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1.
Proc Natl Acad Sci U S A ; 121(5): e2309575121, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38266051

RESUMEN

During the last decades, macroecology has identified broad-scale patterns of abundances and diversity of microbial communities and put forward some potential explanations for them. However, these advances are not paralleled by a full understanding of the dynamical processes behind them. In particular, abundance fluctuations of different species are found to be correlated, both across time and across communities in metagenomic samples. Reproducing such correlations through appropriate population models remains an open challenge. The present paper tackles this problem and points to sparse species interactions as a necessary mechanism to account for them. Specifically, we discuss several possibilities to include interactions in population models and recognize Lotka-Volterra constants as a successful ansatz. For this, we design a Bayesian inference algorithm to extract sets of interaction constants able to reproduce empirical probability distributions of pairwise correlations for diverse biomes. Importantly, the inferred models still reproduce well-known single-species macroecological patterns concerning abundance fluctuations across both species and communities. Endorsed by the agreement with the empirically observed phenomenology, our analyses provide insights into the properties of the networks of microbial interactions, revealing that sparsity is a crucial feature.


Asunto(s)
Microbiota , Teorema de Bayes , Metagenoma , Algoritmos , Metagenómica
2.
Proc Natl Acad Sci U S A ; 120(9): e2208998120, 2023 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-36827262

RESUMEN

The brain is in a state of perpetual reverberant neural activity, even in the absence of specific tasks or stimuli. Shedding light on the origin and functional significance of such a dynamical state is essential to understanding how the brain transmits, processes, and stores information. An inspiring, albeit controversial, conjecture proposes that some statistical characteristics of empirically observed neuronal activity can be understood by assuming that brain networks operate in a dynamical regime with features, including the emergence of scale invariance, resembling those seen typically near phase transitions. Here, we present a data-driven analysis based on simultaneous high-throughput recordings of the activity of thousands of individual neurons in various regions of the mouse brain. To analyze these data, we construct a unified theoretical framework that synergistically combines a phenomenological renormalization group approach and techniques that infer the general dynamical state of a neural population, while designing complementary tools. This strategy allows us to uncover strong signatures of scale invariance that are "quasiuniversal" across brain regions and experiments, revealing that all the analyzed areas operate, to a greater or lesser extent, near the edge of instability.


Asunto(s)
Encéfalo , Neuronas , Animales , Ratones , Encéfalo/fisiología , Neuronas/fisiología
3.
Proc Natl Acad Sci U S A ; 120(37): e2217144120, 2023 09 12.
Artículo en Inglés | MEDLINE | ID: mdl-37669363

RESUMEN

Multiple ecological forces act together to shape the composition of microbial communities. Phyloecology approaches-which combine phylogenetic relationships between species with community ecology-have the potential to disentangle such forces but are often hard to connect with quantitative predictions from theoretical models. On the other hand, macroecology, which focuses on statistical patterns of abundance and diversity, provides natural connections with theoretical models but often neglects interspecific correlations and interactions. Here, we propose a unified framework combining both such approaches to analyze microbial communities. In particular, by using both cross-sectional and longitudinal metagenomic data for species abundances, we reveal the existence of an empirical macroecological law establishing that correlations in species-abundance fluctuations across communities decay from positive to null values as a function of phylogenetic dissimilarity in a consistent manner across ecologically distinct microbiomes. We formulate three variants of a mechanistic model-each relying on alternative ecological forces-that lead to radically different predictions. From these analyses, we conclude that the empirically observed macroecological pattern can be quantitatively explained as a result of shared population-independent fluctuating resources, i.e., environmental filtering and not as a consequence of, e.g., species competition. Finally, we show that the macroecological law is also valid for temporal data of a single community and that the properties of delayed temporal correlations can be reproduced as well by the model with environmental filtering.


Asunto(s)
Metagenoma , Microbiota , Filogenia , Estudios Transversales , Metagenómica
4.
Lupus ; 32(12): 1409-1417, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37840528

