Body size as a magic trait in two plant-feeding insect species.

When gene flow accompanies speciation, recombination can decouple divergently selected loci and loci conferring reproductive isolation. This barrier to sympatric divergence disappears when assortative mating and disruptive selection involve the same "magic" trait. Although magic traits could be widespread, the relative importance of different types of magic traits to speciation remains unclear. Because body size frequently contributes to host adaptation and assortative mating in plant-feeding insects, we evaluated several magic trait predictions for this trait in a pair of sympatric Neodiprion sawfly species adapted to different pine hosts. A large morphological dataset revealed that sawfly adults from populations and species that use thicker-needled pines are consistently larger than those that use thinner-needled pines. Fitness data from recombinant backcross females revealed that egg size is under divergent selection between the preferred pines. Lastly, mating assays revealed strong size-assortative mating within and between species in three different crosses, with the strongest prezygotic isolation between populations that have the greatest interspecific size differences. Together, our data support body size as a magic trait in pine sawflies and possibly many other plant-feeding insects. Our work also demonstrates how intraspecific variation in morphology and ecology can cause geographic variation in the strength of prezygotic isolation.

Use of Extracorporeal Membrane Oxygenation and Surgical Embolectomy for Massive Pulmonary Embolism in the Emergency Department.

BACKGROUND: Massive pulmonary embolism (PE) carries significant morbidity and mortality with current standard of care modalities. CASE REPORT: We present the case of a 63-year-old male status post abdominal surgery 2 weeks before presenting to the emergency department with a massive pulmonary embolism and subsequent acute cardiopulmonary failure. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Here we describe a case of extracorporeal membrane oxygenation (ECMO) deployed in the emergency department as a bridge to embolectomy to successfully treat massive pulmonary embolism. This provided the opportunity to establish a "Code ECMO" protocol and algorithm for PE with cardiopulmonary instability so that patients can be rapidly triaged to the appropriate treatment modality.

Novel ETF dehydrogenase mutations in a patient with mild glutaric aciduria type II and complex II-III deficiency in liver and muscle.

We describe a 22-year-old male who developed severe hypoglycemia and lethargy during an acute illness at 4 months of age and subsequently grew and developed normally. At age 4 years he developed recurrent vomiting with mild hyperammonemia and dehydration requiring frequent hospitalizations. Glutaric aciduria Type II was suspected based upon biochemical findings and managed with cornstarch, carnitine and riboflavin supplements. He did not experience metabolic crises between ages 4-12 years. He experienced recurrent vomiting, mild hyperammonemia, and generalized weakness associated with acute illnesses and growth spurts. At age 18 years, he developed exercise intolerance and proximal muscle weakness leading to the identification of multiple acyl-CoA dehydrogenase and complex II/III deficiencies in both skeletal muscle and liver. Subsequent molecular characterization of the ETFDH gene revealed novel heterozygous mutations, p.G274X:c.820 G > T (exon 7) and p.P534L: c.1601 C > T (exon 12), the latter within the iron sulfur-cluster and predicted to affect ubiquinone reductase activity of ETFDH and the docking of ETF to ETFDH. Our case supports the concept of a structural interaction between ETFDH and other enzyme partners, and suggests that the conformational change upon ETF binding to ETFDH may play a key role in linking ETFDH to II/III super-complex formation.

Indicators for tracheostomy in patients with traumatic brain injury.

Our objective was to develop criteria to identify patients with traumatic brain injury (TBI) who require a tracheostomy (TR). From January 1994 to May 2000 all TBI patients requiring intubation on presentation and who survived >7 days were identified from our trauma registry. Demographics, Glasgow Coma Score (GCS), Injury Severity Score (ISS), and ventilator days, ICU days, hospital days, need for TR, and development of pneumonia were statistically analyzed. Of 246 patients with TBI 211 without TR and 35 with TR were identified (mean time to TR 13.3+/-7.0 days). Logistic regression analysis identified presenting GCS < or =8, ISS > or =25, and ventilator days >7 as significant predictors for TR. Applying these three predictors to our population identified 48 patients (21 with TR, 18 without TR, and nine who died on the ventilator without TR) with a sensitivity of 60 per cent, a specificity of 87 per cent, a positive predictive value of 44 per cent, and a negative predictive value of 93 per cent. Patients with TR had lower presenting GCS and higher ventilator, ICU, and hospital days (P < 0.05). Pneumonia rates were similar. Time to neurologic recovery (GCS > or =9) was longer for the TR patients as compared with the patients without TR. We conclude that patients with TBI presenting with a GCS < or =8, an ISS > or =25, and ventilator days >7 are more likely to require TR. Performing TR late did not reduce pneumonia rates or ventilator, ICU, or hospital days. By identifying the at-risk population early TR could be performed in an attempt to decrease morbidity and length of stay.