Dendrite intercalation between epidermal cells tunes nociceptor sensitivity to mechanical stimuli in Drosophila larvae.

An animal's skin provides a first point of contact with the sensory environment, including noxious cues that elicit protective behavioral responses. Nociceptive somatosensory neurons densely innervate and intimately interact with epidermal cells to receive these cues, however the mechanisms by which epidermal interactions shape processing of noxious inputs is still poorly understood. Here, we identify a role for dendrite intercalation between epidermal cells in tuning sensitivity of Drosophila larvae to noxious mechanical stimuli. In wild-type larvae, dendrites of nociceptive class IV da neurons intercalate between epidermal cells at apodemes, which function as body wall muscle attachment sites, but not at other sites in the epidermis. From a genetic screen we identified miR-14 as a regulator of dendrite positioning in the epidermis: miR-14 is expressed broadly in the epidermis but not in apodemes, and miR-14 inactivation leads to excessive apical dendrite intercalation between epidermal cells. We found that miR-14 regulates expression and distribution of the epidermal Innexins ogre and Inx2 and that these epidermal gap junction proteins restrict epidermal dendrite intercalation. Finally, we found that altering the extent of epidermal dendrite intercalation had corresponding effects on nociception: increasing epidermal intercalation sensitized larvae to noxious mechanical inputs and increased mechanically evoked calcium responses in nociceptive neurons, whereas reducing epidermal dendrite intercalation had the opposite effects. Altogether, these studies identify epidermal dendrite intercalation as a mechanism for mechanical coupling of nociceptive neurons to the epidermis, with nociceptive sensitivity tuned by the extent of intercalation.

Paracrine signalling by pancreatic δ cells determines the glycaemic set point in mice.

While pancreatic ß and α cells are considered the main drivers of blood glucose homeostasis through insulin and glucagon secretion, the contribution of δ cells and somatostatin (SST) secretion to glucose homeostasis remains unresolved. Here we provide a quantitative assessment of the physiological contribution of δ cells to the glycaemic set point in mice. Employing three orthogonal mouse models to remove SST signalling within the pancreas or transplanted islets, we demonstrate that ablating δ cells or SST leads to a sustained decrease in the glycaemic set point. This reduction coincides with a decreased glucose threshold for insulin response from ß cells, leading to increased insulin secretion to the same glucose challenge. Our data demonstrate that ß cells are sufficient to maintain stable glycaemia and reveal that the physiological role of δ cells is to provide tonic feedback inhibition that reduces the ß cell glucose threshold and consequently lowers the glycaemic set point in vivo.

Dendrite intercalation between epidermal cells tunes nociceptor sensitivity to mechanical stimuli in Drosophila larvae.

An animal's skin provides a first point of contact with the sensory environment, including noxious cues that elicit protective behavioral responses. Nociceptive somatosensory neurons densely innervate and intimately interact with epidermal cells to receive these cues, however the mechanisms by which epidermal interactions shape processing of noxious inputs is still poorly understood. Here, we identify a role for dendrite intercalation between epidermal cells in tuning sensitivity of Drosophila larvae to noxious mechanical stimuli. In wild-type larvae, dendrites of nociceptive class IV da neurons intercalate between epidermal cells at apodemes, which function as body wall muscle attachment sites, but not at other sites in the epidermis. From a genetic screen we identified miR-14 as a regulator of dendrite positioning in the epidermis: miR-14 is expressed broadly in the epidermis but not in apodemes, and miR-14 inactivation leads to excessive apical dendrite intercalation between epidermal cells. We found that miR-14 regulates expression and distribution of the epidermal Innexins ogre and Inx2 and that these epidermal gap junction proteins restrict epidermal dendrite intercalation. Finally, we found that altering the extent of epidermal dendrite intercalation had corresponding effects on nociception: increasing epidermal intercalation sensitized larvae to noxious mechanical inputs and increased mechanically evoked calcium responses in nociceptive neurons, whereas reducing epidermal dendrite intercalation had the opposite effects. Altogether, these studies identify epidermal dendrite intercalation as a mechanism for mechanical coupling of nociceptive neurons to the epidermis, with nociceptive sensitivity tuned by the extent of intercalation.

