Antibacterial profile and antiproliferative activities over human tumor cells of new silver(I) complexes containing two distinct trifluoromethyl uracil isomers.

New silver(I) complexes of 5-(trifluoromethyl)uracil (5TFMU) and 6-(trifluoromethyl)uracil (6TFMU) isomers were synthesized, characterized, and evaluated as antibacterial and antiproliferative agents. Based on elemental and thermogravimetric analyses, the Ag-5TFMU and Ag-6TFMU species are formulated as AgC5H2F3N2O2 and Ag2C5HF3N2O2, respectively. Infrared and 13C solid-state nuclear magnetic resonance spectroscopies suggest coordination of the trifluoromethyluracil isomers to silver by both nitrogen and oxygen atoms. Confirmation of their structure and connectivity was achieved, in the absence of single crystals of suitable quality, by state-of-the-art structural powder diffraction methods. In Ag-5TFMU, the organic ligand is tridentate and two distinct metal coordination environments are found (linear AgN2 as well as C2v AgO4 geometries), whereas Ag-6TFMU contains a complex polymeric structure with tetradentate dianionic 6TFMU moieties and five distinct AgX2 (X = N, O) fragments, further stabilized by ancillary (longer) Ag…O contacts. These species presented modest activity over Gram-positive and Gram-negative bacterial strains, whereas Ag-6TFMU was active over a set of tumor cells, with the best activity over prostate (PC-3) and kidney cell lines and selectivity indices of 4.6 and 1.3, respectively. On the other hand, Ag-5TFMU was active over all considered tumor cells except MCF-7 (breast cancer). The best activity was found for PC-3 cells, but no selectivity was observed. The Ag-5TFMU and Ag-6TFMU species also reduced the proliferation of tongue squamous cell carcinoma cell lines SCC - 4 and SCC-15. Preliminary biophysical assays by circular dichroism suggest that the Ag-5TFMU complex interacts with DNA by intercalation, an effect not seen in Ag-6TFMU.

The Miniaturized Isolation of Neutrophil Granules (MING) method allowed a deep proteome mapping of human neutrophil granules.

Neutrophils are the innate immune system's first line of defense, and their storage organelles are essential to their function. The storage organelles are divided into three different granule types named azurophilic, specific, and gelatinase granules, besides a fourth component called secretory vesicles. The isolation of neutrophil's granules is challenging, and the existing procedures rely on large sample volumes, about 400 mL of peripheral blood, precluding the use of multiple biological and technical replicates. Therefore, the aim of this study was to develop a miniaturized isolation of neutrophil granules (MING) method, using biochemical assays, mass spectrometry-based proteomics and a machine learning approach to investigate the protein content of these organelles. Neutrophils were isolated from 40 mL of blood collected from three apparently healthy volunteers and disrupted using nitrogen cavitation; the organelles were fractionated with a discontinuous 3-layer Percoll density gradient. The isolation was proven successful and allowed for a reasonable separation of neutrophil's storage organelles using a gradient approximately 37 times smaller than the methods described in the literature. Moreover, mass spectrometry-based proteomics identified 368 proteins in at least 3 of the 5 analyzed samples, and using a machine learning strategy aligned with markers from the literature, the localization of 50 proteins was predicted with confidence. When using markers determined within our dataset by a clusterization tool, the localization of 348 proteins was confidently determined. Importantly, this study was the first to investigate the proteome of neutrophil granules using technical and biological replicates, creating a reliable database for further studies.

Impact of antiparasitic used in livestock: effects of ivermectin spiked sediment in Prochilodus lineatus, an inland fishery species of South America.

