Phototrophy by antenna-containing rhodopsin pumps in aquatic environments.

Energy transfer from light-harvesting ketocarotenoids to the light-driven proton pump xanthorhodopsins has been previously demonstrated in two unique cases: an extreme halophilic bacterium1 and a terrestrial cyanobacterium2. Attempts to find carotenoids that bind and transfer energy to abundant rhodopsin proton pumps3 from marine photoheterotrophs have thus far failed4-6. Here we detected light energy transfer from the widespread hydroxylated carotenoids zeaxanthin and lutein to the retinal moiety of xanthorhodopsins and proteorhodopsins using functional metagenomics combined with chromophore extraction from the environment. The light-harvesting carotenoids transfer up to 42% of the harvested energy in the violet- or blue-light range to the green-light absorbing retinal chromophore. Our data suggest that these antennas may have a substantial effect on rhodopsin phototrophy in the world's lakes, seas and oceans. However, the functional implications of our findings are yet to be discovered.

Preclinical investigation in FAAH inhibition as a neuroprotective therapy for frontotemporal dementia using TDP-43 transgenic male mice.

BACKGROUND: Frontotemporal dementia (FTD) is a heterogeneous group of early onset and progressive neurodegenerative disorders, characterized by degeneration in the frontal and temporal lobes, which causes deterioration in cognition, personality, social behavior and language. Around 45% of the cases are characterized by the presence of aggregates of the RNA-binding protein TDP-43. METHODS: In this study, we have used a murine model of FTD that overexpresses this protein exclusively in the forebrain (under the control of the CaMKIIα promoter) for several biochemical, histological and pharmacological studies focused on the endocannabinoid system. RESULTS: These mice exhibited at postnatal day 90 (PND90) important cognitive deficits, signs of emotional impairment and disinhibited social behaviour, which were, in most of cases, maintained during the first year of life of these animals. Motor activity was apparently normal, but FTD mice exhibited higher mortality. Their MRI imaging analysis and their ex-vivo histopathological evaluation proved changes compatible with atrophy (loss of specific groups of pyramidal neurons: Ctip2- and NeuN-positive cells) and inflammatory events (astroglial and microglial reactivities) in both cortical (medial prefrontal cortex) and subcortical (hippocampus) structures at PND90 and also at PND365. The analysis of the endocannabinoid system in these mice proved a decrease in the hydrolysing enzyme FAAH in the prefrontal cortex and the hippocampus, with an increase in the synthesizing enzyme NAPE-PLD only in the hippocampus, responses that were accompanied by modest elevations in anandamide and related N-acylethanolamines. The potentiation of these elevated levels of anandamide after the pharmacological inactivation of FAAH with URB597 resulted in a general improvement in behaviour, in particular in cognitive deterioration, associated with the preservation of pyramidal neurons of the medial prefrontal cortex and the CA1 layer of the hippocampus, and with the reduction of gliosis in both structures. CONCLUSIONS: Our data confirmed the potential of elevating the endocannabinoid tone as a therapy against TDP-43-induced neuropathology in FTD, limiting glial reactivity, preserving neuronal integrity and improving cognitive, emotional and social deficits.

Glycosylation differences of an anti-VEGF monoclonal antibody (PRO-169) and its extensive comparison with Bevacizumab.

PRO-169 is an anti-VEGF monoclonal antibody developed by Laboratorios Sophia that shares its sequence with Bevacizumab (BVZ); though, PRO-169 is intended for intravitreal administration. In this study, analytical characterization showed that PRO-169 had glycosylation differences in comparison to BVZ reference product (RP); since it had more content of G1F, G2F, sialic acid and high mannose. Further investigation was performed to evaluate if differences between both products would affect the efficacy and safety profile of PRO-169. PRO-169 had no alteration in its in vitro biological activity; moreover, no cytotoxicity or immunogenicity concerns should be expected as demonstrated by different orthogonal methods at analytical, in vitro and in vivo assays. These results support moving to the clinical testing of PRO-169 since no major complications will be expected with its clinical use for the treatment of ophthalmic diseases.

Microalgae, Seaweeds and Aquatic Bacteria, Archaea, and Yeasts: Sources of Carotenoids with Potential Antioxidant and Anti-Inflammatory Health-Promoting Actions in the Sustainability Era.

