PubMed Health⌕ Search

Biomedical subjects

W Tritschler

Publications and source records attributed to W Tritschler.

17 recordsLinked to original sources
PubMed1995

Multicenter evaluation of a new capillary blood prothrombin time monitoring system.

The analytical performance of the new capillary blood prothrombin time monitoring system CoaguChek was examined in a multicenter evaluation at six hospitals. The coefficients of variation of the INR obtained in the CoaguChek imprecision study were approximately 7% in the control plasma provided (within-run and day-to-day) and 4% in blood (within-run). The prothrombin times were ascertained in capillary blood (CoaguChek PT Test) and citrated venous plasma (Hepato Quick, Thromborel S) from 359 patients under oral anticoagulation therapy with phenprocoumon, acenocoumarin or warfarin. The agreement with the test results obtained with the comparison methods was acceptable versus Hepato Quick assay (n = 359; y = 1.23 x -0.49, r = 0.888) and good versus Thromborel S method (n = 359; y = 1.09 x -0.28, r = 0.895). A simplified assessment of all test results (n = 795) in a nine-field comparison table showed a concordance with the comparison methods of more than 80 (Hepato Quick: 81%, Thromborel S: 83%). The concordance between Hepato-Quick and Thromborel S was slightly higher (88%). Its good analytical performance and convenient handling recommend the CoaguChek system as a suitable system for decentralized prothrombin time testing.

Blood Chemical Analysis↗
PubMed1993

Determination of potassium by dry reagent carrier technology: a multicentre evaluation.

We describe the construction, the reaction principle and the performance of Reflotron K+, a new Reflotron test for the quantitative determination of potassium in serum and heparinized plasma. The reaction principle is based on the introduction of the potassium cation via valinomycin into a non-polar phase; the accompanying loss of protons from the non-polar phase is detected by the colour change of a pH indicator. The multicentre evaluation of the reagent carrier system showed in median CVs of < 0.9% (within-series in heparinized plasmas) and 1.3% (run-to-run in control sera). The recovery in control sera was +/- 4% for seven laboratories. In the method comparison with flame emission spectrometry, using sera and heparinized plasma samples, regression analysis yielded correlations with slopes of 1.00 +/- 0.04 (median slope 1.005) and negligible intercepts. The reagent carrier system showed a linear response in the measuring range 2-12 mmol/l. Bilirubin (up to 513 mumol/l), triacylglycerols (up to 5,7 mmol/l), sodium (135-189 mmol/l) and ammonium ions (up to 590 mumol/l) did not interfere with the test. Comparison with the results from flame atomic emission spectrometry shows that the recoveries of Reflotron K+ and the direct potentiometric method are slightly and similarly influenced by total protein. With a panel of 28 drugs tested, no interference could be detected. Reflotron K+ provides a precise and reliable procedure for the measurement of potassium in serum and heparinized plasma.

Chemistry, Clinical↗
PubMed1988

Evaluation of determination of uric acid in serum and whole blood with the Reflotron.

The performance of the Reflotron system (Boehringer Mannheim) for the determination of urate in whole blood and serum was evaluated. Within-run and day-to-day imprecision of the system were comparable with those for a solution-chemistry enzymatic method (overall CVs in the range 2.2-2.5%). Results for 100 individual specimens with urate concentrations ranging from 16 to 134 mg/L agreed well with the comparison method, both for serum and whole blood. We saw no significant interference from lipemia or hemoglobin. Bilirubin interfered at concentrations greater than 100 mg/L. Hematocrit variation between 25% and 55% did not affect results for whole blood; variation of the applied sample volume from 28 microL to 35 microL (stated sample volume requirement: 30 microL) did not significantly influence the measured value. We consider results produced by the system to be of the same analytical quality as those obtained by the more conventional solution-chemistry methods that are currently available.

Bilirubin↗
PubMed1983

[alpha 2-Macroglobulin in serum and plasma: reference values with carbobenzoxy-valyl-glycyl-arginine-p-nitroanilide, a chromogenic substrate].

