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PubMed1986

Inhibitory activity of whole urine: a comparison of urines from stone formers and healthy subjects.

The inhibitory activity of whole urines from 32 healthy subjects and 50 calcium oxalate renal stone formers was assessed in terms of their ability to withstand increasing quantities of oxalate before undergoing spontaneous nucleation of calcium oxalate, and their response to a standard 30-mumol challenge of oxalate above their measured metastable limits. The concentrations of calcium (p less than 0.05), oxalate (p less than 0.05), urate (p less than 0.01) and glycosaminoglycans (p less than 0.005) were significantly lower in the stone formers than in the controls and were associated with a significantly higher 24-h urinary volume (p less than 0.001). The majority of urine samples precipitated envelope crystals of calcium oxalate dihydrate, while the remainder precipitated the monohydrate. A significantly (p less than 0.02) greater proportion of the urines from stone formers than from controls deposited calcium oxalate monohydrate, and this was attributed to a lower concentration of calcium in these urines. The minimum amounts of oxalate necessary to induce crystal nucleation did not differ between the two groups, but when the measured metastable limits were expressed as the product of the total (i.e. endogenous + that added to induce nucleation) concentrations of oxalate and calcium at which precipitation occurred, then these limits were significantly lower (p less than 0.05) in the stone formers than in the healthy subjects. However, when the metastable limits of a subgroup of stone formers and controls matched for 24-h urinary volume and calcium and urate concentrations were compared, no differences between the groups could be discerned.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium↗
PubMed2005

Urine sediment examination: a comparison between the manual method and the iQ200 automated urine microscopy analyzer.

BACKGROUND: Microscopic examination of the urine sediment is an essential part in the evaluation of renal and urinary tract diseases. Traditionally, manual microscopic techniques have several methodological steps that may contribute to imprecision, inaccuracy, and are time-consuming. Recently, the iQ200 automated urine microscopy analyzer has been introduced to analyze the unspun urine, thereby improving accuracy, precision and throughput. METHODS: In this study, we compared its performance with manual routine slide and chamber counts. Fresh urine samples were obtained from 400 subjects. RESULTS: The reference values of white blood cells, red blood cells and squamous epithelial cells obtained by the above methods were not significant difference when the results reported as cells per high-power field. For the specimens of patients (n=280), a significant correlation was found when the iQ200 results of cellular elements were compared with those obtained from manual microscopy. No significant difference was found when the post-review results of the iQ200 were compared with the chamber count. However, the presence of casts, crystals, bacteria, and budding yeast needs further characterization under the microscope. CONCLUSIONS: There is substantial agreement between the iQ200 and manual microscopic methods. The iQ200 provides for a rapid turnaround time.

Adult↗
PubMed1986

Dipstick testing of urine--can it replace urine microscopy?

One thousand consecutive urine specimens were studied to assess the sensitivity of a commercially available dipstick (Chemstrip 8, Boehringer Mannheim Corp., Indianapolis, IN) to predict the presence or absence of microscopic abnormalities. The Chemstrip 8 had a sensitivity of 78%, specificity of 54%, and a false negative rate of 38%. An additional 1,000 consecutive urine specimens were then studied using the Chemstrip 9, a reagent dipstick that includes the leukocyte esterase (LE) test. The Chemstrip 9 had a sensitivity of 82%, specificity of 42%, and a false negative rate of 36%. Chi-squared analysis revealed that the two dipsticks were not significantly different (chi 2 = 0.17, P greater than 0.5). Clinical review of patients with false negative results showed that approximately one-third to one-half of these patients had either spinal cord injury or genitourinary problems. Maximal potential savings in workload of approximately 10% were found if microscopic examinations were to be performed only on urine specimens with abnormal dipsticks. Our data suggest that in our patient population, we should not eliminate microscopic urine examination based on abnormal dipstick findings.

Esterases↗
PubMed1981

Mannose-specific adherence of Escherichia coli freshly excreted in the urine of patients with urinary tract infections, and of isolates subcultured from the infected urine.

