Super-Resolution Reconstruction of Multi-Slice T2-W FLAIR MRI Improves Multiple Sclerosis Lesion Segmentation.

Due to acquisition time constraints, T2-w FLAIR MRI of Multiple Sclerosis (MS) patients is often acquired with multi-slice 2D protocols with a low through-plane resolution rather than with high-resolution 3D protocols. Automated lesion segmentation on such low-resolution (LR) images, however, performs poorly and leads to inaccurate lesion volume estimates. Super-resolution reconstruction (SRR) methods can then be used to obtain a high-resolution (HR) image from multiple LR images to serve as input for lesion segmentation. In this work, we evaluate the effect on MS lesion segmentation of three SRR approaches: one based on interpolation, a state-of-the-art self-supervised CNN-based strategy, and a recently proposed model-based SRR method. These SRR strategies were applied to LR acquisitions simulated from 3D T2-w FLAIR MRI of MS patients. Each SRR method was evaluated in terms of image reconstruction quality and subsequent lesion segmentation performance. When compared to segmentation on LR images, the three considered SRR strategies demonstrate improved lesion segmentation. Furthermore, in some scenarios, SRR achieves a similar segmentation performance compared to segmentation of HR images.Clinical relevance- This study demonstrates the positive impact of super-resolution reconstruction from T2-w FLAIR multi-slice MRI acquisitions on segmentation performance of MS lesions.

Contribution of N-Linked Mannosylation Pathway to Candida parapsilosis and Candida tropicalis Biofilm Formation.

Background: Mycoses are a growing threat to human health, and systemic candidiasis caused by Candida parapsilosis and Candida tropicalis is frequent in immunocompromised patients. Biofilm formation is a virulence factor found in these organisms, as sessile cells adhere to surfaces, the stratification and production of extracellular matrix provides protection and resistance to antifungal drugs. Previous evidence indicated that the N-linked mannosylation pathway is relevant to C. albicans biofilms, but its contribution to other species remains unknown. Methods: C. parapsilosis and C. tropicalis och1∆ mutants, which have a disrupted N-linked mannosylation pathway, were used to form biofilms. In addition, wild-type and mutant cells were also treated to remove N-linked mannans or block this pathway. Biofilms were analyzed by quantifying the included fungal biomass, and extracellular matrix components. Moreover, gene expression and secreted hydrolytic enzymes were also quantified in these biofilms. Results: The och1∆ mutants showed a reduced ability to form biofilms in both fungal species when compared to the wild-type and control strains. This observation was confirmed by trimming N-linked mannans from walls or blocking the pathway with tunicamycin B. According to this observation, mutant, and treated cells showed an altered composition of the extracellular matrix and increased susceptibility to antifungal drugs when compared to control or untreated cells. The gene expression of secreted virulence factors, such as aspartyl proteinases and phospholipases, was normal in all the tested cells but the secreted activity was reduced, suggesting a defect in the secretory pathway, which was later confirmed by treating cells with brefeldin A. Conclusion: Proper N-linked mannosylation is required for biofilm formation in both C. parapsilosis and C. tropicalis. Disruption of this posttranslational modification affected the secretory pathway, offering a link between glycosylation and biofilm formation.

Investigating Tissue-Specific Abnormalities in Alzheimer's Disease with Multi-Shell Diffusion MRI.

BACKGROUND: Most studies using diffusion-weighted MRI (DW-MRI) in Alzheimer's disease (AD) have focused their analyses on white matter (WM) microstructural changes using the diffusion (kurtosis) tensor model. Although recent works have addressed some limitations of the tensor model, such as the representation of crossing fibers and partial volume effects with cerebrospinal fluid (CSF), the focus remains in modeling and analyzing the WM. OBJECTIVE: In this work, we present a brain analysis approach for DW-MRI that disentangles multiple tissue compartments as well as micro- and macroscopic effects to investigate differences between groups of subjects in the AD continuum and controls. METHODS: By means of the multi-tissue constrained spherical deconvolution of multi-shell DW-MRI, underlying brain tissue is modeled with a WM fiber orientation distribution function along with the contributions of gray matter (GM) and CSF to the diffusion signal. From this multi-tissue model, a set of measures capturing tissue diffusivity properties and morphology are extracted. Group differences were interrogated following fixel-, voxel-, and tensor-based morphometry approaches while including strong FWE control across multiple comparisons. RESULTS: Abnormalities related to AD stages were detected in WM tracts including the splenium, cingulum, longitudinal fasciculi, and corticospinal tract. Changes in tissue composition were identified, particularly in the medial temporal lobe and superior longitudinal fasciculus. CONCLUSION: This analysis framework constitutes a comprehensive approach allowing simultaneous macro and microscopic assessment of WM, GM, and CSF, from a single DW-MRI dataset.

Vitamin D-induced LL-37 modulates innate immune responses of human primary macrophages during DENV-2 infection.

