Real-time visualization of structural dynamics of synapses in live cells in vivo.

The structural plasticity of synapses is crucial for regulating brain functions. However, currently available methods for studying synapse organization based on split fluorescent proteins (FPs) have been limited in assessing synaptic dynamics in vivo due to the irreversible binding of split FPs. Here, we develop 'SynapShot', a method for visualizing the structural dynamics of intact synapses by combining dimerization-dependent FPs (ddFPs) with engineered synaptic adhesion molecules. SynapShot allows real-time monitoring of reversible and bidirectional changes of synaptic contacts under physiological stimulation. The application of green and red ddFPs in SynapShot enables simultaneous visualization of two distinct populations of synapses. Notably, the red-shifted SynapShot is highly compatible with blue light-based optogenetic techniques, allowing for visualization of synaptic dynamics while precisely controlling specific signaling pathways. Furthermore, we demonstrate that SynapShot enables real-time monitoring of structural changes in synaptic contacts in the mouse brain during both primitive and higher-order behaviors.

ARAF mutations confer resistance to the RAF inhibitor belvarafenib in melanoma.

Although RAF monomer inhibitors (type I.5, BRAF(V600)) are clinically approved for the treatment of BRAFV600-mutant melanoma, they are ineffective in non-BRAFV600 mutant cells1-3. Belvarafenib is a potent and selective RAF dimer (type II) inhibitor that exhibits clinical activity in patients with BRAFV600E- and NRAS-mutant melanomas. Here we report the first-in-human phase I study investigating the maximum tolerated dose, and assessing the safety and preliminary efficacy of belvarafenib in BRAFV600E- and RAS-mutated advanced solid tumours (NCT02405065, NCT03118817). By generating belvarafenib-resistant NRAS-mutant melanoma cells and analysing circulating tumour DNA from patients treated with belvarafenib, we identified new recurrent mutations in ARAF within the kinase domain. ARAF mutants conferred resistance to belvarafenib in both a dimer- and a kinase activity-dependent manner. Belvarafenib induced ARAF mutant dimers, and dimers containing mutant ARAF were active in the presence of inhibitor. ARAF mutations may serve as a general resistance mechanism for RAF dimer inhibitors as the mutants exhibit reduced sensitivity to a panel of type II RAF inhibitors. The combination of RAF plus MEK inhibition may be used to delay ARAF-driven resistance and suggests a rational combination for clinical use. Together, our findings reveal specific and compensatory functions for the ARAF isoform and implicate ARAF mutations as a driver of resistance to RAF dimer inhibitors.

Anterior cingulate cortex-related functional hyperconnectivity underlies sensory hypersensitivity in Grin2b-mutant mice.

Sensory abnormalities are observed in ~90% of individuals with autism spectrum disorders (ASD), but the underlying mechanisms are poorly understood. GluN2B, an NMDA receptor subunit that regulates long-term depression and circuit refinement during brain development, has been strongly implicated in ASD, but whether GRIN2B mutations lead to sensory abnormalities remains unclear. Here, we report that Grin2b-mutant mice show behavioral sensory hypersensitivity and brain hyperconnectivity associated with the anterior cingulate cortex (ACC). Grin2b-mutant mice with a patient-derived C456Y mutation (Grin2bC456Y/+) show sensory hypersensitivity to mechanical, thermal, and electrical stimuli through supraspinal mechanisms. c-fos and functional magnetic resonance imaging indicate that the ACC is hyperactive and hyperconnected with other brain regions under baseline and stimulation conditions. ACC pyramidal neurons show increased excitatory synaptic transmission. Chemogenetic inhibition of ACC pyramidal neurons normalizes ACC hyperconnectivity and sensory hypersensitivity. These results suggest that GluN2B critically regulates ASD-related cortical connectivity and sensory brain functions.

Exploring Molecular Genetic Alterations and RAF Fusions in Melanoma: A Belvarafenib Expanded Access Program in Patients with RAS/RAF-Mutant Melanoma.

