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BACKGROUND: Dermal transfer of nicotine during tobacco harvest can cause green tobacco sickness (GTS), characterized by nausea, vomiting, headache and dizziness. Rainfall and high temperatures are etiological factors known to increase the prevalence of GTS. We analyzed recent and projected trends in these factors for major tobacco-growing regions to assess potential exacerbation in GTS occurrence. METHODS: We analyzed climate parameters, including recent trends (since the 1970s) in temperature and precipitation metrics during the tobacco harvest period for Southern Brazil; Yunnan Province, China; Andhra State, India; and North Carolina, USA. We applied Shared Socio-economic Pathways (SSPs) based scenarios for Tier 1 Scenario Model Intercomparison Project (ScenarioMIP) within the Coupled Model Intercomparison Project phase 6 (CMIP6), (SSPs of 1-2.6, 3-7.0 and 5-8.5 from 2020 to 2100). Established protocol for nicotine dermal patches and temperature were used as a proxy to estimate potential nicotine absorption. RESULTS: For three locations, cumulative maximum temperatures during harvest and temperature extremes rose significantly since the 1970s as did cumulative rainfall during harvest. Projected maximum temperatures at SSP 3-7.0 and 5-8.5 projections through 2100 did increase for all locations. Estimates of nicotine skin absorption with rising temperature show significant increases for both recent changes in three locations, and for all locations for SSP projections of 3-7.0 and 5-8.5 from 2020 to 2100. CONCLUSIONS: This study across multiple continents, highlights a potential link between recent and projected anthropogenic change and potential increases in GTS risk. Under SSP 5-8.5, nicotine absorption could increase by ~50% by the end of the century, which may have widespread impacts on the incidence of GTS, especially among younger tobacco workers.
Transfer of nicotine from tobacco leaves to the skin can result in a type of poisoning called green tobacco sickness (GTS) for field workers who harvest tobacco. Transfer is linked to temperature and rainfall, which are both impacted by global climate change. We examined recent (from 1970-present) and projected future (present to 2100) changes in these measures for four global locations where tobacco is grown. North Carolina, Brazil, China and India all show an increase in average maximum temperatures or rainfall since the 1970s. We find that recent or future changes in the climate are associated with an increased likelihood of skin absorption of nicotine. This study, across multiple continents, highlights a potential link between climate change that could increase the risk of GTS for tobacco workers.
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BACKGROUND: There is evidence that global anthropogenic climate change may be impacting floral phenology and the temporal and spatial characteristics of aero-allergenic pollen. Given the extent of current and future climate uncertainty, there is a need to strengthen predictive pollen forecasts. METHODS: The study aims to use CatBoost (CB) and deep learning (DL) models for predicting the daily total pollen concentration up to 14 days in advance for 23 cities, covering all five continents. The model includes the projected environmental parameters, recent concentrations (1, 2 and 4 weeks), and the past environmental explanatory variables, and their future values. RESULTS: The best pollen forecasts include Mexico City (R2(DL_7) ≈ .7), and Santiago (R2(DL_7) ≈ .8) for the 7th forecast day, respectively; while the weakest pollen forecasts are made for Brisbane (R2(DL_7) ≈ .4) and Seoul (R2(DL_7) ≈ .1) for the 7th forecast day. The global order of the five most important environmental variables in determining the daily total pollen concentrations is, in decreasing order: the past daily total pollen concentration, future 2 m temperature, past 2 m temperature, past soil temperature in 28-100 cm depth, and past soil temperature in 0-7 cm depth. City-related clusters of the most similar distribution of feature importance values of the environmental variables only slightly change on consecutive forecast days for Caxias do Sul, Cape Town, Brisbane, and Mexico City, while they often change for Sydney, Santiago, and Busan. CONCLUSIONS: This new knowledge of the ecological relationships of the most remarkable variables importance for pollen forecast models according to clusters, cities and forecast days is important for developing and improving the accuracy of airborne pollen forecasts.
