Urine 24-hour collection

Urine may be collected for assays of enzyme activities following cleansing of the genitalia with mild antiseptic soap followed by rinsing with water. The urine is collected in a chemically clean container with no preservative. As the activity of urinary enzymes is a function of the volume of the specimen it is important to time the collection accurately. A collection period of 8 hours is quite adequate, and the use of longer periods is not desirable because enzyme activities can rapidly decrease in the relatively hostile medium of the urine. The urine should be refrigerated and transferred promptly to the laboratory, where it should also be processed promptly. 

Ucr = urine creatinine concentration, mg/dL V = volume of urine, mL Scr = serum creatinine concentration, mg/dL T = time of urine collection, minute (Note time equals 1440 minutes for a 24-hour collection)... 

No data were located regarding absorption in animals after inhalation exposure to organophosphate ester hydraulic fluids or specific organophosphate esters, except for the observation that parent material was not detected by gas chromatography in the blood or urine of male rats exposed to 5,120 mg/m3 of an aerosol of a cyclotriphosphazene (99.9%) hydraulic fluid for 4 hours, thereby suggesting that the extent of absorption was limited (Kinkead and Bashe 1987). Blood samples were collected at 0, 24, and 48 hours after exposure was terminated. Urine was collected for 24 hours after exposure. 

When male Wistar rats were exposed to -hexane at concentrations up to 3,074 ppm for 8 hours, analysis of urine showed that 2-hexanol was the major metabolite, accounting for about 60-70% of the total metabolites collected over the 48-hour collecting period (Fedtke and Bolt 1987). This is in contrast to humans, in which the major urinary metabolite is 2,5-hexanedione (Perbellini et al. 1981). The amounts of metabolites excreted were linearly dependent on the exposure concentration, up to an exposure of about 300 ppm. 2-Hexanol and 2-hexanone were detected in the first sample (obtained during the 8-hour exposure) excretion of 2,5-hexanedione was delayed and was not detected until 8-16 hours after exposure began. The amount of 2,5-hexanedione detected depended on sample treatment total excreted amounts over 48 hours were approximately 350 g/kg 2,5-hexanedione without acid treatment and 3,000 g/kg with total acid hydrolysis, indicating conversion of 4,5-dihydroxy-2-hexanone with acid treatment. 

The effect of concentration on the fate of [14C] -hexane after inhalation exposure has been studied in Fischer 344 rats (Bus et al. 1982). The disposition of radioactivity was dose-dependent, with 12, 24, 38, and 62% of the acquired body burden excreted as -hexane by the lung with increasing exposure concentration (500, 1,000, 3,000, and 10,000 ppm, respectively). In contrast, 38, 31, 27, and 18% of the body burden of radioactivity was recovered as expired C02 and 35, 40, 31, and 18% was recovered in the urine with increasing -hexane concentration (expired air and urine were collected for 72 hours after exposure). Radioactivity remaining in the tissues and carcass 72 hours after exposure represented 6.1, 8.8, 7.4, and 5.4% of the body burden for the respective exposures. The dose-dependent elimination of radioactivity was apparently due in part to an inhibition of -hexane metabolism reflected by a decrease in total 14C02 and urinary 14C excretion after 10,000 ppm exposure compared to the 3,000 ppm exposure. Half-lives for excretion were estimated from the data. Urinary half-time for excretion of radioactivity was 12.7 hours at 500 ppm. 

Methods and Experimental. In the study reported by Beecher et al. (17), nine men aged 23-39 years served as subjects. On the day prior to the initiation of the first experiment, the subjects selected their day s meals from a limited menu. The quantity and choice of foods were then repeated on each subsequent pre-experimental day. The subjects fasted overnight, voided upon rising and then drank 300 ml of water. Upon arrival at the research center (0730-0830 hrs), fasting blood was drawn and urine collected. The subjects then ingested one of the liquid meals and drank 200 ml of water. The subjects also drank 200 ml of water each 1/2 hour during the duration of the experiment to induce diuresis. Blood was drawn at 1/2, 1, 2, and 3 hours post-meal urine was collected at each 1/2 hour for 3 hours post-meal. Seven to 14 days elapsed between experiments. 

The serum creatinine concentration of a human volunteer was found to be 1.2 mg/dL. Over a 24-hour period, 1.6 L of urine was collected and the concentration of creatinine in urine was found to be 98 mg/dL. What is the creatinine clearance of the volunteer ... 

Urine was collected into individual test tubes at one hour... 

Suppression tests For Cushing syndrome, give 1 mg at 11 pm. Draw blood for plasma cortisol determination the following day at 8 am. For greater accuracy, give 0.5 mg every 6 hours for 48 hours. Collect 24-hour urine to determine 17-hydroxycorticosteroid excretion. 

