Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “URINATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources
PubMed1989

Oxalate is overestimated in alkaline urines collected during administration of bicarbonate with no specimen pH adjustment.

We compared measurements of daily urine oxalate excretion in urines collected at the prevailing urine pH with measurements of urine oxalate excretion in urines collected into 20 mL of 6 mol/L HCl. We studied eight healthy adults fed constant diets. Urines were collected during control conditions and, in each subject, during the administration of NaCl, KCl, NaHCO3, or KHCO3, 90 mmol/day. Daily urine oxalate excretion calculated for collections made in acid averaged 271 (SD 79) mumol/day and did not vary with any of the salt supplements. When urines were collected at ambient urine pH (average 5.94, SD 0.23) during control conditions, and during the administration of NaCl or KCl, urine oxalate excretion averaged 263 (SD 88) mumol/day, a value not different from that for collections in acid. However, when urine was collected with no pH adjustment during NaHCO3 or KHCO3 administration (average pH 6.90, SD 0.14), apparent urine oxalate excretion averaged 398 (SD 132) mumol/day, significantly (P less than 0.025) exceeding the mean observed when urines were collected in acid. Moreover, the percentage increase in apparent oxalate excretion increased with urinary pH. These observations reinforce recommendations that urine specimens for measurement of oxalate be collected in acid to avoid the increase in apparent oxalate content that occurs during collection of alkaline urines. This increase presumably results from the well-known in vitro nonenzymatic conversion of ascorbate to oxalate.

Adult↗
PubMed1995

A prospective study of microorganisms in urine and bladder biopsies from interstitial cystitis patients and controls.

OBJECTIVES: Interstitial cystitis (IC) is a chronic inflammatory condition of the bladder of unknown etiology. We tested the hypothesis that a microorganism would be found at higher prevalence in urine or bladder tissue from women with IC than from control women. METHODS: Urine and bladder tissue were obtained at cystoscopy from 11 IC patients and 7 control subjects. These specimens were cultured for a variety of fastidious and nonfastidious bacteria, mycobacteria, fungi, and viruses. In addition, special staining techniques were used to examine biopsy specimens and cytospun urine, and tissue sections and outgrowths of explanted bladder cells were examined by electron microscopy. RESULTS: Cultures of urine from 6 of 11 IC patients grew five different bacteria (Corynebacterium sp. Klebsiella pneumoniae, Lactobacillus sp, Streptococcus constellatus, and Streptococcus morbillorum), human cytomegalovirus, or Torulopsis glabrata; one of these organisms (Lactobacillus sp) was found in urine from 2 patients. Although contamination by urethral organisms is possible, the prevalence of microorganisms in urine of IC patients (6 of 11) was significantly greater than in urine of control subjects (0 of 7) (P < 0.05). Acridine orange staining revealed rods with appropriate morphology in urine from 4 of the 5 IC patients who had positive bacterial cultures and yeastlike organisms in urine and bladder tissue specimens that grew Torulopsis. Additionally, rodlike organisms were seen in urine from 2 IC patients with negative bacterial cultures and cocci were seen in the urine of 1 control patient. Biopsy specimens from 2 IC patients grew Torulopsis sp or Lactobacillus sp, in agreement with the results of acridine orange staining and culture of urine from these patients; in contrast, specimens from 3 control subjects grew small numbers of Pseudomonas sp or Staphylococcus epidermidis, but no organisms were cultured from urine or seen in acridine orange-stained tissue smears. All other cultures and stains were negative. CONCLUSIONS: These data do not provide evidence that IC is associated with infection or colonization by a single microorganism. However, they do generate the hypothesis that the prevalence of microorganisms, especially bacteria at low concentrations, is greater in the urine of IC patients than of control subjects. If these results are confirmed by other controlled studies, the question of whether the presence of these organisms is a cause or a result of IC should be addressed.

Biopsy↗
PubMed1997

The bladder tumor antigen (BTA) test compared to voided urine cytology in the detection of bladder neoplasms.

