The fluorometric procedure of determining coproporphyrin has been adapted to determine coproporphyrin on random urine specimens. This adaptation depends on determining both coproporphyrin and creatinine. A mathematical relationship is established for the amount of coproporphyrin excreted when 1200 mg. of creatinine is excreted. An important advantage of the random procedure is the elimination o...

Two nomograms are given for use in calculating standard, C3, or maximum, Cm, urea clearance. The first nomogram calculates the urine flow rate, f, from the urine collection time and volume data. With the second nomogram, values of f and urea nitrogen concentrations in blood serum (or plasma) and urine are used to calculate either C3 or Cm, according to the value of f. There is no intermediate c...

OBJECTIVE To investigate the incidence, prevalence, and clinical characteristics of diabetes among U.S. non-Hispanic white (NHW) youth. RESEARCH DESIGN AND METHODS Data from the SEARCH for Diabetes in Youth Study (SEARCH study), a multicenter study of diabetes among youth aged 0-19 years, were examined. Incidence rates were calculated per 100,000 person-years across 4 incident years (2002-200...

INTRODUCTION: Analysis of urine is often used to detect the presence or determine the concentration of various biologically active compounds or xenobiotics. Urine has become the preferred specimen since many compounds can be detected for longer time periods in urine than in blood. Furthermore, urine collection does not require phlebotomy, and urine is typically an ample and stable sample. In mo...

Quantification of proteinuria is usually predicated upon 24-hour urine collection. Multiple factors influence urine collection and the rate of protein and creatinine excretion. Urine collection is often incomplete, and therefore creatinine and protein excretion rates are underestimated. A random urine protein-creatinine (P-C) ratio has been shown over the years to be a reliable alternative to t...

OBJECTIVE To evaluate the accuracy of urine sample collection methods among children suspected of having urinary tract infections. SUBJECTS AND METHODS Four methods for urine sample collection were evaluated in 1,067 children aged 0-16 years with suspected urinary tract infections over 2 months at Dr. Sami Ulus Children's Hospital. Within 30 min of collection, all specimens were sent to the l...

BACKGROUND Since seaweed is a common component of the Japanese diet, iodine intake in Japanese is expected to be high. However, urinary iodine excretion, measured using 24-hour urine samples, and its dietary determinants are not known. METHODS Apparently healthy adults aged 20 to 69 years living in 20 areas throughout Japan were recruited in February and March, 2013. Urinary iodine excretion ...

Measurement of creatinine has many applications. We review the determination of urinary creatinine as a valid index of completeness of 24-h urine collection, the clinical utility of the determination of creatinine clearance ratios, and measurement of the ratio of the clearance of specific analytes, such as amylase, to the ratio of clearance of creatinine. The chemistry and variables that affect...

First-void urine (FVU) is the preferred specimen for the diagnosis of urogenital Chlamydia trachomatis infection in men. We have developed FirstBurst, a urine collection device that collects the first 4 to 5 ml of FVU and yields a specimen with a sixfold higher C. trachomatis organism load than the regular urine cup by quantitative PCR (32,533 versus 5,271 plasmids/ml; P < 0.0001). Consequently...