Based on Ag nanoparticles as the surface-enhanced Raman spectroscopy (SERS)-active nanostructure, the SERS of uric acid was presented in the paper. The absorption spectroscopies of uric acid and the mixture of silver colloids and uric acid were measured. The possible enhancing mechanism of the uric acid on silver colloid was speculated. The characteristic SERS bands of uric acid were tentatively assigned. The influence of absorption time and different ion on the SERS of uric acid were also discussed. The SERS spectral intensity changes linearly with the uric acid concentration, which indicated that the SERS might provide a new kind of direct and fast detecting method for the detection of uric acid. The detection limit of uric acid in silver sol is found to be 1 mg/L.
Metal Nanoparticles ; chemistry ; Silver ; chemistry ; Spectrum Analysis, Raman ; methods ; Surface Properties ; Uric Acid ; analysis

OBJECTIVE: To evaluate the relationship between 24 h urinary ion content and kidney stones, and to explore the diagnostic values of kidney stone in primary gout patients. METHODS: Patients diagnosed with primary gout had ultrasound scanning of both feet and kidneys in Peking University First Hospital from Jan. 2020 to May 2021. Their clinical characteristics were compared between the positive and negative kidney stone groups, and the relationship between kidney stone and urinary ion composition were analyzed. Risk factors of kidney stone were analyzed. The explored diagnostic values were evaluated for urinary oxalate and citrate according with uric acid kidney stones by dual-energy computed tomography (DECT). RESULTS: Among the 100 gouty patients, 80 patients had uric acid crystal deposition in lower joints of extremity by ultrasonography, 61 patients had kidney stone, and 34 had kidney uric acid stones by DECT. All the multiple kidney stones were proved as uric acid kidney stones by DECT. Compared with patients without kidney stone group proved by ultrasonography, patients with kidney stone had longer gouty duration [(48.7±26.6) months vs. (84.0±30.6) months, P=0.01], higher 24 h urinary oxalate [(20.1±9.6) mg vs. (28.6±20.7) mg, P=0.001] and lower 24 h urinary citrate [(506.3±315.4) mg vs. (355.7±219.6) mg, P=0.001]. Compared with the patients without kidney stone by DECT, the patients with uric acid kidney stone also had longer disease duration [(49.1±28.4) months vs. (108.3±72.2) months, P=0.001], higher 24 h urinary oxalate [(23.6±16.9) mg vs. (28.5±18.8) mg, P < 0.05], lower 24 h urinary citrate [(556.0±316.3) mg vs. (391.7±261.2) mg, P < 0.05], higher serum uric acid [(466.2±134.5) μmol/L vs. (517.2±18.1) μmol/L, P < 0.05] and higher 24 h urinary uric acid [(1 518.1±893.4) mg vs. (1 684.2±812.1) mg, P < 0.05]. Logistic regression analysis showed long gout disease duration (OR=1.229, 95%CI: 1.062-1.522, P < 0.05), high serum uric acid level (OR=1.137, 95%CI: 1.001-1.213, P=0.01), low 24 h urinary citrate (OR=0.821, 95%CI: 0.659-0.952, P=0.01) were all risk factors of kidney stones by ultrasonography. Also, long gout disease duration (OR=1.201, 95%CI: 1.101-1.437, P=0.005), high serum creatine uric level (OR=1.145, 95%CI: 1.001-1.182, P=0.04), low 24 h urinary citrate (OR=0.837, 95%CI: 0.739-0.931, P=0.02) were all risk factors of kidney uric acid stones by DECT. CONCLUSION Long disease duration and low 24 h urinary citrate were risk factors for kidney stones.
Humans ; Urinary Calculi ; Uric Acid/analysis* ; Citric Acid ; Kidney Calculi/diagnostic imaging* ; Gout/diagnostic imaging* ; Citrates ; Oxalates