Subject(s)
Allergens , Forecasting , Pollen , Pollen/immunology , Forecasting/methods , Humans , Climate Change , Models, Theoretical , Environmental Monitoring/methodsABSTRACT
Elevated atmospheric carbon dioxide (eCO2) can affect plant growth and physiology, which can, in turn, impact herbivorous insects, including by altering pollen or plant tissue nutrition. Previous research suggests that eCO2 can reduce pollen nutrition in some species, but it is unknown whether this effect is consistent across flowering plant species. We experimentally quantified the effects of eCO2 across multiple flowering plant species on plant growth in 9 species and pollen chemistry (%N an estimate for protein content and nutrition in 12 species; secondary chemistry in 5 species) in greenhouses. For pollen nutrition, only buckwheat significantly responded to eCO2, with %N increasing in eCO2; CO2 treatment did not affect pollen amino acid composition but altered secondary metabolites in buckwheat and sunflower. Plant growth under eCO2 exhibited two trends across species: plant height was taller in 44% of species and flower number was affected for 63% of species (3 species with fewer and 2 species with more flowers). The remaining growth metrics (leaf number, above-ground biomass, flower size, and flowering initiation) showed divergent, species-specific responses, if any. Our results indicate that future eCO2 is unlikely to uniformly change pollen chemistry or plant growth across flowering species but may have the potential to alter ecological interactions, or have particularly important effects on specialized pollinators.
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Carbon Dioxide , Pollen , Carbon Dioxide/metabolism , Pollen/growth & development , Pollen/metabolism , Atmosphere/chemistry , Species Specificity , Magnoliopsida/growth & development , Magnoliopsida/metabolism , Magnoliopsida/physiology , Flowers/growth & development , Flowers/metabolism , Plant Development/drug effectsABSTRACT
This study explored the link between park size and crime risk in Alabama, analyzing 564 parks across 73 cities with populations over 10,000. Park dimensions were measured using Google Earth Pro, and crime data, covering violent and property crimes, were sourced from Applied Geographic Solutions. Additional data on population density, mental health prevalence, social vulnerability, and alcohol expenditure (indicative of affluence) were obtained from the U.S. Census Bureau, CDC, and ESRI. A multiple regression analysis revealed a significant negative association between park size and crime risk, meaning that larger park sizes tended to have lower crime rates. Key covariates-mental health, social vulnerability, and alcohol spending- were also significantly related to crime rates. Our findings have policy implications for local governments and community organizations seeking to reduce crime rates.
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Pain is one of the most common concerns among chronically ill older adults. However, access to pain management is not equitable among certain populations, including rural residents. This qualitative study explored rural older adults' experiences with pain and its treatment. Eighteen participants were recruited from rural counties of Alabama, who were age 60+, cognitively intact, community-dwelling, had one or more chronic/serious illnesses, and experienced pain. Open-ended questions were asked in individual interviews, and inductive, thematic analysis was used for data analysis. Findings revealed the impact of pain (physical limitations, psychological distress, and coping strategies), the impact of COVID-19 (physical/mental health and pain management), challenges in pain management in rural areas (lack of provider and healthcare resources, transportation-related issues, mistrust, and limited insurance coverage) and suggestions to address these challenges. Program and policy-level interventions are crucial in improving the resources and education/training needed for effective pain management for rural older adults.
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BACKGROUND: The relationship between systolic blood pressure (SBP) and longevity is not fully understood. We aimed to determine which SBP levels in women ≥65 years of age with or without blood pressure medication were associated with the highest probability of surviving to 90 years of age. METHODS: The study population consisted of 16 570 participants enrolled in the Women's Health Initiative who were eligible to survive to 90 years of age by February 28, 2020, without a history of cardiovascular disease, diabetes, or cancer. Blood pressure was measured at baseline (1993 through 1998) and then annually through 2005. The outcome was defined as survival to 90 years of age with follow-up. Absolute probabilities of surviving to 90 years of age were estimated for all combinations of SBP and age using generalized additive logistic regression modeling. The SBP that maximized survival was estimated for each age, and a 95% CI was generated. RESULTS: During a median follow-up of 19.8 years, 9723 of 16 570 women (59%) survived to 90 years of age. Women with an SBP between 110 and 130 mm Hg at attained ages of 65, 70, 75, and 80 years had a 38% (95% CI, 34%-48%), 54% (52%-56%), 66% (64%-67%), or 75% (73%-78%) absolute probability to survive to 90 years of age, respectively. The probability of surviving to 90 years of age was lower for greater SBP levels. Women at the attained age of 80 years with 0%, 20%, 40%, 60%, 80%, or 100% time in therapeutic range (defined as an SBP between 110 and 130 mm Hg) had a 66% (64%-69%), 68% (67%-70%), 71% (69%-72%), 73% (71%-74%), 75% (72%-77%), or 77% (74%-79%) absolute survival probability to 90 years of age. CONCLUSIONS: For women >65 years of age with low cardiovascular disease and other chronic disease risk, an SBP level <130 mm Hg was found to be associated with longevity. These findings reinforce current guidelines targeting an SBP target <130 mm Hg in older women.