Age-Friendly Ecosystems: Expert Voices from the Field.

(1) Background: With the growth of the age-friendly movement, age-friendly ecosystems (AFE) garnered more attention. The successful development of an AFE is contingent on unified efforts across different stakeholders; however, limited efforts were made to help create a common understanding of the necessary components of an AFE. (2) Methodology: In response, The John A. Hartford Foundation and The Age-Friendly Institute hosted a series of convenings of international experts to identify a working definition of the characteristics composing an AFE. The goal of these convenings was to provide a foundation on which to unite cross-sector age-friendly work. (3) Results: This paper discussed the findings of the convenings and provided a framework from which future age-friendly work must draw upon. (4) Conclusions: This paper presented a necessary change in how we conceive AFEs.

AgRP neurons are not indispensable for body weight maintenance in adult mice.

In addition to their role in promoting feeding and obesity development, hypothalamic arcuate agouti-related protein/neuropeptide Y (AgRP/NPY) neurons are widely perceived to be indispensable for maintaining normal feeding and body weight in adults, and consistently, acute inhibition of AgRP neurons is known to reduce short-term food intake. Here, we adopted complementary methods to achieve nearly complete ablation of arcuate AgRP/NPY neurons in adult mice and report that lesioning arcuate AgRP/NPY neurons in adult mice causes no apparent alterations in ad libitum feeding or body weight. Consistent with previous studies, loss of AgRP/NPY neurons blunts fasting refeeding. Thus, our studies show that AgRP/NPY neurons are not required for maintaining ad libitum feeding or body weight homeostasis in adult mice.

SARS-COV-2 viroporins activate the NLRP3-inflammasome by the mitochondrial permeability transition pore.

Background: Compared to healthy controls, severe COVID19 patients display increased levels of activated NLRP3-inflammasome (NLRP3-I) and interleukin (IL)-1ß. SARS-CoV-2 encodes viroporin proteins E and Orf3a(2-E+2-3a) with homologs to SARS-CoV-1, 1-E+1-3a, which elevate NLRP3-I activation; by an unknown mechanism. Thus, we investigated how 2-E+2-3a activates the NLRP3-I to better understand the pathophysiology of severe COVID-19. Methods: We generated a polycistronic expression-vector co-expressing 2-E+2-3a from a single transcript. To elucidate how 2-E+2-3a activates the NLRP3-I, we reconstituted the NLRP3-I in 293T cells and used THP1-derived macrophages to monitor the secretion of mature IL-1ß. Mitochondrial physiology was assessed using fluorescent microscopy and plate reader assays, and the release of mitochondrial DNA (mtDNA) was detected from cytosolic-enriched fractions using Real-Time PCR. Results: Expression of 2-E+2-3a in 293T cells increased cytosolic Ca++ and elevated mitochondrial Ca++, taken up through the MCUi11-sensitive mitochondrial calcium uniporter. Increased mitochondrial Ca++ stimulated NADH, mitochondrial reactive oxygen species (mROS) production and the release of mtDNA into the cytosol. Expression of 2-E+2-3a in NLRP3-I reconstituted 293T cells and THP1-derived macrophages displayed increased secretion of IL-1ß. Increasing mitochondrial antioxidant defenses via treatment with MnTBAP or genetic expression of mCAT abolished 2-E+2-3a elevation of mROS, cytosolic mtDNA levels, and secretion of NLRP3-activated-IL-1ß. The 2-E+2-3a-induced release of mtDNA and the secretion of NLRP3-activated-IL-1ß were absent in cells lacking mtDNA and blocked in cells treated with the mitochondrial-permeability-pore(mtPTP)-specific inhibitor NIM811. Conclusion: Our findings revealed that mROS activates the release of mitochondrial DNA via the NIM811-sensitive mitochondrial-permeability-pore(mtPTP), activating the inflammasome. Hence, interventions targeting mROS and the mtPTP may mitigate the severity of COVID-19 cytokine storms.

