Correlation Between Skeletal Muscle Mass and Fat-Free Mass in Infants Born Very Preterm.

Assessing growth quality in preterm infants present challenges, particularly with the use of the standard fat-free mass measurement. We report here a moderate correlation between indirect skeletal muscle mass measurements using the D3-creatine dilution method and fat-free mass measured with air-displacement plethysmography. Skeletal muscle mass could serve as an indicator of growth quality.

Risk Assessment of Cognitive Impairment at 2 Years of Age in Infants Born Extremely Preterm Using the INTERGROWTH-21st Growth Standards.

OBJECTIVE: To assess the risk of cognitive impairment among infants born extremely preterm using the INTERGROWTH-21st standards. STUDY DESIGN: We analyzed anthropometric data at birth and 36 weeks postmenstrual age (PMA) from infants born extremely preterm (24-26 weeks of gestation) admitted to US neonatal units between 2008 and 2018. To determine INTERGROWTH-21st z-score values that indicate an increased risk of cognitive impairment at 2 years of age (Bayley cognitive score <85), we employed classification and regression trees and redefined growth failure (weight, length, and head circumference z-scores at 36 weeks PMA) and growth faltering (weight, length, and head circumference z-score declines from birth to 36 weeks PMA). RESULTS: Among 5393 infants with a mean gestational age of 25 weeks, growth failure defined as a weight z-score of -1.8 or below at 36 weeks PMA and growth faltering defined as a weight z-score decline of 1.1 or greater from birth to 36 weeks PMA indicated a higher likelihood of cognitive impairment. A length z-score less than -1 at 36 weeks PMA had the highest sensitivity to detect cognitive impairment at 2 years (80%). A head circumference z-score decline of 2.43 or greater from birth to 36 weeks PMA had the highest specificity (86%). Standard definitions had fair to low sensitivity and specificity for risk detection of cognitive impairment. CONCLUSIONS: Length and head circumference z-scores had the highest sensitivity and specificity for risk detection of cognitive impairment. Monitoring these growth parameters could guide earlier individualized interventions with potential to reduce cognitive impairment. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov ID Generic Database: NCT00063063.

Transcriptional dynamics orchestrating the development and integration of neurons born in the adult hippocampus.

The adult hippocampus generates new granule cells (aGCs) with functional capabilities that convey unique forms of plasticity to the preexisting circuits. While early differentiation of adult radial glia-like cells (RGLs) has been studied extensively, the molecular mechanisms guiding the maturation of postmitotic neurons remain unknown. Here, we used a precise birthdating strategy to study aGC differentiation using single-nuclei RNA sequencing. Transcriptional profiling revealed a continuous trajectory from RGLs to mature aGCs, with multiple immature stages bearing increasing levels of effector genes supporting growth, excitability, and synaptogenesis. Analysis of differential gene expression, pseudo-time trajectory, and transcription factors (TFs) revealed critical transitions defining four cellular states: quiescent RGLs, proliferative progenitors, immature aGCs, and mature aGCs. Becoming mature aGCs involved a transcriptional switch that shuts down pathways promoting cell growth, such SoxC TFs, to activate programs that likely control neuronal homeostasis. aGCs overexpressing Sox4 or Sox11 remained immature. Our results unveil precise molecular mechanisms driving adult RGLs through the pathway of neuronal differentiation.

Zika virus non-coding RNAs antagonize antiviral responses by PKR-mediated translational arrest.

Zika virus (ZIKV) is an emerging mosquito-borne flavivirus that causes severe outbreaks in human populations. ZIKV infection leads to the accumulation of small non-coding viral RNAs (known as sfRNAs) that are crucial for evasion of antiviral responses and for viral pathogenesis. However, the mechanistic understanding of how sfRNAs function remains incomplete. Here, we use recombinant ZIKVs and ribosome profiling of infected human cells to show that sfRNAs block translation of antiviral genes. Mechanistically, we demonstrate that specific RNA structures present in sfRNAs trigger PKR activation, which instead of limiting viral replication, enhances viral particle production. Although ZIKV infection induces mRNA expression of antiviral genes, translation efficiency of type I interferon and interferon stimulated genes were significantly downregulated by PKR activation. Our results reveal a novel viral adaptation mechanism mediated by sfRNAs, where ZIKV increases its fitness by repurposing the antiviral role of PKR into a proviral factor.

scX: a user-friendly tool for scRNAseq exploration.