BACKGROUND: Melanoma incidence is on the rise in East Asia, yet studies of the molecular landscape are lacking in this population. We examined patients with melanoma who underwent next-generation sequencing (NGS) at a single tertiary center in South Korea, focusing on patients harboring NRAS or RAF alterations who received belvarafenib, a pan-RAF dimer inhibitor, through the Expanded Access Program (EAP). PATIENTS AND METHODS: Data were collected from 192 patients with melanoma who underwent NGS between November 2017 and May 2023. Variant call format data were obtained and annotated. Patients in the EAP received 450 mg twice daily doses of belvarafenib. RESULTS: Alterations in the RAS/RTK pathway were the most prevalent, with BRAF and NRAS alteration rates of 22.4% and 17.7%, respectively. NGS enabled additional detection of fusion mutations, including 6 BRAF and 1 RAF1 fusion. Sixteen patients with NRAS or RAF alterations received belvarafenib through the EAP, and disease control was observed in 50%, with 2 patients demonstrating remarkable responses. CONCLUSIONS: Our study highlights the value of NGS in detecting BRAF, NRAS mutations and RAF fusions, expanding possibilities for targeted therapies in malignant melanoma. Belvarafenib showed clinical benefit in patients harboring these alterations. Ongoing trials will provide further insights into the safety and efficacy of belvarafenib.

The PFC-LH-VTA pathway contributes to social deficits in IRSp53-mutant mice.

Dopamine (DA) neurons in the ventral tegmental area (VTA) promote social brain functions by releasing DA onto nucleus accumbens neurons, but it remains unclear how VTA neurons communicate with cortical neurons. Here, we report that the medial prefrontal cortex (mPFC)-lateral hypothalamus (LH)-VTA pathway contributes to social deficits in mice with IRSp53 deletion restricted to cortical excitatory neurons (Emx1-Cre;Irsp53fl/fl mice). LH-projecting mutant mPFC neurons display abnormally increased excitability involving decreased potassium channel gene expression, leading to excessive excitatory synaptic input to LH-GABA neurons. A circuit-specific IRSp53 deletion in LH-projecting mPFC neurons also increases neuronal excitability and induces social deficits. LH-GABA neurons with excessive mPFC excitatory synaptic input show a compensatory decrease in excitability, weakening the inhibitory LHGABA-VTAGABA pathway and subsequently over-activating VTA-GABA neurons and over-inhibiting VTA-DA neurons. Accordingly, optogenetic activation of the LHGABA-VTAGABA pathway improves social deficits in Emx1-Cre;Irsp53fl/fl mice. Therefore, the mPFC-LHGABA-VTAGABA-VTADA pathway contributes to the social deficits in Emx1-Cre;Irsp53fl/fl mice.

Effects of Ambient Air Pollution on Brain Cortical Thickness and Subcortical Volume: A Longitudinal Neuroimaging Study.

INTRODUCTION: Several cross-sectional studies have shown that long-term exposures to air pollutants are associated with smaller brain cortical volume or thickness. Here, we investigated longitudinal associations of long-term air pollution exposures with cortical thickness and subcortical volume. METHODS: In this longitudinal study, we included a prospective cohort of 361 adults residing in four cities in the Republic of Korea. Long-term concentrations of particulate matter with aerodynamic diameters of ≤10 µm (PM10) and ≤2.5 µm (PM2.5) and nitrogen dioxide (NO2) at residential addresses were estimated. Neuroimaging markers (cortical thickness and subcortical volume) were obtained from brain magnetic resonance images at baseline (August 2014 to March 2017) and at the 3-year follow-up (until September 2020). Linear mixed-effects models were used, adjusting for covariates. RESULTS: A 10-µg/m3 increase in PM10 was associated with reduced whole-brain mean (ß = -0.45, standard error [SE] = 0.10; p < 0.001), frontal (ß = -0.53, SE = 0.11; p < 0.001) and temporal thicknesses (ß = -0.37, SE = 0.12; p = 0.002). A 10-ppb increase in NO2 was associated with a decline in the whole-brain mean cortical thickness (ß = -0.23, SE = 0.05; p < 0.001), frontal (ß = -0.25, SE = 0.05; p < 0.001), parietal (ß = -0.12, SE = 0.05; p = 0.025), and temporal thicknesses (ß = -0.19, SE = 0.06; p = 0.001). Subcortical structures associated with air pollutants included the thalamus. CONCLUSIONS: Long-term exposures to PM10 and NO2 may lead to cortical thinning in adults.

