Bothrops snake venom L-amino acid oxidases impair biofilm formation of clinically relevant bacteria.

The present work addressed the abilities of two L-amino acid oxidases isolated from Bothrops moojeni (BmooLAAO-I) and Bothrops jararacussu (BjussuLAAO-II) snake venoms to control the growth and prevent the biofilm formation of clinically relevant bacterial pathogens. Upon S. aureus (ATCC BAA44) and S. aureus (clinical isolates), BmooLAAO-I (MIC = 0.12 and 0.24 µg/mL, respectively) and BjussuLAAO-II (MIC = 0.15 µg/mL) showed a potent bacteriostatic effect. Against E. coli (ATCC BAA198) and E. coli (clinical isolates), BmooLAAO-I (MIC = 15.6 and 62.5 µg/mL, respectively) and BjussuLAAO-II (MIC = 4.88 and 9.76 µg/mL, respectively) presented a lower extent effect. Also, BmooLAAO-I (MICB50 = 0.195 µg/mL) and BjussuLAAO-II (MICB50 = 0.39 µg/mL) inhibited the biofilm formation of S. aureus (clinical isolates) in 88% and 89%, respectively, and in 89% and 53% of E. coli (clinical isolates). Moreover, scanning electron microscopy confirmed that the toxins affected bacterial morphology by increasing the roughness of the cell surface and inhibited the biofilm formation. Furthermore, analysis of the tridimensional structures of the toxins showed that the surface-charge distribution presents a remarkable positive region close to the glycosylation motif, which is more pronounced in BmooLAAO-I than BjussuLAAO-II. This region may assist the interaction with bacterial and biofilm surfaces. Collectively, our findings propose that venom-derived antibiofilm agents are promising biotechnological tools which could provide novel strategies for biofilm-associated infections.

ADDovenom: Thermostable Protein-Based ADDomer Nanoparticles as New Therapeutics for Snakebite Envenoming.

Snakebite envenoming can be a life-threatening medical emergency that requires prompt medical intervention to neutralise the effects of venom toxins. Each year up to 138,000 people die from snakebites and threefold more victims suffer life-altering disabilities. The current treatment of snakebite relies solely on antivenom-polyclonal antibodies isolated from the plasma of hyperimmunised animals-which is associated with numerous deficiencies. The ADDovenom project seeks to deliver a novel snakebite therapy, through the use of an innovative protein-based scaffold as a next-generation antivenom. The ADDomer is a megadalton-sized, thermostable synthetic nanoparticle derived from the adenovirus penton base protein; it has 60 high-avidity binding sites to neutralise venom toxins. Here, we outline our experimental strategies to achieve this goal using state-of-the-art protein engineering, expression technology and mass spectrometry, as well as in vitro and in vivo venom neutralisation assays. We anticipate that the approaches described here will produce antivenom with unparalleled efficacy, safety and affordability.

Unravelling the Gastroprotective Potential of Kefir: Exploring Antioxidant Effects in Preventing Gastric Ulcers.

The present study was conducted to evaluate the protective effect of milk kefir against NSAID-induced gastric ulcers. Male Swiss mice were divided into three groups: control (Vehicle; UHT milk at a dose of 0.3 mL/100 g), proton pump inhibitor (PPI; lansoprazole 30 mg/kg), and 4% milk kefir (Kefir; 0.3 mL/100 g). After 14 days of treatment, gastric ulcer was induced by oral administration of indomethacin (40 mg/kg). Reactive oxygen species (ROS), nitric oxide (NO), DNA content, cellular apoptosis, IL-10 and TNF-α levels, and myeloperoxidase (MPO) enzyme activity were determined. The interaction networks between NADPH oxidase 2 and kefir peptides 1-35 were determined using the Residue Interaction Network Generator (RING) webserver. Pretreatment with kefir for 14 days prevented gastric lesions. In addition, kefir administration reduced ROS production, DNA fragmentation, apoptosis, and TNF-α systemic levels. Simultaneously, kefir increased NO bioavailability in gastric cells and IL-10 systemic levels. A total of 35 kefir peptides showed affinity with NADPH oxidase 2. These findings suggest that the gastroprotective effect of kefir is due to its antioxidant and anti-inflammatory properties. Kefir could be a promising natural therapy for gastric ulcers, opening new perspectives for future research.

