Molecular Docking and Antibacterial Activity of Campesterol Derivatives Against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa multiresistant strains.

This work describes the evaluation the potentiating activity of antibiotics by campesterol (1) and its derivatives (2-11) against multiresistant strains of Staphylococcusaureus 10, Escherichia coli 06 and Pseudomonas aeruginosa 24 employing the microdilution test. When subjected to the in vitro potentiating activity bioassay, all compounds showed a potentiating effect associated with norfloxacin against E. coli and P. aeruginosa with a reduction in the MIC of the antibiotic of up to 75%. These compounds also reduced the MIC of gentamicin by 37% to 87% in S. aureus and E. coli. Additionally, molecular docking studies were conducted to gain a deeper understanding of the interactions between the appropriate proteins and the most effective compounds (2, 4, 9, and 10 against E. coli; 1, 2, 3, 5, 8, and 9 against S. aureus), including antibiotics. This paper registers for the first time the in vitro and in silico studies on the action of compounds 1-11 in antibiotic potentiation.

Surface tension-driven sorting of human perilipins on lipid droplets.

Perilipins (PLINs), the most abundant proteins on lipid droplets (LDs), display similar domain organization including amphipathic helices (AH). However, the five human PLINs bind different LDs, suggesting different modes of interaction. We established a minimal system whereby artificial LDs covered with defined polar lipids were transiently deformed to promote surface tension. Binding of purified PLIN3 and PLIN4 AH was strongly facilitated by tension but was poorly sensitive to phospholipid composition and to the presence of diacylglycerol. Accordingly, LD coverage by PLIN3 increased as phospholipid coverage decreased. In contrast, PLIN1 bound readily to LDs fully covered by phospholipids; PLIN2 showed an intermediate behavior between PLIN1 and PLIN3. In human adipocytes, PLIN3/4 were found in a soluble pool and relocated to LDs upon stimulation of fast triglyceride synthesis, whereas PLIN1 and PLIN2 localized to pre-existing LDs, consistent with the large difference in LD avidity observed in vitro. We conclude that the PLIN repertoire is adapted to handling LDs with different surface properties.

Accumulation of damaged mitochondria in aging astrocytes due to mitophagy dysfunction: Implications for susceptibility to mitochondrial stress.

Aging disrupts brain function, leading to cognitive decline and neurodegenerative diseases. Senescent astrocytes, a hallmark of aging, contribute to this process through unknown mechanisms. This study investigates how senescence impacts astrocytic mitochondrial dynamics, which are critical for brain health. Our research, conducted using aged mouse brains, represents the first evidence of morphologically damaged mitochondria in astrocytes, along with functional alterations in mitochondrial respiration. In vitro experiments revealed that senescent astrocytes exhibit an increase in mitochondrial fragmentation and impaired mitophagy. Concurrently, there was an upregulation of mitochondrial biogenesis, indicating a compensatory response to mitochondrial damage. Importantly, these senescent astrocytes were more susceptible to mitochondrial stress, a vulnerability reversed by rapamycin treatment. These findings suggest a potential link between senescence, impaired mitochondrial quality control, and increased susceptibility to mitochondrial stress in astrocytes. Overall, our study highlights the importance of addressing mitochondrial dysfunction and senescence-related changes in astrocytes as a promising approach for developing therapies to counter age-related neurodegeneration and improve brain health.

Assigning roles in Chlamydomonas ribosome biogenesis: The conserved factor NIP7.

