Severe Acute Respiratory Syndrome Coronavirus 2 Pandemic: Chilean Air Force Experience in the Air Transport of Critically Ill Patients-The First 100 Cases.

OBJECTIVE: Critical care air transport has played an important role during the coronavirus disease 2019 (COVID-19) pandemic. The goal of this article is to analyze results and lessons learned from the evacuation of the first 100 COVID-19 patients transported between medical facilities in Chile. METHODS: We reviewed prospective data of patients who were referred for air transport between March 27, 2020, and July 9, 2020. RESULTS: Of 115 referred patients, 100 were transported by air. All patients were intubated and mechanically ventilated. Hypertension, diabetes, and obesity were the most commonly observed comorbidities. Our service did not experience any major problems in patient care en route or among the crewmembers. We did not observe any severe acute respiratory syndrome coronavirus 2 infections among our flight team members during the study period. Twelve (12%) patients died at their destination intensive care unit, whereas the remaining 88 patients (88%) returned to their primary hospitals after recovery. CONCLUSIONS: Air transport of mechanically ventilated patients with COVID-19 infection has been shown to be a safe way of transport, with no in-flight deaths and an in-hospital mortality of 12%, which compares favorably with the in-hospital mortality of similar patients who did not undergo air transport.

The Impact of Metal-Rich Sediments Derived from Mining on Freshwater Stream Life.

Metal-rich sediments have the potential to impair life in freshwater streams and rivers and, thereby, to inhibit recovery of ecological conditions after any remediation of mine water discharges. Sediments remain metal-rich over long time periods and have long-term potential ecotoxicological interactions with local biota, unless the sediments themselves are physically removed or replaced by less metal-rich sediment. Laboratory-derived environmental quality standards are difficult to apply to the field situation, as many complicating factors exist in the real world. Therefore, there is a strong case to consider other, field-relevant, measures of toxic effects as alternatives to laboratory-derived standards and to seek better biological tools to detect, diagnose and ideally predict community-level ecotoxicological impairment. Hence, this review concentrated on field measures of toxic effects of metal-rich sediment in freshwater streams, with less emphasis on laboratory-based toxicity testing approaches. To this end, this review provides an overview of the impact of metal-rich sediments on freshwater stream life, focusing on biological impacts linked to metal contamination.

Molecular evidence for a new endemic species of Acartia (Copepoda, Calanoida) from the Southeast Pacific coast.

The loss of biodiversity in marine populations is one of the consequences of the increased events of extreme environmental conditions in the oceans, which can condition the persistence of populations to future scenarios of climate change. Therefore, it is extremely necessary to explore and monitor the genetic diversity of natural populations. In the Southeast Pacific Ocean (SEPO), specifically on the coast of Chile, the presence of the copepod Acartia tonsa has been indicated solely using morphological evidence, due to the absence of genetic information. In the present work, the genetic diversity, population structure and phylogenetic position within the genus Acartia, of populations identified morphologically as A. tonsa, was evaluated by amplification of the mitochondrial cytochrome c oxidase subunit I and nuclear marker 18 s. Our results showed that the populations identified as A. tonsa correspond to a new monophyletic group endemic to SEPO (GMYC = 1.00; PTP = 0.95). The populations showed moderate to high genetic diversity with an incipient structuring between populations and biogeographic zones. Our results suggest that despite the homogenizing effect of the Humboldt Current, isolation by distance and contrasting environmental conditions at different geographic scales have an important influence on the genetic diversity of zooplankton in the SEPO region.

Diversity and toxicity of the planktonic diatom genus Pseudo-nitzschia from coastal and offshore waters of the Southeast Pacific, including Pseudo-nitzschia dampieri sp. nov.