Motivation: Single-cell RNA sequencing (scRNAseq) has transformed our ability to explore biological systems. Nevertheless, proficient expertise is essential for handling and interpreting the data. Results: In this article, we present scX, an R package built on the Shiny framework that streamlines the analysis, exploration, and visualization of single-cell experiments. With an interactive graphic interface, implemented as a web application, scX provides easy access to key scRNAseq analyses, including marker identification, gene expression profiling, and differential gene expression analysis. Additionally, scX seamlessly integrates with commonly used single-cell Seurat and SingleCellExperiment R objects, resulting in efficient processing and visualization of varied datasets. Overall, scX serves as a valuable and user-friendly tool for effortless exploration and sharing of single-cell data, simplifying some of the complexities inherent in scRNAseq analysis. Availability and implementation: Source code can be downloaded from https://github.com/chernolabs/scX. A docker image is available from dockerhub as chernolabs/scx.

Morphological and molecular characterization of brown-banded broodsacs and metacercariae of Leucochloridium (Trematoda: Leucochloridiidae) parasitizing the semi-slug Omalonyx unguis (Succineidae) in Argentina.

Trematodes of the genus Leucochloridium exhibit an unusual transmission strategy among mollusks (intermediate host). The fully developed sporocyst, housing encysted metacercariae, displays vivid coloration and rhythmic activity in the snail's tentacle, mimicking insect larvae. These strategies attract insectivorous birds, their final hosts, thereby increasing the chances of completing their life cycle. In South America, the reports of adults and larval stages of Leucochloridium are scarce. Brown-banded broodsac of Leucochloridium sp. were obtained from Omalonyx unguis collected in a shallow lake from Corrientes Province, Argentina. Here, we morphologically characterized the larval stages (broodsac and metacercaria), identified the parasite through DNA sequences from nuclear 28S-rRNA (28S) and the mitochondrial cytochrome c oxidase I (COI) genes, and explored its evolutionary affinities with the Leucochloridium species available in GenBank. The present broodsac displays brown bands, with a yellowish background in the first two-thirds and yellowish-white in the last third. Based on morphological comparisons, the broodsac and metacercaria described in this study could not be conclusively categorized under any known South American species of Leucochloridium. In relation to the phylogenetic reconstructions, Leucochloridium sp. consistently clustered with L. perturbatum, and species delimitation analyses resulted in recognized Leucochloridium sp. from Argentina as a distinct species. The DNA sequences obtained in this study constitute the first genetic data generated for sporocyst broodsacs in South America. Future studies, incorporating morphology, genetic, and biological data, will be essential for both species identification and the elucidation of leucochloridiid diversity in the region.

Advances and knowledge gaps on climate change impacts on honey bees and beekeeping: A systematic review.

The Western honey bee Apis mellifera is a managed species that provides diverse hive products and contributing to wild plant pollination, as well as being a critical component of crop pollination systems worldwide. High mortality rates have been reported in different continents attributed to different factors, including pesticides, pests, diseases, and lack of floral resources. Furthermore, climate change has been identified as a potential driver negatively impacting pollinators, but it is still unclear how it could affect honey bee populations. In this context, we carried out a systematic review to synthesize the effects of climate change on honey bees and beekeeping activities. A total of 90 articles were identified, providing insight into potential impacts (negative, neutral, and positive) on honey bees and beekeeping. Interest in climate change's impact on honey bees has increased in the last decade, with studies mainly focusing on honey bee individuals, using empirical and experimental approaches, and performed at short-spatial (<10 km) and temporal (<5 years) scales. Moreover, environmental analyses were mainly based on short-term data (weather) and concentrated on only a few countries. Environmental variables such as temperature, precipitation, and wind were widely studied and had generalized negative effects on different biological and ecological aspects of honey bees. Food reserves, plant-pollinator networks, mortality, gene expression, and metabolism were negatively impacted. Knowledge gaps included a lack of studies at the apiary and beekeeper level, a limited number of predictive and perception studies, poor representation of large-spatial and mid-term scales, a lack of climate analysis, and a poor understanding of the potential impacts of pests and diseases. Finally, climate change's impacts on global beekeeping are still an emergent issue. This is mainly due to their diverse effects on honey bees and the potential necessity of implementing adaptation measures to sustain this activity under complex environmental scenarios.

