DNA methylation impacts soybean early development by modulating hormones and metabolic pathways.

Genomic DNA methylation patterns play a crucial role in the developmental processes of plants and mammals. In this study, we aimed to investigate the significant effects of epigenetic mechanisms on the development of soybean seedlings and metabolic pathways. Our analyses show that 5-azaC-treatment affects radicle development from two Days After Imbibition (DAI), as well as both shoot and root development. We examined the expression levels of key genes related to DNA methylation and demethylation pathways, such as DRM2, which encodes RNA-directed DNA Methylation (RdDM) pathway, SAM synthase, responsible for methyl group donation, and ROS1, a DNA demethylase. In treated seedling roots, we observed an increase in DRM2 expression and a decrease in ROS1 expression. Additionally, 5-azaC treatment altered protein accumulation, indicating epigenetic control over stress response while inhibiting nitrogen assimilation, urea cycle, and glycolysis-related proteins. Furthermore, it influenced the levels of various phytohormones and metabolites crucial for seedling growth, such as ABA, IAA, ethylene, polyamines (PUT and Cad), and free amino acids, suggesting that epigenetic changes may shape soybean responses to pathogens, abiotic stress, and nutrient absorption. Our results assist in understanding how hypomethylation shapes soybean responses to pathogens, abiotic stress, and nutrient absorption crucial for seedling growth, suggesting that the plant's assimilation of carbon and nitrogen, along with hormone pathways, may be influenced by epigenetic changes.

Giants of the Amazon: How does environmental variation drive the diversity patterns of large trees?

For more than three decades, major efforts in sampling and analyzing tree diversity in South America have focused almost exclusively on trees with stems of at least 10 and 2.5 cm diameter, showing highest species diversity in the wetter western and northern Amazon forests. By contrast, little attention has been paid to patterns and drivers of diversity in the largest canopy and emergent trees, which is surprising given these have dominant ecological functions. Here, we use a machine learning approach to quantify the importance of environmental factors and apply it to generate spatial predictions of the species diversity of all trees (dbh ≥ 10 cm) and for very large trees (dbh ≥ 70 cm) using data from 243 forest plots (108,450 trees and 2832 species) distributed across different forest types and biogeographic regions of the Brazilian Amazon. The diversity of large trees and of all trees was significantly associated with three environmental factors, but in contrasting ways across regions and forest types. Environmental variables associated with disturbances, for example, the lightning flash rate and wind speed, as well as the fraction of photosynthetically active radiation, tend to govern the diversity of large trees. Upland rainforests in the Guiana Shield and Roraima regions had a high diversity of large trees. By contrast, variables associated with resources tend to govern tree diversity in general. Places such as the province of Imeri and the northern portion of the province of Madeira stand out for their high diversity of species in general. Climatic and topographic stability and functional adaptation mechanisms promote ideal conditions for species diversity. Finally, we mapped general patterns of tree species diversity in the Brazilian Amazon, which differ substantially depending on size class.

Flagellin and mannitol modulate callose biosynthesis and deposition in soybean seedlings.

Callose is a polymer deposited on the cell wall and is necessary for plant growth and development. Callose is synthesized by genes from the glucan synthase-like family (GSL) and dynamically responds to various types of stress. Callose can inhibit pathogenic infection, in the case of biotic stresses, and maintain cell turgor and stiffen the plant cell wall in abiotic stresses. Here, we report the identification of 23 GSL genes (GmGSL) in the soybean genome. We performed phylogenetic analyses, gene structure prediction, duplication patterns, and expression profiles on several RNA-Seq libraries. Our analyses show that WGD/Segmental duplication contributed to expanding this gene family in soybean. Next, we analyzed the callose responses in soybean under abiotic and biotic stresses. The data show that callose is induced by both osmotic stress and flagellin 22 (flg22) and is related to the activity of ß-1,3-glucanases. By using RT-qPCR, we evaluated the expression of GSL genes during the treatment of soybean roots with mannitol and flg22. The GmGSL23 gene was upregulated in seedlings treated with osmotic stress or flg22, showing the essential role of this gene in the soybean defense response to pathogenic organisms and osmotic stress. Our results provide an important understanding of the role of callose deposition and regulation of GSL genes in response to osmotic stress and flg22 infection in soybean seedlings.