To expand knowledge of Pseudo-nitzschia species in the Southeast Pacific, we isolated specimens from coastal waters of central Chile (36°S-30°S), the Gulf of Corcovado, and the oceanic Robinson Crusoe Island (700 km offshore) and grew them into monoclonal strains. A total of 123 Pseudo-nitzschia strains were identified to 11 species based on sequencing of the ITS region of the nuclear rDNA and on ultrastructural and morphometric analyses of the frustule in selected representatives of each clade: P. australis, P. bucculenta, P. cf. chiniana, P. cf. decipiens, P. fraudulenta, P. hasleana, P. multistriata, P. plurisecta, P. cf. sabit, the new species P. dampieri sp. nov., and one undescribed species. Partial 18S and 28S rDNA sequences, including the hypervariable V4 and D1-D3 regions used for barcoding, were gathered from representative strains of each species to facilitate future metabarcoding studies. Results showed different levels of genetic, and at times ultrastructural, diversity among the above-mentioned entities, suggesting morphological variants (P. bucculenta), rapidly radiating complexes with ill-defined species boundaries (P. cf. decipiens and P. cf. sabit), and the presence of new species (P. dampieri sp. nov., Pseudo-nitzschia sp. 1, and probably P. cf. chiniana). Domoic acid (DA) was detected in 18 out of 82 strains tested, including those of P. australis, P. plurisecta, and P. multistriata. Toxicity varied among species mostly corresponding to expectations from previous reports, with the prominent exception of P. fraudulenta; DA was not detected in any of its 10 strains tested. In conclusion, a high diversity of Pseudo-nitzschia exists in Chilean waters, particularly offshore.

Antagonistic interplay between pH and food resources affects copepod traits and performance in a year-round upwelling system.

Linking pH/pCO2 natural variation to phenotypic traits and performance of foundational species provides essential information for assessing and predicting the impact of ocean acidification (OA) on marine ecosystems. Yet, evidence of such linkage for copepods, the most abundant metazoans in the oceans, remains scarce, particularly for naturally corrosive Eastern Boundary Upwelling systems (EBUs). This study assessed the relationship between pH levels and traits (body and egg size) and performance (ingestion rate (IR) and egg reproduction rate (EPR)) of the numerically dominant neritic copepod Acartia tonsa, in a year-round upwelling system of the northern (23° S) Humboldt EBUs. The study revealed decreases in chlorophyll (Chl) ingestion rate, egg production rate and egg size with decreasing pH as well as egg production efficiency, but the opposite for copepod body size. Further, ingestion rate increased hyperbolically with Chl, and saturated at ~1 µg Chl. L-1. Food resources categorized as high (H, >1 µg L-1) and low (L, <1 µg L-1) levels, and pH-values categorized as equivalent to present day (≤400 µatm pCO2, pH > 7.89) and future (>400 µatm pCO2, pH < 7.89) were used to compare our observations to values globally employed to experimentally test copepod sensitivity to OA. A comparison (PERMANOVA) test with Chl/pH (2*2) design showed that partially overlapping OA levels expected for the year 2100 in other ocean regions, low-pH conditions in this system negatively impacted traits and performance associated with copepod fitness. However, interacting antagonistically with pH, food resource (Chl) maintained copepod production in spite of low pH levels. Thus, the deleterious effects of ocean acidification are modulated by resource availability in this system.

Temperature and pCO2 jointly affect the emergence and survival of cercariae from a snail host: implications for future parasitic infections in the Humboldt Current system.

Ocean warming and acidification are general consequences of rising atmospheric CO2 concentrations. In addition to future predictions, highly productive systems such as the Humboldt Current System are characterized by important variations in both temperature and pCO2 level, but how these physical-chemical ocean changes might influence the transmission and survival of parasites has not been assessed. This study experimentally evaluated the effects of temperature (14, 18 and 25 °C) and the combined effects of temperature (∼15 and 20 °C) and pCO2 level (∼500 and 1400 microatmospheres (µatm) on the emergence and survival of two species of marine trematodes-Echinostomatidae gen. sp. and Philophthalmidae gen. sp.-both of which infect the intertidal snail Echinolittorina peruviana. Snails were collected from intertidal rocky pools in a year-round upwelling area of the northern Humboldt Current System (23°S). Two experiments assessed parasite emergence and survival by simulating emersion-immersion tidal cycles. To assess parasite survival, 2 h old cercariae (on average) were taken from a pool of infected snails incubated at 20-25 °C, and their mortality was recorded every 6 h until all the cercariae were dead. For both species, a trade-off between high emergence and low survival of cercariae was observed in the high temperature treatment. Species-specific responses to the combination of temperature and pCO2 levels were also observed: the emergence of Echinostomatidae cercariae was highest at 20 °C regardless of the pCO2 levels. By contrast, the emergence of Philophthalmidae cercariae was highest at elevated pCO2 (15 and 20 °C), suggesting that CO2 may react synergistically with temperature, increasing transmission success of this parasite in coastal ecosystems of the Humboldt Current System where water temperature and pH are expected to decrease. In conclusion, our results suggest that integrating temperature-pCO2 interactions in parasite studies is essential for understanding the consequence of climate change in future marine ecosystem health.

