The physical and functional behavior of capture antibodies adsorbed on polystyrene.

Six monoclonal and two polyclonal antibodies to fluorescein (FLU) were affinity purified and immobilized on Immulon 2 polystyrene as capture antibodies (CAbs): (a) by passive adsorption at pH 9.6, (b) via a streptavidin bridge to a biotinylated carrier molecule, and (c) via an antiglobulin which had been previously adsorbed passively to the polystyrene. Data show that less than 3.0% of the binding sites of monoclonal CAbs and approximately 5-10% of those of polyclonal CAbs were capable of capturing antigen (FLU4.2-BSA) after passive adsorption. Immobilization of CAbs via an antiglobulin or a streptavidin bridge, resulted in the preservation of antibody binding sites to greater than 70% for some monoclonals although immobilization via the streptavidin bridge resulted in the highest number of functional sites/well. The data presented are consistent with studies on other adsorbed proteins which demonstrate that passive adsorption on polystyrene results in the loss of protein function. Furthermore, these data show that generally less than half of the binding sites of antibodies available in solution are available after solid-phase immobilization even when non-adsorptive methods are employed. Some polyclonal anti-FLU also have lower average avidity following passive adsorption compared with CAbs immobilization via a streptavidin bridge. Immunochemical studies revealed that adsorbed polyclonal-CAbs performed like monoclonals when tested with multivalent antigens (FLU10-IgA) but in an expected heterogeneous manner in Scatchard plots when tested using univalent FLU-insulin. This observation implied cross-linking of immobilized CAbs by the multivalent antigen. Because only 5-10% of adsorbed polyclonal CAbs are active, the survivors must be non-randomly distributed in clusters to explain the cross-linking. This was confirmed by scanning electron microscopy which gave rise to the hypothesis that antibodies which retain activity after adsorption, are those present in clusters, i.e., the functional adsorbed CAb is an antibody cluster. Data presented in this report on the behavior of adsorbed CAbs, and reviewed from the work of others for various adsorbed proteins, indicate that the method of passive adsorption at pH 9.6, which is widely used in popular microtiter ELISAs, and which has in many ways revolutionized immunoassay, is a method of protein denaturation. Assayists that utilize passive adsorption of proteins on hydrophobic supports as part of their research need to be cognizant of this phenomenon, while inventors of immunoassay should develop alternative methods of immobilization which do not destroy 90% of the functional activity of solid-phase reactant.

[Continuous block of the lumbar plexus with the 3-in-1-block catheter technic in pain therapy]. / Die kontinuierliche Blockade des Plexus lumbalis mit der "3-in-1-Block-Kathetertechnik" in der Schmerztherapie.

The evaluation of the test protocols on continuous lumbar plexus blockade using the 3-in-1 block with a lumbar plexus catheter showed the following results: The study included 104 patients. In 91.3% of cases, puncture of the fascial sheath of the femoral nerve proved successful. In 95.7% of cases, the plexus catheter could be positioned and left in place (Table 1). Four catheters had to be removed due to intravascular misplacement. Good analgesic results were achieved in 85.7% of patients. In 14.3% of cases, the judgement of pain reduction could not be sufficiently or definitely ascertained (Table 1). From the third day on we started with the injection of 0.25% bupivacaine. The administration of this local anesthetic achieved satisfactory results in terms of facilitating the necessary mobilization procedures. With regard to the individual indication groups, the efficacy differed according to the respective supply area. The most impressive analgestic results (100%) were observed in all the patients who underwent femoral amputation or suffered from pelvic pain. A good outcome could be ascertained after surgical procedures on the knee (87.5%), and satisfactory results were achieved in the femur and hip areas (70.9%). The average indwelling time of the catheter was 6 days, the maximum amounted to 44 days. All catheters could be left in place without complications until the end of therapy. Changing the catheter is possible at any time, as is the replacement of the catheter hub. Such steps were carried out in 5 cases.

[Supraclavicular puncture of the anonymous vein]. / Die supraklavikuläre Anonymapunktion.

