SOLVOLYSABLE DEOXYCORTICOSTERONE CONJUGATES IN HUMAN URINE

1976 ◽  
Vol 68 (2) ◽  
pp. 273-281 ◽  
Author(s):  
C. L. COPE ◽  
S. LOIZOU
Keyword(s):  
Human Urine ◽  
Room Temperature ◽  
Urine Samples ◽  
Variable Ratio ◽  
The Mean ◽  
Sulphate Conjugate ◽  
Urine Specimens

SUMMARY The nature of the urinary conjugate converted by solvolysis, to free unconjugated deoxycorticosterone (DOC) was studied. A comparison of 11 solvolysis techniques has shown that the method employed in this study yielded 86% of the highest yield by any of the techniques tried. Three successive chromatographic systems on paper showed that no appreciable amounts of contaminants were present in the free DOC eluates, following solvolysis. By preparing authentic [3H]DOC sulphate and subjecting it to solvolysis it was shown that more than 90% of the tritiated DOC was recovered, after chromatography of the free DOC extract. This suggests that much of the solvolysable DOC in human urine is present in the form of the sulphate conjugate. The levels of DOC, excreted as the solvolysable conjugate in a variety of urine specimens, were shown to be much higher than those of free DOC, the former being 4·8 to 127 times higher than the amount of the latter. This highly variable ratio suggests that the site of production of solvolysable DOC is different from that for free DOC. The only correlation between free and solvolysable DOC was shown in dexamethasone-suppressed patients, in whom the mean percentage remaining after suppression was 30·6% for free DOC, 24·1% for solvolysable DOC and 22·2% for cortisol. As solvolysable DOC is present in much larger amounts in urine, care is necessary in the storage of urine samples in which free DOC estimates are to be made, as we found that urine specimens left at room temperature for 1 week could show rises of as much as 400% of their starting free DOC levels.

New sandwich ELISA for human urinary N-acetyl-β-d-glucosaminidase isoenzyme B as a useful clinical test

1997 ◽  
Vol 43 (4) ◽  
pp. 569-574 ◽  
Author(s):  
Yoshito Numata ◽  
Atsushi Morita ◽  
Yoko Kosugi ◽  
Kazunori Shibata ◽  
Nozomu Takeuchi ◽  
...  
Keyword(s):  
Human Urine ◽  
Sandwich Elisa ◽  
Sample Volume ◽  
Mean Value ◽  
Cross Reactivity ◽  
Urine Samples ◽  
Clinical Test ◽  
The Mean ◽  
Dilution Curves

Abstract We have developed a new ELISA for quantifying N-acetyl-β-d-glucosaminidase (NAG) isoenzyme B in human urine after raising monoclonal antibodies against the isoenzyme from human placenta. Though the obtained antibodies reacted not only to isoenzyme B but also to A, we could detect isoenzyme B selectively by a two-step sandwich ELISA with a pair of selected antibodies at low pH in the first reaction. The detected limit was 0.5 μg/L for a sample volume of 25 μL. Within-run CVs ranged from 2.5% to 5.4% and between-run CVs ranged from 6.2% to 9.1%. Recoveries of NAG isoenzyme B added to each of three urine samples ranged from 91% to 114%. The dilution curves of urine samples showed good linearity. The cross-reactivity of NAG isoenzyme A was practically negligible (2–3%). The mean value for NAG isoenzyme B in spot urines from healthy adults was 2.9 μg/g creatinine. This ELISA method is rapid and precise enough for routine determination of NAG isoenzyme B in human urine.

Stability of ascorbate in urine: relevance to analyses for ascorbate and oxalate.

1985 ◽  
Vol 31 (10) ◽  
pp. 1703-1705 ◽  
Author(s):  
A H Chalmers ◽  
D M Cowley ◽  
B C McWhinney
Keyword(s):  
Room Temperature ◽  
Final Concentration ◽  
Disodium Edta ◽  
Ph Values ◽  
Ascorbate Concentration ◽  
The Mean ◽  
Urine Specimens

Abstract Ascorbate is unstable in urine at room temperature at pH values ranging from 1 to 12. At pH 7 and above, oxalate is generated in amounts directly proportional to the ascorbate concentration. In 12 different urines, adjusted to pH 12 and incubated for 20 h at room temperature, there was a significant correlation between the amount of oxalate formed and the initial ascorbate concentration (r = 0.97, p less than 0.01). The mean (+/- SD) concentration of oxalate (1.32 +/- 0.70 mmol/L) formed during this period approximated the initial ascorbate concentration (1.57 +/- 1.09 mmol/L). Disodium EDTA, 10 mmol/L final concentration, stabilizes ascorbate in urine and inhibits its conversion to oxalate at pH values of 4.4 to 7.0 during a 24-h period. We therefore propose that urine specimens for ascorbate and oxalate analyses be collected with disodium EDTA present such as to give about this final concentration.

