The disposal of chemical waste from hospital laboratories as background for the handling of waste from H1.
Explore the source record for details and available documents.
Blood↗
Biomedical subjects
A Uldall
Publications and source records attributed to A Uldall.
Kits for the diagnosis of infectious mononucleosis compared with the Paul-Bunnell test.
We compared the results obtained with six different test kits for infectious mononucleosis with those obtained with the Paul-Bunnell test. The investigation was carried out in one laboratory using 149 selected pools of patient sera. Each pool was tested three times with the Paul-Bunnell test and once with each kit. The results obtained with the kits were grouped according to the titre found with the Paul-Bunnell test. The percentage of positive results within each group was calculated for each kit. The Paul-Bunnell titre, which would have classified 50% of the specimens as positive, was estimated for each kit and this was designated the 50% cut off value. In general, there was good agreement. However, false positive test results were found rather frequently with one kit (19%) and the 50% cut off values differed. One kit showed a 50% cut off value at about 8, another at about 16, and the rest at between 16 and 32. We suggest the introduction of improved internal quality control combined with external quality assessment.
Antibodies, Heterophile↗
Preparation of fresh frozen human sera for external quality assessment.
A procedure for preparation of unmodified and modified fresh frozen human quality testing sera is described. The materials have been used for external quality assessment in Denmark. Examples of improvements in external quality assessment schemes using this type of material are shown.
Alanine Transaminase↗
Quality assurance in clinical chemistry.
Explore the source record for details and available documents.
Chemistry, Clinical↗
Strategies and methods for the analytical investigation of urinary calculi.
Methods for the investigation of urinary calculi are briefly reviewed. Infrared spectrometry and X-ray diffraction provide results on the actual salts, including the different degree of hydration, in contrast to wet chemistry which only measures the ions of salts. Most often the quantitated ions can, however, be combined into salts by calculation, but the different degree of hydration cannot easily be recorded by wet chemistry. Wet chemistry, infrared spectrometry and X-ray diffraction can all provide reliable results. Routine performance should be generally improved by providing quantitative instead of 'qualitative' results. In wet chemistry calculation of recovery should be obligatory. Spectra covering 4000-400 cm-1 and probably also objective evaluation are important fields for improving infrared spectrometry. A laboratory service based on X-ray diffraction or infrared spectrometry should be available for laboratories using wet chemistry to investigate rare calculi. The results should preferably be given in molar units in accordance with IFCC recommendations. Names of components should conform to the IUPAC-nomenclature and trivial names should be avoided.
Humans↗
Quality assurance in clinical chemistry--time to go from theory to action.
Explore the source record for details and available documents.
Chemistry, Clinical↗
Visual tests for urinary amylase investigated in the routine laboratory.
Ninety-seven fresh urine specimens were tested in the routine laboratory with the Rapignost Amylase test strip, and the results were compared to those obtained using Phadebas Amylase test tablets to investigate the transferability of the results obtained by the Rapignost method to those of the Phadebas method under routine conditions. The fraction of conflicting negative results of Phadebas-positive specimens was 9% and the corresponding fraction of conflicting positive results was 13%. An attempt to improve the transferability by changing the comparison scale slightly did not succeed. However, a visual binary test based on 180 s incubation at 37 degrees C of 400 microliters urine in a suspension of a Phadebas Amylase test tablet seemed more suitable in selection of specimens with Phadebas amylase activity less than 2000 U/l (upper limit of the reference interval). These specimens amounted to approximately 75% of all amylase specimens in our laboratory.
Amylases↗
Measurement of ionized calcium with five types of instruments. An external quality assessment.
An external quality assessment for ionized calcium determinations was carried out in 24 laboratories in Northern Europe. Both protein-free and protein-containing test materials were included in the study. The average within-laboratory variation (CV) for all test materials was 3.1, 1.7, 1.2, 1.8 and 1.3% for the AVL 980 (AVL, Graz, Austria), the Microlyte (Kone, Espoo, Finland), the Nova 2 (Nova Biomedical, Newton, Ma USA), the Orion SS-20 (Orion, Cambridge, Mass., USA), and the ICA1 (Radiometer, Copenhagen, Denmark) respectively. The corresponding interlaboratory CV was 3.1, 2.9, 3.1 and 2.4%. The variation between types of instruments was even larger and caused differences of up to 33%. The results indicate a need for well-defined protein-containing control material.
Calcium↗
Preparation of frozen reference sera and examples of applications.
We describe procedures for preparation of human serum from ACD bank blood and bovine serum from slaughter house blood. Preparation techniques including filtration and dialysis are described in detail as well as how to obtain desired concentrations. Special attention has been drawn to procedures yielding low lactate dehydrogenase activity. Long-term storage should take place at -75 degrees C. Different frozen reference sera have been used for calibration purposes, internal quality control and external quality assessment.
Animals↗
Assessment of analytical quality in Nordic clinical chemistry laboratories using data from contemporary national programs.
The aim of this investigation was primarily to assess analytical quality expressed as between-laboratory, within-laboratory, and total imprecision, not in order to detect laboratories with poor performance, but in the positive sense to provide data for improving critical steps in analytical methodology. The aim was also to establish the present state of the art in comparison with earlier investigations to see if improvement in analytical quality could be observed.
Blood Chemical Analysis↗
Improvements in the routine investigation of urinary calculi.
Results from an external quality assessment program of urinary calculi analysis are shown. Some analytical improvements have been observed since a similar investigation two years earlier. Many erroneous results, however, were found. Best agreement was found between laboratories which produced results on an interval scale ("quantitative"). The laboratories in this group used either x-ray diffraction, infrared spectrometry, or wet chemistry. This, however, did not apply to the wet chemistry kit Merckognost 11003, which was used by 24 of the 57 participating laboratories. A study of this kit by our laboratory led to several improvements including better calibration and reduced imprecision. General recommendations of how to present the analytical results to the clinician are given.
