Saint Louis University

About: Saint Louis University is a education organization based out in St Louis, Missouri, United States. It is known for research contribution in the topics: Population & Health care. The organization has 18927 authors who have published 34895 publications receiving 1267475 citations. The organization is also known as: SLU & St. Louis University.

Particle bombardment and the genetic enhancement of crops: Myths and realities

Abstract: DNA transfer by particle bombardment makes use of physical processes to achieve the transformation of crop plants. There is no dependence on bacteria, so the limitations inherent in organisms such as Agrobacterium tumefaciens do not apply. The absence of biological constraints, at least until DNA has entered the plant cell, means that particle bombardment is a versatile and effective transformation method, not limited by cell type, species or genotype. There are no intrinsic vector requirements so transgenes of any size and arrangement can be introduced, and multiple gene cotransformation is straightforward. The perceived disadvantages of particle bombardment compared to Agrobacterium-mediated transformation, i.e. the tendency to generate large transgene arrays containing rearranged and broken transgene copies, are not borne out by the recent detailed structural analysis of transgene loci produced by each of the methods. There is also little evidence for major differences in the levels of transgene instability and silencing when these transformation methods are compared in agriculturally important cereals and legumes, and other non-model systems. Indeed, a major advantage of particle bombardment is that the delivered DNA can be manipulated to influence the quality and structure of the resultant transgene loci. This has been demonstrated in recently reported strategies that favor the recovery of transgenic plants containing intact, single-copy integration events, and demonstrating high-level transgene expression. At the current time, particle bombardment is the most efficient way to achieve plastid transformation in plants and is the only method so far used to achieve mitochondrial transformation. In this review, we discuss recent data highlighting the positive impact of particle bombardment on the genetic transformation of plants, focusing on the fate of exogenous DNA, its organization and its expression in the plant cell. We also discuss some of the most important applications of this technology including the deployment of transgenic plants under field conditions.

Medical student mental health 3.0: improving student wellness through curricular changes.

Abstract: Medical education can have significant negative effects on the well-being of medical students. To date, efforts to improve student mental health have focused largely on improving access to mental health providers, reducing the stigma and other barriers to mental health treatment, and implementing ancillary wellness programs. Still, new and innovative models that build on these efforts by directly addressing the root causes of stress that lie within the curriculum itself are needed to properly promote student wellness. In this article, the authors present a new paradigm for improving medical student mental health, by describing an integrated, multifaceted, preclinical curricular change program implemented through the Office of Curricular Affairs at the Saint Louis University School of Medicine starting in the 2009–2010 academic year. The authors found that significant but efficient changes to course content, contact hours, scheduling, grading, electives, learning communities, and required resilience/mindfulness experiences were associated with significantly lower levels of depression symptoms, anxiety symptoms, and stress, and significantly higher levels of community cohesion, in medical students who participated in the expanded wellness program compared with those who preceded its implementation. The authors discuss the utility and relevance of such curricular changes as an overlooked component of change models for improving medical student mental health.

Mitogenomic evolution and interrelationships of the Cypriniformes (Actinopterygii: Ostariophysi): the first evidence toward resolution of higher-level relationships of the world's largest freshwater fish clade based on 59 whole mitogenome sequences.

Abstract: Fishes of the order Cypriniformes are almost completely restricted to freshwater bodies and number > 3400 species placed in 5 families, each with poorly defined subfamilies and/or tribes. The present study represents the first attempt toward resolution of the higher-level relationships of the world's largest freshwater-fish clade based on whole mitochondrial (mt) genome sequences from 53 cypriniforms (including 46 newly determined sequences) plus 6 outgroups. Unambiguously aligned, concatenated mt genome sequences (14,563 bp) were divided into 5 partitions (first, second, and third codon positions of the protein-coding genes, rRNA genes, and tRNA genes), and partitioned Bayesian analyses were conducted, with protein-coding genes being treated in 3 different manners (all positions included; third codon positions converted into purine [R] and pyrimidine [Y] [RY-coding]; third codon positions excluded). The resultant phylogenies strongly supported monophyly of the Cypriniformes as well as that of the families Cyprinidae, Catostomidae, and a clade comprising Balitoridae + Cobitidae, with the 2 latter loach families being reciprocally paraphyletic. Although all of the data sets yielded nearly identical tree topologies with regard to the shallower relationships, deeper relationships among the 4 major clades (the above 3 major clades plus Gyrinocheilidae, represented by a single species Gyrinocheilus aymonieri in this study), were incongruent depending on the data sets. Treatment of the rapidly saturated third codon-position transitions appeared to be a source of such incongruities, and we advocate that RY-coding, which takes only transversions into account, effectively removes this likely "noise" from the data set and avoids the apparent lack of signal by retaining all available positions in the data set.

Autistic traits in a population-based ADHD twin sample.

Abstract: Background: Most diagnostic nomenclatures do not allow for the concurrent diagnosis of autism and attention-deficit/hyperactivity disorder (ADHD). Clinic-based studies suggest autistic symptoms are common in children with ADHD, but such studies are prone to referral bias. This study assesses whether children with ADHD selected from the general twin population have elevated levels of autistic traits. Methods: Nine hundred forty-six twins identified by Missouri birth records were assigned to DSM-IV ADHD diagnoses and seven population-derived ADHD subtypes defined through latent class analysis of DSM-IV ADHD symptoms. The Social Responsiveness Scale (SRS) was used as a quantitative measure of autistic traits. Linear regression was used to evaluate whether mean SRS scores differed between ADHD diagnostic groups. Results: Mean SRS scores for DSM-IV predominantly inattentive subtype and combined subtype ADHD groups were significantly higher than for subjects without DSMIV ADHD (p < .001, both comparisons). Five of the population-derived ADHD subtypes (talkativeimpulsive, mild and severe inattentive, mild and severe combined) had significantly higher mean SRS scores compared to the latent class subtype with few ADHD symptoms (p < .001, all comparisons). DSM-IV combined subtype and the population-derived severe combined subtype had the highest mean total SRS scores and the highest mean scores for each of the three autism symptom domains, with a substantial proportion of individuals scoring in the clinically significant range. Conclusions: This study provides population-based evidence for clinically significant elevations of autistic traits in children meeting diagnostic criteria for ADHD. These results have implications for the design and interpretation of studies of both disorders. Keywords: ADHD, autism, PDD, Social Responsiveness Scale.