BACKGROUND: To understand causes of abnormal reaction for the urinalysis, we analyze the interfering substances of clinical urine samples. We focused the effect of urinary vitamin C and fluorescein sodium to the urine chemistry especially glucose, hemoglobin, and leukocyte esterase. METHODS: Incidence of urinary vitamin C was determined for patients and people underwent a medical check–up. We decided dipstick results of glucose, hemoglobin, and leukocyte esterase as false negative based on urine sediment and serum glucose results. Dipstick urinalysis was tested by URiSCAN Pro III with URiSCAN 11 strip (YD Diagnostics, Korea). Urine sediments tests were performed by manual microscopic analysis or Sysmex UF–1000i (Sysmex Co., Japan). RESULTS: The incidence of vitamin C was 20.4% for all subjects. The positive rate of the medical check-up group (34.6%) was higher than others. When vitamin C was detected in clinical urine samples, 42.3%, 10.6%, and 8.2% were defined as false negative for glucose, hemoglobin, and leukocyte esterase dipstick tests, respectively. Fluorescein sodium also interfered on the results of hemoglobin and leukocyte esterase of the dipstick reagents. CONCLUSIONS: Vitamin C was frequently found in the clinical urine samples, and its incidence was higher in the people who underwent medical check-up. The urinary vitamin C and fluorescein sodium can cause interferences in urine dipstick results. Thus, it is expected that present study will give useful information to predict false negative rates of urine dipstick tests by vitamin C and fluorescein sodium.
Ascorbic Acid ; Blood Glucose ; Chemistry ; Fluorescein ; Glucose ; Humans ; Incidence ; Indicators and Reagents ; Leukocytes ; Urinalysis*

Bronchiolitis obliterans organizing pneumonia (BOOP) is a clinicopathological syndrome associated with a variety of disease entities. The aim of this study was to review cases with initial diagnosis of BOOP applying uniform histopathologic criteria, and analyze the clinical characteristics of proven cases of BOOP including rapidly progressive form. A total of 81 cases, initially diagnosed as BOOP and with available tissue sections, was collected. Thirty six cases (44.4%) were excluded from the study, more than two thirds of which were given a revised diagnosis of interstitial pneumonitis/fibrosis other than BOOP. Thirty one patients were classified as idiopathic BOOP, 8 patients as secondary BOOP, and 6 patients as rapidly progressive BOOP. Open lung biopsy specimen from all six cases with lethal outcome showed more severe interstitial inflammation and septal fibrosis and/or alveolar exudate with a varying degree than those with good prognosis. There was no difference by the sexes. The two most frequent presenting symptoms were cough and dyspnea. Bilateral multifocal consolidation was a common radiological finding. More than 70% cases of idiopathic BOOP experienced clinical improvements. The diagnosis of BOOP is usually suggested by clinicoradiologic findings, but needs to be confirmed histopathologically, preferably through surgical open or video-assisted thoracoscopic biopsy.
Adult ; Blood Gas Analysis ; Bronchoalveolar Lavage ; Cryptogenic Organizing Pneumonia/drug therapy/pathology/*physiopathology ; Disease Progression ; Female ; Forced Expiratory Volume ; Humans ; Korea ; Male ; Middle Aged ; Treatment Outcome