RESUMEN

This investigation aimed to determine the effects of 24 weeks of resistance training (RT) on cardiac function in older women. Seventy-three physically independent older women were selected for this investigation. Participants were randomized into a training group (TG, n = 38) and a control group (CG, n = 35). The RT program was conducted over 24 weeks and consisted of three sessions a week. Participants performed eight exercises for the whole body in three sets of 8-12 repetitions. Tissue Doppler echocardiography was performed, according to current guidelines, before and after 24 weeks of the intervention. One-repetition maximum (1-RM) tests were used to assess muscular strength. A group vs. time interaction (P < 0.05) was shown for left ventricular end-diastolic volume (TG = - 8.3% vs. CG = - 0.6%), left ventricular end-systolic volume (TG = - 10.6% vs. CG = + 1.1%), and left atrial volume index (TG = - 9.1% vs. CG = + 3.9%). A main time effect (P < 0.05) was found for left ventricular mass index (TG = + 4.9% vs. CG = - 0.6%), septal thickness (TG = + 3.3% vs. CG = - 1.7%), left ventricular ejection fraction (TG = + 3.7% vs. CG = - 0.5%), E'/E septal (TG = - 4.8% vs. CG = + 0.5%), deceleration time (TG = - 4.1% vs. CG = + 3.9%), E septal (TG = + 4.6% vs. CG = - 0.6%), and E lateral (TG = + 5.2% vs. CG = - 1.1%). These results suggest that 24 weeks of RT improves cardiac morphological and functional variables in older women.

RESUMEN

The impacts of grazing on rangelands have historically been studied within the framework of the equilibrium model, which predicts significant impacts of grazing on ecosystems. However, in recent decades, studies have observed a non-equilibrium pattern, suggesting that abiotic factors play a primary role compared to grazing. These studies are primarily focused on rangelands, despite animal husbandry occurring in other biomes, such as seasonally dry tropical forests. Our study examines the influence of goat grazing on biodiversity and forest succession in the Brazilian dry forest (Caatinga). Considering its high interannual precipitation variability, we hypothesize a response that aligns with the non-equilibrium paradigm. We established a gradient of grazing intensity and history in areas at different stages of vegetation succession. A survey of tree - shrub and herbaceous species was conducted at each site and the biomass of both strata was quantified. Linear mixed models and Permanova were employed to assess differences in richness, composition, structure, and biomass among the areas. Our results suggest that grazing (history and intensity) and forest fallow age did not affect species richness, but only species composition. Low and high grazing intensity drive ecosystems toward similar compositions, which align with the non-equilibrium model predictions. Biomass in the herbaceous layer remained unaffected by grazing history, intensity, or forest fallow age, whereas woody biomass was influenced by grazing intensity in older forest fallows. Although trees in low-intensity grazing sites were significantly taller compared to those in other levels, overall, grazing did not disrupt the natural succession process. Older forest fallows exhibited greater diversity and higher basal area compared to new forest fallows, irrespective of grazing intensity. Our findings suggest that: a) grazing has minimal effects on biodiversity and biomass due to non-equilibrium dynamics, and b) with appropriate management, grazing can coexist with the conservation of the Caatinga.

Asunto(s)

Biodiversidad , Bosques , Herbivoria , Brasil , Animales , Biomasa , Cabras , Monitoreo del Ambiente , Árboles