RESUMEN

BACKGROUND: Pregnancy in SLE continues to be a challenge. The neutrophil-to-lymphocyte ratio (NLR) and chemerin are predictors of preeclampsia in the general population; however, their role as predictors of maternal-fetal complications in pregnant SLE patients has not been analyzed. OBJECTIVE: To investigate the prognostic value of NLR and serum chemerin, to predict maternal-fetal complications in pregnant SLE patients, and compare both biomarkers among three study groups. METHODS: Design: Analytical cross-sectional study of cases and controls with the following study groups: systemic lupus erythematosus (SLE), preeclampsia, and healthy. NLR and chemerin serum were determined between 20 and 25 weeks of gestation. Patients were evaluated every 4-6 weeks until pregnancy resolution. Maternal and fetal outcomes were registered. We employed Receiver Operating Characteristic (ROC) curves to validate prognostic values. RESULTS: Seventy pregnant patients were included: 20 with SLE, 20 with preeclampsia, and 30 healthy pregnant women; NLR values were 4 (2.3-5.6) in SLE, 6 (4.6-9.2) in preeclampsia, and 2.8 (2.1-2.9) in the group of healthy women (p = .0001). Chemerin levels were: 26 (15.3-56.2) in SLE, 96 (37.3-146.2) in preeclampsia, and 24.6 ng/mL (15.3-47.4) in the healthy group (p = .007) Maternal complications were observed in 11 (55%), 20 (100%), and 8 (26%) per group, respectively. Thrombocytopenia was the most frequent complication in all pregnant women, followed by hypertensive disorders. Fetal complications were registered in 12 (60%), 16 (80%), and 2 (6.7%), respectively. Congenital malformations and prematurity were the most frequent fetal complications. NLR had good diagnostic accuracy in predicting maternal-fetal complications (AUROC 0.715) p = .015, CI 95% 0.56-0.86, cut-off point level: 2.9, sensitivity 61%, specificity 78%, positive predictive value (PPV) 65%, negative predictive value (NPV) 75%. Regarding chemerin, a cut-off point level >43 ng/mL had a sensitivity of 75%, specificity of 72% AUROC 0.75, p = .001, CI 95% 0.61-0.89, PPV 51.7% NPV 87.8%, meaning that 51.7% of patients with chemerin levels >43 ng/mL have or will have preeclampsia. CONCLUSION: The NLR may help predict maternal-fetal complications in SLE pregnancy, constituting a marker of subclinical inflammation. Chemerin levels may be associated with preeclampsia. These biomarkers could improve the care of SLE patients with timely intervention of potential complications during pregnancy.


Asunto(s)
Lupus Eritematoso Sistémico , Preeclampsia , Complicaciones del Embarazo , Humanos , Embarazo , Femenino , Lupus Eritematoso Sistémico/diagnóstico , Resultado del Embarazo/epidemiología , Pronóstico , Neutrófilos , Estudios Transversales , Complicaciones del Embarazo/diagnóstico , Biomarcadores , Linfocitos , Estudios Retrospectivos
5.
HPB (Oxford) ; 25(4): 400-408, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-37028826

RESUMEN

BACKGROUND: The European registry for minimally invasive pancreatic surgery (E-MIPS) collects data on laparoscopic and robotic MIPS in low- and high-volume centers across Europe. METHODS: Analysis of the first year (2019) of the E-MIPS registry, including minimally invasive distal pancreatectomy (MIDP) and minimally invasive pancreatoduodenectomy (MIPD). Primary outcome was 90-day mortality. RESULTS: Overall, 959 patients from 54 centers in 15 countries were included, 558 patients underwent MIDP and 401 patients MIPD. Median volume of MIDP was 10 (7-20) and 9 (2-20) for MIPD. Median use of MIDP was 56.0% (IQR 39.0-77.3%) and median use of MIPD 27.7% (IQR 9.7-45.3%). MIDP was mostly performed laparoscopic (401/558, 71.9%) and MIPD mostly robotic (234/401, 58.3%). MIPD was performed in 50/54 (89.3%) centers, of which 15/50 (30.0%) performed ≥20 MIPD annually. This was 30/54 (55.6%) centers and 13/30 (43%) centers for MIPD respectively. Conversion rate was 10.9% for MIDP and 8.4% for MIPD. Overall 90 day mortality was 1.1% (n = 6) for MIDP and 3.7% (n = 15) for MIPD. CONCLUSION: Within the E-MIPS registry, MIDP is performed in about half of all patients, mostly using laparoscopy. MIPD is performed in about a quarter of patients, slightly more often using the robotic approach. A minority of centers met the Miami guideline volume criteria for MIPD.


Asunto(s)
Laparoscopía , Neoplasias Pancreáticas , Procedimientos Quirúrgicos Robotizados , Humanos , Neoplasias Pancreáticas/cirugía , Procedimientos Quirúrgicos Robotizados/efectos adversos , Páncreas/cirugía , Pancreatectomía/efectos adversos , Pancreaticoduodenectomía/efectos adversos , Procedimientos Quirúrgicos Mínimamente Invasivos , Laparoscopía/efectos adversos , Sistema de Registros , Complicaciones Posoperatorias/etiología , Resultado del Tratamiento
6.
PLoS Comput Biol ; 17(9): e1009417, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34555011

