Specimen collection urine

The U.S. Department of Labor (OSHA) has ruled that an employee s exposure to dimethyl acetamide in any 8-h work shift of a 40-h work week shall not exceed a time-weighted average of 10 ppm DMAC vapor in air by volume or 35 mg/m in air by weight (7). If there is significant potential for skin contact with DMAC, biological monitoring should be carried out to measure the level of DMAC metaboHtes in urine specimens collected at the end of the shift. One industrial limit is 40 ppm DMAC metaboHtes, expressed as AJ-methylacetamide [79-16-3] for individuals, and 20 ppm metaboHte average for workers on the job (8). 

Mycobacteria of the Mycobacterium avium complex are implicated in disseminated bacterial infections in AIDS patients. RFLP studies followed by hybridization with radiolabeled probe specific for an insertion sequence in M. avium (IS 1311) have been useful for typing M. avium stains (R2). A variety of molecular techniques are available for the diagnosis of Chlamydia trachomatis infection. In addition to PCR, a method based on the ligase chain reaction has also been found to be sensitive to the detection of C. trachomatis infection in urine specimens collected from male and female subjects (VI). The differentiation between low-risk genotypes of human papilloma virus (HPV 6 or 11) from genotypes of high... 

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... 

A urine specimen, collected from the same volunteer 60 minutes after smoking, was subjected to alka-... 

Figure 43-6 Histogram of the debrisoquine metabolic ratio in a typical Caucasian population. Metabolic ratios were determined from the concentrations of debrisoquine and 4-hydroxydebrisoquine (metabolite) in a urine specimen collected 8 hours after a 10 mg dose of debrisoquine.The data demonstrate a clear distinction between PM, EM, and UM phenotypes. (From Caldwell J. Pharmacogenetics and Individual variation in the range of amino acid adequacy the biological aspects. J Nutr 2004 134 16005 45 discussion 30S-32S, 67S-72S. Reproduced by permission from the American Society for Nutritional Sciences.)...

Fig. 7. Excretion patterns of/l -tetrahydrocannabinol (THC) concentrations (ng/ml) in oral fluid and plasma, and urinary 1 l-nor-9-carboxy-/l -tetrahydrocannabinol (ng THCCOOH/mg creatinine) in one human subject following smoking of a single cannabis cigarette (3.55%). The ng THCCOOH/mg creatinine ratio is illustrated for all urine specimens collected through the last positive specimen. Analyses were performed by GC-MS at cutoff concentrations of 0.5 ng/ml for oral fluid and plasma and 15 ng/ml for urine. (Reproduced from the Journal of Analytic Toxicology by permission of Preston Publications, a division of Preston Industries Huestis and Cone 2004, Fig. 2 therein)...

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... 

Renal Effects. Five hours after a worker was accidentally sprayed in the face with molten MBOCA, his urine contained 220 mg/L of protein, indicating damage to the renal tubules (Hosein and van Roosmalen 1978). However, 11 hours after the accident, there was only a trace of protein in the urine. Two urine specimens collected within 24 hours after the accident had low specific gravities, suggesting that damage to the renal tubules was transitory. The level of exposure was not reported. 

A split specimen is a second urine specimen, collected at the same time as the first, that is sent to the laboratory and retained tmopened. If the employee requests a split-specimen test, the specimen is transported to a second lab for testing. If the driver does request the split specimen be tested you cannot retmm the driver to safety sensitive functions at the time of the request. The driver must stay removed from safety sensitive functions until the results of the split specimen test are reported. 

Spot or timed (24-hr) urine specimens may be assayed. The latter should be collected in acid-washed bottles containing HCl (5 mL, 6 mol/liter). Urine specimens collected without acid should be adjusted with concentrated HCl to pH 3-4 at the time of receipt and before an aliquot is removed for measurement or storage. 

In the acute porphyrias, symptomatic and latent phases alternate, and during the latter, biochemical abnormalities may be only minor or even absent. Therefore, in questionable cases porphyrin precursors and porphyrins should be assessed in a urine specimen collected during a symptomatic period that allows one to prove or exclude the diagnosis. 

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. 

