Transcriptional control of neural crest specification into peripheral glia

The neural crest is a transient migratory multipotent cell population that originates from the neural plate border and is formed at the end of gastrulation and during neurulation in vertebrate embryos. These cells give rise to many different cell types of the body such as chondrocytes, smooth muscle cells, endocrine cells, melanocytes, and cells of the peripheral nervous system including different subtypes of neurons and peripheral glia. Acquisition of lineage-specific markers occurs before or during migration and/or at final destination. What are the mechanisms that direct specification of neural crest cells into a specific lineage and how do neural crest cells decide on a specific migration route? Those are fascinating and complex questions that have existed for decades and are still in the research focus of developmental biologists. This review discusses transcriptional events and regulations occurring in neural crest cells and derived lineages, which control specification of peripheral glia, namely Schwann cell precursors that interact with peripheral axons and further differentiate into myelinating or nonmyelinating Schwann cells, satellite cells that remain tightly associated with neuronal cell bodies in sensory and autonomous ganglia, and olfactory ensheathing cells that wrap olfactory axons, both at the periphery in the olfactory mucosa and in the central nervous system in the olfactory bulb. Markers of the different peripheral glia lineages including intermediate multipotent cells such as boundary cap cells, as well as the functions of these specific markers, are also reviewed. Enteric ganglia, another type of peripheral glia, will not be discussed in this review

Chromatin-remodeling enzymes in control of Schwann cell development, maintenance and plasticity

Gene regulation is essential for cellular differentiation and plasticity. Schwann cells (SCs), the myelinating glia of the peripheral nervous system (PNS), develop from neural crest cells to mature myelinating SCs and can at early developmental stage differentiate into various cell types. After a PNS lesion, SCs can also convert into repair cells that guide and stimulate axonal regrowth, and remyelinate regenerated axons. What controls their development and versatile nature? Several recent studies highlight the key roles of chromatin modifiers in these processes, allowing SCs to regulate their gene expression profile and thereby acquire or change their identity and quickly react to their environment

Increasing stability and interpretability of gene expression signatures

Motivation : Molecular signatures for diagnosis or prognosis estimated from large-scale gene expression data often lack robustness and stability, rendering their biological interpretation challenging. Increasing the signature's interpretability and stability across perturbations of a given dataset and, if possible, across datasets, is urgently needed to ease the discovery of important biological processes and, eventually, new drug targets. Results : We propose a new method to construct signatures with increased stability and easier interpretability. The method uses a gene network as side interpretation and enforces a large connectivity among the genes in the signature, leading to signatures typically made of genes clustered in a few subnetworks. It combines the recently proposed graph Lasso procedure with a stability selection procedure. We evaluate its relevance for the estimation of a prognostic signature in breast cancer, and highlight in particular the increase in interpretability and stability of the signature

Does Sita Sing the Blues? Reworking the Ramayana Narrative

This paper analyzes whether Nina Paley\u27s 2008 animated film, Sita Sings the Blues, is consonant with Ramayana traditions by evaluating it in relation to the Valmiki Ramayana and Chandravati Ramayana

Description rétrospective des rhabdomyolyses intenses de l'enfant

Summary: The goals of our study were to describe the clinical presentation, the evolution and the etiologies of high-CPK rhabdomyolysis (CPK>6000 IU/L) in children and then to analyze the diagnostic approach carried out to establish its cause.Patients and methods: We performed a retrospective study of patients under 18 who were hospitalized in our pediatric hospital and had CPK levels higher than 6000 IU/L.Results: 119 files (75 males and 44 females) were found and studied. The median of the highest CPK was 13120 IU/L (range 6023-690760). 64 patients (54%) had been hospitalized in intensive care units, 31 (26%) in the neurometabolism department, 8 (7%) in the emergency room and 16 (13%) in other departments. They exhibited an alteration of clinical status (28%), myalgia (21%) or symptoms of viral infection (28%). 46% had respiratory symptoms and 50% hemodynamic failure; 12% were dialyzed and 20% died. For 50%, the cause of the rhabdomyolysis was already known on admission. In 25% the diagnostic has been established with certainty while the others 25% remained uncertain. The most common causes were visceral failures (28%), myopathies (20%), infections (15%), trauma (15%), surgery (14%), metabolic diseases (10%), LPIN1 mutations (3%). In 34%, different causes could explain the rhabdomyolysis. For 47% of the patients with uncertain diagnosis, the advised etiologic explorations had not been done.As a conclusion, causes of rhabdomyolysis with CPK levels higher than 6000 IU/L are specific. These patients are more often hospitalized in intensive care units and have a higher mortality rate. They are also more likely to have a metabolic disease than patients with lower CPK rates.L’objectif de notre étude est de décrire la présentation clinique, l’évolution et les étiologies des rhabdomyolyses intenses de l’enfant (CPK>6000 UI/L) et d’analyser la démarche diagnostique mise en place pour en déterminer la cause.Patients et méthodes : Il s’agit d’une étude rétrospective sur 5 ans sur les patients de moins de 18 ans hospitalisés à l’hôpital Necker-Enfants Malades (Paris) qui avaient un dosage de CPK supérieur à 6000 UI/L.Résultats : 119 dossiers ont été étudiés. La médiane des CPK maximales était à 13120 UI/L (6023-690760). Soixante-quatre patients (54%) étaient hospitalisés en réanimation, 31 (26%) en neuro-métabolisme, 8 (7%) aux urgences et 16 (13%) dans d’autres services. Ils présentaient une altération de l’état général (28%), des myalgies (21%) ou des symptômes viraux (28%). Au cours du séjour, 12% ont été dialysés et 20% sont décédés. Pour 50% des patients, la cause de la rhabdomyolyse était connue à l’arrivée ; le diagnostic a été déterminé avec certitude dans 25% des cas et est resté incertain chez 25%. Les causes de l’épisode étaient des défaillances viscérales (28%), des infections (15%), des traumatismes (15%), de la chirurgie lourde (14%), des maladies métaboliques (10%), des myopathies (20%), des mutations LPIN1 (3%). Plusieurs causes expliquaient la rhabdomyolyse chez 34%. Pour 47% des patients sans diagnostic certain, les explorations étiologiques recommandées n’avaient pas été réalisées.Conclusion : les patients qui présentent des CPK supérieures à 6000 UI/L sont souvent hospitalisés en réanimation et ont une mortalité élevée. Ils sont plus susceptibles d’avoir une maladie métabolique que les patients avec des CPK moins élevées