RESUMEN

BACKGROUND: SARS-CoV2 virus, responsible for the COVID-19 pandemic, has four structural proteins and 16 nonstructural proteins. S-protein is one of the structural proteins exposed on the virus surface and is the main target for producing neutralizing antibodies and vaccines. The S-protein forms a trimer that can bind the angiotensin-converting enzyme 2 (ACE2) through its receptor binding domain (RBD) for cell entry. AIMS: The goal of this study was to express in HEK293 cells a new RBD recombinant protein in a constitutive and stable manner in order to use it as an alternative immunogen and diagnostic tool for COVID-19. MATERIALS & METHODS: The protein was designed to contain an immunoglobulin signal sequence, an explanded C-terminal section of the RBD, a region responsible for the bacteriophage T4 trimerization inducer, and six histidines in the pCDNA-3.1 plasmid. Following transformation, the cells were selected with geneticin-G418 and purified from serum-fre culture supernatants using Ni2+-agarand size exclusion chromatography. The protein was structurally identified by cross-linking and circular dichroism experiments, and utilized to immunize mice in conjuction with AS03 or alum adjuvants. The mice sera were examined for antibody recognition, receptor-binding inhibition, and virus neutralization, while spleens were evaluated for γ-interferon production in the presence of RBD. RESULTS: The protein released in the culture supernatant of cells, and exhibited a molecular mass of 135 kDa with a secondary structure like the monomeric and trimeric RBD. After purification, it formed a multimeric structure comprising trimers and hexamers, which were able to bind the ACE2 receptor. It generated high antibody titers in mice when combined with AS03 adjuvant (up to 1:50,000). The sera were capable of inhibiting binding of biotin-labeled ACE2 to the virus S1 subunit and could neutralize the entry of the Wuhan virus strain into cells at dilutions up to 1:2000. It produced specific IFN-γ producing cells in immunized mouse splenocytes. DISCUSSION: Our data describe a new RBD containing protein, forming trimers and hexamers, which are able to induce a protective humoral and cellular response against SARS-CoV2. CONCLUSION: These results add a new arsenal to combat COVID-19, as an alternative immunogen or antigen for diagnosis.

Asunto(s)

Enzima Convertidora de Angiotensina 2 , Anticuerpos Neutralizantes , Anticuerpos Antivirales , COVID-19 , Proteínas Recombinantes , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Animales , Humanos , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/química , Ratones , Anticuerpos Neutralizantes/inmunología , SARS-CoV-2/inmunología , COVID-19/inmunología , COVID-19/prevención & control , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/genética , Proteínas Recombinantes/química , Células HEK293 , Enzima Convertidora de Angiotensina 2/metabolismo , Enzima Convertidora de Angiotensina 2/inmunología , Anticuerpos Antivirales/inmunología , Vacunas contra la COVID-19/inmunología , Ratones Endogámicos BALB C , Femenino , Multimerización de Proteína , Dominios Proteicos/inmunología , Unión Proteica

RESUMEN

Studies on the interaction sites of peptide toxins and ion channels typically involve site-directed mutations in toxins. However, natural mutant toxins exist among them, offering insights into how the evolutionary process has conserved crucial sequences for activities and molecular target selection. In this study, we present a comparative investigation using electrophysiological approaches and computational analysis between two alpha toxins from evolutionarily close scorpion species of the genus Tityus, namely, Tst3 and Ts3 from T. stigmurus and T. serrulatus, respectively. These toxins exhibit three natural substitutions near the C-terminal region, which is directly involved in the interaction between alpha toxins and Nav channels. Additionally, we characterized the activity of the Tst3 toxin on Nav1.1-Nav1.7 channels. The three natural changes between the toxins did not alter sensitivity to Nav1.4, maintaining similar intensities regarding their ability to alter opening probabilities, delay fast inactivation, and induce persistent currents. Computational analysis demonstrated a preference for the down conformation of VSD4 and a shift in the conformational equilibrium towards this state. This illustrates that the sequence of these toxins retained the necessary information, even with alterations in the interaction site region. Through electrophysiological and computational analyses, screening of the Tst3 toxin on sodium isoform revealed its classification as a classic α-NaTx with a broad spectrum of activity. It effectively delays fast inactivation across all tested isoforms. Structural analysis of molecular energetics at the interface of the VSD4-Tst3 complex further confirmed this effect.

Asunto(s)

Venenos de Escorpión , Escorpiones , Venenos de Escorpión/química , Venenos de Escorpión/genética , Animales , Brasil , Humanos , Xenopus laevis , Activación del Canal Iónico/efectos de los fármacos , Secuencia de Aminoácidos , Animales Ponzoñosos