The mannose-specific adherence to yeast cells of Escherichia coli excreted in the urine of patients with urinary tract infections was compared with that of isolates from the same urine after growth of the bacteria in broth. The results revealed that although E. coli excreted in only 2 of 24 urine specimens exhibited mannose-specific adherence, about half of the broth cultures from these specimens did so. Examination of representative specimens of E. coli excreted in urine showed that coating antibodies, mannose-containing glycoproteins, and encapsulation were not responsible for the lack of the mannose-specific adherence. Our results suggest that E. coli strains that are genetically capable of exhibiting mannose-specific adherence may, when growing in the bladder, be in a phase of growth which suppresses the phenotypic expression of this trait. Mannose-specific adherence is indicative of the presence on the bacterial surface of adhesions (lectins) that bind the organisms to mannose residues on both epithelial and phagocytic cells. We propose that whereas at the initial stages of infection the bacteria may benefit from their ability to bind to mannose residues on epithelial cells, loss of this ability at the later stages of the infection is also beneficial, since the bacteria can no longer adhere to mannose residues on phagocytes, and are thus resistant to nonimmune phagocytosis.

Cell Adhesion↗
PubMedDate not supplied

[Delayed testing for the diagnosis of fungi in the urines. Evaluation of the BD Vacutainer C&S tubes for the storage of urine samples at room temperature].

The study included 37 urine samples which have been artificially infected with low levels (10(3) CFU/mL) of various fungi strains. We compared the effects of sample storage, up to 48 hours, at room temperature, in a urine evacuated tube containing specific additives with storage at + 4 degrees C, for the same length of time, in a urine evacuated tube without any additives. There have been no differences of results (speed of growth and colony size) between the 2 modes of storage. However, the experience has shown that samples needed a careful mixing before seeding to avoid underdetection of the strains. Based on the study results, the BD Vacutainer C&S tubes are suitable for delayed testing for the diagnosis of urine fungal infection.

Equipment Design↗
PubMed1985

Results of dipstick tests, visual inspection, microscopic examination of urine sediment, and microbiological cultures of urine compared for simplifying urinalysis.

Using microscopic sediment examination, reagent dipsticks, visual appearance, and microbiological culture, we studied 196 urine specimens collected under sterile conditions. We conclude that the sensitivities and specificities noted in the comparison of dipstick urinalysis with urine microscopy justify eliminating many microscopic examinations if a procedural flowchart is used. All 33 (16.8%) of the uncontaminated urine specimens showing substantial potential pathogen content on culture had either a turbid appearance or positive results for one or more dipstick tests. A positive dipstick test result for nitrite most consistently indicated that the urine should be cultured.

Bacteriuria↗
PubMedDate not supplied

Urine cytology as a medical surveillance tool: a study of variability in interpretation of urine cytology slides.

This study examines the value of urine cytology as a medical surveillance technique in the industrial setting through an evaluation of the variability in interpretation of urine cytology slides. Urine samples were collected from 259 individuals for cytological examination. The slides were read by pathologists and screeners at one large Army medical center and separately read again by an independent pathologist at another Army medical center. The two independent readings for each of the 259 cases were compared. The comparison indicated that overall agreement was fairly high in reporting the presence or absence of inflammatory cells, red blood cells, and atypical (including metaplastic) cells. However, considering positive findings of the presence of red blood cells or atypical cells only, significant differences between the two independent readings were noted when the sign test was applied. Implications of these findings are discussed in light of the use of urine cytology as a medical surveillance tool in occupational medicine.

Drug-Related Side Effects and Adverse Reactions↗
PubMed1995

Urine cytology and urine flow cytometry in renal transplantation--a prospective double blind study.

