Using the Operating Room Black Box to Assess Surgical Team Member Adaptation Under Uncertainty: An Observational Study.

OBJECTIVE: Identify how surgical team members uniquely contribute to teamwork and adapt their teamwork skills during instances of uncertainty. BACKGROUND: The importance of surgical teamwork in preventing patient harm is well documented. Yet, little is known about how key roles (nurse, anesthesiologist, surgeon, and medical trainee) uniquely contribute to teamwork during instances of uncertainty, particularly when adapting to and rectifying an intraoperative adverse event (IAE). METHODS: Audiovisual data of 23 laparoscopic cases from a large community teaching hospital were prospectively captured using OR Black Box. Human factors researchers retrospectively coded videos for teamwork skills (backup behavior, coordination, psychological safety, situation assessment, team decision-making, and leadership) by team role under 2 conditions of uncertainty: associated with an IAE versus no IAE. Surgeons identified IAEs. RESULTS: In all, 1015 instances of teamwork skills were observed. Nurses adapted to IAEs by expressing more backup behavior skills (5.3× increase; 13.9 instances/hour during an IAE vs 2.2 instances/hour when no IAE) while surgeons and medical trainees expressed more psychological safety skills (surgeons: 3.6× increase; 30.0 instances/hour vs 6.6 instances/hour and trainees: 6.6× increase; 31.2 instances/hour vs 4.1 instances/hour). All roles expressed fewer situation assessment skills during an IAE versus no IAE. CONCLUSIONS: OR Black Box enabled the assessment of critically important details about how team members uniquely contribute during instances of uncertainty. Some teamwork skills were amplified, while others dampened when dealing with IAEs. The knowledge of how each role contributes to teamwork and adapts to IAEs should be used to inform the design of tailored interventions to strengthen interprofessional teamwork.

Environmental impact of microplastics and potential health hazards.

Microscopic plastic (microplastic) pollutants threaten the earth's biodiversity and ecosystems. As a result of the progressive fragmentation of oversized plastic containers and products or manufacturing in small sizes, microplastics (particles of a diameter of 5 mm with no lower limit) are used in medicines, personal care products, and industry. The incidence of microplastics is found everywhere in the air, marine waters, land, and even food that humans and animals consume. One of the greatest concerns is the permanent damage that is created by plastic waste to our fragile ecosystem. The impossibility of the complete removal of all microplastic contamination from the oceans is one of the principal tasks of our governing body, research scientists, and individuals. Implementing the necessary measures to reduce the levels of plastic consumption is the only way to protect our environment. Cutting off the plastic flow is the key remedy to reducing waste and pollution, and such an approach could show immense significance. This review offers a comprehensive exploration of the various aspects of microplastics, encompassing their composition, types, properties, origins, health risks, and environmental impacts. Furthermore, it delves into strategies for comprehending the dynamics of microplastics within oceanic ecosystems, with a focus on averting their integration into every tier of the food chain.

Additive-manufactured paper-PMMA hybrid microfluidic chip for simultaneous monitoring of creatinine and pH in artificial urine.

Nowadays, kidney dysfunction is a common health issue due to the modernized lifestyle. Even though medications are commercially available to treat kidney diseases, early diagnosis is crucial and challenging. Clinically, measuring urine creatinine and pH has gained significant interest as a way to diagnose kidney diseases early. In the present work, we attempted to develop a low-cost, robust, accurate and naked-eye colorimetric method to determine both creatinine levels and pH variations in artificial urine samples using a simple 3D-printed hybrid microfluidic device. Creatinine was detected by the incorporation of the traditional Jaffe test onto the hybrid paper-PMMA microfluidic device and pH (4-8) was measured by a simple anthocyanin test. Notably, the tests were established without employing any sophisticated or costly instrument clusters. The developed 3D-printed microfluidic probe showed a limit of detection (LOD) of 0.04 mM for creatinine over a concentration range of 1-10 mM, with a regression coefficient (R2) of 0.995 in laboratory conditions. Interestingly, the experimental data obtained with artificial urine exhibited a wide linear range from 0.1 mM to 5 mM under different pH values ranging from 4 to 8 in the presence of matrices commonly found in urine samples other than proteins, indicating the potential use of this method in pre-clinical analysis. Since the wide linear range of urine creatinine in artificial urine samples falls well below the clinically relevant concentrations in humans (0.07-0.27 mM), the developed lab-on-chip device is further suitable for clinical evaluation with proper ethical clearance. This 3D-printed hybrid microfluidic colorimetry-based creatinine detection and pH indicator platform can be beneficial in the healthcare sector due to the on-site testing capability, cost-effectiveness, ease of use, robustness, and instrument-free approach.

