IFCC primary reference procedures for the measurement of catalytic activity concentrations of enzymes at 37°C. Part 9: Reference procedure for the measurement of catalytic concentration of alkaline phosphatase International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Scientific Division, Committee on Reference Systems of Enzymes (C-RSE) 1)
Schumann G.,Institute For Klinische Chemie |
Klauke R.,Institute For Klinische Chemie |
Canalias F.,Autonomous University of Barcelona |
Bossert-Reuther S.,Hoffmann-La Roche |
And 7 more authors.
Clinical Chemistry and Laboratory Medicine | Year: 2011
This paper is the ninth in a series dealing with reference procedures for the measurement of catalytic activity concentrations of enzymes at 37 °C and the certification of reference preparations. Other parts deal with: Part 1. The concept of reference procedures for the measurement of catalytic activity concentrations of enzymes; Part 2. Reference procedure for the measurement of catalytic concentration of creatine kinase; Part 3. Reference procedure for the measurement of catalytic concentration of lactate dehydrogenase; Part 4. Reference procedure for the measurement of catalytic concentration of alanine aminotransferase; Part 5. Reference procedure for the measurement of catalytic concentration of aspartate aminotransferase; Part 6. Reference procedure for the measurement of catalytic concentration of γ-glutamyltransferase; Part 7. Certification of four reference materials for the determination of enzymatic activity of γ-glutamyltransferase, lactate dehydrogenase, alanine aminotransferase and creatine kinase at 37 °C; Part 8. Reference procedure for the measurement of catalytic concentration of α-amylase. The procedure described here is derived from the previously described 30 °C IFCC reference method. Differences are tabulated and commented on in Appendix 1. © 2011 by Walter de Gruyter Berlin Boston.
Heiligers-Duckers C.,Klinisch Chemisch en Hematologisch Laboratorium |
Werner P.T.,Afd. Interne Geneeskunde |
Van Drunen M.E.P.,Klinisch Chemisch en Hematologisch Laboratorium
Nederlands Tijdschrift voor Geneeskunde | Year: 2014
Reticulocytes are immature erythrocytes; the number of reticulocytes in the peripheral blood reflects erythropoietic activity. Two cases are described to illustrate the use of the reticulocyte count in the diagnostic workup of anaemia. The first patient was a 62-year-old woman presenting with fatigue. Laboratory evaluation showed severe macrocytic anaemia, thrombocytopaenia and the presence of schistocytes. A low reticulocyte count suggested decreased erythropoiesis underlying the anaemia; this led to the diagnosis of vitamin B12 deficiency. The second patient, a 52-year-old woman, also presented with fatigue and macrocytic anaemia. A high reticulocyte count indicated increased erythrocyte degradation, and the patient was eventually diagnosed with autoimmune haemolytic anaemia. The role of reticulocytes in the differential diagnostic workup of anaemia was explored on the basis of these case descriptions. The test methodology, analytical performance, reference values and pitfalls were discussed, as well as the reticulocyte indices and their use in monitoring therapy.
Pandit A.,Leiden University |
Wawrzyniak P.K.,Leiden University |
Van Gammeren A.J.,Leiden University |
Van Gammeren A.J.,Klinisch Chemisch en Hematologisch Laboratorium |
And 3 more authors.
Biochemistry | Year: 2010
Protein nuclear magnetic resonance (NMR) secondary chemical shifts are widely used to predict the secondary structure, and in solid-state NMR, they are often the only unambiguous structural parameters available. However, the employed prediction methods are empirical in nature, relying on the assumption that secondary shifts are only affected by shielding effects of neighboring atoms. We analyzed the secondary shifts of a photosynthetic membrane protein with a high density of chromophores and very tight packing, the lightharvesting 2 (LH2) complex of Rhodopseudomonas acidophila. A relation was found between secondary shift anomalies and protein-protein or pigment-protein tertiary and quaternary contacts. For several residues, including the bacteriochlorophyll- coordinating histidines (αH31 and βH30) and the phenylalanine αF41 that has strongly twisted Cb-Ca-C and C a-C-N conformations in the LH2 crystal structure, the perturbing effects on the backbone chemical shifts were tested by density functional theory (DFT) calculations. We propose that higher-order interactions in the tightly packed complex can induce localized perturbations of the backbone conformation and electronic structure, related to functional pigment-protein or protein-protein interactions. ©2009 American Chemical Society.
