Preferential eosinophil chemotactic activity exhibiting a molecular weight comparable to that released from sensitized human lung fragments challenged with specific antigen and designated eosinophil chemotactic factor of anaphylaxis has been isolated from extracts of human lung fragments by sequential purification on Sephadex G-25, Dowex-1, Sephadex G-10, and paper chromatography. Two eosinophi...

2,3-Diphosphoglycerate was first isolated from red cells and identified by Greenwald (1). Greenwald’s procedure and modifications of it (2, 3) have been commonly used for isolation of this material, although the chemical synthesis has also been reported (4). Both the isolation procedure and the chemical synthesis are time consuming and do not lend themselves to the preparation of large quantiti...

The spectrophotometric procedure for determining the specific activity of the enzyme and the preparation of reagents employed in the assay have been described previously (3). DPiV-Commercial preparations of DPN (60 per cent) were used in routine assays. For critical experiments, commercial DPN was further purified by several adsorptions on Dowex 1 formate columns by the method of Kornberg and P...

We combined column and partition chromatography to isolate, purify, and quantify biological organic acids in urine and cerebrospinal fluid (CSF). Urine and CSF samples were introduced onto a preconditioned cation-exchange column (Dowex 50 W x 8 resin) to remove the biological interferences. The effluent with water was extracted with ethyl acetate two times (pH 1 and 3) and the organic acids wer...

In this screening method for urinary porphobilinogen (PBG), urine is added to Dowex 2 resin under alkaline conditions in a test tube and mixed. The supernate is removed and the adsorbed PBG is eluted with acid and reacted with Ehrlich's reagent. We compared results with those by the Watson-Schwartz screening method, using urine samples from normal people with and without added PBG. At a PBG con...

Tachyphylaxis to angiotensin and some analogues has been demonstrated on spirally cut arterial strips from cat, dog, sheep and rat, and on venous strips from rabbit and cat. Rabbit and guinea pig arteries do not appear to become tachyphylactic. A free C-terminal carboxyl group of angiotensin is necessary for binding with receptor sites and development of tachyphylaxis. Tachyphylaxis seems to re...

We describe a rapid, reliable "high-performance" liquid-chromatographic method of simultaneously analyzing for 4-hydroxy-3-methoxymandelic acid (I) and 4-hydroxy-3-methoxyphenylacetic acid (II) in urine. Paired-ion chromatography and amperometric detection are used in the method. A 5-mL aliquot of urine is adjusted to pH 6.1 and subjected to anion-exchange chromatography (Dowex AG 1-X4, 1.8 X 0...

No cytokinin activity was found in methanolic mesocarp extracts after purification with petroleum ether and ethyl acetate. Cytokinin activity did appear, however, in aqueous fraction after acid hydrolysis or passage through Dowex 50 (H(+)) ion exchange columns. The level of this activity, the fruit growth rate, and the cell division rate were found to be positively correlated (with each other)....

The inhibitory activity of an angiotensin I-converting enzyme (ACE) detected in soy sauce was fractionated into two major fractions ef high molecular weight (Hw) and low molecular weight (Lw) by gel fi1tration chromatography on Bio-gel P-2 after treatifig with ethanol. The Hw fractien reduced the blood pressure in hypertensive rats after orally administering, while the Lw fraction did not. The ...

The increased urinary excretion of methylmalonic acid in vitamin B12 deficiency has attracted attention and several studies have suggested that it has clinical value as a test of vitamin B12 deficiency (Cox and White, 1962; Bashir, Hinterberger, and Jones, 1966). Chromatographic methods of estimation have been used but are either time consuming or only semiquantitative over a narrow range of me...