RESUMEN
Regenerative medicine is a novel discipline that both excites undergraduates and may be used as a vehicle to expose students to scientific concepts and opportunities. The goal of this article is to describe the implementation of a National Science Foundation-funded Targeted Infusion Project in which underrepresented minority undergraduates are exposed to laboratory-bench skills and summer research opportunities that they may not have encountered otherwise. A 3-wk infusion of laboratory-bench and data presentation skills, in the context of a regenerative medicine/bioengineering project, aimed to engage students and expose them to opportunities as summer researchers and teaching assistants. The infusion aimed to assess the extent to which students improved 1) attitudes toward laboratory-bench-based techniques, using attitudes toward science as a proxy; 2) perceptions of scientific inquiry; 3) intentions to engage in undergraduate research; and 4) intentions to persist in science, technology, engineering, and mathematics (STEM)-related fields. Results indicate that the 3-wk infusion had no effect on science attitudes, but transcribed responses to structured interviews administered after the summer research experience indicated that students who completed summer research projects had positive experiences. Differences in intentions to engage in research were detected between groups of students in different STEM majors, in addition to differences in intentions to pursue a career in science. We describe the implementation of the infusion and briefly discuss quantitative outcomes. We conclude that infusion of laboratory-bench modules in the context of a regenerative medicine/bioengineering project may play a small but important role in increasing (minority) participation and persistence in the STEM pipeline.
Asunto(s)
Curriculum , Ciencia del Laboratorio Clínico/educación , Grupos Minoritarios/educación , Fisiología/educación , Medicina Regenerativa/educación , Estudiantes Premédicos , Ingeniería Biomédica/educación , Investigación Biomédica/educación , Humanos , Encuestas y CuestionariosRESUMEN
Two conserved charged amino acids, aspartate-186 and arginine-190, localized in the aqueous head region of the iron-sulfur protein of the cytochrome bc(1) complex of yeast mitochondria, were mutated to alanine, glutamate, or asparagine and isoleucine, respectively. The R190I mutation resulted in the complete loss of antimycin- and myxothiazol-sensitive cytochrome c reductase activity due to loss of more than 60% of the iron-sulfur protein in the complex. Mitochondria isolated from the D186A mutant had a 50% decrease in cytochrome c reductase activity but no loss of the iron-sulfur protein or the [2Fe-2S] cluster. The midpoint potential of the [2Fe-2S] cluster of the D186A mutant was decreased from 281 to 178 mV. The D186E and D186N mutations did not result in a loss of cytochrome c reductase activity or content of iron-sulfur protein; however, the redox potential of the [2Fe-2S] cluster of D186N was decreased from 281 to 241 mV. Molecular modeling/dynamics studies predicted that substituting an alanine for Asp-186 causes global structural changes in the head group of the iron-sulfur protein resulting in changes in the orientation of the [2Fe-2S] cluster and consequently a lowered redox potential. The rate of electrogenic proton pumping in the bc(1) complex isolated from mutant D186A reconstituted into proteoliposomes decreased 64%; however, the H(+)/2e(-) ratio of 1.9 was identical in the mutant and the wild-type complexes. The carboxyl binding reagent, N-(ethoxycarbonyl)-2-ethoxyl-1,2-dihydroquinoline (EEDQ) blocked electrogenic proton pumping in the bc(1) complex reconstituted into proteoliposomes without affecting electron transfer resulting in a decrease in the H(+)/2e(-) ratio to 1.2 and 1.1, respectively. EEDQ was bound to the iron-sulfur protein and core protein II in both the wild type and the D186A mutant, indicating that Asp-186 of the iron-sulfur protein is not required for proton translocation in the bc(1) complex.
Asunto(s)
Ácido Aspártico/metabolismo , Complejo III de Transporte de Electrones/metabolismo , Transporte de Electrón/fisiología , Levaduras/metabolismo , Sustitución de Aminoácidos , Arginina/metabolismo , Complejo III de Transporte de Electrones/genética , Mitocondrias/metabolismo , Modelos Moleculares , Mutagénesis Sitio-Dirigida , Estructura Terciaria de ProteínaRESUMEN
Improvement of adherence in patients with a chronic disease state such as diabetes can be facilitated through well-crafted social support strategies. Family and friends are support options for many individuals living with diabetes. A systematic search of three databases was conducted to evaluate literature published from 2006 to April 2013 regarding social support in adults with diabetes conducted in the USA and Europe. While various studies had different findings, the overall trend shows that social support can result in a positive influence on both the ability of the patient to initiate and sustain diabetes management that can potentially result in positive health outcomes. This appears true even when the patient has low psychosocial skills and a small social support network. Healthcare professional involvement also correlates with patient improvement in specific outcomes not overlapped by the patient's social network. Support facilitated by peers can be a viable option along with the multitude of electronic options to help with social support.
RESUMEN
Mutations in the hinge region connecting the membrane anchor to the extra-membranous head-group of the iron-sulfur protein can impede proper assembly and function of the cytochrome bc(1) complex. Mutating the conserved alanines, residues 86, 90, and 92, located in the hinge region resulted in a 30-50% decrease in enzymatic activity without loss of the iron-sulfur protein [J. Bioenerg. Biomembr. 31 (1999) 215]. The lowered enzymatic activity in the A86L mutant was shown to result from steric interference between the side chains of Leu-86 and Leu-89 [Biochemistry 40 (2001) 327]. The compensatory double mutant A86L/L89A restored activity to wild type levels and relieved the steric hindrance; however, the L89A mutant did not assemble properly into the bc(1) complex. Molecular modeling studies of these mutants compared to the wild type have suggested that the hydrophobic residues located in the hinge region are critical to the motion of the head group of the iron-sulfur protein during catalysis.