Epidemics of dengue, an acute and potentially severe disease caused by mosquito-borne dengue virus (DENV), pose a major challenge to clinicians and health care services across the sub(tropics). Severe disease onset is associated with a dysregulated inflammatory response to the virus, and there are currently no drugs to alleviate disease symptoms. LL-37 is a potent antimicrobial peptide with a wide range of immunoregulatory properties. In this study, we assessed the effect of LL-37 on DENV-2-induced responses in human monocyte-derived macrophages (MDMs). We show that simultaneous exposure of exogenous LL-37 and DENV-2 resulted in reduced replication of the virus in MDMs, while the addition of LL-37 postexposure to DENV-2 did not. Interestingly, the latter condition reduced the production of IL-6 and increased the expression of genes involved in virus sensing and antiviral response. Finally, we demonstrate that low endogenous levels and limited production of LL-37 in MDMs in response to DENV-2 infection can be increased by differentiating MDMs in the presence of Vitamin D (VitD3). Taken together, this study demonstrates that in addition to its antimicrobial properties, LL-37 has immunomodulatory properties in the curse of DENV infection and its production can be increased by VitD3.

Vitamin D Regulates the Expression of Immune and Stress Response Genes in Dengue Virus-infected Macrophages by Inducing Specific MicroRNAs.

BACKGROUND: The pathogenesis associated with Dengue virus (DENV) infection is marked by the impairment of host immune response. Consequently, the modulation of immune response has emerged as an important therapeutic target for the control of DENV infection. Vitamin D has been shown to regulate the immune response in DENV infection, although the molecular mechanism remains poorly understood. Post-transcriptional regulation of mRNA by miRNAs offers an opportunity to gain insight into the immunomodulation mediated by vitamin D. OBJECTIVE: Previously, it has been observed that a high dose of vitamin D (4000 IU) decreased DENV-2 infection and inflammatory response in monocyte-derived macrophages (MDMs). Here, we examine whether high or low doses of vitamin D supplements exert differential effect on miRNA expression in DENV-infected macrophages. METHODS: We analyzed miRNA expression profiles in MDMs isolated from healthy individuals who were given either 1000 or 4000 IU/day of vitamin D for 10 days. MDMs before or after vitamin D supplementation were challenged with DENV-2, and miRNAs profiles were analyzed by qPCR arrays. RESULTS: DENV-2 infected MDMs supplemented with 4000 IU, showed up-regulation of miR-374a-5p, miR-363-3p, miR-101-3p, miR-9-5p, miR-34a-5p, miR-200a-3p, and the family of miRNAs miR-21-5p, and miR-590-p. The miRNA profile and predicted target mRNAs suggested regulatory pathways in MDMs obtained from healthy donors who received higher doses of vitamin D. These DENV-2 infected MDMs expressed a unique set of miRNAs that target immune and cellular stress response genes. CONCLUSION: The results suggest vitamin D dose-dependent differential expression of miRNAs target key signaling pathways of the pathogenesis of dengue disease.

Regulation of innate immune responses in macrophages differentiated in the presence of vitamin D and infected with dengue virus 2.

A dysregulated or exacerbated inflammatory response is thought to be the key driver of the pathogenesis of severe disease caused by the mosquito-borne dengue virus (DENV). Compounds that restrict virus replication and modulate the inflammatory response could thus serve as promising therapeutics mitigating the disease pathogenesis. We and others have previously shown that macrophages, which are important cellular targets for DENV replication, differentiated in the presence of bioactive vitamin D (VitD3) are less permissive to viral replication, and produce lower levels of pro-inflammatory cytokines. Therefore, we here evaluated the extent and kinetics of innate immune responses of DENV-2 infected monocytes differentiated into macrophages in the presence (D3-MDMs) or absence of VitD3 (MDMs). We found that D3-MDMs expressed lower levels of RIG I, Toll-like receptor (TLR)3, and TLR7, as well as higher levels of SOCS-1 in response to DENV-2 infection. D3-MDMs produced lower levels of reactive oxygen species, related to a lower expression of TLR9. Moreover, although VitD3 treatment did not modulate either the expression of IFN-α or IFN-ß, higher expression of protein kinase R (PKR) and 2'-5'-oligoadenylate synthetase 1 (OAS1) mRNA were found in D3-MDMs. Importantly, the observed effects were independent of reduced infection, highlighting the intrinsic differences between D3-MDMs and MDMs. Taken together, our results suggest that differentiation of MDMs in the presence of VitD3 modulates innate immunity in responses to DENV-2 infection.

Quantification of cognitive impairment to characterize heterogeneity of patients at risk of developing Alzheimer's disease dementia.