Ribosome biogenesis (RB) is a highly conserved process across eukaryotes that results in the assembly of functional ribosomal subunits. Studies in Saccharomyces cerevisiae and Homo sapiens have identified numerous RB factors (RBFs), including the NIP7 protein, which is involved in late-stage pre-60S ribosomal maturation. NIP7 expression has also been observed in Chlamydomonas reinhardtii, highlighting its evolutionary significance. This study aimed to characterize the function of the NIP7 protein from C. reinhardtii (CrNip7) through protein complementation assays and a paromomycin resistance test, assessing its ability to complement the role of NIP7 in yeast. Protein interaction studies were conducted via yeast two-hybrid assay to identify potential protein partners of CrNip7. Additionally, rRNA modeling analysis was performed using the predicted structure of CrNip7 to investigate its interaction with rRNA. The study revealed that CrNip7 can complement the role of NIP7 in yeast, implicating CrNip7 in the biogenesis of the 60S ribosomal subunit. Furthermore, two possible partner proteins of CrNip7, UNC-p and G-patch, were identified through yeast two-hybrid assay. The potential of these proteins to interact with CrNip7 was explored through in silico analyses. Furthermore, nucleic acid interaction was also evaluated, indicating the involvement of the N- and C-terminal domains of CrNIP7 in interacting with rRNA. Collectively, our findings provide valuable insights into the RBFs CrNip7, offering novel information for comparative studies on RB among eukaryotic model organisms, shedding light on its evolutionary conservation and functional role across species.

Development of a clinical investigation protocol for occupational auditory health.

Introduction: Considering that noise is present in different work environments, occupational health regulations have been created that advocate for the care of employees' auditory system in these environments. Occupational hearing assessment should be performed by audiologists through audiological examinations, otoscopy, as well as an interview to assess possible risk factors for the development of hearing loss. However, up to the present moment, a standardized set of updated questions for this interview has not been defined. Objectives: To develop a clinical investigation instrument for occupational auditory health that provides support for clinical decision-making and differential diagnosis. Methods: The study was conducted using Design Thinking as a methodological approach in its stages of inspiration (problem identification), ideation (theoretical foundation and protocol design), and prototyping (protocol construction). Experience report: This study was conducted with the objective of providing support for clinical decision-making and differential diagnosis of the auditory aspects of the assisted population. The Protocolo de Investigação Clínica da Saúde Auditiva Ocupacional was developed, consisting of six main sections that address medical history, lifestyle habits, exposure to non-occupational noise, work history, extra-auditory symptoms, and auditory and vestibular signs and symptoms, aimed at investigating workers' auditory health and related aspects. Conclusions: The developed instrument can be used for data collection and assist audiologists in the occupational health teams in diagnosis and decision-making processes.

Introdução: Considerando que o ruído está presente em diferentes ambientes laborais, foram criadas normas regulamentadoras de saúde ocupacional que preconizam o cuidado com o sistema auditivo dos colaboradores destes ambientes. A avaliação auditiva ocupacional deve ser realizada pelo fonoaudiólogo através dos exames de audiometria e meatoscopia, além de uma entrevista para avaliar possíveis fatores de risco para o desenvolvimento de perdas auditivas. Entretanto, até o presente momento não foi definido um padrão de perguntas atualizado para esta entrevista. Objetivos: Desenvolver um instrumento de investigação clínica da saúde auditiva ocupacional que ofereça suporte para tomadas de decisões clínicas e diagnóstico diferencial. Métodos: O estudo foi desenvolvido utilizando o design thinking como abordagem metodológica em suas etapas de inspiração (observada a problemática), ideação (fundamentação e delineamento teórico do protocolo) e prototipação (construção do protocolo). Relato da experiência: Este estudo foi realizado objetivando oferecer suporte para tomadas de decisões clínicas e diagnóstico diferencial dos aspectos auditivos da população assistida. Foi desenvolvido o Protocolo de Investigação Clínica da Saúde Auditiva Ocupacional, composto de seis seções principais que abordam o histórico clínico, hábitos de vida, exposição a ruído extraocupacional, histórico laboral, sintomas extra-auditivos e sinais e sintomas auditivos e vestibulares, que visam investigar a saúde auditiva do trabalhador e aspectos relacionados a ela. Conclusões: O instrumento desenvolvido poderá servir para a coleta de dados e auxílio para diagnóstico e tomada de decisões dos fonoaudiólogos das equipes de saúde ocupacional.