Ivermectin (IVM) is a widely used antiparasitic. Concerns have been raised about its environmental effects in the wetlands of Río de la Plata basin where cattle have been treated with IVM for years. This study investigated the sublethal effects of environmentally relevant IVM concentrations in sediments on the Neotropical fish Prochilodus lineatus. Juvenile P. lineatus were exposed to IVM-spiked sediments (2 and 20 µg/Kg) for 14 days, alongside a control sediment treatment without IVM. Biochemical and oxidative stress responses were assessed in brain, gills, and liver tissues, including lipid damage, glutathione levels, enzyme activities, and antioxidant competence. Muscle and brain acetylcholinesterase activity (AChE) and stable isotopes of 13C and 15N in muscle were also measured. The lowest IVM treatment resulted in an increase in brain lipid peroxidation, as measured by thiobarbituric acid reactive substances (TBARs), decreased levels of reduced glutathione (GSH) in gills and liver, increased catalase activity (CAT) in the liver, and decreased antioxidant capacity against peroxyl radicals (ACAP) in gills and liver. The highest IVM treatment significantly reduced GSH in the liver. Muscle (AChE) was decreased in both treatments. Multivariate analysis showed significant overall effects in the liver tissue, followed by gills and brain. These findings demonstrate the sublethal effects of IVM in P. lineatus, emphasizing the importance of considering sediment contamination and trophic habits in realistic exposure scenarios.

Homo- and Heterogeneous Benzyl Alcohol Catalytic Oxidation Promoted by Mononuclear Copper(II) Complexes: The Influence of the Ligand upon Product Conversion.

The catalytic properties of three copper complexes, [Cu(en)2](ClO4)2 (1), [Cu(amp)2](ClO4)2, (2) and [Cu(bpy)2](ClO4)2 (3) (where en = ethylenediamine, amp = 2-aminomethylpyridine and bpy = 2,2'-bipyridine), were explored upon the oxidation of benzyl alcohol (BnOH). Maximized conversions of the substrates to their respective products were obtained using a multivariate analysis approach, a powerful tool that allowed multiple variables to be optimized simultaneously, thus creating a more economical, fast and effective technique. Considering the studies in a fluid solution (homogeneous), all complexes strongly depended on the amount of the oxidizing agent (H2O2), followed by the catalyst load. In contrast, time seemed to be statistically less relevant for complexes 1 and 3 and not relevant for 2. All complexes showed high selectivity in their optimized conditions, and only benzaldehyde (BA) was obtained as a viable product. Quantitatively, the catalytic activity observed was 3 > 2 > 1, which is related to the π-acceptor character of the ligands employed in the study. Density functional theory (DFT) studies could corroborate this feature by correlating the geometric index for square pyramid Cu(II)-OOH species, which should be generated in the solution during the catalytic process. Complex 3 was successfully immobilized in silica-coated magnetic nanoparticles (Fe3O4@SiO2), and its oxidative activity was evaluated through heterogenous catalysis assays. Substrate conversion promoted by 3-Fe3O4@SiO2 generated only BA as a viable product, and the supported catalyst's recyclability was proven. Reduced catalytic conversions in the presence of the radical scavenger (2,2,6,6-tetrametil-piperidi-1-nil)oxil (TEMPO) indicate that radical and non-radical mechanisms are involved.

Improving access to cancer clinical research in Brazil: recent advances and new opportunities. Expert opinions from the 4th CURA meeting, São Paulo, 2023.