Therapy may be monitored with a 24-hour urinary copper analysis periodically (ie, every 6 to 12 months). Urine must be collected in copper-free glassware. Because a low copper diet should keep copper absorption down to less than 1 mg/day, the patient probably will be in the desired state of negative copper balance if 0.5 to 1 mg of copper is present in a 24-hour collection of urine. 

Urinary diterpenes excretion. Absorption and excretion of the cholesterol-raising coffee diterpenes cafestol and kahweol were observed in nine healthy patients with ileostomies. Ileostomy effluent was collected for 14 hours, and urine was collected for 24 hours. Approximately 70% of the ingested cafestol and kahweol was absorbed. Only small part of the diterpene was excreted as a conjugate of glucuronic acid or sulphate in urine, mean excretion was 1.2% of the ingested amount for cafesterol and 0.4% for kahweol . 

Erasure. Only one biomarker of exposure, HD A, was located in the surveyed literature (Brorson et al. 1990). This biomarker may be some use for acute-duration exposmes, but only if urine is collected from the exposed person within 6-12 hours after exposure. No reliable biomarkers of exposure are available for chronic, low-level exposures in humans, although blood immunoglobulins (in particular IgG) may be useful in determining exposures to the diisocyanates as a group, and not a specific exposme to HDl. Studies to determine other biomarkers that would be sensitive enough to detect chronic, low-level exposures to HDl/HDl prepolymers and be specific to HDl only, with low cross-reactivity to other diisocyanates, would be extremely useful, and would enhance the database. 

A controlled dermal exposure study was conducted recently at Oregon State University in which 2,1, 5-T ester formulation was applied to the skin of humans (lU) Four concentrations of 2,1+,5-T ester emulsion were applied to the point of runoff on bleached denim patches, 900 square centimeters in area. The patches were then held in close contact with the skin on the upper thigh of four volunteers, including one woman. The patches were removed after 2 hours and total urine was collected for 5 days. As shown in Table IV, less than 0.5% of the applied 2,U,5-T was absorbed from the cloth, even when soaked with concentrated spray solutions. 

Figure 1 1H NMR spectra of urine obtained from a rat before and after oral administration of galactosamine (500mg/kg). Urine was collected over a 24-hour period and prepared for NMR analyses (600 mHz) following addition of an internal standard (3-trimethylsilyl propionic acid).

An acute, oral dose of radioactive chromium(III) as chromium chloride or chromium(VI) as sodium chromate was administered to humans after which feces and urine were collected for 24 hours and 6 days, respectively, and analyzed for chromium. The amount of chromium in the 6-day fecal collection was 99.6 and 89.4% of the dose for chromium(ni) and chromium(VI) compounds, respectively. The amount of chromium in the 24-hour urine collection was 0.5 and 2.1% of the dose for chromium(ni) and chromium(VI) compounds, respectively (Donaldson and Barreras 1966). In subjects drinking 0.001-0.1 mg chromium(VI)/kg/day as potassium chromate in water for 3 days, <2-8% of the dose was excreted in the urine (Finley et al. 1997). The percentage of the dose excreted appeared to increase with increasing dose. 

Urine samples collected from two human subjects, prior to (minus 24 to 0 hours) and after (plus 2 to 6 hours) oral administration of 30 mg A9-THC, were hydrolyzed and extracted as described in the experimental section. Pre- and post-drug extracts corresponding to equivalent urinary creatinine levels were separated by reverse phase HPLC. The pre-drug extract was used as a... 

The assay was also used for the measurement of THC-CRC levels in plasma and 24-hour urine specimens collected following the smoking of a cigarette impregnated with 5 mg pure THC by each of 4 volunteers (12). Figure 7 shows the plasma levels detected in each of the volunteers. As a comparison the plasma THC level in a car driver fatally injured in a traffic accident (13) was measured. The driver s plasma level of... 

Either 24 hour urine collection or timed urine samples collected at the same time each day is recommended, with the activity expressed per unit of time (Price 1982, Plummer et al. 1986). If the assessment is to be repeated with time, the samples should be collected over the same time period on each day because there is pronounced diurnal variation in excretion rate of some enzymes (Maruhn et al. 1977, Price 1982, Gossett et al. 1987). For spot urine samples or those where accurate timed collection is not possible, normalization of activity per unit of creatinine can be done and this has been shown to be reasonably well correlated to 24 hour enzyme activity (Vanderlinde 1981, Grauer et al. 1995). Diet and age-matched controls must be included if enzyme activity is to be normalized to creatinine, to control for the effects of these variables on creatinine excretion (Plummer et al. 1986, Casadevall et al. 1995). 

Blood for serum creatinine is collected at various time intervals up to 12 months. In association with this, 24-hour urines are collected for measurement of creatinine, protein, and specific gravity. 

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