RESUMEN

Ecological and evolutionary dynamics have been historically regarded as unfolding at broadly separated timescales. However, these two types of processes are nowadays well-documented to intersperse much more tightly than traditionally assumed, especially in communities of microorganisms. Advancing the development of mathematical and computational approaches to shed novel light onto eco-evolutionary problems is a challenge of utmost relevance. With this motivation in mind, here we scrutinize recent experimental results showing evidence of rapid evolution of tolerance by lag in bacterial populations that are periodically exposed to antibiotic stress in laboratory conditions. In particular, the distribution of single-cell lag times-i.e., the times that individual bacteria from the community remain in a dormant state to cope with stress-evolves its average value to approximately fit the antibiotic-exposure time. Moreover, the distribution develops right-skewed heavy tails, revealing the presence of individuals with anomalously large lag times. Here, we develop a parsimonious individual-based model mimicking the actual demographic processes of the experimental setup. Individuals are characterized by a single phenotypic trait: their intrinsic lag time, which is transmitted with variation to the progeny. The model-in a version in which the amplitude of phenotypic variations grows with the parent's lag time-is able to reproduce quite well the key empirical observations. Furthermore, we develop a general mathematical framework allowing us to describe with good accuracy the properties of the stochastic model by means of a macroscopic equation, which generalizes the Crow-Kimura equation in population genetics. Even if the model does not account for all the biological mechanisms (e.g., genetic changes) in a detailed way-i.e., it is a phenomenological one-it sheds light onto the eco-evolutionary dynamics of the problem and can be helpful to design strategies to hinder the emergence of tolerance in bacterial communities. From a broader perspective, this work represents a benchmark for the mathematical framework designed to tackle much more general eco-evolutionary problems, thus paving the road to further research avenues.


Asunto(s)
Fenómenos Fisiológicos Bacterianos , Modelos Biológicos , Adaptación Fisiológica , Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Evolución Biológica , Variación Biológica Poblacional , Biología Computacional , Simulación por Computador , Tolerancia a Medicamentos , Microbiota/efectos de los fármacos , Microbiota/fisiología , Fenotipo , Estrés Fisiológico
7.
Philos Trans A Math Phys Eng Sci ; 380(2227): 20200424, 2022 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-35599563

RESUMEN

Many of the amazing functional capabilities of the brain are collective properties stemming from the interactions of large sets of individual neurons. In particular, the most salient collective phenomena in brain activity are oscillations, which require the synchronous activation of many neurons. Here, we analyse parsimonious dynamical models of neural synchronization running on top of synthetic networks that capture essential aspects of the actual brain anatomical connectivity such as a hierarchical-modular and core-periphery structure. These models reveal the emergence of complex collective states with intermediate and flexible levels of synchronization, halfway in the synchronous-asynchronous spectrum. These states are best described as broad Griffiths-like phases, i.e. an extension of standard critical points that emerge in structurally heterogeneous systems. We analyse different routes (bifurcations) to synchronization and stress the relevance of 'hybrid-type transitions' to generate rich dynamical patterns. Overall, our results illustrate the complex interplay between structure and dynamics, underlining key aspects leading to rich collective states needed to sustain brain functionality. This article is part of the theme issue 'Emergent phenomena in complex physical and socio-technical systems: from cells to societies'.


Asunto(s)
Encéfalo , Neuronas , Encéfalo/fisiología , Neuronas/fisiología
8.
Heart Lung Circ ; 31(2): 183-193, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34373190