Preclinical study of experimental burns treated with photobiomodulation and Human Amniotic Membrane, both isolated and associated / Estudo pré-clínico de queimaduras experimentais tratadas com fotobiomodulação e membrana amniótica humana, isoladas e associadas / Estudio preclínico de quemaduras experimentales tratadas con fotobiomodulación y membrana amniótica humana, solas y combinadas

Abstract Objective: to evaluate the effect of photobiomodulation with low-level 660 nm laser alone or associated with Human Amniotic Membrane in the repair of partial-thickness burns in rats. Method: an experimental study conducted with 48 male Wistar rats, randomized into four groups: Control, Human Amniotic Membrane, Low-Level Laser Therapy, and Low-Level Laser Therapy associated with Human Amniotic Membrane. The histopathological characteristics of the skin samples were analyzed 7 and 14 days after the burn. The data obtained were submitted to the Kolmogorov-Smirnov and Mann-Whitney tests. Results: the histological analysis of the burn injuries showed a decrease in inflammation (p<0.0001) and an increase in proliferation of fibroblasts (p<0.0001) mainly at 7 days in all treatments related to the control group. At 14 days, the greater effectiveness in accelerating the healing process was significant (p<0.0001) in the Low-Level Laser Therapy group associated with the Human Amniotic Membrane. Conclusion: the association of photobiomodulation therapies with the Human Amniotic Membrane allowed verifying a reduction in the healing process time of the experimental lesions, stimulating its proposal as a treatment protocol in partial-thickness burns.

Resumo Objetivo: avaliar o efeito da fotobiomodulação com laser de baixa intensidade 660 nm isoladamente ou associada à membrana amniótica humana no reparo de queimaduras de espessura parcial em ratos. Método: estudo experimental com 48 ratos Wistar machos, randomizados em quatro grupos: Controle, Membrana Amniótica Humana, Terapia a Laser de Baixa Intensidade e Terapia a Laser de Baixa Intensidade associado à Membrana Amniótica Humana. As características histopatológicas das amostras de pele foram analisadas aos 7 e 14 dias após a queimadura. Os dados obtidos foram submetidos aos testes de Kolmogorov-Smirnov e Mann Whitney. Resultados: a análise histológica das lesões por queimadura mostrou a diminuição da inflamação (p <0,0001) e aumento da proliferação de fibroblastos (p <0,0001), principalmente nos 7 dias em todos os tratamentos relacionados ao grupo controle. Aos 14 dias, a maior efetividade na aceleração do processo cicatricial foi significativa (p<0,0001) no grupo Terapia a Laser de Baixa Intensidade associado à Membrana Amniótica Humana. Conclusão: a associação das terapias de fotobiomodulação à membrana amniótica humana permitiu comprovar redução no tempo do processo cicatricial das lesões experimentais, estimulando sua proposição como protocolo de tratamento em queimaduras de espessura parcial.

Resumen Objetivo: evaluar el efecto de la fotobiomodulación con láser de baja intensidad 660 nm de sola o combinada con la membrana amniótica humana en la reparación de quemaduras de espesor parcial en ratas. Método: estudio experimental con 48 ratas Wistar macho, aleatorizadas en cuatro grupos: Control, Membrana Amniótica Humana, Terapia con Láser de Baja Intensidad y Terapia con Láser de Baja Intensidad combinada con la Membrana Amniótica Humana. Las características histopatológicas de las muestras de piel fueron analizadas a los 7 y 14 días después de la quemadura. Los datos obtenidos fueron sometidos a las pruebas de Kolmogorov-Smirnov y Mann-Whitney. Resultados: el análisis histológico de las lesiones por quemadura mostró una disminución de la inflamación (p <0,0001) y un aumento de la proliferación de fibroblastos (p <0,0001) principalmente a los 7 días en todos los tratamientos en comparación con el grupo control; a los 14 días, en el grupo de Terapia con Láser de Baja Intensidad combinada con la Membrana Amniótica Humana la mayor efectividad en la aceleración del proceso de cicatrización fue significativa (p<0,0001). Conclusión: la asociación de terapias de fotobiomodulación con la membrana amniótica humana permitió comprobar que hubo una reducción en el tiempo del proceso de cicatrización de lesiones experimentales, lo cual favorece que se proponga como protocolo de tratamiento en quemaduras de espesor parcial.

Inhibition of bacterial biofilms by the snake venom proteome.

