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Pathogenic Chlamydia species are coccoid bacteria that use the rod-shape determining protein MreB to direct septal peptidoglycan synthesis during their polarized cell division process. How the site of polarized budding is determined in this bacterium, where contextual features like membrane curvature are seemingly identical, is unclear. We hypothesized that the accumulation of the phospholipid, cardiolipin (CL), in specific regions of the cell membrane induces localized membrane changes that trigger the recruitment of MreB to the site where the bud will arise. To test this, we ectopically expressed cardiolipin synthase (Cls) and observed a polar distribution for this enzyme in Chlamydia trachomatis. In early division intermediates, Cls was restricted to the bud site where MreB is localized and peptidoglycan synthesis is initiated. The localization profile of 6xHis tagged Cls (Cls_6xH) throughout division mimicked the distribution of lipids that stain with NAO, a dye that labels CL. Treatment of Chlamydia with 3',6-dinonylneamine (diNN), an antibiotic targeting CL-containing membrane domains, resulted in redistribution of Cls_6xH and NAO-staining phospholipids. In addition, 6xHis tagged MreB localization was altered by diNN treatment, suggesting an upstream regulatory role for CL-containing membranes in directing the assembly of MreB. This hypothesis is consistent with the observation that the clustered localization of Cls_6xH is not dependent upon MreB function or peptidoglycan synthesis. Furthermore, expression of a CL-binding protein at the inner membrane of C. trachomatis dramatically inhibited bacterial growth supporting the importance of CL in the division process. Our findings implicate a critical role for localized CL synthesis in driving MreB assembly at the bud site during the polarized cell division of Chlamydia.
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Chlamydia trachomatis , Peptidoglicano , Antibacterianos , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Cardiolipinas , División Celular , Chlamydia trachomatis/metabolismo , Fosfolípidos/metabolismoRESUMEN
BACKGROUND: A multi-phase Canadian study was conducted as part of a large-scale community and academic research partnership focused on understanding and improving the employment experiences of people with intellectual disabilities. METHOD: This multi-method study utilized a sequential approach, using findings from qualitative interviews (n = 28) to inform an online survey (n = 149). Participants were invited to share their experiences with paid employment or with persons with intellectual disabilities. RESULTS: Thematic analysis of data across interview and survey findings resulted in six themes: (1) assumptions and attitudes, (2) knowledge and awareness, (3) accessibility of processes, (4) use of accommodations, (5) workplace relationships, and (6) supports and resources. CONCLUSIONS: A holistic and systemic approach has the potential to improve inclusive employment experiences of people with intellectual disabilities. Action is needed mainly at the policy and employer level to reduce barriers and improve on facilitating measures reinforced by the themes shared in this study.
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Personas con Discapacidad , Discapacidad Intelectual , Adulto , Humanos , Defensa del Paciente , Canadá , EmpleoRESUMEN
Chlamydia trachomatis is an obligate intracellular bacterial pathogen. In evolving to the intracellular niche, Chlamydia has reduced its genome size compared to other bacteria and, as a consequence, has a number of unique features. For example, Chlamydia engages the actin-like protein MreB, rather than the tubulin-like protein FtsZ, to direct peptidoglycan (PG) synthesis exclusively at the septum of cells undergoing polarized cell division. Interestingly, Chlamydia possesses another cytoskeletal element-a bactofilin ortholog, BacA. Recently, we reported BacA is a cell size-determining protein that forms dynamic membrane-associated ring structures in Chlamydia that have not been observed in other bacteria with bactofilins. Chlamydial BacA possesses a unique N-terminal domain, and we hypothesized this domain imparts the membrane-binding and ring-forming properties of BacA. We show that different truncations of the N terminus result in distinct phenotypes: removal of the first 50 amino acids (ΔN50) results in large ring structures at the membrane whereas removal of the first 81 amino acids (ΔN81) results in an inability to form filaments and rings and a loss of membrane association. Overexpression of the ΔN50 isoform altered cell size, similar to loss of BacA, suggesting that the dynamic properties of BacA are essential for the regulation of cell size. We further show that the region from amino acid 51 to 81 imparts membrane association as appending it to green fluorescent protein (GFP) resulted in the relocalization of GFP from the cytosol to the membrane. Overall, our findings suggest two important functions for the unique N-terminal domain of BacA and help explain its role as a cell size determinant. IMPORTANCE Bacteria use a variety of filament-forming cytoskeletal proteins to regulate and control various aspects of their physiology. For example, the tubulin-like FtsZ recruits division proteins to the septum whereas the actin-like MreB recruits peptidoglycan (PG) synthases to generate the cell wall in rod-shaped bacteria. Recently, a third class of cytoskeletal protein has been identified in bacteria-bactofilins. These proteins have been primarily linked to spatially localized PG synthesis. Interestingly, Chlamydia, an obligate intracellular bacterium, does not have PG in its cell wall and yet possesses a bactofilin ortholog. In this study, we characterize a unique N-terminal domain of chlamydial bactofilin and show that this domain controls two important functions that affect cell size: its ring-forming and membrane-associating properties.