A novel approach for Venezia ovoid commissioning with a comprehensive analysis of source positions in high-dose-rate brachytherapy.

PURPOSE: The lunar design of a Venezia ovoid makes commissioning of the applicator very challenging with traditional autoradiography. In this study, we propose a novel solution to ovoid commissioning and a quality assurance (QA) workflow to effectively assess the entire source path. METHODS AND MATERIALS: A two-step commissioning process, using electron radiation and radiochromic films, was developed to verify the most distal source position. The ovoid was first attached to a film and was irradiated with a 12 MeV linac beam. This process was repeated on a separate, unexposed film, followed by irradiating it with a HDR source at the most distal position. Two lengths, including the ovoid thickness and the distance between the irradiated spot and the ovoid's outer surface, were obtained from the films' intensity maps. The offset value was calculated from the subtraction of the two measured lengths. Besides acquiring the offset, a source positional simulator (SPS) and a series of planar x-rays from two orthogonal orientations were used to characterize source movement within the ovoid. RESULTS: Compared to x-ray-based autoradiography, the electron exposure significantly improved the ovoid's visibility on film. Our approach did not use surrogate, which further improved measurement outcomes by decreasing inherent uncertainties. The SPS results suggested the source movement was complex within the cervicovaginal area, but it was predictable with the proposed QA workflow. CONCLUSION: We introduced a novel, surrogate-free method to commission the Venezia ovoid, which facilitated a manual applicator reconstruction. Additionally, we recommended QA multiple source positions to safely use the ovoid in clinical settings.

Combination of common mtDNA variants results in mitochondrial dysfunction and a connective tissue dysregulation.

Mitochondrial dysfunction can be associated with a range of clinical manifestations. Here, we report a family with a complex phenotype including combinations of connective tissue, neurological, and metabolic symptoms that were passed on to all surviving children. Analysis of the maternally inherited mtDNA revealed a novel genotype encompassing the haplogroup J - defining mitochondrial DNA (mtDNA) ND5 m.13708G>A (A458T) variant arising on the mtDNA haplogroup H7A background, an extremely rare combination. Analysis of transmitochondrial cybrids with the 13708A-H7 mtDNA revealed a lower mitochondrial respiration, increased reactive oxygen species production (mROS), and dysregulation of connective tissue gene expression. The mitochondrial dysfunction was exacerbated by histamine, explaining why all eight surviving children inherited the dysfunctional histidine decarboxylase allele (W327X) from the father. Thus, certain combinations of common mtDNA variants can cause mitochondrial dysfunction, mitochondrial dysfunction can affect extracellular matrix gene expression, and histamine-activated mROS production can augment the severity of mitochondrial dysfunction. Most important, we have identified a previously unreported genetic cause of mitochondrial disorder arising from the incompatibility of common, nonpathogenic mtDNA variants.

Surface-Guided Patient Setup Versus Traditional Tattoo Markers for Radiation Therapy: Is Tattoo-Less Setup Feasible for Thorax, Abdomen and Pelvis Treatment?

