Search Results (468)

Background and Clinical Significance: Paroxysmal extreme pain disorder (PEPD) is an extremely rare autosomal dominant sodium channelopathy caused by SCN9A gain-of-function variants. It is characterized by infantile-onset excruciating paroxysmal pain, typically in rectal, ocular, or mandibular regions, triggered by innocuous stimuli and accompanied by autonomic flares. Carbamazepine is dramatically effective in most reported cases. To date, only two genetically confirmed cases have been documented in Chinese patients, and fewer than 20 disease-causing variants are reported worldwide. We report the third Chinese case harboring a novel likely pathogenic SCN9A variant (p.Leu1623Gln), notable for its unusually severe, progressive, and carbamazepine-refractory phenotype, as well as life-threatening psychiatric sequelae, highlighting phenotypic heterogeneity and the devastating impact when standard therapy fails. Case Presentation: A Chinese male proband with positive family history presented with lifelong trigger-induced catastrophic burning and tearing pain in the perineum and lower limbs, associated with erythema, swelling, and occasional non-epileptic seizures. Attacks worsened with age despite escalating polypharmacy, including high-dose opioids, benzodiazepines, topical lidocaine and carbamazepine. Both the proband and his father developed profound psychosocial sequelae including severe depression and suicidal attempts. Next-generation sequencing in the proband revealed a novel heterozygous likely pathogenic variant NM_001365536.1 (SCN9A): c.4868T>A p.(Leu1623Gln). Conclusions: This third reported ethnic Chinese PEPD case expands the genotypic and phenotypic spectrum of SCN9A-related channelopathies, demonstrating that some variants can produce carbamazepine-refractory, progressive, and profoundly disabling disease with high suicidality risk. Early genetic diagnosis is critical in family planning and cascade testing, and has the potential in guiding targeted therapy that is under active research. Full article

Background: Osteoporosis is highly prevalent in postmenopausal women, yet genome-wide association studies often miss disease-relevant variants because of incomplete single nucleotide polymorphism (SNP) coverage and platform-specific limitations. We aimed to identify genetic contributors to osteoporosis risk by integrating two exome-based genotyping platforms with multilayer analytic approaches. Methods: We analyzed extreme osteoporosis phenotypes in Korean postmenopausal women from the Korean Genome and Epidemiology Study (KoGES) Ansan–Anseong cohorts using the Illumina Infinium HumanExome BeadChip and the Affymetrix Axiom Exome Array. After standard quality control, single-SNP logistic regression, cross-platform overlap analysis, and three machine-learning models were applied. Predicted functional impact was evaluated using multiple in silico algorithms and conservation scores. Finally, datasets from both platforms were merged, and cross-platform linkage disequilibrium (LD) blocks were defined to identify loci containing SNPs with p < 1 × 10⁻⁴. Results: No overlapped SNP reached genome-wide significance, but rs2076212 in PNPLA3 achieved suggestive significance (p < 1 × 10⁻⁵) only on the Illumina array. Cross-platform analysis identified 111 overlapping SNPs in 70 genes. Integrated machine-learning, in silico, and conservation evidence prioritized ARMS2, CCDC92, NQO1, ZNF510, PTPRB, and DYNC2H1 as candidate genes. LD-block analysis revealed 10 blocks with at least one SNP at p < 1 × 10⁻⁴, including four chromosome 12 loci (NAV2, BICD1, CCDC92, ZNF664) that became apparent only when LD patterns were evaluated jointly across platforms. Conclusions: Combining dual exome arrays with LD-block analysis, machine learning, and functional prediction improved sensitivity for detecting low bone mineral density-related loci and highlighted CCDC92, DYNC2H1, NQO1, and related genes as biologically plausible candidates for future validation. Full article