Urine cytology (UC) has proved to correlate well with core and fine-needle aspiration kidney biopsies of renal allograft recipients undergoing acute rejection (AR). This study was undertaken to compare the relative usefulness of urine flow immunocytometry (UFC) (using fluorescinated antibodies anti-HLA-DR, anti-CD3 and antirenal epithelial cells) with UC in its ability to diagnose AR by analyzing 200 urine specimens during a prospective double-blind study of 40 renal transplant recipients. Clinical diagnosis was retrospectively assigned to one of the following categories: group I--AR, 15; group II--ischemic injury period (first 5 days postop.), 12; group III, 173 (including 168 stable grafts, 1 pyelonephritis and 4 cyclosporine toxicity), by investigators blinded to the urine results. Both tests were highly sensitive for the diagnosis of AR (UC = 86.6% vs. UFC = 100%; P = NS) with a specificity after the ischemic injury period of 78% by UC and 87.9% by UFC. Samples obtained during AR revealed higher levels of expression of HLA-DR as well as higher numbers of CD3-positive cells. These tests had specificity values of 95.3% and 97.6%, respectively, for the diagnosis of AR. The degree of immune activation (established by numbers of lymphocytes/lymphoblasts seen by UC) correlated with the severity of biopsy-proven ARs and with response to antirejection therapy. In conclusion, both test are highly accurate in diagnosing AR. The highest specificity value was obtained when both UC and UFC were utilized together (93%). We suggest that the routine use of these tests can provide an important adjunct to the evaluation of renal transplant recipients.

Adolescent↗
PubMed1994

[The value of urine phosphohexose isomerase activity in comparison with urine cytology. First diagnosis and tumor after-care in patients with cancer of the urinary bladder].

The importance of phosphohexose (PHI) activity in the urine of patients with carcinoma of the urinary bladder is examined on the basis of enzyme-histochemical studies in tumor cell homogenizates after transurethral resection for transitional cell carcinoma. The results gave rise to the question of whether the enzyme-histochemical activity patterns were reflected in the urine in the form of photometrically measurable activity, and thus whether the PHI activity can be used in screening as a marker to complement the standard urine cytological procedure. The sensitivity of PHI measurement was determined at 89%. The measurement of PHI in the urine of patients with an ileum neobladder or of patients with urinary tract infections does not provide any useful information.

Adult↗
PubMed2002

Are 24-hour urine samples and creatinine adjustment required for analysis of inorganic arsenic in urine in population studies?

Compliance with 24-h urine samples can be low in population-based studies and first morning void urine samples are often collected for convenience. Interpretation of arsenic concentrations in urine is influenced by a range of factors unrelated to exposure. To reduce the influence of such factors, creatinine adjustment is routinely used. This study aimed to determine whether first morning void urinary inorganic arsenic concentrations approximate 24-h urinary arsenic concentrations and whether creatinine adjustment improved the correlation between environmental arsenic concentrations and urinary inorganic arsenic concentrations. One hundred sixty spot samples and corresponding 24-h urine samples were collected from people living in areas with a range of environmental arsenic concentrations and analyzed for inorganic arsenic using borohydride arsine generation followed by atomic absorption spectrophotometry. There were no significant differences between the urinary inorganic arsenic concentrations for the different sample types or whether creatinine adjusted or not. Significant correlations were observed between adjusted and unadjusted samples. The data set was highly skewed and when only detectable arsenic samples were considered, the relationship between sample types became nonsignificant. The results of this study suggest that spot samples may be adequate for measuring short-term exposure, using inorganic arsenic as the outcome variable; however, additional work on a larger data set is required. Creatinine adjustment of urinary inorganic arsenic concentrations may not be required in population studies investigating environmental exposure.

Arsenic↗
PubMed1989

Correlation between urinary levels of histamine metabolites in 24-hour urine and morning urine samples of man: influence of histamine-rich food.

In this study, we have determined and correlated the excretion of the 2 most important histamine metabolites, N tau-methylhistamine and N tau-methylimidazoleacetic acid, in 24-hour urine and morning urine samples of 14 normal healthy persons. We found no significant difference between morning urine and 24-hour urine samples, provided that the subjects were on a histamine-poor diet for at least 24 hours. We also studied the influence of the consumption of histamine-rich foodstuffs on the reliability of these parameters. The morning urinary N tau-methylhistamine excretion is less affected by histamine-rich food-stuffs and therefore proposed to be the most reliable parameter for endogeneous histamine release.

Adult↗
PubMed2004

Urine collection pads: are samples reliable for urine biochemistry and microscopy?

