Uric Acid Level and Erectile Dysfunction In Patients With Coronary Artery Disease

    PubMed Central

    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

    2013-01-01

    Introduction Erectile dysfunction (ED) is a frequent complaint of elderly subjects, and is closely associated with endothelial dysfunction and cardiovascular disease. Uric acid is also associated with endothelial dysfunction, oxidative stress and cardiovascular disease, raising the hypothesis that an increased serum uric acid might predict erectile dysfunction in patients who are at risk for coronary artery disease. Aim 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. Methods This is a cross-sectional study of 312 adult male patients with suspected coronary artery disease who underwent exercise stress test (EST) for workup of chest pain and completed a sexual health inventory for men (SHIM) 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. Main Outcome Measures The short version of the international index of erectile function (IIEF-5) questionnaire diagnosed ED (cutoff score ≤21). Serum Uric acid levels were determined. Patients with chest pain of suspected cardiac origin underwent an exercise stress test. Results 149 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, CRP, triglycerides compared with patients without ED. Uric acid levels were associated with ED by univariate analysis (OR = 1.36, p = 0.002); however, this association was not observed in multivariate analysis adjusted for eGFR. Conclusion Subjects presenting with chest pain of presumed cardiac origin are more likely to have ED if they have elevated uric acid levels. PMID:24433559

  12. Does high serum uric acid level cause aspirin resistance?

    PubMed

    Yildiz, Bekir S; Ozkan, Emel; Esin, Fatma; Alihanoglu, Yusuf I; Ozkan, Hayrettin; Bilgin, Murat; Kilic, Ismail D; Ergin, Ahmet; Kaftan, Havane A; Evrengul, Harun

    2016-06-01

    In patients with coronary artery disease (CAD), though aspirin inhibits platelet activation and reduces atherothrombotic complications, it does not always sufficiently inhibit platelet function, thereby causing a clinical situation known as aspirin resistance. As hyperuricemia activates platelet turnover, aspirin resistance may be specifically induced by increased serum uric acid (SUA) levels. In this study, we thus investigated the association between SUA level and aspirin resistance in patients with CAD. We analyzed 245 consecutive patients with stable angina pectoris (SAP) who in coronary angiography showed more than 50% occlusion in a major coronary artery. According to aspirin resistance, two groups were formed: the aspirin resistance group (Group 1) and the aspirin-sensitive group (Group 2). Compared with those of Group 2, patients with aspirin resistance exhibited significantly higher white blood cell counts, neutrophil counts, neutrophil-to-lymphocyte ratios, SUA levels, high-sensitivity C-reactive protein levels, and fasting blood glucose levels. After multivariate analysis, a high level of SUA emerged as an independent predictor of aspirin resistance. The receiver-operating characteristic analysis provided a cutoff value of 6.45 mg/dl for SUA to predict aspirin resistance with 79% sensitivity and 65% specificity. Hyperuricemia may cause aspirin resistance in patients with CAD and high SUA levels may indicate aspirin-resistant patients. Such levels should thus recommend avoiding heart attack and stroke by adjusting aspirin dosage. PMID:26656902

  13. Reduction of urinary uric acid excretion in patients with proteinuria.

    PubMed

    Zou, Huiqing; Xiang, Mingfeng; Ye, Xinming; Xiong, Yuanzhen; Xie, Baogang; Shao, Jianghua

    2015-12-01

    Serum uric acid (UA) concentration is positively associated with proteinuria. However, the relationship between proteinuria and urinary metabolites of purine metabolism remains unknown. This study developed a hydrophilic interaction chromatography (HILIC)-based HPLC method with ultraviolet detection (UV) to quantify creatinine (Cr), UA, xanthine, and hypoxanthine in human urine simultaneously. The urinary concentrations of UA and Cr obtained by our method are consistent with those measured by an autoanalyzer. The HPLC-HILIC-UV method was validated as selective and robust with simple sample preparation for measuring UA, xanthine, hypoxanthine and Cr, which is suitable for large clinical studies. The UA/Cr ratios in random urine samples were 5.5 times lower in proteinuria patients (0.077±0.008) than in healthy individuals (0.424±0.037). Moreover, the UA/hypoxanthine ratio in proteinuria patients was approximately 10 times lower than that in healthy individuals. Our findings revealed a reduced urinary UA excretion, which is one of the factors leading to increased serum UA in proteinuria patients.

  14. The Role of Uric Acid in Kidney Fibrosis: Experimental Evidences for the Causal Relationship

    PubMed Central

    Kim, Il Young; Lee, Dong Won; Kwak, Ihm Soo

    2014-01-01

    Hyperuricemia is a common finding in chronic kidney disease due to decreased uric acid clearance. The role of uric acid as a risk factor for chronic kidney disease has been largely debated, and recent studies suggested a role of uric acid in the causation and progression of kidney fibrosis, a final common pathway in chronic kidney disease. Uric acid and xanthine oxidase may contribute to kidney fibrosis mainly by inducing inflammation, endothelial dysfunction, oxidative stress, and activation of the renin-angiotensin system. Besides, hyperuricemia induces alterations in renal hemodynamics via afferent arteriolopathy and contributes to the onset and progression of kidney fibrosis. Xanthine oxidase inhibitors may prevent kidney damage via lowering uric acid and/or inhibiting xanthine oxidase. However, there is still no sufficient evidence from interventional clinical researches supporting the causal relationship between uric acid and kidney fibrosis. The effect and role of xanthine oxidase inhibitors in preventing kidney fibrosis and chronic kidney disease progression must be further explored by performing future large scale clinical trials. PMID:24877124

  15. 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.

  16. 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.

  17. Uric acid levels predict future blood pressure and new onset hypertension in the general Japanese population.

    PubMed

    Takase, H; Kimura, G; Dohi, Y

    2014-09-01

    We tested the hypothesis that uric acid levels predict new-onset hypertension in the Japanese general population. Normotensive individuals who visited our hospital for a yearly health checkup (n=8157, men=61.0% and age=50.7±12.2 years) were enrolled in the present study. After baseline evaluation, participants were followed up for a median of 48.3 months (range 4.9-101.0 months), with the endpoint being the development of hypertension, defined as systolic blood pressure (BP) > or = 140 mm Hg, diastolic BP > or = 90 mm Hg or the use of antihypertensive medication. The impact of uric acid and other cardiovascular risk factors at baseline on future BP and development of hypertension was assessed. During follow-up, 19.0% of women (n=605) and 29.5% of men (n=1469) participants developed hypertension. Incident hypertension was increased across the quartiles for baseline uric acid levels (P<0.0001), and multivariate Cox proportional hazards analysis revealed a significant and independent association between the uric acid level and the onset of hypertension in both men and women participants (P<0.05). Furthermore, uric acid was independently and positively correlated with future BP (P<0.05). Thus, uric acid is an independent predictor of new-onset hypertension in both women and men.

  18. Serum Uric Acid and Hypertension in Adults: a Paradoxical Relationship in Type 1 Diabetes

    PubMed Central

    Bjornstad, Petter; Wadwa, R. Paul; Sirota, Jeffrey C.; Snell-Bergeon, Janet K.; McFann, Kimberly; Rewers, Marian; Rivard, Christopher J.; Jalal, Diana; Chonchol, Michel B.; Johnson, Richard J.; Maahs, David M.

    2014-01-01

    Adults with type 1 diabetes have lower serum uric acid levels compared to non-diabetic adults. Little is known about the relationship between serum uric acid and blood pressure in type 1 diabetes and whether it differs from the positive relationship found in non-diabetic adults. We assessed the cross-sectional and longitudinal relationships over 6-years between serum uric acid and blood pressure in adults with (35±9 years, n=393) and without (38±9 years n=685) T1D in the Coronary Artery Calcification in Type 1 Diabetes study. In non-diabetic adults, serum uric acid was associated with systolic blood pressure in multivariable-models adjusted for cardiovascular risk-factors. In adults with type 1 diabetes, a negative association was observed between serum uric acid and systolic blood pressure after multivariable-adjustments. A positive association was observed between serum uric acid and systolic blood pressure in non-diabetic adults. In contrast, an inverse relationship was demonstrated after multivariable-adjustments in type 1 diabetes. PMID:24667019

  19. Serum uric acid and hypertension in adults: a paradoxical relationship in type 1 diabetes.

    PubMed

    Bjornstad, Petter; Paul Wadwa, R; Sirota, Jeffrey C; Snell-Bergeon, Janet K; McFann, Kimberly; Rewers, Marian; Rivard, Christopher J; Jalal, Diana; Chonchol, Michel B; Johnson, Richard J; Maahs, David M

    2014-04-01

    Adults with type 1 diabetes have lower serum uric acid levels compared with nondiabetic adults. Little is known about the relationship between serum uric acid and blood pressure in type 1 diabetes and whether it differs from the positive relationship found in nondiabetic adults. The authors assessed the cross-sectional and longitudinal relationships over 6 years between serum uric acid and blood pressure in adults with (35±9 years [n=393]) and without (38±9 years [n=685]) type 1 diabetes in the Coronary Artery Calcification in Type 1 Diabetes study. In nondiabetic adults, serum uric acid was associated with systolic blood pressure in multivariable models adjusted for cardiovascular risk factors. In adults with type 1 diabetes, a negative association was observed between serum uric acid and systolic blood pressure after multivariable adjustments. A positive association was observed between serum uric acid and systolic blood pressure in nondiabetic adults. In contrast, an inverse relationship was demonstrated after multivariable adjustments in type 1 diabetes. PMID:24667019

  20. Effect of canagliflozin on serum uric acid in patients with type 2 diabetes mellitus.

    PubMed

    Davies, M J; Trujillo, A; Vijapurkar, U; Damaraju, C V; Meininger, G

    2015-04-01

    Hyperuricaemia is associated with an increased risk of gout, kidney stones and cardiovascular disease. The present post hoc analysis of pooled data from four placebo-controlled phase III studies assessed the effect of canagliflozin, a sodium-glucose co-transporter 2 inhibitor, on serum uric acid levels in patients with type 2 diabetes mellitus (T2DM) and in a subset of patients with hyperuricaemia [defined as baseline serum uric acid ≥475 µmol/l (∼8 mg/dl)]. At week 26, canagliflozin 100 and 300 mg were associated with a ∼13% reduction in serum uric acid compared with placebo. In the subset of patients with hyperuricaemia, placebo-subtracted percent reductions in serum uric acid were similar to those in the overall cohort. More patients in the hyperuricaemic group achieved a serum uric acid level of <360 µmol/l (∼6 mg/dl) with both canagliflozin 100 mg (23.5%) and 300 mg (32.4%) compared with placebo (3.1%). Incidences of gout and kidney stones were low and similar across groups. In conclusion, canagliflozin treatment decreased serum uric acid in patients with T2DM, including those with baseline hyperuricaemia.

  1. Genotype-based changes in serum uric acid affect blood pressure

    PubMed Central

    Parsa, Afshin; Brown, Eric; Weir, Matthew R.; Fink, Jeffrey C.; Shuldiner, Alan R.; Mitchell, Braxton D.; McArdle, Patrick F.

    2013-01-01

    Elevated serum levels of uric acid consistently correlate with hypertension, but the directionality of the association remains debated. To help define this relationship, we used a controlled setting within a homogeneous Amish community and the Mendelian randomization of a nonsynonymous coding single-nucleotide polymorphism, rs16890979 (Val253Ile), in the SLC2A9 gene. This gene expresses the GLUT9 transporter that also transports uric acid and is associated with lower serum uric acid levels. We studied the unconfounded association between genotype and blood pressure in 516 Amish adults, each placed for 6 days on standardized diets, first with high sodium, followed by low sodium, with an intervening washout period. Blood pressure, measured using 24-h ambulatory monitoring, during both diet periods was used as the primary outcome. All participants were free of diuretic or other antihypertensive medications and the relationships between GLUT9 genotype and both serum uric acid and blood pressure were assessed. Each copy of the GLUT9 minor Ile allele was found to confer a significant 0.44 mg/dl reduction in serum uric acid and was associated with a significant mean decrease in the systolic blood pressure of 2.2 and 1.5 mm Hg on the high- and low-sodium diet, respectively. Thus, a Mendelian randomization analysis using variants in the GLUT9 gene indicates that a decrease in serum uric acid has a causal effect of lowering blood pressure. PMID:22189840

  2. An amperometric uric acid biosensor based on chitosan-carbon nanotubes electrospun nanofiber on silver nanoparticles.

    PubMed

    Numnuam, Apon; Thavarungkul, Panote; Kanatharana, Proespichaya

    2014-06-01

    A novel amperometric uric acid biosensor was fabricated by immobilizing uricase on an electrospun nanocomposite of chitosan-carbon nanotubes nanofiber (Chi-CNTsNF) covering an electrodeposited layer of silver nanoparticles (AgNPs) on a gold electrode (uricase/Chi-CNTsNF/AgNPs/Au). The uric acid response was determined at an optimum applied potential of -0.35 V vs Ag/AgCl in a flow-injection system based on the change of the reduction current for dissolved oxygen during oxidation of uric acid by the immobilized uricase. The response was directly proportional to the uric acid concentration. Under the optimum conditions, the fabricated uric acid biosensor had a very wide linear range, 1.0-400 μmol L(-1), with a very low limit of detection of 1.0 μmol L(-1) (s/n = 3). The operational stability of the uricase/Chi-CNTsNF/AgNPs/Au biosensor (up to 205 injections) was excellent and the storage life was more than six weeks. A low Michaelis-Menten constant of 0.21 mmol L(-1) indicated that the immobilized uricase had high affinity for uric acid. The presence of potential common interfering substances, for example ascorbic acid, glucose, and lactic acid, had negligible effects on the performance of the biosensor. When used for analysis of uric acid in serum samples, the results agreed well with those obtained by use of the standard enzymatic colorimetric method (P > 0.05). PMID:24718436

  3. Serum uric acid is inversely proportional to estimated stroke volume and cardiac output in a large sample of pharmacologically untreated subjects: data from the Brisighella Heart Study.

    PubMed

    Cicero, Arrigo Francesco Giuseppe; Rosticci, Martina; Parini, Angelo; Baronio, Cristina; D'Addato, Sergio; Borghi, Claudio

    2014-09-01

    Serum uric acid is representative for xanthine-oxidase, the key enzyme involved in the production of uric acid, which is up-regulated in the failing heart, and may play an important role in the pathophysiologic process that leads to heart failure. In our study, we investigated the relation between stroke volume, cardiac output and serum uric acid in a large sample of overall healthy pharmacologically untreated subjects. The Brisighella Heart Study included 2,939 men and women between the ages of 14-84 without prior coronary heart disease or cerebrovascular disease who were not taking antihypertensive therapy at baseline. For this study, we selected 734 adult subjects enrolled in the last Brisighella population survey not taking antihypertensive, antidiabetic, lipid-lowering and uric acid-lowering drugs, and who were also not affected by chronic heart failure or by gout. The main predictors of cardiac functionality parameters were mean arterial pressure (MAP), HR, SUA and age (all p < 0.001), while gender, BMI, LDL-cholesterol, HDL-cholesterol, triglycerides, fasting plasma glucose, creatinine, estimated glomerular filtration rate, physical activity and smoking habit were not significantly associated (all p > 0.05). In particular, there is a strong relation between estimated cardiac output and serum uric acid (B = -0.219, p < 0.001) and between stroke volume and serum uric acid (B = -3.684, p < 0.001). These observations might have an impact on future considerations about serum uric acid as an early inexpensive marker of heart function decline in the general population. PMID:24214336

  4. The Effects of Fructose Intake on Serum Uric Acid Vary among Controlled Dietary Trials1234

    PubMed Central

    Wang, D. David; Sievenpiper, John L.; de Souza, Russell J.; Chiavaroli, Laura; Ha, Vanessa; Cozma, Adrian I.; Mirrahimi, Arash; Yu, Matthew E.; Carleton, Amanda J.; Di Buono, Marco; Jenkins, Alexandra L.; Leiter, Lawrence A.; Wolever, Thomas M. S.; Beyene, Joseph; Kendall, Cyril W. C.; Jenkins, David J. A.

    2012-01-01

    Hyperuricemia is linked to gout and features of metabolic syndrome. There is concern that dietary fructose may increase uric acid concentrations. To assess the effects of fructose on serum uric acid concentrations in people with and without diabetes, we conducted a systematic review and meta-analysis of controlled feeding trials. We searched MEDLINE, EMBASE, and the Cochrane Library for relevant trials (through August 19, 2011). Analyses included all controlled feeding trials ≥7 d investigating the effect of fructose feeding on uric acid under isocaloric conditions, where fructose was isocalorically exchanged with other carbohydrate, or hypercaloric conditions, and where a control diet was supplemented with excess energy from fructose. Data were aggregated by the generic inverse variance method using random effects models and expressed as mean difference (MD) with 95% CI. Heterogeneity was assessed by the Q statistic and quantified by I2. A total of 21 trials in 425 participants met the eligibility criteria. Isocaloric exchange of fructose for other carbohydrate did not affect serum uric acid in diabetic and nondiabetic participants [MD = 0.56 μmol/L (95% CI: −6.62, 7.74)], with no evidence of inter-study heterogeneity. Hypercaloric supplementation of control diets with fructose (+35% excess energy) at extreme doses (213–219 g/d) significantly increased serum uric acid compared with the control diets alone in nondiabetic participants [MD = 31.0 mmol/L (95% CI: 15.4, 46.5)] with no evidence of heterogeneity. Confounding from excess energy cannot be ruled out in the hypercaloric trials. These analyses do not support a uric acid-increasing effect of isocaloric fructose intake in nondiabetic and diabetic participants. Hypercaloric fructose intake may, however, increase uric acid concentrations. The effect of the interaction of energy and fructose remains unclear. Larger, well-designed trials of fructose feeding at “real world” doses are needed. PMID:22457397

  5. Uric acid and cognition in Parkinson's disease: a follow-up study.

    PubMed

    Annanmaki, Tua; Pohja, Marjatta; Parviainen, Tiina; Hakkinen, Paula; Murros, Kari

    2011-06-01

    Cognitive changes are common in Parkinson's disease (PD). Low plasma uric acid (UA) level is associated with risk of PD and predicts faster progression of motor symptoms in established disease. Whether UA levels predict cognitive changes has not been studied. In a crossectional study, our group has previously shown an association of plasma and urine UA levels with cognition in PD. The aim of the present controlled longitudinal study was to examine the evolution of cognitive changes and the prognostic value of the UA levels on cognition in the previously reported PD-patient cohort. Of the original 40 patients, 31 were available for follow-up after three years. Both plasma and daily urine UA levels were measured, nutrition was evaluated using 4-day dietary recall diary and cognition was assessed by a thorough neuropsychological examination including computerized tasks with Cognispeed©. The plasma and urine UA levels of the patients remained stable during the follow-up. At the same time, the rate of cognitive decline was unexpectedly slow. A statistically significant deterioration was noted in verbal fluency (p=0.04) and in Cognispeed©'s vigilance task (p=0.0001). In forward linear regression analysis only the baseline daily urine UA level contributed to verbal fluency (p=0.01), picture completion (p=0.001), block design (p=0.006), vigilance (p=0.006), subtraction (p=0.01) and statement verification (p=0.04) tasks. The implications of the study results are discussed.

  6. 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

  7. A Comparative Study of Serum Uric Acid levels and Lipid Ratios in Coronary Artery Disease Patients

    PubMed Central

    Sathiya, R.; Velu, V. Kuzhandai; Niranjan, G.; Srinivasan, A. R.; Amirtha, Ganesh B.; Ramesh, R.; Babu, M. Sathish; Saha, Subiman

    2014-01-01

    Introduction: Coronary Artery Disease (CAD) appears to be common in the Indian population of different geographical origins, religions and languages. Measurement of lipid fractions and ratios are widely recommended for risk assessment. A few studies have shown that serum uric acid plays a role in the development of cardiovascular morbidity. Very few reports are cited linking serum uric acid with the lipid fraction in CAD Objectives: To find the significance of non-HDL cholesterol, LDL-c/HDL-c ratio, TC/HDL ratio and serum uric acid level in CAD patients Subjects and Methodology: In this study, we included fifty CAD patients as subjects and an equal number of controls. Both subjects and controls were assessed for anthropometric, physiological and biochemical parameters Results: The present study showed significant increased levels of total cholesterol (p=0.002), TAGs (p<0.001), HDL (p=0.005), LDL (p<0.006) and non-HDL cholesterol (p<0.001). LDL-c/HDL-c ratio (p<0.001) and TC/HDL ratio (p<0.001) in CAD patients (subjects) were also significant when compared to controls. Uric acid level in CAD patients was increased (p<0.001). Conclusion: Serum Uric Acid, TC/HDL and LDL/HDL ratios could be regarded as objective markers, in association with existing atherogenic dyslipidemia in patients with CAD. PMID:25018681

  8. The role of uric acid in the insulin resistance in children and adolescents with obesity

    PubMed Central

    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

    2015-01-01

    Objective: To investigate the association between serum uric acid levels and insulin resistance in children and adolescents with obesity. Methods: Cross-sectional study with 245 children and adolescents (134 obese and 111 controls), aged 8-18 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. Results: 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 1.40-2.62; p<−0.001). Conclusions: 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. PMID:26300523

  9. Maternal fructose drives placental uric acid production leading to adverse fetal outcomes

    PubMed Central

    Asghar, Zeenat A.; Thompson, Alysha; Chi, Maggie; Cusumano, Andrew; Scheaffer, Suzanne; Al-Hammadi, Noor; Saben, Jessica L.; Moley, Kelle H.

    2016-01-01

    Maternal metabolic diseases increase offspring risk for low birth weight and cardiometabolic diseases in adulthood. Excess fructose consumption may confer metabolic risks for both women and their offspring. However, the direct consequences of fructose intake per se are unknown. We assessed the impact of a maternal high-fructose diet on the fetal-placental unit in mice in the absence of metabolic syndrome and determined the association between maternal serum fructose and placental uric acid levels in humans. In mice, maternal fructose consumption led to placental inefficiency, fetal growth restriction, elevated fetal serum glucose and triglyceride levels. In the placenta, fructose induced de novo uric acid synthesis by activating the activities of the enzymes AMP deaminase and xanthine oxidase. Moreover, the placentas had increased lipids and altered expression of genes that control oxidative stress. Treatment of mothers with the xanthine oxidase inhibitor allopurinol reduced placental uric acid levels, prevented placental inefficiency, and improved fetal weights and serum triglycerides. Finally, in 18 women delivering at term, maternal serum fructose levels significantly correlated with placental uric acid levels. These findings suggest that in mice, excess maternal fructose consumption impairs placental function via a xanthine oxidase/uric acid-dependent mechanism, and similar effects may occur in humans. PMID:27125896

  10. Inverse Association Between Serum Uric Acid Levels and Alzheimer's Disease Risk.

    PubMed

    Du, Na; Xu, Donghua; Hou, Xu; Song, Xuejia; Liu, Cancan; Chen, Ying; Wang, Yangang; Li, Xin

    2016-05-01

    The association between Alzheimer's disease and uric acid levels had gained great interest in recent years, but there was still lack of definite evidence. A systematic review and meta-analysis of relevant studies was performed to comprehensively estimate the association. Relevant studies published before October 26, 2014, were searched in PubMed, Embase, and China Biology Medicine (CBM) databases. Study-specific data were combined using random-effects or fixed-effects models of meta-analysis according to between-study heterogeneity. Twenty-four studies (21 case-control and 3 cohort studies) were finally included into the meta-analysis. Those 21 case-control studies included a total of 1128 cases of Alzheimer's disease and 2498 controls without Alzheimer's disease. Those 3 cohort studies included a total of 7327 participants. Meta-analysis showed that patients with Alzheimer's disease had lower levels of uric acid than healthy controls (weighted mean difference (WMD) = -0.77 mg/dl, 95% CI -2.28 to -0.36, P = 0.0002). High serum uric acid levels were significantly associated with decreased risk of Alzheimer's disease (risk ratio (RR) = 0.66, 95% CI 0.52-0.85, P = 0.001). There was low risk of publication bias in the meta-analysis. There is an inverse association between serum uric acid levels and Alzheimer's disease. High serum uric acid level is a protective factor of Alzheimer's disease.

  11. Low Serum Uric Acid Level Is a Risk Factor for Death in Incident Hemodialysis Patients

    PubMed Central

    Lee, S.M. Kurt; Lee, Andrew L.; Winters, Thomas J.; Tam, Emily; Jaleel, Mohammed; Stenvinkel, Peter; Johnson, Richard J.

    2009-01-01

    Background A reverse epidemiology of classic cardiovascular risk factors was observed in hemodialysis patients with a high comorbidity burden. We hypothesized that uric acid, a novel cardiovascular risk factor, also has an altered association with survival in these patients. Methods A retrospective study was conducted on 168 consecutive outpatient hemodialysis patients over a 6-year period. Serum uric acid, albumin levels and relevant laboratory information were recorded monthly. The disease severity was assessed using Comorbidity Index (CoI) scores. Patients were stratified into 3 groups according to their serum uric acid concentrations: group I was the lowest quintile, group II was the middle 3 quintiles and group III was the highest quintile. The risks of death were calculated utilizing a Cox regression model. Results Using group II as a reference group, the hazard ratio of group I was 2.23 [95% confidence interval (CI) 1.21–4.11, p = 0.01] and group III was 0.89 (95% CI 0.47–1.71, p = 0.74). The serum uric acid levels correlated inversely with CoI scores (r = −0.31, 95% CI −0.44 to −0.17, p < 0.0001) and positively with serum albumin levels (r = 0.35, 95% CI 0.21–0.48, p < 0.0001). Conclusion Low serum uric acid is a mortality risk factor in incident hemodialysis patients with a high comorbidity burden and hypoalbuminemia. PMID:18689987

  12. 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.

  13. Serum uric acid levels during leprosy reaction episodes

    PubMed Central

    Alves-Junior, Eduardo R.; Arruda, Talita A.; Lopes, Jose C.; Fontes, Cor J.F.

    2016-01-01

    Background. Leprosy reactions are acute inflammatory episodes that occur mainly in the multibacillary forms of the disease. The reactions are classified as type 1 (reverse reaction) or type 2 (erythema nodosum leprosum). Leprosy-associated oxidative stress has been widely demonstrated. Several recent studies have shown uric acid (UA) to have antioxidative effects under pathologic conditions. The objective of this study was to assess serum levels of UA in patients with leprosy reactions, with the aim of monitoring their levels before and after treatment, compared with levels in leprosy patients without reactions. Methods. The study included patients aged 18–69 years assisted at a leprosy treatment reference center in the Central Region of Brazil. Patients who were pregnant; were using immunosuppressant drugs or immunobiologicals; or had an autoimmune disease, human immunodeficiency virus infection, acquired immune deficiency syndrome, or tuberculosis were excluded. Upon recruitment, all individuals were clinically assessed for skin lesions and neural or systemic impairment. Some patients had already completed treatment for leprosy, while others were still undergoing treatment or had initiated treatment after being admitted. The treatment of the reactional episode was started only after the initial evaluation. Laboratory assessments were performed upon admission (baseline) and at approximately 30 and 60 days (time points 1 and 2, respectively). Results. A total of 123 leprosy patients were recruited between June 2012 and June 2015; among them, 56, 42, and 25 presented with type 1, type 2, and no reactions, respectively. Serum UA levels were significantly reduced in patients with type 2 leprosy reactions compared with patients in the control group and remained lower in the two subsequent assessments, after initiation of anti-reaction treatments, with similar values to those recorded before the treatment. Discussion. The decreased serum UA levels in patients with

  14. Prognostic Significance of Uric Acid Levels in Ischemic Stroke Patients.

    PubMed

    Zhang, Xia; Huang, Zhi-Chao; Lu, Tao-Sheng; You, Shou-Jiang; Cao, Yong-Jun; Liu, Chun-Feng

    2016-01-01

    The importance and function of serum uric acid (UA) levels in patients with cardiovascular disease or stroke are unclear. We sought to evaluate the appropriate UA levels for stroke patients and the association between endogenous UA levels and clinical outcomes in acute ischemic stroke (AIS) patients, particularly regarding the possible interaction between gender and UA levels with respect to AIS prognosis. We examined 303 patients who had an onset of ischemic stroke within 48 h. Of those, 101 patients received thrombolytic treatment. Serum UA (μmol/L) levels were measured the second morning after admission. Patient prognosis was evaluated 90 days after clinical onset by modified Rankin Scale. Patients were divided into four groups according to serum UA quartiles. A binary multivariate logistic regression model was used to assess clinical relevance in regard to functional outcome and endogenous UA levels. Analysis of subgroups by gender and normal glomerular filtration rate were also been done. Poor functional outcome was associated with older age, history of atrial fibrillation, or higher baseline National Institutes of Health Stroke Scale scores. After adjustment for potential confounders, patients with higher UA levels (>380 μmol/L) or lower UA levels (≤250 μmol/L) were 2-3 times more likely to have a poor outcome (OR 2.95, 95% CI 1.14-7.61; OR 2.78, 95% CI 1.02-7.58, respectively) compared to the baseline group (UA level 316-380 μmol/L). The same results were observed in thrombolyzed patients. Patients with high and low UA levels were 9-18 times more likely to having poor outcomes compared to the baseline group (UA level: 316-380 μmol/L; OR 18.50, 95% CI: 2.041-167.67; OR 9.66, 95% CI 1.42-65.88, respectively). In men, patients with high UA levels were 6 times more likely to have poor outcomes compared to the baseline group (UA level: 279-334 μmol/L; OR 6.10, 95% CI 1.62-22.93). However, female patients with UA level 271-337 μmol/L were seven times more

  15. Lower serum uric acid level predicts mortality in dialysis patients

    PubMed Central

    Bae, Eunjin; Cho, Hyun-Jeong; Shin, Nara; Kim, Sun Moon; Yang, Seung Hee; Kim, Dong Ki; Kim, Yong-Lim; Kang, Shin-Wook; Yang, Chul Woo; Kim, Nam Ho; Kim, Yon Su; Lee, Hajeong

    2016-01-01

    Abstract We evaluated the impact of serum uric acid (SUA) on mortality in patients with chronic dialysis. A total of 4132 adult patients on dialysis were enrolled prospectively between August 2008 and September 2014. Among them, we included 1738 patients who maintained dialysis for at least 3 months and had available SUA in the database. We categorized the time averaged-SUA (TA-SUA) into 5 groups: <5.5, 5.5–6.4, 6.5–7.4, 7.5–8.4, and ≥8.5 mg/dL. Cox regression analysis was used to calculate the hazard ratio (HR) of all-cause mortality according to SUA group. The mean TA-SUA level was slightly higher in men than in women. Patients with lower TA-SUA level tended to have lower body mass index (BMI), phosphorus, serum albumin level, higher proportion of diabetes mellitus (DM), and higher proportion of malnourishment on the subjective global assessment (SGA). During a median follow-up of 43.9 months, 206 patients died. Patients with the highest SUA had a similar risk to the middle 3 TA-SUA groups, but the lowest TA-SUA group had a significantly elevated HR for mortality. The lowest TA-SUA group was significantly associated with increased all-cause mortality (adjusted HR, 1.720; 95% confidence interval, 1.007–2.937; P = 0.047) even after adjusting for demographic, comorbid, nutritional covariables, and medication use that could affect SUA levels. This association was prominent in patients with well nourishment on the SGA, a preserved serum albumin level, a higher BMI, and concomitant DM although these parameters had no significant interaction in the TA-SUA-mortality relationship except DM. In conclusion, a lower TA-SUA level <5.5 mg/dL predicted all-cause mortality in patients with chronic dialysis. PMID:27310949

  16. Benfotiamine attenuates nicotine and uric acid-induced vascular endothelial dysfunction in the rat.

    PubMed

    Balakumar, Pitchai; Sharma, Ramica; Singh, Manjeet

    2008-01-01

    The study has been designed to investigate the effect of benfotiamine, a thiamine derivative, in nicotine and uric acid-induced vascular endothelial dysfunction (VED) in rats. Nicotine (2 mg kg(-1)day(-1), i.p., 4 weeks) and uric acid (150 mg kg(-1)day(-1), i.p., 3 weeks) were administered to produce VED in rats. The development of VED was assessed by employing isolated aortic ring preparation and estimating serum and aortic concentration of nitrite/nitrate. Further, the integrity of vascular endothelium was assessed using the scanning electron microscopy (SEM) of thoracic aorta. Moreover, the oxidative stress was assessed by estimating serum thiobarbituric acid reactive substances (TBARS) and aortic superoxide anion generation. The administration of nicotine and uric acid produced VED by impairing the integrity of vascular endothelium and subsequently decreasing serum and aortic concentration of nitrite/nitrate and attenuating acetylcholine-induced endothelium dependent relaxation. Further, nicotine and uric acid produced oxidative stress, which was assessed in terms of increase in serum TBARS and aortic superoxide generation. However, treatment with benfotiamine (70 mg kg(-1)day(-1), p.o.) or atorvastatin (30 mg kg(-1)day(-1) p.o., a standard agent) markedly prevented nicotine and uric acid-induced VED and oxidative stress by improving the integrity of vascular endothelium, increasing the concentration of serum and aortic nitrite/nitrate, enhancing the acetylcholine-induced endothelium dependent relaxation and decreasing serum TBARS and aortic superoxide anion generation. Thus, it may be concluded that benfotiamine reduces the oxidative stress and consequently improves the integrity of vascular endothelium and enhances the generation of nitric oxide to prevent nicotine and uric acid-induced experimental VED. PMID:18951979

  17. Is hyperuricemia a risk factor for arteriosclerosis? Uric acid and arteriosclerosis in apolipoprotein e-deficient mice.

    PubMed

    Wakuda, Hirokazu; Uchida, Shinya; Ikeda, Masahiko; Tabuchi, Masaki; Akahoshi, Yasumitsu; Shinozuka, Kazumasa; Yamada, Shizuo

    2014-01-01

    Although hyperlipidemia, high blood pressure, and diabetes increase the risk of arteriosclerosis, it is not clear whether hyperuricemia increases the risk of arteriosclerosis or not. We examined the effects of uric acid and curative drugs for hyperuricemia on atherosclerosis-susceptible C57BL/6J apolipoprotein E-deficient (apoE(-/-)) mice. Male apoE(-/-) mice (age: 6 weeks) were fed a normal diet (normal diet group) or a uric acid-enriched diet. Mice fed the uric acid-enriched diet were divided into three groups and administered a drinking vehicle (high uric acid diet group), allopurinol (20 mg·kg(-1)·d(-1)), or benzbromarone (20 mg·kg(-1)·d(-1)) for 10 weeks. Serum uric acid concentrations were higher in the high uric acid diet group than in the normal diet group, and concentrations in the allopurinol and benzbromarone groups were lower than in the high uric acid diet group. Serum total cholesterol and triglyceride levels were lower in the allopurinol group than in the high uric acid diet group. Oxidative stress was lower in the benzbromarone group than in the high uric acid diet group. Atherosclerotic lesion areas were smaller in the allopurinol and benzbromarone groups than in the high uric acid diet group. Thus, hyperuricemia may not be an independent risk factor for arteriosclerosis; however, the administration of allopurinol and benzbromarone prevented the development of atherosclerosis in apoE(-/-) mice fed a uric acid-enriched diet. The anti-atherosclerotic effect was in part due to lower total cholesterol and oxidative stress in the serum. Other possible mechanisms underlying this effect should be investigated.

  18. Genetic background of uric acid metabolism in a patient with severe chronic tophaceous gout.

    PubMed

    Petru, Lenka; Pavelcova, Katerina; Sebesta, Ivan; Stiburkova, Blanka

    2016-09-01

    Hyperuricemia depends on the balance of endogenous production and renal excretion of uric acid. Transporters for urate are located in the proximal tubule where uric acid is secreted and extensively reabsorbed: secretion is principally ensured by the highly variable ABCG2 gene. Enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT) plays a central role in purine metabolism and its deficiency is an X-linked inherited metabolic disorder associated with clinical manifestations of purine overproduction. Here we report the case of a middle-aged man with severe chronic tophaceous gout with a poor response to allopurinol and requiring repeated surgical intervention. We identified the causal mutations in the HPRT1 gene, variant c.481G>T (p.A161S), and in the crucial urate transporter ABCG2, a heterozygous variant c.421C>A (p.Q141K). This case shows the value of an analysis of the genetic background of serum uric acid. PMID:27288985

  19. Stable isotope ratios and uric acid preservation in termites belonging to three feeding habits in Thailand.

    PubMed

    Tayasu, I; Hyodo, F; Takematsu, Y; Sugimoto, A; Inoue, T; Kirtibutr, N; Abe, T

    2000-01-01

    Nitrogen and carbon stable isotope ratios and uric acid concentrations in termites sampled from a dry evergreen forest in Thailand, were determined across three kinds of feeding habits. Feeding habits of Microcerotermes crassus, which is an abundant wood-feeder, and Dicuspiditermes makhamensis, a common soil-feeding termite, were confirmed by isotopic signatures. Lichen feeding termites (Hospitalitermes birmanicus, H. bicolor and H. ataramensis) were characterized by low delta15N values, suggesting that they assimilated nitrogen deposited from the atmosphere. There was also a significant difference in uric acid concentrations between termites representing different feeding habits. No significant relationships were found between uric acid concentrations and delta15N or delta13C in Hospitalitermes. However, delta15N values were correlated with C/N ratios in H. birmanicus, except in one colony of H. ataramensis. delta13C values in both species were negatively correlated with C/N ratios.

  20. The effect of erythropoietin on serum uric acid levels during renal ischemia reperfusion injury in rats

    PubMed Central

    Tsompos, Constantinos; Panoulis, Constantinos; Toutouzas, Konstantinos; Zografos, George; Papalois, Apostolos

    2014-01-01

    Objective: The aim of this experimental study was to assess the effect of erythropoietin on a rat model, particularly under a renal ischemia reperfusion protocol. The beneficial or lack of effects of that molecule on the excreted renal product of serum uric acid were studied biochemically. Material and methods: Forty rats were used with a mean weight of 247.7 gr. Serum uric acid levels were measured measured at 60 min after reperfusion (Groups A and C) and at 120 min after reperfusion (groups B and D). Results: 1) Erythropoietin administration non-significantly decreased the serum uric acid levels non-significantly by 0.02 mg/dL [−0.2415423 mg/dL-0.2015423 mg/dL] (p=0.8560), in accordance with the paired t-test (p=0.8438). Reperfusion time non-significantly increased the serum uric acid levels non-significantly by 0.17 mg/dL [−0.0444933 mg/dL-0.3844933 mg/dL] (p=0.1169), in accordance with the paired t-test (p=0.1648). 3) The interaction of erythropoietin administration and reperfusion time non-significantly increased the serum uric acid levels non-significantly by 0.1 mg/dL [−0.0295564 mg/dL-0.2295564 mg/dL] (p=0.1264). Conclusion: Erythropoietin administration, reperfusion time and their interaction have no significant short-term alterations on serum uric acid levels. Conclusions cannot be extracted by non-significant p-values within 2 hours. Obviously, longer study times may permit safer results. PMID:26328161

  1. Leptin and uric acid as predictors of metabolic syndrome in jordanian adults

    PubMed Central

    Ahmad, Mousa N.; Haddad, Fares H.; Azzeh, Firas S.

    2016-01-01

    BACKGROUND/OBJECTIVES Metabolic syndrome (MetS) is a set of interrelated metabolic risk factors that increase the risk of cardiovascular morbidity and mortality. Studies regarding the specificity and sensitivity of serum levels of leptin and uric acid as predictors of MetS are limited. The aim of this study was to evaluate the serum levels of leptin and uric acid in terms of their specificity and sensitivity as predictors of MetS in the studied Jordanian group. SUBJECTS/METHODS In this cross sectional study, 630 adult subjects (308 men and 322 women) were recruited from the King Hussein Medical Center (Amman, Jordan). The diagnosis of MetS was made according to the 2005 International Diabetes Federation criteria. Receiver operating characteristic curves were used to determine the efficacy of serum levels of leptin and uric acid as predictors of MetS in the studied Jordanian group. RESULTS Study results showed that for identification of subjects with MetS risk, area under the curve (AUC) for leptin was 0.721 and 0.683 in men and women, respectively. Serum uric acid levels in men showed no significant association with any MetS risk factors and no significant AUC, while uric acid AUC was 0.706 in women. CONCLUSION Serum leptin levels can be useful biomarkers for evaluation of the risk of MetS independent of baseline obesity in both men and women. On the other hand, serum uric acid levels predicted the risk of MetS only in women. PMID:27478548

  2. Uric acid levels in subjects with bipolar disorder: A comparative meta-analysis.

    PubMed

    Bartoli, Francesco; Crocamo, Cristina; Mazza, Mario Gennaro; Clerici, Massimo; Carrà, Giuseppe

    2016-10-01

    Previous research has hypothesised increased uric acid levels, possibly because of an amplified purinergic metabolism and a reduced adenosine activity, in subjects with bipolar disorder. This systematic review and meta-analysis aimed at estimating if individuals with bipolar disorder had uric acid levels higher than both healthy controls and subjects with major depression (trait marker hypothesis). It also tested if uric acid levels could differ in different phases of bipolar disorder (state marker hypothesis). Meta-analyses were carried out generating pooled standardized mean differences (SMDs), using random-effects models. Heterogeneity between studies was estimated using the I(2) index. Relevant sensitivity and meta-regression analyses were conducted. We searched main Electronic Databases, identifying twelve studies that met our inclusion criteria. Meta-analyses showed increased uric acid levels in individuals with bipolar disorder as compared with both healthy controls (SMD = 0.65, p < 0.001, I(2) = 82.9%) and those with major depression (SMD = 0.46, p < 0.001; I(2) = 68.7%). However, meta-regression analyses confirmed this association only as compared with healthy controls. Finally, though uric acid levels were higher in manic/mixed phases as compared with depressive ones (SMD = 0.34; p = 0.04, I(2) = 58.8%), a sensitivity analysis did not confirm the association. In sum, our meta-analysis shows that subjects with bipolar disorder have uric acid levels higher than healthy controls. The potential role of factors that might clarify the nature of this association deserves additional research.

  3. Serum uric acid levels and long-term outcomes in chronic kidney disease.

    PubMed

    Miyaoka, Tokiko; Mochizuki, Toshio; Takei, Takashi; Tsuchiya, Ken; Nitta, Kosaku

    2014-07-01

    Hyperuricemia is common in chronic kidney disease (CKD), but data regarding the relationship between serum uric acid levels and the long-term outcomes of CKD patients have been limited. The present study evaluated the associations between baseline serum uric acid levels with mortality and end-stage renal disease (ESRD). The subjects of this study were 551 stage 2-4 CKD patients. Cox proportional hazards models were used to evaluate the relationship between serum uric acid tertiles and all-cause mortality, cardiovascular disease (CVD) mortality, 50 % reduction in estimated glomerular filtration rate (eGFR), and development of ESRD, initially without adjustment, and then after adjusting for several groups of covariates. The mean age of the study subjects was 58.5 years, 59.3 % were men, and 10.0 % had diabetes. The mean eGFR was 42.02 ± 18.52 ml/min/1.73 m(2). In all subjects, the mean serum uric acid level was 6.57 ± 1.35 mg/dl, and 52.2 % of study subjects were on hypouricemic therapy (allopurinol; 48.3 %) at baseline. Thirty-one patients (6.1 %) died during a follow-up period of approximately 6 years. There was no significant association between serum uric acid level and all-cause mortality, CVD mortality, development of ESRD and 50 % reduction in eGFR in the unadjusted Cox models. In the adjusted models, hyperuricemia was found to be associated with all-cause mortality and CVD mortality after adjustment with CVD risk factors, kidney disease factors, and allopurinol, but not associated with development of ESRD and 50 % reduction in eGFR. The results of this study showed that hyperuricemia but not serum uric acid levels were associated with all-cause mortality, CVD mortality after adjustments with CVD risk factors, kidney disease factors, and allopurinol in stage 2-4 CKD patients.

  4. Tuna extract reduces serum uric acid in gout-free subjects with insignificantly high serum uric acid: A randomized controlled trial

    PubMed Central

    Kubomura, Daiki; Yamada, Masanori; Masui, Ayano

    2016-01-01

    Long-term reduction of serum urate levels is vital in the treatment of gout. However, it is difficult to convince gout-free individuals of the necessity of treatment as few appropriate over-the-counter remedies and dietary supplements are available. Therefore, the present study aimed to investigate the antihyperuricemic efficacy and safety of a tuna extract containing the imidazole compounds to evaluate its potential as a functional food ingredient. A randomized, 4-week, double-blind, placebo-controlled study was conducted. A total of 48 male gout-free subjects with insignificantly high serum uric acid were randomly assigned to low- and high-dose tuna extract groups or a placebo group. The efficacy of the extract was assessed by measuring serum uric acid levels. Furthermore, a safety assessment was performed by physical parameters, hematology, blood biochemistry and urinalysis. The results indicated that the uric acid level was decreased at week 4 during the intervention in the tuna extract groups (low and high dose, −0.23 and −0.34 mg/dl, respectively) compared to the placebo group (−0.07 mg/dl). At week 4 after the intervention, a significant reduction in uric acid levels (−0.41 mg/dl; P<0.05) was observed in the high-dose tuna extract group compared with the placebo group (+0.11 mg/dl). No dose-related adverse events were observed during and following the intervention. Therefore, the present results suggest that oral administration of tuna extract containing the imidazole compounds has hypouricemic activity with no undesirable side effects. PMID:27446553

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  6. Uric acid attenuates nitric oxide production by decreasing the interaction between endothelial nitric oxide synthase and calmodulin in human umbilical vein endothelial cells: a mechanism for uric acid-induced cardiovascular disease development.

    PubMed

    Park, Jung-Hyun; Jin, Yoon Mi; Hwang, Soojin; Cho, Du-Hyong; Kang, Duk-Hee; Jo, Inho

    2013-08-01

    The elevated level of uric acid in the body is associated with increased risk of cardiovascular diseases, which is mediated by endothelial dysfunction. However, its underlying mechanism is not fully understood, although dysregulation of endothelial nitric oxide (NO) production is likely to be involved. Using human umbilical vascular endothelial cells (HUVEC), we explored the molecular mechanism of uric acid on endothelial NO synthase (eNOS) activity and NO production. Although high dose of uric acid (12mg/dl for 24h treatment) significantly decreased eNOS activity and NO production, it did not alter eNOS expression and phosphorylations at eNOS-Ser(1177), eNOS-Thr(495) and eNOS-Ser(114). Under this condition, we also found no alterations in the dimerization and acetylation of eNOS, compared with the control. Furthermore, uric acid did not change the activity of arginase II, an enzyme degrading l-arginine, a substrate of eNOS, and intracellular level of calcium, a cofactor for eNOS activation. We also found that uric acid did not alter xanthine oxidase activity, suggesting no involvement of xanthine oxidase-derived O2(-) production in the observed inhibitory effects. In vitro and in cell coimmunoprecipitation studies, however, revealed that uric acid significantly decreased the interaction between eNOS and calmodulin (CaM), an eNOS activator, although it did not change the intracellular CaM level. Like in HUVEC, uric acid also decreased eNOS-CaM interaction in bovine aortic EC. Finally, uric acid attenuated ionomycin-induced increase in the interaction between eNOS and CaM. This study suggests firstly that uric acid decreased eNOS activity and NO production through reducing the binding between eNOS and CaM in EC. Our result may provide molecular mechanism by which uric acid induces endothelial dysfunction.

  7. 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.

  8. 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.

  9. Uric acid accumulation in an Arabidopsis urate oxidase mutant impairs seedling establishment by blocking peroxisome maintenance.

    PubMed

    Hauck, Oliver K; Scharnberg, Jana; Escobar, Nieves Medina; Wanner, Gerhard; Giavalisco, Patrick; Witte, Claus-Peter

    2014-07-01

    Purine nucleotides can be fully catabolized by plants to recycle nutrients. We have isolated a urate oxidase (uox) mutant of Arabidopsis thaliana that accumulates uric acid in all tissues, especially in the developing embryo. The mutant displays a reduced germination rate and is unable to establish autotrophic growth due to severe inhibition of cotyledon development and nutrient mobilization from the lipid reserves in the cotyledons. The uox mutant phenotype is suppressed in a xanthine dehydrogenase (xdh) uox double mutant, demonstrating that the underlying cause is not the defective purine base catabolism, or the lack of UOX per se, but the elevated uric acid concentration in the embryo. Remarkably, xanthine accumulates to similar levels in the xdh mutant without toxicity. This is paralleled in humans, where hyperuricemia is associated with many diseases whereas xanthinuria is asymptomatic. Searching for the molecular cause of uric acid toxicity, we discovered a local defect of peroxisomes (glyoxysomes) mostly confined to the cotyledons of the mature embryos, which resulted in the accumulation of free fatty acids in dry seeds. The peroxisomal defect explains the developmental phenotypes of the uox mutant, drawing a novel link between uric acid and peroxisome function, which may be relevant beyond plants. PMID:25052714

  10. Volatile disinfection byproducts resulting from chlorination of uric acid: implications for swimming pools.

    PubMed

    Lian, Lushi; E, Yue; Li, Jing; Blatchley, Ernest R

    2014-03-18

    Cyanogen chloride (CNCl) and trichloramine (NCl3) are important disinfection byproducts in chlorinated swimming pools. However, some unknowns exist regarding the precursors of their formation. In this study, uric acid is shown to be an efficient precursor to formation of CNCl and NCl3. The molar yields of CNCl and NCl3 were observed to be as high as 44% (pH = 6.0, chlorine/precursor molar ratio [Cl/P] = 6.4) and 108% (pH = 7.0, Cl/P = 30), respectively, both being strong functions of Cl/P, pH, and temperature. Analysis of swimming pool water samples, combined with the results of experiments involving chlorination of uric acid, and chlorination of body fluid analog mixtures, indicated that uric acid chlorination may account for a large fraction of CNCl formation in swimming pools. Moreover, given that uric acid introduction to pools is attributable to urination, a voluntary action for most swimmers, these findings indicate important benefits to pool water and air chemistry that could result from improved hygiene habits on the part of swimmers.

  11. 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…

  12. Dietary fructose in relation to blood pressure and serum uric acid in adolescent boys and girls.

    PubMed

    Bobridge, K S; Haines, G L; Mori, T A; Beilin, L J; Oddy, W H; Sherriff, J; O'Sullivan, T A

    2013-04-01

    Evidence that fructose intake may modify blood pressure is generally limited to adult populations. This study examined cross-sectional associations between dietary intake of fructose, serum uric acid and blood pressure in 814 adolescents aged 13-15 years participating in the Western Australian Pregnancy Cohort (Raine) Study. Energy-adjusted fructose intake was derived from 3-day food records, serum uric acid concentration was assessed using fasting blood and resting blood pressure was determined using repeated oscillometric readings. In multivariate linear regression models, we did not see a significant association between fructose and blood pressure in boys or girls. In boys, fructose intake was independently associated with serum uric acid (P<0.01), and serum uric acid was independently associated with systolic blood pressure (P<0.01) and mean arterial pressure (P<0.001). Although there are independent associations, there is no direct relationship between fructose intake and blood pressure. Our data suggest that gender may influence these relationships in adolescence, with significant associations observed more frequently in boys than girls.

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

    PubMed

    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

  14. 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

  15. Effect of losartan on serum uric acid in hypertension treated with a diuretic: the COMFORT study.

    PubMed

    Matsumura, Kiyoshi; Arima, Hisatomi; Tominaga, Mitsuhiro; Ohtsubo, Toshio; Sasaguri, Toshiyuki; Fujii, Koji; Fukuhara, Masayo; Uezono, Keiko; Morinaga, Yuki; Ohta, Yuko; Otonari, Takatoshi; Kawasaki, Junya; Kato, Isao; Tsuchihashi, Takuya

    2015-01-01

    It has been shown that losartan, an angiotensin II receptor blocker (ARB), reduces serum uric acid levels. However, the effects of losartan on serum uric acid levels in the patients treated with a thiazide diuretic have not been fully elucidated. We have investigated the effects of losartan compared with other ARBs on blood variables and blood pressure control in hypertensive patients treated with a thiazide diuretic using data from the COMFORT study. The present analysis included a total of 118 hypertensive subjects on combination treatment with ARBs except for losartan and a diuretic who were randomly assigned to a daily regimen of a combination pill (losartan 50 mg/hydrochlorothiazide 12.5 mg) or to continuation of two pills, an ARB except for losartan and a diuretic. Blood pressures were evaluated at 1, 3, and 6 months after randomization and changes in blood variables including serum uric acid were evaluated during 6 months treatment period. Mean follow-up blood pressure levels were not different between the combination pill (losartan treatment) group and the control (ARBs except for losartan) group. On the other hand, serum uric acid significantly decreased in the combination pill group compared with the control group (-0.44 versus + 0.10 mg/dl; p = 0.01), although hematocrit, serum creatinine, sodium and potassium were not different between the groups. These results suggest that the treatment regimen switched from a combination therapy of ARBs except for losartan and a diuretic to a combination pill (losartan/ hydrochlorothiazide) decreases serum uric acid without affecting blood pressure control.

  16. Uric acid concentration in subjects at risk of type 2 diabetes mellitus: relationship to components of the metabolic syndrome.

    PubMed

    Costa, A; Igualá, I; Bedini, J; Quintó, L; Conget, I

    2002-03-01

    High uric acid concentration is a common finding in subjects with risk factors for cardiovascular disease (CVD), including some characteristics of the metabolic syndrome. However, its exact role in this setting and in the progression to type 2 diabetes mellitus (DM) is not well understood and could be affected by confounding factors such as hypertriglyceridemia. Our study aimed to establish the relationship between uric acid (avoiding the interference of high triglyceride levels), insulin sensitivity, and components of the metabolic syndrome in a group of subjects at high risk of developing DM. Among 201 subjects included in the study, 111 (55.2%) showed an abnormal oral glucose tolerance and uric acid levels higher than those measured in subjects with normal glucose tolerance. Body mass index (BMI), triglycerides, diastolic blood pressure (DBP), and 2-hour glycemia in the oral glucose tolerance test (OGTT) contributed independently to uric acid concentration (R2 =.59). However, uric acid did not affect either insulin sensitivity or glucose tolerance. The recovery tests revealed that a triglyceride concentration > or = 3 mmol/L interfered with the measurement of uric acid level when a colorimetric method was used, but not when a dry-chemistry method was used. In conclusion, uric acid concentration is higher in subjects at high risk of DM with abnormal glucose tolerance and is independently determined by various components of the metabolic syndrome.

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

    PubMed

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

    2015-10-01

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

  18. Uric Acid-Induced Adipocyte Dysfunction Is Attenuated by HO-1 Upregulation: Potential Role of Antioxidant Therapy to Target Obesity

    PubMed Central

    Sodhi, Komal; Hilgefort, Jordan; Banks, George; Gilliam, Chelsea; Stevens, Sarah; Ansinelli, Hayden A.; Getty, Morghan; Abraham, Nader G.; Shapiro, Joseph I.

    2016-01-01

    Increased uric acid levels have been implicated in the pathogenesis of metabolic syndrome. To examine the mechanisms by which this occurs, we hypothesized that an increase in heme oxygenase 1, a potent antioxidant gene, will decrease uric acid levels and adipocyte dysfunction via suppression of ROS and xanthine oxidase (XO) levels. We examined the effect of uric acid on adipogenesis in human mesenchymal stem cells (MSCs) in the presence and absence of cobalt protoporphyrin (CoPP), an HO-1 inducer, and tin mesoporphyrin (SnMP), an HO activity inhibitor. Uric acid increased adipogenesis by increasing NADPH oxidase expression and elevation in the adipogenesis markers C/EBPα, PPARγ, and Mest, while decreasing small lipid droplets and Wnt10b levels. We treated MSCs with fructose, a fuel source that increases uric acid levels. Our results showed that fructose increased XO expression as compared to the control and concomitant treatment with CoPP significantly decreased XO expression and uric acid levels. These beneficial effects of CoPP were reversed by SnMP, supporting a role for HO activity in mediating these effects. These findings demonstrate that increased levels of HO-1 appear crucial in modulating the phenotype of adipocytes exposed to uric acid and in downregulating XO and NADPH oxidase levels. PMID:26681956

  19. Nanostructure Modified Microelectrode for Electrochemical Detection of Dopamine with Ascorbic Acid and Uric Acid.

    PubMed

    Kim, Kyeong-Jun; Choi, Jin-Ha; Pyo, Su-Hyun; Yun, Kwang-Seok; Lee, Ji-Young; Choi, Jeong-Woo; Oh, Byung-Keun

    2016-03-01

    Dopamine (DA) is one kind of neurotransmitter in central nervous system which is indicator of neural disease. For this reason, determination of DA concentration in central nervous system is very important for early diagnosis of neural disease. In this study, we designed micro electrode array and fabricated by MEMS technology. Furthermore, we fabricated 3-D conducting nanostructure on electrode surface for enhanced sensitivity and selectivity due to increased surface area. Compared with macro and normal micro electrode, the 3-D nanostructure modified micro electrode shows better electrical performance. These surface modified pin type electrode was applied to detect low concentration of DA and successfully detect various concentration of DA from 100 μM to 1 μM with linear relationship in the presence of ascorbic acid and uric acid. From these results, our newly designed electrode shows possibility to be applied as brain biosensor for neural disease diagnosis such as Parkinson's diseases. PMID:27455760

  20. [EXPERIENCE OF USE OF BLEMAREN® IN THE TREATMENT OF PATIENTS IN URIC ACID AND CALCIUM OXALATE UROLITHIASIS].

    PubMed

    Konstantinova, O V; Yanenko, E K

    2015-01-01

    154 patients with urolithiasis were under outpatient observation for 2-8 years. Among them there were 76 women and 78 men aged 21-66 years, of which 46 patients with uric acid urolithiasis, and 88--with calcium oxalate urolithiasis. Treatment of patients was carried out systematically, depending on their condition. Indications for the application of Blemaren® included the presence of uric acid stones, uric acid and/or oxalate crystalluria. The duration of treatment was 6.1 months. The dosage of the drug varied from 6 to 18 g per day and was selected individually, depending on the purpose of the appointment of Blemaren®. Reduction of the urine pH to 6.2- 6.8-7.2 was the criterion for properly selected dose. To dissolve uric acid stones in the presence of hyperuricemia and/or hyperuricuria, Blemaren® was administered in combination with allopurinol at a dose of 0.1 g 3-4 times a day. Besides pharmacotherapy, treatment included diet therapy. It was found that the morning urine pH in urate urolithiasis is sustainable and has a range of 5.0-6.0, in 80.4% of cases--range of 5.0-5.5. In calcium oxalate urolithiasis this parameter is also stable and has a range of 5.0-6.7, in 82.9% of cases--range of 5.5-6.0. Optimal urine pH to eliminate uric acid and oxalate crystalluria in patients with uric acid and calcium oxalate urolithiasis is the interval of 6.2-6.4. It was shown that Blemaren® is a highly effective agent for treatment and prevention of uric acid and calcium oxalate crystalluria in calcium oxalate and uric acid urolithiasis. Further, its effectiveness in dissolving of uric acid stones in the absence of an infectious inflammatory process is 82.3%. PMID:26859932

  1. Association between SLC2A9 transporter gene variants and uric acid phenotypes in African American and white families

    PubMed Central

    de Andrade, Mariza; Matsumoto, Martha; Mosley, Tom H.; Kardia, Sharon; Turner, Stephen T.