The investigation concerns a series of percutaneous, supraclavicular punctures and catheterisations of the anonymous veins conducted in the course of 8 years. 9042 patients were involved. The specific advantages of the anonymous vein puncture and catheterisation pertain to the easy accessibility of the vessel in all circulatory conditions and to the reduced risk of complications (rate of pneumothorax only 0.2%).

The use of alpha-system set for arterial catheterization.

The use of a new set for arterial catheterization (Alpha-system) is presented. In fifty patients arterial cannulation was performed (femoral artery was used in 47 cases). The mean duration of cannulation was 6.7 days. Some minor complications, such as haematoma (5 cases), kinking of catheter (2 cases) and technical difficulties are described. Five out of 50 catheter tips were colonized by gram-negative germs. The use of the Alpha-system set avoids to a large extent haematoma, as the tapping hole is completely occluded by the catheter, and the plastic sound (instead of a metallic one) neither perforates the opposite wall nor dislodges an atheromatous plaque. We recommend a careful clinical and arteriographic control of the region supplied by the cannulated artery as well as a strict aseptic technique of puncture and dressing.

[Caval catheterization via the innominate vein (author's transl)]. / Die Kavakatheterisierung über die Vena anonyma (Vena brachiocephalica).

Experience gained in 3500 supraclavicular innominate vein punctures for catheterization of the superior vena cava with the indirect technique is explained and discussed. The innominate vein is easily accessible in every state of blood circulation, even intraoperatively when the patient is covered by drapes. The thrombosis risk is reduced because of the wide lumen and the straight course of the vessel (vena anonyma dextra). The special advantages of the indirect technique are the small puncture trauma and absence of false positions. The only important complication observed during an average infusion time of 8 days was pneumothorax at a rate of 1.4%.

[Caval catheterization via the internal jugular vein (author's transl)]. / Die Kavakatheterisierung über die Vena jugularis interna.

Catheterization of the superior vena cava via the internal jugular vein with the indirect technique is practically always successful. The occurence of a pneumothorax is extremely rare. The special advantages of the indirect technique are: small puncture trauma, quick placement of the catheter in the superior vena cava and non-occurrence of false position. Heart irritations or even heart perforations are avoided because of standard catheter length respectively graduated catheters.

[Special technique for the catheterization of "central" veins (Seldinger's or indirect technique) (author's transl)]. / Spezielle Punktionstechnik für "zentrale" Venen. (Technik nach Seldinger oder indirekte Technik).

Catheterization of the superior caval vein with the indirect technique of the alpha system is practically always successful. The integrated guide wire combines high elasticity with firmness; this makes it possible to employ highly flexible catheters thereby reducing tissue damage and, consequently, the incidence of thrombosis. The advantages of the indirect technique of catheterization of the caval vein are: minimum trauma at the site of puncture; a high success rate; avoidance of misplacement of the catheter (the catheter is safely guided by the plastic wire); avoidance of cardiac disturbances as the catheters are of uniform lenght or are graduated.

[The supraclavicular approach to the V. Anonyma (author's transl)]. / Die supraclaviculäre Anonymapunktion

Experience gained with supraclavicular anonyma (brachiocephalica) catherizations carried out on more than 2,500 patients in an emergency and for prolonged infusion therapy is explained and discussed in the following on the bases of 800 registered tappings. A detailed description and discussion is given of the technical and methodical aspects of applying the Seldinger method and a constant catheter length, and in using a recently developed catheter which has the advantage of letter fixation; The only clinical complications observed during an average infusion time of six days was pneumothorax in 1.2% of the tappings and phlebitis in 0.9% of the catherizations. For vena anonyma tapping, the particular advantages are the easy accessibility of the vessel in every state of blood circulation at a high rate of 95%, the non-existence of false positions, the excellent catheter compatibility, the possibility of recatheterization, the possibility of optimum fixation, the safety in nursing, and the unrestricted mobility of the patient.