Morpholino Gene Knockdown in Adult Fundulus heteroclitus: Role of SGK1 in Seawater Acclimation

The Atlantic killifish (Fundulus heteroclitus) is an environmental sentinel organism used extensively for studies on environmental toxicants and salt (NaCl) homeostasis. Previous research in our laboratory has shown that rapid acclimation of killifish to seawater is mediated by trafficking of CFTR chloride channels from intracellular vesicles to the plasma membrane in the opercular membrane within the first hour in seawater, which enhances chloride secretion into seawater, thereby contributing to salt homeostasis. Acute transition to seawater is also marked by an increase in both mRNA and protein levels of serum glucocorticoid kinase 1 (SGK1) within 15 minutes of transfer. Although the rise in SGK1 in gill and its functional analog, the opercular membrane, after seawater transfer precedes the increase in membrane CFTR, a direct role of SGK1 in elevating membrane CFTR has not been established in vivo. To test the hypothesis that SGK1 mediates the increase in plasma membrane CFTR we designed two functionally different vivo-morpholinos to knock down SGK1 in gill, and developed and validated a vivo-morpholino knock down technique for adult killifish. Injection (intraperitoneal, IP) of the splice blocking SGK1 vivo-morpholino reduced SGK1 mRNA in the gill after transition from fresh to seawater by 66%. The IP injection of the translational blocking and splice blocking vivo-morpholinos reduced gill SGK1 protein abundance in fish transferred from fresh to seawater by 64% and 53%, respectively. Moreover, knock down of SGK1 completely eliminated the seawater induced rise in plasma membrane CFTR, demonstrating that the increase in SGK1 protein is required for the trafficking of CFTR from intracellular vesicles in mitochondrion rich cells to the plasma membrane in the gill during acclimation to seawater. This is the first report of the use of vivo-morpholinos in adult killifish and demonstrates that vivo-morpholinos are a valuable genetic tool for this environmentally relevant model organism

Populations of Radial Glial Cells Respond Differently to Reelin and Neuregulin1 in a Ferret Model of Cortical Dysplasia

Radial glial cells play an essential role during corticogenesis through their function as neural precursors and guides of neuronal migration. Both reelin and neuregulin1 (NRG1) maintain the radial glial scaffold; they also induce expression of Brain Lipid Binding Protein (BLBP), a well known marker of radial glia. Although radial glia in normal ferrets express both vimentin and BLBP, this coexpression diverges at P3; vimentin is expressed in the radial glial processes, while BLBP appears in cells detached from the ventricular zone. Our lab developed a model of cortical dysplasia in the ferret, resulting in impaired migration of neurons into the cortical plate and disordered radial glia. This occurs after exposure to the antimitotic methylazoxymethanol (MAM) on the 24th day of development (E24). Ferrets treated with MAM on E24 result in an overall decrease of BLBP expression; radial glia that continue to express BLBP, however, show only mild disruption compared with the strongly disrupted vimentin expressing radial glia. When E24 MAM-treated organotypic slices are exposed to reelin or NRG1, the severely disrupted vimentin+ radial glial processes are repaired but the slightly disordered BLBP+ processes are not. The realignment of vimentin+ processes was linked with an increase of their BLBP expression. BLBP expressing radial glia are distinguished by being both less affected by MAM treatment and by attempts at repair. We further investigated the effects induced by reelin and found that signaling was mediated via VLDLR/Dab1/Pi3K activation while NRG1 signaling was mediated via erbB3/erbB4/Pi3K. We then tested whether radial glial repair correlated with improved neuronal migration. Repairing the radial glial scaffold is not sufficient to restore neuronal migration; although reelin improves migration of neurons toward the cortical plate signaling through ApoER2/Dab1/PI3K activation, NRG1 does not

Measurement of general and specific approaches to physical activity parenting: a systematic review

