Antiviral Activity of Kappaphycus alvarezii Seaweed against ZIKV.

INTRODUCTION: Zika virus (ZIKV) is a flavivirus transmitted through the bites of infected Aedes mosquitoes. These viruses can also be transmitted through sexual contact, vertical transmission, and possibly transfusion. Most cases are asymptomatic, but symptoms can include rash, conjunctivitis, fever, and arthralgia, which are characteristic of other arboviruses. Zika infection can lead to complications such as microcephaly, miscarriage, brain abnormalities, and Guillain-Barré syndrome (GBS). OBJECTIVE: The aim is to determine the inhibitory potential of the algae Kappaphycus alvarezii (K. alvarezii) on ZIKV replication. METHODOLOGY: Cytotoxicity experiments were performed using Vero cells to determine the CC50, and ZIKV replication inhibition assays (ATCC® VR-1839™) were conducted to determine the EC50. The mechanism of action was also studied to assess any synergistic effect with Ribavirin. RESULTS: K. alvarezii demonstrated low toxicity with a CC50 of 423 µg/mL and a potent effect on ZIKV replication with an EC50 of 0.65 µg/mL and a Selectivity Index (SI) of 651, indicating the extract's safety. Virucidal effect assays were carried out to evaluate the possible mechanism of action, and the compound addition time was studied, showing the potential to delay the treatment of infected cells by up to 6 hours. A potential synergistic effect was observed when K. alvarezii extract was combined with suboptimal concentrations of Ribavirin, resulting in 99% inhibition of viral replication. CONCLUSION: Our data demonstrate the significant potential of K. alvarezii extract and highlight the need for further studies to investigate its mechanism of action. We propose this extract as a potential anti-Zika compound.

SEM Image Processing Assisted by Deep Learning to Quantify Mesoporous γ-Alumina Spatial Heterogeneity and Its Predicted Impact on Mass Transfer.

The pore network architecture of porous heterogeneous catalyst supports has a significant effect on the kinetics of mass transfer occurring within them. Therefore, characterizing and understanding structure-transport relationships is essential to guide new designs of heterogeneous catalysts with higher activity and selectivity and superior resistance to deactivation. This study combines classical characterization via N2 adsorption and desorption and mercury porosimetry with advanced scanning electron microscopy (SEM) imaging and processing approaches to quantify the spatial heterogeneity of γ-alumina (γ-Al2O3), a catalyst support of great industrial relevance. Based on this, a model is proposed for the spatial organization of γ-Al2O3, containing alumina inclusions of different porosities with respect to the alumina matrix. Using original, advanced SEM image analysis techniques, including deep learning semantic segmentation and porosity measurement under gray-level calibration, the inclusion volume fraction and interphase porosity difference were identified and quantified as the key parameters that served as input for effective tortuosity factor predictions using effective medium theory (EMT)-based models. For the studied aluminas, spatial porosity heterogeneity impact on the effective tortuosity factor was found to be negligible, yet it was proven to become significant for an inclusion content of at least 30% and an interphase porosity difference of over 20%. The proposed methodology based on machine-learning-supported image analysis, in conjunction with other analytical techniques, is a general platform that should have a broader impact on porous materials characterization.

Antiviral activity of terpenes isolated from marine brown seaweeds against herpes simplex virus type 2.

Herpes simplex virus type 2 (HSV-2) is the most common agent of sexually transmitted infections around the world. Currently, no vaccine is available, and acyclovir is the reference compound in treatment HSV-2 infections. However, the emergence of resistant strains has reduced the efficacy in treatment. Several studies have shown marine seaweed biological activities, but there are no studies yet about the activity anti-HSV-2 of two its secundary metabolites, atomaric acid (1) and marine dolastane (2), isolated from Stypopodium zonale and Canistrocarpus cervicornis respectively. Therefore, we evaluated the anti-HSV-2 activity of compounds 1 and 2. Both compounds showed anti-HSV-2 activity with low cytotoxicity and compound 1 inactivated 90% of the viral particles at 50 µM. Both compounds inhibited the penetration and results in silico indicated the compound 1 as possible therapy alternative anti -HSV-2.

PrP meets alpha-synuclein: Molecular mechanisms and implications for disease.

