Linking photosynthesis and yield reveals a strategy to improve light use efficiency in a climbing bean breeding population.

Photosynthesis drives plant physiology, biomass accumulation, and yield. Photosynthetic efficiency, specifically the operating efficiency of PSII (Fq'/Fm'), is highly responsive to actual growth conditions, especially to fluctuating photosynthetic photon fluence rate (PPFR). Under field conditions, plants constantly balance energy uptake to optimize growth. The dynamic regulation complicates the quantification of cumulative photochemical energy uptake based on the intercepted solar energy, its transduction into biomass, and the identification of efficient breeding lines. Here, we show significant effects on biomass related to genetic variation in photosynthetic efficiency of 178 climbing bean (Phaseolus vulgaris L.) lines. Under fluctuating conditions, the Fq'/Fm' was monitored throughout the growing period using hand-held and automated chlorophyll fluorescence phenotyping. The seasonal response of Fq'/Fm' to PPFR (ResponseG:PPFR) achieved significant correlations with biomass and yield, ranging from 0.33 to 0.35 and from 0.22 to 0.31 in two glasshouse and three field trials, respectively. Phenomic yield prediction outperformed genomic predictions for new environments in four trials under different growing conditions. Investigating genetic control over photosynthesis, one single nucleotide polymorphism (Chr09_37766289_13052) on chromosome 9 was significantly associated with ResponseG:PPFR in proximity to a candidate gene controlling chloroplast thylakoid formation. In conclusion, photosynthetic screening facilitates and accelerates selection for high yield potential.

Disección de aorta secundario a trauma, manejo clínico en Hospital General / Aortic dissection secondary to trauma, clinical management in General Hospital

INTRODUCCIÓN. La disección de aorta es una patología poco frecuente, cuando se presenta, lo hace de una manera catastrófica manifestada por dolor torácico o lumbar intenso acompañado de compromiso hemodinámico agudo, un diagnóstico y tratamiento temprano suelen ser cruciales para evitar la muerte del paciente, así mismo, una disección de aorta puede ser secundario a un trauma torácico por desaceleración y se presenta en 1,5% a 2%, lo que induce sobre todo a un desgarro localizado en la región del istmo aórtico. CASO CLÍNICO. Paciente masculino de 35 años, con antecedente de accidente en vehículo motorizado que provocó un traumatismo cráneo encefálico moderado, hematoma epidural parietal derecho, con resolución quirúrgica hace 18 meses, se descartó lesiones a nivel de tórax con radiografía de tórax normal, además se realizó ecografía FAST en ventana perihepática, suprapúbica, periesplénica y subxi-foidea sin encontrar alteración. Acudió al servicio de emergencia por un cuadro de hemiparesia derecha más disartria de 4 horas de evolución, se realiza tomografía de cráneo sin encontrarse lesión, catalogándose como evento cerebrovascular isquémico con recuperación neurológica. Durante su estancia hospitalaria presenta un cuadro de disnea de grandes esfuerzos y tras realizar exámenes complementarios de control se llega a una conclusión de una cardiomegalia, por lo que es referido a consulta de cardiología donde se realiza ecocardiograma, en la cual se observa disección de aorta ascendente más aneurisma por lo que se decide su ingreso y se instaura tratamiento mediante medidas de soporte, con derivación a hospital de especialidades para cirugía cardiotorácica. CONCLUSIONES. La disección de aorta secundario a un traumatis-mo es poco frecuente, sin embargo, el diagnostico siempre debe estar presente en caso de trauma por desaceleración, ya que es vital para la supervivencia del paciente y su manejo oportuno.

