Structure-guided mutagenesis of OSCAs reveals differential activation to mechanical stimuli.

The dimeric two-pore OSCA/TMEM63 family has recently been identified as mechanically activated ion channels. Previously, based on the unique features of the structure of OSCA1.2, we postulated the potential involvement of several structural elements in sensing membrane tension (Jojoa-Cruz et al., 2018). Interestingly, while OSCA1, 2, and 3 clades are activated by membrane stretch in cell-attached patches (i.e. they are stretch-activated channels), they differ in their ability to transduce membrane deformation induced by a blunt probe (poking). Here, in an effort to understand the domains contributing to mechanical signal transduction, we used cryo-electron microscopy to solve the structure of Arabidopsis thaliana (At) OSCA3.1, which, unlike AtOSCA1.2, only produced stretch- but not poke-activated currents in our initial characterization (Murthy et al., 2018). Mutagenesis and electrophysiological assessment of conserved and divergent putative mechanosensitive features of OSCA1.2 reveal a selective disruption of the macroscopic currents elicited by poking without considerable effects on stretch-activated currents (SAC). Our results support the involvement of the amphipathic helix and lipid-interacting residues in the membrane fenestration in the response to poking. Our findings position these two structural elements as potential sources of functional diversity within the family.

Microencapsulation and controlled release of Bacillus clausii through a novel non-digestible carbohydrate formulation as revolutionizing probiotic delivery.

Probiotics have gained significant attention in recent years due to the growing awareness of physical health and well-being. However, maintaining high concentrations of probiotics throughout the product's shelf life and during the gastrointestinal tract is crucial for ensuring their health-promoting effects. After determining an optimal formulation through a fractional factorial model, this study optimizes probiotic Bacillus Clausii delivery through spray-drying microencapsulation using a novel maltodextrin-alginate-inulin (MDX-ALG-IN) formulation (optimized ratio: 7:2:1). Notably, this formulation exclusively comprises non-digestible carbohydrates, marking a novel approach in probiotic encapsulation. Achieving a high Product Yield (51.06 %) and Encapsulation Efficiency (80.53 %), the study employed SEM for morphological analysis, revealing an irregular form and extensive surface in dentations characteristic of maltodextrin involvement. With a low moisture content of 3.02 % (±0.23 %) and 90.52 % solubility, the powder displayed exceptional properties. Probiotic viability remained robust, surviving up to 60 % even after 180 days at 4 °C, 25 °C, and 37 °C. Thermal characterization unveiled microcapsule resilience, exhibiting a glass transition temperature (Tg) at 138.61 °C and a melting point of 177.28 °C. The study systematically addresses crucial aspects of microencapsulation, including formulation optimization, morphological characteristics, and powder properties. Notably, the MDX-ALG-IN microcapsules demonstrated stability in simulated gastrointestinal conditions, indicating potential application for supplements and complex food matrices. In summary, this research contributes to microencapsulation understanding, emphasizing the MDX-ALG-IN formulation's efficacy in preserving probiotic viability across production stages and simulated digestive processes.

Structure-guided mutagenesis of OSCAs reveals differential activation to mechanical stimuli.

The dimeric two-pore OSCA/TMEM63 family has recently been identified as mechanically activated ion channels. Previously, based on the unique features of the structure of OSCA1.2, we postulated the potential involvement of several structural elements in sensing membrane tension1. Interestingly, while OSCA1, 2, and 3 clades are activated by membrane stretch in cell-attached patches (i.e., they are stretch-activated channels), they differ in their ability to transduce membrane deformation induced by a blunt probe (poking). In an effort to understand the domains contributing to mechanical signal transduction, we used cryo-electron microscopy to solve the structure of Arabidopsis thaliana (At) OSCA3.1, which, unlike AtOSCA1.2, only produced stretch- but not poke-activated currents in our initial characterization2. Mutagenesis and electrophysiological assessment of conserved and divergent putative mechanosensitive features of OSCA1.2 reveal a selective disruption of the macroscopic currents elicited by poking without considerable effects on stretch-activated currents (SAC). Our results support the involvement of the amphipathic helix and lipid-interacting residues in the membrane fenestration in the response to poking. Our findings position these two structural elements as potential sources of functional diversity within the family.

Structure of mechanically activated ion channel OSCA2.3 reveals mobile elements in the transmembrane domain.