Discarded substrates from soilless hydroponic horticulture as potential amendments for metal-contaminated soils.

Soil contamination with metals is a major threat for the environment and public health since most metals are toxic to humans and to non-human biota, even at low concentrations. Thus, new sustainable remediation approaches are currently needed to immobilize metals in soils to decrease their mobility and bioavailability. In this work, we explore the application of discarded substrates from hydroponic cultivation, namely coconut shell and a mixture of coconut shell and pine bark, for immobilization of metals (Cd, Cr, Ni, Cu, Pb, Hg, Sb and As) in a naturally contaminated soil from a mining region in Portugal. The immobilization capacity of substrates (added to the soil at 5% mass ratio) was assessed both individually and also combined with other traditional agriculture soil additives (limestone and gypsum, at 2% mass ratio) and nanoparticles of zero-valent iron (nZVI) at 1-3% mass ratio. The overall results obtained after a 30-d incubation showed that the discarded substrates are a viable, economic, and environmental-friendly solution for metal remediation in soils, with the capacity of immobilization ranging from 20 to 91% for the metals and metalloids studied. Furthermore, they showed the capacity to reduce the soil toxicity (EC50 ∼ 6000 mg/L) to non-toxic levels (EC50 > 10000 mg/L) to the bacteria Aliivrio fischeri.

SCI1, a flower regulator of cell proliferation, and its partners NtCDKG2 and NtRH35 interact with the splicing machinery.

Successful plant reproduction depends on the adequate development of flower organs controlled by cell proliferation and other processes. The SCI1 gene regulates cell proliferation and affects the final size of the female reproductive organ. To unravel the molecular mechanism exerted by SCI1 in cell proliferation control, we searched for its interaction partners through semi-in vivo pulldown experiments, uncovering a cyclin-dependent kinase, NtCDKG;2. Bimolecular fluorescence complementation (BiFC) and co-localization experiments showed that SCI1 interacts with NtCDKG;2 and its cognate NtCyclin L in nucleoli and splicing speckles. The screening of a yeast two-hybrid (Y2H) cDNA library using SCI1 as bait revealed a novel DEAD-box RNA helicase (NtRH35). The interaction between the NtCDKG;2-NtCyclin L complex, and NtRH35 was also shown. Subcellular localization experiments showed that SCI1, NtRH35, and the NtCDKG;2-NtCyclin L complex associate with each other within splicing speckles. The Y2H screening of NtCDKG;2 and NtRH35 identified the conserved spliceosome components U2a', NKAP, and CACTIN. This work presents SCI1 and its interactors NtCDKG;2-NtCyclin L complex, and NtRH35 as new spliceosome-associated proteins. Our findings reveal a network of interactions and suggest that SCI1 may regulate cell proliferation through the splicing process. This study provides new valuable insights into the intricate molecular pathways governing plant development.

Predicting the Threat Status of Mosses Using Functional Traits.

Mosses are an early lineage of the plant kingdom, with around 13,000 species. Although an important part of biodiversity, providing crucial ecosystem services, many species are threatened with extinction. However, only circa 300 species have so far had their extinction risk evaluated globally for the IUCN Red List. Functional traits are known to help predict the extinction risk of species in other plant groups. In this study, a matrix of 15 functional traits was produced for 723 moss species from around the world to evaluate the potential of such predictability. Binary generalized linear models showed that monoicous species were more likely to be threatened than dioicous species, and the presence of a sporophyte (sexual reproduction), vegetative reproduction and an erect (straight) capsule instead of a pendent (immersed) one lowers the risk of species extinction. A longer capsule, seta and stem length, as well as broader substrate breadth, are indicative of species with a lower risk of extinction. The best-performing models fitted with few traits were able to predict extinction risks of species with good accuracy. These models applied to Data Deficient (DD) species proved how useful they may be to speed up the IUCN Red List assessment process while reducing the number of listed DD species, by selecting species most in need of a full, detailed assessment. Some traits tested in this study are a novelty in conservation research on mosses, opening new possibilities for future studies. The traits studied and the models presented here are a significant contribution to the knowledge of mosses at risk of extinction and will help to improve conservation efforts.

