Learning Discriminatory Information for Object Detection on Urine Sediment Image

In clinical practice,the microscopic examination of urine sediment is considered an important in vitro examination with many broad applications.Measuring the amount of each type of urine sediment allows for screening,diagnosis and evaluation of kidney and urinary tract disease,providing insight into the specific type and severity.However,manual urine sediment examination is labor-intensive,time-consuming,and subjective.Traditional machine learning based object detection methods require hand-crafted features for localization and classification,which have poor generalization capabilities and are difficult to quickly and accurately detect the number of urine sediments.Deep learning based object detection methods have the potential to address the challenges mentioned above,but these methods require access to large urine sediment image datasets.Unfortunately,only a limited number of publicly available urine sediment datasets are currently available.To alleviate the lack of urine sediment datasets in medical image analysis,we propose a new dataset named UriSed2K,which contains 2465 high-quality images annotated with expert guidance.Two main challenges are associated with our dataset:a large number of small objects and the occlusion between these small objects.Our manuscript focuses on applying deep learning object detection methods to the urine sediment dataset and addressing the challenges presented by this dataset.Specifically,our goal is to improve the accuracy and efficiency of the detection algorithm and,in doing so,provide medical professionals with an automatic detector that saves time and effort.We propose an improved lightweight one-stage object detection algorithm called Discriminatory-YOLO.The proposed algorithm comprises a local context attention module and a global background suppression module,which aid the detector in distinguishing urine sediment features in the image.The local context attention module captures context information beyond the object region,while the global background suppression module emphasizes objects in uninformative backgrounds.We comprehensively evaluate our method on the UriSed2K dataset,which includes seven categories of urine sediments,such as erythrocytes(red blood cells),leukocytes(white blood cells),epithelial cells,crystals,mycetes,broken erythrocytes,and broken leukocytes,achieving the best average precision(AP)of 95.3%while taking only 10 ms per image.The source code and dataset are available at https://github.com/binghuiwu98/discriminatoryyolov5.

Measurement of very low-molecular weight metabolites by traveling wave ion mobility and its use in human urine samples

The collision cross-sections(CCS)measurement using ion mobility spectrometry(IMS)in combination with mass spectrometry(MS)offers a great opportunity to increase confidence in metabolite identification.However,owing to the lack of sensitivity and resolution,IMS has an analytical challenge in studying the CCS values of very low-molecular-weight metabolites(VLMs250 Da).Here,we describe an analytical method using ultrahigh-performance liquid chromatography(UPLC)coupled to a traveling wave ion mobility-quadrupole-time-of-flight mass spectrometer optimized for the measurement of VLMs in human urine samples.The experimental CCS values,along with mass spectral properties,were reported for the 174 metabolites.The experimental data included the mass-to-charge ratio(m/z),retention time(RT),tandem MS(MS/MS)spectra,and CCS values.Among the studied metabolites,263 traveling wave ion mobility spectrometry(TWIMS)-derived CCS values(TWCCSN2)were reported for the first time,and more than 70%of these were CCS values of VLMs.The TWCCSN2 values were highly repeatable,with inter-day variations of<1%relative standard deviation(RSD).The developed method revealed excellent TWCCSN2 accuracy with a CCS difference(DCCS)within±2%of the reported drift tube IMS(DTIMS)and TWIMS CCS values.The complexity of the urine matrix did not affect the precision of the method,as evidenced by DCCS within±1.92%.According to the Metabolomics Standards Initiative,55 urinary metabolites were identified with a confidence level of 1.Among these 55 metabolites,53(96%)were VLMs.The larger number of confirmed compounds found in this study was a result of the addition of TWCCSN2 values,which clearly increased metabolite identification confidence.

Landscape of urine biomarkers for bladder cancer:molecular function,cell-of-origin,and bibliometric trend