Venom is a key evolutionary innovation of venomous organisms in the long-term process of survival adaptation. As one of the oldest arthropods, scorpions produce venom rich in bioactive peptides that also constitute a valuable pharmacological resource. Omics-driven discovery and structural biology have expanded the peptide catalog and clarified structure–function principles across disulfide-bridged (DBPs) and non-disulfide-bridged peptides (NDBPs). Within this arsenal, ion-channel targeting neurotoxins predominantly modulate Nav, Kv, Calcium, Chloride, and TRP channels to achieve predation, defense, and competition. Owing to their unique mechanisms of action and significant therapeutic potential, scorpion venom peptides have attracted sustained interest as leads and scaffolds for drug development. This review synthesizes current knowledge of scorpion venom composition, with an emphasis on the pivotal role of neurotoxins, covering their molecular diversity, structural features, and modes of ion-channel modulation, as well as emerging applications in disease treatment. Full article

Background: As pediatric head and neck cancer (pHNC) incidence increases, the development of new surgical oncology techniques to reduce morbidity are essential. Intraoperative navigation (iNav) represents the most translatable technology among both the model-comparative and integrative surgical navigation technologies to optimize surgical outcomes. Methods: A scoping review of the literature was performed according to PRISMA guidelines from 1970 to present (February 2025), investigating the use of iNav in cases of pHNC. Patient case details and authors’ perception of iNav’s utility were analyzed. A single-center retrospective case series review (September 2022 to September 2025) of the senior authors’ experience employing iNav in pHNC cases was also performed. Results: The scoping review identified twenty-seven cases of pHNC from sixteen studies that both utilized iNav and met the inclusion criteria. Many of the authors commented favorably on the utility of iNav technology, while concurrently agreeing upon its limitations. The case series review identified five cases of pHNC that met the inclusion criteria. This small case series revealed a 100% R0 resection rate with the use of iNav in four pHNC resections. The fifth case used iNav for biopsy site selection. Conclusions: The results of our scoping review as well as our institutional experience with this technology demonstrate its utility in guiding surgical approach, confirming depth of resection, and navigating marginal assessment. This study was limited by incidental and incomplete reporting of iNav’s clinical application to pHNC; several extensive institutional reports had to be excluded due to insufficiently detailed data linkage. Our review builds upon the existing pediatric surgical literature, anchoring the evidentiary justification for the application of iNav to pediatric head and neck surgery. Full article

Dravet Syndrome (DS) is a severe genetic epileptic encephalopathy caused by mutations in the SCN1A gene that encodes the voltage-gated sodium channel (Na_V1.1) subunit alpha. DS is characterized by intractable seizures, progressive developmental delay, cognitive impairment, and high mortality due to sudden unexpected death in epilepsy (SUDEP). SUDEP is mediated by respiratory dysfunction, but the exact molecular underpinnings are unclear. Though hippocampal metabolic alterations have been reported in DS mice, such changes in brain regions controlling breathing have not been studied. We used Scn1a^A1783V/WT DS mice to study temporal alterations in the brain metabolome, including analysis of brainstem and forebrain regions. Glycolytic and pentose phosphate pathway intermediates were significantly elevated in the brainstem of DS mice during the period of enhanced susceptibility to mortality (post-natal days P20–30). In older P40–P50 mice, mitochondrial aconitate and the antioxidant glutathione were significantly elevated in the brainstem. Single-nuclei RNA sequencing (snRNA seq) and proteomic analyses revealed alterations in genes associated with neurotransmission, cellular respiration, and protein translation, as well as reorganization of protein kinase-mediated pathways that are specific to the brainstem. These findings suggest that there are widespread metabolic changes in the brainstem of DS mice. Full article