Cytotoxicity, biocompatibility and osteoinductive profile of an MTA-hydrogel-based cement: An in vitro and animal study.

AIM: This study aimed to evaluate the cytotoxicity, biocompatibility and osteoinductive profile of a mineral trioxide aggregate (MTA)-hydrogel-based material (MTA Flow) in comparison with MTA Angelus. METHODOLOGY: Cell viability was evaluated in human periodontal ligament stem cells (hPDLSCs) using the methyl-thiazol-tetrazolium (MTT) colourimetric assay. Polyethylene tubes containing the tested materials and empty polyethylene tubes (control) were implanted in the subcutaneous tissue of Wistar rats. Cellular (lymphocyte infiltration) and extracellular events (ECM; collagen fibres) were analysed in histological sections. Immunohistochemical (collagen I, osteopontin, bone sialoprotein, bone morphogenetic protein4) analyses were also performed. RESULTS: At 24, 48 and 72 h, all tested groups showed cell viability similar to control (p > .05). Regarding biocompatibility, all groups showed similar cellular events represented by a slight inflammatory reaction characterized by hyperaemia and a mild lymphocytic inflammatory infiltrate. The analysis of lymphocytes during the time showed a decrease in these cells in the control group and a significant interaction between MTA Angelus and control (p < .001), with MTA Angelus showing a more extensive inflammatory infiltrate. Regarding fibres, an increase in content was observed in all groups during the experimental time (7, 30 and 60 days), however, no difference was detected among the experimental groups (p = .063). After 60 days, the immunoexpression of bone matrix proteins in the MTA Flow group was similar to or higher than that observed in the MTA Angelus and in the control group. CONCLUSIONS: MTA Flow showed a non-cytotoxic behaviour, biocompatibility and ability to stimulate tissue mineralization.

cis-Aconitic Acid, a Constituent of Echinodorus grandiflorus Leaves, Inhibits Antigen-Induced Arthritis and Gout in Mice.

cis-Aconitic acid is a constituent from the leaves of Echinodorus grandiflorus, a medicinal plant traditionally used in Brazil to treat inflammatory conditions, including arthritic diseases. The present study aimed to investigate the anti-arthritic effect of cis-aconitic acid in murine models of antigen-induced arthritis and monosodium urate-induced gout. The possible underlying mechanisms of action was evaluated in THP-1 macrophages. Oral treatment with cis-aconitic acid (10, 30, and 90 mg/kg) reduced leukocyte accumulation in the joint cavity and C-X-C motif chemokine ligand 1 and IL-1ß levels in periarticular tissue. cis-Aconitic acid treatment reduced joint inflammation in tissue sections of antigen-induced arthritis mice and these effects were associated with decreased mechanical hypernociception. Administration of cis-aconitic acid (30 mg/kg p. o.) also reduced leukocyte accumulation in the joint cavity after the injection of monosodium urate crystals. cis-Aconitic acid reduced in vitro the release of TNF-α and phosphorylation of IκBα in lipopolysaccharide-stimulated THP-1 macrophages, suggesting that inhibition of nuclear factor kappa B activation was an underlying mechanism of cis-aconitic acid-induced anti-inflammatory effects. In conclusion, cis-aconitic acid has significant anti-inflammatory effects in antigen-induced arthritis and monosodium urate-induced arthritis in mice, suggesting its potential for the treatment of inflammatory diseases of the joint in humans. Additionally, our findings suggest that this compound may contribute to the anti-inflammatory effect previously reported for E. grandiflorus extracts.

Systematic analysis of 1298 RNA-Seq samples and construction of a comprehensive soybean (Glycine max) expression atlas.