The discovery of prions has challenged dogmas and has revolutionized our understanding of protein-misfolding diseases. The concept of self-propagation via protein conformational changes, originally discovered for the prion protein (PrP), also applies to other proteins that exhibit similar behavior, such as alpha-synuclein (aSyn), a central player in Parkinson's disease and in other synucleinopathies. aSyn pathology appears to spread from one cell to another during disease progression, and involves the misfolding and aggregation of aSyn. How the transfer of aSyn between cells occurs is still being studied, but one important hypothesis involves receptor-mediated transport. Interestingly, recent studies indicate that the cellular prion protein (PrPC ) may play a crucial role in this process. PrPC has been shown to act as a receptor/sensor for protein aggregates in different neurodegenerative disorders, including Alzheimer's disease and amyotrophic lateral sclerosis. Here, we provide a comprehensive overview of the current state of knowledge regarding the interaction between aSyn and PrPC and discuss its role in synucleinopathies. We examine the properties of PrP and aSyn, including their structure, function, and aggregation. Additionally, we discuss the current understanding of PrPC 's role as a receptor/sensor for aSyn aggregates and identify remaining unanswered questions in this area of research. Ultimately, we posit that exploring the interaction between aSyn and PrPC may offer potential treatment options for synucleinopathies.

Inhibition of SARS-CoV-2 Infection in Vero Cells by Bovine Lactoferrin under Different Iron-Saturation States.

Despite the rapid mass vaccination against COVID-19, the emergence of new SARS-CoV-2 variants of concern, such as omicron, is still a great distress, and new therapeutic options are needed. Bovine lactoferrin (bLf), a multifunctional iron-binding glycoprotein available in unsaturated (apo-bLf) and saturated (holo-bLf) forms, has been shown to exert broad-spectrum antiviral activity against many viruses. In this study, we evaluated the efficacy of both forms of bLf at 1 mg/mL against infection of Vero cells by SARS-CoV-2. As assessed with antiviral assays, an equivalent significant reduction in virus infection by about 70% was observed when either form of bLf was present throughout the infection procedure with the SARS-CoV-2 ancestral or omicron strain. This inhibitory effect seemed to be concentrated during the early steps of virus infection, since a significant reduction in its efficiency by about 60% was observed when apo- or holo-bLf were incubated with the cells before or during virus addition, with no significant difference between the antiviral effects of the distinct iron-saturation states of the protein. However, an ultrastructural analysis of bLf treatment during the early steps of virus infection revealed that holo-bLf was somewhat more effective than apo-bLf in inhibiting virus entry. Together, these data suggest that bLf mainly acts in the early events of SARS-CoV-2 infection and is effective against the ancestral virus as well as its omicron variant. Considering that there are no effective treatments to COVID-19 with tolerable toxicity yet, bLf shows up as a promising candidate.

Chloroquinolone Carboxamide Derivatives as New Anti-HSV-1 Promising Drugs.

BACKGROUND: Since the emergence of HSV resistant strains, new antiviral agents have emerged and still are urgently needed, especially those with alternative targets. OBJECTIVE: In this work, we evaluated new quinolone derivatives as anti-HSV. METHODS: For this study, cells were infected and treated with different components to evaluate the profile of HSV replication in vitro. In addition, studies were performed to determine the pharmacokinetic toxicity and profile of the compound. RESULTS: Indeed the EC50 values of these promising molecules ranged between 8 µM and 32 µM. We have also showed that all compounds inhibited the expression of ICP27 viral proteins, which gives new insights in the search for new target for antiherpetic therapy. Chlorine in positions C6 and phosphonate in position C1 have shown to be important for viral inhibition. The chloroquinolone carboxamide derivatives fulfilled "Lipinsky Rule of Five" for good oral bioavailability and showed higher intestinal absorption and blood brain barrier penetration, as well as lower toxicity profile. CONCLUSION: Although the inhibition activities of chloroquinolone carboxamide derivatives were lower than acyclovir, they showed different modes of action in comparison to the drugs currently available. These findings encourage us to continue pre-clinical studies for the development of new anti-HSV-1 agents.

Bovine Lactoferrin Induces Cell Death in Human Prostate Cancer Cells.

Bovine lactoferrin (bLf) is a multifunctional protein widely associated with anticancer activity. Prostate cancer is the second most frequent type of cancer worldwide. This study was aimed at evaluating the influence of bLf on cell viability, cell cycle progression, reactive oxygen species (ROS) production, and rate of apoptosis in the human prostate cancer cell line (DU-145). MTT assay and trypan blue exclusion were used to analyze cell viability. Morphological changes were analyzed through optical microscopy after 24 h and 48 h of bLf treatment. FITC-bLf internalization and cellular damage were observed within 24 h by confocal fluorescence microscopy. Cell cycle analyses were performed by flow cytometry and propidium iodide. For caspases 3/7 activation and reactive oxygen species production evaluation, cells were live-imaged using the high-throughput system Operetta. The cell viability assays demonstrated that bLf induces cell death and morphological changes after 24 h and 48 h of treatment compared to control on DU-145 cells. The bLf internalization was detected in DU-145 cells, G1-phase arrest of the cell cycle, caspase 3/7 activation, and increased oxidative stress on bLf-treated cells. Our data support that bLf has an important anticancer activity, thus offering new perspectives in preventing and treating prostate cancer.