PURPOSE: Tests to detect recurrent bladder neoplasms are limited and none is consistently accurate. Recent studies suggest that the bladder tumor antigen (BTA) test, an agglutination reaction for basement membrane complexes, is superior to voided urine cytology in clinical practice. We compared BTA and voided urine cytology to bladder washings and cystoscopy, emphasizing diagnostic yield among patients with causes of basement membrane complexes other than bladder cancer. MATERIALS AND METHODS: Random voided urine specimens from 67 patients with a history of bladder neoplasms were collected before cystoscopy and bladder washing. Urine also was obtained from 34 patients with inflammatory bladder conditions including 5 with a history of prostate cancer. Each urine was tested for BTA according to a commercial kit. Positive results were indicated by yellow on a test pad. Blinded to all other results, each urine and each bladder washing were examined microscopically, and a positive test had malignant/suspicious cells. Bladder biopsies were performed when endoscopic lesions were seen. Specimens were grouped into 4 categories: group 1--biopsy proved bladder neoplasm, group 2--history of bladder cancer but not biopsy proved, group 3--history of prostate cancer and group 4--no history of urological cancer. RESULTS: Voided urine cytology was positive in 54% of specimens from patients with biopsy proved bladder neoplasms compared to 29% for BTA. Relative yield for voided urine cytology versus BTA was not changed if all group 2 cases having a positive bladder washing and positive cystoscopy were assumed to have bladder cancer, nor was relative yield altered by subsequent short-term followup. Of voided urine specimens 14% from group 1 patients and 41% from group 2 patients had scant cells. Overall diagnostic yield was superior for bladder washing. False-positive BTA occurred in 7 of 34 patients with no history of urological or prostate cancer. There were no false-positive voided urine cytology interpretations in these groups. CONCLUSIONS: BTA is not superior to voided urine cytology in detecting bladder neoplasms and may be limited by false-positive reactions in patients with other causes of basement membrane complexes in urine. Voided urine samples may be limited by high frequency of hypocellularity. Of 34 patients with a hypocellular urine specimen 4 had biopsy proved bladder cancer. Bladder washing yields best results but requires instrumentation. No test, including cystoscopy, is accurate always.

Antigens, Neoplasm↗
PubMed2001

Twenty-four-hour urine chemistries and the risk of kidney stones among women and men.

BACKGROUND: Results of a 24-hour urine collection are integral to the selection of the most appropriate intervention to prevent kidney stone recurrence. However, the currently accepted definitions of normal urine values are not firmly supported by the literature. In addition, little information is available about the relationship between risk of stone formation and the levels of urinary factors. Unfortunately, the majority of previous studies of 24-hour urine chemistries were limited by the inclusion of recurrent stone formers and poorly defined controls. METHODS: We obtained 24-hour urine collections from 807 men and women with a history of kidney stone disease and 239 without a history who were participants in three large ongoing cohort studies: the Nurses' Health Study I (NHS I; mean age of 61 years), the Nurses' Health Study II (NHS II; mean age of 42 years), and the Health Professionals Follow-up Study (HPFS; mean age of 59 years). RESULTS: Mean 24-hour urine calcium excretion was higher and urine volume was lower in cases than controls in NHS I (P < or = 0.01), NHS II (P < or = 0.13) and HPFS (P < or = 0.01), but urine oxalate and citrate did not differ. Among women, urine uric acid was similar in cases and controls but was lower in cases in men (P = 0.06). The frequency of hypercalciuria was higher among the cases in NHS I (P = 0.26), NHS II (P = 0.03), and HPFS (P = 0.02), but 27, 17, and 14% of the controls, respectively, also met the definition of hypercalciuria. The frequency of hyperoxaluria did not differ between cases and controls, but was three times more common among men compared with women. After adjusting for the other urinary factors, the relative risk of stone formation increased with increasing urine calcium levels and concentration in all three cohorts but not in a linear fashion. Compared with individuals with a urine calcium concentration of <75 mg/L, the relative risk of stone formation among those with a urine calcium concentration of > or =200 mg/L for NHS I was 4.34 (95% CI, 1.59 to 11.88), for NHS II was 51.09 (4.27 to 611.1), and for HPFS was 4.30 (1.71 to 10.84). There was substantial variation in the relative risks for stone formation for the concentration of other urine factors within the different cohorts. CONCLUSIONS: The traditional definitions of normal 24-hour urine values need to be reassessed, as a substantial proportion of controls would be defined as abnormal, and the association with risk of stone formation may be continuous rather than dichotomous. The 24-hour urine chemistries are important for predicting risk of stone formation, but the significance and the magnitudes of the associations appear to differ by age and gender.

Adult↗
PubMed1982

Urine culture transport tubes: effect of sample volume on bacterial toxicity of the preservative.

