Evolution at the tips: Asclepias phylogenomics and new perspectives on leaf surfaces.

PREMISE OF THE STUDY: Leaf surface traits, such as trichome density and wax production, mediate important ecological processes such as anti-herbivory defense and water-use efficiency. We present a phylogenetic analysis of Asclepias plastomes as a framework for analyzing the evolution of trichome density and presence of epicuticular waxes. METHODS: We produced a maximum-likelihood phylogeny using plastomes of 103 species of Asclepias. We reconstructed ancestral states and used model comparisons in a likelihood framework to analyze character evolution across Asclepias. KEY RESULTS: We resolved the backbone of Asclepias, placing the Sonoran Desert clade and Incarnatae clade as successive sisters to the remaining species. We present novel findings about leaf surface evolution of Asclepias-the ancestor is reconstructed as waxless and sparsely hairy, a macroevolutionary optimal trichome density is supported, and the rate of evolution of trichome density has accelerated. CONCLUSIONS: Increased sampling and selection of best-fitting models of evolution provide more resolved and robust estimates of phylogeny and character evolution than obtained in previous studies. Evolutionary inferences are more sensitive to character coding than model selection.

A global perspective on Campanulaceae: Biogeographic, genomic, and floral evolution.

PREMISE OF THE STUDY: The Campanulaceae are a diverse clade of flowering plants encompassing more than 2300 species in myriad habitats from tropical rainforests to arctic tundra. A robust, multigene phylogeny, including all major lineages, is presented to provide a broad, evolutionary perspective of this cosmopolitan clade. METHODS: We used a phylogenetic framework, in combination with divergence dating, ancestral range estimation, chromosome modeling, and morphological character reconstruction analyses to infer phylogenetic placement and timing of major biogeographic, genomic, and morphological changes in the history of the group and provide insights into the diversification of this clade across six continents. KEY RESULTS: Ancestral range estimation supports an out-of-Africa diversification following the Cretaceous-Tertiary extinction event. Chromosomal modeling, with corroboration from the distribution of synonymous substitutions among gene duplicates, provides evidence for as many as 20 genome-wide duplication events before large radiations. Morphological reconstructions support the hypothesis that switches in floral symmetry and anther dehiscence were important in the evolution of secondary pollen presentation mechanisms. CONCLUSIONS: This study provides a broad, phylogenetic perspective on the evolution of the Campanulaceae clade. The remarkable habitat diversity and cosmopolitan distribution of this lineage appears to be the result of a complex history of genome duplications and numerous long-distance dispersal events. We failed to find evidence for an ancestral polyploidy event for this clade, and our analyses indicate an ancestral base number of nine for the group. This study will serve as a framework for future studies in diverse areas of research in Campanulaceae.

A Regional Experience With Vascular Surgery Mock Oral Examinations.

INTRODUCTION: In 2006 the Southern Association for Vascular Surgery (SAVS) implemented a mock oral examination program to prepare trainees for the Vascular Surgery Certifying Examination (VCE). METHODS: Participating examinees and examiners were identified from SAVS Recorder records and contacted via e-mail with a request to participate in an anonymous online survey. Examinees were asked about passage on American Board of Surgery examinations and perceptions of the mock oral program. Examiners were asked for their perceptions of the examination, applicant performance, and perceived areas for training improvement. Board passage rates for the group and national comparison data were provided in a de-identified fashion by American Board of Surgery. RESULTS: From 2006 to 2014, 158 examinees and 86 examiners participated in the SAVS mock orals program. In all, 33% of examinees and 35% of examiners completed the anonymous survey. Of the examinees, 27 (60%) reported passage of the mock oral examination on their first attempt and 7 of 9 (78%) reported passage on the second attempt. Second year in training was significantly associated with passage of the mock oral (p = 0.002). Of the examinees questioned, 100% "would recommend" the SAVS mock oral examinations to future trainees. Of the responding examiners, 90% felt that the SAVS mock oral examinations were "comparable" to the VCE and 87% "strongly agreed" that the exercise was a valuable preparatory tool. Examiners identified "ability to describe technical aspects of open vascular techniques" and "management of complications associated with vascular disease processes and operations" as commonly displayed deficits among examinees (80% and 77%, respectively). In all, 115 examinee participants from the SAVS mock orals had taken the VCE between 2006 and 2014. Of them, 90 (78%) passed the VCE on their first attempt. During the same time interval, the national first-time pass rate for the VCE was 86%. CONCLUSIONS: Although participation in the SAVS mock orals was overwhelmingly assessed as a positive preparatory experience by examinees and examiners, no incremental advantage in VCE passage was observed. Explanations for the worse-than-average performance on the VCE are not clear but likely involve numerous factors, including participation bias. Importantly, examiners in the SAVS mock oral process felt that the exercise closely simulated the VCE and uniformly reported pervasive deficits in the areas of demonstrated understanding of open surgical techniques and management of complications. This investigation guides further examination of VCE simulation exercises to assist in guiding the use of educational resources at both institutional and professional society levels.