Members of the OSCA/TMEM63 family are mechanically activated ion channels and structures of some OSCA members have revealed the architecture of these channels and structural features that are potentially involved in mechanosensation. However, these structures are all in a similar state and information about the motion of different elements of the structure is limited, preventing a deeper understanding of how these channels work. Here, we used cryoelectron microscopy to determine high-resolution structures of Arabidopsis thaliana OSCA1.2 and OSCA2.3 in peptidiscs. The structure of OSCA1.2 matches previous structures of the same protein in different environments. Yet, in OSCA2.3, the TM6a-TM7 linker adopts a different conformation that constricts the pore on its cytoplasmic side. Furthermore, coevolutionary sequence analysis uncovered a conserved interaction between the TM6a-TM7 linker and the beam-like domain (BLD). Our results reveal conformational heterogeneity and differences in conserved interactions between the TMD and BLD among members of the OSCA family.

Nano-biomaterials and advanced fabrication techniques for engineering skeletal muscle tissue constructs in regenerative medicine.

Engineered three-dimensional (3D) tissue constructs have emerged as a promising solution for regenerating damaged muscle tissue resulting from traumatic or surgical events. 3D architecture and function of the muscle tissue constructs can be customized by selecting types of biomaterials and cells that can be engineered with desired shapes and sizes through various nano- and micro-fabrication techniques. Despite significant progress in this field, further research is needed to improve, in terms of biomaterials properties and fabrication techniques, the resemblance of function and complex architecture of engineered constructs to native muscle tissues, potentially enhancing muscle tissue regeneration and restoring muscle function. In this review, we discuss the latest trends in using nano-biomaterials and advanced nano-/micro-fabrication techniques for creating 3D muscle tissue constructs and their regeneration ability. Current challenges and potential solutions are highlighted, and we discuss the implications and opportunities of a future perspective in the field, including the possibility for creating personalized and biomanufacturable platforms.

Structure of mechanically activated ion channel OSCA2.3 reveals mobile elements in the transmembrane domain.

Members of the OSCA/TMEM63 are mechanically activated ion channels and structures of some OSCA members have revealed the architecture of these channels and structural features that are potentially involved in mechanosensation. However, these structures are all in a similar state and information about the motion of different elements of the structure is limited, preventing a deeper understanding of how these channels work. Here, we used cryo-electron microscopy to determine high resolution structures of Arabidopsis thaliana OSCA1.2 and OSCA2.3 in peptidiscs. The structure of OSCA1.2 resembles previous structures of the same protein in different environments. Yet, in OSCA2.3 the TM6a-TM7 linker constricts the pore on its cytoplasmic side, revealing conformational heterogeneity within the OSCA family. Furthermore, coevolutionary sequence analysis uncovered a conserved interaction between TM6a-TM7 linker and the Beam-Like Domain. Our results support the involvement of TM6a-TM7 in mechanosensation and potentially in the diverse response of OSCA channels to mechanical stimuli.

Targeting Inflammation in Acne: Current Treatments and Future Prospects.

Acne is a common, chronic inflammatory condition affecting millions of people worldwide, with significant negative impact on quality of life and mental health. Acne is characterized by comedones, inflammatory papules, pustules, and nodulocystic lesions, with long-lasting sequelae including scarring and dyspigmentation, the latter of which is more common in skin of color. The four main pillars of acne pathophysiology include alteration of sebum production and concentration, hyperkeratinization of the follicular unit, Cutibacterium acnes strains, and an inflammatory immune response. Newer research has provided greater insight into these pathophysiologic categories. This greater understanding of acne pathogenesis has led to numerous new and emerging treatment modalities. These modalities include combinations of existing treatments, repurposing of existing agents historically used for other conditions, new topical treatments, novel antibiotics, topical and oral probiotics, and various procedural devices. This article will provide an overview of emerging treatments of acne and their link to our current and improved understanding of acne pathogenesis.

The psychosocial impacts of vitiligo, psoriasis, and alopecia areata on pediatric patients.

Children and adolescents with chronic cutaneous conditions are at risk of experiencing adverse psychosocial effects such as anxiety, depression, and loneliness. The well-being of these children's families may also be impacted by their child's condition. It is important for the quality of life of patients and their families to better understand the psychosocial impact caused by pediatric dermatologic conditions and interventions that help mitigate these effects. This review summarizes the psychological impact of the common pediatric dermatological disorders, vitiligo, psoriasis, and alopecia areata, on children and their caregivers. Studies examining quality of life, psychiatric conditions, and other measures of psychosocial impact in children and caregivers, as well as those evaluating the effectiveness of interventions aimed at addressing psychosocial effects, were included. This review highlights the increased risk that children with these conditions have in experiencing adverse psychosocial effects including quality of life impairment, psychological pathology, and social stigmatization. In addition, the specific risk factors within this population that are associated with increased negative effect such as age and severity of disease are discussed. This review demonstrates a need for increased support of these patients and their families and additional research on the effectiveness of current interventions.