Soybean (Glycine max [L.] Merr.) is a major crop in animal feed and human nutrition, mainly for its rich protein and oil contents. The remarkable rise in soybean transcriptome studies over the past 5 years generated an enormous amount of RNA-seq data, encompassing various tissues, developmental conditions and genotypes. In this study, we have collected data from 1298 publicly available soybean transcriptome samples, processed the raw sequencing reads and mapped them to the soybean reference genome in a systematic fashion. We found that 94% of the annotated genes (52 737/56 044) had detectable expression in at least one sample. Unsupervised clustering revealed three major groups, comprising samples from aerial, underground and seed/seed-related parts. We found 452 genes with uniform and constant expression levels, supporting their roles as housekeeping genes. On the other hand, 1349 genes showed heavily biased expression patterns towards particular tissues. A transcript-level analysis revealed that 95% (70 963 of 74 490) of the assembled transcripts have intron chains exactly matching those from known transcripts, whereas 3256 assembled transcripts represent potentially novel splicing isoforms. The dataset compiled here constitute a new resource for the community, which can be downloaded or accessed through a user-friendly web interface at http://venanciogroup.uenf.br/resources/. This comprehensive transcriptome atlas will likely accelerate research on soybean genetics and genomics.

Metabolic activity of hydro-carbon-oxo-borate on a multispecies subgingival periodontal biofilm: a short communication.

OBJECTIVE: This study evaluated the metabolic activity of hydro-carbon-oxo-borate complex (HCOBc) on a multispecies subgingival biofilm as well as its effects on cytotoxicity. MATERIALS AND METHODS: The subgingival biofilm with 32 species related to periodontitis was formed in the Calgary Biofilm Device (CBD) for 7 days. Two different therapeutic schemes were adopted: (1) treatment with HCOBc, 0.12% chlorhexidine (CHX), and negative control group (without treatment) from day 3 until day 6, two times a day for 1 min each time, totaling 8 treatments and (2) a 24-h treatment on a biofilm grown for 6 days. After 7 days of formation, biofilm metabolic activity was determined by colorimetry assay, and bacterial counts and proportions of complexes were determined by DNA-DNA hybridization. Both substances' cytotoxicity was evaluated by cell viability (XTT assay) and clonogenic survival assay on ovary epithelial CHO-K1 cells and an osteoblast precursor from calvaria MC3T3-E1 cells. RESULTS: The first treatment scheme resulted in a significant reduction in biofilm's metabolic activity by means of 77% by HCOBc and CHX treatments versus negative control. The total count of 11 and 25 species were decreased by treatment with hydro-carbon-oxo-borate complex and CHX, respectively, compared with the group without treatment (p < 0.05), highlighting a reduction in the levels of Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, and Fusobacterium periodontium. CHX significantly reduced the count of 10 microorganisms compared to the group treated with HCOBc (p < 0.05). HCOBc and CHX significantly decreased the pathogenic red-complex proportion compared with control-treated biofilm, and HCOBc had even a more significant effect on the red complex than CHX had (p ≤ 0.05). For the second treatment scheme, HCOBc complex and CHX significantly decreased 61 and 72% of control biofilms' metabolic activity and the counts of 27 and 26 species, respectively. HCOBc complex did not significantly affect the proportions of formed biofilms, while CHX significantly reduced red, orange, and yellow complexes. Both substances exhibited similar cytotoxicity results. CONCLUSIONS: This short communication suggested that the HCOBc complex reduced a smaller number of bacterial species when compared to chlorhexidine during subgingival biofilm formation, but it was better than chlorhexidine in reducing red-complex bacterial proportions. Although HCOBc reduced the mature 6-day-old subgingival multispecies biofilms, it did not modify bacterial complexes' ratios as chlorhexidine did on the biofilms mentioned above. Future in vivo studies are needed to validate these results. CLINICAL RELEVANCE: HCOBc complex could be used to reduce red-complex periodontal bacterial proportions.

Xq22 deletions and correlation with distinct neurological disease traits in females: Further evidence for a contiguous gene syndrome.

