A comparative study of normal and reverse phase high pressure liquid chromatography for analysis of porphyrins accumulated after 5-aminolaevulinic acid treatment of colon adenocarcinoma cells.

Primary adenocarcinoma cells of the rectosigmoid colon (WiDr-cells) were treated with 5-aminolevulinic acid (5-ALA). Cellular porphyrins were separated and quantified by high performance liquid chromatography (HPLC), both as free porphyrin acids after an easy extraction method with a subsequent reverse phase technique, and then as porphyrin esters after a more laborious extraction method and subsequent normal phase technique. The porphyrins were detected by means of a fluorescence detector.

The concentration of high molecular weight compounds in interstitial tissue fluid: a study in patients with post-reconstructive leg oedema.

Objectives: To study whether relative changes in the concentration of different proteins of the subcutaneous interstitial tissue fluid in patients with postreconstructive leg oedema could give information on the integrity of the capillary wall following vascular reconstruction.

Materials: Sixteen patients developed ipsilateral leg oedema following femoropopliteal (n = 14) or femorotibial (n = 2) bypass surgery for intermittent claudication (n = 10) or critical lower limb ischaemia (n = 6) caused by obliterating atherosclerosis.

Methods: The leg volume increase was measured according to the formula of a truncated cone.

The effect of brief illumination on intracellular free calcium concentration in cells with 5-aminolevulinic acid-induced protoporphyrin IX synthesis.

The effect of illumination on intracellular free calcium concentration, [Ca2+]i, was studied in a cell line (WiDr cells) derived from a primary adenocarcinoma of the rectosigmoid colon. In these cells the biosynthesis of protoporphyrin IX was stimulated by 5-aminolevulinic acid to reach levels of 600-700 pmol of protoporphyrin IX per mg cell protein. A brief (1-min) exposure of the cells to light (70% of light energy at 340-380 nm) resulted in an increase in [Ca2+]i.

Protein concentration of subcutaneous interstitial fluid in the human leg. A comparison between the wick technique and the blister suction technique.

The wick technique and the blister suction technique are the most common methods for sampling of subcutaneous interstitial tissue fluid in man. The blister suction technique has the advantage of being less invasive than the wick technique, but the reliability of this method is still controversial. The aim of this study was to evaluate whether the simpler blister suction technique using large (8 mm) blisters could replace the wick technique in the investigation of patients with postreconstructive leg edema.

The interaction of gadolinium complexes with isolated rat hepatocytes.

The lanthanide metal, gadolinium, is currently used in contrast agents for magnetic resonance imaging. We have performed a study of the interaction between isolated rat hepatocytes and 153Gd complexed to diethylene-triamine pentaacetic acid (DTPA) or to DTPA-albumin conjugates. The study shows that isolated hepatocytes are able to take up both types of 153Gd complexes.