Unraveling the mechanisms of benzo[a]pyrene degradation by Pigmentiphaga kullae strain KIT-003 using a multi-omics approach.

Polycyclic aromatic hydrocarbons (PAHs), notably benzo[a]pyrene (BaP), are environmental contaminants with multiple adverse ecological implications. Numerous studies have suggested the use of BaP biodegradation using various bacterial strains to remove BaP from the environment. This study investigates the BaP biodegradation capability of Pigmentiphaga kullae strain KIT-003, isolated from the Nak-dong River (South Korea) under specific environmental conditions. The optimum conditions of biodegradation were found to be pH 7.0, 35°C, and a salinity of 0 %. GC-MS analysis suggested alternative pathways by which KIT-003 produced catechol from BaP through several intermediate metabolites, including 4-formylchrysene-5-carboxylic acid, 5,6-dihydro-5,6-dihydroxychrysene-5-carboxylic acid (isomer: 3,4-dihydro-3,4-dihydroxychrysene-4-carboxylic acid), naphthalene-1,2-dicarboxylic acid, and 2-hydroxy-1-naphthoic acid. Proteomic profiles indicated upregulation of enzymes associated with aromatic compound degradation, such as nahAc and nahB, and of those integral to the tricarboxylic acid cycle, reflecting the strain's adaptability to and degradation of BaP. Lipidomic analysis of KIT-003 demonstrated that BaP exposure induced an accumulation of glycerolipids such as diacylglycerol and triacylglycerol, indicating their crucial role in bacterial adaptation mechanisms under BaP stress. This study provides significant scientific knowledge regarding the intricate mechanisms involved in BaP degradation by microorganisms.

Sports-related concussion history, reporting behaviours, knowledge, and attitudes in Pakistani university student-athletes.

Objective: To assess student-athletes' knowledge and attitudes towards sport-related concussions and to investigate concussion history and reporting behaviours. METHODS: The cross-sectional, survey-based study was conducted from September 2020 to June 2021 after approval from the research ethics committee of Universiti Malaya, Malaysia, and comprised student-athletes of either gender aged 18 years or above at various universities across Pakistan and who played contact or collision sports for their universities. Data was collected using the Urdu version of the Rosenbaum Concussion Knowledge and Attitudes Survey-Student Version. Data was also gathered about the participants' self-reported exposure to formal concussion education, previous sport-related concussion history, and reporting behaviours, where applicable. Data was analysed using SPSS 23. RESULTS: Of the 369 participants, 224(60.7%) were males and 145(39.3%) were females. The overall mean age was 19.95±1.75 years. Among the participants, 327(88.6%) had not received formal concussion education. The mean knowledge score was 12.76±2.73 out of a possible 25 points, and the mean attitude score was 38.63±10.30 out of 75 points. Knowledge had a weak positive correlation with attitude towards sport-related concussions SRC (p<0.05). Females displayed better attitudes towards sport-related concussions than their male counterparts (p<0.05). Overall, 126(34%) participants had experienced sport-related concussion symptoms following a blow to the head in the preceding 12 months, and 81(64.3%) of them had continued playing while being symptomatic. Conclusion: Pakistani university student-athletes lacked adequate concussion knowledge and held poor attitudes towards sport-related concussions.

Exploring transfer effects on memory and its neural mechanisms through a computerized cognitive training in mild cognitive impairment: randomized controlled trial.

