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1.
J Med Educ Curric Dev ; 8: 23821205211025861, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34377836

RESUMEN

Educational systems across the globe were disrupted by the COVID-19 pandemic, and faculty, staff, and students had to rapidly transition to e-learning platforms. These groups had little preparation to cope with the challenges of this newly adopted system. However, as we begin to emerge from the COVID-19 era, efforts are being made to assess the impact of this transition and develop a framework of best practices to help educators prepare for possible future disruptions. This commentary aims to discuss some of the challenges associated with the rapid transition to the new academic environment, including the modes of instruction employed, technical obstacles encountered, student responses to change and efforts made to evaluate didactic and practical aspects of the curriculum in the contexts of premedical and medical education, at the newly established College of Medicine at Khalifa University of Science and Technology in the United Arab Emirates.

2.
J Med Educ Curric Dev ; 8: 23821205211025858, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34179499

RESUMEN

The authors recount the challenges they overcame to deliver lecture content and assessments while engaging students at their newly established medical school. Faculty must multitask in new and added ways to achieve the same goal in e-learning platforms. Online course delivery introduces additional barriers to engaging students, atypical of face-to-face sessions. We received valuable feedback, adjusted our delivery, and allowed our students to access lecture recordings at their convenience. Our sessions with students were more than just a lecture but a way to help people through a unprecedented time. Remote learning platforms also provided faculty with opportunities to develop new pedagogical skills and alternative assessments.

3.
Foods ; 9(11)2020 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-33172200

RESUMEN

National nutrition surveys have shown that over half of all adults in Ireland, the United Kingdom (UK), and the United States of America (USA) have low vitamin K intakes. Thus, dietary strategies to improve vitamin K intakes are needed, and vitamin K biofortification of food may be one food-based approach. The primary aim of our study was to establish whether increasing the vitamin K3 content of hen feed can increase the vitamin K content of eggs, and the secondary aims were to examine the effects on hen performance parameters, as well as egg and eggshell quality parameters. A 12 week hen feeding trial was conducted in which Hyline chickens were randomized into four treatment groups (n = 32/group) and fed diets containing vitamin K3 (as menadione nicotinamide bisulfite) at 3 (control), 12.9, 23.7, and 45.7 mg/kg feed. Vitamin K1, menaquinone (MK)-4, MK-7, and MK-9 were measured in raw whole eggs via a liquid chromatography tandem mass spectrometry method. MK-4 was the most abundant form of vitamin K (91-98%) found in all eggs. Increasing the vitamin K3 content of hen feed over the control level significantly (p < 0.001) enhanced the MK-4 content of eggs (mean range: 46-51 µg/100 g, representing ~42-56% of US Adequate Intake values). Vitamin K biofortification also led to significant (p < 0.05) increases in the yellowness of egg yolk and in eggshell weight and thickness, but no other changes in egg quality or hen performance parameters. In conclusion, high-quality vitamin K-biofortified eggs can be produced with at least double the total vitamin K content compared to that in commercially available eggs.

4.
Curr Dev Nutr ; 4(7): nzaa112, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32704612

RESUMEN

BACKGROUND: Red meat and meat products can contribute meaningfully to the mean daily intake of vitamin D. Beef and lamb can contain vitamin D3 and 25-hydroxyvitamin D3 [25(OH)D3] but also potentially vitamin D2 and 25-hydroxyvitamin D2 [25(OH)D2], all of which contribute to meat's vitamin D activity. OBJECTIVES: We aimed to measure the vitamin D3, vitamin D2, 25(OH)D3, and 25(OH)D2 content of Irish beef and lamb. METHODS: Full striploin steaks (longissimus dorsi) (n = 39) from beef cattle slaughtered in winter, spring, summer, and autumn as well as lamb steaks (hind leg) from sheep slaughtered in autumn (n = 8) were sourced and homogenized. The contents of all 4 vitamin D-related compounds were analyzed using an LC-tandem MS method in conjunction with the National Institute of Standards and Technology's standard reference material no. 1546a-Meat Homogenate. The total vitamin D activity of meat was defined as: {vitamin D3 + [25(OH)D3 × 5] + vitamin D2 + [25(OH)D2 × 5]}. RESULTS: The median (IQR) total vitamin D activity of striploin beef steak (n = 39, irrespective of season) was 0.56 (0.37-0.91) µg/100 g. The content of all 4 vitamin D compounds in beef steak varied significantly (P < 0.0001) with season (n = 8-11/season group). Median total vitamin D activity of beef steak increased in a stepwise manner (P < 0.0001) from winter to the following autumn (increasing from 0.31 to 1.07 µg/100 g). The mean total vitamin D activity of lamb samples (n = 8) from autumn was 0.47 µg/100 g. CONCLUSIONS: About one-third of the total vitamin D activity of Irish beef was attributable to its combined vitamin D2 and 25(OH)D2 content, estimates of which are largely or completely missed in food composition tables. There was significant seasonal variation in all 4 vitamin D compounds as well as in total vitamin D activity, which has implications for vitamin D nutrient claims for beef.

