Biomedical subjects
E Magid
Publications and source records attributed to E Magid.
Some concepts and principles of clinical test evaluation. Classification, analytical performance, monitoring and clinical interpretation.
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4. Bergmeyer Conference--Introduction.
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[Evaluation of a clinical examination in theory and practice: capillary bleeding time].
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[Costs and prices of laboratory services].
Cost accounting is performed in private and public laboratories. Guidelines for these activities are required and with this objective in mind, the Board of the Danish Society of Clinical Chemistry commissioned a working group to produce a position paper which is presented now in this report. The report discusses the objectives, the principles and the general requirements for cost accounting. The significance of information on costs for the clinicians' rational use of the laboratory is also illustrated. The working group points out that prerequisites for lucid and appropriate costing guidelines are clarification of which purposes information on costs are meant to serve, identification of the relevant cost centers and quality assurance of laboratory services to a defined extent. It is common practice to express laboratory costs as costs per test. The report advocates calculation of the cost per patient contact, i.e. the overall costs for laboratory service in a given investigative situation.
Project outline proposals for two immunomethod reference systems.
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Improvement of the clinical laboratory--regulations, paradigms, and professional responsibilities.
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Bergmeyer conference: laboratory measurements in lipid disorders.
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Annual reports from departments of clinical chemistry: a NORDKEM project.
The purpose of this report is to describe briefly the structure and purpose of NORDKEM, to illustrate how projects are developed within NORDKEM, and to discuss the results obtained in the project chosen for this presentation.
Adrenergic effects on secretion of amylase from the rat salivary glands.
The present study was undertaken to investigate the effect of adrenergic agents on secretion of amylase from the salivary glands in vivo. Saliva was collected from the distal oesophagus in conscious rats. Adrenaline increased the concentration of amylase in saliva and serum significantly. The result of infusion of alpha- and beta-adrenergic antagonists as well as noradrenaline and isoproterenol showed that secretion of salivary amylase is predominantly mediated by stimulation of beta-adrenergic receptors, especially of the beta 1-subtype. Investigation of the isoenzyme pattern in saliva, pancreatic juice and serum demonstrated that the major component in serum is salivary amylase. This study has shown that beta-adrenergic agents stimulate secretion of amylase from the salivary glands in rats. Though the secretion is mainly exocrine small amounts of amylase is found in serum, which seems to originate from the salivary glands.
Salivary secretion of rat haptocorrin and amylase is stimulated by vasoactive intestinal polypeptide.
Rat salivary glands secrete the cobalamin-binding protein haptocorrin and the enzyme amylase. We report the secretion to be stimulated in a dose-dependent manner by vasoactive intestinal polypeptide (VIP). VIP especially enhances the secretion of amylase. The concentration of amylase increases in saliva and in serum while the concentration of haptocorrin increases only in saliva. Serum contains a cobalamin-binding protein that differs from the binding protein in saliva. The serum cobalamin-binding protein is classified as transcobalamin.
Concentrations of secretin and CCK in plasma and pancreatico-biliary secretion in response to intraduodenal acid and fat.
To study the effect of emulsified oleic acid on pancreatic secretion and concentrations of secretin and cholecystokinin (CCK) in plasma, eight normal subjects received three sets of duodenal perfusates containing peptone pH 6.0 or pH 2.7, with and without 20 mM oleic acid. Pancreatic secretion was measured by an indicator dilution technique. At pH 6.0, peptone and oleic acid was about as effective as peptone pH 2.7 in stimulating secretin release. However, oleic acid in addition produced a three-fold increase in plasma CCK and was five times as effective as pH 2.7 in stimulating duodenal flow. Also, at pH 2.7, oleic acid augmented pancreatic secretion and concentrations of CCK and secretin in plasma. Duodenal output of amylase and bile salts was independent of the pH of infusate. Low pH alone was a very weak stimulant of CCK release and did not stimulate output of amylase and bile. Emulsified oleic acid is a potent releaser of secretin and CCK and augments the acid-induced pancreatic secretion.
SCE Nordic alpha-amylase study. II: Assessment of proposed calibration procedure. A report by the Scandinavian Committee on Enzymes (SCE).
