Exploring nasopharyngeal microbiota profile in children affected by SARS-CoV-2 infection.

The relationship between COVID-19 and nasopharyngeal (NP) microbiota has been investigated mainly in the adult population. We explored the NP profile of children affected by COVID-19, compared to healthy controls (CTRLs). NP swabs of children with COVID-19, collected between March and September 2020, were investigated at the admission (T0), 72 h to 7 days (T1), and at the discharge (T2) of the patients. NP microbiota was analyzed by 16S rRNA targeted-metagenomics. Data from sequencing were investigated by QIIME 2.0 and PICRUSt 2. Multiple machine learning (ML) models were exploited to classify patients compared to CTRLs. The NP microbiota of COVID-19 patients (N = 71) was characterized by reduction of α-diversity compared to CTRLs (N = 59). The NP microbiota of COVID-19 cohort appeared significantly enriched in Streptococcus, Haemophilus, Staphylococcus, Veillonella, Enterococcus, Neisseria, Moraxella, Enterobacteriaceae, Gemella, Bacillus, and reduced in Faecalibacterium, Akkermansia, Blautia, Bifidobacterium, Ruminococcus, and Bacteroides, compared to CTRLs (FDR < 0.001). Exploiting ML models, Enterococcus, Pseudomonas, Streptococcus, Capnocytopagha, Tepidiphilus, Porphyromonas, Staphylococcus, and Veillonella resulted as NP microbiota biomarkers, in COVID-19 patients. No statistically significant differences were found comparing the NP microbiota profile of COVID-19 patients during the time-points or grouping patients on the basis of high, medium, and low viral load (VL). This evidence provides specific pathobiont signatures of the NP microbiota in pediatric COVID-19 patients, and the reduction of anaerobic protective commensals. Our data suggest that the NP microbiota may have a specific disease-related signature since infection onset without changes during disease progression, regardless of the SARS-CoV-2 VL. IMPORTANCE: Since the beginning of pandemic, we know that children are less susceptible to severe COVID-19 disease. A potential role of the nasopharyngeal (NP) microbiota has been hypothesized but to date, most of the studies have been focused on adults. We studied the NP microbiota modifications in children affected by SARS-CoV-2 infection showing a specific NP microbiome profile, mainly composed by pathobionts and almost missing protective anaerobic commensals. Moreover, in our study, specific microbial signatures appear since the first days of infection independently from SARS-CoV-2 viral load.

Long-term urological outcome of cloaca patients with multidisciplinary management.

PURPOSE: Urological management of Cloacal Malformation (CM) focuses on preserving renal function and continence. Study aim was to analyze urinary and intestinal outcomes in CM patients, considering the length of common channel (CC) and presence of occult spinal dysraphism (OSD). METHODS: Retrospective review of CM treated at our institution by a multidisciplinary team from 1999 to 2020. Patients with follow-up < 2.5 years were excluded. Length of CC, renal function, urinary and bowel outcomes, presence of associated anomalies (especially OSD) were evaluated. RESULTS: Twenty patients were included, median age at follow-up: 8 years (4-15). A long CC > 3 cm was described in 11 (55%). Chronic kidney disease was found in 3 patients. Urinary continence was achieved in 8/20 patients, dryness (with intermittent catheterization) in 9/20. Fecal continence was obtained in 3/20, cleanliness in 14 (under bowel regimen). OSD was present in 10 patients (higher prevalence in long-CC, 73%). Among OSD, 1 patient reached fecal continence, 7 were clean; 2 achieved urinary continence, while 6 were dry. CONCLUSIONS: Length of CC and OSD may affect urinary and fecal continence. An early counseling can improve outcome at long-term follow-up. Multidisciplinary management with patient centralization in high grade institutions is recommended to achieve better results.

The usefulness of ecotoxicological tools to improve the assessment of water bodies in a climate change reality.