BACKGROUND: Computerized cognitive training (CCT) has been proposed as a potential therapy for cognitive decline. One of the benefits of CCT is a transfer effect, but its mechanism on the memory domain is unclear. This study aimed to investigate the transfer effect of non-memory multidomain CCT on the memory domain and its neural basis in patients with mild cognitive impairment (MCI) through a randomized controlled trial. METHODS: Patients with MCI recruited from memory clinics were randomly assigned to either the CCT or the control group. The CCT group received multidomain CCT training excluding memory training, while the control group read educational books with learning-based quizzes twice a week for 8 weeks. Participants underwent memory tests yielding a composite score, other cognitive domain tests, non-cognitive scales, and resting-state functional magnetic resonance imaging (rsfMRI), at baseline and after intervention. Within- and between-group comparisons, group × time interactions, and seed-to-voxel analyses in memory-involving brain networks were performed. RESULTS: The CCT group showed improvement over the control group in memory domain (Group × time, F = 5.87, P = 0.03, η2 = 0.31), which was related with the increased connectivity in the hippocampal-frontal and fusiform-occipital network. No other cognitive and non-cognitive symptoms differed between groups after adjusting for covariates. CONCLUSION: Eight weeks of multidomain CCT without memory training improved memory function and restored functional network in the hippocampal and medial temporal region in MCI patients. These results can provide evidence for the transferring ability of CCT on memory functioning with its neural basis.

Detection of Cerebral Microbleeds in MR Images Using a Single-Stage Triplanar Ensemble Detection Network (TPE-Det).

BACKGROUND: Cerebral microbleeds (CMBs) are microscopic brain hemorrhages with implications for various diseases. Automated detection of CMBs is a challenging task due to their wide distribution throughout the brain, small size, and visual similarity to their mimics. For this reason, most of the previously proposed methods have been accomplished through two distinct stages, which may lead to difficulties in integrating them into clinical workflows. PURPOSE: To develop a clinically feasible end-to-end CMBs detection network with a single-stage structure utilizing 3D information. This study proposes triplanar ensemble detection network (TPE-Det), ensembling 2D convolutional neural networks (CNNs) based detection networks on axial, sagittal, and coronal planes. STUDY TYPE: Retrospective. SUBJECTS: Two datasets (DS1 and DS2) were used: 1) 116 patients with 367 CMBs and 12 patients without CMBs for training, validation, and testing (70.39 ± 9.30 years, 68 women, 60 men, DS1); 2) 58 subjects with 148 microbleeds and 21 subjects without CMBs only for testing (76.13 ± 7.89 years, 47 women, 32 men, DS2). FIELD STRENGTH/SEQUENCE: A 3 T field strength and 3D GRE sequence scan for SWI reconstructions. ASSESSMENT: The sensitivity, FPavg (false-positive per subject), and precision measures were computed and analyzed with statistical analysis. STATISTICAL TESTS: A paired t-test was performed to investigate the improvement of detection performance by the suggested ensembling technique in this study. A P value < 0.05 was considered significant. RESULTS: The proposed TPE-Det detected CMBs on the DS1 testing set with a sensitivity of 96.05% and an FPavg of 0.88, presenting statistically significant improvement. Even when the testing on DS2 was performed without retraining, the proposed model provided a sensitivity of 85.03% and an FPavg of 0.55. The precision was significantly higher than the other models. DATA CONCLUSION: The ensembling of multidimensional networks significantly improves precision, suggesting that this new approach could increase the benefits of detecting lesions in the clinic. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.

Associations of Particulate Matter Exposures With Brain Gray Matter Thickness and White Matter Hyperintensities: Effect Modification by Low-Grade Chronic Inflammation.

BACKGROUND: Numerous studies have shown the effect of particulate matter exposure on brain imaging markers. However, little evidence exists about whether the effect differs by the level of low-grade chronic systemic inflammation. We investigated whether the level of c-reactive protein (CRP, a marker of systemic inflammation) modifies the associations of particulate matter exposures with brain cortical gray matter thickness and white matter hyperintensities (WMH). METHODS: We conducted a cross-sectional study of baseline data from a prospective cohort study including adults with no dementia or stroke. Long-term concentrations of particulate matter ≤ 10 µm in diameter (PM10) and ≤ 2.5 µm (PM2.5) at each participant's home address were estimated. Global cortical thickness (n = 874) and WMH volumes (n = 397) were estimated from brain magnetic resonance images. We built linear and logistic regression models for cortical thickness and WMH volumes (higher versus lower than median), respectively. Significance of difference in the association between the CRP group (higher versus lower than median) was expressed as P for interaction. RESULTS: Particulate matter exposures were significantly associated with a reduced global cortical thickness only in the higher CRP group among men (P for interaction = 0.015 for PM10 and 0.006 for PM2.5). A 10 µg/m3 increase in PM10 was associated with the higher volumes of total WMH (odds ratio, 1.78; 95% confidence interval, 1.07-2.97) and periventricular WMH (2.00; 1.20-3.33). A 1 µg/m3 increase in PM2.5 was associated with the higher volume of periventricular WMH (odds ratio, 1.66; 95% confidence interval, 1.08-2.56). These associations did not significantly differ by the level of high sensitivity CRP. CONCLUSION: Particulate matter exposures were associated with a reduced global cortical thickness in men with a high level of chronic inflammation. Men with a high level of chronic inflammation may be susceptible to cortical atrophy attributable to particulate matter exposures.

