Cell Membrane Tension Gradients, Membrane Flows, and Cellular Processes.

Cell membrane tension affects and is affected by many fundamental cellular processes, yet it is poorly understood. Recent experiments show that membrane tension can propagate at vastly different speeds in different cell types, reflecting physiological adaptations. Here we briefly review the current knowledge about membrane tension gradients, membrane flows, and their physiological context.

Nav1.8 in small dorsal root ganglion neurons contributes to vincristine-induced mechanical allodynia.

Vincristine-induced peripheral neuropathy (VIPN) is a common side effect of vincristine treatment, which is accompanied by pain and can be dose-limiting. The molecular mechanisms that underlie vincristine-induced pain are not well understood. We have established an animal model to investigate pathophysiological mechanisms of vincristine induced pain. Our previous studies have shown that the tetrodotoxin-sensitive (TTX-S) voltage-gated sodium channel NaV1.6 in medium-diameter dorsal root ganglion (DRG) neurons contributes to the maintenance of vincristine-induced allodynia. In this study, we investigated the effects of vincristine administration on excitability in small-diameter DRG neurons and whether the tetrodotoxin-resistant (TTX-R) NaV1.8 channels contribute to mechanical allodynia. Current-clamp recordings demonstrated that small DRG neurons become hyper-excitable following vincristine treatment, with both reduced current threshold and increased firing frequency. Using voltage-clamp recordings in small DRG neurons we now show an increase in TTX-R current density and a -7.3 mV hyperpolarizing shift in V1/2 of activation of NaV1.8 channels in vincristine-treated animals, which likely contributes to the hyperexcitability that we observed in these neurons. Notably, vincristine treatment did not enhance excitability of small DRG neurons from NaV1.8 knockout mice, and the development of mechanical allodynia was delayed but not abrogated in these mice. Together, our data suggest that sodium channel NaV1.8 in small DRG neurons contributes to the development of vincristine-induced mechanical allodynia.

Reproductive justice for Black, Indigenous, Women of Color: Uprooting race and colonialism.

Historically, atrocities against Black, Indigenous, and Women of Color's (BIWoC) reproductive rights have been committed and continue to take place in contemporary society. The atrocities against BIWoC have been fueled by White supremacy ideology of the "desirable race" and colonial views toward controlling poverty and population growth, particularly that of "undesirable" races and ethnicities. Grounded in Critical Race Theory, this paper aims to provide a critical analysis of historical and contemporary violations of BIWoC reproductive rights; discuss interventions based on empowerment and advocacy principles designed to promote women's reproductive justice; and discuss implications for future research, action, and policy from the lenses of Critical Race Theory and Community Psychology. This paper contributes to the special issue by critically analyzing historical and contemporary racism and colonialism against BIWoC, discussing implications for future research and practice, and making policy recommendations.

The endocrine disruptor DE-79 alters oxytocinergic transmission and sexual behavior expression in male rats.

Polybrominated diphenyl ethers (PBDEs), used as flame retardants are persistent organic pollutants exerting important health effects. PBDEs with >5 bromide substitutions were considered less harmful and therefore extensively used commercially. DE-79 was a widely used PBDE mixture of hexa-, hepta-, octa- and nona-brominated compounds that increases vasopressin (AVP) production. AVP and oxytocin (OT) are both produced in neurons of the supraoptic (SON) and paraventricular (PVN) hypothalamic nuclei projecting to the neurohypophysis and to brain regions involved in copulatory behavior. OT plays an important role in male copulation. Since DE-79 alters AVP expression in the SON and PVN, it might also modify OT content and alter male sexual behavior. We analyzed if repeated DE-79 exposure of adult male rats affected OT content and OT receptor (OTR) density in the SON, PVN, medial preoptic area (mPOA), ventral tegmental area, nucleus accumbens, and amygdala, and if male copulatory behavior was affected. We show that DE-79 exposure produces a generalized decrease in brain OT immunoreactivity, increases OTR density in all brain regions analyzed but the mPOA, and reduces the ejaculatory threshold after a first ejaculation. The documented ejaculation-induced OT release might participate in this last effect. Thus, one-week DE-79 exposure alters the OT-OTR system and modifies male rat sexual performance. Based on the literature it could be speculated that these effects are related to the putative endocrine disrupting actions of DE-79, ultimately altering brain OT levels and OTR expression that might affect copulation and other important OT-mediated brain functions.