Fetal programming effect of rumen-protected methionine on primiparous Angus × Simmental offspring's performance and skeletal muscle gene expression.

Primiparous Angus × Simmental dams (n = 22) with an average body weight (BW) of 449 ±â€…32 kg of BW were divided based on two nutritional treatments: control (CTRL) and rumen-protected methionine (RPM). The control group received bermudagrass hay, corn gluten, and soybean hulls pellets supplementation (base diet); whereas the RPM group received the base diet in addition to 0.07% of DM of RPM at a fixed rate during the last trimester of gestation and the first ~80 d of lactation, in which calves (n = 17) were early weaned. Only male calves were included in this study. After weaning, calves born to RPM dams also received RPM from weaning (day 1) to day 100. Blood sampling and skeletal muscle biopsies for subsequent quantitative polymerase chain reaction (PCR) analysis were conducted on days 1, 25, 50, and 100 on calves. Quantitative PCR data were analyzed using GLIMMIX, and blood metabolites concentrations, BW, and body condition score (BCS) were analyzed using the MIXED procedure of SAS. There was no difference in maternal BW and BCS between treatments. Glucose and blood metabolites that served as biomarkers for liver health (e.g., aspartate transaminase, albumin, alkaline phosphatase, and alanine transaminase) were in the normal levels for all calves (P > 0.40). Calves in the RPM group had a greater expression of adipogenic genes (e.g., PPARG, LPL, and CEBPD) at day 100 compared with CTRL (P < 0.01). In addition, DNA methylation (DNMT1) and oxidative stress-related genes (SOD2 and NOS3) in the RPM group were upregulated at day 100 compared with CTRL (P < 0.01). These results may suggest that calves born to primiparous dams exposed to RPM supplementation are more prone to develop greater adipose tissue than CTRL calves. Furthermore, RPM supplementation may improve methylation processes, as shown by the upregulation of DNMT1. The results shown in our study aim at expanding the knowledge on fetal programming and early-life growth and development of beef cattle under supplementation with RPM.

Plane of nutrition plays a critical role in fetal and postnatal growth in beef cattle offspring. Methionine, a limiting amino acid in ruminants, is also involved in DNA methylation due to its role as S-adenosyl methionine precursor. A complete randomized design experiment was conducted to assess the fetal programming effect of rumen-protected methionine (RPM) supplementation on beef cattle. Calves born to primiparous beef heifers, that individually received RPM during the last trimester of gestation and lactation, had a greater expression of genes related to adipose tissue development, oxidative stress, and DNA methylation compared with those born to dams that did not receive rumen-protected supplementation. No difference in animal performance or blood parameters that serve as biomarkers for liver health status was detected. Our results suggest that maternal supplementation with RPM during the last trimester of gestation and lactation, and supplementation to the offspring after early weaning, could potentially increase adipose tissue development on male calves.

Disposable paper electrodes for detection of changes in dopamine concentrations in rat brain homogenates.

Dopamine, the main catecholamine neurotransmitter plays an important role in renal, cardiovascular, central nervous systems, and pathophysiological processes. The abnormal dopamine levels can result in neurological disorders such as Parkinson's, Alzheimer's, schizophrenia, acute anxiety, neuroblastoma and also contribute to cognitive dysfunctions. Given the widespread importance of dopamine concentration levels, it is imperative to develop sensors that are able to monitor dopamine. Herein, we have developed pre-anodized disposable paper electrode modified with 1-pyrenebutyric acid, for the selective and sensitive determination of dopamine. The sensor was characterized with Fourier transform infrared spectroscopy, Energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and electrochemical techniques for addressing the robust formation and electrochemical activity. The modified electrode exhibited excellent electrocatalytic activity towards dopamine without the common interference from ascorbic acid. The calibration plot for the dopamine sensor resulted linear range from 0.003 µM to 0.5 µM with a detection limit of 0.11 nM. The sensor's potential utility was tested by monitoring dopamine concentration changes in rat brain homogenates when subjected to neurotoxicity. The developed sensor was validated with gold-standard UV-Vis spectroscopy studies and computational studies were performed to understand the interaction between 1-pyrenebutyric acid and dopamine.