Although there are a number of literature on the chemical composition of urinary stones, problems of the urolithiasis, particularly concerning [the pathogenesis of stone formation, are yet to be solved. This paper is to study the chemical composition of urinary stones from Korean patients with urolithiasis. The stones were analyzed by the spectroscopic method (infrared absorption spectra and X-ray diffraction). All of the 68 cases who were subjected to this study had been admitted to the Department of Urology, Seoul National University Hospital. The observed results are as follows: 1) In the cases of oxalate stones, only the monohydrates were found in this study. This finding is inconsistent with the reports from the other countries, that is, in most other studies, dihydrates and mixed stones were reported much more frequently. 2) In the cases with urate stones, there was no case with hydrate or salt forms. Only the pure crystalline forms of uric acid stone were found in this study. 3) In this series, not a single case of cystine or xanthine stone was found 4) Qualitative analysis of phosphate and oxalate stones were carried out by the infrared absorption spectra, and in some degree quantitative analysis were possible by the intensity of absorption spectra. 5) X-ray diffraction method, by which we analyzed the chemical composition and the crystal types, seemed to be the better method in studying the urinary stones in connection with the pathogenesis of urolitbiasis Differences in the chemical composition and crystalline forms of urinary calculi in this study from the report of the other countries suggest that geographic, racial and dietary factors may play important roles in the pathogenesis of urolithiasis.
Absorption ; Crystallins ; Cystine ; Humans ; Seoul ; Spectrum Analysis ; Uric Acid ; Urinary Calculi* ; Urolithiasis ; Urology ; X-Ray Diffraction ; Xanthine

BACKGROUND: The role of uric acid in cerebrovascular disease is controversial. Uric acid may be an independent risk factor for cerebrovascular diseases but its neuroprotective role as an antioxidant has also been suggested. We studied the effects of uric acid on the early prognosis in acute ischemic stroke. METHODS: The subjects were 721 patients with moderate-to-severe acute stroke who arrived at hospital within 48 hours from the onset of symptoms. Patients were divided into quartiles based on serum uric acid levels at admission. In-hospital stroke outcome were calculated on the National Institutes of Health Stroke Scale (NIHSS) and analyzed by multivariate logistic regression. RESULTS: Differences in NIHSS scores between baseline and discharge in the patients were not significantly related to serum uric acid levels. However, in large artery atherosclerosis group, the proportion of patients with neurological improvement and differences in NIHSS score between baseline and discharge differed between the quartile uric acid groups (p<0.01 and p=0.04, respectively). A multivariate analysis adjusting for known vascular risk factors showed that a higher uric acid level was associated with a higher probability of a good in-hospital outcome (odds ratio, 1.31 per additional 1 mg/dL; 95% confidence interval, 1.07-1.60 per additional 1 mg/dL), but only in those with large-artery atherosclerosis. CONCLUSIONS: Uric acid level is independently correlated with the neurological improvement in patients with acute ischemic stroke caused by large-artery atherosclerosis.
Arteries ; Atherosclerosis ; Humans ; Hyperuricemia ; Logistic Models ; Multivariate Analysis ; National Institutes of Health (U.S.) ; Prognosis ; Risk Factors ; Stroke ; Uric Acid

One hundred thirty-seven urinary calculi were analyzed by means of X-ray, diffraction, ultraviolet spectroscopy and chemical method. 1. The most frequently found constituent in these 137 calculi was calcium oxalate that was found in 101 calculi (76.0% of the series). Of these 104 calculi pure calcium oxalate was identified in 41, of which 14 (10.2%) were composed of pure monohydrate and 27(19.7%) were mixtures of monohydrate and dihydrate. The dihydrates were only found to be mixed with monohydrates and the two hydrates could be identified only by X-ray diffraction but not by chemical method. 2. Identification of phosphate by X-ray diffraction was difficult because of its low peak intensity, while chemical method was proved to be more sensitive and accurate for phosphate. Calcium phosphate was found not in the pure state but in the: mixed form with calcium oxalate in 39 calculi (28.5%). 3. Pure uric acid constituent was very rare, being oily found in 2 calculi (1.5%). But there were 41 calculi (29.9%) mixed with a minute amount of uric acid, of which 28 (68.3%) were associated with calcium oxalate monohydrate. Only one calculus of uric acid, which did not appear to be crystallized, was detected by ultraviolet spectroscopy. 4. There were 23 calculi (16.8%) of magnesium ammonium phosphate, of which 13 (56.5%) were mixed with calcium phosphate and only 3 (13. 0%) were found to be in the pure state. 5. Xanthine was found as a minor constituent in t calculi, all coexistent with uric acid. There was no calculus of cystine detected. 6. X-ray diffraction method bad the advantages of providing a permanent record and a semiquantitative result and of identifying minute components. However it was unsatisfactory for detecting phosphate constituent.
Ammonium Compounds ; Calcium ; Calcium Oxalate ; Calculi ; Cystine ; Magnesium ; Spectrum Analysis ; Uric Acid ; Urinary Calculi* ; Urolithiasis ; X-Ray Diffraction ; Xanthine

