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Biomedical subjects

K Paschen

Publications and source records attributed to K Paschen.

At least 19 recordsLinked to original sources
PubMed1992

[Results of multicenter evaluation of reagents for determination of sodium, potassium and chloride ions using enzyme activation].

We present the results of a multicentre evaluation with Boehringer Mannheim/Hitachi instruments of new "enzymatic" methods for the determination of Na+, K+, and Cl- in serum or plasma. The between-day coefficient of variation was less than 1.4% (Na+), less than 2.6% (K+) and less than 1.7% (Cl-). The linear range of the assays were at least 80 to 200 mmol/l (Na+), 1.5 to 17 mmol/l (K+) and about 30 to at least 200 mmol/l (Cl-). The comparisons with routine flame atomic emission spectrometry and coulometry showed a satisfactory agreement of the test results. The "enzymatic" assays are insensitive to even grossly elevated levels of bilirubin and lipids (sodium, potassium, and chloride assays), NH4+ (potassium assay) and amylase (chloride assay). Interference by various drugs was not detected. Since the new methods can easily be adapted to photometric clinical chemistry instruments, they represent a valuable alternative to the use of ion-selective electrodes, flame atomic emission spectrometry and coulometry.

Calibration↗
PubMed1989

A candidate reference method for the determination of magnesium in serum.

A candidate reference method for the determination of magnesium in serum (analytical range 0.5 to 2.0 mmol/l) by flame atomic absorption spectrometry was commissioned. The relative standard deviation of the 4 replicates of each value ranged from 0.18 to 1.07%, and the standard error of the mean ranged from 0.63 to 8.34 mumol/l. In the analysis of 3 different standard solutions (prepared by weighing the analyte), which was performed in each of three different experiments the values recorded by the candidate reference method deviated by -0.15, 0.44 and 0.24%, respectively. The reference method value did not differ significantly from the definitive value. As the method seems to be as reliable as comparable reference methods for the determination of sodium, potassium or calcium, tests of transferability should now be undertaken.

Animals↗
PubMed1984

Serum beta 2-microglobulin level in type I diabetes: its dependence on the duration of diabetes and the quality of metabolic control.

As the level of serum beta 2-microglobulin (beta 2-M) has been shown to reflect renal function, its concentration was determined in serum and urine of patients affected by diabetes type I of various duration and quality of metabolic control. 104 diabetic patients, aged 7-39 (mean, 14.8) years, with an average duration of diabetes of 5.7 +/- 4.8 years studied as outpatients. Haemoglobin A1, beta 2-M in serum and urine, serum creatinine and protein were determined. The patients were classified into groups according to the quality of control (excellent, satisfactory or poor) and the duration of diabetes (less than 5 years, 5-8 years, more than 8 years). In patients with a duration of less than five years, lower beta 2-M levels were found if the quality of metabolic control was good than in patients controlled poorly (1.36 and 1.64 mg/l, respectively). Again in the group with a duration exceeding 8 years, patients with better control had a lower beta 2-M level than poorly controlled ones. Diabetes exhibiting a beta 2-M level higher than 1.6 mg/l, the upper limit of the normal range, had had diabetes for 8.6 years on the average, while those with a normal serum value only for 3.8 years. These findings have also been confirmed in 47 type I diabetics participating in a holiday camp.

Adolescent↗
PubMed1983

[Myoglobin-latex test. A new rapid test for the improvement of the early diagnosis of acute myocardial infarct].

Myoglobin concentrations were determined radioimmunologically and with a semiquantitative rapid latex test in 684 serum samples. There was a good correlation of both tests. The latex test becomes positive above 90 micrograms/l, i.e. the diagnostically relevant range. Myoglobin was determined in 27 patients with acute myocardial infarction at the same time as serum values of enzymes CK, CK-MB, LDH and GOT. This was done during three days every two hours. Diagnostically useful myoglobin increases were found on average already 2.6 +/- 0.9 hours after onset of pain, i.e. 3-4 hours before the first increase of enzymes CK-MB and CK. Out of 85 patients with acute myocardial infarction already 70% had a positive myoglobin latex test at the time of admission. In contrast, only 30% had increased enzyme activities (CK and CK-MB). Non-infarct-associated increases of myoglobin in serum were seen in patients with terminal renal failure, severe shock, muscle trauma, muscle diseases, alcohol intoxication and after reanimation.

Creatine Kinase↗
PubMed1982

[Correlations between lipoproteins and glycosylated hemoglobins in juvenile diabetes mellitus (author's transl)].

Based upon a 3-week observation at a summer camp for diabetic children whose medical therapy, metabolic rate, diet, physical exercise and special training could be closely monitored, the following parameters were measured at the beginning and at the end: In whole blood and young erythrocytes HbA1, in serum triglycerides, cholesterol, HDL-cholesterol, as well as apolipoprotein A and B. From these data, the LDL-cholesterol and the atherosclerosis indices (LDL-cholesterol/HDL-cholesterol and apolipoprotein B/apolipoprotein A) were determined. The following results were obtained: the parameters of lipid-metabolism recognized as risk factors for vascular complications such as triglycerides, cholesterol, LDL-cholesterol and apolipoprotein B, were the same as those obtained from a control group of healthy children in the same age. Using HbA1 as the basis for the observations, the risk factors were reduced by normalisation of glucose metabolism. On the other hand, the apolipoprotein A and HDL-cholesterol, well known as protective factors against atherosclerosis, are higher than in the control group and show a further increase with metabolic normalisation. The conclusion is: If medical therapy, metabolic rate, diet, physical exercise and special training are better controlled, the risk of diabetes developing macroangiopathy can be diminished.

Adolescent↗
PubMed1976

[Anaerobic serum ultrafiltration--a new method for determination of protein-binding rates of drugs under physiological conditions (author's transl)].

Only the free and not the protein-bound fraction of a drug shows pharmacologic activity. Therefore the rates of drug-binding to serum proteins are of great importance for clinical and pharmacological purposes. A basis prerequisite for accurate measurements are experimental designs giving the possibility of keeping the most important factors influencing the protein-binding rate within physiological ranges. In vivo these factors are, among others, the concentration of albumin, the absorption of different exogenous and endogenous substances to albumin, the type and the amount of ions present, the total ionic strength, the pH-value and hence the pCO2 as well as the temperature. An experimental set-up was described giving the possibility of keeping all these factors absolutely constant under in vivo conditions by means of a newly developed and simply to handle ultrafiltration device. From withdrawing the blood sample from the vein to the complete separation of the protein-bound fraction the blood sample can be processed under strictly anaerobic conditions (to prevent loss of CO2!). Compared to common methods generally used for the determination of protein-binding rates, such as equilibrium dialysis, column chromatography and ultracentrifugation, this new procedure saves a considerable amount of time. Within 1 h up to 8 samples can be processed in a single device. Besides short filtration times there is no need for any additional sample preparation such as buffering or adding antibacterial substances, etc.

Blood Proteins↗