Alterations in electrolyte and trace-element concentrations during simulated extracorporeal blood circulation

In our studies with simulated extracorporeal blood circulation we observed damaging effects on blood cells, especially under oxygenating conditions. In order to characterize these effects we also analysed electrolyte and trace-element concentrations in plasma during and after simulated extracorporeal blood circulation. Highest resorption effects for magnesium and highest desorption effects for calcium, copper and iron are found with oxygen gas flow in the system. Membrane permeability for electrolytes seems to be induced as well. Cellular damage due only to mechanical stress within the perfusion system can be neglected.

[Changes in the kallikrein-kinin and complement system in angiography using non-ionic contrast media]

To examine alterations of the kallikrein-kinin system and of the complement due to the bolus injection of newer non-ionic contrast agents, venous blood samples were taken before and 3 min after angiography. There were no adverse contrast reactions clinically evident. Prekallikrein, kallikrein inhibition, beta-factor XIIa inhibition, C1-esterase inhibitor, C1q, C3, ATIII, HMW-kininogen, fibrinogen and factor XII were determined. Bolus injection of the contrast medium caused an activation of the kallikrein-kinin system (p less than 0.05) with reduction of prekallikrein, kallikrein-inhibition, beta-factor XIIa inhibition and C1-esterase inhibitor. The levels of C1q and C3 were also decreased (p less than 0.05) indicating an activation of the complement. Our results demonstrate, that angiography causes a significant activation of the kallikrein-kinin as well as of the complement system in spite of the use of newer non-ionic contrast agents.

A modification of Reiber's laser-nephelometric protein determination method interferences of selected substances

A modification of Reiber's laser-nephelometric protein quantitation method is described. Salts, (zwitterionic) buffers, sugars, chelating and reducing agents do not interfere with this method. Protein quantitation in the presence of Percoll or nonionic detergents yields erroneous results. The method is compared with two modifications of Lowry's protein determination.

[Activation of the kallikrein-kinin system by intravenous administration of ionic and non-ionic radiographic contrast media]

Conventional ionic contrast media (sodium meglumine and amidotrizoate) were injected intravenously in 22 patients (group A); the nonionic, low-osmolar contrast medium iohexol was similarly administered to 24 patients (group B). This resulted in a significant (group A: P less than 0.05; group B: P less than 0.01) reduction in prekallikrein (93 and 94%, respectively), inhibition of kallikrein (90 and 88%), beta-factor XIIa inhibition (86 and 85%), and C1 inhibition (90 and 91%). Factor XII levels remained unchanged in both groups. These results indicate that the kallikrein-kinin system is activated even during routine, complication-free radiographic procedures involving contrast-media injection. There was no difference between ionic and nonionic contrast media.

Studies on the interference of selected substances with two modifications of the Lowry protein determination

Two modifications of Lowry's procedure (Markwell's and Kresze's) were investigated for interference by zwitterionic buffers) (HEPES, HEPPS, PIPES, MES, MOPS, CHES, CAPS, Tris, glycylglycine, bicine), detergents (Triton-X-100, digitonin), sugars (sucrose, mannitol, sorbitol), salts (NaCl, KCl, ammonium acetate), chelators (EDTA), and reducing agents (dithiothreitol, GSH, ascorbic acid). The degree and type of interference are presented, and possible means of elimination of interference are discussed.

[Complement activation after the intravascular administration of contrast media: a comparison between ionic and nonionic x-ray contrast media]

The effects of intravascular radiographic contrast media on the complement system were investigated in 46 patients. An ionic (sodium-/meglumine amidotrizoate, n = 22) or a non-ionic (iohexol, n = 24) contrast agent was applied for an i.v. urography. The levels of the complement-compounds C1q, C3, C5 and of the C1 inhibitor were determined at the end of the infusion and 20 minutes later. In both groups we obtained a significant (p less than 0.01) decrease of C3 during infusion for 10 to 15%. 20 minutes later these values were almost normalized again. Infusion of iohexol additionally caused a marked consumption of C5 and C1q (reduction to 85%), while the ionic contrast agent had no significant effect on these components. Both contrast media caused a decrease of the C1-inhibitor levels. Our results demonstrate an activation of the complement system by i.v. application of radiographic contrast media. The decrease of the C1q-level due to infusion of iohexol indicates an additional involvement of the classical activation pathway of the complement cascade.