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Blood Pressure , Women's Health , Humans , Female , Aged , Aged, 80 and over , Longevity , Follow-Up Studies , Age Factors , Hypertension/mortality , Hypertension/physiopathology , Hypertension/epidemiology , Hypertension/diagnosis , Risk Factors , Systole , Antihypertensive Agents/therapeutic useABSTRACT
REINVENT 4 is a modern open-source generative AI framework for the design of small molecules. The software utilizes recurrent neural networks and transformer architectures to drive molecule generation. These generators are seamlessly embedded within the general machine learning optimization algorithms, transfer learning, reinforcement learning and curriculum learning. REINVENT 4 enables and facilitates de novo design, R-group replacement, library design, linker design, scaffold hopping and molecule optimization. This contribution gives an overview of the software and describes its design. Algorithms and their applications are discussed in detail. REINVENT 4 is a command line tool which reads a user configuration in either TOML or JSON format. The aim of this release is to provide reference implementations for some of the most common algorithms in AI based molecule generation. An additional goal with the release is to create a framework for education and future innovation in AI based molecular design. The software is available from https://github.com/MolecularAI/REINVENT4 and released under the permissive Apache 2.0 license. Scientific contribution. The software provides an open-source reference implementation for generative molecular design where the software is also being used in production to support in-house drug discovery projects. The publication of the most common machine learning algorithms in one code and full documentation thereof will increase transparency of AI and foster innovation, collaboration and education.
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INTRODUCTION: The association between chronic pain and frailty might indicate that pain is an independent driver of frailty but might alternatively be explained by inclusion within frailty identification tools of morbidities that commonly lead to chronic pain. This research examines the extent to which the association of pain with frailty might be attributed to morbidities. METHODS: A cross-sectional analysis of older people in a UK cohort with or at risk of musculoskeletal problems or frailty (Investigating Musculoskeletal Health and Wellbeing study), used multivariable logistic regression and Z-tests to assess the degrees of associations of pain (McGill Pain Rating Index), and painful and non-painful morbidity counts with frailty (modified FRAIL questionnaire). RESULTS: Data were from 2,185 participants, 56% female, median age 73 (range 60 to 96) years. 430 (20%) participants were classified as frail. In a fully adjusted standardised model, pain (aOR 2.07 (95%CI 1.83 to 2.33) and 'any' morbidity aOR (1.74 (95%CI 1.54 to 1.97) were both significantly associated with frailty. When morbidity was subclassified as painful or non-painful, painful (aOR 1.48 (95%CI 1.30 to 1.68) and non-painful (aOR1.39 (95%CI 1.24 to 1.56)) morbidities each were associated with frailty, as also was pain (aOR 2.07 (95%CI 1.83 to 2.34, p < 0.001). CONCLUSIONS: Pain is associated with frailty, over and above any effect of painful and non-painful morbidities. This forms the justification for future research which focuses on pain management in the identification, prevention, and treatment of frailty.
