Search Results (111)

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

The cecal microbiota is essential for intestinal health and performance. This study describes the succession patterns of the cecal microbiota in Japanese quail (Coturnix japonica) until 42 days of age. Sixty quails were raised using standard conditions and fed corn–soybean meal diets. Cecal contents were sampled from five birds weekly from 7 to 42 days of age and submitted to Illumina 16S rRNA sequencing for metabarcoding analysis. Diversity and functional prediction were carried out with QIIME2, PICRUSt2, STAMP and MicrobiomeAnalyst 2.0. Firmicutes increased from 50% at 7 days to more than 80% at 42 days, whereas Bacteroidota decreased from 45% to 12% in the same period. Alpha diversity progressively increased with age, indicating a richer and more balanced microbiota at later ages. Genera such as Bacteroides were predominant in the beginning and later were replaced by Lachnospiraceae, Ruminococcus and Faecalibacterium. These developmental taxonomic features aligned with significant shifts in ten metabolic pathways identified by prediction, revealing a transition from biosynthetic functions to complex carbohydrate metabolism and cell wall biosynthesis. The first seven days are considered a critical window for probiotics intervention, which may favor the establishment of a microbiota that is more stable and beneficial to quail performance. Full article

Despite the current level of public immunity to SARS-CoV-2, the early inflammatory events associated with respiratory distress in COVID-19 patients are not fully elucidated. Syrian golden hamsters, facultative hibernators, recapitulate the phenotype of SARS-CoV-2-induced severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)—induced severe acute lung injury seen in patients. In this study, we describe the predominance of the innate immune response in hamsters inoculated with four different SARS-CoV-2 variants, underscoring phenotypic differences among them. Severe inflammatory lung injury was chronologically associated with acute and significant weight loss, mainly in animals inoculated with A.2 and Delta variants. Omicron-infected animals had lower overall histopathology scores compared to other variants. We highlight the central role of endothelial injury and activation in the pathogenesis of experimental SARS-CoV-2 infection in hamsters, characterised by the presence of proliferative type I and type II pneumocytes with abundant surfactant expression, thereby maintaining hyperinflated alveolar fields. Additionally, there was evidence of intrapulmonary lymphatic vessel proliferation, which was accompanied by a lack of detectable microthrombosis in the lung parenchyma. However, white microthrombi were observed in lymphatic vessels. Our findings suggest that the physiological compensatory mechanisms that maintain respiratory homeostasis in Golden Syrian hamsters prevent severe respiratory distress and death after SARS-CoV-2 infection. Full article

The mosquito Aedes aegypti is the vector responsible for the transmission of important arboviruses such as dengue fever, Chikungunya, Zika virus, and yellow fever. These diseases affect millions of people and exert impacts on healthcare systems throughout the world. Given the increasing resistance to synthetic insecticides, essential oils from plants constitute an ecologically viable alternative for the control of this vector. The aim of the present study was to investigate the larvicidal activity of the essential oil (EO), aqueous extract, rutin, and hydrolate from the leaves of Myrciaria floribunda against Aedes aegypti larvae in the initial L4 stage. The yield of EO was 0.47%. Thirty-seven chemical constituents were identified and quantified using chromatographic methods. The major constituents were (E)-caryophyllene (27.35%), 1,8-cineole (11.25%), β-selinene (4.92%), and α-muurolene (4.92%). In the larvicidal tests, the lethal concentration (LC₅₀) was 201.73 ppm for the essential oil, 15.85% for the aqueous extract, and 22.46 ppm for rutin. The hydrolate had no larvicidal activity. The compounds that exhibited larvicidal activity against Aedes aegypti constitute a promising option for the development of natural formulations to diminish the propagation of this vector. Full article