Stable bacterial counts in urine specimens before culture are necessary to assure the accurate diagnosis of urinary tract infections. Preservative-containing tubes are commercially available for urine transport. As these tube containers are not always filled to the manufacturer's specifications, we studied the effects of stabilizer formation with low urine volumes. The Sage Urine Culture Tube and the Becton-Dickinson Urine Culture Kit were evaluated by using 30 cultures diluted in urine to 10(5) colony-forming units per ml. Both tube types were injected with 1, 2, 3, and 4 to 5 ml (tube capacity) of urine containing each culture. Specimens were held at 22 degrees C and cultured at 0, 4, and 24 h. Colony counts were corrected for the dilution due to the preservative. The Becton-Dickinson Urine Culture Kits were toxic to Escherichia coli and Klebsiella pneumoniae in specimens containing up to 2 ml of urine, and the minimum usable amount of urine for reliable results was 3 ml. The Sage Urine Culture Tube maintained the number of bacteria in 1 to 4.5 ml of urine in 83% of the specimens. However, the Sage tube was toxic to E. coli when held for 24 h. Quantitative counts of enterococci tended to significantly increase in specimens that contained 2 ml or more of urine with either system. The limitation of preservative-containing tubes for urine transport need to be recognized in order to avoid false-positive and false-negative results.

Bacteria↗
PubMed1997

Influence of first morning urine volume, fasting blood glucose and glycosylated hemoglobin on first morning urinary albumin concentration.

The aim of the present study was to evaluate the effect of first morning urinary volume (collected on three different non-consecutive days), fasting blood glucose (determined on the first and third days of urine collection), and glycosylated hemoglobin (determined on the first and third days of urine collection) on the albumin concentration in first morning urine samples collected on three different days. We found 3.6% asymptomatic bacteriuria in the urine samples; therefore, every urine sample must be tested to exclude infection. One hundred and fifty urine samples were provided by 50 IDDM patients aged 21.9 +/- 7 (12-38) years with a disease duration of 6.8 +/- 5.8 (0.4-31) years attending the Diabetes Clinic at the State University Hospital of Rio de Janeiro. There were no differences in albumin concentration (6.1 vs 5.8 vs 6.2 micrograms/ml; P = NS) or urinary volume (222.5 vs 210 vs 200 ml) between the three samples. In addition, there were no differences in fasting blood glucose (181.9 +/- 93.6 vs 194.6 +/- 104.7 mg%; P = NS) or glycosylated hemoglobin (HbA1) (8.4 +/- 1.3 vs 8.8 +/- 1.5%; P = NS) between the first and third blood samples. Six patients (group 1) had a mean urinary albumin concentration of more than 20 micrograms/ml for the three urine samples. This group was compared with the 44 patients (group 2) with a mean urinary albumin concentration for the three urine samples of less than 20 micrograms/ml. No difference was found between groups 1 and 2 in relation to fasting blood glucose (207.1 +/- 71.7 vs 187.6 +/- 84.6 mg/dl), HbA1 (8.1 +/- 0.9 vs 8.6 +/- 1.1%) or urinary volume [202 (48.3-435) vs 246 (77.3-683.3) ml]. Stepwise multiple regression analysis with albumin concentration of first morning urine samples as the dependent variable, and urinary volume, fasting blood glucose and glycosylated hemoglobin as independent variables, showed that only 12% (P = 0.01) of the albumin concentration could be accounted for by the independent effect of morning urine volume on the first day of urine collection. No urine samples showed a change in the cutoff level of 20 micrograms/ml of albumin concentration as the result of volume. Fasting blood glucose and glycosylated hemoglobin did not influence the urinary albumin concentration. Considerable variability in urinary albumin concentration was found in the three morning urine samples with a mean intraindividual coefficient variation of 56%. In conclusion, in the present study, urinary volume had a minimal, though not constant, effect on first morning urinary albumin concentration. Day-to-day metabolic and clinical control of IDDM patients, except probably for ketoacidosis, should not contraindicate microalbuminuria screening in first morning urine samples.

Adolescent↗
PubMed2004

Protein-to-creatinine ratio in spot urine samples as a predictor of quantitation of proteinuria.

