Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 125
Filtrar
1.
An Acad Bras Cienc ; 96(2): e20231336, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38747801

RESUMO

The disease coronavirus COVID-19 has been the cause of millions of deaths worldwide. Among the proteins of SARS-CoV-2, non-structural protein 12 (NSP12) plays a key role during COVID infection and is part of the RNA-dependent RNA polymerase complex. The monitoring of NSP12 polymorphisms is extremely important for the design of new antiviral drugs and monitoring of viral evolution. This study analyzed the NSP12 mutations detected in circulating SARS-CoV-2 during the years 2020 to 2022 in the population of the city of Manaus, Amazonas, Brazil. The most frequent mutations found were P323L and G671S. Reports in the literature indicate that these mutations are related to transmissibility efficiency, which may have contributed to the extremely high numbers of cases in this location. In addition, two mutations described here (E796D and R914K) are close and have RMSD that is similar to the mutations M794V and N911K, which have been described in the literature as influential on the performance of the NSP12 enzyme. These data demonstrate the need to monitor the emergence of new mutations in NSP12 in order to better understand their consequences for the treatments currently used and in the design of new drugs.


Assuntos
COVID-19 , Mutação , SARS-CoV-2 , Proteínas não Estruturais Virais , SARS-CoV-2/genética , Brasil , Proteínas não Estruturais Virais/genética , COVID-19/virologia , COVID-19/transmissão , Mutação/genética , Humanos , Simulação por Computador
2.
Sci Rep ; 14(1): 9521, 2024 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-38664450

RESUMO

Obesity is a highly prevalent disease with numerous complications. Both intensive medical treatment with the use of pharmacological drugs and bariatric surgery are current options. The objective of this meta-analysis was to compare, in the long-term, intensive medical treatment and surgery based on twelve parameters related to weight loss, cardiovascular and endocrine changes. A review of the literature was conducted in accordance with the PRISMA guidelines (PROSPERO: CRD42021265637). The literature screening was done from inception to October 2023 through PubMed, EMBASE and Web of Science databases. We included randomized clinical trials that had separate groups for medical treatment and bariatric surgery as an intervention for obesity. The risk of bias was assessed through RoB2. A meta-analysis was performed with measures of heterogeneity and publication bias. Subgroup analysis for each surgery type was performed. Data is presented as forest-plots. Reviewers independently identified 6719 articles and 6 papers with a total 427 patients were included. All studies were randomized controlled trials, three had a follow up of 5 years and two had a follow up of 10 years. Both groups demonstrated statistical significance for most parameters studied. Surgery was superior for weight loss (- 22.05 kg [- 28.86; - 15.23), total cholesterol (- 0.88 [- 1.59; - 0.17]), triglycerides (- 0.70 [- 0.82; - 0.59]), HDL (0.12 [0.02; 0.23]), systolic pressure (- 4.49 [- 7.65; - 1.33]), diastolic pressure (- 2.28 [- 4.25; - 0.31]), Hb glycated (- 0.97 [- 1.31; - 0.62]), HOMA IR (- 2.94; [- 3.52; - 2.35]) and cardiovascular risk (- 0.08; [- 0.10; - 0.05]). Patient in the surgical treatment group had better long term outcomes when compared to the non-surgical group for most clinical parameters.


Assuntos
Cirurgia Bariátrica , Obesidade , Redução de Peso , Humanos , Cirurgia Bariátrica/métodos , Obesidade/tratamento farmacológico , Obesidade/cirurgia , Redução de Peso/efeitos dos fármacos , Resultado do Tratamento , Ensaios Clínicos Controlados Aleatórios como Assunto
3.
Heliyon ; 10(4): e26115, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38404894

RESUMO

Heat stress is a challenge for the milk production chain, especially in tropical environments. Thus, the objective was to evaluate the knowledge and the perception of milk producers about heat stress and determine what corrective measures they adopted to minimize losses in the productive performance of dairy cows due to high temperatures. A questionnaire was applied to 112 dairy farmers in the states of Minas Gerais and Goiás, Brazil in 2019 and 2020. The collected data were submitted to descriptive statistics using the G test of independence and multivariate correspondence analysis. Among the surveyed producers, 89% stated that they had already been informed about what heat stress is and how it affects the animals; 94% declared that they had already noticed in their day-to-day activities that heat stress impairs productivity and milk quality, and 92% stated that they have tried to reduce the heat stress to which the animals in their herd are exposed. There was an association among previous knowledge about heat stress and farm size, daily volume of milk produced, number of lactating cows, type of milking and presence of technical assistance. There was also an association among the adoption of measures that minimize the negative effects of heat stress with the size of the property, the number of cows in lactation and with the producer's perception of heat stress in their daily lives. It was concluded that, in important municipalities of the Brazilian dairy chain, most milk producers surveyed have knowledge and perception of the negative effects of heat stress on the productive performance of dairy cows and sought to adopt measures that could alleviate them.

