ABSTRACT
Over 125 million years of ant-plant interactions have culminated in one of the most intriguing evolutionary outcomes in life history. The myrmecophyte Duroia hirsuta (Rubiaceae) is known for its mutualistic association with the ant Myrmelachista schumanni and several other species, mainly Azteca, in the north-western Amazon. While both ants provide indirect defences to plants, only M. schumanni nests in plant domatia and has the unique behaviour of clearing the surroundings of its host tree from heterospecific plants, potentially increasing resource availability to its host. Using a 12-year survey, we asked how the continuous presence of either only M. schumanni or only Azteca spp. benefits the growth and defence traits of host trees. We found that the continuous presence of M. schumanni improved relative growth rates and leaf shearing resistance of Duroia better than trees with Azteca. However, leaf herbivory, dry matter content, trichome density, and secondary metabolite production were the same in all trees. Survival depended directly on ant association (> 94% of trees died when ants were absent). This study extends our understanding of the long-term effects of strict ant-plant mutualism on host plant traits in the field and reinforces the use of D. hirsuta-M. schumanni as a model system suitable for eco-co-evolutionary research on plant-animal interactions.
Subject(s)
Ants , Myrmecophytes , Plant Leaves , Rubiaceae , Symbiosis , Animals , Ants/physiology , Herbivory , Myrmecophytes/growth & development , Myrmecophytes/physiology , Plant Leaves/growth & development , Rubiaceae/growth & development , Rubiaceae/physiology , Trees/growth & developmentABSTRACT
OBJECTIVE: Molar crown configuration plays an important role in systematics, and functional and comparative morphology. In particular, the number of cusps on primate molars is often used to identify fossil species and infer their phylogenetic relationships. However, this variability deserves renewed consideration as a number of studies now highlight important developmental mechanisms that may be responsible for the presence of molar cusps in some mammalian taxa. Experimental studies of rodent molars suggest that cusps form under a morphodynamic, patterning cascade model of development (PCM) that involve the iterative formation of enamel knots. This model posits that the size, shape and location of the first-forming cusps determines the presence and positioning of later-forming cusps. DESIGN: Here we test whether variation in accessory cusp presence in 13 Macaca fascicularis mandibular second molars (M2s) is consistent with predictions of the PCM. Using micro-CT, we imaged these M2s and employed geometric morphometrics to examine whether shape variation in the enamel-dentine junction (EDJ) correlates with accessory cusp presence. RESULTS: We find that accessory cusp patterning in macaque M2s is broadly consistent with the PCM. Molars with accessory cusps were larger in size and possessed shorter relative cusp heights compared to molars without accessory cusps. Peripheral cusp formation was also associated with more centrally positioned primary cusps, as predicted by the PCM. CONCLUSIONS: While these results demonstrate that a patterning cascade model is broadly appropriate for interpreting cusp variation in Macaca fascicularis molars, it does not explain all manifestations of accessory cusp expression in this sample.
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A crop boom is a sudden, nonlinear and intense expansion of a new crop. Despite their large impacts, boom-bust dynamics are not well understood; booms are largely unpredictable and difficult to steer once they unfold. Based on the striking resemblances between land regime shifts and crop booms, we apply complex systems theory, highlighting the potential for regime shifts, to provide new insights about crop boom dynamics. We analyse qualitative and quantitative data of rubber and banana plantation expansion in two forest frontier regions of northern Laos. We show that preconditions, including previous booms, explain the occurrence (why) of booms, and triggers like policy and market changes explain their timing (when). Yet, the most important features of booms, their intensity and nonlinearity (how), strongly depended on internal self-reinforcing feedbacks. We identify built-in feedbacks (neighbourhood effects and imitation) and emergent feedbacks (land rush) and show that they were social in nature, multi-scale from plot to region and subject to thresholds. We suggest that these are regular features of booms and propose a definition and causal-mechanistic explanation of crop booms, examining the overlap between booms and regime shifts and the role of frontiers. We then identify opportunities for management interventions before, during and after booms.