RESUMEN

BACKGROUND: Indigenous Australians have a high rate of ischaemic heart disease (IHD). There is a paucity of local data for North Queensland regarding the clinical characteristics of Indigenous people who present to the emergency department (ED) with chest pain. The aim of the study is to compare the cardiovascular risk factors, social characteristics, and the clinical outcomes between Indigenous and non-Indigenous patients who presented with cardiac-related chest pain. METHODS: This is a retrospective single-centre audit. The data was collected through chart reviews of chest pain presentations to the Townsville University Hospital Emergency Department, Queensland, Australia, from January to December 2017. We categorised the patients into Indigenous and non-Indigenous groups and compared their cardiac risk factors and social characteristics. We further classified the patients into three diagnosis groups and we measured the clinical outcomes in the patients with a diagnosis of cardiac-related chest pain. We used a data linkage to the Registry of Births, Deaths and Marriages for the death outcomes. A multivariable analysis was done to determine the risk of major adverse cardiac event (MACE) for Indigenous vs non-Indigenous patients. RESULTS: Indigenous patients were over-represented making up 19.1% of the total cohort (compared with 11.1% of the North Queensland Indigenous population) and presented at a younger age (median age: 45 vs 52, p<0.005). Traditional cardiovascular risk factors were significantly higher in Indigenous patients. The incidence of discharge against medical advice was also higher (6.5% vs 2.7%, p<0.005). There was an underutilisation of the local chest pain pathway amongst the Indigenous group (35.8% vs 44.7%, p<0.005). In patients with a diagnosis of cardiac-related chest pain, the rate of receiving invasive coronary angiogram procedures was similar in both cohorts (44.5% vs 43.7%, p=0.836). With regards to outcomes, Indigenous patients suffered from acute coronary syndrome (ACS) at a younger median age (51 vs 64, p<0.005) and were more likely to have severe three vessel disease (17% vs 6%, p<0.005) leading to coronary bypass graft surgery (CABG) (19% vs 6%, p<0.005). When adjusted for age, gender, and comorbidities, Indigenous patients were more likely to have MACE within 1 year of their chest pain presentation, compared with non-Indigenous patients with the same diagnosis (adjusted odds ration [AOR]=2.0, 95% CI [1.1, 3.8], p=0.03). CONCLUSION: In our study, Indigenous patients carried a heavier burden of cardiovascular risk factors, presented at a younger age, with more severe coronary disease and had a higher rate of CABG. We found an underutilisation of the local chest pain protocol amongst the Indigenous cohort, which suggests a need to improve support structures in the ED. In our multivariable analysis, Indigenous patients suffered from a significantly higher MACE compared to non-Indigenous patients which indicates that more collaborative efforts are needed to improve the cardiovascular health of local Aboriginal and Torres Strait Islander people.


Asunto(s)
Enfermedad de la Arteria Coronaria , Nativos de Hawái y Otras Islas del Pacífico , Australia , Dolor en el Pecho/diagnóstico , Dolor en el Pecho/epidemiología , Dolor en el Pecho/etiología , Servicio de Urgencia en Hospital , Hospitales , Humanos , Persona de Mediana Edad , Estudios Retrospectivos
9.
Behav Res Methods ; 54(1): 475-492, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34244984

RESUMEN

Illusion of control (IOC) is a bias in the judgment of personal success with implications to learning theories and health policies; some important questions in the investigation of IOC may be related to traditional measures in the field, namely self-assessment using Likert scales about the sense of control. Statistical process control (SPC) and Shewhart charts are methods developed to monitor and control industrial processes, never applied in psychological studies before. The present two studies investigated the use of the technique of Shewhart charts in the analysis of IOC. The purpose was to explore the use of SPC and Shewhart charts in the analysis of data sequences from psychological experiments; the objective was to analyze the results of reaction time (RT) data sequences plotted in SPC charts, in comparison with self-assessment judgments from an IOC task. Participants were 63 undergraduate students (Study 1) and 103 mine workers (Study 2) instructed to try to control a traffic light on a computer by pressing or not the keyboard. Higher probabilities of the successful outcome generated judgments of illusion and shifts (due to cognitive activity) in the charts of RT; lower probabilities resulted in null illusion and RT presented a random and stable profile. Patterns for different groups emerged in Shewhart charts. SPC can contribute to the analysis of the behavior of sequences of data in psychological studies, so that the charts indicate changes and patterns not detected by traditional ANOVA and other linear models.


Asunto(s)
Ilusiones , Humanos
10.
N Engl J Med ; 378(25): e34, 2018 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-29897866

RESUMEN

BACKGROUND: Observational cohort studies and a secondary prevention trial have shown inverse associations between adherence to the Mediterranean diet and cardiovascular risk. METHODS: In a multicenter trial in Spain, we assigned 7447 participants (55 to 80 years of age, 57% women) who were at high cardiovascular risk, but with no cardiovascular disease at enrollment, to one of three diets: a Mediterranean diet supplemented with extra-virgin olive oil, a Mediterranean diet supplemented with mixed nuts, or a control diet (advice to reduce dietary fat). Participants received quarterly educational sessions and, depending on group assignment, free provision of extra-virgin olive oil, mixed nuts, or small nonfood gifts. The primary end point was a major cardiovascular event (myocardial infarction, stroke, or death from cardiovascular causes). After a median follow-up of 4.8 years, the trial was stopped on the basis of a prespecified interim analysis. In 2013, we reported the results for the primary end point in the Journal. We subsequently identified protocol deviations, including enrollment of household members without randomization, assignment to a study group without randomization of some participants at 1 of 11 study sites, and apparent inconsistent use of randomization tables at another site. We have withdrawn our previously published report and now report revised effect estimates based on analyses that do not rely exclusively on the assumption that all the participants were randomly assigned. RESULTS: A primary end-point event occurred in 288 participants; there were 96 events in the group assigned to a Mediterranean diet with extra-virgin olive oil (3.8%), 83 in the group assigned to a Mediterranean diet with nuts (3.4%), and 109 in the control group (4.4%). In the intention-to-treat analysis including all the participants and adjusting for baseline characteristics and propensity scores, the hazard ratio was 0.69 (95% confidence interval [CI], 0.53 to 0.91) for a Mediterranean diet with extra-virgin olive oil and 0.72 (95% CI, 0.54 to 0.95) for a Mediterranean diet with nuts, as compared with the control diet. Results were similar after the omission of 1588 participants whose study-group assignments were known or suspected to have departed from the protocol. CONCLUSIONS: In this study involving persons at high cardiovascular risk, the incidence of major cardiovascular events was lower among those assigned to a Mediterranean diet supplemented with extra-virgin olive oil or nuts than among those assigned to a reduced-fat diet. (Funded by Instituto de Salud Carlos III, Spanish Ministry of Health, and others; Current Controlled Trials number, ISRCTN35739639 .).