Quantification and morphological characterization of microfibers emitted from textile washing.

Microplastics are a subject of growing interest as they are a potential threat for living organisms. Textile microfibers (MFs) are an important microplastics sub-group that have been reported as a major source of microplastics release into the environment. This pollution occurs mainly during the washing of synthetic garments. However, standardized methods to quantify and characterize these MFs are scarce. This study proposes a new analytical protocol to characterize these MFs in number and size by means of filtration techniques, optical and electronic microscopy and automatic image post-processing. This approach was developed and validated on effluents from washing machines produced in different conditions (5 different garments, sequential cycles, and presence or not of detergent). Among the analyzed effluents, it was found that 40 to 75% of microfibers have a length comprised between 50 and 200 µm, with average microfiber diameters ranging from 8 to 17 µm depending on the type of textile. The emission range of microfibers was estimated to be between 220,000 to 2,820,000 microfibers per kg of textile depending on the type of garment and the washing conditions. The counting method developed is adapted to a certain range of textiles, such as 100% polyester fleece jackets (PET-1), 100% smooth polyester T-shirt (PET-2) and 100% acrylic sweater (PAN), and is not affected by the presence of detergent. The proposed method of characterization of these MFs lengths can also be extrapolated to the counting of other objects that have a similar morphology to the analyzed fibers. Hence, it can be helpful to develop new testing capture technologies and, thus, contribute to the enhancement of filtering techniques of several pollutants.

What is the role of lipids in prion conversion and disease?

The molecular cause of transmissible spongiform encephalopathies (TSEs) involves the conversion of the cellular prion protein (PrPC) into its pathogenic form, called prion scrapie (PrPSc), which is prone to the formation of amorphous and amyloid aggregates found in TSE patients. Although the mechanisms of conversion of PrPC into PrPSc are not entirely understood, two key points are currently accepted: (i) PrPSc acts as a seed for the recruitment of native PrPC, inducing the latter's conversion to PrPSc; and (ii) other biomolecules, such as DNA, RNA, or lipids, can act as cofactors, mediating the conversion from PrPC to PrPSc. Interestingly, PrPC is anchored by a glycosylphosphatidylinositol molecule in the outer cell membrane. Therefore, interactions with lipid membranes or alterations in the membranes themselves have been widely investigated as possible factors for conversion. Alone or in combination with RNA molecules, lipids can induce the formation of PrP in vitro-produced aggregates capable of infecting animal models. Here, we discuss the role of lipids in prion conversion and infectivity, highlighting the structural and cytotoxic aspects of lipid-prion interactions. Strikingly, disorders like Alzheimer's and Parkinson's disease also seem to be caused by changes in protein structure and share pathogenic mechanisms with TSEs. Thus, we posit that comprehending the process of PrP conversion is relevant to understanding critical events involved in a variety of neurodegenerative disorders and will contribute to developing future therapeutic strategies for these devastating conditions.

In vitro antiviral activity against Zika virus from a natural product of the Brazilian red seaweed Bryothamnion triquetrum.

Zika virus (ZIKV) is an arthropod-borne flavivirus that reemerged in 2007 and, since then, has caused several outbreaks and spread to over 80 countries worldwide. Along with this, ZIKV infections have been associated with severe clinical outcomes, including neurological manifestations, especially in newborns, posing a major threat to human health. However, there are no licensed vaccines or specific antiviral agents available yet; thereby, there is an urgent need for the discovery of novel therapeutic strategies to fight this infection. In this context, seaweeds are proven sources of biologically relevant products, including antiviral ones, that remain poorly explored. Herein, we evaluated the antiviral potential of the dichloromethane extract of the red seaweed Bryotamnion triquetrum against ZIKV. MTT assay was carried out to evaluate the extract's toxicity in Vero cells, while standard plaque assays were performed for viral titer quantification in the antiviral assays. The B. triquetrum extract possessed great inhibitory activity on the ZIKV replication in Vero cells, with an EC50 of 1.38 µg/ml and a higher selectivity index than ribavirin (289.85 and 75.20, respectively), a licensed antiviral drug. The investigation of its mechanism of action revealed a moderate virucidal effect while it strongly impaired virus replication at both early and late steps of the virus replication cycle with moderate inhibition at the attachment stage. Finally, the B. triquetrum extract presented a remarkable synergistic effect with ribavirin at suboptimal concentrations, which also highlights the promising antiviral potential of this product as a drug candidate to combat ZIKV infection. Keywords: Rhodophyta; Algae; arbovirus; antiviral; Zika.