Xq22 deletions that encompass PLP1 (Xq22-PLP1-DEL) are notable for variable expressivity of neurological disease traits in females ranging from a mild late-onset form of spastic paraplegia type 2 (MIM# 312920), sometimes associated with skewed X-inactivation, to an early-onset neurological disease trait (EONDT) of severe developmental delay, intellectual disability, and behavioral abnormalities. Size and gene content of Xq22-PLP1-DEL vary and were proposed as potential molecular etiologies underlying variable expressivity in carrier females where two smallest regions of overlap (SROs) were suggested to influence disease. We ascertained a cohort of eight unrelated patients harboring Xq22-PLP1-DEL and performed high-density array comparative genomic hybridization and breakpoint-junction sequencing. Molecular characterization of Xq22-PLP1-DEL from 17 cases (eight herein and nine published) revealed an overrepresentation of breakpoints that reside within repeats (11/17, ~65%) and the clustering of ~47% of proximal breakpoints in a genomic instability hotspot with characteristic non-B DNA density. These findings implicate a potential role for genomic architecture in stimulating the formation of Xq22-PLP1-DEL. The correlation of Xq22-PLP1-DEL gene content with neurological disease trait in female cases enabled refinement of the associated SROs to a single genomic interval containing six genes. Our data support the hypothesis that genes contiguous to PLP1 contribute to EONDT.

Prevalence of mental health problems in preschoolers and the impact of maternal depression.

A large number of children of depressed mothers have one or more mental disorders. This study aimed to evaluate the impact of maternal depression on the mental health of 4-5-year-old children of adolescent mothers, according to the hypotheses generated from the model of accumulation. Between October 2009 and March 2011, all pregnant adolescents who received prenatal care from the public health system in Pelotas (southern Brazil) were invited to participate in the study and have been prospectively followed. Of these individuals, 413 participants were evaluated in the postpartum period and when the child was 2-3 years old and 4-5 years old (current stage). The Strengths and Difficulties Questionnaire was used to assess mental health problems in children, and the Mini International Neuropsychiatric Interview (MINI)-Plus version was used to assess maternal depression. We applied a structured modeling approach to examine the relations between three different hypothesized life course models (accumulation, critical period, and mobility) and maternal depression. After selecting the most appropriate model, we used a logistic regression analysis to assess the effect of depression on mental health problems in 4-5-year-old children of adolescent mothers. We used the Chi square test to estimate the prevalence of mental health problems in 4-5-year-old children. The longer the time of exposure to maternal depression, the greater the probability that the child would present behavioral problems. Investments in strategies to prevent mental disorders beginning in the gestational period are important.

Klotho deficiency aggravates sepsis-related multiple organ dysfunction.

Sepsis-induced organ failure is characterized by a massive inflammatory response and oxidative stress. Acute kidney injury (AKI) occurs in approximately half of patients in septic shock, and the mortality associated with sepsis-induced AKI is unacceptably high. Klotho is a protein expressed by renal cells and has anti-senescence properties. Klotho has also been shown to protect the kidneys in ischemia-reperfusion injury and to have antioxidant properties. To analyze the role of Klotho in sepsis-related organ dysfunction and AKI, we used a cecal ligation and puncture (CLP) model of sepsis in heterozygous Klotho-haploinsufficient mice and their wild-type littermates (CLP- Kl/+ and CLP-WT mice, respectively). In comparison with the CLP-WT mice, CLP- Kl/+ mice showed lower survival, impaired renal function, impaired hepatic function, greater oxidative stress, upregulation of inflammatory pathways (at the systemic and kidney tissue levels), and increased NF-κB activation. It is noteworthy that CLP- Kl/+ mice also showed lower heart-rate variability, less sympathetic activity, impaired baroreflex sensitivity to sodium nitroprusside, and a blunted blood pressure response to phenylephrine. We also demonstrated that sepsis creates a state of acute Klotho deficiency. Given that low Klotho expression exacerbates sepsis and multiple organ dysfunction, Klotho might play a protective role in sepsis, especially in elderly individuals in whom Klotho expression is naturally reduced.

Cell wall dynamics and gene expression on soybean embryonic axes during germination.