Outcomes of revascularized acute mesenteric ischemia in the American College of Surgeons National Surgical Quality Improvement Program database.

This report examines outcomes of revascularization for acute arterial mesenteric ischemia (AAMI) using the American College of Surgeons National Surgical Quality Improvement Program database. Patients with International Classification of Diseases, 9th Revision and Current Procedural Terminology codes indicating AAMI with concomitant mesenteric revascularization were identified. Demographic, risk factor, procedural, morbidity, and mortality data were examined. Associations with morbidity and mortality were analyzed by logistic regression. One hundred forty-two cases of AAMI were identified. Seventy-one cases were thrombotic and 71 were embolic according to revascularization codes. Mean age was 66 years, 84 per cent of patients were white, and 54 per cent were female. Unadjusted major morbidity and mortality rates were 69 and 30 per cent, respectively. Patients with thrombotic AAMI were more likely to have a lower body mass index, greater than 10 per cent weight loss in the past 6 months, and a history of smoking. Patients with embolic AAMI were more likely to present emergently with sepsis. Unadjusted morbidity and mortality rates were 78 and 38 per cent for embolic and 61 and 23 per cent for thrombotic AAMI, respectively. Multivariable predictors of morbidity included bowel resection at the time of revascularization, transfer admission, and involvement of a surgical resident. Multivariable predictors of mortality included impaired functional status, increased age, and postoperative sepsis. Cause of AAMI was not a significant predictor of morbidity or mortality. In a large sample of AAMI cases, AAMI remained a highly lethal and morbid condition. Predictors of morbidity and mortality included indicators of advanced presentation, treatment delay, and patient-related factors specific to AAMI, including debility and advanced age. Efforts directed at prevention and increasing the speed of diagnosis and definitive treatment appear to be necessary to improve outcomes.

Tissue-specific actions of the Ept1, Ept2, Ept6, and Ept9 genetic determinants of responsiveness to estrogens in the female rat.

Ept1, Ept2, Ept6, and Ept9 are quantitative trait loci mapped in crosses between the ACI and Copenhagen (COP) rat strains as genetic determinants of responsiveness of the pituitary gland to estrogens. We have developed four congenic rat strains, each of which carries, on the genetic background of the ACI rat strain, alleles from the COP rat strain that span one of these quantitative trait loci. Relative to the female ACI rats, female ACI.COP-Ept1 rats exhibited reduced responsiveness to 17beta-estradiol (E2) in the pituitary gland, as evidenced by quantification of pituitary mass and circulating prolactin, and in the mammary gland, as evidenced by reduced susceptibility to E2-induced mammary cancer. The ACI.COP-Ept2 rat strain exhibited reduced responsiveness to E2 in the pituitary gland but did not differ from the ACI strain in regard to susceptibility to E2-induced mammary cancer. Interestingly, female Ept2 congenic rats exhibited increased responsiveness to E2 in the thymus, as evidenced by enhanced thymic atrophy. The ACI.COP-Ept6 rat strain exhibited increased responsiveness to E2 in the pituitary gland, which was associated with a qualitative phenotype suggestive of enhanced pituitary vascularization. The ACI.COP-Ept9 rat strain exhibited reduced responsiveness to E2 in the anterior pituitary gland, relative to the ACI rat strain. Neither Ept6 nor Ept9 impacted responsiveness to E2 in the mammary gland or thymus. These data indicate that each of these Ept genetic determinants of estrogen action is unique in regard to the tissues in which it exerts its effects and/or the direction of its effect on estrogen responsiveness.

Genetic mapping of loci controlling diethylstilbestrol-induced thymic atrophy in the Brown Norway rat.