    2011-01-01

    Objectives. SLC2A9 gene variants associate with serum uric acid in white populations, but little is known about African American populations. Since SLC2A9 is a transporter, gene variants may be expected to associate more closely with the fractional excretion of urate, a measure of renal tubular transport, than with serum uric acid, which is influenced by production and extrarenal clearance. Methods. Genotypes of single nucleotide polymorphisms (SNPs) distributed across the SLC2A9 gene were obtained in the Genetic Epidemiology Network of Arteriopathy cohorts. The associations of SNPs with serum uric acid, fractional excretion of urate and urine urate-to-creatinine ratio were assessed with adjustments for age, sex, diuretic use, BMI, homocysteine and triglycerides. Results. We identified SLC2A9 gene variants that were associated with serum uric acid in 1155 African American subjects (53 SNPs) and 1132 white subjects (63 SNPs). The most statistically significant SNPs in African American subjects (rs13113918) and white subjects (rs11723439) were in the latter half of the gene and explained 2.7 and 2.8% of the variation in serum uric acid, respectively. After adjustment for this SNP in African Americans, 0.9% of the variation in serum uric acid was explained by an SNP (rs1568318) in the first half of the gene. Unexpectedly, SLC2A9 gene variants had stronger associations with serum uric acid than with fractional excretion of urate. Conclusions. These findings support two different loci by which SLC2A9 variants affect uric acid levels in African Americans and suggest SLC2A9 variants affect serum uric acid level via renal and extrarenal clearance. PMID:21186168

  2. Uric acid in the early risk stratification of ST-elevation myocardial infarction.

    PubMed

    Lazzeri, Chiara; Valente, Serafina; Chiostri, Marco; Picariello, Claudio; Gensini, Gian Franco

    2012-02-01

    Controversy still exists about uric acid as a potential prognostic risk factor for outcomes in patients with acute myocardial infarction. We prospectively assessed, in 856 patients with ST-elevation myocardial infarction (STMI) consecutively admitted to our Intensive Cardiac Care Unit after primary percutaneous coronary intervention (PCI) whether uric acid (UA) levels are associated with in-hospital mortality and complications. Killip classes III-IV were more frequent in the 3° UA tertile that was associated with the highest values of peak Tn I (p = 0.005), NT-proBNP (p < 0.001), and fibrinogen (p = 0.036). Uric acid was associated with mortality (crude OR: 1.24; 95% CI 1.03-1.51; p = 0.025), but, when adjusted for Tn I and renal failure (as inferred by eGFR <60 ml/min/1.73 m(2)), uric acid lost its statistical significance, while Tn I (100 pg/ml step OR: 1.002; 95% CI 1.000-1.003; p = 0.007) and renal failure (OR 9.16; 95% CI 3.60-23.32; p < 0.001) were independent predictors for in-ICCU mortality. Uric acid remained as independent predictor for in-ICCU complications (1 mg/dl step OR: 1.11; 95% CI 1.01-1.21; p = 0.030) together with admission glycemia (1 g/dl step OR: 1.50; 95% CI 1.19-1.91; p < 0.001) and renal failure (OR: 1.46; 95% CI 0.99-2.16; p < 0.001). In STEMI patients submitted to PCI, increased uric acid levels identify a subgroup more prone to in-ICCU complications, probably because hyperuricemia stems from several complex mechanisms ranging from pre-existing risk factors to the degree of myocardial ischemia (as indicated by Killip class, ejection fraction) and to the acute metabolic response (as inferred by glucose levels). Hyperuricemia is not independently associated with early mortality when adjusted for renal function and the degree of myocardial damage.

  3. 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

  4. [Two cases of uric acid stones unsuccessfully dissociated by oral chemolysis].

    PubMed

    Funahashi, Makoto; Yamada, Tetsuo; Murayama, Tetsuo

    2006-01-01

    We report two patients with renal uric acid (UA) stones in whom chemolysis by oral administration of alkaline citrate and allopurinol was unsuccessful. The stone in a 58-year old female did not dissolve because her urinary pH remained low throughout the day after alkaline citrate administration. The stone in a 50-year old man did not dissolve because his urinary pH was 5.5-6.0 after alkaline citrate administration. Alkalization of the urine helps reduce the stone size and the calcification of the stone. Extracorporeal shockwave lithotripsy was performed and the stone composition showed mixed calcium oxalate and calcium phosphate. The indication of oral chemolysis of uric acid stones is discussed.

  5. Serum and Urinary Malondialdehyde (MDA), Uric acid, and Protein as markers of perinatal asphyxia

    PubMed Central

    El Bana, Sawsan Mahmoud; Maher, Sheren Esam; Gaber, Amani Fawzy; Aly, Sanaa Shaker

    2016-01-01

    Introduction Perinatal asphyxia (PA) is among the leading causes of neonatal morbidity and death in neonatal intensive care units (NICUs). The aims of this research were to determine the concentrations of malondialdehyde (MDA), urine MDA, uric acid, and protein in the cord blood of neonates with perinatal asphyxia and to determine their relationship with the severity of perinatal asphyxia. Methods This matched case-control study was conducted from October 2012 to March 2013. All of the cases and controls were selected from the Gynecology & Obstetrics Department and the NICUs, at Qous Central Hospital in Qena, Egypt. We allocated 20 full-term neonates who had perinatal asphyxia to the case group. Also, we selected 20 healthy neonates for the control group. The subjects were matched with respect to age and gender. At birth and 48 hours later, measurements were made of MDA in cord blood and urine, and uric acid, protein, and creatinine also were measured in both groups. The data were analyzed by SPSS, version 17, using the independent-samples t-test, ANOVA, Tukey’s test, and Spearman’s correlation coefficient. Results At birth and 48 hr later, the newborns’ with PA had significantly higher levels of MDA in the cord blood, mean urinary uric acid/creatinine (UUA:Cr), protein/creatinine (UP:Cr), and MDA/creatinine ratio (UMDA:Cr) than the controls; their PA levels were correlated with the degree of hypoxic-ischemic encephalopathy (HIE). The babies who died due to PA had significantly higher levels of cord blood MDA, and they also had higher UUA:Cr, UP:Cr, and UMDA:Cr ratios than the babies who survived. Conclusion The concentration of MDA in cord blood can be used as a diagnostic marker of oxidative stress in asphyxiated neonates. The ratios of the urinary excretion rates of uric acid, protein, and MDA to creatinine increased as the severity of perinatal asphyxia and associated brain damage increased. PMID:27648187

  6. Serum and Urinary Malondialdehyde (MDA), Uric acid, and Protein as markers of perinatal asphyxia

    PubMed Central

    El Bana, Sawsan Mahmoud; Maher, Sheren Esam; Gaber, Amani Fawzy; Aly, Sanaa Shaker

    2016-01-01

    Introduction Perinatal asphyxia (PA) is among the leading causes of neonatal morbidity and death in neonatal intensive care units (NICUs). The aims of this research were to determine the concentrations of malondialdehyde (MDA), urine MDA, uric acid, and protein in the cord blood of neonates with perinatal asphyxia and to determine their relationship with the severity of perinatal asphyxia. Methods This matched case-control study was conducted from October 2012 to March 2013. All of the cases and controls were selected from the Gynecology & Obstetrics Department and the NICUs, at Qous Central Hospital in Qena, Egypt. We allocated 20 full-term neonates who had perinatal asphyxia to the case group. Also, we selected 20 healthy neonates for the control group. The subjects were matched with respect to age and gender. At birth and 48 hours later, measurements were made of MDA in cord blood and urine, and uric acid, protein, and creatinine also were measured in both groups. The data were analyzed by SPSS, version 17, using the independent-samples t-test, ANOVA, Tukey’s test, and Spearman’s correlation coefficient. Results At birth and 48 hr later, the newborns’ with PA had significantly higher levels of MDA in the cord blood, mean urinary uric acid/creatinine (UUA:Cr), protein/creatinine (UP:Cr), and MDA/creatinine ratio (UMDA:Cr) than the controls; their PA levels were correlated with the degree of hypoxic-ischemic encephalopathy (HIE). The babies who died due to PA had significantly higher levels of cord blood MDA, and they also had higher UUA:Cr, UP:Cr, and UMDA:Cr ratios than the babies who survived. Conclusion The concentration of MDA in cord blood can be used as a diagnostic marker of oxidative stress in asphyxiated neonates. The ratios of the urinary excretion rates of uric acid, protein, and MDA to creatinine increased as the severity of perinatal asphyxia and associated brain damage increased.

  7. 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

  8. 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. PMID:27402177

  9. Prevention of comorbidity and acute attack of gout by uric acid lowering therapy.

    PubMed

    Joo, Kowoon; Kwon, Seong-Ryul; Lim, Mie-Jin; Jung, Kyong-Hee; Joo, Hoyeon; Park, Won

    2014-05-01

    The object of this study was to evaluate the effect of uric acid lowering therapy in reducing the new development of comorbidities and the frequency of acute attacks in gout patients. We retrospectively reviewed patients who were diagnosed to have gout with at least 3 yr of follow up. They were divided into 2 groups; 53 patients with mean serum uric acid level (sUA)<6 mg/dL and 147 patients with mean sUA≥6 mg/dL. Comorbidities of gout such as hypertension (HTN), type II diabetes mellitus (DM), chronic kidney disease, cardiovascular disease (CVD) and urolithiasis were compared in each group at baseline and at last follow-up visit. Frequency of acute gout attacks were also compared between the groups. During the mean follow up period of 7.6 yr, the yearly rate of acute attack and the new development of HTN, DM, CVD and urolithiasis was lower in the adequately treated group compared to the inadequately treated group. Tight control of uric acid decreases the incidence of acute gout attacks and comorbidities of gout such as HTN, DM, CVD and urolithiasis.

  10. Urea nitrogen, creatinine, and uric acid levels in postmortem serum, vitreous humor, and pericardial fluid.

    PubMed

    Palmiere, Cristian; Mangin, Patrice

    2015-03-01

    Urea nitrogen, creatinine, and uric acid are relatively stable in postmortem serum and may, therefore, be used for diagnostic purposes when chronic kidney disease and end-stage renal failure are investigated as causes of death. Nevertheless, uncertainties remain in defining the best alternative to postmortem serum for the identification and assessment of significantly decreased kidney function. In this study, we investigated urea nitrogen, creatinine, and uric acid levels in postmortem serum, pericardial fluid, and vitreous humor in a series of medico-legal cases (500 autopsies) with various causes of death. No postmortem interval-related differences were observed in any of the investigated fluids for any analyzed parameter, confirming the biochemical stability of all compounds after death. Data analysis failed to reveal statistically significant differences between postmortem serum and pericardial fluid urea nitrogen, creatinine, and uric acid concentrations. Conversely, statistically significant differences were observed in all analyzed biomarkers between postmortem serum and vitreous humor levels, with lower concentrations of all markers measured in vitreous. The results of this study suggest that, in order to estimate as accurately as possible blood analyte concentrations at the time of death, pericardial fluid should be preferred to vitreous humor.

  11. Association of Serum Uric Acid Concentration with Diabetic Retinopathy and Albuminuria in Taiwanese Patients with Type 2 Diabetes Mellitus

    PubMed Central

    Liang, Ching-Chao; Lin, Pi-Chen; Lee, Mei-Yueh; Chen, Szu-Chia; Shin, Shyi-Jang; Hsiao, Pi-Jung; Lin, Kun-Der; Hsu, Wei-Hao

    2016-01-01

    Patients with type 2 diabetes mellitus (DM) may experience chronic microvascular complications such as diabetic retinopathy (DR) and diabetic nephropathy (DN) during their lifetime. In clinical studies, serum uric acid concentration has been found to be associated with DR and DN. The goal of this study was to evaluate the relationship between the increases in serum uric acid level and the severity of DR and albuminuria in Taiwanese patients with type 2 DM. We recorded serum uric acid concentration, the severity of DR, and the severity of albuminuria by calculating urinary albumin-to-creatinine ratio (UACR) in 385 patients with type 2 DM. In multivariate logistic regression analysis, a high uric acid concentration was a risk factor for albuminuria (odds ratio (OR), 1.227; 95% confidence interval (CI) = 1.015–1.482; p = 0.034) and DR (OR, 1.264; 95% CI = 1.084–1.473; p = 0.003). We also demonstrated that there was a higher concentration of serum uric acid in the patients with more severe albuminuria and DR. In conclusion, an increased serum uric acid level was significantly correlated with the severity of albuminuria and DR in Taiwanese patients with type 2 DM. PMID:27490538

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

    PubMed Central

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

    2015-01-01

    Objective To investigate the relationship between mid-gestational serum uric acid and birth weight in diabetic pregnant women with or without insulin resistance. Methods: 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. Results: 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. Conclusions: 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. PMID:25810959

  13. Total antioxidant status at high altitude in lowlanders and native highlanders: role of uric acid.

    PubMed

    Sinha, Sanchari; Singh, Som Nath; Ray, Uday Sankar

    2009-01-01

    Hypobaric hypoxia causes oxidative stress and the antioxidant system of the body plays a vital role in controlling it. Urate contributes up to two-thirds of the antioxidant capacity of human blood. The urate production is catalyzed by xanthine oxidase with a concomitant release of free radicals. This study was designed to appraise the role of urate as an antioxidant at high altitude. The study was conducted on 92 male lowlanders and 66 highlanders after ascent to high altitude at 4560 m. Blood was collected at sea level and after 4 weeks of high altitude exposure. In lowlanders, a significant increase in levels of hydroperoxide (551.4 +/- 4.2 micromol/mL vs. 582.0 +/- 3.55, p < 0.001], protein carbonyl (2.4 +/- 0.11 micromol/mL/mg protein vs. 3.03 +/- 0.11, p < 0.001), TAS (1.02 +/- 0.01 mmol/L vs. 1.19 +/- 0.02, p < 0.001), and UA (298.0 +/- 6.68 micromol/L vs. 383.0 +/- 6.55, p < 0.001) was observed at high altitude. These measurements were significantly lower in highlanders than in lowlanders at high altitude. Total antioxidant status (TAS) and uric acid (UA) showed a positive correlation in lowlanders at sea level and in highlanders at high altitude. Hydroperoxide and TAS also showed a positive correlation in both groups at high altitude. This indicates increased oxidative stress at high altitude despite an increase in antioxidant capacity in lowlanders. To conclude, a hypoxia-induced increase in UA contributes an appreciable portion of plasma total antioxidant capacity, but may not be effective in preventing oxidative stress at high altitude. PMID:19775217

  14. Serum Uric Acid Levels were Dynamically Coupled with Hemoglobin A1c in the Development of Type 2 Diabetes

    PubMed Central

    Wei, Fengjiang; Chang, Baocheng; Yang, Xilin; Wang, Yaogang; Chen, Liming; Li, Wei-Dong

    2016-01-01

    The aim of the study was to decipher the relationship between serum uric acid (SUA) and glycated hemoglobin A1c (HbA1c) or fasting plasma glucose (FPG) in both type 2 diabetes mellitus (T2DM) patients and normal subjects. A total of 2,250 unrelated T2DM patients and 4,420 Han Chinese subjects from a physical examination population were recruited for this study. In T2DM patients SUA levels were negatively correlated with HbA1c (rs = −0.109, P = 0.000) and 2 h plasma glucose levels (rs = −0.178, P = 0.000). In the physical examination population, SUA levels were inversely correlated with HbA1c (rs = −0.175, P = 0.000) and FPG (rs = −0.131, P = 0.009) in T2DM patients but positively correlated with HbA1c (rs = 0.040, P = 0.012) and FPG (rs = 0.084, P = 0.000) in normal-glucose subjects. Multivariate analyses showed that HbA1c was significantly negatively associated with HUA both in T2DM patients (OR = 0.872, 95% CI: 0.790~0.963) and in the physical examination T2DM patients (OR = 0.722, 95% CI: 0.539~0.968). Genetic association studies in T2DM patients showed that alleles of two glucose-uric acid transporter genes, ABCG2 and SLC2A9 were significantly associated with SUA levels (P < 0.05). SUA level is inversely correlated with HbA1c in T2DM patients but positively correlated with HbA1c in normal-glucose subjects. The reverse transporting of uric acid and glucose in renal tubules might be accounted for these associations. PMID:27328642

  15. Uric acid induces oxidative stress and growth inhibition by activating adenosine monophosphate-activated protein kinase and extracellular signal-regulated kinase signal pathways in pancreatic β cells.

    PubMed

    Zhang, Yongneng; Yamamoto, Tetsuya; Hisatome, Ichiro; Li, Youfeng; Cheng, Weijie; Sun, Ning; Cai, Bozhi; Huang, Tianliang; Zhu, Yuzhang; Li, Zhi; Jing, Xubin; Zhou, Rui; Cheng, Jidong

    2013-08-15

    Hyperuricaemia is a disorder of purine metabolism, and is strongly associated with insulin resistance and abnormal glucose metabolism. As the producer of insulin, pancreatic β cells might be affected by elevated serum uric acid levels and contribute to the disregulated glucose metabolism. In this study, we investigated the effect of high uric acid on rat pancreatic β cell function. Under high uric acid condition, proliferation of pancreatic β cells was inhibited, production of reactive oxygen species increased, and glucose stimulated insulin secretion was also compromised. Further examination on signal transduction pathways revealed that uric acid-induced ROS is involved in the activation of adenosine monophosphate-activated protein kinase (AMPK), and extracellular signal-regulated kinase (ERK). Pharmacological inhibition of ERK activation rescued β cells from growth inhibition. More importantly, activation of ERK induced by uric acid is significantly diminished by AMPK inhibitor, indicating ERK as a downstream target of AMPK in response to high uric acid condition. We also investigated the transportation channel for uric acid into pancreatic β cells. While major urate transporter URAT1 is not expressed in β cells, organic anion transporter (OAT) inhibitor successfully blocked the activation of ERK by uric acid. Our data indicate that high uric acid levels induce oxidative damage and inhibit growth of rat pancreatic β cells by activating the AMPK and ERK signal pathways. Hyperuricemia may contribute to abnormal glucose metabolism by causing oxidative damage and function inhibition of pancreatic β cells.

  16. Glycation of aspartate aminotransferase by methylglyoxal, effect of hydroxycitric and uric acid.

    PubMed

    Bousová, Iva; Bacílková, Eliska; Dobrijević, Sanja; Drsata, Jaroslav

    2009-11-01

    Glycation is a process closely related to the aging and pathogenesis of diabetic complications. Reactive alpha-dicarbonyl compounds (e.g., methylglyoxal) are formed during middle stage of glycation reaction. Compounds that would inhibit the glycation process have been seeked for years. The objective of this study was to investigate the inhibitory effect of hydroxycitric (0.25-2.5 mM) and uric acid (0.4-1.2 mM) on middle stage of protein glycation in vitro using the model containing aspartate aminotransferase (AST) and 0.5 mM methylglyoxal. Hydroxycitric acid, at all tested concentrations, reduced AST activity decrease and formation of fluorescent AGEs during incubation of the enzyme with methylglyoxal at 37 degrees C. This compound also prevented formation of high-molecular weight protein cross-links and changes in molecular charge of AST caused by glycation. Uric acid showed no positive anti-glycation activity. The results support the hypothesis that hydroxycitric acid has beneficial effects in controlling protein glycation. PMID:19449196

  17. 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. PMID:27006878

  18. Optimization of pH values to formulate the bireagent kit for serum uric acid assay.

    PubMed

    Huang, Ya; Chen, Yuanxiang; Yang, Xiaolan; Zhao, Hua; Hu, Xiaolei; Pu, Jun; Liao, Juan; Long, Gaobo; Liao, Fei

    2015-01-01

    A new formulation of the bireagent kit for serum uric acid assay was developed based on the effects of pH on enzyme stability. At 4 °C, half-lives of uricases from Bacillus fastidious and Arthrobacter globiforms were longer than 15 months at pH 9.2, but became shorter at pH below 8.0; half-lives of ascorbate oxidase and peroxidase were comparable at pH 6.5 and 7.0, but became much shorter at pH higher than 7.4. In the new formulation of the bireagent kit, Reagent A contained peroxidase, 4-aminoantipyrine, and ascorbate oxidase in 50 mM phosphate buffer at pH 6.5; Reagent B contained B. fastidious or A. globiforms uricase in 50 mM sodium borate buffer at pH 9.2; Reagents A and B were mixed at 4:1 to produce a final pH from 7.2 to 7.6 for developing a stable color. The new bireagent kit consumed smaller quantities of three enzymes for the same shelf life. With the new bireagent kit, there were linear responses of absorbance at 546 nm to uric acid up to 34 mM in reaction mixtures and a good correlation of uric acid levels in clinical sera with those by a commercial kit, but stronger resistance to ascorbate. Therefore, the new formulation was advantageous.

  19. 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.

  20. 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. PMID:24326318

  1. Effects of a fermented barley extract on subjects with slightly high serum uric acid or mild hyperuricemia.

    PubMed

    Hokazono, Hideki; Omori, Toshiro; Yamamoto, Tetsuro; Akaoka, Ieo; Ono, Kazuhisa

    2010-01-01

    The uric acid-lowering effect and safety of a fermented barley extract P (FBEP) prepared from barley-shochu distillery by-products were investigated in a randomized, placebo-controlled, parallel-group, double-blinded study. A total of 111 subjects with serum uric acid levels of 6.0-7.9 mg/dl were provided with either a drink containing 2 g/d of FBEP (test group) or a placebo drink. After 12 weeks, the serum uric acid levels changed by -0.21+/-0.56 mg/dl in the test group, showing a significant decrease in comparison to those of the placebo group (+0.02+/-0.54 mg/dl). Additionally, the uric acid clearance in the test group showed a tendency to increase after 12 weeks more than in the placebo group (p=0.054). No abnormalities in the physical and clinical tests were observed, and no adverse diagnostic findings were attributed to the intake of the test meal. These results demonstrated the benefits and safety of the FBEP treatment to subjects with slightly high serum uric acid or mild hyperuricemia.

  2. Renal clearance of uric acid is linked to insulin resistance and lower excretion of sodium in gout patients.

    PubMed

    Perez-Ruiz, Fernando; Aniel-Quiroga, Maria Angeles; Herrero-Beites, Ana María; Chinchilla, Sandra Pamela; Erauskin, Gorka Garcia; Merriman, Toni

    2015-09-01

    Inefficient renal excretion of uric acid is the main pathophysiological mechanism for hyperuricemia in gout patients. Polymorphisms of renal tubular transporters linked with sodium and monosaccharide transport have yet to be demonstrated. We intended to evaluate the impact of insulin resistance, evaluated with the homeostasis model assessment (HOMA), through a transversal study of non-diabetic patients with gout, with normal renal function, not treated with any medication but colchicine as prophylaxis. One hundred and thirty-three patients were evaluated. Clearance of uric acid was inversely correlated with insulin resistance and directly correlated with fractional excretion of sodium. In multivariate analysis, hypertension and hyperlipidemia, in addition to insulin resistance and fractional excretion of sodium, were associated with renal clearance of uric acid. HOMA cutoff for efficient versus inefficient renal handling of uric acid was 2.72, close to that observed in studies of reference population. The impact of insulin resistance and renal handling of sodium on renal clearance of uric acid may help to explain why hyperuricemia is more commonly associated with diabetes and hypertension. PMID:25763991

  3. Associations of Uric Acid with Polymorphisms in the δ-Aminolevulinic Acid Dehydratase, Vitamin D Receptor, and Nitric Oxide Synthase Genes in Korean Lead Workers

    PubMed Central

    Weaver, Virginia M.; Schwartz, Brian S.; Jaar, Bernard G.; Ahn, Kyu-Dong; Todd, Andrew C.; Lee, Sung-Soo; Kelsey, Karl T.; Silbergeld, Ellen K.; Lustberg, Mark E.; Parsons, Patrick J.; Wen, Jiayu; Lee, Byung-Kook

    2005-01-01

    Recent research suggests that uric acid may be nephrotoxic at lower levels than previously recognized and that it may be one mechanism for lead-related nephrotoxicity. Therefore, in understanding mechanisms for lead-related nephrotoxicity, it would be of value to determine whether genetic polymorphisms that are associated with renal outcomes in lead workers and/or modify associations between lead dose and renal function are also associated with uric acid and/or modify associations between lead dose and uric acid. We analyzed data on three such genetic polymorphisms: δ-aminolevulinic acid dehydratase (ALAD), endothelial nitric oxide synthase (eNOS), and the vitamin D receptor (VDR). Mean (± SD) tibia, blood, and dimercaptosuccinic acid–chelatable lead levels were 37.2 ± 40.4 μg/g bone mineral, 32.0± 15.0 g/dL, and 0.77± 0.86 μg/mg creatinine, respectively, in 798 current and former lead workers. Participants with the eNOS Asp allele had lower mean serum uric acid compared with those with the Glu/Glu genotype. Among older workers (age ≥ median of 40.6 years), ALAD genotype modified associations between lead dose and uric acid levels. Higher lead dose was significantly associated with higher uric acid in workers with the ALAD1-1 genotype; associations were in the opposite direction in participants with the variant ALAD1-2 genotype. In contrast, higher tibia lead was associated with higher uric acid in those with the variant VDR B allele; however, modification was dependent on participants with the bb genotype and high tibia lead levels. We conclude that genetic polymorphisms may modify uric acid mediation of lead-related adverse renal effects. PMID:16263504

  4. 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.

  5. Bilateral uric acid nephrolithiasis and ureteral hypertrophy in a free-ranging river otter (Lontra canadensis)

    USGS Publications Warehouse

    Grove, Robert A.; Bildfell, Rob; Henny, Charles J.; Buhler, D.R.

    2003-01-01

    We report the first case of uric acid nephrolithiasis in a free-ranging river otter (Lontra canadensis). A 7 yr old male river otter collected from the Skagit River of western Washington (USA) had bilateral nephrolithiasis and severely enlarged ureters (one of 305 examined [0.33%]). The uroliths were 97% uric acid and 3% protein. Microscopic changes in the kidney were confined to expansion of renal calyces, minor loss of medullary tissue, and multifocal atrophy of the cortical tubules. No inflammation was observed in either kidney or the ureters. The ureters were enlarged due to marked hypertrophy of smooth muscle plus dilation of the lumen. Fusion of the major calyces into a single ureteral lumen was several cm distal to that of two adult male otters used as histopathologic control specimens. This case report is part of a large contaminant study of river otters collected from Oregon and Washington. It is important to understand diseases and lesions of the otter as part of our overall evaluation of this population.

  6. Comparatve uric acid lowering studies of allopurinol with an indigenous medicinal plant in rabbits.

    PubMed

    Mohammad, Imran Shair; Latif, Sana; Yar, Muhammad; Nasar, Faiza; Ahmad, Irshad; Naeem, Muhammad

    2014-01-01

    The aim of this research was to carry out a comparative study of lowering of uric acid by the use of dried powder of Colchicum luteum and allopathic drug (allopurinol) in rabbits, to determine whether herbal drugs can be used by patients instead of allopathic drugs. The herbal medicine, dried corm powder of Colchicum luteum 2.5 mg/kg/day and dried powder of allopurinol 2 mg/kg/day an allopathic medicine, was used in the study. The results of these medicines were observed in animal model, using 12 adult rabbits, which were divided into three groups A, B and C, respectively, where group C was taken as control. The SPSS version 17 was used for statistical analysis and analysis of variance (ANOVA) was used for comparing the data in different groups and the level of significance was 5%. It was resulted that dried corm of Colchicum luteum significantly reduced the uric acid in adult rabbits as reduced by allopathic medicine--allopurinol. In the light of present research we concluded that the herbal medicines can be used in lieu of allopathic drugs. Thus, the risk of side effects that are associated with the prolonged use of allopathic drugs can be minimized.

  7. 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

  8. Increased Serum Uric Acid Levels Blunt the Antihypertensive Efficacy of Lifestyle Modifications in Children at Cardiovascular Risk.

    PubMed

    Viazzi, Francesca; Rebora, Paola; Giussani, Marco; Orlando, Antonina; Stella, Andrea; Antolini, Laura; Valsecchi, Maria Grazia; Pontremoli, Roberto; Genovesi, Simonetta

    2016-05-01

    Primary hypertension is a growing concern in children because of the obesity epidemic largely attributable to western lifestyles. Serum uric acid is known to be influenced by dietary habits, correlates with obesity, and could represent a risk factor for hypertension. Preliminary studies in children highlighted uric acid as a potentially modifiable risk factor for the prevention and treatment of hypertension. The effect of lifestyle changes (increase of physical activity and dietary modifications) on blood pressure values, weight status, and serum uric acid levels in a cohort of 248 children referred for cardiovascular risk assessment were evaluated over a mean 1.5-year follow-up. At baseline, 48% of children were obese and 50% showed blood pressure values >90th percentile. At follow-up, a significant improvement in weight class (24% obese;P<0.0001) and blood pressure category (22% >90th percentile;P<0.0001) was found. Systolic blood pressure z-score (P<0.0001), uric acid value (P=0.0056), and puberty at baseline (P=0.0048) were independently associated with higher systolic blood pressure z-score at follow-up, whereas a negative association was observed with body mass index z-score decrease during follow-up (P=0.0033). The risk of hypertension at follow-up was associated with body mass index (P=0.0025) and systolic blood pressure (P<0.0001) z-score at baseline and inversely related to delta body mass index (P=0.0002), whereas the risk of showing hypertension ≥99th percentile was more than doubled for each baseline 1 mg/dL increase of serum uric acid (P=0.0130). Uric acid is a powerful determinant of blood pressure over time, independent of lifestyle modifications. PMID:27021006

  9. Relationship between High-Performance Liquid Chromatography Fingerprints and Uric Acid-Lowering Activities of Cichorium intybus L.

    PubMed

    Zhu, Chun-Sheng; Zhang, Bing; Lin, Zhi-Jian; Wang, Xue-Jie; Zhou, Yue; Sun, Xiao-Xia; Xiao, Ming-Liang

    2015-01-01

    This study aimed to explore the spectrum-effect relationships between high-performance liquid chromatography fingerprints and the uric acid-lowering activities of chicory. Chemical fingerprints of chicory samples from ten different sources were determined by high-performance liquid chromatography, and then investigated by similarity analysis and hierarchical clustering analysis. Pharmacodynamics experiments were conducted in animals to obtain the uric acid-lowering activity information of each chicory sample. The spectrum-effect relationships between chemical fingerprints and the uric acid-lowering activities of chicory were established by canonical correlation analysis. The structures of potential effective peaks were identified by liquid chromatography with tandem mass spectrometry. The results showed that a close correlation existed between the spectrum and effect of chicory. Aesculin, chlorogenic acid, chicoric acid, isochlorogenic acid A/B/C and 13,14-seco-stigma5(6),14(15)-diene-3α-ol might be the main effective constituents. This work provides a general model of the combination of high-performance liquid chromatography and uric acid-lowering activities to study the spectrum-effect relationships of chicory, which can be used to discover the principle components responsible for the bioactivity. PMID:26007193

  10. Relationship between High-Performance Liquid Chromatography Fingerprints and Uric Acid-Lowering Activities of Cichorium intybus L.

    PubMed

    Zhu, Chun-Sheng; Zhang, Bing; Lin, Zhi-Jian; Wang, Xue-Jie; Zhou, Yue; Sun, Xiao-Xia; Xiao, Ming-Liang

    2015-05-22

    This study aimed to explore the spectrum-effect relationships between high-performance liquid chromatography fingerprints and the uric acid-lowering activities of chicory. Chemical fingerprints of chicory samples from ten different sources were determined by high-performance liquid chromatography, and then investigated by similarity analysis and hierarchical clustering analysis. Pharmacodynamics experiments were conducted in animals to obtain the uric acid-lowering activity information of each chicory sample. The spectrum-effect relationships between chemical fingerprints and the uric acid-lowering activities of chicory were established by canonical correlation analysis. The structures of potential effective peaks were identified by liquid chromatography with tandem mass spectrometry. The results showed that a close correlation existed between the spectrum and effect of chicory. Aesculin, chlorogenic acid, chicoric acid, isochlorogenic acid A/B/C and 13,14-seco-stigma5(6),14(15)-diene-3α-ol might be the main effective constituents. This work provides a general model of the combination of high-performance liquid chromatography and uric acid-lowering activities to study the spectrum-effect relationships of chicory, which can be used to discover the principle components responsible for the bioactivity.

  11. The Relation between Serum Uric Acid and HbA1c Is Dependent upon Hyperinsulinemia in Patients with Newly Diagnosed Type 2 Diabetes Mellitus

    PubMed Central

    Cui, Yuliang; Bu, Hemei; Zhao, Sha; Li, Xiaona; Lu, Shan

    2016-01-01

    Objective. The aim of our study was to explore the dependent condition of the relationship between uric acid and blood glucose in type 2 diabetes. Research Design and Methods. We measured the HbA1c, serum uric acid, creatinine, lipids profiles, and so forth of 605 newly diagnosed type 2 diabetes patients, and oral glucose tolerance tests (OGTTs) were performed on each patient. The population was divided into high and low insulin groups. Multiple linear regression analyses were conducted to assess the relationship between uric acid and HbA1c. Results. Serum uric acid and HbA1c levels were low in newly diagnosed type 2 diabetes patients. However, we found no significant relationship between uric acid and HbA1c by regression analysis after adjusting total insulin. The concentration of uric acid was inversely correlated with HbA1c in the high insulin group, regardless of patient sex. However, no associations were found in low insulin group. Conclusions. The negative correlation between uric acid and HbA1c is conditional in newly diagnosed type 2 diabetes patients and is related to hyperinsulinemia. Therefore, uric acid is likely only useful as a biomarker of blood glucose in patients exhibiting hyperinsulinemia. PMID:27403443

  12. 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. PMID:27207036

  13. The cockroach Blattella germanica obtains nitrogen from uric acid through a metabolic pathway shared with its bacterial endosymbiont.

    PubMed

    Patiño-Navarrete, Rafael; Piulachs, Maria-Dolors; Belles, Xavier; Moya, Andrés; Latorre, Amparo; Peretó, Juli

    2014-07-01

    Uric acid stored in the fat body of cockroaches is a nitrogen reservoir mobilized in times of scarcity. The discovery of urease in Blattabacterium cuenoti, the primary endosymbiont of cockroaches, suggests that the endosymbiont may participate in cockroach nitrogen economy. However, bacterial urease may only be one piece in the entire nitrogen recycling process from insect uric acid. Thus, in addition to the uricolytic pathway to urea, there must be glutamine synthetase assimilating the released ammonia by the urease reaction to enable the stored nitrogen to be metabolically usable. None of the Blattabacterium genomes sequenced to date possess genes encoding for those enzymes. To test the host's contribution to the process, we have sequenced and analysed Blattella germanica transcriptomes from the fat body. We identified transcripts corresponding to all genes necessary for the synthesis of uric acid and its catabolism to urea, as well as for the synthesis of glutamine, asparagine, proline and glycine, i.e. the amino acids required by the endosymbiont. We also explored the changes in gene expression with different dietary protein levels. It appears that the ability to use uric acid as a nitrogen reservoir emerged in cockroaches after its age-old symbiotic association with bacteria.

  14. Intake of Added Sugar and Sugar-Sweetened Drink and Serum Uric Acid Concentration in US Men and Women

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fructose-induced hyperuricemia might have a causal role in metabolic syndrome, hypertension, and other chronic disease. However, no study has investigated whether sugar added to foods or sugar-sweetened beverages, which are major sources of fructose, are associated with serum uric acid concentration...

  15. Effect of processing parameters for electrocatalytic properties of SnO(2) thin film matrix for uric acid biosensor.

    PubMed

    Arora, Kashima; Tomar, Monika; Gupta, Vinay

    2014-02-21

    RF sputtered tin oxide (SnO2) thin film matrix has been efficiently exploited for the detection of uric acid. The deposition parameters for SnO2 thin film have been optimized to yield better electrocatalytic properties. A correlation between its electrocatalytic properties with the structural and electrical properties has been made. SnO2 thin film prepared under optimized growth parameter (70% argon in reactive gas ambient of Ar and O2) exhibits higher mobility of charge carrier and high carrier concentration thereby resulting in enhanced charge transfer characteristics. High surface coverage of uricase onto SnO2 thin films (4.28 × 10(-4) mole cm(-2)), low value of Michaelis-Menten constant (km) 0.18 mM, good linearity in detection of uric acid in the range 0.05-1.00 mM and a fast response of 5 s are attractive features of prepared SnO2 thin film based bioelectrodes for efficient detection of uric acid. The nanoporous and rough surface morphology of SnO2 thin film besides its high carrier mobility in comparison to that of ITO is responsible for the obtained enhanced sensitivity (∼700 μA mM(-1)) and improved sensing response characteristics towards uric acid. PMID:24396852

  16. Potential Role of Uric Acid in Metabolic Syndrome, Hypertension, Kidney Injury, and Cardiovascular Diseases: Is It Time for Reappraisal?

    PubMed Central

    Soltani, Zohreh; Rasheed, Kashef; Kapusta, Daniel R.; Reisin, Efrain

    2013-01-01

    Elevated serum uric acid concentration is a common laboratory finding in subjects with metabolic syndrome/obesity, hypertension, kidney disease and cardiovascular events. Hyperuricemia has been attributed to hyperinsulinemia in metabolic syndrome and to decreased uric acid excretion in kidney dysfunction and is not acknowledged as a main mediator of metabolic syndrome, renal disease, and cardiovascular disorder development. However, more recent investigations have altered this traditional view and shown by providing compelling evidence to support an independent link between hyperuricemia and increased risk of metabolic syndrome, diabetes, hypertension, kidney disease and cardiovascular disorders. However, despite these new findings, controversy regarding the exact role of uric acid in inducing these diseases remains to be unfolded. Furthermore, recent data suggest that the high-fructose diet in the United State, as a major cause of hyperuricemia, may be contributing to the metabolic syndrome/obesity epidemic, diabetes, hypertension, kidney disease and cardiovascular disorder. Our focus in this review is to discuss the available evidence supporting a role for uric acid in the development of metabolic syndrome, hypertension, renal disease, and cardiovascular disorder; and the potential pathophysiology mechanisms involved. PMID:23588856

  17. 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)

  18. The Use of Serum Uric Acid Concentration as an Indicator of Laparoscopic Sleeve Gastrectomy Success

    PubMed Central

    Menenakos, Evangelos; Doulami, Georgia; Tzanetakou, Irene P.; Natoudi, Maria; Kokoroskos, Nikolaos; Almpanopoulos, Konstantinos; Leandros, Emmanouil; Zografos, George; Theodorou, Dimitrios

    2015-01-01

    Laparoscopic sleeve gastrectomy (LSG) effectively reduces weight by restricting gastric capacity and altering gut hormones levels. We designed a prospective study to investigate the correlation of serum uric acid (SUA) concentration and weight loss. SUA and body mass index (BMI) were measured preoperatively and on first postoperative month and year in patients who underwent LSG in our department of bariatric surgery. Data on 55 patients were analyzed. Preoperative SUA concentration had a significant positive correlation with percentage of total weight loss (TWL) on first postoperative month (P = 0.001) and year (P = 0.002). SUA concentration on first postoperative month had a positive correlation with percentage of TWL on first postoperative year (P = 0.004). SUA concentration could be used as a predictor of LSG's success and could help in early detection of patients with rapid loss of weight, in order to prevent complications. PMID:25594659

  19. Label-free and selective sensing of uric acid with gold nanoclusters as optical probe.

    PubMed

    Wang, Jian; Chang, Yong; Wu, Wen Bi; Zhang, Pu; Lie, Shao Qing; Huang, Cheng Zhi

    2016-05-15

    Clinically, the amount of uric acid (UA) in biological fluids is closely related to some diseases such as hyperuricemia and gout, thus it is of great significance to sense UA in clinical samples. In this work, red gold nanoclusters (AuNCs) with relatively high fluorescence quantum yield and strong fluorescence emission were facilely available using bovine serum albumin (BSA) as template. The fluorescence of BSA-protected AuNCs can be sensitively quenched by H2O2, which is further capable of sensing UA through the specific catalytic oxidation with uricase, since it generates stoichiometric quantity of H2O2 by-product. The proposed assay allows for the selective detection of UA in the range of 10-800 μM with a detection limit of 6.6 μM, which is applicable to sense UA in clinical samples with satisfactory results, suggesting its great potential for diagnostic purposes. PMID:26992526

  20. Analytical methods for measuring uric acid in biological samples and food products.

    PubMed

    Pachla, L A; Reynolds, D L; Wright, D S; Kissinger, P T

    1987-01-01

    During the last 7 decades, uric acid methodology has kept pace with the introduction of state-of-the-art technology (e.g., spectroscopy, electrochemistry, chromatography) or the discovery of unique chemical processes (e.g., redox, enzymatic). We envision this practice will continue in the future. There never will be a single analytical method applicable for biofluids or foodstuffs. Therefore, it is imperative that the analyst not only understand the advantages and disadvantages of a procedure, but also thoroughly understand its underlying chemical and technological principles. Since many procedures available for analysis of biofluids and foodstuffs rely on identical chemical or technological principles, this report shall review both sample types and the available spectroscopic, electroanalytical, and chromatographic methods.

  1. Cu nanoparticles incorporated polypyrrole modified GCE for sensitive simultaneous determination of dopamine and uric acid.

    PubMed

    Ulubay, Sükriye; Dursun, Zekerya

    2010-01-15

    Cu nanoparticles have been electrochemically incorporated polypyrrole film that was used for modification of the glassy carbon electrode surface. The performance of the electrode has been characterized by cyclic voltammetry and atomic force microscopy. The electrode has shown high electrocatalytic activity towards the oxidation of dopamine (DA) and uric acid (UA) simultaneously in a phosphate buffer solution (pH 7.00). The electrocatalytic oxidation currents of UA and DA were found linearly related to concentration over the range 1x10(-9) to 1x10(-5)M for UA and 1x10(-9) to 1x10(-7)M for DA using DPVs method. The detection limits were determined as 8x10(-10)M (s/n=3) for UA and 8.5x10(-10)M (s/n=3) for DA at a signal-to-noise ratio of 3.

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

    PubMed

    Yang, Y; Zhou, Y; Cheng, S; Sun, J L; Yao, H; Ma, L

    2016-01-01

    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. PMID:27420973

  3. Changes in serum uric acid levels after allogeneic hematologic stem cell transplantation: A retrospective cohort study

    PubMed Central

    Joo, Sang Hyun; Park, Jin Kyun; Lee, Eunyoung Emily; Song, Yeong Wook

    2016-01-01

    Background Since cell turnover in the hematopoietic system constitutes a major source of uric acid (UA) production, we investigated whether hematopoietic stem cell transplantation (HSCT) is associated with significant changes in serum UA levels in patients with hematological disorders. Methods Patients who underwent HSCT at our institution between 2001 and 2012 were retrospectively enrolled. Serum UA levels at 3 months before, 1 week before, and 3 months and 1 year after HSCT were examined. Results Complete clinical and laboratory information including data regarding UA levels was available for 93 patients. At baseline, the mean UA level was 4.9±2.1 mg/dL, with an overall prevalence of hyperuricemia of 15% (defined as serum UA>6.8 mg/dL). Mean UA levels tended to be higher in patients with acute myeloid leukemia (4.8±2.0 mg/dL) and non-Hodgkin lymphoma (5.1±2.3 mg/dL) and lower in patients with aplastic anemia (mean, 4.2±1.8 mg/dL). UA levels dropped during myeloablative conditioning, reaching a nadir on the day of HSCT (3.27±1.4 mg/dL). Over the 3 months following HSCT, UA levels rose sharply (5.0±2.1 mg/dL) and remained stable up to 1 year after HSCT (5.5±1.6 mg/dL). UA levels in HSCT recipients at 12 months correlated with those of their respective graft donors (Pearson r=0.406, P=0.001). Conclusion HSCT is associated with significant changes in uric acid levels in patients with hematologic disorders. PMID:27722132

  4. Effect of serum uric acid on the positive predictive value of dobutamine stress echocardiography.

    PubMed

    Aribas, Alpay; Akilli, Hakan; Kayrak, Mehmet; Alibasic, Hayrudin; Yildirim, Oguzhan; Sertdemir, Ahmet Lutfi; Karanfil, Mustafa; Ozdemir, Kurtulus

    2016-03-01

    There is controversial data regarding the relationship between uric acid (UA) and coronary artery disease and cardiovascular events. Despite the deleterious effects of hyperuricemia on endothelial function, the effect of UA on myocardial ischemia has not been previously studied. We aimed to investigate the relationship between UA and myocardial ischemia that was identified using dobutamine stress echocardiography (DSE). In this retrospective study, the laboratory and DSE reports of 548 patients were reviewed. The patients were divided into two groups based on the presence of ischemia and further subdivided into three groups according to the extent of ischemia (none, ischemia in 1-3 segments, ischemia in >3 segments). Serum UA levels were compared. Determinants of ischemia were assessed using a regression model. UA was increased in patients with ischemia and was correlated with the number of ischemic segments (p < 0.001). A cutoff value of UA > 5 mg/dl had 63.9 % sensitivity, 62.0 % specificity, 42.5 % positive predictive value (PPV), and 79.6 % negative predictive value for ischemia. When the positive DSE exams were further sorted according to the UA cutoff, the PPV of DSE increased from 80.2 to 94.0 %. Uric acid (odds ratio 1.51; 95 % CI 1.14-1.99), diabetes mellitus, HDL and glomerular filtration rate were found to be independent determinants of myocardial ischemia in DSE. Increased UA is associated with both the presence and extent of DSE-identified myocardial ischemia. A UA cutoff may be a good method to improve the PPV of DSE.

  5. The Effects of Lead Exposure on Serum Uric Acid and Hyperuricemia in Chinese Adults: A Cross-Sectional Study.

    PubMed

    Dai, Haijiang; Huang, Zhijun; Deng, Qihong; Li, Ying; Xiao, Ting; Ning, Xingping; Lu, Yao; Yuan, Hong

    2015-08-18

    The aim of this study was to assess the correlation between blood lead levels and both serum uric acid and hyperuricemia in adult residents living within an area of China with lead pollution. We conducted a cross-sectional analysis of 2120 subjects (1180 of whom were male) between the ages of 20 and 75 years who had undergone health examinations at the Centers for Disease Control and Prevention (CDC) in a lead-polluted area of China between January 2013 and August 2014. Blood lead was positively correlated with serum uric acid in both males (r = 0.095, p = 0.001) and females (r = 0.134, p < 0.001). Multivariate linear regression analysis demonstrated that for males, blood lead (p = 0.006), age (p = 0.001), current smoking (p = 0.012), education (p = 0.001), triglycerides (TG) (p < 0.001), and serum creatinine (p < 0.001) were independently associated with serum uric acid. For females, blood lead (p < 0.001), body mass index (BMI) (p = 0.009), and TG (p < 0.001) were independently associated with serum uric acid. After multiple adjustments, blood lead was significantly associated with a higher prevalence of hyperuricemia when female subjects were categorized into quartiles (for the highest quartile vs. the lowest quartile, odds ratio (OR) = 2.190; 95% confidence interval (CI): 1.106-4.338; p = 0.025); however, no such association was observed for male subjects. Continuous lead exposure has an independent impact on serum uric acid for both males and females, although this impact is more pronounced for females than for males. Lead exposure is significantly associated with hyperuricemia for females but not for males.

  6. 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. PMID:26774005

  7. Effects of low birth weight in 8- to 13-year-old children: implications in endothelial function and uric acid levels.

    PubMed

    Franco, Maria C P; Christofalo, Dejaldo M J; Sawaya, Ana Lydia; Ajzen, Sérgio A; Sesso, Ricardo

    2006-07-01

    Low birth weight has been associated with an increased incidence of adult cardiovascular disease. Endothelial dysfunction and high levels of serum uric acid are associated with hypertension. In this study, we have determined whether uric acid is related to blood pressure and vascular function in children with low birth weight. We evaluated vascular function using high-resolution ultrasound, blood pressure, and uric acid levels in 78 children (35 girls, 43 boys, aged 8 to 13 years). Increasing levels of uric acid and systolic blood pressure were observed in children with low birth weight. Birth weight was inversely associated with both systolic blood pressure and uric acid; on the other hand, uric acid levels were directly correlated with systolic blood pressure in children of the entire cohort. Low birth weight was associated with reduced flow-mediated dilation (r=0.427, P<0.001). Because the children with low birth weight had elevated uric acid as well as higher systolic blood pressure levels, we evaluated the correlation between these variables. In the low birth weight group, multiple regression analysis revealed that uric acid (beta=-2.886; SE=1.393; P=0.040) had a graded inverse relationship with flow-mediated dilation, which was not affected in a model adjusting for race and gender. We conclude that children with a history of low birth weight show impaired endothelial function and increased blood pressure and uric acid levels. These findings may be early expressions of vascular compromise, contributing to susceptibility to disease in adult life. PMID:16682609

  8. A common non-synonymous variant in GLUT9 is a determinant of serum uric acid levels in Old Order Amish

    PubMed Central

    McArdle, Patrick F.; Parsa, Afshin; Chang, Yen-Pei C.; Weir, Matthew R.; O'Connell, Jeffery R.; Mitchell, Braxton D.; Shuldiner, Alan R.

    2009-01-01

    Objective Uric acid is the primary end product of purine metabolism. Increased serum uric acid has been associated with gouty arthritis as well as with a variety of cardiovascular related phenotypes. Methods A 500,000 SNP genome wide association study of serum uric acid levels was performed in a cohort of Old Order Amish from Lancaster County, Pennsylvania. Results The scan confirmed a previously identified region on chromosome 4 to be strongly associated with uric acid levels (p = 4.2×10−11 for rs10489070). Follow-up genotyping revealed a non-synonymous coding SNP (Val253Ile; rs16890979) in GLUT9 that was most strongly associated with uric acid levels, with each copy of the minor allele associated with 0.47 mg/dl less uric acid (95% confidence interval: 0.31 − 0.63; p = 1.43 × 10−11). The effect of this variant tended to be stronger in women than in men (p = 0.16 for sex × genotype interaction). The genotypic effect was not modified by the inclusion of several cardiovascular risk factors suggesting that GLUT9 is directly related to uric acid homeostasis. The same SNP (rs10489070) identified in the Amish genome wide scan was significantly associated with gout in the Framingham Heart Study (p = 0.004). Conclusions We conclude that GLUT9, which is expressed in the kidney may be a novel regulator of uric acid elimination and a common non-synonymous variant in this gene contributes to abnormalities in uric acid homeostasis and gout. PMID:18759275

  9. 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

  10. Spectroscopic analyses and studies on respective interaction of cyanuric acid and uric acid with bovine serum albumin and melamine

    NASA Astrophysics Data System (ADS)

    Chen, Dandan; Wu, Qiong; Wang, Jun; Wang, Qi; Qiao, Heng

    2015-01-01

    In this work, the fluorescence quenching was used to study the interaction of cyanuric acid (CYA) and uric acid (UA) with bovine serum albumin (BSA) at two different temperatures (283 K and 310 K). The bimolecular quenching constant (Kq), apparent quenching constant (Ksv), effective binding constant (KA) and corresponding dissociation constant (KD), binding site number (n) and binding distance (r) were calculated by adopting Stern-Volmer, Lineweaver-Burk, Double logarithm and overlap integral equations. The results show that CYA and UA are both able to obviously bind to BSA, but the binding strength order is BSA + CYA < BSA + UA. And then, the interactions of CYA and UA with melamine (MEL) under the same conditions were also studied by using similar methods. The results indicates that both CYA and UA can bind together closely with melamine (MEL). It is wished that these research results would facilitate the understanding the formation of kidney stones and gout in the body after ingesting excess MEL.

  11. PEDOT-Au nanocomposite films for electrochemical sensing of dopamine and uric acid.

    PubMed

    Mathiyarasu, J; Senthilkumar, S; Phani, K L N; Yegnaraman, V

    2007-06-01

    In this work, conducting polymer impregnated gold nanoparticles are synthesized through a sequence of chemical and electrochemical routes. The nanocomposite film is characterized using UV-vis, FTIR spectroscopy, and SEM techniques to study the formation of oxidized PEDOT and Au0. The advantages of these films are demonstrated for sensing biologically important compounds such as dopamine and uric acid in presence of excess ascorbic acid, one of the major interferants in the detection of DA and UA (mimicking the physiological conditions), with superior selectivity and sensitivity when compared to the polymer film alone. Simultaneous determination is realized at 115 mV and 246 mV for DA and UA, respectively. The PEDOT matrix is recognized to be responsible for the peak separation (selectivity) while also favouring catalytic oxidation of the above compounds and the nanometer-sized gold particles allow nanomolar sensing of DA and UA (sensitivity). Thus, it is possible to detect nanomolar levels of DA and UA in presence of excess of AA. The combined effect of Au nanoparticles and the PEDOT matrix is rationalized that the Aunano surrounded by a "hydrophobic sheath (PEDOT)" tending to reside within these hydrophobic regions of PEDOT, thus favouring the selectivity and sensitivity of the DA/UA detection. This new generation of nanocomposites is expected to enhance the value of electroanalytical techniques, as it is possible to tune their properties suiting the analytical needs.

  12. Uric Acid Induces Hepatic Steatosis by Generation of Mitochondrial Oxidative Stress

    PubMed Central

    Lanaspa, Miguel A.; Sanchez-Lozada, Laura G.; Choi, Yea-Jin; Cicerchi, Christina; Kanbay, Mehmet; Roncal-Jimenez, Carlos A.; Ishimoto, Takuji; Li, Nanxing; Marek, George; Duranay, Murat; Schreiner, George; Rodriguez-Iturbe, Bernardo; Nakagawa, Takahiko; Kang, Duk-Hee; Sautin, Yuri Y.; Johnson, Richard J.

    2012-01-01

    Metabolic syndrome represents a collection of abnormalities that includes fatty liver, and it currently affects one-third of the United States population and has become a major health concern worldwide. Fructose intake, primarily from added sugars in soft drinks, can induce fatty liver in animals and is epidemiologically associated with nonalcoholic fatty liver disease in humans. Fructose is considered lipogenic due to its ability to generate triglycerides as a direct consequence of the metabolism of the fructose molecule. Here, we show that fructose also stimulates triglyceride synthesis via a purine-degrading pathway that is triggered from the rapid phosphorylation of fructose by fructokinase. Generated AMP enters into the purine degradation pathway through the activation of AMP deaminase resulting in uric acid production and the generation of mitochondrial oxidants. Mitochondrial oxidative stress results in the inhibition of aconitase in the Krebs cycle, resulting in the accumulation of citrate and the stimulation of ATP citrate lyase and fatty-acid synthase leading to de novo lipogeneis. These studies provide new insights into the pathogenesis of hepatic fat accumulation under normal and diseased states. PMID:23035112

  13. Analysis of ABCG2 and other urate transporters in uric acid homeostasis in chronic kidney disease: potential role of remote sensing and signaling

    PubMed Central

    Bhatnagar, Vibha; Richard, Erin L.; Wu, Wei; Nievergelt, Caroline M.; Lipkowitz, Michael S.; Jeff, Janina; Maihofer, Adam X.; Nigam, Sanjay K.

    2016-01-01

    Background In the setting of chronic kidney disease (CKD), altered extra-renal urate handling may be necessary to regulate plasma uric acid. The Remote Sensing and Signaling Hypothesis (Nigam S. What do drug transporters really do? Nat Rev Drug Discov 2015; 14: 29–44) suggests that multispecific solute carrier (SLC) and ATP-binding cassette (ABC) drug transporters in different tissues are part of an inter-organ communication system that maintains levels of urate and other metabolites after organ injury. Methods Data from the Chronic Renal Insufficiency Cohort (CRIC; n = 3598) were used to study associations between serum uric acid and single nucleotide polymorphisms (SNPs) on the following uric acid transporters: ABCG2 (BRCP), SLC22A6 (OAT1), SLC22A8 (OAT3), SLC22A10 (OAT5), SLC22A11 (OAT4), SLC22A12 (URAT1), SLC22A13 (OAT10), SLC17A1-A3 (NPTs), SLC2A9 (GLUT9), ABCC2 (MRP2) and ABCC4 (MRP4). Regression models, controlling for principal components age, gender and renal function, were run separately for those of European (EA) and African ancestry (AA), and P-values corrected for multiple comparisons. A twin cohort with participants of EA and normal renal function was used for comparison. Results Among those of EA in CRIC, statistically significant signals were observed for SNPs in ABCG2 (rs4148157; beta-coefficient = 0.68; P = 4.78E-13) and SNPs in SLC2A9 (rs13125646; beta-coefficient = −0.30; P = 1.06E-5). Among those of AA, the strongest (but not statistically significant) signals were observed for SNPs in SLC2A9, followed by SNPs in ABCG2. In the twin study (normal renal function), only SNPs in SLC2A9 were significant (rs4481233; beta-coefficient=−0.45; P = 7.0E-6). In CRIC, weaker associations were also found for SLC17A3 (NPT4) and gender-specific associations found for SLC22A8 (OAT3), SLC22A11 (OAT4), and ABCC4 (MRP4). Conclusions In patients of EA with CKD (CRIC cohort), we found striking associations between uric acid and SNPs on ABCG2, a key transporter

  14. Serum Uric Acid and Its Association with Longitudinal Cognitive Change Among Urban Adults.

    PubMed

    Beydoun, May A; Canas, Jose-Atilio; Dore, Gregory A; Beydoun, Hind A; Rostant, Ola S; Fanelli-Kuczmarski, Marie T; Evans, Michele K; Zonderman, Alan B

    2016-04-21

    Uric acid, a waste metabolite among humans, was linked to various cognitive outcomes. We describe sex and age-group specific associations of baseline serum uric acid (SUAbase) and significant change in SUA (ΔSUA: 1 versus 0 = decrease versus no change; 2 versus 0 = increase versus no change) with longitudinal annual rate of cognitive change among a large sample of urban adults. Data from the Healthy Aging in Neighborhoods of Diversity across the Life Span study, 2004-2009 (visit 1) and 2009-2013 (visit 2) were used. Of 3,720 adults selected at baseline (age range: 30-64 y), complete data were available for N = 1,487-1,602 with a mean repeat of 1.5-1.7 visits/participant. Cognitive test domains spanned attention, processing speed, learning/memory, executive function, visuo-spatial/visuo-construction ability, language/verbal, and global cognitive function. SUA was measured at both visits. Multiple mixed-effects regression analyses were conducted. In the total population, a higher SUAbase was associated with a faster annual rate of decline on a measure of visual memory/visuo-construction ability (the Benton Visual Retention Test) by γ= 0.07 with a standard error of 0.02, p < 0.001. Among older men, a significant increase in SUA was associated with slower decline on a test of attention/processing speed, namely Trailmaking test, Part A, measured in seconds to completion (γ= -6.91 ± 1.73, p < 0.001). In sum, a higher SUAbase was associated with faster cognitive decline over-time in a visual memory/visuo-construction ability test. ΔSUA had particular beneficial effects of an increasing ΔSUA on the domain of attention/processing speed among older men. More longitudinal studies are needed to examine cognitive domain-specific effects of over-time change in SUA within sex and age groups. PMID:27104899

  15. Conductimetric Biosensor for the Detection of Uric Acid by Immobilization Uricase on Nata de Coco Membrane—Pt Electrode

    PubMed Central

    Mulyasuryani, Ani; Srihardiastutie, Arie

    2011-01-01

    A conductimetric enzyme biosensor for uric acid detection has been developed. The uricase, as enzyme, is isolated from Candida utilis and immobilized on a nata de coco membrane-Pt electrode. The biosensor demonstrates a linear response to urate over the concentration range 1–6 ppm and has good selectivity properties. The response is affected by the membrane thickness and pH change in the range 7.5–9.5. The response time is three minutes in aqueous solutions and in human serum samples. Application of the biosensor to the determination of uric acid in human serum gave results that compared favourably with those obtained by medical laboratory. The operational stability of the biosensor was not less than three days and the relative error is smaller than 10%. PMID:21792276

  16. Conductimetric biosensor for the detection of uric Acid by immobilization uricase on nata de coco membrane-pt electrode.