[Analysis of the operational conditions to preserve immunobiological products in vaccination rooms in Brazil: a mixed study]. / Análise das condições operacionais para conservação de imunobiológicos nas salas de vacinação do Brasil: estudo misto.

This study aimed to analyze the operational conditions to preserve immunobiological products in Brazil. This mixed-method study with a sequential explanatory design was developed in vaccination rooms in several Brazilian regions from 2021 to 2022. Its quantitative stage developed a descriptive cross-sectional study by applying the Immunobiological Conservation Assessment Scale to nursing professionals. Data were analyzed by descriptive statistics. Its qualitative stage developed a descriptive-exploratory study in cold chain instances with the respective technical managers and nursing professionals. The interviews were evaluated by thematic content analysis. The data were combined by connection, and joint-displays and meta-inferences were elaborated. Overall, 280 rooms were analyzed. Most were for exclusive use (79.6%), had polyurethane boxes (77.8%), and kept their equipment away from sunlight/heat (73.5%). Only 27.5% had batteries/generators and 26.5% had other temperature measuring instruments. In total, 60% had refrigerated rooms and 67.6%, air-conditioned rooms. This study found weaknesses associated with geographical conditions, infrastructure, material inputs, human and financial resources, work organization and management, turnover, and training. These findings showed the plurality of the Brazilian cold chain and identified the potentialities and weaknesses related to the structures and work processes in preserving immunobiological products, which require improvement.

Este estudo objetivou analisar as condições operacionais para conservação de imunobiológicos no Brasil. Trata-se de um estudo de método misto com delineamento explanatório sequencial, desenvolvido nas salas de vacinação de distintas regiões brasileiras entre 2021 e 2022. Na etapa quantitativa, desenvolveu-se um estudo transversal descritivo, com a aplicação da Escala de Avaliação da Conservação de Imunobiológicos aos profissionais de enfermagem. Os dados foram analisados por meio de estatística descritiva. Já na etapa qualitativa, desenvolveu-se um estudo descritivo-exploratório nas instâncias da cadeia de frio, com os respectivos responsáveis técnicos e profissionais de enfermagem. Analisou-se as entrevistas por meio da Análise de Conteúdo na Modalidade Temática. Os dados foram combinados mediante conexão, com elaboração de joint-displays e metainferências. Foram analisadas 280 salas, em que grande parte: era de uso exclusivo (79,6%); utilizava caixas de poliuretano (77,8%); e mantinha seus equipamentos distantes da incidência de luz solar/fontes de calor (73,5%). Apenas 27,5% dispunham de baterias/geradores e 26,5% de outros instrumentos de medição de temperatura. Sessenta por cento detinham câmaras refrigeradas e 67,6% ambientes climatizados. Revelaram-se fragilidades associadas a condições geográficas, infraestrutura, insumos materiais, recursos humanos e financeiros, organização e gestão do trabalho, rotatividade e capacitação. Os achados possibilitaram conhecer a pluralidade da cadeia de frio brasileira e permitiram a identificação de potencialidades e fragilidades na conservação de imunobiológicos relacionadas às estruturas e aos processos de trabalho que requerem aprimoramento.