Upwelling modulation of functional traits of a dominant planktonic grazer during "warm-acid" El Niño 2015 in a year-round upwelling area of Humboldt Current.

Climate change is expected to exacerbate upwelling intensity and natural acidification in Eastern Boundaries Upwelling Systems (EBUS). Conducted between January-September 2015 in a nearshore site of the northern Humboldt Current System directly exposed to year-round upwelling episodes, this study was aimed at assessing the relationship between upwelling mediated pH-changes and functional traits of the numerically dominant planktonic copepod-grazer Acartia tonsa (Copepoda). Environmental temperature, salinity, oxygen, pH, alkalinity, chlorophyll-a (Chl), copepod adult size, egg production (EP), and egg size and growth were assessed through 28 random oceanographic surveys. Agglomerative clustering and multidimensional scaling identified three main di-similitude nodes within temporal variability of abiotic and biotic variables: A) "upwelling", B) "non-upwelling", and C) "warm-acid" conditions. Nodes A and B represented typical features within the upwelling phenology, characterized by the transition from low temperature, oxygen, pH and Chl during upwelling to higher levels during non-upwelling conditions. However, well-oxygenated, saline and "warm-acid" node C seemed to be atypical for local climatology, suggesting the occurrence of a low frequency oceanographic perturbation. Multivariate (LDA and ANCOVA) analyses revealed upwelling through temperature, oxygen and pH were the main factors affecting variations in adult size and EP, and highlighted growth rates were significantly lower under node C. Likely buffering upwelling pH-reductions, phytoplankton biomass maintained copepod reproduction despite prevailing low temperature, oxygen and pH levels in the upwelling setting. Helping to better explain why this species is among the most recurrent ones in these variable yet productive upwelling areas, current findings also provide opportune cues on plankton responses under warm-acid conditions, which are expected to occur in productive EBUS as a consequence of climate perturbations.

Curcumin decreases epithelial­mesenchymal transition by a Pirin­dependent mechanism in cervical cancer cells.

Curcumin is a natural antioxidant polyphenol, which decreases epithelial­mesenchymal transition (EMT) and cell migration in cervical cancer cells. However, the mechanism by which such a decrease occurs is unclear. It is well established that cervical cancer can be caused by high­risk human papillomavirus (HPV), which overexpresses E6 and E7 oncoproteins. Recent findings have suggested that viral oncoproteins regulate the expression of Pirin, which is an oxidative stress sensor involved in EMT and cell migration. Molecular markers associated with EMT, pirin and HPV were evaluated using reverse transcription­reverse quantitative PCR and western blotting. In addition, the migratory ability of cells was evaluated using a Transwell assay. In order to evaluate the role of Pirin in curcumin­mediated inhibition of EMT, SiHa cervical carcinoma cells, which contain two integrated copies of HPV16, were exposed to curcumin. Cell migration, and the expression levels of EMT biomarkers and the pirin protein, which is a product of the PIR gene, were subsequently evaluated. The results demonstrated a significant decrease in EMT following exposure to 20 µM curcumin for 72 h. This finding was supported by a decrease in the protein expression levels of N­cadherin, Vimentin and Slug. Furthermore, it was observed that PIR expression and Pirin protein levels were significantly decreased when SiHa cells were exposed to curcumin. Subsequently, to analyze the effects of Pirin on EMT, SiHa cells were transfected with a small interfering RNA (siRNA) to knockdown PIR. A significant increase in E­cadherin mRNA expression and a decrease in N­cadherin protein expression were observed. In addition, a similar decrease was observed when SiHa cells were exposed to both PIR siRNA and curcumin. Finally, a significant decrease in SiHa cell migration was observed in the presence of 20 µM curcumin compared with in the control group. These findings suggested that curcumin may decrease EMT, at least in part by a Pirin­dependent mechanism. Therefore, Pirin protein may be an important pharmacological target for cervical cancer treatment.

