New immunoassay for the detection of Helicobacter pylori infection compared with urease test, 13C breath test and histology: validation in the primary care setting.

Helicobacter pylori plays a major role in peptic ulcer disease and, as a result, testing for H. pylori infection among patients with dyspepsia has often been advocated. The aim of the study was to determine the diagnostic accuracy, the analytical performance, and optimal cut-off point of a new serological assay, the Pyloriset EIA-G III for the detection of H. pylori infection in the primary care setting. For 113 primary care patients with dyspepsia urea breath test, CLO test, histology and serology tests were performed. Diagnostic accuracy of the Pyloriset EIA-G III was evaluated against a reference standard of a carbon urea breath test (CUBT), CLO test and histology (from gastric biopsies). Precision, linearity and correlation of the serological assay with the CUBT and former Pyloriset were also determined. At the optimal cut-off level of 40 U/ml, the positive predictive value was 92.1%, negative predictive value 96.3%, sensitivity 87.5%, and specificity 93.9%. The within-run precision was high. The recovery data were good. The correlation of both CUBT and the former Pyloriset EIA-G and the Pyloriset EIA-G III was high. At the cut-off level of 40 U/ml, the new Pyloriset EIA-G III is a reliable method to detect H. pylori infection in the primary care setting.

Standardized comparison of processing capacity and efficiency of five new-generation immunoassay analyzers.

BACKGROUND: With the trend toward laboratory and workstation consolidation, more studies are necessary to evaluate instrumentation, solutions for coping with workflow and test diversity, and opportunities for increasing the overall efficiency of laboratory testing. We assessed the processing capacity and efficiency of new-generation immunoassay analyzers by determining productivity parameters of five commercially available systems. METHODS: A workload protocol was developed and used to assess processing capacity and efficiency parameters of five immunoassay analyzers under standardized conditions in a real-life routine situation. We studied the ACS:Centaur((R)) (analyzer A), Architect(TM) i2000 (analyzer B), Elecsys((R)) 2010 tandem (analyzer C), Immulite((R)) 2000 (analyzer D), and Vitros ECi (analyzer E) on the basis of a standardized workload protocol that reflected a routine laboratory situation. This workload encompassed reflex and STAT testing, dilutions, and in-run calibration of a new reagent lot number. The analyzers were compared for hands-on labor time, unattended time (UT), throughput, and differentiated relative productivity indexes [RPI((UT)); number of reportable results/(processing time - sum of unattended time)]. The RPI data for analyzers linked to an automated (aut) sample-handling system [RPI((aut))] were also calculated. RESULTS: The evaluation produced a set of parameters for the productivity of the instruments. An overview of the most important parameters revealed the following: the throughput was 193, 123, 97, 109, and 46 tests/hour for instruments A, B, C, D and E, respectively; the RPI((10)) was 425, 238, 161, 445, and 151 tests/operator-hour; the RPI((30)) was 229, 136, 118, 264, and 86 tests/operator-hour; the RPI((10,aut)) was 1701, 637, 235, 964, and 223 tests/operator-hour; and the RPI((30, aut)) was 298, 150, 174, 400, and 114 tests/operator-hour. CONCLUSIONS: The combination of a standardized workload protocol and determination of parameters for productivity and labor efficiency, especially the differentiated RPIs, made it possible to make an objective comparison of the organizational consequences of the use of these instruments. The described parameters allow for a scientifically based choice, given a certain workflow and a particular laboratory organization.

[The effect of age and activity on arterial oxygen pressure and arterial oxygen saturation in hospitalized patients]. / Het effect van leeftijd en activiteit op arteriële zuurstofspanning en arteriële zuurstofsaturatie bij gehospitaliseerde patiënten.

In order to obtain adequate normal values for arterial blood gas values, the effect of aging and activity was investigated by cross-sectional selection in an in-patient population of 108 patients aged between 20 and 90 years. The patients were free of pulmonary, cardiac and metabolic disease. Smoking and obesity were tolerated up to specified limits. Arterial blood was obtained during standardised resting and active states. The results show a clinically important and highly significant (p less than 0.001) decline of the oxygen tension (PaO2) with age and also a considerable effect of minor activity (p less than 0.01) on blood gas values. However, the relationship of both oxygen tension and oxygen saturation with age is not a linear function as suggested in previous studies. For the interpretation of arterial oxygen tension values or to define hypoxaemia, only normal values related to age and activity should be used. In the elderly, low levels of PaO2 are encountered regularly. Determination of the oxygen saturation may be helpful, especially in differentiating between a normal and a pathological state.