Clinical research is the cornerstone of improvements in cancer care. However, it has been conducted predominantly in high-income countries with few clinical trials available in Brazil and other low-and-middle-income countries (LMIC). Of note, less than one-third of registered clinical trials addressing some of the most commonly diagnosed cancers (breast, lung and cervical) recruited patients from LMIC in the last years. The Institute Project CURA promoted the fourth CURA meeting, discussing barriers to cancer clinical research and proposing potential solutions. A meeting was held in São Paulo, Brazil, in June 2023 with representatives from different sectors: Brazilian Health Regulatory Agency (Anvisa), National Commission of Ethics in Research (CONEP), non-governmental organisations, such as the Latin American Cooperative Oncology Group, the Brazilian Society of Clinical Oncology (SBOC), Contract Research Organisations, pharmaceutical companies and investigators. A total of 16 experts pointed out achievements as shortening the time of regulatory processes involving Anvisa and CONEP, development of staff training programs, maintenance of the National Program of Oncological Attention (PRONON), and the foundation of qualified centres in North and Northeast Brazilian regions. Participants also highlighted the need to be more competitive in the field, which requires optimising ongoing policies and implementing new strategies as decentralisation of clinical research centres, public awareness campaigns, community-centered approaches, collaborations and partnerships, expansion of physicians-directed policies, exploring the role of the steering committee. Active and consistent reporting of the initiatives might help to propagate ongoing advances, increasing Brazilian participation in clinical cancer research. Engagement of all players is crucial to maintain continuous progress with further improvements in critical points including regulatory timelines and increments in qualified human resources which aligned with new educational initiatives focused on physicians and the general population will expand access to cancer clinical trials in Brazil.

The influence of thioether-substituted ligands in dicopper(II) complexes: Enhancing oxidation and biological activities.

This paper describes the synthesis, structural analysis, as well as the magnetic and spectroscopic characterizations of three new dicopper(II) complexes with dinucleating phenol-based ligands containing different thioether donor substituents: aromatic (1), aliphatic (2) or thiophene (3). Temperature-dependent magnetometry reveals the presence of antiferromagnetic coupling for 1 and 3 (J = -2.27 cm-1 and -5.01 cm-1, respectively, H = -2JS1S2) and ferromagnetic coupling for 2 (J = 5.72 cm-1). Broken symmetry DFT calculations attribute this behavior to a major contribution from the dz2 orbitals for 1 and 3, and from the dx2-y2 orbitals for 2, along with the p orbitals of the oxygens. The bioinspired catalytic activities of these complexes related to catechol oxidase were studied using 3,5-di-tert-butylcatechol as substrate. The order of catalytic rates for the substrate oxidation follows the trend 1 > 2 > 3 with kcat of (90.79 ± 2.90) × 10-3 for 1, (64.21 ± 0.99) × 10-3 for 2 and (14.20 ± 0.32) × 10-3 s-1 for 3. The complexes also cleave DNA through an oxidative mechanism with minor-groove preference, as indicated by experimental and molecular docking assays. Antimicrobial potential of these highly active complexes has shown that 3 inhibits both Staphylococcus aureus bacterium and Epidermophyton floccosum fungus. Notably, the complexes were found to be nontoxic to normal cells but exhibited cytotoxicity against epidermoid carcinoma cells, surpassing the activity of the metallodrug cisplatin. This research shows the multifaceted properties of these complexes, making them promising candidates for various applications in catalysis, nucleic acids research, and antimicrobial activities.

Immune-pineal-ocular axis in amphibians: unveiling a novel connection?

Melatonin is a hormone known as an endogenous temporal marker signaling the dark phase of the day. Although the eyes seem to be the main site of melatonin production in amphibians, little information is available about the natural variation in the ocular melatonin levels and its modulation following immune stimulation. We investigated the daily variation of plasma and ocular melatonin levels in bullfrogs (Lithobates catesbeianus) and their modulation following an immune stimulation with lipopolysaccharide (LPS) in yellow cururu toads (Rhinella icterica). For the daily variation, bullfrogs were bled and then euthanized for eye collection every 3h over 24h to determine plasma and ocular melatonin levels. We found a positive correlation between ocular and plasma melatonin levels, with maximum values at night (22h) for both plasma and the eyes. For immune stimulation, yellow cururu toads received an intraperitoneal injection of LPS or saline solution during the day (10h) or at night (22h). Two hours after injection, toads were bled and euthanized for eye collection to obtain plasma and ocular melatonin levels. In addition, the liver and bone marrow were collected to investigate local melatonin modulation. Our results demonstrate that retina light-controlled rhythmic melatonin production is suppressed while liver and bone marrow melatonin levels increase during the inflammatory assemblage in anurans. Interestingly, the LPS injection decreased only ocular melatonin levels, reinforcing the central role of the eyes (i.e., retina) as an essential organ of melatonin production, and a similar role to the pineal gland during the inflammatory response in amphibians. Together, these results point to a possible immune-pineal-ocular axis in amphibians, yet to be fully described in this group.