The ratio of Cam/Ccr can be determined on a random urine sample and thus avoids the time, labor, and errors involved in collecting the timed urine specimen required for the urinary amylase determination. 

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. 

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. 

Successive 24-hr urine specimens were provided by each volunteer. Collection in the dosimeter studies began 24 hr prior to the chlorpyrifos exposure (study day 0) and continued for 3 days based upon the 27-hr half-life of chlorpyrifos in humans (Nolan et al., 1984). Pre-exposure controls were obtained in all cases. Total urine volume was measured for each of the days, and 20- to 30-mL portions were stored frozen prior to analysis. The Sacramento collections were 48 hr and the Riverside collections were approximately 84 hr after re-entry. 

With respect to worker safety and re-entry studies, reference substances are necessary to assay the test substance (and, if applicable, any control substance) and determine its stability and for the analyses of specimens collected in the study. Specimens may include plant material (dislodgeable residues), adsorbent media (inhalation), or clothing/dosimeter materials collected during a worker safety study to assess exposure. If biomonitoring is involved, blood and/or urine specimens may be analyzed against reference substances of known purity. 

In environmental health studies conducted near four NPL sites (plus a comparison area for each), ATSDR collected lead concentration data from both environmental media and human body fluids to estimate low-level exposure risk and to document the magnitude of human exposure to lead near those sites. Environmental samples collected at participants homes included drinking water, yard soil, house dust, and house paint body fluids collected from participants included venous blood and urine specimens. For the four sites, mean concentrations of lead in soil ranged from 317 to 529 mg/kg, and mean concentrations of lead in dust ranged from 206 to 469 mg/kg (ATSDR 1995). 

There are stability problems in urines stored for analysis. Fifty percent of delta-aminolevulinic acid was lost in specimens stored without preservative and exposed to light for 24 hours (V3). The loss increased to 80% in 48 hours, 85% in 72 hours, and 95% in 2 weeks. However, the same specimens acidified with tartaric acid and stored in the dark lost 2% of the aminolevulinic acid in 72 hours and 6% in 2 weeks (V3). The destruction of catecholamines collected in nonacidified urine specimens is well documented (Cll). Urinary acid phosphatase was destroyed on freezing (S15). The effect was related to increasing salt concentration during freezing and was prevented by the addition of albumin (S15). 

Collect stool and urine specimens to monitor effectiveness... 

The determination of mandelic acid in urine is recommended as a biological exposure test for ethylbenzene. The Biological Exposure Index (BEI) Committee of the American Conference of Governmental Industrial Hygienists recommends a mandelic acid concentration in urine of 1.5 g/g creatinine [about 10 mmol/L] as a BEI for ethylbenzene exposure. BEIs represent the levels of the determinants that are most likely to be observed in biological samples collected from healthy workers exposed by inhalation to air concentrations at the level of the TLV. Urine specimens must be collected during... 

Urine is collected from patients suspected to have an organic acidemia preferably during an acute metabolic decompensation. As this is often not possible, an early morning specimen should be collected. The sample should be sent frozen and without preservatives. 

In general, untimed urine specimens can be used for this assay. However, preferably 24-h urine samples should be used. Samples should be frozen as soon as possible after collection. 

For collection of dried urine specimens, fresh random urine is processed as described for the liquid specimen (see above). Filter paper strips (3x5 cm, filter paper backing 165-0921, BioRad, Richmond, USA) are dipped into the clear supernatant of the oxidized urine up to 1 cm below the upper edge. Excess urine is wiped off and the filter paper is left to completely dry at room temperature in dim light. The filter strip is then sent to the laboratory in an envelope by express mail. 

Radioactive L-cystathionine (10) (765 mg.) containing 6.85 x 106 counts per minute of S35 was fed to the human cystinuric patient who had served previously as the subject in an experiment demonstrating the formation of cystine from sulfur-labeled methionine (11). The same precautions were followed with regard to human experimentation involving radioactive material as in the latter experiment. After the feeding of the cystathionine, 24-hour urine specimens were collected for 3 days and sulfur distributions were determined by the titrimetric method of Fiske (6). Cystine determinations were carried out by the procedure of Sullivan, Hess, and Howard (12). 

---