5.
Peptides ; 47: 54-9, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23871693

RESUMEN

Gamma(2)-melanocyte-stimulating hormone (γ2MSH) is a peptide hormone released by the pituitary gland which is thought to act directly on the renal inner medulla to promote increased sodium excretion into urine (natriuresis). The aim of this study was to determine if a stable analog, [Nle(3), D-Phe(6)]-γ2MSH (NDP-γ2MSH), of the native peptide regulated the activity, expression and cellular localization of epithelial sodium channel (ENaC) in a murine inner medullary collecting duct (mIMCD-3) cell line. Our results indicate that expression of the γ2MSH receptor, melanocortin receptor 3 receptor (MC3R), is up-regulated by culturing the cells in media with an increased osmolality (∼400mOsm/kg). Furthermore, stimulation of cAMP signaling and sodium transport by 1nM NDP-γ2MSH occurs only in cells cultured in the high osmolality media. Finally, treatment of mIMCD-3 cells cultured in high osmolality medium for 1h with 1nM NDP-γ2MSH causes a reduction in expression of serum- and glucocorticoid-induced kinase (sgk1) and a reduction in expression and cell surface abundance of the alpha subunit of ENaC. Collectively, this data suggest that γ2MSH directly regulates both ENaC expression and cellular localization in the inner medulla to exert its natriuretic effect.


Asunto(s)
Células Epiteliales/metabolismo , Canales Epiteliales de Sodio/genética , Túbulos Renales Colectores/metabolismo , gamma-MSH/genética , Animales , Línea Celular , Medios de Cultivo , AMP Cíclico/metabolismo , Células Epiteliales/citología , Células Epiteliales/efectos de los fármacos , Canales Epiteliales de Sodio/metabolismo , Regulación de la Expresión Génica , Proteínas Inmediatas-Precoces/genética , Proteínas Inmediatas-Precoces/metabolismo , Transporte Iónico , Túbulos Renales Colectores/citología , Túbulos Renales Colectores/efectos de los fármacos , Ratones , Natriuresis/genética , Concentración Osmolar , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Receptor de Melanocortina Tipo 3/genética , Receptor de Melanocortina Tipo 3/metabolismo , Transducción de Señal , Sodio/metabolismo , alfa-MSH/análogos & derivados , alfa-MSH/farmacología , gamma-MSH/metabolismo
6.
Biochem Pharmacol ; 71(11): 1629-36, 2006 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-16620786

RESUMEN

2, 3, 5, 6-Tetrachloro-1, 4-benzoquinone (TCBQ) is a metabolite of pentachlorophenol known to react with cysteines of glutathione transferases (GSTs). TCBQ treatment of rat kidney rGSTA1-2 and rGSTA1-1 abolishes 70-80% conjugation of glutathione (GSH) to 1-chloro-2, 4-dinitrobenzene and results in strongly correlated quenching of intrinsic fluorescence of Trp-20 (R>0.96). rGSTA2-2 is only inhibited by 25%. Approximately 70% (rGSTA1-1) and 60% (rGSTA1-2) conjugation activity is abolished at TCBQ: GST stoichiometries near 1:1. The inactivation follows a Kitz/Wilson model with K(D) of 4.77+/-2.5microM for TCBQ and k(3) for inactivation of 0.036+/-0.01min(-1). A single tryptic peptide labelled with TCBQ was isolated from kidney rGSTA1-2 containing Cys-17 which we identify as the site of modification. Treatment with more than stoichiometric amounts of TCBQ modified other residues but resulted in only modest further inhibition of catalysis. We interpret these findings in terms of localised steric effects on the relatively rigid alpha-helix 1 adjacent to the catalytic site of subunit 1 possibly affecting the Alpha class-specific alpha-helix 9 which acts as a "lid" on the hydrophobic part of the active site. Homology modelling of rGSTA1-1 modified at Cys-17 of one subunit revealed only modest structural perturbations in the second subunit and tends to exclude global structural effects.