Toxoplasma gondii infection in people with schizophrenia is related to higher hair glucocorticoid levels.

Introduction: Toxoplasma gondii (TG) is a common protozoan parasite infecting approximately one third of the human population. Animal studies have shown that this parasite can manipulate its host behavior. Based on this, human studies have assessed if TG can be involved in mental health disorders associated with important behavioral modifications such as schizophrenia. However, results have been discrepant. Given that TG has a strong impact on fear and risk-taking processes in animal studies and that fear and risk-taking behaviors are associated with the human stress response, we tested whether glucocorticoid biomarkers (salivary and hair) differ in people with schizophrenia and controls as a function of TG status. Methods: We measured TG antibodies in blood samples, as well as salivary and hair glucocorticoid levels in 226 people with schizophrenia (19.9% women, mean age = 39 years old) and 129 healthy individuals (controls) (45.7% women, mean age = 41 years old). Results: The results showed that people with schizophrenia infected with TG presented significantly higher hair glucocorticoid concentrations than non-infected people with schizophrenia. This effect was not found in control participants. No effect was observed for salivary glucocorticoid levels. Additionally, there were no associations between TG infection and positive psychotic symptoms nor impulsivity. Discussion: These results show that people with schizophrenia present high levels of hair glucocorticoid levels only when they are infected with TG. Further studies performed in populations suffering from other mental health disorders are needed to determine if this effect is specific to schizophrenia, or whether it is generalized across mental health disorders.

Learning to embrace one's stress: the selective effects of short videos on youth's stress mindsets.

BACKGROUND AND OBJECTIVES: Stress is not inherently negative. As youth will inevitably experience stress when facing the various challenges of adolescence, they can benefit from developing a stress-can-be-enhancing mindset rather than learning to fear their stress responses and avoid taking on challenges. We aimed to verify whether a rapid intervention improved stress mindsets and diminished perceived stress and anxiety sensitivity in adolescents. DESIGN AND METHODS: An online experimental design randomly exposed 233 Canadian youths aged 14-17 (83% female) to four videos of the Stress N' Go intervention (how to embrace stress) or to control condition videos (brain facts). Validated questionnaires assessing stress mindsets, perceived stress, and anxiety sensitivity were administered pre- and post-intervention, followed by open-ended questions. RESULTS: The intervention content successfully instilled a stress-can-be-enhancing mindset compared to the control condition. Although Bayes factor analyses showed no main differences in perceived stress or anxiety sensitivity between conditions, a thematic analysis revealed that the intervention helped participants to live better with their stress. CONCLUSIONS: Overall, these results suggest that our intervention can rapidly modify stress mindsets in youth. Future studies are needed to determine whether modifying stress mindsets is sufficient to alter anxiety sensitivity in certain adolescents and contexts.

Occipital-temporal cortical tuning to semantic and affective features of natural images predicts associated behavioral responses.

In everyday life, people need to respond appropriately to many types of emotional stimuli. Here, we investigate whether human occipital-temporal cortex (OTC) shows co-representation of the semantic category and affective content of visual stimuli. We also explore whether OTC transformation of semantic and affective features extracts information of value for guiding behavior. Participants viewed 1620 emotional natural images while functional magnetic resonance imaging data were acquired. Using voxel-wise modeling we show widespread tuning to semantic and affective image features across OTC. The top three principal components underlying OTC voxel-wise responses to image features encoded stimulus animacy, stimulus arousal and interactions of animacy with stimulus valence and arousal. At low to moderate dimensionality, OTC tuning patterns predicted behavioral responses linked to each image better than regressors directly based on image features. This is consistent with OTC representing stimulus semantic category and affective content in a manner suited to guiding behavior.

Tumor microenvironment immunomodulation by nanoformulated TLR 7/8 agonist and PI3k delta inhibitor enhances therapeutic benefits of radiotherapy.