This study aimed to analyse the added value of using ecotoxicological tools to complement and improve the assessment of natural water bodies status, in situations of climate change, with a higher frequency of extreme events as floods or droughts. Four water bodies of streams in the Guadiana Basin (Álamos, Amieira, Lucefécit, Zebro) were studied in 2017 and 2018 and classified based on the Water Framework Directive (WFD) parameters: Biological Quality Element - Phytobenthos (diatoms), General chemical and physicochemical elements, Specific pollutants, and Priority Substances. Complementarily, bioassays (including lethal and sublethal parameters) were carried out with organisms of different trophic levels: (i) the bacteria Aliivibrio fischeri; (ii) the microalgae Pseudokirchneriella subcapitata; (iii) the crustaceans Daphnia magna, Thamnocephalus platyurus and Heterocypris incongruens. A classification system with 5 scores was developed, permitting to classify water bodies from non-toxic (EC50 > 100 %; growth and feeding rate > 80 %; blue) to highly toxic (EC50 < 10 %; growth and feeding rate < 10 %; red). The comparison between the classification based on the WFD parameters and on ecotoxicological endpoints showed similar results for 71 % of the samples, and significant positive Pearson correlations were detected between the diatom-based Specific Polluosensitivity Index (SPI) and EC50V.fisheri, the algae growth rate and Shannon diversity index. These results indicate that when the biological quality elements cannot be used (namely under drought or flooding conditions) the application of ecotoxicological bioassays may be a good alternative. Further, when ecotoxicological parameters were included, an increase of worse classifications (Bad and Poor) was observed, revealing an improvement in the sensitivity of the classification, mainly in presence of specific and priority substances. So, the ecotoxicological analysis appears to provide useful information regarding the potential presence of both known and unknown contaminants at concentrations that cause biological effects (even within the WFD limits), in agreement with several authors that have already suggested its use in biomonitoring.

Inactivation Mechanism of the Fatty Acid Amide Hydrolase Inhibitor BIA 10-2474.

BIA 10-2474 is a time-dependent inhibitor of fatty acid amide hydrolase (FAAH) that was under clinical development for the treatment of neurological conditions when the program was terminated after one subject died and four were hospitalized with neurological symptoms during a first-in-human clinical study. The present work describes the mechanism of FAAH inhibition by BIA 10-2474 as a target-specific covalent inhibition, supported by quantum mechanics and molecular modelling studies. The inhibitor incorporates a weakly reactive electrophile which, upon specific binding to the enzyme's active site, is positioned to react readily with the catalytic residues. The reactivity is enhanced on-site by the increased molarity at the reaction site and by specific inductive interactions with FAAH. In the second stage, the inhibitor reacts with the enzyme's catalytic nucleophile to form a covalent enzyme-inhibitor adduct. The hydrolysis of this adduct is shown to be unlikely under physiological conditions, therefore leading to irreversible inactivation of FAAH. The results also reveal the important role played by FAAH Thr236 in the reaction with BIA 10-2474, which is specific to FAAH and is not present in other serine hydrolases. It forms a hydrogen bond with the imidazole nitrogen of the inhibitor and helps lowering the activation free energy of the first step of the reaction, by pre-orienting and stabilizing the inhibitor in a near-reactive configuration. In the second step, Thr236 can also serve as a mechanistic alternative to protonate the leaving group.

Exploring the destiny and distribution of thiocyanate in the water-soil-plant system and the potential impacts on human health.

Endocrine disruptors like thiocyanate are some of the principal causes of chronic disorders worldwide. Prenatal and postnatal exposure to thiocyanate can interfere with normal neurological development in both fetuses and newborns. Currently, little information regarding thiocyanate levels and potential sources of exposure is available. In this study, we evaluated thiocyanate uptake and accumulation in chard and spinach grown under greenhouse conditions. Both chard and spinach are commonly used to produce baby foods. Three thiocyanate concentrations were compared: Control, T1 (30 ng mL-1), and T2 (70 ng mL-1). Thiocyanate accumulation depended on the concentration and exposure time. Chard was found to accumulate more thiocyanate than spinach, with leaf accumulation > stem accumulation (p < 0.0194) and maximum concentrations of 76 ng g-1 (control), 112 ng g-1, (T1), and 134 ng g-1 (T2). The estimated daily intake (EDI) of thiocyanate for chard and spinach (fresh) exceeded the subchronic reference dose of 200 ng-1 kg-1 day-1 and the chronic reference dose of 600 ng-1 kg-1 day-1. In addition, the EDI of thiocyanate for spinach in baby food exceeded twice the chronic reference dose in the vulnerable newborn-1 year age group. However, all EDIs were lower than the lowest observed adverse effect level (LOAEL) of 1.9 × 105 ng kg-1 day-1. Further studies are needed that increase our knowledge of thiocyanate levels and potential environmental sources to reduce opportunities for exposure, especially in vulnerable groups.