RESUMEN

This study aims to evaluate the antitrypanosomiasis activity of a synthetic dichloro-substituted aminochalcone via in vitro assays against infected cell cultures, as well as a theoretical characterization of pharmacokinetics and pharmacodynamics against the protein targets of the evolutionary cycle of T. cruzi. The in vitro evaluation of parasite proliferation inhibition was performed via cytotoxicity analysis on mammalian host cells, effect on epimastigote and trypomastigote forms, and cell death analysis, while computer simulations characterized the electronic structure of (2E)-1-(4-aminophenyl)-3-(2,4-dichlorophenyl)prop-2-en-1-one (DCl), the mechanism of action against the proteins of the evolutionary cycle of T. cruzi: Cruzain, Trypanothione reductase, TcGAPDH, and CYP51 by molecular docking and dynamics and predictive pharmacokinetics by MPO-based ADMET. The in vitro tests showed that the DCl LC50 in order of 178.9 ± 23.9 was similar to the BZN, evidencing the effectiveness of chalcone against Trypomastigotes. Molecular docking and dynamics simulations suggest that DCl acts on the active site of the CYP51 receptor, with hydrogen interactions that showed a high degree of occupation, establishing a stable complex with the target. MPO analysis and ADMET prediction tests suggest that the compound presents an alignment between permeability and hepatic clearance, although it presents low metabolic stability. Chalcone showed stable pharmacodynamics against the CYP51 target, but can form reactive metabolites from N-conjugation and C = C epoxidation, as an indication of controlled oral dose, although the estimated LD50 rate > 500 mg/kg is a indicative of low incidence of lethality by ingestion, constituting a promising therapeutic strategy.

Asunto(s)

Chalconas , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Tripanocidas , Trypanosoma cruzi , Tripanocidas/farmacología , Tripanocidas/química , Trypanosoma cruzi/efectos de los fármacos , Animales , Chalconas/farmacología , Chalconas/química , Proteínas Protozoarias/metabolismo , Humanos , NADH NADPH Oxidorreductasas/antagonistas & inhibidores , NADH NADPH Oxidorreductasas/metabolismo , Teoría Cuántica , Ratones , Enfermedad de Chagas/tratamiento farmacológico

RESUMEN

Snakebites affect millions of people worldwide. The majority of research and management about snakebites focus on venom and antivenom, with less attention given to snake ecology. The fundamental factor in snakebites is the snakes' defensive biting behavior. Herein we examine the effects of environmental variables (temperature, time of day, and human stimulus) and biological variables (sex and body size) on the biting behavior of a medically significant pit viper species in Brazil, Bothrops jararaca (Viperidae), and associate it with the epidemiology of snakebites. Through experimental simulations of encounters between humans and snakes, we obtained behavioral models applicable to epidemiological situations in the State of São Paulo, Brazil. We found a significant overlap between behavioral, morphological, environmental, and epidemiological data. Variables that increase snakebites in epidemiological data also enhance the tendency of snakes to bite defensively, resulting in snakebites. We propose that snakebite incidents are influenced by environmental and morphological factors, affecting the behavior of snakes and the proportion of incidents. Thus, investigating behavior of snakes related to snakebite incidents is a valuable tool for a better understanding of the epidemiology of these events, helping the prediction and, thus, prevention of snakebites.

Asunto(s)

Conducta Animal , Bothrops , Mordeduras de Serpientes , Mordeduras de Serpientes/epidemiología , Mordeduras de Serpientes/psicología , Animales , Humanos , Masculino , Femenino , Brasil/epidemiología , Serpientes Venenosas

RESUMEN

ABSTRACT: Nunes, JP, Blazevich, AJ, Schoenfeld, BJ, Kassiano, W, Costa, BDV, Ribeiro, AS, Nakamura, M, Nosaka, K, and Cyrino, ES. Determining changes in muscle size and architecture after exercise training: One site does not fit all. J Strength Cond Res 38(4): 787-790, 2024-Different methods can be used to assess muscle hypertrophy, but the effects of training on regional changes in muscle size can be detected only using direct muscle measurements such as muscle thickness, cross-sectional area, or volume. Importantly, muscle size increases vary across regions within and between muscles after resistance training programs (i.e., heterogeneous, or nonuniform, muscle hypertrophy). Muscle architectural changes, including fascicle length and pennation angle, after resistance and stretch training programs are also region-specific. In this paper, we show that the literature indicates that a single-site measure of muscle shape does not properly capture the effects achieved after exercise training interventions and that conclusions concerning the magnitude of muscle adaptations can vary substantially depending on the muscle site to be examined. Thus, we propose that measurements of muscle size and architecture should be completed at multiple sites across regions between the agonist muscles within a muscle group and along the length of the muscles to provide an adequate picture of training effects.