Reducing citrus effluent toxicity: Biological-electrochemical treatment with diamond anode.

One challenge of the citrus industry is the treatment and disposal of its effluents due to their high toxicity, substantial organic load, and consequent resistance to conventional biotechnological processes. This study introduces a novel approach, using electrochemical oxidation with a boron-doped diamond anode to efficiently remove organic compounds from biodegraded pulp wash (treated using the fungus Pleurotus sajor-caju.) The findings reveal that employing a current density of 20 mA cm-2 achieves notable results, including a 44.1% reduction in color, a 70.0% decrease in chemical oxygen demand, an 88.0% reduction in turbidity, and an impressive 99.7% removal of total organic carbon (TOC) after 6 h of electrolysis. The energy consumption was estimated at 2.93 kWh g-1 of removed TOC. This sequential biological-electrochemical procedure not only significantly reduced the mortality rate (85%) of Danio rerio embryos but also reduced the incidence of morphologically altered parameters. Regarding acute toxicity (LC50) of the residue, the process demonstrated a mortality reduction of 6.97% for D. rerio and a 40.88% lethality decrease for Lactuca sativa seeds. The substantial reduction in toxicity and organic load observed in this study highlights the potential applicability of combined biological and electrochemical treatments for real agroindustrial residues or their effluents.

A fluorescence-based multivariate method for biodiesel quantification in undiluted diesel-biodiesel blends without sample preparation.

In this work, excitation-emission matrices (EEMs) were used in association with parallel factor analysis (PARAFAC) to assess biodiesel content in undiluted diesel-biodiesel blends (DBBs) without pre-sample preparation. EEMs were decomposed using the PARAFAC (EEMs-PARAFAC), and the loading values of the PARAFAC component as a function of biodiesel content in the blends were used to build an analytical model to quantify the biodiesel content in DBBs. The proposed model presenting a limit of detection (LOD) and a limit of quantification (LOQ) of 2.5% and 11% w/w, respectively, successfully predicted the biodiesel content in the validation samples. The robustness of the model was confirmed by a close analysis of the root mean square error of prediction, standard error of prediction, relative standard deviation of prediction, and Bias. Therefore, an accurate and robust analytical model based on EEMs-PARAFAC was developed to quantify the biodiesel content in undiluted DBBs without sample preparation.

Gene duplication as a major force driving the genome expansion in some giant viruses.

IMPORTANCE: Giant viruses are noteworthy not only due to their enormous particles but also because of their gigantic genomes. In this context, a fundamental question has persisted: how did these genomes evolve? Here we present the discovery of cedratvirus pambiensis, featuring the largest genome ever described for a cedratvirus. Our data suggest that the larger size of the genome can be attributed to an unprecedented number of duplicated genes. Further investigation of this phenomenon in other viruses has illuminated gene duplication as a key evolutionary mechanism driving genome expansion in diverse giant viruses. Although gene duplication has been described as a recurrent event in cellular organisms, our data highlights its potential as a pivotal event in the evolution of gigantic viral genomes.

Introduction, Dispersal, and Predominance of SARS-CoV-2 Delta Variant in Rio Grande do Sul, Brazil: A Retrospective Analysis.