11.
Proc Natl Acad Sci U S A ; 115(7): E1356-E1365, 2018 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-29378970

RESUMEN

Understanding the origin, nature, and functional significance of complex patterns of neural activity, as recorded by diverse electrophysiological and neuroimaging techniques, is a central challenge in neuroscience. Such patterns include collective oscillations emerging out of neural synchronization as well as highly heterogeneous outbursts of activity interspersed by periods of quiescence, called "neuronal avalanches." Much debate has been generated about the possible scale invariance or criticality of such avalanches and its relevance for brain function. Aimed at shedding light onto this, here we analyze the large-scale collective properties of the cortex by using a mesoscopic approach following the principle of parsimony of Landau-Ginzburg. Our model is similar to that of Wilson-Cowan for neural dynamics but crucially, includes stochasticity and space; synaptic plasticity and inhibition are considered as possible regulatory mechanisms. Detailed analyses uncover a phase diagram including down-state, synchronous, asynchronous, and up-state phases and reveal that empirical findings for neuronal avalanches are consistently reproduced by tuning our model to the edge of synchronization. This reveals that the putative criticality of cortical dynamics does not correspond to a quiescent-to-active phase transition as usually assumed in theoretical approaches but to a synchronization phase transition, at which incipient oscillations and scale-free avalanches coexist. Furthermore, our model also accounts for up and down states as they occur (e.g., during deep sleep). This approach constitutes a framework to rationalize the possible collective phases and phase transitions of cortical networks in simple terms, thus helping to shed light on basic aspects of brain functioning from a very broad perspective.


Asunto(s)
Encéfalo/fisiología , Corteza Cerebral/fisiología , Modelos Neurológicos , Red Nerviosa/fisiología , Neuronas/fisiología , Sueño/fisiología , Potenciales de Acción , Fenómenos Electrofisiológicos , Humanos , Plasticidad Neuronal
12.
Heart Lung Circ ; 30(8): 1193-1199, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33712400

RESUMEN

BACKGROUND: Coronary artery disease (CAD) remains the leading cause of death amongst Indigenous Australians accounting for 12.1% of all deaths in this population. However, there is little evidence to suggest that Indigenous status is an independent risk factor for the development of coronary artery disease. This study assessed the association between Indigenous status and the severity of CAD in patients presenting with chest pain at a regional hospital emergency department. METHODS: This was a retrospective single-centre audit over 12 months from January to December 2017. Charts were reviewed for both Indigenous and non-Indigenous patients 18 years and older who presented with chest pain and subsequently underwent an invasive coronary angiogram. Multivariable logistic regression was performed to examine the association of Indigenous status with the severity of CAD. RESULTS: Indigenous patients are 2.7 times more likely to experience significant CAD compared to non-Indigenous patients (Adjusted odds ratio [AOR]=2.73, 95% CI [1.38, 5.39], p≤0.001) even after adjusting for other risk factors. Those aged 65 years and older are more prone to significant CAD (AOR=2.96, 95% CI [1.12, 7.78], p=0.03), while women were less likely to have significant CAD compared to men, (AOR=0.46, 95% CI [0.27, 0.78], p<0.01). CONCLUSION: In this study cohort, our analysis indicates that there is a strong association between Indigenous status and significant coronary artery disease, independent of the increased burden of traditional cardiovascular risk factors among Indigenous Australians.