Case Report: Role of Anterior Segment Optical Coherence Tomography for Managing Failed Endothelial Keratoplasty Graft.

SIGNIFICANCE: Some patients show poor visual outcomes after Descemet stripping automated endothelial keratoplasty. In such cases, secondary Descemet membrane endothelial keratoplasty can be performed to achieve complete visual recovery. Anterior segment optical coherence tomography (AS-OCT) is a valuable tool for the follow-up of posterior lamellar keratoplasty outcomes and complications. PURPOSE: This study aimed to report the clinical outcome of secondary Descemet membrane endothelial keratoplasty for managing poor visual results in a patient with graft failure after a previous Descemet stripping automated endothelial keratoplasty, highlighting the importance of AS-OCT in the follow-up of endothelial keratoplasty. CASE REPORT: A 38-year-old woman with high myopia underwent Descemet stripping automated endothelial keratoplasty for bullous keratopathy after explantation of an angle-supported phakic intraocular lens. Two years after keratoplasty, the patient experienced poor visual acuity (counting fingers), and significant corneal edema was observed on clinical examination hindering visualization of the anterior chamber structures. Anterior segment optical coherence tomography showed a failed and thickened graft adhering well to the recipient cornea in an anterior chamber without other comorbidities. Therefore, the graft was removed and replaced with a Descemet membrane endothelial keratoplasty graft without any complications. One year later, the clinical outcome was evaluated by comparing the pre-operative and post-operative best-corrected visual acuity, biomicroscopy findings, endothelial cell density, and corneal central thickness. CONCLUSIONS: Anterior segment optical coherence tomography is an important tool when deciding on the surgical technique to be applied and for the post-surgical monitoring of endothelial corneal grafts. This case demonstrates the successful management of Descemet stripping automated endothelial keratoplasty graft failure with Descemet membrane endothelial keratoplasty graft, highlighting the importance of AS-OCT in detecting complications such as graft dislocation and primary graft failure. In addition, corneal thickness measured using AS-OCT serves as a critical predictor of graft failure, as observed in this case.

Factors associated with self-medication of antibiotics by caregivers in pediatric patients attending the emergency department: a case-control study.

INTRODUCTION: Antibiotic self-medication is a common practice in pediatric caregivers in low-income countries with limited resources and represents a public health problem. Our study sought to determine what factors are associated with this practice, including differences in knowledge or attitudes of caregivers who attend a pediatric emergency service. METHODS: Case-control study based on surveys of caregivers of pediatric patients brought to the emergency room with clinical symptoms suggestive of acute infection. Cases were defined as those caregivers who reported self-medication of antibiotics for the current illness and controls where those who did not report self-medication. Information was collected through a self-administered questionnaire that inquired about demographic and family characteristics, attitudes and knowledge toward self-medication of antibiotics. Data were compared using logistic regression and are presented with odd ratios and confidence intervals. RESULTS: A total of 728 caregivers, 182 cases and 546 controls were included. We found that higher parental education, both in mothers (OR 0.56, 95% CI 0.40-0.79) and fathers (OR 0.62, 95% CI 0.43-0.89) was associated with less self-medication. Attitudes such as always requesting antibiotics from their doctors (OR 3.92, 95% CI 1.59-9.66), frequently buying antibiotics without a prescription (OR 23.66, 95% CI 11.76-47.59) and giving advice on antibiotics among family members (OR 2.90, 95% CI 1.75-4.82) resulted in an increased likelihood of self-medication. There was also a higher probability of antibiotic self-medication in older children (OR 1.13, 95% CI 1.09-1.17), those with a greater number of siblings (OR 1.25, 95% CI 1.09-1.43) and in those cases that received antibiotics within the last 3 months (OR 6.27, 95% CI 4.35-9.04). Overall knowledge of risk of antibiotic self-medication was low. CONCLUSIONS: Some patient and family characteristics such as age, number of siblings, recent antibiotic usage and inappropriate attitudes are strongly related to antibiotic self-medication. These findings will inform future interventions to reduce self-medication in children.

