Zeitschrift fur medizinische Laboratoriumsdiagnostik最新文献

A further investigation of the Arzneibuch (Diagnostic Laboratory Methods) GDR-method for the estimation of N-acetylneuraminic acid was performed. By this was found, that the formation of the dye complex is not still finished after 15 minutes and the reaction product shows an exponential decomposition. The decomposition rate was much greater in the reaction medium than in n-amyl alcohol. By increasing the ferric (III)-chloride concentration the specificity of the method could be essentially improved. With the fivefold ferric (III)-chloride concentration the physiological concentrations of the protein bound monosaccharides of the serum changed the accuracy of the measuring results by less than or equal to 2.0%.

A solid-phase enzyme immunoassay, a radioimmunoassay and the passive hemagglutination were tested for the determination of antithyroglobulin autoantibodies. The antibody-titres detected with these methods showed a good correlation. The sensitivities of the solid-phase immunoassays are four times higher than the sensitivity of the passive hemagglutination. For the diagnosis of thyroid autoimmune diseases the enzyme immunoassay.

The positivepaper DDP 111 manufactured in the Fotopapierwerk Dresden is presented. It allows to make copies (1:1) of electrophoreses. Independently of the used staining procedure it is a simple, quickly and cameraless possibly to obtain reproductions with a high quality. The DDP 111 allows to resolve the problem of documentation of electropherograms (especially of wet flat gels) and to build up collections and data files respectively.

The degree of nonenzymatic glycation of serum proteins was estimated in 500 nondiabetic subjects and in 124 Type 2 diabetic out-patients. The values were evaluated in relation to a DMF calibration curve, a secondary glycated protein standard and to serum protein concentrations. Neglecting the evaluation with respect to the protein concentration 0.4% of the samples from nondiabetics and 9% from diabetic patients would have been incorrectly interpreted. The fructosamine values from nondiabetic subjects showed a Gaussian distribution. The use of secondary protein standards is a premise to a widespread application of the fructosamine assay in diabetic care. The calibration of such secondary glycated protein standards results in some problems when using DMF protein mixtures as primary standards, because albumin preparations from the same or different suppliers gave variable standardization curves.

A method for measurement of the spontaneous platelet aggregation in citrated whole blood (SPAV) was tested using the Coulter Counter S plus VI and a simple mechanism for sample rotation. The underlying principle of the procedure consists in the sequential measurement of the decrease of free platelets in a specimen of citrated whole blood which ist rotated at 37 degrees C for 20 minutes. SPAV offers advantages compared to other methods for spontaneous aggregation in platelet rich plasma. First experiences about application of the SPAV-procedure are presented.

The punctates of the biochemical joint function test contain hydroxyethyl starch which disturbs the assay of uronic acid and glucosamine for the estimation of hyaluronate. Therefore hyaluronate (0.03-0.75 g/l) was estimated by precipitation with Alcian blue on cellulose acetate membranes and measuring of the absorbance at 678 nm after dissolution in aqueous SDS (75 g/l). The gel-filtration HPLC separates the high-molecular-mass hyaluronate from low-molecular-mass impurities of biological samples. By comparing with a standard curve (0.5-2.5 g/l hyaluronate) the concentration can be determined. The results obtained by the two methods were significantly correlated (p less than 0.05). The Alcian blue technique is useful for rapid screening, the HPLC technique to confirm these values.

If a clinician is faced with acute intoxications a rapid toxicological test is essential. The toxic substances are identified by a combined use of various systems of analysis such as gas chromatography, thin-layer chromatography or UV-spectroscopy. As the result of the analysis a data pattern is obtained which can be interpreted by comparing it with substance-related reference patterns. This paper describes a computer-program which allows more efficient reference comparisons and which gives a support of the decisions. The algorithms of the comparisions are based on fuzzy-theory.