Asunto(s)
Enfermedad de la Arteria Coronaria , Australia , Dolor en el Pecho/diagnóstico , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico , Enfermedad de la Arteria Coronaria/epidemiología , Servicio de Urgencia en Hospital , Femenino , Hospitales , Humanos , Masculino , Nativos de Hawái y Otras Islas del Pacífico , Estudios Retrospectivos , Factores de Riesgo
13.
HPB (Oxford) ; 23(12): 1873-1885, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34103246

RESUMEN

BACKGROUND: There is still uncertainty regarding the role of perioperative chemotherapy (CTx) in patients with resectable colorectal liver metastases (CRLM), especially in those with a low-risk of recurrence. METHODS: Multicentre retrospective analysis of patients with CRLM undergoing liver resection between 2010-2015. Patients were divided into two groups according to whether they received perioperative CTx or not and were compared using propensity score matching (PSM) analysis. Then, they were stratified according to prognostic risk scores, including: Clinical Risk Score (CRS), Tumour Burden Score (TBS) and Genetic And Morphological Evaluation (GAME) score. RESULTS: The study included 967 patients with a median follow-up of 68 months. After PSM analysis, patients with perioperative CTx presented prolonged overall survival (OS) in comparison with the surgery alone group (82.8 vs 52.5 months, p = 0.017). On multivariable analysis perioperative CTx was an independent predictor of increased OS (HR 0.705, 95%CI 0.705-0.516, p = 0.029). The benefits of perioperative CTx on survival were confirmed in patients with CRS and TBS scores ≤2 (p = 0.022 and p = 0.020, respectively) and in patients with a GAME score ≤1 (p = 0.006). CONCLUSION: Perioperative CTx demonstrated an increase in OS in patients with CRLM. Patients with a low-risk of recurrence seem to benefit from systemic treatment.


Asunto(s)
Neoplasias Colorrectales , Neoplasias Hepáticas , Neoplasias Colorrectales/cirugía , Hepatectomía/efectos adversos , Humanos , Neoplasias Hepáticas/cirugía , Recurrencia Local de Neoplasia/cirugía , Pronóstico , Puntaje de Propensión , Estudios Retrospectivos , Factores de Riesgo
14.
BMC Bioinformatics ; 21(Suppl 2): 92, 2020 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-32164533

RESUMEN

BACKGROUND: Chronic diseases are becoming more widespread each year in developed countries, mainly due to increasing life expectancy. Among them, diabetes mellitus (DM) and essential hypertension (EH) are two of the most prevalent ones. Furthermore, they can be the onset of other chronic conditions such as kidney or obstructive pulmonary diseases. The need to comprehend the factors related to such complex diseases motivates the development of interpretative and visual analysis methods, such as classification trees, which not only provide predictive models for diagnosing patients, but can also help to discover new clinical insights. RESULTS: In this paper, we analyzed healthy and chronic (diabetic, hypertensive) patients associated with the University Hospital of Fuenlabrada in Spain. Each patient was classified into a single health status according to clinical risk groups (CRGs). The CRGs characterize a patient through features such as age, gender, diagnosis codes, and drug codes. Based on these features and the CRGs, we have designed classification trees to determine the most discriminative decision features among different health statuses. In particular, we propose to make use of statistical data visualizations to guide the selection of features in each node when constructing a tree. We created several classification trees to distinguish among patients with different health statuses. We analyzed their performance in terms of classification accuracy, and drew clinical conclusions regarding the decision features considered in each tree. As expected, healthy patients and patients with a single chronic condition were better classified than patients with comorbidities. The constructed classification trees also show that the use of antipsychotics and the diagnosis of chronic airway obstruction are relevant for classifying patients with more than one chronic condition, in conjunction with the usual DM and/or EH diagnoses. CONCLUSIONS: We propose a methodology for constructing classification trees in a visually guided manner. The approach allows clinicians to progressively select the decision features at each of the tree nodes. The process is guided by exploratory data analysis visualizations, which may provide new insights and unexpected clinical information.


Asunto(s)
Árboles de Decisión , Diabetes Mellitus/clasificación , Hipertensión/clasificación , Enfermedad Crónica , Bases de Datos Factuales , Diabetes Mellitus/diagnóstico , Estado de Salud , Humanos , Hipertensión/diagnóstico
15.
PLoS Comput Biol ; 15(4): e1006529, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30998676

RESUMEN

In ecology, species can mitigate their extinction risks in uncertain environments by diversifying individual phenotypes. This observation is quantified by the theory of bet-hedging, which provides a reason for the degree of phenotypic diversity observed even in clonal populations. Bet-hedging in well-mixed populations is rather well understood. However, many species underwent range expansions during their evolutionary history, and the importance of phenotypic diversity in such scenarios still needs to be understood. In this paper, we develop a theory of bet-hedging for populations colonizing new, unknown environments that fluctuate either in space or time. In this case, we find that bet-hedging is a more favorable strategy than in well-mixed populations. For slow rates of variation, temporal and spatial fluctuations lead to different outcomes. In spatially fluctuating environments, bet-hedging is favored compared to temporally fluctuating environments. In the limit of frequent environmental variation, no opportunity for bet-hedging exists, regardless of the nature of the environmental fluctuations. For the same model, bet-hedging is never an advantageous strategy in the well-mixed case, supporting the view that range expansions strongly promote diversification. These conclusions are robust against stochasticity induced by finite population sizes. Our findings shed light on the importance of phenotypic heterogeneity in range expansions, paving the way to novel approaches to understand how biodiversity emerges and is maintained.