BACKGROUND: Normal individuals usually excrete very small amounts of protein in the urine. Persistently increased protein excretion is usually a marker of kidney damage. Quantifying protein in urine is commonly used in the diagnosis of kidney diseases, detection of treatment effects and evaluation of prognosis. We evaluated the use of the total protein-to-creatinine ratio (P/C) in spot urine specimens as a predictor of urine protein excretion in 24-h collections. METHODS: The correlation between P/C in first morning and random urine specimens and urinary protein excretion in 24-h collections were analyzed. The cutoff value of P/C in first morning urine specimens for screening urinary protein excretion of 1 and 3 g in 24-h collections was determined by receiver operating characteristics (ROC) curve. RESULTS: For patients with Ccr 10 ml/min, the correlation was highly significant. Similar results were obtained for random urine specimens. By ROC curve analysis, the P/C of 0.94 and 2.84 g/gcr in first morning urine specimens represent the best threshold to detect urine protein excretion of 1 and 3 g in 24-h collections, respectively. There is a good correlation between P/C in first morning urine specimens and random urine specimens from inpatients and outpatients. But the P/C in random specimens is significantly higher than that in first morning specimens in outpatients. CONCLUSION: The P/C in spot urine samples could be used as an alternative to urine protein excretion in 24-h collections in patients with Ccr>10 ml/min. The P/C in first morning urine samples is better than that in random specimens, especially for outpatients.

Adolescent↗
PubMed2006

[Examination of urine in the child].

The examination of urine in children can be very complex, due to the difficulty to obtain clean urine specimens in infants and toddlers. Clean catch is an easy system to obtain urine but patience is needed. Transurethral catheterization or suprapubic aspiration is useful in infants and toddlers with sign of pyelonephritis. Urine bag specimens are not useful in the diagnosis of urinary tract infection because of the high rate of false positive cultures. The 24 hours urine collection is frequently replaced by a spot urine and the ratio of the measured substances with the urine creatinine are calculated. Urine microscopy is needed for the evaluation of pathological results in the dipstick testing: confirm that red urine is due to haematuria by demonstration of red blood cells on urine microscopy, dysmorphic cells and red-cell casts are pathognomonic of glomerular bleeding, white-cell casts signify glomerular inflammation and bacteria are easily seen in unstained urine. A urine culture is pathologic if the colony count exceeds 10(4) in the transurethral catheterization or clean void. In the suprapubic aspiration is any number of colony pathologic. Urate crystals in the urine of infants may cause a pink discoloration to nappies. Urine screenings are not very useful and should be performed only at the age of 5 years or by sexual-active adolescents.

Bacteriuria↗
PubMed2001

Assessment of skin basement membrane zone antibodies in the urine of patients with acquired subepidermal immunobullous diseases.

BACKGROUND: In bullous pemphigoid (BP), cicatricial pemphigoid (CP) and linear IgA disease (LAD), autoantibodies to the basement membrane zone (BMZ) are found in skin and mucosa, blood and blister fluid. OBJECTIVES: To assess whether BMZ antibodies might also be detected in urine. METHODS: Urine and serum samples from 62 patients (32 with BP, 17 with CP and 13 with LAD) were analysed for antibody isotypes and subclasses by indirect immunofluorescence, and urine and serum samples from 40 patients (25 with BP, eight with CP and seven with LAD) were screened for target antigens using immunoblotting. RESULTS: Fourteen of 32 patients with BP had detectable levels of IgG BMZ autoantibodies in their urine, and all 32 had positive sera. Of these 14 BP patients, 13 had epidermal-binding serum autoantibodies at a titre > 1 : 160, and one had dermal-binding serum antibodies at a titre of 1 : 40. BMZ autoantibodies were not detected in the urine of the CP or LAD patients, but the corresponding sera were of low titre or negative. IgG subclasses (IgG1-4) were less frequently detected in urine than in serum. IgG4 was the predominant subgroup found (10 urine samples and all 14 sera), followed by IgG1 (two urine samples and 12 sera); IgG2 was detected in a single urine sample and three sera, and IgG3 was not detected. Eight of 25 BP and one of eight CP urine samples were positive on immunoblotting, and bound BP230 and/or BP180 with IgA and/or IgG autoantibodies. IgA autoantibodies were not detected in the urine of the seven LAD patients. The corresponding sera were often more positive, with 21 of 25 BP, five of eight CP and six of seven LAD sera immunoblotting the major BP antigens. CONCLUSIONS: The detection of IgG autoantibodies from urine samples using indirect immunofluorescence correlated with a high titre of IgG autoantibodies in the serum. IgG and IgA autoantibodies in the urine were detected by immunoblotting, although less frequently than in serum. The finding of BMZ antibodies in the urine of many BP patients may have clinical relevance, and may have a restricted application in the diagnosis of immunobullous disease.