    PubMed

    Mulyasuryani, Ani; Srihardiastutie, Arie

    2011-01-01

    A conductimetric enzyme biosensor for uric acid detection has been developed. The uricase, as enzyme, is isolated from Candida utilis and immobilized on a nata de coco membrane-Pt electrode. The biosensor demonstrates a linear response to urate over the concentration range 1-6 ppm and has good selectivity properties. The response is affected by the membrane thickness and pH change in the range 7.5-9.5. The response time is three minutes in aqueous solutions and in human serum samples. Application of the biosensor to the determination of uric acid in human serum gave results that compared favourably with those obtained by medical laboratory. The operational stability of the biosensor was not less than three days and the relative error is smaller than 10%.

  17. Uric acid and transforming growth factor in fructose-induced production of reactive oxygen species in skeletal muscle.

    PubMed

    Madlala, Hlengiwe P; Maarman, Gerald J; Ojuka, Edward

    2016-04-01

    The consumption of fructose, a major constituent of the modern diet, has raised increasing concern about the effects of fructose on health. Research suggests that excessive intake of fructose (>50 g/d) causes hyperuricemia, insulin resistance, mitochondrial dysfunction, de novo lipogenesis by the liver, and increased production of reactive oxygen species (ROS) in muscle. In a number of tissues, uric acid has been shown to stimulate the production of ROS via activation of transforming growth factor β1 and NADPH (nicotinamide adenine dinucleotide phosphate) oxidase 4. The role of uric acid in fructose-induced production of ROS in skeletal muscle, however, has not been investigated. This review examines the evidence for fructose-induced production of ROS in skeletal muscle, highlights proposed mechanisms, and identifies gaps in current knowledge.

  18. Hypouricemic effect of allopurinol are improved by Pallidifloside D based on the uric acid metabolism enzymes PRPS, HGPRT and PRPPAT.

    PubMed

    Li, Hong-Gang; Hou, Pi-Yong; Zhang, Xi; He, Yi; Zhang, Jun; Wang, Shu-Qing; Anderson, Samantha; Zhang, Yan-Wen; Wu, Xiao-Hui

    2016-09-01

    Allopurinol is a commonly used medication to treat hyperuricemia and its complications. Pallidifloside D, a saponin glycoside constituent from the total saponins of Smilax riparia, had been proved to enhanced hypouricemic effect of allopurinol based on uric acid metabolism enzyme XOD. In this study, we evaluated whether Pallidifloside D (5mg/kg) enhanced hypouricemic effect of allopurinol (5mg/kg) related to others uric acid metabolism enzymes such as PRPS, HGPRT and PRPPAT. We found that, compared with allopurinol alone, the combination of allopurinol and Pallidifloside D significantly up-regulated HGPRT mRNA expression and down-regulated the mRNA expression of PRPS and PRPPAT in PC12 cells (all P<0.01). These results strongly suggest that hypouricemic effect of allopurinol are improved by Pallidifloside D via numerous mechanisms and our data may have a potential value in clinical practice in the treatment of gout and other hyperuricemic conditions. PMID:27370097

  19. Uric acid and transforming growth factor in fructose-induced production of reactive oxygen species in skeletal muscle.

    PubMed

    Madlala, Hlengiwe P; Maarman, Gerald J; Ojuka, Edward

    2016-04-01

    The consumption of fructose, a major constituent of the modern diet, has raised increasing concern about the effects of fructose on health. Research suggests that excessive intake of fructose (>50 g/d) causes hyperuricemia, insulin resistance, mitochondrial dysfunction, de novo lipogenesis by the liver, and increased production of reactive oxygen species (ROS) in muscle. In a number of tissues, uric acid has been shown to stimulate the production of ROS via activation of transforming growth factor β1 and NADPH (nicotinamide adenine dinucleotide phosphate) oxidase 4. The role of uric acid in fructose-induced production of ROS in skeletal muscle, however, has not been investigated. This review examines the evidence for fructose-induced production of ROS in skeletal muscle, highlights proposed mechanisms, and identifies gaps in current knowledge. PMID:26946251

  20. Serum uric acid correlates in elderly men and women with special reference to body composition and dietary intake (Dutch Nutrition Surveillance System).

    PubMed

    Loenen, H M; Eshuis, H; Löwik, M R; Schouten, E G; Hulshof, K F; Odink, J; Kok, F J

    1990-01-01

    In 460 apparently healthy Dutch elderly, aged 65-79 years, serum uric acid correlates were studied by linear regression analyses, for men and women separately. Diuretic therapy, total serum cholesterol (women only) and creatinine clearance (in bivariate analysis only) were significantly associated with serum uric acid level. Positive associations of serum uric acid with body weight, body mass index, body fatness (men) and lean body mass (men) were observed, with and without adjustment for diuretic therapy, creatinine clearance and age. Serum uric acid levels, whether adjusted or not for these variables and for body mass index, were positively associated with alcohol intake (men) and consumption of meat and fish (women), and inversely with consumption of bread, margarine and milk products (women). These results indicate that limited medication with diuretics, weight control and restriction of alcohol use may help to prevent hyperuricemia in the elderly.

  1. 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.

  2. 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.

  3. 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. PMID:27628060

  4. The facile surface chemical modification of a single glass nanopore and its use in the nonenzymatic detection of uric acid.

    PubMed

    He, Haili; Xu, Xiaolong; Wang, Ping; Chen, Lizhen; Jin, Yongdong

    2015-02-01

    A conical glass nanopore was first modified with ultrathin gold nanofilm via a simple and innovative chemical reduction of HAuCl4 on a surface-attached poly(L-histidine) monolayer in the presence of a mild reductant, NH2OH·HCl, followed by surface functionalization with 2-thiouracil, and exploited for the selective nonenzymatic detection of uric acid and especially for serum sample detection. PMID:25531580

  5. One-step electrochemical synthesis of ultrathin graphitic carbon nitride nanosheets and their application to the detection of uric acid.

    PubMed

    Lu, Qiujun; Deng, Jianhui; Hou, Yuxin; Wang, Haiyan; Li, Haitao; Zhang, Youyu

    2015-08-01

    Ultrathin graphitic carbon nitride nanosheets (g-C3N4) with a thickness of about 2 nm were synthesized by a one-step electrochemical method for the first time. The possible mechanism of the electrochemical synthesis was discussed. This as-synthesized g-C3N4 showed intrinsic peroxidase-like activity and was successfully applied for the detection of uric acid.

  6. Evaluation of postmortem urea nitrogen, creatinine and uric acid levels in pericardial fluid in forensic autopsy.

    PubMed

    Zhu, Bao-Li; Ishikawa, Takaki; Michiue, Tomomi; Li, Dong-Ri; Zhao, Dong; Quan, Li; Maeda, Hitoshi

    2005-10-01

    In postmortem biochemistry, there is insufficient data available for the practical analysis of factors in the pericardial fluid. The aim of the present study was to examine postmortem pericardial fluid for urea nitrogen (UN), creatinine (Cr) and uric acid (UA) levels to investigate the pathophysiology of death in forensic autopsy cases (total, n = 409; within 48 h postmortem), which included blunt, sharp instrument injury, asphyxiation, drowning, fire fatalities, hyperthermia, hypothermia, methamphetamine-related fatalities, other poisoning, delayed death from trauma and natural diseases. There was a significant elevation in the three markers for chronic renal failure, gastrointestinal bleeding, hyperthermia, hypothermia, methamphetamine fatalities and delayed traumatic death, which was comparable with the clinical criteria for their serum levels. These postmortem findings showed azotemia due to renal failure, elevated protein catabolism and rhabdomyolysis. Although the pericardial levels were otherwise similar to the clinical serum reference ranges, only the drowning fatalities showed significantly lower levels for each marker. These observations suggested the stability of UN, Cr and UA in the pericardial fluid within 48 h postmortem and their usefulness for the pathophysiological investigation of death involving azotemia.

  7. Lonicera hypoglauca inhibits xanthine oxidase and reduces serum uric acid in mice.

    PubMed

    Chien, Shih-Chang; Yang, Chen-Wei; Tseng, Yen-Hsueh; Tsay, Hsin-Sheng; Kuo, Yueh-Hsiung; Wang, Sheng-Yang

    2009-03-01

    Xanthine oxidase (XOD) catalyzes the oxidation of hypoxanthine to xanthine and then to uric acid, and is a key enzyme in the pathogenesis of hyperuricemia. The ability of extracts of Lonicera hypoglauca (Caprifoliaceae) to inhibit XOD was investigated in this study. An ethanol extract (LH-crude) of the leaves of L. hypoglauca and its derived EtOAc soluble sub-fractions (LH-EA) significantly inhibited XOD activity, with IC50 values for LH-crude and LH-EA of 48.8 and 35.2 microg/mL. Moreover, LH-EA reduced serum urate levels IN VIVO in a potassium oxonate-induced hyperuricemic mouse model, by 70.1% and 93.7% of the hyperuricemic untreated group at doses of 300 and 500 mg/kg of LH-EA, respectively. Finally, we used bioactivity-guided fractionation to isolate a new bisflavonoid, loniceraflavone, which showed significant inhibition of XOD (IC50=0.85 microg/mL). These results suggest that L. hypoglauca and its extracts may have a considerable potential for development as an anti-hyperuricemia agent for clinical application.

  8. Fungal Community Associated with Dactylopius (Hemiptera: Coccoidea: Dactylopiidae) and Its Role in Uric Acid Metabolism.

    PubMed

    Vera-Ponce de León, Arturo; Sanchez-Flores, Alejandro; Rosenblueth, Mónica; Martínez-Romero, Esperanza

    2016-01-01

    We studied fungal species associated with the carmine cochineal Dactylopius coccus and other non-domesticated Dactylopius species using culture-dependent and -independent methods. Thirty seven fungi were isolated in various culture media from insect males and females from different developmental stages and Dactylopius species. 26S rRNA genes and ITS sequences, from cultured fungal isolates revealed different species of Cryptococcus, Rhodotorula, Debaryomyces, Trametes, and Penicillium, which are genera newly associated with Dactylopius. Uric acid (UA) and uricase activity were detected in tissues extracts from different insect developmental stages. However, accumulation of high UA levels and low uricase activities were found only after antifungal treatments, suggesting an important role of fungal species in its metabolism. Additionally, uricolytic fungal isolates were identified and characterized that presumably are involved in nitrogen recycling metabolism. After metagenomic analyses from D. coccus gut and hemolymph DNA and from two published data sets, we confirmed the presence of fungal genes involved in UA catabolism, suggesting that fungi help in the nitrogen recycling process in Dactylopius by uricolysis. All these results show the importance of fungal communities in scale insects such as Dactylopius. PMID:27446001

  9. Fungal Community Associated with Dactylopius (Hemiptera: Coccoidea: Dactylopiidae) and Its Role in Uric Acid Metabolism

    PubMed Central

    Vera-Ponce de León, Arturo; Sanchez-Flores, Alejandro; Rosenblueth, Mónica; Martínez-Romero, Esperanza

    2016-01-01

    We studied fungal species associated with the carmine cochineal Dactylopius coccus and other non-domesticated Dactylopius species using culture-dependent and -independent methods. Thirty seven fungi were isolated in various culture media from insect males and females from different developmental stages and Dactylopius species. 26S rRNA genes and ITS sequences, from cultured fungal isolates revealed different species of Cryptococcus, Rhodotorula, Debaryomyces, Trametes, and Penicillium, which are genera newly associated with Dactylopius. Uric acid (UA) and uricase activity were detected in tissues extracts from different insect developmental stages. However, accumulation of high UA levels and low uricase activities were found only after antifungal treatments, suggesting an important role of fungal species in its metabolism. Additionally, uricolytic fungal isolates were identified and characterized that presumably are involved in nitrogen recycling metabolism. After metagenomic analyses from D. coccus gut and hemolymph DNA and from two published data sets, we confirmed the presence of fungal genes involved in UA catabolism, suggesting that fungi help in the nitrogen recycling process in Dactylopius by uricolysis. All these results show the importance of fungal communities in scale insects such as Dactylopius. PMID:27446001

  10. Serum Uric Acid Predicts Progression of Subclinical Coronary Atherosclerosis in Individuals Without Renal Disease

    PubMed Central

    Rodrigues, Ticiana C.; Maahs, David M.; Johnson, Richard J.; Jalal, Diana I.; Kinney, Gregory L.; Rivard, Christopher; Rewers, Marian; Snell-Bergeon, Janet K.

    2010-01-01

    OBJECTIVE To examine uric acid (UA) as a possible predictor of the progression of coronary artery calcification (CAC) using data from the prospective Coronary Artery Calcification in Type 1 Diabetes (CACTI) Study. RESEARCH DESIGN AND METHODS CAC was measured by electron beam tomography at the baseline and at a follow-up 6.0 ± 0.5 years later. The study population included 443 participants with type 1 diabetes and 526 control subjects who were free of diagnosed coronary artery disease at baseline. The presence of renal disease was defined by the presence of albuminuria and/or low glomerular filtration rate. RESULTS In subjects without renal disease, serum UA predicted CAC progression (odds ratio 1.30 [95% CI 1.07–1.58], P = 0.007) independent of conventional cardiovascular risk factors including diabetes and the presence of metabolic syndrome. CONCLUSIONS Serum UA levels predict the progression of coronary atherosclerosis and may be useful in identifying who is at risk for vascular disease in the absence of significant chronic kidney disease. PMID:20798338

  11. Uric acid enhances the antitumor immunity of dendritic cell-based vaccine.

    PubMed

    Wang, Yihan; Ma, Xuelei; Su, Chao; Peng, Bin; Du, Jing; Jia, Hongyuan; Luo, Min; Fang, Chunju; Wei, Yuquan

    2015-01-01

    Uric acid (UA) released from dying cells has been recognized by the immune system as a danger signal. In response to UA, dendritic cells (DC) in the immune system mature and enhance the T cell response to foreign antigens. It is conceivable that the antitumor immunity of a tumor vaccine could be promoted by the administration of UA. To test this concept, we applied UA as an adjuvant to a DC-based vaccine, and discovered that the administration of UA as an adjuvant significantly enhanced the ability of the tumor lysate-pulsed DC vaccine in delaying the tumor growth. The antitumor activity was achieved with adoptively transferred lymphocytes, and both CD8(+) T cells and NK cells were required to achieve effective immunity. This resulted in an increased accumulation of activated CD8(+) T cells and an elevated production of IFN-γ. Collectively, our study shows that the administration of UA enhances the antitumor activity of tumor lysate-pulsed DC vaccine, thus providing the preclinical rationale for the application of UA in DC-based vaccine strategies.

  12. Fungal Community Associated with Dactylopius (Hemiptera: Coccoidea: Dactylopiidae) and Its Role in Uric Acid Metabolism.

    PubMed

    Vera-Ponce de León, Arturo; Sanchez-Flores, Alejandro; Rosenblueth, Mónica; Martínez-Romero, Esperanza

    2016-01-01

    We studied fungal species associated with the carmine cochineal Dactylopius coccus and other non-domesticated Dactylopius species using culture-dependent and -independent methods. Thirty seven fungi were isolated in various culture media from insect males and females from different developmental stages and Dactylopius species. 26S rRNA genes and ITS sequences, from cultured fungal isolates revealed different species of Cryptococcus, Rhodotorula, Debaryomyces, Trametes, and Penicillium, which are genera newly associated with Dactylopius. Uric acid (UA) and uricase activity were detected in tissues extracts from different insect developmental stages. However, accumulation of high UA levels and low uricase activities were found only after antifungal treatments, suggesting an important role of fungal species in its metabolism. Additionally, uricolytic fungal isolates were identified and characterized that presumably are involved in nitrogen recycling metabolism. After metagenomic analyses from D. coccus gut and hemolymph DNA and from two published data sets, we confirmed the presence of fungal genes involved in UA catabolism, suggesting that fungi help in the nitrogen recycling process in Dactylopius by uricolysis. All these results show the importance of fungal communities in scale insects such as Dactylopius.

  13. The Relationship between Uric Acid Levels and Huntington’s Disease Progression

    PubMed Central

    Auinger, Peggy; Kieburtz, Karl; McDermott, Michael P.

    2009-01-01

    Uric acid (UA) may be associated with the progression of Parkinson’s disease and related neurodegenerative conditions; however, its association with Huntington’s disease (HD) progression has not been explored. A secondary analysis of 347 subjects from the CARE-HD clinical trial was performed to examine the relationship between baseline UA levels and the level of functional decline in HD. Outcomes included change in scores at 30 months for the Unified Huntington’s Disease Rating Scale components. There was less worsening of total functional capacity over time with increasing baseline UA levels (adjusted mean worsening in scores: 3.17, 2.99, 2.95, 2.28, 2.21, from lowest to highest UA quintile, p=0.03). These data suggest a possible association between higher UA levels and slower HD progression, particularly as measured by total functional capacity. If confirmed, UA could be an important predictor and potentially modifiable factor affecting the rate of HD progression. PMID:20063429

  14. Role of Serum Uric Acid and Ferritin in the Development and Progression of NAFLD

    PubMed Central

    Lombardi, Rosa; Pisano, Giuseppina; Fargion, Silvia

    2016-01-01

    Nonalcoholic fatty liver disease (NAFLD), tightly linked to the metabolic syndrome (MS), has emerged as a leading cause of chronic liver disease worldwide. Since it is potentially progressive towards non-alcoholic steatohepatitis (NASH) and hepatic fibrosis, up to cirrhosis and its associated complications, the need for predictive factors of NAFLD and of its advanced forms is mandatory. Despite the current “gold standard” for the assessment of liver damage in NAFLD being liver biopsy, in recent years, several non-invasive tools have been designed as alternatives to histology, of which fibroscan seems the most promising. Among the different serum markers considered, serum uric acid (SUA) and ferritin have emerged as possible predictors of severity of liver damage in NAFLD. In fact, as widely described in this review, they share common pathogenetic pathways and are both associated with hepatic steatosis and MS, thus suggesting a likely synergistic action. Nevertheless, the power of these serum markers seems to be too low if considered alone, suggesting that they should be included in a wider perspective together with other metabolic and biochemical parameters in order to predict liver damage. PMID:27077854

  15. Amperometric uric acid biosensor based on poly(vinylferrocene)-gelatin-carboxylated multiwalled carbon nanotube modified glassy carbon electrode.

    PubMed

    Erden, Pınar Esra; Kaçar, Ceren; Öztürk, Funda; Kılıç, Esma

    2015-03-01

    In this study, a new uric acid biosensor was constructed based on ferrocene containing polymer poly(vinylferrocene) (PVF), carboxylated multiwalled carbon nanotubes (c-MWCNT) and gelatin (GEL) modified glassy carbon electrode (GCE). Uricase enzyme (UOx) was immobilized covalently through N-ethyl-N'-(3-dimethyaminopropyl) carbodiimide (EDC) and N-hydroxyl succinimide (NHS) chemistry onto c-MWCNT/GEL/PVF/GCE. The c-MWCNT/GEL/PVF composite was characterized by scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. Various experimental parameters such as pH, applied potential, enzyme loading, PVF and c-MWCNT concentration were investigated in detail. Under the optimal conditions the dynamic linear range of uric acid was 2.0×10(-7) M-7.1×10(-4) M (R=0.9993) with the detection limit low to 2.3×10(-8) M. With good selectivity and sensitivity, the biosensor was successfully applied to determine the uric acid in human serum. The results of the biosensor were in good agreement with those obtained from standard method. Therefore, the presented biosensor could be a good promise for practical applications in real samples.

  16. Uric Acid Induces Trophoblast Il-1β Production Via The Inflammasome: Implications For The Pathogenesis Of Preeclampsia

    PubMed Central

    Mulla, Melissa J.; Myrtolli, Kledia; Potter, Julie; Boeras, Crina; Kavathas, Paula B.; Sfakianaki, Anna K.; Tadesse, Serkelem; Norwitz, Errol R.; Guller, Seth; Abrahams, Vikki M.

    2010-01-01

    Problem Preeclampsia is associated with hyperuricemia, which correlates with the disease severity. Levels of circulating uric acid increase before the clinical manifestations, suggesting they may be causally related. Uric acid, or monosodium urate (MSU), activates the Nod-like receptor, Nalp3, leading to inflammasome activation and IL-1β processing. Since preeclampsia is associated with placental immune/inflammatory dysregulation, we sought to determine in the trophoblast, the presence of the Nalp3 inflammasome, and the effect of MSU on its activation. Method of Study Isolated first and third trimester trophoblast were assessed for expression of the inflammasome components, Nalp1, Nalp3 and ASC. First trimester trophoblast cells were incubated with or without MSU, after which, IL-1β secretion and processing and caspase-1 activation was determined. Results Trophoblast cells expressed Nalp1, Nalp3 and ASC under basal conditions. Following incubation with MSU, first trimester trophoblast IL-1β secretion was upregulated. This correlated with increased expression levels of active IL-1β and active caspase-1. ASC knockdown reduced MSU-induced IL-1β secretion. Conclusion These findings demonstrate that uric acid activates the inflammasome in the trophoblast, leading to IL-1β production. This may provide a novel mechanism for the induction of inflammation at the maternal-fetal interface leading to placental dysfunction and adverse pregnancy outcome, including preeclampsia. PMID:21352397

  17. Fructose containing sugars do not raise blood pressure or uric acid at normal levels of human consumption.

    PubMed

    Angelopoulos, Theodore J; Lowndes, Joshua; Sinnett, Stephanie; Rippe, James M

    2015-02-01

    The impact of fructose, commonly consumed with sugars by humans, on blood pressure and uric acid has yet to be defined. A total of 267 weight-stable participants drank sugar-sweetened milk every day for 10 weeks as part of their usual, mixed-nutrient diet. Groups 1 and 2 had 9% estimated caloric intake from fructose or glucose, respectively, added to milk. Groups 3 and 4 had 18% of estimated caloric intake from high fructose corn syrup or sucrose, respectively, added to the milk. Blood pressure and uric acid were determined prior to and after the 10-week intervention. There was no effect of sugar type on either blood pressure or uric acid (interaction P>.05), and a significant time effect for blood pressure was noted (P<.05). The authors conclude that 10 weeks of consumption of fructose at the 50th percentile level, whether consumed as pure fructose or with fructose-glucose-containing sugars, does not promote hyperuricemia or increase blood pressure. PMID:25496265

  18. Mechanism and kinetics of electrochemical degradation of uric acid using conductive-diamond anodes.

    PubMed

    Dbira, Sondos; Bensalah, Nasr; Bedoui, Ahmed

    2016-12-01

    Uric acid (UA) is one of the principal effluents of urine wastewaters, widely used in agriculture as fertilizer, which is potentially dangerous and biorefractory. Hence, the degradation of UA (2,6,8-trihydroxy purine) in aqueous solution of pH 3.0 has been studied by conductive-diamond electrochemical oxidation. Hydroxyl radicals formed from water oxidation at the surface of boron-doped diamond anodes were the main oxidizing agents. Effects of current density and supporting electrolyte on the degradation rate and process efficiency are assessed. Results show that the increase of current density from 20 to 60 mA cm(-2) leads to a decrease in the efficiency of the electrochemical process. In addition, the best degradation occurred in the presence of NaCl as conductive electrolyte. Interestingly, an almost total mineralization of 50 ppm UA was obtained when anodic oxidation was performed at low current densities (20 mA cm(-2)) and in the presence of NaCl. This result confirmed that the electrolysis using diamond anodes is a very interesting technology for the treatment of UA. The identification of UA transformation products was performed by high-performance liquid chromatography (HPLC). HPLC analysis of treated solutions revealed that oxalic acid and urea were the two intermediates found. Oxalic acid was the most persistent product. Based on detected intermediates and bibliographic research, a mechanism of UA mineralization by anodic oxidation has been proposed. Ionic chromatography analysis confirmed the release of [Formula: see text] and [Formula: see text] ions during UA mineralization. PMID:27108970

  19. Mechanism and kinetics of electrochemical degradation of uric acid using conductive-diamond anodes.

    PubMed

    Dbira, Sondos; Bensalah, Nasr; Bedoui, Ahmed

    2016-12-01

    Uric acid (UA) is one of the principal effluents of urine wastewaters, widely used in agriculture as fertilizer, which is potentially dangerous and biorefractory. Hence, the degradation of UA (2,6,8-trihydroxy purine) in aqueous solution of pH 3.0 has been studied by conductive-diamond electrochemical oxidation. Hydroxyl radicals formed from water oxidation at the surface of boron-doped diamond anodes were the main oxidizing agents. Effects of current density and supporting electrolyte on the degradation rate and process efficiency are assessed. Results show that the increase of current density from 20 to 60 mA cm(-2) leads to a decrease in the efficiency of the electrochemical process. In addition, the best degradation occurred in the presence of NaCl as conductive electrolyte. Interestingly, an almost total mineralization of 50 ppm UA was obtained when anodic oxidation was performed at low current densities (20 mA cm(-2)) and in the presence of NaCl. This result confirmed that the electrolysis using diamond anodes is a very interesting technology for the treatment of UA. The identification of UA transformation products was performed by high-performance liquid chromatography (HPLC). HPLC analysis of treated solutions revealed that oxalic acid and urea were the two intermediates found. Oxalic acid was the most persistent product. Based on detected intermediates and bibliographic research, a mechanism of UA mineralization by anodic oxidation has been proposed. Ionic chromatography analysis confirmed the release of [Formula: see text] and [Formula: see text] ions during UA mineralization.

  20. Upconversion ratiometric fluorescence and colorimetric dual-readout assay for uric acid.

    PubMed

    Fang, Aijin; Wu, Qiongqiong; Lu, Qiujun; Chen, Hongyu; Li, Haitao; Liu, Meiling; Zhang, Youyu; Yao, Shouzhuo

    2016-12-15

    A new upconversion colorimetric and ratiometric fluorescence detection method for uric acid (UA) has been designed. Yb(3+), Er(3+) and Tm(3+) co-doped NaYF4 nanoparticles (UCNPs) was synthesized. The co-doped NaYF4 nanoparticles, emit upconversion fluorescence with four typical emission peaks centered at 490nm, 557nm, 670nm and 705nm under the 980nm near-infrared (NIR) irradiation. The ZnFe2O4 magnetic nanoparticles (MNPs) possessing excellent peroxidase-like activity was prepared and used to catalyze oxidation the coupling of N-ethyl-N-(3-sulfopropyl)-3-methylaniline sodium salt (TOPS) and 4-amino-antipyrine (4-AAP) in the presence of H2O2 to form purple products (compound 1) which has a characteristic absorption peak located at 550nm. The upconversion fluorescence at 557nm was quenched by the compound 1 while the upconversion emission at 705nm was essentially unchanged, the fluorescence ratio ((I557/I705)0/(I557/I705)) is positively proportional to UA concentration in existence of uricase. More importantly, colorimetric signal can be easily observed and applied to directly distinguish the concentration of UA by the naked eye. Under the optimized conditions, the linear range of colorimetric and ratiometric fluorescence sensing towards UA was 0.01-1mM, the detection limits were as low as 5.79μM and 2.86μM (S/N=3), respectively. The proposed method has been successfully applied to the analysis of UA in human serum. These results indicate that the colorimetric and ratiometric fluorescence dual-readout assay method has great potential for applications in physiological and pathological diagnosis. PMID:27471157

  1. Controlling serum uric acid using febuxostat in cancer patients at risk of tumor lysis syndrome.

    PubMed

    Takai, Mihoko; Yamauchi, Takahiro; Fujita, Kei; Lee, Shin; Ookura, Miyuki; Kishi, Shinji; Urasaki, Yoshimasa; Yoshida, Akira; Iwasaki, Hiromichi; Ueda, Takanori

    2014-10-01

    Tumor lysis syndrome (TLS) is a life-threatening oncological emergency, in which control of serum uric acid (S-UA) levels is important. S-UA-lowering efficacy of a new xanthine oxidase inhibitor, febuxostat, was retrospectively evaluated in seven patients with hematological malignancies who were at an intermediate risk of developing TLS. A 10-mg dose of febuxostat was initiated and chemotherapy was started within 24 h of administering the first dose of febuxostat. Febuxostat was continued until at least day 7 of chemotherapy treatment. The UA-lowering treatment was considered effective if febuxostat reduced S-UA levels to ≤7.5 mg/dl by day 5. The mean S-UA level at base line was 6.4±2.6 mg/dl and, on day 5, the mean S-UA level was 4.7±1.8 mg/dl. All the patients achieved S-UA levels ≤7.5 mg/dl. Serum creatinine levels decreased from 0.93±0.25 to 0.85±0.25 mg/dl. The estimated glomerular filtration rate values increased from 69.7±24.5 to 76.9±26.2 ml/min. No adverse reactions were noted during the study period and no patients experienced progressive TLS. Successful control of S-UA and improved renal function were obtained in response to febuxostat treatment in cancer patients at a risk of TLS.

  2. Association between Serum Uric Acid and Elevated Alanine Aminotransferase in the General Population

    PubMed Central

    Chen, Shuang; Guo, Xiaofan; Yu, Shasha; Sun, Guozhe; Yang, Hongmei; Li, Zhao; Sun, Yingxian

    2016-01-01

    Background: Both the serum uric acid (SUA) level and elevated alanine aminotransferase (ALT) are related to metabolic syndrome. However, the association between SUA and elevated ALT has not been elucidated in the general population. The objective of this study was to investigate the association between SUA and elevated ALT in the general population of China; Methods: A total of 11,572 adults (≥35 years of age) participated in this survey. Elevated ALT was defined as >40 U/L. SUA ≥ 7.0 mg/dL in males or ≥6.0 mg/dL in females was defined as hyperuricemia. SUA within the reference range was divided into quartiles, and its associations with elevated ALT were evaluated by logistic regressions; Results: A total of 7.4% participants had elevated ALT. The prevalence of hyperuricemia was 14.9% in males and 7.3% in females. There was a significantly positive dose-response association between SUA levels and the prevalence of elevated ALT. After adjusting for potential confounders, a positive relationship for elevated ALT was observed in subjects with hyperuricemia (odds ratio [OR]: 2.032, 95% confidence interval [CI]: 1.443–2.861 for men; OR: 2.045, 95% CI: 1.221–3.425 for women, both p < 0.05). Within the reference range, the association between SUA and elevated ALT persisted in the fourth quartile (OR: 1.467, 95% CI: 1.063–2.025 for men; OR: 1.721, 95% CI: 1.146–2.585 for women, both p < 0.05); Conclusions: Our results indicated that an increased SUA level, even within the reference range, was independently associated with elevated ALT in Chinese adults. PMID:27563918

  3. Serum uric acid and insulin sensitivity in adolescents and adults with and without type 1 diabetes

    PubMed Central

    Bjornstad, Petter; Snell-Bergeon, Janet K.; McFann, Kimberly; Wadwa, R. Paul; Rewers, Marian; Rivard, Christopher J.; Jalal, Diana; Chonchol, Michel B.; Johnson, Richard J.; Maahs, David M.

    2014-01-01

    Hypothesis Decreased insulin sensitivity (IS) exists in type 1 diabetes. Serum uric acid (SUA), whose concentration is related to renal clearance, predicts vascular complications in type 1 diabetes. SUA is also inversely associated with IS in non-diabetics, but has not been examined in type 1 diabetes. We hypothesized SUA would be associated with reduced IS in adolescents and adults with type 1 diabetes. Methods The cross-sectional and longitudinal associations of SUA with IS was investigated in 254 adolescents with type 1 diabetes and 70 without in the Determinants of Macrovascular Disease in Adolescents with Type 1 Diabetes Study, and in 471 adults with type 1 diabetes and 571 without in the Coronary Artery Calcification in Type 1 diabetes (CACTI) study. Results SUA was lower in subjects with type 1 diabetes (p<0.0001), but still remained inversely associated with IS after multivariable adjustments- in adolescents (β±SE: −1.99±0.62, p=0.001, R2=2%) and adults (β±SE:−0.91±0.33, p=0.006, R2=6%) with type 1 diabetes, though less strongly than in non-diabetic controls (adolescents: β±SE: −2.70±1.19, p=0.03, R2=15%, adults: β±SE:−5.99±0.75, p<0.0001, R2=39%). Conclusion We demonstrated a significantly weaker relationship between SUA and reduced IS in subjects with type 1 diabetes than non-diabetic controls. PMID:24461546

  4. Serum Uric Acid Is Positively Associated with Handgrip Strength among Japanese Community-Dwelling Elderly Women.

    PubMed

    Kawamoto, Ryuichi; Ninomiya, Daisuke; Kasai, Yoshihisa; Kusunoki, Tomo; Ohtsuka, Nobuyuki; Kumagi, Teru; Abe, Masanori

    2016-01-01

    Serum uric acid (UA) has strong anti-oxidant properties. Muscle strength and mass decrease with age, and recently, this decrease has been defined as sarcopenia. Sarcopenia may be triggered by oxidative stress. We investigated whether serum UA is associated with handgrip strength (HGS), which is a useful indicator of sarcopenia, among Japanese community-dwelling elderly persons. The present study included 602 men aged 72 ± 7 years and 847 women aged 71 ± 6 years from a rural village. We examined the cross-sectional relationship between serum UA and HGS. In both genders, HGS increased significantly with increased serum UA levels. A multiple linear regression analysis using HGS as an objective variable and various confounding factors as explanatory variables showed that in men age, drinking status, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and estimated glomerular filtration ratio (eGFRCKDEPI) were independently and significantly associated with HGS, and in women, serum UA as well as age, body mass index, drinking status, diastolic blood pressure, and eGFRCKDEPI were independently and significantly associated with HGS. In women, age and multivariate-adjusted HGS were significantly higher in the Quartile-3 (4.8-5.4 mg/dL) and Quartile-4 groups (5.5-9.3 mg/dL) of serum UA than in the lower groups (0.7-4.7 mg/dL). These results suggest that serum UA may have a protective role in aging-associated decline in muscle strength in community-dwelling elderly women. PMID:27078883

  5. Lower Serum Bilirubin and Uric Acid Concentrations in Patients with Parkinson's Disease in China.

    PubMed

    Qin, Xiao-Ling; Zhang, Qing-Shan; Sun, Li; Hao, Meng-Wei; Hu, Zhao-Ting

    2015-05-01

    The objective of the study is to investigate the correlation between bilirubin and uric acid (UA) concentrations and symptoms of Parkinson's disease (PD) in Chinese population. A total of 425 PD patients and 460 controls were included in the current study. Patients were diagnosed by a neurologist and assessed using the Hoehn & Yahr (H&Y) scale. Venous blood samples were collected, and bilirubin and UA concentrations were analyzed. Compared to controls, indirect bilirubin (IBIL) and UA concentrations were lower in PD patients (P IBIL = 0.015, P UA = 0.000). Serum IBIL in different age subgroups and H&Y stage subgroups were also lower compared to the control group (P IBIL = 0.000, P UA = 0.000) but were not significantly different among these subgroups. Females in the control group had significantly lower serum IBIL and UA concentrations than males (P IBIL = 0.000, P UA = 0.000) and the PD group (P IBIL = 0.027, P UA = 0.000). In early PD (patients with <2-year medical history and no treatment), serum IBIL and UA concentrations were also lower than the controls (P IBIL = 0.013, P UA = 0.000). Although IBIL concentration was positively correlated with UA concentration in controls (R IBIL = 0.229, P IBIL = 0.004), this positive association was not observed in the PD group (R IBIL = -0.032, P IBIL = 0.724). Decreased levels of serum IBIL and UA were observed in PD patients. It is possible that individuals with decreased serum bilirubin and UA concentrations lack the endogenous defense system to prevent peroxynitrite and other free radicals from damaging and destroying dopaminergic cells in the substantia nigra. Our results provide a basis for further investigation into the role of bilirubin in PD.

  6. Serum Uric Acid Is Positively Associated with Handgrip Strength among Japanese Community-Dwelling Elderly Women

    PubMed Central

    Kawamoto, Ryuichi; Ninomiya, Daisuke; Kasai, Yoshihisa; Kusunoki, Tomo; Ohtsuka, Nobuyuki; Kumagi, Teru; Abe, Masanori

    2016-01-01

    Serum uric acid (UA) has strong anti-oxidant properties. Muscle strength and mass decrease with age, and recently, this decrease has been defined as sarcopenia. Sarcopenia may be triggered by oxidative stress. We investigated whether serum UA is associated with handgrip strength (HGS), which is a useful indicator of sarcopenia, among Japanese community-dwelling elderly persons. The present study included 602 men aged 72 ± 7 years and 847 women aged 71 ± 6 years from a rural village. We examined the cross-sectional relationship between serum UA and HGS. In both genders, HGS increased significantly with increased serum UA levels. A multiple linear regression analysis using HGS as an objective variable and various confounding factors as explanatory variables showed that in men age, drinking status, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and estimated glomerular filtration ratio (eGFRCKDEPI) were independently and significantly associated with HGS, and in women, serum UA as well as age, body mass index, drinking status, diastolic blood pressure, and eGFRCKDEPI were independently and significantly associated with HGS. In women, age and multivariate-adjusted HGS were significantly higher in the Quartile-3 (4.8–5.4 mg/dL) and Quartile-4 groups (5.5–9.3 mg/dL) of serum UA than in the lower groups (0.7–4.7 mg/dL). These results suggest that serum UA may have a protective role in aging-associated decline in muscle strength in community-dwelling elderly women. PMID:27078883

  7. Influence of Salt Intake on Association of Blood Uric Acid with Hypertension and Related Cardiovascular Risk

    PubMed Central

    Hou, Lei; Zhang, Mingtao; Han, Wei; Tang, Yong; Xue, Fang; Liang, Shaohua; Zhang, Biao; Wang, Weizhi; Asaiti, Kuliqian; Wang, Yanhong; Pang, Haiyu; Wang, Zixing; Wang, Yuyan; Qiu, Changchun; Jiang, Jingmei

    2016-01-01

    Background A relationship of blood uric acid (UA) with hypertension and cardiovascular risk is under debate thus salt intake is hypothesized to contribute to such associations. Methods In this cross-sectional study, stratified cluster random sampling elicited a sample of 1805 Kazakhs with 92.4% compliance. Hypertension and moderate-or-high total cardiovascular risk (mTCR) were defined according to guidelines. Sodium intake was assessed by urinary sodium excretion. Prevalence ratios (PRs) were used to express associations of UA with hypertension and mTCR. Results In the highest tertile of sodium intake in women, the adjusted PRs (95% confidence intervals) of low to high quartiles compared with the lowest quartile of UA, were 1.22(0.78–1.91), 1.18(0.75–1.85), and 1.65(1.09–2.51) for hypertension and 1.19(0.74–1.90), 1.39(0.91–2.11), and 1.65(1.10–2.47) for mTCR (P for trend <0.05). However, these findings were not shown for other sodium intake levels. There were similar results in men. PRs markedly increased with a concomitant increase in UA and sodium intake and there was a significant interaction (P = 0.010) for mTCR with PRs of 1.69(1.10–2.60) for men and 3.70(2.09–6.52) for women in those with the highest compared with the lowest quartile of UA and tertile of sodium intake. Similar findings were shown for hypertension. Conclusions This study implied that a high salt intake may enhance the associations of UA with hypertension and cardiovascular risk. PMID:27042828

  8. Uric acid in relapsing-remitting multiple sclerosis: a 2-year longitudinal study.

    PubMed

    Moccia, Marcello; Lanzillo, Roberta; Costabile, Teresa; Russo, Cinzia; Carotenuto, Antonio; Sasso, Gabriella; Postiglione, Emanuela; De Luca Picione, Carla; Vastola, Michele; Maniscalco, Giorgia Teresa; Palladino, Raffaele; Brescia Morra, Vincenzo

    2015-01-01

    Uric acid (UA) is reduced in multiple sclerosis (MS), and possibly relates to MS outcomes, with lower UA levels in subjects experiencing a relapse or presenting higher disability scores. The present retrospective longitudinal study evaluated UA variations in MS, in relation to clinical relapses, disability progression, and cognitive functions. We included 141 subjects with relapsing-remitting MS (RRMS) and performed expanded disability status scale (EDSS), symbol digit modalities test (SDMT) and UA evaluation at baseline visit and after 2-year follow-up. Paired t test showed significantly lower UA levels after 2-year follow-up than at baseline (3.987 ± 1.135 and 4.167 ± 1.207 mg/dL, respectively) (p = 0.001). The difference in UA levels between 2-year follow-up and baseline related to EDSS sustained progression (p < 0.001; OR = 0.099), and presented a trend for clinical relapses at logistic regression (p = 0.211; OR = 0.711) and for the time to relapse at Cox regression (p = 0.236; HR = 0.792). Analysis of variance showed reduced baseline UA levels in subjects with impaired SDMT at baseline (p = 0.045; adjusted R(2) = 0.473) and after 2-year follow-up (p = 0.034; adjusted R(2) = 0.470). This is the first study showing a progressive reduction of UA levels during the course of RRMS, suggesting a progressive decrease of antioxidant reserves, in relation to relapse risk, disability progression and cognitive function. PMID:25673130

  9. ABCG2 dysfunction increases serum uric acid by decreased intestinal urate excretion.

    PubMed

    Takada, Tappei; Ichida, Kimiyoshi; Matsuo, Hirotaka; Nakayama, Akiyoshi; Murakami, Keizo; Yamanashi, Yoshihide; Kasuga, Hiroshi; Shinomiya, Nariyoshi; Suzuki, Hiroshi

    2014-01-01

    ATP-binding cassette transporter G2 (ABCG2), also known as breast cancer resistance protein (BCRP), is identified as a high-capacity urate exporter and its dysfunction has an association with serum uric acid (SUA) levels and gout/hyperuricemia risk. However, pathophysiologically important pathway(s) responsible for the ABCG2-mediated urate excretion were unknown. In this study, we investigated how ABCG2 dysfunction affected the urate excretion pathways. First, we revealed that mouse Abcg2 mediates urate transport using the membrane vesicle system. The export process by mouse Abcg2 was ATP-dependent and not saturable under the physiological concentration of urate. Then, we characterized the excretion of urate into urine, bile, and intestinal lumen using in vivo mouse model. SUA of Abcg2-knockout mice was significantly higher than that of control mice. Under this condition, the renal urate excretion was increased in Abcg2-knockout mice, whereas the urate excretion from the intestine was decreased to less than a half. Biliary urate excretion showed no significant difference regardless of Abcg2 genotype. From these results, we estimated the relative contribution of each pathway to total urate excretion; in wild-type mice, the renal excretion pathway contributes approximately two-thirds, the intestinal excretion pathway contributes one-third of the total urate excretion, and the urate excretion into bile is minor. Decreased intestinal excretion could account for the increased SUA of Abcg2-knockout mice. Thus, ABCG2 is suggested to have an important role in extra-renal urate excretion, especially in intestinal excretion. Accordingly, increased SUA in patients with ABCG2 dysfunction could be explained by the decreased excretion of urate from the intestine.

  10. Serum Uric Acid Predicts Declining of Circulating Proangiogenic Mononuclear Progenitor Cells in Chronic Heart Failure Patients

    PubMed Central

    Berezin, Alexander E.; Kremzer, Alexander A.; Samura, Tatyana A.; Berezina, Tatyana A.; Martovitskaya, Yulia V.

    2014-01-01

    Introduction: Serum uric acid (SUA) is considered a marker for natural progression of chronic heart failure (CHF) mediated cardiovascular remodelling. CHF associates with declining of circulating mononuclear progenitor cells (MPCs). The objective of this study was to evaluate the interrelationship between SUA concentrations and proangiogenic MPCs in ischemic CHF patients. Methods: The study population was structured retrospectively after determining the coronary artery disease (CAD) by contrast-enhanced spiral computed tomography angiography in 126 subjects with symptomatic ischemic mild-to-severe CHF and 128 CAD subjects without CHF. Baseline biomarkers were measured in all patients. Cox proportional multivariate hazard ratio was calculated for predictors of MPCs declining in both CHF and non-CHF patient population predictors of MPCs declining in CHF subjects were examined in stepwise logistic regression. C-statistics, integrated discrimination indices (IDI) and net-reclassification improvement were utilized for prediction performance analyses. Results: Cox proportional adjusted hazard ratio analyses for CD14+CD309+ and CD14+CD309+Tie2+ MPCs by SUA has shown that the higher quartiles (Q3 and Q4) of SUA compared to the lower quartiles (Q1 and Q2) are associated with increased risks of depletion of both CD14+CD309+ and CD14+CD309+Tie2+ MPCs. The addition of Q4 SUA to the ABC model improved the relative IDI by 13.8% for depletion of CD14+CD309+ MPCs and by 14.5% for depletion of CD14+CD309+Tie2+ MPCs. Conclusion: Circulating levels of proangiogenic MPCs are declined progressively depending on the levels of SUA in the HF subjects with CHF. We suggest that even mild elevations of SUA might be used to predict of relative depletion of proangiogenic MPCs among chronic HF patients. PMID:25320662

  11. Metabolic danger signals, uric acid and ATP, mediate inflammatory cross-talk between hepatocytes and immune cells in alcoholic liver disease.

    PubMed

    Petrasek, Jan; Iracheta-Vellve, Arvin; Saha, Banishree; Satishchandran, Abhishek; Kodys, Karen; Fitzgerald, Katherine A; Kurt-Jones, Evelyn A; Szabo, Gyongyi

    2015-08-01

    Inflammation defines the progression of ALD from reversible to advanced stages. Translocation of bacterial LPS to the liver from the gut is necessary for alcohol-induced liver inflammation. However, it is not known whether endogenous, metabolic danger signals are required for inflammation in ALD. Uric acid and ATP, 2 major proinflammatory danger signals, were evaluated in the serum of human volunteers exposed to a single dose of ethanol or in supernatants of primary human hepatocytes exposed to ethanol. In vitro studies were used to evaluate the role of uric acid and ATP in inflammatory cross-talk between hepatocytes and immune cells. The significance of signaling downstream of uric acid and ATP in the liver was evaluated in NLRP3-deficient mice fed a Lieber-DeCarli ethanol diet. Exposure of healthy human volunteers to a single dose of ethanol resulted in increased serum levels of uric acid and ATP. In vitro, we identified hepatocytes as a significant source of these endogenous inflammatory signals. Uric acid and ATP mediated a paracrine inflammatory cross-talk between damaged hepatocytes and immune cells and significantly increased the expression of LPS-inducible cytokines, IL-1β and TNF-α, by immune cells. Deficiency of NLRP3, a ligand-sensing component of the inflammasome recognizing uric acid and ATP, prevented the development of alcohol-induced liver inflammation in mice and significantly ameliorated liver damage and steatosis. Endogenous metabolic danger signals, uric acid, and ATP are involved in inflammatory cross-talk between hepatocytes and immune cells and play a crucial role in alcohol-induced liver inflammation.

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

    PubMed Central

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

    2016-01-01

    Using starch as the carbon precursor and different-sized ZnO naoparticles as the hard template, a series of porous carbon materials for electrochemical sensing were prepared. Experiments of scanning electron microscopy, transmission electron microscopy and Nitrogen adsorption-desorption isotherms reveal that the particle size of ZnO has big impacts on the porous morphology and surface area of the resulting carbon materials. Through ultrasonic dispersion of porous carbon and subsequent solvent evaporation, different sensing interfaces were constructed on the surface of glassy carbon electrode (GCE). The electrochemical behaviors of ascorbic acid (AA), dopamine (DA) and uric acid (UA) were studied. On the surface of porous carbon materials, the accumulation efficiency and electron transfer ability of AA, DA and UA are improved, and consequently their oxidation signals enhance greatly. Moreover, the interface enhancement effects of porous carbon are also controlled by the particle size of hard template. The constructed porous carbon interface displays strong signal amplification ability and holds great promise in constructing a sensitive platform for the simultaneous determination of AA, DA and UA. PMID:26924080

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

    PubMed

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

    2011-06-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

  15. Vitamin C, uric acid, and glutathione gradients in murine stratum corneum and their susceptibility to ozone exposure.

    PubMed

    Weber, S U; Thiele, J J; Cross, C E; Packer, L

    1999-12-01

    The stratum corneum has been recognized as the main cutaneous oxidation target of atmospheric ozone (O3), a major part of photochemical smog. This study reports the presence and distribution of vitamin C, glutathione, and uric acid in murine stratum corneum, and evaluates their susceptibility to acute environmental exposure to O3. Based on tape stripping and a modified extraction method with high performance liquid chromatography electrochemical analysis, we detected vitamin C (208.0 +/- 82.5 pmol per 10 consecutive pooled tapes), glutathione (283.7 +/-96.3), and uric acid (286.4 +/-47.1) in murine stratum corneum as compared with only 16.5 +/- 1.4 pmol alpha-tocopherol. Vitamin C, glutathione (both p < 00.001), and urate (p < 0.01) were found to exhibit a gradient with the lowest concentrations in the outer layers and a steep increase in the deeper layers. To investigate the effect of O3 exposure on hydrophilic antioxidants, we exposed SKH-1 hairless mice to O3 concentrations of 0, 0.8, 1, and 10 p.p.m., and stratum corneum was analyzed before and after exposure. Whereas mock exposure with 0 p.p. m. for 2 h had no significant effect, O3 doses of 1 p.p.m. for 2 h and above showed depletion of all three antioxidants. Vitamin C was decreased to 80% +/- 15% of its pretreatment content (p < 0.05), GSH to 41% +/- 24% (p < 0.01), and uric acid to 44% +/- 28% (p < 0.01). This report demonstrates the previously unrecognized role of hydrophilic antioxidants in the stratum corneum and provides further evidence that O3 induces oxidative stress in this outer skin layer.

  16. Protective effect of iridoid glycosides from Paederia scandens (LOUR.) MERRILL (Rubiaceae) on uric acid nephropathy rats induced by yeast and potassium oxonate.

    PubMed

    Hou, Shi-xiang; Zhu, Wen-jing; Pang, Ming-qun; Jeffry, Joseph; Zhou, Lan-lan

    2014-02-01

    Iridoid glycosides of Paederia scandens (IGPS) are an active component isolated from Chinese herb P. scandens (LOUR.) MERRILL (Rubiaceae). Uric acid nephropathy (UAN) is caused by excessive uric acid, which results in damage of kidney tissue via urate crystals deposition in the kidneys. This study aimed to investigate the protective effects of IGPS on UAN in rats induced by yeast and potassium oxonate. Treatment groups received different doses of IGPS and allopurinol (AP) daily for 35 days respectively. The results showed that treatment with IGPS significantly prevented the increases of uric acid in serum and the elevation of systolic blood pressure (SBP), attenuated renal tissue injury, improved renal function and reserved the biological activity of NOS-1. IGPS also inhibited the biological activity of TNF-α and TGF-β1, and suppressed the mRNA expressions of TNF-α and TGF-β1 in renal tissue. Taken together, the present and our previous findings suggest that IGPS exerts protective effects against kidney damage in UAN rats through its uric acid-lowering, anti-inflammatory and immunomodulatory properties. Furthermore, decreasing SBP by up regulation of NOS-1 expression and down regulation of TNF-α and TGF-β1 expression are involved in the effect of IGPS on high uric acid-induced nephropathy. PMID:24287205

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

    PubMed

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

    2015-01-01

    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.

  18. Relation of Lipid Content of Coronary Plaque to Level of Serum Uric Acid.

    PubMed

    Saito, Yuichi; Nakayama, Takashi; Sugimoto, Kazumasa; Fujimoto, Yoshihide; Kobayashi, Yoshio

    2015-11-01

    Elevated serum uric acid (SUA) level is known to be a prognostic factor in patients with acute coronary syndrome (ACS). However, the pathogenesis of the relation between SUA level and coronary plaque characteristics has not been fully evaluated. The aim of this study was to investigate the relation between SUA level and plaque composition of nonculprit lesions in patients with ACS. A total of 81 patients with ACS who underwent intravascular ultrasound (IVUS)-guided percutaneous coronary intervention were included. They were classified into 3 groups according to tertiles of SUA level. Using integrated backscatter (IB)-IVUS system, tissue components were classified into 4 categories: calcium deposits, dense fibrosis, fibrosis, and lipid. Tertiles of SUA level were as follows: low tertile <5.0 mg/dl; intermediate tertile 5.0 to 6.4 mg/dl; and high tertile >6.4 mg/dl. There was a trend toward greater vessel volume in the high tertile group than in the low and intermediate tertile groups (19.4 ± 3.7 vs 17.4 ± 4.4 vs 16.7 ± 4.1 mm(3)/mm, p = 0.05). There was no significant difference in lumen volume between the 3 groups. Plaque volume was significantly greater in the high than in the low tertile group (8.6 ± 2.4 vs 6.7 ± 2.2 mm(3)/mm, p = 0.01). IB-IVUS analysis demonstrated greater lipid (59.1 ± 9.1% vs 49.7 ± 10.9% vs 51.1 ± 9.3%, p = 0.001) and less fibrous components (36.8 ± 7.8% vs 44.3 ± 7.8% vs 43.2 ± 6.7%, p <0.001) in the high than in the low and intermediate tertile groups. Multivariate analysis showed high SUA as an independent predictor of increasing lipid volume. In conclusion, elevated SUA level is associated with greater lipid content of coronary plaque in patients with ACS than in patients with normal levels.

  19. Serum uric acid and subsequent cognitive performance in patients with pre-existing cardiovascular disease.

    PubMed

    Molshatzki, Noa; Weinstein, Galit; Streifler, Jonathan Y; Goldbourt, Uri; Tanne, David

    2015-01-01

    High serum uric acid (UA) levels are associated with numerous vascular risk factors, and vascular disease, that predispose patients to cognitive impairment, yet UA is also a major natural antioxidant and higher levels have been linked to slower progression of several neurodegenerative disease. In-order to test the association between UA and subsequent cognitive performance among patients that carry a high vascular burden, UA levels were determined by calorimetric enzymatic tests in a sub-cohort of patients with chronic cardiovascular disease who previously participating in a secondary prevention trial. After an average of 9.8±1.7 years, we assessed cognitive performance (Neurotrax Computerized Cognitive Battery) as well as cerebrovascular reactivity (CVR) and common carotid intima-media thickness (IMT). Among 446 men (mean age 62.3±6.4 yrs) mean UA levels were 5.8±1.1 mg/dL. Adjusted linear regression models revealed that low UA levels (bottom quintile) were associated with poorer cognitive performance. Adjusted differences between the bottom quintile and grouped top UA quintiles were (B coefficient±SE) -4.23±1.28 for global cognitive scores (p = 0.001), -4.69±1.81 for memory scores (p = 0.010), -3.32±1.43 for executive scores (p = 0.020) and -3.43±1.97 for visual spatial scores (p = 0.082). Significant difference was also found for attention scores (p = 0.015). Additional adjustment for impaired CVR and high common carotid IMT slightly attenuated the relationship. Stronger UA effect on cognitive performance was found for older (age>65) patients with significant age interaction for global cognitive score (p = 0.016) and for executive (p = 0.018) and attention domains (p<0.001). In conclusion, we demonstrate that low UA levels in patients with preexisting cardiovascular disease are associated with poorer cognitive function a decade later. These findings lend support to the hypothesis that oxidative stress may be involved in the pathogenesis of age

  20. Diclofenac toxicity in Gyps vulture is associated with decreased uric acid excretion and not renal portal vasoconstriction.

    PubMed

    Naidoo, V; Swan, G E

    2009-04-01

    Diclofenac (DF), a non-steroidal anti-inflammatory drug (NSAID), is largely regarded as one of the most devastating environmental toxicant in recent times, after accidental exposure via their food-chain lead to massive mortalities in three vulture species on the Asian subcontinent. Although the use of diclofenac was recently banned on the Indian subcontinent, following the favourable safety profile of meloxicam, its mechanism of toxicity remains unknown. In an attempt to establish this mechanism, we test three hypotheses using models established from either the domestic chicken (Gallus domesticus) or the African White-backed vulture (Gyps africanus). We demonstrate that both DF and meloxicam are toxic to renal tubular epithelial (RTE) cells following 12 h of exposure, due to an increase in production of reactive oxygen species (ROS), which could be temporarily ameliorated by pre-incubation with uric acid (UA). When cultures were incubated with either drug for only 2 h, meloxicam showed no toxicity in contrast to diclofenac. In both cases no increase in ROS production was evident. In addition, diclofenac decreased the transport of uric acid, by interfering with the p-amino-hippuric acid (PAH) channel. We conclude that vulture susceptibility to diclofenac results from a combination of an increased ROS, interference with UA transport and the duration of exposure.

  1. Uric Acid and Coronary Artery Disease, Two Sides of a Single Coin: A Determinant of Antioxidant System or a Factor in Metabolic Syndrome

    PubMed Central

    Bagheri, Babak; Zargari, Mehryar; Meshkini, Fatemeh; Dinarvand, Kolsoum; Mokhberi, Vahid; Azizi, Soheil

    2016-01-01

    Introduction Uric acid has antioxidant activity and it is expected to protect against coronary artery disease (CAD). Contradictory, it is a component of metabolic syndrome and so a risk factor for CAD. The associations of plasma total antioxidant capacity (TAOC) and uric acid (UA) as well as other risk factors were investigated relative to the occurrence and severity of CAD. Materials and Methods The study population consisted of 148 males and 152 females aged 35-76 years who were classified as CAD cases and controls according to the results of coronary angiography. The severity of CAD was scored on the basis of the number and the extent of lesions at coronary arteries. The concentrations of UA and TAOC were measured by using of FRAP and enzymatic uricase methods. Results The prevalence of hypertension, cigarette smoking and diabetes mellitus was more frequent in CAD cases than controls. Patients with CAD when compared with the controls had increased levels of glucose, triglycerides, creatinine, UA, TAOC and decreased levels of HDL- cholesterol. Serum UA was high positive correlate of serum total and LDL-cholesterol, triglyceride, creatinine, BUN, bilirubin, TAOC and negative correlate of glucose and HDL-C. TAOC and its major determinant UA but not bilirubin and albumin are significantly associated with the prevalence and severity of CAD. In multivariate analysis and in the absence of hypertension, UA but not TAOC would remain and be associated with CAD by the OR of 1.57 (1.07-2.29), p=0.02. If the results adjusted for all major risk factors including hypertension, neither TAOC nor UA would remain in the regression equation. Conclusion The results suggest that TAOC and UA but not bilirubin and albumin are associated with CAD significantly. But, the correlation is not independent and is attributed to the metabolic syndrome. The measurement of UA and TAOC will not improve the prognostic power beyond the classical risk factors. PMID:27042498

  2. 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

  3. ZnO-CuxO/polypyrrole nanocomposite modified electrode for simultaneous determination of ascorbic acid, dopamine, and uric acid.