This study assessed the correlation between obesity markers and mental stress reactivity. Mainly, it evaluated whether physical exercise (PE) influences cardiovascular reactivity to the Stroop color word test (SCWT) in teachers. Thirty-one school teachers were evaluated. The SCWT was carried out under (1) baseline and (2) 30 min after aerobic PE conditions. Teachers performed 30 min of PE. The reactivity to mental stress (Δ) during the SCWT for blood pressure (BP) was determined, with Δ being the highest value observed [Δ2 or Δ4: with pre-test values (0 min)]. Of the teachers, 64.52% were considered overweight/obese and 19.35% had a high clinical BP. However, 67.74% of teachers were considered physically active. Systolic BP (SBP) reactivity to SCWT correlated negatively with obesity markers (Rho = −0.36 to −0.60; p < 0.05). The SBP and diastolic BP (DBP) were higher at 2 and 4 min compared to 0 during the SCWT under both conditions (p < 0.01). Moreover, SBP was always lower after PE (p < 0.01) and DBP was lower at 2 and 4 min after PE (p < 0.01). In summary, SBP reactivity to mental stress correlated negatively with obesity markers. Moderate-intensity acute PE reduced BP reactivity to mental stress in teachers. Full article

Background: Commiphora leptophloeos has long been used in Latin American folk medicine for the treatment of respiratory and gastrointestinal disorders. Therefore, toxicological and phytochemical investigations are required to assess the safety and support the evidence-based use of its bark in medicinal applications. This study aimed to evaluate the aqueous bark extract of C. leptophloeos, focusing on its chemical composition and its antioxidant, cytotoxic, and genotoxic properties. Methods: The aqueous extract was obtained by decoction of dried bark samples. Phytochemical characterization was conducted using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS), and data were processed using the NP³ MS Workflow 1.1.4 software, allowing for the annotation of key secondary metabolites. Antioxidant activity was assessed through multiple in vitro assays, including DPPH, ABTS, phosphomolybdenum, and reducing power tests. Cytotoxicity was evaluated using the MTT assay, while genotoxicity was investigated through the Ames test and micronucleus assay. Results: Phytochemical analysis revealed several flavonoids, with procyanidin B2 annotated as a major compound. The extract exhibited strong antioxidant activity, with EC₅₀ values of 5.43 μg/mL (DPPH), 12.40 μg/mL (ABTS), 35.20 μg/mL (phosphomolybdenum), and 31.27 μg/mL (reducing power). The MTT assay showed no cytotoxic effects at concentrations up to 6400 μg/mL. Furthermore, both the Ames and micronucleus assays showed the absence of genotoxic effects at concentrations up to 1600 μg/plate and 400 μg/mL, respectively. Conclusions: The aqueous bark extract of C. leptophloeos demonstrates strong antioxidant potential and a favorable safety profile, with no detectable cytotoxicity or genotoxicity at concentrations effective in antioxidant assays. Further studies are recommended to confirm and validate its traditional medicinal properties using appropriate in vivo models, followed by pre-clinical evaluations. Full article

Enteric viruses, such as the Aichi virus (AiV), pose a potential health risk due to their high excretion rates through fecal elimination, limited removal during treatment processes, and prolonged survival, highlighting the need to assess the potential for exposure and disease transmission through sanitation systems. This study investigated the prevalence of AiV at three key stages of sewage treatment in the city of São José do Rio Preto, São Paulo state, Brazil, as well as its viral concentrations, infectious potential, and molecular characterization. The data were also analyzed for potential correlations with reported diarrheal disease cases in the city and the physicochemical properties of sewage. The methodology employed included Nested PCR, qPCR, Sanger Sequencing, and phylogenetic analysis, as well as infectivity testing in cell cultures. The prevalence of AiV throughout the year in raw sewage samples was 90.4%, 78.8% in post-anaerobic biological treatment, and 71.1% in post-chemical treatment, totaling 125 positive samples out of 156, being characterized as AiV genotype A. The virus also demonstrated persistence and infectious potential at all three stages analyzed. The AiV-A mean concentration ranged from 2.05 log¹⁰ to 4.64 GC/mL, 2.31 to 4.72 log¹⁰ GC/mL, and 2.13 to 2.85 log¹⁰ GC/mL for the same treatment stages, respectively. A significant difference (p ≤ 0.05) suggests higher viral concentrations in summer at the three sewage process points analyzed, while lower viral concentrations were observed in post-chemical treatment samples (p ≤ 0.01). Additionally, no statistically significant relationship was observed between the virus occurrence in samples and cases of acute diarrheal diseases in the city. In conclusion, this study highlights that much remains to be understood about AiV while providing valuable insights into the relationship between AiV, environmental factors, and public health. Full article

