30 research outputs found
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Immune nutrition and exercise: narrative review and practical recommendations
Evidence suggests that periods of heavy intense training can result in impaired immune cell function, and whether this leaves elite athletes at greater risk of infections and upper respiratory symptoms (URS) is still debated. There is some evidence that episodes of URS do cluster around important periods of competition and intense periods of training. Since reducing URS, primarily from an infectious origin, may have implications for performance, a large amount of research has focused on nutritional strategies to improve immune function at rest and in response to exercise. Although there is some convincing evidence that meeting requirements of high intakes in carbohydrate and protein and avoiding deficiencies in nutrients such as vitamin D and antioxidants is integral for optimal immune health, well-powered randomised controlled trials reporting improvements in URS beyond such intakes are lacking. Consequently, there is a need to first understand whether the nutritional practices adopted by elite athletes increases their risk of URS. Second, promising evidence in support of efficacy and mechanisms of immune-enhancing nutritional supplements (probiotics, bovine colostrum) on URS needs to be followed up with more randomised controlled trials in elite athletes with sufficient participant numbers and rigorous procedures with clinically relevant outcome measures of immunity
Biphasic Electrical Currents Stimulation Promotes both Proliferation and Differentiation of Fetal Neural Stem Cells
The use of non-chemical methods to differentiate stem cells has attracted
researchers from multiple disciplines, including the engineering and the
biomedical fields. No doubt, growth factor based methods are still the most
dominant of achieving some level of proliferation and differentiation control -
however, chemical based methods are still limited by the quality, source, and
amount of the utilized reagents. Well-defined non-chemical methods to
differentiate stem cells allow stem cell scientists to control stem cell biology
by precisely administering the pre-defined parameters, whether they are
structural cues, substrate stiffness, or in the form of current flow. We have
developed a culture system that allows normal stem cell growth and the option of
applying continuous and defined levels of electric current to alter the cell
biology of growing cells. This biphasic current stimulator chip employing ITO
electrodes generates both positive and negative currents in the same culture
chamber without affecting surface chemistry. We found that biphasic electrical
currents (BECs) significantly increased the proliferation of fetal neural stem
cells (NSCs). Furthermore, BECs also promoted the differentiation of fetal NSCs
into neuronal cells, as assessed using immunocytochemistry. Our results clearly
show that BECs promote both the proliferation and neuronal differentiation of
fetal NSCs. It may apply to the development of strategies that employ NSCs in
the treatment of various neurodegenerative diseases, such as Alzheimer's
and Parkinson's diseases
Biphasic Electrical Currents Stimulation Promotes both Proliferation and Differentiation of Fetal Neural Stem Cells
The use of non-chemical methods to differentiate stem cells has attracted
researchers from multiple disciplines, including the engineering and the
biomedical fields. No doubt, growth factor based methods are still the most
dominant of achieving some level of proliferation and differentiation control -
however, chemical based methods are still limited by the quality, source, and
amount of the utilized reagents. Well-defined non-chemical methods to
differentiate stem cells allow stem cell scientists to control stem cell biology
by precisely administering the pre-defined parameters, whether they are
structural cues, substrate stiffness, or in the form of current flow. We have
developed a culture system that allows normal stem cell growth and the option of
applying continuous and defined levels of electric current to alter the cell
biology of growing cells. This biphasic current stimulator chip employing ITO
electrodes generates both positive and negative currents in the same culture
chamber without affecting surface chemistry. We found that biphasic electrical
currents (BECs) significantly increased the proliferation of fetal neural stem
cells (NSCs). Furthermore, BECs also promoted the differentiation of fetal NSCs
into neuronal cells, as assessed using immunocytochemistry. Our results clearly
show that BECs promote both the proliferation and neuronal differentiation of
fetal NSCs. It may apply to the development of strategies that employ NSCs in
the treatment of various neurodegenerative diseases, such as Alzheimer's
and Parkinson's diseases
INDUCED PLURIPOTENT STEM CELLS FOR BASIC AND TRANSLATIONAL RESEARCH ON HD
The expression of mutant HTT leads to many cellular alterations, including abnormal vesicle recycling, loss of signalling by brain-derived neurotrophic factor, excitotoxicity, perturbation of Ca2+ signalling, decreases in intracellular ATP, alterations of gene transcription, inhibition of protein clearance pathways, mitochondrial and metabolic disturbances, and ultimately cell death. While robust mammalian systems have been developed to model disease and extensive mechanistic insights have emerged, significant differences between rodent and human cells and between non-neuronal cells and neurons limit the utility of these models for accurately representing human disease. Human pluripotent stem cells can generate highly specified cell populations, including DARPP32-positive MSNs of the striatum, and provide a method for modelling HD in human neurons carrying the mutation. As it is caused by one single gene, HD is an ideal disorder for exploring the utility of modelling disease in induced pluripotent stem cells (iPSCs) through reprogramming adult cells from HD patients with known patterns of disease onset and duration
Ocular retardation mouse caused by Chx10 homeobox null allele: impaired retinal progenitor proliferation and bipolar cell differentiation.
Ocular retardation (or) is a murine eye mutation causing microphthalmia, a thin hypocellular retina and optic nerve aplasia. Here we show that mice carrying the OrJ allele have a premature stop codon in the homeobox of the Chx10 gene, a gene expressed at high levels in uncommitted retinal progenitor cells and mature bipolar cells. No CHX10 protein was detectable in the retinal neuroepithelium of orJ homozygotes. The loss of CHX10 leads both to reduced proliferation of retinal progenitors and to a specific absence of differentiated bipolar cells. Other major retinal cell types were present and correctly positioned in the mutant retina, although rod outer segments were short and retinal lamination was incomplete. These results indicate that Chx10 is an essential component in the network of genes required for the development of the mammalian eye, with profound effects on retinal progenitor proliferation and bipolar cell specification or differentiation. of