Snake venoms possess a range of pharmacological and toxicological activities. Here we evaluated the antibacterial and anti-biofilm activity against methicillin-susceptible and methicillin-resistant Staphylococcus aureus (MSSA and MRSA) of venoms from the Samar spitting cobra Naja samarensis and the Puff adder Bitis arietans. Both venoms prevented biofilm production by pathogenic S. aureus in a growth-independent manner, with the B. arietans venom being most potent. Fractionation showed the active molecule to be heat-labile and >10 kDa in size. Proteomic profiles of N. samarensis venom revealed neurotoxins and cytotoxins, as well as an abundance of serine proteases and three-finger toxins, while serine proteases, metalloproteinases and C-lectin types were abundant in B. arietans venom. These enzymes may have evolved to prevent bacteria colonising the snake venom gland. From a biomedical biotechnology perspective, they have valuable potential for anti-virulence therapy to fight antibiotic resistant microbes.

Next-Generation Sequencing for Venomics: Application of Multi-Enzymatic Limited Digestion for Inventorying the Snake Venom Arsenal.

To improve the characterization of snake venom protein profiles, we report the application of a new generation of proteomic methodology to deeply characterize complex protein mixtures. The new approach, combining a synergic multi-enzymatic and a time-limited digestion (MELD), is a versatile and straightforward protocol previously developed by our group. The higher number of overlapping peptides generated during MELD increases the quality of downstream peptide sequencing and of protein identification. In this context, this work aims at applying the MELD strategy to a venomics purpose for the first time, and especially for the characterization of snake venoms. We used four venoms as the test models for this proof of concept: two Elapidae (Dendroaspis polylepis and Naja naja) and two Viperidae (Bitis arietans and Echis ocellatus). Each venom was reduced and alkylated before being submitted to two different protocols: the classical bottom-up proteomics strategy including a digestion step with trypsin only, or MELD, which combines the activities of trypsin, Glu-C and chymotrypsin with a limited digestion approach. The resulting samples were then injected on an M-Class chromatographic system, and hyphenated to a Q-Exactive Mass Spectrometer. Toxins and protein identification were performed by Peaks Studio X+. The results show that MELD considerably improves the number of sequenced (de novo) peptides and identified peptides from protein databases, leading to the unambiguous identification of a greater number of toxins and proteins. For each venom, MELD was successful, not only in terms of the identification of the major toxins (increasing of sequence coverage), but also concerning the less abundant cellular components (identification of new groups of proteins). In light of these results, MELD represents a credible methodology to be applied as the next generation of proteomics approaches dedicated to venomic analysis. It may open new perspectives for the sequencing and inventorying of the venom arsenal and should expand global knowledge about venom composition.

Oxidative stress induced by Pollonein-LAAO, a new L-amino acid oxidase from Bothrops moojeni venom, prompts prostate tumor spheroid cell death and impairs the cellular invasion process in vitro.

Cancer cells produce abnormal levels of reactive oxygen species (ROS) that contribute to promote their malignant phenotype. In this framework, we hypothesized that the change in ROS concentration above threshold could impair key events of prostate cancer cells (PC-3) progression. Our results demonstrated that Pollonein-LAAO, a new L-amino acid oxidase obtained from Bothrops moojeni venom, was cytotoxic to PC-3 cells in two-dimensional and in tumor spheroid assays. Pollonein-LAAO was able to increase the intracellular ROS generation that culminates in cell death from apoptosis by both intrinsic and extrinsic pathways due to the up-regulation of TP53, BAX, BAD, TNFRSF10B and CASP8. Additionally, Pollonein-LAAO reduced mitochondrial membrane potential and caused G0/G1 phase to delay, due to the up-regulation of CDKN1A and the down-regulation of the expression of CDK2 and E2F. Interestingly, Pollonein-LAAO inhibited critical steps of the cellular invasion process (migration, invasion and adhesion), due to the down-regulation of SNAI1, VIM, MMP2, ITGA2, ITGAV and ITGB3. Furthermore, the Pollonein-LAAO effects were associated with the intracellular ROS production, since the presence of catalase restored the invasiveness of PC-3 cells. In this sense, this study contributes to the potential use of Pollonein-LAAO as ROS-based agent to enhance the current understanding of cancer treatment strategies.

Biochemical characterization and assessment of leishmanicidal effects of a new L-amino acid oxidase from Crotalus durissus collilineatus snake venom (CollinLA AO-I).

