The risks of self-made diets: the case of an amateur bodybuilder.

BACKGROUND: Following DIY (do it yourself) diets as well as consuming supplements exceeding by far the recommended daily intake levels, is common among athletes; these dietary habits often lead to an overconsumption of some macro and/or micronutrients, exposing athletes to potential health risks. The aim of this study is to document the development of possible adverse effects in a 33 year-old amateur bodybuilder who consumed for 16 years a DIY high protein diet associated to nutrient supplementation. Body composition, biochemical measures and anamnestic findings were evaluated. We present this case to put on alert about the possible risks of such behavior repeated over time, focusing on the adverse gastrointestinal effects. We discuss the energy and nutrient composition of his DIY diet as well as the use of supplements. CONCLUSION: This study provides preliminary data of the potential risks of a long-term DIY dietary supplementation and a high protein diet. In this case, permanent abdominal discomfort was evidenced in an amateur body builder with an intake exceeding tolerable upper limit for vitamin A, selenium and zinc, according to our national and updated recommendations. As many amateur athletes usually adopt self-made diets and supplementation, it would be advisable for them to be supervised in order to prevent health risks due to a long-term DIY diet and over-supplementation.

Human fetal striatum-derived neural stem (NS) cells differentiate to mature neurons in vitro and in vivo.

Clonogenic neural stem (NS) cell lines grown in adherent cultures have previously been established from embryonic stem cells and fetal and adult CNS in rodents and from human fetal brain and spinal cord. Here we describe the isolation of a new cell line from human fetal striatum (hNS cells). These cells showed properties of NS cells in vitro such as monolayer growth, high proliferation rate and expression of radial glia markers. The hNS cells expressed an early neuronal marker while being in the proliferative state. Under appropriate conditions, the hNS cells were efficiently differentiated to neurons, and after 4 weeks about 50% of the cells were ßIII tubulin positive. They also expressed the mature neuronal marker NeuN and markers of neuronal subtypes, GABA, calbindin, and DARPP32. After intrastriatal implantation into newborn rats, the hNS cells survived and many of them migrated outside the transplant core into the surrounding tissue. A high percentage of cells in the grafts expressed the neuroblast marker DCX, indicating their neurogenic potential, and some of the cells differentiated to NeuN+ mature neurons. The human fetal striatum-derived NS cell line described here should be a useful tool for studies on cell replacement strategies in models of the striatal neuronal loss occurring in Huntington's disease and stroke.

Impaired generation of mature neurons by neural stem cells from hypomorphic Sox2 mutants.

The transcription factor Sox2 is active in neural stem cells, and Sox2 'knockdown' mice show defects in neural stem/progenitor cells in the hippocampus and eye, and possibly some neurons. In humans, heterozygous Sox2 deficiency is associated with eye abnormalities, hippocampal malformation and epilepsy. To better understand the role of Sox2, we performed in vitro differentiation studies on neural stem cells cultured from embryonic and adult brains of 'knockdown' mutants. Sox2 expression is high in undifferentiated cells, and declines with differentiation, but remains visible in at least some of the mature neurons. In mutant cells, neuronal, but not astroglial, differentiation was profoundly affected. beta-Tubulin-positive cells were abundant, but most failed to progress to more mature neurons, and showed morphological abnormalities. Overexpression of Sox2 in neural cells at early, but not late, stages of differentiation, rescued the neuronal maturation defect. In addition, it suppressed GFAP expression in glial cells. Our results show an in vitro requirement for Sox2 in early differentiating neuronal lineage cells, for maturation and for suppression of alternative lineage markers. Finally, we examined newly generated neurons from Sox2 ;knockdown' newborn and adult mice. GABAergic neurons were greatly diminished in number in newborn mouse cortex and in the adult olfactory bulb, and some showed abnormal morphology and migration properties. GABA deficiency represents a plausible explanation for the epilepsy observed in some of the knockdown mice, as well as in SOX2-deficient individuals.

Conserved POU binding DNA sites in the Sox2 upstream enhancer regulate gene expression in embryonic and neural stem cells.

The Sox2 transcription factor is expressed early in the stem cells of the blastocyst inner cell mass and, later, in neural stem cells. We previously identified a Sox2 5'-regulatory region directing transgene expression to the inner cell mass and, later, to neural stem cells and precursors of the forebrain. Here, we identify a core enhancer element able to specify transgene expression in forebrain neural precursors of mouse embryos, and we show that the same core element efficiently activates transcription in inner cell mass-derived embryonic stem (ES) cells. Mutation of POU factor binding sites, able to recognize the neural factors Brn1 and Brn2, shows that these sites contribute to transgene activity in neural cells. The same sites are also essential for activity in ES cells, where they bind different members of the POU family, including Oct4, as shown by gel shift assays and chromatin immunoprecipitation with anti-Oct4 antibodies. Our findings indicate a role for the same POU binding motifs in Sox2 transgene regulation in both ES and neural precursor cells. Oct4 might play a role in the regulation of Sox2 in ES (inner cell mass) cells and, possibly, at the transition between inner cell mass and neural cells, before recruitment of neural POU factors such as Brn1 and Brn2.

Sox2 deficiency causes neurodegeneration and impaired neurogenesis in the adult mouse brain.

In many species, the Sox2 transcription factor is a marker of the nervous system from the beginning of its development, and we have previously shown that Sox2 is expressed in embryonic neural stem cells. It is also expressed in, and is essential for, totipotent inner cell mass stem cells and other multipotent cell lineages, and its ablation causes early embryonic lethality. To investigate the role of Sox2 in the nervous system, we generated different mouse mutant alleles: a null allele (Sox2beta-geo 'knock-in'), and a regulatory mutant allele (Sox2DeltaENH), in which a neural cell-specific enhancer is deleted. Sox2 is expressed in embryonic early neural precursors of the ventricular zone and, in the adult, in ependyma (a descendant of the ventricular zone). It is also expressed in the vast majority of dividing precursors in the neurogenic regions, and in a small proportion of differentiated neurones, particularly in the thalamus, striatum and septum. Compound Sox2(beta-geo/DeltaENH) heterozygotes show important cerebral malformations, with parenchymal loss and ventricle enlargement, and L-dopa-rescuable circling behaviour and epilepsy. We observed striking abnormalities in neurones; degeneration and cytoplasmic protein aggregates, a feature common to diverse human neurodegenerative diseases, are observed in thalamus, striatum and septum. Furthermore, ependymal cells show ciliary loss and pathological lipid inclusions. Finally, precursor cell proliferation and the generation of new neurones in adult neurogenic regions are greatly decreased, and GFAP/nestin-positive hippocampal cells, which include the earliest neurogenic precursors, are strikingly diminished. These findings highlight a crucial and unexpected role for Sox2 in the maintenance of neurones in selected brain areas, and suggest a contribution of neural cell proliferative defects to the pathological phenotype.