INTRODUCTION. Aortic dissection is an infrequent pathology; when it occurs, it does so in a catastrophic manner manifested by intense thoracic or lumbar pain accompanied by acute he-modynamic compromise. Early diagnosis and treatment are usually crucial to avoid the patient's death; likewise, aortic dissection can be secondary to thoracic trauma due to deceleration and occurs in 1.5% to 2%, which mainly induces a localized tear in the region of the aortic isthmus. CLINICAL CASE. 35-year-old male patient, with a history of motor vehicle accident that caused a moderate head injury, right parietal epidural hematoma, with surgical resolution 18 months ago, chest injuries were ruled out with normal chest X-ray, and FAST ultrasound was performed in perihepatic, suprapubic, perisplenic and subxiphoid window without finding any alteration. She went to the emergency department for a picture of right hemiparesis and dysarthria of 4 hours of evolution, a cranial tomography was performed without finding any lesion, being clas-sified as an ischemic cerebrovascular event with neurological recovery. During his hospital stay he presented with dyspnea of great effort and after performing complementary control tests, a cardiomegaly was found, so he is referred to a cardiology clinic where an echocardiogram is per-formed, which showed dissection of the ascending aorta plus aneurysm, admission is decided and treatment is instituted through supportive measures, with referral to a specialty hospital for cardiothoracic surgery. CONCLUSIONS. Aortic dissection secondary to trauma is rare, however, the diagnosis should always be present in case of trauma due to deceleration, as it is vital for the survival of the patient and its timely treatment.

Photosynthesis and biochemical characterization of the green alga Chlamydopodium fusiforme (Chlorophyta) grown in a thin-layer cascade.

Photosynthesis, growth and biochemical composition of the biomass of the freshwater microalga Chlamydopodium fusiforme cultures outdoors in a thin-layer cascade were investigated. Gross oxygen production measured off-line in samples taken from the outdoor cultures was correlated with the electron transport rate estimated from chlorophyll a fluorescence measurements. According to photosynthesis measurements, a mean of 38.9 ± 10.3 mol of photons were required to release one mole of O2, which is 4.86 times higher than the theoretical value (8 photons per 1 O2). In contrast, according to the fluorescence measurements, a mean of 11.7 ± 0.74 mol of photons were required to release 1 mol of O2. These findings indicate that fluorescence-based photosynthesis rates may not be fully replace oxygen measurements to evaluate the performance of an outdoor culture. Daily gross biomass productivity was 0.3 g DW L-1 day-1 consistently for 4 days. Biomass productivity was strongly affected by the suboptimal concentration at which the culture was operated and by the respiration rate, as the substantial volume of culture was kept in the dark (about 45% of the total volume). As the cells were exposed to excessive light, the photosynthetic activity was mainly directed to the synthesis of carbohydrates in the biomass. In the morning, carbohydrate content decreased because of the dark respiration. Per contra, protein content in the biomass was lower at the end of the day and higher in the morning due to carbohydrate consumption by respiration. The data gathered in these trials are important for the future exploitation of Chlamydopodium fusiforme as a potential novel species in the field of microalgae for the production of bio-based compounds.

Phylogenetic diversity and the structure of host-epiphyte interactions across the Neotropics.

Understanding the mechanisms driving community assembly has been a major focus of ecological research for nearly a century, yet little is known about these mechanisms in commensal communities, particularly with respect to their historical/evolutionary components. Here, we use a large-scale dataset of 4,440 vascular plant species to explore the relationship between the evolutionary distinctiveness (ED) (as measured by the 'species evolutionary history' (SEH)) of host species and the phylogenetic diversity (PD) of their associated epiphyte species. Although there was considerable variation across hosts and their associated epiphyte species, they were largely unrelated to host SEH. Our results mostly support the idea that the determinants of epiphyte colonization success might involve host characteristics that are unrelated to host SEH (e.g., architectural differences between hosts). While determinants of PD of epiphyte assemblages are poorly known, they do not appear to be related to the evolutionary history of host species. Instead, they might be better explained by neutral processes of colonization and extinction. However, the high level of phylogenetic signal in epiphyte PD (independent of SEH) suggests it might still be influenced by yet unrecognized evolutionary determinants. This study highlights how little is still known about the phylogenetic determinants of epiphyte communities.