INTRODUCTION: Neuropsychological test scores are limited and standard outcomes may mask the heterogeneity of cognitive impairment. This article presents the calculation and evaluation of six composite scores that quantify domain-specific impairment. METHODS: Parameters for composite scores calculation were learned by performing confirmatory factor analysis in a sample of participants from the Alzheimer's Disease Neuroimaging Initiative database. The obtained scores were evaluated with a separate sample of mild cognitive impairment (MCI) in two automated tasks: unsupervised partition in different subgroups and prediction of progression to dementia for different time windows. RESULTS: MCI subgroups with distinctive cognitive profiles and risk of progression emerged from cluster analysis. Composite scores outperform standard neuropsychological tests when automatically predicting progression within time windows up to 5 years. CONCLUSIONS: Domain-specific composite scores are useful to delineate profiles of impairment, stratify the MCI risk, and predict progression to dementia.

Características de pacientes atendidos en dos clínicas de anticoagulación de Colombia / Characteristics of patients in two anticoagulation clinics in Colombia

Resumen Objetivo: Establecer las características demográficas, clínicas y terapéuticas de los pacientes anticoagulados atendidos en las clínicas de anticoagulación del Hospital Universitario Fundación Santa Fe de Bogotá (HUFSFB) y del Hospital Universitario San Vicente Fundación Medellín (HUSVF), en los años 2015 y 2016. Método: Se realizó un estudio descriptivo, retrospectivo y transversal. La población de referencia la conformaron los pacientes atendidos en las clínicas de anticoagulación del HUSVF y el HUFSFB en el periodo comprendido entre marzo de 2015 y marzo de 2016. La información se tomó de los registros clínicos de ambos hospitales y para el análisis se utilizó estadística descriptiva. Resultados: Se evaluaron 502 pacientes en las dos clínicas de anticoagulación, con una edad promedio de 64 años en el HUFSFB y de 61 años en el HUSVF. La principal indicación de anticoagulación fue fibrilación o flutter auricular en el HUSVF (46.5%) y enfermedad tromboembólica venosa en el HUFSFB (69.7%). El 100% de los pacientes del HUSVF fueron anticoagulados con warfarina, frente a solo el 23% de los del HUFSFB; el tiempo en rango terapéutico fue del 69% en el HUFSFB y del 55% en el HSVF. Se presentó retrombosis en tres pacientes en cada una de las instituciones, y los eventos de sangrado fueron 7 (3,8%) en el HUFSFB y 30 (9,3%) en el HUSVF. Conclusiones: Las diferencias administrativas entre las dos instituciones se ven reflejadas en los resultados obtenidos. Existe, ligada al sistema de salud de nuestro país, una gran diferencia en la población, las enfermedades y el acceso a los servicios y a los medicamentos.

Abstract Objective: To establish the demographic, clinical and therapeutic characteristics of the anticoagulated patients treated at the anticoagulation clinics of Fundación Santa Fe de Bogotá (HUSVF) and Hospital Universitario San Vicente Fundación Medellin (HUFSFB), between 2015 and 2016. Method: A transversal retrospective descriptive study was carried out. The reference population consist in patients treated in the anticoagulation clinics of the HUSVF in Medellin and the HUFSFB in Bogotá between March 2015 to 2016. The information was taken from the clinical records of both hospitals and descriptive statistics were used for the data analysis. Results: A total of 502 patients were evaluated in both anticoagulation clinics. Patients' average age in HUFSFB was 64 years while in HUSVF was 61; the main pathology that required anticoagulation was the fibrillation/auricular flutter in HUSVF (46,5%) and venous thromboembolic disease in HUFSFB (69.7%). 100% of HUSVF patients are anticoagulated using warfarin and only 23% of those in HUFSFB; the time in therapeutic range (TTR) was 69% in HUFSFB and 55% in HSVF. Re-thrombosis was presented in 3 patients in each of the institutions and the bleeding events were 7 (3.8%) in HUFSFB and 30 (9.3%) in HUSVF. Conclusions: The administrative differences between the two institutions are reflected in the results obtained; there is a great difference in the population, pathologies, access to services and medicines, linked to the health system of our country.

Análisis del Papel de los Intermediarios en el Mercado Agrícola Tradicional. Caso de Estudio Antioquia, Colombia / Analysis of the Role of Intermediaries in the Traditional Agricultural Market. Case Study Antioquia, Colombia / Análise do Papel dos Intermediários no Mercado Agrícola Tradicional. Estudo de Caso Antioquia, Colômbia