PURPOSE: In this study, patient setup accuracy was compared between surface guidance and tattoo markers for radiation therapy treatment sites of the thorax, abdomen and pelvis. METHODS AND MATERIALS: A total of 608 setups performed on 59 patients using both surface-guided and tattoo-based patient setups were analyzed. During treatment setup, patients were aligned to room lasers using their tattoos, and then the six-degree-of-freedom (6DOF) surface-guided offsets were calculated and recorded using AlignRT system. While the patient remained in the same post-tattoo setup position, target localization imaging (radiographic or ultrasound) was performed and these image-guided shifts were recorded. Finally, surface-guided vs tattoo-based offsets were compared to the final treatment position (based on radiographic or ultrasound imaging) to evaluate the accuracy of the two setup methods. RESULTS: The overall average offsets of tattoo-based and surface-guidance-based patient setups were comparable within 3.2 mm in three principal directions, with offsets from tattoo-based setups being slightly less. The maximum offset for tattoo setups was 2.2 cm vs. 4.3 cm for surface-guidance setups. Larger offsets (ranging from 2.0 to 4.3 cm) were observed for surface-guided setups in 14/608 setups (2.3%). For these same cases, the maximum observed tattoo-based offset was 0.7 cm. Of the cases with larger surface-guided offsets, 13/14 were for abdominal/pelvic treatment sites. Additionally, larger rotations (>3°) were recorded in 18.6% of surface-guided setups. The majority of these larger rotations were observed for abdominal and pelvic sites (~84%). CONCLUSIONS: The small average differences observed between tattoo-based and surface-guidance-based patient setups confirm the general equivalence of the two potential methods, and the feasibility of tattoo-less patient setup. However, a significant number of larger surface-guided offsets (translational and rotational) were observed, especially in the abdominal and pelvic regions. These cases should be anticipated and contingency setup methods planned for.

Nicotinamide riboside alleviates exercise intolerance in ANT1-deficient mice.

OBJECTIVE: Mitochondrial disorders are often characterized by muscle weakness and fatigue. Null mutations in the heart-muscle adenine nucleotide translocator isoform 1 (ANT1) of both humans and mice cause cardiomyopathy and myopathy associated with exercise intolerance and muscle weakness. Here we decipher the molecular underpinnings of ANT1-deficiency-mediated exercise intolerance. METHODS: This was achieved by correlating exercise physiology, mitochondrial function and metabolomics of mice deficient in ANT1 and comparing this to control mice. RESULTS: We demonstrate a peripheral limitation of skeletal muscle mitochondrial respiration and a reduced complex I respiration in ANT1-deficient mice. Upon exercise, this results in a lack of NAD+ leading to a substrate limitation and stalling of the TCA cycle and mitochondrial respiration, further limiting skeletal muscle mitochondrial respiration. Treatment of ANT1-deficient mice with nicotinamide riboside increased NAD+ levels in skeletal muscle and liver, which increased the exercise capacity and the mitochondrial respiration. CONCLUSION: Increasing NAD+ levels with nicotinamide riboside can alleviate the exercise intolerance associated to ANT1-deficiency, indicating the therapeutic potential of NAD+-stimulating compounds in mitochondrial myopathies.

2.2 Å Cryo-EM Tetra-Protofilament Structure of the Hamster Prion 108-144 Fibril Reveals an Ordered Water Channel in the Center.

Fibrils of the hamster prion peptide (sHaPrP, sequence 108-144) were prepared in an acidic solution, and their structure was solved by cryogenic electron microscopy with a resolution of 2.23 Å based on the gold-standard Fourier shell correlation (FSC) curve. The fibril has a novel architecture that has never been found in other amyloid fibrils. Each fibril is assembled by four protofilaments (PFs) and has an ordered water channel in the center. Each protofilament contains three ß-strands (125-130, 133-135, and 138-141) arranged in an "R"-shaped construct. The structural data indicate that these three ß-strand segments are the most amyloidogenic region of the prion peptide/protein and might be the site of nucleation during fibrillization under conditions without denaturants.

Risk factors for labor epidural conversion failure requiring general anesthesia for cesarean delivery.