Influence of iron binding in the structural stability and cellular internalization of bovine lactoferrin.

Lactoferrin (Lf) is an iron-binding glycoprotein and a component of many external secretions with a wide diversity of functions. Structural studies are important to understand the mechanisms employed by Lf to exert so varied functions. Here, we used guanidine hydrochloride and high hydrostatic pressure to cause perturbations in the structure of bovine Lf (bLf) in apo and holo (unsaturated and iron-saturated, respectively) forms, and analyzed conformational changes by intrinsic and extrinsic fluorescence spectroscopy. Our results showed that the iron binding promotes changes on tertiary structure of bLf and increases its structural stability. In addition, we evaluated the effects of bLf structural change on the kinetics of bLf internalization in Vero cells by confocal fluorescence microscopy, and observed that the holo form was faster than the apo form. This finding may indicate that structural changes promoted by iron binding may play a key role in the intracellular traffic of bLf. Altogether, our data improve the comprehension of bLf stability and uptake, adding knowledge to its potential use as a biopharmaceutical.

Viral and Prion Infections Associated with Central Nervous System Syndromes in Brazil.

Virus-induced infections of the central nervous system (CNS) are among the most serious problems in public health and can be associated with high rates of morbidity and mortality, mainly in low- and middle-income countries, where these manifestations have been neglected. Typically, herpes simplex virus 1 and 2, varicella-zoster, and enterovirus are responsible for a high number of cases in immunocompetent hosts, whereas other herpesviruses (for example, cytomegalovirus) are the most common in immunocompromised individuals. Arboviruses have also been associated with outbreaks with a high burden of neurological disorders, such as the Zika virus epidemic in Brazil. There is a current lack of understanding in Brazil about the most common viruses involved in CNS infections. In this review, we briefly summarize the most recent studies and findings associated with the CNS, in addition to epidemiological data that provide extensive information on the circulation and diversity of the most common neuro-invasive viruses in Brazil. We also highlight important aspects of the prion-associated diseases. This review provides readers with better knowledge of virus-associated CNS infections. A deeper understanding of these infections will support the improvement of the current surveillance strategies to allow the timely monitoring of the emergence/re-emergence of neurotropic viruses.

Semisynthesis of Dolabellane Diterpenes: Oxygenated Analogues with Increased Activity against Zika and Chikungunya Viruses.

Brown algae and soft corals represent the main marine sources of dolabellane diterpenes. The antiviral activity of dolabellanes has been studied for those isolated from algae, whereas dolabellanes isolated from soft corals have been barely studied. In this work, a collection of dolabellane diterpenes consisting of five natural and 21 semisynthetic derivatives was constructed, and their antiviral activities against Zika (ZIKV) and Chikungunya (CHIKV) viruses were tested. Dolabellatrienone (1) and (1R,7R,8R,11S)-7,8-epoxy-13-keto-dolabella-3,12(18)-diene (2), isolated from Eunicea genus soft corals, were employed to obtain 21 dolabellane and dolastane diterpenes by reactions such as allylic oxidations, reductions, acid-catalyzed epoxide ring opening, and acetylations. All of the compounds were identified by a combination of one- and two-dimensional NMR, mass spectrometry, and X-ray diffraction experiments. The cytotoxicites against Vero cells and the antiviral activities against ZIKV and CHIKV was tested to calculate the half-maximal effective concentration (EC50) and selectivity indexes (SIs). In general, the addition of oxygen-containing functional groups improved the bioactivity of dolabellane and dolastane diterpenes against ZIKV and CHIKV replication. Compound 9 showed an EC50 = 0.92 ± 0.08 µM and SI = 820 against ZIKV.