This study reports the isolation of CollinLAAO-I, a new L-amino acid oxidase from Crotalus durissus collilineatus snake venom, its biochemical characterization and leishmanicidal potential in Leishmania spp. CollinLAAO-I (63.1 kDa) was successfully isolated with high purity using two chromatographic steps and represents 2.5% of total venom proteins. CollinLAAO-I displayed high enzymatic activity (4262.83 U/mg/min), significantly reducing after 28 days. The enzymatic activity of CollinLAAO-I revealed higher affinity for hydrophobic amino acids such as L-leucine, high enzymatic activity in a wide pH range (6.0-10.0), at temperatures from 0 to 25 °C, and showed complete inhibition in the presence of Na+ and K+. Cytotoxicity assays revealed IC50 of 18.49 and 11.66 µg/mL for Leishmania (L.) amazonensis and Leishmania (L.) infantum, respectively, and the cytotoxicity was completely suppressed by catalase. CollinLAAO-I significantly increased the intracellular concentration of reactive oxygen species (ROS) and reduced the mitochondrial potential of both Leishmania species. Furthermore, CollinLAAO-I decreased the parasite capacity to infect macrophages by around 70%, indicating that even subtoxic concentrations of CollinLAAO-I can interfere with Leishmania vital processes. Thus, the results obtained for CollinLAAO-I provide important support for developing therapeutic strategies against leishmaniasis.

Preclinical study of experimental burns treated with photobiomodulation and Human Amniotic Membrane, both isolated and associated.

OBJECTIVE: to evaluate the effect of photobiomodulation with low-level 660 nm laser alone or associated with Human Amniotic Membrane in the repair of partial-thickness burns in rats. METHOD: an experimental study conducted with 48 male Wistar rats, randomized into four groups: Control, Human Amniotic Membrane, Low-Level Laser Therapy, and Low-Level Laser Therapy associated with Human Amniotic Membrane. The histopathological characteristics of the skin samples were analyzed 7 and 14 days after the burn. The data obtained were submitted to the Kolmogorov-Smirnov and Mann-Whitney tests. RESULTS: the histological analysis of the burn injuries showed a decrease in inflammation (p<0.0001) and an increase in proliferation of fibroblasts (p<0.0001) mainly at 7 days in all treatments related to the control group. At 14 days, the greater effectiveness in accelerating the healing process was significant (p<0.0001) in the Low-Level Laser Therapy group associated with the Human Amniotic Membrane. CONCLUSION: the association of photobiomodulation therapies with the Human Amniotic Membrane allowed verifying a reduction in the healing process time of the experimental lesions, stimulating its proposal as a treatment protocol in partial-thickness burns.

Isolation and characterization of the first phosphodiesterase (Bj-PDE) from the venom of Bothrops jararacussu snake.

Phosphodiesterases are exonucleases that sequentially hydrolyse phosphodiester bonds of polynucleotides from the 3'-end and release 5-mononucleotides. After more than one decade without any advance in the study of Bothropic phosphodiesterases, we described here the isolation of the first phosphodiesterase from Bothrops jararacussu, which we named Bj-PDE. A five-step column chromatography procedure (size exclusion, hydrophobic interaction, cation exchange, lentil lectin affinity, and blue sepharose affinity) enabled isolation of Bj-PDE with preserved and stable enzymatic activity (bis(p-nitrophenyl) phosphate substrate), Km = 6.9 mM (± 0.7 mM), kcat/Km = 1.7 × 104 M-1 s-1 (± 0.2 × 104 M-1 s-1), MW = 116 kDa (SDS-PAGE), optimum activity around 45 °C at pH 8.0, and stability for 81 days at different storage temperatures (8, -20, and - 80 °C). Ca2+ and Mg2+ ions positively influenced Bj-PDE activity, while EDTA had the opposite action. Zn2+ restored >50 % of enzyme activity after its inhibition by EDTA. The Bj-PDE partial sequence identified by mass spectrometry was very similar to the sequence of BATXPDE1 from Bothrops atrox, which was evolutionarily close to this new PDE. Therefore, our study represents an important progress on the isolation of this minor toxin and sheds new lights on the properties and bioprospection of bothropic phosphodiesterases.

