Disentangling top-down drivers of mortality underlying diel population dynamics of Prochlorococcus in the North Pacific Subtropical Gyre.

Photosynthesis fuels primary production at the base of marine food webs. Yet, in many surface ocean ecosystems, diel-driven primary production is tightly coupled to daily loss. This tight coupling raises the question: which top-down drivers predominate in maintaining persistently stable picocyanobacterial populations over longer time scales? Motivated by high-frequency surface water measurements taken in the North Pacific Subtropical Gyre (NPSG), we developed multitrophic models to investigate bottom-up and top-down mechanisms underlying the balanced control of Prochlorococcus populations. We find that incorporating photosynthetic growth with viral- and predator-induced mortality is sufficient to recapitulate daily oscillations of Prochlorococcus abundances with baseline community abundances. In doing so, we infer that grazers in this environment function as the predominant top-down factor despite high standing viral particle densities. The model-data fits also reveal the ecological relevance of light-dependent viral traits and non-canonical factors to cellular loss. Finally, we leverage sensitivity analyses to demonstrate how variation in life history traits across distinct oceanic contexts, including variation in viral adsorption and grazer clearance rates, can transform the quantitative and even qualitative importance of top-down controls in shaping Prochlorococcus population dynamics.

Metapopulation model of phage therapy of an acute Pseudomonas aeruginosa lung infection.

Infections caused by multi-drug resistant (MDR) pathogenic bacteria are a global health threat. Phage therapy, which uses phage to kill bacterial pathogens, is increasingly used to treat patients infected by MDR bacteria. However, the therapeutic outcome of phage therapy may be limited by the emergence of phage resistance during treatment and/or by physical constraints that impede phage-bacteria interactions in vivo. In this work, we evaluate the role of lung spatial structure on the efficacy of phage therapy for Pseudomonas aeruginosa infection. To do so, we developed a spatially structured metapopulation network model based on the geometry of the bronchial tree, and included the emergence of phage-resistant bacterial mutants and host innate immune responses. We model the ecological interactions between bacteria, phage, and the host innate immune system at the airway (node) level. The model predicts the synergistic elimination of a P. aeruginosa infection due to the combined effects of phage and neutrophils given sufficiently active immune states and suitable phage life history traits. Moreover, the metapopulation model simulations predict that local MDR pathogens are cleared faster at distal nodes of the bronchial tree. Notably, image analysis of lung tissue time series from wild-type and lymphocyte-depleted mice (n=13) revealed a concordant, statistically significant pattern: infection intensity cleared in the bottom before the top of the lungs. Overall, the combined use of simulations and image analysis of in vivo experiments further supports the use of phage therapy for treating acute lung infections caused by P. aeruginosa while highlighting potential limits to therapy given a spatially structured environment, such as impaired innate immune responses and low phage efficacy.

Macrophage-induced reduction of bacteriophage density limits the efficacy of in vivo pulmonary phage therapy.

The rise of antimicrobial resistance has led to renewed interest in evaluating phage therapy. In murine models highly effective treatment of acute pneumonia caused by Pseudomonas aeruginosa relies on the synergistic antibacterial activity of bacteriophages with neutrophils. Here, we show that depletion of alveolar macrophages (AM) shortens the survival of mice without boosting the P. aeruginosa load in the lungs. Unexpectedly, upon bacteriophage treatment, pulmonary levels of P. aeruginosa were significantly lower in AM-depleted than in immunocompetent mice. To explore potential mechanisms underlying the benefit of AM-depletion in treated mice, we developed a mathematical model. Integration of model simulations suggest that AM reduce bacteriophage density in the lungs. We experimentally confirmed that the in vivo decay of phage is faster in immunocompetent compared to AM-depleted animals. These findings demonstrate the involvement of feedback between bacteriophage, bacteria, and the immune system in shaping the outcomes of phage therapy in clinical settings.