Continuing invariant solutions towards the turbulent flow.

A new mathematical framework is proposed for characterizing the coherent motion of fluctuations around a mean turbulent channel flow. We search for statistically invariant coherent solutions of the unsteady Reynolds-averaged Navier-Stokes equations written in a perturbative form with respect to the turbulent mean flow, using a suitable approximation of the Reynolds stress tensor. This is achieved by setting up a continuation procedure of known solutions of the perturbative Navier-Stokes equations, based on the continuous increase of the turbulent eddy viscosity towards its turbulent value. The recovered solutions, being sustained only in the presence of the Reynolds stress tensor, are representative of the statistically coherent motion of turbulent flows. For small friction Reynolds number and/or domain size, the statistically invariant motion is almost identical to the corresponding invariant solution of the Navier-Stokes equations. Whereas, for sufficiently large friction number and/or domain size, it considerably departs from the starting invariant solution of the Navier-Stokes equations, presenting spatial structures, main wavelengths and scaling very close to those characterizing both large- and small-scale motion of turbulent channel flows. This article is part of the theme issue 'Mathematical problems in physical fluid dynamics (part 2)'.

Accumulation and distribution of perchlorate in spinach and chard growing under greenhouse: Implications for food safety in baby foods commodities.

Very little information is available with regards to the bioavailability of perchlorate in spinach or chard used in the production of baby foods commodities. In the present study, the uptake and accumulation of perchlorate were compared under two different treatments (T1: 1 and T2: 10 mg L-1 ClO4-). Our results indicate that spinach has a higher capacity to accumulate perchlorate than chard (p < 0.0185). Concentrations of perchlorate in leaves, stems and roots (leaves > stem > roots) all gradually increased (p < 0.0001) as vegetable growing and treatment (T2 > T1). No significant differences were found between the control and T1. The daily intake for perchlorate (control) is below the proposed international standard, however, it was exceeded in T1 and T2. The results suggested that perchlorate is actively accumulate in high concentrations in vegetables used in the production of baby food commodities and the exposure of perchlorate via the food consumption (baby foods) was evaluated as not safe.

Occurrence, distribution and dynamics of perchlorate in soil, water, fertilizers, vegetables and fruits and associated human exposure in Chile.

Perchlorate (ClO4-) has been identified as a persistent environmental contaminant of concern. Perchlorate exposure is a potential health concern because it interferes with hormone production by thyroid gland. Food (fruits and vegetables) and drinking water are an important source of human exposure to perchlorate. However, little is known about the occurrence of perchlorate in Chile. The purpose of this study was to determine the occurrence of perchlorate in 145 samples (soil, drinking water, surface water, groundwater, fertilizers, fruits and vegetables) collected across Chile and estimate associated exposure to consumers. Our results show that perchlorate was detected in soil (median: 22.2 ng g-1), drinking water (median: 3.0 ng mL-1), fruits (median: 0.91 ng g-1 fresh weight [FW]), lettuce (median: 5.0 ng g-1 FW) and chard (median: 4.15 ng g-1 FW). Interestingly, perchlorate concentrations detected in drinking water from three regions (Serena, Copiapo and Illapel) exceeded the USEPA interim drinking water health advisory level of 15 ng mL-1. Median concentrations of perchlorate in non-nitrogenous fertilizers (3.1 mg kg-1) were higher than those in nitrogenous fertilizers (1.3 mg kg-1). Estimated daily intake (EDI) of perchlorate via drinking water was lower than the USEPA's reference dose (7000 ng kg-1 bw day-1). The EDI of perchlorate via vegetables (chard and lettuce) produced in northern Chile was three times higher than those produced in other regions. The results of this study provide information about perchlorate sources in Chile, which will be helpful in modifying current regulations.

