[State of the carotid artery bifurcation after surgery involving the use of absorbable suture material].

The authors present herein a clinical case report assessing the state of the carotid artery bifurcation zone while performing secondary operation for restenosis 7 years after the primary operation (eversion carotid endarterectomy). The redo operation was carried out using absorbable suture material during anastomosis formation. This suture material used in arterial reconstructions turned out to result in good reparation of the anastomosis, not inducing coarse deformity of the vascular wall, thus in the long run making it possible to simplify the course of the redo operation.

[Endovascular treatment of traumatic arteriovenous fistulas of the vertebral artery].

The authors describe herein the use of balloon-distensible stent grafts for endovascular treatment of patients presenting with traumatic arteriovenous fistulas in the first segment of the vertebral artery, exemplified by two clinical case reports. In both cases, the arteriovenous fistula formed after a stab-and-slash wound in the neck area. In order to exclude the arteriovenous aneurysm from the blood flow in the first case we performed endoprosthetic repair of the first segment of the subclavian artery with shutting off of the ostium of the vertebral artery carrying the aneurysm. In the second case, in order to remove the arteriovenous shunt we carried out performed endoprosthetic repair of the first segment of the vertebral artery. These cases show possibilities of roentgenoendovascular methods of treatment, making it possible to successfully replace technically complicated surgical interventions in traumatic arteriovenous fistulas of vertebral arteries.

[Possibilities of surgical management of paraganglioma of the neck extending to the base of the skull].

Presented in the article is a rare clinical case report concerning successful treatment of a female patient with vaginal paraganglioma of the neck - a tumour extending from the level of the trunk of the common carotid artery in cranial direction to the base of the skull. Mentioned are difficulties of carrying out an operational intervention requiring the use of certain surgical techniques. The tumour was removed as a single block with the involvement into the process of the major vessels of the neck and nervous formations. The reconstructive operation performed was common carotid - internal carotid prosthetic repair with a 6.3-4.5 mm cone-shape prosthesis 'Gore-tex' on the right.

Application of high-performance liquid chromatography to the determination of vinblastine in Catharanthus roseus.

A method for the determination of vinblastine in Catharanthus roseus by HPLC is described. A crude alkaloid extract, obtained by extraction of leaves with toluene, 2% citric or tartaric acid and benzene, was separated by TLC. The vinblastine fraction was cut out and vinblastine was eluted from the sorbent. The amount of vinblastine was determined by HPLC with peak-height measurement. The standard deviation is 0.2 microgram/ml. The detection limit is 0.05 ng of vinblastine in a sample applied to the HPLC column.

Interaction of lambda cro repressor with synthetic operator OR3 studied by competition binding with minor groove binders.

In the present work, we employ a combination of CD spectroscopy and gel retardation technique to characterize thermodynamically the binding of lambda phage cro repressor to a 17 base pair operator OR3. We have found that three minor groove-binding antibiotics, distamycin A, netropsin and sibiromycin, compete effectively with the cro for binding to the operator OR3. Among these antibiotics, sibiromycin binds covalently to DNA in the minor groove at the NH2 of guanine, whereas distamycin A and netropsin interact preferentially with runs of AT base pairs and avoid DNA regions containing guanine bases in the two polynucleotide strands. Only subtle DNA conformation changes are known to take place upon binding of these antibiotics. Both the CD spectral profiles and the results of the gel retardation experiments indicate that distamycin A and netropsin can displace cro repressor from the operator OR3. The binding of cro repressor to the OR3 is accompanied by considerable changes in CD in the far-UV region which appear to be attributed to a DNA-dependent structural transition in the protein. Spectral changes are also induced in the wavelength region of 270-290 nm. The CD spectral profile of the cro-OR3 mixture in the presence of distamycin A can be represented as a sum of the CD spectrum of the repressor-operator complex and spectrum of distamycin-DNA complex at the appropriate molar ratio of the bound antibiotic to the operator DNA (r). When r tends to the saturation level of binding the CD spectrum in the region of 270-360 nm approaches a CD pattern typical of complexes of the antibiotic with the free DNA oligomer. This suggests that simultaneous binding of cro repressor and distamycin A to the same DNA oligomer is not possible and that distamycin A and netropsin can be used to determine the equilibrium affinity constant of cro repressor to the synthetic operator from competition-type experiments. The binding constant of cro repressor to the OR3 is found to be (6 +/- 1).10(6)M-1 at 20 degrees C in 10 mM sodium cacodylate buffer (pH 7.0) in the presence of 0.1 M NH4F.