alpha 2-Macroglobulin can be determined using the amidolytic activity of the alpha 2-macroglobulin-trypsin-complex. Reference values are reported using a commercially available kit for continuous assay at 25 degrees C. Reference ranges obtained in a population of 235 children and adults aged between 1 day and 61 years were found to be age-dependent. Reference ranges established for the different age groups of children were grouped together in order to obtain useful guide values. The following values were obtained for serum: 1 to 10 days: 5-11 kU/l 11 days to 18 years: 8-16 kU/l The reference values (5th to 95th percentile) determined for juveniles and adults were as follows: 19 to 25 years: 4.1-12.2 kU/l (serum); 4.0-11.2 kU/l (citrated plasma) greater than or equal to 25 to 61 years: 4.1-8.1 kU/l (serum); 3.7-7.4 kU/l (citrated plasma) No variation according to sex was observed, nor was any difference noted between preprandial and postprandial catalytic concentrations, or between values in smokers and non-smokers or between values in the group of women taking hormonal contraceptives and the group not taking such drugs. If the dilution of the blood sample with citrate solution is taken into account when calculating the catalytic concentrations in citrated plasma, the values in plasma are higher than those in serum (median 11%). Measurement of the alpha 2-macroglobulin-trypsin complex in plasma is assumed to give a more realistic reflection of the in vivo activity than measurement in serum. Comparison with two immunological methods (radial immunodiffusion and kinetic nephelometry) revealed that there is a linear relationship between the measurement of the catalytic concentration of the alpha 2-macroglobulin-trypsin complex and the immunological concentration of alpha 2-macroglobulin. Therefore mutual conversion is possible for the described concentration range.

Adolescent↗
PubMed1983

[Acid phosphatase in blood (substrate: alpha-naphthylphosphate): reference values and diagnostic significance].

We report the results obtained with a modification of Hillmann's method (1) for determination of the catalytic concentration of acid phosphatase in serum using alpha-naphthylphosphate as the substrate. In a group of 158 males aged 16-85 years, the upper limit of the reference range (95th percentile) for the total acid phosphatase was established as 4.7 U/l (37 degrees C) and 4.2 U/l (30 degrees C), respectively; the corresponding values for the tartrate-inhibited acid phosphatase were 1.6 U/l (37 degrees C) and 1.5 U/l (30 degrees C). The upper limit of the reference range (95th percentile) for the total acid phosphatase determined in 60 females aged 18-80 years was 3.7 U/l (37 degrees C) and 3.0 U/l (30 degrees C). The catalytic concentrations in men and women did not show any age-related differences. The catalytic concentration of the tartrate-inhibited acid phosphatase was determined with the substrates alpha-naphthylphosphate and p-nitrophenylphosphate in a group of 89 patients with prostatic carcinoma (stages C and D). In 74 of these patients, the concentration of the prostatic specific acid phosphatase was assayed by enzyme-immunoassay and radioimmunoassay. The sensitivity of the method with p-nitrophenylphosphate was found to be unsatisfactory (66%), while that obtained with the other methods was superior and intercomparable (approx. 90%). The results obtained with the two substrates (p-nitrophenylphosphate vs. alpha-naphthylphosphate) differed significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Phosphatase↗
PubMed1983

[Cholinesterase (EC 3.1.1.8) with butyrylthiocholine-iodide as substrate: references depending on age and sex with special reference to hormonal effects and pregnancy].

Referance values are reported for the assay of cholinesterase (substratae: butyrylthiocholine iodide) in serum at 25 degrees C. There was no evidence of any age-dependency or sex-specific distinction in children (1 to 15 years, N = 309), nor were there any age-dependent changes observed in males (16 to 94 years, N = 718). Compared with the reference range for children, there was no detectable difference in the location and distribution of catalytic cholinesterase concentrations. In females (16 to 99 years, N = 861), an age-dependent difference in cholinesterase values became apparent: Regardless of pregnancy or use of hormonal contraceptives, the catalytic concentrations were found to be lower in younger females (16 to 39 years) than in older ones (greater than or equal to 40 years); the reference values in the older age group (40 to 99 years) did not differ from those of males and children. Therefore the following reference values are proposed (in each case 2.5 to 97.5 percentile: Children, males and females above 40 Years: 3.5 to 8.5 kU/l, Females (16-39 years, nonpregnant, not taking hormonal contraceptives): 2.8 to 7.4 kU/l, Females (18-41 years, pregnant or taking hormonal contraceptives): 2.4 to 6.0 kU/l.

Adolescent↗
PubMed1982

[alpha 1-antitrypsin: reference values in serum and plasma with benzoyl-D,L-arginine-p-nitroanilide, a chromogenic substrate].