La abeja occidental Apis mellifera es una especie manejada que proporciona diversos productos de la colmena y servicios de polinización, los cuales son cruciales para plantas silvestres y cultivos en todo el mundo. En distintos continentes se han registrado altas tasas de mortalidad, las cuales son atribuidas a diversos factores, como el uso de pesticidas, plagas, enfermedades y falta de recursos florales. Además, el cambio climático ha sido identificado como un potencial factor que afecta negativamente a los polinizadores, pero aún no está claro cómo podría afectar a las poblaciones de abejas melíferas. En este contexto, realizamos una revisión sistemática de la literatura disponible para sintetizar los efectos del cambio climático en las abejas melíferas y las actividades apícolas. En total, se identificaron 90 artículos que proporcionaron información sobre los posibles efectos (negativos, neutros y positivos) en las abejas melíferas y la apicultura. El interés por el impacto del cambio climático en las abejas melíferas ha aumentado en la última década, con estudios centrados principalmente en individuos de abejas melíferas, utilizando enfoques empíricos y experimentales y realizados a escalas espaciales (<10 km) y temporales (<5 años) cortas. Además, los análisis ambientales fueron basaron principalmente en datos a corto plazo (meteorológicos) y se concentraron sólo en algunos países. Variables ambientales como la temperatura, las precipitaciones y el viento fueron ampliamente estudiadas y tuvieron efectos negativos generalizados sobre distintos aspectos biológicos y ecológicos de las abejas melíferas. Además, las reservas alimenticias, las interacciones planta-polinizador, la mortalidad, la expresión génica y el metabolismo se vieron afectados negativamente. Entre los vacios de conocimiento cabe mencionar la falta de estudios a nivel de colmenar y apicultor, la escasez de estudios de predicción y percepción, la escasa representación de las grandes escalas espaciales y a mediano plazo, el déficit de análisis climáticos y la escasa comprensión de los impactos potenciales de plagas y enfermedades. Por último, las repercusiones del cambio climático en la apicultura mundial siguen siendo un tema emergente, que debe estudiarse en los distintos países. Esto se debe principalmente a sus diversos efectos sobre las abejas melíferas y a la necesidad potencial de aplicar medidas de adaptación para mantener esta actividad crucial en escenarios medioambientales complejos.

scX: A user-friendly tool for scRNA-seq exploration.

Single-cell RNA sequencing (scRNA-seq) has transformed our ability to explore biological systems. Nevertheless, proficient expertise is essential for handling and interpreting the data. In this paper, we present scX, an R package built on the Shiny framework that streamlines the analysis, exploration, and visualization of single-cell experiments. With an interactive graphic interface, implemented as a web application, scX provides easy access to key scRNAseq analyses, including marker identification, gene expression profiling, and differential gene expression analysis. Additionally, scX seamlessly integrates with commonly used single-cell Seurat and Single-CellExperiment R objects, resulting in efficient processing and visualization of varied datasets. Overall, scX serves as a valuable and user-friendly tool for effortless exploration and sharing of single-cell data, simplifying some of the complexities inherent in scRNAseq analysis.

Development of a Framework for the Communication System Based on KNX for an Interactive Space for UX Evaluation.

Domotics (Home Automation) aims to improve the quality of life of people by integrating intelligent systems within inhabitable spaces. While traditionally associated with smart home systems, these technologies have potential for User Experience (UX) research. By emulating environments to test products and services, and integrating non-invasive user monitoring tools for emotion recognition, an objective UX evaluation can be performed. To achieve this objective, a testing booth was built and instrumented with devices based on KNX, an international standard for home automation, to conduct experiments and ensure replicability. A framework was designed based on Python to synchronize KNX systems with emotion recognition tools; the synchronization of these data allows finding patterns during the interaction process. To evaluate this framework, an experiment was conducted in a simulated laundry room within the testing booth to analyze the emotional responses of participants while interacting with prototypes of new detergent bottles. Emotional responses were contrasted with traditional questionnaires to determine the viability of using non-invasive methods. Using emulated environments alongside non-invasive monitoring tools allowed an immersive experience for participants. These results indicated that the testing booth can be implemented for a robust UX evaluation methodology.