Infiltration of immunosuppressive cells into the breast tumor microenvironment (TME) is associated with suppressed effector T cell (Teff) responses, accelerated tumor growth, and poor clinical outcomes. Previous studies from our group and others identified infiltration of immunosuppressive myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs) as critical contributors to immune dysfunction in the orthotopic claudin-low tumor model, limiting the efficacy of adoptive cellular therapy. However, approaches to target these cells in the TME are currently lacking. To overcome this barrier, polymeric micellular nanoparticles (PMNPs) were used for the co-delivery of small molecule drugs activating Toll-like receptors 7 and 8 (TLR7/8) and inhibiting PI3K delta (PI3Kδ). The immunomodulation of the TME by TLR7/8 agonist and PI3K inhibitor led to type 1 macrophage polarization, decreased MDSC accumulation and selectively decreased tissue-resident Tregs in the TME, while enhancing the T and B cell adaptive immune responses. PMNPs significantly enhanced the anti-tumor activity of local radiation therapy (RT) in mice bearing orthotopic claudin-low tumors compared to RT alone. Taken together, these data demonstrate that RT combined with a nanoformulated immunostimulant diminished the immunosuppressive TME resulting in tumor regression. These findings set the stage for clinical studies of this approach.

Tumor microenvironment immunomodulation by nanoformulated TLR 7/8 agonist and PI3k delta inhibitor enhances therapeutic benefits of radiotherapy.

Infiltration of immunosuppressive cells into the breast tumor microenvironment (TME) is associated with suppressed effector T cell (Teff) responses, accelerated tumor growth, and poor clinical outcomes. Previous studies from our group and others identified infiltration of immunosuppressive myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs) as critical contributors to immune dysfunction in the orthotopic triple-negative breast cancer (TNBC) tumor model limiting the efficacy of adoptive cellular therapy. However, approaches to target these cells specifically in the TME are currently lacking. To overcome this barrier, polymeric micelles nanoparticles (PMNPs) were used for co-delivery of small molecule drugs activating Toll-like receptors 7 and 8 (TLR7/8) and inhibiting PI3K delta. The immunomodulation of the TME by TLR7/8 agonist and PI3K inhibitor altered macrophage polarization, reduced MDSC accumulation and selectively decreased tissue-resident Tregs in the TME, while enhancing the T and B cell adaptive immune response. PMNPs significantly enhanced the anti-tumor activity of local radiation therapy (RT) in mice bearing orthotopic TNBC tumors compared to RT alone. Taken together, these data demonstrate that RT combined with a nanoformulated immunostimulant restructured the TME and has promising potential for future translation combined with RT for patients with TNBC.

Structural and biophysical analysis of cytochrome P450 2C9*14 and *27 variants in complex with losartan.

The human cytochrome P450 (CYP) 1, 2 and 3 families of enzymes are responsible for the biotransformation of a majority of the currently available pharmaceutical drugs. The highly polymorphic CYP2C9 predominantly metabolizes many drugs including anticoagulant S-warfarin, anti-hypertensive losartan, anti-diabetic tolbutamide, analgesic ibuprofen, etc. There are >80 single nucleotide changes identified in CYP2C9, many of which significantly alter the clearance of important drugs. Here we report the structural and biophysical analysis of two polymorphic variants, CYP2C9*14 (Arg125His) and CYP2C9*27 (Arg150Leu) complexed with losartan. The X-ray crystal structures of the CYP2C9*14 and *27 illustrate the binding of two losartan molecules, one in the active site near heme and another on the periphery. Both losartan molecules are bound in an identical conformation to that observed in the previously solved CYP2C9 wild-type complex, however, the number of losartan differs from the wild-type structure, which showed binding of three molecules. Additionally, isothermal titration calorimetry experiments reveal a lower binding affinity of losartan with *14 and *27 variants when compared to the wild-type. Overall, the results provide new insights into the effects of these genetic polymorphisms and suggests a possible mechanism contributing to reduced metabolic activity in patients carrying these alleles.

Hepatic transcript profiling in beef cattle: Effects of feeding endophyte-infected tall fescue seeds.

