Search Results (338)

This review aims to discuss how heat stress affects ovarian follicles and oocytes, steroidogenesis, and embryo development in ruminants. The literature shows that quiescent primordial follicles appear to be less susceptible to heat stress, but from the primary follicle stage onwards, they begin to suffer the consequences of heat stress. These adverse effects are exacerbated when the follicles are cultured in vitro. In antral follicles, heat stress reduces granulosa cell viability and proliferation in both in vivo and in vitro models. Oocyte maturation, both nuclear and cytoplasmic, is also compromised, and embryo quality declines under elevated thermal conditions. These effects are linked to intracellular disturbances, including oxidative imbalance, mitochondrial dysfunction, and altered hormonal signaling. The differences between in vivo and in vitro responses reflect the complexity of the biological impact of heat stress and emphasize the protective role of the physiological microenvironment. A better understanding of how heat stress alters the function of ovarian follicles, oocytes, and embryos is crucial. This knowledge is critical to devise effective strategies that mitigate damage, support fertility, and improve outcomes in assisted reproduction for livestock exposed to high environmental temperatures. Full article

Background: Chlamydia trachomatis is the most prevalent bacterial sexually transmitted infection (STI) globally, linked to severe complications such as pelvic inflammatory disease and infertility. In the Brazilian Amazon, socioeconomic vulnerability and the absence of screening policies exacerbate risks, particularly among female sex workers (FSWs). Objective: This study aimed to determine the seroprevalence of anti-C. trachomatis IgG antibodies among FSWs in five municipalities of Pará State, Brazilian Amazon, and identify epidemiological factors associated with infection. Methods: A retrospective cross-sectional study (2005–2007) included 348 FSWs recruited via convenience sampling. Sociodemographic and behavioral data were collected through questionnaires, and blood samples were analyzed by ELISA for anti-C. trachomatis IgG. Statistical analyses included Fisher’s exact tests, odds ratios (ORs), and 95% confidence intervals (CIs), using SPSS 21.0. Results: Overall seroprevalence was 93.9% (327/348; 95% CI: 83.1–90%). Significant associations included a household income of 1–3 minimum wages (98.4%; p = 0.0002), sexual partners from the same region (98.8%; p = 0.0421), and age >42 years (96.3%). Most reported inconsistent condom use (43.7%), multiple monthly partners (54.6%), and illicit drug use (53.4%). Discussion: The extremely high seroprevalence reflects chronic C. trachomatis exposure, driven by socioeconomic deprivation and limited healthcare access. Comparisons with global data underscore the urgent need for screening policies, absent in Brazil for FSWs, and highlight the vulnerability of this population. Conclusions: The findings reveal an alarming burden of C. trachomatis exposure among Amazonian FSWs. Integrated strategies, including routine screening, sexual health education, and inclusion of FSWs in priority health programs, are critical to reduce transmission and associated complications. Full article

Papillomaviruses (PVs) are double-stranded DNA viruses known to induce a variety of epithelial lesions in dogs, ranging from benign hyperplasia to malignancies. In regions of rich biodiversity such as the Western Amazon, data on the circulation and genetic composition of canine papillomaviruses (CPVs) remain scarce. This study investigated CPV types present in oral and cutaneous papillomatous lesions in domiciled dogs from Acre and Rondônia States, Brazil. Sixty-one dogs with macroscopically consistent lesions were clinically evaluated, and tissue samples were collected for histopathological examination and PCR targeting the L1 gene. Among these, 37% were histologically diagnosed as squamous papillomas or fibropapillomas, and 49.2% (30/61) tested positive for papillomavirus DNA. Sequencing of the L1 gene revealed that most positive samples belonged to CPV1 (Lambdapapillomavirus 2), while one case was identified as CPV8 (Chipapillomavirus 3). Complete genomes of three CPV1 strains were obtained via high-throughput sequencing and showed high identity with CPV1 strains from other Brazilian regions. Phylogenetic analysis confirmed close genetic relationships among isolates across distinct geographic areas. These findings demonstrate the circulation of genetically conserved CPVs in the Amazon and reinforce the value of molecular and histopathological approaches for the accurate diagnosis and surveillance of viral diseases in domestic dogs, especially in ecologically complex regions. Full article