MAIN CONCLUSION: Identification of the structural changes and cell wall-related genes likely involved in cell wall extension, cellular water balance and cell wall biosynthesis on embryonic axes during germination of soybean seeds. Cell wall is a highly organized and dynamic structure that provides mechanical support for the cell. During seed germination, the cell wall is critical for cell growth and seedling establishment. Although seed germination has been widely studied in several species, key aspects regarding the regulation of cell wall dynamics in germinating embryonic axes remain obscure. Here, we characterize the gene expression patterns of cell wall pathways and investigate their impact on the cell wall dynamics of embryonic axes of germinating soybean seeds. We found 2143 genes involved in cell wall biosynthesis and assembly in the soybean genome. Key cell wall genes were highly expressed at specific germination stages, such as expansins, UDP-Glc epimerases, GT family, cellulose synthases, peroxidases, arabinogalactans, and xyloglucans-related genes. Further, we found that embryonic axes grow through modulation of these specific cell wall genes with no increment in biomass. Cell wall structural analysis revealed a defined pattern of cell expansion and an increase in cellulose content during germination. In addition, we found a clear correlation between these structural changes and expression patterns of cell wall genes during germination. Taken together, our results provide a better understanding of the complex transcriptional regulation of cell wall genes that drive embryonic axes growth and expansion during soybean germination.

Chronic nicotine exposure reduces klotho expression and triggers different renal and hemodynamic responses in klotho-haploinsufficient mice.

The klotho gene, which encodes a single-pass transmembrane protein and a secreted protein, is expressed predominantly by the distal renal tubules and is related to calcium phosphorus metabolism, ion channel regulation, intracellular signaling pathways, and longevity. Klotho deficiency aggravates acute kidney injury and renal fibrosis. Exposure to nicotine also worsens kidney injury. Here, we investigated renal Klotho protein expression in a mouse model of chronic (28-day) nicotine exposure, in which mice received nicotine or vehicle (saccharine) in drinking water, comparing wild-type (WT) mice, klotho-haploinsufficient ( kl/+) mice, and their respective controls, in terms of the effects of that exposure. Nicotine exposure was associated with a significant decline in renal Klotho expression in WT and kl/+ mice as well as a reduction in the glomerular filtration rate in WT mice. Although plasma electrolytes were similar among the groups, fractional excretion of sodium was reduced in both nicotine-exposed groups. The nicotine-WT mice presented augmented baroreflex sensitivity to nitroprusside and augmented sympathetic cardiac modulation. However, nicotine- kl/+ mice presented higher plasma levels of urea and aldosterone together with a higher α-index (spontaneous baroreflex) and higher peripheral sympathetic modulation, as evaluated by spectral analysis. We can conclude that nicotine downregulates Klotho expression as well as that renal and autonomic responses to nicotine exposure are modified in kl/+ mice.

Effect of the Hydroethanolic Extract from Echinodorus grandiflorus Leaves and a Fraction Enriched in Flavone-C-Glycosides on Antigen-Induced Arthritis in Mice.

The leaves of Echinodorus grandiflorus are traditionally used in Brazil to treat several inflammatory conditions, including arthritis. This study aimed to investigate the antiarthritis activity of the 70% ethanol extract of E. grandiflorus leaves and a standardized flavonoid-rich fraction in an antigen-induced arthritis model in mice. Previously immunized mice were treated per os with saline (control group), 70% ethanol extract (100-1000 mg/kg), or a flavonoid-rich fraction (0.7-7.2 mg/kg) 40 minutes before and 3 and 6 hours after the challenge with antigen into the knee joint. The administration of the 70% ethanol extract and flavonoid-rich fraction to mice significantly reduced neutrophil recruitment to the joint cavity and in periarticular tissue. The levels of chemokine (C-X-C motif) ligand 1, tumor necrosis factor-α, and interleukin-1ß quantified by the enzyme-linked immunosorbent assay (ELISA) in the periarticular tissue were also diminished in mice treated with the 70% ethanol extract and flavonoid-rich fraction, as well as mechanical hypernociception. Histological analysis confirmed that both the 70% ethanol extract and flavonoid-rich fraction suppressed joint inflammation and inhibited cartilage and bone destruction when compared to the control group. Our results demonstrate, for the first time, that E. grandiflorus has anti-inflammatory activity in an experimental arthritis model and highlights the role of flavonoids in the observed response.