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Chronic Pain , Frailty , Humans , Female , Aged , Aged, 80 and over , Male , Frailty/diagnosis , Frailty/epidemiology , Independent Living , Cross-Sectional Studies , Frail Elderly , Chronic Pain/diagnosis , Chronic Pain/epidemiology , Chronic Pain/therapy , Morbidity , Geriatric AssessmentABSTRACT
BACKGROUND AND OBJECTIVES: While the highest prevalence of dementia occurs in individuals older than 80 years, most imaging studies focused on younger populations. The rates of ß-amyloid (Aß) accumulation and the effect of Alzheimer disease (AD) pathology on progression to dementia in this age group remain unexplored. In this study, we examined the relationship between changes in Aß deposition over time and incident dementia in nondemented individuals followed during a period of 11 years. METHODS: We examined 94 participants (age 85.9 + 2.8 years) who had up to 5 measurements of Pittsburgh compound-B (PiB)-PET and clinical evaluations from 2009 to 2020. All 94 participants had 2 PiB-PET scans, 76 participants had 3 PiB-PET scans, 18 participants had 4 PiB-PET scans, and 10 participants had 5 PiB-PET scans. The rates of Aß deposition were compared with 120 nondemented individuals younger than 80 years (69.3 ± 5.4 years) from the Australian Imaging, Biomarker, and Lifestyle (AIBL) study who had 3 or more annual PiB-PET assessments. RESULTS: By 2020, 49% of the participants developed dementia and 63% were deceased. There was a gradual increase in Aß deposition in all participants whether they were considered Aß positive or negative at baseline. In a Cox model controlled for age, sex, education level, APOE-4 allele, baseline Mini-Mental State Examination, and mortality, short-term change in Aß deposition was not significantly associated with incident dementia (HR 2.19 (0.41-11.73). However, baseline Aß burden, cortical thickness, and white matter lesions volume were the predictors of incident dementia. Aß accumulation was faster (p = 0.01) in the older cohort (5.6%/year) when compared with AIBL (4.1%/year). In addition, baseline Aß deposition was a predictor of short-term change (mean time 1.88 years). DISCUSSION: There was an accelerated Aß accumulation in cognitively normal individuals older than 80 years. Baseline Aß deposition was a determinant of incident dementia and short-term change in Aß deposition suggesting that an active Aß pathologic process was present when these participants were cognitively normal. Consequently, age may not be a limiting factor for the use of the emergent anti-Aß therapies.
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Alzheimer Disease , Amyloid beta-Peptides , Humans , Aged, 80 and over , Australia , Alzheimer Disease/diagnostic imaging , Alzheimer Disease/epidemiology , Educational Status , Life StyleABSTRACT
BACKGROUND: A goal of gerontology is to discover phenotypes that reflect biological aging distinct from disease pathogenesis. Biomarkers that are strongly associated with mortality could be used to define such a phenotype. However, the relation of such an index with multiple chronic conditions warrants further exploration. METHODS: A biomarker index (BI) was constructed in the Cardiovascular Health Study (Nâ =â 3 197), with a mean age of 74 years. The BI incorporated circulating levels of new biomarkers, including insulin-like growth factor-1, interleukin-6, amino-terminal pro-B-type natriuretic peptide, cystatin-C, C-reactive protein, tumor necrosis factor-alpha soluble receptor 1, fasting insulin, and fasting glucose, and was built based on their relationships with mortality. Cox proportional hazards models predicting a composite of death and chronic disease involving cardiovascular disease, dementia, and cancer were calculated with 6 years of follow-up. RESULTS: The hazard ratio (HR, 95% CI) for the composite outcome of death or chronic disease per category of BI was 1.65 (1.52, 1.80) and 1.75 (1.58, 1.94) in women and men, respectively. The HR (95% CI) per 5 years of age was 1.57 (1.48, 1.67) and 1.55 (1.44, 1.67) in women and men, respectively. Moreover, BI could attenuate the effect of age on the composite outcome by 16.7% and 22.0% in women and men, respectively. CONCLUSIONS: Biomarker index was significantly and independently associated with a composite outcome of death and chronic disease, and attenuated the effect of age. The BI that is composed of plasma biomarkers may be a practical intermediate phenotype for interventions aiming to modify the course of aging.