Background:The effective management of bladder cancer(BCa)depends on the early diagnosis and surveillance.Previous studies have explored numerous urinary molecules as potential biomarkers of BCa.However,the molecular functions and cell-of-origin profiles of these biomarkers are yet to be elucidated.In this study,we aimed to provide a comprehensive overview of the landscape of urinary biomarker genes for BCa.Methods:We conducted an exhaustive literature search in PubMed,through which 555 biomarker genes were identified.We then analyzed the BCa single-cell atlas to infer the cellular origin of these BCa urine biomarker genes and performed functional enrichment analysis to gain insights into the functional molecular implications of these biomarkers.Results:These genes are involved in tumor proliferation,angiogenesis,cellmigration,and cell death and are predominantly expressed in epithelial and stromal cells.Interestingly,our analysis ofmultiomics tumor data revealed a discordance between tissue and urine in terms of differential methylation and RNA expression,suggesting that biomarker discovery for liquid biopsies should ideally begin with the analysis of bodily fluids rather than relying interest and that test strategies incorporating multiple molecular markers represent an ongoing trend.Conclusions:Collectively,our study has built a landscape of BCa urine biomarker genes,uncovered molecular insights into these biomarkers,and revealed the bibliometric trends in this field,which will contribute to the discovery of novel biomarkers in the future.

Effects of Inhabiting and Life Patterns on the UV Spectral Properties of Small Mammalian Herbivores’ Urine

It is well known that avian predators can use prey excretions such as urine and feces to track their prey, and the urine and feces of small mammalian herbivores can reflect ultraviolet (UV) light and emit fluorescent light. There are still some debates as to whether UV visibility of small mammalian herbivores’ urine is used as a hunting cue by avian raptors. Some studies in Europe have demonstrated that diurnal raptors are capable of utilizing these cues to target key prey species. However, researchers in Australia have argued that raptors do not use the UV visibility of urine while hunting. To our knowledge, there are no reports from Asia concerning the ultraviolet spectral characteristics of small mammal herbivores’ urine. This study examined the UV spectral properties of urine from 6 small mammal herbivores species by comparing the UV reflectance and fluorescence spectra of urine from small mammalian herbivores living in plateau meadows, plateau shrubs, open marshland, farmland, and semi-desert grassland in China. In addition, we compared the UV spectral properties of urine from ground-dwelling species of rodents and subterranean species to determine whether ultraviolet visibility of small mammal herbivores’ urine could be used as a visual signal by Asian vole-eating raptors. The results showed that: 1) the SC370 values of urine from four small mammal herbivores species were ordered as plateau pika (plateau meadow) > root voles (plateau bush) > reed voles (swampland) > Brandt’s vole (desert grassland);and 2) UV fluorescence peak intensity and the wavelengths of urine from ground-dwelling species (such as the root vole, plateau pika, or Brandt’s vole) were significantly higher than those of subterranean-dwelling species (mandarin vole and plateau zokor). These results indicate that UV visibility of small mammal herbivores’ urine may act as a visual cue for raptors.

Can the Urine Dipstick Test Be an Alternative in the Screening of Urinary Tract Infections for Inpatients in the Context of a Low-Income Country?

Background: Urinary Tract Infection (UTI), a prevalent bacterial infection in adults, heavily relies on cytobacteriological examination of urine (CBEU) for diagnosis. However, in resource-limited countries, accessibility to CBEU remains hindered by cost and availability. This study aims to assess the utility of the Urinary Dipstick Test (UDT) in diagnosing UTIs among hospitalized patients in the context of limited resources. Methods: A cross-sectional study was conducted from February to May 2019, encompassing hospitalized patients who underwent CBEU at the bacteriology unit of Sour? Sanou University Hospital. UDT and CBEU were concurrently performed, and UDT’s analytical and diagnostic performance was evaluated against CBEU, considered the gold standard. Results: A total of 274 CBEU requests were registered, involving 274 patients (159 males) with a mean age of 45.8 ± 21.3 years (ranging from 1 to 90 years). UTI was confirmed in 90 patients, yielding a frequency of 32.85%. The UTI bacteriological profile was dominated by Enterobacteriaceae (75.23%), primarily Escherichia coli (60.55%). Nitrite and Leukocytes were positive in 54 (19.8%) and 157 (53.6%) of the samples tested. Among patients with confirmed UTI, Nitrite, and Leukocytes were positive in 30 (33%) and 71 (79%) patients respectively. UDT demonstrated variable performance based on nitrite and leukocyte combination: Sensitivity (57%-82%), Specificity (7%-98%), Positive Predictive Value (PPV) (43%-57%), Negative Predictive Value (NPV) (43%-67%). UDT performed slightly better in women (NPV = 88%) and inpatients without urinary catheters (NPV = 75% and PPV = 80%). Conclusion: This study underscores UDT’s potential utility in excluding UTIs among women, younger patients, and inpatients without urinary catheters, albeit with limited confidence. The UDT emerges as a complementary tool for UTI screening, particularly in resource-limited settings.