Naive B-cell trafficking is shaped by local chemokine availability and LFA-1-independent stromal interactions.

It is not known how naive B cells compute divergent chemoattractant signals of the T-cell area and B-cell follicles during in vivo migration. Here, we used two-photon microscopy of peripheral lymph nodes (PLNs) to analyze the prototype G-protein-coupled receptors (GPCRs) CXCR4, CXCR5, and CCR7 during B-cell migration, as well as the integrin LFA-1 for stromal guidance. CXCR4 and CCR7 did not influence parenchymal B-cell motility and distribution, despite their role during B-cell arrest in venules. In contrast, CXCR5 played a nonredundant role in B-cell motility in follicles and in the T-cell area. B-cell migration in the T-cell area followed a random guided walk model, arguing against directed migration in vivo. LFA-1, but not α4 integrins, contributed to B-cell motility in PLNs. However, stromal network guidance was LFA-1 independent, uncoupling integrin-dependent migration from stromal attachment. Finally, we observed that despite a 20-fold reduction of chemokine expression in virus-challenged PLNs, CXCR5 remained essential for B-cell screening of antigen-presenting cells. Our data provide an overview of the contribution of prototype GPCRs and integrins during naive B-cell migration and shed light on the local chemokine availability that these cells compute.

HIV-1 Nef interferes with T-lymphocyte circulation through confined environments in vivo.

HIV-1 negative factor (Nef) elevates virus replication and contributes to immune evasion in vivo. As one of its established in vitro activities, Nef interferes with T-lymphocyte chemotaxis by reducing host cell actin dynamics. To explore Nef's influence on in vivo recirculation of T lymphocytes, we assessed lymph-node homing of Nef-expressing primary murine lymphocytes and found a drastic impairment in homing to peripheral lymph nodes. Intravital imaging and 3D immunofluorescence reconstruction of lymph nodes revealed that Nef potently impaired T-lymphocyte extravasation through high endothelial venules and reduced subsequent parenchymal motility. Ex vivo analyses of transendothelial migration revealed that Nef disrupted T-lymphocyte polarization and interfered with diapedesis and migration in the narrow subendothelial space. Consistently, Nef specifically affected T-lymphocyte motility modes used in dense environments that pose high physical barriers to migration. Mechanistically, inhibition of lymph node homing, subendothelial migration and cell polarization, but not diapedesis, depended on Nef's ability to inhibit host cell actin remodeling. Nef-mediated interference with in vivo recirculation of T lymphocytes may compromise T-cell help and thus represents an important mechanism for its function as a HIV pathogenicity factor.

Topical Aloe Vera (Aloe barbadensis Miller) Extract Does Not Accelerate the Oral Wound Healing in Rats.

The effect of topical application of Aloe Vera (Aloe barbadensis Miller) extract was assessed on the healing of rat oral wounds in an in vivo model using 72 male Wistar rats divided into three groups (n = 24): control, placebo and Aloe Vera (0.5% extract hydroalcoholic). Traumatic ulcers were caused in the dorsum of the tongue using a 3-mm punch tool. The Aloe Vera and placebo group received two daily applications. The animals were sacrificed after 1, 5, 10 and 14 days. Clinical analysis (ulcer area and percentage of repair) and histopathological analysis (degree of re-epithelialization and inflammation) were performed. The comparison of the differences between scores based on group and experimental period, both in quantitative and semi-quantitative analyses, was performed using the Kruskal-Wallis test. The significance level was 5%. On day 1, all groups showed predominantly acute inflammatory infiltrate. On day 5, there was partial epithelialization and chronic inflammatory infiltrate. On the days 10 and 14 total repair of ulcers was observed. There was no significant difference between groups in the repair of mouth ulcers. It is concluded that treatment using Aloe Vera as an herbal formulation did not accelerate oral wound healing in rats.

Physico-chemical characterization of acid base disorders in patients with COVID-19: A cohort study.