Adult↗
PubMed2000

Monitoring opiate use in substance abuse treatment patients with sweat and urine drug testing.

Although urine testing remains the standard for drug use monitoring, sweat testing for drugs of abuse is increasing, especially in criminal justice programs. One reason for this increase is sweat testing may widen the detection window compared to urine testing. Drug metabolites are rapidly excreted in urine limiting the window of detection of a single use to a few days. In contrast, sweat collection devices can be worn for longer periods of time. This study was designed to compare the efficacy of sweat testing versus urine testing for detecting drug use. Paired sweat patches that were applied and removed weekly on Tuesdays were compared to 3-5 consecutive urine specimens collected Mondays, Wednesdays, and Fridays (355 matched sweat and urine specimen sets) from 44 patients in a methadone-maintenance outpatient treatment program. All patches (N = 925) were extracted in 2.5 mL of solvent and analyzed by ELISA immunoassay for opiates (cutoff concentration 10 ng/mL). A subset (N = 389) of patches was analyzed by gas chromatography-mass spectrometry (GC-MS). Urine specimens (N = 1886) were subjected to qualitative analysis by EMIT (cutoff 300 ng/mL). Results were evaluated to (1) determine the identity and relative amounts of opiates in sweat; (2) assess replicability in duplicate patches; (3) compare ELISA and GC-MS results for opiates in sweat; and (4) compare the detection of opiate use by sweat and urine testing. Opiates were detected in 38.5% of the sweat patches with the ELISA screen. GC-MS analysis confirmed 83.4% of the screen-positive sweat patches for heroin, 6-acetylmorphine, morphine, and/or codeine (cutoff concentration 5 ng/mL) and 90.2% of the screen-negative patches. The sensitivity, specificity, and efficiency of ELISA opiate results as compared to GC-MS results in sweat were 96.7%, 72.2%, and 89.5%, respectively. Heroin and/or 6-acetylmorphine were detected in 78.1% of the GC-MS-positive sweat patches. Median concentrations of heroin, 6-acetylmorphine, morphine, and codeine in the positive sweat samples were 10.5, 13.6, 15.9, and 13.0 ng/mL, respectively. Agreement in paired sweat patch test results was 90.6% by ELISA analysis. For the purposes of this comparison of ELISA sweat patch to EMIT urine screening for opiates, the more commonly used urine test was considered to be the reference method. The sensitivity, specificity, and efficiency of sweat patch results to urine results for opiates were 68.6%, 86.1%, and 78.6%, respectively. There were 13.5% false-negative and 7.9% false-positive sweat results as compared to urine tests. Analysis of sweat patches provides an alternate method for objectively monitoring drug use and provides an advantage over urine drug testing by extending drug detection times to one week or longer. In addition, identification of heroin and/or 6-acetylmorphine in sweat patches confirmed the use of heroin in 78.1% of the positive cases and differentiated illicit heroin use from possible ingestion of codeine or opiate-containing foods. However, the percentage of false-negative results, at least in this treatment population, indicates that weekly sweat testing may be less sensitive than thrice weekly urine testing in detecting opiate use.

Adolescent↗
PubMed2003

Detection of anti-Leishmania immunoglobulin G antibodies in urine specimens of dogs with leishmaniasis.

For years, anti-Leishmania immunoglobulin G (IgG) antibodies have been detected in the sera of dogs living in areas of leishmaniasis endemicity. They have also been found in the aqueous humor and cerebrospinal fluid. In contrast, a review of the literature failed to identify the detection of anti-Leishmania antibodies in urine samples from dogs with leishmaniasis. Ninety-five dog urine samples were examined for the presence of anti-Leishmania antibodies by using a protein A enzyme-linked immunosorbent assay (ELISA). Twenty additional urine samples were collected from healthy dogs as controls. An IgG2 ELISA was performed on 26 urine samples found positive by the protein A ELISA. Twenty-three urine samples found positive to anti-Leishmania antibodies were tested for the local production of anti-Leishmania antibodies in the urinary tract by means of the urine antibody coefficient. Ten urine samples (and the corresponding serum samples) were compared by Western blot (WB) analysis. Thirty-five out of the 95 urine samples were found positive, 57 were found negative, and 3 were found inconclusive for antibody detection by the protein A ELISA. A high correlation between protein A and IgG2 levels was found in positive urine samples. Anti-Leishmania antibodies were present in the urine of dogs that had leishmaniasis, urinary protein/creatinine (U P/C) ratios of greater than one, and normal urinary sediment. A statistically significant correlation was observed between the U P/C ratios and the levels of anti-Leishmania antibodies in positive urine samples. In general, WB analysis and the urine antibody coefficient suggested that the presence of anti-Leishmania antibodies in urine was the consequence of an impairment of filtration of the glomerular barrier. However, in some dogs, WB analysis could be interpreted as suggesting that the presence of anti-Leishmania antibodies was caused, to a lesser extent, by local antibody production in the urinary tract. Antibody detection in urine could be a noninvasive method for leishmaniasis diagnosis and prognosis in dogs with glomerulonephropathies.