DNA oxidative damage in oral cancer: 8-hydroxy-2´-deoxyguanosine immunoexpression assessment

Background: The development and establishment of oral squamous cell carcinoma are confined to carcinogenesis, which involves oxidative stress via oxygen-free radical production as a hydroxyl radical (HO•), considered the most important cause of oxidative damage to basic biomolecules since it targets DNA strands. 8-Hydroxy-2´- deoxyguanosine (8-OHdG) is considered a free radical with a promutagenic capacity due to its ability to pair with adenosine instead of cytosine during replication. Material and Methods: We collected 30 paraffin-embedded tissue samples of OSCC from patients treated between 2013 and 2018. We recorded risk habits, disease stage, disease free survival and death with at least 3 years of followup. 8-Hydroxyguanosine was evaluated by immunohistochemistry and subsequently classified as weak-moderate or strong positive expression. Additionally, we noted whether it was expressed in the cytoplasm and/or nucleus. Results: Most of the cases expressed 8-OHdG with a strong intensity (80%). All neoplastic cells were preferentially stained in only the cytoplasm (70.0%), but nuclear positivity was found in 30%, independent of the intensity. Based on the location in the cytoplasm and/or nucleus, tumors >4 cm showed a high frequency (95.5%) of 8-OHdG expression in only the cytoplasm, with a significant difference (p value ≤ 0.001). Additionally, overall survival was affected when immunoexpression was present in the cytoplasm and nucleus because all deaths were in this group were statistically significant (p value = 0.001). Conclusions: All tumors showed DNA oxidative damage, and 8-OHdG was preferentially expressed in the cytoplasm. This finding was associated with tumor size and, when present in the nucleus, might also be related to death. (AU)

Selection of Salinity-Adapted Endorhizal Fungal Consortia from Two Inoculum Sources and Six Halophyte Plants.

Soil salinity is a limiting factor in crop productivity. Inoculating crops with microorganisms adapted to salt stress is an alternative to increasing plant salinity tolerance. Few studies have simultaneously propagated arbuscular mycorrhizal fungi (AMF) and dark septate fungi (DSF) using different sources of native inoculum from halophyte plants and evaluated their effectiveness. In alfalfa plants as trap culture, this study assessed the infectivity of 38 microbial consortia native from rhizosphere soil (19) or roots (19) from six halophyte plants, as well as their effectiveness in mitigating salinity stress. Inoculation with soil resulted in 26-56% colonization by AMF and 12-32% by DSF. Root inoculation produced 10-56% and 8-24% colonization by AMF and DSF, respectively. There was no difference in the number of spores of AMF produced with both inoculum types. The effective consortia were selected based on low Na but high P and K shoot concentrations that are variable and are relevant for plant nutrition and salt stress mitigation. This microbial consortia selection may be a novel and applicable model, which would allow the production of native microbial inoculants adapted to salinity to diminish the harmful effects of salinity stress in glycophyte plants in the context of sustainable agriculture.

Artificial Intelligence for Image Analysis in Oral Squamous Cell Carcinoma: A Review.

Head and neck tumor differential diagnosis and prognosis have always been a challenge for oral pathologists due to their similarities and complexity. Artificial intelligence novel applications can function as an auxiliary tool for the objective interpretation of histomorphological digital slides. In this review, we present digital histopathological image analysis applications in oral squamous cell carcinoma. A literature search was performed in PubMed MEDLINE with the following keywords: "artificial intelligence" OR "deep learning" OR "machine learning" AND "oral squamous cell carcinoma". Artificial intelligence has proven to be a helpful tool in histopathological image analysis of tumors and other lesions, even though it is necessary to continue researching in this area, mainly for clinical validation.

Consenso SOCHOG/SOCHUMB: utilizar en Chile la curva estándar OMS ultrasonográfica de crecimiento fetal / SOCHOG/SOCHUMB consensus: OMS fetal ultrasound curve is the standard curve for ultrasound growth assessment to use in Chile

La Sociedad Chilena de Obstetricia y Ginecología (SOCHOG) y la Sociedad Chilena de Ultrasonido en Medicina y Biología (SOCHUMB) convocaron a un comité de expertos en el tema de ultrasonido y crecimiento fetal con el fin de proponer utilizar la curva fetal que mejor se adapte a la población chilena. Luego de la discusión, al no contar con curvas chilenas de crecimiento fetal, se concluye proponer que la curva estándar de la Organización Mundial de la Salud (OMS) sería la indicada dada la calidad de su metodología y por ser multicéntrica.