The objective of our study was to evaluate the effect of endophyte-infected tall fescue (E+) seeds intake on liver tissue transcriptome in growing Angus × Simmental steers and heifers through RNA-seq analysis. Normal weaned calves (~8 months old) received either endophyte-free tall fescue (E-; n = 3) or infected tall fescue (E+; n = 6) seeds for a 30-d period. The diet offered was ad libitum bermudagrass (Cynodon dactylon) hay combined with a nutritional supplement of 1.61 kg (DM basis) of E+ or E- tall fescue seeds, and 1.61 kg (DM basis) of energy/protein supplement pellets for a 30-d period. Dietary E+ tall fescue seeds were included in a rate of 20 µg of ergovaline/kg BW/day. Liver tissue was individually obtained through biopsy at d 30. After preparation and processing of the liver samples for RNA sequencing, we detected that several metabolic pathways were activated (i.e., upregulated) by the consumption of E+ tall fescue. Among them, oxidative phosphorylation, ribosome biogenesis, protein processing in endoplasmic reticulum and apoptosis, suggesting an active mechanism to cope against impairment in normal liver function. Interestingly, hepatic protein synthesis might increase due to E+ consumption. In addition, there was upregulation of "thermogenesis" KEGG pathway, showing a possible increase in energy expenditure in liver tissue due to consumption of E+ diet. Therefore, results from our study expand the current knowledge related to liver metabolism of growing beef cattle under tall fescue toxicosis.

Type II innate lymphoid cell plasticity contributes to impaired reconstitution after allogeneic hematopoietic stem cell transplantation.

Type II innate lymphoid cells (ILC2s) maintain homeostasis and barrier integrity in mucosal tissues. In both mice and humans, ILC2s poorly reconstitute after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Determining the mechanisms involved in their impaired reconstitution could improve transplant outcomes. By integrating single-cell chromatin and transcriptomic analyses of transplanted ILC2s, we identify a previously unreported population of converted ILC1-like cells in the mouse small intestine post-transplant. Exposure of ILC2s to proinflammatory cytokines resulted in a mixed ILC1-ILC2 phenotype but was able to convert only a small population of ILC2s to ILC1s, which were found post-transplant. Whereas ILC2s protected against acute graft-versus-host disease (aGVHD) mediated mortality, infusion of proinflammatory cytokine-exposed ILC2s accelerated aGvHD. Interestingly, murine ILC2 reconstitution post-HSCT is decreased in the presence of alloreactive T cells. Finally, peripheral blood cells from human patients with aGvHD have an altered ILC2-associated chromatin landscape compared to transplanted controls. These data demonstrate that following transplantation ILC2s convert to a pro-pathogenic population with an ILC1-like chromatin state and provide insights into the contribution of ILC plasticity to the impaired reconstitution of ILC2 cells, which is one of several potential mechanisms for the poor reconstitution of these important cells after allo-HSCT.

UCP1 expression in human brown adipose tissue is inversely associated with cardiometabolic risk factors.

OBJECTIVE: Brown adipose tissue (BAT) is a therapeutic target for obesity. 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) is commonly used to quantify human BAT mass and activity. Detectable 18F-FDG uptake by BAT is associated with reduced prevalence of cardiometabolic disease. However, 18F-FDG uptake may not always be a reliable marker of BAT thermogenesis, for example, insulin resistance may reduce glucose uptake. Uncoupling protein 1 (UCP1) is the key thermogenic protein in BAT. Therefore, we hypothesised that UCP1 expression may be altered in individuals with cardiometabolic risk factors. METHODS: We quantified UCP1 expression as an alternative marker of thermogenic capacity in BAT and white adipose tissue (WAT) samples (n = 53) and in differentiated brown and white pre-adipocytes (n = 85). RESULTS: UCP1 expression in BAT, but not in WAT or brown/white differentiated pre-adipocytes, was reduced with increasing age, obesity, and adverse cardiometabolic risk factors such as fasting glucose, insulin, and blood pressure. However, UCP1 expression in BAT was preserved in obese subjects of <40 years of age. To determine if BAT activity was also preserved in vivo, we undertook a case-control study, performing 18F-FDG scanning during mild cold exposure in young (mean age ∼22 years) normal weight and obese volunteers. 18F-FDG uptake by BAT and BAT volume were similar between groups, despite increased insulin resistance. CONCLUSION: 18F-FDG uptake by BAT and UCP1 expression are preserved in young obese adults. Older subjects retain precursor cells with the capacity to form new thermogenic adipocytes. These data highlight the therapeutic potential of BAT mass expansion and activation in obesity.