Magnesium ions regulate synaptic and nonsynaptic neuronal excitability from intracellular (Mg²⁺_i) and extracellular (Mg²⁺_o) domains, modulating voltage- and ligand-gated ion channels. K+ inward rectifier (Kir) channel inward rectification arises from Mg²⁺_i blocking the pore and outward K⁺ current, while Mg²⁺_o targets external sites. Mg²⁺_i causes voltage-dependent Ca²⁺ voltage-gated (Ca_V) and Na⁺ voltage-gated (Na_V) channel block while phosphorylation modulates channel activity. Mg²⁺_o elicits direct voltage-dependent Ca_V channel block, and screens surface charge, and in Na_V channels reduces conduction and may cause depolarization by quantum tunneling across closed channels. Mg²⁺_i is an allosteric large conductance Ca²⁺-activated K⁺ (BK) channel activator, binding to low-affinity sites to alter Ca²⁺ and voltage sensitivity but reduces small conductance Ca²⁺-activated K⁺ (SK) channels’ outward K⁺ current and induces inward rectification. N-Methyl-D-aspartate receptor (NMDAR) channels are inhibited by Mg²⁺_i binding within the pore, while Mg²⁺_o stabilizes excitability through voltage-dependent block, Mg²⁺_o forms Mg-ATP complex modifying purinergic P2X receptor (P2XR) channel affinity and gating and directly blocks the pore. Mg²⁺_o reduces gamma-aminobutyric acid type A receptor (GABA_AR) channel Cl⁻ current amplitude and augments susceptibility to blockers. Mg²⁺_o and Mg²⁺_i block nicotinic acetylcholine receptor (nAChR) channels through voltage-dependent pore binding and surface charge screening, impeding current flow and altering gating. Full article

Background: Neuropathic pain is a complex condition often resistant to current therapies due to limited efficacy and adverse effects. Nutraceuticals offer promising alternatives, combining antioxidant and anti-inflammatory properties with good tolerability. This study aimed to compare the effects of a commercial nutraceutical formulation, SUPERALA CARNITINE^® (Pharma Suisse Laboratories SpA, Milan, Italy), containing Alpha-Lipoic Acid (ALA), with a novel formulation, called SUPERALA CARNITINE^® Forte, where ALA and vitamin B6 were replaced by N-acetylcysteine (NAC), Glutathione (GSH), and Uridine monophosphate (UMP). Methods: An indirect gut–peripheral nerve axis was employed to simulate oral absorption, metabolism, and effect on nervous tissues using 3D in vitro models. Both formulations and their individual components were assessed for cytotoxicity and permeability in the gut model (Caco-2 cells in Transwell^®) and, after gut metabolism, for antioxidant capacity, anti-inflammatory activity, and neuroprotective potential in the peripheral nerve model. Results: SUPERALA CARNITINE^® Forte improved cell viability and favoured the maintenance of intestinal integrity, showing enhanced permeability, and significantly reduced oxidative stress (OS) and pro-inflammatory cytokines (TNF-α, IL-2) at the peripheral nervous system. In addition, it increased levels of neuronal markers (p75, MPZ, NRG1, ERβ) and decreased NaV1.7 and NaV1.8 activity, indicating greater neuroprotection and analgesic modulation than the ALA-based formula. Conclusions: The replacement of ALA and vitamin B6 with NAC, GSH, and UMP produced favorable responses in vitro on neuronal cells, supporting a hypothetical potential interest in this nutraceutical combination and justifying further future in vivo investigations. Full article

Sodium-ion batteries (SIBs) have arisen as a potential alternative to lithium-ion batteries (LIBs) as a result of the abundant availability of sodium resources at low production costs, making them in line with the United Nations Sustainable Development Goals (SDGs) for affordable and clean energy (Goal 7). The current review intends to comprehensively analyse the various modification techniques deployed to improve the performance of cathode materials for SIBs, including element doping, surface coating, and morphological control. These techniques have demonstrated prominent improvements in electrochemical properties, such as specific capacity, cycling stability, and overall efficiency. The findings indicate that element doping can optimise electronic and ionic conductivity, while surface coatings can enhance stability in addition to mitigating side reactions throughout cycling. Furthermore, morphological control is an intricate technique to facilitate efficient ion diffusion and boost the use of active materials. Statistically, the Cr-doped NaV_1−xCr_xPO₄F achieves a reversible capacity of 83.3 mAh/g with a charge–discharge performance of 90.3%. The sodium iron–nickel hexacyanoferrate presents a discharge capacity of 106 mAh/g and a Coulombic efficiency of 97%, with 96% capacity retention over 100 cycles. Furthermore, the zero-strain cathode Na₄Fe₇(PO₄)₆ maintains about 100% capacity retention after 1000 cycles, with only a 0.24% change in unit-cell volume throughout sodiation/desodiation. Notwithstanding these merits, this review ascertains the importance of ongoing research to resolve the associated challenges and unlock the full potential of SIB technology, paving the way for sustainable and efficient energy storage solutions that would aid the conversion into greener energy systems. Full article

