Default mode network abnormalities in idiopathic generalized epilepsy

Idiopathic generalized epilepsy (IGE) is associated with widespread cortical network abnormalities on electroencephalography. Resting state functional connectivity (RSFC), based on fMRI, can assess the brain's global functional organization and its disruption in clinical conditions. We compared RSFC associated with the 'default mode network' (DMN) between people with IGE and healthy controls. Strength of functional connectivity within the DMN associated with seeds in the posterior cingulate cortex (PCC) and medial prefrontal cortices (MPFC) was compared between people with IGE and healthy controls and was correlated with seizure duration, age of seizure onset and age at scan. Those with IGE showed markedly reduced functional network connectivity between anterior and posterior cortical seed regions. Seizure duration positively correlates with RSFC between parahippocampal gyri and the PCC but negatively correlates with connectivity between the PCC and frontal lobe. The observed pattern of disruption provides evidence for integration- and segregation-type network abnormalities and supports aberrant network organization among people with IGE.     

Oxidative phosphorylation, not glycolysis, powers presynaptic and postsynaptic mechanisms underlying brain information processing

Neural activity has been suggested to initially trigger ATP production by glycolysis, rather than oxidative phosphorylation, for three reasons: glycolytic enzymes are associated with ion pumps; neurons may increase their energy supply by activating glycolysis in astrocytes to generate lactate; and activity increases glucose uptake more than O? uptake. In rat hippocampal slices, neuronal activity rapidly decreased the levels of extracellular O? and intracellular NADH (reduced nicotinamide adenine dinucleotide), even with lactate dehydrogenase blocked to prevent lactate generation, or with only 20% superfused O? to mimic physiological O? levels. Pharmacological analysis revealed an energy budget in which 11% of O? use was on presynaptic action potentials, 17% was on presynaptic Ca2? entry and transmitter release, 46% was on postsynaptic glutamate receptors, and 26% was on postsynaptic action potentials, in approximate accord with theoretical brain energy budgets. Thus, the major mechanisms mediating brain information processing are all initially powered by oxidative phosphorylation, and an astrocyte-neuron lactate shuttle is not needed for this to occur.     

Efficacy of very low‐energy diet programs for weight loss: A systematic review with meta‐analysis of intervention studies in children and adolescents with obesity

The objective of this review was to evaluate the efficacy and safety of very low‐energy diet (VLED) programs for weight loss in children and adolescents with obesity. Six electronic databases were searched identifying 24 eligible studies (16 pre‐post studies, four nonrandomized trials, two randomized controlled trials [RCTs], and two chart reviews) published up to October 2018. Studies were in English, implemented a VLED (≤3360 kJF/day [≤800 kcal/day] or <50% estimated energy requirements) in 5‐ to 18‐year‐olds with obesity, and reported at least one weight‐related outcome. Weight‐related outcomes significantly improved postintervention in all studies. Meta‐analysis of 20 studies indicated a mean 10.1 kg (95% confidence interval [CI], 8.7‐11.4 kg, P < 0.001; I² = 92.3%) weight loss following interventions lasting 3 to 20 weeks. Moderator analysis indicated greater weight loss in adolescent‐only studies (10‐18 years) and formulated meal replacement interventions and inpatient settings. Meta‐analysis of seven studies reporting weight at follow‐up (5‐14.5 months from baseline) indicated 5.3 kg mean weight loss (CI, 2.5‐8.0 kg, P < 0.001; I² = 50.6%). Details of adverse events were limited. VLED programs are effective for treating children and adolescents with obesity. However, conclusions on their safety cannot be drawn from the existing literature at this time. Future studies should include long‐term follow‐up with ongoing support and comprehensive monitoring of all adverse events.     

An 11‐country study to benchmark the implementation of recommended nutrition policies by national governments using the Healthy Food Environment Policy Index, 2015‐2018

The Healthy Food Environment Policy Index (Food‐EPI) aims to assess the extent of implementation of recommended food environment policies by governments compared with international best practices and prioritize actions to fill implementation gaps. The Food‐EPI was applied in 11 countries across six regions (2015‐2018). National public health nutrition panels (n = 11‐101 experts) rated the extent of implementation of 47 policy and infrastructure support good practice indicators by their government(s) against best practices, using an evidence document verified by government officials. Experts identified and prioritized actions to address implementation gaps. The proportion of indicators at “very low if any,” “low,” “medium,” and “high” implementation, overall Food‐EPI scores, and priority action areas were compared across countries. Inter‐rater reliability was good (GwetAC2 = 0.6‐0.8). Chile had the highest proportion of policies (13%) rated at “high” implementation, while Guatemala had the highest proportion of policies (83%) rated at “very low if any” implementation. The overall Food‐EPI score was “medium” for Australia, England, Chile, and Singapore, while “very low if any” for Guatemala. Policy areas most frequently prioritized included taxes on unhealthy foods, restricting unhealthy food promotion and front‐of‐pack labelling. The Food‐EPI was found to be a robust tool and process to benchmark governments' progress to create healthy food environments.     

Focused ultrasound surgery in oncology: overview and principles

Focused ultrasound surgery (FUS) is a noninvasive image-guided therapy and an alternative to surgical interventions. It presents an opportunity to revolutionize cancer therapy and to affect or change drug delivery of therapeutic agents in new focally targeted ways. In this article the background, principles, technical devices, and clinical cancer applications of image-guided FUS are reviewed.