Histone Methylation in the Nervous System: Functions and Dysfunctions

Chromatin remodeling is a key epigenetic process controlling the regulation of gene transcription. Local changes of chromatin architecture can be achieved by post-translational modifications of histones such as methylation, acetylation, phosphorylation, ubiquitination, sumoylation, and ADP-ribosylation. These changes are dynamic and allow for rapid repression or de-repression of specific target genes. Chromatin remodeling enzymes are largely involved in the control of cellular differentiation, and loss or gain of function is often correlated with pathological events. For these reasons, research on chromatin remodeling enzymes is currently very active and rapidly expanding, these enzymes representing very promising targets for the design of novel therapeutics in different areas of medicine including oncology and neurology. In this review, we focus on histone methylation in the nervous system. We provide an overview on mammalian histone methyltransferases and demethylases and their mechanisms of action, and we discuss their roles in the development of the nervous system and their involvement in neurodevelopmental, neurodegenerative, and behavioral disorder

Water quality monitoring and hydraulic evaluation of a household roof runoff harvesting system in France

The quality of harvested rainwater used for toilet flushing in a private house in the south-west of France was assessed over a one-year period. Twenty-one physicochemical parameters were screened using standard analytical techniques. The microbiological quality of stored roof runoff was also investigated and total flora at 22°C and 36°C, total coliforms, Escherichia Coli, enteroccocci, Cryptospridium oocysts, Giardia cysts, Legionella species, Legionella pneumophila, Aeromonas, and Pseudomonas aeruginosa were analysed. Chemical and microbiological parameters fluctuated during the course of the study, with the highest levels of microbiological contamination observed in roof runoffs collected during the summer. Overall, the collected rainwater had a relatively good physicochemical quality but variable, and, did not meet the requirements for drinking water and a microbiological contamination of the water was observed. The water balance of a 4-people standard family rainwater harvesting system was also calculated in this case study. The following parameters were calculated: rainfall, toilets flushing demand, mains water, rainwater used and water saving efficiency. The experimental water saving efficiency was calculated as 87 %. The collection of rainwater from roofs, its storage and subsequent use for toilet flushing can save 42 m3 of potable water per year for the studied system

Monitoring of water quality from roof runoff: Interpretation using multivariate analysis

The quality of harvested rainwater used for toilet flushing in a private house in the south-west of France was assessed over a one-year period. Temperature, pH, conductivity, colour, turbidity, anions, cations, alkalinity, total hardness and total organic carbon were screened using standard analytical techniques. Total flora at 22°C and 36°C, total coliforms, Escherichia coli and enterococci were analysed. Overall, the collected rainwater had good physicochemical quality but did not meet the requirements for drinking water. The stored rainwater is characterised by low conductivity, hardness and alkalinity compared to mains water. Three widely used bacterial indicators - total coliforms, E. coli and enterococci - were detected in the majority of samples, indicating microbiological contamination of the water. To elucidate factors affecting the rainwater composition, principal component analysis and cluster analysis were applied to the complete data set of 50 observations. Chemical and microbiological parameters fluctuated during the course of the study, with the highest levels of microbiological contamination observed in roof runoffs collected during the summer. Escherichia coli and enterococci occurred simultaneously, and their presence was linked to precipitation. Runoff quality is also unpredictable because it is sensitive to the weather. Cluster analysis differentiated three clusters: ionic composition, parameters linked with the microbiological load and indicators of faecal contamination. In future surveys, parameters from these three groups will be simultaneously monitored to more accurately characterise roof collected rainwater

How Histone Deacetylases Control Myelination

Myelinated axons are a beautiful example of symbiotic interactions between two cell types: Myelinating glial cells organize axonal membranes and build their myelin sheaths to allow fast action potential conduction, while axons regulate myelination and enhance the survival of myelinating cells. Axonal demyelination, occurring in neurodegenerative diseases or after a nerve injury, results in severe motor and/or mental disabilities. Thus, understanding how the myelination process is induced, regulated, and maintained is crucial to develop new therapeutic strategies for regeneration in the nervous system. Epigenetic regulation has recently been recognized as a fundamental contributing player. In this review, we focus on the central mechanisms of gene regulation mediated by histone deacetylation and other key functions of histone deacetylases in Schwann cells and oligodendrocytes, the myelinating glia of the peripheral and central nervous system

Help Seeking, Work Status, and Outcome: Counseling Psychologist’s Prospective Role

Exploring the effects on mental health outcome when individuals who admit they are in need of mental health help and actually do engage in help seeking (versus those who admit a need but do not seek help), in addition to work status may provide support to bolster the education and promotion of help seeking and work engagement. Moreover, counseling psychologists may be best positioned to understand how career and mental health issues interact by addressing the concerns of occupational mental health. The current study examined the effects of actual mental health help seeking and work status on mental health outcome