Euphorbia hirta L. is traditionally used to treat tumors and has demonstrated anticancer effects. This study evaluated the phytochemical composition, toxicity, and antitumor activity of saline extract (SE) from E. hirta leaves in mice. Phytochemical analysis included thin layer chromatography, high-performance liquid chromatography, and quantification of phenols, flavonoids, and proteins. Acute toxicity (2000 mg/kg) assessed mortality, hematological, biochemical, histological parameters, water/feed intake, and body weight. Genotoxicity was evaluated via comet and micronucleus assays. Antitumor activity was tested in vitro and in vivo on sarcoma 180. SE contained 107.3 mg GAE/g phenolics and 22.9 mg QE/g flavonoids; the presence of gallic and ellagic acids was detected. Protein concentration was 12.16 mg/mL with lectin activity present. No mortality, organ damage, or genotoxic effects occurred in toxicity tests. SE demonstrated in vitro cytotoxicity against sarcoma cells (IC₅₀: 10 µg/mL). In vivo, SE (50–200 mg/kg) reduced tumor weight by 70.2–72.3%. SE modulated IL-2, IL-4, IL-6, IL-17, IFN-γ, and TNF-α in tumor environment. Tumors showed inflammatory infiltrate, necrosis, and fibrosis after treatment. These findings position the extract as a promising candidate for further development as a safe, plant-based antitumor agent. Full article

Inselbergs are rocky outcrops with specialized vegetation, including woody species growing in poorly developed soils. We investigated whether populations of the lithophytic tree Pseudobombax petropolitanum A. Robyns (Malvaceae), a key species endemic to Atlantic Forest inselbergs, have convergent or divergent patterns of functional traits related to leaf chemistry. This study was carried out on three inselbergs located in southeastern Brazil. Green and senescent leaves from nine healthy trees and soil samples were collected in each inselberg. The carbon, nitrogen, phosphorus, potassium, calcium, and magnesium concentrations, and the natural abundances of δ¹³C and δ¹⁵N, were measured in leaves and soil, and the C/N, C/P, and N/P ratios were calculated. The specific leaf area (SLA) was measured, and the nutrient retranslocation rate between green and senescent leaves was estimated. Divergences between populations were observed in the concentrations of potassium and magnesium in the green and senescent leaves, as well as in the C/P and N/P ratios in senescent leaves. Our results suggest that nutrient and water dynamics may differ in some inselbergs due to specific nutrients or their relationships, even though there were convergences in most functional traits related to leaf chemistry among the Pseudobombax populations. The divergences among the populations could have important implications for species selection in the ecological restoration context. Full article

Background: COVID-19 led to social isolation, potentially reducing physical activity (PA), increasing sedentary time, and lowering quality of life (QoL). This study investigated the association between these factors in patients with Chagas disease (ChD) during the pandemic. Methods: This cross-sectional study included 187 patients with ChD. PA and sedentary time were assessed by the IPAQ-short and QoL by the WHOQOL-Bref. The relationship between PA levels and sedentary time with QoL were assessed using unadjusted and adjusted generalized linear models. Results: The highest tertile of total PA was positively associated with the psychological (Exp β = 1.11; 95% CI: 1.02–1.22) and environmental (Exp β = 1.12; 95% CI: 1.01–1.23) QoL domains. The intermediate (Exp β = 1.12; 95% CI: 1.01–1.25) and highest (Exp β = 1.14; 95% CI: 1.02–1.27) tertiles of moderate-to-vigorous PA were positively associated with the physical domain. Similarly, both the intermediate (Exp β = 1.11; 95% CI: 1.01–1.22) and highest (Exp β = 1.12; 95% CI: 1.01–1.21) tertiles of moderate-to-vigorous PA were positively associated with the psychological domain. The highest tertile of sedentary time was associated with a decrease in the physical domain (Exp β = 0.88; 95% CI: 0.79–0.98). Conclusions: Higher levels of total and moderate-to-vigorous PA were associated with better QoL, while greater sedentary time was associated with poorer QoL. Full article

This study evaluated the pH, fluoride (F), and calcium (Ca) concentrations in saliva-derived microcosm biofilms following treatments with dentifrices applied at different amounts and F concentration. Human saliva was inoculated into McBain culture medium, and treatments were applied at 72/78/96 h (1 min). Fluoridated dentifrices containing 550 or 1100 ppm F (550F and 1100F, respectively) were used at the following combinations (intensities): (i-1) 550F/0.08 g or 1100F/0.04 g; (i-2) 550F/0.16 g or 1100F/0.08 g; (i-3) 550F/0.32 g or 1100F/0.16 g. A negative control (fluoride-free dentifrice—PLA) was also included. Biofilm F and Ca were measured with an ion-selective electrode and colorimetrically, respectively, while pH in the culture medium was measured with a pH electrode. Data were subjected to ANOVA and Student–Newman–Keuls’ test (p < 0.05). F-dentifrices did not significantly alter pH compared to PLA, except for 1100F at i-3. Biofilm F levels at i-1 and i-2 were comparable, for both 550F and 1100F, while 1100F at i-3 led to the highest biofilm F concentration. All F-groups showed significantly higher Ca levels than PLA, especially at i-2 and i-3. In conclusion, the interplay between dentifrice amount and F concentration was more influential on the biofilm’s inorganic composition and pH than either variable alone. Full article