OBJECTIVETo measure uric acid of seminal plasma in fertile and infertile males.

METHODSOne hundred and sixty-three infertile males were divided into an obstructive azoospermic group (15 cases), a non-obstructive azoospermic group (36 cases), an oligozoospermic group (43 cases), and an asthenozoospermic group (69 cases). Twenty fertile males were included in the control group. Uric acid concentrations of seminal plasma in the fertile and infertile men were assessed by spectrophotometer, and sperm parameters were analyzed by computer-assisted semen analysis (CASA) system.

RESULTSUric acid concentration of seminal plasma in the control group was significantly higher than all the infertile groups (P < 0.01), and that of the obstructive azoospermic group significantly lower than the other infertile groups (P < 0.1), but no significant difference was observed among the other infertile groups (P > 0.05).

CONCLUSIONUric acid may play an important role in male reproduction because of its antioxidative property.

Adult ; Azoospermia ; metabolism ; Case-Control Studies ; Humans ; Infertility, Male ; metabolism ; Male ; Oligospermia ; metabolism ; Semen ; chemistry ; Uric Acid ; analysis

OBJECTIVETo study the correlation between lacunar cerebral infarction and level of serum uric acid in elderly male hypertension patients.

METHODSNinety-eight elderly male hypertension patients were enrolled in this study. They all underwent cerebral magnetic resonance imaging (MRI) scan, and their clinical and laboratory data were collected. The patients were divided into the 1st group (n = 32), the 2nd group (n = 32) and the 3rd group (n = 34) according to the level of serum uric acid.

RESULTSThe numbers of lacuner infarction, serum creatinine, urea and high density lipoprotein(HDL) were significantly diferrent from the other groups. The numbers of lacuner infarction were positively related with serum uric acid and urea. Multiple variant analysis showed that serum uric acid was the independent factor of the numbers of lacuner infarction.

CONCLUSIONThe elevated level of serum uric acid may contribute to the risk factors of lacuner infarction.

Aged, 80 and over ; Cerebral Infarction ; etiology ; Humans ; Hypertension ; blood ; complications ; Male ; Regression Analysis ; Risk Factors ; Uric Acid ; blood

OBJECTIVETo establish the method of seminal uric acid (UA) determination and investigate the correlation between the seminal UA level and semen parameters.

METHODSThe method of seminal UA determination was established by modifying the method of serum UA detection, and its intraassay coefficient of variation (CV) and the difference of the results between different technicians were also observed to evaluate the acceptability of the method. In the meanwhile, the correlations of the seminal UA level with the patients' age, abstinence time, semen volume, pH, sperm concentration, motility, the percentage of grade a and b sperm, and the percentage of morphologically normal sperm.

RESULTSThe intraassay CV was 9. 16% for the method of seminal UA detection, and there was no significant difference in the UA level detected by 2 technicians (P = 0.541). The seminal UA level was positively correlated with the percentage of morphologically normal sperm (r = 0.350, P = 0.025) , with a tendency of positive correlation with sperm motility (r = 0.147, P = 0.085) and the percentage of grade a and b sperm (r = 0.156, P = 0.068), but not with other parameters such as semen volume, pH, sperm concentration, abstinence time and the patients' age.