An epilepsy-causing mutation leads to co-translational misfolding of the Kv7.2 channel.

BACKGROUND: The amino acid sequence of proteins generally carries all the necessary information for acquisition of native conformations, but the vectorial nature of translation can additionally determine the folding outcome. Such consideration is particularly relevant in human diseases associated to inherited mutations leading to structural instability, aggregation, and degradation. Mutations in the KCNQ2 gene associated with human epilepsy have been suggested to cause misfolding of the encoded Kv7.2 channel. Although the effect on folding of mutations in some domains has been studied, little is known of the way pathogenic variants located in the calcium responsive domain (CRD) affect folding. Here, we explore how a Kv7.2 mutation (W344R) located in helix A of the CRD and associated with hereditary epilepsy interferes with channel function. RESULTS: We report that the epilepsy W344R mutation within the IQ motif of CRD decreases channel function, but contrary to other mutations at this site, it does not impair the interaction with Calmodulin (CaM) in vitro, as monitored by multiple in vitro binding assays. We find negligible impact of the mutation on the structure of the complex by molecular dynamic computations. In silico studies revealed two orientations of the side chain, which are differentially populated by WT and W344R variants. Binding to CaM is impaired when the mutated protein is produced in cellulo but not in vitro, suggesting that this mutation impedes proper folding during translation within the cell by forcing the nascent chain to follow a folding route that leads to a non-native configuration, and thereby generating non-functional ion channels that fail to traffic to proper neuronal compartments. CONCLUSIONS: Our data suggest that the key pathogenic mechanism of Kv7.2 W344R mutation involves the failure to adopt a configuration that can be recognized by CaM in vivo but not in vitro.

Adaptive Resetting of Tuberoinfundibular Dopamine (TIDA) Network Activity during Lactation in Mice.

Giving birth triggers a wide repertoire of physiological and behavioral changes in the mother to enable her to feed and care for her offspring. These changes require coordination and are often orchestrated from the CNS, through as of yet poorly understood mechanisms. A neuronal population with a central role in puerperal changes is the tuberoinfundibular dopamine (TIDA) neurons that control release of the pituitary hormone, prolactin, which triggers key maternal adaptations, including lactation and maternal care. Here, we used Ca2+ imaging on mice from both sexes and whole-cell recordings on female mouse TIDA neurons in vitro to examine whether they adapt their cellular and network activity according to reproductive state. In the high-prolactin state of lactation, TIDA neurons shift to faster membrane potential oscillations, a reconfiguration that reverses upon weaning. During the estrous cycle, however, which includes a brief, but pronounced, prolactin peak, oscillation frequency remains stable. An increase in the hyperpolarization-activated mixed cation current, Ih, possibly through unmasking as dopamine release drops during nursing, may partially explain the reconfiguration of TIDA rhythms. These findings identify a reversible plasticity in hypothalamic network activity that can serve to adapt the dam for motherhood.SIGNIFICANCE STATEMENT Motherhood requires profound behavioral and physiological adaptations to enable caring for offspring, but the underlying CNS changes are poorly understood. Here, we show that, during lactation, neuroendocrine dopamine neurons, the "TIDA" cells that control prolactin secretion, reorganize their trademark oscillations to discharge in faster frequencies. Unlike previous studies, which typically have focused on structural and transcriptional changes during pregnancy and lactation, we demonstrate a functional switch in activity and one that, distinct from previously described puerperal modifications, reverses fully on weaning. We further provide evidence that a specific conductance (Ih) contributes to the altered network rhythm. These findings identify a new facet of maternal brain plasticity at the level of membrane properties and consequent ensemble activity.

A 49-residue sequence motif in the C terminus of Nav1.9 regulates trafficking of the channel to the plasma membrane.