Síndrome de Miller Fisher, un desafío diagnóstico de oftalmoplejía: reporte de un caso / Miller Fisher syndrome, a diagnostic challenge of ophthalmoplegia: a case report

El síndrome de Guillain-Barré (SGB), y sus derivados, entre ellos el síndrome de Miller Fisher (SMF); junto a otras patologías de origen neurológico como la Polineuropatía desmielinizante inflamatoria crónica (CIDP), las polineuropatías de causa metabólica, miastenia gravis, esclerosis lateral amiotrófica (ELA), síndrome de Lambert-Eaton, encefalopatía de Wernicke entre otras; presentan signos y síntomas neurológicos de presentación común. De este modo, la importancia del examen neurológico acabado; y los exámenes de apoyo diagnóstico como: laboratorio -destacando el líquido cefalorraquídeo (LCR)-, electromiografía, y toma de imágenes, son cruciales para esclarecer el diagnóstico. Así, es posible ofrecer un tratamiento de forma precoz, basado en la evidencia, y con el objetivo de disminuir la letalidad de la enfermedad. En el presente texto se plasma un subgrupo de patología de SGB, el SMF, el cual posee una incidencia significativamente baja, una clínica característica, y un pronóstico bastante ominoso sin un tratamiento adecuado. En el presente texto se plasma el reporte de un caso abordado en el Hospital San Pablo de Coquimbo, Chile.

Guillain-Barré syndrome (GBS) and its derivatives, including Miller Fisher syndrome (MFS), along others pathologies of neurological origin such as chronic inflammatory demyelinating polyneuropathy (CIDP), metabolic polyneuropathies, myasthenia gravis, amyotrophic lateral sclerosis (ALS), Lambert-Eaton syndrome, Wernicke's encephalopathy and well as others, have common neurological signs and symptoms. In this way, the importance of a thorough neurological examination, and supporting diagnostic tests such as: laboratory, -cerebrospinal fluid (CSF)-electromyography, and imaging, are crucial to clarify the diagnosis. Thus, it is possible to offer early, evidence-based treatment with an aim of reducing the disease's lethality. In the text below we present a subgroup of GBS pathology, MFS, which has a significantly low incidence, a characteristic clinical picture, and a rather ominous prognosis without adequate treatment. In the following text/paper is shown the report of a case approached in San Pablo Hospital, from Coquimbo, Chile.

Occurrence and risk assessment of pesticides in a Mediterranean Basin with strong agricultural pressure (Guadiana Basin: Southern of Portugal).

The study aimed to assess the occurrence and the environmental risk of a group of 51 selected pesticides in the Guadiana Basin (a biodiversity hotspot, in the Mediterranean). The most abundant pesticides were bentazone and 2,4-D, while terbuthylazine together with terbutryn constituted the most ubiquitous pesticides. Eighteen out of the 38 pesticides detected are no longer approved in Europe, and 5 of them are included in the list of priority substances. The risk assessment showed that azinphos ethyl, diflufenican, irganol, imidacloprid, and oxadiazon occurred occasionally, but always in concentrations above their respective ecotoxicological threshold value. Contrary, bentazone, terbuthylazine, and terbutryn presented a high risk in most of the sampled locations and periods. The site-specific risk assessment showed a spatial and temporal pattern, with a higher risk occurring mainly in intermittent streams, in the drought period. The presence of pesticides banned from the EU market since 2009 showed the importance of improving the monitoring process, to identify the main sources of pollution and the fate of these emerging compounds. The results showed the need of implementing actions to improve the sustainable use of pesticides in agricultural areas, working with farmers and management entities to reduce the contamination of aquatic ecosystems. Transboundary water governance is also required to solve potential transboundary contamination problems.

Remodelling compartment in root cementum.

BACKGROUND: Bone remodelling represents the most remarkable bone response to mechanical stress and mineral homeostasis. It is the consequence of complex highly orchestrated and tightly regulated cellular processes taking place in a specialised entity - the bone remodelling compartment (BRC). MATERIALS AND METHODS: Cementum is an understudied tissue that requires more research to understand its biology, pathology, and potential for regeneration. Although analogue to bone in structure and composition distinct structural and functional differences were ascribed to each of these mineralised tissues. The precise role of cementocytes in cementum turnover is unclear but they may work the same way as osteocytes in bone remodelling, regulating the full process. RESULTS: Although cementum is not liable to regular physiological remodelling as bone is, pathological cases triggered by orthodontic forces or large periapical periodontitis, those lesions can acutely induce cementum remodelling. Nevertheless, the cellular mechanisms behind this particular remodelling process are yet to be identified, as its eventual involvement of specialised anatomic structures as the BRC. CONCLUSIONS: Hypothesizing that similar cellular mechanisms underlie bone and cementum remodelling, the present work shows, for the first time, the histological evidence of a specialized remodelling compartment in dental hard tissues.