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The combination of radiotherapy/chemoradiotherapy and immune checkpoint blockade can result in poor outcomes in patients with locally advanced head and neck squamous cell carcinoma (HNSCC). Here, we show that combining ATR inhibition (ATRi) with radiotherapy (RT) increases the frequency of activated NKG2A+PD-1+ T cells in animal models of HNSCC. Compared with the ATRi/RT treatment regimen alone, the addition of simultaneous NKG2A and PD-L1 blockade to ATRi/RT, in the adjuvant, post-radiotherapy setting induces a robust antitumour response driven by higher infiltration and activation of cytotoxic T cells in the tumour microenvironment. The efficacy of this combination relies on CD40/CD40L costimulation and infiltration of activated, proliferating memory CD8+ and CD4+ T cells with persistent or new T cell receptor (TCR) signalling, respectively. We also observe increased richness in the TCR repertoire and emergence of numerous and large TCR clonotypes that cluster based on antigen specificity in response to NKG2A/PD-L1/ATRi/RT. Collectively, our data point towards potential combination approaches for the treatment of HNSCC.
Subject(s)
Ataxia Telangiectasia Mutated Proteins , B7-H1 Antigen , Immunotherapy , Squamous Cell Carcinoma of Head and Neck , Tumor Microenvironment , Tumor Microenvironment/immunology , Tumor Microenvironment/radiation effects , Animals , Humans , Mice , Squamous Cell Carcinoma of Head and Neck/immunology , Squamous Cell Carcinoma of Head and Neck/radiotherapy , Squamous Cell Carcinoma of Head and Neck/therapy , Squamous Cell Carcinoma of Head and Neck/pathology , Immunotherapy/methods , B7-H1 Antigen/antagonists & inhibitors , B7-H1 Antigen/metabolism , Ataxia Telangiectasia Mutated Proteins/metabolism , Ataxia Telangiectasia Mutated Proteins/antagonists & inhibitors , Head and Neck Neoplasms/immunology , Head and Neck Neoplasms/therapy , Head and Neck Neoplasms/radiotherapy , Cell Line, Tumor , Immune Checkpoint Inhibitors/pharmacology , Immune Checkpoint Inhibitors/therapeutic use , NK Cell Lectin-Like Receptor Subfamily C/metabolism , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Programmed Cell Death 1 Receptor/metabolism , CD8-Positive T-Lymphocytes/immunology , Female , T-Lymphocytes, Cytotoxic/immunology , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/radiation effects , Mice, Inbred C57BL , CD40 Antigens/metabolism , CD40 Antigens/immunology , CD40 Antigens/antagonists & inhibitorsABSTRACT
Objectives: Healthcare professionals (HCPs) need to identify potentially serious musculoskeletal (MSK) presentations in children and refer them to specialists appropriately. Our aim was to develop 'pGALSplus' (paediatric gait, arms, legs and spine plus) to support clinical assessment, aid decision-making and assess feasibility and acceptability in exemplar MSK pathologies. Methods: We used a three-phase mixed methods approach: phase 1, preliminary stakeholder engagement and scoping review to propose pGALSplus; phase 2, iterative development of pGALSplus involving an expert working group; and phase 3, testing the feasibility of pGALSplus in exemplar MSK conditions [JIA, mucopolysaccharidoses (MPS), muscular dystrophy (MD), developmental coordination disorder (DCD) and healthy controls (HCs)]. The final pGALSplus was derived from analysis of phase 3 data and feedback from HCPs, families and expert consensus input from an international e-survey (n = 22) and virtual event (n = 13). Results: Feasibility was tested in 45 children (JIA, n = 10; MPS, n = 6; MD, n = 9; DCD, n = 10; HCs, n = 10). Overall the assessment was achievable in the target age range (2-10 years) and quick to complete [median 12 min (range 8-20)], with high acceptability from families. Expert feedback deemed pGALSplus to be very useful and of particular use to non-specialists in MSK paediatrics. The final pGALSplus comprises 26 clinical observations/skills with a colour-coding approach to aid decision-making and identification of more serious MSK presentations and additional resources to support its use in clinical practice. Conclusions: pGALSplus is a novel evidence- and consensus-based assessment building on pGALS, with high acceptability and feasibility. As community-based MSK assessment in children becomes more established, we propose that pGALSplus will facilitate and inform decision-making to promote access to specialist care.