    PubMed

    Ghanbari, Kh; Hajheidari, N

    2015-03-15

    Novel zinc oxide (ZnO) nanosheets and copper oxide (CuxO, CuO, and Cu2O) decorated polypyrrole (PPy) nanofibers (ZnO-CuxO-PPy) have been successfully fabricated for the simultaneous determination of ascorbic acid (AA), dopamine (DA), and uric acid (UA). The morphology and structure of ZnO-CuxO-PPy nanocomposites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. Compared with the bare glassy carbon electrode (GCE), PPy/GCE, CuxO-PPy/GCE, and ZnO-PPy/GCE, ZnO-CuxO-PPy/GCE exhibits much higher electrocatalytic activities toward the oxidation of AA, DA, and UA with increasing peak currents and decreasing oxidation overpotentials. Cyclic voltammetry (CV) results show that AA, DA, and UA could be detected selectively and sensitively at ZnO-CuxO-PPy/GCE with peak-to-peak separation of 150 and 154 mV for AA-DA and DA-UA, respectively. The calibration curves for AA, DA, and UA were obtained in the ranges of 0.2 to 1.0 mM, 0.1 to 130.0 μM, and 0.5 to 70.0 μM, respectively. The lowest detection limits (signal/noise=3) were 25.0, 0.04, and 0.2 μM for AA, DA, and UA, respectively. With good selectivity and sensitivity, the current method was applied to the determination of DA in injectable medicine and UA in urine samples.

  4. ZnO-CuxO/polypyrrole nanocomposite modified electrode for simultaneous determination of ascorbic acid, dopamine, and uric acid.

    PubMed

    Ghanbari, Kh; Hajheidari, N

    2015-03-15

    Novel zinc oxide (ZnO) nanosheets and copper oxide (CuxO, CuO, and Cu2O) decorated polypyrrole (PPy) nanofibers (ZnO-CuxO-PPy) have been successfully fabricated for the simultaneous determination of ascorbic acid (AA), dopamine (DA), and uric acid (UA). The morphology and structure of ZnO-CuxO-PPy nanocomposites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. Compared with the bare glassy carbon electrode (GCE), PPy/GCE, CuxO-PPy/GCE, and ZnO-PPy/GCE, ZnO-CuxO-PPy/GCE exhibits much higher electrocatalytic activities toward the oxidation of AA, DA, and UA with increasing peak currents and decreasing oxidation overpotentials. Cyclic voltammetry (CV) results show that AA, DA, and UA could be detected selectively and sensitively at ZnO-CuxO-PPy/GCE with peak-to-peak separation of 150 and 154 mV for AA-DA and DA-UA, respectively. The calibration curves for AA, DA, and UA were obtained in the ranges of 0.2 to 1.0 mM, 0.1 to 130.0 μM, and 0.5 to 70.0 μM, respectively. The lowest detection limits (signal/noise=3) were 25.0, 0.04, and 0.2 μM for AA, DA, and UA, respectively. With good selectivity and sensitivity, the current method was applied to the determination of DA in injectable medicine and UA in urine samples. PMID:25576954

  5. Urea, creatinine, uric acid, and phosphate spaces and their relationship to total body water during chronic hemodialysis

    SciTech Connect

    Ericsson, F.; Odar-Cederloef, I.E.; Eriksson, C.G.; Lindgren, S.; Kjellstrand, C.M.

    1988-07-01

    The authors determined total body water (TBW) with tritium in 11 patients on chronic hemodialysis and compared this space to that estimated by 60% of body weight, and removal spaces of urea, creatinine, uric acid, and phosphate (PO4). The latter spaces were determined by dividing the total amount of substance (measured in total dialysate) by pre- minus post-dialysis concentrations. Body water X 0.6 was more than 10% less than the tritium space, and showed a maximal variation of 10 liters, or 24%. The removal space of urea was 80% of the tritium space, but correlated closely with it. The difference between total body water and urea removal space was variable and dependent on fluid excess (edema) in the patients. Creatinine, uric acid, and phosphate removal spaces were highly variable and not correlated to total body water. The authors suggest that actual measured TBW should be used, rather than estimations using BW X 0.6, for V in K X T/V, where K = clearance, T = duration of dialysis, and V = the removal space of urea. Furthermore, one may need to introduce a correction factor for urea removal space over TBW in the equation to allow better quantification of dialysis in edematous patients and during very fast dialyses.

  6. Genome wide association study of uric acid in Indian population and interaction of identified variants with Type 2 diabetes.

    PubMed

    Giri, Anil K; Banerjee, Priyanka; Chakraborty, Shraddha; Kauser, Yasmeen; Undru, Aditya; Roy, Suki; Parekatt, Vaisak; Ghosh, Saurabh; Tandon, Nikhil; Bharadwaj, Dwaipayan

    2016-02-23

    Abnormal level of Serum Uric Acid (SUA) is an important marker and risk factor for complex diseases including Type 2 Diabetes. Since genetic determinant of uric acid in Indians is totally unexplored, we tried to identify common variants associated with SUA in Indians using Genome Wide Association Study (GWAS). Association of five known variants in SLC2A9 and SLC22A11 genes with SUA level in 4,834 normoglycemics (1,109 in discovery and 3,725 in validation phase) was revealed with different effect size in Indians compared to other major ethnic population of the world. Combined analysis of 1,077 T2DM subjects (772 in discovery and 305 in validation phase) and normoglycemics revealed additional GWAS signal in ABCG2 gene. Differences in effect sizes of ABCG2 and SLC2A9 gene variants were observed between normoglycemics and T2DM patients. We identified two novel variants near long non-coding RNA genes AL356739.1 and AC064865.1 with nearly genome wide significance level. Meta-analysis and in silico replication in 11,745 individuals from AUSTWIN consortium improved association for rs12206002 in AL356739.1 gene to sub-genome wide association level. Our results extends association of SLC2A9, SLC22A11 and ABCG2 genes with SUA level in Indians and enrich the assemblages of evidence for SUA level and T2DM interrelationship.

  7. Genome wide association study of uric acid in Indian population and interaction of identified variants with Type 2 diabetes

    PubMed Central

    Giri, Anil K; Banerjee, Priyanka; Chakraborty, Shraddha; Kauser, Yasmeen; Undru, Aditya; Roy, Suki; Parekatt, Vaisak; Ghosh, Saurabh; Tandon, Nikhil; Bharadwaj, Dwaipayan

    2016-01-01

    Abnormal level of Serum Uric Acid (SUA) is an important marker and risk factor for complex diseases including Type 2 Diabetes. Since genetic determinant of uric acid in Indians is totally unexplored, we tried to identify common variants associated with SUA in Indians using Genome Wide Association Study (GWAS). Association of five known variants in SLC2A9 and SLC22A11 genes with SUA level in 4,834 normoglycemics (1,109 in discovery and 3,725 in validation phase) was revealed with different effect size in Indians compared to other major ethnic population of the world. Combined analysis of 1,077 T2DM subjects (772 in discovery and 305 in validation phase) and normoglycemics revealed additional GWAS signal in ABCG2 gene. Differences in effect sizes of ABCG2 and SLC2A9 gene variants were observed between normoglycemics and T2DM patients. We identified two novel variants near long non-coding RNA genes AL356739.1 and AC064865.1 with nearly genome wide significance level. Meta-analysis and in silico replication in 11,745 individuals from AUSTWIN consortium improved association for rs12206002 in AL356739.1 gene to sub-genome wide association level. Our results extends association of SLC2A9, SLC22A11 and ABCG2 genes with SUA level in Indians and enrich the assemblages of evidence for SUA level and T2DM interrelationship. PMID:26902266

  8. Effects of acute exercise on the levels of iron, magnesium, and uric acid in liver and spleen tissues.

    PubMed

    Kaptanoğlu, B; Turgut, G; Genç, O; Enli, Y; Karabulut, I; Zencir, M; Turgut, S

    2003-02-01

    In this study, we investigated the effects of acute exercise on tissue levels of iron, magnesium, and uric acid of rats. Twenty adult Wistar albino rats were used for the study. They were divided into two groups: controls (n=10) and the study group (n=10). The study group was left into a small water pool and allowed to do swimming exercise for 30 min while controls rested. All of the animals were sacrificed, and their livers and spleens removed and homogenized immediately. The iron, magnesium, and uric acid levels of the homogenates were measured by an autoanalyzer (ILAB 900, Italy) with commercial kits from the same company. Results were evaluated by the Mann-Whitney U-test. According to our results, the liver iron levels increased significantly with exercise, whereas spleen iron levels decreased significantly (p<0.05) compared to controls. We found no significant differences in the levels of the other two parameters with exercise. These results show that the iron distribution in organs changes with exercise. PMID:12719612

  9. Development and validation of a simple determination of urine metabolites (oxalate, citrate, uric acid and creatinine) by capillary zone electrophoresis.

    PubMed

    Muñoz, Jose A; López-Mesas, Montserrat; Valiente, Manuel

    2010-04-15

    Oxalate, citrate, uric acid and creatinine are important urine markers for the evaluation and treatment of urolithiasic patients. They have been traditionally analysed by enzymatic and chromatographic techniques which present practical drawbacks, mainly in the sample pre-treatment step. The purpose of this study was to evaluate those markers in urine samples, by an easy multi-analyte assay using capillary zone electrophoresis. The four urine metabolites were determined, at 25 degrees C, by using a 50 cm x 75 microm capillary in 50 mmol l(-1) phosphate buffer (pH 6.5), at constant voltage of -30 kV and UV detection at 195 nm (for oxalate and citrate) or 30 kV and 234 nm (for creatinine and uric acid). The sample pre-treatment was minimum, 5- and 20-fold dilution of the urine sample and acidification to pH 3-4. Validation parameters (linear range, sensitivity, accuracy, precision and detection limits) were statistically comparable to those obtained with the official methods normally used in the clinical practice. The effect of freezing as a conservation method of urine samples is also discussed in terms of recoveries of the analytes. The analytical method developed is highly useful as a diagnostic tool for detecting metabolic renal disorders due to its simplicity, time consuming, easy automation, cost efficiency and analytical effectiveness, accomplishing with the clinical requirements.

  10. Use of immobilized enzymes in automated clinical analysis: determination of uric acid and glucose using immobilized enzymes in column form.

    PubMed

    Endo, J; Tabata, M; Okada, S; Murachi, T

    1979-07-16

    We studied the use of immobilized enzymes, covalently bound to alkylaminosilane derivative of porous glass, to automated clinical analysis on uric acid and glucose in blood, serum and urine. A microcolumn with an immobilized enzyme was prepared and used in an AutoAnalyzer I continuous flow system. Uricase (EC 1.7.3.3) from Candida utilis and glucose oxidase (EC 1.1.3.4) from Aspergillus niger were immobilized for the determination of uric acid and glucose, respectively. Hydrogen peroxide produced by these oxidases was colorimetrically determined using horse-radish peroxidase (EC 1.11.1.7) and a hydrogen acceptor in solution. Sensitivity and wash charactertistics of a column with immobilized enzyme, 1.5 mm of inner diameter and up to 40 mm in length, were satisfactory at an assay speed of 50 samples per hour. The results correlated well with those obtained by other well established methods utilizing the AutoAnalyzer system. The immobilized enzymes were sufficiently stable for at least two months of 2000 tests when used repeatedly. Clinical trials proved that this method is capable of replacing the soluble enzyme method, giving reliable and reproducible results at lower cost.

  11. 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.

  12. 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.

  13. Highly sensitive and selective uric acid biosensor based on a three-dimensional graphene foam/indium tin oxide glass electrode.

    PubMed

    Yue, Hong Yan; Zhang, Hong; Chang, Jing; Gao, Xin; Huang, Shuo; Yao, Long Hui; Lin, Xuan Yu; Guo, Er Jun

    2015-11-01

    A three-dimensional (3D) continuous and interconnected network graphene foam (GF) was synthesized by chemical vapor deposition using nickel foam as a template. The morphologies of the GF were observed by scanning electron microscopy. X-ray diffraction and Raman spectroscopy were used to investigate the structure of GF. The graphene with few layers and defect free was closely coated on the backbone of the 3D nickel foam. After etching nickel, the GF was transferred onto indium tin oxide (ITO) glass, which acted as an electrode to detect uric acid using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The GF/ITO electrode showed a high sensitivity for the detection of uric acid: approximately 9.44 mA mM(-1) in the range of 25 nM-0.1 μM and 1.85 mA mM(-1) in the range of 0.1-60 μM. The limit of detection of GF/ITO electrode for uric acid is 3 nM. The GF/ITO electrode also showed a high selectivity for the detection of uric acid in the presence of ascorbic acid. This electrode will have a wide range of potential application prospects in electrochemical detection.

  14. Urinary Uric Acid/Creatinine Ratio as a Marker of Mortality and Unfavorable Outcome in NICU-Admitted Neonates

    PubMed Central

    Nariman, Shahin; Mosayebi, Ziba; Sagheb, Setareh; Rastad, Hadith; Hosseininodeh, Seyyed Saeed

    2016-01-01

    Background The survival of neonates who have been admitted to the NICU, especially premature infants with few mortality and morbidity, is the most important attitude. Objectives We presumed whether urinary uric acid/creatinine (UUA/Cr) ratio can be a marker of mortality and adverse outcome in neonates which were admitted to the NICU. Patients and Methods All preterm infants admitted to our NICU after birth from March 2014 to April 2015 were enrolled in this prospective cohort study. UUA/Cr was measured during the first day of life. The severity of diseases (indicated by the need for high set-up of mechanical ventilation, complications of prematurity, and duration of stay in the NICU) and neonatal death were considered to be the final unfavorable outcomes. The relationship between the Log-transformation (Ln) urinary uric acid/creatinine ratio and the Apgar score at the first and 5th minute after birth and the duration of stay were analyzed by using linear regression. Statistical analysis was done by using STATA version 11 (STATA Corp, TX, USA). A P < 0.05 was considered to be statistically significant. Results A total of 362 preterm infants with a mean gestational age of 32.7 (± 3.9) weeks were admitted to the NICU, out of whom 64 (17.6%) had severe disease and 43 (11.8%) died. The mean UUA/Cr ratio was significantly higher in the admitted neonates (3.30 ± 1.95 vs. 1.36 ± 0.42. P = 0.0001). There was a negative correlation between the UUA/Cr ratio and the 1-minute Apgar score (r = -0.17, P = 0.006) and the 5-minute Apgar score (r = -0.19, P = 0.003). The 1-minute Apgar scores were negatively correlated with the outcome (OR = 0.68; P < 0.001) and the duration of stay (β = -.28; P < 0.001). There was no significant correlation between 5-minute Apgar scores and the outcome. There was a significant positive correlation between the UUA/Cr ratio and an unfavorable outcome (OR = 1.24; CI %95: 1.06 to 1.43, P = 0.006) and increasing duration of stay (β = 0.17; P = 0

  15. High Uric Acid (UA) Negatively Affects Serum Tartrate-Resistant Acid Phosphatase 5b (TRACP 5b) Immunoassay

    PubMed Central

    Wu, Zhi-Qi; Zhang, Yan; Xie, Erfu; Song, Wei-Juan; Yang, Rui-Xia; Yan, Cheng-Jing; Zhang, Bing-Feng; Xu, Hua-Guo

    2016-01-01

    Background Bone metastases often occur in the majority of patients with advanced cancer, such as prostate cancer, lung cancer and breast cancer. Serum tartrate-resistant acid phosphatase 5b (TRACP 5b), a novel bone resorption marker, has been used gradually in the clinics as a specific and sensitive marker of bone resorption for the early diagnosis of cancer patients with bone metastasis. Here, we reported that high concentrations of uric acid (UA) lead to decrease of TRACP 5b levels and determined whether TRACP 5b level was associated with UA in interference experiment. Methods A total of 77 patients with high concentrations of UA and 77 healthy subjects were tested to evaluate the differences in their TRACP 5b levels. Serial dilutions of UA were respectively spiked with a known concentration of TRACP 5b standard sample, then Serum TRACP 5b was detected by using bone TRAP® Assay. A correction equation was set to eliminate UA-derived TRACP 5b false-decrease. The effect of this correction was evaluated in high-UA individuals. Results The average TRACP level of the high-UA individuals (1.47± 0.62 U/L) was significantly lower than that of the healthy subjects (2.62 ± 0.63 U/L) (t-test, p<0.0001). The UA correction equation derived: ΔTRACP 5b = -1.9751lgΔUA + 3.7365 with an R2 = 0.98899. Application of the UA correction equation resulted in a statistically non-significant difference in TRACP 5b values between the healthy subjects and high-UA individuals (p = 0.24). Conclusions High UA concentrations can falsely decrease TRACP 5b levels due to a method-related systematic error. To avoid misdiagnoses or inappropriate therapeutic decisions, increased attention should be paid to UA interference, when TRACP 5b is used for early diagnosis of cancer patients with bone metastasis, evaluation of the aggressiveness of osteosarcoma or prediction of survival in prostate cancer and breast cancer with bone metastases. PMID:26800211

  16. The Role of Uric Acid and Methyl Derivatives in the Prevention of Age-Related Neurodegenerative Disorders.

    PubMed

    Cutler, Roy G; Camandola, Simonetta; Malott, Kelli F; Edelhauser, Maria A; Mattson, Mark P

    2015-01-01

    High uric acid (UA levels have been correlated with a reduced risk of many neurodegenerative diseases through mechanisms involving chelating Fenton reaction transitional metals, antioxidant quenching of superoxide and hydroxyl free radicals, and as an electron donor that increases antioxidant enzyme activity (e.g. SOD. However, the clinical usefulness of UA is limited by its' low water solubility and propensity to form inflammatory crystals at hyperuricemic levels. This review focuses on the role of UA in neuroprotection, as well as potential strategies aimed at increasing UA levels in the soluble range, and the potential therapeutic use of more water-soluble methyl-UA derivatives from the natural catabolic end-products of dietary caffeine, theophylline, and theobromine. PMID:26059354

  17. Electrochemical detection of uric acid using ruthenium-dioxide-coated carbon nanotube directly grown onto Si wafer

    NASA Astrophysics Data System (ADS)

    Shih, Yi-Ting; Lee, Kuei-Yi; Lin, Chung-Kuang

    2015-12-01

    Carbon nanotubes (CNTs) directly grown onto a Si substrate by thermal chemical vapor deposition were used in uric acid (UA) detection. The process is simple and formation is easy without the need for additional chemical treatments. However, CNTs lack selectivity and sensitivity to UA. To enhance the electrochemical analysis, ruthenium oxide was used as a catalytic mediator in the modification of electrodes. The electrochemical results show that RuO2 nanostructures coated onto CNTs can strengthen the UA signal. The peak currents of RuO2 nanostructures coated onto CNTs linearly increase with increasing UA concentration, meaning that they can work as electrodes for UA detection. The lowest detection limit and highest sensitivity were 55 nM and 4.36 µA/µM, respectively. Moreover, the characteristics of RuO2 nanostructures coated onto CNTs were examined by scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy.

  18. Interaction between Marine-Derived n-3 Long Chain Polyunsaturated Fatty Acids and Uric Acid on Glucose Metabolism and Risk of Type 2 Diabetes Mellitus: A Case-Control Study.

    PubMed

    Li, Kelei; Wu, Kejian; Zhao, Yimin; Huang, Tao; Lou, Dajun; Yu, Xiaomei; Li, Duo

    2015-08-26

    The present case-control study explored the interaction between marine-derived n-3 long chain polyunsaturated fatty acids (n-3 LC PUFAs) and uric acid (UA) on glucose metabolism and risk of type 2 diabetes mellitus (T2DM). Two hundred and eleven healthy subjects in control group and 268 T2DM subjects in case group were included. Plasma phospholipid (PL) fatty acids and biochemical parameters were detected by standard methods. Plasma PL C22:6n-3 was significantly lower in case group than in control group, and was negatively correlated with fasting glucose (r = -0.177, p < 0.001). Higher plasma PL C22:6n-3 was associated with lower risk of T2DM, and the OR was 0.32 (95% confidence interval (CI), 0.12 to 0.80; p = 0.016) for per unit increase of C22:6n-3. UA was significantly lower in case group than in control group. UA was positively correlated with fasting glucose in healthy subjects, but this correlation became negative in T2DM subjects. A significant interaction was observed between C22:6n-3 and UA on fasting glucose (p for interaction = 0.005): the lowering effect of C22:6n-3 was only significant in subjects with a lower level of UA. In conclusion, C22:6n-3 interacts with UA to modulate glucose metabolism.

  19. Effect of Oral Vitamin C Supplementation on Serum Uric Acid: A Meta-analysis of Randomized Controlled Trials

    PubMed Central

    Juraschek, Stephen P.; Miller, Edgar R.; Gelber, Allan C.

    2011-01-01

    Objective To assess the effect of vitamin C supplementation on serum uric acid (SUA) by pooling the findings from published randomized, controlled trials (RCTs). Methods A total of 2,082 publications identified through systematic search were subjected to the following inclusion criteria: (1) RCTs conducted on human subjects; (2) reported end-trial SUA means and variance; (3) study design with oral vitamin C supplementation and concurrent control groups; and (4) trial duration of at least one week. Trials that enrolled children or patients on dialysis were excluded. Two investigators independently abstracted trial and participant characteristics. SUA effects were pooled by random-effects models and weighted by inverse variance. Results Thirteen RCTs were identified in MEDLINE, EMBASE, and CENTRAL databases. The total number of participants was 556, median dose of vitamin C was 500 mg/d, trial size ranged from 8 to 184 participants, and median study duration was 30 days. Pretreatment SUA values ranged from 2.9 to 7.0 mg/dL (SI: 172.5 – 416.4 μmol/L). The combined effect of these trials was a significant reduction in SUA of -0.35 mg/dL (95% CI: -0.66, -0.03; P = 0.032; SI: -20.8 μmol/L). Trial heterogeneity was significant (I2 = 77%; P < 0.01). Subgroup analyses based on trial characteristics indicated larger reductions in uric acid in trials that were placebo-controlled. Conclusions In aggregate, vitamin C supplementation significantly lowered SUA. Future trials are needed to determine whether vitamin C supplementation can reduce hyperuricemia or prevent incident and recurrent gout. PMID:21671418

  20. Substrate Orientation and Catalytic Specificity in the Action of Xanthine Oxidase: The Sequential Hydroxylation of Hypoxanthine to Uric Acid

    SciTech Connect

    Cao, Hongnan; Pauff, James M.; Hille, Russ

    2010-11-29

    Xanthine oxidase is a molybdenum-containing enzyme catalyzing the hydroxylation of a sp{sup 2}-hybridized carbon in a broad range of aromatic heterocycles and aldehydes. Crystal structures of the bovine enzyme in complex with the physiological substrate hypoxanthine at 1.8 {angstrom} resolution and the chemotherapeutic agent 6-mercaptopurine at 2.6 {angstrom} resolution have been determined, showing in each case two alternate orientations of substrate in the two active sites of the crystallographic asymmetric unit. One orientation is such that it is expected to yield hydroxylation at C-2 of substrate, yielding xanthine. The other suggests hydroxylation at C-8 to give 6,8-dihydroxypurine, a putative product not previously thought to be generated by the enzyme. Kinetic experiments demonstrate that >98% of hypoxanthine is hydroxylated at C-2 rather than C-8, indicating that the second crystallographically observed orientation is significantly less catalytically effective than the former. Theoretical calculations suggest that enzyme selectivity for the C-2 over C-8 of hypoxanthine is largely due to differences in the intrinsic reactivity of the two sites. For the orientation of hypoxanthine with C-2 proximal to the molybdenum center, the disposition of substrate in the active site is such that Arg880 and Glu802, previous shown to be catalytically important for the conversion of xanthine to uric acid, play similar roles in hydroxylation at C-2 as at C-8. Contrary to the literature, we find that 6,8-dihydroxypurine is effectively converted to uric acid by xanthine oxidase.

  1. 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.

  2. Validation of a multi-analyte HPLC-DAD method for determination of uric acid, creatinine, homovanillic acid, niacinamide, hippuric acid, indole-3-acetic acid and 2-methylhippuric acid in human urine.

    PubMed

    Remane, Daniela; Grunwald, Soeren; Hoeke, Henrike; Mueller, Andrea; Roeder, Stefan; von Bergen, Martin; Wissenbach, Dirk K

    2015-08-15

    During the last decades exposure sciences and epidemiological studies attracts more attention to unravel the mechanisms for the development of chronic diseases. According to this an existing HPLC-DAD method for determination of creatinine in urine samples was expended for seven analytes and validated. Creatinine, uric acid, homovanillic acid, niacinamide, hippuric acid, indole-3-acetic acid, and 2-methylhippuric acid were separated by gradient elution (formate buffer/methanol) using an Eclipse Plus C18 Rapid Resolution column (4.6mm×100mm). No interfering signals were detected in mobile phase. After injection of blank urine samples signals for the endogenous compounds but no interferences were detected. All analytes were linear in the selected calibration range and a non weighted calibration model was chosen. Bias, intra-day and inter-day precision for all analytes were below 20% for quality control (QC) low and below 10% for QC medium and high. The limits of quantification in mobile phase were in line with reported reference values but had to be adjusted in urine for homovanillic acid (45mg/L), niacinamide 58.5(mg/L), and indole-3-acetic acid (63mg/L). Comparison of creatinine data obtained by the existing method with those of the developed method showing differences from -120mg/L to +110mg/L with a mean of differences of 29.0mg/L for 50 authentic urine samples. Analyzing 50 authentic urine samples, uric acid, creatinine, hippuric acid, and 2-methylhippuric acid were detected in (nearly) all samples. However, homovanillic acid was detected in 40%, niacinamide in 4% and indole-3-acetic acid was never detected within the selected samples.

  3. Differentiation of human kidney stones induced by melamine and uric acid using surface desorption atmospheric pressure chemical ionization mass spectrometry.

    PubMed

    Jia, Bin; Ouyang, Yongzhong; Sodhi, Rana N S; Hu, Bin; Zhang, Tingting; Li, Jianqiang; Chen, Huanwen

    2011-03-01

    Clinically obtained human kidney stones of different pathogenesis were dissolved in acetic acid/methanol solutions and then rapidly analyzed by surface desorption atmospheric pressure chemical ionization mass spectrometry (SDAPCI-MS) without any desalination treatment. The mass spectral fingerprints of six groups of kidney stone samples were rapidly recorded in the mass range of m/z 50-400. A set of ten melamine-induced kidney stone samples and nine uric acid derived kidney stone samples were successfully differentiated from other groups by principal component analysis of SDAPCI-MS fingerprints upon positive-ion detection mode. In contrast, the mass spectra recorded using negative-ion detection mode did not give enough information to differentiate those stone samples. The results showed that in addition to the melamine, the chemical compounds enwrapped in the melamine-induced kidney stone samples differed from other kidney stone samples, providing useful hints for studying on the formation mechanisms of melamine-induced kidney stones. This study also provides useful information on establishing a MS-based platform for rapid analysis of the melamine-induced human kidney stones at molecular levels.

  4. Associations between concentrations of uric acid with concentrations of vitamin A and beta-carotene among adults in the United States☆

    PubMed Central

    Ford, Earl S.; Choi, Hyon K.

    2015-01-01

    Our objective was to examine the cross-sectional associations between concentrations of vitamin A and beta-carotene, a major source of vitamin A, with concentrations of uric acid in a nationally representative sample of adults from the United States. We conducted a cross-sectional study using data from up to 10893 participants aged ≥20 years of National Health and Nutrition Examination Survey from 2001 to 2006. Concentrations of uric acid adjusted for numerous covariates increased from 305.8 μmol/L in the lowest quintile of vitamin A to 335.3 μmol/L in the highest quintile (p for linear trend <0.001). The prevalence ratio for hyperuricemia also increased progressively across quintiles of serum vitamin A reaching 1.82 (95% confidence interval [CI]: 1.52, 2.16; p for linear trend <0.001) in the top quintile in the maximally adjusted model. Adjusted mean concentrations of uric acid decreased progressively from quintile 1 (333.8 μmol/L) through quintile 4 of concentrations of beta-carotene and were similar for quintiles 4 (313.5 μmol/L) and 5 (313.8 μmol/L). Concentrations of beta-carotene were inversely associated with hyperuricemia (adjusted prevalence ratio comparing highest with lowest quintile = 0.61; 95% CI: 0.52, 0.72; p for linear trend <0.001). Concentrations of uric acid were significantly and positively associated with concentrations of vitamin A and inversely with concentrations of beta-carotene. These cross-sectional findings require confirmation with experimental studies of vitamin A and beta-carotene supplementation. PMID:24267038

  5. Uric acid, indoxyl sulfate, and methylguanidine activate bulbospinal neurons in the RVLM via their specific transporters and by producing oxidative stress.

    PubMed

    Oshima, N; Onimaru, H; Matsubara, H; Uchida, T; Watanabe, A; Takechi, H; Nishida, Y; Kumagai, H

    2015-09-24

    Patients with chronic renal failure often have hypertension, but the cause of hypertension, other than an excess of body fluid, is not well known. We hypothesized that the bulbospinal neurons in the rostral ventrolateral medulla (RVLM) are stimulated by uremic toxins in patients with chronic renal failure. To investigate whether RVLM neurons are sensitive to uremic toxins, such as uric acid, indoxyl sulfate, or methylguanidine, we examined changes in the membrane potentials (MPs) of bulbospinal RVLM neurons of Wister rats using the whole-cell patch-clamp technique during superfusion with these toxins. A brainstem-spinal cord preparation that preserved the sympathetic nervous system was used for the experiments. During uric acid, indoxyl sulfate, or methylguanidine superfusion, almost all the RVLM neurons were depolarized. To examine the transporters for these toxins on RVLM neurons, histological examinations were performed. The uric acid-, indoxyl sulfate-, and methylguanidine-depolarized RVLM neurons showed the presence of urate transporter 1 (URAT 1), organic anion transporter (OAT)1 or OAT3, and organic cation transporter (OCT)3, respectively. Furthermore, the toxin-induced activities of the RVLM neurons were suppressed by the addition of an anti-oxidation drug (VAS2870, an NAD(P)H oxidase inhibitor), and a histological examination revealed the presence of NAD(P)H oxidase (nox)2 and nox4 in these RVLM neurons. The present results show that uric acid, indoxyl sulfate, and methylguanidine directly stimulate bulbospinal RVLM neurons via specific transporters on these neurons and by producing oxidative stress. These uremic toxins may cause hypertension by activating RVLM neurons.

  6. Uric acid-dependent inhibition of AMP kinase induces hepatic glucose production in diabetes and starvation: evolutionary implications of the uricase loss in hominids.

    PubMed

    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

    2014-08-01

    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 × 10(7) 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.

  7. Isolation and characterization of anaerobic bacteria for symbiotic recycling of uric acid nitrogen in the gut of various termites.

    PubMed

    Thong-On, Arunee; Suzuki, Katsuyuki; Noda, Satoko; Inoue, Jun-ichi; Kajiwara, Susumu; Ohkuma, Moriya

    2012-01-01

    Recycling of the nitrogenous waste uric acid (UA) of wood-feeding termites by their gut bacteria is one of the significant aspects of symbiosis for the conservation of nitrogen sources. Diverse anaerobic UA-degrading bacteria comprising 16 species were isolated from the gut of eight termite species, and were assigned to Clostridia, Enterobacteriaceae, and low G+C Gram-positive cocci. UA-degrading Clostridia had never been isolated from termite guts. UA-degrading ability was sporadically distributed among phylogenetically various culturable anaerobic bacteria from termite guts. A strain of Clostridium sp., which was commonly isolated from three termite species and represented a probable new species in cluster XIVa of clostridia, utilized UA as a nitrogen source but not as a sole carbon and energy source. This feature is in clear contrast to that of well-studied purinolytic clostridia or previously isolated UA degraders from termite guts, which also utilize UA as a sole carbon and energy source. Ammonia is the major nitrogenous product of UA degradation. Various purines stimulated the growth of this strain when added to an otherwise growth-limiting, nitrogen poor medium. The bacterial species involved the recycling of UA nitrogen in the gut microbial community of termites are more diverse in terms of both taxonomy and nutritional physiology than previously recognized. PMID:22791052

  8. Isolation and characterization of anaerobic bacteria for symbiotic recycling of uric acid nitrogen in the gut of various termites.

    PubMed

    Thong-On, Arunee; Suzuki, Katsuyuki; Noda, Satoko; Inoue, Jun-ichi; Kajiwara, Susumu; Ohkuma, Moriya

    2012-01-01

    Recycling of the nitrogenous waste uric acid (UA) of wood-feeding termites by their gut bacteria is one of the significant aspects of symbiosis for the conservation of nitrogen sources. Diverse anaerobic UA-degrading bacteria comprising 16 species were isolated from the gut of eight termite species, and were assigned to Clostridia, Enterobacteriaceae, and low G+C Gram-positive cocci. UA-degrading Clostridia had never been isolated from termite guts. UA-degrading ability was sporadically distributed among phylogenetically various culturable anaerobic bacteria from termite guts. A strain of Clostridium sp., which was commonly isolated from three termite species and represented a probable new species in cluster XIVa of clostridia, utilized UA as a nitrogen source but not as a sole carbon and energy source. This feature is in clear contrast to that of well-studied purinolytic clostridia or previously isolated UA degraders from termite guts, which also utilize UA as a sole carbon and energy source. Ammonia is the major nitrogenous product of UA degradation. Various purines stimulated the growth of this strain when added to an otherwise growth-limiting, nitrogen poor medium. The bacterial species involved the recycling of UA nitrogen in the gut microbial community of termites are more diverse in terms of both taxonomy and nutritional physiology than previously recognized.

  9. Mendelian randomization analysis associates increased serum urate, due to genetic variation in uric acid transporters, with improved renal function.

    PubMed

    Hughes, Kim; Flynn, Tanya; de Zoysa, Janak; Dalbeth, Nicola; Merriman, Tony R

    2014-02-01

    Increased serum urate predicts chronic kidney disease independent of other risk factors. The use of xanthine oxidase inhibitors coincides with improved renal function. Whether this is due to reduced serum urate or reduced production of oxidants by xanthine oxidase or another physiological mechanism remains unresolved. Here we applied Mendelian randomization, a statistical genetics approach allowing disentangling of cause and effect in the presence of potential confounding, to determine whether lowering of serum urate by genetic modulation of renal excretion benefits renal function using data from 7979 patients of the Atherosclerosis Risk in Communities and Framingham Heart studies. Mendelian randomization by the two-stage least squares method was done with serum urate as the exposure, a uric acid transporter genetic risk score as instrumental variable, and estimated glomerular filtration rate and serum creatinine as the outcomes. Increased genetic risk score was associated with significantly improved renal function in men but not in women. Analysis of individual genetic variants showed the effect size associated with serum urate did not correlate with that associated with renal function in the Mendelian randomization model. This is consistent with the possibility that the physiological action of these genetic variants in raising serum urate correlates directly with improved renal function. Further studies are required to understand the mechanism of the potential renal function protection mediated by xanthine oxidase inhibitors.

  10. Serum Uric Acid Is Associated with Carotid Plaques: The National Heart, Lung, and Blood Institute Family Heart Study

    PubMed Central

    NEOGI, TUHINA; ELLISON, R. CURTIS; HUNT, STEVEN; TERKELTAUB, ROBERT; FELSON, DAVID T.; ZHANG, YUQING

    2009-01-01

    Objective To examine the association of serum uric acid (SUA) with a marker of preclinical cardiovascular disease (CVD), carotid atherosclerotic plaques (PLQ), where early evidence of risk may be evident, focusing on individuals without CV risk factors. Methods The National Heart, Lung, and Blood Institute Family Heart Study is a multicenter study designed to assess risk factors for heart disease. PLQ were assessed with carotid ultrasound. We conducted sex-specific logistic regression to assess the association of SUA with presence of PLQ, including analyses among persons without risk factors related to both CVD and hyperuricemia. Results In total, 4866 participants had both SUA and carotid ultrasound assessed (54% women, mean age 52 yrs, mean body mass index 27.6). The association of SUA with PLQ increased with increasing SUA levels, demonstrating a dose-response relation for men [OR 1.0, 1.29, 1.61, 1.75, for SUA categories < 5 (reference), 5 to < 6, 6 to < 6.8, ≥ 6.8 mg/dl, respectively; p = 0.002]. Similar associations were found in men without CV risk factors. We found no relation of SUA with PLQ in women. Conclusion In this large study, SUA was associated with carotid atherosclerotic plaques in men. Results were similar in the absence of CV risk factors. These results suggest that SUA may have a pathophysiologic role in atherosclerosis in men. (J Rheumatol First Release Nov 15 2008; doi:10.3899/jrheum.080646) PMID:19012359

  11. Impact of different adiposity measures on the relation between serum uric acid and blood pressure in young adults.

    PubMed

    Lyngdoh, T; Viswanathan, B; Myers, G J; Bochud, M; Bovet, P

    2012-11-01

    Serum uric acid (SUA) concentration is independently associated with blood pressure (BP) in adults. We examined this association in young adults at an age where anti-hypertension treatment, other potential confounding factors and co-morbidity are unlikely to occur. We assessed BP, anthropometric variables including weight, height, waist circumference (WC), body fat percent (using bioimpedance), lifestyle behaviors, SUA and blood lipids in 549 participants aged 19-20 years from a population-based cohort study (Seychelles Child Development Study). Mean (s.d.) SUA was higher in males than females, 0.33 (0.08) and 0.24 (0.07) mmol l(-1), respectively. Body mass index (BMI) was higher in females than males but BP was markedly higher in males than in females. SUA was associated with both systolic and diastolic BP. However, the magnitude of the linear regression coefficients relating BP and SUA decreased by up to 50% upon adjustment for BMI, WC or body fat percent. The association between SUA and BP was not altered upon further adjustment for alcohol intake, smoking, triglycerides or renal function. In fully adjusted models, SUA remained associated with BP (P<0.05) in females. In conclusion, adiposity substantially decreased the association between SUA and BP in young adults, and BP was independently associated with SUA in females. These findings suggest a role of adiposity in the link between hyperuricemia and hypertension.

  12. Facet dependent binding and etching: ultra-sensitive colorimetric visualization of blood uric acid by unmodified silver nanoprisms.

    PubMed

    Tan, Kanghui; Yang, Guang; Chen, Huide; Shen, Pengfei; Huang, Yucheng; Xia, Yunsheng

    2014-09-15

    By combination of experiments and density functional theory calculations, we present a simple but effective "facet dependent binding and etching" strategy for non-enzymatic and non-aggregated colorimetric sensing of blood uric acid (UA), using unmodified Ag nanoprisms as the signal readout. In the absence of UA, the triangular Ag nanoprisms are etched alongside (110) facets by H2O2 and form round nanodiscs, and a more than 160 nm surface plasmon resonance (SPR) blue shift is observed. Because of special affinity between UA and side facets of the Ag nanoprisms, pre-added UA can well protect the Ag nanoprisms from etching. Such protection effect can be used for well quantifying UA in the range of 10-3000 nM, based on the inverse proportion of the SPR blue shift with the added analyte. Due to very thin plate morphology (5 nm) and facet dependent binding/etching effects of the Ag nanoprisms, the sensing system has ultrahigh sensitivity. The detection limit is only 10nM, which is about 2 to 4 orders of magnitude lower than that of previous colorimetric sensing systems. In addition to accurate quantitation, the proposed strategy can conveniently discriminate the patient of hyperuricemia from normal person by naked eyes. So, the present simple, low-cost and visualized UA chemosensor has great potential in the applications for point-of-care diagnostics.

  13. Performance of in-vessel composting of food waste in the presence of coal ash and uric acid.

    PubMed

    An, Chun-Jiang; Huang, Guo-He; Yao, Yao; Sun, Wei; An, Kai

    2012-02-15

    Massive quantities of food waste often coexist with other agroindustrial and industrial waste, which might contain coal ash (CA) and uric acid (UA). This study investigated the influence of CA and UA on the composting of food waste in the in-vessel system. The patterns of food waste composting were compared among various combinations. The results showed that the temperature level was enhanced in the presence of CA and UA during the first 8 days. The significant drop in pH was observed in the treatment without any amendment. But the presence of CA could alleviate the drop of pH. More intensive organic mass reduction took place in the treatments with amended CA and UA in the first half of process. The O(2) uptake rate in the reactor with CA and UA was higher than that with only CA in the early stage. Both thermophilic and mesophilic microorganisms were present throughout the composting period. The populations of both thermophilic and mesophilic microorganisms were influenced when amended with CA and UA. The decreasing trend in C/N ratio was shown in all the reactors, while a relatively lower C/N ratio was obtained in the series with both CA and UA.

  14. Sex-Specific Association between Serum Uric Acid and Nonalcoholic Fatty Liver Disease in Type 2 Diabetic Patients

    PubMed Central

    Fan, Nengguang; Zhang, Lijuan; Xia, Zhenhua; Peng, Liang; Wang, Yufan; Peng, Yongde

    2016-01-01

    Across-sectional study was performed in 541 type 2 diabetic patients to determine the relationship between serum uric acid (SUA) and NAFLD in type 2 diabetic patients. Clinical parameters including SUA were determined and NAFLD was diagnosed by ultrasonography. SUA was significantly higher in type 2 diabetic subjects with NAFLD than in those without NAFLD in men, but not in women. Furthermore, the prevalence rate of NAFLD increased progressively across the sex-specific SUA tertiles only in men (37.9%, 58.6%, and 72.6%, resp., P for trend < 0.001). After adjusting for confounding factors, the odd ratios (95% CI) for NAFLD were 1 (reference), 2.93 (95%CI 1.25–6.88), and 3.93 (95% CI 1.55–9.98), respectively, across the tertiles of SUA in men. Contrastingly, SUA levels in women were not independently associated with the risk of NAFLD. Our data suggests that SUA is specifically associated with NAFLD in male type 2 diabetic subjects, independent of insulin resistance and other metabolic factors. PMID:27382573

  15. Determination of creatinine, uric and ascorbic acid in bovine milk and orange juice by hydrophilic interaction HPLC.

    PubMed

    Zuo, Ruiting; Zhou, Si; Zuo, Yuegang; Deng, Yiwei

    2015-09-01

    Creatinine (Cr), uric (UA) and ascorbic acid (AA) are common constituents in human fluids. Their abnormal concentrations in human fluids are associated with various diseases. Thus, apart from the endogenous formation in human body, it is also important to examine their sources from food products. In this study, a rapid and accurate HILIC method was developed for simultaneous determination of Cr, UA and AA in bovine milk and orange juice. Milk samples were pretreated by protein precipitation, centrifugation and filtration, followed by HPLC separation and quantification using a Waters Spherisorb S5NH2 column. The developed method has been successfully applied to determine the concentration of UA, AA and Cr in milk and fruit juice samples. The milk samples tested were found to contain UA and creatinine in the concentration range of 24.1-86.0 and 5.07-11.2 μg mL(-1), respectively. The orange juices contain AA over 212 μg mL(-1).

  16. Association between serum free thyroxine (FT4) and uric acid levels in populations without overt thyroid dysfunction.

    PubMed

    Ye, Yicong; Gai, Xiaorong; Xie, Hongzhi; Jiao, Li; Zhang, Shuyang

    2015-01-01

    In this study, we investigated the relationship between thyroid function and serum uric acid (UA) levels in subjects without overt thyroid dysfunction. A total of 6,085 patients were included in this cross-sectional study. Free thyroxine (FT4) levels were positively and linearly associated with serum UA levels (p<0.001), even after adjusting for age, thyroid-stimulating hormone, renal function, and other metabolic components (B 37.13; 95%CI 25.99-48.28; p<0.001). Furthermore, quartile analysis indicated that the prevalence of hyperuricemia was significantly elevated with increasing FT4 levels (quartile II: OR 1.232, 95%CI 1.022-1.486, p=0.029; quartile III: OR 1.234, 95%CI 1.025-1.486, p=0.026; quartile IV: OR 1.409, 95%CI 1.168-1.701, p<0.001). In summary, FT4 is linearly associated with serum UA levels in subjects lacking clinical thyroid dysfunction, and the prevalence of hyperuricemia is elevated with increasing FT4 levels. PMID:25696010

  17. Association between serum free thyroxine (FT4) and uric acid levels in populations without overt thyroid dysfunction.

    PubMed

    Ye, Yicong; Gai, Xiaorong; Xie, Hongzhi; Jiao, Li; Zhang, Shuyang

    2015-01-01

    In this study, we investigated the relationship between thyroid function and serum uric acid (UA) levels in subjects without overt thyroid dysfunction. A total of 6,085 patients were included in this cross-sectional study. Free thyroxine (FT4) levels were positively and linearly associated with serum UA levels (p<0.001), even after adjusting for age, thyroid-stimulating hormone, renal function, and other metabolic components (B 37.13; 95%CI 25.99-48.28; p<0.001). Furthermore, quartile analysis indicated that the prevalence of hyperuricemia was significantly elevated with increasing FT4 levels (quartile II: OR 1.232, 95%CI 1.022-1.486, p=0.029; quartile III: OR 1.234, 95%CI 1.025-1.486, p=0.026; quartile IV: OR 1.409, 95%CI 1.168-1.701, p<0.001). In summary, FT4 is linearly associated with serum UA levels in subjects lacking clinical thyroid dysfunction, and the prevalence of hyperuricemia is elevated with increasing FT4 levels.

  18. Airway uric acid is a sensor of inhaled protease allergens and initiates type 2 immune responses in respiratory mucosa1

    PubMed Central

    Hara, Kenichiro; Iijima, Koji; Elias, Martha K.; Seno, Satoshi; Tojima, Ichiro; Kobayashi, Takao; Kephart, Gail M.; Kurabayashi, Masahiko; Kita, Hirohito

    2014-01-01

    While type 2 immune responses to environmental antigens are thought to play pivotal roles in asthma and allergic airway diseases, the immunological mechanisms that initiate the responses are largely unknown. Many allergens have biologic activities, including enzymatic activities and abilities to engage innate pattern-recognition receptors such as TLR4. Here we report that IL-33 and thymic stromal lymphopoietin (TSLP) were produced quickly in the lungs of naïve mice exposed to cysteine proteases, such as bromelain and papain, as a model for allergens. IL-33 and TSLP sensitized naïve animals to an innocuous airway antigen OVA, which resulted in production of type 2 cytokines and IgE antibody and eosinophilic airway inflammation when mice were challenged with the same antigen. Importantly, upon exposure to proteases, uric acid (UA) was rapidly released into the airway lumen, and removal of this endogenous UA by uricase prevented type 2 immune responses. UA promoted secretion of IL-33 by airway epithelial cells in vitro, and administration of UA into the airways of naïve animals induced extracellular release of IL-33, followed by both innate and adaptive type 2 immune responses in vivo. Finally, a potent UA synthesis inhibitor, febuxostat, mitigated asthma phenotypes that were caused by repeated exposure to natural airborne allergens. These findings provide mechanistic insights into the development of type 2 immunity to airborne allergens and recognize airway UA as a key player that regulates the process in respiratory mucosa. PMID:24663677

  19. Essential oil from leaves of Cinnamomum osmophloeum acts as a xanthine oxidase inhibitor and reduces the serum uric acid levels in oxonate-induced mice.

    PubMed

    Wang, S Y; Yang, C W; Liao, J W; Zhen, W W; Chu, F H; Chang, S T

    2008-11-01

    The xanthine oxidase (XOD) inhibitory activity and anti-hyperuricemia effect in mice of Cinnamomum osmophloeum, which is an endemic tree in Taiwan, were evaluated in this study. The results demonstrated that the essential oil of C. osmophloeum leaves presented the strongest XOD inhibition activity (IC(50)=16.3 μg/ml); however, no significant XOD inhibition activities were found in ethanolic and hot water extracts. Furthermore, among the main compounds of essential oil, the cinnamaldehyde exhibited the potent XOD inhibition activity with an IC(50)=8.4 μg/ml. Besides, the reducing serum uric acid levels in oxonate-induced mice by cinnamaldehyde were further investigated. The hyperuricemic mice were oral administrated cinnamaldehyde at a dosage of 150 mg/kg, the uric acid value in serum was reduced from 5.25±0.63 to 2.10±0.04 mg/dl, the levels of serum uric acid in mice was lowered down by 84.48% as compared to the hyperuricemic control group. Based on the results obtained in this study, cinnamaldehyde may be a potential lead compound for developing the pharmaceutic for anti-hyperuricemia agent. PMID:18693097

  20. In vitro and in vivo studies on adlay-derived seed extracts: phenolic profiles, antioxidant activities, serum uric acid suppression, and xanthine oxidase inhibitory effects.

    PubMed

    Zhao, Mouming; Zhu, Dashuai; Sun-Waterhouse, Dongxiao; Su, Guowan; Lin, Lianzhu; Wang, Xiao; Dong, Yi

    2014-08-01

    This study aimed to explore the potential of polished adlay, brown adlay, adlay bran, and adlay hull to prevent and treat hyperuricemia. Brown adlay extract effectively decreased the serum uric acid levels of oxonate-induced hyperuricemic rats. Free and bound phenolic extracts from these materials contained significant amounts of phenolics, with free phenolics dominated by chlorogenic acid and p-coumaric acid while bound phenolics dominated by p-coumaric acid and ferulic acid. Free and bound phenolics of adlay bran exhibited significant xanthine oxidase inhibition activities, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities, oxygen radical absorbance capacities, and superoxide radical scavenging activities. Adlay bran phenolics could be effective xanthine oxidase inhibitors and radical scavengers. p-Coumaric acid is a xanthine oxidase inhibitor with strong superoxide radical scavenging activity. However, ferulic acid is a xanthine oxidase inhibitor with weak superoxide radical scavenging activity. Chlorogenic acid is a superoxide radical scavenger with weak xanthine oxidase inhibitory activity.

  1. Biochemical and Structural Characterization of a Ureidoglycine Aminotransferase in the Klebsiella pneumoniae Uric Acid Catabolic Pathway

    SciTech Connect

    French, Jarrod B.; Ealick, Steven E.

    2010-09-03

    Many plants, fungi, and bacteria catabolize allantoin as a mechanism for nitrogen assimilation. Recent reports have shown that in plants and some bacteria the product of hydrolysis of allantoin by allantoinase is the unstable intermediate ureidoglycine. While this molecule can spontaneously decay, genetic analysis of some bacterial genomes indicates that an aminotransferase may be present in the pathway. Here we present evidence that Klebsiella pneumoniae HpxJ is an aminotransferase that preferentially converts ureidoglycine and an {alpha}-keto acid into oxalurate and the corresponding amino acid. We determined the crystal structure of HpxJ, allowing us to present an explanation for substrate specificity.

  2. Esterification by the Plasma Acidic Water: Novel Application of Plasma Acid

    NASA Astrophysics Data System (ADS)

    Gu, Ling

    2014-03-01

    This work explores the possibility of plasma acid as acid catalyst in organic reactions. Plasma acidic water was prepared by dielectric barrier discharge and used to catalyze esterification of n-heptanioc acid with ethanol. It is found that the plasma acidic water has a stable and better performance than sulfuric acid, meaning that it is an excellent acid catalyst. The plasma acidic water would be a promising alternative for classic mineral acid as a more environment friendly acid.

  3. A Pharmacist-Staffed, Virtual Gout Management Clinic for Achieving Target Serum Uric Acid Levels: A Randomized Clinical Trial

    PubMed Central

    Goldfien, Robert; Pressman, Alice; Jacobson, Alice; Ng, Michele; Avins, Andrew

    2016-01-01

    Context: Relatively few patients with gout receive appropriate treatment. Objective: To determine whether a pharmacist-staffed gout management program is more effective than usual care in achieving target serum uric acid (sUA) levels in gout patients. Design: A parallel-group, randomized controlled trial of a pharmacist-staffed, telephone-based program for managing hyperuricemia vs usual care. Trial duration was 26 weeks. Main Outcome Measures: Primary outcome measure was achieving sUA levels at or below 6 mg/dL at the 26-week visit. Secondary outcome was mean change in sUA levels in the control and intervention groups. Participants were adults with recurrent gout and sUA levels above 6.0 mg/dL. Participants were randomly assigned to management by a clinical pharmacist following protocol or to monitoring of sUA levels but management of their gout by their usual treating physician. Results: Of 102 patients who met eligibility criteria, 77 subjects obtained a baseline sUA measurement and were entered into the trial. Among 37 participants in the intervention group, 13 (35%) had sUA levels at or below 6.0 mg/dL at 26 weeks, compared with 5 (13%) of 40 participants in the control group (risk ratio = 2.8, 95% confidence interval [CI] = 1.1 to 7.1, p = 0.03). The mean change in sUA levels among controls was +0.1 mg/dL compared with −1.5 mg/dL in the intervention group (sUA difference = −1.6, 95% CI = −0.9 to −2.4, p < 0.001). Conclusions: A structured pharmacist-staffed program was more effective than usual care for achieving target sUA levels. These results suggest a structured program could greatly improve gout management. PMID:27352414

  4. Differences in postmortem urea nitrogen, creatinine and uric acid levels between blood and pericardial fluid in acute death.

    PubMed

    Zhu, Bao-Li; Ishikawa, Takaki; Michiue, Tomomi; Tanaka, Sayaka; Zhao, Dong; Li, Dong-Ri; Quan, Li; Oritani, Shigeki; Maeda, Hitoshi

    2007-05-01

    Previous studies showed significant differences in postmortem urea nitrogen (UN), creatinine (Cr) and uric acid (UA) levels in heart blood depending on the causes of death, including acute death. In addition, the levels in pericardial fluid approximated the clinical serum reference ranges, and their elevations may be assessed based on clinical criteria. The present study investigated difference between blood and pericardial levels of these markers. Medicolegal autopsy cases (n=556, within 48h postmortem) of the following causes of death were examined: injury (n=136), asphyxiation (n=50), drowning (n=39), fire fatalities (n=99), hyperthermia (n=11), hypothermia (n=8), poisoning (n=26), delayed traumatic death (n=44) and natural diseases (n=143). When serum UN, Cr and UA levels were compared with the pericardial levels, there was an equivalency for delayed traumatic death and chronic renal failure, although each level was markedly elevated. Parallel increases in serum and pericardial UA and/or Cr levels were also observed for hypothermia and gastrointestinal bleeding. However, in drowning cases, the left cardiac and pericardial UN levels were lower than the right cardiac and peripheral levels, suggesting the influence of water aspiration. Significant elevations in serum and pericardial Cr and UA levels with a higher serum/pericardial UA ratio for fatal methamphetamine intoxication suggest progressive skeletal muscle damage due to advanced hypoxia/acidosis. Similar findings were often observed for other acute and subacute deaths. These findings suggest that a comparison between blood and pericardial nitrogenous compounds would be useful for investigating the cause and process of death.

  5. Degradation Network Reconstruction in Uric Acid and Ammonium Amendments in Oil-Degrading Marine Microcosms Guided by Metagenomic Data.

    PubMed

    Bargiela, Rafael; Gertler, Christoph; Magagnini, Mirko; Mapelli, Francesca; Chen, Jianwei; Daffonchio, Daniele; Golyshin, Peter N; Ferrer, Manuel

    2015-01-01

    Biostimulation with different nitrogen sources is often regarded as a strategy of choice in combating oil spills in marine environments. Such environments are typically depleted in nitrogen, therefore limiting the balanced microbial utilization of carbon-rich petroleum constituents. It is fundamental, yet only scarcely accounted for, to analyze the catabolic consequences of application of biostimulants. Here, we examined such alterations in enrichment microcosms using sediments from chronically crude oil-contaminated marine sediment at Ancona harbor (Italy) amended with natural fertilizer, uric acid (UA), or ammonium (AMM). We applied the web-based AromaDeg resource using as query Illumina HiSeq meta-sequences (UA: 27,893 open reading frames; AMM: 32,180) to identify potential catabolic differences. A total of 45 (for UA) and 65 (AMM) gene sequences encoding key catabolic enzymes matched AromaDeg, and their participation in aromatic degradation reactions could be unambiguously suggested. Genomic signatures for the degradation of aromatics such as 2-chlorobenzoate, indole-3-acetate, biphenyl, gentisate, quinoline and phenanthrene were common for both microcosms. However, those for the degradation of orcinol, ibuprofen, phenylpropionate, homoprotocatechuate and benzene (in UA) and 4-aminobenzene-sulfonate, p-cumate, dibenzofuran and phthalate (in AMM), were selectively enriched. Experimental validation was conducted and good agreement with predictions was observed. This suggests certain discrepancies in action of these biostimulants on the genomic content of the initial microbial community for the catabolism of petroleum constituents or aromatics pollutants. In both cases, the emerging microbial communities were phylogenetically highly similar and were composed by very same proteobacterial families. However, examination of taxonomic assignments further revealed different catabolic pathway organization at the organismal level, which should be considered for designing

  6. Degradation Network Reconstruction in Uric Acid and Ammonium Amendments in Oil-Degrading Marine Microcosms Guided by Metagenomic Data.