Genetic and functional studies have confirmed an important role for the voltage-gated sodium channel Nav1.9 in human pain disorders. However, low functional expression of Nav1.9 in heterologous systems (e.g. in human embryonic kidney 293 (HEK293) cells) has hampered studies of its biophysical and pharmacological properties and the development of high-throughput assays for drug development targeting this channel. The mechanistic basis for the low level of Nav1.9 currents in heterologous expression systems is not understood. Here, we implemented a multidisciplinary approach to investigate the mechanisms that govern functional Nav1.9 expression. Recombinant expression of a series of Nav1.9-Nav1.7 C-terminal chimeras in HEK293 cells identified a 49-amino-acid-long motif in the C terminus of the two channels that regulates expression levels of these chimeras. We confirmed the critical role of this motif in the context of a full-length channel chimera, Nav1.9-Ct49aaNav1.7, which displayed significantly increased current density in HEK293 cells while largely retaining the characteristic Nav1.9-gating properties. High-resolution live microscopy indicated that the newly identified C-terminal motif dramatically increases the number of channels on the plasma membrane of HEK293 cells. Molecular modeling results suggested that this motif is exposed on the cytoplasmic face of the folded C terminus, where it might interact with other channel partners. These findings reveal that a 49-residue-long motif in Nav1.9 regulates channel trafficking to the plasma membrane.

Is advanced esophageal adenocarcinoma a distinct entity from intestinal subtype gastric cancer? Data from the AGAMENON-SEOM Registry.

BACKGROUND: Advanced esophageal adenocarcinoma (EAC) is generally treated similarly to advanced gastroesophageal junction (GEJ-AC) and gastric (GAC) adenocarcinomas, although GAC clinical trials rarely include EAC. This work sought to compare clinical characteristics and treatment outcomes of advanced EAC with those of GEJ-AC and GAC and examine prognostic factors. PATIENTS AND METHODS: Participants comprised patients with advanced EAC, intestinal GEJ-AC, and GAC treated with platin and fluoropyrimidine (plus trastuzumab when HER2 status was positive). Overall and progression-free survival were estimated using the Kaplan-Meier method. Cox proportional hazards regression gauged the prognostic value of the AGAMENON model. RESULTS: Between 2008 and 2019, 971 participants from the AGAMENON-SEOM registry were recruited at 35 centers. The sample included 67.3% GAC, 13.3% GEJ-AC, and 19.4% EAC. Pulmonary metastases were most common in EAC and peritoneal metastases in GAC. Median PFS and OS were 7.7 (95% CI 7.3-8.0) and 13.9 months (12.9-14.7). There was no difference in PFS or OS between HER2- and HER2+ tumors from the three locations (p > 0.05). Five covariates were found to be prognostic for the entire sample: ECOG-PS, histological grade, number of metastatic sites, NLR, and HER2+ tumors treated with trastuzumab. In EAC, the same variables were prognostic except for grade. The favorable prognosis for HER2+ cancers treated with trastuzumab was homogenous for all three subgroups (p = 0.351) and, after adjusting for the remaining covariates, no evidence supported primary tumor localization as a prognostic factor (p = 0.331). CONCLUSION: Our study supports the hypothesis that EAC exhibits clinicopathological characteristics, prognostic factors, and treatment outcomes comparable to intestinal GEJ-AC and GAC.

External validity of docetaxel triplet trials in advanced gastric cancer: are there patients who still benefit?