Diagnosis of an intermediate case of maple syrup urine disease:A case report

BACKGROUND Maple syrup urine disease(MSUD)is an autosomal recessive genetic disorder caused by defects in the catabolism of the branched-chain amino acids(BCAAs).However,the clinical and metabolic screening is limited in identifying all MSUD patients,especially those patients with mild phenotypes or are asymptomatic.This study aims to share the diagnostic experience of an intermediate MSUD case who was missed by metabolic profiling but identified by genetic analysis.CASE SUMMARY This study reports the diagnostic process of a boy with intermediate MSUD.The proband presented with psychomotor retardation and cerebral lesions on magnetic resonance imaging scans at 8 mo of age.Preliminary clinical and metabolic profiling did not support a specific disease.However,whole exome sequencing and subsequent Sanger sequencing at 1 year and 7 mo of age identified bi-allelic pathogenic variants of the BCKDHB gene,confirming the proband as having MSUD with non-classic mild phenotypes.His clinical and laboratory data were retrospectively analyzed.According to his disease course,he was classified into an intermediate form of MSUD.His management was then changed to BCAAs restriction and metabolic monitoring conforming to MSUD.In addition,genetic counseling and prenatal diagnosis were provided to his parents.CONCLUSION Our work provides diagnostic experience of an intermediate MSUD case,suggesting that a genetic analysis is important for ambiguous cases,and alerts clinicians to avoid missing patients with non-classic mild phenotypes of MSUD.

Diagnostic value of matrix metalloproteinases 2, 7 and 9 in urine for early detection of colorectal cancer

BACKGROUND A noninvasive biomarker with high diagnostic performance is urgently needed for the early diagnosis of colorectal cancer(CRC).AIM To evaluate the diagnostic value of matrix metalloproteinases(MMPs)2,7 and 9 in urine for CRC.METHODS Of 59 healthy controls,47 patients with colon polyps and 82 patients with CRC were included in this study.Carcinoembryonic antigen(CEA)in serum and MMP2,MMP7,and MMP9 in urine were detected.The combined diagnostic model of the indicators was established by binary logistic regression.The receiver operating characteristic curve(ROC)of the subjects was used to evaluate the independent and combined diagnostic value of the indicators.RESULTS The MMP2,MMP7,MMP9,and CEA levels in the CRC group differed significantly from levels in the healthy controls(P<0.05).The levels of MMP7,MMP9,and CEA also differed significantly between the CRC group and the colon polyps group(P<0.05).The area under the curve(AUC)distinguishing between the healthy control and the CRC patients using the joint model with CEA,MMP2,MMP7 and MMP9 was 0.977,and the sensitivity and specificity were 95.10%and 91.50%,respectively.For early-stage CRC,the AUC was 0.975,and the sensitivity and specificity were 94.30%and 98.30%,respectively.For advanced stage CRC,the AUC was 0.979,and the sensitivity and specificity were 95.70%and 91.50%,respectively.Using CEA,MMP7 and MMP9 to jointly established a model distinguishing the colorectal polyp group from the CRC group,the AUC was 0.849,and the sensitivity and specificity were 84.10%and 70.20%,respectively.For early-stage CRC,the AUC was 0.818,and the sensitivity and specificity were 76.30%and 72.30%,respectively.For advanced stage CRC,the AUC was 0.875,and the sensitivity and specificity were 81.80%and 72.30%,respectively.CONCLUSION MMP2,MMP7 and MMP 9 may exhibit diagnostic value for the early detection of CRC and may serve as auxiliary diagnostic markers for CRC.

Multivariate Analysis of Female Stress Urinary Incontinence and Establishment of a Prediction Model

Stress urinary incontinence(SUI)is a symptom of uncontrolled urine outflow that affects millions of women worldwide[1].SUI is a significant healthcare issue that affects the quality of life of women across numerous domains,including social activities,physical health,mental well-being,employment,and sexual life.