Resumen: Introducción: En este trabajo se analiza la participación de los intermediarios en el mercado agrícola tradicional de frutas y hortalizas en fresco en el departamento de Antioquia, Colombia; sus resultados sirven de apoyo para explicar las relaciones entre intermediarios con productores, consumidores y otros intermediarios. Objetivo: es analizar el papel de los intermediarios y su poder de negociación; a fin de explorar las diferentes interacciones, condiciones del sistema y las ventajas y desventajas, se analiza las similitudes que presentan algunos intermediarios de plazas de mercado. Materiales y métodos: para ello se realizó entrevistas y un cuestionario estructurado a 26 intermediarios ubicados en 13 municipios de las 9 subregiones de Antioquia, adicionalmente se realizaron algunos cuestionarios a intermediarios de tiendas de barrio, consumidores y productores para contrastar diferentes puntos de vista; a la información obtenida se le realizó análisis de conglomerados, análisis multivariado, comparación de varias muestras y análisis de componentes principales. Resultados: arrojaron que los intermediarios eliminan fronteras de negociación definiendo criterios de comercio, tienen gran participación tanto en procedencia como en oferta y presentan similitudes entre una zona y otra que no precisamente corresponden a proximidades geográficas. Conclusión: En suma, frente a la alta participación de estos agentes en las cadenas de suministro de alimentos, son ellos quienes aprovechan las fallas y dinámicas del sistema para definir reglas de negociación cuando están en su rol de vendedores a otros intermediarios o cuando están en el rol de compradores a productores.

Abstract Introduction: This paper analyzes the participation of intermediaries in the traditional agricultural market for fresh fruits and vegetables in the department of Antioquia, Colombia; their results serve as support to explain the relationships between intermediaries with producers, consumers, and other intermediaries. Objective: is to analyze the role of intermediaries and their bargaining power; In order to explore the different interactions, system conditions and the advantages and disadvantages, the similarities that some marketplace intermediaries presents are analyzed. Materials and methods: For this purpose, interviews and a structured questionnaire were conducted with 26 intermediaries located in 13 municipalities of the 9 subregions. From Antioquia; additionally, some questionnaires were made to intermediaries of neighborhood stores, consumers and producers to contrast different points of view. The information obtained was subjected to a cluster analysis, multivariate analysis, comparison of several samples and an analysis of main components. Results: showed that intermediaries eliminate negotiation borders by defining trade criteria, they have a large participation both in origin and on offer and show similarities between area and area that do not precisely correspond to geographical proximity. Conclusion: In sum, given the high participation of these agents in the food supply chains, it is they who take advantage of the failures and dynamics of the system to define negotiation rules when they are in their role as sellers to other intermediaries or when they are in the role from buyers to producers.

Resumo Introdução: Este artigo analisa a participação dos intermediários no mercado agrícola tradicional de frutas e verduras frescas no departamento de Antioquia, Colômbia; seus resultados servem de suporte para explicar as relações entre intermediários com produtores, consumidores e outros intermediários. Objetivo: é analisar o papel dos intermediários e seu poder de barganha; A fim de explorar as diferentes interações, condições do sistema e as vantagens e desvantagens, são analisadas as semelhanças que alguns intermediários de mercado apresentam. Materiais e métodos: para o efeito, foram realizadas entrevistas e um questionário estruturado com 26 intermediários localizados em 13 municípios das 9 sub-regiões. de Antioquia, adicionalmente, alguns questionários foram feitos a intermediários de lojas de bairro, consumidores e produtores para contrastar diferentes pontos de vista. Resultados: Sobre as informações obtidas foram realizadas uma análise de conglomerado, uma análise multivariada, uma comparação de várias amostras e uma análise de componentes principais, e os resultados mostraram que os intermediários eliminam as fronteiras da negociação definindo critérios comerciais, eles têm uma grande participação tanto na origem como em oferta e mostram semelhanças entre uma área e outra que não correspondem exatamente à proximidade geográfica. Conclusão: Em suma, dada a alta participação desses agentes nas cadeias de abastecimento de alimentos, são eles que se aproveitam das falhas e da dinâmica do sistema para definir regras de negociação quando estão na função de vendedores para outros intermediários ou quando estão em o papel dos compradores aos produtores.

Influences of the Culturing Media in the Virulence and Cell Wall of Sporothrix schenckii, Sporothrix brasiliensis, and Sporothrix globosa.

Sporothrix schenckii, Sporothrix brasiliensis, and Sporothrix globosa are etiological agents of sporotrichosis, a human subcutaneous mycosis. Although the protocols to evaluate Sporothrix virulence in animal models are well described, the cell preparation before inoculation is not standardized, and several culturing media are used to grow yeast-like cells. Here, we found that carbon or nitrogen limitation during fungal cell preparation negatively impacted the ability of S. schenckii and S. brasiliensis to kill Galleria mellonella larvae, but not S. globosa. The fungal growth conditions associated with the short median survival of animals were accompanied by increased hemocyte countings, phenoloxidase activity, and cytotoxicity. The fungal growth under carbon or nitrogen limitation also affected the cell wall composition of both S. schenckii and S. brasiliensis and showed increased exposure of ß-1,3-glucan at the cell surface, while those growing conditions had a minimal impact on the S.globosa wall, which had higher levels of this polysaccharide exposed on the wall regardless of the culture condition. This polysaccharide exposure was linked to the increased ability of insect hemocytes to uptake fungal cells, suggesting that this is one of the mechanisms behind the lower virulence of S.globosa or cells from the other species grown in carbon or nitrogen limitation.