Mutations in the SARS-CoV-2 genome can alter the virus' fitness, leading to the emergence of variants of concern (VOC). In Brazil, the Gamma variant dominated the pandemic in the first half of 2021, and from June onwards, the first cases of Delta infection were documented. Here, we investigate the introduction and dispersal of the Delta variant in the RS state by sequencing 1077 SARS-CoV-2-positive samples from June to October 2021. Of these samples, 34.7% were identified as Gamma and 65.3% as Delta. Notably, 99.2% of Delta sequences were clustered within the 21J lineage, forming a significant Brazilian clade. The estimated clock rate was 5.97 × 10-4 substitutions per site per year. The Delta variant was first reported on 17 June in the Vinhedos Basalto microregion and rapidly spread, accounting for over 70% of cases within nine weeks. Despite this, the number of cases and deaths remained stable, possibly due to vaccination, prior infections, and the continued mandatory mask use. In conclusion, our study provides insights into the Delta variant circulating in the RS state, highlighting the importance of genomic surveillance for monitoring viral evolution, even when the impact of new variants may be less severe in a given region.

B-cell small lymphocytic lymphoma in a free-ranging South American fur seal (Arctocephalus australis).

Lymphomas are malignant neoplasms of the hematopoietic system arising from lymphocytes with highly variable biologic behavior. B-cell small lymphocytic lymphoma (B-SLL) is a non-Hodgkin lymphoma infrequently described in domestic and wild animals. The present study describes a case of B-SLL in a free-ranging adult male Arctocephalus australis in Brazil. The main necropsy findings included poor body condition, generalized lymphadenomegaly, severe and diffuse splenomegaly, and multiple, white to yellow nodules in the kidneys and small intestine. Histologically, these organs were partially or totally effaced by neoplastic small lymphocytes arranged in sheets, with moderate anisocytosis and anisokaryosis and a low mitotic count. These cells diffusely immunolabeled for CD79α and CD20, and were negative for CD3. A diagnosis of multicentric B-SLL was established and to the authors' knowledge, it has not been previously described in this genus.

Comprehensive inventory of páramo birds and their habitat affinities in a conservation hotspot, the Macizo del Cajas Biosphere Reserve, southern Ecuador

The páramo ecosystem is a significant centre of Andean bird diversity with high concentrations of threatened species. The Macizo del Cajas Biosphere Reserve's páramos are a district of the biogeographic páramo province of northern Andes and are therefore considered a conservation hotspot with representative bird diversity. To enhance regional conservation efforts, comprehensive inventories of bird species that occupy this páramo are required. We present an updated bird inventory for the páramos of Macizo del Cajas and included validated records from eBird and GBIF databases along with records from continuous monitoring across this páramo landscape for five years. We also provide notes on habitat affinity and important new, rare, restricted range, and threatened birds. We report 112 bird species within the reserve, including five endemics, and three globally and 12 nationally threatened species. Finally, we discuss the use of habitat affinities as indicators of biodiversity patterns in páramo to improve conservation tools for key habitats.

El ecosistema de páramo es un centro importante de diversidad de aves andinas con altas concentraciones de especies amenazadas. Los páramos de la Reserva de la Biosfera Macizo del Cajas son un distrito biogeográfico de la provincia del páramo de los Andes del norte y por tanto, son un punto crítico de conservación con una diversidad de aves representativa. Inventarios exhaustivos de la avifauna que ocupa este páramo son requeridos para asegurar esfuerzos de conservación regional. El presente estudio brinda un inventario actualizado de aves de los páramos del Macizo del Cajas. Se incluyen registros verificados desde eBird y GBIF, así como registros de cinco años continuos de monitoreo a través del paisaje de páramo. Además, se incluyen notas acerca de la afinidad de hábitat y registros importantes, nuevos, raros y de aves amenazadas. En total, se reportan 112 especies de aves dentro de la reserva, incluyen cinco endémicas, tres globalmente amenazadas y 12 a escala nacional. Finalmente, se discute el uso de la afinidad de hábitat como indicador de los patrones de biodiversidad en el páramo para mejorar herramientas de conservación para hábitats clave.

Role of Female Sex Hormones and Immune Response in Salt-Sensitive Hypertension Development: Evidence from Experimental Models.