Animals↗
PubMed1997

A urine analysis method suitable for children's nappies.

BACKGROUND: Urinary tract infection in infancy continues to be underdiagnosed, despite its association with renal scarring and thus hypertension, renal failure, and other sequelae. Low ascertainment of urinary tract infections reflects the many difficulties in establishing a diagnosis, some of which could be eliminated by a simple, reliable method for preliminary investigation of children's urine. AIM: To assess the accuracy of a new, simple method for testing urine for nitrite and leucocyte esterase, which could be applied to children in primary care. METHODS: An in vitro study was carried out to compare the results of conventional urine analysis with urine analysis on urine soaked on to panty-liners, and with the laboratory investigation. Two urine analysis stick types were used (Boehringer Mannheim Nephur sticks and Bayer Multistix 8SG) and two brands of panty-liners. Analysis examined evidence of agreement and bias for different methods in addition to sensitivity, specificity, and negative predictive values for urine analysis. RESULTS: Pressing urine analysis test sticks on to panty-liners soaked with urine achieved consistent results compared with the results of conventional dipstick urine analysis. At a prevalence of 21.8%, sensitivity and negative predictive values of urine analysis for laboratory confirmed urinary tract infection were 94% and 98%, respectively, for Boehringer sticks, and 76% and 93%, respectively, for Bayer sticks. At prevalences of 5% and 1% (prevalences that could be expected in primary care) Bayer sticks had negative predictive values of 98.7% and 99.7%, respectively, and Boehringer sticks had values of 99.6% and 99.9%, respectively. CONCLUSIONS: Testing urine on panty-liners is accurate compared with conventional urine analysis. It may be possible to apply this method to testing unwell children presenting in primary care to identify those who require microbiological urine culture to confirm or eliminate a diagnosis of urinary tract infection.

Adolescent↗
PubMed2000

How effective are screening tests for microalbuminuria in random urine specimens?

The effectiveness of four urine screening tests-microalbumin (MAlb), total protein (TProt), total protein/creatinine ratio (TProt/Cr R), and dipstick (DPalb) test for albumin-were evaluated for the detection of MAlb in random urine specimens. The following criteria were used to assess the effectiveness of each urine screening test: 100% specificity (no false positive results); cost effectiveness; rapidity and ease of performing the screening test; and increased laboratory efficiency. A "gold standard" for presence of MAlb in random urine samples was defined as a microalbumin/creatinine ratio (MAlb/Cr R) of > or = 30 mg/g. The least costly urine screening test was the DPalb, which, if assigned a value of 1.0, allowed a cost ranking order for the screening tests-DPalb (1.0) < urine TProt (1.03) < urine TProt/Cr R (2.1) < urine MAlb (7.0). Two hundred urine samples from diabetic inpatients and outpatients were tested. Only two screening tests--MAlb and DPalb--achieved 100% specificity without increasing laboratory costs (small net savings), whereas the other two screening tests--TProt and TProt/Cr R-only achieved 100% specificity with increased laboratory costs. Theoretical prevalence rate analysis showed that urine MAlb screening would be effective at all prevalence rates for overt nephropathy. TProt and DPalb urine screening testing would be most effective in populations with prevalence rates of > or = 15% for overt nephropathy. The TProt/Cr R ratio would only be effective in populations with prevalence rates of > or = 30%. Of the four urine screening tests, only DPalb would significantly streamline the process of measuring urine MAlb. The dipstick test is inexpensive, easy and rapid to perform, does not delay measuring the ratio, since there is no wait for the screening test result, and can be used by referring laboratories to screen urine specimens before they are submitted to a central laboratory, thereby reducing laboratory workload.