Conhecimento e adesão de estudantes de enfermagem às medidas de precaução-padrão / Conocimientos y adhesión de estudiantes de enfermería a las medidas de precaución estándar / Nursing students' knowledge and compliance with standard precautions

Resumo Objetivo Descrever o conhecimento e a adesão dos estudantes de graduação em enfermagem às medidas de precaução-padrão. Métodos Estudo descritivo e quantitativo com 161 acadêmicos de enfermagem. Os dados foram coletados entre setembro e outubro de 2020, mediante formulário eletrônico e processados no programa Statistical Package for the Social Sciences, por meio de análises descritivas. Resultados Os escores médios de conhecimento e adesão às medidas de precaução-padrão demonstraram níveis satisfatórios, ou seja, superiores à metade do escore possível. Os estudantes reconheceram que essas medidas se estendem além dos cuidados para com pacientes com diagnósticos de infecção ou que se encontram no período de incubação do processo infeccioso. Contudo, limitam seu objetivo à proteção da equipe de saúde, preterindo a proteção do paciente. A higienização das mãos, assim como a utilização de luvas em procedimentos que envolviam contato com material biológico potencialmente contaminado, foram as medidas mais adotadas pelos estudantes. Observou-se que a adesão às medidas protetivas é maior nos períodos finais da graduação. Conclusão Evidenciaram-se fragilidades no conhecimento dos estudantes no que tange às noções básicas que norteiam e embasam a adoção das medidas de segurança; revela-se ser fundamental um currículo de enfermagem que, de forma contínua, ao longo dos ciclos acadêmicos incorpore no seu escopo de discussões a prevenção e o controle das infecções relacionadas à assistência à saúde. Tal cuidado se refletirá não só na qualidade da assistência prestada, como também na manutenção da saúde desse estudante - futuro trabalhador da área.

Resumen Objetivo Describir los conocimientos y la adhesión de estudiantes de la carrera de enfermería a las medidas de precaución estándar. Métodos Estudio descriptivo y cuantitativo con 161 académicos de enfermería. Los datos fueron recopilados entre septiembre y octubre de 2020, mediante formulario electrónico, y fueron procesados en el programa Statistical Package for the Social Sciences, por medio de análisis descriptivos. Resultados La puntuación promedio de conocimiento y adhesión a las medidas de precaución estándar demostraron niveles satisfactorios, es decir, superiores a la mitad de la puntuación posible. Los estudiantes admitieron que estas medidas se extienden más allá de los cuidados a pacientes con diagnóstico de infección o que se encuentran en el período de incubación del proceso infeccioso. No obstante, limitan su objetivo a la protección del equipo de salud, descuidando la protección del paciente. La higienización de las manos, así como el uso de guantes en procedimientos que implicaban contacto con material biológico potencialmente contaminado, fueron las medidas más adoptadas por los estudiantes. Se observó que la adhesión a las medidas de protección es mayor en los períodos finales de la carrera. Conclusión Se evidenciaron debilidades en los conocimientos de los estudiantes en lo que atañe a las nociones básicas que orientan y respaldan la adopción de las medidas de seguridad. Resulta fundamental un diseño curricular de enfermería que, de forma continua y a lo largo de los ciclos académicos, incorpore en sus temas de discusión la prevención y el control de las infecciones asociadas a la atención de salud. Este cuidado se verá reflejado no solo en la calidad de la atención brindada, sino también en la conservación de la salud de ese estudiante, futuro trabajador del área.

Abstract Objective To describe nursing students' knowledge and compliance with standard precautions. Methods This is a descriptive and quantitative study with 161 nursing students. Data were collected between September and October 2020, through an electronic form and processed in the Statistical Package for the Social Sciences program, through descriptive analyses. Results The mean scores of knowledge and compliance with standard precautions showed satisfactory levels, i.e., higher than half of the possible score. Students recognized that these measures extend beyond care for patients diagnosed with infection or who are in the incubation period of the infectious process. However, they limit their objective to the health team protection, neglecting patient protection. Hand hygiene, as well as the use of gloves in procedures involving contact with potentially contaminated biological material, was the most adopted measure by students. It was observed that compliance with protective measures is higher in the final periods of graduation. Conclusion We identified weaknesses in students' knowledge regarding the basic notions that guide and support the adoption of security measures. It is essential to have a nursing curriculum that, throughout the academic cycles, continuously incorporates the prevention and control of infections related to health care in its scope of discussions. This care will be reflected not only in the quality of the care provided, but also in the maintenance of students' health - future workers in the area.

Evaluation of Stress and Fatigue on Different Implant Lengths in the Rehabilitation of Atrophic Mandibles with Full-Arch Fixed Prosthesis Using Finite Element Method.