The Chilean Society of Obstetrics and Gynecology (SOCHOG) and the Chilean Society of Ultrasound in Medicine and Biology (SOCHUMB) have convened a committee of experts on the subject of ultrasound and fetal growth in order to propose using the fetal curve that best adapts to the Chilean population. After the discussion, since there are no Chilean fetal growth curves, it is concluded that the World Health Organization (WHO) standard curve would be the one to use given the quality of its methodology and the fact that it is multicentric.

Citrate-coated cobalt ferrite nanoparticles for the nano-enabled biofortification of wheat.

A pot experiment was conducted in an open greenhouse to explore the use of citrate-coated cobalt ferrite nanoparticles (CoFe2O4 NPs) as a source for Fe fortification of three wheat lines (Triticum aestivum L.). Two of the three wheat lines tested differ in their efficiency concerning Zn storage in their grains (efficient and inefficient), and one had inefficient P-absorption. The NPs were supplied by foliar or soil application of Fe at 330 mg L-1, and 46 or 68 mg kg-1 soil, respectively. A positive control (Fe-EDTA salt, a conventional iron fertilizer) and a negative control (no fertilization) were also included to compare the efficiency of NP fertilization. Soil fertilization with NPs improved the grain yield and Fe concentration in the grains compared with the foliar application of NPs and conventional Fe fertilizer. Application of soil NPs at 68 mg kg-1 increased the grain yield by 52% and 21% compared with the control and soil Fe-EDTA treatments, respectively. Likewise, grain Fe concentration increased by 96% and 72% compared with the control and soil Fe-EDTA treatments, respectively. The phytic acid concentration in grains and the phytic acid:Fe ratio decreased by 6% and 62%, respectively, due to the soil application of NPs (68 mg Fe per kg). The Fe grain concentration of lines inefficient for Zn storage and P-uptake in plants from soil fertilized with NPs (68 mg Fe per kg) was 1.37 and 0.26 fold above the target biofortification concentration (60 mg Fe per kg). Cobalt concentration in grains ranged from 9 to 16 mg kg-1. These concentrations were below the maximum allowable limit of Co in grains (50 mg kg-1) recommended by FAO and the WHO. Our results showed that Fe supplied as NPs may improve the nutritional quality of wheat grains, and the economic yield. However, there remains a long way to go to achieve effective and economic use of nanotechnology for the nutritional development of wheat.

Connexin 43 expression in tooth germ and benign odontogenic tumors.

OBJECTIVE: The aim of this study was to investigate and compare the immunohistochemical expression of connexin 43 (Cx43) in tooth germs (TGs), ameloblastic fibromas (AFs), ameloblastic fibro-odontomas (AFOs), and conventional ameloblastomas (AMs). STUDY DESIGN: Nine TGs, 12 AFs, 12 AFOs, and 27 AMs were evaluated for Cx43 expression by immunohistochemistry. RESULTS: Most of the TGs expressed Cx43 in the mesenchyme (77.6%) and in the late stages of odontogenesis. Cx43 was more highly expressed (P < .05) in the mesenchymal layer of all groups than in the epithelial layer except for the AFOs. When comparing the expression of Cx43 in the different layers of the analyzed groups, statistically significant differences were observed between AFO vs AM (*P = .0158) in the epithelial layer and between AF vs AFO (P** = .0046) in the mesenchymal layer. CONCLUSIONS: The results obtained in this study showed that Cx43 is a protein with important expression in the mesenchymal layer of the embryonic and odontogenic tissues studied. It could be speculated that Cx43 participates in mineralization events based on the relationship of the expression of this protein between the epithelial and mesenchymal layers of odontogenic tissues.

Starting from scratch: Step-by-step development of diagnostic tests for SARS-CoV-2 detection by RT-LAMP.

The pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected millions of people worldwide. Public health strategies to reduce viral transmission are based on widespread diagnostic testing to detect and isolate contagious patients. Several reverse transcription (RT)-PCR tests, along with other SARS-CoV-2 diagnostic assays, are available to attempt to cover the global demand. Loop-mediated isothermal amplification (LAMP) based methods have been established as rapid, accurate, point of care diagnostic tests for viral infections; hence, they represent an excellent alternative for SARS-CoV-2 detection. The aim of this study was to develop and describe molecular detection systems for SARS-CoV-2 based on RT-LAMP. Recombinant DNA polymerase from Bacillus stearothermophilus and thermostable engineered reverse transcriptase from Moloney Murine Leukemia Virus were expressed using a prokaryotic system and purified by fast protein liquid chromatography. These enzymes were used to set up fluorometric real time and colorimetric end-point RT-LAMP assays. Several reaction conditions were optimized such as reaction temperature, Tris-HCl concentration, and pH of the diagnostic tests. The key enzymes for RT-LAMP were purified and their enzymatic activity was determined. Standardized reaction conditions for both RT-LAMP assays were 65°C and a Tris-HCl-free buffer at pH 8.8. Colorimetric end-point RT-LAMP assay was successfully used for viral detection from clinical saliva samples with 100% sensitivity and 100% specificity compared to the results obtained by RT-qPCR based diagnostic protocols with Ct values until 30. The developed RT-LAMP diagnostic tests based on purified recombinant enzymes allowed a sensitive and specific detection of the nucleocapsid gene of SARS-CoV-2.

A Systematic Review and Meta-Analysis of the Relationship Between the Severity of Dental Fluorosis and Fluoride Biomarkers in Endemic Areas.

The intake of high concentrations of fluoride, mainly through drinking water, diet and fluoridated dentifrices, produces fluorosis, which in its early stages is manifested as dental fluorosis (DF). To recognize exposure to fluoride in endemic areas and to evaluate the risk of developing health impairment, the WHO has established several biomarkers that are used to determine systemic fluorine (F-) exposure. Thus, the aim of this study was to conduct a systematic review and meta-analysis of the relationship between the severity of DF and fluoride biomarkers in endemic areas. The protocol of this study was previously registered as CRD42021244974. A digital search was carried out in PubMed/Medline, SpringerLink, Scopus, Cochrane and Google Scholar by employing the keywords "urine", "nails", "hair", "plasma", "saliva" and "dental fluorosis" for the original studies with content associated with F- for the biomarkers and DF. The mean difference was established as the effect measure for the meta-analysis. Seven studies fulfilled the eligibility criteria, among which five assessed urine and two employed nails as fluoride biomarkers. A positive significant difference was found between the biomarkers and the severity of DF (0.27, p < 0.001) and individually for each biomarker (urine: 0.14, p = 0.001; nails: 0.88, p < 0.05). The F- concentration in urine and nails is correlated with the severity of DF, with the most evident differences between healthy individuals and those with mild severity. Both biomarkers are adequate to assess this relationship in endemic areas of fluoride and DF.

Modeling shield immunity to reduce COVID-19 transmission in long-term care facilities.

PURPOSE: Nursing homes and long-term care facilities have experienced severe outbreaks and elevated mortality rates of COVID-19. When available, vaccination at-scale has helped drive a rapid reduction in severe cases. However, vaccination coverage remains incomplete among residents and staff, such that additional mitigation and prevention strategies are needed to reduce the ongoing risk of transmission. One such strategy is that of "shield immunity", in which immune individuals modulate their contact rates and shield uninfected individuals from potentially risky interactions. METHODS: Here, we adapt shield immunity principles to a network context, by using computational models to evaluate how restructured interactions between staff and residents affect SARS-CoV-2 epidemic dynamics. RESULTS: First, we identify a mitigation rewiring strategy that reassigns immune healthcare workers to infected residents, significantly reducing outbreak sizes given weekly testing and rewiring (48% reduction in the outbreak size). Second, we identify a preventative prewiring strategy in which susceptible healthcare workers are assigned to immunized residents. This preventative strategy reduces the risk and size of an outbreak via the inadvertent introduction of an infectious healthcare worker in a partially immunized population (44% reduction in the epidemic size). These mitigation levels derived from network-based interventions are similar to those derived from isolating infectious healthcare workers. CONCLUSIONS: This modeling-based assessment of shield immunity provides further support for leveraging infection and immune status in network-based interventions to control and prevent the spread of COVID-19.

Periodontal Disease in Obese Patients; Interleukin-6 and C-Reactive Protein Study: A Systematic Review.