Background/Objectives: The digitalization of healthcare in general, and particularly of surgical care, increasingly requires patients to navigate online information and digital follow-up systems. Limited digital or navigational health literacy may hinder safe recovery and exacerbate health inequities. This study aimed to assess levels of digital and navigational health literacy and their associations in a sample of surgical patients. Methods: A cross-sectional study was conducted with ninety-four adults undergoing elective or emergency surgery, using the validated HLS19-DIGI (digital health literacy) and HLS19-NAV (navigational health literacy) instruments. Data collection took place between March 2025, and 28 August 2025, at a hospital in the Lisbon district. Descriptive analyses, bivariate analysis, and multiple regression were used to identify sociodemographic and clinical predictors. Results: Digital literacy varied significantly across age groups (p = 0.038), with median scores declining from 87.5 (31–45 years) to 31.2 (>65 years). Navigational literacy was lower in emergency versus elective surgery patients (41.7 vs. 83.3; p = 0.036). In adjusted models, self-employment predicted lower digital literacy (β = −36.06, p = 0.009), while emergency surgery remained the only predictor of navigational literacy (β = −31.07, p = 0.018). Digital and navigational literacy were strongly correlated (ρ = 0.859). Conclusions: The surgical patients in this study demonstrated marked literacy deficits, particularly older adults and those undergoing emergency procedures. Digital and navigational literacy appear to reflect overlapping competencies. As healthcare shifts toward digital models, it is essential to develop age-adapted strategies to promote equity and prevent exclusion. Full article

Scorpion venom toxins are important peptides being studied for their clinical significance. These peptides act by binding to ion channels in the membrane of nerve cells, causing the symptoms associated with scorpion stings (scorpionism). They principally affect the function of voltage-gated sodium channels (Nav) and are valuable for studying ion channels. Scorpions from the Buthidae family contain toxins that affect sodium channels and have a high affinity for mammalian channels. In this study, two sodium toxins isolated from the venom of the scorpion Centruroides hirsutipalpus, a member of the Buthidae family, were identified as belonging to the beta-type subfamily. These toxins were purified from whole venom using molecular exclusion, cationic-exchange, and reverse-phase chromatography techniques. Their molecular masses were determined using mass spectrometry, while their amino acid sequences were obtained by Edman degradation. A comparative analysis revealed that the sequences are identical to ChiNaBet60 and ChiNaBet50 toxins (now named Chirp7 and Chirp9, respectively) previously identified in the venom gland transcriptomics from C. hirsutipalpus. Furthermore, toxicity studies showed that these toxins were lethal to mammals. Electrophysiological analysis revealed that these peptides act as sodium channel–modulating toxins. In addition, interaction assays with antibodies were performed to analyze the structural determinants governing the binding mechanism. Full article

Tetrodotoxin (TTX) is an extremely potent neurotoxin, a selective blocker of voltage-gated sodium (NaV) channels, produced by bacteria and accumulated across a wide range of taxa. Several TTX-bearing animals have developed molecular adaptations in their NaV channels that provide TTX resistance, making this toxin one of the factors of molecular evolution. However, the molecular basis of TTX resistance in NaV channels of a significant proportion of tetrodotoxic species remains poorly studied. Nemertea is a phylum of marine worms, comprising both TTX-bearing and non-TTX-bearing species. Here, we analyzed the amino acid sequences of the NaV1 channel regions responsible for TTX binding from 22 species of nemerteans. Substitutions previously characterized as conferring TTX resistance in other taxa were detected in sixteen nemerteans; local clustering was observed within several families. These findings suggest that TTX resistance in nemerteans evolved multiple times independently and may serve as either as an adaptation facilitating TTX accumulation for subsequent use for defense and predation, or as a mechanism allowing consumption of tetrodotoxic prey without toxin accumulation. Full article