PURPOSE: This research aimed to evaluate the stress and fatigue generated in short implants compared to regular implants in rehabilitation with fixed full-arch implant-supported prostheses in atrophic mandibles using the finite element method (FEM). MATERIALS AND METHODS: Four models were constructed with different implants lengths: 4, 6, 8, and 10 mm. A 100-N oblique load was applied to evaluate the stress on the bone, implant, and prosthetic components. RESULTS: Similar behavior was observed for all groups, except for 4 mm, which showed more discrepant values. During the fatigue test, all the groups exhibited infinite lives except G4. CONCLUSION: Based on the similarity of all the models, it is suggested that all short implants investigated are seemingly viable alternatives for the rehabilitation of atrophic mandibles. However, the 6-mm-long and 8-mm-long implants evinced more favorable mechanical behavior than the 4-mm-long type.

Heterologous expression of Ts8, a neurotoxin from Tityus serrulatus venom, evidences its antifungal activity.

In this study we expressed the Ts8, a neurotoxin from Tityus serrulatus scorpion venom, in Pichia pastoris yeast. We evaluated the peptide expression in different conditions, such as pH, temperature, and addition of casamino acids supplement. Analyses of expressed products by mass spectrometry and Edman degradation showed that rTs8 has sites that allow its cleavage by yeast proteases released into the culture medium. The casamino acids addition was favourable for toxin expression, however, was not sufficient to minimize proteolytic degradation. Functional assays with recombinant toxin fragments and native toxins have demonstrated the release of cytokines such as TNF-α and IL-1ß in some peptides tested. In addition, the toxins were shown to inhibit the Pichia pastoris growth in antifungal test and were not toxic to alveolar macrophages cells at the concentrations analyzed The electrophysiological screening, by voltage clamp technique, showed that the rTs8 fragment with the highest molecular weight inhibited the Kv1.3 channel, whereas the N-terminal fragment had no activity on the ion channels tested.

Impacto da pandemia na saúde mental dos discentes de enfermagem no contexto da COVID-19 / Impact of the pandemic on the mental health of nursing students in the context of COVID-19 / Impacto de la pandemia en la salud mental de los estudiantes de enfermería en el contexto del COVID-19

Objetivo: Investigar os impactos da pandemia da COVID-19 na saúde mental dos discentes de enfermagem e avaliar a relação entre o evento e os indicadores para transtorno de estresse pós-traumático (TEPT). Método: estudo exploratório, analítico, transversal, com abordagem quantitativa. A amostra estudada foi constituída por 164 estudantes de uma instituição de ensino superior privada, matriculado no curso de Enfermagem, convidado por meio eletrônico, que responderam ao questionário on-line sobre dados sociodemográficos, percepção de risco pela pandemia COVID-19 e sintomas de estresse pós-traumático avaliados pela Impact of Event Scale (IES-R) em sua versão brasileira validada. Resultados: A maioria dos participantes eram da faixa etária de 18 a 23 anos (70,8%), do sexo feminino (91,5%), sem filhos (86%), residem com 2 a 4 pessoa (75%). 51,2% apresentam indicação alta para TEPT, 14,0% apresentam preocupação clínica para TEPT. Houve associação do escore da IES-R com a idade, quantidade de filhos e quantidade de pessoas com quem reside. Conclusão: O evento da pandemia da Covid-19 provocou um impacto na saúde mental dos discentes de Enfermagem, com uma elevada classificação de participantes com indicação alta para TEPT. Esses dados são importantes para futuras intervenções psicológicas e pedagógicas entre estudantes.

Objective: To investigate the impacts of the COVID-19 pandemic on the mental health of nursing students and to assess the relationship between the event and the indicators for post-traumatic stress disorder (PTSD). Method: exploratory, analytical, cross-sectional study with a quantitative approach. The sample studied consisted of 164 students from a private higher education institution, enrolled in the Nursing course, invited by electronic means, who answered the online questionnaire on sociodemographic data, risk perception by the COVID-19 pandemic and symptoms of stress. trauma assessed by the Impact of Event Scale (IES-R) in its validated Brazilian version. Results: Most participants were aged between 18 and23 years (70.8%), female (91.5%), without children (86%), living with 2 to 4 people (75%). 51.2% have a high indication for PTSD, 14.0% have clinical concern for PTSD. There was an association of the IES-R score with age, number of children and number of people with whom they live. Conclusion: The Covid-19 pandemic event had an impact on the mental health of Nursing students, with a high rating of participants with a high indication for PTSD. These data are important for future psychological and pedagogical interventions among students.