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Proteínas Bacterianas , Tubulina (Proteína) , Proteínas Bacterianas/metabolismo , Actinas , Peptidoglicano/metabolismo , Proteínas del Citoesqueleto/genética , Proteínas del Citoesqueleto/metabolismo , Chlamydia trachomatis/genética , Chlamydia trachomatis/metabolismo , AminoácidosRESUMEN
SOURCE CITATION: Carbone F, Van den Houte K, Besard L, et al. Diet or medication in primary care patients with IBS: the DOMINO study-a randomised trial supported by the Belgian Health Care Knowledge Centre (KCE Trials Programme) and the Rome Foundation Research Institute. Gut. 2022. [Epub ahead of print]. 35483886.
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Síndrome del Colon Irritable , Automanejo , Teléfono Inteligente , Dieta , Dieta Baja en Carbohidratos , Humanos , Síndrome del Colon Irritable/diagnóstico , Síndrome del Colon Irritable/tratamiento farmacológico , Compuestos de Amonio CuaternarioRESUMEN
INTRODUCTION: Excessive daytime sleepiness is a debilitating symptom of obstructive sleep apnea (OSA) linked to cardiovascular disease, and metabolomic mechanisms underlying this relationship remain unknown. We examine whether metabolites from inflammatory and oxidative stress-related pathways that were identified in our prior work could be involved in connecting the two phenomena. METHODS: This study included 57 sleepy (Epworth Sleepiness Scale (ESS) ≥ 10) and 37 non-sleepy (ESS < 10) participants newly diagnosed and untreated for OSA that completed an overnight in-lab or at home sleep study who were recruited from the Emory Mechanisms of Sleepiness Symptoms Study (EMOSS). Differences in fasting blood samples of metabolites were explored in participants with sleepiness versus those without and multiple linear regression models were utilized to examine the association between metabolites and mean arterial pressure (MAP). RESULTS: The 24-h MAP was higher in sleepy 92.8 mmHg (8.4) as compared to non-sleepy 88.8 mmHg (8.1) individuals (P = 0.03). Although targeted metabolites were not significantly associated with MAP, when we stratified by sleepiness group, we found that sphinganine is significantly associated with MAP (Estimate = 8.7, SE = 3.7, P = 0.045) in non-sleepy patients when controlling for age, BMI, smoking status, and apnea-hypopnea index (AHI). CONCLUSION: This is the first study to evaluate the relationship of inflammation and oxidative stress related metabolites in sleepy versus non-sleepy participants with newly diagnosed OSA and their association with 24-h MAP. Our study suggests that Sphinganine is associated with 24 hour MAP in the non-sleepy participants with OSA.