Este estudio tuvo como objetivo analizar las condiciones operativas para la conservación de inmunobiológicos en Brasil. Estudio de método mixto con diseño explicativo secuencial, desarrollado en las salas de vacunación de las distintas regiones brasileñas, entre 2021 y 2022. En la etapa cuantitativa se desarrolló un estudio transversal descriptivo, con la aplicación de la Escala de Evaluación de la Conservación de Inmunobiológicos a los profesionales de enfermería. Los datos fueron analizados mediante estadística descriptiva. En la etapa cualitativa se desarrolló un estudio descriptivo-exploratorio en las instancias de la cadena de frío, con los respectivos responsables técnicos y profesionales de enfermería. Las entrevistas se analizaron por medio del Análisis de Contenido en la Modalidad Temática. Los datos fueron combinados mediante conexión, con elaboración de joint-displays y metainferencias. Se analizaron 280 salas. Gran parte era de uso exclusivo (79,6%); utilizaba cajas de poliuretano (77,8%) y mantenía sus equipos alejados de la incidencia de la luz solar/fuentes de calor (73,5%). Solo el 27,5% disponía de baterías/generadores y el 26,5% de otros instrumentos de medición de temperatura. El 60% tenía cámaras refrigeradas y el 67,6% ambientes climatizados. Se revelaron debilidades asociadas a las condiciones geográficas, la infraestructura, los insumos de materiales, los recursos humanos y financieros, la organización y gestión del trabajo, la rotación y la capacitación. Los hallazgos posibilitaron conocer la pluralidad de la cadena de frío brasileña y permitieron la identificación de potencialidades y debilidades de la conservación de inmunobiológicos relacionadas con las estructuras y los procesos de trabajo que requieren mejoras.

Dual challenge inside the womb: a case report of concomitant fetal atrio-ventricular block associated with maternal anti-SSA antibodies and fetal tachyarrhythmia diagnosed as Wolff-Parkinson-White syndrome after birth.

Fetal autoimmune atrioventricular block (AVB) is a rare but potentially life-threatening condition. It results from the passage of maternal anti-SSA/Ro or Anti SSB/La auto-antibodies into the fetal circulation, leading to inflammation and fibrosis of the AV node and often to irreversible damage. Besides AVB, these antibodies can also cause cardiomyopathies, but there is no evidence linking them to tachyarrhythmias. We present the case of a patient with significant risk factors for fetal AVB: a prior history of hydrops fetalis, high anti-SSA/Ro antibody levels and hypothyroidism. In this case, the use of dexamethasone and intravenous immunoglobulin may have contributed to reversing the first-degree atrioventricular block detected at 19 weeks of gestation. Additionally, at 21 weeks, the fetus developed a tachyarrhythmia that needed treatment with flecainide. Soon after the birth, the newborn underwent ECG Holter and Wolff-Parkinson-White Syndrome (WPWS) was diagnosed. To our knowledge, the coexistence of fetal AVB and WPWS has never been described.

Thiazine-derived compounds in inhibiting efflux pump in Staphylococcus aureus K2068, mepA gene expression, and membrane permeability alteration.

Staphylococcus aureus is a bacterium responsible for resistance to multiple drugs and the efflux system is widely studied among the resistance mechanisms developed by this species. The present study evaluates the inhibition of the MepA efflux pump by thiadiazine-derived compounds. For this purpose, thiadiazine-derived compounds (IJ-14 to IJ-20) were tested against S. aureus K2068 strains. Microdilution tests were initially conducted to assess the Minimum Inhibitory Concentration (MIC) of the compounds and their efflux pump inhibition activity. In addition, fluorimetry tests were performed using BrEt emission and tests were conducted to inhibit the expression of the mepA gene. This involved comparing the bacterial gene expression with the antibiotic alone to the gene expression after combining compounds (IJ-17 and IJ-20) with the antibiotic. Furthermore, membrane permeability assessment tests and in silico molecular docking tests were performed. It was observed that the IJ17 and IJ20 compounds exhibited direct activity against the tested strain. The IJ17 compound produced significant results in the gene inhibition tests, which was also evidenced through the membrane permeability alteration test. These findings suggest that thiadiazine-derived compounds have promising effects against one of the main resistance mechanisms, with the IJ17 compound presenting observable mechanisms of action.

Assessment In vitro and In silico of the Activity of Thiadiazines as NorA Efflux Pump Inhibitors.