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RATIONALE & OBJECTIVE: Growth failure is a common problem among children with chronic kidney disease (CKD). Reduced height is associated with psychosocial burden, social stigma, and impaired quality of life. This study aimed to describe the aspects of growth impairment that are most impactful from the perspectives of children with CKD, their parents, and health professionals. STUDY DESIGN: Qualitative study. SETTINGS & PARTICIPANTS: 120 children with CKD (aged 8-21 years), 250 parents, and 445 health professionals from 53 countries participated in 16 focus groups, two consensus workshops, and a Delphi survey. ANALYTICAL APPROACH: A thematic analysis of all qualitative data concerning growth from the Standardized Outcomes in Nephrology - Children and Adolescents (SONG-Kids) initiative. RESULTS: We identified five themes: diminishing psychological wellbeing (compared to and judged by peers, tired of explaining to others, damaging self-esteem), constrained life participation and enjoyment (deprived of normal school experiences, excluded from sports or competing at a disadvantage, impaired quality of life in adulthood); grappling with impacts of symptoms and treatment (difficulty understanding short stature and accessing help, lack of appetite, uncertainty regarding bone pains, medication side effects, burden of growth hormone treatment); facilitating timely interventions and optimizing outcomes (early indicator of disease, assessing management, maximizing transplant outcomes, minimizing morbidity); and keeping growth and health priorities in perspective (quality of life and survival of utmost priority, achieved adequate height). LIMITATIONS: Only English-speaking participants were included. CONCLUSIONS: Impaired growth may diminish psychological wellbeing, self-esteem, and participation in daily activities for children with CKD. Balancing different treatments that can affect growth complicates decision-making. These findings may inform the psychosocial support needed by children with CKD and their caregivers to address concerns about growth.
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Adenoid cystic carcinoma (AdCC) is a salivary gland neoplasm that infrequently appears in the sinonasal region. The aim of this study was to evaluate the outcome and clinicopathological parameters of sinonasal AdCC. A retrospective analysis was conducted on all cases of AdCC affecting the nasal cavity or paranasal sinuses between 2000 and 2018 at the University Hospital Zurich. Tumor material was examined for morphological features and analyzed for molecular alterations. A total of 14 patients were included. Mean age at presentation was 57.7 years. Sequencing revealed MYB::NFIB gene fusion in 11/12 analyzable cases. Poor prognostic factors were solid variant (p < 0.001), histopathological high-grade transformation (p < 0.001), and tumor involvement of the sphenoid sinus (p = 0.02). The median recurrence-free survival (RFS) and OS were 5.2 years and 11.3 years. The RFS rates at 1-, 5-, and 10-year were 100%, 53.8%, and 23.1%. The OS rates at 1-, 5-, and 10- years were 100%, 91.7%, and 62.9%, respectively. In Conclusion, the solid variant (solid portion > 30%), high-grade transformation, and sphenoid sinus involvement are negative prognostic factors for sinonasal AdCC. A high prevalence of MYB::NFIB gene fusion may help to correctly classify diagnostically challenging (e.g. metatypical) cases.