The objective was to determine whether dairy cows may activate traditional and alternative inflammatory pathways by consuming a combination of a phytogenic diet (essential oil and pepper resin). Twenty pregnant Jersey cows in the final (third) lactation phase (260 days in milk) were divided into two groups: control, with no additive consumption, and test, with the addition of the phytogenic to the concentrate portion of the diet (150 mg/day/kg dry matter). Blood samples were collected on experimental days 1, 7, 14, 21, 28, 35, and 42 by coccygeal vein puncture to assess the complete blood count, serum biochemistry of levels of total protein, albumin, and globulin, as well as carbohydrate metabolism (glucose), lipid metabolism (cholesterol and triglycerides), protein metabolism (urea), activities of hepatic enzymes (gamma-glutamyl transferase (GGT) and aspartate aminotransferase (AST)), cytokine levels (interleukins IL-1β, IL-6, and IL-10), antioxidant response [thiobarbituric acid reactive substances (TBARS), reactive oxygen species (ROS), total thiol (PSH), and non-protein thiol (NPSH), and glutathione S(GST)], cholinergic system [total cholinesterase (ChE) and acetylcholinesterase (AChE)], purinergic signaling [NTPDase, 5′ectonucleotidase and adenosine deaminase (ADA)], and energetic metabolism enzymes [creatine kinase (CK), pyruvate kinase (PK), and adenylate kinase (AK)]. Productive performance was assessed through feed intake and milk production. The results revealed that the use of phytogenic compounds significantly influenced the cholinergic system and purinergic signaling associated with immunology. The reduction in cholinesterase (ChE) activity and the increase in acetylcholinesterase (AChE) activity in lymphocytes suggest the modulation of the cholinergic system, enhancing the immune response. Furthermore, the elevated activity of adenosine deaminase (ADA) in lymphocytes and platelets, together with increased ATP and ADP hydrolysis in platelets, indicates the beneficial regulation of purinergic signaling, potentially contributing to inflammatory modulation. These effects were accompanied by a lower production of pro-inflammatory cytokines (IL-1β and IL-6) and a higher production of IL-10, reinforcing an anti-inflammatory profile. The reduced leukocyte and lymphocyte counts may reflect a lower inflammatory demand, while the increased levels of NPSH and GST antioxidants suggest cellular protection. Despite these physiological changes, productive performance and milk quality remained unaffected. In summary and practical terms, including this additive in the cows’ diet benefits the cow’s health in the final third of gestation when the animal already has a reduced immune response due to advanced gestation. Full article

Background/Objectives: Tributyltin (TBT), a potent biocide used in antifouling paints, is highly toxic to aquatic environments, causing oxidative stress, endocrine dysfunction, and metabolic disorders in aquatic organisms, including crustaceans. The blue crab Callinectes sapidus is an economically and ecologically important species in several countries worldwide and is considered an invasive species in Europe. Methods: This study evaluated the effects of 7 days of exposure to environmentally relevant TBT concentrations (100 and 1000 ng.L⁻¹) on the intermediary metabolism and oxidative balance of the blue crab Callinectes sapidus. After exposure, hemolymph samples were analyzed to determine glucose, lactate, total protein, and cholesterol levels. In tissue samples, concentrations of triglycerides, glycogen, total glutathione (GSH), reactive oxygen species (ROS), sulfhydryls, lipid peroxidation (LPO), and glutathione S-transferase (GST) activity were assessed. Results: In the hemolymph, glucose and lactate levels increased, while the total cholesterol, triglycerides, and total proteins decreased in all exposed groups. The GST activity increased in exposed tissues, while the total GSH and sulfhydryl content decreased. The ROS concentration increased in response to higher TBT concentrations. Conclusions: These findings highlight the toxicity of TBT and show that 7 days of exposure to environmentally relevant concentrations disrupts the metabolic homeostasis and oxidative balance in C. sapidus. Additionally, this study demonstrates that C. sapidus is sensitive to TBT exposure and has potential as a model species for ecotoxicological studies. Full article