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Aging , Cardiovascular Diseases , Male , Humans , Female , Aged , Risk Factors , Prospective Studies , Biomarkers , Peptide Fragments , Chronic Disease , Natriuretic Peptide, Brain , Proportional Hazards ModelsABSTRACT
Pulmonary hypertension (PH) is a significant health problem that contributes to high morbidity and mortality in diverse cardiac, pulmonary, and systemic diseases in children. Evidence-based advances in PH care have been challenged by a paucity of quality endpoints for assessing clinical course and the lack of robust clinical trial data to guide pharmacologic therapies in children. While the landmark adult AMBITION trial demonstrated the benefit of up-front combination PH therapy with ambrisentan and tadalafil, it remains unknown whether upfront combination therapy leads to more rapid and sustained clinical benefits in children with various categories of PH. In this article, we describe the inception of the Kids Mod PAH Trial, a multicenter Phase III trial, to address whether upfront combination therapy (sildenafil and bosentan vs. sildenafil alone) improves PH outcomes in children, recognizing that marked differences between the etiology and therapeutic response between adults and children exist. The primary endpoint of this study is WHO functional class (FC) 12 months after initiation of study drug therapy. In addition to the primary outcome, secondary endpoints are being assessed, including a composite measure of time to clinical worsening, WHO FC at 24 months, echocardiographic assessment of PH and quantitative assessment of right ventricular function, 6-min walk distance, and NT-proBNP levels. Exploratory endpoints include selected biomarkers, actigraphy, and assessments of quality of life. This study is designed to pave the way for additional clinical trials by establishing a robust infrastructure through the development of a PPHNet Clinical Trials Network.
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Background: Kidney transplant (KT) candidates have historically low immunization rates against recommended vaccines. A retrospective single-center study of contemporary KT candidates was conducted to assess vaccination rates and vaccine uptake. Methods: All KT candidates ≥18 y evaluated between January 1, 2020, and December 31, 2020, were retrospectively reviewed for history of prior vaccination against tetanus, diphtheria, and pertussis; 13-valent pneumococcal conjugate vaccine; 23-valent pneumococcal polysaccharide vaccine; and recombinant zoster vaccine. Positive hepatitis A IgG total, hepatitis B surface antibody, measles, mumps, rubella, and varicella IgG were assessed as surrogate markers of immunity. Vaccine uptake among vaccine-eligible candidates was also assessed. Results: Among 150 KT candidates, the rate of prior vaccination against tetanus, diphtheria, and pertussis; 13-valent pneumococcal conjugate vaccine; 23-valent pneumococcal polysaccharide vaccine; and recombinant zoster vaccine (latter among patients ≥50 y) was found to be as low as 11%. Hepatitis A IgG total, hepatitis B surface antibody, measles, mumps, rubella, and varicella IgG seropositivity rates were 30%, 66%, 88%, 78%, 90%, and 96%, respectively. Only 7 (5%) of 150 patients had complete immunization or seropositivity. Five (3%) of 143 vaccine-eligible patients declined vaccination. Hepatitis A vaccine declination was relatively common with 15 (16%) of 94 vaccine-eligible patients declining it. Conclusions: KT candidates have low baseline rates of prior immunization/seropositivity against most recommended vaccines. Overall vaccine uptake among eligible candidates was high.
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Collection of finger sweat is explored here as a rapid and convenient way of monitoring patient adherence to antipsychotic drugs. Finger sweat samples (n = 426) collected from patients receiving treatment with clozapine, quetiapine and olanzapine were analysed by liquid chromatography mass spectrometry, including a subgroup of patients with paired plasma samples. Finger sweat samples were also analysed from a negative control group and patients who had handled antipsychotic medication only. The finger sweat test (based on the detection of parent drug in one donated sample) was 100% effective in monitoring adherence within commonly prescribed dosing ranges. In comparison to participants who handled the medication only, the test could distinguish between contact and administration through monitoring of the drug metabolite, or the level of parent drug. Additionally, in a subgroup of patients prescribed clozapine, a statistically significant correlation was observed between the mass of parent drug in finger sweat and plasma concentration. The finger sweat technology shows promise as a dignified, noninvasive method to monitor treatment adherence in patients taking antipsychotics.