If new technologies can increase production efficiency and reduce the consumption of natural resources, they can also bring new environmental risks. This dynamic is particularly relevant for the automotive industry, since it is one of the sectors that invests most in R&D, but at the same time also contributes a significant portion of greenhouse gas emissions and consumes a large amount of energy. This article aims to analyze the feasibility of meeting the environmental targets in place within 32 European countries in light of the recent technological trajectory of the automotive industry, namely with regard to the adoption of the propulsion model’s alternative to oil and diesel. Using data disaggregated by countries from 2000 up until 2020, in this paper, the estimated regressions aimed to not only verify whether electrical vehicles had a positive impact on CO₂ emissions found in the European market, but to also assess whether they will meet the target set for the next 30 years, with attention to the economy recovery after 2025 and a more robust EV market penetration in replacement of traditional fossil fuels cars. Full article

Trypanosoma cruzi is a kinetoplastid parasite and etiological agent of Chagas disease. Given the significant morbidity and mortality rates of this parasitic disease, possible treatment alternatives need to be studied. 3-Bromopyruvate (3-BrPA) is a synthetic analog of pyruvate that was introduced in the early 21st century as an anticancer agent, affecting the proliferation and motility of certain microorganisms. Therefore, this work aims to evaluate the role of 3-BrPA in the energy metabolism, proliferation, and infectivity of T. cruzi, with a primary focus on the mitochondrial state, ATP production, and the key glycolytic pathway enzymes. It was observed that mitochondrial function in 3-BrPA cells was impaired compared to control cells. Accordingly, cells maintained in control conditions have a higher intracellular ATP content than cells maintained with 3-BrPA and higher ecto-phosphatase activity. However, the 3-BrPA reduced ecto-nuclease activity and was capable of hydrolyzing 5′-AMP, ADP, and ATP. When we evaluated two key glycolytic pathway enzymes, glucose kinase (GK) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), we observed that 3-BrPA induced higher GAPDH activity but did not alter GK activity. The compensatory energy mechanisms presented in T. cruzi may influence the process of cell metabolism and, consequently, the functional infectious process, suggesting the potential use of 3-BrPA in future clinical applications for Chagas disease. Full article

Trichlorfon is an antiparasitic agent widely used to control pests and parasites in farmed fish. Tambaqui (C. macropomum) is the most commercially important characid species farmed in the Amazon region. Trichlorfon exposure is known to cause physiological damage in fish due to its organophosphate nature. In this study, we used RNA-Seq to investigate the hepatic response of tambaqui following exposure to 0.435 mg/L of trichlorfon. The analysis revealed activation of several metabolic pathways, particularly those related to tumor processes, immune responses, and apoptosis. Additionally, we identified upregulation of solute carrier (SLC) genes, which may facilitate trichlorfon entry into hepatocytes. These findings enhance our understanding of fish responses to antiparasitic agents and support further research into the molecular impacts of organophosphate compounds in aquaculture species. Full article

MicroRNAs (miRNAs) are key post-transcriptional regulators involved in a wide range of biological processes in insects, yet little is known about their roles in stingless bees. Here, we present the first characterization of miRNAs in Melipona quadrifasciata using small RNAs (sRNAs) deep sequencing. A total of 193 high-confidence mature miRNAs were identified, including 106 M. quadrifasciata-exclusive sequences. Expression profiling revealed that mqu-miR-1 and mqu-miR-276 together accounted for over 70% of all miRNA reads, suggesting their central roles in development and reproduction. Comparative analyses showed a higher conservation of M. quadrifasciata miRNAs with other Hymenopterans, especially Apis mellifera and Bombus spp. Putative target genes were predicted using a consensus approach, and functional annotation indicated their involvement in diverse biological regulatory pathways. This work represents the first comprehensive identification of the miRNA repertoire in stingless bees using sRNAs and provides a valuable foundation for understanding miRNA-mediated gene regulation in this ecologically and economically important pollinator. Full article