Subject(s)
Carcinoma, Adenoid Cystic , Paranasal Sinus Neoplasms , Humans , Carcinoma, Adenoid Cystic/genetics , Carcinoma, Adenoid Cystic/pathology , Carcinoma, Adenoid Cystic/mortality , Carcinoma, Adenoid Cystic/epidemiology , Middle Aged , Male , Female , Aged , Retrospective Studies , Adult , Paranasal Sinus Neoplasms/pathology , Paranasal Sinus Neoplasms/genetics , Paranasal Sinus Neoplasms/epidemiology , Prognosis , NFI Transcription Factors/genetics , Oncogene Proteins, Fusion/genetics , Proto-Oncogene Proteins c-myb/genetics , PrevalenceABSTRACT
Lanthanide-doped nanoparticles (LnNPs) possess unique optical properties and are employed in various optoelectronic and bioimaging applications. One fundamental limitation of LnNPs is their low absorption cross-section. This hurdle can be overcome through surface modification with organic chromophores with large absorption cross-sections. Controlling energy transfer from organic molecules to LnNPs is crucial for creating optically bright systems, yet the mechanisms are not well understood. Using pump-probe spectroscopy, we follow singlet energy transfer (SET) and triplet energy transfer (TET) in systems comprising different length 9,10-bis(phenylethynyl)anthracene (BPEA) derivatives coordinated onto ytterbium and neodymium-doped nanoparticles. Photoexcitation of the ligands forms singlet excitons, some of which convert to triplet excitons via intersystem crossing when coordinated to the LnNPs. The triplet generation rate and yield are strongly distance-dependent. Following their generation, TET occurs from the ligands to the LnNPs, exhibiting an exponential distance dependence, independent of solvent polarity, suggesting a concerted Dexter-type process with a damping coefficient of 0.60 Å-1. Nevertheless, TET occurs with near-unity efficiency for all BPEA derivatives due to the lack of other triplet deactivation pathways and long intrinsic triplet lifetimes. Thus, we find that close coupling is primarily important to ensure efficient triplet generation rather than efficient TET. Although SET is faster, we find its efficiency to be lower and more strongly distance-dependent than the TET efficiency. Our results present the first direct distance-dependent energy transfer measurements in LnNP@organic nanohybrids and establish the advantage of using the triplet manifold to achieve the most efficient energy transfer and best sensitization of LnNPs with π-conjugated ligands.
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The SARS-CoV-2 pandemic has generated a considerable number of infections and associated morbidity and mortality across the world. Recovery from these infections, combined with the onset of large-scale vaccination, have led to rapidly-changing population-level immunological landscapes. In turn, these complexities have highlighted a number of important unknowns related to the breadth and strength of immunity following recovery or vaccination. Using simple mathematical models, we investigate the medium-term impacts of waning immunity against severe disease on immuno-epidemiological dynamics. We find that uncertainties in the duration of severity-blocking immunity (imparted by either infection or vaccination) can lead to a large range of medium-term population-level outcomes (i.e. infection characteristics and immune landscapes). Furthermore, we show that epidemiological dynamics are sensitive to the strength and duration of underlying host immune responses; this implies that determining infection levels from hospitalizations requires accurate estimates of these immune parameters. More durable vaccines both reduce these uncertainties and alleviate the burden of SARS-CoV-2 in pessimistic outcomes. However, heterogeneity in vaccine uptake drastically changes immune landscapes toward larger fractions of individuals with waned severity-blocking immunity. In particular, if hesitancy is substantial, more robust vaccines have almost no effects on population-level immuno-epidemiology, even if vaccination rates are compensatorily high among vaccine-adopters. This pessimistic scenario for vaccination heterogeneity arises because those few individuals that are vaccine-adopters are so readily re-vaccinated that the duration of vaccinal immunity has no appreciable consequences on their immune status. Furthermore, we find that this effect is heightened if vaccine-hesitants have increased transmissibility (e.g. due to riskier behavior). Overall, our results illustrate the necessity to characterize both transmission-blocking and severity-blocking immune time scales. Our findings also underline the importance of developing robust next-generation vaccines with equitable mass vaccine deployment.
Subject(s)
COVID-19 Vaccines , COVID-19 , SARS-CoV-2 , Humans , COVID-19/immunology , COVID-19/prevention & control , COVID-19/epidemiology , SARS-CoV-2/immunology , COVID-19 Vaccines/immunology , Vaccination Hesitancy/statistics & numerical data , Severity of Illness Index , Vaccination/statistics & numerical data , Pandemics/prevention & control , Computational BiologyABSTRACT
Memories are encoded by sparse populations of neurons but how such sparsity arises remains largely unknown. We found that a neuron's eligibility to be recruited into the memory trace depends on its epigenetic state prior to encoding. Principal neurons in the mouse lateral amygdala display intrinsic chromatin plasticity, which when experimentally elevated favors neuronal allocation into the encoding ensemble. Such chromatin plasticity occurred at genomic regions underlying synaptic plasticity and was accompanied by increased neuronal excitability in single neurons in real time. Lastly, optogenetic silencing of the epigenetically altered neurons prevented memory expression, revealing a cell-autonomous relationship between chromatin plasticity and memory trace formation. These results identify the epigenetic state of a neuron as a key factor enabling information encoding.