Transcription factor NAC1 activates expression of peptidase-encoding AtCEPs in roots to limit root hair growth.

Plant genomes encode a unique group of papain-type Cysteine EndoPeptidases (CysEPs) containing a KDEL endoplasmic reticulum (ER) retention signal (KDEL-CysEPs or CEPs). CEPs process the cell-wall scaffolding EXTENSIN (EXT) proteins that regulate de novo cell-wall formation and cell expansion. Since CEPs cleave EXTs and EXT-related proteins, acting as cell-wall-weakening agents, they may play a role in cell elongation. The Arabidopsis (Arabidopsis thaliana) genome encodes 3 CEPs (AtCPE1-AtCEP3). Here, we report that the genes encoding these 3 Arabidopsis CEPs are highly expressed in root-hair (RH) cell files. Single mutants have no evident abnormal RH phenotype, but atcep1-3 atcep3-2 and atcep1-3 atcep2-2 double mutants have longer RHs than wild-type (Wt) plants, suggesting that expression of AtCEPs in root trichoblasts restrains polar elongation of the RH. We provide evidence that the transcription factor NAC1 (petunia NAM and Arabidopsis ATAF1, ATAF2, and CUC2) activates AtCEPs expression in roots to limit RH growth. Chromatin immunoprecipitation indicates that NAC1 binds to the promoter of AtCEP1, AtCEP2, and, to a lower extent, AtCEP3 and may directly regulate their expression. Inducible NAC1 overexpression increases AtCEP1 and AtCEP2 transcript levels in roots and leads to reduced RH growth while the loss of function nac1-2 mutation reduces AtCEP1-AtCEP3 gene expression and enhances RH growth. Likewise, expression of a dominant chimeric NAC1-SRDX repressor construct leads to increased RH length. Finally, we show that RH cell walls in the atcep1-3 atcep3-2 double mutant have reduced levels of EXT deposition, suggesting that the defects in RH elongation are linked to alterations in EXT processing and accumulation. Our results support the involvement of AtCEPs in controlling RH polar growth through EXT processing and insolubilization at the cell wall.

r/K selection of GC content in prokaryotes.

The guanine/cytosine (GC) content of prokaryotic genomes is species-specific, taking values from 16% to 77%. This diversity of selection for GC content remains contentious. We analyse the correlations between GC content and a range of phenotypic and genotypic data in thousands of prokaryotes. GC content integrates well with these traits into r/K selection theory when phenotypic plasticity is considered. High GC-content prokaryotes are r-strategists with cheaper descendants thanks to a lower average amino acid metabolic cost, colonize unstable environments thanks to flagella and a bacillus form and are generalists in terms of resource opportunism and their defence mechanisms. Low GC content prokaryotes are K-strategists specialized for stable environments that maintain homeostasis via a high-cost outer cell membrane and endospore formation as a response to nutrient deprivation, and attain a higher nutrient-to-biomass yield. The lower proteome cost of high GC content prokaryotes is driven by the association between GC-rich codons and cheaper amino acids in the genetic code, while the correlation between GC content and genome size may be partly due to functional diversity driven by r/K selection. In all, molecular diversity in the GC content of prokaryotes may be a consequence of ecological r/K selection.

Variation in Caregiver-Reported Child Sleep Patterns and Problems by Family Socioeconomic Indicators.