    PubMed

    Bargiela, Rafael; Gertler, Christoph; Magagnini, Mirko; Mapelli, Francesca; Chen, Jianwei; Daffonchio, Daniele; Golyshin, Peter N; Ferrer, Manuel

    2015-01-01

    Biostimulation with different nitrogen sources is often regarded as a strategy of choice in combating oil spills in marine environments. Such environments are typically depleted in nitrogen, therefore limiting the balanced microbial utilization of carbon-rich petroleum constituents. It is fundamental, yet only scarcely accounted for, to analyze the catabolic consequences of application of biostimulants. Here, we examined such alterations in enrichment microcosms using sediments from chronically crude oil-contaminated marine sediment at Ancona harbor (Italy) amended with natural fertilizer, uric acid (UA), or ammonium (AMM). We applied the web-based AromaDeg resource using as query Illumina HiSeq meta-sequences (UA: 27,893 open reading frames; AMM: 32,180) to identify potential catabolic differences. A total of 45 (for UA) and 65 (AMM) gene sequences encoding key catabolic enzymes matched AromaDeg, and their participation in aromatic degradation reactions could be unambiguously suggested. Genomic signatures for the degradation of aromatics such as 2-chlorobenzoate, indole-3-acetate, biphenyl, gentisate, quinoline and phenanthrene were common for both microcosms. However, those for the degradation of orcinol, ibuprofen, phenylpropionate, homoprotocatechuate and benzene (in UA) and 4-aminobenzene-sulfonate, p-cumate, dibenzofuran and phthalate (in AMM), were selectively enriched. Experimental validation was conducted and good agreement with predictions was observed. This suggests certain discrepancies in action of these biostimulants on the genomic content of the initial microbial community for the catabolism of petroleum constituents or aromatics pollutants. In both cases, the emerging microbial communities were phylogenetically highly similar and were composed by very same proteobacterial families. However, examination of taxonomic assignments further revealed different catabolic pathway organization at the organismal level, which should be considered for designing

  7. Degradation Network Reconstruction in Uric Acid and Ammonium Amendments in Oil-Degrading Marine Microcosms Guided by Metagenomic Data

    PubMed Central

    Bargiela, Rafael; Gertler, Christoph; Magagnini, Mirko; Mapelli, Francesca; Chen, Jianwei; Daffonchio, Daniele; Golyshin, Peter N.; Ferrer, Manuel

    2015-01-01

    Biostimulation with different nitrogen sources is often regarded as a strategy of choice in combating oil spills in marine environments. Such environments are typically depleted in nitrogen, therefore limiting the balanced microbial utilization of carbon-rich petroleum constituents. It is fundamental, yet only scarcely accounted for, to analyze the catabolic consequences of application of biostimulants. Here, we examined such alterations in enrichment microcosms using sediments from chronically crude oil-contaminated marine sediment at Ancona harbor (Italy) amended with natural fertilizer, uric acid (UA), or ammonium (AMM). We applied the web-based AromaDeg resource using as query Illumina HiSeq meta-sequences (UA: 27,893 open reading frames; AMM: 32,180) to identify potential catabolic differences. A total of 45 (for UA) and 65 (AMM) gene sequences encoding key catabolic enzymes matched AromaDeg, and their participation in aromatic degradation reactions could be unambiguously suggested. Genomic signatures for the degradation of aromatics such as 2-chlorobenzoate, indole-3-acetate, biphenyl, gentisate, quinoline and phenanthrene were common for both microcosms. However, those for the degradation of orcinol, ibuprofen, phenylpropionate, homoprotocatechuate and benzene (in UA) and 4-aminobenzene-sulfonate, p-cumate, dibenzofuran and phthalate (in AMM), were selectively enriched. Experimental validation was conducted and good agreement with predictions was observed. This suggests certain discrepancies in action of these biostimulants on the genomic content of the initial microbial community for the catabolism of petroleum constituents or aromatics pollutants. In both cases, the emerging microbial communities were phylogenetically highly similar and were composed by very same proteobacterial families. However, examination of taxonomic assignments further revealed different catabolic pathway organization at the organismal level, which should be considered for designing

  8. Lower Serum Levels of Uric Acid in Uterine Fibroids and Fibrocystic Breast Disease Patients in Dongying City, China

    PubMed Central

    CHEN, Qicai; XIAO, Juan; ZHANG, Pengpeng; CHEN, Lili; CHEN, Xiaoxiao; WANG, Shumei

    2016-01-01

    Background: Increasing serum levels of uric acid (SUA) after menopause in women brought up a hypothesis that estrogenic effect may protectively regulate SUA. Estrogenic effect is a major etiology of uterine fibroids and fibrocystic breast disease. The study aimed to explore SUA among patients suffering from these diseases to enhance the hypothesis. Methods: Overall, 1349 female participants were selected into three cases: Case I having uterine fibroids (n=568), Case II having fibrocycstic breast disease (n=608) and Case III having uterine fibroids combining with fibrocycstic breast disease (n=173); 4206 participants without these diseases were selected as controls. Based on health check-up data from 2011 to 2012, in Dongying Shengli Oilfield Central Hospital, a cross-sectional study was conducted to examine the difference in SUA between the case and control. We adjusted covariates by generalized linear regression mode. Results: From 19 to 44 yr, SUA of Case I to Case III were lower than controls by 8.46 umol/L (P=0.011), 5.88umol/L (P=0.014) and 9.39 umol/L (P=0.059), respectively. From 45–54 yr, no significant differences were between three cases and controls. In Case I and its control: from 54–59 yr, differences were not significant; from 60 to 72 yr, SUA in Case I was lower than the control by 32.02umol/L (P=0.003). Conclusion: Participants of uterine fibroids and fibrocystic breast disease had a lower SUA except the stage of menopause, which indirectly supported that estrogenic effect, may protectively decrease SUA. PMID:27398332

  9. Association of serum uric acid level with mortality and morbidity of patients with acute ST-elevation myocardial infarction

    PubMed Central

    Hajizadeh, Reza; Ghaffari, Samad; Salehi, Rezvanieh; Mazani, Sarvin; Aghavali, Sharmin

    2016-01-01

    Introduction: Investigating the clinical impact of serum uric acid (UA) and its lowering agents on the complications and mortality of acute ST-elevation myocardial infarction (STEMI) can open a new era in STEMI treatment. The aim of this study was to evaluate the effect of on admission serum UA level on the mortality and morbidity of patients admitted with STEMI. Methods: A number of 608 patients with STEMI were enrolled in this study from December 21, 2012 until February 19, 2014. Patients were followed for 20 months. Male to female ratio was 2.53, and the mean age of patients was 62.6±13.4. The relationship between the level of UA and patients’ mortality and morbidity, left ventricular ejection fraction (LVEF), atrial and ventricular arrhythmia was analyzed. Results: Patients with high serum UA level had higher Killip class after STEMI (P=0.001). Mean LVEF was measured to be 39.5±9.6 in normal UA group and 34.6±11.6 in high UA group (P=0.001). In comparison with normal UA group, high UA group had significantly higher cTnI (2.68±0.09 vs 4.09±0.42, respectively, P=0.001), increased blood pressure (P=0.009), and higher atrial fibrillation (AF) occurrence (P=0.03), but no association was seen between ventricular tachycardia and serum UA level. Short term and midterm mortality were not different in two groups (P=0.44 and 0.31, respectively). Conclusion: In the current study, high serum UA level in patients with acute myocardial infarction (MI) was not associated with higher in-hospital or midterm mortality, but it was associated with lower LVEF, higher Killip class, elevated cTnI, creatinine, triglyceride, and higher AF. PMID:27489597

  10. Serum uric acid level and association with cognitive impairment and dementia: systematic review and meta-analysis.

    PubMed

    Khan, Aamir A; Quinn, Terence J; Hewitt, Jonathan; Fan, Yuhua; Dawson, Jesse

    2016-02-01

    Serum uric acid (sUA) level may be associated with cognitive impairment/dementia. It is possible this relationship varies with dementia subtype, particularly between vascular dementias (VaD) and Alzheimer's (AD) or Parkinson's disease (PDD)-related dementia. We aimed to present a synthesis of all published data on sUA and relationship with dementia/cognition through systematic review and meta-analysis. We included studies that assessed the association between sUA and any measure of cognitive function or a clinical diagnosis of dementia. We pre-defined subgroup analyses for patients with AD, VaD, PDD, mild cognitive impairment (MCI), and mixed or undifferentiated. We assessed risk of bias/generalizability, and where data allowed, we performed meta-analysis to describe pooled measures of association across studies. From 4811 titles, 46 papers (n = 16,688 participants) met our selection criteria. Compared to controls, sUA was lower in dementia (SDM -0.33 (95%CI)). There were differences in association by dementia type with apparent association for AD (SDM -0.33 (95%CI)) and PDD (SDM -0.67 (95%CI)) but not in cases of mixed dementia (SDM 0.19 (95%CI)) or VaD (SDM -0.05 (95%CI)). There was no correlation between scores on Mini-Mental State Examination and sUA level (summary r 0.08, p = 0.27), except in patients with PDD (r 0.16, p = 0.003). Our conclusions are limited by clinical heterogeneity and risk of bias in studies. Accepting this caveat, the relationship between sUA and dementia/cognitive impairment is not consistent across all dementia groups and in particular may differ in patients with VaD compared to other dementia subtypes.

  11. Association of serum uric acid with incident atrial fibrillation (from the Atherosclerosis Risk in Communities [ARIC] study).

    PubMed

    Tamariz, Leonardo; Agarwal, Sunil; Soliman, Elsayed Z; Chamberlain, Alanna M; Prineas, Ronald; Folsom, Aaron R; Ambrose, Marietta; Alonso, Alvaro

    2011-11-01

    Atrial fibrillation (AF) is one of the most common arrhythmias seen in clinical practice. Current evidence suggests that serum uric acid (SUA) could be a marker of oxidative damage, a factor reported as a part of the mechanisms of AF. The purpose of the present study was to evaluate whether SUA predicted AF in the Atherosclerosis Risk In Communities (ARIC) study. The present analysis included 15,382 AF-free black and white men and women, aged 45 to 64 years, from the ARIC study, a population-based prospective cohort in the United States. SUA was determined using the uricase-peroxidase method at baseline. The primary outcome was the incidence of AF, defined as the occurrence of AF detected using hospital discharge codes, scheduled study electrocardiograms, and/or death certificates during the follow-up period (1987 to 2004). We identified 1,085 cases of incident AF. In Cox proportional hazards models adjusted for age, gender, race, center, education, body mass index, serum glucose, systolic and diastolic blood pressure, low-density lipoprotein cholesterol, alcohol use, prevalent coronary heart disease and heart failure, serum creatinine, diuretics, and P-wave duration on the electrocardiogram (as a measure of left atrial size) at baseline, the hazard ratio of AF associated with a SD increment in SUA was 1.16 (95% confidence interval 1.06 to 1.26). The association of SUA with AF risk differed by race and gender (p for interaction <0.01). In conclusion, elevated SUA is associated with a greater risk of AF, particularly among blacks and women. Additional studies should replicate this association and explore potential mechanisms.

  12. Uric Acid as a predictor of adverse maternal and perinatal outcomes in women hospitalized with preeclampsia.

    PubMed

    Livingston, Joel R; Payne, Beth; Brown, Mark; Roberts, James M; Côté, Anne-Marie; Magee, Laura A; von Dadelszen, Peter

    2014-10-01

    Objectif : Bien qu’un taux sérique élevé d’acide urique soit couramment constaté chez les femmes qui présentent une prééclampsie, son utilité pour ce qui est de la prévision des issues indésirables a récemment été remise en question. Nous avions pour objectif d’analyser les données issues d’une importante cohorte de femmes présentant une prééclampsie, afin de déterminer l’utilité du taux sérique d’acide urique pour ce qui est de la prévision des issues indésirables maternelles et périnatales. Méthodes : Les données ont été tirées d’une étude prospective internationale toujours en cours qui porte sur des femmes hospitalisées présentant une prééclampsie (Pre-eclampsia Integrated Estimate of RiSk). Une régression logistique univariée a été utilisée pour déterminer la relation entre la concentration sérique en acide urique (tant absolue que corrigée en fonction de l’âge gestationnel [score Z]) et les issues indésirables (maternelles et périnatales). Des analyses ont été menées pour comparer des cohortes de femmes présentant une prééclampsie définie par l’hypertension et la protéinurie à des cohortes de femmes présentant une prééclampsie définie par l’hypertension et l’hyperuricémie. Résultats : Le score Z quant à l’acide urique était associé à des issues périnatales indésirables (RC, 1,5; IC à 95 %, 1,4 - 1,7) et comptait une estimation ponctuelle > 0,7 (surface sous la courbe de la fonction d’efficacité de l’observateur, 0,72; IC à 95 %, 0,69 - 0,74). Une association significative a également été constatée entre la concentration sérique en acide urique et des issues indésirables maternelles; toutefois, l’estimation ponctuelle était < 0,7. Aucune différence significative n’a été constatée entre les groupes « prééclampsie définie par l’hypertension et la protéinurie » et « prééclampsie définie par l’hypertension et l

  13. Tuning Surface Charge and Morphology for the Efficient Detection of Dopamine under the Interferences of Uric Acid, Ascorbic Acid, and Protein Adsorption.

    PubMed

    Chen, Chien-Hsun; Luo, Shyh-Chyang

    2015-10-01

    In this research, we aimed to evaluate the impact of the surface charges and morphologies of electrodes on electrochemically detecting dopamine (DA) in the presence of protein adsorption, uric acid (UA), and ascorbic acid (AA). Through the electropolymerization of functionalized 3,4-ethylenedioxythiophenes (EDOT) directly on Au electrodes, we successfully created PEDOT-coated electrodes with three different functional groups and nanostructures. Negatively charged carboxylic acid groups attracted DA while reducing the interferences of UA and AA due to electrostatic effect. We used charge-free tetra(ethylene glycol) and zwitterionic phosphocholine groups are used to evaluate the interference of protein adsorption on DA sensing because they both can effectively prevent the nonspecific adsorption of proteins. These two electrodes can avoid protein adsorption, yet proved ineffective for DA sensing: both tetra(ethylene glycol) and the phosphocholine groups are electroneutral and have minimal electrostatic interactions with DA. We also used three proteins of different isoelectric points - bovine serum albumin, lysozyme, and fibrinogen - to evaluate the influence of protein adsorption on DA detection. We found that for an electrode coated with carboxylic acid-functionalized PEDOT, the adsorption of positively charged lysozyme can promote the detection sensitivity of AA and UA, and that all protein adsorption lowers the sensitivity of DA. In contrast, nanostructures promote the detection sensitivity of all three molecules. All of our tested functionalized PEDOT-coated electrodes demonstrated good stability and functionality in buffers.

  14. Ascorbic acid protects lipids in human plasma and low-density lipoprotein against oxidative damage

    SciTech Connect

    Frei, B. )

    1991-12-01

    The authors exposed human blood plasma and low-density lipoprotein (LDL) to many different oxidative challenges and followed the temporal consumption of endogenous antioxidants in relation to the initiation of oxidative damage. Under all types of oxidizing conditions, ascorbic acid completely protects lipids in plasma and LDL against detectable peroxidative damage as assessed by a specific and highly sensitive assay for lipid peroxidation. Ascorbic acid proved to be superior to the other water-soluble plasma antioxidants bilirubin, uric acid, and protein thiols as well as to the lipoprotein-associated antioxidants alpha-tocopherol, ubiquinol-10, lycopene, and beta-carotene. Although these antioxidants can lower the rate of detectable lipid peroxidation, they are not able to prevent its initiation. Only ascorbic acid is reactive enough to effectively intercept oxidants in the aqueous phase before they can attack and cause detectable oxidative damage to lipids.

  15. ELEVATED SERUM URIC ACID LEVELS ARE ASSOCIATED WITH NON-ALCOHOLIC FATTY LIVER DISEASE INDEPENDENTLY OF METABOLIC SYNDROME FEATURES IN THE UNITED STATES: LIVER ULTRASOUND DATA FROM THE NATIONAL HEALTH AND NUTRITION EXAMINATION SURVEY

    PubMed Central

    Sirota, Jeffrey C.; McFann, Kim; Targher, Giovanni; Johnson, Richard J.; Chonchol, Michel; Jalal, Diana I.

    2012-01-01

    Objective Experimental and observational studies suggest a role for uric acid in non-alcoholic fatty liver disease (NAFLD). We examined the association between serum uric acid levels and NAFLD in a large population-based study from the United States. Materials/Methods A cross-sectional analysis of 10,732 nondiabetic adults who participated in the National Health and Nutrition Examination Survey 1988–1994. Sex specific uric acid quartiles were defined: ≤5.2, 5.3–6.0, 6.1–6.9, and >6.9 mg/dL for men and ≤3.7, 3.8–4.5, 4.6–5.3, and >5.3 mg/dL for women. NAFLD presence and severity were defined by ultrasonographic detection of steatosis in the absence of other liver diseases. We modeled the probability that more severe NAFLD would be associated with the highest quartiles of uric acid. Results Compared to the 1st quartile, the odds ratio for NAFLD was 1.79 (95% C.I. 1.49–2.15, p < 0.001) and 3.14 (95% C.I. 2.63–3.75, p < 0.001) for the 3rd and 4th quartiles, respectively. After adjusting for demographics, hypertension, waist circumference, triglycerides, high-density lipoprotein-cholesterol, homeostasis model assessment-estimated insulin resistance, estimated glomerular filtration rate, and aspartate aminotransferase, uric acid (4th quartile) was significantly associated with NAFLD (odds ratio 1.43; 95% C.I. 1.16–1.76, p < 0.001). Positive parameter estimates suggest increasing uric acid is associated with greater severity of NAFLD. Conclusions Elevated uric acid level is independently associated with ultrasound-diagnosed NAFLD in a nationally representative sample of United States nondiabetic adults. Increasing uric acid is associated with increasing severity of NAFLD on ultrasonography. These findings warrant further studies on the role of uric acid in NAFLD. PMID:23036645

  16. Role of serum sodium in assessing hospital mortality in cancer patients with spontaneous tumour lysis syndrome inducing acute uric acid nephropathy.

    PubMed

    Hsu, H-H; Chen, Y-C; Tian, Y-C; Chan, Y-L; Kuo, M-C; Tang, C-C; Fang, J-T; Lee, S-Y; Yang, C-W

    2009-05-01

    Spontaneous tumour lysis syndrome (STLS) inducing acute uric acid nephropathy, a rare and neglected disease, presents more insidiously than conventional post-treatment tumour lysis syndrome. Although STLS is a serious and potentially fatal complication in patients with neoplastic disorders, few investigations have addressed the relevance of clinical and laboratory features in assessing prognosis. A retrospective study was conducted, reviewing the records of all patients who developed acute renal failure (ARF) at Chang Gung memorial hospital between 1 July 1999 and 30 June 2003. STLS-induced acute uric acid nephropathy was identified in 12 of 1072 ARF patients (1.1%) during the study period. All patients had advanced stage tumours with large tumour burden, and 66.7% of cases had abdominal organ involvement. All 12 hyperuricemic patients became oliguric despite conservative therapy, and remained hyperuricemic (21.6 +/- 5.2 mg/dl) before dialysis therapy. Diuresis developed in eight patients (66.7%), with associated resolution of hyperuricemia, azotemia and metabolic derangements following dialysis initiation. Overall hospital mortality was 58.3%. Death in most patients was related to hyponatremia and hypoalbuminemia on admission. The serum sodium was found to have the best Youden index (0.86) and highest overall prediction accuracy (93%). Moreover, serum sodium and serum albumin for individual patients were significantly and positively correlated (r = 0.617, p = 0.032). This investigation confirms a grave prognosis for cancer patients with STLS inducing acute uric acid nephropathy. Hyponatremia and hypoalbuminemia on the first day of admission indicate poor prognosis in such patients.

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

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

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

  18. Electroanalysis and simultaneous determination of 6-thioguanine in the presence of uric acid and folic acid using a modified carbon nanotube paste electrode.

    PubMed

    Beitollahi, Hadi; Raoof, Jahan-Bakhsh; Hosseinzadeh, Rahman

    2011-01-01

    The present work describes the preparation and characterization of a carbon nanotube paste electrode modified with 2,7-bis(ferrocenyl ethyl)fluoren-9-one (2,7-BF). This electrode showed an efficient catalytic activity for the electro-oxidation of 6-thioguanine (6-TG), which leads to lowering 6-TG overpotential by more than 610 mV. Also, the values of catalytic rate constant (k = 2.7 × 10(3) mol(-1) L s(-1)), and diffusion coefficient (D = 2.7 × 10(-5) cm(2) s) were calculated. In 0.1 M phosphate buffer solution of pH 7.0, the oxidation current increased linearly with two concentration intervals of 6-TG, one is 0.06 to 10.0 µmol L(-1) and the other is 10.0 to 160.0 µmol L(-1). The detection limit (3σ) obtained by differential pulse voltammetry (DPV) was 22.0 nmol L(-1). DPV was used for simultaneous determination of 6-TG, uric acid (UA) and folic acid (FA) at the modified electrode, and for quantification of 6-TG, UA and FA in some real samples by the standard addition method.

  19. Optimization of modified carbon paste electrode with multiwalled carbon nanotube/ionic liquid/cauliflower-like gold nanostructures for simultaneous determination of ascorbic acid, dopamine and uric acid.

    PubMed

    Afraz, Ahmadreza; Rafati, Amir Abbas; Najafi, Mojgan

    2014-11-01

    We describe the modification of a carbon paste electrode (CPE) with multiwalled carbon nanotubes (MWCNTs) and an ionic liquid (IL). Electrochemical studies by using a D-optimal mixture design in Design-Expert software revealed an optimized composition of 60% graphite, 14.2% paraffin, 10.8% MWCNT and 15% IL. The optimal modified CPE shows good electrochemical properties that are well matched with model prediction parameters. In the next step, the optimized CPE was modified with gold nanostructures by applying a double-pulse electrochemical technique. The resulting electrode was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and electrochemical impedance spectroscopy. It gives three sharp and well-separated oxidation peaks for ascorbic acid (AA), dopamine (DA), and uric acid (UA). The sensor enables simultaneous determination of AA, DA and UA with linear responses from 0.3 to 285, 0.08 to 200, and 0.1 to 450 μM, respectively, and with 120, 30 and 30 nM detection limits (at an S/N of 3). The method was successfully applied to the determination of AA, DA, and UA in spiked samples of human serum and urine.

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

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

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

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

    PubMed

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

    2013-08-15

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

  2. Targeting Uric Acid and the Inhibition of Progression to End-Stage Renal Disease—A Propensity Score Analysis

    PubMed Central

    Ota, Tatsuru; Tamura, Yoshifuru; Shiraishi, Takeshi; Kumagai, Takanori; Shibata, Shigeru; Fujigaki, Yoshihide; Hosoyamada, Makoto; Kaneko, Kiyoko; Shen, Zhong Yang; Fujimori, Shin

    2015-01-01

    Background The role of uric acid (UA) in the progression of chronic kidney disease (CKD) remains controversial due to the unavoidable cause and result relationship. This study was aimed to clarify the independent impact of UA on the subsequent risk of end-stage renal disease (ESRD) by a propensity score analysis. Methods A retrospective CKD cohort was used (n = 803). Baseline 23 covariates were subjected to a multivariate binary logistic regression with the targeted time-averaged UA of 6.0, 6.5 or 7.0 mg/dL. The participants trimmed 2.5 percentile from the extreme ends of the cohort underwent propensity score analyses consisting of matching, stratification on quintile and covariate adjustment. Covariate balances after 1:1 matching without replacement were tested for by paired analysis and standardized differences. A stratified Cox regression and a Cox regression adjusted for logit of propensity scores were examined. Results After propensity score matching, the higher UA showed elevated hazard ratios (HRs) by Kaplan-Meier analysis (≥6.0 mg/dL, HR 4.53, 95%CI 1.79–11.43; ≥6.5 mg/dL, HR 3.39, 95%CI 1.55–7.42; ≥7.0 mg/dL, HR 2.19, 95%CI 1.28–3.75). The number needed to treat was 8 to 9 over 5 years. A stratified Cox regression likewise showed significant crude HRs (≥6.0 mg/dL, HR 3.63, 95%CI 1.25–10.58; ≥6.5 mg/dL, HR 3.46, 95%CI 1.56–7.68; ≥7.0 mg/dL, HR 2.05, 95%CI 1.21–3.48). Adjusted HR lost its significance at 6.0 mg/dL. The adjustment for the logit of the propensity scores showed the similar results but with worse model fittings than the stratification method. Upon further adjustment for other covariates the significance was attained at 6.5 mg/dL. Conclusions Three different methods of the propensity score analysis showed consistent results that the higher UA accelerates the progression to the subsequent ESRD. A stratified Cox regression outperforms other methods in generalizability and adjusting for residual bias. Serum UA should be

  3. Short term tolvaptan increases water intake and effectively decreases urinary calcium oxalate, calcium phosphate, and uric acid supersaturations

    PubMed Central

    Cheungpasitporn, Wisit; Erickson, Stephen B.; Rule, Andrew D.; Enders, Felicity; Lieske, John C.

    2016-01-01

    Purpose Many patients cannot effectively increase water intake and urine volume to prevent urinary stones. Tolvaptan, a V2 receptor antagonist, blocks water reabsorption in the collecting duct and should reduce urinary supersaturation (SS) of stone forming solutes, but this has never been proven. Materials and Methods We conducted a double blind, randomized, placebo-controlled, crossover study in 21 adult calcium urinary stone formers stratified as majority calcium oxalate(CaOx, n=10) or calcium phosphate(CaP, n=11). Patients received tolvaptan 45 mg/day or placebo for 1 week, followed by a washout week and crossover to tolvaptan or placebo for week 3. A 24h urines was collected at the end of weeks 1 and 3. Results Tolvaptan vs. placebo decreased urinary osmolality (204±96 vs 529±213 mOsm/kg, P<0.001) and increased urinary volume (4.8±2.9 vs 1.8±0.9 L, P<0.001). The majority of urinary solute excretion rates including sodium and calcium did not significantly change, although oxalate secretion slightly increased (23±8 to 15±8 mg/24h, P = 0.009). Urinary CaOx SS (−0.01±1.14 vs 0.95±0.87 DG, P<0.001), CaP SS (−1.66±1.17 vs −0.13±1.02 DG, P<0.001) and Uric Acid SS (−2.05±4.05 vs −5.24±3.12 DG, P=0.04) all dramatically decreased. Effects did not differ between CaOx and CaP groups (P>0.05 for all interactions). Conclusions Tolvaptan increases urine volume and decreases urinary SS in calcium stone formers. Further study is needed to determine if long term use of V2 receptor antagonists results in fewer stone events. PMID:26598423

  4. [Simultaneous determination of creatinine, pseudouridine and uric acid in serum and urine by high performance liquid chromatography].

    PubMed

    Peng, Z; Wang, C; Li, C; Gao, Q; Wang, Z; Zhang, G; Zhang, J; Li, X; Peng, J

    1998-03-01

    In this paper a sensitive, rapid and simple HPLC method for the simultaneous determination of creatinine (Cr), pseudouridine (Pu) and uric acid(UA) has been established. We have evaluated clinical value of the method in the early diagnosis of diabetic nephropathy (DN). Separation was obtained using Shim-pack CLC-ODS 15 x 0.6 cm column and mobile phase of buffer solution of phosphate (pH 3.0, 0.02 mol/L) with flow rate of 1 mL/min. Detection was performed with UV detector at an automatic adjustment of wavelength. The recoveries of Cr, Pu and UA were 101.4%, 104.9% and 105.0% respectively. The calibration curves were linear within the concentration range of 8.6-274.6 mumol/L for Cr, 0.72-22.93 mumol/L for Pu and 19.1-612.7 mumol/L for UA (n = 6, r > 0.999, p < 0.01). The CV for within day and between day measurements were < 2.5% and < 5.0% respectively. In addition, Pu, Cr and UA were simultaneously determined in serum and urine of 39 patients with diabetic mellitus (DM). 15 patients with nephrotic syndrome (NS) and 53 normal subjects by the method. Results include: 1. the levels of serum Pu in all DM patients (100%) with microalbuminuria (MiAU) and macroalbuminuria (MaAU) were greater than maximum of normal subjects (X + 2S). In addition, in 9 DM patients (41%) with normal albuminuria (NAU) the levels were also greater than the maximum. 2. In patients with DM, there was no correlation between the serum Pu and the urinary albumin excretion (UAE), whereas the serum Pu correlated closely with the serum Cr. However, the incidence for serum Pu increase was significantly greater in patients. 3. The levels of serum Pu in patients with NS were greater than those in control subjects and patients with DM. Conclusion is that the determination of serum Pu could be used as sensitivity index for the early diagnosis of DN.

  5. Overview of Serum Uric Acid Treatment Targets in Gout: Why Less Than 6 mg/dL?

    PubMed

    Ruoff, Gary; Edwards, N Lawrence

    2016-09-01

    Gout is a progressive, painful, debilitating form of inflammatory arthritis. It is caused by factors that elevate the concentration of serum uric acid (sUA), leading to hyperuricemia (sUA >6.8 mg/dL). Continued elevated sUA can result in monosodium urate (MSU) crystal deposition in joints and soft tissues, and can cause acute and chronic inflammation. The prevalence of hyperuricemia and gout has increased over the last few decades, likely due to an aging population, changes in lifestyles and diet, and an increase in gout-associated comorbidities. Untreated or improperly treated gout can lead to chronic manifestation of the disease, including persistent inflammation, increased number of flares, development of tophi, and structural joint damage. Data show that even when patients are asymptomatic, ongoing inflammation and subsequent damage occurs locally at the joint and systemically. The aim of long-term treatment of gout is to reduce sUA levels to <6 mg/dL, which is below the saturation point of MSU (6.8 mg/dL), to inhibit formation of new crystals and to promote dissolution of existing crystals. Gout treatment should improve disease outcomes by eliminating gout flares, inducing long-term resolution of tophi, and more effectively managing comorbidities, many of which are associated with hyperuricemia. A number of studies have demonstrated that treating to the target of <6 mg/dL, by using effective therapies to lower sUA, results in reduction in the incidence of gout flares as well as shrinkage and eventual disappearance of tophi. Gout is often poorly managed due to a number of factors including lack of physician and patient adherence to treatment guidelines. Patients need to be educated about their diagnosis and management of the disease, such as the influence of diet and the importance of compliance with long-term treatment. With treatment, regular sUA monitoring, and patient adherence, gout is a curable disease. PMID:27558643

  6. Association Between Sex-Specific Serum Uric Acid and Non-Alcoholic Fatty Liver Disease in Chinese Adults

    PubMed Central

    Wu, Sheng-Jie; Zhu, Gui-Qi; Ye, Bo-Zhi; Kong, Fan-Qi; Zheng, Zai-Xing; Zou, Hai; Shi, Ke-Qing; Lin, Lu; Braddock, Martin; Huang, Wei-Jian; Chen, Yong-Ping; Zheng, Ming-Hua

    2015-01-01

    Abstract The aim of this study was to examine the association between sex-specific serum uric acid (sUA) levels and NAFLD in a large population-based study. A total of 60,455 subjects from 2 separate medical centers were included. Sex-specific sUA quartiles (Q1–Q4) were defined: ≤330, 331–380, 381–435, and ≥436 μmol/L for male; ≤230, 231–270, 271–310, and ≥311 μmol/L for female. The odds ratios (ORs), hazard ratios (HRs), and 95% confidence intervals (CIs) for NAFLD were calculated across each quartile of sUA, using the Q1 as reference. After adjusting for known confounding variables in this study, the ORs for NAFLD in the cross-sectional population were 1.211 (95% CI 1.109–1.322), 1.519 (95% CI 1.395–1.654), 1.903 (95% CI 1.748–2.072) for Q2, Q3, and Q4, respectively. In the longitudinal population, compared with the reference group, those in Q2, Q3, and Q4 had HRs of 1.127 (95% CI 0.956–1.330), 1.380 (95% CI 1.157–1.644), 1.589 (95% CI 1.310–1.927) for NAFLD, respectively. Analysis for the sex-specific subgroup showed the adjusted ORs for Q4 versus Q1 were 2.898 (95% CI 2.36–3.588) in female and 1.887 (95% CI 1.718–2.072) in male in the cross-sectional population. In the longitudinal population, the HRs for the Q4 were 2.355 (95% CI 1.702–3.259) in female and 1.249 (95% CI 0.975–1.601) in male, compared with Q1. We report that a sex-specific sUA level is independently associated with NAFLD. The association between sUA and NAFLD was significantly greater in females than in males. PMID:25929934

  7. Uric acid urine test

    MedlinePlus

    Burns CM, Wortmann RL. Clinical features and treatment of gout. In: Firestein GS, Budd RC, Gabriel SE, et al., eds. Kelly's Textbook of Rheumatology . 9th ed. Philadelphia, PA: Elsevier Saunders; 2013:chap 95. ...

  8. Determination of uric acid in urine, saliva and calcium oxalate renal calculi by high-performance liquid chromatography/mass spectrometry.

    PubMed

    Perelló, Joan; Sanchis, Pilar; Grases, Félix

    2005-09-25

    A very simple and direct method for determination of uric acid, in various biological matrices, based on high-performance liquid chromatography and mass spectrometry is described. Chromatographic separations were performed with a stationary phase Zorbax Sax Column, an anion exchange resin, with 50% sodium citrate 1 mM at pH 6.5 and 50% acetonitrile as mobile phase delivered at a flow rate of 1 ml/min. The detector counted negative ions by monitoring m/z 167.1, which corresponds to the urate anion. The method does not use an internal standard but quality control samples were used. Intra-day precision ranged between 1.1 and 1.5%, whereas inter-day precision was between 1.3 and 2.8% (n=5) working with some selected standards. Recovery tests of added standard have been successfully performed in urine and saliva samples, thus showing an appropriate accuracy of the method. The limit of quantitation found was 70 microg/l. Different urine and saliva samples were analyzed using an alternative analytical methodology based on an enzymatic reaction and photometric detection at 520 nm, resulting both methods comparable at a 95% confidence level. The method has been also applied to the determination of trace amounts of uric acid in the core of some selected calcium oxalate renal calculi. PMID:16061429

  9. Association between serum uric acid levels and cardiovascular risk among university workers from the State of Mexico: a nested case–control study

    PubMed Central

    2013-01-01

    Background Recent evidence suggests that serum uric acid (SUA) can be an inexpensive and easy-to-obtain indicator of cardiovascular risk (CR). This is especially important in developing countries with high prevalence of cardiovascular disease. We examined the association between SUA levels and 10-year global CR among university workers from the State of Mexico, Mexico. Methods A case–control study nested within a cohort was conducted between 2004 and 2006. Anthropometric measures, lifestyle variables, family background and CR factors were assessed. The analysis estimated odds ratios using conditional logistic regression. Results The study included 319 cases with CR and 638 controls. Subjects in the upper tertile of SUA had 48.0% higher odds of having an elevated CR than those in the lower tertile (OR = 1.48, 95% CI: 1.04 - 2.10) in the crude analysis, but the association was non-significant when adjusting for other covariates. Among physically inactive individuals, being in the third tertile of SUA doubled the odds of high CR, compared with those who perform physical activity three or more hours per week being in the first tertile of SUA (OR = 2.35, 95% CI: 1.24 - 4.45). Conclusion Serum concentration of uric acid is associated with 10-year global CR among individuals with high levels of physical inactivity. PMID:23631758

  10. Mutation of a novel ABC transporter gene is responsible for the failure to incorporate uric acid in the epidermis of ok mutants of the silkworm, Bombyx mori.

    PubMed

    Wang, Lingyan; Kiuchi, Takashi; Fujii, Tsuguru; Daimon, Takaaki; Li, Muwang; Banno, Yutaka; Kikuta, Shingo; Kikawada, Takahiro; Katsuma, Susumu; Shimada, Toru

    2013-07-01

    ok mutants of the silkworm, Bombyx mori, exhibit highly translucent larval skin resulting from the inability to incorporate uric acid into the epidermal cells. Here we report the identification of a gene responsible for the ok mutation using positional cloning and RNAi experiments. In two independent ok mutant strains, we found a 49-bp deletion and a 233-bp duplication, respectively, in mRNAs of a novel gene, Bm-ok, which encodes a half-type ABC transporter, each of which results in translation of a truncated protein in each mutant. Although the Bm-ok sequence was homologous to well-known transporter genes, white, scarlet, and brown in Drosophila, the discovery of novel orthologs in the genomes of lepidopteran, hymenopteran, and hemipteran insects identifies it as a member of a new distinct subfamily of transporters. Embryonic RNAi of Bm-ok demonstrated that repression of Bm-ok causes a translucent phenotype in the first-instar silkworm larva. We discuss the possibility that Bm-ok forms a heterodimer with another half-type ABC transporter, Bmwh3, and acts as a uric acid transporter in the silkworm epidermis.

  11. Human nails metabolite analysis: A rapid and simple method for quantification of uric acid in human fingernail by high-performance liquid chromatography with UV-detection.

    PubMed

    Li, Xi-Ling; Li, Gao; Jiang, Ying-Zi; Kang, Dongzhou; Jin, Cheng Hua; Shi, Qing; Jin, Toufeng; Inoue, Koichi; Todoroki, Kenichiro; Toyo'oka, Toshimasa; Min, Jun Zhe

    2015-10-01

    A rapid and simple analytical method for the quantification of uric acid (UA) in human fingernails by high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection is described. UA was extracted from human fingernail samples at 90°C for 20min, then separated on an Inertsil ODS-2 column (250×4.6mm I.D., 5.0μm, GL Sciences) by isocratic elution using methanol: 74mM phosphate buffer (pH 2.2) 2:98 (v/v). An UV detector was used to monitor at 284nm. The results indicated that under optimized measurement conditions results were achieved within 8.0min, and a good linearity was achieved from the calibration curves (r(2)>0.9999) in the range of 1.0-10000ng; the limit of detection (S/N=3) was 2.0pg, the inter-day and intra-day assay precisions were all less than 0.46% and the mean recoveries (%) of the uric acid spiked in the human fingernail were 101.95%. The amounts of UA in the fingernails of healthy volunteers were determined.

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

    PubMed

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

    2015-07-09

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

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

    PubMed Central

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

    2015-01-01

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

  14. Electrochemical Sensor Based on Fe Doped Hydroxyapatite-Carbon Nanotubes Composite for L-Dopa Detection in the Presence of Uric Acid.

    PubMed

    Kanchana, P; Radhakrishnan, S; Navaneethan, M; Arivanandhan, M; Hayakawa, Y; Sekar, C

    2016-06-01

    A novel amperometric sensor based on iron doped hydroxyapatite (Fe-HA) and multiwalled carbon nanotubes (CNT) composite immobilized on a glassy carbon electrode (GCE) has been fabricated. The hybrid composite made of Fe-HA nanoparticles and CNT promotes electron transfer kinetics between the analyte levodopa (L-dopa) and the modified GC electrode. Under optimum conditions, the fabricated sensor gave a linear response range of 1.0 x 10(-7)-1.1 x 10(-6) M with the detection limit as low as 62 nM. The Fe-HA/CNT modified electrode showed good selectivity towards the determination of L-dopa in the presence of ascorbic acid (AA), uric acid (UA) and other common interferents. The sensor displays a high sensitivity, good reproducibility and long-term stability and it was successfully applied for the detection of L-dopa in pharmaceutical and medicinal plant samples. PMID:27427688

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

    PubMed

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

    2016-01-15

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

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

    PubMed

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

    2016-01-15

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

  17. Poly(brilliant green) and poly(thionine) modified carbon nanotube coated carbon film electrodes for glucose and uric acid biosensors.

    PubMed

    Ghica, M Emilia; Brett, Christopher M A

    2014-12-01

    Poly(brilliant green) (PBG) and poly(thionine) (PTH) films have been formed on carbon film electrodes (CFEs) modified with carbon nanotubes (CNT) by electropolymerisation using potential cycling. Voltammetric and electrochemical impedance characterisation were performed. Glucose oxidase and uricase, as model enzymes, were immobilised on top of PBG/CNT/CFE and PTH/CNT/CFE for glucose and uric acid (UA) biosensing. Amperometric determination of glucose and UA was carried out in phosphate buffer pH 7.0 at -0.20 and +0.30 V vs. SCE, respectively, and the results were compared with other similarly modified electrodes existing in the literature. An interference study and recovery measurements in natural samples were successfully performed, indicating these architectures to be good and promising biosensor platforms.

  18. Effects of anthocyanins from purple sweet potato (Ipomoea batatas L. cultivar Eshu No. 8) on the serum uric acid level and xanthine oxidase activity in hyperuricemic mice.

    PubMed

    Zhang, Zi-Cheng; Su, Guan-Hua; Luo, Chun-Li; Pang, Ya-Lu; Wang, Lin; Li, Xing; Wen, Jia-Hao; Zhang, Jiu-Liang

    2015-09-01

    This study was aimed at evaluating the hypouricemic effect of the anthocyanin-rich purple sweet potato extract (APSPE). In vitro, APSPE has been proved to significantly inhibit XO activity in a dose-dependent manner. In vivo, APSPE could not only inhibit the XO activity in mouse liver, but also reduce the serum uric acid level in hyperuricemic mice and affect the expression of mRNA levels of related renal transporters, such as mURAT1, mGLUT9, mOAT1 and mOCTN2. Moreover, APSPE could effectively regulate BUN and Cr levels to normal and decrease the inflammatory cellular influx in the tubule of the hyperuricemic mice. This study indicates the potential clinical utility of APSPE as a safe and effective anti-hyperuricemia bioactive agent or functional food. PMID:26201407

  19. Effects of anthocyanins from purple sweet potato (Ipomoea batatas L. cultivar Eshu No. 8) on the serum uric acid level and xanthine oxidase activity in hyperuricemic mice.

    PubMed

    Zhang, Zi-Cheng; Su, Guan-Hua; Luo, Chun-Li; Pang, Ya-Lu; Wang, Lin; Li, Xing; Wen, Jia-Hao; Zhang, Jiu-Liang

    2015-09-01

    This study was aimed at evaluating the hypouricemic effect of the anthocyanin-rich purple sweet potato extract (APSPE). In vitro, APSPE has been proved to significantly inhibit XO activity in a dose-dependent manner. In vivo, APSPE could not only inhibit the XO activity in mouse liver, but also reduce the serum uric acid level in hyperuricemic mice and affect the expression of mRNA levels of related renal transporters, such as mURAT1, mGLUT9, mOAT1 and mOCTN2. Moreover, APSPE could effectively regulate BUN and Cr levels to normal and decrease the inflammatory cellular influx in the tubule of the hyperuricemic mice. This study indicates the potential clinical utility of APSPE as a safe and effective anti-hyperuricemia bioactive agent or functional food.

  20. Poly(brilliant green) and poly(thionine) modified carbon nanotube coated carbon film electrodes for glucose and uric acid biosensors.

    PubMed

    Ghica, M Emilia; Brett, Christopher M A

    2014-12-01

    Poly(brilliant green) (PBG) and poly(thionine) (PTH) films have been formed on carbon film electrodes (CFEs) modified with carbon nanotubes (CNT) by electropolymerisation using potential cycling. Voltammetric and electrochemical impedance characterisation were performed. Glucose oxidase and uricase, as model enzymes, were immobilised on top of PBG/CNT/CFE and PTH/CNT/CFE for glucose and uric acid (UA) biosensing. Amperometric determination of glucose and UA was carried out in phosphate buffer pH 7.0 at -0.20 and +0.30 V vs. SCE, respectively, and the results were compared with other similarly modified electrodes existing in the literature. An interference study and recovery measurements in natural samples were successfully performed, indicating these architectures to be good and promising biosensor platforms. PMID:25159399

  1. A novel third generation uric acid biosensor using uricase electro-activated with ferrocene on a Nafion coated glassy carbon electrode.

    PubMed

    Ghosh, Tanushree; Sarkar, Priyabrata; Turner, Anthony P F

    2015-04-01

    A new uric acid biosensor was constructed using ferrocene (Fc) induced electro-activated uricase (UOx) deposited within Nafion (Naf) on glassy carbon electrode (GCE). Electro-activation of UOx was successfully achieved by cyclic voltammetry through the electrostatic interaction of Fc with Trp residues within the hydrophobic pockets in UOx. The Naf/UOx/Fc composite was characterised by AFM, FTIR and EDX to ensure proper immobilisation. The interaction of Fc with the enzyme was analysed by Trp fluorescence spectroscopy and the α-helicity of the protein was measured by CD spectropolarimetry. The charge transfer resistance (Rct), calculated from electrochemical impedance spectroscopy, for the modified sensor was lowered (1.39 kΩ) and the enzyme efficiency was enhanced by more than two fold as a result of Fc incorporation. Cyclic voltammetry, differential pulse voltammetry and amperometry all demonstrated the excellent response of the Naf/UOx/Fc/GCE biosensor to uric acid. The sensor system generated a linear response over a range of 500 nM to 600 μM UA, with a sensitivity and limit of detection of 1.78 μA μM(-1) and 230 nM, respectively. The heterogeneous rate constant (ks) for UA oxidation was much higher for Naf/UOx/Fc/GCE (1.0 × 10(-4) cm s(-1)) than for Naf/UOx/GCE (8.2 × 10(-5) cm s(-1)). Real samples, i.e. human blood, were tested for serum UA and the sensor yielded accurate results at a 95% confidence limit.

  2. Serum uric acid levels predict the development of albuminuria over 6 years in patients with type 1 diabetes: Findings from the Coronary Artery Calcification in Type 1 Diabetes study

    PubMed Central

    Jalal, Diana I.; Rivard, Christopher J.; Johnson, Richard J.; Maahs, David M.; McFann, Kimberly; Rewers, Marian; Snell-Bergeon, Janet K.

    2010-01-01

    Background. Recent studies suggest that uric acid is a mediator of diabetic nephropathy. We hypothesized that elevated serum uric acid levels are a strong predictor of albuminuria in patients with type 1 diabetes. Methods. We analyzed data from the Coronary Artery Calcification in Type 1 Diabetes study, a prospective observational study. A stepwise logistic regression model was applied to predict the development of micro- or macroalbuminuria after 6 years of follow-up in 324 participants who had no evidence of micro- or macroalbuminuria at baseline. A P-value <0.1 was used as the criteria for entry into and removal from the model. Results. The following factors were selected in the stepwise multivariate model as predictors of micro- or macroalbuminuria at the 6-year follow-up visit: baseline serum uric acid levels, HbA1c and pre-albuminuria. For every 1-mg/dl increase in serum uric acid levels at baseline, there was an 80% increased risk of developing micro- or macroalbuminuria at 6 years (odds ratio 1.8; 95% confidence interval 1.2, 2.8; P = 0.005). Additional covariates considered in the stepwise model were sex, age, duration of diabetes, angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker treatment, waist circumference, waist/hip ratio, body mass index, systolic and diastolic blood pressure, smoking, serum creatinine, cystatin C, high-density lipoprotein cholesterol and triglycerides. Conclusion. Elevated serum uric acid levels are a strong predictor of the development of albuminuria in patients with type 1 diabetes. PMID:20064950

  3. PDK2 and ABCG2 genes polymorphisms are correlated with blood glucose levels and uric acid in Tibetan gout patients.

    PubMed

    Ren, Y C; Jin, T B; Sun, X D; Geng, T T; Zhang, M X; Wang, L; Feng, T; Kang, L L; Chen, C

    2016-01-01

    Previous studies have shown that the PDK2 and ABCG2 genes play important roles in many aspects of gout development in European populations. However, a detailed genotype-phenotype analysis was not performed. The aim of the present study was to investigate the potential association between variants in these two genes and metabolism-related quantitative phenotypes relevant to gout in a Chinese Tibetan population. In total, 316 Chinese Tibetan gout patients were recruited from rheumatology outpatient clinics and 6 single nucleotide polymorphisms in PDK2 and ABCG2 were genotyped, which were possible etiologic variants as identified in the HapMap Chinese Han Beijing population. A significant difference in blood glucose levels was detected between different genotypes of rs2728109 (P = 0.005) in the PDK2 gene. We also detected a significant difference in the mean serum uric levels between different genotypes of rs3114018 (P = 0.004) in the ABCG2 gene. All P values remained significant after Bonferroni's correction for multiple testing. Our data demonstrate potential roles for PDK2 and ABCG2 polymorphisms in the metabolic phenotypes of Tibetan gout patients, which may provide new insights into the etiology of gout. Further studies are required to confirm these findings. PMID:26909964

  4. Capillary ion electrophoresis of inorganic anions and uric acid in human saliva using a polyvinyl alcohol coated capillary column and hexamethonium chloride as additive of background electrolyte.

    PubMed

    Mori, Masanobu; Yamamoto, Tsukasa; Kaseda, Maki; Yamada, Sachiko; Itabashi, Hideyuki

    2012-03-01

    A combination of polyvinyl alcohol chemically coated capillary (PVA capillary) and background electrolyte (BGE) with ion-pair reagent (hexamethonium dichloride, HMC) was used on capillary ion electrophoresis-UV detection (CIE-UV) for analysis of Br⁻, I⁻, NO₂⁻, NO₃⁻, SCN⁻ and uric acid in human saliva. The PVA capillary prepared in our laboratory minimized electro-osmotic flow (EOF) at the BGE in pH 3-10, and did not affect the UV detection at 210 nm by the PVA-layer on capillary wall. Therefore, use of the PVA capillary was suitable for sensitive UV detection for analyte anions, as well as suppression of protein adsorption. In this study, we optimized the BGE of 10 mM phosphate plus 10 mM HMC with applying a voltage of -15 kV. HMC as an additive to BGE could manipulate the electrophoretic mobility of anions, without electrostatic adsorption to the PVA capillary. The CIE-UV could separate and determine analyte anions in human saliva containing proteins by the direct injection without pretreatments such as dilution or deproteinization within 13 min. The relative standard deviations (n=10) were ranged of 0.5-1.6% in migration times, 2.2-6.8% in peak heights and 2.8-8.4% in peak areas. The limits of detection (S/N=3) were ranged of 3.42-6.87 μM. The peak height of anions in this system was gradually decreased through the successive injections of saliva samples, but the problem was successfully solved by periodically conditioning the PVA capillary. The quantifiability of anions in human saliva samples by the CIE-UV was evaluated through the recoveries by standard addition methods and comparison of other representative analytical methods, as well as identification by ion chromatography (IC). From the anion analyses in 12 different saliva samples, the CIE-UV demonstrated that can obtain obvious differences in concentrations of SCN⁻ between of smoker and non-smoker and those of uric acid between male and female with satisfactory results.

  5. Is Uric Acid a Missing Link between Previous Gestational Diabetes Mellitus and the Development of Type 2 Diabetes at a Later Time of Life?

    PubMed Central

    Fronczyk, Aneta; Safranow, Krzysztof; Majkowska, Lilianna

    2016-01-01

    Introduction A high level of uric acid (UA) is a strong, independent risk factor for type 2 diabetes mellitus. The relationship between UA levels and the development of type 2 diabetes in women with previous gestational diabetes mellitus (pGDM) remains unclear. The aim of study was to evaluate the UA levels in pGDM women in relation to their current nutritional status and carbohydrate metabolism. Material and Methods 199 women with pGDM diagnoses based on oral glucose tolerance tests (OGTTs) 5–12 years previously and a control group of 50 women without pGDM. The assessment included anthropometric parameters, body composition (Tanita SC-330S), current OGTT, insulin resistance index (HOMA-IR), β-cell function (HOMA-%B), HbA1c, lipids, and uric acid. Results No differences between groups were found in terms of age, time from the index pregnancy, anthropometric parameters, lipids or creatinine levels. The incidences of overweight and obesity were similar. Carbohydrate abnormalities were more frequent in the pGDM group than the control group (43.2% vs 12.0% p<0.001). The women with pGDM had significantly higher fasting glucose, HbA1c, glucose and insulin levels in the OGTTs, but similar HOMA-IR values. Their UA levels were significantly higher (258±58 vs 230±50 μmol/L, p<0.005) and correlated with BMI and the severity of carbohydrate disorders. The normal weight and normoglycemic pGDM women also demonstrated higher UA levels than a similar control subgroup (232±48 vs 208±48 μmol/L, p<0.05). Multivariate analysis revealed significant correlations of UA level with BMI (β = 0.38, 95% CI 0.25–0.51, p<0.0001), creatinine level (β = 0.23, 95% CI 0.11–0.35, p<0.0005), triglycerides (β = 0.20, 95% CI 0.07–0.33, p<0.005) and family history of diabetes (β = 0.13, 95% CI 0.01–0.25, p<0.05). In logistic regression analysis, the association between higher UA level (defined as value ≥297 μmol/L) and presence of any carbohydrate metabolism disorder (IFG, IGT or

  6. Photochemiluminescent detection of antiradical activity. VI. Antioxidant characteristics of human blood plasma, low density lipoprotein, serum albumin and amino acids during in vitro oxidation.

    PubMed

    Popov, I; Lewin, G

    1999-01-01

    During investigation of the mechanism of therapeutic efficacy of UV (254 nm)-irradiated autologous blood, the antioxidant capacity (AC) of plasma, serum albumin, 20 amino acids, uric acid, ascorbic acid and alpha-tocopherol was measured after irradiation in vitro. AC of plasma demonstrated a biphasic time course (decrease to in a minimum (greater zero) followed by an increase). AC of uric acid, ascorbic acid and alpha-tocopherol diminished under irradiation to zero. In contrast, albumin and seven amino acids developed AC following irradiation. During the Cu(+2)-induced oxidation of low-density lipoprotein (LDL), the AC measured in a system for water-soluble substances appeared, after a lag-phase, to be comparable to that of the conjugated diene formation; AC of LDL measured in a system for lipid-soluble substances demonstrated a biphasic course. Our results suggest that: (a) the oxidized products of some amino acids and proteins acquire antiradical properties at the same time that they are being produced; (b) the biphasic character of changes of antioxidant properties of blood plasma during UV irradiation represents the overlapping of two processes: disappearing of antioxidants and acquisition of AC by (lipo)proteins; and (c) the measurement of AC of blood plasma (lipo)proteins can possibly serve to detect the existence and extent of oxidative stress in human organism.

  7. 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.

  8. An 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid)-immobilized electrode for the simultaneous detection of dopamine and uric acid in the presence of ascorbic acid.

    PubMed

    Chih, Yi-Kai; Yang, Ming-Chang

    2013-06-01

    An 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS)-immobilized carbon nanotube (CNT) electrode was used to simultaneously detect dopamine (DA) and uric acid (UA) in the presence of ascorbic acid (AA) with differential pulse voltammetry. When ABTS was immobilized onto the CNT electrode in the presence of DA, UA and 100 μM AA, the sensitivity to DA increased from 0.600 (±0.013) to 1.334 (±0.010) μA/μM in the concentration ranges of 0.90-10 μM and 1.87-20 μM, respectively, and the sensitivity to UA increased from 0.030 (±0.005) to 0.078 (±0.006) μA/μM in the concentration ranges of 2.16-240 μM and 3.07-400 μM, respectively. These findings demonstrate that the ABTS-immobilized CNT electrode attained a higher sensitivity to UA and also a wider linear range of concentrations.

  9. Selective detection of uric acid in the presence of ascorbic acid at physiological pH by using a beta-cyclodextrin modified copolymer of sulfanilic acid and N-acetylaniline.

    PubMed

    Wu, Shouguo; Wang, Taoling; Gao, Zongyong; Xu, Haihong; Zhou, Baineng; Wang, Chuanqin

    2008-07-15

    A beta-cyclodextrin (CD) modified copolymer membrane of sulfanilic acid (p-ASA) and N-acetylaniline (SPNAANI) on glassy carbon electrode (GCE) was prepared and used to determine uric acid (UA) in the presence of a large excess of ascorbic acid (AA) by differential pulse voltammetry (DPV). The properties of the copolymer were characterized by X-ray photoelectron spectra (XPS) and Raman spectroscopy. The oxidation peaks of AA and UA were well separated at the composite membrane modified electrode in phosphate buffer solution (PBS, pH 7.4). A linear relationship between the peak current and the concentration of UA was obtained in the range from 1.0 x 10(-5) to 3.5 x 10(-4)mol L(-1), and the detection limit was 2.7 x 10(-6)mol L(-1) at a signal-to-noise ratio of 3. Two hundred and fifty-fold excess of AA did not interfere with the determination of UA. The application of the prepared electrode was demonstrated by measuring UA in human serum samples without any pretreatment, and the results were comparatively in agreement with the spectrometric clinical assay method.

  10. An ultrasensitive electrochemical sensor for simultaneous determination of xanthine, hypoxanthine and uric acid based on Co doped CeO2 nanoparticles.

    PubMed

    Lavanya, N; Sekar, C; Murugan, R; Ravi, G

    2016-08-01

    A novel electrochemical sensor has been fabricated using Co doped CeO2 nanoparticles for selective and simultaneous determination of xanthine (XA), hypoxanthine (HXA) and uric acid (UA) in a phosphate buffer solution (PBS, pH5.0) for the first time. The Co-CeO2 NPs have been prepared by microwave irradiation method and characterized by Powder XRD, Raman spectroscopy, HRTEM and VSM measurements. The electrochemical behaviours of XA, HXA and UA at the Co-CeO2 NPs modified glassy carbon electrode (GCE) were studied by cyclic voltammetry and square wave voltammetry methods. The modified electrode exhibited remarkably well-separated anodic peaks corresponding to the oxidation of XA, HXA and UA over the concentration range of 0.1-1000, 1-600 and 1-2200μM with detection limits of 0.096, 0.36, and 0.12μM (S/N=3), respectively. For simultaneous detection by synchronous change of the concentrations of XA, HXA and UA, the linear responses were in the range of 1-400μM each with the detection limits of 0.47, 0.26, and 0.43μM (S/N=3), respectively. The fabricated sensor was further applied to the detection of XA, HXA and UA in human urine samples with good selectivity and high reproducibility.

  11. The impact of serum uric acid on the natural history of glomerular filtration rate: a retrospective study in the general population

    PubMed Central

    Xu, Ying; Liu, Xiang; Sun, Xiaohe

    2016-01-01

    Serum uric acid (SUA) level has been proposed to have important connections with chronic kidney disease (CKD), while the impact of SUA level on the natural history of glomerular filtration rate (GFR) decline remains unknown. The present study aims to study the association of the SUA level with the GFR decline in a general population. Two thousand, seven hundred and eighty-nine subjects who visited the Health Checkup Clinic both at 2008 and 2013 were identified. A significant inverse correlation was observed between change in SUA from 2008–2013 (ΔSUA) and change in eGFR (ΔeGFR) during the same period. Multivariate regression analysis of ΔeGFR indicated that the increase in SUA over time were a negative predictor of the change in eGFR. Our result indicates that the decline of eGFR over years is larger in subjects with an increased SUA level, which helps to underline the importance of SUA level management in the context of kidney function preservation. PMID:27069799

  12. High loading of uniformly dispersed Pt nanoparticles on polydopamine coated carbon nanotubes and its application in simultaneous determination of dopamine and uric acid

    NASA Astrophysics Data System (ADS)

    Lin, Mouhong; Huang, Haoliang; Liu, Yingju; Liang, Canjian; Fei, Shidong; Chen, Xiaofen; Ni, Chunlin

    2013-02-01

    Multiwalled carbon nanotubes (MWCNT) were homogeneously covered with a bio-functional polydopamine (PDOP) by a simple dip-coating approach in mild basic solution. Then, uniformly dispersed and highly loaded platinum nanoparticles (PtNPs) were deposited on MWCNT@PDOP by a mild reductant, and were characterized by transmission electron microscopy and x-ray photoelectron spectroscopy. Afterwards, this nanocomposite was modified on the glass carbon electrode and applied to simultaneously determine dopamine (DA) and uric acid (UA) by differential pulse voltammetry (DPV). Results showed that a linear electro-oxidation response was found for DA and UA in the range of 0.25-20 μM and 0.3-13 μM with the detection limit (S/N = 3) of 0.08 μM and 0.12 μM, respectively. In addition, the detection sensitivities for DA and UA by DPV were 1.03 μA μM-1 and 2.09 μA μM-1, respectively, which were much higher than those from a cyclic voltammogram. Finally, the reproducibility and stability of the nanocomposite were also evaluated, demonstrating that such MWCNT@PDOP@PtNPs can be a promising candidate for advanced electrode material in electrochemical sensing and other electrocatalytic applications.

