White matter maturation of normal human fetal brain. An in vivo diffusion tensor tractography study

We demonstrate for the first time the ability to determine in vivo and in utero the transitions between the main stages of white matter (WM) maturation in normal human fetuses using magnetic resonance diffusion tensor imaging (DTI) tractography. Biophysical characteristics of water motion are used as an indirect probe to evaluate progression of the tissue matrix organization in cortico-spinal tracts (CSTs), optic radiations (OR), and corpus callosum (CC) in 17 normal human fetuses explored between 23 and 38 weeks of gestation (GW) and selected strictly on minimal motion artifacts. Nonlinear polynomial (third order) curve fittings of normalized longitudinal and radial water diffusivities (Z-scores) as a function of age identify three different phases of maturation with specific dynamics for each WM bundle type. These phases may correspond to distinct cellular events such as axonal organization, myelination gliosis, and myelination, previously reported by other groups on post-mortem fetuses using immunostaining methods. According to the DTI parameter dynamics, we suggest that myelination (phase 3) appears early in the CSTs, followed by the OR and by the CC, respectively. DTI tractography provides access to a better understanding of fetal WM maturation

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Budget-Friendly Generation, Biochemical Analyses, and Lentiviral Transduction of Patient-Derived Colon Organoids.

For the past decade, three-dimensional (3D) culture models have been emerging as powerful tools in translational research to overcome the limitations of two-dimensional cell culture models. Thanks to their ability to recapitulate the phenotypic and molecular heterogeneity found in numerous organs, organoids have been used to model a broad range of tumors, such as colorectal cancer. Several approaches to generate organoids exist, with protocols using either pluripotent stem cells, embryonic stem cells, or organ-restricted adult stem cells found in primary tissues, such as surgical resections as starting material. The latter, so-called patient-derived organoids (PDOs), have shown their robustness in predicting patient drug responses compared to other models. Because of their origin, PDOs are natural offspring of the patient tumor or healthy surrounding tissue, and therefore, have been increasingly used to develop targeted drugs and personalized therapies. Here, we present a new protocol to generate patient-derived colon organoids (PDCOs) from tumor and healthy tissue biopsies. We emphasize budget-friendly and reproducible techniques, which are often limiting factors in this line of research that restrict the development of this 3D-culture model to a small number of laboratories worldwide. Accordingly, we describe efficient and cost-effective techniques to achieve immunoblot and high-resolution microscopy on PDCOs. Finally, a novel strategy of lentiviral transduction of PDCOs, which could be applied to all organoid models, is detailed in this article. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Establishment of PDCOs from biopsies Basic Protocol 2: Long-term maintenance and expansion of PDCOs in BME domes Basic Protocol 3: Cryopreservation and thawing of PDCOs Basic Protocol 4: Lentiviral transduction of PDCOs Basic Protocol 5: Immunoblot and evaluation of variability between donors Basic Protocol 6: Immunofluorescence labeling and high-resolution microscopy of PDCOs Basic Protocol 7: Transcriptomic analyses of PDCOs by RT-qPCR

Visual activity enhances neuronal excitability in thalamic relay neurons

The dorsal lateral geniculate nucleus (dLGN) has long been held to act as a basic relay forvisual information travelling from the retina to cortical areas, but recent findings suggest alargely underestimated functional plasticity of dLGN neurons. However, the cellularmechanisms supporting this functional plasticity have not been yet explored. In particular, itremains to elucidate whether intrinsic neuronal excitability change upon visual stimuli. Weshow here that monocular deprivation for 10 days reduces the intrinsic excitability of dorsalLGN relay cells. Furthermore, dLGN neurons exhibit long-term potentiation of their intrinsicexcitability (LTP-IE) when suprathreshold afferent retinal inputs are stimulated at 40 Hz orwhen spikes are induced with direct somatic current injection to reproduce patterns of retinalactivity. LTP-IE is observed after eye opening and requires calcium influx mediated by L-typecalcium channels. It involves activation of PKA and is expressed through the down-regulationof Kv1 potassium channels. In conclusion, our study provides the first evidence for intrinsicplasticity in dLGN relay cells, thus further pointing the role of thalamic neurons in activity-dependent visual plasticity and amblyopia

Triage of children with headache at the ED: a guideline implementation study

We present a multicenter validation of a modified Manchester Triage System (MTS) flowchart for pediatric patients who present with headache to the emergency department. A prospective observational study was conducted across 5 European pediatric emergency departments. The standard MTS headache flowchart and a modified MTS headache flowchart were tested in the participating centers, and results were compared with triage categories identified by either the physician at the end of the clinical examination or the reference classification matrix (RCM). Fifty-three patients were enrolled in the preimplementation phase and 112 in the postimplementation phase. When compared with physician's triage and RCM, the modified MTS flowchart demonstrated good sensitivity (79% and 70%, respectively), specificity (77% and 76%, respectively), and a high positive likelihood ratio (9.14 and 16.75, respectively) for the identification of low-risk children. Conclusions: Our modified headache flowchart is safe and reliable in pediatric emergency settings, especially for lower classes of urgency