Tobacco Exposure Enhances Human Papillomavirus 16 Oncogene Expression via EGFR/PI3K/Akt/c-Jun Signaling Pathway in Cervical Cancer Cells.

High-risk human papillomavirus (HR-HPV) infection is not a sufficient condition for cervical cancer development because most infections are benign and naturally cleared. Epidemiological studies revealed that tobacco smoking is a cofactor with HR-HPV for cervical cancer initiation and progression, even though the mechanism by which tobacco smoke cooperates with HR-HPV in this malignancy is poorly understood. As HR-HPV E6/E7 oncoproteins overexpressed in cervical carcinomas colocalize with cigarette smoke components (CSC), in this study we addressed the signaling pathways involved in a potential interaction between both carcinogenic agents. Cervical cancer-derived cell lines, CaSki (HPV16; 500 copies per cell) and SiHa (HPV16; 2 copies per cell), were acutely exposed to CSC at various non-toxic concentrations and we found that E6 and E7 levels were significantly increased in a dose-dependent manner. Using a reporter construct containing the luciferase gene under the control of the full HPV16 long control region (LCR), we also found that p97 promoter activity is dependent on CSC. Non-synonymous mutations in the LCR-resident TPA (12-O-tetradecanoylphorbol 13-acetate)-response elements (TRE) had significantly decreased p97 promoter activation. Phosphoproteomic arrays and specific inhibitors revealed that CSC-mediated E6/E7 overexpression is at least in part reliant on EGFR phosphorylation. In addition, we showed that the PI3K/Akt pathway is crucial for CSC-induced E6/E7 overexpression. Finally, we demonstrated that HPV16 E6/E7 overexpression is mediated by JUN. overexpression, c-Jun phosphorylation and recruitment of this transcription factor to TRE sites in the HPV16 LCR. We conclude that acute exposure to tobacco smoke activates the transcription of HPV16 E6 and E7 oncogenes through p97 promoter activation, which involves the EGFR/PI3K/Akt/C-Jun signaling pathway activation in cervical cancer cells.

Species-specific responses to ocean acidification should account for local adaptation and adaptive plasticity.

Global stressors, such as ocean acidification, constitute a rapidly emerging and significant problem for marine organisms, ecosystem functioning and services. The coastal ecosystems of the Humboldt Current System (HCS) off Chile harbour a broad physical-chemical latitudinal and temporal gradient with considerable patchiness in local oceanographic conditions. This heterogeneity may, in turn, modulate the specific tolerances of organisms to climate stress in species with populations distributed along this environmental gradient. Negative response ratios are observed in species models (mussels, gastropods and planktonic copepods) exposed to changes in the partial pressure of CO2 (pCO2) far from the average and extreme pCO2 levels experienced in their native habitats. This variability in response between populations reveals the potential role of local adaptation and/or adaptive phenotypic plasticity in increasing resilience of species to environmental change. The growing use of standard ocean acidification scenarios and treatment levels in experimental protocols brings with it a danger that inter-population differences are confounded by the varying environmental conditions naturally experienced by different populations. Here, we propose the use of a simple index taking into account the natural pCO2 variability, for a better interpretation of the potential consequences of ocean acidification on species inhabiting variable coastal ecosystems. Using scenarios that take into account the natural variability will allow understanding of the limits to plasticity across organismal traits, populations and species.