BACKGROUND: The purpose of our study was to develop an online calculator to estimate the effect of docetaxel triplets (DPF) in first line of advanced gastric cancer (AGC), and to assess the external validity of docetaxel trials in individual patients. METHODS: The study includes patients with HER2(-) AGC treated with platin and fluoropyrimidine (PF) or with DPF in first line. Treatment effect and interactions were assessed using Bayesian accelerated failure time models. RESULT: The series comprises 1376 patients; 238 treated with DPF and 1138 with PF between 2008 and 2019. DPF was associated with increased progression-free survival (PFS) and overall survival (OS) with time ratio (TR) 1.27 (95% credible interval [CrI], 1.15-1.40), and TR 1.19 (95% CrI, 1.09-1.27), respectively. Serious adverse events were more common with DPF, particularly hematological effects (32% vs 22%). Younger participants received greater DPF dose density without achieving greater disease control, while severe toxicity was likewise higher. DPF yielded superior OS in Lauren intestinal (TR 1.27, 95% CrI, 1.08-1.11) vs diffuse subtype (TR 1.17, 95% CrI, 1.09-1.24) and the probability of increasing OS > 15% was 90% vs 67% in each subtype, respectively. The effect dwindles over time, which can be attributed to pathological changes and clinical practice changes. CONCLUSION: Our study confirms the effect of DPF is highly dependent on several clinical-pathological variables, with discreet and gradually declining benefit over platinum doublets in later years, at the expense of increased toxicity. These results may help to underpin the idea that external validity of AGC trials should be revised regularly.

Pharmacokinetic variability of eslicarbazepine in real clinical practice.

INTRODUCTION: Eslicarbazepine acetate (ESL) is a sodium channel blocker indicated for partial-onset seizures with or without secondary generalization, at a single daily dose. There are very few publications on the levels of ESL metabolites in real clinical practice. OBJECTIVE: To describe the serum levels of licarbazepine (main metabolite of ESL) in patients with refractory epilepsy in real clinical practice. To evaluate the influence of age, sex, and polytherapy on levels and adverse effects. METHODS: This study involved a retrospective analysis of patients diagnosed with epilepsy treated with ESL for whom plasma levels of licarbazepine were available, measured by spectrophotometry. RESULTS: Sixty-four patients were included. One patient had licarbazepine levels of 0 (admitted not taking the drug) was not analyzed. Mean licarbazepine levels of 7.66 µg/mL (400 mg/day dose), 16.56 µg/mL (800-mg dose), and 20.80 µg/mL (1200 mg) were significantly different. There was a significant correlation between daily dose and serum levels (p < 0.05) and between the concentration/dose ratio and lower to higher doses (p < 0.05). Pharmacokinetic variability (coefficient of variation for the concentration/dose ratio) was 33.2%. We found a decrease in the concentration/dose ratio in the 1200 mg/day dose, compared to lower doses. We did not find differences by sex or intake of other antiepileptic inducers or metabolic inhibitors. Fifteen patients (23.8%) had mild nonsymptomatic hyponatremia. CONCLUSION: These results suggest that it is not necessary to routinely determine licarbazepine levels. In specific cases, licarbazepine levels can be useful to assess adherence to treatment and for personalized dose adjustment.

Cumulative Burden of Mental Health Factors and Engagement in HIV Care in Argentina.

BACKGROUND: Cumulative burden of multiple mental health conditions may worsen physical health outcomes in vulnerable populations. Accordingly, identifying cumulative burdens of mental health conditions that may affect HIV treatment and care can guide public health strategies to reduce their impact on HIV-related health outcomes. This study examined the relationship between the cumulative burden of mental health conditions and factors associated with engagement in HIV care in Argentina. METHOD: Data for this study was obtained at baseline from Conexiones y Opciones Positivas en la Argentina 2 (COPA2). Participants (N = 360) were cisgender patients living with HIV who were lost to care, recruited from seven clinics serving people living with HIV in four Argentine urban centers. Cumulative burden of mental health conditions (i.e., depressive symptoms, problematic substance use, unhealthy alcohol use, and psychotic symptoms) was assessed. RESULTS: Every one-point increase in the number of mental health conditions present was associated with a decrement in patient-provider communication (b = - 0.22, p < .001), self-efficacy (b = - 0.13, p = .012), and motivation for adherence (b = - 0.11, p = .039). CONCLUSION: This study found cumulative burden of depression, problematic substance use, unhealthy alcohol use, and psychotic symptoms to be negatively associated with factors related to engagement in HIV care. Results highlight the importance of identification and treatment of challenges to mental health, in order to ameliorate their influence on engagement in HIV care.