Chlorogenic acid biosynthesis: characterization of a light-induced microsomal 5-O-(4-coumaroyl)-D-quinate/shikimate 3'-hydroxylase from carrot (Daucus carota L.) cell suspension cultures

Microsomal preparations from carrot (Daucus carota L.) cell suspension cultures catalyze the formation of trans-5-O-caffeoyl-D-quinate (chlorogenate) from trans-5-O-(4-coumaroyl)-D-quinate. trans-5-O-(4-Coumaroyl)shikimate is converted to about the same extent to trans-5-O-caffeoylshikimate. trans-4-O-(4-Coumaroyl)-D-quinate, trans-3-O-(4-coumaroyl)-D-quinate, trans-4-coumarate, and cis-5-O-(4-coumaroyl)-D-quinate do not act as substrates. The reaction is strictly dependent on molecular oxygen and on NADPH as reducing cofactor. NADH and ascorbic acid cannot substitute for NADPH. Cytochrome c, Tetcyclacis, and carbon monoxide inhibit the reaction suggesting a cytochrome P-450-dependent mixed-function monooxygenase. Competition experiments as well as induction and inhibition phenomena indicate that there is only one enzyme species which is responsibl for the hydroxylation of the 5-O-(4-coumaric) esters of both D-quinate and shikimate. The activity of this enzyme is greatly increased by in vivo irradiation of the cells with blue/uv light. We conclude that the biosynthesis of the predominant caffeic acid conjugates in carrot cells occurs via the corresponding 4-coumaric acid esters. Thus, in this system, 5-O-(4-coumaroyl)-D-quinate can be seen as the final intermediate in the chlorogenic acid pathway.

Red blood cell T-activation and hemolysis in surgical intensive care patients with severe infections

The exposure of Thomsen-Friedenreich (T) antigens on RBCs, serum neuraminidase, and serum hemoglobin levels were investigated in 53 adult surgical intensive care unit (ICU) patients with septicemia. Unmasked T-antigens were assayed by a hemagglutination test using peanut agglutinin (PNA) (direct anti-T test), and by an indirect anti-T test employing rabbit anti-PNA globulin. RBC T-activation was demonstrated in 17/53 patients (32%); in 2/53 patients (4%) the direct anti-T test was positive, indicating strong T-exposure. No polyagglutination phenomena were observed. Serum neuraminidase was elevated in 12/17 (71%) patients with T-activation and in 7/36 (19%) patients without T-activation. Free serum hemoglobin was elevated in 12/17 (71%) patients with T-activation and in 5/36 (14%) patients without T-activation. Correlations between T-activation and serum neuraminidase and between T-activation and serum hemoglobin were significant (p less than 0.001). Potentially neuraminidase-releasing bacteria were demonstrated in 13/17 (76%) patients with RBC T-exposure. We conclude that neuraminidase-induced RBC T-activation and subsequent hemolysis may be involved in the pathomechanism of hemolytic anemia in patients with severe infections.

[Effect of L-carnitine on post-stress metabolism in surgical patients]

The positive influence of L-carnitine administration on postaggression metabolism was investigated. Clinical examinations were executed on three groups of patients K1, K2, K3). Comparable surgical operations like stomach- and intestinal- resections were performed on these groups of patients. During the first three days after operation a nutritional diet (parenteral, standardized hypocaloric) with (K2: 2 g; K3: 4g) and without L-carnitine (K1) was given. The effects of L-carnitine administration were evaluated by the following parameters: free fatty acids (FFS), triglycerides (TG), beta-hydroxybutyric acid (beta-OH-BS), acetacetate (ACAC), blood sugar (BZ), insulin (INS), lactate (LAK), pyruvate (PYR), total protein (GE), cholinesterase (CHE), urea production rate (PU), nitrogen of alpha-aminogroups (alpha-AN), nitrogen balance (NB), catabolic index (KI), BUN-Creatinine-quotient (B/K), total carnitine (GC), free carnitine (FC), acetyl carnitine (AC) and also the ratio between acetyl carnitine and free carnitine (AC/FC) in serum and urine. The results show no statistical significance. But they could lead to the following conclusions: Carnitine obviously reduces the insulin resistance. But it does not influence the post-operative perturbation of glucose-utilization. Carnitine reinforces the utilization of long chain fatty acids and thus improves the energy conversion. Carnitine leads to an earlier positive nitrogen balance. By giving 4 g of carnitine a day, already after three days a repletion of tissue deposits is possible, and a dose dependence for carnitine administration exists for the utilization of long chain fatty acids and the repletion of tissue deposits.