Ermens A.A.,Klinisch chemisch en hematologisch laboratorium
Nederlands tijdschrift voor geneeskunde | Year: 2011
A 1-year-old Moroccan boy was referred because of jaundice. A peripheral blood smear showed 'blister cells'. This finding is characteristic for haemolysis caused by glucose-6-phosphate dehydrogenase deficiency. It appeared hemolysis occurred because the boy ate fava beans.
Herpers R.L.J.M.,Klinisch Chemisch en Hematologisch Laboratorium |
Van Den Tooren-De Groot R.K.,Klinisch Chemisch en Hematologisch Laboratorium |
Van Rossum A.P.,Klinisch Chemisch en Hematologisch Laboratorium
Nederlands Tijdschrift voor Geneeskunde | Year: 2015
Coeliac disease can cause major growth retardation and failure to thrive in young children. However, the diagnosis of coeliac disease is not always straightforward. In this article, diagnostic approaches are discussed, i.e. when small bowel biopsy is needed, or when serological tests alone will suffice. Furthermore, two cases of young children potentially suffering from coeliac disease are presented. The first case is a fouryearold boy with growth retardation and gastrointestinal symptoms, the second case a 14monthold girl with growth retardation, gastrointestinal symptoms and rhinorrhoea. Using the current diagnostic algorithm for coeliac disease in young children, we analyse both cases, providing background information on the different laboratory tests involved. Conflict of interest: none declared. Financial support: none declared.
Cuperus F.J.C.,Klinisch Chemisch En Hematologisch Laboratorium |
Oosterwijk P.R.,Klinisch Chemisch En Hematologisch Laboratorium |
Vos A.,Klinisch Chemisch En Hematologisch Laboratorium |
Remijn J.A.,Klinisch Chemisch En Hematologisch Laboratorium |
And 2 more authors.
Nederlands Tijdschrift voor Geneeskunde | Year: 2013
We report 2 cases of visceral leishmaniasis in Dutch patients after a stay in Greece and the former Yugoslavia, respectively. Patient A, a 69-year-old woman, was referred to our department with abdominal pain. Additional examinations were suggestive of chronic liver disease. After a liver biopsy, which demonstrated hepatic granulomas, we admitted the patient due to a sudden onset of cyclic fever. Patient B, a 50-year-old woman, was admitted with cyclic fever and abdominal pain. We treated the patient with IV antibiotics and discontinued the methotrexate treatment for her rheumatoid arthritis. Both patients were diagnosed with visceral leishmaniasis and treated with liposomal amphotericin-B. Patient A, an immunocompetent patient, had stayed in Greece for prolonged periods. Patient B had lived in the former Yugoslavia until 1999, and her methotrexate use had likely activated an asymptomatic Leishmania infection. Visceral leishmaniasis, a potentially lethal protozoan disease, should be considered in patients who have travelled in Southern Europe.
Outsourcing laboratoria diagnostics - An analysis of the logistics using the Delft Systems Approach [Uitbesteding van laboratoriumdiagnostiek - Een analyse van de logistiek met behulp van de Delft Systems Approach]
Bos J.,Technical University of Delft |
De Jonge N.,Klinisch Chemisch en Hematologisch Laboratorium |
Veeke H.P.M.,Technical University of Delft
Nederlands Tijdschrift voor Klinische Chemie en Laboratoriumgeneeskunde | Year: 2014
The insourcing and outsourcing of diagnostic tests has a relatively large impact on the workload for clinical laboratories. The goal of this study is to gain insight in the logistical system of orders between clinical laboratories in the Netherlands. We observed the process and interviewed employees in three clinical laboratories, a transporter and a transportation service provider. We performed the analysis according to the Delft Systems Approach. The logistical system is subject to many requirements. However, evaluating the system on quantitative performance measures is not possible because of the lack of systematic feedback. The absence of unified protocols necessitates supplementing order information and gives rise to a relatively large workload for both the outsourcing and insourcing laboratory. Adding time and error registration will enable evaluation of the logistical system based on throughput times, throughput volume and success rate. Implementation of unified protocols can reduce the workload of the logistical system. © 1997-2014 Nederlandse V ereniging voor Klinische Chemie en Laboratoriumgeneeskunde.