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Apnea Obstructiva del Sueño , Somnolencia , Presión Arterial , Humanos , Metabolómica , Apnea Obstructiva del Sueño/complicaciones , Apnea Obstructiva del Sueño/diagnóstico , Esfingosina/análogos & derivadosRESUMEN
BACKGROUND: Bingo is often understood as a low-harm form of gambling. This view has been challenged by a growing body of literature identifying gambling harm to bingo players in a range of countries. In this study, we aimed to identify which conditions enabled, facilitated, intensified or mitigated gambling harm for bingo players in three populations in Victoria in the context of corporate, technological and regulatory changes. METHODS: Our qualitative study investigated experiences of bingo-related gambling harm in three populations in Victoria, Australia where bingo was popular and structural disadvantage common: Indigenous people in the east, Pacific people in the state's north and older people on low or fixed incomes in the capital. Data was generated through interviews with 53 bingo players and 13 stakeholders as well as 12 participant observations of bingo sessions. RESULTS: We found that while bingo is overwhelmingly positive for many players, a minority of bingo players and their families experience notable harm. Harm was generated through traditional paper-based bingo games, new technologies such as tablet-based bingo and by the widespread tactic of placing bingo sessions in close proximity to harmful electronic gambling machines. Overall, the risk of harm to bingo players appears to be escalating due to commercial, technological and regulatory changes. CONCLUSIONS: These changes can be better managed by regulators: reforms are needed to safeguard bingo's distinct character as a lower-risk form of gambling at a time when it, and its players, are under threat. Significantly, we found that harm to bingo players is intensified by factors external to gambling such as racialised poverty and adverse life events. Strategies that recognise these factors and grapple with gambling harm to bingo players are needed.
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Juego de Azar , Anciano , Juego de Azar/epidemiología , Humanos , Renta , Investigación Cualitativa , Victoria/epidemiologíaRESUMEN
Bactofilins are polymer-forming cytoskeletal proteins that are widely conserved in bacteria. Members of this protein family have diverse functional roles such as orienting subcellular molecular processes, establishing cell polarity, and aiding in cell shape maintenance. Using sequence alignment to the conserved bactofilin domain, we identified a bactofilin ortholog, BacACT, in the obligate intracellular pathogen Chlamydia trachomatis. Chlamydia species are obligate intracellular bacteria that undergo a developmental cycle alternating between infectious nondividing elementary bodies (EBs) and noninfectious dividing reticulate bodies (RBs). As Chlamydia divides by a polarized division process, we hypothesized that BacACT may function to establish polarity in these unique bacteria. Utilizing a combination of fusion constructs and high-resolution fluorescence microscopy, we determined that BacACT forms dynamic, membrane-associated filament- and ring-like structures in Chlamydia's replicative RB form. Contrary to our hypothesis, these structures are distinct from the microbe's cell division machinery and do not colocalize with septal peptidoglycan or MreB, the major organizer of the bacterium's division complex. Bacterial two-hybrid assays demonstrated BacACT interacts homotypically but does not directly interact with proteins involved in cell division or peptidoglycan biosynthesis. To investigate the function of BacACT in chlamydial development, we constructed a conditional knockdown strain using a newly developed CRISPR interference system. We observed that reducing bacACT expression significantly increased chlamydial cell size. Normal RB morphology was restored when an additional copy of bacACT was expressed in trans during knockdown. These data reveal a novel function for chlamydial bactofilin in maintaining cell size in this obligate intracellular bacterium.
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Proteínas Bacterianas/metabolismo , Infecciones por Chlamydia/microbiología , Chlamydia trachomatis/fisiología , Proteínas del Citoesqueleto/metabolismo , Interacciones Huésped-Patógeno , División Celular , Regulación Bacteriana de la Expresión Génica , Humanos , Peptidoglicano/metabolismoRESUMEN
BACKGROUND: Accrual to cancer clinical trials is suboptimal. Few data exist regarding whether financial reimbursement might increase accruals. OBJECTIVE: The objective of this study was to assess perceptions about reimbursement to overcome barriers to trial accrual. RESEARCH DESIGN: This was a cross-sectional survey. SUBJECTS: Oncologists identified from the American Medical Association Physician Masterfile. MEASURES: We report descriptive statistics, associations of physician characteristics with perceptions of reimbursement, domains, and subthemes of free-text comments. RESULTS: Respondents (n=1030) were mostly medical oncologists (59.4%), ages 35-54 (67%), and male (75%). Overall, 30% reported discussing trials with >25% of patients. Barriers perceived were administrative/regulatory, physician/staff time, and eligibility criteria. National Cancer Institute cooperative group participants and practice owners were more likely to endorse higher reimbursement. Respondents indicated targeted reimbursement would help improve infrastructure, but also noted potential ethical problems with reimbursement for discussion (40.7%) and accrual (85.9%). Free-text comments addressed reimbursement sources, recipients, and concerns about the real and apparent conflict of interest. CONCLUSIONS: Though concerns about a potential conflict of interest remain paramount and must be addressed in any new system of reimbursement, oncologists believe reimbursement to enhance infrastructure could help overcome barriers to trial accrual.