Effectiveness of ultrasound-guided dual nerve block in the below-knee amputation.

PURPOSE: Below knee amputation (BKA) is a common surgical procedure for diabetic foot ulcers and necrotizing lower limb fasciitis patients. However, it is a painful procedure and inadequate postoperative analgesia impedes rehabilitation and prolongs hospitalization. An ideal pain management regimen should provide superior analgesia while minimizing opioid consumption and improving rehabilitation. METHODS: We retrospectively reviewed medical charts of 218 patients who underwent BKA for diabetic foot ulcer or necrotizing lower limb fasciitis at a single center between January 2017 and September 2020. Two groups were analyzed: patients who received dual nerve block (DNB) before surgery (Group I; n = 104), and patients who did not (Group II; n = 93). By the exclusion criteria, 21 patients were excluded. The femoral and sciatic nerves were each blocked separately under ultrasound guidance. This procedure was performed immediately before the operation. RESULTS: Group I patients' subjective pain scores were significantly lower than that of Group II at 6, 12, and 24 h after BKA (P < 0.05). Group I's morphine milligram equivalent (MME) was significantly lower than those of Group II at 72 h after BKA (P < 0.05). Moreover, the rate of postoperative nausea and vomiting (PONV) and delirium was significantly lower in Group I patients than that in Group II patients. CONCLUSION: Ultrasound-guided lower extremity nerve block surgery is excellent for early postoperative pain control, could be used as an accurate and effective pain control method, and can reduce the side effects of opioid consumption after BKA.

Triphenylamine-Based Conjugated Polyelectrolyte as a Hole Transport Layer for Efficient and Scalable Perovskite Solar Cells.

π-Conjugated polyelectrolytes (CPEs) have been studied as interlayers on top of a separate hole transport layer (HTL) to improve the wetting, interfacial defect passivation, and crystal growth of perovskites. However, very few CPE-based HTLs have been reported without rational molecular design as ideal HTLs for perovskite solar cells (PeSCs). In this study, the authors synthesize a triphenylamine-based anionic CPE (TPAFS-TMA) as an HTL for p-i-n-type PeSCs. TPAFS-TMA has appropriate frontier molecular orbital (FMO) levels similar to those of the commonly used poly(bis(4-phenyl)-2,4,6-trimethylphenylamine) (PTAA) HTL. The ionic and semiconducting TPAFS-TMA shows high compatibility, high transmittance, appropriate FMO energy levels for hole extraction and electron blocking, as well as defect passivating properties, which are confirmed using various optical and electrical analyses. Thus, the PeSC with the TPAFS-TMA HTL exhibits the best power conversion efficiency (PCE) of 20.86%, which is better than that of the PTAA-based device (PCE of 19.97%). In addition, it exhibits negligible device-to-device variations in its photovoltaic performance, contrary to the device with PTAA. Finally, a large-area PeSC (1 cm2 ) and mini-module (3 cm2 ), showing PCEs of 19.46% and 18.41%, respectively, are successfully fabricated. The newly synthesized TPAFS-TMA may suggest its great potential as an HTL for large-area PeSCs.

Reduced brain subcortical volumes in patients with glaucoma: a pilot neuroimaging study using the region-of-interest-based approach.