4.
Parasitol Res ; 123(1): 52, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-38099974

RESUMO

In a 2018 report, an unusual case of cutaneous leishmaniasis was described in a 72-year-old female patient residing in Arizona, United States of America (USA). Preliminary analysis of the 18S rDNA and glyceraldehyde-3-phosphate dehydrogenase genes supported the conclusion that the Leishmania strain (strain 218-L139) isolated from this case was a novel species, though a complete taxonomic description was not provided. Identification of Leishmania at the species level is critical for clinical management and epidemiologic investigations so it is important that novel human-infecting species are characterized taxonomically and assigned a unique scientific name compliant with the ICZN code. Therefore, we sought to provide a complete taxonomic description of Leishmania strain 218-L139. Phylogenetic analysis of several nuclear loci and partial maxicircle genome sequences supported its position within the subgenus Leishmania and further clarified the distinctness of this new species. Morphological characterization of cultured promastigotes and amastigotes from the original case material is also provided. Thus, we conclude that Leishmania (Leishmania) ellisi is a new cause of autochthonous cutaneous leishmaniasis in the USA.


Assuntos
Leishmania , Leishmaniose Cutânea , Feminino , Humanos , Estados Unidos , Idoso , Leishmania/genética , Filogenia , DNA Ribossômico/genética
6.
Sci Rep ; 13(1): 7306, 2023 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-37147348

RESUMO

The rapid spread of the SARS-CoV-2 Variant of Concern (VOC) Gamma in Amazonas during early 2021 fueled a second large COVID-19 epidemic wave and raised concern about the potential role of reinfections. Very few cases of reinfection associated with the VOC Gamma have been reported to date, and their potential impact on clinical, immunological, and virological parameters remains largely unexplored. Here we describe 25 cases of SARS-CoV-2 reinfection in Brazil. SARS-CoV-2 genomic analysis confirmed that individuals were primo-infected with distinct viral lineages between March and December 2020 (B.1.1, B.1.1.28, B.1.1.33, B.1.195, and P.2) and reinfected with the VOC Gamma between 3 to 12 months after primo-infection. We found a similar mean cycle threshold (Ct) value and limited intra-host viral diversity in both primo-infection and reinfection samples. Sera of 14 patients tested 10-75 days after reinfection displayed detectable neutralizing antibodies (NAb) titers against SARS-CoV-2 variants that circulated before (B.1.*), during (Gamma), and after (Delta and Omicron) the second epidemic wave in Brazil. All individuals had milder or no symptoms after reinfection, and none required hospitalization. These findings demonstrate that individuals reinfected with the VOC Gamma may display relatively high RNA viral loads at the upper respiratory tract after reinfection, thus contributing to onward viral transmissions. Despite this, our study points to a low overall risk of severe Gamma reinfections, supporting that the abrupt increase in hospital admissions and deaths observed in Amazonas and other Brazilian states during the Gamma wave was mostly driven by primary infections. Our findings also indicate that most individuals analyzed developed a high anti-SARS-CoV-2 NAb response after reinfection that may provide some protection against reinfection or disease by different SARS-CoV-2 variants.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , Brasil/epidemiologia , COVID-19/epidemiologia , Diversidade de Anticorpos , Raios gama , Reinfecção , Gravidade do Paciente
7.
Nat Commun ; 14(1): 2048, 2023 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-37041143