Reference values for alpha 1-antitrypsin were determined using a commercially available kit for continuous assay at 25 degrees C. With a population of 100 probands aged between 20 and 60 years, a reference range of 1.4-2.4 kIU/l (1.9-3.4 g/l) was obtained for serum, and 1.4-2.1 kIU/l (1.9-3.0 g/l) for plasma. In each case, these ranges correspond to the 5th to 95th percentile. No variations according to age or sex were observed, or was any difference noted between preprandial and postprandial activities, or between values in smokers and nonsmokers. Significantly different values were found in the group of women taking oral steroid contraceptives and the group not taking such contraceptives. If the dilution of the blood sample with citrate solution is taken into account in calculating the activity in citrated plasma, it is apparent that higher values are found in plasma than in serum (median 13%): Hence, the in vivo-alpha 1-antitrypsin activity can most probably be better determined using a plasma sample.

Adult↗
PubMed1981

[Antithrombin III: reference values found with a chromogenic substrate (chromozym TH) (author's transl)].

A new kinetic assay for antithrombin III (heparin-cofactor) in plasma was used to determine reference values. Ranges of 10--15 IU/ml at 25 degrees C and 20--29 IU/ml at 37 degrees C were found for a reference population of 219 men and 204 women 15--93 years of age. There was no evidence that these values vary with age or sex, nor was there any difference between pre- and postprandial antithrombin activities, or between smokers' and non-smokers' values. None of the illnesses present in the reference population nor any related drug therapy affected the antithrombin III level, and there was no statistically significant difference between the values for women taking oral contraceptives and those who did not. However, this latter observation does not preclude the possibility of individual variation.

Adolescent↗
PubMed1980

[Creatine kinase "NAC-activated": reference values for children (author's transl)].

Reference values for 327 children aged between 1 day and 15 years are given for the revised standard method for the determination of serum creatine kinase (CK) activity by activation with N-acetylcysteine (NAC). No sex-dependence could be observed, but CK activity was found to vary markedly with age. The following values are suggested as upper limits of the reference ranges for measurements at 25 degrees C: neonates: 1-3 days: less than or equal to 370 U/l, 4-10 days: less than or equal to 200 U/l, 11-31 days: less than or equal to 100 U/l; children (2 months-15 years): less than or equal to 90 U/l.

Acetylcysteine↗
PubMed1979

[Diagnostic significance of lactate concentration in CSF in patients with meningitis (author's transl)].

White-cell count and differential blood count, total protein, lactate dehydrogenase activity (E.C. 1.1.1.27) and lactate concentration were determined in 496 CSF samples, obtained by lumbar puncture. Lactate was measured with a new enzymatic test. Reference values were determined for lactate and lactate dehydrogenase (90% limits: 1.2-2.1 mmol/l and 6-26 U/l, respectively). Lactate content proved to be best in the differential diagnosis between acute bacterial and abacterial meningitis: concentrations of 3.5 mmol/ml and above were found exclusively in bacterial meningitis. As for other diseases, markedly increased lactate concentrations were measured only in patients with brain tumour or cerebrovascular disease (up to 9.3 mmol/l). Determination of lactate concentration alone would have led to a misdiagnosis of acute bacterial meningitis in 3% of cases. If the CSF contains 3.5 mmol/l lactate or more and the leucocyte cell count is above 800/microliter, brain tumour or cerebrovascular disease can be practically excluded and the diagnosis of bacterial meningitis made with a high degree of reliability.

Adolescent↗
PubMed1977

[CSF cytology using prestained slides (author's transl)].

A new and rapid vital-stain method for the diagnosis of CSF cells demonstrates not only red blood cells but also white blood cell types, predominantly by differentiating nuclear patterns. 20 microliter untreated CSF are put on the prestained slides and a cover slip put over it. Differentiation can be made after 15 minutes. The lower limit is at 3-4 WBC/ml of CSF. At room temperature the preparation keeps for about an hour. The method is reproducible and has the advantage also over other routine methods that the CSF volume is very small and there is neither loss of cells nor cell denaturation.

Cerebrospinal Fluid↗
PubMedDate not supplied

[alpha-Amylase standard values in children].

In a group of 216 healthy children (age: 3 days-16 years) normal values of alpha-amylase in serum were found out (substrate: p-nitrophenyl-alpha, D-maltoheptaosid). Infants (age: 3-353 days) mostly showed lower catalytic concentrations than older children: alpha-amylase (25 degrees C) up to 30 U/L; alpha-amylase 37 degrees C): up to 60 U/L. But, the collective was too small (n = 30) to give any statistical statement, on the other hand biological and analytical deviations of catalytic concentrations were big. In children (n = 186; age: 1-16 years) the values were not dependent on sex or age. As normal range we propose for children aged 1-16 years alpha-amylase (25 degrees C): 20-110 U/L; alpha-amylase (37 degrees C): 40-200 U/L.

Adolescent↗