scholarly journals High Throughput Quantitative Bioanalytical LC/MS/MS Determination of Gemifloxacin in Human Urine

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Adnan A. Kadi ◽  
Rihab F. Angawi ◽  
Mohamed W. Attwa ◽  
Hany W. Darwish ◽  
Ali Saber Abdelhameed
Keyword(s):  
Human Urine ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
Urine Samples ◽  
Triple Quadrupole Mass Spectrometer ◽  
Mass Spectrometer System ◽  
The Mean ◽  
Syringe Filter ◽  
Spectrometer System

A highly specific, sensitive, and rapid method, to quantify gemifloxacin in human urine using HPLC coupled to the triple quadrupole mass spectrometer system, was developed and validated. Gemifloxacin and ofloxacin (internal standard) were rapidly extracted from urine samples without any tedious pretreatment procedure. Urine samples were filtered through a Millex-GP, 0.22 μm syringe filter. Optimal chromatographic separation of the analytes was achieved on Zorbax SB-C18(30 mm × 2 mm i.d., 3.5 μm maintained at ambient temperature). The mobile phase consisted of 0.1% formic acid (pH 3.2) and acetonitrile (80 : 20) and a flow rate of 0.2 mL min−1for 4 min. The analytes were monitored by electrospray ionization in positive ion multiple reaction monitoring mode. The method provided a linear response (r=0.9998) from a quantitation range of 5 ng mL−1to at least 500 ng mL−1. The mean extraction recovery % of gemifloxacin from spiked human urine was 101.33 ± 2.58%. The reproducibility of the method was reliable with the intra- and inter-day precision of <2% and accuracy within 2%. The established method was reliably applied for the determination of gemifloxacin in volunteers’ urine samples with the mean recoveries of gemifloxacin from Factive tablets 320 mg > 97.0%.

scholarly journals Evaluation of an ELISA for metanephrines in feline urine

2018 ◽  
Vol 30 (6) ◽  
pp. 887-893
Author(s):  
Thanikul Srithunyarat ◽  
Anna Svensson ◽  
Sofia Hanås ◽  
Odd V. Höglund ◽  
Ragnvi Hagman ◽  
...  
Keyword(s):  
Neuroendocrine Tumors ◽  
Home Environment ◽  
Human Urine ◽  
Room Temperature ◽  
Storage Time ◽  
Stability Study ◽  
Urine Samples ◽  
Urine Sampling ◽  
The Stability ◽  
And Storage

Catecholamines can be used to evaluate neuroendocrine tumors, stress, and potentially pain, but catecholamines degrade rapidly. Their metabolites normetanephrine (NME) and metanephrine (ME) have better stability in urine. In cats, urine sampling in a home environment would be beneficial to reduce effects of clinical stress and simplify sampling. We evaluated a human urine ELISA for analysis of NME and ME in feline urine, and investigated the effects of acidification, cat tray pellets, and storage time at room temperature up to 8.5 h. In 26 feline urine samples, mean NME concentration was 192 ± 80 ng/mL, mean intra- and inter-assay CV was 6.5% and 4.2%, respectively, and spike recovery was 98–101%, but dilutional recovery was unsatisfactory. For ME, mean intra- and inter-assay CV was 10.2% and 4.1%, respectively. Mean urine ME concentration was 32.1 ± 18.3 ng/mL, close to the kit’s lowest standard, and spike recovery was 65–90%; the ELISA could not be validated for ME. The stability study, performed for NME on 12 urine samples, did not identify differences between acidified and non-acidified samples, cat tray pellets, or storage time, and no interaction effects. The ME ELISA was not suitable for feline urine; performance of the NME ELISA was acceptable, except for dilution recovery. For analysis of NME, feline urine can be sampled at home using cat tray pellets and stored at room temperature up to 8.5 h without acidification.