Field Utilization of Dried Water Hyacinth for Phosphorous Recovery from Source-Separated Human Urine

This research demonstrated the feasibility of converting source-separated human urine into a solid fertilizer by means of continuous absorption and solar thermal evaporation using dried water hyacinth as adsorbent. In a preliminary experiment, the dried petioles of water hyacinth (DWH) absorbed urine in a mean rate of 18.78 ml·g-1 within 7 d, retrieving about 3.46% urine dissolved solids (UDS). In an advanced experiment, the DWH’s capacity of urine absorption declined from an initial 2.73 L·kg-1·d-1 to 0.68 L·kg-1·d-1, with a requirement of material change in about 25 effective days and an average ratio of 25 (L) to 1 (kg). Phosphorus (P2O5) concentration in the adsorbent increased from 0.46% (material baseline) to 3.14% (end product), suggesting a satisfactory recovery of the element. In field application, the urine was discharged, not in wet weather, onto the DWH via a tube connected to a waterless urinal. There are several ways to use the UDS-DWH as P(K)-rich fertilizer, e.g., making soluble fertilizer for foliage spraying to encourage prolific flowering and fruiting. Apparently, utilization of water hyacinth waste to recover dissolved plant nutrient elements from source-separated urine will benefit the environment in a wide range of perspectives. The herein innovative use of water hyacinth is also expected to be useful in the recycling of certain dissolved hazardous materials.

Metabolic dynamics in chronic gastritis:Examining urinary profiles post Helicobacter pylori eradication

Chronic gastritis is the persistent and insidious inflammation of the gastric lining.Helicobacter pylori(H.pylori)has been identified as the most common cause of chronic gastritis and consequently elimination of H.pylori can lead to its cure.This editorial explores the use of urinary metabolic profiles before and after eradication to identify biomarkers that can aid in prognosis and treatment.Despite providing promising insights,there are limitations such as a small sample size(17 patients),a narrow treatment period of 2 wk,and treatment heterogeneity,which raise concerns.Nevertheless,these findings have opened a gateway to enhancing the treatment and prognosis of chronic gastritis through urinary metabolomics.

影响Urine-H-11干化学法检测尿液分析的因素

Urine—H—11尿液试纸是干化学法检测尿液分析的一种方法，利用干化学法进行尿液分析，能够简便，快速为临床诊断、治疗、预防和监测疾病提供可靠的实验依据，但是，Urine—H—11干化学法也受许多因素的影响，而导致结果的准确性，为了使大家更多的了解影响Urine-H—11干化学法检测尿液的各项因素，准确的为临床提供诊断依据，现将有关Urine—H—11干化学法检测尿液的影响因素总结如下：

Detection of Neisseria Gonorrhoeae from Urine with Ligase Chain Reaction

Objective: To evaluate the value of ligase chainreaction(LCR) in the diagnosis of diplococcusgonorrhoeae in urine. Methods: LCR detection of the urine for Neisseriagonorrhoeae and bacteria culture of discharge was per-formed simultaneously to 276 patients with urethritisor cervicitis seeking treatment in sex transmitted dis-eases (STDs) outpatient clinic. For specimens withdiscordant results, polymerase chain reaction wasconducted. The purpose was to detect the respectivesensitivity and specificity of bacteria culture and LCR. Results: 24 of 276(8.7%) patients had positive LCRresults and 21 of 276(7.6%) were positive for culture.5 specimens had discordant results from LCR andbacteria culture. The sensitivity and specificity of LCRin the diagnosis of gonorrhoeae were 92.3% and100% respectively. Conclusion: This study showed that LCR had ahigher sensitivity and specificity for the diagnosis ofgonorrhoeae from urine.

Determination of urine catecholamines and metanephrines by reversed-phase liquid chromatography-tandem mass spectrometry

The measurement of urine catecholamine and metanephrine concentrations is important for biochemical screening and diagnosis of pheochromocytoma.The goal of this work was to develop a simple liquid chromatography-tandem mass spectrometry(LC-MS/MS)method for determining catecholamines and metanephrines in urine to replace an existing liquid chromatographic method using electrochemical detection.Urine samples were prepared using Oasis weak-cation-exchange cartridges.The eluate was analyzed on an Agilent ZORBAX Eclipse Plus Phenyl-Hexyl column in 3 min.Adrenaline,noradrenaline,dopamine,metanephrine,normetanephrine,and their deuterated internal standards were monitored in positive electrospray ionization mode by multiple reaction monitoring(MRM).No evidence of ion suppression was observed.The assay was linear up to 5μmol/L for adrenaline,5μmol/L for noradrenaline,6.1μmol/L for dopamine,5.6μmol/L for metanephrine,and 34.6μmol/L for normetanephrine,with lower limits of quantification of 5,5,12,6 and 7nmol/L,respectively.The intra-day and inter-day precisions for all analytes ranged from 0.59%to 4.64%and1.98%to 4.80%,respectively.External quality assurance samples were assayed and showed excellent agreement with the target values.This simple method provides an improved assay for determining urine catecholamines and metanephrines.