The Signature Biobank: A longitudinal biopsychosocial repository of psychiatric emergency patients.

The Signature Biobank is a longitudinal repository of biospecimen, psychological, sociodemographic, and diagnostic data that was created in 2012. The Signature Consortium represents a group of approximately one hundred Quebec-based transdisciplinary clinicians and research scientists with various expertise in the field of psychiatry. The objective of the Signature Biobank is to investigate the multi-faceted underpinnings of psychiatric disorders among patients in crisis. The Signature Consortium is expanding and includes new active members that seek to highlight the contributions made by Signature Biobank since its inception. This article details our research protocol, directions, and summarizes contributions. To date, we have collected biological samples (n = 1,986), and questionnaire data (n = 2,085) from psychiatric emergency patients of the Institut universitaire en santé mentale de Montréal (Quebec, Canada), with a large proportion from whom both data types were collected (n = 1,926). In addition to this, a subsample of patients was followed-up at hospital discharge, and two additional outpatient clinic appointments (n = 958 with at least one follow-up). In addition, a socio-demographically matched comparison group of individuals who were not hospitalized for psychiatric disorders (n = 149) was recruited from the surrounding catchment area. To summarize, a systematic review of the literature shows that the Signature Biobank has contributed to better characterizing psychiatric comorbidities, biological profiles, and psychosocial functioning across some of the most common psychiatric disorders, including psychosis, mood, anxiety, and substance use disorders. The Signature Biobank is now one of the world's largest repositories of data collected from patients receiving care at a psychiatric emergency unit.

Chemical composition and seasonality variability of the Spiranthera odoratissima volatile oils leaves

ABSTRACT Spiranthera odoratissima A. St.-Hil., Rutaceae, known as "manacá" is a shrub native of the Brazilian Cerrado. Their leaves and roots are popularly used to treat rheumatism, infection and abdominal pain. This study analyzed the chemical composition of volatile oils from leaves of S. odoratissima and verified the seasonal variability of its chemical composition. The volatile oils were obtained by hydrodistillation using a Clevenger type apparatus and analyzed by gas chromatography coupled to mass spectrometry. The main chemical components found in samples of volatile oils were β-caryophyllene, bicyclogermacrene, δ-cadinene, amorphous-4,7(11)-diene, α-epi-muurolol, α-cadinol, α-muurolol and γ-cadinene. The hierarchical clustering identified three groups: the first was characterized by α-epi-muurolol, the second by amorphous-4,7(11)-diene and the third group was characterized by α-muurolol. The discriminant canonical analysis was used to differentiate between clusters on the basis of oil composition. The results suggest that the rainfall presented a relationship with the chemical composition of the volatile oil. This is the first study conducted on the seasonal behavior of the chemical constituents in volatile oil from leaves of S. odoratissima.

Chromogranin A (CgA) as a biomarker in carcinoid heart disease and NETG1/G2 neuroendocrine neoplasms of the small intestine (SI-NENs) related carcinoid syndrome

IntroductionProgression of carcinoid syndrome (CS) to carcinoid heart disease (CHD) is difficult to predict. This retrospective analysis evaluates the use of chromogranin A (CgA), a biomarker widely used in the diagnosis of neuroendocrine tumours (NET), in monitoring CS and disease progression.Patients and methods108 patients with confirmed CS, selected from a group of 351 patients with neuroendocrine neoplasms of the small intestine (SI-NENs), including NETG1 well 40% and NETG2 60% moderately differentiated NET. CgA concentration was measured during initial diagnosis and clinical follow up in 84 patients, 27 of them subsequently developed CHD. The patient's overall survival (OS) was evaluated using the Kaplan-Meier method.ResultsPatients with CHD, were found to have significantly shorter OS than patients with CS but without CHD (67.22 vs. 73.03 months). Univariate and multivariate analyses revealed that initial high concentration of CgA and/or increased concentration of CgA is significantly associated with decreased median OS in patients with CS (p<0.05).ConclusionCgA has potential as a clinically useful biomarker in reporting disease status and predicting outcome in patients with CS and with CHD. (AU)

