A model for micellar aggregates of a bile salt: crystal structure of sodium taurodeoxycholate monohydrate.

Crystals of sodium taurodeoxycholate monohydrate, NaC26H44NO6S X H2O, are trigonal, space group P3(1), with a = 18.393(1), c = 7.097(1)A, V = 2079.3(5)A3, and Z = 3. The structure was solved by direct methods and Fourier techniques and refined by full-matrix least-squares calculations. The final R index is 0.051. The side chair of the anion displays an approximate folded-back conformation. The cyclopentane ring assumes an intermediate conformation between the half-chain and the beta-envelope. The sodium ion shows a distorted octahedral coordination with six oxygen atoms, giving rise to ion-ion and ion-dipole interactions. The molecules form helices, characterized by threefold screw axes, with a radius of about 16 A. The helices are packed in such a way as to be embedded in each other as cog-wheels. The helix found in this crystal structure will be used as a model and checked in the study of the micellar solutions of sodium taurodeoxycholate, following the same strategy satisfactorily employed in the case of sodium deoxycholate.

[Cardiovascular manifestations of dermatopolymyositis]. / Le manifestazioni cardiovascolari della dermatopolimiosite.

The cardiovascular symptoms of six patients suffering from polymyositis were considered with reference to Pearson's classification. Transmural ischaemia type ventricular repolarisation anomalies were noted in two patients while clinica signis of cardiopathy were not present. A progressive disturbance in intraventricular condition was noted in one case. In another patient signs of atrial tachycardial type paroxysms with a variable A-V block were noted. Dilatative cardiomyopathy with progressive congestive decompensation and hyperkinetic ventricular arrhythmias were noted in two patients. These conditions responded partially to medical treatment. ECGraphic signs of pseudonecrosis and clinicoechographic signs of mitral valve prolapse were noted in another patient. These signs were not accompanied by either coronary or valvular clinical involvement equivalents.