Índices de oxigenación, índice de choque diastólico y tiempo en presión soporte como predictores de éxito en el retiro de la ventilación mecánica invasiva en paciente críticamente enfermo con COVID-19 / Oxygenation indices, diastolic shock index, and time in support pressure as predictors of success in the removal of invasive mechanical ventilation in critically ill patients with COVID-19 / Índices de oxigenação, índice de choque diastólico e tempo em pressão de suporte como preditores de sucesso na retirada de ventilação mecânica invasiva em pacientes em estado crítico com COVID-19

Resumen Introducción: El porcentaje de pacientes gravemente enfermos por COVID-19 que toleran el retiro de la ventilación mecánica es mínimo, por lo cual es fundamental determinar cuáles son los predictores de éxito en el retiro de la ventilación mecánica. Objetivos: Determinar si los índices de oxigenación, tiempo en presión soporte e índice de choque diastólico son predictores de éxito en el retiro de la ventilación mecánica en pacientes críticamente enfermos por COVID-19. Material y métodos: Estudio de cohorte prospectivo en pacientes con COVID-19 que ingresaron a la Unidad de Cuidados Intensivos y fueron sometidos a pruebas de ventilación espontánea, siendo posteriormente liberados del ventilador mecánico. Se recolectaron datos demográficos, resultados de laboratorio y parámetros ventilatorios con la finalidad de analizar y determinar predictores de éxito en el retiro de la ventilación mecánica. Resultados: Se observó una diferencia significativa entre los pacientes que toleraron y los que no toleraron el retiro de la ventilación mecánica en las siguientes variables: índice de respiración rápida superficial 47 ± 17.9 vs 90 ± 20.2 (p = 0.08), días de ventilación mecánica 5.8 vs 9.3 (p = 0.03), sesiones de prono 1.36 vs 2.33 (p = 0.058) y presión arterial diastólica 57 ± 3.6 (p = 0.027). Conclusión: En los pacientes críticamente enfermos por COVID-19 que son candidatos a retiro de la ventilación mecánica sugerimos usar como predictores de éxito: el índice de respiraciones rápidas superficiales < 64, días de ventilación mecánica < 8, presión arterial diastólica > 57 mmHg y haber tenido máximo dos sesiones de prono como predictores de éxito en el retiro de la ventilación mecánica.

Abstract Introduction: The percentage of critically ill patients due to COVID-19 who tolerate the withdrawal of mechanical ventilation is minimal. It is essential to determine which are the predictors of success in weaning. Objectives: To determine if the oxygenation indices, time in pressure support, and diastolic shock index are predictors of success in the withdrawal of mechanical ventilation in critically ill patients due to COVID-19. Material and methods: Prospective cohort study in patients with COVID-19 who were admitted to the ICU and underwent tests of spontaneous ventilation, being later released from the mechanical ventilator. Demographic data, laboratory results, ventilatory parameters were collected in order to analyze and determine predictors of success in weaning. Results: A significant difference was found between those who tolerated and those who did not tolerate the withdrawal of mechanical ventilation in the following variables: rapid shallow breathing index 47 ± 17.9 vs 90 ± 20.2 (p = 0.08), days of mechanical ventilation 5.8 vs 9.3 (p = 0.03), prone sessions 1.36 vs 2.33 (p = 0.058), diastolic blood pressure 57 ± 3.6 (p = 0.027). Conclusion: In critically ill patients due to COVID-19 who are candidates for withdrawal from mechanical ventilation, we suggest using as predictors of success: Index of rapid shallow breaths < 64, days of mechanical ventilation < 8, diastolic blood pressure > 57 mmHg and having had a maximum two prone sessions as predictors of success in the withdrawal of mechanical ventilation.