BACKGROUND: While numerous neuroimaging studies have demonstrated that glaucoma is associated with smaller volumes of the visual cortices in the brain, only a few studies have linked glaucoma with brain structures beyond the visual cortices. Therefore, the objective of this study was to compare brain imaging markers and neuropsychological performance between individuals with and without glaucoma. METHODS: We identified 64 individuals with glaucoma and randomly selected 128 age-, sex-, and education level-matched individuals without glaucoma from a community-based cohort. The study participants underwent 3 T brain magnetic resonance imaging and neuropsychological assessment battery. Regional cortical thickness and subcortical volume were estimated from the brain images of the participants. We used a linear mixed model after adjusting for potential confounding variables. RESULTS: Cortical thickness in the occipital lobe was significantly smaller in individuals with glaucoma than in the matched individuals (ß = - 0.04 mm, P = 0.014). This did not remain significant after adjusting for cardiovascular risk factors (ß = - 0.02 mm, P = 0.67). Individuals with glaucoma had smaller volumes of the thalamus (ß = - 212.8 mm3, P = 0.028), caudate (ß = - 170.0 mm3, P = 0.029), putamen (ß = - 151.4 mm3, P = 0.051), pallidum (ß = - 103.6 mm3, P = 0.007), hippocampus (ß = - 141.4 mm3, P = 0.026), and amygdala (ß = - 87.9 mm3, P = 0.018) compared with those without glaucoma. Among neuropsychological battery tests, only the Stroop color reading test  score was significantly lower in individuals with glaucoma compared with those without glaucoma (ß = - 0.44, P = 0.038). CONCLUSIONS: We found that glaucoma was associated with smaller volumes of the thalamus, caudate, putamen, pallidum, amygdala, and hippocampus.

Perinatal Outcomes According to Accessibility to Maternal-Fetal and Neonatal Intensive Care Units by Region in Korea.

BACKGROUND: Herein, we aimed to evaluate the maternal mortality ratio and perinatal mortality rate for different perinatal medical care service areas (PMCSAs), which were established by considering their geographical accessibility to maternal-fetal intensive care units (MFICUs) and neonatal intensive care units (NICUs), and to compare the PMCSAs according to their accessibility to these perinatal care services. METHODS: Based on the 70 hospital service areas (HSAs) across the country confirmed through the Dartmouth Atlas methodology analysis and gathering of expert opinions, the PMCSAs were designated by merging HSAs without MFICUs and NICUs to the nearest HSA that contained MFICUs and NICUs, based on which MFICU and NICU could be reached within the shortest amount of time from population-weighted centroids in HSAs. PMCSAs where 30% or more of the population could not access MFICUs and NICUs within 60 minutes were identified using the service module ArcGIS and were defined as having access vulnerability. RESULTS: Thirty-three of 70 HSAs in the country did not contain MFICUs and NICUs, and 39 PMCSAs were finally derived by merging 70 HSAs. Ten of 39 PMCSAs (25.6%) were classified as having access vulnerability to MFICUs and NICUs. The national maternal mortality ratio was 9.42, with the highest ratio seen in the region of Wonju (25.86) and the lowest in Goyang (2.79). The national perinatal mortality rate was 2.86, with the highest and lowest rates observed in the Gunsan (4.04) and Sejong (1.99) regions, respectively. The perinatal mortality rates for areas vulnerable and invulnerable to maternal and neonatal healthcare accessibility were 2.97 and 2.92, respectively, but there was no statistically significant difference in this rate (P = 0.789). The maternal mortality ratio for areas vulnerable and invulnerable to maternal and neonatal healthcare accessibility were 14.28 and 9.48, respectively; this ratio was significantly higher in areas vulnerable to accessibility (P = 0.022). CONCLUSION: Of the PMCSAs across the country, 25.6% (10/39) were deemed to be vulnerable to MFICU and NICU accessibility. There was no difference in the perinatal mortality rate between the vulnerable and invulnerable areas, but the maternal mortality ratio in vulnerable areas was significantly higher than that in invulnerable areas.

IntraBrain Injector (IBI): A Stereotactic-Guided Device for Repeated Delivery of Therapeutic Agents Into the Brain Parenchyma.

