42 research outputs found

    A single bacterial genus maintains root growth in a complex microbiome

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    Plants grow within a complex web of species that interact with each other and with the plant1–10. These interactions are governed by a wide repertoire of chemical signals, and the resulting chemical landscape of the rhizosphere can strongly affect root health and development7–9,11–18. Here, to understand how interactions between microorganisms influence root growth in Arabidopsis, we established a model system for interactions between plants, microorganisms and the environment. We inoculated seedlings with a 185-member bacterial synthetic community, manipulated the abiotic environment and measured bacterial colonization of the plant. This enabled us to classify the synthetic community into four modules of co-occurring strains. We deconstructed the synthetic community on the basis of these modules, and identified interactions between microorganisms that determine root phenotype. These interactions primarily involve a single bacterial genus (Variovorax), which completely reverses the severe inhibition of root growth that is induced by a wide diversity of bacterial strains as well as by the entire 185-member community. We demonstrate that Variovorax manipulates plant hormone levels to balance the effects of our ecologically realistic synthetic root community on root growth. We identify an auxin-degradation operon that is conserved in all available genomes of Variovorax and is necessary and sufficient for the reversion of root growth inhibition. Therefore, metabolic signal interference shapes bacteria–plant communication networks and is essential for maintaining the stereotypic developmental programme of the root. Optimizing the feedbacks that shape chemical interaction networks in the rhizosphere provides a promising ecological strategy for developing more resilient and productive crops

    Specific modulation of the root immune system by a community of commensal bacteria

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    Plants have an innate immune system to fight off potential invaders that is based on the perception of nonself or modified-self molecules. Microbe-associated molecular patterns (MAMPs) are evolutionarily conserved microbial molecules whose extracellular detection by specific cell surface receptors initiates an array of biochemical responses collectively known as MAMP-triggered immunity (MTI). Well-characterized MAMPs include chitin, peptidoglycan, and flg22, a 22-amino acid epitope found in the major building block of the bacterial flagellum, FliC. The importance of MAMP detection by the plant immune system is underscored by the large diversity of strategies used by pathogens to interfere with MTI and that failure to do so is often associated with loss of virulence. Yet, whether or how MTI functions beyond pathogenic interactions is not well understood. Here we demonstrate that a community of root commensal bacteria modulates a specific and evolutionarily conserved sector of the Arabidopsis immune system. We identify a set of robust, taxonomically diverse MTI suppressor strains that are efficient root colonizers and, notably, can enhance the colonization capacity of other tested commensal bacteria. We highlight the importance of extracellular strategies for MTI suppression by showing that the type 2, not the type 3, secretion system is required for the immunomodulatory activity of one robust MTI suppressor. Our findings reveal that root colonization by commensals is controlled by MTI, which, in turn, can be selectively modulated by specific members of a representative bacterial root microbiota

    Non-motor symptom burden in patients with Parkinson's disease with impulse control disorders and compulsive behaviours : results from the COPPADIS cohort

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    The study was aimed at analysing the frequency of impulse control disorders (ICDs) and compulsive behaviours (CBs) in patients with Parkinson's disease (PD) and in control subjects (CS) as well as the relationship between ICDs/CBs and motor, nonmotor features and dopaminergic treatment in PD patients. Data came from COPPADIS-2015, an observational, descriptive, nationwide (Spain) study. We used the validated Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS) for ICD/CB screening. The association between demographic data and ICDs/CBs was analyzed in both groups. In PD, this relationship was evaluated using clinical features and treatment-related data. As result, 613 PD patients (mean age 62.47 ± 9.09 years, 59.87% men) and 179 CS (mean age 60.84 ± 8.33 years, 47.48% men) were included. ICDs and CBs were more frequent in PD (ICDs 12.7% vs. 1.6%, p < 0.001; CBs 7.18% vs. 1.67%, p = 0.01). PD patients had more frequent previous ICDs history, premorbid impulsive personality and antidepressant treatment (p < 0.05) compared with CS. In PD, patients with ICDs/CBs presented younger age at disease onset, more frequent history of previous ICDs and premorbid personality (p < 0.05), as well as higher comorbidity with nonmotor symptoms, including depression and poor quality of life. Treatment with dopamine agonists increased the risk of ICDs/CBs, being dose dependent (p < 0.05). As conclusions, ICDs and CBs were more frequent in patients with PD than in CS. More nonmotor symptoms were present in patients with PD who had ICDs/CBs compared with those without. Dopamine agonists have a prominent effect on ICDs/CBs, which could be influenced by dose

    Effectiveness of an mHealth intervention combining a smartphone app and smart band on body composition in an overweight and obese population: Randomized controlled trial (EVIDENT 3 study)