Albuminuria↗
PubMed2001

Spot urine uric acid to creatinine ratio used in the estimation of uric acid excretion in primary gout.

OBJECTIVE: Uric acid overexcretion in patients with gout is frequently assessed by the measurement of 24 hour urinary uric acid excretion, which is cumbersome with ambulatory patients, and requires accurate timing and complete collection of the specimen. We assessed whether uric acid to creatinine ratio (Uua/Ucr) in spot urine is useful for the estimation of uric acid overexcretion in patients with gout. METHODS: One hundred thirty male patients with gout and 33 non-gout male control subjects were studied. Early morning urine and/or a portion of 24 h collected urine (24 h urine) were used as spot urine samples. Uric acid overexcreters were defined as those with a 24 h urinary uric acid excretion > or = 1000 mg/day, while uric acid underexcreters were defined as those with uric acid clearance < 6 ml/min. RESULTS: There was a significant relationship between 24 h urinary uric acid excretion and early morning urine Uua/Ucr in patients with gout, while no such relationship was observed in controls. No significant difference in Uua/Ucr was observed between patients with gout and controls, or in Uua/Ucr between gout uric acid overexcreters and underexcreters in early morning urine. A significant difference in this value was observed between the 2 groups in the 24 h urine specimens. Although the diagnostic accuracy of gout uric acid overexcretion was 87.2% using early morning urine and 89.6% using 24 h urine, the sensitivity of gout uric acid overexcretion was only 25.0% when using early morning urine and 25.0% when using 24 h urine, when the cutoff value of Uua/Ucr was 0.63 and 0.64, respectively. CONCLUSION: Uua/Ucr using spot urine, especially early morning urine, is not an accurate indicator of uric acid overexcretion in patients with gout.

Chemistry, Clinical↗
PubMed2002

A simple method of selecting gout patients for treatment with uricosuric agents, using spot urine and blood samples.

OBJECTIVE: To develop a simple means of selecting gout patients for treatment with uricosuric agents. METHODS: In 124 gout patients, spot urine and blood were sampled before breakfast and after overnight fast (except water) on the day of 24 h urine collection. Spot urine uric acid/creatinine ratio (Ua/Cr mmol/mmol) and serum creatinine x Ua/Cr (Scr*Ua/Cr micromol/l) were calculated together with 24 h urinary uric acid excretion/body surface (24 Ua/S). The patients were then classified either below or above 2.84 mmol/m2/day for 24 Ua/S. RESULTS: Classifications based on spot urine Ua/Cr (cut off value set at 0.34), spot urine Scr*Ua/Cr (cut off value set at 28.1), and a combination of spot urine Ua/Cr and Scr*Ua/Cr were found to be not significantly different in diagnostic accuracy for the detection of patients with 24 Ua/S below 2.84 mmol/m2 (77%, 81%, and 81%, respectively) and sensitivity (80%, 83%, and 76%, respectively). However, specificity by a combination of spot urine Ua/Cr, and spot urine Scr*Ua/Cr was higher than by spot urine Ua/Cr alone (91% vs 74%, P < 0.05), although the specificity was not significantly different between a combination and spot urine Scr*Ua/Cr alone (91% vs 78%) or between spot urine Ua/Cr and spot urine Scr*Ua/Cr (74% vs 78%). CONCLUSION: A combination of spot urine Ua/Cr and spot urine Scr*Ua/Cr may be clinically useful in selecting gout patients with 24 Ua/S below 2.84 mmol/m2 for treatment with uricosuric agents without adverse effects.

Adult↗
PubMed2002

Relation between nocturnal voiding frequency and nocturnal urine production in older men:a population-based study.