Toxins as channel probes, small guanidinium alkaloids, such as tetrodotoxin and saxitoxin, canonical pore occlusion in voltage-gated Na⁺ channels. Cystine-rich peptides from spiders, scorpions, cone snails, and sea anemones, which act as pore blockers or gating modifiers targeting voltage-sensing domains. Recent structural and electrophysiological studies have identified specific binding sites on ion channels, including the S5–S6 pore loops, outer vestibule and turret regions, and S3–S4 “paddle” motifs in NaV, Kv, and CaV channels. These discrete binding epitopes are recognized by different peptide toxins, enabling isoform- and state-specific modulation; for example, μ-conotoxins bind the NaV pore, whereas charybdotoxin and agitoxin target the Kv outer vestibule. Beyond mechanistic insights, peptide toxins inspire translational strategies, including emerging therapies for retinal degenerative diseases. Photopharmacology using chemical photoswitches allows reversible, light-controlled modulation of ion channels in retinal ganglion cells without genetic manipulation or cell transplantation. Although BENAQ was discovered by small-molecule screening rather than toxin-guided design, its ion channel control demonstrates the potential of toxin-based molecular determinants for engineering synthetic compounds. This review thus integrates structural, functional, and translational perspectives, emphasizing the versatility of animal-derived peptide toxins as molecular probes and as blueprints for precision ion channel modulation in health and disease. Full article

Background/Objective: Acute and chronic pain affect millions of individuals, yet there are currently no molecular imaging tools to directly assess pain-related mechanisms in the central nervous system (CNS). The voltage-gated sodium channel Na_V1.8 plays a pivotal role in neuropathic pain by increasing the excitability of nociceptive neurons following nerve injury or inflammation. In this work, we aimed to develop a novel positron emission tomography (PET) imaging probe for Na_V1.8 to facilitate noninvasive quantification of this target in the CNS and thereby advance our understanding of pain neurobiology. Methods: We selected the compound suzetrigine, a U.S. FDA-approved, highly selective non-opioid Na_V1.8 inhibitor, as the first candidate for a Na_V1.8-targeted PET tracer. The compound was first assessed using in silico docking and CNS multiparameter optimization (MPO) analysis to evaluate target binding and predicted brain penetrability. Radiolabeling was accomplished by O-methylation with [¹¹C]methyl iodide to yield [¹¹C]suzetrigine without structural modification. The tracer was then evaluated using in vitro binding assays, including autoradiography and saturation binding on rat brain tissues, to determine binding parameters (K_D, B_max), and using in vivo PET imaging in rats to assess brain uptake, time–activity curves (TACs), and tracer behavior under baseline and pretreatment conditions. Pretreatment was performed with unlabeled suzetrigine, the P-glycoprotein (P-gp) inhibitor verapamil, and the heterologous Na_V1.8 inhibitor A-803467. Results: In silico docking demonstrated favorable binding of suzetrigine to the Na_V1.8 active site, and the calculated CNS MPO score (>3.5) suggested adequate brain penetration. Radiochemical synthesis of [¹¹C]suzetrigine via O-methylation yielded a high decay-corrected radiochemical yield (19.2 ± 2.7%, n = 3), excellent purity (>98%, n = 3), and moderate molar activity (62.9 ± 51.8 MBq/nmol, n = 3). Autoradiography on rat brain tissue confirmed saturable and selective binding of [¹¹C]suzetrigine to Na_V1.8. Saturation binding assays revealed a B_max = 93 fmol/mg and a K_D = 0.1 nM, supporting the imageability of Na_V1.8 in the brain using this tracer. In vivo PET imaging in rats demonstrated rapid and sufficient brain uptake but revealed unexpected tracer behavior: signal intensity markedly increased following pretreatment with either unlabeled suzetrigine or the P-gp inhibitor verapamil, and showed a slight increase after pretreatment with the heterologous Na_V1.8 inhibitor A-803467. Detailed analysis of PET images, TACs, and normalized area-under-curve (AUC) values indicated that these atypical uptake patterns were primarily attributable to P-gp-mediated effects, although additional factors may also contribute. Conclusions: [¹¹C]Suzetrigine exhibits high affinity, good brain uptake, and selective target engagement in vitro, supporting its potential as a first-in-class Na_V1.8-PET tracer. However, in vivo performance is confounded by P-gp-mediated efflux and possibly other mechanisms that limit accurate quantification of Na_V1.8 in the living brain. These findings underscore the critical role of efflux transporters in CNS radiotracer development and highlight the need for design strategies that mitigate P-gp interaction when targeting ion channels in the brain. Future studies will include imaging under constant P-gp inhibition, arterial blood sampling for radiometabolite analysis and full kinetic modeling, and evaluation in non-human primates to assess translational feasibility. Full article