Background and Aims: To evaluate the rate and risk factors of labor epidural conversion failure requiring general anesthesia for Caesarean delivery (CD). Material and Methods: Pregnant patients requiring conversion from labor to CD with a pre-existing labor epidural at our institution from 2009 to 2014 were identified. Through a retrospective review, we compared successful epidural conversion with those who required general anesthesia for CD. Patient characteristics were analyzed to identify risk factors for failed epidural conversion for CD. Results: A total of 673 patients were included in the study. The rate of epidural conversion failure was 21%. Main risk factors for epidural conversion failure requiring general anesthesia included: younger maternal age (95% CI 0.94, P = 0.0002) and supplementation of intravenous fentanyl (95% CI 0.19, P < 0.0001) or midazolam (95% CI 0.26, P = 0.0008) during CD. A higher risk of conversion failure was also associated with a more urgent CD (CD category 1, 2, and 3 vs category 4). Conclusion: Consistent with previous reports, young age and the urgency of CD increases the likelihood of epidural conversion failure. While conversion failure is likely multifactorial and complex, many of these factors are suggestive of inadequate and poorly functioning labor epidurals prior to CD. Prospective studies to further evaluate these factors are necessary, and the best prevention of epidural conversion failure is diligent diagnosis and evaluation of ineffective labor epidural analgesia prior to impending CD.

Telemedicine and artificial intelligence to support self-isolation of COVID-19 patients: Recent updates and challenges.

Background: Asymptomatic and high-risk COVID-19 patients are advised to self-isolate at home. However, patients may not realize that the condition is deteriorating until too late. Objective: This study aims to review various artificial intelligence-based telemedicine research during the COVID-19 outbreak and proposes a framework for developing telemedicine powered by artificial intelligence to monitor progression in COVID-19 patients during isolation at home. It also aims to map challenges using artificial intelligence-based telemedicine in the community. Methods: A systematic review was performed for the related articles published in 2019-2021 and conducted in the PubMed and ScienceDirect database using the keywords "telemedicine," "artificial intelligence," and "COVID-19". The inclusion criteria were full-text articles and original research written in the English language. Results: Thirteen articles were included in this review to describe the current application of artificial intelligence-based telemedicine during the COVID-19 pandemic. Various current applications have been implemented, such as for early diagnosis and tracing of contact for the users, to monitor symptoms and decision-making treatment, clinical management, and virtual and remote treatment. We also proposed the framework of telemedicine powered by artificial intelligence for support the self-isolation of COVID-19 patients based on the recent update in technology. However, we identified some challenges for using digital health technologies because of the ethical and practical use, the policy and regulation, and device use both for healthcare workers and patients. Conclusion: Artificial intelligence promises to improve the practice of medicine in various ways. However, practical applications still need to be explored, and medical professionals also need to adapt to these advances for better healthcare delivery to the public.

Structure-to-process design framework for developing safer pesticides.

Rational design of pesticides with tunable degradation properties and minimal ecotoxicity is among the grand challenges of green chemistry. While computational approaches have gained traction in predictive toxicology, current methods lack the necessary multifaceted approach and design-vectoring tools needed for system-based chemical development. Here, we report a tiered computational framework, which integrates kinetics and thermodynamics of indirect photodegradation with predictions of ecotoxicity and performance, based on cutoff values in mechanistically derived physicochemical properties and electronic parameters. Extensively validated against experimental data and applied to 700 pesticides on the U.S. Environmental Protection Agency's registry, our simple yet powerful approach can be used to screen existing molecules to identify application-ready candidates with desirable characteristics. By linking structural attributes to process-based outcomes and by quantifying trade-offs in safety, depletion, and performance, our method offers a user-friendly roadmap to rational design of novel pesticides.

Subpalpebral Antibiotic Lavage as Safe, Emergent, and Cost-Effective Management of Acute Infectious Keratitis Related to Contact Lens Overwear: Case Report and Literature Review.