The Impact of Neighborhood Disadvantage on Asthma Prevalence in a Predominantly African-American, Chicago-Based Cohort.

This study aimed to investigate the joint effect of neighborhood disadvantages on asthma prevalence and evaluate whether individual-level variables protect residents against neighborhood disadvantages. Data from the Chicago Multiethnic Prevention and Surveillance Study (from 2013-2020) were analyzed. Eight neighborhood characteristics were measured using the Chicago Health Atlas, including neighborhood unsafety, limited access to healthy food, neighborhood alienation, severe rent burden, vacant housing, single-parent household, neighborhood poverty, and unemployment. A structured questionnaire measured asthma diagnosis (childhood or adulthood) and individual-level variables including sex, age, income, education, and race. Weighted quantile sum (WQS) regression was used to evaluate the impact of neighborhood disadvantages. Stratified analysis was performed by income and education. A total of 6,592 participants (mean age = 53.5 (standard deviation, 11.1) years) were included. Most of the study population were non-Hispanic Black (82.5%) and reported an annual household income less than $15,000 (53%). Asthma prevalence was 23.6%. The WQS index, which represents the overall neighborhood disadvantages, was associated with asthma prevalence (odds ratio = 1.14, 95% confidence interval: 1.07, 1.22) when adjusted for individual-level confounders. Neighborhood poverty contributed 40.8% to the overall impact, followed by vacant housing (23.1%) and neighborhood alienation (22.9%). When stratified by individual-level income or education, no difference was observed for the association between WQS index and asthma prevalence.

High-precision estimation of emitter positions using Bayesian grouping of localizations.

Single-molecule localization microscopy super-resolution methods rely on stochastic blinking/binding events, which often occur multiple times from each emitter over the course of data acquisition. Typically, the blinking/binding events from each emitter are treated as independent events, without an attempt to assign them to a particular emitter. Here, we describe a Bayesian method of inferring the positions of the tagged molecules by exploring the possible grouping and combination of localizations from multiple blinking/binding events. The results are position estimates of the tagged molecules that have improved localization precision and facilitate nanoscale structural insights. The Bayesian framework uses the localization precisions to learn the statistical distribution of the number of blinking/binding events per emitter and infer the number and position of emitters. We demonstrate the method on a range of synthetic data with various emitter densities, DNA origami constructs and biological structures using DNA-PAINT and dSTORM data. We show that under some experimental conditions it is possible to achieve sub-nanometer precision.

The Clinical Presentation and Comorbidities Associated with Granuloma Annulare in the Pediatric Population: A Retrospective Study.

Granuloma annulare (GA) is a cutaneous inflammatory disorder of unknown cause, typically characterized by an annular arrangement of dermal papules and nodules. While GA in adults has been linked to diabetes mellitus (DM) and other conditions, these associations have been less studied in children. A retrospective chart review was conducted of all pediatric patients diagnosed with GA at an urban academic institution over a 7-year period. A total of 47 patients were reviewed. Of these, 41 (85.1%) patients had localized GA, 3 (6.38%) had subcutaneous GA, 2 (4.26%) had generalized GA, and 1 (2.13%) had both localized and subcutaneous GA. The extremities were the most common site of involvement across all morphologies. Atopic conditions were determined in 23 (48.9%) patients, 16 (34.0%) of which had asthma, either alone or in conjunction with atopic dermatitis or allergic rhinitis. None of the patients carried a diagnosis of DM, and all 11 patients who were tested within 3 years of the documented visit had normal results. In summary, this retrospective series characterizes the presentation of pediatric GA and highlights a potential association with atopy. An association with DM was not observed.

Structural insights into the Venus flytrap mechanosensitive ion channel Flycatcher1.

Flycatcher1 (FLYC1), a MscS homolog, has recently been identified as a candidate mechanosensitive (MS) ion channel involved in Venus flytrap prey recognition. FLYC1 is a larger protein and its sequence diverges from previously studied MscS homologs, suggesting it has unique structural features that contribute to its function. Here, we characterize FLYC1 by cryo-electron microscopy, molecular dynamics simulations, and electrophysiology. Akin to bacterial MscS and plant MSL1 channels, we find that FLYC1 central core includes side portals in the cytoplasmic cage that regulate ion preference and conduction, by identifying critical residues that modulate channel conductance. Topologically unique cytoplasmic flanking regions can adopt 'up' or 'down' conformations, making the channel asymmetric. Disruption of an up conformation-specific interaction severely delays channel deactivation by 40-fold likely due to stabilization of the channel open state. Our results illustrate novel structural features and likely conformational transitions that regulate mechano-gating of FLYC1.