Consensus statement from the international consensus meeting on post-traumatic cranioplasty.

BACKGROUND: Due to the lack of high-quality evidence which has hindered the development of evidence-based guidelines, there is a need to provide general guidance on cranioplasty (CP) following traumatic brain injury (TBI), as well as identify areas of ongoing uncertainty via a consensus-based approach. METHODS: The international consensus meeting on post-traumatic CP was held during the International Conference on Recent Advances in Neurotraumatology (ICRAN), in Naples, Italy, in June 2018. This meeting was endorsed by the Neurotrauma Committee of the World Federation of Neurosurgical Societies (WFNS), the NIHR Global Health Research Group on Neurotrauma, and several other neurotrauma organizations. Discussions and voting were organized around 5 pre-specified themes: (1) indications and technique, (2) materials, (3) timing, (4) hydrocephalus, and (5) paediatric CP. RESULTS: The participants discussed published evidence on each topic and proposed consensus statements, which were subject to ratification using anonymous real-time voting. Statements required an agreement threshold of more than 70% for inclusion in the final recommendations. CONCLUSIONS: This document is the first set of practical consensus-based clinical recommendations on post-traumatic CP, focusing on timing, materials, complications, and surgical procedures. Future research directions are also presented.

Características de los coronavirus, origen del SARS-CoV-2, características estructurales, proteínas y factores de virulencia, variantes genéticas / Characteristics of coronaviruses, origin of SARS-CoV-2, characteristics structural, proteins and factors of virulence, genetic variants

Coronaviruses (CoVs) were identified in 1937, they were considered innocuous viruses until the appearance of three highly pathogenic variants, SARS-CoV, MERS-CoV and SARS-CoV-2 causing the current pandemic of Covid-19, so far it is known that its origin is zoonotic, the main reservoir could be bats considering the high homology of CoVs that inhabit this species. Its transmissibility is much higher than that of previous CoVs, possibly in the process of natural selection; it has acquired some or all the mutations necessary for a much more efficient transmission in our species. This condition is specifically attributed to unique characteristics of the SARS-CoV-2 Spike protein that allow it greater affinity and therefore greater infectivity by binding to the angiotensin receptor 2 (ACE-2) present in the host cells. Since the Covid-19 outbreak began at the end of 2019, more than 1,500 mutations have been detected throughout the SARS-CoV-2 genome, however the most significant are those that occur near or in the receptor binding domain (RBD) that could provide variations between 4x to 100x greater infectivity, such is the case of the new variants identified in the United Kingdom, South Africa, Brazil and Japan that force us to take extreme preventive measures and continue research to elucidate strategies to combat the current crisis. (AU)

Inmunodeficiencias en contexto de infección por SARS-CoV-2 / Immunodeficiencies in the context of SARS-CoV-2 infection

SARS-CoV-2 infection in the people has been characterized by great variability in the clinical manifestations, ranging from an asymptomatic infection in some individuals to a fatal disease in others. Recently, the importance of human genetics in determining clinical response has been highlighted. Within this context there are patients who don't become infected despite viral exposure and others who, being young without comorbidities, develop a severe disease.On the other hand, it's under constant investigation whether the presence of a concomitant primary or secondary immunodeficiency determines a different clinical course. (AU)

Prevalencia de resistencia transmitida a drogas antirretrovirales en pacientes con infección por VIH en Chile (2014-2018)