Carotenoids are a large group of health-promoting compounds used in many industrial sectors, such as foods, feeds, pharmaceuticals, cosmetics, nutraceuticals, and colorants. Considering the global population growth and environmental challenges, it is essential to find new sustainable sources of carotenoids beyond those obtained from agriculture. This review focuses on the potential use of marine archaea, bacteria, algae, and yeast as biological factories of carotenoids. A wide variety of carotenoids, including novel ones, were identified in these organisms. The role of carotenoids in marine organisms and their potential health-promoting actions have also been discussed. Marine organisms have a great capacity to synthesize a wide variety of carotenoids, which can be obtained in a renewable manner without depleting natural resources. Thus, it is concluded that they represent a key sustainable source of carotenoids that could help Europe achieve its Green Deal and Recovery Plan. Additionally, the lack of standards, clinical studies, and toxicity analysis reduces the use of marine organisms as sources of traditional and novel carotenoids. Therefore, further research on the processing of marine organisms, the biosynthetic pathways, extraction procedures, and examination of their content is needed to increase carotenoid productivity, document their safety, and decrease costs for their industrial implementation.

Determination of pizzas quality and acceptability by physic-mechanical tests.

The growing need for developing more efficient and sustainable technologies for the processing of bakery products leads to the need for replacing the current subjective methodology by an instrumental method to evaluate the quality of these products. In this work, relevant physic characteristics that define the quality and acceptability of pizzas were identified, and instrumental methods were established to evaluate them. Cooking quality of the pizza base was established through rapid visco analysis and scanning electron microscopy. The physic attributes considered of the pizza base with and without toppings were final cooking temperature, specific volume, water content, color, and texture. Aiming to validate the applicability of the instrumental methods, we prepared well-accepted pizzas, using three different oven technologies, and carried out a sensory test with 60 non-trained panelists. We observed that the proposed method is sensitive enough to identify differences in the quality of pizzas produced by the oven technologies. However, those variations were not enough to be recognized by participants of the sensory panel. The values of pizza attributes obtained in this work could be used as a baseline of comparison for pizzas produced by new and more efficient cooking technologies. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at (10.1007/s13197-021-05148-8).

Characterization and biological activities of carotenoids produced by three haloarchaeal strains isolated from Algerian salt lakes.

Halophilic archaea represent a promising natural source of carotenoids. However, little information is available about these archaeal metabolites and their biological effects. In the present work, carotenoids of strains Haloferax sp. ME16, Halogeometricum sp. ME3 and Haloarcula sp. BT9, isolated from Algerian salt lakes, were produced, extracted and identified by high-performance liquid chromatography-diode array detector and liquid chromatography-mass spectrometry. Analytical results revealed a variation in the composition depending on the strain with a predominance of bacterioruberin. The evaluation of antioxidant capacity using ABTS [(2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] and DPPH (2,2-diphenyl-1-picrylhydrazyl) assays showed that these extracts have a strong antioxidant potential, in particular those of Haloferax sp. ME16 which displayed antioxidant power significantly higher than that of ascorbic acid used as standard. Antibacterial activity of carotenoid extracts against four human-pathogenic strains and four fish-pathogenic strains was evaluated by agar disk diffusion method. The results showed a good antibacterial activity. These findings suggest that the C50 carotenoids from the studied strains offer promising prospects for biotechnological applications.

Bioprospecting and characterization of pigmented halophilic archaeal strains from Algerian hypersaline environments with analysis of carotenoids produced by Halorubrum sp. BS2.