A fast and sensitive nanosensor based on MgO nanoparticle room-temperature ionic liquid carbon paste electrode for determination of methyldopa in pharmaceutical and patient human urine samples

Ionics ◽  
2013 ◽  
Vol 19 (12) ◽  
pp. 1907-1914 ◽  
Author(s):  
Javad Vahedi ◽  
Hassan Karimi-Maleh ◽  
Mehdi Baghayeri ◽  
Asfaneh L. Sanati ◽  
Mohammad A. Khalilzadeh ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Carbon Paste Electrode ◽  
Human Urine ◽  
Room Temperature ◽  
Urine Samples ◽  
Carbon Paste ◽  
Liquid Carbon ◽  
Paste Electrode ◽  
Mgo Nanoparticle

The Effect of Storing Temperature and Duration on Urinary Hydration Markers

2017 ◽  
Vol 27 (1) ◽  
pp. 18-24 ◽  
Author(s):  
J.D. Adams ◽  
Stavros A. Kavouras ◽  
Evan C. Johnson ◽  
Lisa T. Jansen ◽  
Catalina Capitan-Jimenez ◽  
...  
Keyword(s):  
Specific Gravity ◽  
Urine Sample ◽  
Human Urine ◽  
Room Temperature ◽  
Storage Temperature ◽  
Urine Specific Gravity ◽  
Urinary Sediment ◽  
C Storage ◽  
Urine Color ◽  
Urine Specimens

The purpose of this investigation was to quantify the effects of storage temperature, duration, and the urinary sediment on urinary hydration markers. Thirty-six human urine samples were analyzed fresh and then the remaining sample was separated into 24 separate vials, six in each of the following four temperatures: 22 °C, 7 °C, -20 °C, and -80 °C. Two of each sample stored in any given temperature, were analyzed after 1, 2, and 7 days either following vortexing or centrifugation. Each urine sample was analyzed for osmolality (UOsm), urine specific gravity (USG), and urine color (UC). UOsm was stable at 22 °C, for 1 day (+5–9 mmol∙kg-1, p > .05) and at 7 °C, UOsm up to 7 days (+8–8 mmol∙kg-1, p > .05). At -20 and -80 °C, UOsm decreased after 1, 2, and 7 days (9–61 mmol∙kg-1, p < .05). Vortexing the sample before analysis further decreased only UOsm in the -20 °C and -80 °C storage. USG remained stable up to 7 days when samples were stored in 22 °C or 7 °C (p > .05) but declined significantly when stored in -20 °C, and -80 °C (p < .001). UC was not stable in any of the storing conditions for 1, 2, and 7 days. In conclusion, these data indicate that urine specimens analyzed for UOsm or USG remained stable in refrigerated (7 °C) environment for up to 7 days, and in room temperature for 1 day. However, freezing (-20 and -80 °C) samples significantly decreased the values of hydration markers.

scholarly journals Quantification of normetanephrine in canine urine using ELISA: evaluation of factors affecting results

2021 ◽  
pp. 104063872110529
Author(s):  
Katja Höglund ◽  
Hanna Palmqvist ◽  
Sara Ringmark ◽  
Anna Svensson
Keyword(s):  
Human Urine ◽  
Room Temperature ◽  
Plasma Catecholamines ◽  
Urine Samples ◽  
Factors Affecting ◽  
Low Concentration ◽  
Elisa Kit ◽  
Healthy Dogs ◽  
Temperature Storage ◽  
Positive Controls

Catecholamine release increases in dogs with pheochromocytomas and in situations of stress. Although plasma catecholamines degrade rapidly, their metabolites, normetanephrine (NME) and metanephrine (ME), are stable in acidified urine. Our aim was to verify a human urine ELISA kit for the quantification of NME and ME in canine urine and to determine the effects on metabolite stability of sampling time (morning or midday) and day (ordinary or day spent in a clinic). We analyzed 179 urine samples from 17 healthy dogs. For NME, the mean intra-assay CV was 6.0% for all samples and 4.3% for the canine control; inter-assay CVs were 3.3, 3.8, and 12% for high and low concentration human urine positive controls supplied in the ELISA kit and a positive canine control, respectively; spike-recovery was 90–101%. For ME, mean intra-assay CV was 6.5% for samples and 9.0% for the canine control; inter-assay CVs were 12.7, 7.2, and 22.5% for high and low concentration human urine positive controls supplied in the ELISA kit and a positive canine control, respectively; spike-recovery was 85–89%. Dilution recovery was unsatisfactory for both metabolites. Based on our verification results, NME was selected for remaining analyses. We found no effect on NME concentrations of acidification or room temperature storage for up to 24 h. The NME:creatinine ratio was higher after the first of 3 clinic days compared to the same morning (111.2 ± 5.5 vs. 82.9 ± 5.3; p < 0.0001), but not on the other days. NME verification results were generally superior to ME. Dilution studies were unsatisfactory for both metabolites. Given that NME was stable without acidification at room temperature, urine samples can be collected at home. The clinic environment can cause higher NME:creatinine ratios, especially in unaccustomed dogs.

