Low Energy Availability in Athletes 2020: An Updated Narrative Review of Prevalence, Risk, Within-Day Energy Balance, Knowledge, and Impact on Sports Performance.

Low energy availability (EA) underpins the female and male athlete triad and relative energy deficiency in sport (RED-S). The condition arises when insufficient calories are consumed to support exercise energy expenditure, resulting in compromised physiological processes, such as menstrual irregularities in active females. The health concerns associated with longstanding low EA include menstrual/libido, gastrointestinal and cardiovascular dysfunction and compromised bone health, all of which can contribute to impaired sporting performance. This narrative review provides an update of our previous review on the prevalence and risk of low EA, within-day energy deficiency, and the potential impact of low EA on performance. The methods to assess EA remain a challenge and contribute to the methodological difficulties in identifying "true" low EA. Screening female athletic groups using a validated screening tool such as the Low Energy Availability in Females Questionnaire (LEAF-Q) has shown promise in identifying endurance athletes at risk of low EA. Knowledge of RED-S and its potential implications for performance is low among coaches and athletes alike. Development of sport and gender-specific screening tools to identify adolescent and senior athletes in different sports at risk of RED-S is warranted. Education initiatives are required to raise awareness among coaches and athletes of the importance of appropriate dietary strategies to ensure that sufficient calories are consumed to support training.

Is Melanoma a stem cell tumor? Identification of neurogenic proteins in trans-differentiated cells.

BACKGROUND: Although several genes and proteins have been implicated in the development of melanomas, the molecular mechanisms involved in the development of these tumors are not well understood. To gain a better understanding of the relationship between the cell growth, tumorigenesis and differentiation, we have studied a highly malignant cat melanoma cell line that trans-differentiates into neuronal cells after exposure to a feline endogenous retrovirus RD114. METHODS: To define the repertoire of proteins responsible for the phenotypic differences between melanoma and its counterpart trans-differentiated neuronal cells we have applied proteomics technology and compared protein profiles of the two cell types and identified differentially expressed proteins by 2D-gel electrophoresis, image analyses and mass spectrometry. RESULTS: The melanoma and trans-differentiated neuronal cells could be distinguished by the presence of distinct sets of proteins in each. Although approximately 60-70% of the expressed proteins were shared between the two cell types, twelve proteins were induced de novo after infection of melanoma cells with RD114 virus in vitro. Expression of these proteins in trans-differentiated cells was significantly associated with concomitant down regulation of growth promoting proteins and up-regulation of neurogenic proteins (p = < 0.001). Based on their physiologic properties, >95% proteins expressed in trans-differentiated cells could be associated with the development, differentiation and regulation of nervous system cells. CONCLUSION: Our results indicate that the cat melanoma cells have the ability to differentiate into distinct neuronal cell types and they express proteins that are essential for self-renewal. Since melanocytes arise from the neural crest of the embryo, we conclude that this melanoma arose from embryonic precursor stem cells. This model system provides a unique opportunity to identify domains of interactions between the expressed proteins that halt the tumorigenic potential of melanoma cells and drive them toward neurogenerative pathways involved in early neurogenesis. A better understanding of these proteins in a well-coordinated signaling network would also help in developing novel approaches for suppression of highly malignant tumors that arise from stem-like embryonic cells.

Estudio de la sintomatología ansiosa y depresiva de una muestra de preescolares inhibidos / Analysis of anxious and depressive symptoms of a sample of inhibited preschoolers

Aunque la inhibición conductual no es condición necesaria ni suficiente para el desarrollo de un trastorno de ansiedad, la literatura indica que los niños inhibidos son más propensos a desarrollar este tipo de trastornos en comparación con los desinhibidos. Algunos estudios han sugerido una conexión (probablemente mediada por la ansiedad) entre la inhibición conductual y la sintomatología depresiva. De acuerdo con esta línea de investigación, el objetivo del presente trabajo es examinar la relación existente entre la inhibición conductual y la sintomatología depresiva, partiendo de la hipótesis de que los preescolares con mayores puntuaciones en inhibición conductual exhibirán mayor número de síntomas de ansiedad y depresión que aquéllos con puntuaciones menores. Tras evaluar una muestra de niños (n~697) de 3 a 6 años, los resultados indican que los niños inhibidos muestran mayores niveles de ansiedad y depresión que los controles. Este hallazgo apoya a la hipótesis de que el rasgo temperamental conocido como inhibición conductual aumenta el riesgo de psicopatología ansioso-depresiva (AU)

Despite behavioural inhibition is neither necessary nor sufficient for the development of anxiety disorders, there are some indications in the literature that behaviourally inhibited children are more likely to develop anxiety disorders than uninhibited ones. Some studies suggest that there is a connection (probably carried by anxiety) between behavioral inhibition and depression symptoms. According to this line of research, the aim 01 the present work is to examine the relationship between behavioral inhibition and internalizing psychopathology, hypothesising that preschoolers with highest scores on behavioral inhibition will exhibit more anxiety and depression symptoms than those with lowest scores. After the assessment of a sample of children (N=697) aged 3 to 6, results indicate that most inhibited children have higher levels of anxiety and depression than controls. This finding add support to the hypothesis that the temperamental feature called 'behavioural inhibition' leads to anxious and depressive psychopathology (AU)