Asunto(s)

Músculo Esquelético , Entrenamiento de Fuerza , Humanos , Músculo Esquelético/fisiología , Fuerza Muscular/fisiología , Músculo Cuádriceps/fisiología , Ejercicio Físico/fisiología , Entrenamiento de Fuerza/métodos , Hipertrofia

RESUMEN

Background: SARS‐CoV2 virus, responsible for the COVID‐19 pandemic, hasfour structural proteins and 16 nonstructural proteins. S‐protein is one of thestructural proteins exposed on the virus surface and is the main target forproducing neutralizing antibodies and vaccines. The S‐protein forms a trimerthat can bind the angiotensin‐converting enzyme 2 (ACE2) through itsreceptor binding domain (RBD) for cell entry.Aims: The goal of this study was to express in HEK293 cells a new RBDrecombinant protein in a constitutive and stable manner in order to use it asan alternative immunogen and diagnostic tool for COVID‐19.Materials & Methods: The protein was designed to contain an immuno-globulin signal sequence, an explanded C‐terminal section of the RBD, aregion responsible for the bacteriophage T4 trimerization inducer, and sixhistidines in the pCDNA‐3.1 plasmid. Following transformation, the cells wereselected with geneticin‐G418 and purified from serum‐fre culture super-natants using Ni2+‐agarand size exclusion chromatography. The protein wasstructurally identified by cross‐linking and circular dichroism experiments,and utilized to immunize mice in conjuction with AS03 or alum adjuvants.The mice sera were examined for antibody recognition, receptor‐bindinginhibition, and virus neutralization, while spleens were evaluated forγ‐interferon production in the presence of RBD. Results: The protein released in the culture supernatant of cells, andexhibited a molecular mass of 135 kDa with a secondary structure like themonomeric and trimeric RBD. After purification, it formed a multimericstructure comprising trimers and hexamers, which were able to bind the ACE2receptor. It generated high antibody titers in mice when combined with AS03adjuvant (up to 1:50,000). The sera were capable of inhibiting binding ofbiotin‐labeled ACE2 to the virus S1 subunit and could neutralize the entry ofthe Wuhan virus strain into cells at dilutions up to 1:2000. It produced specificIFN‐γ producing cells in immunized mouse splenocytes.Discussion: Our data describe a new RBD containing protein, formingtrimers and hexamers, which are able to induce a protective humoral andcellular response against SARS‐CoV2.Conclusion: These results add a new arsenal to combat COVID‐19, as analternative immunogen or antigen for diagnosis.

RESUMEN

Snakebites affect millions of people worldwide. The majority of research and management about snakebites focus on venom and antivenom, with less attention given to snake ecology. The fundamental factor in snakebites is the snakes’ defensive biting behavior. Herein we examine the effects of environmental variables (temperature, time of day, and human stimulus) and biological variables (sex and body size) on the biting behavior of a medically significant pit viper species in Brazil, Bothrops jararaca (Viperidae), and associate it with the epidemiology of snakebites. Through experimental simulations of encounters between humans and snakes, we obtained behavioral models applicable to epidemiological situations in the State of São Paulo, Brazil. We found a significant overlap between behavioral, morphological, environmental, and epidemiological data. Variables that increase snakebites in epidemiological data also enhance the tendency of snakes to bite defensively, resulting in snakebites. We propose that snakebite incidents are influenced by environmental and morphological factors, affecting the behavior of snakes and the proportion of incidents. Thus, investigating behavior of snakes related to snakebite incidents is a valuable tool for a better understanding of the epidemiology of these events, helping the prediction and, thus, prevention of snakebites.

RESUMEN

The presence of invasive species in the environment can be highly detrimental. The success of these species depends on their interaction with native ones. The prey–predator relationship between invasive and native species can result in biodiversity loss or the introduction of new food items for local predators. Due to its tropical and extensive nature, Brazil is vulnerable to the colonization of invasive species. Snakes are a group of animals that can act as both predators and prey for invasive species. The pitviper Bothrops jararaca is an abundant and widely distributed native species on the Brazilian coast. Based on this, we conducted a study on the feeding preferences of naive B. jararaca juveniles regarding invasive and native prey. We found that this species exhibits a greater preference for native anurans compared to Rana catesbeiana, an invasive amphibian associated with significant environmental impacts. Additionally, the gecko Hemidactylus mabouia, a prey that triggered intense predatory responses from the pitviper, reveals that this species, even with a short period of coexistence with B. jararaca, has established an intense prey–predator relationship. The negative correlation between prey size and feeding interest, guided solely by olfactory cues, adds a layer of complexity to understanding the feeding choices of B. jararaca, providing valuable insights for conservation and environmental management strategies.