  13. Effect of Soy Sauce on Serum Uric Acid Levels in Hyperuricemic Rats and Identification of Flazin as a Potent Xanthine Oxidase Inhibitor.

    PubMed

    Li, Huipin; Zhao, Mouming; Su, Guowan; Lin, Lianzhu; Wang, Yong

    2016-06-15

    This is the first report on the ability of soy sauce to effectively reduce the serum uric acid levels and xanthine oxidase (XOD) activities of hyperuricemic rats. Soy sauce was partitioned sequentially into ethyl acetate and water fractions. The ethyl acetate fraction with strong XOD inhibition effect was purified further. On the basis of xanthine oxidase inhibitory (XOI) activity-guided purification, nine compounds including 3,4-dihydroxy ethyl cinnamate, diisobutyl terephthalate, harman, daidzein, flazin, catechol, thymine, genistein, and uracil were obtained. It was the first time that 3,4-dihydroxy ethyl cinnamate and diisobutyl terephthalate had been identified from soy sauce. Flazin with hydroxymethyl furan ketone group at C-1 and carboxyl at C-3 exhibited the strongest XOI activity (IC50 = 0.51 ± 0.05 mM). According to fluorescence quenching and molecular docking experiments, flazin could enter into the catalytic center of XOD to interact with Lys1045, Gln1194, and Arg912 mainly by hydrophobic forces and hydrogen bonds. Flazin, catechol, and genistein not only were potent XOD inhibitors but also held certain antioxidant activities. According to ADME (absorption, distribution, metabolism, and excretion) simulation in silico, flazin had good oral bioavailability in vivo. PMID:27181598

  14. Total saponins from dioscorea septemloba thunb reduce serum uric acid levels in rats with hyperuricemia through OATP1A1 up-regulation.

    PubMed

    Chen, Yan; Chen, Xiao-lin; Xiang, Ting; Sun, Bao-guo; Luo, Hao-xuan; Liu, Meng-ting; Chen, Ze-xiong; Zhang, Shi-jun; Wang, Chang-Jun

    2016-04-01

    The aim of this study is to evaluate the efficacy of total saponins of Dioscorea (TSD), an extract of the Chinese herbal Bi Xie, on hyperuricemia and to elucidate the underlying mechanisms. The rat hyperuricemia model was established by administration of adenine. Thirty-two rats were randomly allocated into 4 groups: model group, low/high-dose TSD-treated groups, and allopurinol-treated group. Meanwhile, 8 rats were used as normal controls. Serum uric acid (UA), blood urea nitrogen (BUN), serum creatinine (Scr), and organic anion transporting polypeptide 1A1 (OATP1A1) levels were measured. Comparison between the model group and treatment (allopurinol and TSD) groups showed the serum UA levels were significantly decreased in treatment groups. TSD had similar effects to allopurinol. It was found that the OATP1A1 protein expression levels in treatment groups were higher than in model group and normal controls. And different from the allopurinol-treated groups, TSD-treated group had elevated OATP1A1 expression levels in the stomach, liver, small intestine and large intestine tissues. It was suggested that TSD may facilitate the excretion of UA and lower UA levels by up-regulating OATP1A1 expression.

  15. In vitro Xanthine Oxidase Inhibitory Studies of Lippia nodiflora and Isolated Flavonoids and Phenylethanoid Glycosides as Potential Uric Acid-lowering Agents.

    PubMed

    Cheng, Lee-Chuen; Murugaiyah, Vikneswaran; Chan, Kit-Lam

    2015-06-01

    Lippia nodiflora has been traditionally used for treatment of knee joint pain. Hitherto, no studies have been reported on the effective use of L. nodiflora against hyperuricemia, gout or other metabolic disorders. In this present study, L. nodiflora was examined for its ability to lower uric acid levels using an in vitro xanthine oxidase inhibitory assay. The whole plant methanolic extract was subjected to bioactivity-guided fractionation to yield 4 fractions (F1-F4). F3 displayed the highest potency and was further purified by column chromatography to afford two phenylethanoid glycosides, arenarioside (1) and verbascoside (2), and three flavonoids, 6-hydroxyluteolin (3), 6-hydroxyluteolin-7-O-glycoside (4), and nodifloretin (5). These compounds inhibited xanthine oxidase activity, with IC50 values between 7.52 ± 0.01 and 130.00 ± 2.25 μM, of which 3 was the most potent. In contrast, allopurinol, serving as a positive control, was 0.22 ± 0.00 μM. Thus, L. nodiflora, and its chemical constituents are worthy of further studies as potential anti-hyperuricemic agents.

  16. Serum Uric Acid and Prehypertension Among Adults Free of Cardiovascular Diseases and Diabetes: Baseline of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

    PubMed

    Lotufo, Paulo A; Baena, Cristina P; Santos, Itamar S; Bensenor, Isabela M

    2016-02-01

    The association between serum uric acid (SUA) and prehypertension was evaluated in a racially admixed sample of civil servants aged 35 to 74 years, enrolled (2008-2010) in the Brazilian Longitudinal Study of Health (ELSA-Brasil). Of the 15 105 patients who enrolled in the study, we analyzed 3412 after excluding those who reported previous cardiovascular diseases, diabetes, or hypertension; were heavy drinkers; or had a body mass index (BMI) ≥ 35 kg/m(2). Among the men, logistic regression, adjusted for age, race, income, birth weight, salt intake, insulin resistance, BMI, and renal function revealed odds ratios (ORs) and 95% confidence intervals (CIs) of prehypertension from the bottom quartile (referent) to the top quartile of SUA levels as follows: 0.84 (95% CI, 0.61-1.38), 0.97 (0.71-1.34) and 1.44 (1.04-2.0; P for trend .01). Analyzing for 1-standard deviation of change in SUA, the ORs were 1.19 (1.06-1.32). This association persisted in the subgroup analysis consisting of patients who were white, overweight, with a high salt intake but with normal renal function, and without metabolic syndrome. No association was found among women. In conclusion, SUA levels were associated with prehypertension among men.

  17. Electrocatalytic determination of dopamine in the presence of uric acid using an indenedione derivative and multiwall carbon nanotubes spiked in carbon paste electrode.

    PubMed

    Nasirizadeh, Navid; Shekari, Zahra; Zare, Hamid R; Makarem, Somayeh

    2013-04-01

    In the present study, a modified carbon paste electrode (CPE) containing multi-wall carbon nanotubes and an indenedione derivative(IMWCNT-CPE) was constructed and was successfully used for dopamine(DA) electrocatalytic oxidation and simultaneous determination of DA and uric acid (UA). Cyclic voltammograms of the IMWCNT-CPE show a pair of well-defined and reversible redox. The obtained results indicate that the peak potential of DA oxidation at IMWCNT-CPE shifted by about 65 and 185 mV toward the negative values compared with that at a MWCNT and indenedione modified CPE, respectively. The electron transfer coefficient, α, and the heterogeneous electron transfer rate constant, k', for the oxidation of DA at IMWCNT-CPE were calculated 0.4±0.01 and (1.13±0.03)×10(-3) cm s(-1), respectively. Furthermore, differential pulse voltammetry (DPV) exhibits two linear dynamic ranges of 1.9-79.4 μM, and 79.4-714.3 μM and a detection limit of 0.52 μM for DA determination. Then IMWCNT-CPE was applied to the simultaneous determination of DA and UA with DPV. Finally, the activity of the modified electrode was also investigated for determination of DA and UA in real samples, such as injection solution of DA and urine, with satisfactory results.

  18. Serum Uric Acid and Prehypertension Among Adults Free of Cardiovascular Diseases and Diabetes: Baseline of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

    PubMed

    Lotufo, Paulo A; Baena, Cristina P; Santos, Itamar S; Bensenor, Isabela M

    2016-02-01

    The association between serum uric acid (SUA) and prehypertension was evaluated in a racially admixed sample of civil servants aged 35 to 74 years, enrolled (2008-2010) in the Brazilian Longitudinal Study of Health (ELSA-Brasil). Of the 15 105 patients who enrolled in the study, we analyzed 3412 after excluding those who reported previous cardiovascular diseases, diabetes, or hypertension; were heavy drinkers; or had a body mass index (BMI) ≥ 35 kg/m(2). Among the men, logistic regression, adjusted for age, race, income, birth weight, salt intake, insulin resistance, BMI, and renal function revealed odds ratios (ORs) and 95% confidence intervals (CIs) of prehypertension from the bottom quartile (referent) to the top quartile of SUA levels as follows: 0.84 (95% CI, 0.61-1.38), 0.97 (0.71-1.34) and 1.44 (1.04-2.0; P for trend .01). Analyzing for 1-standard deviation of change in SUA, the ORs were 1.19 (1.06-1.32). This association persisted in the subgroup analysis consisting of patients who were white, overweight, with a high salt intake but with normal renal function, and without metabolic syndrome. No association was found among women. In conclusion, SUA levels were associated with prehypertension among men. PMID:25972396

  19. Magnetic core-shell Fe₃O₄@SiO₂/MWCNT nanocomposite modified carbon paste electrode for amplified electrochemical sensing of uric acid.

    PubMed

    Arvand, Majid; Hassannezhad, Morassa

    2014-03-01

    A new type of nanocomposite based on multi-walled carbon nanotubes decorated with magnetic core-shell Fe3O4@SiO2 nanoparticles (Fe3O4@SiO2/MWCNTs) was prepared and used to fabricate a modified carbon paste electrode (CPE). The nanocomposite was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectroscopy (FT-IR) techniques. Electrochemical behavior of uric acid (UA) was investigated on Fe3O4@SiO2/MWCNTs-CPE by cyclic voltammetry (CV) and square wave voltammetry (SWV) in phosphate buffer solution (pH6.0). Under the optimized conditions, the peak currents increased linearly with the concentration of UA in the range from 0.60 to 100.0 μM, with a detection limit of 0.13 μM. The proposed sensor was successfully applied for the determination of UA in biological fluids.

  20. Long-chain-substituted uric acid and 5,6-diaminouracil derivatives as novel agents against free radical processes: synthesis and in vitro activity.

    PubMed

    Fraisse, L; Verlhac, J B; Roche, B; Rascle, M C; Rabion, A; Seris, J L

    1993-05-14

    A new series of N-alkylated uric acids (2,6,8-purinetrione) and 5,6-diaminouracils (5,6-diamino-2,4-pyrimidinedione) were synthesized, and their activities against free radicals were evaluated. Long-chain derivatives of both series exhibited a large inhibitory activity against oxygen radical induced lipid peroxidation in bovine heart mitochondria (IC50 lower than 1 microM), compared to the reference antioxidants trolox C or alpha-tocopherol. This activity appeared related to (i) the ability of these compounds to reduce the stable radical 1,1-diphenyl-2-picrylhydrazyl and (ii) their lipophilicity estimated by log P determination. In order to study the scavenging mechanisms of diaminouracils and urate derivatives against lipid radicals, they were also tested against the azo-initiated peroxidation of either methyl linoleate in organic solvents or a liposomal suspension of dilinoleoylphosphatidylcholine. Urate derivatives reacted moderately with lipid radicals and were slowly consumed, significantly affecting the propagation of the peroxidation. Diaminouracils strongly reduced the propagation rate. They were quickly consumed and were able to deactivate about 1 mol of lipid radical per mole of compound in organic solvent. Dodecyl urates and decyl- and dodecyldiaminouracils were chosen for further in vitro investigation and in vivo evaluation.

  1. Effects of chicory inulin on serum metabolites of uric acid, lipids, glucose, and abdominal fat deposition in quails induced by purine-rich diets.

    PubMed

    Lin, Zhijian; Zhang, Bing; Liu, Xiaoqing; Jin, Rui; Zhu, Wenjing

    2014-11-01

    Inulin, a group of dietary fibers, is reported to improve the metabolic disorders. In the present study, we investigated the effects of chicory inulin on serum metabolites of uric acid (UA), lipids, glucose, and abdominal fat deposition in quail model induced by a purine-rich diet. In this study, 60 male French quails were randomly allocated to five groups: CON (control group), MOD (model group), BEN (benzbromarone-treated group), CHI-H (high-dosage chicory inulin-treated group), and CHI-L (low-dosage chicory inulin-treated group). The serum UA level was significantly increased in the model group from days 7 to 28, as well as triglyceride (TG) and free fatty acid (FFA) increased later in the experimental period. The abdominal fat ratio was increased on day 28. Benzbromarone can decrease UA levels on days 14 and 28. The high and low dosage of chicory inulin also decreased serum UA levels on days 7, 14, and 28. The abdominal fat ratio, activity, and protein of acetyl-CoA carboxylase (ACC) were decreased in chicory inulin-treated groups. The activities of xanthine oxidase (XOD) and fatty acid synthase (FAS) were increased in the model group and decreased in the benzbromarone and chicory inulin groups. This study evaluated a quail model of induced hyperuricemia with other metabolic disorders caused by a high-purine diet. The results indicated that a purine-rich diet might contribute to the development of hyperuricemia, hypertriglyceridemia, and abdominal obesity. Chicory inulin decreased serum UA, TG, and abdominal fat deposition in a quail model of hyperuricemia by altering the ACC protein expression and FAS and XOD activities.

  2. 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. PMID:24491759

  3. Voltammetric behavior of uric acid on carbon paste electrode modified with salmon sperm dsDNA and its application as label-free electrochemical sensor.

    PubMed

    Mohamadi, Maryam; Mostafavi, Ali; Torkzadeh-Mahani, Masoud

    2014-04-15

    A simple and sensitive label-free electrochemical DNA biosensor was proposed for the rapid determination of uric acid (UA) using a carbon nano tube paste electrode (CNTPE) modified with salmon sperm dsDNA. At first, the interaction between UA and the DNA was studied using differential pulse voltammetry (DPV). The addition of the DNA to UA solution resulted in a decrease in the peak current of UA and at the same time, a positive shift in the peak potential indicating an intercalative interaction. Then, the voltammetric response of a DNA-immobilized CNTPE was investigated for the determination of UA. The immobilization of the DNA was carried out using acid-functionalized carbon nanotubes and studied using Fe(CN)6(3-)/Fe(CN)6(4-) redox indicator. Compared with unmodified CNTPE, the oxidation signal of UA showed a significant increase at the DNA-coated electrode, and shifted to more positive potentials attributed to the pre-concentration of UA at the electrode surface due to interaction with the surface-confined DNA layer. This interaction was used for the fabrication of a simple and sensitive biosensor for determining UA. After the optimization of operational parameters, a linear dependence of the peak current on the UA concentration was observed in the range of 7.0×10(-7) to 1.1×10(-4) mol L(-1), with the detection and quantification limits of 1.8×10(-7) and 5.8×10(-7) mol L(-1), respectively. The proposed biosensor was successfully applied to validate its capability for the analysis of UA in human serum and urine samples.

  4. Flower-like ZnO decorated polyaniline/reduced graphene oxide nanocomposites for simultaneous determination of dopamine and uric acid.

    PubMed

    Ghanbari, Kh; Moloudi, M

    2016-11-01

    A novel sensor was fabricated by electrochemical deposition of ZnO flower-like/polyaniline nanofiber/reduced graphene oxide nanocomposite (ZnO/PANI/RGO) on glassy carbon electrode (GCE) for direct detection of dopamine (DA) and uric acid (UA) in the presence of fixed concentration of ascorbic acid (AA). Surface morphology and characterization of the modified electrodes were confirmed by field emission scanning microscopy (FE-SEM), X-ray diffraction (XRD), Raman and FT-IR spectroscopies. For individual detection, the linear responses were in the two concentration ranges of 0.001-1 μM and 1-1000 μM with detection limit 0.8 nM (S/N = 3) for DA, and also 0.1-100 μM and 100-1000 μM with detection limit 0.042 μM (S/N = 3) for UA. Simultaneous determination of these species in their mixture solution showed the linear responses in the two concentration ranges of 0.1-90 μM and 90-1000 μM with detection limit 0.017 μM (S/N = 3) for DA and also showed two linear range of 0.5-90 μM and 100-1000 μM with detection limit 0.12 μM (S/N = 3) for UA, with coexistence of 1000 μM AA. The applicability of sensor for the analysis of DA, and UA in dopamine injection solution, human serum and human urine samples was successfully demonstrated.

  5. Flower-like ZnO decorated polyaniline/reduced graphene oxide nanocomposites for simultaneous determination of dopamine and uric acid.

    PubMed

    Ghanbari, Kh; Moloudi, M

    2016-11-01

    A novel sensor was fabricated by electrochemical deposition of ZnO flower-like/polyaniline nanofiber/reduced graphene oxide nanocomposite (ZnO/PANI/RGO) on glassy carbon electrode (GCE) for direct detection of dopamine (DA) and uric acid (UA) in the presence of fixed concentration of ascorbic acid (AA). Surface morphology and characterization of the modified electrodes were confirmed by field emission scanning microscopy (FE-SEM), X-ray diffraction (XRD), Raman and FT-IR spectroscopies. For individual detection, the linear responses were in the two concentration ranges of 0.001-1 μM and 1-1000 μM with detection limit 0.8 nM (S/N = 3) for DA, and also 0.1-100 μM and 100-1000 μM with detection limit 0.042 μM (S/N = 3) for UA. Simultaneous determination of these species in their mixture solution showed the linear responses in the two concentration ranges of 0.1-90 μM and 90-1000 μM with detection limit 0.017 μM (S/N = 3) for DA and also showed two linear range of 0.5-90 μM and 100-1000 μM with detection limit 0.12 μM (S/N = 3) for UA, with coexistence of 1000 μM AA. The applicability of sensor for the analysis of DA, and UA in dopamine injection solution, human serum and human urine samples was successfully demonstrated. PMID:27555438

  6. Plasma fatty acid profile and alternative nutrition.

    PubMed

    Krajcovicová-Kudlácková, M; Simoncic, R; Béderová, A; Klvanová, J

    1997-01-01

    Plasma profile of fatty acids was examined in a group of children consisting of 7 vegans, 15 lactoovovegetarians and 10 semivegetarians. The children were 11-15 years old and the average period of alternative nutrition was 3.4 years. The results were compared with a group of 19 omnivores that constituted an average sample with respect to biochemical and hematological parameters from a larger study of health and nutritional status of children in Slovakia. Alternative nutrition groups had significantly lower values of saturated fatty acids. The content of oleic acid was identical to omnivores. A significant increase was observed for linoleic and alpha-linolenic (n-3) acids. The dihomo-gamma-linolenic (n-6) acid and arachidonic (n-6) acid values were comparable to omnivores for all alternative nutrition groups. Values of n-3 polyunsaturated fatty acids in lactoovovegetarians were identical to those of omnivores whereas they were significantly increased in semivegetarians consuming fish twice a week. Due to the total exclusion of animal fats from the diet, vegans had significantly reduced values of palmitoleic acid as well as eicosapentaenoic (n-3) acid and docosahexaenoic (n-3) acid resulting in an increased n-6/n-3 ratio. Values of plasma fatty acids found in alternative nutrition groups can be explained by the higher intake of common vegetable oils (high content of linoleic acid), oils rich in alpha-linolenic acid (cereal germs, soybean oil, walnuts), as well as in n-3 polyunsaturated fatty acids (fish). The results of fatty acids (except n-3 in vegans) and other lipid parameters confirm the beneficial effect of vegetarian nutrition in the prevention of cardiovascular diseases.

  7. Horseradish peroxidase-catalyzed polymerization of L-DOPA for mono-/bi-enzyme immobilization and amperometric biosensing of H2O2 and uric acid.

    PubMed

    Dai, Mengzhen; Huang, Ting; Chao, Long; Xie, Qingji; Tan, Yueming; Chen, Chao; Meng, Wenhua

    2016-03-01

    Horseradish peroxidase (HRP)-catalyzed polymerization of L-DOPA (vs. dopamine) in the presence of H2O2 (and uricase (UOx)) was exploited to immobilize mono-/bi-enzymes for hydroquinone-mediated amperometric biosensing of H2O2 and uric acid (UA). The relevant polymeric biocomposites (PBCs) were prepared in phosphate buffer solution containing HRP and L-DOPA (or plus UOx) after adding H2O2. The mono-/bi-enzyme amperometric biosensors were prepared simply by casting some of the PBCs on Au-plated Au (Au(plate)/Au) electrodes, followed by coating with an outer-layer chitosan (CS) film for each. UV-vis spectrophotometry, scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy were used for film characterization and/or process monitoring. The HRP immobilized by enzyme catalysis well preserved its bioactivity, as confirmed by UV-vis spectrophotometry. Under optimized conditions, the monoenzyme CS/HRP-poly(L-DOPA) (PD)/Au(plate)/Au electrode potentiostated at -0.1V responded linearly to H2O2 concentration from 0.001 to 1.25mM with a sensitivity of 700μA mM(-1)cm(-2) and a limit of detection (LOD) of 0.1μM, and the bienzyme CS/UOx-HRP-PD/Au(plate)/Au electrode at -0.1V responded linearly to UA concentration from 0.001 to 0.4mM with a sensitivity of 349μA mM(-1)cm(-2) and a LOD of 0.1μM. The mono-/bi-enzyme biosensors based on biosynthesized PD performed better than many reported analogues and those based on similarly biosynthesized polydopamine. PMID:26717822

  8. Synthesis of [¹¹C]uric acid, using [¹¹C]phosgene, as a possible biomarker in PET imaging for diagnosis of gout.

    PubMed

    Yashio, Keiji; Katayama, Yumiko; Takashima, Tadayuki; Ishiguro, Naoki; Doi, Hisashi; Suzuki, Masaaki; Wada, Yasuhiro; Tamai, Ikumi; Watanabe, Yasuyoshi

    2012-01-01

    The synthesis and in vivo evaluation of (11)C -labeled uric acid ([(11)C]1), a potential imaging agent for the diagnosis of urate-related life-style diseases, was performed using positron emission tomography (PET) image analysis. First, the synthesis of [(11)C]1 was achieved by reacting 5,6-diaminouracil (2) with (11)C-labeled phosgene ([(11)C]COCl(2)). The radiochemical yield of [(11)C]1 was 37±7% (decay-corrected based on [(11)C]COCl(2)) with specific radioactivities of 96-152GBq/μmol at the end of synthesis (n=6). The average time of radiosynthesis from the end of bombardment, including formulation, was about 30min with >98% radiochemical purity. Second, the synthetic approach to [(11)C]1 was optimized using 5,6-diaminouracil sulfate (3) with [(11)C]COCl(2) in the presence of 1,8-bis(dimethylamino)naphthalene. [(11)C]1 was synthesized in 36±6% radiochemical yield, 89-142GBq/μmol of specific radioactivities, and 98% radiochemical purity by this method (n=5). This allowed the synthesis of [(11)C]1 to be carried out repeatedly and the radiochemical yield, specific radioactivities, average time of synthesis, and radiochemical purity of [(11)C]1 were similar to those obtained using 2. PET studies in rats showed large differences in the accumulation of radioligand in the limbs under normal and hyperuricemic conditions. Thus, an efficient and convenient automated synthesis of [(11)C]1 has been developed, and preliminary PET evaluation of [(11)C]1 confirmed the increased accumulation of radioactivity in the limbs of a rat model of hyperuricemia.

  9. Modeling and Simulation for Estimating the Influence of Renal Dysfunction on the Hypouricemic Effect of Febuxostat in Hyperuricemic Patients Due to Overproduction or Underexcretion of Uric Acid.

    PubMed

    Hirai, Toshinori; Kimura, Toshimi; Echizen, Hirotoshi

    2016-01-01

    Whether renal dysfunction influences the hypouricemic effect of febuxostat, a xanthine oxidase (XO) inhibitor, in patients with hyperuricemia due to overproduction or underexcretion of uric acid (UA) remains unclear. We aimed to address this question with a modeling and simulation approach. The pharmacokinetics (PK) of febuxostat were analyzed using data from the literature. A kinetic model of UA was retrieved from a previous human study. Renal UA clearance was estimated as a function of creatinine clearance (CLcr) but non-renal UA clearance was assumed constant. A reversible inhibition model for bovine XO was adopted. Integrating these kinetic formulas, we developed a PK-pharmacodynamic (PK-PD) model for estimating the time course of the hypouricemic effect of febuxostat as a function of baseline UA level, febuxostat dose, treatment duration, body weight, and CLcr. Using the Monte Carlo simulation method, we examined the performance of the model by comparing predicted UA levels with those reported in the literature. We also modified the models for application to hyperuricemia due to UA overproduction or underexcretion. Thirty-nine data sets comprising 735 volunteers or patients were retrieved from the literature. A good correlation was observed between the hypouricemic effects of febuxostat estimated by our PK-PD model and those reported in the articles (observed) (r=0.89, p<0.001). The hypouricemic effect was estimated to be augmented in patients with renal dysfunction irrespective of the etiology of hyperuricemia. While validation in clinical studies is needed, the modeling and simulation approach may be useful for individualizing febuxostat doses in patients with various clinical characteristics.

  10. Reduction in Serum Uric Acid May Be Related to Methotrexate Efficacy in Early Rheumatoid Arthritis: Data from the Canadian Early Arthritis Cohort (CATCH)

    PubMed Central

    Lee, Jason J.; Bykerk, Vivian P.; Dresser, George K.; Boire, Gilles; Haraoui, Boulos; Hitchon, Carol; Thorne, Carter; Tin, Diane; Jamal, Shahin; Keystone, Edward C.; Pope, Janet E.

    2016-01-01

    OBJECTIVES The mechanism of action of methotrexate in rheumatoid arthritis (RA) is complex. It may increase adenosine levels by blocking its conversion to uric acid (UA). This study was done to determine if methotrexate lowers UA in early RA (ERA). METHODS Data were obtained from Canadian Early Arthritis Cohort, an incident ERA cohort. All ERA patients with serial UA measurements were included, comparing those with methotrexate use vs. no methotrexate exposure (controls). Analyses were exploratory. Patients with concomitant gout or taking UA-lowering therapies were excluded. RESULTS In total, 49 of the 2,524 ERA patients were identified with data available for both pre-methotrexate UA levels and post-methotrexate UA levels (300 µmol/L and 273 µmol/L, respectively; P = 0.035). The control group not taking methotrexate had a mean baseline UA level of 280 µmol/L and a follow-up level of 282 µmol/L (P = 0.448); mean change in UA with methotrexate was −26.8 µmol/L vs. 2.3 µmol/L in the no methotrexate group (P = 0.042). Methotrexate users with a decrease in UA had a disease activity score of 2.37 for 28 joints when compared with the controls (3.26) at 18 months (P = 0.042). Methotrexate users with decreased UA had a lower swollen joint count (SJC) of 0.9 at 18 months, whereas methotrexate users without lowering of UA had an SJC of 4.5 (P = 0.035). Other analyses were not significant. CONCLUSIONS Methotrexate response is associated with lowering of serum UA in ERA compared to nonusers. This may be due to changes in adenosine levels. Methotrexate response is associated with lower UA and fewer swollen joints compared to nonresponders. PMID:27081318

  11. Abundant local interactions in the 4p16.1 region suggest functional mechanisms underlying SLC2A9 associations with human serum uric acid

    PubMed Central

    Wei, Wen-Hua; Guo, Yunfei; Kindt, Alida S.D.; Merriman, Tony R.; Semple, Colin A.; Wang, Kai; Haley, Chris S.

    2014-01-01

    Human serum uric acid concentration (SUA) is a complex trait. A recent meta-analysis of multiple genome-wide association studies (GWAS) identified 28 loci associated with SUA jointly explaining only 7.7% of the SUA variance, with 3.4% explained by two major loci (SLC2A9 and ABCG2). Here we examined whether gene–gene interactions had any roles in regulating SUA using two large GWAS cohorts included in the meta-analysis [the Atherosclerosis Risk in Communities study cohort (ARIC) and the Framingham Heart Study cohort (FHS)]. We found abundant genome-wide significant local interactions in ARIC in the 4p16.1 region located mostly in an intergenic area near SLC2A9 that were not driven by linkage disequilibrium and were replicated in FHS. Taking the forward selection approach, we constructed a model of five SNPs with marginal effects and three epistatic SNP pairs in ARIC—three marginal SNPs were located within SLC2A9 and the remaining SNPs were all located in the nearby intergenic area. The full model explained 1.5% more SUA variance than that explained by the lead SNP alone, but only 0.3% was contributed by the marginal and epistatic effects of the SNPs in the intergenic area. Functional analysis revealed strong evidence that the epistatically interacting SNPs in the intergenic area were unusually enriched at enhancers active in ENCODE hepatic (HepG2, P = 4.7E−05) and precursor red blood (K562, P = 5.0E−06) cells, putatively regulating transcription of WDR1 and SLC2A9. These results suggest that exploring epistatic interactions is valuable in uncovering the complex functional mechanisms underlying the 4p16.1 region. PMID:24821702

  12. Serum uric acid predicts vascular complications in adults with type 1 diabetes: the coronary artery calcification in type 1 diabetes study.

    PubMed

    Bjornstad, Petter; Maahs, David M; Rivard, Christopher J; Pyle, Laura; Rewers, Marian; Johnson, Richard J; Snell-Bergeon, Janet K

    2014-10-01

    Epidemiologic evidence supports a link between serum uric acid (SUA) and vascular complications in diabetes, but it remains unclear whether SUA improves the ability of conventional risk factor to predict complications. We hypothesized that SUA at baseline would independently predict the development of vascular complications over 6 years and that the addition of SUA to American Diabetes Association's ABC risk factors (HbA1c, BP, LDL-C) would improve vascular complication prediction over 6 years in adults with type 1 diabetes. Study participants (N = 652) were 19-56 year old at baseline and re-examined 6 years later. Diabetic nephropathy was defined as incident albuminuria or rapid GFR decline (>3.3 %/year) estimated by the CKD-EPI cystatin C. Diabetic retinopathy (DR) was based on self-reported history, and proliferative diabetic retinopathy (PDR) was defined as laser eye therapy; coronary artery calcium (CAC) was measured using electron-beam computed tomography. Progression of CAC (CACp) was defined as a change in the square-root-transformed CAC volume ≥2.5. Predictors of each complication were examined in stepwise logistic regression with subjects with complications at baseline excluded from analyses. C-statistics, integrated discrimination indices and net-reclassification improvement were utilized for prediction performance analyses. SUA independently predicted development of incident albuminuria (OR 1.8, 95 % CI 1.2-2.7), rapid GFR decline (1.9, 1.1-3.3), DR (1.4, 1.1-1.9), PDR (2.1, 1.4-3.0) and CACp (1.5, 1.1-1.9). SUA improved the discrimination and net-classification risk of vascular complications over 6 years. SUA independently predicted the development of vascular complications in type 1 diabetes and also improved the reclassification of vascular complications. PMID:24929955

  13. Serum Uric Acid Predicts Vascular Complications in Adults with Type 1 Diabetes: the Coronary Artery Calcification in Type 1 Diabetes Study

    PubMed Central

    Bjornstad, Petter; Maahs, David M.; Rivard, Christopher J.; Pyle, Laura; Rewers, Marian; Johnson, Richard J.; Snell-Bergeon, Janet K.

    2015-01-01

    Hypothesis Epidemiologic evidence support a link between serum uric acid (SUA) and vascular complications in diabetes, but it remains unclear whether SUA improves the ability of conventional risk factor to predict complications. We hypothesized that SUA at baseline would independently predict the development of vascular complications over 6 years, and that the addition of SUA to American Diabetes Association’s ABC risk factors (HbA1c, BP, LDL-C) would improve vascular complication prediction over 6-years in adults with type 1 diabetes. Methods Study participants (N=652) were 19–56 year old at baseline and re-examined 6-years later. Diabetic nephropathy (DN) was defined as incident albuminuria or rapid GFR decline (>3.3%/year) estimated by the CKD-EPI cystatin C. Diabetic retinopathy (DR) was based on self-reported history, proliferative diabetic retinopathy (PDR) was defined as laser eye therapy; coronary artery calcium (CAC) was measured using electron-beam computed-tomography. Progression of CAC (CACp) was defined as a change in the square-root transformed CAC-volume ≥ 2.5. Predictors of each complication were examined in stepwise logistic regression with subjects with complications at baseline excluded from analyses. C-statistics, integrated-discrimination indices and net-reclassification improvement were utilized for prediction performance analyses. Results SUA independently predicted development of incident albuminuria (OR: 1.8, 95% CI 1.2–2.7), rapid GFR decline (1.9, 1.1–3.3), DR (1.4, 1.1–1.9), PDR (2.1, 1.4–3.0) and CACp (1.5 (1.1–1.9). SUA improved the discrimination and net-classification risk of vascular complications over 6-years. Conclusion SUA independently predicted the development of vascular complications in type 1 diabetes, and also improved the reclassification of vascular complications. PMID:24929955

  14. Elevated Serum Uric Acid Is Associated with Greater Bone Mineral Density and Skeletal Muscle Mass in Middle-Aged and Older Adults

    PubMed Central

    He, Juan; Wang, Chen; Qiu, Rui; Chen, Yu-ming

    2016-01-01

    Background and objective Previous studies have suggested a positive link between serum uric acid (UA) and bone mineral density (BMD). In this study, we re-examined the association between UA and BMD and further explored whether this was mediated by skeletal muscle mass in a general Chinese population. Method This community-based cross-sectional study was conducted among 3079 (963 men and 2116 women) Chinese adults aged 40–75 years. Face-to-face interviews and laboratory analyses were performed to determine serum UA and various covariates. Dual-energy X-ray absorptiometry was used to assess the BMD and appendicular skeletal muscle mass. The skeletal muscle mass index (SMI = ASM/Height2, kg/m2) for the total limbs, arms, and legs was then calculated. Results The serum UA was graded and, in general, was significantly and positively associated with the BMD and muscle mass, after adjustment for multiple covariates in the total sample. Compared with participants in lowest quartile of UA, those participants in highest quartile showed a 2.3%(whole body), 4.1%(lumbar spine), 2.4%(total hip), and 2.0% (femoral neck) greater BMDs. The mean SMIs in the highest (vs. lowest) quartile increased by 2.7% (total), 2.5% (arm), 2.7% (leg) respectively. In addition, path analysis suggested that the favorable association between UA and BMD might be mediated by increasing SMI. Conclusion The elevated serum UA was associated with a higher BMD and a greater muscle mass in a middle-aged and elderly Chinese population and the UA-BMD association was partly mediated by muscle mass. PMID:27144737

  15. A facile one-pot synthesis of carbon nitride dots-reduced graphene oxide nanocomposites for simultaneous enhanced detecting of dopamine and uric acid.

    PubMed

    Yang, Ziyin; Zheng, Xiaohui; Li, Zhi; Zheng, Jianbin

    2016-08-01

    In this study, we described the facile synthesis of carbon nitride dots-reduced graphene oxide nanocomposites (CNDs-rGO) and their application for the enhanced electrochemical determination of dopamine (DA) and uric acid (UA). CNDs-rGO were synthesized for the first time through a green and facile one-step approach, carried out by hydrothermal heat-treatment of an aqueous solution containing GO and chitosan without introduction of other reducing agents or surface modifier. Then, the morphology and composition of CNDs-rGO nanocomposites were characterized by transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. TEM observations revealed that CNDs with a size of about 5.0 nm were homogeneously and densely distributed on the surface of rGO. Electrochemical investigations indicated that CNDs-rGO nanocomposites exhibited an excellent performance toward DA and UA. The linear range for DA was estimated to be from 80 nM to 227 μM with a sensitivity of 154.3 μA mM(-1) cm(-2) and a low detection limit of 0.03 μM. Meanwhile, the linear range for UA was estimated to be from 80 nM to 328 μM with a high sensitivity of 178.1 μA mM(-1) cm(-2) and a low detection limit of 0.05 μM. Therefore, CNDs-rGO nanocomposites showed great application potential for constructing electrochemical sensors for the detection of DA and UA.

  16. Serum uric acid is associated with increased risk of idiopathic venous thromboembolism in high HDL-C population: A case-control study

    PubMed Central

    YU, MIAO; LING, KEN; TENG, YUNFEI; LI, QIN; MEI, FEI; LI, YIQING; OUYANG, CHENXI

    2016-01-01

    Many studies have indicated that metabolic disorders are positively correlated with idiopathic venous thromboembolism (VTE), whereas the risk factor serum uric acid (SUA) for idiopathic VTE has yet to be investigated. In this retrospective case-control study, 276 idiopathic VTE patients and 536 gender- and age-matched control subjects were included. The subjects in the case and control groups exhibiting common known VTE risk factors and the patients with a first VTE onset in one month were excluded. For the control group, primary and secondary VTE patients were excluded. High-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, total cholesterol, fasting blood glucose, and current smoking were significantly associated with idiopathic VTE in the univariate analysis. Hyperuricemia was detected in 56/276 (20.29%) idiopathic patients compared with 71/536 (13.25%) in the control group. HDL-C was considered the most prominent interactive factor for SUA in idiopathic VTE by the interaction analysis. After testing for the interaction terms, SUA was closely associated with idiopathic VTE in the high HDL-C population (P=0.0026 for interaction), while there was no such correlation in the low HDL-C group. The results indicated no obvious correlation between triglyceride and hypertension to idiopathic VTE. In conclusion, SUA is closely associated with an increased risk of idiopathic VTE in the high HDL-C population. The abnormality of SUA may act as an important linkage between atherosclerosis and idiopathic VTE through HDL-C. PMID:27284315

  17. Graphitic carbon nitrides modified hollow fiber solid phase microextraction for extraction and determination of uric acid in urine and serum coupled with gas chromatography-mass spectrometry.

    PubMed

    Sun, Ying-pei; Chen, Juan; Qi, Huan-yang; Shi, Yan-ping

    2015-11-01

    An elevated uric acid (UA) in urine or serum can affect renal function and blood pressure, which is an indicator of gout, cardiovascular and renal diseases, hypertension, etc. In this work, a new type of mixed matrix membrane (MMM), based on graphitic carbon nitrides (g-CNs) and hollow fiber (HF), was prepared and combined with solid phase microextraction (SPME) mode to determine UA in urine and serum followed by gas chromatography-mass spectrometry (GC/MS). The porous g-CNs were dispersed in ammonia, and then the exfoliated g-CNs nanosheets were held in the pores of HF by capillary forces and sonification. The prepared g-CNs modified HF (g-CNs-HF) was immersed in biofluid directly to extract UA with SPME mode and the solvent-free mode is convenient for further derivatization and analysis. To achieve the highest extraction efficiency (EF), main extraction and derivatization parameters, such as g-CNs-HF immobilizing time, sonification power and time of extraction, derivatization and desorption time, were optimized. Under the optimum extraction conditions, a favorable linearity of UA was obtained in the range 0.1-200μgmL(-1) with correlation coefficients higher than 0.9990, and the average recoveries at three spiked levels of UA in urine and serum ranged from 80.7% to 121.6%, from 84.7% to 101.1%, respectively. The obtained results demonstrated the developed g-CNs-HF-SPME is a simple, rapid, cost-effective, solvent-free method for the analysis of UA in biofluid.

  18. Graphitic carbon nitrides modified hollow fiber solid phase microextraction for extraction and determination of uric acid in urine and serum coupled with gas chromatography-mass spectrometry.

    PubMed

    Sun, Ying-pei; Chen, Juan; Qi, Huan-yang; Shi, Yan-ping

    2015-11-01

    An elevated uric acid (UA) in urine or serum can affect renal function and blood pressure, which is an indicator of gout, cardiovascular and renal diseases, hypertension, etc. In this work, a new type of mixed matrix membrane (MMM), based on graphitic carbon nitrides (g-CNs) and hollow fiber (HF), was prepared and combined with solid phase microextraction (SPME) mode to determine UA in urine and serum followed by gas chromatography-mass spectrometry (GC/MS). The porous g-CNs were dispersed in ammonia, and then the exfoliated g-CNs nanosheets were held in the pores of HF by capillary forces and sonification. The prepared g-CNs modified HF (g-CNs-HF) was immersed in biofluid directly to extract UA with SPME mode and the solvent-free mode is convenient for further derivatization and analysis. To achieve the highest extraction efficiency (EF), main extraction and derivatization parameters, such as g-CNs-HF immobilizing time, sonification power and time of extraction, derivatization and desorption time, were optimized. Under the optimum extraction conditions, a favorable linearity of UA was obtained in the range 0.1-200μgmL(-1) with correlation coefficients higher than 0.9990, and the average recoveries at three spiked levels of UA in urine and serum ranged from 80.7% to 121.6%, from 84.7% to 101.1%, respectively. The obtained results demonstrated the developed g-CNs-HF-SPME is a simple, rapid, cost-effective, solvent-free method for the analysis of UA in biofluid. PMID:26444336

  19. {sup 13}C-enrichment at carbons 8 and 2 of uric acid after {sup 13}C-labeled folate dose in man

    SciTech Connect

    Baggott, Joseph E.; Gorman, Gregory S.; Morgan, Sarah L.; Tamura, Tsunenobu . E-mail: tamurat@uab.edu

    2007-09-21

    To evaluate folate-dependent carbon incorporation into the purine ring, we measured {sup 13}C-enrichment independently at C{sub 2} and C{sub 8} of urinary uric acid (the final catabolite of purines) in a healthy male after an independent oral dose of [6RS]-5-[{sup 13}C]-formyltetrahydrofolate ([6RS]-5-H{sup 13}CO-H{sub 4}folate) or 10-H{sup 13}CO-7,8-dihydrofolate (10-H{sup 13}CO-H{sub 2}folate). The C{sub 2} position was {sup 13}C-enriched more than C{sub 8} after [6RS]-5-H{sup 13}CO-H{sub 4}folate, and C{sub 2} was exclusively enriched after 10-H{sup 13}CO-H{sub 2}folate. The enrichment of C{sub 2} was greater from [6RS]-5-H{sup 13}CO-H{sub 4}folate than 10-H{sup 13}CO-H{sub 2}folate using equimolar bioactive doses. Our data suggest that formyl C of [6RS]-10-H{sup 13}CO-H{sub 4}folate was not equally utilized by glycinamide ribotide transformylase (enriches C{sub 8}) and aminoimidazolecarboxamide ribotide (AICAR) transformylase (enriches C{sub 2}), and the formyl C of 10-H{sup 13}CO-H{sub 2}folate was exclusively used by AICAR transformylase. 10-HCO-H{sub 2}folate may function in vivo as the predominant substrate for AICAR transformylase in humans.

  20. Sunlight assisted synthesis of silver nanoparticles in zeolite matrix and study of its application on electrochemical detection of dopamine and uric acid in urine samples.

    PubMed

    Meenakshi, S; Devi, S; Pandian, K; Devendiran, R; Selvaraj, M

    2016-12-01

    Sunlight assisted reduction of silver ions were accomplished for the synthesis of silver nanoparticles incorporated within the mesoporous silicate framework of zeolite Y. The zeolite-Y and AgNP/Zeo-Y were characterized by field emission scanning electron microscopy, transmission electron microscopy, N2 adsorption-desorption BET isotherm and X-ray diffraction techniques. The incorporation of silver nanoparticles within the porous framework was further confirmed by cyclic voltammetry and electrochemical impedance spectroscopy. An enhanced electrocatalytic oxidation of biologically important molecules like dopamine and uric acid using AgNP/Zeo-Y modified glassy carbon electrode has been developed. A simultaneous oxidation of DA and UA peaks were obtained at +0.31V and +0.43V (vs. Ag/AgCl) using AgNP/Zeo-Y/GCE under the optimum experimental condition. A well-resolved peak potential window (~120mV) for the oxidation of both DA and UA were observed at AgNP/Zeo-Y/GCE system. The calibration curves for DA and UA were obtained within the dynamic linear range of 0.02×10(-6) to 0.18×10(-6)M (R(2)=0.9899) and 0.05×10(-6) to 0.7×10(-6)M (R(2)=0.9996) and the detection limits were found to be 1.6×10(-8)M and 2.51×10(-8)M by using differential pulse voltammetry (DPV) method. The proposed method was successfully applied for the determination of both DA and UA in human urine samples with a related standard deviation was <3%, and n=5 using the standard addition method. PMID:27612692

  1. Higher serum uric acid level increases risk of prehypertension in subjects with normal glucose tolerance, but not pre-diabetes and diabetes.

    PubMed

    Wu, I-H; Wu, J-S; Sun, Z-J; Lu, F-H; Chang, C-S; Chang, C-J; Yang, Y-C

    2016-08-01

    Although the association between serum uric acid (SUA) levels and prehypertension has been reported in previous studies, it is unknown whether their relationship is similar in subjects with diabetes, pre-diabetes and normal glucose tolerance (NGT). This study thus aimed to investigate the relationship between SUA and prehypertension in subjects with different glycemic status, including NGT, pre-diabetes and diabetes. A total of 12 010 participants were included after excluding subjects with blood pressure ⩾140/90 mm Hg, history of hypertension, leukaemia, lymphoma, hypothyroidism, medication for hypertension and hyperuricemia and missing data. Subjects were divided into four groups based on SUA quartiles (male Q1: ⩽345.0, Q2: 345.0-392.6, Q3: 392.6-440.2, Q4: ⩾440.2 μmol l(-1) and female Q1: ⩽249.8, Q2: 249.8-285.5, Q3: 285.5-333.1, Q4: ⩾333.1 μmol l(-1)). Diabetes, pre-diabetes and NGT were assessed according to the 2010 American Diabetes Association diagnostic criteria. Normotension and prehypertension were defined according to the JNC-7 (The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure) criteria. The SUA was significantly higher in prehypertensive subjects as compared with normotensive subjects. SUA, as a continuous variable, was positively associated with prehypertension in subjects with NGT but not pre-diabetes and diabetes. Besides, NGT subjects with the highest quartile of SUA exhibited a higher risk of prehypertension after adjustment for other confounding factors. In pre-diabetes and diabetes groups, none of SUA quartiles was significantly related to prehypertension. SUA was significantly associated with an increased risk of prehypertension in subjects with NGT but insignificantly in subjects with pre-diabetes and diabetes. PMID:26911534

  2. Plasma amino acid relationships during parenteral nutrition.

    PubMed

    Wells, F E; Smits, B J

    1980-01-01

    The plasma amino acidfs of 17 patients were studied before and during total parenteral nutrition (TPN). The amino acid (AA) pattern changed similarly for all patients. The AA concentration changes relative to preinfusion (PAER) were the most informative index of change. Two groups of AA were defined, the "branched chain" group (five amino acids) and the "hepatic" group (four amino acids) based on the correlation of PAER values. Comparison of PAER values with the ratio of AA intake to requirement indicated that the requirements of the sick patients were more similar to those of children than those of healthy adults.

  3. Emergent Biomarkers of Residual Cardiovascular Risk in Patients with Low HDL-c and/or High Triglycerides and Average LDL-c Concentrations: Focus on HDL Subpopulations, Oxidized LDL, Adiponectin, and Uric Acid

    PubMed Central

    Mascarenhas-Melo, Filipa; Sereno, José; Freitas, Isabel; Isabel-Mendonça, Maria; Pinto, Rui; Teixeira, Frederico

    2013-01-01

    This study intended to determine the impact of HDL-c and/or TGs levels on patients with average LDL-c concentration, focusing on lipidic, oxidative, inflammatory, and angiogenic profiles. Patients with cardiovascular risk factors (n = 169) were divided into 4 subgroups, combining normal and low HDL-c with normal and high TGs patients. The following data was analyzed: BP, BMI, waist circumference and serum glucose, Total-c, TGs, LDL-c, oxidized-LDL, total HDL-c and HDL subpopulations, paraoxonase-1 (PON1) activity, hsCRP, uric acid, TNF-α, adiponectin, VEGF, and iCAM1. The two populations with increased TGs levels, regardless of the normal or low HDL-c, presented obesity and higher waist circumference, Total-c, LDL-c, Ox-LDL, and uric acid. Adiponectin concentration was significantly lower and VEGF was higher in the population with cumulative low values of HDL-c and high values of TGs, while HDL quality was reduced in the populations with impaired values of HDL-c and/or TGs, viewed by reduced large and increased small HDL subfractions. In conclusion, in a population with cardiovascular risk factors, low HDL-c and/or high TGs concentrations seem to be associated with a poor cardiometabolic profile, despite average LDL-c levels. This condition, often called residual risk, is better evidenced by using both traditional and nontraditional CV biomarkers, including large and small HDL subfractions, Ox-LDL, adiponectin, VEGF, and uric acid. PMID:24319364

  4. Relation of serum uric acid to severity and progression of coronary artery calcium in postmenopausal White and Filipino women (from the Rancho Bernardo study).

    PubMed

    Calvo, Richard Y; Araneta, Maria Rosario G; Kritz-Silverstein, Donna; Laughlin, Gail A; Barrett-Connor, Elizabeth

    2014-04-01

    Elevated serum uric acid (UA) is associated with cardiovascular disease (CVD) but its association with coronary artery calcium (CAC) is inconsistent. This study examined ethnic differences in the association of UA levels with CAC severity and progression. Participants included 202 white and 166 Filipino postmenopausal women without known CVD. White women originated from the Rancho Bernardo cohort study, whereas Filipino women were convenience sampled from comparable localities. Baseline UA levels and CVD risk factors were measured in 1995 to 1999. CAC was assessed by electron beam computed tomography (EBCT) in 2000 to 2002 (EBCT1) and repeated in 2005 to 2007 (EBCT2). EBCT1 CAC density scores were categorized by severity: minimal 0 to 10, mild 11 to 100, moderate 101 to 399, and severe ≥400. Progression was defined as CAC volume score increases of ≥2.5 mm3 between scans. White women were older at baseline than Filipinas (64.6 vs 59.3 years, p<0.001). Filipinas had increased UA levels (235.8 vs 294.2 μmol/L, p<0.001), diabetes (35.5% vs 5.2%, p<0.001), hypertension (69.6% vs 45.2%, p<0.001), and statin use (32.8% vs 18.7%, p=0.002). CAC severity did not vary by ethnicity (p=0.502), but Filipinas experienced more CAC progression than whites (53.0% vs 39.1%, p=0.016). Adjustment for CVD risk factors identified a positive association between UA levels and increasing CAC severity at EBCT1 in Filipinas (odds ratio [OR] 1.34, 95% confidence interval [CI] 1.05 to 1.71) but not whites (OR 0.94, 95% CI 0.71 to 1.25). Higher UA levels predicted CAC progression in both cohorts (OR 1.26, 95% CI 1.02 to 1.56). In conclusion, these results support use of UA as an ethnicity-specific marker of CAC severity and as a marker of CAC progression among postmenopausal women. PMID:24513465

  5. Electrodeposition of gold nanoclusters on overoxidized polypyrrole film modified glassy carbon electrode and its application for the simultaneous determination of epinephrine and uric acid under coexistence of ascorbic acid.

    PubMed

    Li, Jing; Lin, Xiang-Qin

    2007-07-23

    A novel biosensor was fabricated by electrochemical deposition of gold nanoclusters on ultrathin overoxidized polypyrrole (PPyox) film, formed a nano-Au/PPyox composite on glassy carbon electrode (nano-Au/PPyox/GCE). The properties of the nanocomposite have been characterized by field emission scanning electron microscope (FE-SEM), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD) and electrochemical investigations. The nano-Au/PPyox/GCE had strongly catalytic activity toward the oxidation of epinephrine (EP), uric acid (UA) and ascorbic acid (AA), and resolved the overlapping voltammetric response of EP, UA and AA into three well-defined peaks with a large anodic peak difference. The catalytic peak currents obtained from differential pulse voltammetry increased linearly with increasing EP and UA concentrations in the range of 3.0x10(-7) to 2.1x10(-5) M and 5.0x10(-8) to 2.8x10(-5) M with a detection limit of 3.0x10(-8) and 1.2x10(-8) M (s/n=3), respectively. The results showed that the modified electrode can selectively determine EP and UA in the coexistence of a large amount of AA. In addition, the sensor exhibited excellent sensitivity, selectivity and stability. The nano-Au/PPyox/GCE has been applied to determination of EP in epinephrine hydrochloride injection and UA in urine samples with satisfactory results.

  6. Component analyses of urinary nanocrystallites of uric acid stone formers by combination of high-resolution transmission electron microscopy, fast Fourier transformation, energy dispersive X-ray spectroscopy, X-ray diffraction and Fourier transform infrared spectroscopy.

    PubMed

    Sun, Xin-Yuan; Xue, Jun-Fa; Xia, Zhi-Yue; Ouyang, Jian-Ming

    2015-06-01

    This study aimed to analyse the components of nanocrystallites in urines of patients with uric acid (UA) stones. X-ray diffraction (XRD), Fourier transform infrared spectroscopy, high-resolution transmission electron microscopy (HRTEM), fast Fourier transformation (FFT) of HRTEM, and energy dispersive X-ray spectroscopy (EDS) were performed to analyse the components of these nanocrystallites. XRD and FFT showed that the main component of urinary nanocrystallites was UA, which contains a small amount of calcium oxalate monohydrate and phosphates. EDS showed the characteristic absorption peaks of C, O, Ca and P. The formation of UA stones was closely related to a large number of UA nanocrystallites in urine. A combination of HRTEM, FFT, EDS and XRD analyses could be performed accurately to analyse the components of urinary nanocrystallites.

  7. Circulating nucleic acids in plasma and serum: an overview.

    PubMed

    Lo, Y M

    2001-09-01

    The recent interest in nucleic acids in plasma and serum has opened up numerous new areas of investigation and new possibilities for molecular diagnosis. In oncology, tumor-derived genetic changes, epigenetic alterations, and viral nucleic acids have been found in the plasma/serum of cancer patients. These findings have important implications for the detection, monitoring, and prognostication of many types of malignancies. In prenatal diagnosis, the discovery of fetal DNA in maternal plasma and serum has provided a noninvasive source of fetal genetic material for analysis. This development has important implications for the realization of noninvasive prenatal diagnosis and has provided new methods for the monitoring of pregnancy-associated disorders. Plasma DNA technology has also found recent applications in the fields of organ transplantation, posttrauma monitoring, and infectious agent detection. Future areas of study include circulating RNA in plasma and the elucidation of the biology of release, clearance, and possible functionality of plasma nucleic acids.

  8. Free amino acids in human blood plasma during space flights.

    PubMed

    Ushakov, A S; Vlasova, T F

    1976-10-01

    The present investigation presents results of studying free amino acids of peripheral plasma in cosmonauts who made space flights of different duration onboard the spacecraft Soyuz-12, Soyuz-16 and the orbital station Salyut-4. The study showed changes in the content of free amino acids which varied for different amino acids. Most pronounced changes were found in the content of glutamic and aspartic acids, sulfur-containing amino acids and arginine.

  9. Effect of octreotide acetate on the plasma concentration and urinary excretion of uridine and purine bases.

    PubMed

    Yamamoto, Tetsuya; Moriwaki, Yuji; Takahashi, Sumio; Tsutsumi, Zenta; Ka, Tsuneyoshi; Hada, Toshikazu

    2002-04-01

    To determine the effect of octreotide acetate on urinary excretion of uric acid and plasma concentration of uridine, we subcutaneously administered octreotide acetate (1 microg/kg of body weight) to 5 healthy subjects. Ninety minutes after administration, octreotide acetate increased the plasma concentration of uridine by 15% and decreased the plasma concentration of glucagon by 24% and that of insulin to below the detection limits. In addition, octreotide acetate decreased the urinary excretion of uric acid, sodium, and chloride by 60%, 40%, and 38%, respectively, at 1 hour after administration. However, octreotide acetate did not affect the concentrations of hypoxanthine, xanthine, uric acid, cyclic AMP in plasma, lactic acid and pyruvic acid in blood, urinary excretion of hypoxanthine and xanthine, or creatinine clearance. From these results, we speculated that octreotide acetate decreases the urinary excretion of uric acid by decreasing the concentration of glucagon and/or urinary excretion of sodium, and increases the plasma concentration of uridine via decreased concentrations of glucagon and insulin.

  10. Preparation of poly(3,4-ethylenedioxythiophene) nanofibers modified pencil graphite electrode and investigation of over-oxidation conditions for the selective and sensitive determination of uric acid in body fluids.

    PubMed

    Özcan, Ali; İlkbaş, Salih

    2015-09-01

    In this study, we have performed the preparation of over-oxidized poly(3,4-ethylenedioxythiophene) nanofibers modified pencil graphite electrode (Ox-PEDOT-nf/PGE) to develop a selective and sensitive voltammetric uric acid (UA) sensor. It was noted that the over-oxidation potential and time had a prominent effect on the UA response of the Ox-PEDOT-nf/PGE. Characterizations of PEDOT-nf/PGE and Ox-PEDOT-nf/PGE have been performed by cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy. The highest voltammetric response of UA was obtained at pH 2.0. A linear relationship between the concentration of UA and oxidation peak currents was observed in the concentration range of 0.01-20.0 μM. The detection limit (1.3 nM according to S/N = 3) and reproducibility (RSD: 4.6 % for N:10) have also been determined. The effects of different substances on the determination of UA have been investigated. A very high peak separation value of 423 mV was obtained between UA and ascorbic acid which is the major interfering substance for UA. The use of Ox-PEDOT-nf/PGE has been successfully tested in the determination of UA in human blood serum and urine samples for the first time in the literature.

  11. Plasma polymerization of acrylic acid onto polystyrene by cyclonic plasma at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Chang, Yi-Jan; Lin, Chin-Ho; Huang, Chun

    2016-01-01

    The cyclonic atmospheric-pressure plasma is developed for chamberless deposition of poly(acrylic acid) film from argon/acrylic acid mixtures. The photoemission plasma species in atmospheric-pressure plasma polymerization was identified by optical emission spectroscopy (OES). The OES diagnosis data and deposition results indicated that in glow discharge, the CH and C2 species resulted from low-energy electron-impact dissociation that creates deposition species, but the strong CO emission lines are related to nondeposition species. The acrylic acid flow rate is seen as the key factor affecting the film growth. The film surface analysis results indicate that a smooth, continuous, and uniform surface of poly(acrylic acid) films can be formed at a relatively low plasma power input. This study reveals the potential of chamberless film growth at atmospheric pressure for large-area deposition of poly(acrylic acid) films.