Antimicrobials fight microorganisms, preventing and treating infectious diseases. However, antimicrobial resistance (AMR) is a growing concern due to the inappropriate and excessive use of these drugs. Several mechanisms can lead to resistance, including efflux pumps such as the NorA pump in Staphylococcus aureus, which reduces the effectiveness of fluoroquinolones. Thiadiazines are heterocyclic compounds whose chemical structure resembles that of cephalosporins. Therefore, these compounds and their derivatives have been studied for their potential in combating increased bacterial resistance. To analyze this hypothesis, direct activity assays, antibiotic action-modifying activity, fluorescence assays to evaluate the retention of ethidium bromide inside bacteria, and molecular docking were carried out. These experiments involved serial dilutions in microplates against Staphylococcus aureus strain 1199B under the influence of six thiadiazine derivatives (IJ10, IJ11, IJ21, IJ22, IJ23, and IJ25). The tests revealed that, despite not showing effective direct activity, some thiadiazine derivatives (IJ11, IJ21, and IJ22) inhibited the function of the bromide pump both in microdilution tests and in fluorescence and docking assays. Particularly, the IJ11 compound stood out for its activity similar to efflux inhibitors, as well as its inhibition of the norfloxacin pump of this bacterium. Among the results of this study, it deserves to be highlighted for anchoring future experiments, as it represents the first investigation of this group of thiadiazine derivatives against the NorA pump.

Withaphysalin Derivatives from Iochroma arborescens Induce Antiproliferative and Antimigratory Activities in vitro.

Withanolides are steroidal lactones commonly found in plants of the Solanaceae family that have significant medicinal value. In this study, three withanolides extracted from Iochroma arborescens leaves were isolated and characterized. These included withaphysalin F (3: ) and two newly identified epimeric compounds: 18R- and 18S-O-methyl-withaphysalin F (1: and 2: ). Their structures were elucidated by NMR, IR, MS, CD, and X-ray diffraction analysis, and their potential against cell proliferation and migration was investigated. The cytotoxic assay revealed activity against different tumor and non-tumor cell lines. (18S)-O-methyl-withaphysalin F (2: ) presented cell death effects after at least 6 hours of exposure. MDA-MB-231 cells were exposed to 0.06 and 0.6 µM of (18S)-O-methyl-withaphysalin F (2: ), and reductions in cell adhesion, migration, and clonogenicity were observed. Morphological analysis revealed negative regulation in filopodia, salience, and roughness, as well as alterations in cellular microarchitecture. These results provide clues as to the effects of (18S)-O-methyl-withaphysalin F (2: ), allowing new molecular modifications to improve potency and selectivity and increase our antineoplastic arsenal.

Topological properties of psychopathological networks of healthy and disordered individuals across mental disorders.

The identification of psychopathological markers has been the focus of several scientific fields. The results were inconsistent due to lack of a clear nosology. Network analysis, focusing on the interactions between symptoms, provided important insights into the nosology of mental disorders. These interactions originate several topological properties that could constitute markers of psychopathology. One of these properties is network connectivity, which has been explored in recent years. However, the results have been inconsistent, and the topological properties of psychopathological networks remain largely unexplored and unknown. We compared several topological properties (i.e., connectivity, average path length, assortativity, average degree, modularity, global clustering) of psychopathological networks of healthy and disordered participants across depression (N = 2830), generalized anxiety (N = 13,463), social anxiety (N = 12,814), and obsessive-compulsive disorder (N = 16,426). Networks were estimated using Bayesian Gaussian Graphical Models. The Janson-Shannon measure of divergence was used to identify differences between the network properties. Network connectivity distinguished healthy and disordered participants' networks in all disorders. However, in depression and generalized anxiety, network connectivity was higher in healthy participants. The presence and number of motifs also distinguished the networks of healthy and disordered participants. Other topological properties (i.e., modularity, clustering, average path length and average degree) seem to be disorder-specific. The psychopathological significance of network connectivity must be clarified. Some topological properties of psychopathological networks are promising markers of psychopathology and may contribute to clarifying the nosology of mental disorders.