BACKGROUND: To deliver therapeutics into the brain, it is imperative to overcome the issue of the blood-brain-barrier (BBB). One of the ways to circumvent the BBB is to administer therapeutics directly into the brain parenchyma. To enhance the treatment efficacy for chronic neurodegenerative disorders, repeated administration to the target location is required. However, this increases the number of operations that must be performed. In this study, we developed the IntraBrain Injector (IBI), a new implantable device to repeatedly deliver therapeutics into the brain parenchyma. METHODS: We designed and fabricated IBI with medical grade materials, and evaluated the efficacy and safety of IBI in 9 beagles. The trajectory of IBI to the hippocampus was simulated prior to surgery and the device was implanted using 3D-printed adaptor and surgical guides. Ferumoxytol-labeled mesenchymal stem cells (MSCs) were injected into the hippocampus via IBI, and magnetic resonance images were taken before and after the administration to analyze the accuracy of repeated injection. RESULTS: We compared the planned vs. insertion trajectory of IBI to the hippocampus. With a similarity of 0.990 ± 0.001 (mean ± standard deviation), precise targeting of IBI was confirmed by comparing planned vs. insertion trajectories of IBI. Multiple administrations of ferumoxytol-labeled MSCs into the hippocampus using IBI were both feasible and successful (success rate of 76.7%). Safety of initial IBI implantation, repeated administration of therapeutics, and long-term implantation have all been evaluated in this study. CONCLUSION: Precise and repeated delivery of therapeutics into the brain parenchyma can be done without performing additional surgeries via IBI implantation.

Human Pluripotent Stem Cell-Derived Alveolar Organoid with Macrophages.

Alveolar organoids (AOs), derived from human pluripotent stem cells (hPSCs) exhibit lung-specific functions. Therefore, the application of AOs in pulmonary disease modeling is a promising tool for understanding disease pathogenesis. However, the lack of immune cells in organoids limits the use of human AOs as models of inflammatory diseases. In this study, we generated AOs containing a functional macrophage derived from hPSCs based on human fetal lung development using biomimetic strategies. We optimized culture conditions to maintain the iMACs (induced hPSC-derived macrophages) AOs for up to 14 days. In lipopolysaccharide (LPS)-induced inflammatory conditions, IL-1ß, MCP-1 and TNF-α levels were significantly increased in iMAC-AOs, which were not detected in AOs. In addition, chemotactic factor IL-8, which is produced by mononuclear phagocytic cells, was induced by LPS treatment in iMACs-AOs. iMACs-AOs can be used to understand pulmonary infectious diseases and is a useful tool in identifying the mechanism of action of therapeutic drugs in humans. Our study highlights the importance of immune cell presentation in AOs for modeling inflammatory pulmonary diseases.

Olmutinib in T790M-positive non-small cell lung cancer after failure of first-line epidermal growth factor receptor-tyrosine kinase inhibitor therapy: A global, phase 2 study.

BACKGROUND: In this open-label, international phase 2 study, the authors assessed the efficacy and safety of olmutinib in patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) who had a confirmed T790M mutation and disease progression on previous epidermal growth factor receptor-tyrosine kinase inhibitor therapy. METHODS: Patients aged ≥20 years received once-daily oral olmutinib 800 mg continuously in 21-day cycles. The primary endpoint was the objective response rate (patients who had a confirmed best overall response of a complete or partial response), assessed by central review. Secondary endpoints included the disease control rate, the duration of objective response, progression-free survival, and overall survival. Adverse events were graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (version 4.03). RESULTS: Overall, 162 patients (median age, 63 years; women, >60%) were enrolled from 68 sites in 9 countries. At the time of database cutoff, 23.5% of enrolled patients remained on treatment. The median treatment duration was 6.5 months (range, 0.03-21.68 months). Overall, 46.3% of patients (95% CI, 38.4%-54.3%) had a confirmed objective response (all partial responses). The best overall response (the objective response rate regardless of confirmation) was 51.9% (84 patients; 95% CI, 43.9%-59.8%). The confirmed disease control rate for all patients was 86.4% (95% CI, 80.2%-91.3%). The median duration of objective response was 12.7 months (95% CI, 8.3-15.4 months). Estimated median progression-free survival was 9.4 months (95% CI, 6.9-12.3 months), and estimated median overall survival was 19.7 months (95% CI, 15.1 months to not reached). All patients experienced treatment-emergent adverse events, and 71.6% of patients had grade ≥3 treatment-emergent adverse events. CONCLUSIONS: Olmutinib has meaningful clinical activity and a manageable safety profile in patients with T790M-positive non-small cell lung cancer who received previous epidermal growth factor receptor-tyrosine kinase inhibitor therapy.