A set of 110 extremely halophilic archaeal strains were isolated from seven distinct saline habitats located in different regions of Algeria. The physicochemical characterization of the samples showed that these habitats were thalassohaline. The carotenoid production from isolated strains varied from 0.1 to 3.68 µg/ml. Based on their physiological characteristics and pigment production, 43 strains were selected and identified by means of phenotypic tests and 16S ribosomal RNA gene sequencing. Phylogenetic analysis indicated that the isolates corresponded to the class Halobacteria and were closely related to genera Halorubrum, Haloarcula, Haloferax, Natrinema, Halogeometricum, Haloterrigena, and Halopiger. Carotenoids of the highest producer, strain Halorubrum sp. BS2 were identified using high-performance liquid chromatography-diode array detector and liquid chromatography-mass spectrometry. Bacterioruberin and bisanhydrobacterioruberin were the predominant carotenoids. The scavenging activity of these carotenoids reached 99% at a concentration of 18 µg/ml, which was much higher than that of ascorbic acid used as a reference compound. These carotenoids also exhibited significant antibacterial activities against four human-pathogenic strains and four fish-pathogenic strains. Variations in salinity, agitation rate, temperature, and light intensity were found to influence growth and carotenoid production of Halorubrum sp. BS2. Our results suggest that halophilic archaea represent a potential source for carotenoids, which are characterized by high antioxidant and antibacterial activities.

Characterization of the Microbial Population Inhabiting a Solar Saltern Pond of the Odiel Marshlands (SW Spain).

The solar salterns located in the Odiel marshlands, in southwest Spain, are an excellent example of a hypersaline environment inhabited by microbial populations specialized in thriving under conditions of high salinity, which remains poorly explored. Traditional culture-dependent taxonomic studies have usually under-estimated the biodiversity in saline environments due to the difficulties that many of these species have to grow at laboratory conditions. Here we compare two molecular methods to profile the microbial population present in the Odiel saltern hypersaline water ponds (33% salinity). On the one hand, the construction and characterization of two clone PCR amplified-16S rRNA libraries, and on the other, a high throughput 16S rRNA sequencing approach based on the Illumina MiSeq platform. The results reveal that both methods are comparable for the estimation of major genera, although massive sequencing provides more information about the less abundant ones. The obtained data indicate that Salinibacter ruber is the most abundant genus, followed by the archaea genera, Halorubrum and Haloquadratum. However, more than 100 additional species can be detected by Next Generation Sequencing (NGS). In addition, a preliminary study to test the biotechnological applications of this microbial population, based on its ability to produce and excrete haloenzymes, is shown.

Low-abundant protein extraction from complex protein sample using a novel continuous aqueous two-phase systems device.

The present work describes the application of a novel continuous aqueous two-phase system prototype for the recovery of biomolecules. The prototype is an alternative platform for protein recovery and α-amylase from soybean extracts was used as a model system. The system was selected as an example of low-abundant protein present in complex mixtures. Compared with batch systems, continuous operation in this prototype seems to increase partition coefficient with higher recovery efficiencies. Processing time is reduced at least three times in the continuous system when compared to batch mode, while hold up (volumetric quantity of the opposing phase in a determined phase sample) decreases with decreasing phases flow. Furthermore, similar partition coefficient (Kp > 4) with a higher top phase enzyme recovery (81%) is also obtained in this system probably due to better contact surface between phases, compared with that obtained in batch (79%). A continuous aqueous two-phase system process with purification factor 40-fold higher than batch experiments was achieved. These preliminary results exhibit the potential of continuous systems for the recovery of low-abundant proteins from complex mixtures. The promising performance of this prototype can raise the attention of the industry for the adoption of aqueous two-phase system processes.

Determinants of adherence to treatment in patients with ophthalmic conditions.

BACKGROUND: The objective of this study was to identify and determine factors associated with patients' ophthalmic adherence in common ocular conditions from randomized clinical trials (RCT). RESEARCH DESIGN METHODS: A univariate analysis with proportions, a bivariate analysis using polychoric correlations, and logistic regression (LR) models were used. The collected dataset was made up of records from RCT. Using three validated LR models, factors were identified and ranked based on their adjusted odds ratio and their statistical significance to adherence. RESULTS: A total of 1,087 valid patients were included in this analysis, of which 88.96% presented adherence. All models were calibrated, had a good performance, were well specified and cost-effective using the Hosmer-Lemeshow test, metrics for class imbalance, link test approach and Akaike's criteriums, respectively. CONCLUSION: We identified as determinants for encouraging good ophthalmic adherence the adverse events presented, duration of the study, female sex, and older age; other determinants such as medical condition, protocol treatment, type of treatment and disease are all risk factors for adherence. Improvements in ophthalmic adherence may be achieved by focused attention to young male patients with chronic degenerative diseases such as glaucoma or ocular hypertension (especially those who need combination therapy) and developing medications with reduced side effects.