Eighty-seven Nordic Hospital laboratories participated in a joint SCE-NORDKEM follow-up study of the long-term stability of the previously established calibration factors for a number of alpha-amylase routine methods based on six different substrates. Human control materials with 90% pancreatic, 90% salivary, and pure pancreatic alpha-amylases were measured by the participants. The data were plotted before and after calibration of each method using a human pancreatic calibrator with an assigned catalytic concentration of 390 U/l (Phadebas blue starch method, 37 degrees C). As in the previous study, carried out 9 months earlier, the pre-calibration values varied over a six-fold range. The post-calibration values of all methods except those based on a tetraose substrate showed an acceptable inter-laboratory comparability. As a temporary measure, SCE recommends that the Nordic laboratories calibrate the accepted routine methods by their individual calibration factor. Detailed suggestions for calibration procedures and a discussion of the principles of transferability will shortly be published by the SCE in this journal.
Duodenal output of lactoferrin in normal subjects and correlation to output of amylase, bicarbonate, and total bile acids.
Nineteen normal subjects were studied before and after pancreatic stimulation. Duodenal flow was quantitated by means of a dilution indicator technique, and the secretion pattern of lactoferrin, amylase, total bile acids, and bicarbonate was studied. Output of lactoferrin in the duodenum was increased both after stimulation with a test meal and after hormonal stimulation by cholecystokinin alone or cholecystokinin in combination with secretin. Output of lactoferrin was not affected by stimulation by secretin alone. Lactoferrin was secreted in parallel with amylase and bile acids. The results indicate that the origin of lactoferrin in duodenum can be bile or pancreatic juice, or a combination of these.
Duodenal output and concentration of lactoferrin in chronic pancreatitis: correlation to amylase secretion and duct morphology.
To evaluate the clinical value of lactoferrin determination in duodenal contents in patients with chronic pancreatitis, three different studies were performed. No significant difference in meal stimulated output or secretion pattern was found between seven patients with chronic pancreatitis and six controls. After a meal test in 88 patients suspected for pancreatitis no correlation between concentration of lactoferrin and amylase was found. No correlation was found between degree of obstruction at endoscopic retrograde pancreaticography and duodenal concentration of lactoferrin. We conclude that the diagnostic value of lactoferrin determinations in chronic pancreatitis is doubtful.
[Quantitative estimation of isoamylase in the serum of patients with acute abdomen].
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SCE Nordic alpha-amylase method selection and calibration study. A report by the Committee of Enzymes of the Scandinavian Society for Clinical Chemistry (SCE).
Seventy-six Nordic routine laboratories participated in a joint SCE-NORDKEM study comprising evaluation, selection, and temporary calibration of amylase methods. Human control materials with known fractions of salivary and pancreatic amylase were determined by seven routine amylase assays based on substrates with glucosyl (G) chain lengths G4, G5, G5-6, G7, G9, amylopectin and blue starch polymer (Phadebas). The data were plotted before and after calibration of each method using a human pancreatic calibrator with an assigned value of 390 U/l (37 degrees C, Phadebas). the study led to three conclusions: The analytical overestimation of salivary to pancreatic amylase ratio (S:P) increased with decreasing number of glucosyl units in the substrates. Relative to the S:P value of blue starch polymer (set at 1.00), for example, tetraose mean S:P value was 1.55. The hydrolysis rates relative to that with blue starch polymer decreased with the number of glucosyl units in the substrates. The precalibration values of all methods spread over an approximately six-fold range. Post-calibration values of all methods, except tetraose, showed an acceptable inter-laboratory comparability. The CV values for low, medium, and high controls were about 5.5, and 6% respectively. As a temporary solution to the current problem of diverse amylase assays, the SCE suggests calibration of the methods considered acceptable in this study. The long-term effects will be evaluated in a follow-up study within a year.
The clinical significance of salivary amylase in duodenal aspirates in evaluation of exocrine pancreas function.
Salivary and pancreatic amylases in duodenal aspirates were quantitated in 419 consecutive tests performed on 378 patients suspected of having insufficiency of the exocrine pancreatic function. Salivary amylase was detected in samples from 31% of the tests. However, the amount of salivary amylase was sufficient to cause a misinterpretation in 13 tests only. Five of these tests originated from patients with a history of surgery for peptic ulcer disease. This group of patients tended to have large amounts of salivary amylase in the duodenal aspirates. In the unoperated patients (n = 336) 200 tests yielded values for the total amylase concentration above the lower level of the reference interval, and only in 8 of these tests (4%) did correction for salivary amylase change the results to values below the reference interval. It it concluded that quantitation of isoamylase activity in duodenal samples is unlikely to be of significant value in patients without a history of surgery for peptic ulcer disease.