OBJECTIVE: Previous studies of sleep patterns, as well as rates and correlates of perceived problems in early childhood, indicate variation by neighborhood-level socioeconomic indicators. The purpose of this study was to examine variation in (1) sleep patterns, behaviors, and problems by family-based socioeconomic indicators (income-to-needs ratio and caregiver education level) and (2) sociodemographic and sleep correlates of a caregiver-endorsed child sleep problem across and within socioeconomic indicator groups in a diverse sample. METHODS: Two hundred eighty-three caregiver-child dyads (ages 1-5 years) completed the Brief Child Sleep Questionnaire. Family-level socioeconomic indicators included income-to-needs ratio and caregiver educational level. RESULTS: Sleep patterns varied based on income-to-needs ratio, with children living in poverty experiencing the longest sleep onset latencies and night awakening durations and shortest nighttime sleep durations. Rates of an endorsed child sleep problem were similar across income-to-needs groups. Although sleep patterns did not vary by caregiver education level, caregivers with an education beyond high school were more likely to endorse a child sleep problem; later bedtimes, more frequent night awakenings, and greater bedtime difficulties were the strongest correlates of a perceived sleep problem in this subgroup. No specific correlates of a child sleep problem emerged for those with a high school education or less. CONCLUSION: Sleep patterns may be more robustly linked to family income-to-needs ratio, whereas perceptions of a child sleep problem may be more linked to caregiver education level. Clinicians should consider expanding sleep screening questions to include specific sleep outcomes to effectively assess child sleep and guide intervention.

Ecology theory disentangles microbial dichotomies.

Microbes are often discussed in terms of dichotomies such as copiotrophic/oligotrophic and fast/slow-growing microbes, defined using the characterisation of microbial growth in isolated cultures. The dichotomies are usually qualitative and/or study-specific, sometimes precluding clear-cut results interpretation. We can unravel microbial dichotomies as life history strategies by combining ecology theory with Monod curves, a laboratory mathematical tool of bacterial physiology that relates the specific growth rate of a microbe with the concentration of a limiting nutrient. Fitting of Monod curves provides quantities that directly correspond to key parameters in ecological theories addressing species coexistence and diversity, such as r/K selection theory, resource competition and community structure theory and the CSR triangle of life strategies. The resulting model allows us to reconcile the copiotrophic/oligotrophic and fast/slow-growing dichotomies as different subsamples of a life history strategy triangle that also includes r/K strategists. We also used the number of known carbon sources together with community structure theory to partially explain the diversity of heterotrophic microbes observed in metagenomics experiments. In sum, we propose a theoretical framework for the study of natural microbial communities that unifies several existing proposals. Its application would require the integration of metagenomics, metametabolomics, Monod curves and carbon source data.

On the causes and consequences of the free-roaming dog problem in southern Chile.

Free-roaming dogs are an important concern for public health, livestock production and the environment. Human behaviors-such as allowing pets to roam, abandoning dogs, or feeding stray animals-could influence free-roaming dog abundance and the frequency of occurrence of dog-caused problems. Here we aim to determine patterns of free-roaming dog abundance in urban and rural areas, to reveal spatial variation in human behaviors underlying the free-roaming dog problem, and to test for associations between free-roaming dog abundance and related problems. We conducted our study in Chile, where dogs are a major environmental issue. In Chile, as in many other Global South countries, many people leave their dogs to roam, partly due to norms and to lax enforcement of dog control laws. To address our objectives, we counted dogs in 213 transects in urban and rural areas to model dog abundance using N-mixture models. Then we conducted interviews in 553 properties around the transects to determine people's dog management, their behavior towards free-roaming dogs and the prevalence of dog-caused problems. Dog abundance was higher in transects where a higher number of owned dogs was allowed to roam, as well as in lower-income neighborhoods (based on property tax valuation). Meanwhile, rural citizens were more likely to let their dogs' roam. Dog abandonment was reported more frequently in lower-income urban neighborhoods and rural areas. Not surprisingly, we found that several problems-such as dog bites-were more frequent where we detected more free-roaming dogs. Our results highlight that the owned dog population is a central component of the free-roaming dog problem, and that human behavior is the key driver underlying the problem. Dog management programs should promote responsible dog-ownership, with a strong message focused on keeping dogs inside properties and preventing abandonment.

Diagnostic accuracy of ASQ for screening of neurodevelopmental delays in low resource countries.