Valuable pigments from microalgae: phycobiliproteins, primary carotenoids, and fucoxanthin.

Phycobiliproteins, carotenoids and fucoxanthin are photosynthetic pigments extracted from microalgae and cyanobacteria with great potential biotechnological applications, as healthy food colorants and cosmetics. Phycocyanin possesses a brilliant blue color, with fluorescent properties making it useful as a reagent for immunological essays. The most important source of phycocyanin is the cyanobacterium Arthrospira platensis, however, recently, the Rhodophyta Galdieria sulphuraria has also been identified as such. The main obstacle to the commercialization of phycocyanin is represented by its chemical instability, strongly reducing its shelf-life. Moreover, the high level of purity needed for pharmaceutical applications requires several steps which increase both the production time and cost. Microalgae (Chlorella, Dunaliella, Nannochloropsis, Scenedesmus) produce several light harvesting carotenoids, and are able to manage with oxidative stress, due to their free radical scavenging properties, which makes them suitable for use as source of natural antioxidants. Many studies focused on the selection of the most promising strains producing valuable carotenoids and on their extraction and purification. Among carotenoids produced by marine microalgae, fucoxanthin is the most abundant, representing more than 10% of total carotenoids. Despite the abundance and diversity of fucoxanthin producing microalgae only a few species have been studied for commercial production, the most relevant being Phaeodactylum tricornutum. Due to its antioxidant activity, fucoxanthin can bring various potential benefits to the prevention and treatment of lifestyle-related diseases. In this review, we update the main results achieved in the production, extraction, purification, and commercialization of these important pigments, motivating the cultivation of microalgae as a source of natural pigments.

Manifestaciones neurológicas en pacientes con diagnóstico de COVID-19

Introducción: La aparición de una nueva variante de coronavirus ha desatado en una pandemia relacionada con un síndrome de distrés respiratorio severo por SARS-CoV-2. Las primeras manifestaciones asociadas a este nuevo síndrome eran netamente respiratorias. Sin embargo, con los diferentes estudios se evidenció no solo afectación pulmonar, si no sistémica especialmente a nivel neurológico en donde los pacientes presentan síntomas centrales y periféricos de afectación por coronavirus. Materiales y Métodos: Se realizó una revisión utilizando base de datos como: PubMed, Scopus, Embase, Cochrane Library, Scielo, incluyendo estudios de tipo observacionales, artículos de revisión, guías clínicas, que evaluaran la presencia de manifestaciones neurológicas en pacientes con diagnóstico de del 2019 al 2021. Resultados: Se incluyeron 26 artículos donde se observó que las manifestaciones neurológicas inespecíficas tal como la cefalea fue la más común con una presentación de 30%. Las manifestaciones neurológicas específicas se presentan con una frecuencia alrededor de 3% pero con mayor gravedad, incluyendo convulsiones e ictus. Conclusiones: es una patología donde su principal característica es la sintomatología pulmonar. Sin embargo, algunos pacientes presentan manifestaciones neurológicas específicas las cuales son menos frecuentes, pero tienen un carácter más grave y en contraste las manifestaciones neurológicas inespecíficas que son más frecuentes pero no ponen en riesgo la vida del paciente. Tal sintomatología es crucial al momento de abordar a un paciente con COVID-19 y se debe tener presente las mismas en la atención médica oportuna.

