The Automated Determination of Serum Uric Acid

1966 ◽  
Vol 12 (11) ◽  
pp. 748-766 ◽  
Author(s):  
Stanley Morgenstern ◽  
Richard V Flor ◽  
James H Kaufman ◽  
Bernard Klein

Abstract An automated procedure is presented for the enzymatic determination of serum uric acid on both the AutoAnalyzer and the Robot Chemist. The procedure measures as the neocuproine complex, the difference in the amount of Cu+ formed by reaction of a Cu++-alkanolamine buffered solution with serum uric acid under precisely controlled conditions before and after uricase treatment of the serum. The difference is proportional to the true serum uric acid content. The elements contributing to the enzymatic reaction, the colorimetric reaction, and the elimination of interferences were investigated. Comparison of serum uric acid values obtained by this method with those obtained by ultraviolet spectrophotometry show very good agreement.

1973 ◽  
Vol 19 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Bernard Klein ◽  
Lois B Lucas

Abstract A new coupled-ferricyanide-redox reaction has been developed for the manual and automated determination of serum uric acid. The 580-nm absorbance of the photometric end point, formation of the violet-blue Fe2+-5-pyridyl benzodiazepin-2-one chelate, is proportional to uric acid concentration. Replicate manual analyses are precise (CV = 1.2%) and reproducible from day-to-day (CV = 3.2%). Adapted to automated (AutoAnalyzer) operation, replicate analyses also show good precision (CV = 1.03%) as well as good day-to-day reproducibility (CV = 3.35%). Recovery of added uric acid averaged 98.5% (range: 92.7-107.5%) in the manual procedure and 99.9% (range: 96.6-103.3%) in the automated mode. Formaldehyde, commonly used to preserve uric acid solutions, has been shown to interfere with recovery analyses in the automated analyses. Results obtained by the present procedure and reference carbonate-phosphotungstate and uricase methods agree well


1962 ◽  
Vol 41 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Pentti A. Järvinen ◽  
Sykkö Pesonen ◽  
Pirkko Väänänen

ABSTRACT The fractional determination of 17-ketosteroids in the daily urine was performed in nine cases of hyperemesis gravidarum and in four control cases, in the first trimester of pregnancy both before and after corticotrophin administration. The excretion of total 17-KS is similar in the two groups. Only in the hyperemesis group does the excretion of total 17-KS increase significantly after corticotrophin administration. The fractional determination reveals no difference between the two groups of patients with regard to the values of the fractions U (unidentified 17-KS), A (androsterone) and Rest (11-oxygenated 17-KS). The excretion of dehydroepiandrosterone is significantly higher in the hyperemesis group than in the control group. The excretion of androstanolone seems to be lower in the hyperemesis group than in the control group, but the difference is not statistically significant. The differences in the correlation between dehydroepiandrosterone and androstanolone in the two groups is significant. The high excretion of dehydroepiandrosterone and low excretion of androstanolone in cases of hyperemesis gravidarum is a sign of adrenal dysfunction.


1983 ◽  
Vol 29 (8) ◽  
pp. 1513-1517 ◽  
Author(s):  
M W McGowan ◽  
J D Artiss ◽  
B Zak

Abstract A procedure for the enzymatic determination of lecithin and sphingomyelin in aqueous solution is described. The phospholipids are first dissolved in chloroform:methanol (2:1 by vol), the solvent is evaporated, and the residue is redissolved in an aqueous zwitterionic detergent solution. The enzymatic reaction sequences of both assays involve hydrolysis of the phospholipids to produce choline, which is then oxidized to betaine, thus generating hydrogen peroxide. The hydrogen peroxide is subsequently utilized in the enzymatic coupling of 4-aminoantipyrine and sodium 2-hydroxy-3,5-dichlorobenzenesulfonate, an intensely red color being formed. The presence of a non-reacting phospholipid enhances the hydrolysis of the reacting phospholipid. Thus we added lecithin to the sphingomyelin standards and sphingomyelin to the lecithin standards. This precise procedure may be applicable to determination of lecithin and sphingomyelin in amniotic fluid.


1996 ◽  
Vol 15 (6) ◽  
pp. 497-503 ◽  
Author(s):  
T. Soriano ◽  
M. Menéndez ◽  
P. Sanz ◽  
M. Repetto

1 The described analytical procedure permits the simultaneous determination of the main n-hexane meta bolites in urine. 2-Hexanone, 2-hexanol, 2, 5-hexanediol and 2, 5-hexanedione, were chosen to dose the rats used in this study. All urine samples were collected and analysed on a daily basis, before and after acidic hydrolysis (pH 0.1) by GC/MS. 2-Hexanone, 2, 5-dimethylfurane, γ-valerolac tone and 2, 5-hexanedione were determined before hydro lysis ; 2-hexanol and 2, 5-hexanediol, after hydrolysis; and 5-hydroxy-2-hexanone and 4, 5-dihydroxy-2-hexanone were calculated by the difference between γ-valerolactone and 2, 5-hexanedione with and without hydrolysis, respectively. 2 A metabolic scheme was proposed reflecting the biotransformations undergone by the four compounds assayed. We consider 2, 5-dimethylfurane as a 'true metabolite' because the quantities detected were always greater before hydrolysis. 3 It has been reported that human and rat n-hexane metabolism follow a similar pattern. Therefore, as a practical application and without increasing either sample or time requirements, the simultaneous quantifi cation of the different metabolites and their excretion profile could provide better information about the metabolic situation of exposed workers than the determi nation of 2, 5-hexanedione alone. According to our experimental results, 4, 5-dihydroxy-2-hexanone itself would be a good toxicity indicator.