Early Virulence Predictors during the Candida Species-Galleria mellonella Interaction.

Fungal infections are a serious and increasing threat for human health, and one of the most frequent etiological agents for systemic mycoses is Candida spp. The gold standard to assess Candida virulence is the mouse model of systemic candidiasis, a restrictive, expensive, and time-consuming approach; therefore, invertebrate models have been proposed as alternatives. Galleria mellonella larvae have several traits that make them good candidates to study the fungal virulence. Here, we showed that a reduction in circulating hemocytes, increased melanin production, phenoloxidase, and lactate dehydrogenase activities were observed at 12 and 24 h postinoculation of highly virulent Candidatropicalis strains, while minimal changes in these parameters were observed in low-virulent strains. Similarly, the most virulent species Candida albicans, Candida tropicalis, Candida auris, Candida parapsilosis, and Candida orthopsilosis have led to significant changes in those parameters; while the low virulent species Candida guilliermondii, Candida krusei, and Candida metapsilosis induced modest variations in these immunological and cytotoxicity parameters. Since changes in circulating hemocytes, melanin production, phenoloxidase and lactate dehydrogenase activities showed a correlation with the larval median survival rates at 12 and 24 h postinoculation, we proposed them as candidates for early virulence predictors in G. mellonella.

Role of Protein Mannosylation in the Candida tropicalis-Host Interaction.

Mannans are components of the fungal wall attached to proteins via N- or O-linkages. In Candida albicans, Och1 is an α1,6-mannosyltransferase that adds the first mannose unit to the N-linked mannan outer chain; whereas Pmr1 is an ion pump that imports Mn2+ into the Golgi lumen. This cation is the cofactor of Golgi-resident mannosyltransferases, and thus Pmr1 is involved in the synthesis of both N- and O-linked mannans. Since we currently have limited information about the genetic network behind the Candida tropicalis protein mannosylation machinery, we disrupted OCH1 and PMR1 in this organism. The C. tropicalis pmr1Δ and och1Δ mutants showed increased doubling times, aberrant colony and cellular morphology, reduction in the wall mannan content, and increased susceptibility to wall perturbing agents. These changes were accompanied by increased exposure of both ß1,3-glucan and chitin at the wall surface of both mutant strains. Our results showed that O-linked mannans are dispensable for cytokine production by human mononuclear cells, but N-linked mannans and ß1,3-glucan are key ligands to trigger cytokine production in a co-stimulatory pathway involving dectin-1 and mannose receptor. Moreover, we found that the N-linked mannan core found on the surface of C. tropicalis och1Δ null mutant was capable of inducing cytokine production; and that a mannan-independent pathway for IL-10 production is present in the C. tropicalis-mononuclear cell interaction. Both mutant strains showed virulence attenuation in the Galleria mellonella and the mouse model of systemic candidiasis. Therefore, mannans are relevant for cell wall composition and organization, and for the C. tropicalis-host interaction.

Cognitive Training in Young Patients With Traumatic Brain Injury: A Fixel-Based Analysis.

Background. Traumatic brain injury (TBI) is associated with altered white matter organization and impaired cognitive functioning. Objective. We aimed to investigate changes in white matter and cognitive functioning following computerized cognitive training. Methods. Sixteen adolescents with moderate-to-severe TBI (age 15.6 ± 1.8 years, 1.2-4.6 years postinjury) completed the 8-week BrainGames program and diffusion weighted imaging (DWI) and cognitive assessment at time point 1 (before training) and time point 2 (after training). Sixteen healthy controls (HC) (age 15.6 ± 1.8 years) completed DWI assessment at time point 1 and cognitive assessment at time point 1 and 2. Fixel-based analyses were used to examine fractional anisotropy (FA), mean diffusivity (MD), and fiber cross-section (FC) on a whole brain level and in tracts of interest. Results. Patients with TBI showed cognitive impairments and extensive areas with decreased FA and increased MD together with an increase in FC in the body of the corpus callosum and left superior longitudinal fasciculus (SLF) at time point 1. Patients improved significantly on the inhibition measure at time point 2, whereas the HC group remained unchanged. No training-induced changes were observed on the group level in diffusion metrics. Exploratory correlations were found between improvements on verbal working memory and reduced MD of the left SLF and between increased performance on an information processing speed task and increased FA of the right precentral gyrus. Conclusions. Results are indicative of positive effects of BrainGames on cognitive functioning and provide preliminary evidence for neuroplasticity associated with cognitive improvements following cognitive intervention in TBI.

1,25-Dihydroxyvitamin D3 induces formation of neutrophil extracellular trap-like structures and modulates the transcription of genes whose products are neutrophil extracellular trap-associated proteins: A pilot study.