Introduction: The appearance of a new variant of coronavirus has unleashed a pandemic related to a severe respiratory distress syndrome due to SARS-CoV-2. The first manifestations associated with this new syndrome were purely respiratory. However, with the different studies it was evidenced not only pulmonary involvement, but also systemic especially at the neurological level where patients present central and peripheral symptoms of coronavirus involvement. Materials and Methods: A review was conducted using databases such as: PubMed, Scopus, Embase, Cochrane Library, SciELO, including observational studies, review articles, clinical guidelines, which evaluated the presence of neurological manifestations in patients diagnosed from 2019 to 2021. Results: Twenty-six articles were included in which it was observed that nonspecific neurological manifestations such as headache was the most common with a presentation of 30%. Specific neurological manifestations occur with a frequency of about 3% but with greater severity, including seizures and stroke. Conclusions: It is a pathology where its main characteristic is pulmonary symptomatology. However, some patients have specific neurological manifestations which are less frequent but have a more severe character and in contrast the nonspecific neurological manifestations are more frequent but do not endanger the patient's life. Such symptomatology is crucial when approaching a patient with COVID-19 and should be kept in mind in timely medical care.

Genetic analysis of resistance to bean leaf crumple virus identifies a candidate LRR-RLK gene.

Bean leaf crumple virus (BLCrV) is a novel begomovirus (family Geminiviridae, genus Begomovirus) infecting common bean (Phaseolus vulgaris L.), threatening bean production in Latin America. Genetic resistance is required to ensure yield stability and reduce the use of insecticides, yet the available resistance sources are limited. In this study, three common bean populations containing a total of 558 genotypes were evaluated in different yield and BLCrV resistance trials under natural infection in the field. A genome-wide association study identified the locus BLC7.1 on chromosome Pv07 at 3.31 Mbp, explaining 8 to 16% of the phenotypic variation for BLCrV resistance. In comparison, whole-genome regression models explained 51 to 78% of the variation and identified the same region on Pv07 to confer resistance. The most significantly associated markers were located within the gene model Phvul.007G040400, which encodes a leucine-rich repeat receptor-like kinase subfamily III member and is likely to be involved in the innate immune response against the virus. The allelic diversity within this gene revealed five different haplotype groups, one of which was significantly associated with BLCrV resistance. As the same genome region was previously reported to be associated with resistance against other geminiviruses affecting common bean, our study highlights the role of previous breeding efforts for virus resistance in the accumulation of positive alleles against newly emerging viruses. In addition, we provide novel diagnostic single-nucleotide polymorphism markers for marker-assisted selection to exploit BLC7.1 for breeding against geminivirus diseases in one of the most important food crops worldwide.

Growth and photosynthetic performance of Nostoc linckia (formerly N. calcicola) cells grown in BG11 and BG110 media.

The biotechnological potential of Nostoc linckia as a biofertilizer and source of bioactive compounds makes it important to study its growth physiology and productivity. Since nitrogen is a fundamental component of N. linckia biomass, we compared the growth and biochemical composition of cultures grown in BG11 (i.e., in the presence of nitrate) and BG110 (in the absence of nitrate). Cultures grown in BG11 accumulated more cell biomass reaching a dry weight of 1.65 ± 0.06 g L-1, compared to 0.92 ± 0.01 g L-1 in BG110 after 240 h of culture. Biomass productivity was higher in culture grown in BG11 medium (average 317 ± 38 mg L-1 day-1) compared to that attained in BG110 (average 262 ± 37 mg L-1 day-1). The chlorophyll content of cells grown in BG11 increased continuously up to (39.0 ± 1.3 mg L-1), while in BG110 it increased much more slowly (13.6 ± 0.8 mg L-1). Biomass grown in BG11 had higher protein and phycobilin contents. However, despite the differences in biochemical composition and pigment concentration, between BG11 and BG110 cultures, both their net photosynthetic rates and maximum quantum yields of the photosystem II resulted in similar.

New Proposal of Epiphytic Bromeliaceae Functional Groups to Include Nebulophytes and Shallow Tanks.