Doxorubicin-galactomannan nanoconjugates for potential cancer treatment.

In this study, we report the synthesis and characterization of pH-responsive nanoconjugates for targeted drug delivery. Galactomannan extracted from D. regia seeds was oxidized to form aldehyde groups, achieving a percentage of oxidation of 25.6 %. The resulting oxidized galactomannan (GMOX) was then copolymerized with PINIPAm-NH2, yielding a copolymer. The copolymer exhibited signals from both GMOX and PNIPAm-NH2 in its NMR spectrum, confirming successful copolymerization. Critical association concentration (CAC) studies revealed the formation of nanostructures, with lower CAC values observed at higher temperatures. The copolymer and GMOX reacted with doxorubicin (DOX), resulting in nanoconjugates with controlled drug release profiles, especially under acidic conditions similar to tumor microenvironments. Cytotoxicity assays demonstrated significant efficacy of the nanoconjugates against melanoma cells with reduced toxicity towards healthy cells. These findings underscore the potential of the pH-responsive nanoconjugates as promising candidates for targeted cancer therapy, offering improved therapeutic efficacy and reduced systemic side effects.

Novel lipid-interaction motifs within the C-terminal domain of Septin10 from Schistosoma mansoni.

Septins are cytoskeletal proteins and their interaction with membranes is crucial for their role in various cellular processes. Septins have polybasic regions (PB1 and PB2) which are important for lipid interaction. Earlier, we and others have highlighted the role of the septin C-terminal domain (CTD) to membrane interaction. However, detailed information on residues/group of residues important for such feature is lacking. In this study, we investigate the lipid-binding profile of Schistosoma mansoni Septin10 (SmSEPT10) using PIP strip and Langmuir monolayer adsorption assays. Our findings highlight the CTD as the primary domain responsible for lipid interaction in SmSEPT10, showing binding to phosphatidylinositol phosphates. SmSEPT10 CTD contains a conserved polybasic region (PB3) present in both animals and fungi septins, and a Lys (K367) within its putative amphipathic helix (AH) that we demonstrate as important for lipid binding. PB3 deletion or mutation of this Lys (K367A) strongly impairs lipid interaction. Remarkably, we observe that the AH within a construct lacking the final 43 amino acid residues is insufficient for lipid binding. Furthermore, we investigate the homocomplex formed by SmSEPT10 CTD in solution by cross-linking experiments, CD spectroscopy, SEC-MALS and SEC-SAXS. Taken together, our studies define the lipid-binding region in SmSEPT10 and offer insights into the molecular basis of septin-membrane binding. This information is particularly relevant for less-studied non-human septins, such as SmSEPT10.

Combining cashew gum with cyclophosphamide in murine melanoma model: A strategy for the reduction of side effects.

The understanding of cancer immunity and antitumor factors generated by natural polysaccharides is not yet fully comprehended. Polysaccharides, like cashew gum (CG), can exhibit immunomodulatory action and may assist in the antitumor process and side effects relieve. This study aimed to determine the antitumor effect of CG alone or in combination with cyclophosphamide (CTX), and its interactions with immune cells, in a murine melanoma model, using the B16-F10 cell line. Tumor growth inhibition, hematological, histopathological, ELISA, flow cytometry, immunofluorescence, and qRT-PCR analyses were performed to elucidate the antitumor potential, involvement of immune cells, and potential toxic effects. CG showed significant tumor growth inhibition, reaching up to 42.9 % alone and 51.4 % in combination with CTX, with mild toxicity to organs. CG enhanced leukocyte count, even in the presence of CTX. Furthermore, CG influenced the activation of tumor-associated macrophages (TAM), characterized by an increase in Il4, as well as a reduction in Ifng, Il1b, Tgfb, and Il6 gene expression. Nevertheless, these effects did not compromise the antitumor activity of CG. In summary, the combination of CG with CTX is a promising approach for leukopenia, one of the most important side effects of cancer treatment and deserves further investigation.