A Study on Bisphenol A,Nonylphenol,and Octylphenol in Human Urine amples Detected by SPE-UPLC-MS

Objective To establish a comprehensive analytical method based on SPE‐UPLC‐MS for the simultaneous determination of bisphenol A （BPA）, nonylphenol （NP）, and octylphenol （OP） in urine samples. Methods Sixty urine samples collected from healthy subjects were analyzed for BPA, NP, and OP concentrations. The samples were de‐conjugated by adding β‐glucuronidase and sulfatase. After the enzymatic treatment, the samples were subjected to the OASIS HLB column solid phase extraction cartridges so as to be cleaned and concentrated. The UPLC separation was performed on a Acquity UPLCTM BEH C18 column （2.1×100 mm, 1.7 μm） with a gradient elution system of methanol‐water as the mobile phase. Triple‐quadrupole mass spectrometry analyzer was used for the qualitative and quantitative analysis of UPLC‐MS/MS system. Results The limit of detection of BPA, NP, and OP was 0.10, 0.10, and 0.15 ng/mL, respectively. The recoveries of BPA, NP and OP were 80.1%‐108%, 81.3%‐109%, and 81.5%‐98.7%, respectively. Among the 60 urine samples, BPA was detected in 8 samples at the level of 0.297‐32.7ng/mL, NP was detected in 29 samples at the level of 1.69‐27.8 ng/mL, and OP was detected in 17 samples at the level of 0.407‐11.1 ng/mL. Conclusion The method is simple with high sensitivity and selectivity, and is suitable for the determination of BPA, NP, and OP in urine. As shown by our analysis , BPA, NP, and OP appear to be prevalent in human urine. This is particularly true for NP. The results from our study is therefore valuable for future studies to assess the exposure to BPA, NP, and OP in the general population.

Simultaneous determination of fluorine and iodine in urine by ion chromatography with electrochemical pretreatment

A new method for the simultaneous determination of fluorine and iodine in urine by ion chromatography （IC） with electrochemical pretreatment has been developed. The pretreatment was performed in a novel electrochemical oxidationneutralization device （EOND）, in which iodide of the sample was oxidized to iodate and the alkaline digestion sample solution was neutralized. Under the optimized conditions, the limits of detection （LOD, S/N = 3） were 2.5 μg/L for fluoride and 20 μg/L for iodate, respectively. The recoveries were in the range of 93-102% for fluoride and 86-98% for iodate.

Urea hydrolysis and recovery of nitrogen and phosphorous as MAP from stale human urine

Laboratory-scale tests for magnesium ammonium phosphate（MAP）precipitation following urea hydrolysis of human urine were conducted using orthogonal experiment design.The effects of initial pH,temperature and the volumetric ratios of stale urine to fresh urine,on urea hydrolysis in urine were studied to determine the final hydrolysis time to recover most nitrogen from separated human urine by MAP.With a volumetric ratio of stale to fresh urine>10% and at temperature≥20℃,urea hydrolysis could be completed in two days.Alkaline pH inhibited urea hydrolysis progress.The final pH values were all around 9.0 following urine hydrolysis,while the suspension pH might act as an indicator to detect the start and extent of urea hydrolysis.Over 95% of ammonium nitrogen and over 85% of phosphorus from hydrolyzed urine as MAP precipitate were obtained using MgCl;·6H;O and Na;HPO;·12H;O as precipitation agents at pH 8.5,molar ratio of Mg;:NH;-N:PO;-P at（1.2-1.3）:1:1,mixing speed of 120 r/min,and precipitation time and reaction time of 3 h and 15 min,respectively.The precipitate has a structure resembling pure MAP crystal.