The aim of the study was to validate the reliability of samples obtained with urine collection pads (UCP) for selected laboratory biochemical analyses, urine cell microscopy, and bedside semi-quantitative stick urinalysis. A series of laboratory experiments was performed to test agreement between urine concentrations, or results, before and after passage through a UCP (incubated for 37 degrees C for 15 min). The following urinalyses were performed: electrolytes, calcium, phosphate, urate, osmolality, pH, protein, catecholamines, toxicology for drugs of abuse, stick urinalysis for glucose, ketones, protein, blood, leucocytes and nitrites, and microscopy for red and white cells. Close agreement was shown for all laboratory analyses except proteinuria, which was underestimated by, on average, 10% after UCP passage. However, stick urinalysis for proteinuria remains sufficiently reliable for clinical use. UCP substantially retain or destroy red and white cells, but stick urinalysis for blood and leucocyte esterase remains reliable. In conclusion, urine samples derived from UCP show good agreement across a clinically relevant range for the biochemical analyses undertaken in this study. Microscopy of UCP samples is unreliable for cellular material but semi-quantitative stick urinalysis for red and white cells is a satisfactory alternative.

Absorbent Pads↗
PubMed1986

A map of urine proteins based on one-dimensional SDS-polyacrylamide gel electrophoresis and Western blotting using one microliter of unconcentrated urine.

A sensitive one-dimensional SDS-polyacrylamide gel electrophoretic system was devised whereby the proteins in 1 microliter of unconcentrated urine could be visualized by silver staining over the range 9,000-900,000 molecular weight. Identification of urine proteins was confirmed by Western blotting using peroxidase labelled antibodies. A map of the major proteins visualized in urine from individuals with renal disease was constructed. We conclude that the information available from the simple analysis of proteins according to their size is limited to general conclusions regarding whether proteinuria is likely to be of tubular or glomerular or mixed origin. More specific identification of individual proteins is not feasible because simple protein staining is not sufficiently reliable to identify individual proteins. The reasons for this conclusion are as follows: many proteins in urine migrate with similar apparent molecular weights, some proteins are not visualized by silver staining, and albumin polymeric complexes and fragments can be present at almost any molecular weight. However, one-dimensional SDS-polyacrylamide gel electrophoresis together with Western blotting does provide reliable information which might be clinically and experimentally useful.

Albuminuria↗
PubMed1981

Dissociation between renal medullary PGE2-synthesis and urine PGE2-excretion. Antagonism by bumetanide of chlorazanil induced urine PGE2-excretion in rats.

Normal conscious female Sprague-Dawley rats were treated with chlorazanil (3 mg/kg i.p.), and urine was collected for 3 hours. Urine prostaglandin E2-excretion increased from 25 +/- 3 to 271 +/- 32 ng/kg/3 h. The enhancement of urine PGE2-excretion was inhibited by pretreatment with bumetanide (75 mg/kg p.o.). In separate experiments the papillary quantity of PGE2 was determined in freshly homogenized tissue. The basal level (14 +/- 2 ng PGE2/papilla) was increased by chlorazanil to 51 +/- 11 ng PGE2/papilla and 24 +/- 7 ng PGE2/papilla at one and two hours respectively after drug administration. The capacity of chlorazanil to increase medullary PGE2 accumulation was unaffected by bumetanide pretreatment. The results show that bumetanide dissociated the medullary PGE2 level from the excretion of PGE2 in urine, when the former was elevated by chlorazanil.

Animals↗
PubMed1993

Quantification of carnitine and specific acylcarnitines by high-performance liquid chromatography: application to normal human urine and urine from patients with methylmalonic aciduria, isovaleric acidemia or medium-chain acyl-CoA dehydrogenase deficiency.

This paper describes the development of a high-performance liquid chromatographic method for the quantitation of free carnitine, total carnitine, acetylcarnitine, propionylcarnitine, isovalerylcarnitine, hexanoylcarnitine and octanoylcarnitine in human urine. Carnitine and acylcarnitines were isolated from 10 or 25 microliters of urine using 0.5-ml columns of silica gel, derivatized with 4'-bromophenacyl trifluoromethanesulfonate and separated by high-performance liquid chromatography. Using 4-(N,N-dimethyl-N-ethylammonio)-3-hydroxybutanoate ("e-carnitine") as the internal standard, standard curves (10-300 nmol/ml) were generated. Carnitine and acylcarnitines were quantified (when they were present) in normal human urine and the urine of patients diagnosed with one of three different disorders of organic acid metabolism: methylmalonic aciduria, isovaleric aciduria, isovaleric acidemia, and medium-chain acyl-CoA dehydrogenase deficiency.

