RESUMEN
Recent times have seen an increasing move towards harnessing the health-promoting benefits of food and dietary constituents while providing scientific evidence to substantiate their claims. In particular, the potential for bioactive protein hydrolysates and peptides to enhance health in conjunction with conventional pharmaceutical therapy is being investigated. Dairy-derived proteins have been shown to contain bioactive peptide sequences with various purported health benefits, with effects ranging from the digestive system to cardiovascular circulation, the immune system and the central nervous system. Interestingly, the ability of dairy proteins to modulate metabolism and appetite has recently been reported. The ghrelin receptor (GHSR-1a) is a G-protein coupled receptor which plays a key role in the regulation of food intake. Pharmacological manipulation of the growth hormone secretagogue receptor-type 1a (GHSR-1a) receptor has therefore received a lot of attention as a strategy to combat disorders of appetite and body weight, including age-related malnutrition and the progressive muscle wasting syndrome known as cachexia. In this study, a milk protein-derivative is shown to increase GHSR-1a-mediated intracellular calcium signalling in a concentration-dependent manner in vitro. Significant increases in calcium mobilisation were also observed in a cultured neuronal cell line heterologously expressing the GHS-R1a. In addition, both additive and synergistic effects were observed following co-exposure of GHSR-1a to both the hydrolysate and ghrelin. Subsequent in vivo studies monitored standard chow intake in healthy male and female Sprague-Dawley rats after dosing with the casein hydrolysate (CasHyd). Furthermore, the provision of gastro-protected oral delivery to the bioactive in vivo may aid in the progression of in vitro efficacy to in vivo functionality. In summary, this study reports a ghrelin-stimulating bioactive peptide mixture (CasHyd) with potent effects in vitro. It also provides novel and valuable translational data supporting the potential role of CasHyd as an appetite-enhancing bioactive. Further mechanistic studies are required in order to confirm efficacy as a ghrelinergic bioactive in susceptible population groups.
Asunto(s)
Caseínas/metabolismo , Ingestión de Alimentos , Expresión Génica , Receptores de Ghrelina/genética , Animales , Calcio/metabolismo , Caseínas/química , Línea Celular , Cromatografía Líquida de Alta Presión , Activación Enzimática , Estabilidad de Enzimas , Femenino , Ghrelina/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Masculino , Imagen Molecular/métodos , Ratas , Receptores de Ghrelina/metabolismoRESUMEN
Undergraduate student participation in course-based research experiences results in many positive outcomes, but there is a lack of evidence demonstrating which elements of a research experience are necessary, especially for non-biology majors. Broad relevance is one element that can be logistically challenging to incorporate into research experiences in large-enrollment courses. We investigated the impacts of broad relevance in a short-term research experience in an introductory biology course for non-majors. Students either participated in an open-inquiry research experience (OI-RE), where they developed their own research question, or a broadly relevant research experience (BR-RE), where they investigated a question assigned to them that was relevant to an ongoing research project. We found a significant association between the type of research project experienced and students' preference for an experience, with half of the students in the OI-RE group and nearly all students in the BR-RE group preferring a broadly relevant research experience. However, since science confidence increased over the course for both groups, these findings indicate that while students who participated in a BR-RE valued it, broadly relevant research experiences may not be necessary for positive outcomes for non-majors.
RESUMEN
INTRODUCTION: The gold standard in general radiography is to place a radiopaque anatomical side marker in the field of view for each radiographic image prior to exposure. The advent of digital radiography has allowed for anatomical side markers to be digitally added to films as part of post-processing. The aim of this audit was to identify whether general X-ray images performed in a tertiary Women's and Children's Hospital were being appropriately annotated with a definitive side marker, and to identify factors that may contribute to inappropriately labelled images. METHODS: Four hundred images from 201 patients' examinations occurring within a randomly selected time period were assessed to ascertain whether radiographic anatomical side markers were visible when images were viewed via the hospitals main viewing platform. The audit occurred in January 2014. The scope included both mobile and in-department general X-ray examinations, with the patient age range extending from 1 day to 18 years. RESULTS: Of the 400 images evaluated, 88 (22%) were found to have a lead marker that matched the anatomy being imaged within the primary beam; 289 (72.3%) images contained a correct digital marker inserted as part of the post-processing of the image. In total, 377 (94.2%) images were appropriately marked. Of the 23 (5.8%) images not marked correctly, 22 images had no marker and 1 was incorrectly marked with a digital marker. There was a noticeable relationship between absent anatomical markers and chest X-rays performed outside of the medical imaging department. CONCLUSIONS: While it is encouraging that the majority of the images assessed were correctly annotated, with only a small number of missing markers, there are opportunities for further improvement. The audit findings suggest that reduced access to lead markers influences marker use. Strategies that may improve compliance at an individual level include distribution of personalised anatomical side markers, and targeted staff education sessions. At a department level, regular audits and monitoring should be encouraged.