Urine specimen

A variety of body fluids can be used for acylcarnitine analysis. While initially the favored specimen, urine acylcarnitine analysis is the least appropriate when an FAO disorder is under diagnostic consideration. Heparinized plasma or whole blood spotted on filter paper are preferred in this context. 

Of 23 indinavir-treated patients with persistent pyuria, four had interstitial nephritis, seven had urothelial inflammation, 10 had both interstitial nephritis and urothelial inflammation, and two had non-specific urinary tract inflammation (26). In all, 21 patients had multinucleated histiocytes identified by cytological testing of urine specimens. Urine abnormalities resolved in all 20 patients who stopped taking indinavir, and pyuria persisted in the other 3. Six patients had raised serum creatinine concentrations, which returned to baseline when indinavir was withdrawn. 

In sum, it becomes clear that the development of MS methods for untargeted metabolomics is complex. Methods should be optimized to each type of specimen (urine, plasma, tissue extracts, etc.) and each application and its results need to be carefully monitored. 

Exactly the same technique (headspace GC) can be applied for the determination of alcohol concentration in other biological specimens (urine, spinal-column fluid, or fluid from the eyes), with the only difference being the standard solutions. 

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). 

Blood and urine are most often analyzed for alcohol by headspace gas chromatography (qv) using an internal standard, eg, 1-propanol. Assays are straightforward and lend themselves to automation (see Automated instrumentation). Urine samples are collected as a voided specimen, ie, subjects must void their bladders, wait about 20 minutes, and then provide the urine sample. Voided urine samples provide the most accurate deterrnination of blood alcohol concentrations. Voided urine alcohol concentrations are divided by a factor of 1.3 to determine the equivalent blood alcohol concentration. The 1.3 value is used because urine has approximately one-third more water in it than blood and, at equiUbrium, there is about one-third more alcohol in the urine as in the blood. 

The iaterpretation of forensic toxicology (18) results is often challenging. Courts frequently ask if an amount of dmg detected ia a specimen could cause a specific type of behavior, ie, would someone be under the influence of a dmg at a specific concentration, would a particular dmg concentration cause diminished capacity, or was the dmg the cause of death In a random employee dmg testing case, a worker screened positive for opiates by EMIT and gc/ms analysis of the urine specimen showed low levels of morphine. Although one possibiUty was that the iadividual was a heroia user, a review of foods eaten ia the prior 24 hours suggested a more innocent cause a poppy-seed bagel. 

Sample Handling System. Venous or capillary blood, urine, and cerebrospinal fluid are specimens routinely used in medical diagnostic testing. Of these biological fluids, the use of venous blood is by far the most prevalent. Collection devices such as syringes and partial vacuum test tubes, eg, Vacutainer, are used to draw ten milliliters or less of venous blood. At collection time, the test tubes are carefully labeled for later identification. 

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. 

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. 

SPEC SPECIMEN, S SERUM, U=URINE, U-D URINE DIALYZED, CSF CEREBROSPINAL FLUID, DF DUODENAL FLUID, ... 

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. 

In this section we first describe some background and case characteristics of the arrestees, and the types of drugs found in their urine specimens. We next describe the persons found to have a urine test positive for PCP and compare them with arrestees having other urine test results. 

Because our subsequent analyses are based upon the urine test results, we present information here only from the subset of arrestees who provided a urine specimen (n=4,847). Other analyses (not presented here) indicate that the persons who provided a specimen were virtually identical on these characteristics to the entire group of persons approached in Central Booking (n=6,406). 

There is some possibility that PCP, like marijuana, may be detected in the urine days or weeks after the last use (Khajawall and Simpson 1983). Thus, a test positive for PCP indicates that the drug was present in the body at the time the specimen was obtained, but does not necessarily mean that the arrestee last used the drug near the time of the crime or the arrest. This may not be too important, however, since the presence of the drug in the body implies a potential effect upon the person. 

For all 12 mother-infant pairs, either the mother or the infant s toxicology report was subsequently positive for PCP. In nine cases, the screens for both mother and infant were positive. In two cases, the mother s results were positive and the infant s were negative. In one case, the infant had a positive result while the mother s test was negative. Test sensitivity, specimen handling procedures, and delays in obtaining specimens undoubtedly contributed to the inconsistency in paired results. Cocaine, codeine, and glutethemide, in addition to phencyclidine, were identified in the urine toxicology screens of two mothers and their neonates. 

Microbiologic studies that allow for direct examination of a specimen (e.g., sputum, blood, or urine) also may aid in a presumptive diagnosis and give an indication of the characteristics of the infecting organism. Generally, microbial cultures are obtained with a Gram stain of the cultured material. 

Example. The plot in Fig. 6 was constructed using the data shown in Table 3. Note that the concentration of the drug in each urine specimen is not the information analyzed. The total amount excreted over each time interval and throughout the entire study must be determined. As a result, the experimental details of a urinary excretion study must be very carefully chosen, and strict adherence to the protocol is required. Loss of a single urine specimen, or even an unknown part of a urine specimen, makes construction of an ARE plot impossible. 

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. 

Besides alkylphosphates, OP metabolism gives rise to the production of other metabolites that can be used as exposure markers (Table 4). Unchanged OP compounds in blood or urine can also be measured to confirm exposure (Table 4), but this method is of limited use for routine biological monitoring of occupational exposure, as OP compounds are rapidly excreted in urine. Moreover, most OP pesticides are unstable, and, with a few exceptions, they are not detectable in biological specimens after a few hours. So far, the measurement of unchanged compounds in biological fluids has been performed primarily for research purposes and has limited practical applicability. 

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. 

This study was conducted to evaluate and compare ADD determined using whole-body dosimetry with results of two situational exposure studies conducted following use of a flea fogger under natural conditions. Chlorpy-rifos was selected due to its general availability as a fogger for indoor flea control. Chlorpyrifos is poorly absorbed by the dermal route and readily cleared from the body in urine (Nolan et al., 1984). Trichloropyridinol was measured in 24-hr urine specimens of the volunteers and was converted to chlorpyrifos equivalents as a measure of absorbed dose. The study provided an opportunity to determine the relationship between intensive, high-contact dosimetry studies and the amounts of chlorpyrifos absorbed by two sets of adults who re-entered fogger-treated homes. 

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. 

Both skin-exposed volunteers and those wearing WBDs were biomonitored for urinary clearance of trichloropyridinol. An unexpected finding was that before exposure (day 0) each 24-hr urine specimen contained measurable... 

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). 

---