Use of different matrices to construct the standard curve for the paracetamol dosage by visible spectrophotometry / Uso de diferentes matrizes na construção da curva padrão para a dosagem de paracetamol por espectrofotometria visível

ABSTRACT Introduction: Acute paracetamol poisoning is confirmed by the determination of its serum level and allows assessing the risk of hepatotoxicity, which can be monitored by the Rumack-Matthew nomogram for the administration of the N-Acetylcysteine antidote, as well as for the prognosis of intoxication. Objective: Because of its analytical importance, we evaluated the influence of different matrices (ultrapure water, serum, and plasma) on the construction of the paracetamol calibration curve, aiming to reduce the analytical cost and facilitate its implementation in clinical and emergency laboratories. Material and methods: A standard stock solution of paracetamol of 1 mg ml-1 was obtained, from which appropriate dilutions originated the following concentrations 20, 50, 100, 150, 200, 250, and 300 mg l-1 in the different matrices, in triplicate, reading at complete after 430 nm in spectrophotometer and reproduced after three months. The results were statistically analyzed (p < 0.05). Results and discussion: Good laboratory practices include remaking the calibration curve when stock reagents are remade aiming to readjust the line equation indicated by a measuring instrument. The biological samples indicated as matrices on a calibration curve are usually serum and plasma. However, these biological products, when commercially purchased, are of high cost. Ultrapure water can replace serum and plasma in the paracetamol calibration curve according to the linearity of the curve, which showed the same trend line for the three matrices. Conclusion: The three matrices can be used in the construction of the paracetamol calibration curve, but the use of ultrapure water reduces the analysis costs.

RESUMEN Introducción: La intoxicación aguda por paracetamol se confirma mediante la determinación de su nivel sérico y permite evaluar el riesgo de hepatotoxicidad, que puede ser monitorizado mediante el nomograma de Rumack-Matthew para la administración del antídoto N-acetilcisteína, así como para el pronóstico de intoxicación. Objetivos: Por su importancia analítica, se evaluó la influencia de diferentes matrices (agua ultrapura, suero y plasma) en la construcción de la curva de calibración del paracetamol, con el objetivo de reducir el costo analítico y facilitar su implementación en laboratorios clínicos y de emergencia. Material y métodos: Se obtuvo una solución madre del estándar (stock) de paracetamol de 1 mg ml-1, de la cual se originaron diluciones adecuadas para obtener las siguientes concentraciones de 20, 50, 100, 150, 200, 250 y 300 mg l-1 con las diferentes matrices, por triplicado, con lectura a 430 nm en epectrofotômetro, reproduciéndose a los tres meses. Los resultados se analizaron estadísticamente (p < 0,05). Resultados y discusión: Las buenas prácticas de laboratorio incluyen rehacer la curva de calibración cuando se rehacen los reactivos del estándar con el fin de reajustar la ecuación lineal indicada por un instrumento de medición. Las muestras biológicas indicadas como matrices en una curva de calibración suelen ser suero y plasma. Sin embargo, estos productos biológicos cuando se compran comercialmente son de alto costo. El agua ultrapura puede reemplazar el suero y el plasma en la curva de calibración de paracetamol de acuerdo con la linealidad de la curva, que mostró la misma línea de tendencia para las tres matrices. Conclusión: Las tres matrices pueden usarse en la construcción de la curva de calibración de paracetamol, pero el uso de agua ultrapura reduce los costos de análisis.

RESUMO Introdução: A intoxicação aguda pelo paracetamol é confirmada pela determinação de seu nível sérico e permite avaliar o risco de hepatotoxicidade, que pode ser monitorado pelo nomograma Rumack-Matthew para a administração do antídoto N-acetilcisteína, bem como para o prognóstico da intoxicação. Objetivos: Diante de sua importância analítica, avaliamos a influência de diferentes matrizes (água ultrapura, soro e plasma) na construção da curva de calibração do paracetamol, visando diminuir o custo analítico e facilitar a sua implantação em laboratórios clínicos e de urgência. Material e métodos: Obtivemos uma solução estoque padrão de paracetamol de 1 mg ml-1, da qual originaram diluições apropriadas para se obter as concentrações de 20, 50, 100, 150, 200, 250 e 300 mg l-1 com as diferentes matrizes, em triplicata, com leituras em espectrofotômetro a 430 nm, sendo reproduzidas após três meses. Os resultados foram analisados estatisticamente (p < 0,05). Resultados e discussão: Nas boas práticas de laboratório, inclui-se o refazimento da curva de calibração quando os reagentes estoques são refeitos visando ao reajuste da equação de reta indicado por um instrumento de medição. As amostras biológicas indicadas como matrizes em uma curva de calibração são, usualmente, soro e plasma. Porém, esses produtos biológicos quando adquiridos comercialmente são de custo elevado. A água ultrapura pode substituir soro e plasma na curva de calibração do paracetamol em função da linearidade da curva, a qual mostrou a mesma linha de tendência para as três matrizes. Conclusão: As três matrizes podem ser utilizadas na construção da curva de calibração do paracetamol, mas o uso de água ultrapura diminui os custos da análise.