Neutrophils are components of the innate immune system that participate in controlling infectious diseases through microbicidal mechanisms such as phagocytosis, degranulation and the release of neutrophil extracellular traps (NETs). NETs are DNA structures that are released through the decondensation and spreading of chromatin and the adherence of various proteins, including neutrophil elastase (NE), myeloperoxidase (MPO) and peptidyl arginine deiminase 4 (PDA4). Since NETs recovered after treatment of activated polymorphonuclear neutrophils can enhance IL-1ß and IFN-α production by LPS-activated macrophages, they are thought to be keys to the host's defenses and inflammation. 1,25(OH)2D3 has been shown to play an important role in modulating neutrophils activation and in preventing infections. Therefore, the aim of this study was to assess the effect of 1,25(OH)2D3 in modulating induction of the release of NETs and in regulating the transcription of genes whose products in human neutrophils are NETs-associated proteins, TLRs and interferon. We observed that 1,25(OH)2D3 induced production of NETs-like structures while also upregulating NE/PAD4/COX-3/GAPDH mRNA levels. Additionally, we found an increase in TLR7 and type I interferon (IFN) mRNA levels as a result of neutrophil activation by 1,25(OH)2D3. Since the transcription of genes whose products constitute NETs-associated proteins are differentially-regulated by 1,25(OH)2D3, we proposed that this might restrict the spread of pathogens, such as virus, by inducing NETs, the expression of TLR7 and secretion of IFN-α. Our results suggest the potential importance of this hormone in preventing infections by inducing NETs formation.

[Modulation of high-density lipoprotein and cytokine IL-1ß and IL-6 levels in patients with dengue]. / Modulación de los niveles de lipoproteínas de alta densidad y las citoquinas IL-1ß e IL-6 en pacientes con dengue.

OBJECTIVES: To assess High-Density Lipoprotein (HDL) and pro-inflammatory cytokine levels in patients with dengue classified according to the severity of the clinical presentation. MATERIALS AND METHODS: A descriptive study was carried out with 70 individuals with dengue, classified as no alarm signs (DSSA), with signs of alarm (DCSA), and severe dengue (DG); 15 healthy donors were included as controls (CS). The serum levels of IL-1ß and IL-6 were quantified through ELISA, and the HDL levels through serum by a colorimetric test. In addition, the platelet count and the hematocrit percentage were determined. RESULTS: Levels of IL-1ß and IL-6 were found to be increased in patients with DENV vs. the healthy controls. Said increase was more evident in patients with dengue and in line with the severity of the clinical presentation. The HDL levels were found to be decreased in patients with dengue versus healthy controls. The correlation analysis showed statistically significant associations between HDL and the platelet number, as well as between the hematocrit percentage and the levels of IL-1ß. CONCLUSIONS: The increased IL-1ß and IL-6 and the decreased HDL levels in the most severe clinical stages suggest that both factors are involved in the development of the pathogenesis and severity. The correlations allow the observation of a potential association between HDL and platelet count, which allows us to provide an approach to the possible role of HDL in the pathogenesis of dengue, but it is still necessary to perform additional studies that will allow to state their importance in the course of the DENV infection.

OBJETIVOS: Evaluar los niveles de lipoproteínas de alta densidad (HDL) y citoquinas proinflamatorias en pacientes con dengue clasificados según la gravedad del cuadro clínico. MATERIALES Y MÉTODOS: Se realizó un estudio descriptivo, incluyendo 70 individuos con dengue, clasificados como: sin signos de alarma (DSSA), con signos de alarma (DCSA) y dengue grave (DG); 15 donantes sanos fueron incluidos como controles (CS). Los niveles séricos de IL-1ß e IL-6 fueron cuantificados por ELISA, y los de HDL en suero por ensayo colorimétrico; además se determinó el recuento de plaquetas y el porcentaje de hematocrito. RESULTADOS: Los niveles de IL-1ß e IL-6 se encontraron aumentados en los pacientes con DENV respecto a los controles sanos. Dicho aumento fue más evidente en los pacientes con dengue, de acuerdo con la gravedad del cuadro clínico. Los niveles de HDL se hallaron disminuidos en los pacientes con dengue comparados con los controles sanos. Los análisis de correlación mostraron asociaciones estadísticamente significativas entre HDL y el número de plaquetas; así como entre el porcentaje de hematocrito y los niveles de IL-1ß. CONCLUSIONES: El aumento de IL-1ß e IL-6 y la disminución de HDL en los estadios clínicos más graves sugieren que ambos factores están implicados en el desarrollo de la patogénesis y severidad. Las correlaciones permiten observar una posible asociación entre HDL y el número de plaquetas que permite dar una aproximación al posible papel de las HDL en la patogénesis del dengue, pero aún es necesario realizar estudios adicionales que permitan elucidar su importancia en el curso de la infección por DENV.

Role of protein phosphomannosylation in the Candida tropicalis-macrophage interaction.