The Effect of Sodium Hyaluronate Eye Drops 2, 4 or 6 Times a Day on Signs and Symptoms of Dry Eye Disease.

Purpose: A randomized clinical trial was run to evaluate the effectiveness of a preservative-free 0.4% sodium hyaluronate eye drop (LOF) in different dosage schemes to alleviate signs and symptoms of dry eye disease (DED). Methods: A total of 116 subjects with mild-to-moderate DED were included, and 111 completed the study (from which 67.6% were female and 65.3% were users of oral contraceptives). Patients were randomly assigned to instill a drop of LOF either 2 (BID), 4 (QID) or 6 (6TD) times a day (at least 3 hours apart) for 30 days. The clinical parameters and symptom endpoints were Ocular Surface Disease Index (OSDI), tear break-up time (TBUT), ocular surface staining, and conjunctival hyperemia. Other parameters evaluated were chemosis, best corrected visual acuity, and the incidence of adverse events (AE). Results: There was a significant reduction in OSDI scores by day 30 in all groups. The recovery of the OSDI score back to normal values was observed in 51.4% of patients treated (50%, 48.6%, and 55.6% in BID, QID, and 6TD, respectively, p = 0.822). Similar improvement was observed for TBUT, 50.5% of patients increased this variable to >10 seconds (39.5%, 51.4%, and 61.1%, p = 0.175), and for ocular surface staining, ≥72% showed Grade 0. There were no significant differences among posology groups regarding ocular surface staining, conjunctival hyperemia, or any safety parameters. No overall improvement in OSDI and TBUT to normal values was noted for 31 patients (21 were female and 71.4% users of contraceptive drugs). Conclusion: The ophthalmic use of preservative free LOF, 2, 4 or 6 times a day, may alleviate clinical parameters and symptoms in 50% of patients with mild-to-moderate DED after a one-month treatment. This improvement seemed to be less ubiquitous in patients within reproductive age and using oral contraceptives. Trial Registration: This trial is registered at clinicaltrials.gov (NCT0704531).

Efficacy and Safety of an Ophthalmic DMPC-Based Nanoemulsion in Patients with Dry Eye Disease: A Phase I/II Randomized Clinical Trial.

Purpose: The goals of this study were to evaluate the safety and efficacy of an ophthalmic 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC)-based nanoemulsion (Nanodrop®) in patients with dry eye disease (DED). Methods: This was a randomized phase I/II multicentric, prospective, double-blind clinical trial. Patients (phase I: n = 25 and phase II: n = 101) were assigned to receive either PRO-176 (Nanodrop®) or Systane Balance® (control) for 29 days. Once the visits of the first 25 subjects were completed, if there were less than 20% of unexpected adverse events (AEs), related to PRO-176, recruitment was continued until the sample was completed for noninferiority (efficacy) analysis (phase II, n = 126). Efficacy endpoints were the ocular surface disease index (OSDI), tear break-up time (TBUT), epithelial defects, best corrected visual acuity (BCVA), and the incidence of expected AE. Results: For the phase I portion of the study, there were no differences between groups regarding the incidence of AE. All related-AE symptoms in both groups were mild and expected. For the phase II subset, there was a significant reduction in OSDI scores at day 29 and noninferiority between treatments was confirmed (p=0.650, CI 95% [-8.7, 5.5]). Similar improvement was observed for TBUT although no significant intergroup differences were found (p=0.518, CI 95% [-0.08, 1.6]). There were no significant differences between treatments for epithelial staining or safety parameters. Conclusions: Topical application of PRO-176 is as safe and effective as the controls. Both groups were clinically similar in terms of efficacy and safety. The results support the hypothesis that ophthalmic DMPC-based nanoemulsion may improve clinical parameters and symptoms in patients with DED. This trial is registered with NCT04111965.

Evaluation of the Relationship Between Diabetic Macular Edema and Renal Function in a Latino Population.

