Solution, heparinized buffered

A modified technique consisting of an electric field applied perpendicular to a flowing buffer solution and using chromatography paper as support(cross-electrophoresis) has been exploited to study the reaction of neomycin with heparin 9 184. Evidence for the formation of a neomycin-heparin complex was obtained by this means. 

By gel chromatography on Sephadex G-200, with an eluant consisting of 0.15 M sodium chloride mixed with 0.12 M sodium phosphate buffer solution, pH 7.4 (9 1, v/v), heparin of porcine mucosal origin has been shown to be highly polymolecular.127 No increase in blood anticoagulant activity with increasing molecular size, indicated by the results of an earlier study,128 was observed when the activity of fractions selected from different parts of the elution curve was determined. The anticoagulant potency of the sample studied was,... 

Various unspecified samples of the sodium salt of heparin have been submitted to Craig counter-current distribution between an aqueous buffer solution and n-pentyl alcohol. Three fractions were obtained, two of which showed anticoagulant activity. 

If the above requirements are met, then the placenta is placed in the artificial uterus and perfusion by heparinized buffered solution (Appendix IA) is started as soon as possible to prevent clotting of the blood already present in the small capillaries. After the placenta is cleaned by perfusing with saline and the intactness of the placental membrane has been established, the blood perfusion is started. When the system has reached steady state (with regard to pressures, temperature, etc.) at physiological conditions, data are collected. 

The CNBr-activated Sepharose 4B support (1 g dry weight) was swelled in 25 mL of hydrochloric acid (0.001 Af), and then washed with 100 mL of 0.5M NaCl, 0.1 M NaHC03 buffer at pH 8.3. To this support 5.5 mL of hydroxylapatite-purified heparinase (0.2 mg/mL protein with an activity of 88 units/mg protein in 0.2M phosphate buffer at pH 7.0) and 60 mg of heparin were added. The mixture was shaken overnight at 4°C, after which the beads were washed and blocked overnight at 4°C with a solution of lysine at pH 8.2 in 0.5M NaCl, 0.1M NaHC03 buffer solution. This support showed an uptake of 87% of the protein and an immobilization of 91% of the heparinase activity. 

U mL and a linear detection range of 0.2—2 U mL. Although heparin adsorption onto PEI in buffer solution had indicated superior sensitivity to that on protamine, in blood plasma it was not specific for heparin and adsorbed plasma species to a steady-state equilibrium. By reducing the incubation time and diluting the plasma samples with buffer to 50%, the nonspecific adsorption of plasma could be controlled and a PEI pretreated with blood plasma could be used successfully for heparin determination. Heparin adsorption in 50% plasma was Hnear between 0.05 and 1 U mL so that heparin plasma levels of 0.1—2 U mL could be determined with a relative error of 11% and an accuracy of 0.05 U mL. ... 

Fig. 5 Screening by affinity CE for interaction of SAP peptides with heparin in solution. An endoproteinase Asp-N-treated Glu-C digest of SAP solubilized in water was injected for 12 s and subjected to CE at 15 kV (detection at 200 nm) in the presence of heparin (Hep) (B) added to the electrophoresis buffer (0.1 M phosphate, pH 7.5) at the concentration indicated. The peptide marked with asterisks was identified by spiking with HPLC-purified fragments and corresponds to the fragment in Figure 6. (From Ref. 71.)...

At respective intervals as described above the monkeys were euthanized by lethal doses of sodium pentobarbital, the chest was opened, and intracardial perfusion of 0.51 ice-cold saline with heparin was performed, immediately followed by 2.51 of ice-cold solution of 4% paraformaldehyde in phosphate-buffered saline (PBS), pH = 7. The cranium was opened, and the brain was removed. 

The protein solution, previously dialyzed against 25 mM Tris/HCl, pH 8.0 containing 50 mM NaCl, or adjusted to pH 7.0 and NaCl added to 50 mM, is applied to the Heparin Sepharose column. The coulmn is washed with two volumes of loading buffer, and the adsorbed protein eluted with a linear gradient of 0.05-1 M NaCl. The pooled fractions are dialyzed and lyophilized as described above. 

An important factor in the interaction of foreign surfaces with blood is the rapid adsorption of plasma proteins onto such surfaces when they are exposed to blood (4). For this reason the adsorption of radioactively tagged blood components on heparinized and unheparinized surfaces was measured. Proteins were dissolved in approximate physiological concentrations in a buffered (pH 7.35) physiological saline solution and the solutions were exposed to the test surfaces for 2 hours at 37 °C. in a static system. After the exposure, the surfaces were rinsed with physiological saline and distilled water and then dried. The amount of protein on the surfaces was determined in a 27r-gas flow proportional counter (7). As shown in Table III, although both heparinized surfaces were nonthrombogenic, there is no consistent pattern of either increased or decreased adsorption of the proteins caused by the heparinization. In-... 

For blood heparinized venous blood is centrifuged and the upper layer is removed. Wash the erythrocyte sediment three times with 0.9% (w/v) NaCl solution. Haemolyse the washed red cells by adding 4 parts (v/v) of distilled water per volume of packed cells to give a stock haemolysate solution (approx. 5% (w/v)). For assay, dilute the stock solution 1 500 with the phosphate buffer immediately before the assay is to be carried out and determine the haemoglobin content of the solution by the method of Drabkin. The catalase activity is expressed per unit of haemoglobin. 

Haemofiltration This procedure turned out to be of more value than haemodialysis. No dialysate fluid is required. Instead, a solution containing buffered bicarbonate is used to replace the ultrafiltrate. In fulminant hepatic failure, continuous venovenous haemofiltration is recommended because of its advantages for the circulation and metabolism. Heparin or prostacyclin can be used as anticoagulants (C.A.E. Gimson et al., 1980). 

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