Nuclear magnetic resonance-based metabolomics and metabolic pathway networks from patient-matched esophageal carcinoma,adjacent noncancerous tissues and urine

BACKGROUND Several studies have demonstrated a correlation between esophageal cancer(EC)and perturbed urinary metabolomic profiles,but none has described the correlation between urine metabolite profiles and those of the tumor and adjacent esophageal mucosa in the same patient.AIM To investigate how urinary metabolic phenotypes were linked to the changes in the biochemical landscape of esophageal tumors.METHODS Nuclear magnetic resonance-based metabolomics were applied to esophageal tumor tissues and adjacent normal mucosal tissues alongside patient-matched urine samples.RESULTS Analysis revealed that specific metabolite changes overlapped across both metrics,including glucose,glutamate,citrate,glycine,creatinine and taurine,indicating that the networks for metabolic pathway perturbations in EC,potentially involved in but not limited to disruption of fatty acid metabolism,glucose and glycolytic metabolism,tricarboxylic acid cycle and glutaminolysis.Additionally,changes in most urinary biomarkers correlated with changes in biomarker candidates in EC tissues,implying enhanced energy production for rapid cell proliferation.CONCLUSION Overall,these associations provide evidence for distinct metabolic signatures and pathway disturbances between the tumor tissues and urine of EC patients,and changes in urinary metabolic signature could reflect reprogramming of the aforementioned metabolic pathways in EC tissues.Further investigation is needed to validate these initial findings using larger samples and to establish the underlying mechanism of EC progression.

Urine versus brushed samples in human papillomavirus screening： study in both genders

Aim： To investigate whether urine is a good medium for screening and whether there is a correlation between the amount of extracted DNA and human papillomavirus （HPV）-positivity. Methods： In the present study, 30 first-voided urine （FVU） specimens and 20 urethroglandular swabs using cervex-brushes from male partners of HPV-positive patients, and 31 FVU specimens and 100 liquid-based cervix cytology leftovers sampled with cervix-brushes from HPV-positive women were examined for the presence of β-globin. Oncogenic HPV were detected using type-specific PCR. Results： β-globin was found in all the brushed samples, whereas it was found in only 68.9% of the FVU specimens. HPV-PCR was positive in 60.0% of the male brushes, in 29% of the female brushes and in 0% of the male FVU specimens. DNA concentration was, respectively, 0.9998 ng/μL, 37.0598 ng/μL and 0.0207 ng/μL. Conclusion： Urine is not a good tool for HPV detection, probably because the low DNA concentration reflects a low amount of collected cells. β-globin is measurable in FVU by real time quantitative PCR, but the DNA concentration is lower compared to brush sampling for both genders. β-globin-positivity of urethral and cervical swabs is 100%, showing a higher mean concentration of DNA, leading to a higher detection rate of HPV. This is the first article linking DNA- concentration to the presence of HPV.

Protective Effect of Distillate and Redistillate of Cow’s Urine in Human Polymorphonuclear Leukocytes Challenged With Established Genotoxic Chemicals

Objective From the ancient period cow’urine has been used as a medicine. In Veda, cow’urine was compared to the nectar. In Susrut, several medicinal properties of cow’ urine have been mentioned and are known to cause weight loss, reversal of certain cardiac and kidney problems, indigestion, stomach ache, edema, etc. However, the literature and scripture did not mention the antigenotoxic properties of cow’urine. Methods In the present investigation, the antigenotoxic/ antioxidant properties of cow’ urine distillate and redistillate were studied in vitro. The antioxidant status and volatile fatty acid levels were determined. Actinomycin-D (0.1ol/L) and hydrogen peroxide (150 mol/L) were used for inducing DNA strand break with 0.1% DMSO as negative control. Dose for the antigenotoxic effect of cow’ urine was chosen from the dose response study carried out earlier. Results Both actinomycin-D and H2O2 caused statistically significant DNA unwinding of 80% & 75% respectively (P<0.001) as revealed by fluorimetric analysis of DNA unwinding (FADU), and the damage could be protected with the redistilled cow urine distillate (1, 50 & 100 ) in simultaneous treatment with genotoxic chemicals. Conclusion The redistillate of cowurine was found to possess total antioxidant status of around 2.6 mmol, contributed mainly by volatile fatty acids (1500 mg/L) as revealed by the GC-MS studies. These fatty acids and other antioxidants might cause the observed protective effects.

Measurement of Orotic Acid in Urine by Supercritical Fluid Chromatography

This work presents a simple, rapid and reliable supercritical fluid chromatography (SFC) method for a sensitive measurement of orotic acid in human urine. The samples were diluted with deionized water and analyzed directly without any pretreatment.