RESUMEN

Cardiomyopathies are major causes of heart failure. Chagas disease (CD) is caused by the parasite Trypanosoma cruzi, and it is endemic in Central and South America. Thirty percent of cases evolve into chronic chagas cardiomyopathy (CCC), which has worse prognosis as compared with other cardiomyopathies. In vivo bioenergetic analysis and ex vivo proteomic analysis of myocardial tissues highlighted worse mitochondrial dysfunction in CCC, and previous studies identified nuclear-encoded mitochondrial gene variants segregating with CCC. Here, we assessed the role of the mitochondrial genome through mtDNA copy number variations and mtDNA haplotyping and sequencing from heart or blood tissues of severe, moderate CCC and asymptomatic/indeterminate Chagas disease as well as healthy controls as an attempt to help decipher mitochondrial-intrinsic genetic involvement in Chagas disease development. We have found that the mtDNA copy number was significantly lower in CCC than in heart tissue from healthy individuals, while blood mtDNA content was similar among asymptomatic Chagas disease, moderate, and severe CCC patients. An MtDNA haplogrouping study has indicated that African haplogroups were over represented in the Chagas subject groups in comparison with healthy Brazilian individuals. The European lineage is associated with protection against cardiomyopathy and the macro haplogroup H is associated with increased risk towards CCC. Using mitochondria DNA sequencing, 84 mtDNA-encoded protein sequence pathogenic variants were associated with CCC. Among them, two variants were associated to left ventricular non-compaction and two to hypertrophic cardiomyopathy. The finding that mitochondrial protein-coding SNPs and mitochondrial haplogroups associate with risk of evolving to CCC is consistent with a key role of mitochondrial DNA in the development of chronic chagas disease cardiomyopathy.

RESUMEN

Histoplasmosis is a respiratory disease caused by Histoplasma capsulatum, a dimorphic fungus, with high mortality and morbidity rates, especially in immunocompromised patients. Considering the small existing therapeutic arsenal, new treatment approaches are still required. Chitosan, a linear polysaccharide obtained from partial chitin deacetylation, has anti-inflammatory, antimicrobial, biocompatibility, biodegradability, and non-toxicity properties. Chitosan with different deacetylation degrees and molecular weights has been explored as a potential agent against fungal pathogens. In this study, the chitosan antifungal activity against H. capsulatum was evaluated using the broth microdilution assay, obtaining minimum inhibitory concentrations (MIC) ranging from 32 to 128 µg/mL in the filamentous phase and 8 to 64 µg/mL in the yeast phase. Chitosan combined with classical antifungal drugs showed a synergic effect, reducing chitosan's MICs by 32 times, demonstrating that there were no antagonistic interactions relating to any of the strains tested. A synergism between chitosan and amphotericin B or itraconazole was detected in the yeast-like form for all strains tested. For H. capsulatum biofilms, chitosan reduced biomass and metabolic activity by about 40% at 512 µg/mL. In conclusion, studying chitosan as a therapeutic strategy against Histoplasma capsulatum is promising, mainly considering its numerous possible applications, including its combination with other compounds.

RESUMEN

The reduction of predation is a potentially important factor for the evolution of the traits of an island animal species. By relaxed selection, insular animals tend to lose their antipredator behaviors. A monophyletic group of pitvipers (genus Bothrops) in southeastern Brazil, which have high genetic affinity and dwell on the mainland and adjacent islands, provide an appropriate setting to study the evolution of antipredator behavior and how different predatory stimuli can influence this behavior. The mainland Bothrops jararaca has several terrestrial and aerial predators, whereas B. insularis and B. alcatraz, restricted to two small islands, Queimada Grande and Alcatrazes, respectively, have a smaller range of aerial predators. Terrestrial predators are absent on Queimada Grande, but one potential snake predator occurs on Alcatrazes. We observed that the defensive repertoire of island snakes has not been lost, but they display different frequencies of some antipredator behaviors. The type of predatory stimuli (terrestrial and aerial) influenced the defensive response. Bothrops insularis most often used the escape strategies, especially against terrestrial predatory stimuli. Bothrops alcatraz displayed the highest rate of strike for both terrestrial and aerial stimuli. Our results indicate that even though relaxed selection may occur in island environments as compared to mainland environments, these pitvipers still retain their antipredator behaviors but with different response degrees to the two predator types.