Intersectoral labour mobility is a key driver of economic resilience and innovation in Europe. The redistribution of workers across sectors and regions enables economies to adapt to shocks, create flexibility and increase the rate of structural change. However, the dynamics of mobility have not been adequately investigated across varying scales of sectoral granularity and spatio-temporal dimensions. This paper applies the Intersectoral Mobility Index (MI) to all European NUTS-2 areas from 2008 to 2020, utilising Eurostat Structural Business Statistics. Two levels of sectoral aggregation (NACE Rev. 2, 1-digit and 2-digit) are employed to compute MI, capturing both broad and fine-grained reallocations. Classical indices of structural change (NAV, Krugman, Shorrocks) are combined with spatio-temporal modelling in ArcGIS Pro, employing Space–Time Cubes, time-series exponential smoothing forecasts, time-series clustering and emerging hot spot analysis. Results indicate that MI distributions are positively skewed and heavy-tailed, with peaks coinciding with systemic crises (2009–2011, 2020). At the 2-digit level, MI values are significantly higher, revealing intra-sectoral changes obscured in aggregated data. A statistically significant downward trend in mobility suggests an increasing structural rigidity following the global financial crisis. Regional clustering highlights heterogeneity: a small number of regions, such as Bremen, Madeira and the Southern Great Plain, have sustained high or unstable mobility, while most exhibit convergent mobility and low reallocation. This paper contributes to the conceptualisation of MI as a dual measure of resilience and innovation preparedness. It underscores the importance of multi-scalar and spatio-temporal methods in monitoring labour market flexibility. The findings have policy implications, including the design of targeted reskilling programmes, proactive labour market policies and just transition plans to maintain regional resilience during the EU’s green and digital transitions. Full article

Spider-derived venoms are a rich source of cystine knot peptides with immense therapeutic potential. Many of these peptides exert unique biological activities through the modulation of ion channels, including of human voltage-gated sodium (Na_V1.1–Na_V1.9) channels. Na_V channel subtypes have diverse functions determined by their tissue and cellular distribution and biophysical properties, and are pathophysiology mediators in various diseases. Therefore, Na_Vs are central in studies of human biology. This work investigated the pharmacological properties of venom of the Thai theraphosid Ornithoctonus aureotibialis on Na_V channels. We discovered a predominant venom peptide named Oa1a and assessed its pharmacological properties across human Na_V channel subtypes. Synthetic forms of the peptide Oa1a showed preferential inhibition of Na_V1.1 and Na_V1.7, while recombinant Oa1a displayed a preference for inhibiting Na_V1.2, Na_V1.6, and Na_V1.7. Interestingly, all versions of Oa1a peptides exerted dual pharmacological effect by reducing the peak current and slowing fast inactivation of Na_V1.3, consistent with Oa1a having more than one binding site on Na_V channels. Such complex pharmacology was previously observed for a venom peptide in a Central American and Costa Rican tarantula, suggesting a conserved mechanism of action amongst these geographically distinct species. However, Oa1a lacked activity in the T-type channels observed in the tarantula peptide from Central America. Structure–function relationships investigated using molecular modelling showed that the dual pharmacology is driven by a conserved mechanism utilizing a mix of aromatic and charged residues, while the T-type activity appears to require additional charged residues in loop 2 and fewer positive charges in loop 4. Future structure–activity relationship studies of Oa1a will guide the development of pharmacological tools as well as next-generation drugs to treat Na_V channel dysfunction associated with neurological disorders. Full article