Synthetic dyes are commonly present in industrial wastewater and when discharged in water bodies without receiving a treatment capable of removing or destroying them, they turn into concerning water pollutants. These organic contaminants threaten living beings due to their toxicity, and some of them can even damage DNA. Consequently, in order to achieve sustainable development, it is necessary to develop eco-friendly tools that can efficiently manage this kind of pollution. In the present study the aqueous extract from the leaves of Leucaena leucocephala (an invasive plant species native to Mexico) was used to produce green nano zero-valent iron (nZVI). The nanomaterial was characterized (TEM, UV–vis, FTIR, SEM, EDS, XRD) and assayed regarding its antioxidant potential (DPPH test) and capacity to remediate the pollution caused by two dyes. It proved to be able to adsorb nigrosine (288.30 mg/g of nanomaterial) and tartrazine (342.50 mg/g of nanomaterial), and also displayed antioxidant activity (effective concentration to discolor 50% of the DPPH solution = 286.02 μg/mL). Therefore, the biogenic antioxidant nanoparticle proved also to be a possible nanotool to be applied to remediate water contamination caused by these synthetic dyes. Full article

Introduction: The health education curricula should explicitly recognize, define, and address the unique needs and health disparities faced by Black and LGBTQIA+ populations, as a means of ensuring that healthcare for these populations is both comprehensive and inclusive. Aim: To map scientific evidence and identify knowledge gaps regarding the health of Black and LGBTQIA+ populations within the global context of health education. Methods: A scoping review will be conducted following the JBI methodology. The articles will be retrieved from Scopus, Web of Science, PubMed, Embase, MEDLINE, BVS, CINAHL, ERIC, Cochrane, BDTD, PQDT, EBSCO, and NDLTD. The search will be conducted without language or time restrictions. Two independent reviewers will screen the studies and extract data using a form specifically developed for this purpose. The concepts, definitions, structures, results, and applications of professional health education worldwide for the healthcare of Black and LGBTQIA+ populations will be summarized and discussed. Inclusion Criteria: Studies related to professional health training at both undergraduate and graduate levels, as well as other educational modalities that address the provision of healthcare for these populations, will be included. The results will be presented in both tabular and graphical formats, accompanied by a narrative summary. Protocol registered in the Open Science Framework (OSF). Full article

This review examines the current status of biomethane development in South America through a comprehensive comparative analysis of national legislation, scientific literature, and institutional data across all South American countries. The methodology consisted of a systematic review of technical and regulatory documents to assess the status of biomethane production, commercialization, and utilization throughout the region. The findings indicate that biomethane remains largely underdeveloped in most South American countries, primarily due to fragmented data, inadequate infrastructure, and a lack of targeted public policies. Brazil emerges as a regional leader, backed by robust legal frameworks such as the RenovaBio program, the Future Fuel Law, and specific regulations governing landfill waste treatment and biomethane quality standards. In contrast, other countries hold considerable biogas potential but lack the regulatory frameworks and financial incentives required to expand biomethane production. The principal contribution of this study is its comprehensive assessment of biomethane development in South America, providing a country-level analysis alongside direct comparisons with global leaders in both production and policy. By mapping legislation, infrastructure conditions, and energy strategies across the continent, this study offers a strategic reference to support future research, investment, and policy development. Full article

Background. Postoperative pancreatic fistula (POPF) remains one of the most relevant complications following pancreaticoduodenectomy (PD), significantly impacting short-term outcomes and delaying adjuvant therapies. Current predictive models offer limited accuracy, often failing to incorporate early postoperative data. This retrospective study aimed to develop and validate machine learning (ML) models to predict the absence and severity of POPF using clinical, surgical, and early postoperative variables. Methods. Data from 216 patients undergoing PD were analyzed. A total of twenty-four machine learning (ML) algorithms were systematically evaluated using the Matthews Correlation Coefficient (MCC) and AUC-ROC metrics. Among these, the GradientBoostingClassifier consistently outperformed all other models, demonstrating the best predictive performance, particularly in identifying patients at low risk of postoperative pancreatic fistula (POPF) during the early postoperative period. To enhance transparency and interpretability, a SHAP (SHapley Additive exPlanations) analysis was applied, highlighting the key role of early postoperative biomarkers in the model predictions. Results. The performance of the GradientBoostingClassifier was also directly compared to that of a traditional logistic regression model, confirming the superior predictive performance over conventional approaches. This study demonstrates that ML can effectively stratify POPF risk, potentially supporting early drain removal and optimizing postoperative management. Conclusions. While the model showed promising performance in a single-center cohort, external validation across different surgical settings will be essential to confirm its generalizability and clinical utility. The integration of ML into clinical workflows may represent a step forward in delivering personalized and dynamic care after pancreatic surgery. Full article