Zeitschrift fur medizinische Laboratoriumsdiagnostik最新文献

The Ni2+/S2O4(2-)-test makes semiquantitative assessment of cystine concentration in urine possible. The reaction principle of the method is based on the formation of a nickel/cysteine/sulfide complex of brown colour. Visual test evaluation is done by classifying the colour intensity of the sample/reagent mixture according to an exact colour shade. Each colour shade on a colour reference table is correlated to a certain range of cystine concentration. Cystine determination is described in detail for two ranges (0.60 and 1.25 mmol/l).

The determination of the biological activity of interferons are carried out on the basis of the inhibition of the cytopathic effect of vesicular stomatitis virus on MDBK cells. Using microtiter-plates and tips made of synthetic polymers incorrect data may be observed due to the adsorption of the protein interferon to the tips and, thus, carryover of activity. The following recommendations may help to avoid this kind of mistakes: 1. Generally changing of the tips, at least for the highest concentrations. 2. Reduction of high initial activities by an appropriate pre-dilution. 3. Addition of the detergent Triton X 100 in concentrations between 50 to 100 mg/l to the dilution media for interferon.

Three methods of the determination of insulin in serum were optimized in order to determine low concentrations of this analyte reliably (Method I: enzymatic after acidic hydrolysis of inulin; Method II: by anthrone/sulfuric acid reagent; Method III: by cysteine/tryptophan reagent). The interfering reaction of glucose in the methods I and II was avoided by the preincubation of samples with glucose oxidase/catalase reagent. The detection limit of all three methods was below 5 mg/l and the within-run precision amounted to values below 5%. Method I and II gave identical results. In comparison with these two methods, method III resulted in inulin values by about 8% lower, because inulin, depending on the lot used, contained alkali-labile fractions which were destroyed during the sample preparation. Method II is recommended for routine measurements because of its an analytical reliability and its cost-effectiveness.

The pretreatment of rats with the substance LPH and LXU caused decrease of lethality in endotoxin shock and suppression of the following changes 6 hours post endotoxin: Increase of plasma ICDH activity, decrease in platelet count, decrease of the hepatic energy state and increase of the ATP content in the lung. The catabolic glucose metabolism during endotoxin shock was not influenced by LPH and LXU administration.

A monodimensional electrophoretic method for the separation of glycosaminoglycans on Titan III Zip Zone cellulose acetate plate based on their different electrophoretic mobilities in barium acetate and different solubilities in ethanol was applied to the Chemetron electrophoretic equipment. Improved timing of individual steps of electrophoretic run, additional cooling and pressure must be introduced for optimal separation of glycosaminoglycans mixture (dermatan sulphate, heparan sulphate, hyaluronic acid, chondroitin-4-sulphate, chondroitin-6-sulphate and keratan sulphate) resulting in five well separated sharp bands. By all these changes in the original procedure of Hopwood and Harrison, the separation of chondroitin-4-sulphate and chondroitin-6-sulphate was not achieved. The modified procedure on Cellogel strip is suitable for the screening of mucopolysaccharidoses.

A method for the immunoturbidimetric analysis of the C-3-component in the complement system was elaborated by means of the antiserum Q-SwAHu/C3 USOL (SEVAG) Praha. A diluted human control serum USOL (SEVAG) Praha with declared values of plasma proteins was applied as a standard solution. The relation between concentration and absorption in an eight step calibration series is well described by a parabola of the 2nd degree. The precision in series and the accuracy of the method are mentioned. The proposed technique is in a relatively good correlation with the radial immunodiffusion according to MANCINI.