Background: Transmitted drug resistance (TDR) occurs in patients with HIV infection who are not exposed to antiretroviral drugs but who are infected with a virus with mutations associated with resistance. Aim: To determine the prevalence of TDR and characterize HIV reverse transcriptase and protease mutation patterns. Material and Methods: HIV infected antiretroviral treatment-naive patients treated in three centers between 2014 and 2018 were studied. A genotyping study was carried out. The HIVdb Program (Stanford University) and the World Health Organization (WHO) TDR surveillance mutation list were used to register resistance-associated mutations. Results: We enrolled 220 patients aged a median of 29 (interquartile range (IQR) 24-34) years, 99% men. Median CD4 count was 365 cells/μL (IQR 250-499 cells/μL) and median viral load was 39.150 copies/mL (IQR 9,270 −120,000). The overall prevalence of RTD was 10.45% (95% CI 6.7-15.2, N = 23/220). The higher frequency of TDR was against non-nucleoside reverse transcriptase inhibitors, reaching 9.0% (95% CI 5.6-13.6), followed by nucleoside reverse transcriptase inhibitors reaching 1.8% (95% CI 0.49-4.5) and protease inhibitors reaching 0.45% (95% CI 0.01-2.5). The mutations in reverse transcriptase were M41L, L210W, D67N, K70E, M184V, K103N (6.36%, 95% CI 3.5-10.4), G190A, E138A, K101E, and I84V in protease. Conclusions: These results should prompt a change in recommendations for starting antiretoviral therapy, especially in first-line regimens that include non-nucleoside reverse transcriptase inhibitors.

Tratamiento artroscópico en lesión osteocondral subtalar / Arthroscopic treatment of subtalar osteochondral lesion

Las lesiones osteocondrales de la articulación subtalar es una patología infrecuente y de incidencia variable, dado su reporte principalmente como hallazgo en el estudio de dolor crónico de tobillo y ya con cambios degenerativos articulares. La sospecha clínica y el estudio imagenológico dirigido, permiten investigar esas lesiones en estadios iniciales, evitando así el uso de técnicas que no preservan la articulación para su manejo. La artroscopía subtalar es una excelente herramienta tanto diagnóstica como terapéutica para la resolución de dichas lesiones. Dadas las características anatómicas y biomecánicas de la articulación, en estadios iniciales, el manejo mediante sinovectomía y microfracturas es una alternativa con excelentes resultados funcionales. Este trabajo incluye dos casos de lesiones osteocondrales de la faceta posterior de la articulación subtalar manejadas vía artroscópica mediante sinovectomía y microfracturas y su posterior evolución.

Osteochondral lesions in the subtalar joint are an uncommon pathology with a variable incidence, being mainly reported as a finding in chronic ankle pain studies and with already visible degenerative joint changes at time of diagnosis. Clinical suspicion and directed imaging study, allows to investigate these lesions during early stages, thus avoiding the use of invasive techniques with scarce joint preservation. Subtalar arthroscopy is an excellent diagnostic and therapeutic tool for the resolution of these lesions. Given the anatomical and biomechanical characteristics of the joint, in the early stages the management by synovectomy and microfractures is an alternative with excellent functional results. This study includes two cases of osteochondral lesions of the posterior facet of the subtalar joint managed through arthroscopically synovectomy and microfractures and their subsequent evolution.

Sources and fates of perchlorate in soils in Chile: A case study of perchlorate dynamics in soil-crop systems using lettuce (Lactuca sativa) fields.

Perchlorate occurs naturally in the environment in deposits of nitrate and can be formed in the atmosphere and precipitate into soil. However, little is known about the occurrence and levels of perchlorate in soils and fertilizers in Chile and its impacts on agricultural systems and food safety. In this study, concentrations of perchlorate were determined in 101 surface soils and 17 fertilizers [nitrogenous (n = 8), nitrogen-phosphorous-potassium (NPK; n = 3), phosphate (n = 2) and non-nitrogenous (n = 4)] collected across Chile from 2017 to 2018. Our results show that perchlorate was detected mainly in agricultural soils (mean: 0.32 ng g-1), grassland rotation sites (0.41 ngg-1) and urban locations (0.38 ng g-1). Interestingly, elevated concentrations of perchlorate (9.66 and 54.0 ng g-1) were found in agricultural soils. All fertilizers contained perchlorate: nitrogenous fertilizers (mean: 32.6 mg kg-1), NPK (mean: 12.6 mg kg-1), non-nitrogenous fertilizers (mean: 10.2 mg kg-1) and phosphates (mean: 11.5 mg kg-1). Only one type of nitrogenous fertilizer (KNO3: 95.3 mg kg-1) exceeded the international regulation limit (50 mg kg-1). For two agronomic practices, the content of perchlorate in lettuce increased as the fertilizer application rate increased, with fertigation promoting a more significant accumulation. However, the concentrations generally remained below regulatory values. Our results suggest that fertilizers constitute an important source of perchlorate in soils.

