Determination of histamine in biological fluids by capillary isotachophoresis and fluorescence.

Analytical isotachophoresis was used for the determination of histamine in biological fluids. For biological fluids with a very low content of histamine a method was developed that combines the fluorescing condensation product of histamine and o-phthaldialdehyde with the high concentration effect of isotachophoresis. This method permits the determination of histamine in serum and other biological fluids down to less than 3 ng/ml.

[Serum proteins of growing Gunn rats. Quantitative analysis with agarose gel electrophoresis (author's transl)]. / Die Serumproteine der wachsenden Gunn-Ratte. Quantitative Untersuchungen mit der Agarosegel-Elektrophorese.

Microprocesses of quantitative agarose gel electrophoresis and biuret total protein evaluation were used for the quantitative estimation of the serum proteins of homozygous and heterozygous Gunn rats. For the analyses carried out in the course of hyperbilirubinemia, 6 microliter of serum were necessary in each case, of which 50-80 microgram were used for electrophoresis. The quantitative evaluation of the phoretogram curves plotted at two wavelengths was carried out with the aid of an analog computer. Eleven fractions were quantitatively covered by the process. Age-related concentration shifts were observed for a number of fractions, especially for albumin, transferrin, and IgG. The results obtained from a large number of animals in longitudinal and cross-sectional examination corroborate various reports found in the relevant literature.

[Alteration of platelet function during intensive replacement therapy in haemophilia A (author's transl)]. / Thrombozytenfunktionsstörung während der hochdosierten Substitutionstherapie bei Hämophilie A.

This report describes two patients with haemophilia A who developed a transient thrombocytopathy with haemorrhagic diathesis during post-operative high-dose replacement therapy with antihaemophilic globulin. At the time of the bleeding the factor VIII-activity was in the normal range in both patients. The fibrinogen level, however, was elevated to 1700 mg-% and the factor VIII-associated antigen rose to more than 6-fold. At no time of replacement therapy with antihaemophilic globulin could either fibrinogen split products or fragments of the factor VIII-protein be detected by the usual methods. In view of the results of the thrombocyte aggregation experiments the authors postulate a disturbance of platelet function at the level of the membrane surface due to an overload of increased amounts of circulating proteins. Both the possible interference of dialysable factor VIII-components and the role of immunpathologic phenomena are discussed.

The effect of various stains on quantitative agarose-gel electrophoresis: evaluation of the results with the aid of an analog computer.

The effect of dyes of varying purity and with different binding mechanisms on quantitative electrophoresis was examined with the aid of agarose-gel electrophoresis, the phoretogram curves being evaluated with an analog computer. Concurrent quantitative results were obtained with the three dyes tested, viz. Amido Black 10 B, Ponceau Red S and Procion Brilliant Blue. It is concluded that no falsification of electrophoresis results will be caused by dyes with colour-producing secondary components.

[Systemic error during measurement of dp/dt using conventional heart catheters and their correction]. / Systematischer MeBfehler bei der Bestimmung der Druckanstiegsgeschwindigkeit dp/dt konventionellen Herzkathetern und seine Korrektur

The influence of 4 different types of conventional cardiac catheter on the systemic error during measurements of dp/dt was investigated by testing the frequency response. This was done by coupling on end of the fluid-filled catheters to a newly developed sine wave pressure generator (0-100 Hz), and the other end ot a pressure transducer (Statham 23 Db). The obtained electrical signal was preamplified and differentiated by means of a differentiation amplifier (linear rise up to 20 Hz). Also investigated was to what extent the dp/dt registration (UV-Oscilloscope) could be improved by damping the signal by means of electrical low pass filters.