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Ongoing and future climate change driven expansion of aeroallergen-producing plant species comprise a major human health problem across Europe and elsewhere. There is an urgent need to produce accurate, temporally dynamic maps at the continental level, especially in the context of climate uncertainty. This study aimed to restore missing daily ragweed pollen data sets for Europe, to produce phenological maps of ragweed pollen, resulting in the most complete and detailed high-resolution ragweed pollen concentration maps to date. To achieve this, we have developed two statistical procedures, a Gaussian method (GM) and deep learning (DL) for restoring missing daily ragweed pollen data sets, based on the plant's reproductive and growth (phenological, pollen production and frost-related) characteristics. DL model performances were consistently better for estimating seasonal pollen integrals than those of the GM approach. These are the first published modelled maps using altitude correction and flowering phenology to recover missing pollen information. We created a web page (http://euragweedpollen.gmf.u-szeged.hu/), including daily ragweed pollen concentration data sets of the stations examined and their restored daily data, allowing one to upload newly measured or recovered daily data. Generation of these maps provides a means to track pollen impacts in the context of climatic shifts, identify geographical regions with high pollen exposure, determine areas of future vulnerability, apply spatially-explicit mitigation measures and prioritize management interventions.
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Allergens , Ambrosia , Humans , Europe , PollenABSTRACT
Diseases of the central nervous system, which once occupied a large component of the pharmaceutical industry research and development portfolio, have for many years played a smaller part in major pharma pipelines-primarily due to the well cited challenges in target validation, valid translational models, and clinical trial design. Unfortunately, this decline in research and development interest has occurred in tandem with an increase in the medical need-in part driven by the success in treating other chronic diseases, which then results in a greater overall longevity along with a higher prevalence of diseases associated with ageing. The lead modality for drug agents targeting the brain remains the traditionally small molecule, despite potential in gene-based therapies and antibodies, particularly in the hugely anticipated anti-amyloid field, clearly driven by the additional challenge of effective distribution to the relevant brain compartments. However, in recognition of the growing disease burden, advanced therapies are being developed in tandem with improved delivery options. Hence, methodologies which were initially restricted to systemic indications are now being actively explored for a range of CNS diseases-an important class of which include the protein degradation technologies.
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Brain , Central Nervous System , Antibodies , Amyloidogenic ProteinsABSTRACT
Background: The association between systolic blood pressure (SBP) and longevity is not fully understood. We aimed to determine survival probabilities to age 90 for various SBP levels among women aged ≥ 65 years with or without BP medication. Methods: We analyzed blood pressure data from participants in the Women's Health Initiative (n=16,570) who were aged 65 or older and without history of cardiovascular disease, diabetes or cancer. Blood pressure was measured at baseline (1993-1998) and then annually through 2005. The outcome was defined as survival to age 90 with follow-up until February 28, 2020. Results: During a follow-up of 18 years, 9,723 (59%) of 16,570 women survived to age 90. The SBP associated with the highest probability of survival was about 120mmHg regardless of age. Compared to an SBP between 110 and 130 mmHg, women with uncontrolled SBP had a lower survival probability across all age groups and with or without BP medication. A 65-year-old women on BP medication with an interpolated SBP between 110 and 130 mmHg in 80% of the first 5 years of follow-up had a 31% (95% confidence interval, 24%, 38%) absolute survival probability. For those with 20% time in range, the probability was 21% (95% confidence interval, 16%, 26%). Conclusions: An SBP level below 130 mmHg was found to be associated with longevity among older women. The longer SBP was controlled at a level between 110 and 130 mmHg, the higher the survival probability to age 90. Preventing age-related rises in SBP and increasing the time with controlled BP levels constitute important measures for achieving longevity.
