Duodenase, a serine protease from bovine duodenum mucosa, was located in endoplasmic reticulum, the Golgi secretory granules of epithelial cells and ducts of Brunner's glands by the A-gold iinmunocytochemical method. Duodenase exhibits trypsin-like and chyinotrypsin-like specificities with a preference for substrates having lysine at the P1 and proline at the P2 positions. The kinetic constants for the hydrolysis of 21 potential duodenase substrates are reported. The best substrates were found to be a-N-tosylglycylprolyllysine 4-nitroanilide (kJK,,, of 35 000 M-' s-'), a-N-succinylthreonylprolyllysine 4-nitroanilide (kc4,/K1,! of 18 000 M-' s-') and a-N-serylprolyllysine 4-nitroanilide (k,JK,, of 2600 M-' s-I), all of which contain the P I -P3 sequence of the enteropeptidase zymogen/activation site. On the basis of its catalytic properties and sites of localization, duodenase has been postulated to be an activator of the enteropeptidase precursor. A tetradecapeptide (LVTQEVSPKIVGGS) having the P9 -PS'sequence of the cleavage site of zymogen activation of bovine proenteropeptidase was synthesized, and kinetic parameters of its hydrolysis by duodenase were determined (K,,, of 87 pM; k,;,, of 1.4 s-I; k,,,/K,,, of 16000 M-' s-I). Crystals of duodenase frozen in a stream of liquid nitrogen diffracted synchrotron Xrays to 0.2-nm resolution.

Purpose. The results of cryoballoon ablation (CBA) procedure have been mainly derived from studies conducted in experienced atrial fibrillation (AF) ablation centres. Here, we report on CBA efficacy and complications resulting from real practice of this procedure at both high- and low-volume centres. Methods. Among 62 Russian centres performing AF ablation, 15 (24%) used CBA technology for pulmonary vein isolation. The centres were asked to provide a detailed description of all CBA procedures performed and complications, if encountered. Results. Thirteen sites completed interviews on all CBAs in their centres (>95% of CBAs in Russia). Six sites were high-volume AF ablation (>100 AF cases/year) centres, and 7 were low-volume AF ablation. There was no statistical difference in arrhythmia-free rates between high- and low-volume centres (64.6 versus 60.8% at 6 months). Major complications developed in 1.5% of patients and were equally distributed between high- and low-volume centres. Minor procedure-related events were encountered in 8% of patients and were more prevalent in high-volume centres. Total event and vascular access site event rates were higher in women than in men. Conclusions. CBA has an acceptable efficacy profile in real practice. In less experienced AF ablation centres, the major complication rate is equal to that in high-volume centres.

Changes in the cell wall of yeast-like fungi Candida albicans caused by bacterial enzyme lyticase were studied under an electron microscope. The results were compared with the findings on phagocytosis of lyticase-treated Candida albicans by rat alveolar macrophages. It was shown that destruction of the mannan and fibrous outer layers of the cell wall of yeast-like fungi treated with the enzyme led to the release of intracellular organelles and their content. Lyticase treatment reduced the resistance of Candida albicans to intracellular digestion by macrophages contributing to completion of phagocytosis.

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