Urine collection

Urine specimens collected overnight at room temperature may lose carbon dioxide or become contaminated with ammonia-producing bacteria this may be indicated by high-alkaline pH. If the urine is not fresh, pH values may also be unreliable. It is preferable not to use liquid preservatives (e.g., toluene), particularly with urine 

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Urine testing can play a role in identifying ketone excretion in patients prone to ketoacidosis. If urine testing is done, it is usually recommended tiiat the nurse use the second voided specimen (ie, fresh urine collected 30 minutes after the initial voiding) to check glucose or acetone levels, ratiier than die first specimen obtained. 

The rate of urine amylase excretion is a sensitive reflection of the amylase released into the blood. The urine amylase remains abnormal 1-2 weeks after the serum returns to normal because the renal clearance of amylase rises 3-fold in acute pancreatitis and takes 1-2 weeks to return to normal. In pancreatitis, a number of investigators have reported a higher percentage of urinary amylase elevations, as contrasted with serum amylase elevations, particularly when the urinary amylase output over an interval is measured. Random urine collections for one, two and 24 hours are 792-4264 (2926 1074 S.D.) units per 24 hours. However, the wide range of normals make interpretation of results difficult. Of 107 patients with elevated serum or urine amylases, 16 were found to have a normal pancreas at operation (78). 

Another option for the researcher is to collect two 12-h urine samples each in 4-L polyethylene urine collection vessels or in large 1-L wide-mouthed polyethylene jars. This allows the researcher to examine the excretion pattern of the active ingredient in two 12-h segments. 

The internal dose (ID) for workers can be calculated by using the analytical data from the urine collection carried out simultaneously with the dosimetry. The calculation of the ID using urine data is complex and will not be dealt with in detail. However, there are several references, that can help guide one through such calculations. Nolan et al have addressed this subject in great detail, as have other researchers. 

FIGURE 5. PCP urinary excretion rate versus the midpoint of the urine collection time in three dogs... 

All patients with ascites require counseling on dietary sodium restriction. Salt intake should be limited to less than 800 mg sodium (2 g sodium chloride) per day. More stringent restriction may cause faster mobilization of ascitic fluid, but adherence to such strict limits is very difficult. Patients usually respond well to sodium restriction accompanied by diuretic therapy.14,22,31,32 The goal of therapy is to achieve urinary sodium excretion of at least 78 mEq (78 mmol) per day.22 While a 24-hour urine collection provides this information, a spot urine sodium/ potassium ratio greater than 1.0 provides the same information and is much less cumbersome to perform. 

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)... 

The primary marker of structural kidney damage is proteinuria, even in patients with normal GFR. Clinically significant proteinuria is defined as urinary protein excretion greater than 300 mg/day or greater than 20 mcg/minute in a timed urine collection. Significant proteinuria can also be determined by a spot urine dipstick greater than 30 mg/dL or... 

Although rarely performed, a 24-hour urine collection can be obtained to determine if the patient is an overproducer or an underexcretor of uric acid. Individuals who excrete more than 800 mg of uric acid in this collection are considered overproducers. Patients with hyperuricemia who excrete less than 600 mg/day are classified as underexcretors of uric acid. 

Because allopurinol (which reduces uric acid production) is effective in both overproducers and underexcretors and is generally well tolerated, many clinicians forgo the 24-hour urine collection and treat patients empirically with it. 

Formula for Estimating Creatinine Clearance from a Measured Urine Collection... 

The product of U X V equals the production of creatinine during the collection period and, at steady state, should equal 20 to 25 mg/kg per day for ideal body weight (IBW) in males and 15 to 20 mg/kg per day for IBW in females. If it is less than this, inadequate urine collection may have occurred, and CrCl will be underestimated. 

Diabetic Rats-Phase I. Laboratory rats (CD strain, 250-300g, male) were made diabetic by a single injection of streptozotocin (STZ), 50 mg/kg, into the tail vein. Nondiabetic controls received an equal volume of citrate buffer. Twenty-four hours after the STZ injection, each rat was individually housed for urine collection. The appearance of glucose in the urine (Ames test strips) and a predictable weight loss or depression of the growth curve were taken as confirming evidence of diabetes. 

Cyclotriphosphazene was not detected by gas chromatography in urine collected for 24 hours after occluded dermal exposure of rats to a hydraulic fluid containing 99.9% cyclotriphosphazene (Kinkead and... 

It must be assumed that urine collections were accurately timed and that complete urine specimens were obtained at each collection time. It is also assumed that the assay procedure is accurate and reproducible. 

Under field exposure conditions, it is recommended to measure PA herbicides in 24-hr urine samples collected starting at the end of the work-shift. Spot samples collected at the end of exposure or the following morning can be used when a 24-hr urine collection is impractical. In this case, the concentration of the compounds should be normalized to creatinine concentration or adjusted for specific gravity. 

Biomonitoring Urine collection of 12-hr samples over a 6-day period (-1, 0,1, 2, 3, 4 days)... 

To monitor the absorbed chlorpyrifos doses in human volunteers, urine was collected before and following a 4-hr activity period on the treated grass surface(re-entry). The urine was analyzed for 3,5,6-trichloropyridinol (3,5,6-TCP), the urinary metabolite of chlorpyrifos, and creatinine, which was determined to verify completeness of urine collection by each volunteer. 