Asunto(s)
Evolución Biológica , Biología Computacional/métodos , Aptitud Genética , Modelos Biológicos , Ecología , Modelos Estadísticos , Dinámica Poblacional
16.
Eur J Nutr ; 59(3): 1219-1232, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31073885

RESUMEN

PURPOSE: Cardiovascular disease remains the global leading cause of death. We evaluated at baseline the association between the adherence to eight a priori high-quality dietary scores and the prevalence of individual and clustered cardiovascular risk factors (CVRF) in the PREDIMED-Plus cohort. METHODS: All PREDIMED-Plus participants (6874 men and women aged 55-75 years, with overweight/obesity and metabolic syndrome) were assessed. The prevalence of 4 CVRF (hypertension, obesity, diabetes, and dyslipidaemia), using standard diagnoses criteria, were considered as outcomes. The adherence to eight a priori-defined dietary indexes was calculated. Multivariable models were fitted to estimate differences in mean values of factors and prevalence ratios for individual and clustered CVRF. RESULTS: Highest conformity to any dietary pattern did not show inverse associations with hypertension. The modified Mediterranean Diet Score (PR = 0.95; 95% CI 0.90-0.99), Mediterranean Diet Adherence Score (MEDAS) (PR = 0.94; 95% CI 0.89-0.98), the pro-vegetarian dietary pattern (PR = 0.95; 95% CI 0.90-0.99) and the Alternate Healthy Eating Index 2010 (PR = 0.92; 95% CI 0.87-0.96) were inversely associated with prevalence of obesity. We identified significant inverse trend among participants who better adhered to the MEDAS and the Prime Diet Quality Score (PDQS) in the mean number of CVRF across categories of adherence. Better adherence to several high-quality dietary indexes was associated with better blood lipid profiles and anthropometric measures. CONCLUSIONS: Highest adherence to dietary quality indexes, especially Mediterranean-style and PDQS scores, showed marginal associations with lower prevalence of individual and clustered CVRF among elderly adults with metabolic syndrome at high risk of cardiovascular disease.


Asunto(s)
Enfermedades Cardiovasculares/epidemiología , Dieta Saludable/métodos , Dieta Saludable/estadística & datos numéricos , Dieta Mediterránea/estadística & datos numéricos , Factores de Riesgo de Enfermedad Cardiaca , Cooperación del Paciente/estadística & datos numéricos , Anciano , Estudios de Cohortes , Estudios Transversales , Femenino , Salud Global , Humanos , Internacionalidad , Masculino , Persona de Mediana Edad , Prevalencia
17.
J Surg Oncol ; 120(4): 722-728, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31332806

RESUMEN

BACKGROUND: There are few data on lymphatic spread concomitant to local recurrence (LR) of colorectal cancer (CRC). The objectives of this study were to determine variables associated with lymphatic spread, to analyze the distribution of LN+, and understand the underlying mechanisms. METHODS: A total of 76 patients underwent resection of LR of CRC between January 2007 and December 2018 at Institut cancérologique de l'Ouest and were retrospectively reviewed. RESULTS: Twenty-five (32.9%) patients had lymph node (LN) involvement with LR. Lymphatics from the mesocolon-rectum and aorto-iliac compartments were involved in 21%, 20.3% and 18.1%, 20.3% for pelvic and retroperitoneal LRs, respectively. In multivariate analysis, the only predictive factor for LN invasion (LN+) was a primary positive LN status (odds ratio, 5.3; P = .007). Despite a trend toward a worse median overall survival in the LN+ group, the difference was not significant in comparison with the LN- group (46 vs. 57 months; P = 0.31) or with the LN- plus LN not assessed groups (46 months vs not reached; P = .07). CONCLUSIONS: LN invasion with LR from CRC is a frequent occurrence without significant impact on survival. The only predictive factor is a primary positive nodal status.