Chronic estrogen administration can lead to thymic atrophy in rodents. In this article we report that the Brown Norway (BN) rat is sensitive to thymic atrophy induced by the estrogen diethylstilbestrol (DES). By contrast, DES does not induce significant thymic atrophy in the August x Copenhagen-Irish (ACI) strain. The sensitivity of the BN rat to DES-induced thymic atrophy appears to segregate as an incompletely dominant trait in crosses between the BN and ACI strains. In a (BN x ACI)F(2) population, we find strong evidence for three major genetic determinants of sensitivity to DES-induced thymic atrophy on rat Chromosome (RNO) 10 and RNO2. Genotypes at these loci, termed Esta1, 2, and 3, do not have a significant impact on the ability of DES to induce pituitary tumorigenesis or inhibit growth of these F(2) rats. These data indicate that the genetic factors that control DES-induced thymic atrophy are distinct from those that control the effects of DES on pituitary mass and body mass. The Esta intervals on RNO10 and RNO2 overlap with loci that control sensitivity to radiation-induced thymocyte apoptosis, as well as susceptibility to a variety of allergic and autoimmune pathologies, including allergic encephalitis, arthritis, and glomerulonephritis in rodents. These observations suggest that common genetic determinants may control sensitivity to estrogen-induced thymic atrophy, maintenance of thymocyte homeostasis, and immune function.

Leiomyosarcoma of the inferior vena cava: surgical management and clinical results.

Leiomyosarcoma of the inferior vena cava (IVC) is a rare lesion with less than 300 cases reported. Optimal management and long-term outcomes are not well described. From August 1984 to June 2004, eight patients with leiomyosarcoma of the IVC were treated at our institution. Clinical and pathologic data, surgical management, and outcomes were assessed. Eight cases were identified (4 males) with a median age of 52 (range 29-66). Presenting symptoms included abdominal pain (n = 5, 63%), lower extremity edema (n = 2, 25%), and palpable mass (n = 2, 25%). Tumor location was between the renal and iliac veins (low) (n = 4, 50%), between the hepatic and renal veins (middle) (n = 3, 38%), and above the hepatic veins with right atrial extension (high) (n = 1, 12%). Two patients with preoperative IVC occlusion were managed with tumor excision and IVC ligation. Three patients had primary repair of the IVC after tumor excision. A polytetrafluorothylene (PTFE) tube graft was used for IVC reconstruction in three cases. There was no postoperative mortality. Postoperative morbidity included deep venous thrombosis (DVT) (n = 1), lower extremity edema (mild n = 1; moderate n = 1), GI bleed (n = 1), and chronic renal insufficiency (n = 1). One patient is currently receiving adjuvant chemotherapy. Four patients received chemotherapy after recurrence, and one received palliative radiation therapy as well. Median survival to this point was 60 months with a median follow-up of 39 months. The 5-year overall survival and disease-free survival was 31 per cent for both (CI 0.1-1.0). The type of IVC reconstruction had no effect on survival (P = 0.22). Recurrence was discovered in four patients (50%) at a median time of 14 months. Resection of leiomyosarcoma of the IVC should be attempted whenever feasible. The management of the IVC can be managed with primary repair, ligation, or prosthetic graft. Long-term survival is possible if complete resection can be achieved.

INTROGRESSION OF COYOTE MITOCHONDRIAL DNA INTO SYMPATRIC NORTH AMERICAN GRAY WOLF POPULATIONS.

Mitochondrial DNA (mtDNA) genotypes of gray wolves and coyotes from localities throughout North America were determined using restriction fragment length polymorphisms. Of the 13 genotypes found among the wolves, 7 are clearly of coyote origin, indicating that genetic transfer of coyote mtDNA into wolf populations has occurred through hybridization. The transfer of mtDNA appears unidirectional from coyotes into wolves because no coyotes sampled have a wolf-derived mtDNA genotype. Wolves possessing coyote-derived genotypes are confined to a contiguous geographic region in Minnesota, Ontario, and Quebec, and the frequency of coyote-type mtDNA in these wolf populations is high (>50%). The ecological history of the hybrid zone suggests that hybridization is taking place in regions where coyotes have only recently become abundant following conversion of forests to farmlands. Dispersing male wolves unable to find conspecific mates may be pairing with female coyotes in deforested areas bordering wolf territories. Our results demonstrate that closely related species of mobile terrestrial vertebrates have the potential for extensive genetic exchange when ecological conditions change suddenly.