Cystic adventitial disease of the popliteal vein: report of a case.

Cystic adventitial disease of the popliteal artery is a rare but classic cause of arterial insufficiency. We report a case in which the disease affected the popliteal vein, causing painless swelling of the left lower limb.

Fractionation of proteins with modified membranes.

The fractionation of two proteins, either positively charged (Lysozyme) or negatively charged (bovine serum albumin, BSA) was investigated by varying the ionic strength with unmodified or positively charged inorganic ultrafiltration membranes. Chemical modification was obtained by coating of polyvinylimidazole which amine groups reacted further with bisepoxiranes in order to have both partly quaternized amine group and pH stable network on membrane surface. The retention of the single protein decreases, with ionic strength when electrostatic interactions between the free protein in the bulk and the adsorbed protein onto the membrane are occurring. An increase of single protein retention with modified membranes appears at high ionic strength due to hydrophobic interactions between proteins and polymer coating. For protein mixtures, at low ionic strength (0.015), observed selectivities are more than 10 whatever the membrane used; both membrane fouling and protein-protein interactions occur in the protein mixture. At intermediate (0.25 M) and high (1 M) ionic strengths, the observed selectivity with modified membranes remains stable (about 6) whereas selectively with unmodified membranes decreases and is close to size selectivity. Hence the fractionation of proteins with modified membranes remains satisfactory in the entire range of ionic strengths due to ionic and salt promoted interactions between protein and membranes.

[Arterial fibromuscular dysplasia and ergotism]. / Dysplasie fibro-musculaire artérielle et ergotisme

Renal arteries of a 29-year-old hypertensive woman are described typical of fibro muscular dysplasia. Segmental stenoses of femoral, humeral and carotid arteries are associated. The histological study of one renal artery discloses a sub-adventitial fibrosis; besides there are pictures which are very close to those found during chronic intoxication with ergotamine tartrate. Patient history confirms this intoxication. Discontinuation of the ergotamine intoxication and administration of vaso-dilating substances are associated with a dramatic subjective and objective improvement of renal and peripheral arterial signs. The reversibility of the symptoms constitutes a serious clinical proof of the hypothesis of Bercquist and coll. (1971): that a prolonged arterial spasm could represent a promoting factor of arterial fibro-muscular dysplasias.