Analysis of the urinary data. The amount of creatinine and 3,5,6-TCP in each urine collection was calculated from the volume of the urine specimen and the concentration of each in that urine specimen. The amount of creatinine excreted per day was compared across days for each volunteer and to standard literature values for creatinine excretion (i.e., mean 1.8 g/24 hr 95% range, 1.1 to 2.5 g/24 hr). The urine collection was considered to be complete if the amount of creatinine was consistent with the amount of creatinine in the other urine specimens provided by that individual and within the literature range for normal creatinine excretion. 

The internal dose of propoxur was measured by assessing the total amount of 2-isopropoxyphenol (IPP) excreted in the urine, collected over a period of 24 hr from the start of exposure, and described in detail in previous studies (Brouwer et al., 1993 Meuling et al., 1991). Volunteer kinetics studies revealed a one-to-one relationship of absorbed propoxur and excreted IPP on a mole basis. Based on the results by Machemer et al. (1982), a pulmonary retention of 40% was used to calculate the relative contribution of the respiratory exposure to the internal exposure. To estimate the contribution of the dermal exposure, the calculated respiratory portion was subtracted from the total amount of IPP excreted in urine. 

Although the measurement of GFR with inulin is quite accurate, it is inconvenient because it requires the continuous infusion of this exogenous substance for several hours. More often, in clinical situations, the plasma clearance of creatinine is used to estimate GFR. Creatinine, an end-product of muscle metabolism, is released into the blood at a fairly constant rate. Consequently, only a single blood sample and a 24-h urine collection are needed. Measurement of the plasma clearance of creatinine provides only an estimate of GFR in fact, this measurement slightly overestimates it. A small amount of creatinine is secreted into the urine (about 10% on average). In other words, the concentration of creatinine in the urine is the result of the amount filtered (as determined by GFR) plus the amount secreted. 

Ohzawa et al. [Ill] studied the metabolism of miconazole after a single oral or intravenous administration of 14C miconazole at a dose of 10 mg/kg. After 1 h oral or intravenous administration to male rats, the four known metabolites besides the unchanged form were observed in the plasma, and the five unknown metabolites were observed in the plasma. At 24 h, metabolites were not detected in plasma except one of the known metabolites. After oral administration to female rats, the unchanged form and four of the known metabolite along with one of the unknown metabolites were observed in the plasma, but one of the known metabolites and three of the unknown metabolites were not detected. After oral or intravenous administration to male rats, two of the known metabolites and five of the unknown metabolites were observed in the urine collected until 24 h. After oral or intravenous administration to male rats, four of the known metabolites and five of the unknown metabolites and one of the known metabolites besides the unchanged form were observed in the feces collected until 24 h. The fecal excretion of the major known metabolite, within 24 h after oral or intravenous administration was 19.4% or 13.3% of the administered radioactivity, respectively. One of the unknown metabolite was isolated from plasma after oral administration to female rats. 

EPO is present in serum and (at very low concentrations) in urine, particularly of anaemic individuals. This cytokine/hormone was first purified in 1971 from the plasma of anaemic sheep, and small quantities of human EPO were later purified (in 1977) from over 2500 1 of urine collected from anaemic patients. Large-scale purification from native sources was thus impractical. The isolation (in 1985) of the human EPO gene from a genomic DNA library facilitated its transfection into CHO cells. This now facilitates large-scale commercial production of the recombinant human product (rhEPO), which has found widespread medical application. 

Intravenous or intramuscular injection urine collected over 24-h period after single application of radiolabeled famphur Intramuscular injection Urinary radioactivity was due to the unchanged O-desmethyl compound (13-24%) A/,/V-dimethyl sulfamoylphenyl glucuronide (32-33%) O./V-bisdesmethylfamphur (31-34%) and /V-methyl sulfamoylphenyl glucuronide (8—15%) 8... 

Every time measured urine collection performed Every time measured urine collection performed Daily... 

Step 2 Estimate creatinine clearance Use CockcrofKiault equation to estimate creatinine clearance or calculate creatinine dearance from timed urine collection... 

Our recent NSF-funded collaboration with Bets has yielded, for example, the first statistically significant evidence that male African elephants can distinguish conspecific female urine collected at the time of ovulation from urine obtained at the mid-luteal time of the estrous cycle (Bagley, Goodwin, Rasmussen and Schulte 2006). Additionally, we have published the first report of insect pheromones in the urine of female African elephants (Goodwin, Eggert, House, Weddell, Schulte and Rasmussen 2006). These findings bode well for the eventual discovery of the first African elephant pheromones. 

According to Stein (S8), 1761-2459 mg of amino adds appears in 24 hours urine collection from normal subjects after its acid hydrolysis. The estimations performed by Muting (M4) showed that the average content of amino acids in 24-hour specimens of urine derived from 20 normal males and the same number of normal female subjects was 2221 and 2288 mg, respectively. The results of these two authors do not, however, represent exclusively the amount of peptide-bound amino acids, but rather the whole of these compounds liberated as a result of the acid... 

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. 

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