Idiopathic pulmonary fibrosis (IPF) is a disease with a poor prognosis and no curative therapies. Fibroblast activation by transforming growth factor β1 (TGFβ1) and disrupted metabolic pathways, including the arginine–polyamine pathway, play crucial roles in IPF development. Polyamines are agonists of the calcium/cation-sensing receptor (CaSR), activation of which is detrimental for asthma and pulmonary hypertension, but its role in IPF is unknown. To address this question, we evaluated polyamine abundance using metabolomic analysis of IPF patient saliva. Furthermore, we examined CaSR functional expression in human lung fibroblasts (HLFs), assessed the anti-fibrotic effects of a CaSR antagonist, NPS2143, in TGFβ1-activated normal and IPF HLFs by RNA sequencing and immunofluorescence imaging, respectively; and NPS2143 effects on polyamine synthesis in HLFs by immunoassays. Our results demonstrate that polyamine metabolites are increased in IPF patient saliva. Polyamines activate fibroblast CaSR in vitro, elevating intracellular calcium concentration. CaSR inhibition reduced TGFβ1-induced polyamine and pro-fibrotic factor expression in normal and IPF HLFs. TGFβ1 directly stimulated polyamine release by HLFs, an effect that was blocked by NPS2143. This suggests that TGFβ1 promotes CaSR activation through increased polyamine expression, driving a pro-fibrotic response. By halting some polyamine-induced pro-fibrotic changes, CaSR antagonists exhibit disease-modifying potential in IPF onset and development. Full article

Background/Objectives: Sleep is essential to human health, playing a vital role in physical and mental well-being. Sleep disorders can lead to significant health complications, such as cardiovascular problems, diabetes, obesity, and depression. In Brazil, plants such as passionflower (Passiflora spp.), chamomile (Matricaria chamomilla L.) and mulungu (Erythrina spp.) are widely used in folk medicine for their sleep-promoting properties. This article reviews the existing literature on the sleep-promoting effects of these plants, focusing on the Brazilian context and popular knowledge of their use. Methods: An integrative literature review was conducted, including scientific articles in English and Portuguese from PubMed, Scielo and Google Scholar databases. Ethnobotanical studies documenting the traditional use of these plants in Brazil and clinical and preclinical research on their sleep-promoting effects were included. Results: The juice and infusion of the leaves and fruits of passionflower are mainly used to treat anxiety and insomnia, chamomile flower tea is used for its sedative effects, and mulungu bark decoctions are used for their sedative and anxiolytic properties. These popular uses are supported by scientific studies demonstrating the efficacy of these plants in treating insomnia, anxiety, and stress. Conclusions: The recognition of traditional knowledge and the inclusion of these plants in RENISUS highlights their importance for public health in Brazil. However, more rigorous clinical trials are needed to confirm their efficacy and safety and ensure their safe integration into modern medicine. Full article

Agroforestry systems (AFSs) exhibit varied composition and dynamics as intrinsic characteristics of their specificities. In this context, a review of the adoption, composition, and dynamics of AFSs in the Amazon biome was conducted to identify the origin, institutions, and researchers of published studies with results on this scientific topic, focused on trends and characteristics of AFSs diversity in the Amazon. The methodology adopted was a scoping review, based on searches in the Scopus and Web of Science databases, using specific keywords to ensure that the articles addressed topics related to the adoption, composition, and dynamics of AFSs in the Amazon. Following the selection of subtopics, 66 articles were selected and analyzed. The analysis revealed that research on AFSs in the Amazon highlights interactions among traditional knowledge, innovations, and sustainability. The analysis of research published between 1996 and 2023 indicated growth in studies with an interdisciplinary focus, primarily from Brazil. However, internationalization, collaborative networks, and funding factors contribute to the prominence of foreign institutions. Research studies often address topics such as species diversity, agrobiodiversity, and tree growth in agroforestry intercrops. In this context, homegarden agroforestry (HAF) emerges as one of the main subjects of study, encompassing multifunctional environments, richness diversity, and ongoing experimentation with plant species. The choice of species for AFSs is influenced by factors such as labor, personal preferences, and market demands, although loggers and commercial forestry systems tend to have lower diversity, contrasting with HAF. AFSs implementation methods vary according to financing, management, and the farmer’s education and gender. Environmental conservation, food security, ecosystem services, and production flexibility are highlighted as benefits of AFSs, while challenges include technical and economic limitations. This research highlights the strengthening and consolidation of AFSs by addressing scientific gaps and demonstrating the need for studies on the adoption, consolidation, and management of these systems, as well as the relationship between diversity and yield. Future research should be concentrated on deepening studies on the relationship between diversity and yield in AFSs, as well as on management strategies that support the consolidation of these systems in the Amazon biome, integrating innovation, public policy support, and traditional knowledge of farmers. Full article