IntroducciónLa progresión hacia la afectación cardiaca en el síndrome carcinoide (SC) es difícil de predecir. En el presente análisis retrospectivo se evaluó el uso de la cromogranina A (CgA), un biomarcador ampliamente utilizado en el diagnóstico de los tumores neuroendocrinos (TNE), en el seguimiento del SC y en la progresión de la enfermedad.Pacientes y métodosSe incluyeron 108 pacientes con SC confirmado, seleccionados de un grupo de 351 pacientes con tumores neuroendocrinos del intestino delgado (TNE-ID). El 40% de pacientes tenían un TNE G1 bien diferenciado y un 60% un TNE G2 moderadamente diferenciado. Los niveles de CgA se determinaron en el momento del diagnóstico y durante el seguimiento en 84 pacientes, 27 de los cuales desarrollaron afectación cardiaca. La supervivencia global de los pacientes se evaluó mediante el método de Kaplan-Meier.ResultadosLos pacientes con afectación cardiaca tuvieron una supervivencia global significativamente más corta que aquellos sin ella (67,22 frente a 73,03 meses). El análisis univariado y multivariado mostró que los niveles inicialmente altos de CgA y/o los niveles elevados de CgA durante la evolución se asocian de forma significativa con una menor supervivencia global en los pacientes con SC (p<0,05).ConclusiónLa CgA constituye un biomarcador clínicamente útil para evaluar la progresión de la enfermedad y la afectación cardiaca en pacientes con SC. (AU)

Análisis de las creencias epistemológicas de estudiantes colombianos según variables sociodemográficas y educativas / Epistemological beliefs of Colombian students according to educational and socio-demographic variables / Análise das crenças epistemológicas de estudantes colombianos segundo variáveis sociodemográficas e educativas

El objetivo principal del presente estudio es analizar y caracterizar la influencia de las variables educativas y sociodemográficas sobre el grado de desarrollo de las creencias epistemológicas (CE) en estudiantes universitarios y de último año de bachillerato. Para conseguir este objetivo se administró un instrumento llamado EQEBI, que mide las CE a una muestra de 1.387 alumnos en Bogotá (Colombia). La metodología utilizada fue cuantitativa y no experimental. Para comparar las CE de acuerdo con los grupos conformados según las variables analizadas, se utilizaron las pruebas estadísticas no paramétricas de Mann-Whitney y Kruskal-Wallis. Los resultados indican diferencias significativas en las CE por sexo, nivel socioeconómico y nivel educativo de los estudiantes y de sus padres. Sin embargo, no se encontraron diferencias según el entorno de procedencia (rural o urbano), ni por la repetición de curso. Este estudio tiene implicaciones para el diseño de programas educativos específicos, según las características de los alumnos, que favorezcan el desarrollo de las CE.

The main goal of the present study is to analyze and characterize the influence of educational and socio-demographic variables on the Epistemological Beliefs (EB) of senior year and university students. With this aim, an instrument that measures EB, called EQEBI, was applied to a sample of 1387 students in Bogota-Colombia. The methodology used was quantitative, non experimental, and the nonparametric statistics tests of Mann-Whitney and Kruskal-Wallis were used to compare the EB according to the groups formed by the variables analyzed. Results indicate significant differences in EB by sex, socioeconomic status and educational level of students and his parents, but no differences according to the environmental background (rural or urban) and grade repetition. This study has implications for the design of specific educational programs, according to the characteristics of students, to encourage the development of EB.

O objetivo principal do presente estudo é analisar e caracterizar a influência de variáveis educativas e sociodemográficas sobre o grau de desenvolvimento das crenças epistemológicas (CE) em estudantes universitários e do último ano do ensino médio. Para atingir esse objetivo, administrou-se um instrumento chamado EQEBI, que mede as CE a uma amostra de 1.387 alunos em Bogotá (Colômbia). A metodologia utilizada foi quantitativa e não experimental. Para comparar as CE de acordo com os grupos formados segundo as variáveis analisadas, utilizaram-se as provas estatísticas não paramétricas de Mann-Whitney e Kruskal-Wallis. Os resultados indicam diferenças significativas nas CE por sexo, nível socioeconômico e nível educativo dos estudantes e de seus pais. Contudo, não se encontraram diferenças segundo o ambiente de procedência (rural ou urbano) nem pela repetição de curso. Este estudo tem implicações para o desenho de programas educativos específicos, conforme as características dos alunos, que favoreçam o desenvolvimento das CE.

