Owl Pellets, a Useful Method to Study Epigean Tenebrionid Beetles in Arid Lands.

Owl pellets, regurgitates formed by the undigested parts of owls' prey, have been used since the 1960s to estimate relative species abundances and community diversity of small mammals in the field. Although insects are important food sources for raptors, the usefulness of owl pellets as a collecting method for entomological studies remains practically unexplored. Many terrestrial arthropods have fragile bodies that degrade during the raptor's digestive process; however, darkling beetles (Tenebrionidae) resist this process. These organisms are abundant and rich in species, and play significant roles in food and nutrient soil cycles in arid regions. Moreover, darkling beetles are well known and represent up to 52% of prey abundances in Bubo magellanicus (Lesson), one of the most common owls in arid Patagonia. The aim of this work is to evaluate the suitability of B. magellanicus pellets as a research tool for studies of tenebrionid beetle biodiversity assessments in arid Patagonia. Thus, we compare tenebrionid relative species abundances, species richness, and their species assemblage estimated from the diet of B. magellanicus with those identified simultaneously by conventional trapping (pitfall trapping and hand collecting) using multivariate techniques and the Fisher's exact test. Mitragenius araneiformis Curtis, Patagonogenius quadricollis Fairmaire, and Emmallodera crenaticostata crenaticostata Blanchard were the most abundant tenebrionid species. Relative abundances of almost all species, the estimation of species richness, and tenebrionid assemblage from both collecting methodologies were similar. Therefore, we propose the owl pellet analysis as a useful sampling tool for rapid estimations of the tenebrionid assemblage structure in arid Patagonia.

The A-Med right heart support for off-pump coronary artery bypass grafting.

BACKGROUND: Off-pump coronary artery bypass grafting (OPCAB) presents several advantages but, mainly due to the impaired diastolic filling of the right ventricle, the displacement of the heart can cause hemodynamic instability. The aim of this study was to investigate the possible role of the A-Med right heart support during OPCAB. METHODS: We report our early experience with the A-Med system (A-Med, West Sacramento, CA, USA) during OPCAB. The system consists of a coaxial cannula, a microcentrifugal pump and a control console. The coaxial cannula is passed through the right atrium with the tip of the cannula positioned in the main pulmonary artery. Thus the blood is actively removed from the right atrium and returned to the pulmonary artery. RESULTS: We successfully used this right heart support in 2 patients undergoing elective OPCAB. In both cases the system was used during the exposure of the proximal portion of the obtuse marginal branch. A mean pump flow of 3.2 l/min guaranteed normal cardiac output and hemodynamic stability during the exposure of the posterior target area. No complication occurred and the patients were discharged shortly after surgery. CONCLUSIONS: In our early experience the A-Med right heart support was safe and effective and allowed achievement of hemodynamic stability during exposure of the posterior areas of the left ventricle.

Open heart surgery in patients with dialysis-dependent renal insufficiency.

OBJECTIVE: Chronic renal failure (CRF) is commonly considered a significant factor for increased morbidity and mortality after cardiac surgery. METHODS: To assess the risk in our population we retrospectively analyzed 28 patients (16 men and 12 women, mean age 58.1+/-10.8 years) with end-stage renal disease (ESRD) undergoing cardiac surgery between 1989 and 2001. Sixteen (57.2%) patients had isolated coronary artery bypass grafting (CABG), nine (32.1%) had isolated valve replacement, and three (10.7%) underwent combined CABG and valve replacement. Preoperatively, 20 (71.4%) patients were on hemodialysis and eight (28.6%) on peritoneal dialysis. Mean preoperative duration of dialysis was 38.7+/-24.9 months (range, 3 to 93 months). RESULTS: There were two perioperative deaths (30-day mortality, 7.1%). Actuarial survival at 1, 2, 5, and 12 years was 0.85+/-0.7, 0.73+/-0.10, 0.65+/-0.12, and 0.54+/-0.14, respectively. Among 22 survivors, mean NYHA class was 1.7+/-0.8 (p < 0.001 vs. preoperatively) and mean CCS class was 1.6+/-0.6 (p < 0.001 vs. preoperatively). CCS/NYHA functional class IV (p = 0.01), urgent/emergency operation (p < 0.001), LVEF < 35% (p < 0.001) were strongly related to early and late mortality. CONCLUSIONS: Open-heart operations can be performed with acceptable short- and long-term results in patients with CRF on dialysis. Adequate preoperative management with identification of high-risk patients and a more aggressive approach before the onset of symptoms of cardiac failure are advisable.