Subject(s)
Chromatin , Epigenesis, Genetic , Memory , Neuronal Plasticity , Neurons , Animals , Mice , Chromatin/metabolism , Neurons/physiology , Memory/physiology , Optogenetics , Male , Mice, Inbred C57BL , Amygdala/physiologyABSTRACT
Patatin-like phospholipase domain-containing lipase 8 (PNPLA8), one of the calcium-independent phospholipase A2 enzymes, is involved in various physiological processes through the maintenance of membrane phospholipids. Biallelic variants in PNPLA8 have been associated with a range of paediatric neurodegenerative disorders. However, the phenotypic spectrum, genotype-phenotype correlations and the underlying mechanisms are poorly understood. Here, we newly identified 14 individuals from 12 unrelated families with biallelic ultra-rare variants in PNPLA8 presenting with a wide phenotypic spectrum of clinical features. Analysis of the clinical features of current and previously reported individuals (25 affected individuals across 20 families) showed that PNPLA8-related neurological diseases manifest as a continuum ranging from variable developmental and/or degenerative epileptic-dyskinetic encephalopathy to childhood-onset neurodegeneration. We found that complete loss of PNPLA8 was associated with the more profound end of the spectrum, with congenital microcephaly. Using cerebral organoids generated from human induced pluripotent stem cells, we found that loss of PNPLA8 led to developmental defects by reducing the number of basal radial glial cells and upper-layer neurons. Spatial transcriptomics revealed that loss of PNPLA8 altered the fate specification of apical radial glial cells, as reflected by the enrichment of gene sets related to the cell cycle, basal radial glial cells and neural differentiation. Neural progenitor cells lacking PNPLA8 showed a reduced amount of lysophosphatidic acid, lysophosphatidylethanolamine and phosphatidic acid. The reduced number of basal radial glial cells in patient-derived cerebral organoids was rescued, in part, by the addition of lysophosphatidic acid. Our data suggest that PNPLA8 is crucial to meet phospholipid synthetic needs and to produce abundant basal radial glial cells in human brain development.
ABSTRACT
BACKGROUND: SARS-CoV-2 remains rapidly evolving, and many biologically important genomic substitutions/indels have characterised novel SARS-CoV-2 lineages, which have emerged during successive global waves of the pandemic. Worldwide genomic sequencing has been able to monitor these waves, track transmission clusters, and examine viral evolution in real time to help inform healthcare policy. One school of thought is that an apparent greater than average divergence in an emerging lineage from contemporary variants may require persistent infection, for example in an immunocompromised host. Due to the nature of the COVID-19 pandemic and sampling, there were few studies that examined the evolutionary trajectory of SARS-CoV-2 in healthy individuals. METHODS: We investigated viral evolutionary trends and participant symptomatology within a cluster of 16 SARS-CoV-2 infected, immunocompetent individuals with no co-morbidities in a closed transmission chain. Longitudinal nasopharyngeal swab sampling allowed characterisation of SARS-CoV-2 intra-host variation over time at both the dominant and minor genomic variant levels through Nimagen-Illumina sequencing. RESULTS: A change in viral lineage assignment was observed in individual infections; however, there was only one indel and no evidence of recombination over the period of an acute infection. Minor and dominant genomic modifications varied between participants, with some minor genomic modifications increasing in abundance to become the dominant viral sequence during infection. CONCLUSIONS: Data from this cohort of SARS-CoV-2-infected participants demonstrated that long-term persistent infection in an immunocompromised host was not necessarily a prerequisite for generating a greater than average frequency of amino acid substitutions. Amino acid substitutions at both the dominant and minor genomic sequence level were observed in immunocompetent individuals during infection showing that viral lineage changes can occur generating viral diversity.