BACKGROUND: Acid-base imbalance has been poorly described in patients with coronavirus disease 2019 (COVID-19). Study by the quantitative acid-base approach may be able to account for minor changes in ion distribution that may have been overlooked using traditional acid-base analysis techniques. In a cohort of critically ill COVID-19 patients, we looked for an association between metabolic acidosis surrogates and worse clinical outcomes, such as mortality, renal dialysis, and length of hospital stay. AIM: To describe the acid-base disorders of critically ill COVID-19 patients using Stewart's approach, associating its variables with poor outcomes. METHODS: This study pertained to a retrospective cohort comprised of adult patients who experienced an intensive care unit stay exceeding 4 days and who were diagnosed with severe acute respiratory syndrome coronavirus 2 infection through a positive polymerase chain reaction analysis of a nasal swab and typical pulmonary involvement observed in chest computed tomography scan. Laboratory and clinical data were obtained from electronic records. Categorical variables were compared using Fisher's exact test. Continuous data were presented as median and interquartile range. The Mann-Whitney U test was used for comparisons. RESULTS: In total, 211 patients were analyzed. The mortality rate was 13.7%. Overall, 149 patients (70.6%) presented with alkalosis, 28 patients (13.3%) had acidosis, and the remaining 34 patients (16.2%) had a normal arterial pondus hydrogenii. Of those presenting with acidosis, most had a low apparent strong ion difference (SID) (20 patients, 9.5%). Within the group with alkalosis, 128 patients (61.0%) had respiratory origin. The non-survivors were older, had more comorbidities, and had higher Charlson's and simplified acute physiology score 3. We did not find severe acid-base imbalance in this population. The analyzed Stewart's variables (effective SID, apparent SID, and strong ion gap and the effect of albumin, lactate, phosphorus, and chloride) were not different between the groups. CONCLUSION: Alkalemia is prevalent in COVID-19 patients. Although we did not find an association between acid-base variables and mortality, the use of Stewart's methodology may provide insights into this severe disease.

Laboratory and field validation of the recombinase polymerase amplification assay targeting the Schistosoma mansoni mitochondrial minisatellite region (SmMIT-RPA) for snail xenomonitoring for schistosomiasis.

Improvements in diagnostics for schistosomiasis in both humans and snail hosts are priorities to be able to reach the World Health Organization (WHO) goal of eliminating the disease as a public health problem by 2030. In this context, molecular isothermal amplification tests, such as Recombinase Polymerase Amplification (RPA), are promising for use in endemic areas at the point-of-need for their accuracy, robustness, simplicity, and time-effectiveness. The developed recombinase polymerase amplification assay targeting the Schistosoma mansoni mitochondrial minisatellite region (SmMIT-RPA) was used to detect S. mansoni DNA from both laboratory and field Biomphalaria snails. Laboratory snails were experimentally infected and used at one, seven, and 28 days post-exposure (dpe) to 10 S. mansoni miracidia to provide samples in the early pre-patent infection stage. Field samples of Biomphalaria spp. were collected from the Mucuri Valley and Jequitinhonha Valley regions in the state of Minas Gerais, Brazil, which are endemic for S. mansoni. The sensitivity and specificity of the SmMIT-RPA assay were analysed and compared with existing loop-mediated isothermal amplification (LAMP), PCR-based methods, parasitological examination of the snails, and nucleotide sequencing. The SmMIT-RPA assay was able to detect S. mansoni DNA in the experimentally infected Biomphalaria glabrata as early as one dpe to 10 miracidia. It also detected S. mansoni infections (55.5% prevalence) in the field samples with the highest accuracy (100% sensitivity and specificity) compared with the other molecular tests used as the reference. Results from this study indicate that the SmMIT-RPA assay is a good alternative test to be used for snail xenomonitoring of S. mansoni due to its high sensitivity, accuracy, and the possibility of detecting early pre-patent infection. Its simplicity and portability also make it a suitable methodology in low-resource settings.

A MaxEnt Model of Citrus Black Fly Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae) under Different Climate Change Scenarios.