2021 ◽  
Vol 10 (3) ◽  
pp. 186-198
Author(s):  
I Komang Wisnu Wardhana ◽  
Hermanto Hermanto ◽  
I Nyoman Nugraha AP

The purpose of this study was to determine the difference in the average abnormal return and trading volume activity before and after the enactment of the tax amnesty law on the LQ-45 index. The type of data used in this study is secondary data with data collection techniques using the documentation method. Determination of the sample in this study using purposive sampling method with certain criteria so as to obtain 45 samples. The analytical technique used in this research is paired sample t-test with an observation period of 10 days. The results of this study indicate that: (1) There is no difference in the average abnormal return before and after the enactment of the tax amnesty law. (2) There is no difference in the average trading volume activity before and after the enactment of the tax amnesty law. 


2022 ◽  
Vol 12 (1) ◽  
pp. 12
Author(s):  
Tsuyoshi Takara ◽  
Kazuo Yamamoto ◽  
Naoko Suzuki ◽  
Shin-ichiro Yamashita ◽  
Shin-ichiro Iio ◽  
...  

Background and objective: Chrysanthemum flowers are consumed as fresh condiments, herbal teas, and processed foods in Japan and Taiwan. They contain luteolin as a major polyphenol and are traditionally used for eye care. We previously demonstrated that the ingestion of Chrysanthemum flower extract (CFE) for 1 month reduced serum uric acid levels. However, the findings obtained were considered to be biased because the study was performed by a CFE manufacturer. Therefore, we herein conducted a clinical trial on CFE on a larger scale and examined its effects on purine base absorption from the intestines, which represents an effective approach for reducing serum uric acid levels. Methods: Both studies were performed as randomized, double-blind, placebo-controlled trials and CFE (100 mg) containing 1 mg of luteolin was used as the active sample. We enrolled 44 healthy Japanese men and women with 6.0 to 7.9 mg/dL serum uric acid. All subjects were randomly allocated to an active group (n=22) or placebo group (n=22) using a computerized random number generator. In the purine base absorption study, CFE was ingested with a purine base-rich diet and serum uric acid levels were measured chronologically. In the 12-week consecutive ingestion study, CFE or placebo was administered between January and April 2021. Serum uric acid levels after 12 weeks were assessed as the primary outcome, and uric acid were measured before and after 4 weeks of the intervention as secondary outcomes. Blood, urine and body parameters were examined to evaluate the safety of CFE. Results: Thirty-nine subjects completed the trial, and the per protocol set comprised 18 and 21 subjects in the active and placebo groups, respectively. In the single dosing study of CFE on subjects loaded by the purine base-rich diet, no significant changes were observed between the CFE and placebo groups. On the other hand, in the 12-week ingestion study, serum uric acid levels were significantly lower in the CFE group than in the placebo group. Laboratory tests revealed no abnormalities to suggest any side effects of CFE.Conclusions: CFE (100 mg/day) containing 1 mg of luteolin reduced serum uric acid levels. CFE may be beneficial for improving hyperurichemia. Trial Registration: UMIN-CTR: UMIN000042327Foundation: The present study was funded by Oryza Oil & Fat Chemical Co., Ltd. Keywords: Chrysanthemum, luteolin, uric acid, purine base


2004 ◽  
Vol 10 (3) ◽  
pp. 278-280 ◽  
Author(s):  
C M Knapp ◽  
C S Constantinescu ◽  
J HY Tan ◽  
R McLean ◽  
G R Cherryman ◽  
...  

Uric acid, an antioxidant, is reduced in multiple sclerosis (MS). Patients with gout have a reduced incidence of MS. O ptic neuritis (O N), often the first manifestation of MS, is not known to be associated with reduced uric acid. Patients with recent onset of O N were investigated to determine whether uric acid levels were reduced at presentatio n. Twenty-o ne patients with O N were included, 17 females and 4 males. The mean (SD) serum uric acid in the O N female group was 184.4 (±55.1) mmol/L (range, 116- 309 mmol/L), whilst in the control group it was 235.2 (±50.2) mmol/L (range, 172- 381 mmol/L). The difference was statistically significant (x2 = 8.93, P = 0.003). In the small male cohort, mean (SD) serum uric acid was 305 (±52.1) mmol/L, whilst in the control group it was 328 (±80.4) mmol/L. These differences were not statistically significant. Reduced antioxidant reserve is possibly an early patho genic mechanism in inflammatory demyelination, and raises the possibility that low uric acid levels could be an indicator of disease activity. Since optic neuropathies of other causes were not investigated, future research needs to determine whether low uric acid represents a unique feature of optic neuritis or is seen in other optic neuropathies.


1966 ◽  
Vol 12 (1) ◽  
pp. 18-24 ◽  
Author(s):  
Wendell T Caraway ◽  
Herman Marable

Abstract A colorimetric carbonate procedure for the determination of uric acid has been modified to include incubation of serum with uricase to destroy uric acid. Residual nonurate chromogens are subtracted from total chromogens to obtain the concentration of "true" uric acid. Result obtained by the carbonate and the uricase-carbonate methods were in good agreement. The mean concentration of nonurate chromogens in serum is approximately 2% of the true uric acid values. Recovery of uric acid added to serum is essentially quantitative. Formaldehyde markedly inhibits uricase activity and interferes with recoveries. The uricase-carbonate method is applicable to hemolytic serum and to serums from patients with uremia or those receiving high doses of salicylate in which excess concentrations of nonurate chromogens may be encountered.


Sign in / Sign up

Export Citation Format

Share Document