Asunto(s)
Neoplasias Colorrectales/patología , Cirugía Colorrectal/métodos , Ganglios Linfáticos/patología , Recurrencia Local de Neoplasia/patología , Neoplasias Colorrectales/cirugía , Femenino , Estudios de Seguimiento , Humanos , Ganglios Linfáticos/cirugía , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/cirugía , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia
18.
Eur J Nutr ; 58(2): 619-627, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29589119

RESUMEN

PROPOSAL: The aim of this study was to examine the association between the consumption of total and specific types of dairy products and the risk of incident cataracts in an elderly Mediterranean population at high cardiovascular risk. METHODS: We prospectively analyzed 5860 subjects from the PREvención con DIeta MEDiterránea (PREDIMED) Study. The time to cataract surgery was calculated as the time between recruitment and the date of the surgery, last visit of the follow-up, date of death, or until the end of the study. Dairy products intake was assessed using validated food frequency questionnaires. We used Cox proportional hazard regression to assess the risk of cataract surgery according to average dietary energy-adjusted total dairy products, milk, yogurt and cheese consumption. RESULTS: We documented a total of 768 new cataract events after a median of 5.6 years of follow-up. Subjects in the second [hazard ratio (HR) 0.62; 95% CI 0.52, 0.74] and third tertile (HR: 0.71; 95% CI 0.60, 0.85) of skimmed yogurt intake had a significantly lower risk of cataracts after adjusting for potential confounders. No significant associations were observed for total dairy products, whole and skimmed milk, whole yogurt and cheese consumption. CONCLUSION: The intake of skimmed yogurt was associated with a reduced risk of cataracts in an elderly Mediterranean population with high cardiovascular risk. No significant associations were observed for other type of dairy product. CLINICAL TRIAL REGISTRATION: International Standard Randomized Controlled Trial Number (ISRCTN): 35739639. Registration date: 5 October 2005.


Asunto(s)
Extracción de Catarata/estadística & datos numéricos , Catarata/epidemiología , Productos Lácteos/estadística & datos numéricos , Dieta Mediterránea/estadística & datos numéricos , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Evaluación Geriátrica/estadística & datos numéricos , Humanos , Incidencia , Masculino , Región Mediterránea/epidemiología , Persona de Mediana Edad , Estudios Prospectivos
19.
Neural Plast ; 2019: 7647204, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31191639

RESUMEN

Neurofeedback is a form of neuromodulation based on learning to modify some aspects of cortical activity. Sensorimotor rhythm (SMR) oscillation is one of the most used frequency bands in neurofeedback. Several studies have shown that subjects can learn to modulate SMR power to control output devices, but little is known about possible related changes in brain networks. The aim of this study was to investigate the enhanced performance and changes in EEG power spectral density at somatosensory cerebral areas due to a bidirectional modulation-based SMR neurofeedback training. Furthermore, we also analyzed the functional changes in somatosensory areas during resting state induced by the training as exploratory procedure. A six-session neurofeedback protocol based on learning to synchronize and desynchronize (modulate) the SMR was implemented. Moreover, half of the participants were enrolled in two functional magnetic resonance imaging resting-state sessions (before and after the training). At the end of the training, participants showed a successful performance enhancement, an increase in SMR power specific to somatosensory locations, and higher functional connectivity between areas associated with somatosensory activity in resting state. Our research increases the better understanding of the relation between EEG neuromodulation and functional changes and the use of SMR training in clinical practice.


Asunto(s)
Encéfalo/diagnóstico por imagen , Red Nerviosa/diagnóstico por imagen , Neurorretroalimentación , Adolescente , Encéfalo/fisiología , Electroencefalografía , Femenino , Humanos , Imagen por Resonancia Magnética , Red Nerviosa/fisiología , Adulto Joven
20.
Proc Natl Acad Sci U S A ; 112(15): E1828-36, 2015 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-25825772

RESUMEN

Transitions between regimes with radically different properties are ubiquitous in nature. Such transitions can occur either smoothly or in an abrupt and catastrophic fashion. Important examples of the latter can be found in ecology, climate sciences, and economics, to name a few, where regime shifts have catastrophic consequences that are mostly irreversible (e.g., desertification, coral reef collapses, and market crashes). Predicting and preventing these abrupt transitions remains a challenging and important task. Usually, simple deterministic equations are used to model and rationalize these complex situations. However, stochastic effects might have a profound effect. Here we use 1D and 2D spatially explicit models to show that intrinsic (demographic) stochasticity can alter deterministic predictions dramatically, especially in the presence of other realistic features such as limited mobility or spatial heterogeneity. In particular, these ingredients can alter the possibility of catastrophic shifts by giving rise to much smoother and easily reversible continuous ones. The ideas presented here can help further understand catastrophic shifts and contribute to the discussion about the possibility of preventing such shifts to minimize their disruptive ecological, economic, and societal consequences.


Asunto(s)
Algoritmos , Desastres/prevención & control , Ecosistema , Modelos Teóricos , Simulación por Computador , Conservación de los Recursos Naturales/métodos , Planificación en Desastres/métodos , Humanos
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