Asunto(s)

Conducta Predatoria , Serpientes , Animales , Conducta Predatoria/fisiología , Brasil

RESUMEN

The COVID-19 pandemic has put pressure on public health systems worldwide since 2020. This article aims to discuss working conditions in Primary Health Care (PHC) in Brazil, while dialoguing with primary health care (CSP, Cuidados de Saúde Primários) in Portugal in the pandemic scenario. For that purpose, data from the study "Working conditions of health professionals in the context of COVID-19 in Brazil" are presented, for further discussion with the report produced by "Family Health Units - National Association (USF-AN, Unidades de Saúde Familiar - Associação Nacional)" on the CSP in Portugal. In Brazil, regarding the sample of 3,895 PHC health professionals, it was observed: multiple employment relationships, lack of institutional support and specific training, living with fake news and the lack of political cohesion between health authorities, with significant changes in these workers' mental health. In Portugal, the increase in the workload and the presence of Burnout Syndrome among FHU professionals was emphasized. The pandemic had a significant impact on the health and daily work of health professionals in PHC and CSP. However, the Brazilian context was more adverse due to fake news and divergences regarding conducts related to the fight against the pandemic, due to the actions and denialism by the federal government.

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A pandemia de COVID-19 pressiona os sistemas públicos de saúde no mundo desde 2020. Este artigo pretende discutir as condições de trabalho na atenção primária à saúde (APS) no Brasil, dialogando também com os cuidados de saúde primários (CSP) em Portugal no cenário pandêmico. Para isso, apresentam-se dados da pesquisa "Condições de trabalho dos profissionais de saúde no contexto da COVID-19 no Brasil", para posterior discussão com o relatório das Unidades de Saúde Familiar - Associação Nacional (USF-AN) sobre os CSP em Portugal. No Brasil, no recorte amostral de 3.895 profissionais de saúde da APS, foram percebidos: múltiplos vínculos trabalhistas, falta de apoio institucional e de treinamentos específicos, convívio com fake news e falta de coesão política entre as autoridades sanitárias, com alterações significativas na saúde mental desses trabalhadores. Em Portugal, destacaram-se o aumento da carga horária de trabalho e presença de síndrome de burnout entre os profissionais das USFs. A pandemia impactou de forma significativa a saúde e o cotidiano de trabalho dos profissionais de saúde na APS e nos CSP. Porém, o contexto brasileiro foi mais adverso devido às fake news e às divergências na condução do combate à pandemia, pela atuação e negacionismo do governo federal.

Asunto(s)

COVID-19 , Humanos , Brasil/epidemiología , Pandemias , Portugal/epidemiología , Atención Primaria de Salud , Condiciones de Trabajo

RESUMEN

Resumo A pandemia de COVID-19 pressiona os sistemas públicos de saúde no mundo desde 2020. Este artigo pretende discutir as condições de trabalho na atenção primária à saúde (APS) no Brasil, dialogando também com os cuidados de saúde primários (CSP) em Portugal no cenário pandêmico. Para isso, apresentam-se dados da pesquisa "Condições de trabalho dos profissionais de saúde no contexto da COVID-19 no Brasil", para posterior discussão com o relatório das Unidades de Saúde Familiar - Associação Nacional (USF-AN) sobre os CSP em Portugal. No Brasil, no recorte amostral de 3.895 profissionais de saúde da APS, foram percebidos: múltiplos vínculos trabalhistas, falta de apoio institucional e de treinamentos específicos, convívio com fake news e falta de coesão política entre as autoridades sanitárias, com alterações significativas na saúde mental desses trabalhadores. Em Portugal, destacaram-se o aumento da carga horária de trabalho e presença de síndrome de burnout entre os profissionais das USFs. A pandemia impactou de forma significativa a saúde e o cotidiano de trabalho dos profissionais de saúde na APS e nos CSP. Porém, o contexto brasileiro foi mais adverso devido às fake news e às divergências na condução do combate à pandemia, pela atuação e negacionismo do governo federal.