Objetivo: Investigar los impactos de la pandemia de COVID-19 en la salud mental de estudiantes de enfermería y evaluar la relación entre el evento y los indicadores de trastorno de estrés postraumático (TEPT). Método: estudio exploratorio, analítico, transversal con enfoque cuantitativo. La muestra estudiada estuvo conformada por 164 estudiantes de una institución de educación superior privada, matriculados en la carrera de Enfermería, invitados por medios electrónicos, quienes respondieron el cuestionario en línea sobre datos sociodemográficos, percepción de riesgo por la pandemia del COVID-19 y síntomas de estrés y trauma evaluados por la Escala de Impacto de Evento (IES-R) en su versión brasileña validada. Resultados: La mayoría de los participantes tenían entre 18 y 23 años (70,8%), sexo femenino (91,5%), sin hijos (86%), viviendo con 2 a 4 personas (75%). El 51,2% tiene una alta indicación de TEPT, el 14,0% tiene preocupación clínica por TEPT. Hubo asociación del puntaje IES-R con la edad, número de hijos y número de personas con las que conviven. Conclusión: El evento pandémico de la Covid-19 tuvo impacto en la saludmental de los estudiantes de Enfermería, con alta calificación de participantes con alta indicación para TEPT. Estos datos son importantes para futuras intervenciones psicológicas y pedagógicas entre los estudiantes.

Insights into structure and function of CdcVEGFs, the vascular endothelial growth factor from Crotalus durissus collilineatus snake venom.

Vascular endothelial growth factors (VEGFs) are crucial molecules involved in the modulation of angiogenesis. Snake venom-derived VEGFs (svVEGFs) are known to contribute significantly to the envenoming due to their capacity of increasing vascular permeability. In our work, we isolated and analyzed the biochemical and functional properties of the VEGF from Crotalus durissus collilineatus venom (CdcVEGF). The venom was fractionated by reversed phase chromatography on FPLC system (Fast Protein Liquid Chromatography) and the eluted fractions were submitted to an ELISA assay using an anti-VEGF-F antibody, for identification of svVEGF. Positive fractions for svVEGF were submitted to SDS-PAGE and to an anion exchange chromatography to isolate the molecule. The subfractions were analyzed by ELISA and SDS-PAGE and six of them presented svVEGFs, named CdcVEGF1 (Q23-3), CdcVEGF2 (Q24-3), CdcVEGF3 (Q24-4), CdcVEGF4 (Q25-3), CdcVEGF5 (Q25-4), and CdcVEGF6 (Q25-5). Their structural characterization was accomplished by mass spectrometry analysis using MALDI-TOF to determine their molecular masses and UPLC-ESI-QTOF to determine their amino acid sequence. Interestingly, all isolated CdcVEGFs induced angiogenesis on HUVEC cells through tube formation on Matrigel when compared to culture medium (negative control). Moreover, CdcVEGF2 and CdcVEGF3 also induced a significant increase in tube formation when compared to the positive control (basic fibroblast growth factor - bFGF). Additionally, crotalid antivenom produced by the Instituto Butantan was able to recognize CdcVEGFs, demonstrating to be immunogenic. This study demonstrates that snake venom cocktail can reveal novel and important molecules, which are potential molecular tools to study diverse biological processes, such as angiogenesis.

Shedding Lights on Crude Venom from Solitary Foraging Predatory Ant Ectatomma opaciventre: Initial Toxinological Investigation.

Some species of primitive predatory ants, despite living in a colony, exercise their hunting collection strategy individually; their venom is painful, paralyzing, digestive, and lethal for their prey, yet the toxins responsible for these effects are poorly known. Ectatomma opaciventre is a previously unrecorded solitary hunting ant from the Brazilian Cerrado. To overcome this hindrance, the present study performed the in vitro enzymatic, biochemical, and biological activities of E. opaciventre to better understand the properties of this venom. Its venom showed several proteins with masses ranging from 1-116 kDa, highlighting the complexity of this venom. Compounds with high enzymatic activity were described, elucidating different enzyme classes present in the venom, with the presence of the first L-amino acid oxidase in Hymenoptera venoms being reported. Its crude venom contributes to a state of blood incoagulability, acting on primary hemostasis, inhibiting collagen-induced platelet aggregation, and operating on the fibrinolysis of loose red clots. Furthermore, the E. opaciventre venom preferentially induced cytotoxic effects on lung cancer cell lines and three different species of Leishmania. These data shed a comprehensive portrait of enzymatic components, biochemical and biological effects in vitro, opening perspectives for bio-pharmacological application of E. opaciventre venom molecules.