[Hemostaseologic study in the use of midazolam-ketamine]

The combination of derivatives of benzodiazepine and analgetics is used now routinely in clinical situations. In former investigations we studied the effect of these drugs on substrates and enzymes of glycolysis and metabolism of lipids, whereby we focused our interest on changes of phosphofructokinase activity. The aim of this study was to monitor the influence of anaesthesia on parameters of haemostasis (Kallikrein-kinin-system, coagulation, fibrinolysis and several proteinase inhibitors). Therefore plasma samples of patients undergoing diagnostic endoscopy were analysed. For anaesthesia a combination of midazolam and ketamine was used.

Efficient uptake of flavonoids into parsley (Petroselinum hortense) vacuoles requires acylated glycosides

Vacuoles were prepared from cultured parsley cells by polyamine-induced rupture of protoplasts. Acid-phosphatase activity, associated exclusively with the vacuoles, served for determination of vacuole yield in subsequent transport studies. Isolated vacuoles rapidly accumulated [2‴-(14)C]apigenin 7-O-(6-O-malonylglucoside) or 2″-(14)C]β-methyl D-6-O-malonylglucoside added at approximately 20 nM and 1.5 μM concentration, respectively, to the incubation mixture. The accumulation was linear with time and strongly dependent on alkaline buffer conditions as well as on the age of the vacuole preparation. Subsequent addition of a malonic hemiester esterase did not relase the label from the vacuoles. Moreover, neither [2-(14)C]apigenin 7-O-glucoside or [2-(14)C]malonic acid accumulated in the vacuoles under any assay conditions, nor did such compounds or β-methyl D-glucopyranoside, a malonic diester, and a succinic monoester inhibit transport of the acylated flavonoid. Transport was, however, inhibited by β-methyl D-6-O-malonylglucopyranoside. Vacuoles which had been incubated for more than 40 min at pH 8.0 did not stain any more with neutral-red dye and concomitantly lost the previously accumulated acylated glucoside. Our data confirm that malonylglucoside uptake by parsley vacuoles involves selective transport sites. It is suggested that changes in the molecular symmetry of the malonylglucosides are responsible for vacuolar trapping of flavonoids in parsley.

Function and energy-rich phosphate content of the hypertrophied ventricle after global ischemia and reperfusion

Using an isolated rat heart preparation (Langendorff perfusion, perfusion pressure 100 cm H2O) the response of the hypertrophied heart (spontaneous hypertensive rats lv/bw ratio 3.6 +/- 0.5) to global normothermic (30 min) and hypothermic (25 degrees C, 120 min) ischemic and cardioplegic arrest and reperfusion (30 min) was examined and compared with normal hearts (Wistar rats lv/bw ratio 2.0 +/- 0.3). St. Thomas solution and verapamil (2 mg/l Ringer solution) were used as cardioplegic agents. Before ischemia hypertrophied hearts had a significantly higher pressure-rate product, a lower myocardial perfusion/g myocardium and a lower myocardial ATP and adenine nucleotide content. Unmodified ischemia reduced myocardial function in the hypertrophied hearts to a greater degree than in normal hearts in both normo- and hypothermia. St. Thomas solution and verapamil protected significantly the myocardial function in the normal and hypertrophied heart after normothermic ischemia in a similar manner (60-70% of the initial value). In the hypertrophied ventricle ATP decay and adenine nucleotide loss was greater in verapamil than in St. Thomas solution treated hearts. In hypothermic ischemia only St. Thomas solution protected left ventricular function and adenine nucleotide loss in both normal and hypertrophied hearts. Verapamil was ineffective in the normal ventricle and protected left ventricular function but not the ATP and adenine nucleotide decay in the hypertrophied heart.