  12. Associations of plasma phospholipid fatty acids with plasma homocysteine in Chinese vegetarians.

    PubMed

    Huang, Tao; Yu, Xiaomei; Shou, Tianxing; Wahlqvist, Mark L; Li, Duo

    2013-05-01

    The association of plasma phospholipid (PL) fatty acid composition with plasma homocysteine (Hcy) in Chinese vegetarians is not understood. The main aim of the present study was to investigate the plasma PL fatty acid status, and its association with plasma Hcy in Chinese vegetarians and omnivores. A total of 103 male vegetarians and 128 male omnivores were recruited in Linyin Temple, Hangzhou. Plasma Hcy and PL fatty acid concentrations were determined by standard methods. Compared with omnivores, plasma PL n-3 PUFA (P< 0·001), 22 : 6n-3 (P< 0·001), 22 : 5n-6 (P= 0·021), 22 : 2n-6 (P< 0·001) and SFA (P= 0·017) were significantly lower, while plasma PL n-6 PUFA (P= 0·007) and total PUFA (P< 0·001) were significantly higher in vegetarians. The prevalence of hyperhomocysteinaemia (HHcy) in vegetarians (26·47 %) was significantly higher than that in omnivores (13·28 %). In vegetarians, plasma PL 22 : 6n-3 (r − 0·257, P= 0·046) was significantly negatively associated with plasma Hcy. In omnivores, plasma PL 18 : 1n-7 (r 0·237, P= 0·030) was significantly positively associated with plasma Hcy. Plasma PL 22 : 6n-3 (r − 0·217, P= 0·048) was negatively associated with plasma Hcy in omnivores. Plasma PL SFA were positively associated with the prevalence of HHcy. It would seem appropriate for vegetarians to increase their dietary n-3 PUFA and decrease dietary SFA, and thus reduce the risk of HHcy.

  13. Plasma polymerized allylamine coated quartz particles for humic acid removal.

    PubMed

    Jarvis, Karyn L; Majewski, Peter

    2012-08-15

    Allylamine plasma polymerization has been used to modify the surface of quartz particles for humic acid removal via an inductively coupled rotating barrel plasma reactor. Plasma polymerized allylamine (ppAA) films were deposited at a power of 25 W, allylamine flow rate of 4.4 sccm and polymerization times of 5-60 min. The influence of polymerization time on surface chemistry was investigated via X-ray photoelectron spectroscopy (XPS), time of flight secondary ion mass spectrometry (ToF-SIMS) and electrokinetic analysis. Acid orange 7 adsorption/desorption quantified the number of surface amine groups. Humic acid removal via ppAA quartz particles was examined by varying pH, removal time, humic acid concentration, and particle mass. Increasing the polymerization time increased the concentration of amine groups on the ppAA quartz surface, thus also increasing the isoelectric point. ToF-SIMS demonstrated uniform distribution of amine groups across the particle surface. Greatest humic acid removal was observed at pH 5 due to electrostatic attraction. At higher pH values, for longer polymerization times, humic acid removal was also observed due to hydrogen bonding. Increasing the initial humic acid concentration increased the mass of humic acid removed, with longer polymerization times exhibiting the greatest increases. Plasma polymerization using a rotating plasma reactor has shown to be a successful method for modifying quartz particles for the removal of humic acid. Further development of the plasma polymerization process and investigation of additional contaminants will aid in the development of a low cost water treatment system.

  14. Plasma and red blood cell fatty acids in peroxisomal disorders.

    PubMed

    Moser, A B; Jones, D S; Raymond, G V; Moser, H W

    1999-02-01

    The demonstration of abnormal levels of fatty acids or plasmalogens in plasma or red blood cells is key to the diagnosis of peroxisomal disorders. We report the levels of 62 fatty acids and plasmalogens in patients with X-linked adrenoleukodystrophy (X-ALD), Zellweger syndrome (ZS), neonatal adrenoleukodystrophy (NALD), and infantile Refsum disease (IRD), both at baseline and after dietary interventions. "Lorenzo's Oil" therapy in X-ALD normalizes the levels of saturated very long chain fatty acids in plasma, but leads to reduced levels of omega 6 and other omega 3 fatty acids, and requires monitoring and appropriate dietary supplements. Patients with ZS, NALD and IRD have reduced levels of docosahexaenoic acid (DHA) and arachidonic acid (AA) which can be normalized by the oral administration of microencapsulated DHA and AA.

  15. Novelty in hypertension in children and adolescents: focus on hypertension during the first year of life, use and interpretation of ambulatory blood pressure monitoring, role of physical activity in prevention and treatment, simple carbohydrates and uric acid as risk factors.

    PubMed

    Strambi, Mirella; Giussani, Marco; Ambruzzi, Maria Amalia; Brambilla, Paolo; Corrado, Ciro; Giordano, Ugo; Maffeis, Claudio; Maringhin, Silvio; Matteucci, Maria Chiara; Menghetti, Ettore; Salice, Patrizia; Schena, Federico; Strisciuglio, Pietro; Valerio, Giuliana; Viazzi, Francesca; Virdis, Raffaele; Genovesi, Simonetta

    2016-07-16

    The present article intends to provide an update of the article "Focus on prevention, diagnosis and treatment of hypertension in children and adolescents" published in 2013 (Spagnolo et al., Ital J Pediatr 39:20, 2013) in this journal. This revision is justified by the fact that during the last years there have been several new scientific contributions to the problem of hypertension in pediatric age and during adolescence. Nevertheless, for what regards some aspects of the previous article, the newly acquired information did not require substantial changes to what was already published, both from a cultural and from a clinical point of view. We felt, however, the necessity to rewrite and/or to extend other parts in the light of the most recent scientific publications. More specifically, we updated and extended the chapters on the diagnosis and management of hypertension in newborns and unweaned babies, on the use and interpretation of ambulatory blood pressure monitoring, and on the usefulness of and indications for physical activity. Furthermore, we added an entirely new section on the role that simple carbohydrates (fructose in particular) and uric acid may play in the pathogenesis of hypertension in pediatric age.

  16. Simultaneous determination of cysteine, uric acid and tyrosine using Au-nanoparticles/poly(E)-4-(p-tolyldiazenyl)benzene-1,2,3-triol film modified glassy carbon electrode.

    PubMed

    Taei, M; Hasanpour, F; Salavati, H; Banitaba, S H; Kazemi, F

    2016-02-01

    A novel Au nanoparticles/poly(E)-4-(p-tolyldiazenyl)benzene-1,2,3-triol (AuNPs/PTAT) film modified glassy carbon electrode (AuNPs/PTAT/GCE) was fabricated for the simultaneous determination of three antioxidants named, cysteine (Cys), uric acid (UA) and tyrosine (Tyr). The bare glassy carbon electrode (GCE) fails to separate the oxidation peak potentials of these molecules, while PTAT film modified electrode can resolve them. Electrochemical impedance spectroscopy (EIS) study indicates that the charge transfer resistance of bare electrode increased as (E)-4-(p-tolyldiazenyl)benzene-1,2,3-triol was electropolymerized at the bare electrode. Furthermore, EIS exhibits enhancement of electron transfer kinetics between analytes and electrode after electrodeposition of Au nanoparticles. Differential pulse voltammetry results show that the electrocatalytic current increases linearly in the ranges of 2-540μmolL(-1) for Cys, 5-820μmolL(-1) for UA and 10-560μmolL(-1) for Tyr with detection limits (S/N=3) of 0.04μmolL(-1), 0.1μmolL(-1) and 2μmolL(-1) for Cys, UA and Tyr, respectively. The proposed method was successfully applied for simultaneous determination of Cys, UA and Tyr in human urine samples.

  17. A Taiwanese food frequency questionnaire correlates with plasma docosahexaenoic acid but not with plasma eicosapentaenoic acid levels: questionnaires and plasma biomarkers

    PubMed Central

    2013-01-01

    Background Little evidence is available for the validity of dietary fish and polyunsaturated fatty acid intake derived from interviewer-administered questionnaires and plasma docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) concentration. Methods We estimated the correlation of DHA and EPA intake from both questionnaires and biochemical measurements. Ethnic Chinese adults with a mean (± SD) age of 59.8 (±12.8) years (n = 297) (47% women) who completed a 38-item semi-quantitative food-frequency questionnaire and provided a plasma sample were enrolled. Plasma fatty acids were analyzed by capillary gas chromatography. Results The Spearmen rank correlation coefficients between the intake of various types of fish and marine n-3 fatty acids as well as plasma DHA were significant, ranging from 0.20 to 0.33 (P < 0.001). In addition, dietary EPA, C22:5 n-3 and DHA were significantly correlated with the levels of marine n-3 fatty acids and DHA, with the Spearman rank correlation coefficients ranging from 0.26 to 0.35 (P < 0.001). Moreover, compared with those in the lowest fish intake quintile, participants in the highest quintile had a significantly higher DHA level (adjusted mean difference, 0.99 ± 0.10%, test for trend, P < 0.001). Similar patterns between dietary DHA intake and plasma DHA levels were found. However, the association between dietary fish intake and plasma EPA was not significant (test for trend, P = 0.69). Conclusions The dietary intakes of fish and of long chain n-3 fatty acids, as determined by the food frequency questionnaire, were correlated with the percentages of these fatty acids in plasma, and in particular with plasma DHA. Plasma DHA levels were correlated to dietary intake of long-chain n-3 fatty acids. PMID:23414574

  18. Polymerization of acrylic acid using atmospheric pressure DBD plasma jet

    NASA Astrophysics Data System (ADS)

    Bashir, M.; Bashir, S.

    2016-08-01

    In this paper polymerization of acrylic acid was performed using non thermal atmospheric pressure plasma jet technology. The goal of this study is to deposit organic functional coatings for biomedical applications using a low cost and rapid growth rate plasma jet technique. The monomer solution of acrylic acid was vaporized and then fed into the argon plasma for coating. The discharge was powered using a laboratory made power supply operating with sinusoidal voltage signals at a frequency of 10 kHz. The optical emission spectra were collected in order to get insight into the plasma chemistry during deposition process. The coatings were characterized using Fourier transform infrared spectroscopy, atomic force microscopy and growth rates analysis. A high retention of carboxylic functional groups of the monomer was observed at the surface deposited using this low power technique.

  19. Plasma Amino Acids Changes in Complex Regional Pain Syndrome

    PubMed Central

    Alexander, Guillermo M.; Reichenberger, Erin; Peterlin, B. Lee; Perreault, Marielle J.; Grothusen, John R.; Schwartzman, Robert J.

    2013-01-01

    Complex regional pain syndrome (CRPS) is a severe chronic pain condition that most often develops following trauma. Blood samples were collected from 220 individuals, 160 CRPS subjects, and 60 healthy pain-free controls. Plasma amino acid levels were compared and contrasted between groups. L-Aspartate, L-glutamate, and L-ornithine were significantly increased, whereas L-tryptophan and L-arginine were significantly decreased in CRPS subjects as compared to controls. In addition, the L-kynurenine to L-tryptophan ratio demonstrated a significant increase, whereas the global arginine bioavailability ratio (GABR) was significantly decreased in the CRPS subjects. The CRPS subjects demonstrated a significant correlation between overall pain and the plasma levels of L-glutamate and the L-kynurenine to L-tryptophan ratio. CRPS subjects also showed a correlation between the decrease in plasma L-tryptophan and disease duration. This study shows that CRPS subjects exhibit significant changes in plasma levels of amino acids involved in glutamate receptor activation and in amino acids associated with immune function as compared to healthy pain-free controls. A better understanding of the role plasma amino acids play in the pathophysiology of CRPS may lead to novel treatments for this crippling condition. PMID:24303215

  20. Effect of a reduction in uric acid on renal outcomes during losartan treatment: a post hoc analysis of the reduction of endpoints in non-insulin-dependent diabetes mellitus with the Angiotensin II Antagonist Losartan Trial.

    PubMed

    Miao, Yan; Ottenbros, Stefan A; Laverman, Goos D; Brenner, Barry M; Cooper, Mark E; Parving, Hans-Henrik; Grobbee, Diederick E; Shahinfar, Shahnaz; de Zeeuw, Dick; Lambers Heerspink, Hiddo J

    2011-07-01

    Emerging data show that increased serum uric acid (SUA) concentration is an independent risk factor for end-stage renal disease. Treatment with the antihypertensive drug losartan lowers SUA. Whether reductions in SUA during losartan therapy are associated with renoprotection is unclear. We therefore tested this hypothesis. In a post hoc analysis of 1342 patients with type 2 diabetes mellitus and nephropathy participating in the Reduction of Endpoints in Non-Insulin-Dependent Diabetes Mellitus With the Angiotensin II Antagonist Losartan Trial, we determined the relationship between month 6 change in SUA and renal endpoints, defined as a doubling of serum creatinine or end-stage renal disease. Baseline SUA was 6.7 mg/dL in placebo and losartan-treated subjects. During the first 6 months, losartan lowered SUA by -0.16 mg/dL (95% CI: -0.30 to -0.01; P=0.031) as compared with placebo. The risk of renal events was decreased by 6% (95% CI: 10% to 3%) per 0.5-mg/dL decrement in SUA during the first 6 months. This effect was independent of other risk markers, including estimate glomerular filtration rate and albuminuria. Adjustment of the overall treatment effects for SUA attenuated losartan's renoprotective effect from 22% (95% CI: 6% to 35%) to 17% (95% CI: 1% to 31%), suggesting that approximately one fifth of losartan's renoprotective effect could be attributed to its effect on SUA. Losartan lowers SUA levels compared with placebo treatment in patients with type 2 diabetes mellitus and nephropathy. The degree of reduction in SUA is subsequently associated with the degree in long-term renal risk reduction and explains part of losartan's renoprotective effect. These findings support the view that SUA may be a modifiable risk factor for renal disease.

  1. Carboxylic Acids Plasma Membrane Transporters in Saccharomyces cerevisiae.

    PubMed

    Casal, Margarida; Queirós, Odília; Talaia, Gabriel; Ribas, David; Paiva, Sandra

    2016-01-01

    This chapter covers the functionally characterized plasma membrane carboxylic acids transporters Jen1, Ady2, Fps1 and Pdr12 in the yeast Saccharomyces cerevisiae, addressing also their homologues in other microorganisms, as filamentous fungi and bacteria. Carboxylic acids can either be transported into the cells, to be used as nutrients, or extruded in response to acid stress conditions. The secondary active transporters Jen1 and Ady2 can mediate the uptake of the anionic form of these substrates by a H(+)-symport mechanism. The undissociated form of carboxylic acids is lipid-soluble, crossing the plasma membrane by simple diffusion. Furthermore, acetic acid can also be transported by facilitated diffusion via Fps1 channel. At the cytoplasmic physiological pH, the anionic form of the acid prevails and it can be exported by the Pdr12 pump. This review will highlight the mechanisms involving carboxylic acids transporters, and the way they operate according to the yeast cell response to environmental changes, as carbon source availability, extracellular pH and acid stress conditions.

  2. Autistic children exhibit distinct plasma amino acid profile.

    PubMed

    Naushad, Shaik Mohammad; Jain, Jamal Md Nurul; Prasad, Chintakindi Krishna; Naik, Usha; Akella, Radha Rama Devi

    2013-10-01

    In order to ascertain whether autistic children display characteristic metabolic signatures that are of diagnostic value, plasma amino acid analyses were carried out on a cohort of 138 autistic children and 138 normal controls using reverse-phase HPLC. Pre-column derivatization of amino acids with phenyl isothiocyanate forms phenyl thio-carbamate derivates that have a lamba(max) of 254 nm, enabling their detection using photodiode array. Autistic children showed elevated levels of glutamic acid (120 +/- 89 vs. 83 +/- 35 micromol/L) and asparagine (85 +/- 37 vs. 47 +/- 19 micromol/L); lower levels of phenylalanine (45 +/- 20 vs. 59 +/- 18 micromol/L), tryptophan (24 +/- 11 vs. 41 +/- 16 micromol/L), methionine (22 +/- 9 vs. 28 +/- 9 micromol/L) and histidine (45 +/- 21 vs. 58 +/- 15 micromol/L). A low molar ratio of (tryptophan/large neutral amino acids) x 100 was observed in autism (5.4 vs 9.2), indicating lesser availability of tryptophan for neurotransmitter serotonin synthesis. To conclude, elevated levels of excitatory amino acids (glutamate and asparagine), decreased essential amino acids (phenylalanine, tryptophan and methionine) and decreased precursors of neurotransmitters (tyrosine and tryptophan) are the distinct characteristics of plasma amino acid profile of autistic children. Thus, such metabolic signatures might be useful tools for early diagnosis of autism.

  3. Plasma phospholipid arachidonic acid and lignoceric acid are associated with the risk of cardioembolic stroke.

    PubMed

    Chung, Hye-Kyung; Cho, Yoonsu; Do, Hyun Ju; Oh, Kyungmi; Seo, Woo-Keun; Shin, Min-Jeong

    2015-11-01

    Cardioembolic (CE) stroke is the most severe subtype of ischemic stroke with high recurrence and mortality. However, there is still little information on the association of plasma fatty acid (FA) with CE stroke. The objective of this study was to test the hypothesis whether the composition of plasma phospholipid FA is associated with the risk of CE stroke. The study subjects were collected from the Korea University Stroke Registry. Twenty-one subjects were selected as CE stroke group, and 39 age- and sex-matched subjects with non-CE stroke were selected as controls. Sociodemographic factors, clinical measurements, and plasma phospholipid FA compositions were compared between the groups. Logistic regression was used to obtain estimates of the associations between the relevant FAs and CE stroke. The result showed that the CE stroke group had higher levels of free FA and lower levels of triglycerides before and after adjustment (all P < .05). In the regression analysis, elaidic acid (18:1Tn9) and arachidonic acid (20:4n6) were positively related, but lignoceric acid (24:0) was negatively related to CE stroke in all constructed models (all P < .05). In conclusion, plasma phospholipid FA composition was associated with CE stroke risk in Korean population, with higher proportions of elaidic acid and arachidonic acid and lower proportion of lignoceric acid in CE stroke. PMID:26452419

  4. Plasma-chemical waste treatment of acid gases

    SciTech Connect

    Harkness, J.B.L.; Doctor, R.D.; Daniels, E.J.

    1993-09-01

    The research to date has shown that a H{sub 2}S waste-treatment process based on plasma-chemical dissociation technology is compatible with refinery and high-carbon-oxide acid-gas streams. The minor amounts of impurities produced in the plasma-chemical reactor should be treatable by an internal catalytic reduction step. Furthermore, the plasma-chemical technology appears to be more efficient and more economical than the current technology. The principal key to achieving high conversions with relatively low energies of dissociation is the concept of the high-velocity, cyclonic-flow pattern in the plasma reaction zone coupled with the recycling of unconverted hydrogen sulfide. Future work will include testing the effects of components that might be carried over to the plasma reactor by ``upset`` conditions in the amine purification system of a plant and testing the plasma-chemical process on other industrial wastes streams that contain potentially valuable chemical reagents. The strategy for the commercialization of this technology is to form a Cooperative Research and Development Agreement with the Institute of Hydrogen Energy and Plasma Technology of the Russian Scientific Center/Kurchatov Institute and with an American start-up company to develop an ``American`` version of the process and to build a commercial-scale demonstration unit in the United States. The timetable proposed would involve building a ``field test`` facility which would test the plasma-chemical reactor and sulfur recovery unit operations on an industrial hydrogen sulfide waste s at a scale large enough to obtain the energy and material balance data required for a final analysis of the commercial potential of this technology. The field test would then be followed by construction of a commercial demonstration unit in two to three years. The commercial demonstration unit would be a fully integrated plant consisting of one commercial-scale module.

  5. Rapid lipid enrichment in omega3 fatty acids: plasma data.

    PubMed

    Carpentier, Yvon A; Peltier, Sebastien; Portois, Laurence; Sener, Abdullah; Malaisse, Willy J

    2008-03-01

    The bolus intravenous injection of a novel medium-chain triglyceride:fish oil emulsion to normal subjects was recently reported to enrich within 60 min the phospholipid content of leucocytes and platelets in long-chain polyunsaturated omega3 fatty acids. The present study, conducted in second generation omega3-depleted rats, aimed at investigating whether such a procedure may also increase within 60 min the phospholipid content of omega3 fatty acids in cells located outwards the bloodstream, in this case liver cells, and whether this coincides with correction of the perturbation in the liver triglyceride fatty acid content and profile otherwise prevailing in these rats. This first report deals mainly with the fatty acid pattern of plasma lipids in male omega3-depleted rats that were non-injected or injected with either the omega3-rich emulsion or a control medium-chain triglyceride:olive oil emulsion. The results provide information on the fate of the exogenous lipids present in the lipid emulsions and injected intravenously 60 min before sacrifice. Moreover, in the uninjected omega3-depleted rats the comparison between individual plasma and liver measurements indicated positive correlations in the fatty acid profile of phospholipids and triglycerides. PMID:18288383

  6. Effects of running the Bostom Marathon on plasma concentrations of large neutral amino acids

    NASA Technical Reports Server (NTRS)

    Conlay, L. A.; Wurtman, R. J.; Lopez G-Coviella, I.; Blusztajn, J. K.; Vacanti, C. A.; Logue, M.; During, M.; Caballero, B.; Maher, T. J.; Evoniuk, G.

    1989-01-01

    Plasma large neutral amino acid concentrations were measured in thirty-seven subjects before and after completing the Boston Marathon. Concentrations of tyrosine, phenylalanine, and methionine increased, as did their 'plasma ratios' (i.e., the ratio of each amino acid's concentration to the summed plasma concentrations of the other large neutral amino acids which compete with it for brain uptake). No changes were noted in the plasma concentrations of tryptophan, leucine, isoleucine, nor valine; however, the 'plasma ratios' of valine, leucine, and isoleucine all decreased. These changes in plasma amino acid patterns may influence neurotransmitter synthesis.

  7. Relation of serum uric acid levels and outcomes among patients hospitalized for worsening heart failure with reduced ejection fraction (from the efficacy of vasopressin antagonism in heart failure outcome study with tolvaptan trial).

    PubMed

    Vaduganathan, Muthiah; Greene, Stephen J; Ambrosy, Andrew P; Mentz, Robert J; Subacius, Haris P; Chioncel, Ovidiu; Maggioni, Aldo P; Swedberg, Karl; Zannad, Faiez; Konstam, Marvin A; Senni, Michele; Givertz, Michael M; Butler, Javed; Gheorghiade, Mihai

    2014-12-01

    We investigated the clinical profiles associated with serum uric acid (sUA) levels in a large cohort of patients hospitalized for worsening chronic heart failure with ejection fraction (EF) ≤40%, with specific focus on gender, race, and renal function based interactions. In 3,955 of 4,133 patients (96%) with baseline sUA data, clinical characteristics and outcomes were compared across sUA quartiles. The primary end points were all-cause mortality and a composite of cardiovascular mortality or heart failure hospitalization. Interaction analyses were performed for gender, race, and baseline renal function. Median follow-up was 9.9 months. Mean sUA was 9.1 ± 2.8 mg/dl and was higher in men than in women (9.3 ± 2.7 vs 8.7 ± 3.0 mg/dl, p <0.001) and in blacks than in whites (10.0 ± 2.7 vs 9.0 ± 2.8 mg/dl, p <0.001). Higher sUA was associated with lower systolic blood pressure and EF, higher natriuretic peptides, and more impaired renal function. After accounting for 24 baseline covariates, in patients with enrollment estimated glomerular filtration rate ≥30 ml/min/1.73 m(2), sUA was strongly associated with increased all-cause mortality (hazard ratio 1.44, 95% confidence interval 1.22 to 1.69, p <0.001) and the composite end point (hazard ratio 1.44, 95% confidence interval 1.26 to 1.64, p <0.001). However, in patients with estimated glomerular filtration rate <30 ml/min/1.73 m(2), sUA was not related with either end point (both p >0.4). Adjusted interaction analyses for gender, race, and admission allopurinol use were not significant. In conclusion, sUA is commonly elevated in patients hospitalized for worsening chronic heart failure and reduced EF, especially in men and blacks. The prognostic use of sUA differs by baseline renal function, suggesting different biologic and pathophysiologic significance of sUA among those with and without significant renal dysfunction. PMID:25312638

  8. Oxidants and anti-oxidants in turbot seminal plasma and their effects on sperm quality

    NASA Astrophysics Data System (ADS)

    Han, Mingming; Ding, Fuhong; Meng, Zhen; Lei, Jilin

    2015-08-01

    In this research, the concentration and activity of oxidants and anti-oxidants in turbot semen, and their effects on sperm quality were studied. The results showed that superoxide dismutase (SOD), catalase, glutathione reductase (GR), uric acid, vitamin E (VE) and vitamin C (VC) were more abundant in seminal plasma than in spermatozoa. The variation for each of them was specific. In seminal plasma, the activity of SOD and GR increased from November 15, November 30 to December 15, and then decreased on December 30. The concentrations of both VC and uric acid decreased during the first 3 sampling times and increased on December 30. The oxidants in seminal plasma accumulated to the highest on December 30. Lactic acid (LA) and ATP levels decreased to the lowest on December 30. The correlation analysis showed that GR had the significant positive relevance to sperm motility and VSL/VCL, while ·OH had negative relevance to them.

  9. Effect on days of lactation and methionine hydroxy analog on incorporation of plasma fatty acids into plasma triglycerides

    SciTech Connect

    Pullen, D.L.; Emergy, R.S. ); Palmquist, D.L. )

    1989-01-01

    Methionine hydroxy analog has been proposed to stimulate hepatic lipoprotein synthesis and incorporation of plasma fatty acids into plasma triglyceride. Seven cows were fed diets containing 0 to 30 g analog/d starting 14 d prepartum. At approximately 30 and 60 d postpartum, cows were continuously infused intravenously with 1-({sup 14}C)palmitic acid for 160 min to achieve steady-state labeling of plasma fatty acid and triglyceride. Turnover of fatty acid and transfer quotients for triglyceride and CO{sub 2} were 3.3 an 2.7 mmol min{sup {minus}1}; 13.0 and 10.0%; and 8.0 and 5.0%, for control and analog, respectively. Proportion of fatty acid turnover incorporated into triglyceride and CO{sub 2} were 14.0 and 15.0%; and 21.0 and 18.0, respectively, for control and analog. Analog increased {sup 14}C recovered in milk fat (52 vs. 36%). Plasma concentration of fatty acids, percent oxidized to CO{sub 2}, and percent of CO{sub 2} from fatty acids decreased with increasing lactation days. Milk fat percent and yield fatty acid turnover, and oxidation were positively correlated with concentration of plasma fatty acids, whereas fatty acid incorporated into plasma triglyceride was negatively correlated with fatty acid concentration. The data suggest that hepatic triglyceride secretion is not increased in early lactation; further, no effects of analog on lipid metabolism were detected.

  10. Plasma long-chain free fatty acids predict mammalian longevity

    PubMed Central

    Jové, Mariona; Naudí, Alba; Aledo, Juan Carlos; Cabré, Rosanna; Ayala, Victoria; Portero-Otin, Manuel; Barja, Gustavo; Pamplona, Reinald

    2013-01-01

    Membrane lipid composition is an important correlate of the rate of aging of animals and, therefore, the determination of their longevity. In the present work, the use of high-throughput technologies allowed us to determine the plasma lipidomic profile of 11 mammalian species ranging in maximum longevity from 3.5 to 120 years. The non-targeted approach revealed a specie-specific lipidomic profile that accurately predicts the animal longevity. The regression analysis between lipid species and longevity demonstrated that the longer the longevity of a species, the lower is its plasma long-chain free fatty acid (LC-FFA) concentrations, peroxidizability index, and lipid peroxidation-derived products content. The inverse association between longevity and LC-FFA persisted after correction for body mass and phylogenetic interdependence. These results indicate that the lipidomic signature is an optimized feature associated with animal longevity, emerging LC-FFA as a potential biomarker of longevity. PMID:24284984

  11. Plasma long-chain free fatty acids predict mammalian longevity.

    PubMed

    Jové, Mariona; Naudí, Alba; Aledo, Juan Carlos; Cabré, Rosanna; Ayala, Victoria; Portero-Otin, Manuel; Barja, Gustavo; Pamplona, Reinald

    2013-11-28

    Membrane lipid composition is an important correlate of the rate of aging of animals and, therefore, the determination of their longevity. In the present work, the use of high-throughput technologies allowed us to determine the plasma lipidomic profile of 11 mammalian species ranging in maximum longevity from 3.5 to 120 years. The non-targeted approach revealed a specie-specific lipidomic profile that accurately predicts the animal longevity. The regression analysis between lipid species and longevity demonstrated that the longer the longevity of a species, the lower is its plasma long-chain free fatty acid (LC-FFA) concentrations, peroxidizability index, and lipid peroxidation-derived products content. The inverse association between longevity and LC-FFA persisted after correction for body mass and phylogenetic interdependence. These results indicate that the lipidomic signature is an optimized feature associated with animal longevity, emerging LC-FFA as a potential biomarker of longevity.

  12. Eskimo plasma constituents, dihomo-gamma-linolenic acid, eicosapentaenoic acid and docosahexaenoic acid inhibit the release of atherogenic mitogens.

    PubMed

    Smith, D L; Willis, A L; Nguyen, N; Conner, D; Zahedi, S; Fulks, J

    1989-01-01

    Studies in man and laboratory animals suggest that omega 3 polyunsaturated fatty acid constituents of fish oils have antiatherosclerotic properties. We have studied the effects of several such polyunsaturated fatty acids for ability to modify the in vitro release of mitogens from human platelets. Such mitogens may produce the fibro-proliferative component of atherosclerotic plaques. Both 5,8,11,14,17-eicosapentaenoic acid (20:5 omega 3) and 4,7,10,13,16,19-docosahexaenoic acid (22:6 omega 3), major constituents of fish oils, inhibited adenosine diphosphate-induced aggregation of platelets and the accompanying release of mitogens. These effects are dose dependent. Linolenic acid (18:3 omega 3), the biosynthetic precursor of eicosapentaenoic acid, also inhibited platelet aggregation and mitogen release. Eicosapentaenoic acid also inhibited mitogen release from human monocyte-derived macrophages, which, in vivo, are an additional source of mitogens during atherogenesis. Potent inhibition of human platelet aggregation and mitogen release was also seen with dihomo-gamma-linolenic acid (8,11,14-eicosatrienoic acid 20:3 omega 6), whose levels are reportedly elevated in Eskimos subsisting on marine diets. We conclude that diets that elevate plasma and/or tissue levels of eicosapentaenoic acid, docosahexaenoic acid and dihomo-gamma-linolenic acid precursor gamma-linolenic acid (18:3 omega 6) may exert antiatherosclerotic effects by inhibiting the release of mitogens from platelets and other cells.

  13. Effects of gas atmospheres on poly(lactic acid) film in acrylic acid plasma treatment

    NASA Astrophysics Data System (ADS)

    Zhao, Yun; Fina, Alberto; Venturello, Alberto; Geobaldo, Francesco

    2013-10-01

    Plasma polymerized acrylic acid (AA) coatings were deposited on poly(lactic acid) (PLA) films in various gas atmospheres during the pre-treatment of PLA and the deposition of AA, respectively. Therefore, this work was twofold: the argon pretreated PLA films followed by a deposition in argon were investigated against the mixture of argon and oxygen pretreated ones under the same deposition conditions; the plasma deposition of AA operating in different atmospheres (argon, oxygen and nitrogen) was employed to modify the pretreated PLA in oxygen. Chemical and physical changes on the plasma-treated surfaces were examined using contact angle, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM) and attenuated total reflection infrared (ATR-FTIR) analysis. The results showed that the discharge gas can have a significant influence on the chemical composition of the PLA surfaces: oxygen plasmas introduced oxygen-containing groups in company with surface etching in pretreatment and deposition, while argon discharges was able to achieve much better hydrophilic behavior and high retention ratio of poly(acrylic acid) (PAA) coating before and after washing in water.

  14. Plasma and brain fatty acid profiles in mild cognitive impairment and Alzheimer's disease.

    PubMed

    Cunnane, Stephen C; Schneider, Julie A; Tangney, Christine; Tremblay-Mercier, Jennifer; Fortier, Mélanie; Bennett, David A; Morris, Martha Clare

    2012-01-01

    Alzheimer's disease (AD) is generally associated with lower omega-3 fatty acid intake from fish but despite numerous studies, it is still unclear whether there are differences in omega-3 fatty acids in plasma or brain. In matched plasma and brain samples provided by the Memory and Aging Project, fatty acid profiles were quantified in several plasma lipid classes and in three brain cortical regions. Fatty acid data were expressed as % composition and as concentrations (mg/dL for plasma or mg/g for brain). Differences in plasma fatty acid profiles between AD, mild cognitive impairment (MCI), and those with no cognitive impairment (NCI) were most apparent in the plasma free fatty acids (lower oleic acid isomers and omega-6 fatty acids in AD) and phospholipids (lower omega-3 fatty acids in AD). In brain, % DHA was lower only in phosphatidylserine of mid-frontal cortex and superior temporal cortex in AD compared to NCI (-14% and -12%, respectively; both p < 0.05). The only significant correlation between plasma and brain fatty acids was between % DHA in plasma total lipids and % DHA in phosphatidylethanolamine of the angular gyrus, but only in the NCI group (+0.77, p < 0.05). We conclude that AD is associated with altered plasma status of both DHA and other fatty acids unrelated to DHA, and that the lipid class-dependent nature of these differences reflects a combination of differences in intake and metabolism. PMID:22466064

  15. Determining important regulatory relations of amino acids from dynamic network analysis of plasma amino acids.

    PubMed

    Shikata, Nahoko; Maki, Yukihiro; Nakatsui, Masahiko; Mori, Masato; Noguchi, Yasushi; Yoshida, Shintaro; Takahashi, Michio; Kondo, Nobuo; Okamoto, Masahiro

    2010-01-01

    The changes in the concentrations of plasma amino acids do not always follow the flow-based metabolic pathway network. We have previously shown that there is a control-based network structure among plasma amino acids besides the metabolic pathway map. Based on this network structure, in this study, we performed dynamic analysis using time-course data of the plasma samples of rats fed single essential amino acid deficient diet. Using S-system model (conceptual mathematical model represented by power-law formalism), we inferred the dynamic network structure which reproduces the actual time-courses within the error allowance of 13.17%. By performing sensitivity analysis, three of the most dominant relations in this network were selected; the control paths from leucine to valine, from methionine to threonine, and from leucine to isoleucine. This result is in good agreement with the biological knowledge regarding branched-chain amino acids, and suggests the biological importance of the effect from methionine to threonine.

  16. Plasma Amino Acids Profiles in Children with Autism: Potential Risk of Nutritional Deficiencies.

    ERIC Educational Resources Information Center

    Arnold, Georgianne L.; Hyman, Susan L.; Mooney, Robert A.; Kirby, Russell S.

    2003-01-01

    The plasma amino acid profiles of 10 children with autism on gluten and casein restricted diets and 26 on unrestricted diets were reviewed. There was a trend for the children on restricted diets to have an increased prevalence of essential amino acid deficiencies and lower plasma levels of essential acids. (Contains references.) (Author/CR)

  17. Plasma fatty acids in chronic kidney disease: nervonic acid predicts mortality.

    PubMed

    Shearer, Gregory C; Carrero, Juan J; Heimbürger, Olof; Barany, Peter; Stenvinkel, Peter

    2012-03-01

    Although the value of red blood cell fatty acids (FAs) in estimating risk for acute coronary syndrome in the general population is evident, the value of FAs in chronic kidney disease (CKD) is unknown. Here, we provide a pilot analysis in a spectrum of CKD patients. Plasma samples were obtained from 20 incident dialysis patients (CKD stage 5), matched with samples from 10 CKD stage 3-4 patients, and 10 control subjects. Whole plasma FAs were measured using gas chromatography. Whereas neither linoleic acid nor arachidonate acid were altered in CKD, metabolic intermediates of arachidonate synthesis (γ-linolenate and dihomo γ-linolenate) were reduced in CKD. Demming (orthogonal) correlation of FA abundance with estimated GFR identified several saturated and unsaturated FAs in addition to the intermediates; again, neither linoleate nor arachidonate were related. Follow-up data within the CKD stage 5 patients revealed that nervonic acid, a component of membrane sphingolipids and phosphatidylethanolamines, was a significant predictor of all-cause mortality; the age-adjusted relative risk for a 0.15% change is 2.1 (1.4, 3.7; 95% CI; P = .0008). These findings support the exploration of FAs in larger studies for validation of the role FAs in cardiovascular risk and mortality in CKD.

  18. Analytic calculation of physiological acid-base parameters in plasma.

    PubMed

    Wooten, E W

    1999-01-01

    Analytic expressions for plasma total titratable base, base excess (DeltaCB), strong-ion difference, change in strong-ion difference (DeltaSID), change in Van Slyke standard bicarbonate (DeltaVSSB), anion gap, and change in anion gap are derived as a function of pH, total buffer ion concentration, and conditional molar equilibrium constants. The behavior of these various parameters under respiratory and metabolic acid-base disturbances for constant and variable buffer ion concentrations is considered. For constant noncarbonate buffer concentrations, DeltaSID = DeltaCB = DeltaVSSB, whereas these equalities no longer hold under changes in noncarbonate buffer concentration. The equivalence is restored if the reference state is changed to include the new buffer concentrations.

  19. The effect of acute stress and long-term corticosteroid administration on plasma metabolites in an urban and desert songbird.

    PubMed

    Davies, Scott; Rodriguez, Natalie S; Sweazea, Karen L; Deviche, Pierre

    2013-01-01

    In response to stressful stimuli, animals activate the hypothalamic-pituitary-adrenal axis, which can result in transition to the "emergency life history stage." A key adaptive characteristic of this life history stage is the mobilization of energy stores. However, few data are available on the metabolic response to acute stress in wild-caught, free-ranging birds. We quantified the effect of acute capture and restraint stress on plasma glucose, free fatty acid, and uric acid in free-ranging Abert's towhees Melozone aberti. Furthermore, birds were caught from urban and desert localities of Phoenix, Arizona, to investigate potential effects of urban versus desert habitats on the corticosterone (CORT) and metabolic response to acute stress. Complementing work on free-ranging birds, captive towhees received CORT-filled Silastic capsules to investigate the response of urban and desert conspecifics to long-term CORT administration. We quantified the effect of CORT administration on baseline plasma glucose and uric acid, liver and pectoralis muscle glycogen stores, kidney phosphoenolpyruvate carboxykinase (PEPCK-C, a key gluconeogenic enzyme), and body mass. Acute stress increased plasma CORT and glucose and decreased plasma uric acid but had no effect on plasma free fatty acid. There was no difference between urban and desert localities in body mass, fat scores, and the response to acute stress. CORT administration decreased body mass but had no effect on glucose and uric acid, pectoral muscle glycogen, or kidney PEPCK-C. However, liver glycogen of CORT-treated urban birds increased compared with corresponding controls, whereas glycogen decreased in CORT-treated desert birds. This study suggests that Abert's towhees principally mobilize glucose during acute stress but urban and desert towhees do not differ in their CORT and metabolic response to acute stress or long-term CORT administration.

  20. Chemical modification of amino acids by atmospheric-pressure cold plasma in aqueous solution

    NASA Astrophysics Data System (ADS)

    Takai, Eisuke; Kitamura, Tsuyoshi; Kuwabara, Junpei; Ikawa, Satoshi; Yoshizawa, Shunsuke; Shiraki, Kentaro; Kawasaki, Hideya; Arakawa, Ryuichi; Kitano, Katsuhisa

    2014-07-01

    Plasma medicine is an attractive new research area, but the principles of plasma modification of biomolecules in aqueous solution remain elusive. In this study, we investigated the chemical effects of atmospheric-pressure cold plasma on 20 naturally occurring amino acids in aqueous solution. High-resolution mass spectrometry revealed that chemical modifications of 14 amino acids were observed after plasma treatment: (i) hydroxylation and nitration of aromatic rings in tyrosine, phenylalanine and tryptophan; (ii) sulfonation and disulfide linkage formation of thiol groups in cysteine; (iii) sulfoxidation of methionine and (iv) amidation and ring-opening of five-membered rings in histidine and proline. A competitive reaction experiment using 20 amino acids demonstrated that sulfur-containing and aromatic amino acids were preferentially decreased by the plasma treatment. These data provide fundamental information for elucidating the mechanism of protein inactivation for biomedical plasma applications.

  1. Plasma levels of ursodeoxycholic acid in black bears, Ursus americanus: seasonal changes.

    PubMed

    Solá, Susana; Garshelis, David L; Amaral, Joana D; Noyce, Karen V; Coy, Pam L; Steer, Clifford J; Iaizzo, Paul A; Rodrigues, Cecília M P

    2006-06-01

    To date, no other studies have examined the seasonal changes in circulating levels of various bile acids in the plasma of wild North American black bears, Ursus americanus. Using gas chromatography, bile acid concentrations were measured in plasma samples obtained during either early or late hibernation, and during summer active periods. Thus, specific compositional changes from individual animals were examined through a given year. Total bile acid concentrations in the plasma of these normal animals were found to range between 0.2 and 3.1 micromol/L (0.9 +/- 0.2 micromol/L, mean +/- SEM). Cholic, ursodeoxycholic and chenodeoxycholic acids were the major bile acid species identified. Ursodeoxycholic acid represented 28.0 +/- 2.6% of the total bile acid pool. Deoxycholic and lithocholic acids were found only in small amounts. In addition, total bile acid concentrations were lower in plasma samples obtained during hibernation compared with those obtained during summer active periods (0.6 +/- 0.1 and 1.2 +/- 0.4 micromol/L, respectively; p < 0.05). However, the relative proportion of ursodeoxycholic acid, was significantly greater in winter than in summer (31.5 +/- 3.2% and 22.2 +/- 4.5%, p < 0.05). Finally, taurine-conjugated bile acids were the predominant species in bear plasma, accounting for >67% of the total bile acids. These data demonstrate that ursodeoxycholic acid is a major bile acid in black bear plasma, mostly conjugated with taurine. Further, the finding of seasonal variation in plasma bile acid composition provides evidence to support the possible role that ursodeoxycholic acid may play in cellular protection in hibernating black bears. PMID:16571381

  2. The seasonal fluctuation of plasma amino acids in aquarium-maintained bottlenose dolphins (Tursiops truncatus).

    PubMed

    Miyaji, Kazuki; Ohta, Mitsuaki; Nagao, Kenji; Ohtani, Nobuyo; Bannai, Makoto

    2012-07-01

    Although there has been extensive research on plasma amino acid profiles of mammals, there is currently a lack of information on seasonal differences in the concentrations of plasma amino acids specifically in cetaceans. The present study examined the response of the plasma amino acids to seasonal changes in the culture environment after controlling for the effect of sex and age. Significant seasonal changes in plasma carnosine (P=0.012), cystine (P=0.0014), isoleucine (P=0.0042), methionine (P=0.002), ornithine (P=0.0096), and taurine (P=0.032) were observed. These amino acids were mainly related to capacity for exercise, ammonia detoxification, thermoregulation, and osmoregulation. We proposed that optimizing plasma amino acids levels by supplementation of amino acids should be of considerable benefit for aquarium-maintained bottlenose dolphins. This study constitutes a first step towards improving our understanding of the metabolism of aquarium-maintained bottlenose dolphins. We also revealed that the ratio of tryptophan to large neutral amino acids significantly declined (P=0.0076), suggesting reduction in serotonin synthesis in winter and autumn. Although further studies are needed, this finding implied that bottlenose dolphins could produce behavioral changes seasonally by the alteration of serotonin activity. To better understand the metabolic machinery for amino acids that facilitate the adaptation of marine mammals to their environments, it is essential to continue monitoring of and further investigations into relationships between plasma amino acids and specific environmental factors. PMID:22333514

  3. The seasonal fluctuation of plasma amino acids in aquarium-maintained bottlenose dolphins (Tursiops truncatus).

    PubMed

    Miyaji, Kazuki; Ohta, Mitsuaki; Nagao, Kenji; Ohtani, Nobuyo; Bannai, Makoto

    2012-07-01

    Although there has been extensive research on plasma amino acid profiles of mammals, there is currently a lack of information on seasonal differences in the concentrations of plasma amino acids specifically in cetaceans. The present study examined the response of the plasma amino acids to seasonal changes in the culture environment after controlling for the effect of sex and age. Significant seasonal changes in plasma carnosine (P=0.012), cystine (P=0.0014), isoleucine (P=0.0042), methionine (P=0.002), ornithine (P=0.0096), and taurine (P=0.032) were observed. These amino acids were mainly related to capacity for exercise, ammonia detoxification, thermoregulation, and osmoregulation. We proposed that optimizing plasma amino acids levels by supplementation of amino acids should be of considerable benefit for aquarium-maintained bottlenose dolphins. This study constitutes a first step towards improving our understanding of the metabolism of aquarium-maintained bottlenose dolphins. We also revealed that the ratio of tryptophan to large neutral amino acids significantly declined (P=0.0076), suggesting reduction in serotonin synthesis in winter and autumn. Although further studies are needed, this finding implied that bottlenose dolphins could produce behavioral changes seasonally by the alteration of serotonin activity. To better understand the metabolic machinery for amino acids that facilitate the adaptation of marine mammals to their environments, it is essential to continue monitoring of and further investigations into relationships between plasma amino acids and specific environmental factors.

  4. Associations between plasma branched-chain amino acids, β-aminoisobutyric acid and body composition.

    PubMed

    Rietman, Annemarie; Stanley, Takara L; Clish, Clary; Mootha, Vamsi; Mensink, Marco; Grinspoon, Steven K; Makimura, Hideo

    2016-01-01

    Plasma branched-chain amino acids (BCAA) are elevated in obesity and associated with increased cardiometabolic risk. β-Aminoisobutyric acid (B-AIBA), a recently identified small molecule metabolite, is associated with decreased cardiometabolic risk. Therefore, we investigated the association of BCAA and B-AIBA with each other and with detailed body composition parameters, including abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). A cross-sectional study was carried out with lean (n 15) and obese (n 33) men and women. Detailed metabolic evaluations, including measures of body composition, insulin sensitivity and plasma metabolomics were completed. Plasma BCAA were higher (1·6 (se 0·08) (×10(7)) v. 1·3 (se 0·06) (×10(7)) arbitrary units; P = 0·005) in obese v. lean subjects. BCAA were positively associated with VAT (R 0·49; P = 0·0006) and trended to an association with SAT (R 0·29; P = 0·052). The association between BCAA and VAT, but not SAT, remained significant after controlling for age, sex and race on multivariate modelling (P < 0·05). BCAA were also associated with parameters of insulin sensitivity (Matsuda index: R -0·50, P = 0·0004; glucose AUC: R 0·53, P < 0·001). BCAA were not associated with B-AIBA (R -0·04; P = 0·79). B-AIBA was negatively associated with SAT (R -0·37; P = 0·01) but only trended to an association with VAT (R 0·27; P = 0·07). However, neither relationship remained significant after multivariate modelling (P > 0·05). Plasma B-AIBA was associated with parameters of insulin sensitivity (Matsuda index R 0·36, P = 0·01; glucose AUC: R -0·30, P = 0·04). Plasma BCAA levels were positively correlated with VAT and markers of insulin resistance. The results suggest a possible complex role of adipose tissue in BCAA homeostasis and insulin resistance. PMID:27313851

  5. Phosphatidic acid phosphatase and phospholipdase A activities in plasma membranes from fusing muscle cells.

    PubMed

    Kent, C; Vagelos, P R

    1976-06-17

    Plasma membrane from fusing embryonic muscle cells were assayed for phospholipase A activity to determine if this enzyme plays a role in cell fusion. The membranes were assayed under a variety of conditions with phosphatidylcholine as the substrate and no phospholipase A activity was found. The plasma membranes did contain a phosphatidic acid phosphatase which was optimally active in the presence of Triton X-100 and glycerol. The enzyme activity was constant from pH 5.2 to 7.0, and did not require divalent cations. Over 97% of the phosphatidic acid phosphatase activity was in the particulate fraction. The subcellular distribution of the phosphatidic acid phosphatase was the same as the distributions of the plasma membrane markers, (Na+ + k+)-ATPase and the acetylcholine receptor, which indicates that this phosphatase is located exclusively in the plasma membranes. There was no detectable difference in the phosphatidic acid phosphatase activities of plasma membranes from fusing and non-fusing cells.

  6. A simplified strong ion model for acid-base equilibria: application to horse plasma.

    PubMed

    Constable, P D

    1997-07-01

    The Henderson-Hasselbalch equation and Stewart's strong ion model are currently used to describe mammalian acid-base equilibria. Anomalies exist when the Henderson-Hasselbalch equation is applied to plasma, whereas the strong ion model does not provide a practical method for determining the total plasma concentration of nonvolatile weak acids ([Atot]) and the effective dissociation constant for plasma weak acids (Ka). A simplified strong ion model, which was developed from the assumption that plasma ions act as strong ions, volatile buffer ions (HCO-3), or nonvolatile buffer ions, indicates that plasma pH is determined by five independent variables: PCO2, strong ion difference, concentration of individual nonvolatile plasma buffers (albumin, globulin, and phosphate), ionic strength, and temperature. The simplified strong ion model conveys on a fundamental level the mechanism for change in acid-base status, explains many of the anomalies when the Henderson-Hasselbalch equation is applied to plasma, is conceptually and algebraically simpler than Stewart's strong ion model, and provides a practical in vitro method for determining [Atot] and Ka of plasma. Application of the simplified strong ion model to CO2-tonometered horse plasma produced values for [Atot] (15.0 +/- 3.1 meq/l) and Ka (2.22 +/- 0.32 x 10(-7) eq/l) that were significantly different from the values commonly assumed for human plasma ([Atot] = 20.0 meq/l, Ka = 3.0 x 10(-7) eq/l). Moreover, application of the experimentally determined values for [Atot] and Ka to published data for the horse (known PCO2, strong ion difference, and plasma protein concentration) predicted plasma pH more accurately than the values for [Atot] and Ka commonly assumed for human plasma. Species-specific values for [Atot] and Ka should be experimentally determined when the simplified strong ion model (or strong ion model) is used to describe acid-base equilibria.

  7. Abnormalities in plasma and red blood cell fatty acid profiles of patients with colorectal cancer.

    PubMed Central

    Baró, L.; Hermoso, J. C.; Núñez, M. C.; Jiménez-Rios, J. A.; Gil, A.

    1998-01-01

    We evaluated total plasma fatty acid concentrations and percentages, and the fatty acid profiles for the different plasma lipid fractions and red blood cell lipids, in 17 patients with untreated colorectal cancer and 12 age-matched controls with no malignant diseases, from the same geographical area. Cancer patients had significantly lower total plasma concentrations of saturated, monounsaturated and essential fatty acids and their polyunsaturated derivatives than healthy controls; when the values were expressed as relative percentages, cancer patients had significantly higher proportions of oleic acid and lower levels of linoleic acid than controls. With regard to lipid fractions, cancer patients had higher proportions of oleic acid in plasma phospholipids, triglycerides and cholesterol esters, and lower percentages of linoleic acid and its derivatives. On the other hand, alpha-linolenic acid was significantly lower in triglycerides from cancer patients and tended to be lower in phospholipids. Its derivatives also tended to be lower in phospholipids and triglycerides from cancer patients. Our findings suggest that colorectal cancer patients present abnormalities in plasma and red blood cell fatty acid profiles characterized by lower amounts of most saturated, monounsaturated and essential fatty acids and their polyunsaturated derivatives, especially members of the n-6 series, than their healthy age-matched counterparts. These changes are probably due to metabolic changes caused by the illness per se but not to malnutrition. PMID:9667678

  8. Response of plasma membrane H+-ATPase in rice (Oryza sativa) seedlings to simulated acid rain.

    PubMed

    Liang, Chanjuan; Ge, Yuqing; Su, Lei; Bu, Jinjin

    2015-01-01

    Understanding the adaptation of plants to acid rain is important to find feasible approaches to alleviate such damage to plants. We studied effects of acid rain on plasma membrane H(+)-ATPase activity and transcription, intracellular H(+), membrane permeability, photosynthetic efficiency, and relative growth rate during stress and recovery periods. Simulated acid rain at pH 5.5 did not affect plasma membrane H(+)-ATPase activity, intracellular H(+), membrane permeability, photosynthetic efficiency, and relative growth rate. Plasma membrane H(+)-ATPase activity and transcription in leaves treated with acid rain at pH 3.5 was increased to maintain ion homeostasis by transporting excessive H(+) out of cells. Then intracellular H(+) was close to the control after a 5-day recovery, alleviating damage on membrane and sustaining photosynthetic efficiency and growth. Simulated acid rain at pH 2.5 inhibited plasma membrane H(+)-ATPase activity by decreasing the expression of H(+)-ATPase at transcription level, resulting in membrane damage and abnormal intracellular H(+), and reduction in photosynthetic efficiency and relative growth rate. After a 5-day recovery, all parameters in leaves treated with pH 2.5 acid rain show alleviated damage, implying that the increased plasma membrane H(+)-ATPase activity and its high expression were involved in repairing process in acid rain-stressed plants. Our study suggests that plasma membrane H(+)-ATPase can play a role in adaptation to acid rain for rice seedlings.

  9. Response of plasma membrane H+-ATPase in rice (Oryza sativa) seedlings to simulated acid rain.

    PubMed

    Liang, Chanjuan; Ge, Yuqing; Su, Lei; Bu, Jinjin

    2015-01-01

    Understanding the adaptation of plants to acid rain is important to find feasible approaches to alleviate such damage to plants. We studied effects of acid rain on plasma membrane H(+)-ATPase activity and transcription, intracellular H(+), membrane permeability, photosynthetic efficiency, and relative growth rate during stress and recovery periods. Simulated acid rain at pH 5.5 did not affect plasma membrane H(+)-ATPase activity, intracellular H(+), membrane permeability, photosynthetic efficiency, and relative growth rate. Plasma membrane H(+)-ATPase activity and transcription in leaves treated with acid rain at pH 3.5 was increased to maintain ion homeostasis by transporting excessive H(+) out of cells. Then intracellular H(+) was close to the control after a 5-day recovery, alleviating damage on membrane and sustaining photosynthetic efficiency and growth. Simulated acid rain at pH 2.5 inhibited plasma membrane H(+)-ATPase activity by decreasing the expression of H(+)-ATPase at transcription level, resulting in membrane damage and abnormal intracellular H(+), and reduction in photosynthetic efficiency and relative growth rate. After a 5-day recovery, all parameters in leaves treated with pH 2.5 acid rain show alleviated damage, implying that the increased plasma membrane H(+)-ATPase activity and its high expression were involved in repairing process in acid rain-stressed plants. Our study suggests that plasma membrane H(+)-ATPase can play a role in adaptation to acid rain for rice seedlings. PMID:25087500

  10. Plasma and skeletal muscle amino acids following severe burn injury in patients and experimental animals.

    PubMed Central

    Stinnett, J D; Alexander, J W; Watanabe, C; MacMillan, B G; Fischer, J E; Morris, M J; Trocki, O; Miskell, P; Edwards, L; James, H

    1982-01-01

    This study describes and analyzes sequential changes in plasma and skeletal muscle free amino acids following severe burn injury. Plasma free amino acids were determined in children (n = 9) with burns averaging 60% total body surface area and were compared with laboratory beagles (n = 44) which received a flame burn totaling 30% of their body surface area. In addition, needle biopsy specimens were obtained from the semitendonosus muscle in the animals to determine free intracellular amino acids. In both patients and animals the amount of total free amino acids in plasma fell following burn, suggesting relative protein deficiency. This drop was primarily due to a 47% drop in nonessential amino acids. However, plasma phenylalanine was consistently higher than normal following burn, and was strongly associated with death and weight loss in both animals and patients, especially when analyzed as a ratio with tyrosine. This finding suggested excessive catabolism, hepatic dysfunction, or both. Plasma levels of several amino acids correlated significantly with weight loss. Alterations in muscle free amino acids generally were similar to plasma amino acids. Exceptions were muscle alanine and glycine which strongly correlated with weight loss. However, the determination of muscle free amino acid profiles did not yield clinically useful information not available from plasma profiles. Plasma levels of liver enzymes suggested progressive hepatic dysfunction. These studies show that the laboratory beagle is a good model for studying the metabolic alterations of amino acids that accompany burn injury, since they mimic humans in many parameters which appear to be most useful with respect to clinical evaluation. PMID:7055386

  11. Plasma amino acid profiles at various reproductive stages in female rats

    PubMed Central

    OKAME, Rieko; NAKAHARA, Keiko; MURAKAMI, Noboru

    2015-01-01

    We measured the plasma levels of amino acids at various reproductive stages in female rats, including the estrous cycle, pregnancy and lactation, and compared the resulting amino acid profiles using two- or three-dimensional figures. These figures revealed that the amino acid profiles of pregnant and lactating dams differed considerably from those during the estrous cycle or in male rats. The plasma levels of individual amino acids were almost the same between proestrus, estrus, metestrus and diestrus, and their profiles did not differ significantly. However, the amino acid profiles changed during pregnancy and lactation in dams. The plasma Ser level decreased significantly in mid and late pregnancy, whereas Tyr, Gly and His decreased significantly in the late and end stages of pregnancy, and Trp and Lys significantly decreased and increased at the end of pregnancy, respectively. Much larger changes in amino acid profiles were observed during lactation, when the levels of many amino acids increased significantly, and none showed a significant decrease. Plasma Pro, Ser and Gly levels increased continuously from day 1 until day 15 of lactation, whereas Asn and Met increased significantly from days 1 and 5 respectively until the end of lactation. These results suggest that the profiles of plasma amino acids show characteristic changes according to reproductive stage and that it may be necessary to consider such differences when performing amino acid-based diagnosis. PMID:25787929

  12. Influence of exercise on plasma and muscle free amino acids in trained rainbow trout.

    PubMed

    Marín, J F; Mendiola, P; Hernández, M D; De Costa, J; Zamora, S

    1999-12-01

    Variations in the concentration of free amino acids in the muscle and plasma of trout submitted to 5 minutes of intense exercise have been studied. The responses of untrained fish and those trained performing the same type of exercise twice daily for 28 days are compared. Total amino acid concentrations in muscle tend to diminish after intense exercise. Significant decreases are observed in muscle content of alanine, beta-alanine, isoleucine and ornithine. Plasma amino acids tend to increase after exercise with significant differences in glutamate, GABA, methionine and NH4+. The small variations due to intense exercise suggest that the amino acids are mobilised. Training led to a decrease in total amino acid concentration in plasma but not in muscle, where levels of aspartate and ornithine increased. This suggests a metabolic adaptation to exercise, with amino acid level retention in the muscle.

  13. Valine entry into rat brain after diet-induced changes in plasma amino acids

    SciTech Connect

    Tews, J.K.; Greenwood, J.; Pratt, O.E.; Harper, A.E.

    1987-01-01

    Passage of amino acids across the blood-brain barrier is assumed to be modified by amino acid composition of the blood. To gain a better understanding of the effects of protein intake on brain amino acid uptake, the authors examined associations among diet, plasma amino acid patterns, and the rate of entry of valine into the brain. Rats were fed diets containing 6, 18, or 50% casein before receiving one meal of a diet containing 0, 6, 18, or 50% casein. After 4-7 h, they were anesthetized and infused intravenously with (/sup 14/C)valine for 5 min before plasma and brain samples were taken for determination of radioactivity and content of individual amino acids. As protein content of the meal was increased from 0 to 50% casein, plasma and brain concentrations of valine and most other large neutral amino acid (LNAA) increased severalfold; also the ratio of (/sup 14/C)valine in brain to that in plasma decreased by >50%, and the rate of valine entry into the brain increased 3.5-fold. The increase in valine flux slowed as plasma levels of LNAA, competitors for valine transport, increased. The results were far more dependent on protein content of the final meal than on that of the adaptation diet; thus changes in protein intake, as reflected in altered plasma amino acid patterns, markedly altered valine entry into the brain.

