European journal of clinical chemistry and clinical biochemistry : journal of the Forum of European Clinical Chemistry Societies
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In order to obtain shared reference limits, three laboratories in the same geographical area with a homogeneous population have developed a proposal to produce multicentric reference values. The strategy simulates a virtual laboratory, actually formed by the laboratories involved; the reference limits produced in the virtual laboratory are in fact derived from the blend of reference values obtained by each laboratory. Each laboratory has chosen its own reference sample and has measured the biochemical quantities under study. ⋯ For each quantity, each laboratory, with the results observed in their reference sample, estimated the diagnostic specificity, using as cut-off values the corresponding multicentric reference limits. Each observed value of diagnostic specificity was compared with the theoretical diagnostic specificity value, equal to 0.975, that should be observed when a reference limit is used as cut-off value. The multicentric reference limits obtained by the virtual laboratory are valid in all cases with the exception of the upper reference limit for the concentrations of calcium(II) and urate in serum in one of the laboratories.
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Eur J Clin Chem Clin Biochem · Apr 1997
Accuracy of cholesterol measurements in Italian clinical laboratories. Joint project GISSI prevention--Italian Society of Clinical Biochemistry. SIBioC GISSI Prevenzione Group.
We report the results of an external quality assessment scheme for serum total cholesterol measurement involving about 100 Italian laboratories participating in an epidemiological study of post myocardial infarction. Two frozen human serum pools with Abell-Kendall assigned values are distributed quarterly at the laboratories (up to now seven events occurred); the obtained results are evaluated and discussed. ⋯ But, while precision (calculated on the six replicates of exercise # 5) is good (90% of the laboratories obtained CV < 3%), inaccuracy problems are evident in every event. Indeed the mean bias from the reference method value ranged from 1.54 and 3.49% in the various events.
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Eur J Clin Chem Clin Biochem · Feb 1997
Coagulation and fibrinolysis activation markers in prostatic carcinoma patients.
In 49 patients with benign prostatic hyperplasia, 24 metastatic prostatic carcinoma patients all under palliative hormonal treatment, 17 untreated prostatic carcinoma patients without metastases and 14 untreated prostatic carcinoma patients with metastases, plasma levels of thrombin-antithrombin III complex, D-dimer and plasmin-alpha2-antiplasmin were determined. The coagulation activation marker thrombin-antithrombin III complex did not show any significant difference between the different patient groups. ⋯ The nature of these findings is discussed and related to other relevant literature. The general conclusion is that fibrinolysis may not play such a prominent role in prostatic carcinoma as described and expected.
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Eur J Clin Chem Clin Biochem · Apr 1996
Report on the symposium "Drug effects in Clinical Chemistry Methods".
The aim of the symposium was to establish a list of 20-30 drugs and to determine test concentrations (at therapeutic levels and above) that would indicate interference to clinical chemistry methods in serum and plasma. The following agents were chosen: Acetaminophen, Acetylcysteine, Acetylsalicylic acid, Ampicillin, Ascorbic acid, Ca-Dobesilate, Cefoxitin, Cyclosporine, Heparin, Ibuprofen, Intralipid, Levodopa, Methyldopa, Metronidazole, Phenylbutazone, Rifampicin, Tetracycline, Theophylline.
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While porphyria cutanea tarda and porphyria variegata are independent diseases, we report on seven rare cases with a coincidence of these two different porphyrias in one individuum. The mutual clinical symptom was a cutaneous photosensitivity, which is a major symptom in porphyria cutanea tarda and a facultative one in porphyria variegata. Additionally, five patients had also experienced episodes of acute abdominal pain, which were in three cases accompanied by neurological symptoms, thus offering evidence for an acute hepatic porphyria, such as porphyria variegata. ⋯ Fecal porphyrin excretion also resembled the variegate-type with a high concentration especially of protoporphyrin (mean 628 nmol/g dry weight, range 401-1018, normal < or = 151), accompanied by an increase of coproporphyrin (mean 194 nmol/g dry weight, range 75-409, normal < or = 37). The urinary porphyrin precursors 5-aminolaevulinic acid and porphobilinogen were markedly elevated only in one patient, who was in an acute porphyric phase at the time of investigation. The activity of uroporphyrinogen decarboxylase in erythrocytes was considerably decreased in six of our cases (33-64%) and slightly diminished in the other one (83% of normal activity).(ABSTRACT TRUNCATED AT 250 WORDS)