The multicausal twilight of South American native mammalian predators (Metatheria, Sparassodonta).

Sparassodonts were the apex mammalian predators of South America throughout most of the Cenozoic, diversifying into a wide array of niches including fox-like and even saber-toothed forms. Their extinction is still controversial, with different authors suggesting competition with other predators (placental carnivorans, terror birds, and carnivorous opossums), extinction of prey, and climate change as causal explanations. Here, we analyse these hypotheses using a novel approach implicating Bayesian analyses. We find that speciation and extinction rates of sparassodonts can be correlated with (i) intrinsic biotic factors such as changes in body mass and diversity of sparassodonts, (ii) extrinsic biotic factors such as potential prey diversity, and iii) extrinsic abiotic factors like the atmospheric CO2, sea level, temperature, and uplift of the Andes. Thus, sparassodonts are a good example of a multilevel mixed model of evolution, where various factors drove the evolutionary history of this clade in a pluralistic way. There is no evidence for competition between Sparassodonta and others predators, and the effect of competition in the face of extinctions of fossil species should be tested and not assumed. Furthermore, we propose a novel approach for evaluating the fossil record when performing macroevolutionary analyses.

Post-operative nausea and vomiting (PONV) after thyroid surgery: a prospective, randomized study comparing totally intravenous versus inhalational anesthetics.

The incidence of postoperative nausea and vomiting (PONV) after thyroidectomy and the association of Propofol versus Sevoflurane use for anesthesia maintenance were investigated during a randomized, prospective study. One hundred and ninety-eight patients underwent thyroidectomy receiving either Sevoflurane (0.5-1.3% end-tidal) or Propofol (50-200 mg/kg/min) for anesthesia maintenance. All patients received Propofol for induction of anesthesia, Succinylcholine or Vecuronium, Nitrous Oxide, and Fentanyl. Prophylactic antiemetics were not administered. The combined incidence of PONV was 54.4 per cent over the 24-hour postoperative evaluation period. PONV was more common in patients receiving Sevoflurane than Propofol for maintenance of anesthesia (64.6% vs 43.8%). In women (n = 117), the incidence of PONV resulted higher when receiving inhalational Sevoflurane than Propofol for maintenance (70.6% vs 42.4%). However, in men (n = 81), there was no significant difference in PONV between anesthetic regimens (47.4% with Sevoflurane vs 49.6% with Propofol). Patients undergoing thyroid surgery are at high risk for the development of PONV. Propofol for maintenance of anesthesia, although more expensive than Sevoflurane, may reduce the rate of PONV.

Cytoreductive surgery (peritonectomy procedures) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) in the treatment of diffuse peritoneal carcinomatosis from ovarian cancer.

BACKGROUND: Because of scarce data from larger series and nonhomogeneous selection criteria, further information is needed on peritonectomy with hyperthermic intraperitoneal chemotherapy (HIPEC) in managing patients with ovarian peritoneal carcinomatosis. METHODS: In an open, prospective, single-center nonrandomized phase 2 study conducted from November 2000 to April 2007, 47 patients with primary advanced or recurrent ovarian cancer and diffuse peritoneal carcinomatosis were enrolled; 22 underwent primary and 25 secondary cytoreduction plus immediate HIPEC followed by systemic chemotherapy. RESULTS: The overall mean Sugarbaker peritoneal cancer index was 14.9 (range, 6-28). A mean of 6 surgical procedures were required per patient (range, 4-10). In 87.3% of the patients debulking achieved optimal cytoreduction (Sugarbaker completeness of cytoreduction [CC] score 0-1), whereas in 12.7% it left macroscopic residual disease (CC-2 or CC-3). Major complications developed in 21.3% of the patients and the in-hospital mortality rate was 4.2%. The mean overall survival was 30.4 months, median survival was 24 months, and mean disease-free survival was 27.4 months. Five-year survival was 16.7%. Univariate (log-rank test and analysis of variance) and multivariate analyses (Cox proportional-hazard model) identified the CC score as the main factor capable of independently influencing survival. CONCLUSIONS: Peritonectomy procedures combined with HIPEC offer promising long-term survival in patients with diffuse peritoneal ovarian carcinomatosis. They achieve high adequate primary and secondary surgical cytoreduction rates with acceptable morbidity and mortality.