Early-stage Parkinson's disease: Abnormal nigrosome 1 and 2 revealed by a voxelwise analysis of neuromelanin-sensitive MRI.

Previous pathologic studies evaluated the substantia nigra pars compacta (SNpc) of a limited number of idiopathic Parkinson's disease (IPD) patients with relatively longer disease durations. Therefore, it remains unknown which region of the SNpc is most significantly affected in early-stage IPD. We hypothesized that a voxelwise analysis of thin-section neuromelanin-sensitive MRI (NM-MRI) may help determine the significantly affected regions of the SNpc in early-stage IPD and localize these areas in each nigrosome on high-spatial-resolution susceptibility map-weighted imaging (SMwI). Ninety-six healthy subjects and 50 early-stage IPD patients underwent both a 0.8 × 0.8 × 0.8 mm3 NM-MRI and a 0.5 × 0.5 × 1.0 mm3 multi-echo gradient-recalled echo imaging for SMwI. Both NM-MRI and SMwI templates were created by using image data from the 96 healthy subjects. Permutation-based nonparametric tests were conducted to investigate spatial differences between the two groups in NM-MRI, and the results were displayed on both NM-MRI and SMwI templates. The posterolateral and anteromedial regions of the SNpc in NM-MRI were significantly different between the two groups, corresponding to the nigrosome 1 and nigrosome 2 regions, respectively, on the SMwI template. There were the areas of significant spatial difference in the hypointense SN on SMwI between early-stage IPD patients and healthy subjects. These areas on SMwI were slightly greater than those on NM-MRI, including the areas showing group difference on NM-MRI. Our voxelwise analysis of NM-MRI suggests that two regions (nigrosome 1 and nigrosome 2) of the SNpc are separately affected in early-stage IPD.

Voxel-wise partial volume correction method for accurate estimation of tissue sodium concentration in 23 Na-MRI at 7 T.

Sodium is crucial for the maintenance of cell physiology, and its regulation of the sodium-potassium pump has implications for various neurological conditions. The distribution of sodium concentrations in tissue can be quantitatively evaluated by means of sodium MRI (23 Na-MRI). Despite its usefulness in diagnosing particular disease conditions, tissue sodium concentration (TSC) estimated from 23 Na-MRI can be strongly biased by partial volume effects (PVEs) that are induced by broad point spread functions (PSFs) as well as tissue fraction effects. In this work, we aimed to propose a robust voxel-wise partial volume correction (PVC) method for 23 Na-MRI. The method is based on a linear regression (LR) approach to correct for tissue fraction effects, but it utilizes a 3D kernel combined with a modified least trimmed square (3D-mLTS) method in order to minimize regression-induced inherent smoothing effects. We acquired 23 Na-MRI data with conventional Cartesian sampling at 7 T, and spill-over effects due to the PSF were considered prior to correcting for tissue fraction effects using 3D-mLTS. In the simulation, we found that the TSCs of gray matter (GM) and white matter (WM) were underestimated by 20% and 11% respectively without correcting tissue fraction effects, but the differences between ground truth and PVE-corrected data after the PVC using the 3D-mLTS method were only approximately 0.6% and 0.4% for GM and WM, respectively. The capability of the 3D-mLTS method was further demonstrated with in vivo 23 Na-MRI data, showing significantly lower regression errors (ie root mean squared error) as compared with conventional LR methods (p < 0.001). The results of simulation and in vivo experiments revealed that 3D-mLTS is superior for determining under- or overestimated TSCs while preserving anatomical details. This suggests that the 3D-mLTS method is well suited for the accurate determination of TSC, especially in small focal lesions associated with pathological conditions.