Calcium Oxalate↗
Apparent interlaboratory variation using different types of reference sera.
Nine reference sera have been investigated in the same types of analyses in nine laboratories. Seven sera were of human origin, and two of animal origin. The analyses were repeated six times. Comparing the apparent interlaboratory variation of each reference serum, specimen associated effects were demonstrated. The effects were often considerable, and they were detected for nearly all of the analytes investigated: albumin, alkaline phosphatase, amylase, bilirubins, calcium (II), cholesterol, cobalamines, creatininium, creatine kinase, glucose, lactate dehydrogenase, magnesium (II), protein (total), and sodium ion. The effects are discussed according to their nature, viz. matrix effects, analyte simulation effects, and analyte concentration effects. These effects seemed distinct when poor methods were compared. Matrix effects were associated with lack of specificity, and analyte concentration effects with lack of linearity. The lyophilized serum from outdated bank blood showed the best agreement with fresh frozen pool of patients sera; the mixed bovine-equine lyophilized serum (AutonormTM, Nyegaard & Co. AS, Norway) showed the most frequent disagreements. Matrix and analyte simulation effects were probably the main cause.
Animals↗
External quality assessment programs in Denmark.
Explore the source record for details and available documents.
Animals↗
Analyte and matrix problems in the calibration and quality assessment of the bromocresol green method for albumin in serum.
Different batches of bromocresol green were used in a study of several modifications of the bromocresol green method for serum albumin. No major batch variation was observed. Lyophilized animal sera and a certain batch of lyophilized human sera, however, responded differently from a pool of fresh human sera when the method was modified. These phenomena should be taken into account in calibration procedures and in quality assessment.
Animals↗
A wet chemistry method for the analysis of urinary calculi.
A procedure for the routine investigation of urinary calculi is described. The investigation scheme was based on existing methods in the routine laboratory for calcium(II), magnesium(II), phosphate and urate in serum. The substance content of oxalate was calculated as non-phosphate-bound calcium(II). Furthermore the test for cystine in urine was utilized. Two specially designed tests were used, one for carbonate apatite and one for verification of the presence of oxalate. The scheme was applied to 30 specimens of human origin. The sum of the mass fractions of identified and calculated components in the calculi was found to be 0.88 on the average (s = 0.05). Low values for this sum may serve as an indication of the presence of rare components that are not included in this analytical programme. A few calculi containing rare components required special methods for the investigation and are most conveniently investigated in a specialized laboratory using X-ray diffraction or infra-red spectrometry. In this paper, however, we describe wet chemistry methods, suitable for reliable cystine determinations and for oxalate in calculi containing, for example, brushite, where the calculated oxalate value is uncertain. These methods may be used as an alternative to the physical methods for many of the rare calculi.
Autoanalysis↗
Inter-laboratory comparison of acid-base variable in human blood and in quality control materials.
Routine results, pH, partial pressure of carbon dioxide (pCO2) and of oxygen (pO2), and standard hydrogen carbonate ion concentration (SBC) in identical specimens of arterial blood from patients deviate substantially. The results from seven laboratories (each laboratory examining the same 12 patients and the same five types of quality control materials) and evaluation in terms of accuracy and precision suggest the variations between days (delta 2) and single measurements (sigma 2) to be the main factors for these deviations. A reduction of these variations must have the highest priority in quality control programmes, since the variations mask possible true level deviations between laboratories. The five control materials (Qualicheck, Quantra whole blood level I-II-III and hemolyzed donor blood) are not fully optimal as substitutes for patient blood in such quality control programmes.
Aged↗
Absorption of doxorubicin hydrochloride during bladder washings in treatment of noninvasive bladder tumors.
The absorption of doxorubicin hydrochloride (Adriamycin) in or through the urothelium has been determined as the difference between the instilled amount and the amount recovered after complete drainage of the bladder in 9 patients suffering from superficial urinary bladder tumors (grade I-II). A total of 22 absorption experiments were done. The relative deficit was found to be between 0 and 16 per cent (median 4 per cent). One of the reasons for the variations in the relative deficit was probably intravesical bleedings. One hundred seventy-two mumol. (100 mg.) doxorubicin was dissolved in 100 ml. isotonic saline, and the instilled liquid was retained in the bladder for one hour. No patient showed any sign of systemic side effects caused by doxorubicin. The results seem to indicate that it is possible to use a dose for intravesical instillation which is five times as high as the maximum dose for intravenous administration.
Absorption↗
Analysis of urinary calculi; a quality control programme.
Results of the first Nordic quality control programme on urinary calculi are described. The programme included nine specimens, nine components and 57 laboratories participated. Most of the specimens were mixtures of selected human calculi. Of the laboratories, 67% used a binary scale for the results("qualitative"); 80% of the laboratories were unable to carry out the analysis on 10 mg material or less. For most components false positive results were rare. Oxalate and calcium (II), however, were exceptions. Results on "mixed stones" were unsatisfactory; frequently 20% of the results were wrong. The fraction of false negative results is 0.10 for cystine and urate, and is generally higher for other components. No difference between the reliability of infrared spectrometry and of wet chemistry is observed. An ordinary internal quality control scheme is suggested to facilitate improvements of the routine analytical performance. Some ideas of the analytical strategy are discussed. The drawbacks of results from a binary scale are stressed, and it is suggested that the examination of urinary calculi be carried out using techniques which give results on continuous scales. At the same time the number of components for analysis in the routine programme may be reduced.
Ammonia↗