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Abstract The COVID-19 pandemic has put pressure on public health systems worldwide since 2020. This article aims to discuss working conditions in Primary Health Care (PHC) in Brazil, while dialoguing with primary health care (CSP, Cuidados de Saúde Primários) in Portugal in the pandemic scenario. For that purpose, data from the study "Working conditions of health professionals in the context of COVID-19 in Brazil" are presented, for further discussion with the report produced by "Family Health Units - National Association (USF-AN, Unidades de Saúde Familiar - Associação Nacional)" on the CSP in Portugal. In Brazil, regarding the sample of 3,895 PHC health professionals, it was observed: multiple employment relationships, lack of institutional support and specific training, living with fake news and the lack of political cohesion between health authorities, with significant changes in these workers' mental health. In Portugal, the increase in the workload and the presence of Burnout Syndrome among FHU professionals was emphasized. The pandemic had a significant impact on the health and daily work of health professionals in PHC and CSP. However, the Brazilian context was more adverse due to fake news and divergences regarding conducts related to the fight against the pandemic, due to the actions and denialism by the federal government.

RESUMEN

OBJECTIVE: Oral candidiasis is a common fungal infection that affects the oral mucosa, and happens when Candida albicans interacts with bacteria in the oral microbiota, such as Streptococcus mutans, causing severe early childhood caries. C. albicans and S. mutans mixed biofilms are challenging to treat with conventional antimicrobial therapies, thus, new anti-infective drugs are required. This study aimed to test a drug delivery system based on chitosan microparticles loaded with geranium and lemongrass essential oils to inhibit C. albicans and S. mutans mixed biofilms. METHODOLOGY: Chitosan microparticles loaded with essential oils (CM-EOs) were obtained by spray-drying. Susceptibility of planktonic were performed according CLSI at 4 to 2,048 µg/mL. Mixed biofilms were incubated at 37ºC for 48 h and exposed to CM-EOs at 256 to 4,096 µg/mL. The antimicrobial effect was evaluated using the MTT assay, with biofilm architectural changes analyzed by scanning electron microscopy. RAW 264.7 cell was used to evaluate compound cytotoxicity. RESULTS: CM-EOs had better planktonic activity against C. albicans than S. mutans. All samples reduced the metabolic activity of mixed C. albicans and S. mutans biofilms, with encapsulated oils showing better activity than raw chitosan or oils. The microparticles reduced the biofilm on the slides. The essential oils showed cytotoxic effects against RAW 264.7 cells, but encapsulation into chitosan microparticles decreased their toxicity. CONCLUSION: This study demonstrates that chitosan loaded with essential oils may provide an alternative method for treating diseases caused by C. albicans and S. mutans mixed biofilm, such as dental caries.

Asunto(s)

Quitosano , Caries Dental , Aceites Volátiles , Preescolar , Humanos , Aceites Volátiles/farmacología , Candida albicans , Streptococcus mutans , Quitosano/farmacología , Caries Dental/prevención & control , Biopelículas

RESUMEN

The growing incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections is associated with increased mortality rates, which has generated interest in the development of antimicrobial peptides (AMP), such as those found in the giant ant Dinoponera quadríceps. In order to improve the net positive charge and the antibacterial activity of the AMP, amino acids with positive side chain single substituted analogues have been proposed, mainly arginine or lysine. The present work aims to study the antimicrobial activity of the analogues of M-PONTX-Dq3a, a 23 amino acid AMP identified in the D. quadriceps venom. M-PONTX-Dq3a[1-15], a fragment containing the 15 central amino acids, and eight derivatives of single arginine or lysine substituted analogues were proposed. The antimicrobial activity of peptides was evaluated against Staphylococcus aureus ATCC 6538 P (MSSA) and ATCC 33591 (MRSA) strains, followed by minimum inhibitory concentration (MIC), minimum lethal concentration (MLC), and minimum biofilm inhibitory concentration (MBIC) measurement. The membrane permeability was then assessed via crystal violet assay and flow cytometry analysis. The effect of exposure time on microbial viability (Time-Kill) was evaluated. Finally, ultrastructural alterations were evaluated through scanning electron microscopy (SEM). Both arginine-substituted peptides [Arg]3M-PONTX-Dq3a[1-15] and [Arg]4M-PONTX-Dq3a[1-15], showed lowest MIC and MLC values (each 0.78 µM). In the biofilm formation assays, the peptide [Arg]3M-PONTX-Dq3a [1-15] showed MBIC of 3.12 µM against the two tested strains. Both peptides were able to alter the membrane permeability approximately by 80%. The treatment with MIC was able to eliminate bacteria after 2 h of contact on the other hand, treatment with half of the MIC, the population of both bacterial strains remained constant for up to 12 h, indicating a possible bacteriostatic effect. The SEM results showed that the treatment with the lowest concentration (0.78 µM) of both peptides caused disruption of the cell membrane, destabilization of the intercellular interaction and the CLM of [Arg]4M-PONTX-Dq3a [1-15] resulted in the complete eradication of the bacteria. Thus, this study describes two AMPs active against MSSA and MRSA and also inhibits the biofilm formation of these stains. This study finds [Arg]3M-PONTX-Dq3a[1-15] and [Arg]4M-PONTX-Dq3a[1-15] as alternative substances to treat resistant and/or biofilm-forming strains.