Asunto(s)
Cloranilo/farmacología , Glutatión Transferasa/química , Glutatión/metabolismo , Isoenzimas/química , Riñón/enzimología , Animales , Dominio Catalítico , Glutatión Transferasa/antagonistas & inhibidores , Glutatión Transferasa/metabolismo , Isoenzimas/antagonistas & inhibidores , Isoenzimas/metabolismo , Ligandos , Masculino , Modelos Moleculares , Subunidades de Proteína , Ratas , Ratas Wistar
7.
Proc Am Thorac Soc ; 2(2): 162-5, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16113486

RESUMEN

Despite advances in the understanding of the pathophysiology of asthma and the availability of effective treatment, the World Health Organization estimates that asthma accounts for 1 in every 250 deaths worldwide. Viruses are associated with half of all asthma exacerbations. The immune response to viral infection may enhance preexisting airway inflammation via the release of chemokines and cytokines and local recruitment of inflammatory cells. Murine models have provided evidence for a deleterious role for CD8+ T cells in the context of respiratory viral infection. Passive transfer of respiratory syncytial virus-specific cytotoxic T lymphocytes (CTLs) to infected mice results in virus clearance, which is associated with acute and sometimes fatal pulmonary disease. Compared with control subjects, CD8+ cells appear to be preferentially sequestered in the airways of individuals with asthma during acute exacerbations. In addition, an expanded CD8+ T cell population, dominated by activated cytotoxic CD8+ lymphocytes, has been documented in biopsies from patients dying as a result of acute asthma in association with a viral infection. Undoubtedly, CD8+ CTLs are a crucial in cell-mediated immunity in response to respiratory viruses. However, it would appear that an aberrant CD8+ T cell response in the context of a viral infection may place individuals with asthma at risk for fatal asthma.


Asunto(s)
Asma/mortalidad , Asma/virología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/virología , Infecciones del Sistema Respiratorio/complicaciones , Infecciones del Sistema Respiratorio/virología , Asma/inmunología , Linfocitos T CD8-positivos/fisiología , Humanos , Infecciones del Sistema Respiratorio/inmunología , Infecciones del Sistema Respiratorio/mortalidad
8.
FEMS Microbiol Lett ; 242(1): 1-12, 2005 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-15621414

RESUMEN

Most fungal glutathione transferases (GSTs) do not fit easily into any of the previously characterised classes by immunological, sequence or catalytic criteria. In contrast to the paucity of studies on GSTs cloned or isolated from fungal sources, a screen of databases revealed 67 GST-like sequences from 21 fungal species. Comparison by multiple sequence alignment generated a dendrogram revealing five clusters of GST-like proteins designated clusters 1, 2, EFIBgamma, Ure2p and MAK16, the last three of which have previously been related to the GST superfamily. Surprisingly, a relatively small number of fungal GSTs belong to mainstream classes and the previously-described fungal Gamma class is not widespread in the 21 species studied. Representative crystal structures are available for the EFIBgamma and Ure2p classes and the domain structures of representative sequences are compared with these. In addition, there are some "orphan" sequences that do not fit into any previously-described class, but show similarity to genes implicated in fungal biosynthetic gene clusters. We suggest that GST-like sequences are widespread in fungi, participating in a wide range of functions. They probably evolved by a process similar to domain "shuffling".


Asunto(s)
Biología Computacional , Evolución Molecular , Hongos/enzimología , Genoma Fúngico , Glutatión Transferasa/genética , Secuencia de Aminoácidos , Secuencia Conservada/genética , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Hongos/genética , Genes Fúngicos , Glutatión Transferasa/química , Modelos Moleculares , Datos de Secuencia Molecular , Filogenia , Estructura Terciaria de Proteína , Alineación de Secuencia , Homología de Secuencia de Aminoácido
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