Evaluation of the appropriate time period between sampling and analyzing for automated urinalysis

Introduction

Preanalytical specifications for urinalysis must be strictly adhered to avoid false interpretations. Aim of the present study is to examine whether the preanalytical factor ‘time point of analysis’ significantly influences stability of urine samples for urine particle and dipstick analysis.

Materials and methods

In 321 pathological spontaneous urine samples, urine dipstick (Urisys™2400, Combur-10-Test™strips, Roche Diagnostics, Mannheim, Germany) and particle analysis (UF-1000 i™, Sysmex, Norderstedt, Germany) were performed within 90 min, 120 min and 240 min after urine collection.

Results

For urine particle analysis, a significant increase in conductivity (120 vs. 90 min: P < 0.001, 240 vs. 90 min: P < 0.001) and a significant decrease in WBC (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), RBC (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), casts (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001) and epithelial cells (120 vs. 90 min P = 0.610, 240 vs. 90 min P = 0.041) were found. There were no significant changes for bacteria. Regarding urine dipstick analysis, misclassification rates between measurements were significant for pH (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), leukocytes (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), nitrite (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), protein (120 vs. 90 min P < 0.001, 240 vs. 90 min P<0.001), ketone (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), blood (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), specific gravity (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001) and urobilinogen (120 vs. 90 min, P = 0.031). Misclassification rates were not significant for glucose and bilirubin.

Conclusion

Most parameters critically depend on the time window between sampling and analysis. Our study stresses the importance of adherence to early time points in urinalysis (within 90 min).Key words: urinalysis, automation, analytical sample preparation methods, flow cytometry, specimen handling     

Restrukturierung objektorientierter Datenbankschemata mittels formaler Begriffsanalyse

Zusammenfassung.   Eine Restrukturierung eines gegebenen Datenbankschemas kann aus unterschiedlichen Gründen notwendig werden. So kann dadurch z.B. die Verst?ndlichkeit des Schemas verbessert werden. Im Bereich der relationalen Datenbanken steht die Normalisierungstheorie zur Verfügung, um z.B. Redundanz zu vermeiden. Der Normalisierung liegt dabei ein Begriff der ?quivalenz von Datenbankschemata zugrunde. Im Bereich der objektorientierten Datenbanken gibt es bislang kaum vergleichbare Ans?tze. In diesem Beitrag pr?sentieren wir daher einen Ansatz, mit dem Klassenhierarchien in objektorientierten Datenbankschemata in eine „normalisierte” Form transformiert werden k?nnen. Dazu mu? zun?chst eine extensionale Analyse durchgeführt werden, die die notwendigen Informationen über extensionale Beziehungen zwischen den gegebenen Klassen liefert. Anschlie?end wenden wir Konzepte der formalen Begriffsanalyse an, um eine „normalisierte” Klassenhierarchie abzuleiten. Eingegangen am 16. Januar 1999 / Angenommen am 3. Oktober 1999     

Can high stakes national testing improve instruction: reexamining conventional wisdom

In this paper, the authors draw on recent international experience to assess the success of five propositions for how high stakes national testing can improve classroom instruction and, ultimately, raise student achievement. Findings indicate that testing can be an effective mechanism for improving instructional practice, but its success is not ensured. It has failed as often as it has succeeded, usually because those implementing the strategy failed to understand the intermediate conditions that had to be met for changes in test content, format, or use to have the desired impact on teachers' classroom practice.     

Assay validity of point-of-care platelet function tests in thrombocytopenic blood samples

IntroductionPoint-of-care (POC) platelet function tests are faster and easier to perform than in-depth assessment by flow cytometry. At low platelet counts, however, POC tests are prone to assess platelet function incorrectly. Lower limits of platelet count required to obtain valid test results were defined and a testing method to facilitate comparability between different tests was established.Materials and methodsWe assessed platelet function in whole blood samples of healthy volunteers at decreasing platelet counts (> 100, 80-100, 50-80, 30-50 and < 30 x10⁹/L) using two POC tests: impedance aggregometry and in-vitro bleeding time. Flow cytometry served as the gold standard. The number of platelets needed to reach 50% of the maximum function (ED₅₀) and the lower reference limit (ED_ref) were calculated to define limits of test validity.ResultsThe minimal platelet count required for reliable test results was 100 x10⁹/L for impedance aggregometry and in-vitro bleeding time but only 30 x10⁹/L for flow cytometry. Comparison of ED₅₀ and ED_ref showed significantly lower values for flow cytometry than either POC test (P value < 0.05) but no difference between POC tests nor between the used platelet agonists within a test method.ConclusionCalculating the ED₅₀ and ED_ref provides an effective way to compare values from different platelet function assays. Flow cytometry enables correct platelet function testing as long as platelet count is > 30 x10⁹/L whereas impedance aggregometry and in-vitro bleeding time are inconsistent unless platelet count is > 100 x10⁹/L.     

Reading Orthographically Strange Nonwords: Modelling Backup Strategies in Reading

The latest version of the connectionist dual process model of reading (CDP++.parser) was tested on a set of nonwords, many of which were orthographically strange (e.g., PSIZ). A grapheme-by-grapheme read-out strategy was used because the normal strategy produced many poor responses. The new strategy allowed the model to produce results similar to individual participants. Given that the strategy uses only simple information acquired in the normal course of learning, it shows that it is a plausible method for reading when the normal method fails and offers insight into how groups with low orthographic exposure might read.     

Becoming Whole: A Letter to a Young,Miseducated Black Teacher

The author uses this conceptual paper to present her personal narrative of transformation from miseducated (schooled) to educated (cultural broker) as a pretext to explore miseducation among young Black teachers. The author’s personal transformation comes in response to the neglect of teacher educators to attend to our few African American preservice teachers. Using a letter format, this paper places a particular focus on African American teachers and teacher educators, who agonize over how to transmit culture when they themselves have been miseducated.     

The Bologna process and its impact on higher education at Russia’s margins: the case of Kaliningrad

Embracing the Russian Federation since 2003, the Bologna process is no longer exclusively confined to western European countries. As early as 1999, Vladimir Putin declared the Russian exclave of Kaliningrad, wedged between Lithuania and Poland, as a potential pilot region for intensified cooperation between Russia and the EU on a number of policy areas, including higher education. In this paper, we study whether the Bologna process has served to underpin these ambitions. With a view to the EU, we will ask to what extent the European Union has proffered a model or directly influenced the path for transformation of Kaliningrad’s higher education system. We argue that a number of Kaliningrad-based actors in higher education have recognized the salience of European models and the need to work closely with partners from the EU, while Moscow only allows for marginal discretion in terms of Kaliningrad’s higher educational policy.