PURPOSEOF REVIEW: Female sex hormones have systemic effects unrelated to their reproductive function. We describe experiences of different research groups and our own, on aspects related to the importance of female sex hormones on blood pressure (BP) regulation and salt-sensitivity-mediated BP response and salt sensitivity without alterations in BP, as well as renal sodium handling and interactions with the immune system. RECENT FINDINGS: Changes in sodium intake in normotensive premenopausal women cause more BP variations than in men. After menopause, women often develop arterial hypertension (HT) with a profile of sodium sensitivity. Besides, experimental results have shown that in adult rat models resembling the postmenopausal hormonal state induced by ovariectomy, controlling BP is not enough to avoid renal and other tissue infiltration with immune cells, which does not occur when sodium intake is low or normal. Therefore, excess sodium promotes an inflammatory state with the involvement of immune cells. The evidence of activation of adaptive immunity, besides changes in T cell subpopulations, includes changes in sodium transporters and receptors. More studies are needed to evaluate the particular sodium sensitivity of women and its meaning. Changes in lifestyle and sodium intake reduction are the main therapeutic steps. However, to face the actual burden of salt-sensitive HT in postmenopausal women and its associated inflammatory/immune changes, it seems reasonable to work on immune cell activity by considering the peripheral blood mononuclear cell phenotypes of molecules and transport proteins related to sodium handle, both to screen for and treat cell activation.

Therapeutic Protocols Using Ketamine and Esketamine for Depressive Disorders: A Systematic Review.

Depression is one of the most prevalent mental health disorders globally, causing severe emotional suffering, reducing life expectancy and increasing the risk of suicide. Recently, the use of dissociative psychedelic substances such as ketamine and esketamine for depressive disorders has expanded treatment options. We sought to analyze, through a systematic review, the existing protocols for the treatment of depression with ketamine and esketamine. The search adopted PRISMA criteria and was performed using PubMed and Web of Science databases. Procedures in each study were compared, focusing on the sample recruited, therapeutic approaches, including the clinical team and professionals engaged in treatment, medical procedures, description of the setting (including music) and factors such as specific medication (ketamine or esketamine), route of administration and dosage employed. Results indicated the predominance of a medical approach, with a limited number of studies on ketamine assisted psychotherapy (KAP) and other modalities of psychedelic assisted therapy. Additionally, there is limited information on psychosocial elements such as preparation, psychological support during session and integration of experience. Altogether these findings suggest that treatment of depression with ketamine or esketamine diverges in relation to the practices employed with psychedelic substances. This is discussed considering future research directions in the field.

Contrasting effects of transdermal and implant corticosterone treatments in the American bullfrog wound healing.

Glucocorticoid (GC) release is triggered by adverse stimuli that activate the hypothalamus-pituitary-adrenal/interrenal axis. Glucocorticoids may enhance or suppress immune functions depending on the level of elevation. In this study, we investigated the effects of transient and chronic increase of corticosterone (CORT) on the wound healing of the American bullfrog. Frogs were submitted to a daily transdermal hormonal application that acutely elevated CORT plasma levels, or vehicle as a control. Other frogs were surgically implanted with a silastic tube filled with CORT that resulted in chronic elevation of CORT plasma levels or received empty implants as a control. A dermal biopsy was performed to create a wound and was photographed every 3 days. Individuals treated with transdermal CORT started healing faster than their control 32 days after the biopsy. Frogs that received CORT implants tended to heal slower than control subjects. Plasma bacterial killing ability was not affected by treatment, which reinforces the constitutive nature of this innate immune trait. By the end of the experiment, frogs from the acute CORT treatment had smaller wounds compared with those receiving the CORT-filled implants, highlighting the differential effects of acute (immunoenhancing) and chronic (immunosuppressive) elevation of CORT plasma levels. This article is part of the theme issue 'Amphibian immunity: stress, disease and ecoimmunology'.