The Bromeliaceae family has been used as a model to study adaptive radiation due to its terrestrial, epilithic, and epiphytic habits with wide morpho-physiological variation. Functional groups described by Pittendrigh in 1948 have been an integral part of ecophysiological studies. In the current study, we revisited the functional groups of epiphytic bromeliads using a 204 species trait database sampled throughout the Americas. Our objective was to define epiphytic functional groups within bromeliads based on unsupervised classification, including species from the dry to the wet end of the Neotropics. We performed a hierarchical cluster analysis with 16 functional traits and a discriminant analysis, to test for the separation between these groups. Herbarium records were used to map species distributions and to analyze the climate and ecosystems inhabited. The clustering supported five groups, C3 tank and CAM tank bromeliads with deep tanks, while the atmospheric group (according to Pittendrigh) was divided into nebulophytes, bromeliads with shallow tanks, and bromeliads with pseudobulbs. The two former groups showed distinct traits related to resource (water) acquisition, such as fog (nebulophytes) and dew (shallow tanks). We discuss how the functional traits relate to the ecosystems inhabited and the relevance of acknowledging the new functional groups.

Photosynthesis Monitoring in Microalgae Cultures Grown on Municipal Wastewater as a Nutrient Source in Large-Scale Outdoor Bioreactors.

Microalgae cultures were used for a WW treatment to remediate nutrients while producing biomass and recycling water. In these trials, raceway ponds (RWPs; 1 and 0.5 ha) were located next to a municipal (WW) treatment plant in Mérida, Spain. The ponds were used for continuous, all-year-round microalgae production using WW as a source of nutrients. Neither CO2 nor air was supplied to cultures. The objective was to validate photosynthesis monitoring techniques in large-scale bioreactors. Various in-situ/ex-situ methods based on chlorophyll fluorescence and oxygen evolution measurements were used to follow culture performance. Photosynthesis variables gathered with these techniques were compared to the physiological behavior and growth of cultures. Good photosynthetic activity was indicated by the build-up of dissolved oxygen concentration up to 380% saturation, high photochemical yield (Fv/Fm = 0.62-0.71), and relative electron transport rate rETR between 200 and 450 µmol e- m-2 s-1 at midday, which resulted in biomass productivity of about 15-25 g DW m-2 day-1. The variables represent reliable markers reflecting the physiological status of microalgae cultures. Using waste nutrients, the biomass production cost can be significantly decreased for abundant biomass production in large-scale bioreactors, which can be exploited for agricultural purposes.

5° Congreso Nacional y 1° Internacional de Ciencias Ambientales "Las Ciencias Ambientales en el Antropoceno". Emisiones generadas y evitadas / 5th National and 1st International Congress of Environmental Sciences "Environmental Sciences in the Anthropocene". Emissions generated and avoided

RESUMEN Las actividades académicas, como los congresos, son muy importantes para la investigación y el desarrollo; sin embargo, las emisiones de carbono derivadas de la realización de eventos presenciales han mostrado estar muy por encima de las que producen eventos en línea. El objetivo de este trabajo fue estimar las emisiones generadas por el 5º Congreso Nacional y 1º Internacional de Ciencias Ambientales "Las Ciencias Ambientales en el Antropoceno", celebrado virtualmente, en su mayor parte. Se estimaron las emisiones del uso directo de computadores y de software (emisiones de los computadores, emisiones de la transferencia de los datos) y las emisiones de otras fuentes (reuniones de los organizadores, búsquedas y visitas a la página Web, uso de monitores externos y lámparas), así como las emisiones evitadas por transporte aéreo y terrestre. El congreso emitió 4,8 tCO2eq y evitó 33 tCO2eq. El desarrollo de eventos online o híbridos es más sostenible ambientalmente y podría ser más accesibles, a un mayor número de personas.

ABSTRACT Academic activities such as conferences are very important for research and development, however, carbon emissions derived from face-to-face events have been shown to be much higher than those produced by online events. The aim of this work was to estimate CO2 emissions generated by the 5th National Congress and 1st International Congress of Environmental Sciences "Environmental Sciences in the Anthropocene". Emissions from direct use of computers and software (emissions from computers, emissions from data transfer) and emissions from other sources (meetings of the organizers, searches and visits to the website, use of external monitors and lamps), as well as emissions avoided by air and land transport. The congress emitted 4.8 tCO2eq and avoided 33 tCO2eq. The development of online or hybrid events is more environmentally sustainable and could be more accessible to a greater number of people.