INTRODUCTION: Diabetic macular edema (DME) is one of the leading causes of vision impairment. The relationship between DME and estimated glomerular filtration rate (eGFR) has not been clearly evaluated in Hispanic or Latino populations. The objective of this study was to evaluate the eGFR in a Latino population with DME. METHODS: A cross-sectional, observational, and descriptive study was carried out on the basis of a multicenter phase III clinical trial. RESULTS: A total of 82 subjects diagnosed with DME (36 women and 46 men) were included in the study. The mean age was 61.93 ± 6.71 years. Mean values of the blood chemistry parameters glycated hemoglobin and eGFR were 7.20 ± 0.95% and 74.42 ± 26.82 mL/min/1.73 m2, respectively. The time elapsed since diagnosis of diabetes mellitus was 15.30 ± 7.35 years, while the duration of DME was 1.41 ± 1.75 years. Mean values for central macular thickness (CMT) and total macular volume (TMV) were 440.99 ± 132.22 µm and 11.97 ± 2.11 mm3, respectively. DME duration had a negative correlation with TMV (Rho - 0.26, p < 0.05) and a positive correlation with mean arterial pressure (Rho 0.26, p < 0.05). CMT was correlated with TMV (Rho 0.43, p < 0.0001) and visual acuity (Rho 0.26, p < 0.05). No significant correlations were observed between eGFR and CMT, TMV, or any demographic variable (p > 0.05). Chronic kidney disease (CKD) was associated with hypertension (OR 9.32, p = 0.035), elevated intraocular pressure (IOP) (OR 0.03, p = 0.011), and advanced age (OR 0.45, p = 0.011). CMT was significantly associated with TMV (ß = 27.69, p < 0.0001). CONCLUSIONS: We did not find a correlation between eGFR and DME. Our findings suggest that the presence of hypertension is associated with a decrease in the GFR < 60 mL/min/1.73 m2, and CKD may be associated with advanced age and elevated IOP which may increase the risk for the development of glaucoma. TRIAL REGISTRATION: NCT05217680 (clinicaltrials.gov).

Up-Regulation of the Nrf2/HO-1 Antioxidant Pathway in Macrophages by an Extract from a New Halophilic Archaea Isolated in Odiel Saltworks.

The production of reactive oxygen species (ROS) plays an important role in the progression of many inflammatory diseases. The search for antioxidants with the ability for scavenging free radicals from the body cells that reduce oxidative damage is essential to prevent and treat these pathologies. Haloarchaea are extremely halophilic microorganisms that inhabit hypersaline environments, such as saltworks or salt lakes, where they have to tolerate high salinity, and elevated ultraviolet (UV) and infrared radiations. To cope with these extreme conditions, haloarchaea have developed singular mechanisms to maintain an osmotic balance with the medium, and are endowed with unique compounds, not found in other species, with bioactive properties that have not been fully explored. This study aims to assess the potential of haloarchaea as a new source of natural antioxidant and anti-inflammatory agents. A carotenoid-producing haloarchaea was isolated from Odiel Saltworks (OS) and identified on the basis of its 16S rRNA coding gene sequence as a new strain belonging to the genus Haloarcula. The Haloarcula sp. OS acetone extract (HAE) obtained from the biomass contained bacterioruberin and mainly C18 fatty acids, and showed potent antioxidant capacity using ABTS assay. This study further demonstrates, for the first time, that pretreatment with HAE of lipopolysaccharide (LPS)-stimulated macrophages results in a reduction in ROS production, a decrease in the pro-inflammatory cytokines TNF-α and IL-6 levels, and up-regulation of the factor Nrf2 and its target gene heme oxygenase-1 (HO-1), supporting the potential of the HAE as a therapeutic agent in the treatment of oxidative stress-related inflammatory diseases.

Analysis of the retention of women in higher education STEM programs.