Periodontal disease (PD) and obesity are characterized by a dysregulated inflammatory state. Both conditions trigger inflammatory and immune responses with an increase in proinflammatory cytokines such as Interleukin 6 (IL-6) and the release of inflammatory mediators such as C-reactive protein (CRP). Individuals with a high body mass index (BMI) present a chronic inflammatory state. The aim of the present study was to perform a systematic review of inflammatory markers (IL-6 and CRP) in obese patients with PD and their possible relationship by analyzing the levels of these markers. A digital literature search was performed in three databases-PubMed, SciElo and Medigraphic-through an advanced search for original articles, employing IL-6 and CRP in obese patients with PD, within a publication period from 2010 to 2021. PRISMA guidelines, the JADAD scale and a qualitative analysis of scientific evidence were performed using the Cochrane collaboration method and the RoB 2 assessment tool. Ten articles were included in this analysis with the variables recorded and associated with subjects with obesity and PD. Of the ten articles included, three analyzed IL-6 and CRP, four analyzed IL-6 and three analyzed CRP. In conclusion, and based on the available evidence, the aforementioned markers of inflammation demonstrate that there is a relationship between PD and obesity.

Ep-CAM (MOC-31) expression in tooth germ and ameloblastoma

Background: Ep-CAM, a transmembrane glycoprotein expressed in most epithelium in normal conditions, hasdiverse roles in these tissues, including in cell adhesion, proliferation, differentiation, cell cycle regu-lation, migration and intracellular signaling. It is also over-expressed in most malignant neoplasia, partic-ipating in theinitiation, progression, and metastatic dissemination of the tumor. The expression and roles of this protein in oralneoplasia, particularly in odontogenic tumors, remain unestablished. The objective of this study consisted in analyzing the expression of this protein in ameloblastoma and tooth germ.Material and Methods: Ep-CAM (MOC-31) expression was evaluated by immunohistochemistry in tooth germs(TG) (n = 16) ameloblastomas (AM) (n = 60) and 2 ameloblastic carcinomas. Sections were visualized in theirtotality with an optical microscope, and positivity observed in cell membrane and cytoplasm was graded according to the following semi-quantitative scale: Neg, "essentially unstained", for negative sections or staining <5% ofcells; + for staining of 5-50% of cells; ++ for staining >50% of cells.Results: Most tooth germs expressed MOC-31 (81.3%), strong staining was observed both in the inner epitheliumof the enamel organ and in the adjacent stellate reticulum. 16.7% of the AM cases showed MOC-31 expression,the immunoexpression expression was diffuse at the cytoplasmic and membrane level. The only two cases ofameloblastic carcinoma included were strong positive to MOC-31. No correlation was observed between proteinexpression and gender, age, clinical variants, or histological subtypes.Conclusions: Overexpression was found in TG and ameloblastic carcinoma compared to AM; further studies withdifferent experimental strategies are suggested to clarify the biological significance of this finding. (AU)

Self-Reported Periodontal Disease and Its Association with SARS-CoV-2 Infection.

Introduction: Knowledge of the oral manifestations associated with SARS-CoV-2 infection, the new coronavirus causing the COVID-19 pandemic, was hindered due to the restrictions issued to avoid proximity between people and to stop the rapid spread of the disease, which ultimately results in a hyperinflammatory cytokine storm that can cause death. Because periodontal disease is one of the most frequent inflammatory diseases of the oral cavity, various theories have emerged postulating periodontal disease as a risk factor for developing severe complications associated with COVID-19. This motivated various studies to integrate questions related to periodontal status. For the present work, we used a previously validated self-report, which is a useful tool for facilitating epidemiological studies of periodontal disease on a large scale. Methodology: A blinded case-control study with participants matched 1:1 by mean age (37.7 years), sex, tobacco habits and diseases was conducted. After the diagnostic samples for SARS-CoV-2 detection were taken in an ad hoc location at Guadalajara University, the subjects were interviewed using structured questionnaires to gather demographic, epidemiological and COVID-19 symptom information. The self-reported periodontal disease (Self-RPD) questionnaire included six questions, and subjects who met the criteria with a score ≥ 2 were considered to have periodontal disease. Results: In total, 369 participants were recruited, with 117 participants included in each group. After indicating the subjects who had self-reported periodontal disease, a statistically significant difference (p value ≤ 0.001) was observed, showing that self-reported periodontal disease (n = 95, 85.1%) was higher in SARS-CoV-2-positive individuals than in controls (n = 66, 56.4%), with an OR of 3.3 (1.8-6.0) for SARS-CoV-2 infection in people with self-reported periodontal disease. Cases reported a statistically higher median of symptoms (median = 7.0, Q1= 5.5, Q3 = 10.0) than controls (p value ≤ 0.01), and cases with positive self-RPD had a significantly (p value ≤ 0.05) higher number of symptoms (median = 8.0, Q1 = 6.0, Q3 = 10.0) in comparison with those who did negative self-RPD (median = 6.0, Q1 = 5.0, Q3 = 8.0). Conclusions: According to this study, self-reported periodontal disease could be considered a risk factor for SARS-CoV-2 infection, and these individuals present more symptoms.