Effect of plate distance on light conversion efficiency of a Synechocystis culture grown outdoors in a multiplate photobioreactor.

In this work, the performance of a vertical multiplate photobioreactor is analyzed and presented. The photobioreactor consisted of 20 vertical plates (1 m2 each) connected by manifolds and a working volume of 1300 L. The total area occupied (footprint) was 10 m2, while the illuminated area was 40 m2, therefore the ratio of illuminated area to volume ratio was about 30 m-1. The performance of the photobioreactor was evaluated using a culture of Synechocystis PCC 6803, circulated by a centrifuge pump. The results showed that the amount of light captured by the photobioreactor at a plate spacing of 0.5 m was 90.2 % of the light incident on the horizontal surface, while at a plate spacing of 1.0 m, 50.3 % was captured. The corresponding biomass yield, calculated based on the ground area occupied by the reactor, was 26.0 g m-2 day-1 and 7.2 g m-2 day-1, when the plates were spaced at 0.5 m and 1.0 m respectively. Therefore, the light conversion efficiency calculated based on the ground area was significantly higher in the configuration with a plate spacing of 0.5 m, reaching 5.43 % based on PAR (photosynthetically active radiation), and 2.44 % based on solar radiation, giving a value 3.7 higher than when the plates were spaced 1.0 m apart. It was concluded that the light conversion efficiency might be further improved by reducing the plate spacing while also reducing the culture light path.

Improving Association Studies and Genomic Predictions for Climbing Beans With Data From Bush Bean Populations.

Common bean (Phaseolus vulgaris L.) has two major origins of domestication, Andean and Mesoamerican, which contribute to the high diversity of growth type, pod and seed characteristics. The climbing growth habit is associated with increased days to flowering (DF), seed iron concentration (SdFe), nitrogen fixation, and yield. However, breeding efforts in climbing beans have been limited and independent from bush type beans. To advance climbing bean breeding, we carried out genome-wide association studies and genomic predictions using 1,869 common bean lines belonging to five breeding panels representing both gene pools and all growth types. The phenotypic data were collected from 17 field trials and were complemented with 16 previously published trials. Overall, 38 significant marker-trait associations were identified for growth habit, 14 for DF, 13 for 100 seed weight, three for SdFe, and one for yield. Except for DF, the results suggest a common genetic basis for traits across all panels and growth types. Seven QTL associated with growth habits were confirmed from earlier studies and four plausible candidate genes for SdFe and 100 seed weight were newly identified. Furthermore, the genomic prediction accuracy for SdFe and yield in climbing beans improved up to 8.8% when bush-type bean lines were included in the training population. In conclusion, a large population from different gene pools and growth types across multiple breeding panels increased the power of genomic analyses and provides a solid and diverse germplasm base for genetic improvement of common bean.

Genomic Prediction of Agronomic Traits in Common Bean (Phaseolus vulgaris L.) Under Environmental Stress.

In plant and animal breeding, genomic prediction models are established to select new lines based on genomic data, without the need for laborious phenotyping. Prediction models can be trained on recent or historic phenotypic data and increasingly available genotypic data. This enables the adoption of genomic selection also in under-used legume crops such as common bean. Beans are an important staple food in the tropics and mainly grown by smallholders under limiting environmental conditions such as drought or low soil fertility. Therefore, genotype-by-environment interactions (G × E) are an important consideration when developing new bean varieties. However, G × E are often not considered in genomic prediction models nor are these models implemented in current bean breeding programs. Here we show the prediction abilities of four agronomic traits in common bean under various environmental stresses based on twelve field trials. The dataset includes 481 elite breeding lines characterized by 5,820 SNP markers. Prediction abilities over all twelve trials ranged between 0.6 and 0.8 for yield and days to maturity, respectively, predicting new lines into new seasons. In all four evaluated traits, the prediction abilities reached about 50-80% of the maximum accuracies given by phenotypic correlations and heritability. Predictions under drought and low phosphorus stress were up to 10 and 20% improved when G × E were included in the model, respectively. Our results demonstrate the potential of genomic selection to increase the genetic gain in common bean breeding. Prediction abilities improved when more phenotypic data was available and G × E could be accounted for. Furthermore, the developed models allowed us to predict genotypic performance under different environmental stresses. This will be a key factor in the development of common bean varieties adapted to future challenging conditions.