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    Background: Mobile health (mHealth) is currently among the supporting elements that may contribute to an improvement in health markers by helping people adopt healthier lifestyles. mHealth interventions have been widely reported to achieve greater weight loss than other approaches, but their effect on body composition remains unclear. Objective: This study aimed to assess the short-term (3 months) effectiveness of a mobile app and a smart band for losing weight and changing body composition in sedentary Spanish adults who are overweight or obese. Methods: A randomized controlled, multicenter clinical trial was conducted involving the participation of 440 subjects from primary care centers, with 231 subjects in the intervention group (IG; counselling with smartphone app and smart band) and 209 in the control group (CG; counselling only). Both groups were counselled about healthy diet and physical activity. For the 3-month intervention period, the IG was trained to use a smartphone app that involved self-monitoring and tailored feedback, as well as a smart band that recorded daily physical activity (Mi Band 2, Xiaomi). Body composition was measured using the InBody 230 bioimpedance device (InBody Co., Ltd), and physical activity was measured using the International Physical Activity Questionnaire. Results: The mHealth intervention produced a greater loss of body weight (–1.97 kg, 95% CI –2.39 to –1.54) relative to standard counselling at 3 months (–1.13 kg, 95% CI –1.56 to –0.69). Comparing groups, the IG achieved a weight loss of 0.84 kg more than the CG at 3 months. The IG showed a decrease in body fat mass (BFM; –1.84 kg, 95% CI –2.48 to –1.20), percentage of body fat (PBF; –1.22%, 95% CI –1.82% to 0.62%), and BMI (–0.77 kg/m2, 95% CI –0.96 to 0.57). No significant changes were observed in any of these parameters in men; among women, there was a significant decrease in BMI in the IG compared with the CG. When subjects were grouped according to baseline BMI, the overweight group experienced a change in BFM of –1.18 kg (95% CI –2.30 to –0.06) and BMI of –0.47 kg/m2 (95% CI –0.80 to –0.13), whereas the obese group only experienced a change in BMI of –0.53 kg/m2 (95% CI –0.86 to –0.19). When the data were analyzed according to physical activity, the moderate-vigorous physical activity group showed significant changes in BFM of –1.03 kg (95% CI –1.74 to –0.33), PBF of –0.76% (95% CI –1.32% to –0.20%), and BMI of –0.5 kg/m2 (95% CI –0.83 to –0.19). Conclusions: The results from this multicenter, randomized controlled clinical trial study show that compared with standard counselling alone, adding a self-reported app and a smart band obtained beneficial results in terms of weight loss and a reduction in BFM and PBF in female subjects with a BMI less than 30 kg/m2 and a moderate-vigorous physical activity level. Nevertheless, further studies are needed to ensure that this profile benefits more than others from this intervention and to investigate modifications of this intervention to achieve a global effect

    Same data, different conclusions: Radical dispersion in empirical results when independent analysts operationalize and test the same hypothesis

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    In this crowdsourced initiative, independent analysts used the same dataset to test two hypotheses regarding the effects of scientists’ gender and professional status on verbosity during group meetings. Not only the analytic approach but also the operationalizations of key variables were left unconstrained and up to individual analysts. For instance, analysts could choose to operationalize status as job title, institutional ranking, citation counts, or some combination. To maximize transparency regarding the process by which analytic choices are made, the analysts used a platform we developed called DataExplained to justify both preferred and rejected analytic paths in real time. Analyses lacking sufficient detail, reproducible code, or with statistical errors were excluded, resulting in 29 analyses in the final sample. Researchers reported radically different analyses and dispersed empirical outcomes, in a number of cases obtaining significant effects in opposite directions for the same research question. A Boba multiverse analysis demonstrates that decisions about how to operationalize variables explain variability in outcomes above and beyond statistical choices (e.g., covariates). Subjective researcher decisions play a critical role in driving the reported empirical results, underscoring the need for open data, systematic robustness checks, and transparency regarding both analytic paths taken and not taken. Implications for organizations and leaders, whose decision making relies in part on scientific findings, consulting reports, and internal analyses by data scientists, are discussed

    Selective nuclear morphometry as a prognostic factor of survival in renal cell carcinoma

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    In the present study, we sought to determine the predictive value of selective nuclear morphometry (SNM) for patient outcome in renal cell carcinoma (RCC). Tumor samples of 140 renal adenocarcinomas diagnosed and treated with radical nephrectomy and hilar lymphadenectomy between 1970 and 1988 with a minimum follow up of 5 years in all the cases were studied by SNM. The morphometric analysis was performed in the most malignant tumor selected zone. Selection was based on cytological criteria including nuclear grade. Nuclear morphometric features analyzed were: area, perimeter, major diameter, major and minor diameter of the equivalent ellipse, volume of the equivalent ellipse and sphere, circumference diameter, and shape factors. The results showed that in the selected zone tumor nuclei were larger than in the zones selected at random. There was an inverse correlation between morphometric parameters and survival and a direct one between tumoral grade and stage. Tumors of the longterm survival group of patients presented nuclei with smaller morphometric measurements than tumors of short term survival group, with significant differences between them (pe0.05). In the survival analysis carried out by the Kaplan-Meier method significant differences existed between different groups formed from break point for: area, perimeter, major diameter, major and minor diameter of the ellipse, volume of the ellipse and sphere, circumference diameter and perimeter shape factor. In the multivariate analysis carried out by the Cox method, the feature with the most predictable value related to survival, was the tumor stage. Morphometric value with the highest punctuation in the test was major nuclear diameter. The rest of the morphometric values (except elliptic shape factor and elongation factor) were also significant but they did not improve prognostic information of the major nuclear diameter. SNM offers a useful aid in a more objective grading of RCC. Multivariate Cox analysis revealed additional value of karyometry to tumor stage. SNM can be a useful tool for stratification of patients with RCC