Vigilancia de la resistencia a los antimicrobianos en cepas de Neisseria gonorrhoeae aisladas en Paraguay. Año 2021

Neisseria gonorrhoeae (N. gonorrhoeae) es el agente causal de la gonorrea, infección de transmisión sexual (ITS) que corresponde a la segunda causa más frecuente de ITS a nivel mundial, provocando una alta morbilidad y costo en atención de salud. En las últimas décadas han aumentado los reportes a nivel mundial de cepas resistentes a penicilina, sulfonamidas, tetraciclina, macrólidos y fluoroquinolonas, y más recientemente a azitromicina y cefalosporinas de espectro extendido como ceftriaxona y cefixima. El objetivo principal de este estudio fue determinar la sensibilidad a los antimicrobianos en cepas de N. gonorrhoeae que fueron enviadas al Laboratorio Central de Salud Pública (LCSP), por los centros colaboradores de la Red de Vigilancia Laboratorial de la Resistencia a los Antimicrobianos (RAM). Para ello, se realizó un estudio prospectivo de corte transversal de enero a diciembre de 2021. Se caracterizaron 128 cepas como N. gonorrhoeae a las cuales se le realizaron pruebas de susceptibilidad obteniéndose 48% de resistencia y 52% de sensibilidad intermedia a penicilina. El 70% presentó resistencia a ciprofloxacina y el 19% a tetraciclina. Se obtuvo 100% de sensibilidad a ceftriaxona y cefixima. El fenotipo de resistencia de mayor prevalencia fue QRNG, asociado con resistencia a ciprofloxacina, seguido del fenotipo PPNG-QRNG, asociado con resistencia a penicilina y ciprofloxacina. Ante estos hallazgos y frente a la emergencia mundial de la resistencia a los antimicrobianos, especialmente de cefalosporinas de espectro extendido, se recomienda que los laboratorios de bacteriología fortalezcan la vigilancia para apoyar la detección de casos y proporcionar el tratamiento adecuado.

Neisseria gonorrhoeae (N. gonorrhoeae) is the causal agent of gonorrhea, a sexually transmitted infection (STI) that is the second most common cause of STIs worldwide, causing high morbidity and cost in health care. In recent decades, reports of strains resistant to penicillin, fluoroquinolones, sulfonamides, tetracycline, macrolides, and more recently to azithromycin and extended-spectrum cephalosporins such as ceftriaxone and cefixime have increased worldwide. The main objective of this study was to determine the sensitivity to antimicrobials in N. gonorrhoeae strains that were sent to the Central Laboratory of Public Health (LCSP), by the collaborating centers of the Antimicrobial Resistance Laboratory Surveillance Network (RAM). For this, a prospective cross-sectional study was carried out from January to December, 2021. One hundred eighty strains were characterized as N. gonorrhoeae, which were subjected to sensitivity tests, obtaining 48% resistance and 52% intermediate sensitivity to penicillin while 70% presented resistance to ciprofloxacin and 19% to tetracycline. Also, 100% sensitivity to ceftriaxone and cefixime was obtained. The most prevalent resistance phenotype was QRNG, associated with resistance to ciprofloxacin, followed by the PPNG-QRNG phenotype, associated with resistance to penicillin and ciprofloxacin. Given these findings and the global emergence of antimicrobial resistance, especially extended-spectrum cephalosporins, it is recommended that bacteriology laboratories fortify surveillance to support case detection and provide appropriate treatment.