Use and misuse of psychoactive medicines: a descriptive cross-sectional study in a densely populated region of Portugal.

Introduction: Although psychoactive medicines (PMed) are needed in several psychiatric conditions, their use and misuse bear risks. We aimed at estimating the prevalence of PMed use and misuse. Methods: Data on all PMed prescribed in 2017 and dispensed in community pharmacies of the Lisbon and Tagus Valley region of Portugal (ARSLVT) were extracted from ARSLVT medicines' dispensing database. For 21 PMed among prescription opioids, benzodiazepines and z-drugs (BZDR), antidepressants (AD) and anticonvulsants (AC), we estimated the number of users of each PMed, and assessed PMed misuse by a set of proxy indicators for studying this practice: chronic use (use of ≥180 DDD during the study period) of PMed intended for short-term treatments, concomitant use of several PMed, in particular if involving long-term (≥ 30 days) opioid analgesic (OA) use, and doctor shopping (patients consulting several physicians in order to have access to a quantity higher than intended by each prescriber). Data were analysed using descriptive statistics and hypothesis testing, and multivariate logistic regression was used to explore potential factors affecting long-term concomitant treatment of chronic OA with other PMed. Results: PMed use prevalence was 21.7%: 6.6% for OA, 12.7% for benzodiazepines (BZD), 5.3% for AD and 2.8% for AC. BZDR were mainly prescribed in primary care and OA in hospital outpatients. Chronic use of PMed was observed in 25%, especially with sertraline and buprenorphine for opioid use disorder (long-term treatment), and lorazepam (short-term treatment). About 56.6% of OA chronic users were long-term concurrent users with other PMed, mainly BZDR. Risk of abuse was low for BZDR, whilst four opioids had meaningful doctor shopping indicators - fentanyl, opioid use disorder buprenorphine, morphine and hydromorphone. Conclusions: BZD are the main PMed used in ARSLVT, often chronically, especially lorazepam. Prevalence of OA use is low, although with higher risk of misuse than BZDR. Concomitant use of several PMed is frequent.

Structural Insights into Ciona intestinalis Septins: Complexes Suggest a Mechanism for Nucleotide-dependent Interfacial Cross-talk.

Septins are filamentous nucleotide-binding proteins which can associate with membranes in a curvature-dependent manner leading to structural remodelling and barrier formation. Ciona intestinalis, a model for exploring the development and evolution of the chordate lineage, has only four septin-coding genes within its genome. These represent orthologues of the four classical mammalian subgroups, making it a minimalist non-redundant model for studying the modular assembly of septins into linear oligomers and thereby filamentous polymers. Here, we show that C. intestinalis septins present a similar biochemistry to their human orthologues and also provide the cryo-EM structures of an octamer, a hexamer and a tetrameric sub-complex. The octamer, which has the canonical arrangement (2-6-7-9-9-7-6-2) clearly shows an exposed NC-interface at its termini enabling copolymerization with hexamers into mixed filaments. Indeed, only combinations of septins which had CiSEPT2 occupying the terminal position were able to assemble into filaments via NC-interface association. The CiSEPT7-CiSEPT9 tetramer is the smallest septin particle to be solved by Cryo-EM to date and its good resolution (2.7 Å) provides a well-defined view of the central NC-interface. On the other hand, the CiSEPT7-CiSEPT9 G-interface shows signs of fragility permitting toggling between hexamers and octamers, similar to that seen in human septins but not in yeast. The new structures provide insights concerning the molecular mechanism for cross-talk between adjacent interfaces. This indicates that C. intestinalis may represent a valuable tool for future studies, fulfilling the requirements of a complete but simpler system to understand the mechanisms behind the assembly and dynamics of septin filaments.