Asunto(s)

Staphylococcus aureus Resistente a Meticilina , Staphylococcus aureus , Lisina/farmacología , Arginina/farmacología , Antibacterianos/farmacología , Péptidos/química , Pruebas de Sensibilidad Microbiana , Aminoácidos

Asunto(s)

Caimanes y Cocodrilos , Lagartos , Entrenamiento de Fuerza , Humanos , Animales , Fibras Musculares Esqueléticas/fisiología , Hipertrofia , Músculo Esquelético/fisiología , Fuerza Muscular

RESUMEN

This study's purpose was to compare the effects of different carbohydrate (CHO) intakes on body composition and muscular strength following eight weeks of resistance training (RT) in pre-conditioned men. In addition, we explored the individual responses to different CHO intakes. Twenty-nine young men volunteered to participate in this study. The participants were divided into two groups according to their relative CHO intake: lower (L-CHO; n = 14) and higher (H-CHO; n = 15). Participants performed a RT program four days a week for eight weeks. The lean soft tissue (LST) and fat mass were determined by dual-energy X-ray absorptiometry. Muscular strength was determined by a one-repetition maximum (1RM) test in the bench press, squat, and arm curl exercises. Both groups increased LST (P < 0.05) with no statistical differences between conditions (L-CHO = +0.8% vs. H-CHO = +3.5%). Neither group demonstrated changes in fat mass. Both groups increased 1RM (P < 0.05) in the bench press (L-CHO = +3.6% vs. H-CHO = +5.8%) and squat (L-CHO = +7.5% vs. H-CHO = +9.4%); however, only H-CHO significantly increased arm curl 1RM (P < 0.05) at post-training (L-CHO = +3.0% vs. H-CHO = +6.6%). Responsiveness was greater in H-CHO vs. L-CHO for LST and arm curl 1RM. In conclusion, lower and higher CHO intakes promote similar increase in LST and muscular strength; however, a greater intake may improve the responsiveness to gains in lean mass and arm curl strength in pre-conditioned men.

RESUMEN

The Covid-19 caused by the SARS-CoV-2 virus has shown how inadequate institutional strategies interact with, and exacerbate, social inequalities, thus impacting upon the intensity of the harm produced and amplifying negative consequences. One of the lessons from this pandemic, which happens against the background of other, interconnected systemic crises, is the urgency of adopting a 'whole-of-society' approach to determining what does and what does not work in the context of a health emergency response. However, how can institutional performance in health emergency response be assessed? How to make sense of success or failure? We argue that the adoption of a risk governance approach sheds light on institutional performance in the response to health emergencies. Risk governance is particularly pertinent in situations where the potential for extreme consequences is considered high, where there are enormous uncertainties regarding the consequences and where different values are present and in dispute. Based on a documentary evidence review, we analyse the Brazilian response to Covid-19 by considering: (1) how the Brazilian federal government performed on its central role of managing the national response, (2) the reactions from other actors prompted by this performance and (3) the main observed effects emerging from this scenario. We argue that the Brazilian federal government response was weak in five risk governance parameters that are essential in a health crisis response: risk communication, transparency and accessibility of data, negotiation between actors, social cohesion and public participation and decisions based on technical and scientific evidence, resources and contexts. The neglect of risk governance parameters, combined with an attempt to spread doubt, confusion and disinformation-which could be termed a 'governance by chaos'-is an important element for making sense of the effects and controversies surrounding Covid-19 in Brazil.

Asunto(s)

COVID-19 , Humanos , COVID-19/epidemiología , SARS-CoV-2 , Pandemias , Salud Global , Urgencias Médicas , Brasil/epidemiología