In vitro Studies on The Inhibition of Replication of Zika and Chikungunya Viruses by Dolastane Isolated from Seaweed Canistrocarpus cervicornis.

The lack of vaccines and antiviral treatment, along with the increasing number of cases of Zika virus (ZIKV) and Chikungunya virus (CHIKV) infections, emphasize the need for searching for new therapeutic strategies. In this context, the marine brown seaweed Canistrocarpus cervicornis has been proved to hold great antiviral potential. Hence, the aim of this work was to evaluate the anti-ZIKV and anti-CHIKV activity of a marine dolastane isolated from brown seaweed C. cervicornis and its crude extract. Vero cells were used in antiviral assays, submitted to ZIKV and CHIKV, and treated with different concentrations of C. cervicornis extract or dolastane. The crude extract of C. cervicornis showed inhibitory activities for both ZIKV and CHIKV, with EC50 values of 3.3 µg/mL and 3.1 µg/mL, respectively. However, the isolated dolastane showed a more significant and promising inhibitory effect (EC50 = 0.95 µM for ZIKV and 1.3 µM for CHIKV) when compared to both the crude extract and ribavirin, which was used as control. Also, the dolastane showed a very potent virucidal activity against CHIKV and was able to inhibit around 90% of the virus infectivity at 10 µM. For the ZIKV, the effects were somewhat lower, although interesting, at approximately 64% in this same concentration. Further, we observed that both the extract and the dolastane were able to inhibit the replication of ZIKV and CHIKV at different times of addition post-infection, remaining efficient even if added after 8 hours post-infection, but declining soon after. A synergistic effect using sub-doses of the extract and isolates was associated with ribavirin, inhibiting above 80% replication even at the lowest concentrations. Therefore, this work has unveiled the anti-ZIKV and CHIKV potential of C. cervicornis crude extract and an isolated dolastane, which, in turn, can be used as a preventive or therapeutic strategy in the future.

Quinolone-N-acylhydrazone hybrids as potent Zika and Chikungunya virus inhibitors.

This work reports the synthesis of quinolone-N-acylhydrazone hybrids, namely 6-R-N'-(2-hydxoxybenzylidene)-4-oxo-1,4-dihydroquinoline-3-carbohydrazide (R = H: 5a, F: 5b, Cl: 5c and Br: 5d), which exhibited excellent activity against arbovirus Zika (ZIKV) and Chikungunya (CHIKV). In vitro screening towards ZIKV and CHIKV inhibition revealed that all substances have significant antiviral activity, most of them being more potent than standard Ribavirin (5a-d: EC50 = 0.75-0.81 µM, Ribavirin: EC50 = 3.95 µM for ZIKV and 5a-d: 1.16-2.85 µM, Ribavirin: EC50 = 2.42 µM for CHIKV). The quinolone-N-acylhydrazone hybrids were non-toxic against Vero cells, in which compounds 5c and 5d showed the best selectivities (SI = 1410 and 630 against ZIKV and CHIKV, respectively). Antiviral activity was identified by inhibition of viral RNA production in a dose-dependent manner. In the evaluation of the time of addition of the compounds, we observed that 5b and 5c remain with strong effect even in the addition for 12 h after infection. The above results indicate that quinolone-N-acylhydrazones represent a new and promising class to be further investigated as anti-ZIKV and anti-CHIKV agents.

Pediatric tracheostomy: epidemiology and characterization of tracheal secretion - a literature review