Subject(s)
COVID-19 , Genome, Viral , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , COVID-19/transmission , COVID-19/virology , COVID-19/genetics , Male , Adult , Female , Middle Aged , Genetic Variation , Immunocompetence , Evolution, Molecular , Phylogeny , AgedABSTRACT
Oxford Nanopore Technologies sequencing, also referred to as Nanopore sequencing, stands at the forefront of a revolution in clinical genetics, offering the potential for rapid, long read, and real-time DNA and RNA sequencing. This technology is currently making sequencing more accessible and affordable. In this comprehensive review, we explore its potential regarding precision cancer diagnostics and treatment. We encompass a critical analysis of clinical cases where Nanopore sequencing was successfully applied to identify point mutations, splice variants, gene fusions, epigenetic modifications, non-coding RNAs, and other pivotal biomarkers that defined subsequent treatment strategies. Additionally, we address the challenges of clinical applications of Nanopore sequencing and discuss the current efforts to overcome them.
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INTRODUCTION: A reconstructive option for extensive chest wall reconstruction is the free myocutaneous vastus lateralis muscle (VL) flap which can be performed in isolation or in conjunction with a fasciocutaneus anterolateral thigh (cVLALT) and/or myofasciocutaneous tensor fascia lata flap (cVLTFL). We aimed to directly compare the outcomes of these reconstructive options. METHODS: Patients who underwent oncological chest wall reconstruction with a free VL, cVLALT, or cVLTFL flap between February 2010 and 2022 were included in this retrospective study. Patient demographics, surgical characteristics, as well as medical and reconstructive outcomes, were evaluated. The operative outcomes between myocutaneous VL, cVLALT, and cVLTFL flap reconstructions were compared. RESULTS: A total of 41 patients underwent chest wall reconstruction with a free myocutaneous VL (n = 25; 61%), cVLALT (n = 14; 34%), or cVLTFL Three acute flap thromboses occurred in the entire cohort (3/41, 7%), with one myocutaneous VL flap failing because of recurrent venous thrombosis during the salvage procedure. Total flap necrosis was seen in two cases (5%; VL flap: n = 1; cVLALT flap: n = 1), and partial flap necrosis in one VL flap (1/25, 4%) and in the distal ALT portion of three cVLALT flaps (3/14, 21%). No significant difference was seen between isolated VL and conjoined VL flaps regarding the partial (p = .28) or total flap necrosis rate (p = .9). CONCLUSION: The free (conjoined) VL flap provides reliable outcomes for obliterating dead space achieving durable reconstruction of complex chest wall defects.
Subject(s)
Fascia Lata , Free Tissue Flaps , Plastic Surgery Procedures , Quadriceps Muscle , Thigh , Thoracic Wall , Humans , Male , Female , Retrospective Studies , Middle Aged , Plastic Surgery Procedures/methods , Thoracic Wall/surgery , Fascia Lata/transplantation , Free Tissue Flaps/transplantation , Aged , Adult , Thigh/surgery , Quadriceps Muscle/transplantation , Quadriceps Muscle/surgery , Myocutaneous Flap/transplantation , Thoracic Neoplasms/surgery , Treatment OutcomeABSTRACT
Purpose: Photoactivated chromophore for keratitis-corneal cross-linking (PACK-CXL) stabilizes the corneal stroma and eliminates microorganisms. Numerous PACK-CXL protocols, using different energy sources and chromophores, have been applied in preclinical studies, including live animal studies, with various experimental designs and endpoints. So far, a systematic mapping of the applied protocols and consistency across studies seems lacking but is essential to guide future research. Methods: The scoping review protocol was in line with the JBI Manual for Evidence Synthesis. Electronic databases were searched (Embase, MEDLINE, Scopus, Web of Science) to identify eligible records, followed by a two-step selection process (title and abstract screening, full text screening) for record inclusion. We extracted information on (1) different PACK-CXL protocol characteristics; (2) infectious pathogens tested; (3) study designs and experimental settings; and (4) endpoints used to determine antimicrobial and tissue stabilizing effects. The information was charted in frequency maps. Results: The searches yielded 3654 unique records, 233 of which met the inclusion criteria. With 103 heterogeneous endpoints, the researchers investigated a wide range of PACK-CXL protocols. The tested microorganisms reflected pathogens commonly associated with infectious keratitis. Bacterial solutions and infectious keratitis rabbit models were the most widely used models to study the antimicrobial effects of PACK-CXL. Conclusions: If preclinical PACK-CXL studies are to guide future translational research, further cross-disciplinary efforts are needed to establish, promote, and facilitate acceptance of common endpoints relevant to PACK-CXL. Translational Relevance: Systematic mapping of PACK-CXL protocols in preclinical studies guides future translational research.