OBJECTIVE: The Bayley Scales of Infant Development (BSID) is the most used diagnostic tool to identify neurodevelopmental disorders in children under age 3 but is challenging to use in low-resource countries. The Ages and Stages Questionnaire (ASQ) is an easy-to-use, low-cost clinical tool completed by parents/caregivers that screens children for developmental delay. The objective was to determine the performance of ASQ as a screening tool for neurodevelopmental impairment when compared with BSID second edition (BSID-II) for the diagnosis of moderate-to-severe neurodevelopmental impairment among infants at 12 and 18 months of age in low-resource countries. METHODS: Study participants were recruited as part of the First Bites Complementary Feeding trial from the Democratic Republic of Congo, Zambia, Guatemala and Pakistan between October 2008 and January 2011. Study participants underwent neurodevelopmental assessment by trained personnel using the ASQ and BSID-II at 12 and 18 months of age. RESULTS: Data on both ASQ and BSID-II assessments of 1034 infants were analysed. Four of five ASQ domains had specificities greater than 90% for severe neurodevelopmental delay at 18 months of age. Sensitivities ranged from 23% to 62%. The correlations between ASQ communications subscale and BSID-II Mental Development Index (MDI) (r=0.38) and between ASQ gross motor subscale and BSID-II Psychomotor Development Index (PDI) (r=0.33) were the strongest correlations found. CONCLUSION: At 18 months, ASQ had high specificity but moderate-to-low sensitivity for BSID-II MDI and/or PDI <70. ASQ, when administered by trained healthcare workers, may be a useful screening tool to detect severe disability in infants from rural low-income to middle-income settings. TRIAL REGISTRATION NUMBER: NCT01084109.

Discrepancies Between Caregiver Reported Early Childhood Sleep Problems and Clinician Documentation and Referral.

OBJECTIVE: The American Academy of Pediatrics recommends routine sleep problem screenings during child well-visits. However, studies suggest a discrepancy between caregiver- and clinician-reported child sleep problems. The present study examines whether caregiver-reported child sleep problems (ie, habitual snoring, insomnia symptoms, poor sleep health) and clinician-documented child sleep problems and management are congruent. METHODS: The sample included 170 caregiver-child dyads (child Mage = 3.3 years, range = 2-5 years; 56.5% girls; 64.1% Black, 20.0% non-Latinx White, and 4.1% Latinx; 86.5% maternal caregiver reporter). Caregivers' questionnaire-based reports of habitual snoring, insomnia symptoms, and sleep health behaviors (nighttime electronics, caffeine intake, insufficient sleep) were compared with clinician documentation in the electronic health record. RESULTS: About 92.3% of children had at least 1 caregiver-reported sleep problem (66% insomnia symptoms, 64% electronics, 38% insufficient sleep, 21% caffeine, 17% snoring). In contrast, a substantially lower percent of children had a clinician documented sleep problem (20% overall; 10% insomnia symptoms, 7% electronics, 0% insufficient sleep, 3% caffeine, 4% snoring), sleep-related referral (1% overall; 0.6% Otolaryngology, 0.6% polysomnogram, 0% sleep clinic), or recommendation (12% overall; 8% insomnia symptoms, 4% electronics, 0% insufficient sleep, 1% caffeine). CONCLUSIONS: There is a vast discrepancy between caregiver-reported child sleep problems and clinician-documented sleep problems and management, with a higher proportion of caregiver reports. To benefit overall child health and well-being, future research and quality improvement initiatives should focus on enhancing screening tools and educational opportunities to improve clinician documentation and enhance family conversations about early childhood sleep problems.

Ziehl-Neelsen stain in the pathology laboaratory: Performance and diagnostic aid for mycobacteria in bronchoalveolar lavage / Coloración de Ziehl-Neelsen en el laboratorio de patología: rendimiento y contribución al diagnóstico de micobacterias en el lavado broncoalveolar.

Introduction: With more than 100 years of use, the Ziehl-Neelsen stain is still currently used worldwide. Objective: To compare the performance of diagnostic tests used to determine mycobacteria in the clinic and pathology laboratory in bronchoalveolar lavage samples. Materials and methods: We retrospectively reviewed 737 bronchoalveolar lavage samples from 2019 to 2020 in the San Vicente Fundación hospital (Medellín, Colombia) comparing the performance of three tests done in parallel: mycobacteria and resistance PCR, culture, and Ziehl-Neelsen stain. Results: In total, 93/737 patients were classified as sick due to a positive result in any of the three tests. The culture, PCR, and Ziehl-Neelsen stain had a sensibility of 0.80, 0.76 y 0.51, respectively. However, only 5/75 (6.5%) of the positive cultures had results within the first four weeks and the rest in eight weeks. The PCR test combined with the Ziehl-Neelsen stain improved the sensibility of the PCR test alone from 0.76 a 0.88, a change that was statistically significant (p = 0.022). Conclusion: At least in bronchoalveolar lavage samples, culture is still the test with better sensibility. The use in parallel of the PCR test and the Ziehl-Neelsen stain improved in a statistically significant manner the performance of the PCR test alone, regardless of the higher turnaround time of the Ziehl-Neelsen stain.