    Advanced Parkinson's disease: Clinical characteristics and treatment. Part II

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    Introduction: Many patients who have had Parkinson's disease (PD) for several years will present severe motor fluctuations and dyskinesias which require more aggressive therapies. The different approaches which are now available include deep brain stimulation of the subthalamic nucleus or medial globus pallidus, subcutaneous infusion of apomorphine, and intestinal infusion of levodopa–carbidopa. Objective: To define the indications and results for the 3 available therapies for advanced PD. Development: Exhaustive review of the literature concerning the indications and results of deep brain stimulation, subcutaneous apomorphine infusion and duodenal infusion of levodopa/carbidopa gel to treat patients with advanced Parkinson disease. Conclusions: Although numerous studies have confirmed the efficacy of the 3 different therapies in advanced PD, there are no comparative studies that would allow us to define the best candidate for each technique. Resumen: Introducción: Muchos de los pacientes con enfermedad de Parkinson (EP) presentan al cabo de varios años fluctuaciones y discinesias graves que requieren de terapias algo más agresivas como la estimulación cerebral profunda del núcleo subtalámico o globo pálido medial, la infusión continua de apomorfina y la infusión intestinal continua de levodopa-carbidopa. Objetivo: Establecer las indicaciones y resultados de las 3 técnicas disponibles en la actualidad para el tratamiento de la EP avanzada. Desarrollo: Revisión exhaustiva de los datos publicados en la literatura sobre las indicaciones y resultados de la estimulación cerebral profunda del núcleo subtalámico, infusión subcutánea de apomorfina e infusión intestinal continua de levodopa-carbidopa en pacientes con EP avanzada. Conclusiones: Aunque existen numerosos estudios que han descrito la eficacia de cada una de estas 3 técnicas, faltan estudios comparativos que permitan definir el candidato ideal para cada una de las técnicas. Keywords: Advanced Parkinson's disease, Deep brain stimulation, Subcutaneous apomorphine infusion, Intestinal levodopa–carbidopa infusion, Palabras clave: Enfermedad de Parkinson avanzada, Estimulación cerebral profunda, Infusión de apomorfina, Infusión intestinal de levodopa-carbidop

    Enfermedad de Parkinson avanzada. Características clínicas y tratamiento (parte I)

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    Resumen: Introducción: Un porcentaje importante de pacientes con enfermedad de Parkinson (EP) desarrollan complicaciones motoras en forma de fluctuaciones motoras, discinesias y síntomas no motores al cabo de 3-5 años del inicio del tratamiento que resultan de difícil control terapéutico. Esta fase de la enfermedad ha sido definida por algunos autores como fase avanzada de la EP. Objetivo: Definir las características clínicas y los factores de riesgo que condicionan que una EP evolucione a un estadio avanzado. Desarrollo: Este documento de consenso se ha realizado mediante una búsqueda bibliográfica exhaustiva y discusión de los contenidos llevadas a cabo por un grupo de expertos en trastornos del movimiento de la Sociedad Espãnola de Neurología coordinados por dos de los autores (JK y MRL). Conclusiones: La presencia de fluctuaciones motoras y discinesias graves, síntomas motores axiales resistentes a la levodopa y síntomas no motores, como los trastornos cognitivos, representan las principales manifestaciones fenotípicas de una EP avanzada. Abstract: Introduction: A large percentage of patients with Parkinson's disease (PD) develop motor fluctuations, dyskinesias, and severe non-motor symptoms within 3 to 5 years of starting dopaminergic therapy, and these motor complications are refractory to treatment. Several authors refer to this stage of the disease as advanced Parkinson's disease. Objective: To define the clinical manifestations of advanced PD and the risk factors for reaching this stage of the disease. Development: This consensus document has been prepared by using an exhaustive literature search and by discussion of the contents by an expert group on movement disorders of the Sociedad Española de Neurología (Spanish Neurology Society), coordinated by two of the authors (JK and MRL). Conclusions: Severe motor fluctuations and dyskinesias, axial motor symptoms resistant to levodopa, and cognitive decline are the main signs in the clinical phenotype of advanced PD. Palabras clave: Enfermedad de Parkinson avanzada, Factores de riesgo, Fenotipo clínico, Escalas de valoración motora, Escalas de valoración no motora, Escalas de calidad de vida, Keywords: Advanced Parkinson's disease, Risk factors, Clinical phenotype, Motor scales, Non-motor scales, Quality of life scale
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