Finding of an ixodid tick inside a late Holocene owl pellet from northwestern Argentina.

In the present study, we report the earliest record of Ixodes sigelos from the late Holocene in Argentina. The tick was recovered from an owl pellet collected within a small mammal sequence in Las Máscaras Cave, Catamarca, Argentina (27 degrees 01'12S'', 66 degrees 44'37''W) and dated at 990 + or - 35 cal yr. Based on bones also present in the pellet, the tick most-likely parasitized a rodent, identified as an Eligmodontia sp., which had been ingested by the owl.

Monovalent cation fluxes and physiological changes of Debaryomyces hansenii grown at high concentrations of KCl and NaCl.

Debaryomyces hansenii showed an increased growth in the presence of either 1 M, KCl or 1 M NaCl and a low acidification of the medium, higher for the cells grown in the presence of NaCl. These cells accumulated high concentrations of the cations, and showed a very fast capacity to exchange either Na+ or K+ for the opposite cation. They showed a rapid uptake of 86Rb+ and 22Na+. 86Rb+ transport was saturable, with K(m) and Vmax values higher for cells grown in 1 M NaCl. 22Na+ uptake showed a diffusion component, also higher for the cells grown with NaCl. Changes depended on growth conditions, and not on further incubation, which changed the internal ion concentration. K+ stimulated proton pumping produced a rapid extrusion of protons, and also a decrease of the membrane potential. Cells grown in 1 M KCl showed a higher fermentation rate, but significantly lower respiratory capacity. ATP levels were higher in cells grown in the presence of NaCl; upon incubation with glucose, those grown in the presence of KCl reached values similar to the ones grown in the presence of NaCl. In both, the addition of KCl produced a transient decrease of the ATP levels. As to ion transport mechanisms, D. hansenii appears to have (a) an ATPase functioning as a proton pump, generating a membrane potential difference which drives K+ through a uniporter; (b) a K+/H+ exchange system; and (c) a rapid cation/cation exchange system. Most interesting is that cells grown in different ionic environments change their studied capacities, which are not dependent on the cation content, but on differences in their genetic expression during growth.

[Extracorporeal biliary lithotripsy: results in 60 cases of single calculus]. / Litotricia biliar extracorpórea: resultados en 60 casos de cálculo único.

The outcome of 60 cases of single biliary stone with a maximum diameter of 25 mm was evaluated. The patients were symptomatic, with functioning gallbladder, and were selected from a group of 180 to evaluate the effects of electrohydraulically generated shockwaves on a priori ideal cases for this procedure. In seven patients fragmentation was not achieved, probably because of the pigmentary character of the stone, that was later verified at cholecystectomy. In 20 out of the 53 in whom fragmentation was satisfactory (38%), fragments were not observed after 24 hours. 32 patients (54%) had a stone-free gallbladder 3 months afterwards; at six months, the number had increased to 40 (66%). This rate becomes 77% if only the cases with fragmentation are considered. In 29% of patients episodes of colicky biliary pain developed as complication. No case of pancreatitis or stuck in gallstone were observed. We conclude that shock waves appear as an excellent therapeutic alternative in single gallstones up to 25 mm in size.