Comparison of the clinical performance of the Atyp.C parameter of the UF-5000 fully automated urine particle analyzer with that of microscopic urine sediment analysis.

A Objectives: Urinalysis is one of the most common laboratory screening tests to detect problems in the renal and urinary system; however, they cannot detect atypical cells (Atyp.Cs). The Sysmex UF-5000, a fully automated urine particle analyzer, can detect Atyp.

Novel absorbance peak of gentisic acid following the oxidation reaction.

Gentisic acid (GA), a metabolite of acetylsalicylic acid (ASA), and homogentisic acid (HGA), which is excreted at high levels in alkaptonuria, are divalent phenolic acids with very similar structures. Urine containing HGA is dark brown in color due to its oxidation. We recently reported a new oxidation method of HGA involving the addition of sodium hydroxide (NaOH) with sodium hypochlorite pentahydrate (NaOCl·5H2O), which is a strong oxidant.

Midstream urine sampling is necessary for accurate measurement of the urinary level of neutrophil gelatinase-associated lipocalin in healthy female subjects.

Background: Urinary neutrophil gelatinase-associated lipocalin is an established biomarker of acute kidney injury, however, the levels are affected by the number of white blood cells in the urine. As we suspected the portion of the urinary stream sampled could also have a significant influence on the urinary NGAL levels in female subjects, we investigated the influence of the urine sampling procedure on the urinary NGAL levels.

Methods: We collected 25-mL urinary specimens from each of initial-stream and midstream urinary specimens, including 28 healthy adult female volunteers without kidney diseases or UTI.

Absorbance measurements of oxidation of homogentisic acid accelerated by the addition of alkaline solution with sodium hypochlorite pentahydrate.

The urine of patients with alkaptonuria turns dark brown due to the oxidation of homogentisic acid (HGA) to benzoquinone acetic acid (BQA), and this is accelerated by the addition of alkali. We recently reported that alkaptonuric urine and HGA after the addition of alkali showed characteristic peaks at 406 and 430 nm. In order to improve the sensitivity of our spectrometric method for the detection of HGA, we accelerated the oxidation of HGA to BQA using sodium hypochlorite pentahydrate (NaOCl·5HO), which is a strong oxidant.

Enhancing the Detection of Dysmorphic Red Blood Cells and Renal Tubular Epithelial Cells with a Modified Urinalysis Protocol.

Urinary sediment is used to evaluate patients with possible urinary tract diseases. Currently, numerous protocols are applied to detect dysmorphic red blood cells (RBCs) and renal tubular epithelial cells (RTECs) in urinary sediment. However, distinct protocols are used by nephrologists and medical technologists for specimen concentration and observation, which leads to major discrepancies in the differential counts of formed elements such as dysmorphic RBCs and RTECs and might interfere with an accurate clinical diagnosis.

Novel round cells in urine sediment and their clinical implications.

Background: Voided urine contains a variety of cells from the kidney and urinary tract and urinalysis provides us various information by investigating cellular components. We investigated urine sediment from renal impaired patients.

Results: We found 'round cell' to be distinct from known cells in sediment and is close to proximal convoluted tubule-derived cells based on morphology and molecular marker expression (GGT1 but not podocalyxin).

[How Far We can Diagnose by Urine Sediment Tests?].

Morphological examinations for renal disease are mainly renal biopsy and urine sediment tests. Biopsy specimens are now evaluated in detail, and test items are evaluated as highly sensitive and specific compared with urine sediments, which reflect renal changes indirectly and are low in sensitivity and specificity. On the other hand, the standardization of urine sediment tests is now in progress, and some labs can provide sediment results beyond screening for distracted RBC, differential WBC, or atypical cells.

Detection of novel visible-light region absorbance peaks in the urine after alkalization in patients with alkaptonuria.

Background: Alkaptonuria, caused by a deficiency of homogentisate 1,2-dioxygenase, results in the accumulation of homogentisic acid (2,5-dihydroxyphenylacetic acid, HGA) in the urine. Alkaptonuria is suspected when the urine changes color after it is left to stand at room temperature for several hours to days; oxidation of homogentisic acid to benzoquinone acetic acid underlies this color change, which is accelerated by the addition of alkali. In an attempt to develop a facile screening test for alkaptonuria, we added alkali to urine samples obtained from patients with alkaptonuria and measured the absorbance spectra in the visible light region.

[Chairmen's introductory remarks].

Recently, mild to moderate renal dysfunction has attracted attention as a new common disease in Japan as well as all over the world. Also, the morbidity of endstage renal disease and progression to dialysis is increasing each year. It is now widely recognized that renal dysfunction is a major risk for cardiovascular disease; therefore, cardio-renal relationships should be investigated.