Validation of the Cognitive Structure of an Arithmetic Test with the Least Squares Distance Model (LSDM) / Validación de la estructura cognitiva de una prueba aritmética con el Modelo de Distancia Mínima de Cuadrados (LSDM)

The aim of the present paper is to collect evidence about validity of the cognitive structure proposed to solve the items of an arithmetic test using an cognitive diagnosis model (based on the Item Response Theory) called Least Squares Distance Model (LSDM). The test was applied to a sample of 382 students of 7th grade from five public high schools in Bogotá-Colombia. With this data the objective was addressed in three ways: first, the analysis of two statistical validity indices; second by a cross -validation of the LSDM results on attribute difficulties using other cognitive model (LLTM), and third, by comparing the LSDM results with the observed scores on individual attributes. The logical behavior of the probability curves for the five attributes under study provides important evidence for their overall validity. Additional specific evidences of validity are also presented in the results.

El objetivo del presente trabajo ha sido reunir evidencias sobre la validez de la estructura cognitiva propuesta para resolver los ítems de un test de aritmética, mediante la aplicación de un modelo de diagnóstico cognitivo basado en la Teoría de Respuesta al Item llamado Modelo de las Distancias Mínimo Cuadráticas (LSDM, por sus siglas en inglés). El test se aplicó a una muestra de 382 estudiantes de séptimo grado en cinco colegios públicos en Bogotá-Colombia. Usando estos datos el objetivo se abordó de tres maneras: en primer lugar se analizaron dos índices estadísticos de validez, en segundo lugar, se realizó una validación cruzada de los resultados del LSDM sobre las dificultades de atributos utilizando otro modelo cognitivo (LLTM) y en tercer lugar, se compararon los resultados del modelo con las puntuaciones observadas en atributos individuales. El comportamiento lógico de las curvas de probabilidad para los cinco atributos estudiados proporciona importante evidencia para su validez general. En los resultados se presentan también otras evidencias concretas de validez de la estructura propuesta.

Detection of Q-matrix misspecification using two criteria for validation of cognitive structures under the Least Squares Distance Model / Detección de errores de especificación en la matriz Q utilizando dos criterios de validación de estructuras cognitivas con el Modelo de las Distancias Mínimo Cuadráticas (LSDM)

Cognitive Diagnostic Models (CDMs) aim to provide information about the degree to which individuals have mastered specific attributes that underlie the success of these individuals on test items. The Q-matrix is a key element in the application of CDMs, because contains links item-attributes representing the cognitive structure proposed for solve the test. Using a simulation study we investigated the performance of two model-fit statistics (MAD and LSD) to detect misspecifications in the Q-matrix within the least squares distance modeling framework. The manipulated test design factors included the number of respondents (300, 500, 1000), attributes (1, 2, 3, 4), and type of model (conjunctive vs disjunctive). We investigated MAD and LSD behavior under correct Q-matrix specification, with Qmisspecifications and in a real data application. The results shows that the two model-fit indexes were sensitive to Q-misspecifications, consequently, cut points were proposed to use in applied context (AU)

Los Modelos de Diagnóstico Cognitivo (MDC) tienen por objeto proporcionar información sobre el grado en que los individuos dominan atributos específicos para resolver correctamente los items de un test. La matriz Q es un elemento clave en la aplicación de los MDC porque contiene vínculos entre items y atributos que representan la estructura cognitiva propuesta para resolver la prueba. Por medio de un estudio de simulación, se determinó el rendimiento de dos estadísticos de ajuste (MAD y LSD) para detectar errores de especificación en la matriz Q dentro del marco del modelo de la distancia mínimo cuadrática. Los factores manipulados en el diseño del test incluyen: número de encuestados (300, 500, 1000), número de atributos (1, 2, 3, 4), y el tipo de modelo (conjuntivo vs disyuntivo). Se investigó el comportamiento de los valores MAD y LSD bajo una correcta especificación de Q, con errores de especificación en Q y en una aplicación de datos reales. Los resultados muestran que los dos índices son sensibles a los errores de especificación de Q, por este motivo se proponen puntos de corte para usar en aplicaciones del Modelo (AU)