The citrus blackfly (CBF), Aleurocanthus woglumi Ashby, is an exotic pest native to Southeast Asia that has spread rapidly to the world's main centers of citrus production, having been recently introduced to Brazil. In this study, a maximum entropy niche model (MaxEnt) was used to predict the potential worldwide distribution of CBF under current and future climate change scenarios for 2030 and 2050. These future scenarios came from the Coupled Model Intercomparison Project Phase 6 (CMIP6), SSP1-2.6, and SSP5-8.5. The MaxEnt model predicted the potential distribution of CBF with area under receiver operator curve (AUC) values of 0.953 and 0.930 in the initial and final models, respectively. The average temperature of the coldest quarter months, precipitation of the rainiest month, isothermality, and precipitation of the driest month were the strongest predictors of CBF distribution, with contributions of 36.7%, 14.7%, 13.2%, and 10.2%, respectively. The model based on the current time conditions predicted that suitable areas for the potential occurrence of CBF, including countries such as Brazil, China, the European Union, the USA, Egypt, Turkey, and Morocco, are located in tropical and subtropical regions. Models from SSP1-2.6 (2030 and 2050) and SSP5-8.5 (2030) predicted that suitable habitats for CBF are increasing dramatically worldwide under future climate change scenarios, particularly in areas located in the southern US, southern Europe, North Africa, South China, and part of Australia. On the other hand, the SSP5-8.5 model of 2050 indicated a great retraction of the areas suitable for CBF located in the tropical region, with an emphasis on countries such as Brazil, Colombia, Venezuela, and India. In general, the CMIP6 models predicted greater risks of invasion and dissemination of CBF until 2030 and 2050 in the southern regions of the USA, European Union, and China, which are some of the world's largest orange producers. Knowledge of the current situation and future propagation paths of the pest serve as tools to improve the strategic government policies employed in CBF's regulation, commercialization, inspection, combat, and phytosanitary management.

NLRP3 inflammasome-mediated neutrophil recruitment and hypernociception depend on leukotriene B(4) in a murine model of gout.

OBJECTIVE: Deposition of monosodium urate monohydrate (MSU) crystals in the joints promotes an intense inflammatory response and joint dysfunction. This study evaluated the role of the NLRP3 inflammasome and 5-lipoxygenase (5-LOX)-derived leukotriene B(4) (LTB(4) ) in driving tissue inflammation and hypernociception in a murine model of gout. METHODS: Gout was induced by injecting MSU crystals into the joints of mice. Wild-type mice and mice deficient in NLRP3, ASC, caspase 1, interleukin-1ß (IL-1ß), IL-1 receptor type I (IL-1RI), IL-18R, myeloid differentiation factor 88 (MyD88), or 5-LOX were used. Evaluations were performed to assess neutrophil influx, LTB(4) activity, cytokine (IL-1ß, CXCL1) production (by enzyme-linked immunosorbent assay), synovial microvasculature cell adhesion (by intravital microscopy), and hypernociception. Cleaved caspase 1 and production of reactive oxygen species (ROS) were analyzed in macrophages by Western blotting and fluorometric assay, respectively. RESULTS: Injection of MSU crystals into the knee joints of mice induced neutrophil influx and neutrophil-dependent hypernociception. MSU crystal-induced neutrophil influx was CXCR2-dependent and relied on the induction of CXCL1 in an NLRP3/ASC/caspase 1/IL-1ß/MyD88-dependent manner. LTB(4) was produced rapidly after injection of MSU crystals, and this was necessary for caspase 1-dependent IL-1ß production and consequent release of CXCR2-acting chemokines in vivo. In vitro, macrophages produced LTB(4) after MSU crystal injection, and LTB(4) was relevant in the MSU crystal-induced maturation of IL-1ß. Mechanistically, LTB(4) drove MSU crystal-induced production of ROS and ROS-dependent activation of the NLRP3 inflammasome. CONCLUSION: These results reveal the role of the NLRP3 inflammasome in mediating MSU crystal-induced inflammation and dysfunction of the joints, and highlight a previously unrecognized role of LTB(4) in driving NLRP3 inflammasome activation in response to MSU crystals, both in vitro and in vivo.