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Ensayos Clínicos como Asunto , Oncología Médica , Motivación , Neoplasias/terapia , Selección de Paciente , Médicos/estadística & datos numéricos , Adulto , Conflicto de Intereses , Estudios Transversales , Femenino , Humanos , Entrevistas como Asunto , Masculino , Persona de Mediana Edad , Participación del PacienteRESUMEN
Anthracnose fruit rot (AFR) and Botrytis fruit rot (BFR) are primary diseases affecting strawberry (Fragaria × ananassa), which typically drive fungicide applications throughout the growing season. The Strawberry Advisory System (StAS), a disease forecasting tool, was originally developed in Florida to better time the fungicide sprays by monitoring AFR and BFR infection risk based on leaf wetness and temperature input in real-time. Thirteen field trials were conducted in Maryland and Virginia between 2017 and 2019 to evaluate the StAS performance in the Mid-Atlantic region. As a result, 55, 18, and 31% fewer sprays were recorded on average in the model-based StAS treatment compared with the grower standard treatment in 2017, 2018, and 2019, respectively. Marketable yield, as well as AFR and BFR incidence, were largely comparable between the two treatments. However, poor disease control occurred during the StAS treatment in four trials in 2017, presumably because of a missed fungicide spray during a high-risk infection event and attributable to heavy rainfall that led to impassable fields. The implementation of the StAS may be further challenged by the employment of floating row covers that are essential for growing strawberries in plasticulture systems in open fields in the Mid-Atlantic region. Preliminary results indicated that row covers can alter canopy-level microclimatic conditions, possibly increasing the risk for disease occurrence. Overall, the StAS can be a valuable tool for Mid-Atlantic growers to control AFR and BFR, but sprays may need to be promptly applied when consecutive or heavy rainfalls are predicted, especially for highly susceptible cultivars. Complications in disease forecasting and management arising from the use of row covers need to be further addressed in this region because of its highly diverse climate.
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Fragaria , Fungicidas Industriales , Botrytis , Mid-Atlantic Region , Enfermedades de las PlantasRESUMEN
Chlamydia is an obligate intracellular bacterial pathogen that has significantly reduced its genome size in adapting to its intracellular niche. Among the genes that Chlamydia has eliminated is ftsZ, encoding the central organizer of cell division that directs cell wall synthesis in the division septum. These Gram-negative pathogens have cell envelopes that lack peptidoglycan (PG), yet they use PG for cell division purposes. Recent research into chlamydial PG synthesis, components of the chlamydial divisome, and the mechanism of chlamydial division have significantly advanced our understanding of these processes in a unique and important pathogen. For example, it has been definitively confirmed that chlamydiae synthesize a canonical PG structure during cell division. Various studies have suggested and provided evidence that Chlamydia uses MreB to substitute for FtsZ in organizing and coordinating the divisome during division, components of which have been identified and characterized. Finally, as opposed to using an FtsZ-dependent binary fission process, Chlamydia employs an MreB-dependent polarized budding process to divide. A brief historical context for these key advances is presented along with a discussion of the current state of knowledge of chlamydial cell division.