CONCLUSIONAn acceptable method of seminal UA determination could be established by modifying the method of serum UA detection. Sperm morphology, motility and the percentage of grade a and b sperm might be related to the level of seminal UA.

Adult ; Humans ; Infertility, Male ; metabolism ; pathology ; physiopathology ; Male ; Semen ; chemistry ; cytology ; Sperm Count ; Sperm Motility ; Uric Acid ; analysis

OBJECTIVETo determine the level of uric acid (UA) in the expressed prostatic secretion (EPS) of chronic prostatitis patients and explore its clinical significance.

METHODSA total of 91 patients with chronic prostatitis diagnosed by NIH standard were divided into a III A (n = 48) and a III B (n = 43) group, and healthy volunteers were selected as the control. The scores on the NIH-Chronic Prostatitis Symptom Index (CPSI) and the WBC count, pH value and UA level in EPS were evaluated for all the three groups.

RESULTSThe EPS UA concentration was (257.02 +/- 144.84) micromol/L in Group III B, significantly higher than in Group III A, (159. 73 +/- 121.49) micromol/L, (P < 0.01), and the control, (78.55 +/- 44.53) micromol/L, (P < 0.01). The level of EPS UA was correlated negatively with pH value (r = -0.398, P = 0.000), but positively with CPSI-P, CPSI-U and CPSI-T (r = 0.436, 0.316 and 0.403, P < 0.01).

CONCLUSIONBackflow of urine into prostatic ducts might cause chemical inflammation reaction by increasing UA concentration. There is a close relationship between the UA level in EPS and chronic prostatitis symptoms. Determination of the UA level in EPS is of great significance for the diagnosis and treatment of chronic prostatitis.

Adolescent ; Adult ; Chronic Disease ; Humans ; Male ; Middle Aged ; Prostate ; pathology ; secretion ; Prostatitis ; diagnosis ; metabolism ; physiopathology ; Uric Acid ; analysis

OBJECTIVE: To explore the changes and clinical significance of saliva urea, creatinine (Cr), uric acid (UA) in both healthy people and chronic kidney disease (CKD) patients, and to provide a noninvasive, quick, accurate and reliable test to diagnose kindey disease. METHODS: Urea, Cr and UA in the saliva and serum collected from both healthy people and the CKD patients were measured by biochemical analyzer. We calculated the correlation coefficient of Urea, Cr and UA between the saliva and serum, compared the levels of saliva Urea, Cr and UA among CKD patients in different periods, drew the receiver operation characteristic (ROC) curve and analyzed the sensitivity and specificity of saliva Urea, Cr and UA to predict CKD patients in various periods. RESULTS: The concentrations of Urea, Cr and UA in both the saliva and the serum were positively correlated in healthy individuals and CKD patients (r = 0.918, 0.932, 0.840 and 0.984, 0.971, 0.920). The levels of saliva Urea, Cr and UA in the CKD patients were significantly higher than those of healthy people (P<0.05). Saliva Urea, Cr and UA concentrations of middle and late stage CKD patients were obviously higher than those of healthy people and early stage CKD patients (P<0.05). Areas under the curve (AUC) of the ROC of Urea, Cr and UA to diagnose diverse periods of CKD were 0.898, 0.897 and 0.848. The sensitivity was 0.806, 0.776 and 0.704; and the specificity was 0.968, 0.989 and 0.871. CONCLUSION The levels of Urea, Cr and UA between the saliva and the serum are closely related. The concentration of saliva Urea, Cr and UA can reflect the renal damage, monitor kidney function of the CKD patients, and help diagnose middle to late stage CKD patients. It is a simple, nonivasive and quick method.
Adolescent ; Adult ; Aged ; Case-Control Studies ; Creatinine ; analysis ; Female ; Humans ; Male ; Middle Aged ; Renal Insufficiency, Chronic ; metabolism ; Saliva ; chemistry ; Urea ; analysis ; Uric Acid ; analysis ; Young Adult