Combined Subcutaneous-Intranasal Immunization With Epitope-Based Antigens Elicits Binding and Neutralizing Antibody Responses in Serum and Mucosae Against PRRSV-2 and SARS-CoV-2.

New vaccine design approaches, platforms, and immunization strategies might foster antiviral mucosal effector and memory responses to reduce asymptomatic infection and transmission in vaccinated individuals. Here, we investigated a combined parenteral and mucosal immunization scheme to induce local and serum antibody responses, employing the epitope-based antigens 3BT and NG19m. These antigens target the important emerging and re-emerging viruses PRRSV-2 and SARS-CoV-2, respectively. We assessed two versions of the 3BT protein, which contains conserved epitopes from the GP5 envelope protein of PRRSV-2: soluble and expressed by the recombinant baculovirus BacDual-3BT. On the other hand, NG19m, comprising the receptor-binding motif of the S protein of SARS-CoV-2, was evaluated as a soluble recombinant protein only. Vietnamese mini-pigs were immunized employing different inoculation routes: subcutaneous, intranasal, or a combination of both (s.c.-i.n.). Animals produced antigen-binding and neut1ralizing antibodies in serum and mucosal fluids, with varying patterns of concentration and activity, depending on the antigen and the immunization schedule. Soluble 3BT was a potent immunogen to elicit binding and neutralizing antibodies in serum, nasal mucus, and vaginal swabs. The vectored immunogen BacDual-3BT induced binding antibodies in serum and mucosae, but PRRSV-2 neutralizing activity was found in nasal mucus exclusively when administered intranasally. NG19m promoted serum and mucosal binding antibodies, which showed differing neutralizing activity. Only serum samples from subcutaneously immunized animals inhibited RBD-ACE2 interaction, while mini-pigs inoculated intranasally or via the combined s.c.-i.n. scheme produced subtle neutralizing humoral responses in the upper and lower respiratory mucosae. Our results show that intranasal immunization, alone or combined with subcutaneous delivery of epitope-based antigens, generates local and systemic binding and neutralizing antibodies. Further investigation is needed to evaluate the capability of the induced responses to prevent infection and reduce transmission.

Trace element adsorption from acid mine drainage and mine residues on nanometric hydroxyapatite.

Mining Ag, Cu, Pb, and Zn sulfides by flotation produces great volume of residues, which oxidized through time and release acid solutions. Leachates from tailing heaps are a concern due to the risk of surface water pollution. Hydroxyapatite nanoparticles may remove trace elements from acid leachate collected from an oxidized tailing heap (pH ranged 1.69 ± 0.3 to 2.23 ± 0.16; [SO42-] = 58 ± 0.67 to 60.69 ± 0.39 mmol). Based on the batch experiments under standard conditions, the average removal efficiency was 96%, 92%, 86%, and 67% for Cd, Pb, Zn, and Cu, respectively. The Zn adsorption was modeled by the Freundlich equation, but Cd, Cu, and Pb isotherms do not fit to Freundlich nor Lagmuir equations. Adsorption and other mechanisms occur during trace elements removal by hydroxyapatite. In the polymetallic system, trace elements saturate the specific surface of hydroxyapatite in the following order Zn, Cd, Cu, and Pb. The pH values must be higher than 7.5 to adsorb trace elements. The dose of 3.8% of hydroxyapatite to acid mine drainage removed efficiently > 80% of the soluble Fe, Cu, Mn, Zn, Cd, Ni, and Pb: 4020.0, 37.3, 34.8, 432.0, 4.4, 0.7, and 0.11 mg L-1 from leachate A and 3357.1, 46.6, 27.8, 569.0, 4.7, 0.6, and 1.7 from leachate B, respectively. The application of 0.7% of hydroxyapatite decreased the extractable Pb in unoxidized tailing heaps from 272 to 100 mg kg-1. It is likely to use hydroxyapatite to control trace element mobility from mine residues to surrounding soils and surface water.