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Proteínas Bacterianas/metabolismo , División Celular/fisiología , Proteínas del Citoesqueleto/metabolismo , Regulación Bacteriana de la Expresión Génica/fisiología , Proteínas Bacterianas/genética , Proteínas del Citoesqueleto/genética , HumanosRESUMEN
Chlamydiae lack the conserved central coordinator protein of cell division FtsZ, a tubulin-like homolog. Current evidence indicates that Chlamydia uses the actin-like homolog, MreB, to substitute for the role of FtsZ in a polarized division mechanism. Interestingly, we observed MreB as a ring at the septum in dividing cells of Chlamydia We hypothesize that MreB, to substitute for FtsZ in Chlamydia, must possess unique properties compared to canonical MreB orthologs. Sequence differences between chlamydial MreB and orthologs in other bacteria revealed that chlamydial MreB possesses an extended N-terminal region, harboring predicted amphipathicity, as well as the conserved amphipathic helix found in other bacterial MreBs. The conserved amphipathic helix-directed green fluorescent protein (GFP) to label the membrane uniformly in Escherichia coli but the extended N-terminal region did not. However, the extended N-terminal region together with the conserved amphipathic region directed GFP to restrict the membrane label to the cell poles. In Chlamydia, the extended N-terminal region was sufficient to direct GFP to the membrane, and this localization was independent of an association with endogenous MreB. Importantly, mutating the extended N-terminal region to reduce its amphipathicity resulted in the accumulation of GFP in the cytosol of the chlamydiae and not in the membrane. The N-terminal domain of MreB was not required for homotypic interactions but was necessary for interactions with cell division components RodZ and FtsK. Our data provide mechanistic support for chlamydial MreB to serve as a substitute for FtsZ by forming a ringlike structure at the site of polarized division.IMPORTANCEChlamydia trachomatis is an obligate intracellular pathogen, causing sexually transmitted diseases and trachoma. The study of chlamydial physiology is important for developing novel therapeutic strategies for these diseases. Chlamydiae divide by a unique MreB-dependent polarized cell division process. In this study, we investigated unique properties of chlamydial MreB and observed that chlamydial species harbor an extended N-terminal region possessing amphipathicity. MreB formed a ring at the septum, like FtsZ in Escherichia coli, and its localization was dependent upon the amphipathic nature of its extended N terminus. Furthermore, this region is crucial for the interaction of MreB with cell division proteins. Given these results, chlamydial MreB likely functions at the septum as a scaffold for divisome proteins to regulate cell division in this organism.
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Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Membrana Celular/metabolismo , Chlamydia trachomatis/metabolismo , Proteínas Bacterianas/genética , División Celular , Membrana Celular/genética , Polaridad Celular , Infecciones por Chlamydia/microbiología , Chlamydia trachomatis/química , Chlamydia trachomatis/citología , Chlamydia trachomatis/genética , Humanos , Dominios ProteicosRESUMEN
Maternal perinatal depression (PND), a common mental disorder with a prevalence of over 10%, is associated with long-term health risks for both mothers and offspring. This study aimed at describing characteristics related to background and lifestyle, pregnancy, delivery, and postpartum of different PND trajectories defined according to the onset of depressive symptoms. Participants were drawn from a large population-based cohort study in Uppsala, Sweden (n = 2,466). Five trajectory groups of depressive symptom onset were created using the Edinburgh Postnatal Depression Scale ≥13 (pregnancy) or ≥12 points (postpartum): (a) healthy (60.6%), (b) pregnancy depression (8.5%), (c) early postpartum onset (10.9%), (d) late postpartum onset (5.4%), and (e) chronic depression (14.6%). In multinomial logistic regressions, the associations between trajectories and the included characteristics were tested using the healthy trajectory as reference. Background characteristics (younger age, lower education, unemployment) were primarily associated with pregnancy depression and chronic depression. Characteristics associated with all PND trajectories were smoking prior to pregnancy, migraine, premenstrual mood symptoms, intimate partner violence, interpersonal trauma, negative delivery expectations, pregnancy nausea, and symphysiolysis. Nulliparity, instrumental delivery, or a negative delivery experience was associated with early postpartum onset. Postpartum factors (e.g., infantile colic, lack of sleep, low partner support, and bonding difficulties) were associated with early and late postpartum onset together with chronic depression. The findings suggest that different PND trajectories have divergent characteristics, which could be used to create individualized treatment options. To find the most predictive characteristics for different PND trajectories, studies with even larger and more diverse samples are warranted.
