Immobilized urokinase column as part of a specific detection system for plasminogen species separated by high-performance affinity chromatography

Immobilized urokinase was used as part of a post-column reactor for the specific detection of human plasminogen species which were fractionated using a high-performance affinity column. After on-line activation of each peak, plasmin activity was measured by mixing the eluate with a specific fluorogenic substrate and the product was detected by a fluorescence monitor. This detection system gave linear calibration graphs for both purified plasminogens (0.1-50 micrograms) and plasminogens contained in plasma (25-100 microliters). Relative standard deviations for the determination of plasminogens in plasma were 6.1-6.6% (n = 12), showing good reproducibility. The detection limit was as low as 0.1 micrograms of plasminogen. Immobilized urokinase was very stable and no appreciable decrease in activity was found after 100 cycles of operation. In combination with an immobilized benzamidine column, this system made it possible to separate and detect Glu-plasminogen and Lys-plasminogen contained in human plasma samples as small as 100 microliters without any pretreatment.     

WAVELENGTH DEPENDENCE OF SINGLET OXYGEN MECHANISM IN ACRIDINE ORANGE-SENSITIZED PHOTODYNAMIC ACTION IN YEAST CELLS: EXPERIMENTS WITH 470 NM

Abstract— The singlet oxygen mechanism was evaluated in terms of acridine orange-sensitized induction of gene conversion in Saccharomyces at 470 nm and by using a concentration dependent protective action of added N;. The singlet oxygen mechanism accounted for 96% of the total photodynamic efTect. This value is to be contrasted with 76% previously observed for 510 nm illumination.     

Solvent extraction of technetium(VII) by primary amine in heptane solution from aqueous alkaline solution

Technetium(VII) extraction has been investigated to obtain useful information concerming the back-extraction of Tc(VII). Radioactive technetium-95m was used to determine the distribution ratio (D _Tc) of^95mTcO ₄ ^– for Tc(VII) extraction using Primene JMT (RNH₂) in heptane solution. An emulsion formation did not occur in the ammonium carbonate system but occurred in the sodium hydroxide solutions. The extraction mechanism has also determined by using the slope analysis method to study the relationships between logD _Tc and log [RNH₂], and between logD _Tc and pH.     

Application of ion-exchange cartridge clean-up in food analysis III. Determination of benzylpenicillin, phenoxymethyl-penicillin, oxacillin, cloxacillin, nafcillin and dicloxacillin in bovine liver and kidney by liquid chromatography with ultraviolet detection

A multiresidue analytical method was developed for the simultaneous determination of benzylpenicillin (PCG), phenoxymethylpenicillin (PCV), oxacillin (MPIPC), cloxacillin (MCIPC), nafcillin (NFPC) and dicloxacillin (MDIPC) in bovine liver and kidney. The method involves the use of an ion-exchange cartridge for sample clean-up followed by ion-pair high-performance liquid chromatography with ultraviolet detection. The recoveries of PCG, PCV, MPIPC, MCIPC, NFPC and MDIPC from bovine liver spiked at levels of 0.5 mg/kg and 0.1 mg/kg were in the range of 73–91% and 83–96% with coefficients of variation of 1.4–4.2% and 3.4–8.7%, respectively. For bovine kidney spiked at levels of 0.5 mg/kg and 0.1 mg/kg, the recoveries of these compounds were 79–92% and 82–92% with RSDs of 1.8–5.9% and 2.7–7.8%, respectively. The detection limits for the six penicillins were 0.02–0.05 mg/kg in bovine liver and kidney.