International fisheries threaten globally endangered sharks in the Eastern Tropical Pacific Ocean: the case of the Fu Yuan Yu Leng 999 reefer vessel seized within the Galápagos Marine Reserve.

Shark fishing, driven by the fin trade, is the primary cause of global shark population declines. Here, we present a case study that exemplifies how industrial fisheries are likely depleting shark populations in the Eastern Tropical Pacific Ocean. In August 2017, the vessel Fu Yuan Yu Leng 999, of Chinese flag, was detained while crossing through the Galápagos Marine Reserve without authorization. This vessel contained 7639 sharks, representing one of the largest seizures recorded to date. Based on a sample of 929 individuals (12%), we found 12 shark species: 9 considered as Vulnerable or higher risk by the IUCN and 8 listed in CITES. Four species showed a higher proportion of immature than mature individuals, whereas size-distribution hints that at least some of the fishing ships associated with the operation may have been using purse-seine gear fishing equipment, which, for some species, goes against international conventions. Our data expose the magnitude of the threat that fishing industries and illegal trade represent to sharks in the Eastern Tropical Pacific Ocean.

Comparison of Horizontal Corneal Diameter Measurements Using Orbscan IIz, OPD Scan III, and IOLMaster 700.

PURPOSE: To compare three automated devices for measuring the horizontal corneal diameter (white to white [WTW]). METHODS: In 65 eyes of 38 patients, the WTW distance was measured independently by three examiners using the following techniques: Orbscan IIz tomography system (Bausch & Lomb), IOLMaster 700 (Carl Zeiss Meditec), and OPD Scan III (NIDEK). We tested for systematic differences in measurements and estimated the limits of agreement (LoA) using linear mixed-effects models. RESULTS: The mean WTW distance was 11.8±0.40 mm with Orbscan IIz, 12.1±0.5 mm with IOLMaster 700 and 12.0±0.4 mm with OPD Scan III. The mean difference between IOLMaster 700 and Orbscan IIz was 0.33 (95% CI, 0.28 to 0.38; P<0.001), between OPD Scan III and Orbscan IIz was 0.24 mm (95% CI, 0.21 to 0.28; P<0.001), and between IOL Master 700 and OPD Scan III was 0.09 (95% CI, 0.05 to 0.12; P<0.001). The 95% LoA for Orbscan IIz versus IOLMaster 700 was -0.69 to 0.03 mm, Orbscan IIz versus OPD Scan III was -0.52 to -0.03 mm, and OPD versus IOLMaster 700 was -0.39 to 0.22 mm. CONCLUSIONS: The data suggest that these devices are not interchangeable for usual clinical practice. Adjustments based on mean differences were not enough to compensate for interinstrument discrepancy in WTW measurements.

Wikipedia: A Medical Student Educational Project to Edit Wikipedia in Preparation for Practicing Evidence-Based Pain Medicine.

OBJECTIVE: Wikipedia is commonly used to acquire information about various medical conditions such as chronic pain. Ideally, better online pain management content could reduce the burden of opioid use disorders. Our goal was to improve the quality of the content available on Wikipedia to make it more accurate and applicable to medical students and the general public while training medical students to practice evidence-based medicine and critically assess their sources of information. METHODS: An elective class in Neuroscience, Pain, and Opioids composed of 10 medical students met biweekly to discuss landmark and practice-changing research articles in the fields of acute pain, chronic pain, and opioid management. The professor chose Wikipedia articles relevant to this course. Three independent viewers analyzed the quality of citations, anecdotal medical content, and content value for both patients and medical professionals. As part of their coursework, students then edited the Wikipedia articles. RESULTS: Although some of the Wikipedia pain topic content (6.7% ± 2.0) was anecdotal, financially biased, or inconsistent with Western Medical Practice content, overall articles included primarily high-quality citations (85.6% ± 3.1). On a 0-5 Likert scale, students felt content would be moderately helpful for both medical students/professionals (3.4 ± 0.2) and laypersons (3.5 ± 0.2). Editing and adding citations was feasible, but novel material was often reverted. CONCLUSION: A significant amount of pain medicine content was relevant and amenable to student editing. Therefore, future use of this tactic could provide a unique opportunity to integrate evidence-based medicine into the medical curriculum and have a direct impact on the widely available medical information. Future refinement in the editorial process may also further improve online information.

Protocolo de desensibilización a nivolumab sin corticoides en una paciente con cáncer renal metastásico / Desensitization protocol to nivolumab without corticosteroid use in a kidney cancer patient

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