Field study on the uptake, accumulation and risk assessment of perchlorate in a soil-chard/spinach system: Impact of agronomic practices and fertilization.

The application of excessive fertilizer represents a primary source of entry for perchlorate into crop systems and thus has raised widespread concern regarding food safety. Several studies have reported the occurrence of perchlorate in vegetables. However, limited information is available on the fate of perchlorate in the soil-plant system. In this study, we performed field experiments to evaluate the effects of the application rate of Chilean nitrate fertilizer and the type of fertilization (manual or fertigation) on the uptake of perchlorate by plants grown in open fields. Interestingly, in the control, chard and spinach accumulated 21.3 and 25.9 µg kg-1, respectively. For both agronomic practices, the content of perchlorate in chard and spinach increased as the fertilizer application rate increased, with fertigation promoting more significant accumulations. Spinach accumulated almost two times more perchlorate than chard for all treatments; however, the concentrations generally remained below regulatory values. The intake of spinach and chard presented a low risk to human health for all age groups. These findings enhance our understanding of the environmental impact of the use of fertilizers in agriculture and food safety.

How to dissect the plasticity of antigen-specific immune response: a tissue perspective.

Generation of antigen-specific humoral responses following vaccination or infection requires the maturation and function of highly specialized immune cells in secondary lymphoid organs (SLO), such as lymph nodes or tonsils. Factors that orchestrate the dynamics of these cells are still poorly understood. Currently, experimental approaches that enable a detailed description of the function of the immune system in SLO have been mainly developed and optimized in animal models. Conversely, methodological approaches in humans are mainly based on the use of blood-associated material because of the challenging access to tissues. Indeed, only few studies in humans were able to provide a discrete description of the complex network of cytokines, chemokines and lymphocytes acting in tissues after antigenic challenge. Furthermore, even fewer data are currently available on the interaction occurring within the complex micro-architecture of the SLO. This information is crucial in order to design particular vaccination strategies, especially for patients affected by chronic and immune compromising medical conditions who are under-vaccinated or who respond poorly to immunizations. Analysis of immune cells in different human tissues by high-throughput technologies, able to obtain data ranging from gene signature to protein expression and cell phenotypes, is needed to dissect the peculiarity of each immune cell in a definite human tissue. The main aim of this review is to provide an in-depth description of the current available methodologies, proven evidence and future perspectives in the analysis of immune mechanisms following immunization or infections in SLO.

[Prevalence of transmitted drug resistance in HIV-infected treatment-naive patients in Chile]. / Prevalencia de resistencia transmitida a drogas antirretrovirales en pacientes con infección por VIH en Chile (2014-2018).

BACKGROUND: Transmitted drug resistance (TDR) occurs in patients with HIV infection who are not exposed to antiretroviral drugs but who are infected with a virus with mutations associated with resistance. AIM: To determine the prevalence of TDR and characterize HIV reverse transcriptase and protease mutation patterns. MATERIAL AND METHODS: HIV infected antiretroviral treatment-naive patients treated in three centers between 2014 and 2018 were studied. A genotyping study was carried out. The HIVdb Program (Stanford University) and the World Health Organization (WHO) TDR surveillance mutation list were used to register resistance-associated mutations. RESULTS: We enrolled 220 patients aged a median of 29 (interquartile range (IQR) 24-34) years, 99% men. Median CD4 count was 365 cells/µL (IQR 250-499 cells/µL) and median viral load was 39.150 copies/mL (IQR 9,270 -120,000). The overall prevalence of RTD was 10.45% (95% CI 6.7-15.2, N = 23/220). The higher frequency of TDR was against non-nucleoside reverse transcriptase inhibitors, reaching 9.0% (95% CI 5.6-13.6), followed by nucleoside reverse transcriptase inhibitors reaching 1.8% (95% CI 0.49-4.5) and protease inhibitors reaching 0.45% (95% CI 0.01-2.5). The mutations in reverse transcriptase were M41L, L210W, D67N, K70E, M184V, K103N (6.36%, 95% CI 3.5-10.4), G190A, E138A, K101E, and I84V in protease. CONCLUSIONS: These results should prompt a change in recommendations for starting antiretoviral therapy, especially in first-line regimens that include non-nucleoside reverse transcriptase inhibitors.