Altered regulation of sleep and feeding contributes to starvation resistance in Drosophila melanogaster.

Animals respond to changes in food availability by adjusting sleep and foraging strategies to optimize their fitness. Wild populations of the fruit fly, Drosophila melanogaster, display highly variable levels of starvation resistance that are dependent on geographic location, food availability and evolutionary history. How behaviors that include sleep and feeding vary in Drosophila with increased starvation resistance is unclear. We have generated starvation-resistant flies through experimental evolution to investigate the relationship between foraging behaviors and starvation resistance. Outbred populations of D. melanogaster were selected for starvation resistance over 60 generations. This selection process resulted in flies with a threefold increase in total lipids that survive up to 18 days without food. We tested starvation-selected (S) flies for sleep and feeding behaviors to determine the effect that selection for starvation resistance has had on foraging behavior. Flies from three replicated starvation-selected populations displayed a dramatic reduction in feeding and prolonged sleep duration compared to fed control (F) populations, suggesting that modified sleep and feeding may contribute to starvation resistance. A prolonged larval developmental period contributes to the elevated energy stores present in starvation-selected flies. By preventing S larvae from feeding longer than F larvae, we were able to reduce energy stores in adult S flies to the levels seen in adult F flies, thus allowing us to control for energy storage levels. However, the reduction of energy stores in S flies fails to generate normal sleep and feeding behavior seen in F flies with similar energy stores. These findings suggest that the behavioral changes observed in S flies are due to genetic regulation of behavior rather than elevated lipid levels. Testing S-F hybrid individuals for both feeding and sleep revealed a lack of correlation between food consumption and sleep duration, indicating further independence in genetic factors underlying the sleep and feeding changes observed in S flies. Taken together, these findings provide evidence that starvation selection results in prolonged sleep and reduced feeding through a mechanism that is independent of elevated energy stores. These findings suggest that changes in both metabolic function and behavior contribute to the increase in starvation resistance seen in flies selected for starvation resistance.

Predicting cost of inhalational anesthesia at low fresh gas flows: impact of a new generation carbon dioxide absorbent.

It is well known that low fresh gas flows result in lower cost of inhalational agents. A new generation of carbon dioxide absorbents allows low flow anesthesia with all anesthetics but these new compounds are more expensive. This study examines the cost of inhalational anesthesia at different fresh gas flows combined with the cost of absorbent. The cost of sevoflurane and desflurane is lower at low fresh gas flows. Paradoxically the cost of isoflurane is cheaper at 2 L/min than at lower fresh gas flows due to increased cost of carbon dioxide absorbent. Therefore low fresh gas flows should be used when feasible with sevoflurane and desflurane, but higher fresh gas flows up to 2 L/min may be more economical with isoflurane during maintenance phase of anesthesia.

Persistent Left Superior Vena Cava (PLSVC) with a Connection to the Azygos System: Case Report and Clinical Implications.

Persistent left superior vena cava (PLSVC) is a rare anatomic variant that has a significant effect on the structure of the heart and venous system with clinical implications that are far-reaching. The presence of this variant is relevant to central venous catheter insertion, cardioverter-defibrillator placement, coronary artery bypass grafting, and numerous other medical procedures. In this report, we describe a rare case of PLSVC with a connection to the azygos system; notably, the vast majority of PLSVCs connect to the coronary sinus. We also discuss the anatomic and anesthetic considerations for individuals with this uncommon variant.

Cost Savings Opportunities in Perioperative Management of the Patients With Orthopaedic Trauma.

Considerable opportunities for cost savings exist surrounding the perioperative management of patients with orthopaedic fracture and trauma. Scientific evidence is available to support each potential cost savings measure. Much of these data had been documented for years but has never been adhered to, resulting in millions of dollars in unnecessary testing and treatment. Careful attention to preoperative laboratory testing can save huge amounts of money and expedite medical clearance for injured patients. The use of a dedicated orthopaedic trauma operating room has been shown to improve resource utilization, decrease costs, and surgical complications. A variety of anesthetic techniques and agents can reduce operative time, recovery room time, and hospital lengths of stay. Strict adherence to blood utilization protocols, appropriate deep venous thrombosis prophylaxis, and multimodal postoperative pain control with oversight from dedicated hip fracture hospitalists is critical to cost containment. Careful attention to postoperative disposition to acute care and management of postoperative testing and radiographs can also be another area of cost containment. Institutional protocols must be created and followed by a team of orthopaedic surgeons, hospitalists, and anesthesiologists to significantly impact the costs associated with care of patient with orthopaedic trauma and fracture.