  14. Regulation of plasma testosterone, corticosterone, and metabolites in response to stress, reproductive stage, and social challenges in a desert male songbird.

    PubMed

    Deviche, Pierre; Beouche-Helias, Benjamin; Davies, Scott; Gao, Sisi; Lane, Samuel; Valle, Shelley

    2014-07-01

    In many male vertebrates, the secretion of reproductive (gonadal androgens) and adrenocortical (glucocorticoids) hormones varies seasonally and in response to environmental stimuli, and these hormones exert numerous behavioral and metabolic effects. We performed two field studies on adult male Rufous-winged Sparrows, Peucaea carpalis, a Sonoran Desert rain-dependent sedentary species, to (a) determine seasonal changes in initial (baseline) and acute stress-induced plasma testosterone (T), corticosterone (CORT), and two metabolites (uric acid and glucose) and (b) compare the effects of two types of social challenge (song playback or simulated territorial intrusion consisting of song playback plus exposure to a live decoy bird) on plasma T, CORT, these metabolites, and territorial behavior. Initial plasma T was higher during the summer breeding period than during post-breeding molt. Acute stress resulting from capture and restraint for 30 min decreased plasma T in breeding condition birds but not in the fall, revealing that this decrease is seasonally regulated. Initial plasma CORT did not change seasonally, but plasma CORT increased in response to acute stress. This increase was likewise seasonally regulated, being relatively smaller during autumnal molt than in the summer. We found no evidence that acute stress levels of CORT are functionally related to stress-depressed plasma T and, therefore, that plasma T decreases during stress as a result of elevated plasma CORT. Thirty minutes of exposure to simulated territorial intrusion resulted in different behavior than 30 min of exposure to song playback, with increased time spent near the decoy and decreased number of overhead flights. Neither type of social challenge influenced plasma T, thus offering no support for the hypothesis that plasma T either responds to or mediates the behavioral effects of social challenge. Exposure to both social challenges elevated plasma CORT, but simulated territorial intrusion was more

  15. Regulation of plasma testosterone, corticosterone, and metabolites in response to stress, reproductive stage, and social challenges in a desert male songbird.

    PubMed

    Deviche, Pierre; Beouche-Helias, Benjamin; Davies, Scott; Gao, Sisi; Lane, Samuel; Valle, Shelley

    2014-07-01

    In many male vertebrates, the secretion of reproductive (gonadal androgens) and adrenocortical (glucocorticoids) hormones varies seasonally and in response to environmental stimuli, and these hormones exert numerous behavioral and metabolic effects. We performed two field studies on adult male Rufous-winged Sparrows, Peucaea carpalis, a Sonoran Desert rain-dependent sedentary species, to (a) determine seasonal changes in initial (baseline) and acute stress-induced plasma testosterone (T), corticosterone (CORT), and two metabolites (uric acid and glucose) and (b) compare the effects of two types of social challenge (song playback or simulated territorial intrusion consisting of song playback plus exposure to a live decoy bird) on plasma T, CORT, these metabolites, and territorial behavior. Initial plasma T was higher during the summer breeding period than during post-breeding molt. Acute stress resulting from capture and restraint for 30 min decreased plasma T in breeding condition birds but not in the fall, revealing that this decrease is seasonally regulated. Initial plasma CORT did not change seasonally, but plasma CORT increased in response to acute stress. This increase was likewise seasonally regulated, being relatively smaller during autumnal molt than in the summer. We found no evidence that acute stress levels of CORT are functionally related to stress-depressed plasma T and, therefore, that plasma T decreases during stress as a result of elevated plasma CORT. Thirty minutes of exposure to simulated territorial intrusion resulted in different behavior than 30 min of exposure to song playback, with increased time spent near the decoy and decreased number of overhead flights. Neither type of social challenge influenced plasma T, thus offering no support for the hypothesis that plasma T either responds to or mediates the behavioral effects of social challenge. Exposure to both social challenges elevated plasma CORT, but simulated territorial intrusion was more

  16. Age-related changes of muscle and plasma amino acids in healthy children.

    PubMed

    Hammarqvist, Folke; Angsten, Gertrud; Meurling, Staffan; Andersson, Kerstin; Wernerman, Jan

    2010-07-01

    The aim of the study was to explore if changes in muscle and plasma amino acid concentrations developed during growth and differed from levels seen in adults. The gradient and concentrations of free amino acids in muscle and plasma were investigated in relation to age in metabolic healthy children. Plasma and specimens from the abdominal muscle were obtained during elective surgery. The children were grouped into three groups (group 1: < 1 year, n = 8; group 2: 1-4 years, n = 13 and group 3: 5-15 years, n = 15). A reference group of healthy adults (21-38 years, n = 22) was included in their comparisons and reflected specific differences between children and adults. In muscle the concentrations of 8 out of 19 amino acids analysed increased with age, namely taurine, aspartate, threonine, alanine, valine, isoleucine, leucine, histidine, as well as the total sums of branched chain amino acids (BCAA), basic amino acids (BAA) and total sum of amino acids (P < 0.05). In plasma the concentrations of threonine, glutamine, valine, cysteine, methionine, leucine, lysine, tryptophane, arginine, BCAA, BAA and the essential amino acids correlated with age (P < 0.05). These results indicate that there is an age dependency of the amino acid pattern in skeletal muscle and plasma during growth.

  17. Plasma bile acid concentrations in response to feeding in peregrine falcons (Falco peregrinus).

    PubMed

    Lumeij, J T; Remple, J D

    1992-01-01

    A significant post-prandial increase of plasma bile acid concentration (PBAC) was observed in peregrine falcons (Falco peregrinus). In order to avoid physiological food-induced elevations in PBAC, which can complicate interpretation of plasma chemistry results in birds of prey, it is recommended that blood samples be obtained after a fasting period of at least 24 hours.

  18. X-linked adrenoleukodystrophy with non-diagnostic plasma very long chain fatty acids.

    PubMed Central

    Kennedy, C R; Allen, J T; Fensom, A H; Steinberg, S J; Wilson, R

    1994-01-01

    Measurement of plasma very long chain fatty acids is widely recognised as a sensitive screening test for X-linked adrenoleukodystrophy (X-ALD). This test has particular importance because of the highly variable clinical expression of X-ALD. In this affected family the progressive childhood form of X-ALD was accompanied by "non-diagnostic" concentrations of plasma very long chain fatty acids. The implications for diagnosis of X-ALD are discussed. PMID:8006665

  19. Phytanic acid: measurement of plasma concentrations by gas-liquid chromatography-mass spectrometry analysis and associations with diet and other plasma fatty acids.

    PubMed

    Allen, Naomi E; Grace, Philip B; Ginn, Annette; Travis, Ruth C; Roddam, Andrew W; Appleby, Paul N; Key, Timothy

    2008-03-01

    Epidemiological data suggest that a diet rich in animal foods may be associated with an increased risk of several cancers, including cancers of the prostate, colorectum and breast, but the possible mechanism is unclear. It is hypothesised that phytanic acid, a C20 branched-chain fatty acid found predominantly in foods from ruminant animals, may be involved in early cancer development because it has been shown to up regulate activity of alpha-methylacyl-coenzyme A racemase, an enzyme commonly found to be over-expressed in tumour cells compared with normal tissue. However, little is known about the distribution of plasma phytanic acid concentrations or its dietary determinants in the general population. The primary aim of the present cross-sectional study was to determine circulating phytanic acid concentrations among ninety-six meat-eating, lacto-ovo-vegetarian and vegan women, aged 20-69 years, recruited into the Oxford component of the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford). Meat-eaters had, on average, a 6.7-fold higher geometric mean plasma phytanic acid concentration than the vegans (5.77 v. 0.86 micromol/l; P < 0.0001) and a 47 % higher mean concentration than the vegetarians (5.77 v. 3.93 micromol/l; P = 0.016). The strongest determinant of plasma phytanic acid concentration appeared to be dairy fat intake (r 0.68; P < 0.0001); phytanic acid levels were not associated with age or other lifestyle factors. These data show that a diet high in fat from dairy products is associated with increased plasma phytanic acid concentration, which may play a role in cancer development. PMID:17868488

  20. Plasma antioxidant status in healthy smoking and non-smoking men.

    PubMed

    Goraca, A; Skibska, B

    2005-01-01

    Human serum contains many different antioxidants which may be important in the maintenance of an antioxidant status. The aim of this study was to evaluate the relationship between lipid peroxidation and total plasma antioxidant capacity in healthy smoking and non-smoking young and elderly subjects. Plasma concetrations of alpha-tocopherol, beta-carotene and ascorbic acid were detected by HPLC. Additionally, in the in vitro experiments, the effects of exogenous compounds (ascorbic acid, uric acid, Trolox) on total ferric reducing activity of plasma were tested. We demonstrated that total antioxidant capacity of plasma obtained from healthy non-smoking young subjects was significantly higher than plasma antioxidant capacity of smoking elderly subjects. The concentration of thiobarbituric acid-reactive substances (TBARS) (p < 0.001) in young non-smoking volunteers was lower than that in young smokers. The concentration of TBARS in elderly non-smoking volunteers was lower than in elderly smokers. Plasma concentrations of alpha-tocopherol, beta-carotene and ascorbic acid were significantly lower in elderly smokers than in elderly non-smokers of same age. No difference in plasma levels of alpha-tocopherol, beta-carotene and ascorbic acid were found in 22-year-old smoking and non-smoking subjects. In vitro addition of ascorbic acid, uric acid, or Trolox to plasma samples significantly increased their total antioxidant capacity. Decrease of FRAP values and increase of TBARS concentra-' tions is a significant physiologic condition of aging process. Supplementation of antioxidants could be useful for the enhancement of plasma antioxidant status (Tab. 1, Fig. 3, Ref: 35).

  1. Elevated plasma bile acid concentrations in two sisters with tyrosinaemia type I.

    PubMed

    Sass, J O; Skladal, D

    2000-02-01

    A 21-month-old girl suffering from tyrosinaemia type I and undergoing treatment with 2-(2-nitro-4-trifluoro-methylbenzoyl)-1,3-cyclohexanedione (NTBC) presented with pruritus which rapidly ceased with administration of high doses of ursodeoxycholic acid. Determination of plasma bile acids revealed clearly elevated levels both in samples taken before and after the onset of NTBC therapy, thus indicating, that the increase was not related to the administration of this drug. This result is corroborated by data from the first patient's newborn sister, diagnosed with the same disease, who showed elevated plasma bile acid concentrations in all samples examined, except for the cord plasma. This is the first report on altered bile acid concentrations in tyrosinaemia type I, and underlines the need for thorough investigation of bile acid metabolism in this disease.

  2. Idiopathic recurrent calcium urolithiasis (IRCU): pathophysiology evaluated in light of oxidative metabolism, without and with variation of several biomarkers in fasting urine and plasma - a comparison of stone-free and -bearing male patients, emphasizing mineral, acid-base, blood pressure and protein status

    PubMed Central

    2011-01-01

    Background IRCU is traditionally considered as lifestyle disease (associations with, among others, overweight, obesity, hypertension, type-2 diabetes), arising from excess, in 24 h urine, of calcium (Ca) salts (calcium oxalate (CaOx), calcium phosphate (CaPi)), supersaturation of, and crystallization in, tubular fluid and urine, causing crystal-induced epithelial cell damage, proteinuria, crystal aggregation and uroliths. Methods Another picture emerges from the present uncontrolled study of 154 male adult IRCU patients (75 stone-bearing (SB) and 79 age-matched stone-free (SF)), in whom stone-forming and other parameters in fasting urine and plasma were contrasted with five biomarkers (see footnote) of oxidative metabolism (OM), without and with variation of markers. Results 1) In SB vs. SF unstratified OM biomarkers were statistically unchanged, but the majority of patients was overweight; despite, in SB vs. SF urine pH, total and non-albumin protein concentration were elevated, fractional urinary uric acid excretion and blood bicarbonate decreased, whereas urine volume, sodium, supersaturation with CaOx and CaPi (as hydroxyapatite) were unchanged; 2) upon variation of OM markers (strata below and above median) numerous stone parameters differed significant!)', among others urine volume, total protein, Ca/Pi ratio, pH, sodium, potassium, plasma Ca/Pi ratio and parathyroid hormone, blood pressure, renal excretion of non-albumin protein and other substances; 3) a significant shift from SF to SB patients occurred with increase of urine pH, decrease of blood bicarbonate, and increase of diastolic blood pressure, whereas increase of plasma uric acid impacted only marginally; 4) in both SF and SB patients a strong curvilinear relationship links a rise of urine Ca/Pi to urine Ca/Pi divided by plasma Ca/Pi, but in SB urine Ca/Pi failed to correlate significantly with urine hydroxyapatite supersaturation; 5) also in SB, plasma Ca/Pi and urinary nitrate were negatively

  3. The effects of short intensive exercise on plasma free amino acids in standardbred trotters.

    PubMed

    Hackl, S; van den Hoven, R; Zickl, M; Spona, J; Zentek, J

    2009-04-01

    The aim of this study was to investigate the effect of short intense exercise on plasma amino acid concentrations in trotters and to test the repeatability of plasma amino acids concentration in samples obtained on two independent days under field conditions. Plasma amino acid concentrations were analysed in blood samples of 36 standardbred trotters before and after intense exercise over a distance of 2000 m. Sampling was repeated in 20 horses after 35 days. Exercise intensity was estimated from post-exercise lactate levels. Horses were divided in two groups according to a cut-off lactate concentration at 15 mmol/l. The plasma concentrations of alanine, aspartate, glutamate, isoleucine, leucine, lysine and taurine increased and arginine, asparagine, citrulline, glutamine, glycine, histidine, methionine, serine, tryptophan and 3-methylhistidine decreased after exercise. Ornithine, threonine, tyrosine, phenylalanine and valine concentrations remained constant. Higher intensity of exercise significantly decreased tryptophan and increased taurine concentrations. Sampling day had a significant effect on the absolute pre- and post-exercise amino acid concentrations. Exercise had a significant influence on the concentrations of most plasma amino acids in trotters. These changes could reflect shifts between the free amino acid compartments, but there were also some indications for muscle catabolism. The amino acid supply of sporting horses could be of specific significance for maintaining muscle integrity and for the improvement of post-exercise recovery of competition horses. PMID:19320929

  4. Plasma and synovial fluid meclofenamic acid concentrations in patients with rheumatoid arthritis of the knee.

    PubMed

    Koup, J R; Thomas, D; Tucker, E; Black, A; Ruderman, M; Dixon, J A; Kinkel, A

    1988-01-01

    We have measured plasma and synovial fluid concentrations of meclofenamic acid at 2, 4, 8, and 12 h during steady-state administration (100 mg three times daily for 4-7 days). Paired plasma and synovial samples were obtained pre-treatment and at one of the above times in twelve patients with a diagnosis of rheumatoid arthritis. In addition, the extent of protein binding of meclofenamic acid was assessed in vitro in the pre-treatment plasma and synovial fluid specimens. Peak total concentrations of 1.73 and 0.86 micrograms.ml-1 were observed in plasma (at 2 h) and synovial fluid (at 4 h) respectively. The extent of protein binding was 99.7 and 99.6% (not significantly different) in plasma and synovial fluid respectively. The results of this study are compared to those from similar reported studies of other nonsteroidal anti-inflamatory compounds.

  5. Plasma Amino Acid Levels in Children with Autism and Their Families.

    ERIC Educational Resources Information Center

    Aldred, Sarah; Moore, Kieran M.; Fitzgerald, Michael; Waring, Rosemary H.

    2003-01-01

    Plasma amino acid levels were measured in autistic (n=12), Asperger syndrome (n=11) patients, their parents and siblings. Patients with autism or Asperger syndrome and their siblings and parents all had raised glutamic acid, phenyalanine, asparagine, tyrosine, alanine, and lysine levels than age-matched controls. Results suggest dysregulated amino…

  6. Determination of fatty acid profile in ram spermatozoa and seminal plasma.

    PubMed

    Díaz, R; Torres, M A; Bravo, S; Sanchez, R; Sepúlveda, N

    2016-08-01

    Fatty acids are important in male reproductive function because they are associated with membrane fluidity, acrosome reaction, sperm motility and viability, but limited information exists about the fatty acid profile of ram semen. Our aim was to determine the fatty acid composition in ram spermatozoa and seminal plasma. Sixty ejaculates were obtained from three ram (20 ejaculates/ram) using artificial vagina. Ram spermatozoa (RS) and seminal plasma (SP) were separated using centrifugation, and the fatty acids were analysed by gas chromatography. Total lipids obtained in ram spermatozoa were 1.8% and 1.6% in seminal plasma. Saturated fatty acid (SFA) was proportionally major in SP (66.6%) that RS (49.9%). The highest proportions of SFA corresponded to C4:0 (RS = 16.3% and SP = 28.8%) and C16:0 (RS = 16.3% and PS = 20%). The most important unsaturated fatty acid (UFA) was docosahexaenoic acid (DHA), 44.9% in RS and 31.5% in SP. The profile of fatty acid and their proportions showed differences between spermatozoa and seminal plasma.

  7. Plasma osmotic and electrolyte concentrations of largemouth bass from some acidic Florida lakes

    SciTech Connect

    Canfield, D.E. Jr.; Maceina, M.J.; Nordlie, F.G.; Shireman, J.V.

    1985-05-01

    Five acidic clear (pH 3.7-4.9), three acidic colored (pH 4.1-4.6), and three neutral (pH 6.9-7.3) north-central Florida lakes were surveyed in 1983 to determine plasma osmotic and electrolyte concentrations, growth, and coefficients of condition for largemouth bass Micropterus salmoides floridanus. Plasma osmotic concentrations averaged greater than 273 milliosmoles/kg in fish from acidic colored and circumneutral lakes, but averaged less than 269 milliosmoles/kg in four of the acidic clear lakes. Growth and coefficients of condition of largemouth bass > 305 mm total length in the acidic lakes were significantly lower than in the neutral lakes. Reductions in fish growth and condition, however, could be related to either acidic conditions or lake trophic status. 29 references, 3 tables.

  8. [Plasma amino acids profile of healthy pregnant adolescents in Maracaibo, Venezuela].

    PubMed

    Ortega, Pablo; Castejón, Haydée V; Argotte, María G; Gómez, Gisela; Bohorquez, Lissette; Urrieta, Jesús R

    2003-06-01

    One hundred female adolescents (13-18 y) were clinical and anthropometrically studied to select only those with adequate nutrition. Most adolescents belonged to IV socio-economic stratum families (worker class). Height, weight, age, body mass index and medial arm circumference were used as anthropometric parameters. After screening, only 41 non pregnant girls (control) and 42 pregnant girls with adequate nutrition were selected to analyze plasma amino acids. Fasting peripheral venous blood was drawn, and plasma amino acids were analyzed by HPLC. Amino acid concentrations were expressed as umol/L +/- SE. SAS/STAT program was used for statistical analysis. Amino acid values of control adolescent group were found in ranges reported by other investigators, with slight variations, mostly in diminution, presumably due to nutritional, metabolic or genetic conditions of people living in tropical regions. In pregnant healthy adolescents, distributed according to gestational age: < 32 weeks (n = 30) and > 32 weeks (n = 12), a diminution of total molar plasma amino acids was found, by comparing with control values. Ten amino acids (Pro, Gly, Gln, Arg, Ser, Orn, Tau, Leu, Thr and Val) appeared significantively diminished throughout gestation, being Gly. Gln and Arg most affected since earlier weeks. During the 2nd period. Thr and Val increased their grade of affectation; whereas some amino acids values (Orn, Pro and Tau) tended to recuperate. Several of affected amino acids are gluconegoenic, thus, they could be utilized to supply the energy required by the pregnant adolescent against her double stress: the fetus development and her own development. The plasma amino acid values reported in both, healthy non pregnant and pregnant adolescents, could be taken as regional referential profile of plasma amino acids in this poblational group for further research on adolescent and fetal--maternal malnutrition.

  9. Amino acid supplementation decreases plasma and liver triglycerides in elderly

    PubMed Central

    Børsheim, Elisabet; Bui, Quynh-Uyen T.; Tissier, Sandrine; Cree, Melanie G.; Rønsen, Ola; Morio, Beatrice; Ferrando, Arny A.; Kobayashi, Hisamine; Newcomer, Bradley R.; Wolfe, Robert R.

    2009-01-01

    Objective Hypertriglyceridemia is a risk factor for coronary heart disease. The aim of this study was to determine the effect of AA supplementation on plasma, liver and muscle lipid concentrations and insulin sensitivity in elderly. Methods Twelve impaired glucose tolerant elderly (67.0 ± 5.6 (SD) years, 7 females, 5 males) ingested 11 g of essential AA + arginine twice a day for 16 weeks, after a 7 week control run in. Diet and activity were not otherwise modified. Plasma lipid concentrations and oral glucose tolerance were measured every 4th week, and tissue lipid concentrations (magnetic resonance spectroscopy) every 8th week. Results No changes in plasma lipids were observed during the control run-in. AA supplementation lowered plasma triglyceride (TG) (P < 0.001), total cholesterol (P = 0.048) and very low density lipoprotein (VLDL)-cholesterol (P < 0.001) concentrations. Plasma TG dropped ~20% from the initial value of 1.45 ± 0.18 (SE) mmol/l (128 ± 16 mg/dl), with greatest decrease in the subjects starting out with highest concentrations (r = −0.83). Similarly, liver fat content (liver TG/intralipid standard) decreased ~50% from the initial value of 0.34 ± 0.06 (P = 0.021; n = 9), with greatest decrease in the subjects that initially had highest values (r = −0.86). Intramuscular fat content and insulin sensitivity did not change. Conclusion Diet supplementation with AA lowers plasma TG, total cholesterol and VLDL-cholesterol concentrations, and liver lipid content in impaired glucose tolerant elderly. AA supplementation may have a potential role in treatment of hypertriglyceridemia or hepatic steatosis. PMID:19041223

  10. Plasma and Urinary Amino Acid Metabolomic Profiling in Patients with Different Levels of Kidney Function

    PubMed Central

    Duranton, Flore; Lundin, Ulrika; Gayrard, Nathalie; Mischak, Harald; Aparicio, Michel; Mourad, Georges; Daurès, Jean-Pierre; Weinberger, Klaus M.

    2014-01-01

    Summary Background and objectives Patients with CKD display altered plasma amino acid profiles. This study estimated the association between the estimated GFR and urinary and plasma amino acid profiles in CKD patients. Design, setting, participants, & measurements Urine and plasma samples were taken from 52 patients with different stages of CKD, and plasma samples only were taken from 25 patients on maintenance hemodialysis. Metabolic profiling was performed by liquid chromatography coupled with tandem mass spectrometry after phenylisothiocyanate derivatization. Results Most plasma amino acid concentrations were decreased in hemodialysis patients, whereas proline, citrulline, asparagine, asymmetric dimethylarginine, and hydroxykynurenine levels were increased (P<0.05). Both plasma levels and urinary excretion of citrulline were higher in the group of patients with advanced CKD (CKD stages 2 and 3 versus CKD stages 4 and 5; in plasma: 35.9±16.3 versus 61.8±23.6 µmol/L, P<0.01; in urine: 1.0±1.2 versus 7.1±14.3 µmol/mol creatinine, P<0.001). Plasma asymmetric dimethylarginine levels were higher in advanced CKD (CKD stages 2 and 3, 0.57±0.29; CKD stages 4 and 5, 1.02±0.48, P<0.001), whereas urinary excretion was lower (2.37±0.93 versus 1.51±1.43, P<0.001). Multivariate analyses adjusting on estimated GFR, serum albumin, proteinuria, and other covariates revealed associations between diabetes and plasma citrulline (P=0.02) and between serum sodium and plasma asymmetric dimethylarginine (P=0.03). Plasma tyrosine to phenylalanine and valine to glycine ratios were lower in advanced CKD stages (P<0.01). Conclusion CKD patients have altered plasma and urinary amino acid profiles that are not corrected by dialysis. Depending on solutes, elevated plasma levels were associated with increased or decreased urinary excretion, depicting situations of uremic retention (asymmetric dimethylarginine) or systemic overproduction (citrulline). These results give some insight in

  11. Association between plasma omega-3 fatty acids and cardiovascular disease risk factors.

    PubMed

    Garneau, Véronique; Rudkowska, Iwona; Paradis, Ann-Marie; Godin, Gaston; Julien, Pierre; Pérusse, Louis; Vohl, Marie-Claude

    2013-03-01

    The consumption of omega-3 (n-3) fatty acids (FA), namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have been linked to reduced cardiovascular disease (CVD) risk. The objective of this study was to examine the relation between n-3 FA in plasma phospholipid (PL) levels and CVD risk factors. n-3 FA levels in plasma PL were determined using gas chromatography in 100 obese (body mass index (BMI), ≥30 kg·m(-2)) and 100 nonobese selected individuals from the Quebec City metropolitan area. The CVD risk factors analysed were BMI, blood pressure, plasma lipids levels, and fasting plasma glucose. Significantly higher levels of alpha-linolenic acid (ALA) and docosapentaenoic acid (DPA) were observed in obese subjects, whereas significantly higher levels of DHA were observed in nonobese subjects. For CVD risk factors, ALA levels were positively correlated with plasma triglyceride concentrations and negatively associated with diastolic blood pressure. None of the CVD risk factors studied was linked to EPA levels. In addition, DPA was negatively related to high-density lipoprotein cholesterol (HDL-C) and positively correlated with the total cholesterol/HDL-C ratio. DHA levels were negatively correlated with BMI, waist circumference, and plasma triglyceride levels, whereas a positive association was observed with HDL-C levels. Total n-3 FA percentages were negatively correlated with BMI. In conclusion, higher DHA percentages in plasma PL are associated with a more favourable CVD risk profile, whereas higher DPA percentages in plasma PL are associated with a more deteriorated CVD risk profile.

  12. Translating plasma and whole blood fatty acid compositional data into the sum of eicosapentaenoic and docosahexaenoic acid in erythrocytes.

    PubMed

    Stark, Ken D; Aristizabal Henao, Juan J; Metherel, Adam H; Pilote, Louise

    2016-01-01

    Specific blood levels of eicosapentaenoic plus docosahexaenoic acid (EPA+DHA, wt% of total) in erythrocytes or "the omega-3 index" have been recommended for cardio-protection, but fatty acids are often measured in different blood fractions. The ability to estimate the % of EPA+DHA in erythrocytes from the fatty acid composition of other blood fractions would enable clinical assessments of omega-3 status when erythrocyte fractions are not available and increase the ability to compare blood levels of omega-3 fatty acids across clinical studies. The fatty acid composition of baseline plasma, erythrocytes and whole blood samples from participants (n=1104) in a prospective, multicenter study examining acute coronary syndrome were determined. The ability to predict the % of EPA+DHA in erythrocytes from other blood fractions were examined using bivariate and multiple linear regression modelling. Concordance analysis was also used to compare the actual erythrocytes EPA+DHA values to values estimated from other blood fractions. EPA+DHA in erythrocytes was significantly (p<0.001) correlated EPA+DHA in plasma (r(2)=0.54) and whole blood (r(2)=0.79). Using multiple linear regression to predict EPA+DHA in erythrocytes resulted in stronger coefficients of determination in both plasma (R(2)=0.70) and whole blood (R(2)=0.84). Concordance analyses indicated agreement between actual and estimated EPA+DHA in erythrocytes, although estimating from plasma fatty acids appears to require translation by categorization rather than by translation as continuous data. This study shows that the fatty acid composition of different blood fractions can be used to estimate erythrocyte EPA+DHA in a population with acute coronary syndrome.

  13. Bread enriched with microencapsulated tuna oil increases plasma docosahexaenoic acid and total omega-3 fatty acids in humans.

    PubMed

    Yep, Yolande L; Li, Duo; Mann, Neil J; Bode, Ortwin; Sinclair, Andrew J

    2002-01-01

    The aim of this study was to determine the acute and chronic effects of low doses of long chain (LC) n-3 polyunsaturated fatty acids (PUFA) (<100 mg per day) on plasma LC n-3 PUFA levels using a novel delivery form; bread containing microencapsulated tuna oil (MTO). Six omnivores (three men and three women) participated in the acute study, which involved ingesting a prototype MTO bread containing approximately 80 mg of LC n-3 PUFA/four slices. Plasma triacylglycerol fatty acid compositions were measured after an overnight fast and postprandially at 2 and 4 h. In the chronic study, 10 vegetarian subjects (nine men and one woman) consumed MTO bread at six to eight slices/day (comprising 60 mg of LC n-3 PUFA) as the only dietary source of these PUFA for three weeks. Fasting plasma total and phospholipid fatty acid compositions were measured at baseline and endpoint. In the acute study, the proportions of 22:6 n-3 and total n-3 PUFA in plasma triacylglycerol were significantly increased (P < 0.05). In the chronic study, the proportions of 20:5 n-3, 22:5 n-3, 22:6 n-3, total n-3 PUFA in plasma, and 22:6 n-3 and total n-3 PUFA in plasma phospholipid fractions were significantly increased (P < 0.05) at the endpoint compared with the baseline. This study showed that a low dose of LC n-3 PUFA, consumed as MTO-enriched bread, was bioavailable, as measured by an increase in LC n-3 PUFA levels in the plasma of human subjects.

  14. Protein and energy intake during weaning. III. Effects on plasma amino acids.

    PubMed

    Axelsson, I; Borulf, S; Abildskov, K; Heird, W; Räihä, N

    1988-01-01

    Preprandial plasma amino acid concentrations were measured at 5 and 6 months of age in 30 healthy term infants who were either breast-fed ad libitum or fed one of two different formulas (1.9 g of protein per 100 ml with a whey:casein ratio of 50:50; 2.9 g of protein per 100 ml with a whey:casein ratio of 20:80) ad libitum, plus the same supplementary food regimen. The mean plasma concentrations of total amino acids and especially total essential amino acids were higher in the formula-fed infants. Those fed formula also had plasma concentrations of methionine, isoleucine, phenylalanine, leucine, valine, threonine, aspartate, proline, lysine, tyrosine, histidine that exceeded plasma concentrations of breast-fed infants by 2 or more standard deviations. Concentrations of arginine, glutamic acid, glutamine, ornithine, serine, cystine did not differ and taurine was higher in the breast-fed infants. The data indicate that formulas in common use today during weaning (4-6 months) provide excessive protein intakes when compared to the breast-fed control infants. A lowering of protein concentration and a further manipulation of the whey:casein ratio is necessary if plasma amino acid patterns similar to those found in breast-fed infants is to be achieved with artificial feeding.

  15. Effects of Eimeria acervulina infection severity on growth performance, apparent ileal amino acid digestibility, and plasma concentrations of amino acids, carotenoids, and α1-acid glycoprotein in broilers.

    PubMed

    Rochell, S J; Parsons, C M; Dilger, R N

    2016-07-01

    An experiment was conducted to evaluate growth performance, apparent ileal digestibility (AID) of amino acids, and plasma concentrations of amino acids, carotenoids, and α1-acid glycoprotein, an acute-phase protein, in broilers inoculated with graded doses of E. acervulina oocysts. Ross 308 male broilers (400 total) were housed in battery cages from 1 to 21 d post-hatch and received common corn-soybean meal-based diets throughout the experiment. At 9 d post-hatch, birds were individually weighed and allotted to 4 treatment groups with 10 replicate cages of 10 birds per cage. At 15 d post-hatch, all birds were inoculated with 1 mL of distilled water that contained 0, 2.5 × 10(5), 5.0 × 10(5), or 1.0 × 10(6) sporulated E. acervulina oocysts. At 21 d, birds were euthanized for collection of blood and ileal digesta. Body weight gain and feed efficiency decreased linearly (P < 0.05) with increasing E. acervulina dose. With the exception of Trp and Gly, AID values decreased (P < 0.05) linearly or quadratically for all amino acids by an average of 2.6 percentage units for birds inoculated with 1.0 × 10(6) oocysts compared with uninfected birds. Infection with E. acervulina caused a quadratic decrease (P < 0.05) in plasma carotenoid concentrations. Plasma concentrations of Arg and Tyr decreased linearly (P < 0.05) with increasing E. acervulina inoculation dose and plasma Gln and Asn decreased quadratically (P < 0.01). Linear increases (P < 0.05) were observed for plasma Lys, Leu, Ile, Val, Pro, and Orn as E. acervulina inoculation dose increased. Plasma α1-acid glycoprotein of broilers was not influenced (P > 0.05) by E. acervulina infection. In conclusion, E. acervulina challenge adversely impacted growth performance, plasma carotenoids, and AID of amino acids in a dose-dependent manner. However, plasma amino acid responses to graded E. acervulina inoculation doses varied considerably among amino acids. Thus, these results indicated that alterations

  16. Effects of Eimeria acervulina infection severity on growth performance, apparent ileal amino acid digestibility, and plasma concentrations of amino acids, carotenoids, and α1-acid glycoprotein in broilers.

    PubMed

    Rochell, S J; Parsons, C M; Dilger, R N

    2016-07-01

    An experiment was conducted to evaluate growth performance, apparent ileal digestibility (AID) of amino acids, and plasma concentrations of amino acids, carotenoids, and α1-acid glycoprotein, an acute-phase protein, in broilers inoculated with graded doses of E. acervulina oocysts. Ross 308 male broilers (400 total) were housed in battery cages from 1 to 21 d post-hatch and received common corn-soybean meal-based diets throughout the experiment. At 9 d post-hatch, birds were individually weighed and allotted to 4 treatment groups with 10 replicate cages of 10 birds per cage. At 15 d post-hatch, all birds were inoculated with 1 mL of distilled water that contained 0, 2.5 × 10(5), 5.0 × 10(5), or 1.0 × 10(6) sporulated E. acervulina oocysts. At 21 d, birds were euthanized for collection of blood and ileal digesta. Body weight gain and feed efficiency decreased linearly (P < 0.05) with increasing E. acervulina dose. With the exception of Trp and Gly, AID values decreased (P < 0.05) linearly or quadratically for all amino acids by an average of 2.6 percentage units for birds inoculated with 1.0 × 10(6) oocysts compared with uninfected birds. Infection with E. acervulina caused a quadratic decrease (P < 0.05) in plasma carotenoid concentrations. Plasma concentrations of Arg and Tyr decreased linearly (P < 0.05) with increasing E. acervulina inoculation dose and plasma Gln and Asn decreased quadratically (P < 0.01). Linear increases (P < 0.05) were observed for plasma Lys, Leu, Ile, Val, Pro, and Orn as E. acervulina inoculation dose increased. Plasma α1-acid glycoprotein of broilers was not influenced (P > 0.05) by E. acervulina infection. In conclusion, E. acervulina challenge adversely impacted growth performance, plasma carotenoids, and AID of amino acids in a dose-dependent manner. However, plasma amino acid responses to graded E. acervulina inoculation doses varied considerably among amino acids. Thus, these results indicated that alterations

  17. Infantile Refsum Disease: Influence of Dietary Treatment on Plasma Phytanic Acid Levels.

    PubMed

    Sá, Maria João Nabais; Rocha, Júlio C; Almeida, Manuela F; Carmona, Carla; Martins, Esmeralda; Miranda, Vasco; Coutinho, Miguel; Ferreira, Rita; Pacheco, Sara; Laranjeira, Francisco; Ribeiro, Isaura; Fortuna, Ana Maria; Lacerda, Lúcia

    2016-01-01

    Infantile Refsum disease (IRD) is one of the less severe of Zellweger spectrum disorders (ZSDs), a group of peroxisomal biogenesis disorders resulting from a generalized peroxisomal function impairment. Increased plasma levels of very long chain fatty acids (VLCFA) and phytanic acid are biomarkers used in IRD diagnosis. Furthermore, an increased plasma level of phytanic acid is known to be associated with neurologic damage. Treatment of IRD is symptomatic and multidisciplinary.The authors report a 3-year-old child, born from consanguineous parents, who presented with developmental delay, retinitis pigmentosa, sensorineural deafness and craniofacial dysmorphisms. While the relative level of plasma C26:0 was slightly increased, other VLCFA were normal. Thus, a detailed characterization of the phenotype was essential to point to a ZSD. Repeatedly increased levels of plasma VLCFA, along with phytanic acid and pristanic acid, deficient dihydroxyacetone phosphate acyltransferase activity in fibroblasts and identification of the homozygous pathogenic mutation c.2528G>A (p.Gly843Asp) in the PEX1 gene, confirmed this diagnosis. Nutritional advice and follow-up was proposed aiming phytanic acid dietary intake reduction. During dietary treatment, plasma levels of phytanic acid decreased to normal, and the patient's development evaluation showed slow progressive acquisition of new competences.This case report highlights the relevance of considering a ZSD in any child with developmental delay who manifests hearing and visual impairment and of performing a systematic biochemical investigation, when plasma VLCFA are mildly increased. During dietary intervention, a biochemical improvement was observed, and the long-term clinical effect of this approach needs to be evaluated.

  18. Quantitative determination of citric acid in seminal plasma by using Raman spectroscopy.

    PubMed

    Huang, Zufang; Chen, Xiwen; Li, Yongzeng; Chen, Jinhua; Lin, Juqiang; Wang, Jing; Lei, Jinping; Chen, Rong

    2013-07-01

    In this study, Raman spectroscopy was first used to study the linear relationship between Raman spectral intensities and citric acid concentrations in aqueous solution. By using the specific Raman band of 942 cm(-1), concentrations of citric acid ranging from 2 to 20 mg/mL were observed linearly (R(2) = 0.993), and the limit of detection was 1.0 mg/mL. Then, citric acid detection in clinical seminal plasma ultrafiltrate samples was performed, and the intensity of the Raman-specific peak demonstrates a good linear correlation (R(2) = 0.946) with citric acid concentrations determined by the enzymatic method. Our results showed that Raman spectroscopy has the potential of being applied to detect concentrations of citric acid in seminal plasma in clinic.

  19. Mental retardation is associated with plasma omega-3 fatty acid levels and the omega-3/omega-6 ratio in children.

    PubMed

    Neggers, Yasmin H; Kim, Eun-Kyung; Song, Ju-Mi; Chung, Eun-Jung; Um, Young-Sook; Park, Taesun

    2009-01-01

    There is evidence that alteration in plasma fatty acid composition may play a role in certain neurological disorders. This case control study was conducted to evaluate the association between plasma fatty acid levels and mental retardation in Korean children. Plasma phospholipid fatty acids, plasma lipids, dietary fatty acids and selected nutrients were measured in 31 mentally retarded boys (mean age 9.93 +/-1.5 yrs) and matched controls. Total plasma omega-3 fatty acids (Sigmaw3), docosahexaenoic acid (DHA) and high density lipoprotein (HDL) concentrations were significantly lower and the Sigmaomega-6/Sigmaomega-3 ratio was significantly higher in cases than in controls. The odds in favor of mental retardation increased by 69 % for each unit increase in the Sigmaomega-6/ Sigmaomega-3 ratio (adjusted odds ratio = 1.69, 95% CI = 1.25-2.29). Significant variation in plasma Sigmaomega-3 and the Sigmaomega-6/ Sigmaomega-3 ratio was explained by mental retardation and plasma HDL concentrations (45% and 37 % respectively). There was a significant inverse association between plasma DHA and mental retardation. For each unit increase in plasma DHA, odds of mental retardation decreased by 74 %. There was no significant difference in either total dietary fat or fatty acids intakes between cases and controls. The energy intake of cases was significantly higher than the controls. These results suggest that proportion of plasma Sigmaomega-3 fatty acids, particularly, DHA, and the Sigmaomega-6/ Sigmaomega-3 ratio are associated with mental retardation in children in this study. PMID:19329391

  20. Mental retardation is associated with plasma omega-3 fatty acid levels and the omega-3/omega-6 ratio in children.

    PubMed

    Neggers, Yasmin H; Kim, Eun-Kyung; Song, Ju-Mi; Chung, Eun-Jung; Um, Young-Sook; Park, Taesun

    2009-01-01

    There is evidence that alteration in plasma fatty acid composition may play a role in certain neurological disorders. This case control study was conducted to evaluate the association between plasma fatty acid levels and mental retardation in Korean children. Plasma phospholipid fatty acids, plasma lipids, dietary fatty acids and selected nutrients were measured in 31 mentally retarded boys (mean age 9.93 +/-1.5 yrs) and matched controls. Total plasma omega-3 fatty acids (Sigmaw3), docosahexaenoic acid (DHA) and high density lipoprotein (HDL) concentrations were significantly lower and the Sigmaomega-6/Sigmaomega-3 ratio was significantly higher in cases than in controls. The odds in favor of mental retardation increased by 69 % for each unit increase in the Sigmaomega-6/ Sigmaomega-3 ratio (adjusted odds ratio = 1.69, 95% CI = 1.25-2.29). Significant variation in plasma Sigmaomega-3 and the Sigmaomega-6/ Sigmaomega-3 ratio was explained by mental retardation and plasma HDL concentrations (45% and 37 % respectively). There was a significant inverse association between plasma DHA and mental retardation. For each unit increase in plasma DHA, odds of mental retardation decreased by 74 %. There was no significant difference in either total dietary fat or fatty acids intakes between cases and controls. The energy intake of cases was significantly higher than the controls. These results suggest that proportion of plasma Sigmaomega-3 fatty acids, particularly, DHA, and the Sigmaomega-6/ Sigmaomega-3 ratio are associated with mental retardation in children in this study.

  1. Amino acid concentrations in plasma and skeletal muscle after transurethral resection syndrome.

    PubMed

    Hahn, R; Essén, P; Wernerman, J

    1992-01-01

    The concentrations of amino acids in plasma and skeletal muscle were measured 1 and 4 hours after transurethral prostatic resection in three patients who developed symptoms of the transurethral resection syndrome. The irrigating solution contained 1.5% of glycine and 1% of ethanol. The concentrations of glycine in plasma and muscle were equal within an hour of the operation, and at four hours the abnormally high glycine concentration persisted in muscle, though it had decreased rapidly in plasma. Our data suggest that skeletal muscle is a quantitatively important reservoir for glycine when this amino acid is supplied in potentially toxic amounts, but that the plasma glycine concentration returns to normal as the patient's clinical condition improves. PMID:1279783

  2. Effects of branched-chain amino acid supplementation on plasma concentrations of free amino acids, insulin, and energy substrates in young men.

    PubMed

    Zhang, Yi; Kobayashi, Hisamine; Mawatari, Kazunori; Sato, Juichi; Bajotto, Gustavo; Kitaura, Yasuyuki; Shimomura, Yoshiharu

    2011-01-01

    The present study was conducted to examine alterations in the concentrations of plasma free amino acids, glucose, insulin, free fatty acids (FFAs), and urea nitrogen induced by branched-chain amino acid (BCAA) supplementation in young men. Overnight-fasted subjects ingested drinks containing 1 or 5 g of a BCAA mixture (weight ratio of 1 : 2.3 : 1.2 for isoleucine : leucine : valine), and blood was intermittently collected for 3 h after ingestion. Ingestion of the BCAA mixture resulted in significant increases in the plasma concentrations of individual BCAAs, corresponding to the amounts of amino acids ingested. On the other hand, plasma concentrations of methionine and aromatic amino acids tended to decrease in the trial with 5 g BCAAs, suggesting that BCAA ingestion affects the metabolism of these amino acids. The ingestion of BCAAs temporarily increased plasma insulin levels and affected plasma concentrations of FFAs, but had almost no effect on glucose or urea nitrogen. PMID:21512300

  3. Simultaneous determination of niacin, niacinamide and nicotinuric acid in human plasma.

    PubMed

    Pfuhl, P; Kärcher, U; Häring, N; Baumeister, A; Tawab, Mona Abdel; Schubert-Zsilavecz, M

    2005-01-01

    A sensitive, specific, accurate, and reproducible HPLC/MS-method for the simultaneous quantitative determination of niacin (NA) and its main metabolites niacinamide (NAM) and nicotinuric acid (NUR) in human plasma using chinolin-3-carboxylic acid as an internal standard was developed and validated according to international guidelines for method validation. All analytes and the internal standard were separated from acidified plasma by solid phase extraction. Afterwards the extracted samples were analyzed by HPLC/MS in the positive electrospray ionization mode (ESI) and selected ion monitoring (SIM). The total run time was 7 min between injections. The assay had a lower limit of quantification of 50.0 ng/mL for each analyte using 1 mL of plasma. The calibration curves were linear in the measured range between 50.0 and 750 ng/mL plasma. The overall precision and accuracy for all concentrations of quality controls and standards was better than 15%. No indications were found for possible instabilities of niacin, niacinamide and nicotinuric acid in plasma at -20 degrees C, in the extraction solvent or after repeated thawing/freezing cycles. In stabilities were observed in whole blood and in plasma at room temperature. The recovery of the extraction method ranged from 86 to 89% for the three analytes.

  4. Determination of Mycophenolic Acid in Plasma Samples Using the Terbium-Sensitized Luminescence Method

    NASA Astrophysics Data System (ADS)

    Shayanfar, A.; Ghavimi, H.; Zolali, E.; Jouyban, A.

    2015-09-01

    The objectives of this work were to provide an analytical method, for the quantitative determination of the mycophenolic acid (MFA) in plasma samples and its application to quantification of the MFA in rat plasma after oral administration. In order to remove the fluorescence interferences of the plasma, the samples were precipitated by acetonitrile in 1:8 ratio and then a few parameters were optimized and the fluorescence intensity measured at 545 nm using an excitation wavelength of 347 nm. Under the optimized concentration, the method provided a linear range between 1.0 and 10.0 mg/l with a correlation coefficient of 0.998. MFA was detected and the validation was performed according to the FDA guidelines. Linearity, accuracy, precision, and selectivity of the developed method were suitable for th determination of the MFA in plasma samples. The proposed analytical approach was applied to determine the MFA concentration in a rat plasma-time profile study.

  5. Acid-base balance and plasma composition in the aestivating lungfish (Protopterus).

    PubMed

    DeLaney, R G; Lahiri, S; Hamilton, R; Fishman, P

    1977-01-01

    Upon entering into aestivation, Protopterus aethiopicus develops a respiratory acidosis. A slow compensatory increase in plasma bicarbonate suffices only to partially restore arterial pH toward normal. The cessation of water intake from the start of aestivation results in hemoconcentration and marked oliguria. The concentrations of most plasma constituents continue to increase progressively, and the electrolyte ratios change. The increase in urea concentration is disproportionately high for the degree of dehydration and constitutes an increasing fraction of total plasma osmolality. Acid-base and electrolyte balance do not reach a new equilibrium within 1 yr in the cocoon. PMID:13665

  6. Plasma Amino Acid Concentrations in 108 Children Receiving a Pediatric Amino Acid Formulation as Part of Parenteral Nutrition

    PubMed Central

    Shelton, Chasity M.; Clark, Amanda J.; Storm, Michael C.; Helms, Richard A.

    2010-01-01

    BACKGROUND Plasma amino acid (PAA) levels can be largely normalized during parenteral nutrition (PN) in infants and children using a pediatric-specific amino acid (AA) formulation. However, these previous results were based on individual clinical studies of small populations of neonates and infants. OBJECTIVE We have now examined AA levels in 108 children (0–7 years of age) receiving a pediatric-specific AA formulation in PN using a single analytical methodology. METHODS Infants and children were enrolled in specific protocols and parents/caregivers gave informed consent. Patients were stable and receiving age-appropriate intakes of AA and non-protein calories. Samples were obtained between 8 and10 am, processed immediately, deproteinized, and AA concentrations (μmol/L) were determined on a Beckman 6300 analyzer. Means and SD were calculated for sub-populations stratified by age: 0–1 month (48 patients, n=139), 1–6 months (36 patients, n=124), 7–12 months (11 patients, n=41), and 1–7 years (13 patients, n=51). Z scores were calculated for each amino acid [(observed mean - normal control mean)/normal control SD]. RESULTS When compared to the neonatal reference range, nonessential AA had Z scores that ranged from −1.84 (asparagine) to +1.48 (threonine). Only plasma free cystine, free tyrosine, and phenylalanine had Z scores outside the −2.0 to +2.0 range (95% confidence limits). Plasma free cystine values were low in all groups except neonates. Free tyrosine levels were low in all groups despite the presence of N-acetyl-L-tyrosine in the pediatric AA formulation. Phenylalanine levels were elevated only in neonates. When children 1 to 7 years old were compared with an age-matched reference range, plasma free cystine values were low (Z score −2.47), as were plasma glutamine values (−3.11), but elevations were found in the dicarboxylic amino acids aspartic acid (+2.5) and glutamic acid (+4.27). Regardless of reference range used for comparison, all

  7. Plasma non-esterified docosahexaenoic acid is the major pool supplying the brain.

    PubMed

    Chen, Chuck T; Kitson, Alex P; Hopperton, Kathryn E; Domenichiello, Anthony F; Trépanier, Marc-Olivier; Lin, Lauren E; Ermini, Leonardo; Post, Martin; Thies, Frank; Bazinet, Richard P

    2015-10-29

    Despite being critical for normal brain function, the pools that supply docosahexaenoic acid (DHA) to the brain are not agreed upon. Using multiple kinetic models in free-living adult rats, we first demonstrate that DHA uptake from the plasma non-esterified fatty acid (NEFA) pool predicts brain uptake of DHA upon oral administration, which enters the plasma NEFA pool as well as multiple plasma esterified pools. The rate of DHA loss by the brain is similar to the uptake from the plasma NEFA pool. Furthermore, upon acute iv administration, although more radiolabeled lysophosphatidylcholine (LPC)-DHA enters the brain than NEFA-DHA, this is due to the longer plasma half-life and exposure to the brain. Direct comparison of the uptake rate of LPC-DHA and NEFA-DHA demonstrates that uptake of NEFA-DHA into the brain is 10-fold greater than LPC-DHA. In conclusion, plasma NEFA-DHA is the major plasma pool supplying the brain.

  8. Plasma non-esterified docosahexaenoic acid is the major pool supplying the brain

    PubMed Central

    Chen, Chuck T.; Kitson, Alex P.; Hopperton, Kathryn E.; Domenichiello, Anthony F.; Trépanier, Marc-Olivier; Lin, Lauren E.; Ermini, Leonardo; Post, Martin; Thies, Frank; Bazinet, Richard P.

    2015-01-01

    Despite being critical for normal brain function, the pools that supply docosahexaenoic acid (DHA) to the brain are not agreed upon. Using multiple kinetic models in free-living adult rats, we first demonstrate that DHA uptake from the plasma non-esterified fatty acid (NEFA) pool predicts brain uptake of DHA upon oral administration, which enters the plasma NEFA pool as well as multiple plasma esterified pools. The rate of DHA loss by the brain is similar to the uptake from the plasma NEFA pool. Furthermore, upon acute iv administration, although more radiolabeled lysophosphatidylcholine (LPC)-DHA enters the brain than NEFA-DHA, this is due to the longer plasma half-life and exposure to the brain. Direct comparison of the uptake rate of LPC-DHA and NEFA-DHA demonstrates that uptake of NEFA-DHA into the brain is 10-fold greater than LPC-DHA. In conclusion, plasma NEFA-DHA is the major plasma pool supplying the brain. PMID:26511533

  9. Plasma Amino Acid Concentrations Predict Mortality in Patients with End-Stage Liver Disease

    PubMed Central

    Kinny-Köster, Benedict; Bartels, Michael; Becker, Susen; Scholz, Markus; Thiery, Joachim

    2016-01-01

    Background The liver plays a key role in amino acid metabolism. In former studies, a ratio between branched-chain and aromatic amino acids (Fischer’s ratio) revealed associations with hepatic encephalopathy. Furthermore, low concentrations of branched-chain amino acids were linked to sarcopenia in literature. Encephalopathy and sarcopenia are known to dramatically worsen the prognosis. Aim of this study was to investigate a complex panel of plasma amino acids in the context of mortality in patients with end-stage liver disease. Methods 166 patients evaluated for orthotopic liver transplantation were included. 19 amino acids were measured from citrated plasma samples using mass spectrometry. We performed survival analysis for plasma amino acid constellations and examined the relationship to established mortality predictors. Results 33/166 (19.9%) patients died during follow-up. Lower values of valine (p<0.001), Fischer’s ratio (p<0.001) and valine to phenylalanine ratio (p<0.001) and higher values of phenylalanine (p<0.05) and tyrosine (p<0.05) were significantly associated with mortality. When divided in three groups, the tertiles discriminated cumulative survival for valine (p = 0.016), phenylalanine (p = 0.024) and in particular for valine to phenylalanine ratio (p = 0.003) and Fischer’s ratio (p = 0.005). Parameters were also significantly correlated with MELD and MELD-Na score. Conclusions Amino acids in plasma are valuable biomarkers to determine increased risk of mortality in patients with end-stage liver disease. In particular, valine concentrations and constellations composed of branched-chain and aromatic amino acids were strongly associated with prognosis. Due to their pathophysiological importance, the identified amino acids could be used to examine individual dietary recommendations to serve as potential therapeutic targets. PMID:27410482

  10. Determination of organic acids in biological fluids by ion chromatography: plasma lactate and pyruvate and urinary vanillylmandelic acid.

    PubMed

    Rich, W; Johnson, E; Lois, L; Kabra, P; Stafford, B; Marton, L

    1980-09-01

    We describe the general aspects of ion chromatography and how on-line counted ion-exchange techniques can be utilized to determine pyruvic and lactic acids in plasma and vanillymandelic acid in urine. Pyruvate and lactate are extracted from deproteinized plasma by use of an ion-exclusion resin. After elution from the resin, the plasma extract is chromatographed on an anion-exchange column, with 0.66 mmol/L sodium bicarbonate as the mobile phase. The effluent is detected with an electrical conductivity cell. Vanillylmandelic acid is extracted from diluted urine by use of an anion-exchange resin. After elution from resin, the urine extract is chromatographed on an ion-exclusion column, followed by electrochemical detection. We evaluated the procedures for precision, linearity, analytical recovery, intefering substances, and correlation with an established procedure. the combination of a preliminary resin extraction, an ion chromatographic separation, and a conductivity or electrochemical detector results in rapid, specific methods that can be adapted for use in the clinical laboratory. Preliminary data for other organic acids are presented.

  11. Interactive network analysis of the plasma amino acids profile in a mouse model of hyperglycemia.

    PubMed

    Tanaka, Takayuki; Mochida, Taiga; Maki, Yukihiro; Shiraki, Yasuko; Mori, Hiroko; Matsumoto, Shirou; Shimbo, Kazutaka; Ando, Toshihiko; Nakamura, Kimitoshi; Endo, Fumio; Okamoto, Masahiro

    2013-12-01

    Amino acids are a group of metabolites that are important substrates for protein synthesis, are important as signaling molecules and play central roles as highly connected metabolic hubs, and therefore, there are many reports that describe disease-specific abnormalities in plasma amino acids profile. However, the causes of progression from a healthy control to a manifestation of the plasma amino acid changes remain obscure. Here, we extended the plasma amino acids profile to relationships that have interactive properties, and found remarkable differences in the longitudinal transition of hyperglycemia as a diabetes emergency. What is especially important is to understand pathogenesis for better treatment and early diagnosis of diabetes. In this study, we performed interactive analysis using time course data of the plasma samples of AKITA mice, which develop hyperglycemia. Primarily, we decided to analyze the interactive property of amino acids which had highly significant association with hyperglycemia, namely alanine, glycine, leucine, isoleucine and valine. Next, we inferred the interactive network structure, which reproduces the actual time course within an error allowance of 10% using an S-system model (a conceptual mathematical model for analyzing and simulating networks). The emphasis of this study was altered interactions of plasma amino acids that show stabilizing and destabilizing features in a variety of clinical settings. By performing sensitivity analysis, the most dominant relations in this network were selected; the control paths from glycine to isoleucine in healthy control and from alanine to glycine in hyperglycemia. This result is in good agreement with the biological knowledge regarding branched-chain amino acids, and suggests the biological importance of the effect from alanine to glycine.

  12. Contrasting plasma free amino acid patterns in elite athletes: association with fatigue and infection

    PubMed Central

    Kingsbury, K. J.; Kay, L.; Hjelm, M.

    1998-01-01

    AIM: There is little information on the plasma free amino acid patterns of elite athletes against which fatigue and nutrition can be considered. Therefore the aim was to include analysis of this pattern in the medical screening of elite athletes during both especially intense and light training periods. METHODS: Plasma amino acid analysis was undertaken in three situations. (1) A medical screening service was offered to elite athletes during an intense training period before the 1992 Olympics. Screening included a blood haematological/biochemical profile and a microbial screen in athletes who presented with infection. The athletes were divided into three groups who differed in training fatigue and were considered separately. Group A (21 track and field athletes) had no lasting fatigue; group B (12 judo competitors) reported heavy fatigue at night but recovered overnight to continue training; group C (18 track and field athletes, one rower) had chronic fatigue and had been unable to train normally for at least several weeks. (2) Athletes from each group were further screened during a post- Olympic light training period. (3) Athletes who still had low amino acid levels during the light training period were reanalysed after three weeks of additional protein intake. RESULTS: (1) The pre-Olympics amino acid patterns were as follows. Group A had a normal amino acid pattern (glutamine 554 (25.2) micromol/l, histidine 79 (6.1) micromol/l, total amino acids 2839 (92.1) micromol/l); all results are means (SEM). By comparison, both groups B and C had decreased plasma glutamine (average 33%; p<0.001) with, especially in group B, decreased histidine, glucogenic, ketogenic, and branched chain amino acids (p<0.05 to p<0.001). None in group A, one in group B, but ten athletes in group C presented with infection: all 11 athletes had plasma glutamine levels of less than 450 micromol/l. No intergroup differences in haematological or other blood biochemical parameters, apart from a

  13. A Fall in Plasma Free Fatty Acid (FFA) Level Activates the Hypothalamic-Pituitary-Adrenal Axis Independent of Plasma Glucose: Evidence for Brain Sensing of Circulating FFA

    PubMed Central

    Oh, Young Taek; Oh, Ki-Sook; Kang, Insug

    2012-01-01

    The brain responds to a fall in blood glucose by activating neuroendocrine mechanisms for its restoration. It is unclear whether the brain also responds to a fall in plasma free fatty acids (FFA) to activate mechanisms for its restoration. We examined whether lowering plasma FFA increases plasma corticosterone or catecholamine levels and, if so, whether the brain is involved in these responses. Plasma FFA levels were lowered in rats with three independent antilipolytic agents: nicotinic acid (NA), insulin, and the A1 adenosine receptor agonist SDZ WAG 994 with plasma glucose clamped at basal levels. Lowering plasma FFA with these agents all increased plasma corticosterone, but not catecholamine, within 1 h, accompanied by increases in plasma ACTH. These increases in ACTH or corticosterone were abolished when falls in plasma FFA were prevented by