Structural basis and energy landscape for the Ca2+ gating and calmodulation of the Kv7.2 K+ channel.

The Kv7.2 (KCNQ2) channel is the principal molecular component of the slow voltage-gated, noninactivating K+ M-current, a key controller of neuronal excitability. To investigate the calmodulin (CaM)-mediated Ca2+ gating of the channel, we used NMR spectroscopy to structurally and dynamically describe the association of helices hA and hB of Kv7.2 with CaM, as a function of Ca2+ concentration. The structures of the CaM/Kv7.2-hAB complex at two different calcification states are reported here. In the presence of a basal cytosolic Ca2+ concentration (10-100 nM), only the N-lobe of CaM is Ca2+-loaded and the complex (representative of the open channel) exhibits collective dynamics on the millisecond time scale toward a low-populated excited state (1.5%) that corresponds to the inactive state of the channel. In response to a chemical or electrical signal, intracellular Ca2+ levels rise up to 1-10 µM, triggering Ca2+ association with the C-lobe. The associated conformational rearrangement is the key biological signal that shifts populations to the closed/inactive channel. This reorientation affects the C-lobe of CaM and both helices in Kv7.2, allosterically transducing the information from the Ca2+-binding site to the transmembrane region of the channel.

Resilience to Pain: A Peripheral Component Identified Using Induced Pluripotent Stem Cells and Dynamic Clamp.

Pain is a complex process that involves both detection in the peripheral nervous system and perception in the CNS. Individual-to-individual differences in pain are well documented, but not well understood. Here we capitalized on inherited erythromelalgia (IEM), a well characterized human genetic model of chronic pain, and studied a unique family containing related IEM subjects with the same disease-causing NaV1.7 mutation, which is known to make dorsal root ganglion (DRG) neurons hyperexcitable, but different pain profiles (affected son with severe pain, affected mother with moderate pain, and an unaffected father). We show, first, that, at least in some cases, relative sensitivity to pain can be modeled in subject-specific induced pluripotent stem cell (iPSC)-derived sensory neurons in vitro; second, that, in some cases, mechanisms operating in peripheral sensory neurons contribute to interindividual differences in pain; and third, using whole exome sequencing (WES) and dynamic clamp, we show that it is possible to pinpoint a specific variant of another gene, KCNQ in this particular kindred, that modulates the excitability of iPSC-derived sensory neurons in this family. While different gene variants may modulate DRG neuron excitability and thereby contribute to interindividual differences in pain in other families, this study shows that subject-specific iPSCs can be used to model interindividual differences in pain. We further provide proof-of-principle that iPSCs, WES, and dynamic clamp can be used to investigate peripheral mechanisms and pinpoint specific gene variants that modulate pain signaling and contribute to interindividual differences in pain.SIGNIFICANCE STATEMENT Individual-to-individual differences in pain are well documented, but not well understood. In this study, we show, first, that, at least in some cases, relative sensitivity to pain can be modeled in subject-specific induced pluripotent stem cell-derived sensory neurons in vitro; second, that, in some cases, mechanisms operating in peripheral sensory neurons contribute to interindividual differences in pain; and third, using whole exome sequencing and dynamic clamp, we show that it is possible to pinpoint a specific gene variant that modulates pain signaling and contributes to interindividual differences in pain.

Acutely altered mental status as the main clinical presentation of multiple strokes in critically ill patients with COVID-19.