SUMMARY INTRODUCTION Despite the benefits, tracheostomized children are susceptible to respiratory infections, since the tube is located in a strategic region where there is colonization by several bacteria and biofilm formation. Biofilm is formed when the bacteria adhere strongly to the surfaces of the tubes, providing protection against various types of aggression, such as antibiotic treatment. OBJECTIVE To carry out a literature review of the last ten years on tracheostomized pediatric patients, in order to characterize the bacteria isolated in children's tracheal secretions, and verify which ones are the most frequent. METHODS Two authors searched the Lilacs, SciELO, Medline Plus, and PubMed databases. The MeSH terms used were: 'tracheostomy' and 'tracheotomy' associated with 'infections', 'children', 'child', and 'bacterial' as qualifiers. RESULTS Of the 512 studies on the subject, 19 were selected for review. The total number of children evaluated in the studies was 4,472, with a mean age of 7.5 years. As for the bacteria found in the secretions of tracheostomized children, 12 species of bacteria were more frequent, P. aeruginosa was the predominant bacterium, followed by S. aureus (63.1%), Klebsiella pneumoniae (57.8%), Streptococcus pneumoniae (47.3%), and Stenotrophomonas maltophilia (47.3%). CONCLUSION One of the main complications treated in tracheostomized patients were infections, since the respiratory system is colonized by several bacteria that can cause serious infections, which are associated with the formation of biofilms. The predominant bacterium in most of the studies was P. aeruginosa, and the second species commonly reported was S. aureus.

RESUMO INTRODUÇÃO Apesar dos benefícios, crianças traqueostomizadas estão suscetíveis a adquirir infecções respiratórias, pois o tubo se encontra em uma região estratégica, na qual existe colonização de diversas bactérias e formação de biofilme. O biofilme é formado quando as bactérias aderem fortemente às superfícies dos tubos, conferindo proteção contra diversos tipos de agressões, como o tratamento por antibióticos. OBJETIVO Realizar uma revisão de literatura dos últimos dez anos sobre pacientes pediátricos traqueostomizados, no intuito de caracterizar as bactérias isoladas em secreções traqueais de crianças, verificando-se quais são as mais frequentes. MÉTODOS Dois autores pesquisaram nas bases de dados do Lilacs, SciELO, Medline Plus e PubMed. Termos MeSH utilizados: tracheostomy e tracheotomy usados associados a infections, children, chlid e bacterial como qualificadores. RESULTADOS Dos 512 estudos relacionados ao tema, 19 foram selecionados para a revisão. O total de crianças avaliadas nos estudos foi de 4.472, com idade média de 7,5 anos. Quanto às bactérias encontradas nas secreções de crianças traqueostomizadas, 12 espécies de bactérias foram mais frequentes; P. aeruginosa foi a bactéria predominante, seguida de S. aureus (63,1%), Klebsiella pneumoniae (57,8%), Streptococcus pneumoniae (47,3%) e Stenotrophomonas maltophilia (47,3%). CONCLUSÃO Umas das principais complicações abordadas em pacientes traqueostomizados foram as infecções, já que o sistema respiratório é colonizado por diversas bactérias, que podem causar infecções graves, sendo estas associadas à formação de biofilmes. A bactéria predominante na maioria dos estudos foi a P. aeruginosa, e a segunda espécie comumente relatada foi a S. aureus.

Inhibition by Marine Algae of Chikungunya Virus Isolated From Patients in a Recent Disease Outbreak in Rio de Janeiro.

Chikungunya virus (CHIKV) infection is one of the most challenging re-emergent diseases caused by a virus, and with no specific antiviral treatment it has now become a major public health concern. In this investigation, 25 blood samples were collected from patients with characteristic CHIKV symptoms and submitted to a virus isolation protocol, which detected 3 CHIKV isolates. These samples were evaluated by sequencing for the characterization of the strains and any homology to viruses circulating in Brazil during a recent outbreak. These viruses were used for the development of antiviral assays. Subsequently, the inhibitory effects of seaweed extracts on CHIKV replication were studied. The marine species of algae tested were Bryothamnion triquetrum, Caulerpa racemosa, Laurencia dendroidea, Osmundaria obtusiloba, Ulva fasciata, and Kappaphycus alvarezii, all of which are found in different countries including Brazil. The results revealed high levels of CHIKV inhibition, including extracts of O. obtusiloba with inhibition values of 1.25 µg/mL and a selectivity index of 420. Viral inhibition was dependent on the time of addition of extract of O. obtusiloba to the infected cells, with the optimal inhibition occurring up to 16 h after infection. Neuron evaluations with O. obtusiloba were performed and demonstrated low toxicity, and in infected neurons we observed high inhibitory activity in a dose-dependent manner. These results indicate that the algal extracts may be promising novel candidates for the development of therapeutic agents against CHIKV infections.

Enzymatic potential and biosurfactant production by endophytic fungi from mangrove forest in Southeastern Brazil.