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Depresión Posparto/psicología , Depresión/psicología , Trastorno Depresivo/psicología , Complicaciones del Embarazo/psicología , Adulto , Factores de Edad , Escolaridad , Empleo , Femenino , Humanos , Madres , Embarazo , Factores de Riesgo , Estrés Psicológico/psicología , Adulto JovenRESUMEN
The resolution offered by genomic data sets coupled with recently developed spatially informed analyses are allowing researchers to quantify population structure at increasingly fine temporal and spatial scales. However, both empirical research and conservation measures have been limited by questions regarding the impacts of data set size, data quality thresholds and the timescale at which barriers to gene flow become detectable. Here, we used restriction site associated DNA sequencing to generate a 2,140 single nucleotide polymorphism (SNP) data set for the copperhead snake (Agkistrodon contortrix) and address the population genomic impacts of recent and widespread landscape modification across an ~1,000-km2 region of eastern Kentucky, USA. Nonspatial population-based assignment and clustering methods supported little to no population structure. However, using individual-based spatial autocorrelation approaches we found evidence for genetic structuring which closely follows the path of a historically important highway which experienced high traffic volumes from c. 1920 to 1970 before losing most traffic to a newly constructed alternative route. We found no similar spatial genomic signatures associated with more recently constructed highways or surface mining activity, although a time lag effect may be responsible for the lack of any emergent spatial genetic patterns. Subsampling of our SNP data set suggested that similar results could be obtained with as few as 250 SNPs, and a range of thresholds for missing data exhibited limited impacts on the spatial patterns we detected. While we were not able to estimate relative effects of land uses or precise time lags, our findings highlight the importance of temporal factors in landscape genetics approaches, and suggest the potential advantages of genomic data sets and fine-scale, spatially informed approaches for quantifying subtle genetic patterns in temporally complex landscapes.
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Agkistrodon/genética , Ecosistema , Variación Genética/genética , Genómica , Animales , Región de los Apalaches , Flujo Génico/genética , Genética de Población , Kentucky , Polimorfismo de Nucleótido Simple/genética , Dinámica Poblacional , Análisis de Secuencia de ADNRESUMEN
BACKGROUND: Patient participation in cancer clinical trials is suboptimal. A challenge to capturing physicians' insights about trials has been low response to surveys. We conducted a study using varying combinations of mail and email to recruit a nationally representative sample of medical, surgical, and radiation oncologists to complete a survey on trial accrual. METHODS: We randomly assigned eligible physicians identified from the American Medical Association MasterFile (n = 13,251) to mail- or email-based recruitment strategies. Mail-based recruitment included a survey packet with: (1) cover letter describing the survey and inviting participation; (2) paper copy of the survey and postage-paid return envelope; and (3) a web link for completing the survey online. Email-based recruitment included an e-mail describing the survey and inviting participation, along with the web link to the survey, and a reminder postcard 2 weeks later. RESULTS: Response was higher for mail-based (11.8, 95% CI 11.0-12.6%) vs. email-based (4.5, 95% CI 4.0-5.0%) recruitment. In email-based recruitment, only one-quarter of recipients opened the email, and even fewer clicked on the link to complete the survey. Most physicians in mail-based recruitment responded after the first invitation (362 of 770 responders, 47.0%). A higher proportion of responders vs. non-responders were young (ages 25-44 years), men, and radiation or surgical (vs. medical) oncologists. CONCLUSIONS: Most physicians assigned to mail-based recruitment actually completed the survey online via the link provided in the cover letter, and those in email-based recruitment did not respond until they received a reminder postcard by mail. Providing the option to return a paper survey or complete it online may have further increased participation in the mail-based group, and future studies should examine how combinations of delivery mode and return options affect physicians' response to surveys.