Candida tropicalis is an opportunistic fungal pathogen responsible for mucosal and systemic infections. The cell wall is the initial contact point between a fungal cell and the host immune system, and mannoproteins are important components that play key roles when interacting with host cells. In Candida albicans, mannans are modified by mannosyl-phosphate moieties, named phosphomannans, which can work as molecular scaffolds to synthesize ß1,2-mannooligosaccharides, and MNN4 is a positive regulator of the phosphomannosylation pathway. Here, we showed that C. tropicalis also displays phosphomannans on the cell surface, but the amount of this cell wall component varies depending on the fungal strain. We also identified a functional ortholog of CaMNN4 in C. tropicalis. Disruption of this gene caused depletion of phosphomannan content. The C. tropicalis mnn4Δ did not show defects in the ability to stimulate cytokine production by human mononuclear cells but displayed virulence attenuation in an insect model of candidiasis. When the mnn4Δ-macrophage interaction was analyzed, results showed that presence of cell wall phosphomannan was critical for C. tropicalis phagocytosis. Finally, our results strongly suggest a differential role for phosphomannans during phagocytosis of C. albicans and C. tropicalis.

Characterization of brain anatomical patterns by comparing region intensity distributions: Applications to the description of Alzheimer's disease.

Purpose: This work presents an automatic characterization of the Alzheimer's disease describing the illness as a multidirectional departure from a baseline defining the control state, being these directions determined by a distance between functional-equivalent anatomical regions. Methods: After a brain parcellation, a region is described by its histogram of gray levels, and the Earth mover's distance establishes how close or far these regions are. The medoid of the control group is set as the reference and any brain is characterized by its set of distances to this medoid. Evaluation: This hypothesis was assessed by separating groups of patients with mild Alzheimer's disease and mild cognitive impairment from control subjects, using a subset of the Open Access Series of Imaging Studies (OASIS) database. An additional experiment evaluated the method generalization and consisted in training with the OASIS data and testing with the Minimal Interval Resonance Imaging in Alzheimer's disease (MIRIAD) database. Results: Classification between controls and patients with AD resulted in an equal error rate of 0.1 (90% of sensitivity and specificity at the same time). The automatic ranking of regions resulting is in strong agreement with those regions described as important in clinical practice. Classification with different databases results in a sensitivity of 85% and a specificity of 91%. Conclusions: This method automatically finds out a multidimensional expression of the AD, which is directly related to the anatomical changes in specific areas such as the hippocampus, the amygdala, the planum temporale, and thalamus.

Modulación de los niveles de lipoproteínas de alta densidad y las citoquinas IL-1β e IL-6 en pacientes con dengue / Modulation of high-density lipoprotein and cytokine IL-1β and IL-6 levels in patients with dengue

RESUMEN Objetivos. Evaluar los niveles de lipoproteínas de alta densidad (HDL) y citoquinas proinflamatorias en pacientes con dengue clasificados según la gravedad del cuadro clínico. Materiales y métodos. Se realizó un estudio descriptivo, incluyendo 70 individuos con dengue, clasificados como: sin signos de alarma (DSSA), con signos de alarma (DCSA) y dengue grave (DG); 15 donantes sanos fueron incluidos como controles (CS). Los niveles séricos de IL-1β e IL-6 fueron cuantificados por ELISA, y los de HDL en suero por ensayo colorimétrico; además se determinó el recuento de plaquetas y el porcentaje de hematocrito. Resultados. Los niveles de IL-1β e IL-6 se encontraron aumentados en los pacientes con DENV respecto a los controles sanos. Dicho aumento fue más evidente en los pacientes con dengue, de acuerdo con la gravedad del cuadro clínico. Los niveles de HDL se hallaron disminuidos en los pacientes con dengue comparados con los controles sanos. Los análisis de correlación mostraron asociaciones estadísticamente significativas entre HDL y el número de plaquetas; así como entre el porcentaje de hematocrito y los niveles de IL-1β. Conclusiones. El aumento de IL-1β e IL-6 y la disminución de HDL en los estadios clínicos más graves sugieren que ambos factores están implicados en el desarrollo de la patogénesis y severidad. Las correlaciones permiten observar una posible asociación entre HDL y el número de plaquetas que permite dar una aproximación al posible papel de las HDL en la patogénesis del dengue, pero aún es necesario realizar estudios adicionales que permitan elucidar su importancia en el curso de la infección por DENV.