Functional composition of epiphyte communities in the Colombian Andes.

We identify changes in the functional composition of vascular epiphytes along a tropical elevational gradient with the aim of quantifying the role of climate in determining the assembly of epiphyte communities. We measured seven leaf functional traits (leaf area, specific leaf area, leaf dry-matter content, leaf thickness, force to punch, stomatal density, and potential conductance index) in the 163 most abundant epiphyte species recorded across 10 sites located along an elevational gradient between 60 and 2,900 m above sea level in the Colombian Andes. We grouped the epiphyte species into seven hierarchical functional groups according to their most characteristic leaf traits. Along the elevational gradient, the two main independent leaf trait dimensions that distinguished community assemblages were defined primarily by leaf area-photosynthetic (LAPS) and mass-carbon (LMCS) gradients. Mean annual temperature was the main determinant of species position along LAPS. In contrast, local changes in specific leaf area due to variation in the epiphytes' relative height of attachment was the main determinant of their position along the LMCS. Our findings indicate that epiphytic plant leaves have evolved to optimize and enhance photosynthesis through a leaf area-based strategy and carbon acquisition through investments in construction costs of leaf area per unit of biomass that aim to regulate light capture and tissue development. Given that most studies of plant functional traits neglect vascular epiphytes, our quantification of the multiple dimensions of epiphyte leaf traits greatly augments our understanding of vascular plant function and adaptation to changing environments.

Role of advanced magnetic resonance imaging in the assessment of malignancies of the mediastinum.

In the new era of functional magnetic resonance imaging (MRI), the utility of chest MRI is increasing exponentially due to several advances, including absence of ionizing radiation, excellent tissue contrast and high capability for lesion characterization and treatment monitoring. The application of several of these diagnostic weapons in a multiparametric fashion enables to better characterize thymic epithelial tumors and other mediastinal tumoral lesions, accurate assessment of the invasion of adjacent structures and detection of pathologic lymph nodes and metastasis. Also, "do not touch lesions" could be identified with the associated impact in the management of those patients. One of the hot-spots of the multiparametric chest MR is its ability to detect with acuity early response to treatment in patients with mediastinal malignant neoplasms. This has been related with higher rates of overall survival and progression free survival. Therefore, in this review we will analyze the current functional imaging techniques available (18F-Fluorodeoxiglucose positron emission tomography/computed tomography, diffusion-weighted imaging, dynamic contrast-enhanced MRI, diffusion tensor imaging and MR spectroscopy) for the evaluation of mediastinal lesions, with a focus in their correct acquisition and post-processing. Also, to review the clinical applications of these techniques in the diagnostic approach of benign and malignant conditions of the mediastinum.

Tumor pardo en esqueleto axial de dos pacientes con enfermedad renal crónica en diálisis / Brown tumor in the axial skeleton of two patients with chronic kidney disease in dialysis

Resumen Los tumores pardos son una forma localizada de osteítis fibrosa no neoplásica, secundaria a hiperparatiroidismo (primario o secundario). Hacen parte de las alteraciones del metabolismo mineral y óseo de la enfermedad renal crónica (ERC). Se manifiestan como lesiones líticas, expansivas, asociadas a masas de tejidos blandos, que pueden estar localizadas en cualquier parte del esqueleto, con predilección por las costillas, clavículas, pelvis, fémur, huesos faciales y mandíbula. Reportamos dos casos de paciente con ERC en terapia de reemplazo renal (TRR), con hiperparatiroidismo secundario y tumores pardos localizados en mandíbula, arcos costales y cuerpos vertebrales, con manifestaciones radiológicas atípicas. Conclusión: los tumores pardos hacen parte de las alteraciones óseas de los pacientes con ERC. El aspecto benigno en los estudios de imágenes (lesiones expansivas sin destrucción de la cortical) en el contexto de un paciente con hiperparatiroidismo, pueden sugerir el diagnóstico. (Acta Med Colomb 2018; 43: 221-225).