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In image-based profiling, software extracts thousands of morphological features of cells from multi-channel fluorescence microscopy images, yielding single-cell profiles that can be used for basic research and drug discovery. Powerful applications have been proven, including clustering chemical and genetic perturbations on the basis of their similar morphological impact, identifying disease phenotypes by observing differences in profiles between healthy and diseased cells and predicting assay outcomes by using machine learning, among many others. Here, we provide an updated protocol for the most popular assay for image-based profiling, Cell Painting. Introduced in 2013, it uses six stains imaged in five channels and labels eight diverse components of the cell: DNA, cytoplasmic RNA, nucleoli, actin, Golgi apparatus, plasma membrane, endoplasmic reticulum and mitochondria. The original protocol was updated in 2016 on the basis of several years' experience running it at two sites, after optimizing it by visual stain quality. Here, we describe the work of the Joint Undertaking for Morphological Profiling Cell Painting Consortium, to improve upon the assay via quantitative optimization by measuring the assay's ability to detect morphological phenotypes and group similar perturbations together. The assay gives very robust outputs despite various changes to the protocol, and two vendors' dyes work equivalently well. We present Cell Painting version 3, in which some steps are simplified and several stain concentrations can be reduced, saving costs. Cell culture and image acquisition take 1-2 weeks for typically sized batches of ≤20 plates; feature extraction and data analysis take an additional 1-2 weeks.This protocol is an update to Nat. Protoc. 11, 1757-1774 (2016): https://doi.org/10.1038/nprot.2016.105.
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Cell Culture Techniques , Image Processing, Computer-Assisted , Image Processing, Computer-Assisted/methods , Microscopy, Fluorescence , Mitochondria , SoftwareABSTRACT
Fetal lung fibroblasts contribute dynamic infrastructure for the developing lung. These cells undergo dynamic mechanical transitions, including cyclic stretch and spreading, which are integral to lung growth in utero. We investigated the role of the nuclear envelope protein emerin in cellular responses to these dynamic mechanical transitions. In contrast to control cells, which briskly realigned their nuclei, actin cytoskeleton, and extracellular matrices in response to cyclic stretch, fibroblasts that were acutely downregulated for emerin showed incomplete reorientation of both nuclei and actin cytoskeleton. Emerin-downregulated fibroblasts were also aberrantly circular in contrast to the spindle-shaped controls and exhibited an altered pattern of filamentous actin organization that was disconnected from the nucleus. Emerin knockdown was also associated with reduced myosin light chain phosphorylation during cell spreading. Interestingly, emerin-downregulated fibroblasts also demonstrated reduced fibronectin fibrillogenesis and production. These findings indicate that nuclear-cytoskeletal coupling serves a role in the dynamic regulation of cytoskeletal structure and function and may also impact the transmission of traction force to the extracellular matrix microenvironment.
Subject(s)
Actomyosin , Cytoskeleton , Actomyosin/metabolism , Down-Regulation , Cytoskeleton/metabolism , Actin Cytoskeleton/metabolismABSTRACT
Reduced cerebral blood flow (CBF) in the temporoparietal region and gray matter volumes (GMVs) in the temporal lobe were previously reported in patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD). However, the temporal relationship between reductions in CBF and GMVs requires further investigation. This study sought to determine if reduced CBF is associated with reduced GMVs, or vice versa. Data came from 148 volunteers of the Cardiovascular Health Study Cognition Study (CHS-CS), including 58 normal controls (NC), 50 MCI, and 40 AD who had perfusion and structural MRIs during 2002-2003 (Time 2). Sixty-three of the 148 volunteers had follow-up perfusion and structural MRIs (Time 3). Forty out of the 63 volunteers received prior structural MRIs during 1997-1999 (Time 1). The relationships between GMVs and subsequent CBF changes, and between CBF and subsequent GMV changes were investigated. At Time 2, we observed smaller GMVs (p<0.05) in the temporal pole region in AD compared to NC and MCI. We also found associations between: (1) temporal pole GMVs at Time 2 and subsequent declines in CBF in this region (p=0.0014) and in the temporoparietal region (p=0.0032); (2) hippocampal GMVs at Time 2 and subsequent declines in CBF in the temporoparietal region (p=0.012); and (3) temporal pole CBF at Time 2 and subsequent changes in GMV in this region (p = 0.011). Therefore, hypoperfusion in the temporal pole may be an early event driving its atrophy. Perfusion declines in the temporoparietal and temporal pole follow atrophy in this temporal pole region.