Use of kefir peptide (Kef-1) as an emerging approach for the treatment of oxidative stress and inflammation in 2K1C mice.

The benefits of kefir consumption are partially due to the rich composition of bioactive molecules released from its fermentation. Angiotensin-converting enzyme (ACE) inhibitors are bioactive molecules with potential use in the treatment or prevention of hypertension, heart failure, and myocardial infarction. Here, the in vivo actions of the Kef-1 peptide, an ACE inhibitor derived from kefir, were evaluated in an angiotensin II-dependent hypertension model. The Kef-1 peptide showed a potential anti-hypertensive effect. Additionally, Kef-1 exhibited systemic antioxidant and anti-inflammatory activities. In smooth muscle cells (SMCs), the Kef-1 peptide decreased ROS production through the reduced participation of NADPH oxidase and mitochondria. The aorta of 2K1C mice treated with Kef-1 showed lesser wall-thickening and partial restoration of the endothelial structure. In conclusion, these novel findings highlight the in vivo biological potential of this peptide demonstrating that Kef-1 may be a relevant nutraceutical treatment for cardiovascular diseases.

Mortality in Systemic Sclerosis-Associated Interstitial Lung Disease in Brazil: A Real-Life, Long-Term Follow-up Observational Study.

OBJECTIVES: The aim of this study was to identify risk factors associated with mortality in patients with systemic sclerosis (SSc), particularly those with interstitial lung disease (ILD), over a long-term follow-up in a large Brazilian SSc cohort. METHODS: We conducted a medical records review study of 380 scleroderma patients from 1982 to 2019. Systemic sclerosis ILD was considered in those with evidence of ILD on chest high-resolution computed tomography (HRCT). Causes of death were determined. RESULTS: Among the 380 SSc patients, SSc-ILD on chest HRCT was observed in 227 patients (59.7%). Seventy-two patients (18.9%) died during a mean follow-up of 7.2 years since the SSc diagnosis; among them, 57 (79.2%) had SSc-ILD, compared with 15 (20.8%) without SSc-ILD (p < 0.001). Of the 72 deaths, 51.4% were considered related to SSc, and ILD was the leading cause of death. The overall survival rates at 5, 10, and 15 years were 87.9%, 81.5%, and 74.9%, respectively. Kaplan-Meier analysis showed a significantly worse prognosis among patients with SSc-ILD than among those without ILD (p < 0.001). Among patients with SSc-ILD, disease duration of less than 4 years (p < 0.001), forced vital capacity <80% at baseline (p = 0.017), and pulmonary systolic arterial pressure ≥40 mm Hg on echocardiography (p < 0.001) were significantly associated with mortality by multivariate analysis. CONCLUSIONS: In Brazilian SSc patients, the presence of ILD was associated with a worse prognosis. The higher mortality among SSc-ILD patients, especially those with a shorter disease duration and forced vital capacity <80%, highlights the need for early screening and closer monitoring before irreversible lung function deterioration occurs.

Shedding lights on crude venom from solitary foraging predatory ant Ectatomma opaciventre: initial toxinological investigation

Some species of primitive predatory ants, despite living in a colony, exercise their hunting collection strategy individually; their venom is painful, paralyzing, digestive, and lethal for their prey, yet the toxins responsible for these effects are poorly known. Ectatomma opaciventre is a previously unrecorded solitary hunting ant from the Brazilian Cerrado. To overcome this hindrance, the present study performed the in vitro enzymatic, biochemical, and biological activities of E. opaciventre to better understand the properties of this venom. Its venom showed several proteins with masses ranging from 1–116 kDa, highlighting the complexity of this venom. Compounds with high enzymatic activity were described, elucidating different enzyme classes present in the venom, with the presence of the first L-amino acid oxidase in Hymenoptera venoms being reported. Its crude venom contributes to a state of blood incoagulability, acting on primary hemostasis, inhibiting collagen-induced platelet aggregation, and operating on the fibrinolysis of loose red clots. Furthermore, the E. opaciventre venom preferentially induced cytotoxic effects on lung cancer cell lines and three different species of Leishmania. These data shed a comprehensive portrait of enzymatic components, biochemical and biological effects in vitro, opening perspectives for bio-pharmacological application of E. opaciventre venom molecules.