Introducción. La coloración de Ziehl-Neelsen, con más de 100 años de uso, continúa vigente mundialmente. Objetivo. Comparar el rendimiento de las pruebas diagnósticas utilizadas para la determinación de micobacterias en el laboratorio clínico de patología en muestras de lavado broncoalveolar. Materiales y métodos. Se revisaron retrospectivamente 737 muestras de lavado broncoalveolar procesadas en el 2019 y el 2020 en el Hospital San Vicente Fundación (Medellín, Colombia) y se compararon las características de tres pruebas diagnósticas realizadas en paralelo: la reacción en cadena de la polimerasa (PCR) para micobacterias con detección de resistencia, el cultivo, y la coloración de Ziehl-Neelsen. Resultados. Se catalogaron como enfermos a 93 de los 737 pacientes a partir de los resultados positivos en alguna de las tres pruebas. El cultivo tuvo una sensibilidad de 0,80, la PCR una de 0,76 y la coloración de Ziehl-Neelsen una de 0,51. Sin embargo, solo 5 de 75 (6,5 %) cultivos fueron positivos a las cuatro semanas y el resto lo fue a las ocho semanas. La PCR combinada con la coloración de Ziehl-Neelsen mejoró la sensibilidad de la PCR por sí sola, de 0,76 a 0,88, diferencia que fue estadísticamente significativa (p=0,022). Conclusión. En las muestras de lavado broncoalveolar, el cultivo sigue siendo la prueba con mejor sensibilidad. El uso conjunto de la prueba de PCR y la coloración de Ziehl-Neelsen mejora significativamente la sensibilidad de la primera, lo que compensa la demora relativa en la entrega de los resultados debida al tiempo requerido para la tinción de Ziehl-Neelsen.

Coloración de Ziehl-Neelsen en el laboratorio de patología: rendimiento y contribución al diagnóstico de micobacterias en el lavado broncoalveolar / Ziehl-Neelsen stain in the pathology laboaratory: Performance and diagnostic aid for mycobacteria in bronchoalveolar lavage

Introducción. La coloración de Ziehl-Neelsen, con más de 100 años de uso, continúa vigente mundialmente. Objetivo. Comparar el rendimiento de las pruebas diagnósticas utilizadas para la determinación de micobacterias en el laboratorio clínico de patología en muestras de lavado broncoalveolar. Materiales y métodos. Se revisaron retrospectivamente 737 muestras de lavado broncoalveolar procesadas en el 2019 y el 2020 en el Hospital San Vicente Fundación (Medellín, Colombia) y se compararon las características de tres pruebas diagnósticas realizadas en paralelo: la reacción en cadena de la polimerasa (PCR) para micobacterias con detección de resistencia, el cultivo, y la coloración de Ziehl-Neelsen. Resultados. Se catalogaron como enfermos a 93 de los 737 pacientes a partir de los resultados positivos en alguna de las tres pruebas. El cultivo tuvo una sensibilidad de 0,80, la PCR una de 0,76 y la coloración de Ziehl-Neelsen una de 0,51. Sin embargo, solo 5 de 75 (6,5 %) cultivos fueron positivos a las cuatro semanas y el resto lo fue a las ocho semanas. La PCR combinada con la coloración de Ziehl-Neelsen mejoró la sensibilidad de la PCR por sí sola, de 0,76 a 0,88, diferencia que fue estadísticamente signifcativa (p=0,022). Conclusión. En las muestras de lavado broncoalveolar, el cultivo sigue siendo la prueba con mejor sensibilidad. El uso conjunto de la prueba de PCR y la coloración de ZiehlNeelsen mejora signifcativamente la sensibilidad de la primera, lo que compensa la demora relativa en la entrega de los resultados debida al tiempo requerido para la tinción de Ziehl-Neelsen.