Background Parents play a significant role in shaping youth physical activity (PA). However, interventions targeting PA parenting have been ineffective. Methodological inconsistencies related to the measurement of parental influences may be a contributing factor. The purpose of this article is to review the extant peer-reviewed literature related to the measurement of general and specific parental influences on youth PA. Methods A systematic review of studies measuring constructs of PA parenting was conducted. Computerized searches were completed using PubMed, MEDLINE, Academic Search Premier, SPORTDiscus, and PsycINFO. Reference lists of the identified articles were manually reviewed as well as the authors' personal collections. Articles were selected on the basis of strict inclusion criteria and details regarding the measurement protocols were extracted. A total of 117 articles met the inclusionary criteria. Methodological articles that evaluated the validity and reliability of PA parenting measures (n=10) were reviewed separately from parental influence articles (n=107). Results A significant percentage of studies used measures with indeterminate validity and reliability. A significant percentage of articles did not provide sample items, describe the response format, or report the possible range of scores. No studies were located that evaluated sensitivity to change. Conclusion The reporting of measurement properties and the use of valid and reliable measurement scales need to be improved considerably

Factores de riesgo de caídas en ancianos: revisión sistemática Fatores de risco de quedas em idosos Risk factors for falls in the elderly: systematic review

OBJETIVO: Sistematizar los hallazgos de los estudios de cohorte prospectivos sobre los múltiples factores de riesgo de caídas en ancianos y valorar la calidad metodológica de los mismos. MÉTODOS: Revisión sistemática de estudios epidemiológicos en las bases de datos Medline, SciELO y Lilacs. Fueron incluidos estudios con número de sujetos >100, con edad >64 años, de ambos sexos, residentes en la comunidad o en instituciones para ancianos. RESULTADOS: De 726 publicaciones encontradas, 15 estudios cumplieron con los criterios de inclusión, habiendo sido publicados entre 1988 y 2005. Los estudios presentaron heterogeneidad metodológica. Los principales factores asociados a un aumento del riesgo de caída son: antecedente de caída, alteración de la marcha, incapacidad funcional, deterioro cognitivo, consumo de medicación psicotrópica y exceso de actividad física. A pesar de hallazgos contradictorios, ser del sexo femenino y tener edad avanzada, también pueden ser predictores de caída. CONCLUSIONES: Se identifican algunas carencias metodológicas de los estudios de cohorte prospectivo sobre caídas: carencia de estudios sobre determinantes extrínsecos, necesidad de enmascaramiento del evaluador durante el seguimiento y de un mejor control del seguimiento con menores intervalos entres las recogidas de datos.<br>OBJETIVO: Sistematizar os achados dos estudos de coorte prospectivos sobre os múltiplos fatores de risco de quedas em idosos e avaliar a qualidade metodológica desses estudos. MÉTODOS: Revisão sistemática de estudos nas bases de dados Medline, SciELO e Lilacs. Foram incluídos estudos com número de sujeitos >100, com idade >64 anos, de ambos os sexos, residentes na comunidade ou em instituições para idosos. RESULTADOS: Das 726 publicações encontradas, 15 estudos cumpriram os critérios de inclusão, tendo sido publicados entre 1988 e 2005. Os estudos apresentaram heterogeneidade metodológica. Os principais fatores associados ao aumento do risco de quedas são: antecedentes de queda, alteração da marcha, incapacidade funcional, impedimento cognitivo, consumo de fármacos psicotrópicos e excesso de atividade física. Apesar de achados contraditórios, ser do sexo feminino e ter idade avançada, também podem ser preditores de quedas. CONCLUSÕES: Identificam-se algumas carências metodológicas dos estudos de coorte prospectivo sobre quedas: carência de estudos sobre determinantes extrínsecos, necessidade de cegamento do avaliador durante o seguimento e de um melhor controle do seguimento com menores intervalos entre as coletas de dados.<br>OBJECTIVE: To systematize results of prospective cohort studies on multiple risk factors for falls in the elderly and to assess their methodological quality. METHODS: Systematic review of epidemiological studies from Medline, SciELO and Lilacs database. We included prospective cohort studies with samples of more than 100 subjects of both sexes, older than 64 years, and living either in the community or a nursing home. RESULTS: Of 726 studied identified, 15 met the inclusion criteria of being published between 1988 and 2005. The methodology of the studies varied. The main factors associated with increased risk of falls include: previous falls, altered gait, functional impairment, cognitive impairment, psychotropic medication use and excessive physical activity. Despite contradictory findings, being a woman at an advanced age may also be a predictor of falls. CONCLUSIONS: Methodological limitations were identified in prospective cohort studies on falls. There is a need for further studies on extrinsic determinants, including evaluator blinding and closer monitoring during follow-up with reduced time of recall