ABSTRACT Objectives. To assess High-Density Lipoprotein (HDL) and pro-inflammatory cytokine levels in patients with dengue classified according to the severity of the clinical presentation. Materials and Methods. A descriptive study was carried out with 70 individuals with dengue, classified as no alarm signs (DSSA), with signs of alarm (DCSA), and severe dengue (DG); 15 healthy donors were included as controls (CS). The serum levels of IL-1β and IL-6 were quantified through ELISA, and the HDL levels through serum by a colorimetric test. In addition, the platelet count and the hematocrit percentage were determined. Results. Levels of IL-1β and IL-6 were found to be increased in patients with DENV vs. the healthy controls. Said increase was more evident in patients with dengue and in line with the severity of the clinical presentation. The HDL levels were found to be decreased in patients with dengue versus healthy controls. The correlation analysis showed statistically significant associations between HDL and the platelet number, as well as between the hematocrit percentage and the levels of IL-1β. Conclusions. The increased IL-1β and IL-6 and the decreased HDL levels in the most severe clinical stages suggest that both factors are involved in the development of the pathogenesis and severity. The correlations allow the observation of a potential association between HDL and platelet count, which allows us to provide an approach to the possible role of HDL in the pathogenesis of dengue, but it is still necessary to perform additional studies that will allow to state their importance in the course of the DENV infection.

High-dose of vitamin D supplement is associated with reduced susceptibility of monocyte-derived macrophages to dengue virus infection and pro-inflammatory cytokine production: An exploratory study.

BACKGROUND: Dengue, one the most important public health problems in tropical and subtropical areas, is the most important mosquito-borne viral infection in humans. In the absence of effective treatment and vaccine against dengue, the active form of vitamin D could play a central role in protection against dengue virus (DENV), the causal agent of dengue. Recently we reported that monocyte-derived macrophages (MDMs) differentiated in the presence of vitamin D, in addition to expressing lower levels of mannose receptor, are less susceptible to DENV infection and produce low levels of pro-inflammatory cytokines, compared to MDMs differentiated in the absence of vitamin D. OBJECTIVE: The aim of this study was to determine that oral vitamin D supplementation exerts an effect on DENV susceptibility and pro-inflammatory cytokine production in MDMs. METHODS: Healthy individuals were supplemented with 1000 or 4000 international units (IU)/day of vitamin D during 10days. Before and after vitamin D supplementation, a peripheral blood (PB) sample was taken and the monocytes recovered were used to obtain MDMs and were challenged with DENV-2. Furthermore, the expression of genes encoding vitamin D receptor (VDR), CYP24A1 and CAMP were analyzed using real-time quantitative PCR. RESULTS: The data indicate that macrophages differentiated from monocytes obtained from healthy donors who received higher doses of vitamin D (4000IU/day), exhibited higher resistance to DENV-2 infection and produced a significant decrease of pro-inflammatory cytokines and high production of interleukin-10 (IL-10). Furthermore, a significant decrease in intracellular toll-like receptor (TLR) and CAMP mRNA was observed. CONCLUSION: A supplement of 4000IU/day of vitamin D may represent an adequate dose to control dengue progression and DENV replication. Although the results of our study suggest that the vitamin D status can influence the immune response, further studies are needed to determine the feasibility of vitamin D as anti-DENV agent and immune modulator.

Phosphomannosylation and the Functional Analysis of the Extended Candida albicans MNN4-Like Gene Family.

Phosphomannosylation is a modification of cell wall proteins that occurs in some species of yeast-like organisms, including the human pathogen Candida albicans. These modified mannans confer a negative charge to the wall, which is important for the interactions with phagocytic cells of the immune systems and cationic antimicrobial peptides. In Saccharomyces cerevisiae, the synthesis of phosphomannan relies on two enzymes, the phosphomannosyltransferase Ktr6 and its positive regulator Mnn4. However, in C. albicans, at least three phosphomannosyltransferases, Mnn4, Mnt3 and Mnt5, participate in the addition of phosphomannan. In addition to MNN4, C. albicans has a MNN4-like gene family composed of seven other homologous members that have no known function. Here, using the classical mini-Ura-blaster approach and the new gene knockout CRISPR-Cas9 system for gene disruption, we generated mutants lacking single and multiple genes of the MNN4 family; and demonstrate that, although Mnn4 has a major impact on the phosphomannan content, MNN42 was also required for full protein phosphomannosylation. The reintroduction of MNN41, MNN42, MNN46, or MNN47 in a genetic background lacking MNN4 partially restored the phenotype associated with the mnn4Δ null mutant, suggesting that there is partial redundancy of function between some family members and that the dominant effect of MNN4 over other genes could be due to its relative abundance within the cell. We observed that additional copies of alleles number of any of the other family members, with the exception of MNN46, restored the phosphomannan content in cells lacking both MNT3 and MNT5. We, therefore, suggest that phosphomannosylation is achieved by three groups of proteins: [i] enzymes solely activated by Mnn4, [ii] enzymes activated by the dual action of Mnn4 and any of the products of other MNN4-like genes, with exception of MNN46, and [iii] activation of Mnt3 and Mnt5 by Mnn4 and Mnn46. Therefore, although the MNN4-like genes have the potential to functionally redundant with Mnn4, they apparently do not play a major role in cell wall mannosylation under most in vitro growth conditions. In addition, our phenotypic analyses indicate that several members of this gene family influence the ability of macrophages to phagocytose C. albicans cells.