Microbial activity is the main route for cycling mangrove nutrients. In general, microorganisms have abilities to degrade lignocellulosic compounds. Among the biotechnological potential of the microbiota from mangroves, it is noteworthy about endophytic fungi, which can be considered as effective sources of different bioactive compounds. In this sense, thirty (30) endophytic fungi were isolated from mangrove forest sampling Cananeia, SP, Brazil. These microorganisms were analyzed about their enzymatic activities including: lignin peroxidase EC 1.11.1.14, manganese peroxidase EC 1.11.1.13 and laccase EC 1.10.3.2, as well endo-cellulase EC 3.2.1.4 and endo-xylanase EC 3.2.1.8. Besides that, production of bioactive secondary metabolites like biosurfactant and/or bioemulsifier was also investigated. As results, nineteen (19) isolates were selected about their ligninolytic abilities, nine (9) of them about cellulase activity and thirteen (13) showed xylanase abilities. The fungal isolate named as 3(3), characterized as Fusarium sambucinum, showed a prominent lignin peroxidase (42.4 U L-1) and manganese peroxidase (23.6 U L-1) activities. The isolate 63.1, also related to Fusarium sp. genera, was selected about its laccase activity (41.5 U L-1). From all the investigated fungi, the isolate 47(4) Trichoderma camerunense was selected about its cellulolytic and xylanolytic activities, showing 45.23 and 26.09 U mL-1, respectively. The same fungi also showed biosurfactant ability demonstrated by superficial tension decreasing to 38 mN/m. In addition, fifteen (15) fungi exhibited bioemulsifier activity, with E24 values up to 62.8%.

Antiretroviral agents against human immunodeficiency virus: an overview of current drugs and new perspectives / Agentes antiretrovirais contra o vírus da imunodeficiência humana: uma visão geral das drogas atuais e novas perspectivas

Introduction: Since its discovery in the 1980s, the human immunodeficiency virus (HIV) has been the target of many studies. Nowadays, estimates show that 36.7 million people are infected with HIV worldwide. In Brazil, HIV infection overcomes 840 thousand people. Globally, only 53% of the HIV infected people are under antiretroviral therapy. Significant advances in antiretroviral therapy have been made since the introduction of zidovudine in 1987. Objective: To advance the discoveries of the available antivirals demonstrating their functional specificities. Methods: We performed a systematic review with a bibliographic survey in the Index Medicus/MEDLINE and PubMed databases for periodical and indexed articles, from 2013 to 2018 that reported on antiretrovirals used or not in the clinical practice. Results: Currently, there are six classes of antiretroviral drugs: nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), fusion inhibitors (FIs), entry inhibitors (CCRIs), and HIV integrase strand transfer inhibitors (INIs or INSTIs). In summary, several antiretroviral agents under development make HIV entry, reverse transcription, integration, and maturation emerging drug become targets. Conclusion: A multifaceted approach to antiretroviral therapy, using combinations of inhibitors that target different steps of the viral life cycle, has the best potential for long-term control of HIV infection.

Introdução: Desde sua descoberta na década de 1980, o vírus da imunodeficiência humana (HIV) tem sido alvo de muitos estudos. Atualmente, as estimativas mostram que 36,7 milhões de pessoas estão infectadas pelo HIV em todo o mundo. No Brasil, a infecção pelo HIV supera 840 mil pessoas. Globalmente, apenas 53% das pessoas infectadas pelo HIV estão sob terapia antirretroviral. Avanços significativos na terapia antirretroviral (TARV) foram feitos desde a introdução da zidovudina (AZT) em 1987. Objetivo: O objetivo deste estudo foi descrever a descoberta dos antivirais disponíveis atualmente, demonstrando suas especificidades funcionais. Métodos: Foi realizada uma revisão sistemática com levantamento bibliográfico nas bases de dados Index Medicus/MEDLINE e PubMed para artigos periódicos e indexados, no período de 2013 a 2018, que relataram antirretrovirais utilizados ou não na prática clínica. Resultados: Atualmente, existem seis classes de medicamentos antirretrovirais: inibidores nucleosídeos da transcriptase reversa (NRTIs), inibidores não-nucleosídeos da transcriptase reversa (NNRTIs), inibidores da protease (IPs), inibidores de fusão (FIs), inibidores de entrada (CCRIs) e transferência da cadeia da integrase do HIV inibidores (INIs ou INSTIs). Em resumo, vários agentes antirretrovirais em desenvolvimento fazem da entrada do HIV, da transcrição reversa, da integração e da maturação, alvos dos medicamentos emergentes. Conclusão: Uma abordagem multifacetada para a TAR, usando combinações de inibidores que visam diferentes etapas do ciclo de vida viral, tem o melhor potencial para o controle da infecção pelo HIV a longo prazo.