Resumo Introdução: A porcentagem de pacientes graves com COVID-19 que toleram a retirada da ventilação mecânica é mínima, por isso é essencial determinar os preditores de sucesso na retirada da ventilação mecânica. Objetivos: Determinar se os índices de oxigenação, tempo em pressão suporte, índice de choque diastólico são preditores de sucesso no desmame da ventilação mecânica em pacientes críticos com COVID-19. Material e métodos: Estudo de coorte prospectivo em pacientes com COVID-19 admitidos na unidade de terapia intensiva e submetidos a testes de ventilação espontânea e posteriormente liberados do ventilador mecânico. Foram coletados dados demográficos, resultados laboratoriais e parâmetros ventilatórios para analisar e determinar os preditores de sucesso no desmame da ventilação mecânica. Resultados: Observou-se uma diferença significativa entre os pacientes que toleraram e os que não toleraram a retirada da ventilação mecânica nas seguintes variáveis: índice de respiração rápida e superficial 47 ±17.9 vs 90 ± 20.2 (p = 0.08), dias de ventilação mecânica 5.8 vs 9.3 (p = 0.03), sessões de prona 1.36 vs 2.33 (p = 0.058) e pressão arterial diastólica 57 ± 3.6 (p = 0.027). Conclusão: Em pacientes em estado crítico com COVID-19 candidatos à retirada da ventilação mecânica, sugerimos usar como preditores de sucesso: índice de respirações rápidas e superficiais < 64, dias de ventilação mecânica < 8, pressão arterial diastólica > 57 mmHg e ter realizado no máximo 2 sessões em decúbito ventral como preditores de sucesso no desmame da ventilação mecânica.

Experimental studies on the feeding and reproduction of Calanoides patagoniensis (Copepoda, Calanoid) in a southern upwelling ecosystem of the Humboldt Current.

Seasonal cohorts of the large-sized copepod Calanoides patagoniensis allowed testing the relative ability of this species to exploit food resources that prevail during winter time in southern upwelling ecosystems of the Humboldt Current. This was achieved by considering a local winter flagellate assemblage (WFA), Thalassiosira rotula isolated from the local spring phytoplankton and a laboratory culture of Prorocentrum minimum, as food offers in consecutive 96 h experiments. Ingestion rates (IR) varied between 7 and 14 µg C f(-1) d(-1), egg production reached a peak of 70 eggs while egg production rates (EPR) varied between 27 ± 6 and 31 ± 4 eggs f(-1) d(-1). Feeding and reproductive traits were dependent on food offer, and after 72 h both IR and EPR decreased by 28% and 40% respectively, when copepods were steadily fed with the diatom. The relatively high reproductive performance supported by WFA was notable; showing the feeding behavior of this species can couple with food availability in the field with successful reproductive outcomes. Migration strategies allowing remain in upper food-rich coastal waters along with this flexible trophic behavior may better explain why this species is among the most recurrent ones in these variable yet productive upwelling areas.

Impact of medium-term exposure to elevated pCO(2) levels on the physiological energetics of the mussel Mytilus chilensis.

This study evaluated the impact of medium-term exposure to elevated pCO(2) levels (750-1200 ppm) on the physiological processes of juvenile Mytilus chilensis mussels over a period of 70 d in a mesocosm system. Three equilibration tanks filled with filtered seawater were adjusted to three pCO(2) levels: ~380 (control), ~750 and ~1200 ppm by bubbling air or an air-CO(2) mixture through the water. For the control, atmospheric air (with aprox. 380 ppm CO(2)) was bubbled into the tank; for the 750 and 1200 ppm treatments, dry air and pure CO(2) were blended to each target concentration using mass flow controllers for air and CO(2). No impact on feeding activity was observed at the beginning of the experiment, but a significant reduction in clearance rate was observed after 35 d of exposure to highly acidified seawater. Absorption rate and absorption efficiency were reduced at high pCO(2) levels. In addition, oxygen uptake fell significantly under these conditions, indicating a metabolic depression. These physiological responses of the mussels resulted in a significant reduction of energy available for growth (scope for growth) with important consequences for the aquaculture of this species during medium-term exposure to acid conditions. The results of this study clearly indicate that high pCO(2) levels in the seawater have a negative effect on the health of M. chilensis. Therefore, the predicted acidification of seawater associated with global climate change could be harmful to this ecologically and commercially important mussel.