van Rossum A.P.,Klinisch Chemisch en Hematologisch Laboratorium
Nederlands tijdschrift voor geneeskunde | Year: 2011
A 77-year-old man with dyspnoea was suspected to have a decompensatio cordis by the general practitioner. A diuretic was prescribed. Additional radiological and laboratory investigation (e.g. natriuretic peptides and D-dimers) showed pulmonary embolism instead of heart failure. A second patient, a woman aged 79 years, with a history of leukaemic mantle cell lymphoma, was treated with poly-chemotherapy (R-CHOP), after which remission was achieved. Four years later the lymphoma recurred and R-CHOP treatment was started. However this was without success, after which R-CHOP treatment was repeated. Subsequently the patient developed dyspnoea and pneumonia. Following additional radiological and laboratory investigation (e.g. natriuretic peptides) the patient was finally diagnosed with doxorubicin-induced heart failure. Based upon these case studies, the role of brain-natriuretic peptides in the differential diagnostic work-up of dyspnoea is highlighted. Test performance, correlation with disease, monitoring, prognostics, differential diagnostic power, reference values and pitfalls of brain natriuretic peptides are discussed.
What can point of care testing offer to a small general hospital for the provision of STAT-laboratory tests? [Wat heeft point of care testing te bieden in een klein algemeen ziekenhuis voor de vraag naar cito-laboratoriumonderzoek?]
Janssens P.M.W.,Klinisch Chemisch en Hematologisch Laboratorium |
Schipper M.H.,Klinisch Chemisch en Hematologisch Laboratorium
Nederlands Tijdschrift voor Klinische Chemie en Laboratoriumgeneeskunde | Year: 2010
In recent years point of care testing (POCT) has become more versatile and of improved quality. In light of the severe economic constraints on hospital-health care we considered whether we could replace the laboratory services provided by the laboratory unit in the small general hospital at the town of Zevenaar (180 beds) with outplacement of the regular laboratory production, while providing the required STAT-testing in the hospital with POCT carried out by the nurses. To this end, we made an inventory of the STAT requests during a 3 month period, and investigated to what extent these requests could be performed by the range of POCT available in The Netherlands. This showed that 3-7 point of care instruments (able to measure multiple constituents) and (singular) tests would be needed for each of the various nursing departments. No POC-instruments or tests are available for 8 laboratory investigations that are required as STAT by the physicians. In addition provisions would have to be made for handling the frequent STAT requests currently dealt with by the laboratory desk.
Van Der Vuurst H.,Klinisch Chemisch en Hematologisch Laboratorium |
Sigger J.,Klinisch Chemisch en Hematologisch Laboratorium |
Kemna E.H.J.M.,Klinisch Chemisch en Hematologisch Laboratorium |
Wissink J.G.A.M.,Klinisch Chemisch en Hematologisch Laboratorium |
Weykamp C.W.,Klinisch Chemisch en Hematologisch Laboratorium
Nederlands Tijdschrift voor Klinische Chemie en Laboratoriumgeneeskunde | Year: 2016
ISO 15189:2012 requires that the measurement uncertainty of tests in the laboratory are known and judged on basis of performance criteria. This is a challenging, and for many laboratories, laborious job. In this publication we describe a simple concept to derive measurement uncertainty from the annual report of the SKML, the External Quality Assessment (EQA) organisation in the Netherlands. Apart from its convenience and simplicity, the concept has the advantage of being the basis for long term monitoring of quality management. With this concept measurement uncertainty is objectively estimated and harmonised when applied by many laboratories. It thereby adds additional value to the EQA reports.