BACKGROUND AND AIMS: Cerebral infarction in COVID-19 patients might be associated with a hypercoagulable state related to a systemic inflammatory response. Its diagnosis might be challenging. We present two critically ill patients with COVID-19 who presented acutely altered mental status as the main manifestation of multiple strokes. METHODS: Clinical presentation and diagnostic work-up of the patients. RESULTS: Two patients in their sixties were hospitalized with a bilateral pneumonia COVID-19. They developed respiratory failure and were admitted to ICU for mechanical ventilation and intense medical treatment. They were started on low-molecular-weight heparin since admission. Their laboratory results showed lymphopenia and increased levels of C-reactive protein and D-dimer. Case 1 developed hypofibrinogenemia and presented several cutaneous lesions with biopsy features of thrombotic vasculopathy. Case 2 was performed a CT pulmonary angiogram at ICU showing a bilateral pulmonary embolism. When waking up, both patients were conscious but with a remarkable global altered mental status without focal neurological deficits. A brain MRI revealed multiple acute bilateral ischemic lesions with areas of hemorrhagic transformation in both patients (case 1: affecting the left frontal and temporal lobes and both occipital lobes; case 2: affecting both frontal and left occipital lobes). Cardioembolic source and acquired antiphospholipid syndrome were ruled out. COVID-19-associated coagulopathy was suspected as the possible main etiology of the strokes. CONCLUSION: Acutely altered mental status might be the main manifestation of multiple brain infarctions in critically ill COVID-19 patients. It should be specially considered in those with suspected COVID-19-associated coagulopathy. Full-dose anticoagulation and clinical-radiological monitoring might reduce their neurological consequences.

Assessment of Collateral Circulation Using Perfusion CT in Middle Cerebral Artery Thrombectomy-Treated Patients.

INTRODUCTION: The prognostic value of leptomeningeal collateral circulation in thrombectomy-treated patients remains unclear. We evaluated the construct validity of assessing leptomeningeal collateral circulation using a new regional perfusion CT source image-based approach, the Perfusion Acquisition for THrombectomy Scale (PATHS). We also compared the prognostic value of PATHS with a further 6 scales based on various techniques: CT-angiography, perfusion CT, and digital subtraction angiography. Additionally, we studied the relationship between the scores for the different scales. PATIENTS AND METHODS: We performed a retrospective study of consecutive patients with stroke and M1/terminal carotid occlusion treated with thrombectomy in our center. Leptomeningeal collateral circulation was prospectively evaluated using 7 scales: Tan and Miteff (CT Angiography); Calleja, Cao, American Society of Intervention and Therapeutic Neuroradiology/Society of Interventional Radiology, and PATHS (perfusion); and Christoforidis (Digital Subtraction Angiography). Correlations were studied using the Spearman method. RESULTS: The study population comprised 108 patients. All scales predicted the modified Rankin Scale at 3 months (P ≤ .02) and all but 1 (Christoforidis) correlated with 24-hour brain infarct volume (P ≤ .02). These correlations were higher with PATHS (rho = -0.47, P < .001 for 3-month modified Rankin Scale; rho = -0.35, P < .001 for follow-up infarct volume). The multivariate analysis showed PATHS to be an independent predictor of modified Rankin Scale at 3 months less than equal to 2. A crosscorrelation analysis revealed a better correlation between scales that used the same techniques. CONCLUSIONS: PATHS can be used to assess leptomeningeal collateral circulation. PATHS had better prognostic value than other scales; therefore, it might be considered for assessment of leptomeningeal collateral circulation in candidates for thrombectomy. The moderate correlation between scales suggests that scores are not interchangeable.

Homomeric Kv7.2 current suppression is a common feature in KCNQ2 epileptic encephalopathy.

OBJECTIVE: To gain insight into the mechanisms underlying KCNQ2 encephalopathy by examining the electrophysiologic properties of mutant Kv7.2 channels in different multimeric configurations. METHODS: We analyzed the genotype-phenotype relationship in 4 patients with KCNQ2 encephalopathy and performed electrophysiologic analysis of M-currents mediated by homomeric Kv7.2 or heteromeric Kv7.2/Kv7.3 channels. RESULTS: Negligible or no current was recorded in cells expressing homomeric E130K, W270R, or G281R de novo mutants, and it was reduced by more than 90% for the L243F maternally inherited mutant. The E130K and G281R mutants presented a marked dominant-negative behavior, whereas the current density was partially reduced (L243F) or not affected (W270R) when coexpressed with wild-type Kv7.2 subunits. In contrast, the extent of Kv7.3 "rescue," which yields negligible currents on its own, followed the sequence E130K > L243F > W270R, whereas no rescue was observed with the G281R mutant. No significant effects on current density were observed when subunits were expressed in a 0.5:0.5:1.0 (Kv7.2:mutant:Kv7.3) DNA ratio to mimic the genetic balance. There was an increase in sensitivity to phosphatidylinositol 4,5-bisphosphate (PIP2 ) depletion for W270R/Kv7.3, but no substantial differences were observed when the mutated subunits were coexpressed with Kv7.2 or both Kv7.2 and Kv7.3. SIGNIFICANCE: There was a marked disparity of the impact of these mutations on Kv7.2 function, which varied on association with Kv7.2 or Kv7.3 subunits. Current density of homomeric channels was the most reliable property relating Kv7.2 function to encephalopathy, but other factors are required to explain the milder phenotype for some individuals carrying the maternally inherited L243F mutation. We hypothesize that the role of homomeric Kv7.2 channels for fine-tuning neuronal connections during development is critical for the severity of the KCNQ2 encephalopathy.

