Endovascular stent-graft treatment of penetrating aortic ulcer

Penetrating aortic atherosclerotic ulcer is an underdiagnosed condition that presents high rates of morbidity and mortality. We report two cases of patients with severe chest pain, with no ischemic features, who underwent chest angiotomography and showed an ulceration of the aortic wall, with contrast penetration into the middle layer. Due to the failure of the medical treatment, the patients underwent percutaneous aortic stent implantation with complete resolution of symptoms.     

Sunflower domestication alleles support single domestication center in eastern North America

Phylogenetic analyses of genes with demonstrated involvement in evolutionary transitions can be an important means of resolving conflicting hypotheses about evolutionary history or process. In sunflower, two genes have previously been shown to have experienced selective sweeps during its early domestication. In the present study, we identified a third candidate early domestication gene and conducted haplotype analyses of all three genes to address a recent, controversial hypothesis about the origin of cultivated sunflower. Although the scientific consensus had long been that sunflower was domesticated once in eastern North America, the discovery of pre-Columbian sunflower remains at archaeological sites in Mexico led to the proposal of a second domestication center in southern Mexico. Previous molecular studies with neutral markers were consistent with the former hypothesis. However, only two indigenous Mexican cultivars were included in these studies, and their provenance and genetic purity have been questioned. Therefore, we sequenced regions of the three candidate domestication genes containing SNPs diagnostic for domestication from large, newly collected samples of Mexican sunflower landraces and Mexican wild populations from a broad geographic range. The new germplasm also was genotyped for 12 microsatellite loci. Our evidence from multiple evolutionarily important loci and from neutral markers supports a single domestication event for extant cultivated sunflower in eastern North America.     

Teaching clinically relevant dental anatomy in the dental curriculum: description and assessment of an innovative module

The primary objective of the preclinical dental anatomy course in the predoctoral dental curriculum is to introduce students to cognitive and psychomotor skills related to the morphology and spatial and functional relationships of human dentition. Traditionally, didactic content for the subject is found in textbooks and course manuals and summarized by the faculty in lectures to the entire class. Psychomotor skills associated with recognition and reproduction of tooth morphology are traditionally learned by examining preserved tooth specimens and their cross-sections, combined with producing two-dimensional line drawings and carving teeth from wax blocks. These activities have little direct clinical application. In most cases, students are passive in the learning process, and assessment of student performance is unilateral and subjective. A recently revised dental anatomy module at the University of Illinois at Chicago College of Dentistry integrates independent class preparation with active small-group discussion and patient scenario-based wax-up exercises to replace missing tooth structure on manikin teeth. The goal of the revision is to shift emphasis away from decontextualized technical learning toward more active and clinically applicable learning that improves conceptual understanding while contributing to early acquisition of psychomotor skills. This article describes the rationale, components, and advantages of the revised module and presents a pre-post comparison of student learning outcomes for three class cohorts (N=203).     

Spatial-temporal mapping of bone structural and elastic properties in a sheep model following osteotomy

The course of bone healing in animal models is conventionally monitored by morphologic approaches, which do not allow the determination of the material properties of the tissues involved. Mechanical characterization techniques are either dedicated to the macroscopic evaluation of the entire organ or to the microscopic evaluation of the tissue matrix. The latter provides insight to regionally specific alterations at the tissue level in the course of healing. In this study, quantitative scanning acoustic microscopy was used at 50 MHz to investigate microstructural and elastic alterations of mineralized callus and cortical tissue after transverse osteotomy in sheep tibiae. Analyses were performed after 2, 3, 6 and 9 weeks of consolidation with stabilization by either a rigid or a semi-rigid external fixator. Increased stiffness and decreased porosity were observed in the callus tissue over the course of the healing process, which was dependent on the fixator type. In the adjacent cortical tissue, stiffness decreased during the first 3 weeks. Cortical porosity increased over time but the time-dependence was different between the two fixator types. The changes of stiffness of cortical and callus tissues were measured with respect to the distance to the periosteal cortex-callus boundary. Stiffness of cortex and callus tissue smoothly decreased as a function of the distance from the inner cortical region. The data obtained in this study can help to understand the processes involved in tissue maturation during endogenous bone healing. (E-mail: kay.raum@charite.de)     

Patient versus informant reporting of ICD symptoms in Parkinson's disease using the QUIP: validity and variability

Questions exist regarding the validity of patient-reporting of psychiatric symptoms in Parkinson's disease (PD). We assessed observer variability and validity in reporting of impulse control disorder (ICD) symptoms in PD by using the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease (QUIP). PD patients and their informants (71 pairs) completed the QUIP to assess four ICDs (compulsive gambling, buying, sexual behavior, and eating) in patients. Trained raters then administered a diagnostic interview. Sensitivity of the QUIP for a diagnosed ICD was 100% for both patient- and informant-completed instruments, and specificity was 75% for both raters. Approximately 40% of patients without an ICD diagnosis had a positive QUIP, suggesting that many PD patients experience subsyndromal ICD symptoms that require ongoing monitoring. Agreement between patient- and informant-reporting of any ICD behaviors on the QUIP was moderate (kappa=0.408), and for individual ICDs was highest for gambling (kappa=0.550). Overall, a negative QUIP from either the patient or informant rules out the possibility of an ICD, while a positive QUIP requires a follow-up diagnostic interview and ongoing monitoring to determine if symptoms currently are, or in the future become, clinically significant.