Gender equity and quality education are Sustainable Development Goals that are present when a culture of equity and inclusion is pursued in society, companies, and institutions. Particularly in undergraduate programs in Science, Technology, Engineering, and Mathematics (STEM), there is a noticeable gender gap between men and women. The objective of this study was to find out the causes of permanence in STEM careers of women, as well as the possible causes of career abandonment towards another STEM or non-STEM career. This was done by analyzing historical data for admission to STEM careers and using an instrument (survey) for data collection carried out in a private university in Mexico. Historical data indicates that only 17% of the total population were women choosing a STEM career. A survey was carried out for 3 months to obtain information on the factors that affect the decision to opt for a STEM career or to remain in it. It was found that men and women prefer inspiring Faculty who motivate them to continue their careers. Factors such as the competitive environment and the difficulty of teaching with less empathetic Faculty were negative and decisive aspects of decision-making. School achievement did not influence the dropout rate of women in STEM careers. The factors of choice and desertion of women in STEM careers were determined, and actions of educational innovation such as mentoring and timely monitoring of already enrolled female students, digital platforms for students and Faculty, awareness workshops for Faculty, and talks with successful women in STEM areas were proposed.

Evaluation of online learning readiness in the new distance learning normality.

The COVID-19 pandemic influenced teaching and learning in higher education. The transformation towards digital education challenged Faculty and students. This research examines the online learning readiness of students in a Higher Education Institution in Mexico. Specifically, we investigated how much prior digital skills, as well as having used the digital resources available by the university, influenced their academic achievement in distance learning settings. Seven dimensions of online learning readiness were selected to evaluate the student's preparation for the online learning process. Questionnaires were applied before the start and at the end of digital courses. Follow-up tools were offered to support the student, and two groups were observed, users and non-users of the digital devices. It was observed that students who used the support developed significantly better critical thinking, problem-solving, and time organization skills than non-users. On the other hand, although the evaluations were not significantly different, the lowest averages were found in the non-user group. Our results indicate that prior training in the use of digital tools is essential for the success of online education; in the same way, a timely follow-up with technical and pedagogical assistance is necessary for developing competencies. Training more autonomous and independent students capable of distance learning in a global world demands experts in digital education urgently. Educational institutions must embrace new technologies and teaching methods to meet the ever-changing needs of students. This research is expected to play a crucial role in promoting constructive discussions and facilitating informed decisions concerning the creation of future educational models.

Advances in Material Modification with Smart Functional Polymers for Combating Biofilms in Biomedical Applications.

Biofilms as living microorganism communities are found anywhere, and for the healthcare sector, these constitute a threat and allied mechanism for health-associated or nosocomial infections. This review states the basis of biofilms and their formation. It focuses on their relevance for the biomedical sector, generalities, and the major advances in modified or new synthesized materials to prevent or control biofilm formation in biomedicine. Biofilm is conceptualized as an aggregate of cells highly communicated in an extracellular matrix, which the formation obeys to molecular and genetic basis. The biofilm offers protection to microorganisms from unfavorable environmental conditions. The most frequent genera of microorganisms forming biofilms and reported in infections are Staphylococcus spp., Escherichia spp., and Candida spp. in implants, heart valves, catheters, medical devices, and prostheses. During the last decade, biofilms have been most commonly related to health-associated infections and deaths in Europe, the United States, and Mexico. Smart, functional polymers are materials capable of responding to diverse stimuli. These represent a strategy to fight against biofilms through the modification or synthesis of new materials. Polypropylene and poly-N-isopropyl acrylamide were used enough in the literature analysis performed. Even smart polymers serve as delivery systems for other substances, such as antibiotics, for biofilm control.

Metabarcoding data of prokaryotes and eukaryotes inhabiting the phosphogypsum stockpiles on the salt marshes of Huelva (SW Spain).

Around 100 Mt of phosphogypsum (PG) of extreme acidity and with high concentrations of heavy metals and radionuclides have been deposited on the salt marshes of the Tinto River estuary in Huelva (SW Spain) for more than forty years. The microbial community able to thrive in these adverse conditions remains totally unknown, despite the fact that it can highly influence the biogeochemical cycle of the phosphogypsum components and include new species with biotechnological interest. High throughput sequencing of 16S/18S rRNA encoding genes is a potent tool to uncover the microbial diversity of extreme environments. This data article describes for the first time the prokaryotic and eukaryotic diversity of two water samples collected in the Huelva phosphogypsum stacks. The raw amplicons of the 16S/18S rRNA maker genes for the two phosphogypsum samples and two reference samples (seawater and the Tinto River water) obtained after sequencing on MiSeq platform are provided. The operational taxonomic units (OTUs) obtained after the treatment and clustering of the obtained reads with the QIIME2 pipeline and their taxonomic assignation performed by comparison with the SILVA database are also presented to complete the information of the article "Exploring the microbial community inhabiting the phosphogypsum stacks of Huelva (SW, Spain) by a high throughput 16S/18S rDNA Sequencing approach".