M-CHAT-R/F Validation as a screening tool for early detection in children with autism spectrum disorder. / Validación del M-CHAT-R/F como instrumento de tamizaje para detección precoz en niños con trastorno del espectro autista.

INTRODUCTION: Screening for Autism Spectrum Disorders (ASD) using the Modified Checklist for Autism in Toddlers, Revised with Follow-up (M-CHAT-R/F) increases early detection, allowing early interventions and improving prognosis. This tool is part of the management in case of suspected ASD in several clinical guidelines. The objective of this article was to conduct the concurrent and discrimi nant validation and the reliability analysis of M-CHAT-R/F in the Chilean population. PATIENTS AND METHOD: This is the second stage of the cross-cultural adaptation of cross-sectional design. M-CHAT- R/F was applied to a sample of 20 children with suspected ASD and 100 randomly selected healthy control children, aged between 16-30 months. Autism Diagnostic Observation Schedule (ADOS-2), considered as reference, was applied to the 20 patients of the clinical sample, to 20 children of the healthy control sample and to those cases of the healthy control sample with M-CHAT-R/F positive. Cronbach alpha was calculated, as well as M-CHAT-R/F and ADOS-2 correlation, sensitivity, and specificity analyses. RESULTS: In the healthy sample, M-CHAT-R/F was positive in two patients, with one of them positive and the other one negative for ASD with ADOS-2 test. In the clinical sample, M- CHAT-R/F was positive in all cases, three of them were negative in the ADOS-2 test. The Alfa relia bility of M-CHART-R/T was 0,889, the discriminant sensitivity and specificity were 100% and 98%, and the concurrent ones were 100% and 87.5% respectively. CONCLUSIONS: The Chilean M-CHAT- R/F version was reliable, sensitive and specific, similar to the original test, which opens the possibility for its use in clinical samples and for research. Validating M-CHAT-R/F is an ongoing process which must be further developed.

Rare RELN variants affect Reelin-DAB1 signal transduction in autism spectrum disorder.

The Reelin-DAB1 signaling pathway plays a crucial role in regulating neuronal migration and synapse function. Although many rare heterozygous variants in the Reelin gene (RELN) have been identified in patients with autism spectrum disorder (ASD), most variants are still of unknown clinical significance. Also, genetic data suggest that heterozygous variants in RELN alone appear to be insufficient to cause ASD. Here, we describe the identification and functional characterization of rare compound heterozygous missense variants in RELN in a patient with ASD in whom we have previously reported hyperfunctional mTORC1 signaling of yet unknown etiology. Using iPSC-derived neural progenitor cells (NPCs) from this patient, we provide experimental evidence that the identified variants are deleterious and lead to diminished Reelin secretion and impaired Reelin-DAB1 signal transduction. Also, our results suggest that mTORC1 pathway overactivation may function as a second hit event contributing to downregulation of the Reelin-DAB1 cascade in patient-derived NPCs, and that inhibition of mTORC1 by rapamycin attenuates Reelin-DAB1 signaling impairment. Taken together, our findings point to an abnormal interplay between Reelin-DAB1 and mTORC1 networks in nonsyndromic ASD.