Subject(s)
Cross-Linking Reagents , Keratitis , Photosensitizing Agents , Riboflavin , Animals , Keratitis/drug therapy , Keratitis/microbiology , Cross-Linking Reagents/therapeutic use , Cross-Linking Reagents/pharmacology , Cross-Linking Reagents/chemistry , Photosensitizing Agents/therapeutic use , Photosensitizing Agents/pharmacology , Riboflavin/therapeutic use , Riboflavin/pharmacology , Humans , Photochemotherapy/methods , Corneal Stroma/metabolism , Corneal Stroma/drug effects , Ultraviolet Rays , Collagen/metabolism , Corneal Cross-LinkingABSTRACT
Critical periods are windows of heightened plasticity occurring during neurodevelopment. Alterations in neural activity during these periods can cause long-lasting changes in the structure, connectivity, and intrinsic excitability of neurons, which may contribute to the pathology of neurodevelopmental disorders. However, endogenous regulators of critical periods remain poorly defined. Here, we study this issue using a fruit fly (Drosophila) model of an early-onset movement disorder caused by BK potassium channel gain of function (BK GOF). Deploying a genetic method to place robust expression of GOF BK channels under spatiotemporal control, we show that adult-stage neuronal expression of GOF BK channels minimally disrupts fly movement. In contrast, limiting neuronal expression of GOF BK channels to a short window during late neurodevelopment profoundly impairs locomotion and limb kinematics in resulting adult flies. During this critical period, BK GOF perturbs synaptic localization of the active zone protein Bruchpilot and reduces excitatory neurotransmission. Conversely, enhancing neural activity specifically during development rescues motor defects in BK GOF flies. Collectively, our results reveal a critical developmental period for limb control in Drosophila that is influenced by BK channels and suggest that BK GOF causes movement disorders by disrupting activity-dependent aspects of synaptic development.
Subject(s)
Drosophila Proteins , Drosophila melanogaster , Large-Conductance Calcium-Activated Potassium Channels , Locomotion , Animals , Large-Conductance Calcium-Activated Potassium Channels/metabolism , Large-Conductance Calcium-Activated Potassium Channels/genetics , Drosophila melanogaster/physiology , Drosophila melanogaster/genetics , Drosophila melanogaster/growth & development , Drosophila Proteins/metabolism , Drosophila Proteins/genetics , Neurons/metabolism , Neurons/physiologyABSTRACT
In all organisms, regulation of gene expression must be adjusted to meet cellular requirements and frequently involves helix-turn-helix (HTH) domain proteins1. For instance, in the arms race between bacteria and bacteriophages, rapid expression of phage anti-CRISPR (acr) genes upon infection enables evasion from CRISPR-Cas defence; transcription is then repressed by an HTH-domain-containing anti-CRISPR-associated (Aca) protein, probably to reduce fitness costs from excessive expression2-5. However, how a single HTH regulator adjusts anti-CRISPR production to cope with increasing phage genome copies and accumulating acr mRNA is unknown. Here we show that the HTH domain of the regulator Aca2, in addition to repressing Acr synthesis transcriptionally through DNA binding, inhibits translation of mRNAs by binding conserved RNA stem-loops and blocking ribosome access. The cryo-electron microscopy structure of the approximately 40 kDa Aca2-RNA complex demonstrates how the versatile HTH domain specifically discriminates RNA from DNA binding sites. These combined regulatory modes are widespread in the Aca2 family and facilitate CRISPR-Cas inhibition in the face of rapid phage DNA replication without toxic acr overexpression. Given the ubiquity of HTH-domain-containing proteins, it is anticipated that many more of them elicit regulatory control by dual DNA and RNA binding.