Atmospheric aerosols significantly influence climate systems and hydrological processes, but their impacts on evapotranspiration remain insufficiently understood, particularly in tropical savanna regions. This study investigates the direct and indirect effects of aerosol optical depth (AOD) on reference evapotranspiration ($E{T}_0$) in the Mato Grosso Cerrado, Brazil, a biome characterized by pronounced seasonal climatic variations. Using data collected from the AERONET network at Fazenda Miranda, AOD was analyzed alongside meteorological variables such as air temperature, global radiation, and $E{T}_0$, estimated using the FAO Penman–Monteith method. The results reveal distinct seasonal patterns, with aerosols having a more pronounced influence during the dry season. Positive correlations were observed between AOD and air temperature, while negative correlations were found between AOD and global radiation, especially during the dry season. The relationship between AOD and $E{T}_0$ varied between years and seasons, with significant reductions in $E{T}_0$ linked to high aerosol concentrations during the dry period. These findings demonstrate that aerosols play a critical role in modulating evapotranspiration and radiation balance, particularly in regions affected by biomass burning. This study provides valuable insights into the interplay between aerosols, climate variables, and hydrological processes, contributing to a better understanding of aerosols’ impacts on tropical ecosystems. Full article

The interest in new sources of bioactive compounds has been driven by the search for natural antioxidants capable of attenuating the toxicity of reactive oxygen species, as well as the emergence of pathogens resistant to antimicrobials. In this sense, we explored the potential of the macaúba epicarp. Compounds such as piceatannol, 3,4,5,3′,5′-penta-hydroxy-trans-stilbene (PHS), and in lower amounts, resveratrol were identified in extracts through techniques such as medium-pressure liquid chromatography, HPLC-MS, and imaging mass spectrometry (IMS), which confirmed the exclusive localization of PHS and piceatannol in the outer epicarp. Extraction with aqueous acetone (Me₂CO:H₂O) and its EtOAC fraction showed the highest yields of stilbenes and, moreover, it efficiently increased the tolerance of Saccharomyces cerevisiae to oxidative stress. Additionally, the Me₂CO:H₂O extract presented antibacterial and anti-cryptococcal activity, with piceatannol and resveratrol increasing survival rates of Galleria mellonella subjected to fungal infection. In silico ADMET (absorption, distribution, metabolism, excretion and toxicity) analysis indicates low toxicity for piceatannol, PHS, and resveratrol, in addition to pharmacokinetic parameters that allow their use. These findings indicate the use of macaúba epicarp as a source of bioactive compounds valuable for the food, cosmetic, and pharmaceutical industries. Full article

Leishmaniasis, a complex disease caused by protozoal parasites of the genus Leishmania, presents various clinical forms, particularly a cutaneous clinical form. Treatment is typically performed with pentavalent antimonial and amphotericin B, both of which have severe side effects that hinder patient compliance. This emphasizes the need for the development of new, effective, and safe treatments. In this study, the leishmanicidal activity of the methanolic extract, an alkaloid-enriched fraction and dicentrine, the main alkaloid of the leaves of Ocotea puberula (Lauraceae), a native Brazilian plant traditionally used by the indigenous population to treat skin affections, was investigated in vitro. Additionally, an in vivo study evaluated the efficacy of a topical cream containing 0.5% dicentrine. The in vitro studies demonstrated high activity and selectivity of methanolic extract, alkaloid-enriched fraction, and dicentrine against the promastigote and amastigote forms of Leishmania (Leishmnia) amazonensis and Leishmania (Viannia) braziliensis. The leishmanicidal effect of dicentrine was related to the modulation of macrophage microbicidal activity. A cream containing 0.5% dicentrine showed high stability and, in permeation studies, dicentrine was retained in a skin-mimicking artificial membrane. This cream effectively inhibited the progression of the skin lesion in BALB/c mice infected with L. (L.) amazonensis, together with a reduced parasite number. Thus, dicentrine offers a promising alternative to the treatment of skin leishmaniasis. Full article