Exploring the microbial community inhabiting the phosphogypsum stacks of Huelva (SW SPAIN) by a high throughput 16S/18S rDNA sequencing approach.

Around 100 Mt of phosphogypsum (PG) have been deposited in large stacks on the salt marshes of the Tinto River estuary in Huelva (SW Spain), covering about 1000 ha. These stacks contain extremely acidic water (pH < 2) with high concentrations of pollutants which can cause emissions into their surroundings, generating important environmental concerns. Despite many chemical, geological or hydrological studies have been conducted to characterize the PG stacks of Huelva, the microbial community inhabiting this extreme environment remains unexplored. Using a 16S/18S-rRNA-high throughput sequencing approach, we have uncovered the main taxonomic groups able to live in the acidic metal-contaminated water, which is in direct contact with the PG, demonstrating for the first time the existence of a huge diversity of microbial species in these extreme conditions. In addition, the physicochemical characteristics of the water sampled have been analyzed. These studies have revealed that the most abundant bacteria found in two different leachate samples of the PG stacks belong to the genera Acidiphilium, Pseudomonas, Leptosprillum, Acidithrix, or Acidithiobacillus, typically found in acid mine drainage (AMD) environments, which in total represent around 50% of the total bacterial community. Biodiversity of eukaryotes in PG water is lower than that of prokaryotes, especially in the water collected from the perimeter channel that surrounds the PG stacks, where the pH reaches a value of 1.5 and the activity concentrations exceed 300 Bq L-1 for 238U or 20 Bq L-1 for 210Po, values which are from four to five orders of magnitude higher than those usually found in unperturbed surface waters. Even so, an unexpected diversity of algae, fungi, and ciliates have been found in the PG stacks of Huelva, where chlorophyte microalgae and basidiomycetes fungi are the most abundant eukaryotes. Additional bioinformatics tools have been used to perform a functional analysis and predict the most common metabolic pathways in the PG microbiota. The obtained data indicate that the extreme conditions of these PG stacks hide an unexpected microbial diversity, which can play an important role in the dynamics of the contaminating compounds of the PG and provide new strains with unique biotechnological applications.

Validation of a preclinical dry eye model in New Zealand white rabbits during and following topical instillation of 1% ophthalmic atropine sulfate.

BACKGROUND: The objective of this study was to validate an animal model for dry eye during and after the administration of 1% ophthalmic atropine sulfate (OAS) in New Zealand white (NZW) rabbits. METHODS: OAS (1%) was applied three times per day to 30 eyes of 15 healthy NZW rabbits. Sacrifice, enucleation, and lacrimal gland removal took place on days 15, 21, and 30 (OAS group). A second group (n = 5) was used as control. Clinical evaluations took place on days 3, 10, 15, 18, 21, 24 and 30. The primary endpoints were: Schirmer I test, tear break-up time (TBUT), and corneal fluorescein staining. As secondary endpoints, clinical changes including intraocular pressure, and histopathology were evaluated. RESULTS: While OAS was administered, the Schirmer I test showed a statistically significant reduction for OAS group versus control (p < 0.001), and versus basal production (p < 0.001). TBUT showed statistically significant differences between groups (days 3 and 10; p = 0.001) and versus basal values (day 3; p < 0.001). Fluorescein staining showed a statistically significant difference (day 3; p = 0.001). The most frequent clinical finding was conjunctival hyperemia (76.9% OAS vs. 20% control). For histopathology, all OAS subjects presented some degree of inflammation (86.7% minimal; 13.3% mild) whereas the control presented only 30% minimal inflammation. Goblet cell density showed no difference. CONCLUSIONS: The effectiveness of the OAS dry eye model in NZW rabbits as reported in previous studies was confirmed, provided that the application of the drug is maintained throughout the intervention; it is not a viable model after OAS administration is suspended.