HYPEROESTROGENISMUS AND RHEUMATOID ARTHRITIS

1960 ◽  
Vol XXXIV (I) ◽  
pp. 45-50 ◽  
Author(s):  
J. L. Kalliomäki ◽  
Lauri Rauramo
Keyword(s):  
Rheumatoid Arthritis ◽  
Cervical Cancer ◽  
Urine Samples ◽  
Menstrual Bleeding ◽  
Menstrual Phase ◽  
Joint Symptoms ◽  
The Mean

ABSTRACT The authors have endeavoured to clarify the frequency of the hyperoestrogenismus syndrome in women with rheumatoid arthritis, aged 17–38 years, by means of clinical and cytologic studies, and by hormonal analyses. The material comprises 32 patients. Of these, 30 were suitable for cytologic observation. In 5 (17 %) of these 30 patients, the hyperoestrogenismus syndrome (17 %) may be considered definitely established. Aggravation of the joint symptoms in the pre-menstrual phase was reported by 41 % of the patients. Values for excretion of oestrogen exceeding 200 mouse units/24 hours were noted one week before menstrual bleeding in 8 of 19 women; the mean for oestrogen excretion was 268 mouse units/24 hours. Gonadotrophins were studied in the same urine samples, and the mean excretion was 22 mouse units/24 hours (range 7–65 m. u.). The excretion mean for 17-ketosteroids, simultaneously studied, was 9.1 mg/24 hours (range 2.3–18.0 mg). Side-finding in the material were made: incipient cervical cancer in one patient, ovarial tumour in one, and trichomoniasis in seven.

The influence of taurine and L-carnitine on 6 β-hydroxycortisol/cortisol ratio in human urine of healthy volunteers

2019 ◽  
Vol 34 (3) ◽  
Author(s):  
Anna A. Makhova ◽  
Eugenia V. Shikh ◽  
Tatiana V. Bulko ◽  
Zhanna M. Sizova ◽  
Victoria V. Shumyantseva
Keyword(s):  
Catalytic Activity ◽  
Healthy Volunteers ◽  
Human Urine ◽  
Biologically Active Compounds ◽  
Biologically Active ◽  
Metabolic Ratio ◽  
Urine Samples ◽  
Cyp3a4 Activity ◽  
Active Compounds ◽  
Cortisol Ratio

Abstract Background Cytochrome P450s (CYPs, EC 1.14.14.1) are the main enzymes of drug metabolism. The functional significance of CYPs also includes the metabolism of foreign chemicals and endogenic biologically active compounds. The CYP3A4 isoform contributes to the metabolism of about half of all marketed medicinal preparations. The aim of this study was to investigate the effects of two biologically active compounds: 2-aminoethane-sulfonic acid (taurine) and 3-hydroxy-4-trimethylaminobutyrate (L-carnitine) on urinary 6β-hydroxycortisol/cortisol (6β-OHC/cortisol) metabolic ratio as a biomarker of the CYP3A4 activity of healthy volunteers. Taurine is used for the treatment of chronic heart failure and liver disease. Cardiologists, nephrologists, neurologists, gerontologists in addition to the main etiopathogenetic therapies, use L-carnitine. The quantification of the 6β-OHC/cortisol metabolic ratio as a biomarker of CYP3A4 activity in human urine was used for the assessment of CYP3A4 catalytic activity as a non-invasive test. Methods The study included 18 healthy male volunteers (aged from 18 to 35 years old). The volunteers took taurine in a dose of 500 mg twice a day or L-carnitine in a dose of 2.5 mL 3 times a day for 14 consecutive days. The test drug was given 20 min before meals. The collection of urine samples was performed before and after 3, 7, 10, and 14 days after taurine intake. The metabolic ratio of 6β-OHC/cortisol in morning spot urine samples was studied by the liquid chromatography/mass spectroscopy (LC/MS) method. Results The ratio of 6-6β-OHC/cortisol was used as a biomarker to study the taurine and L-carnitine influence on CYP3A4 metabolism of cortisol. The ratio of urinary 6β-OCH/cortisol in the morning urine samples of volunteers before the beginning of taurine therapy (baseline ratio) was 2.71 ± 0.2. Seven days after the administration of taurine in a dose of 500 mg twice a day, the 6β-OCH/cortisol ratio was 3.3 ± 0.2, which indicated the increased catalytic activity of CYP3A4 towards cortisol. As for the L-carnitine supplementation, analysis of the 6β-OCH/cortisol ratio in the urine for 14 days did not show any significant changes in this baseline ratio, indicating the lack of L-carnitine influence on the catalytic activity of CYP3A4 to cortisol. Conclusions The results obtained demonstrated the influence of taurine on 6β-OCH/cortisol metabolic ratio as a biomarker of CYP3A4 catalytic activity to cortisol. L-carnitine did not affect the activity of CYP3A4. The lack of a clinically meaningful effect of L-carnitine was established.

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