Introduction: With more than 100 years of use, the Ziehl-Neelsen stain is still currently used worldwide. Objective: To compare the performance of diagnostic tests used to determine mycobacteria in the clinic and pathology laboratory in bronchoalveolar lavage samples. Materials and methods: We retrospectively reviewed 737 bronchoalveolar lavage samples from 2019 to 2020 in the San Vicente Fundación hospital (Medellín, Colombia) comparing the performance of three tests done in parallel: mycobacteria and resistance PCR, culture, and Ziehl-Neelsen stain. Results: In total, 93/737 patients were classifed as sick due to a positive result in any of the three tests. The culture, PCR, and Ziehl-Neelsen stain had a sensibility of 0.80, 0.76 y 0.51, respectively. However, only 5/75 (6.5%) of the positive cultures had results within the frst four weeks and the rest in eight weeks. The PCR test combined with the Ziehl-Neelsen stain improved the sensibility of the PCR test alone from 0.76 a 0.88, a change that was statistically signifcant (p = 0.022). Conclusion: At least in bronchoalveolar lavage samples, culture is still the test with better sensibility. The use in parallel of the PCR test and the Ziehl-Neelsen stain improved in a statistically signifcant manner the performance of the PCR test alone, regardless of the higher turnaround time of the Ziehl-Neelsen stain.

Ionic liquids and deep eutectic solvents as sustainable alternatives for efficient extraction of phenolic compounds from mate leaves.

Mate leaves are highly appreciated in south and central America as food ingredient for tea preparation. Their nutritional importance, due to their high content of polyphenols and other nutraceuticals, has been drawing attention worldwide, especially to produce extracts and biopharmaceuticals. However, the extraction of such nutraceuticals using conventional processes/solvents might impact their profile/concentration. Ionic liquids (ILs) and deep eutectic solvents (DES) have been recognized as green solvents, and more recently the naturally-derived have stood out. In this work, we investigated the use of bioethanol, cholinium chloride ([Ch]Cl), Ch-based DES and less expensive protic ILs derived from acetic acid, in aqueous systems at different concentrations, as potential sustainable alternatives over conventional solvents and more expensive aprotic ILs for the extraction of polyphenols from mate leaves. Simply adding the [Ch]Cl in aqueous-ethanolic mixtures at 50% improved extraction efficiency (∼35 mg/g) in comparison to conventional solvents (∼7-29 mg/g). However, IL (∼41-66 mg/g) and DES (∼47-55 mg/g) systems presented better performance, being the former presenting the best results at 75% (∼66 mg/g). The extraction yield was also related to water concentration, which is interesting to reduce viscosity and IL/DES cost for a more cost-efficient extraction and was also supported by results obtained using COSMO-SAC. Therefore, the low-cost protic IL and DES are promising sustainable solvent alternatives over conventional solvents/ILs for extraction of polyphenols from mate leaves.

Class III Peroxidases PRX01, PRX44, and PRX73 Control Root Hair Growth in Arabidopsis thaliana.

Root hair cells are important sensors of soil conditions. They grow towards and absorb water-soluble nutrients. This fast and oscillatory growth is mediated by continuous remodeling of the cell wall. Root hair cell walls contain polysaccharides and hydroxyproline-rich glycoproteins, including extensins (EXTs). Class-III peroxidases (PRXs) are secreted into the apoplastic space and are thought to trigger either cell wall loosening or polymerization of cell wall components, such as Tyr-mediated assembly of EXT networks (EXT-PRXs). The precise role of these EXT-PRXs is unknown. Using genetic, biochemical, and modeling approaches, we identified and characterized three root-hair-specific putative EXT-PRXs, PRX01, PRX44, and PRX73. prx01,44,73 triple mutation and PRX44 and PRX73 overexpression had opposite effects on root hair growth, peroxidase activity, and ROS production, with a clear impact on cell wall thickness. We use an EXT fluorescent reporter with contrasting levels of cell wall insolubilization in prx01,44,73 and PRX44-overexpressing background plants. In this study, we propose that PRX01, PRX44, and PRX73 control EXT-mediated cell wall properties during polar expansion of root hair cells.