Abstract Brown tumors are a localized form of non-neoplastic osteitis fibrosa, secondary to hyperparathyroidism (primary or secondary). They are part of the alterations of the mineral and bone metabolism of chronic kidney disease (CKD). They manifest as lytic, expansive lesions associated to soft tissue masses that can be located in any part of the skeleton with predilection for the ribs, clavicles, pelvis, femur, facial bones and jaw. Two cases of patients with CKD in renal replacement therapy (RRT), with secondary hyperparathyroidism and brown tumors located in the jaw, costal arches and vertebral bodies, with atypical radiological manifestations are described. Conclusion: brown tumors are part of the bone disorders of patients with CKD. The benign appearance in imaging studies (expansive lesions without destruction of the cortex) in the context of a patient with hyperparathyroidism, may suggest the diagnosis. (Acta Med Colomb 2018; 43: 221-225).

Risk of obstructive sleep apnea in open-angle glaucoma versus controls using the STOP-Bang questionnaire.

OBJECTIVE: To compare the percentage of patients at risk for obstructive sleep apnea (OSA) in open-angle glaucoma (OAG) versus controls using the STOP-Bang questionnaire. METHODS: This study used a cross-sectional survey. Patients with OAG and controls completed the STOP-Bang questionnaire-a validated tool to identify patients at high risk for OSA. Patients were considered at risk if they scored 3 or more points or at high risk for moderate/severe OSA if they scored 5 or more out of the maximum 8 points. Demographic information, medical history, and previous diagnosis of OSA were recorded. Details regarding the patients' glaucoma were obtained from their medical records. RESULTS: A total of 437 patients with OAG and 441 controls were included. The mean STOP-Bang score was 3.01 ± 1.3 for the glaucoma group and 3.03 ± 1.4 for the control group (p = 0.92). There was no significant difference between the percentage of subjects considered at risk for OSA (62.7% OAG vs 59.4% controls, p = 0.37) or at high risk for moderate/severe OSA (12.6% OAG vs 16.5% controls, p = 0.1). Significantly more patients in the control group had a previous diagnosis of OSA (p = 0.01). More patients with OAG reported feeling tired compared with controls (p = 0.003). A risk/high risk for OSA was not associated with glaucoma severity, progression, intraocular pressure control, or glaucoma type. CONCLUSIONS: Our results indicate that a risk or high risk for moderate/severe OSA as measured by the STOP-Bang questionnaire is not correlated with the presence or absence of glaucoma (regardless of the type), glaucoma severity, glaucoma progression, or IOP control.

Quiste tímico multiloculado en un paciente adulto: presentación de caso y revisión de la literatura / Multiloculated thymic cyst in an adult patient: case report and literature review

Los quistes tímicos multiloculados son lesiones generalmente adquiridas, que se diagnostican de manera incidental en la mayoría de pacientes y se asocian con condiciones de naturaleza diversa, como: inflamación, infección, trauma y radioterapia. Se presenta el caso de una mujer de 55 años con un quiste tímico multiloculado, sin antecedentes de importancia o condición clínica particular al momento del diagnóstico.

Multiloculated thymic cysts are acquired lesions, diagnosed incidentally in most patients and associated with other conditions such as inflammation, infection, trauma and radiothera. We present the case of a 55-year-old woman with a multilocular thymic cyst, with no relevant history or particular clinical condition at the time of diagnosis.