OBJECTIVES: To describe the normal values for nocturnal urine production and its determinants, as well as the relation between nocturnal urine production and voiding frequency. METHODS: Data were collected from 1688 men aged 50 to 78 years without bladder or prostate cancer, radical prostatectomy, neurogenic bladder dysfunction, or negative advice from their general practitioner. Measurements included self-administered questionnaires, a 3-day frequency-volume chart, transrectal ultrasonography of the prostate, uroflowmetry, and postvoid residual urine volume measurement. The mean nocturnal urine production was computed from the frequency-volume charts. Linear regression analyses were performed to determine associated factors for nocturnal urine production. Areas under the receiver operating characteristic curves were used to describe the discriminative value of nocturnal urine production on nocturnal voiding frequency. A cutoff value for "increased" nocturnal urine production was defined using logistic regression analysis. RESULTS: The nocturnal urine production was 60.6 mL/hr for the total study population; it increased with age and was significantly higher in men with 24-hour polyuria. Nocturnal urine production was on average higher in men with increased nocturnal voiding frequency, but had only a reasonable discriminative value on nocturnal voiding frequency (areas under receiver operating characteristic curve of 0.71 and 0.76). Nocturnal urine production exceeding 90 mL/hr is suggested as abnormal. CONCLUSIONS: On average, nocturnal voiding frequency is indicative of nocturnal urine production. However, nocturnal urine production is only a modest discriminator for increased nocturnal voiding frequency. Therefore, the use of nocturnal urine production as an explanatory variable for nocturnal voiding frequency in daily practice is of little value.

Age Factors↗
PubMed1999

Biological monitoring of workers exposed to 4,4'-methylene-bis-(2-orthochloroaniline) (MOCA). II. Comparative interest of "free" and "total" MOCA in the urine of exposed workers.

OBJECTIVES: The objectives of the study were to investigate the best urinary marker of exposure to MOCA in urine samples of exposed workers and to study its applicability in exposure evaluation in polyurethane resin production plants. In addition, our intention was to contribute to the question of biological target value in order to reduce exposure levels. METHODS: Urinary MOCA markers were measured in urine samples collected at the end of the workshifts. 40 workers from four factories were observed for three consecutive days in the same week. "Free" MOCA in non-acid-stabilized urines, "total" MOCA in urines after alkaline hydrolysis, "acid-labile" MOCA in sulfamic or citric acid-protected urines were measured in all urine samples. MOCA liberated by heating the non-acid-stabilized urines ("heat-labile" MOCA) was also measured in 17 urine samples of exposed workers. RESULTS: The median value of "free" MOCA was lower than that of "sulfamic acid-labile" MOCA: 6.0 and 12.5 micrograms/l respectively. The difference between "free" and "total" MOCA was statistically significant (Mann-Whitney test, P = 0.023) for the urine samples collected without acid. Correlations between urinary MOCA concentrations in hydrolysed and non-hydrolysed urine samples were high (r = 0.984, 0.966 and 0.950; P < 0.001) for urine samples with sulfamic acid, with citric acid and without acid respectively. For all the factories, the postshift urinary MOCA concentrations ranged between 1 microgram/l (detection limit) and 570 micrograms/l; 25% of "sulfamic acid-labile" MOCA concentrations exceeded 50 micrograms/l. Workers handling crystallized MOCA excreted the highest amounts of MOCA in urine. The urinary MOCA concentrations (median) were: 84.0 micrograms/l (mixer), 15.5 micrograms/l (moulder). 59.0 micrograms/l (maintenance) and 3.0 micrograms/l (others). CONCLUSIONS: MOCA measured in sulfamic acid-protected urine samples without hydrolysis provides a more practical and reliable biomarker than "total" MOCA (after hydrolysis) or "free" MOCA. A biological guiding value of 20 micrograms/l expressed as "sulfamic acid-labile" MOCA is proposed.

Chemical Industry↗
PubMed1997

Use of urine specific gravity to improve screening for albuminuria.

The albumin to creatinine ratio (ACR) can be used to measure urine albumin excretion rates, but is inconvenient and expensive. More rapid and less expensive screening methods estimate only albumin concentration and are subject to errors caused by variation in urine volume. We examined whether urine specific gravity could be used in place of urine creatinine to correct albumin concentration for differences in urine volume in 50 patients. Urine specific gravity accurately estimated urine creatinine concentration (r = 0.79, P < 0.001). The albumin estimated-creatinine ratio (ACestR) in random spot urine sample correlated with urine albumin excretion measured in a 24-hour urine collection (r = 0.98, P < 0.001), as did the ACR (r = 0.95, P < 0.001). For determining microalbuminuria, the sensitivity (0.88) and specificity (0.93) of the ACestR were similar to those of ACR (0.89 and 0.93, respectively). Unfortunately, the sensitivity (0.63) of the Micral-Test was relatively poor, and was only slightly improved by correcting for urine specific gravity (0.69) in this small sample of patients. Nevertheless, these results suggest that as rapid methods for measuring urine albumin concentration improve, combining them with urine specific gravity might produce a less expensive and more convenient alternative to the ACR.

Adult↗