Subject(s)
Bacteriophages , CRISPR-Cas Systems , DNA-Binding Proteins , Gene Expression Regulation, Viral , Helix-Turn-Helix Motifs , RNA-Binding Proteins , Viral Proteins , Bacteriophages/chemistry , Bacteriophages/genetics , Bacteriophages/metabolism , Bacteriophages/ultrastructure , Binding Sites , Clustered Regularly Interspaced Short Palindromic Repeats/genetics , CRISPR-Associated Proteins/metabolism , Cryoelectron Microscopy , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , DNA-Binding Proteins/ultrastructure , Genes, Viral , Models, Molecular , Nucleic Acid Conformation , Pectobacterium carotovorum/virology , Protein Biosynthesis/genetics , Protein Domains , Ribosomes/metabolism , RNA, Messenger/chemistry , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Messenger/ultrastructure , RNA, Viral/chemistry , RNA, Viral/genetics , RNA, Viral/metabolism , RNA, Viral/ultrastructure , RNA-Binding Proteins/chemistry , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , RNA-Binding Proteins/ultrastructure , Substrate Specificity , Transcription, Genetic , Viral Proteins/chemistry , Viral Proteins/genetics , Viral Proteins/metabolism , Viral Proteins/ultrastructureABSTRACT
Physical restraints are widely used and accepted as protective measures during treatment in intensive care unit (ICU). This review of the literature summarizes the adverse events and outcomes associated with physical restraint use, and the risk factors associated with their use during treatment in the ICU. The PubMed, Scopus, and Google Scholar databases were screened using predefined search terms to identify studies pertaining to adverse events and/or outcomes associated with physical restraint use, and the factors associated with their use in adult patients admitted to the ICU. A total of 24 articles (including 6126 patients) that were published between 2006 and 2022 were identified. The described adverse events associated with physical restraint use included skin injuries, subsequent delirium, neurofunctional impairment, and a higher rate of post-traumatic stress disorder. Subsequent delirium was the most frequent adverse event to be reported. No alternative measures to physical restraints were discussed, and only one study reported a standardized protocol for their use. Although physical restraint use has been reported to be associated with adverse events (including neurofunctional impairment) in the literature, the available evidence is limited. Although causality cannot be confirmed, a definite association appears to exist. Our findings suggest that it is essential to improve awareness regarding their adverse impact and optimize approaches for their detection, management, and prevention using protocols or checklists.
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Background: Emergent reperfusion by percutaneous coronary intervention (PCI) within 90 minutes of first medical contact (FMC) is indicated in patients with ST-segment elevation myocardial infarction (STEMI). However, long transport times in rural areas in the Southeast US make meeting this goal difficult. The objective of this study was to determine the number of Southeast US residents with prolonged transport times to the nearest 24/7 primary PCI (PPCI) center. Methods: A cross-sectional study of residents in the Southeastern US was conducted based on geographical and 2022 5-Year American Community Survey data. The geographic information system (GIS) ArcGIS Pro was used to estimate Emergency Medical Services (EMS) transport times for Southeast US residents to the nearest PPCI center. All 24/7 PPCI centers in North Carolina, South Carolina, Georgia, Florida, Mississippi, Alabama, and Tennessee were included in the analysis, as well as nearby PPCI centers in surrounding states. To identify those at risk of delayed FMC-to-device time, the primary outcome was defined as a >30-minute transport time, beyond which most patients would not have PCI within 90 minutes. A secondary outcome was defined as transport >60 minutes, the point at which FMC-to-device time would be >120 minutes most of the time. These cutoffs are based on national median EMS scene times and door-to-device times. Results: Within the Southeast US, we identified 62,880,528 residents and 350 PPCI centers. Nearly 11 million people living in the Southeast US reside greater than 30 minutes from a PPCI center (17.3%, 10,866,710, +/- 58,143), with 2% (1,271,522 +/- 51,858) living greater than 60 minutes from a PPCI hospital. However, most patients reside in short transport zones; 82.7% (52,013,818 +/- 98,741). Within the Southeast region, 8.4% (52/616) of counties have more than 50% of their population in a long transport zone and 42.3% (22/52) of those have more than 90% of their population in long transport areas. Conclusions: Nearly 11 million people in the Southeast US do not have access to timely PCI for STEMI care. This disparity may contribute to increased morbidity and mortality.