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Correo Electrónico , Médicos , Adulto , Humanos , Masculino , Selección de Paciente , Servicios Postales , Encuestas y CuestionariosRESUMEN
The Edinburgh Postnatal Depression Scale (EPDS) was published over 30 years ago as a ten-item self-report questionnaire to facilitate the detection of perinatal depression - and for use in research. It is widely used at the present time in many regions of the world and has been translated into over 60 languages. It is occasionally misused. In this editorial, updated recommendations for optimal use in primary and secondary care as well as research are provided. Future studies to evaluate its use and validity in naturalistic community populations are now required, and to determine the psychometric properties and practical usefulness of the EPDS when completed online.Declaration of interestJ.C. has no financial interest in the use of, or reproduction of, the EPDS.
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Depresión Posparto/diagnóstico , Escalas de Valoración Psiquiátrica/historia , Adulto , Femenino , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Tamizaje Masivo , Embarazo , Psicometría , Reproducibilidad de los ResultadosRESUMEN
In containerized (potted) annual nursery and greenhouse crops, set point-controlled irrigation allows adaptation to increasing water insecurity by precisely reducing water inputs. A key factor influencing adoption is lack of information on disease risk. To facilitate adaptive water use, effects of set-point substrate moisture (SM) control on disease risk and water savings in containerized annual production were evaluated using the Phytophthora capsici-tomato pathosystem (a model system for water stress predisposition to pathogen infection), comparing outcomes of imposing midrange SM (15% volumetric water content [VWC]) and low-range SM (10% VWC) with well-watered (20% VWC) plants. Reducing soil moisture to 10% VWC differentially reduced stem water potential (P < 0.05) and enhanced rate of wilt progress (P = 0.006) and root rot severity (P = 0.03) in P. capsici inoculated plants compared with noninoculated plants. Furthermore, incidence of fine root infections in inoculated asymptomatic plants was greater under reduced SM (10% VWC) compared with in well-watered plants (P < 0.05). Mild reductions to 15% VWC did not influence plant performance (root and shoot weights and plant height) or pathogen infection in either inoculated or noninoculated plants compared with well-watered plants and reduced water inputs by 17%, indicating potential for reducing water usage without increasing disease risk. Furthermore, P. capsici inoculated plants had lower shoot biomass and greater root infection incidence when 15% VWC was applied to older compared with younger plants; the inverse was true for root rot severity, although root rot development was minor overall (P < 0.05). These results indicate that water use reductions pose disease risks, but there is potential to reduce water use and effectively manage plant pathogens in containerized production. Overall, this study indicates that physiological indices should not be solely relied on to develop water reduction methods.
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Phytophthora , Enfermedades de las Plantas/microbiología , Solanum lycopersicum , Productos Agrícolas , Solanum lycopersicum/microbiología , Phytophthora/fisiología , AguaRESUMEN
[This corrects the article DOI: 10.1371/journal.ppat.1005822.].
RESUMEN
Bacterial cell division predominantly occurs by a highly conserved process, termed binary fission, that requires the bacterial homologue of tubulin, FtsZ. Other mechanisms of bacterial cell division that are independent of FtsZ are rare. Although the obligate intracellular human pathogen Chlamydia trachomatis, the leading bacterial cause of sexually transmitted infections and trachoma, lacks FtsZ, it has been assumed to divide by binary fission. We show here that Chlamydia divides by a polarized cell division process similar to the budding process of a subset of the Planctomycetes that also lack FtsZ. Prior to cell division, the major outer-membrane protein of Chlamydia is restricted to one pole of the cell, and the nascent daughter cell emerges from this pole by an asymmetric expansion of the membrane. Components of the chlamydial cell division machinery accumulate at the site of polar growth prior to the initiation of asymmetric membrane expansion and inhibitors that disrupt the polarity of C. trachomatis prevent cell division. The polarized cell division of C. trachomatis is the result of the unipolar growth and FtsZ-independent fission of this coccoid organism. This mechanism of cell division has not been documented in other human bacterial pathogens suggesting the potential for developing Chlamydia-specific therapeutic treatments.
