The critical role of vestibular graviception during cognitive-motor development.

Earth's gravity acts both as a mechanical stimulus on the body and as a sensory stimulus to the vestibular organ, which is transmitted into the brain. The vestibular system has been recently highlighted as the cornerstone of the multisensory cortex and of the dorsal hippocampus related to spatial cognition. Consequently, we have hypothesized that the vestibular sensory perception of gravity by the otoliths might also play a crucial role during the first stages of development in both sensorimotor and cognitive functions and the construction and perception of the 'self' and related functions of orientation and navigation. We have investigated an original mouse model (Head Tilted mice, B6Ei.GL-Nox3het/J) suffering from a selective congenital absence of vestibular otolithic gravisensors. We report that mouse pups suffered from a delay in the acquisition of sensorimotor reflexes, spatial olfactory guidance, path integration, and ultrasonic communication, while maternal care remained normal. We demonstrate that development has a critical period dependent on the vestibular otolithic sensory perception of gravity, probably temporally between the somesthetic and visual critical periods. The symptoms expressed by the congenital otolithic-deficient mice are similar to validated mouse models of autism and highlight the significance of vestibular graviception in the pathophysiology of development.

The role of the neuropediatrician in pediatric intensive care unit: Diagnosis, therapeutics and major participation in collaborative multidisciplinary deliberations about life-sustaining treatments' withdrawal.

BACKGROUND: In Pediatric Intensive Care Unit (PICU) two types of population require the intervention of neuropediatricians (NP): chronic brain diseases' patients who face repetitive and prolonged hospitalizations, and patients with acute brain failure facing the risk of potential neurologic sequelae, and both conditions may result in a limitation of life-sustaining treatments (LLST) decision. OBJECTIVE: To assess NP's involvement in LLST decisions within the PICU of a tertiary hospital. METHOD: Retrospective study of medical reports of patients hospitalized during 2014 in the Necker-Hospital PICU. Patients were selected using keywords ("cardiorespiratory arrest", "death", "withdrawal of treatment", "palliative care", "acute brain failure", or "chronic neurological disease"), and/or if they were assessed by a NP during the hospitalization. Demographic and medical data were analysed, including the NP's assessment and data about Collaborative Multidisciplinary Deliberation (CMD) to discuss potential LLST. RESULTS: Among 1160 children, 274 patients were included and 142 (56%) were assessed by a NP during their hospitalization for diagnosis (n = 55) and/or treatment (n = 95) management. NP was required for 59%-100% of patients with neurological acute failure, and for 14-44% of patients with extra neurological failure. A LLST decision was taken after a CMD for 27 (9.8%) of them, and a NP was involved in 19/27 (70%) of these decisions that occurred during the hospitalization (n = 19) or before (n = 8).12 patients died thereafter the LLST decision (40% of the 30 dead patients). CONCLUSION: NP are clearly involved in the decision-process of LLST for patients admitted in PICU, claiming for close collaboration to improve current practices and the quality of the care provided to children.

[Pasteurella multocida meningoencephalitis in a 14-year-old child]. / Méningo-encéphalite à Pasteurella multocida chez un enfant de 14 ans.

Pasteurella multocida is generally responsible for local infections through animal bites. It can be a cause of meningitis, which tends to affect people at the extreme ages of life or suffering from immunodeficiency. A 14-year-old teenager was hospitalized with typical signs of bacterial meningitis. P. multocida was evidenced in the cerebrospinal fluid. Progression was marked by a degradation on the 4th day of treatment, despite intravenous antibiotic therapy with third-generation cephalosporin, followed by a single seizure on the 7th day of treatment. The CT scan and magnetic resonance imaging showed pansinusitis but no intracerebral complications. Later progression was favorable, without neurological sequelae. The mode of contamination was inoculation via the upper airways with sinusitis. P. multocida meningitis is rare. The contamination does not always involve animal trauma.

[Comparison of palliative care representations between pediatrician residents and oncologist residents: A qualitative study]. / Comparaison des représentations des soins palliatifs des internes de pédiatrie à celles des internes d'onco-hématologie - étude qualitative.