PURPOSE: The aim of this study is to describe the technique of subpalpebral antibiotic lavage (SAL), which is a highly therapeutic, efficient, and cost-effective method for managing severe bacterial keratitis. METHODS: This case report describes a 26-year-old woman with severe bacterial keratitis in the right eye due to contact lens overwear, with progressive corneal thinning, a hypopyon, impending perforation, and marked visual loss to perception of light despite treatment with intensive topical antibiotics. This was managed with SAL that involves the insertion of a cannula transcutaneously into the upper conjunctival fornix to provide continuous antibiotic irrigation of the ocular surface. RESULTS: By 11 weeks after presentation, the cornea and anterior chamber appeared clinically quiescent, and visual acuity improved to 20/40 corrected in the right eye. CONCLUSIONS: Bacterial keratitis is a potentially blinding condition for which contact lens wear is an important risk factor. Most cases are successfully managed with topical medications; however, in cases of treatment failure, a second-line approach such as SAL can be sight-saving. SAL uses readily available equipment for the delivery of high concentrations of antibiotics to the ocular surface, thus increasing therapeutic efficacy and reducing nursing staff workload. Despite its advantages, the literature reveals apparent underutilization of this technique.

Information flow in the spatiotemporal organization of immune responses.

Immune responses must be rapid, tightly orchestrated, and tailored to the encountered stimulus. Lymphatic vessels facilitate this process by continuously collecting immunological information (ie, antigens, immune cells, and soluble mediators) about the current state of peripheral tissues, and transporting these via the lymph across the lymphatic system. Lymph nodes (LNs), which are critical meeting points for innate and adaptive immune cells, are strategically located along the lymphatic network to intercept this information. Within LNs, immune cells are spatially organized, allowing them to efficiently respond to information delivered by the lymph, and to either promote immune homeostasis or mount protective immune responses. These responses involve the activation and functional cooperation of multiple distinct cell types and are tailored to the specific inflammatory conditions. The natural patterns of lymph flow can also generate spatial gradients of antigens and agonists within draining LNs, which can in turn further regulate innate cell function and localization, as well as the downstream generation of adaptive immunity. In this review, we explore how information transmitted by the lymph shapes the spatiotemporal organization of innate and adaptive immune responses in LNs, with particular focus on steady state and Type-I vs. Type-II inflammation.

A simple test-based frailty index to predict survival among cancer patients with an unplanned hospitalization: An observational cohort study.

BACKGROUND: Frailty is a state of increased vulnerability to stressors, and predicts risk of adverse outcomes, such as mortality. Frailty can be defined by a frailty index (FI) using an accumulation of deficits approach. An FI comprised of 20 items derived from our previously studied test-based frailty index (TBFI) and an additional 33 survey-based elements sourced from the standard CGA was developed to evaluate if predictive validity of survival was improved. METHODS: One hundred eighty-nine cancer patients during acute hospitalization were consented between September 2018 and May 2019. Frailty scores were calculated, and patients were categorized into four groups: non-frail (0-0.2), mildly frail (0.2-0.3), moderately frail (0.3-0.4), and severely frail (>0.4). Patients were followed for 1-year to assess FI and TBFI prediction of survival. Area under the curve (AUC) statistics from ROC analyses were compared for the FI versus TBFI. RESULTS: Increasing frailty was similarly associated with increased risk of mortality (HR, 4.5 [95% CI, 2.519-8.075] and HR, 4.1 [95%CI, 1.692-9.942]) and the likelihood of death at 6 months was about 11-fold (odds ratio, 10.9 [95% CI, 3.97-33.24]) and 9.73-fold (95% CI, 2.85-38.50) higher for severely frail patients compared to non-frail patients for FI and TBFI, respectively. This association was independent of age and type of cancer. The FI and TBFI were predictive of survival for older and younger cancer patients with no significant differences between models in discriminating survival (FI AUC, 0.747 [95% CI, 0.6772-0.8157] and TBFI AUC, 0.724 [95% CI, 0.6513-0.7957]). CONCLUSIONS: The TBFI was predictive of survival, and the addition of an in-person assessment (FI) did not greatly improve predictive validity. Increasing frailty, as measured by a TBFI, resulted in a meaningfully increased risk of mortality and may be well-suited for screening of hospitalized cancer patients.