Acetophenones↗
PubMed1996

Solid-phase extraction and derivatisation methods for beta-blockers in human post mortem whole blood, urine and equine urine.

This paper details various rapid and sensitive methods for the extraction and derivatisation of propranolol, metoprolol, sotalol, atenolol, pindolol, timolol, oxprenolol, alprenolol and penbutolol in equine urine and in human post mortem whole blood and urine. Three solid-phase extraction methods are described involving the use of either XtrackT XRDAH515, Bond Elut Certify or Sep-Pak C18 cartridges. Two derivatisation methods are also described involving the formation of cyclised silyl or pentafluoropropionate derivatives with either chloromethyldimethylchlorosilane or pentafluoropropionic anhydride, respectively. Gas chromatographic-mass spectrometry analysis was carried out in select-ion monitoring mode. All these methods were evaluated using drug-free human post mortem blood, urine and equine urine fortified at various levels with the beta-blockers mentioned above. The application of some of these methods on a forensic case study is also presented. This work does not include samples from equine administration trials of beta-blockers.

Adrenergic beta-Antagonists↗
PubMed1988

Promotive effect of urine from patients with primary hyperparathyroidism on calcium oxalate crystal aggregation in an in vitro whole urine system.

Urine from patients with calculi produced by primary hyperparathyroidism was examined to determine its promotive effect on calcium oxalate crystal aggregation. The study was carried out in an in vitro whole urine system and the particle size distribution assay was done by Coulter Counter, Model TAII. Of urine samples from 19 hyperparathyroid patients, 15 showed obvious promotion of calcium oxalate crystal aggregation. It is not known what kind of substances in such urine led to this phenomenon and whether these unknown factors act by actually promoting crystal aggregation or by blocking substances of inhibitors.

Adult↗
PubMed2001

Concentration of 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP) in urine and alkali-hydrolyzed urine after consumption of charbroiled beef.

Heterocyclic amines (HAs) and polycyclic aromatic hydrocarbons are carcinogenic products formed during the cooking of meat at moderate to high temperatures. We have previously shown that the urinary concentration of 1-hydroxypyrene-glucuronide, a metabolite of pyrene, increased significantly in ten subjects who had ingested charbroiled ground beef. We now report the time course and interindividual variation of 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP) concentration in the urine samples from these ten subjects. PhIP concentration was determined in both untreated and alkali-hydrolyzed urine to obtain estimates of the proportion of conjugated PhIP metabolites in each subject. PhIP was measured by gas chromatography-negative ion chemical ionization-mass spectrometry after derivatization with pentafluorobenzyl bromide. Ten healthy non-smoking males consumed identical amounts of broiled beef on five consecutive days. The morning after the first day of broiled beef consumption, urinary concentration of PhIP increased 14-38 fold above mean pre-feed concentration of PhIP in individual alkali-hydrolyzed urine samples. Following cessation of broiled beef consumption, urinary PhIP concentration declined to near pre-feed levels within 48-72 hrs. The ratio of total alkali-labile PhIP metabolites to unmetabolized PhIP varied by about 2.7-fold among subjects, ranging from 18:1 to 48:1, suggesting that interindividual differences in PhIP metabolism occur and can be detected by this method. This study of urinary PhIP following ingestion of meat cooked by charbroiling, that contains both HAs and polycyclic aromatic hydrocarbons, extends previous studies of ingestion of pan-fried meat that contains primarily HAs. The results indicate that significant amounts of PhIP are bioavailable from ingestion of charbroiled ground beef and that measurement of proportions of alkali-labile PhIP metabolites and parent PhIP in human urine may yield information on individual metabolism of ingested PhIP.

Adult↗