BACKGROUND: Pediatrics residents treat patients who are particularly vulnerable and they care for many patients in palliative situations. The purpose of this study was to build a typology detailing the representations of pediatrics and oncology residents on palliative care and how these transfer to their practice, and to determine their knowledge of euthanasia and end-of-life legislation. METHODS: To draw up this typology, we used a semidirective interview method. The topics treated were their definition of palliative care, end of life, the emotions involved in these situations, and their daily practice. Then we asked them to speak about their opinions and knowledge of euthanasia and end-of-life legislation. RESULTS: Thirteen residents were interviewed: eight pediatrics residents, two oncologists, and three hemato-oncologists. Interviews lasted around 45min. Pediatrics and oncology residents had common representations based on "care giving." Nevertheless, pediatrics residents remained within the technical aspects to protect themselves from their negative emotions and stayed away from their patients. Oncology residents set their emotions aside to be able to carry on taking care of their patients. CONCLUSION: It seems necessary to disseminate a palliative culture, particularly in pediatrics, to improve management of children in palliative situations and to improve resident's feelings.

Naked-eye nanobiosensor for therapeutic drug monitoring of methotrexate.

Sensing of methotrexate at clinically-relevant concentrations was achieved with a plasmon-coupling assay. In this assay, free methotrexate and folic acid Au nanoparticles competed for human dihydrofolate reductase (hDHFR)-functionalized Au nanoparticles (Au NP). The hDHFR-functionalized Au NPs were immobilized on a small glass sensor inserted in a portable 4-channel LSPR reader. This allowed rapid (minutes) and sensitive (nanomolar range) measurement of methotrexate concentration by means of total internal reflection plasmonic spectroscopy. The large bathochromic shifts of the plasmon-coupling assay led to striking colour changes visible to the naked eye for methotrexate at clinically-relevant concentrations. The results demonstrate the potential for therapeutic drug monitoring of a widely used chemotherapy agent, as assessed with the naked eye.

Two-beam modulation instability in noninstantaneous nonlinear media.

The development of modulation instability for two beams copropagating in a medium with noninstantaneous nonlinear response is investigated. The frequency dependence of the experimentally observed spectral broadening reveals the presence of two-beam coupling, resulting from the time-delayed Raman part of the third-order nonlinear susceptibility. We present an analysis of the experimental data, which yields a value of tau=27(1) fs for the lifetime of the optical phonons in silica fibers. To our knowledge, this is the first experimentally determined value for this important material parameter.

Experimental studies of the liquid-glass transition in trimethylheptane

The molecular glass former trimethylheptane was studied by calorimetric, dielectric, ultrasonic, neutron scattering, Brillouin scattering, and depolarized light-scattering techniques. The molecular structure appears to be nearly spherical optically as indicated by the low depolarization ratio and dielectric susceptibility values. A preliminary mode-coupling theory (MCT) analysis of the light-scattering and neutron-scattering data indicates that T(C) greater, similar150 K, at least 25 K above T(G). The susceptibility minima were analyzed with the MCT interpolation equation, and disagreement between the light and neutron results was observed despite the apparent isotropy of the molecules.

Duty cycle ratio dependence on the performance of a q-switched laser with an Er3+-Yb3+ codoped glass waveguide.

We examine the performance of a hybrid Q-switched LiNbO(3) and Er(3+)-Yb(3+) doped glass waveguide laser as a modulation function of the duty cycle ratio. As the duty cycle ratio decreases, the laser operates at higher peak power and pulse width. At low duty cycle ratio (<1%), we observe variations in the Q-switched pulse shape; while the laser produces 59-W and 200-ns pulses to a 1-kHz repetition rate for a 50% duty cycle, it yields 27-W and 100-ns pulses to a 10-kHz repetition rate for a 0.01% duty cycle.

Hepatic hemangioendotheliomas, placental chorioangiomas, and dysmorphic kidneys in Beckwith-Wiedemann syndrome.

A 4-month-old female, birth weight 3150 g, had a history of maternal eclampsia, multiple placental chorioangiomas, and persistent neonatal hypoglycemia. Macroglossia and enlarged kidneys were recorded. Autopsy revealed multiple hepatic hemangioendotheliomas (type 1), massive cardiomegaly, and bilateral nephromegaly. Both kidneys were lobulated with active glomerulogenesis and clusters of immature tubules and foci of dysplastic medullary ducts. The features suggest that the nephrogenesis was secondary to the persistence of actively branching nephron-inducing ducts. Nodular hyperplasia of the adrenal cortex (adrenoblastomatosis) was present. This report expands the list of tumors to be found in Beckwith-Wiedemann syndrome (BWS).