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División Celular/fisiología , Chlamydia trachomatis/fisiología , Chlamydia trachomatis/ultraestructura , Polaridad Celular , Células HeLa , Humanos , Immunoblotting , Microscopía Confocal , Microscopía Electrónica de TransmisiónRESUMEN
BACKGROUND: The growing numbers of cancer survivors challenge delivery of high-quality survivorship care by healthcare systems. Innovative ways to improve care coordination for patients with cancer and multiple chronic conditions ("complex cancer survivors") are needed to achieve better care outcomes, improve patient experience of care, and lower cost. Our study, Project CONNECT, will adapt and implement three evidence-based care coordination strategies, shown to be effective for primary care conditions, among complex cancer survivors. Specifically, the purpose of this study is to: 1) Implement a system-level EHR-driven intervention for 500 complex cancer survivors at Parkland; 2) Test effectiveness of the strategies on system- and patient-level outcomes measured before and after implementation; and 3) Elucidate system and patient factors that facilitate or hinder implementation and result in differences in experiences of care coordination between complex patients with and without cancer. METHODS: Project CONNECT is a quasi-experimental implementation study among 500 breast and colorectal cancer survivors with at least one of the following chronic conditions: diabetes, hypertension, chronic lung disease, chronic kidney disease, or heart disease. We will implement three evidence-based care coordination strategies in a large, county integrated safety-net health system: 1) an EHR-driven registry to facilitate patient transitions between primary and oncology care; 2) co-locating a nurse practitioner trained in care coordination within a complex care team; 3) and enhancing teamwork through coaching. Segmented regression analysis will evaluate change in system-level (i.e. composite care quality score) and patient-level outcomes (i.e. self-reported care coordination). To evaluate implementation, we will merge quantitative findings with structured observations and physician and patient interviews. DISCUSSION: This study will result in an evaluation toolkit identifying key model elements, barriers, and facilitators that can be used to guide care coordination interventions in other safety-net settings. Because Parkland is a vanguard of safety-net healthcare nationally, findings will be widely applicable as other safety-nets move toward increased integration, enhanced EHR capability, and experience with growing patient diversity. Our proposal recognizes the complexity of interventions and scaffolds evidence-based strategies together to meet the needs of complex patients, systems of care, and service integration. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02943265 . Registered 24 October 2016.
Asunto(s)
Supervivientes de Cáncer , Continuidad de la Atención al Paciente , Prestación Integrada de Atención de Salud/métodos , Oncología Médica/métodos , Atención Primaria de Salud/métodos , Proveedores de Redes de Seguridad/métodos , Continuidad de la Atención al Paciente/normas , Prestación Integrada de Atención de Salud/normas , Prestación Integrada de Atención de Salud/tendencias , Femenino , Humanos , Masculino , Oncología Médica/normas , Oncología Médica/tendencias , Enfermeras Practicantes/normas , Enfermeras Practicantes/tendencias , Atención Primaria de Salud/normas , Atención Primaria de Salud/tendencias , Calidad de la Atención de Salud/normas , Calidad de la Atención de Salud/tendencias , Proveedores de Redes de Seguridad/normasRESUMEN
Previously, American black bears (Ursus americanus) were thought to follow the pattern of female philopatry and male-biased dispersal. However, recent studies have identified deviations from this pattern. Such flexibility in dispersal patterns can allow individuals greater ability to acclimate to changing environments. We explored dispersal and spatial genetic relatedness patterns across ten black bear populations-including long established (historic), with known reproduction >50 years ago, and newly established (recent) populations, with reproduction recorded <50 years ago-in the Interior Highlands and Southern Appalachian Mountains, United States. We used spatially explicit, individual-based genetic simulations to model gene flow under scenarios with varying levels of population density, genetic diversity, and female philopatry. Using measures of genetic distance and spatial autocorrelation, we compared metrics between sexes, between population types (historic and recent), and among simulated scenarios which varied in density, genetic diversity, and sex-biased philopatry. In empirical populations, females in recent populations exhibited stronger patterns of isolation-by-distance (IBD) than females and males in historic populations. In simulated populations, low-density populations had a stronger indication of IBD than medium- to high-density populations; however, this effect varied in empirical populations. Condition-dependent dispersal strategies may permit species to cope with novel conditions and rapidly expand populations. Pattern-process modeling can provide qualitative and quantitative means to explore variable dispersal patterns, and could be employed in other species, particularly to anticipate range shifts in response to changing climate and habitat conditions.