RESUMO

The SARS-CoV-2 variants of concern (VOCs) Delta and Omicron spread globally during mid and late 2021, respectively. In this study, we compare the dissemination dynamics of these VOCs in the Amazonas state, one of Brazil's most heavily affected regions. We sequenced the virus genome from 4128 patients collected in Amazonas between July 1st, 2021, and January 31st, 2022, and investigated the viral dynamics using a phylodynamic approach. The VOCs Delta and Omicron BA.1 displayed similar patterns of phylogeographic spread but different epidemic dynamics. The replacement of Gamma by Delta was gradual and occurred without an upsurge of COVID-19 cases, while the rise of Omicron BA.1 was extremely fast and fueled a sharp increase in cases. Thus, the dissemination dynamics and population-level impact of new SARS-CoV-2 variants introduced in the Amazonian population after mid-2021, a setting with high levels of acquired immunity, greatly vary according to their viral phenotype.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Brasil , Imunidade Adaptativa
8.
Plants (Basel) ; 12(2)2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36679018

RESUMO

Agricultural crops are exposed to various abiotic stresses, such as salinity, water deficits, temperature extremes, floods, radiation, and metal toxicity. To overcome these challenges, breeding programs seek to improve methods and techniques. Gene editing by Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR/Cas-is a versatile tool for editing in all layers of the central dogma with focus on the development of cultivars of plants resistant or tolerant to multiple biotic or abiotic stresses. This systematic review (SR) brings new contributions to the study of the use of CRISPR/Cas in gene editing for tolerance to abiotic stress in plants. Articles deposited in different electronic databases, using a search string and predefined inclusion and exclusion criteria, were evaluated. This SR demonstrates that the CRISPR/Cas system has been applied to several plant species to promote tolerance to the main abiotic stresses. Among the most studied crops are rice and Arabidopsis thaliana, an important staple food for the population, and a model plant in genetics/biotechnology, respectively, and more recently tomato, whose number of studies has increased since 2021. Most studies were conducted in Asia, specifically in China. The Cas9 enzyme is used in most articles, and only Cas12a is used as an additional gene editing tool in plants. Ribonucleoproteins (RNPs) have emerged as a DNA-free strategy for genome editing without exogenous DNA. This SR also identifies several genes edited by CRISPR/Cas, and it also shows that plant responses to stress factors are mediated by many complex-signaling pathways. In addition, the quality of the articles included in this SR was validated by a risk of bias analysis. The information gathered in this SR helps to understand the current state of CRISPR/Cas in the editing of genes and noncoding sequences, which plays a key role in the regulation of various biological processes and the tolerance to multiple abiotic stresses, with potential for use in plant genetic improvement programs.

9.
Front Public Health ; 11: 1330347, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38259793

RESUMO

Introduction: he challenge was to provide comprehensive health resources to a remote and underserved population living in the Brazil-Colombia-Peru border, amid the most disruptive global crisis of the century. Methods: In August 2021, Fundação Oswaldo Cruz Amazonia (FIOCRUZ Amazônia) and partner collaborators implemented an overarching provisional program for SARS-CoV-2 detection and lineages characterization, training of laboratory personnel and healthcare providers, donation of diagnostic supplies and personal protective equipment, and COVID-19 vaccination. The expedition was conducted at the Port of Tabatinga, a busy terminal with an intense flux of people arriving and departing in boats of all sizes, located in the Amazon River basin. Local government, non-profit organizations, private companies, and other stakeholders supported the intervention. Results: The expedition was accomplished in a convergence point, where migrant workers, traders, army personnel, people living in urban areas, and people from small villages living in riversides and indigenous territories are in close and frequent contact, with widespread cross-border movement. Using a boat as a provisional lab and storage facility, the intervention provided clinical and laboratory monitoring for 891 participants; vaccination for 536 individuals; personal protective equipment for 200 healthcare providers; diagnostic supplies for 1,000 COVID-19 rapid tests; training for 42 community health agents on personal protection, rapid test execution, and pulse oximeter management; and hands-on training for four lab technicians on molecular diagnosis. Discussion: Our experience demonstrates that multilateral initiatives can counterweigh the scarcity of health resources in underserved regions. Moreover, provisional programs can have a long-lasting effect if investments are also provided for local capacity building.


Assuntos
COVID-19 , Masculino , Humanos , COVID-19/diagnóstico , COVID-19/prevenção & controle , SARS-CoV-2 , Brasil , Vacinas contra COVID-19 , Colômbia , Peru
10.
Virus Evol ; 9(2): vead059, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38288387

RESUMO

Dengue virus serotype 2, genotype Cosmopolitan (DENV-2-GII), is one of the most widespread DENV strains globally. In the USA, DENV-2 epidemics have been dominated by DENV-2 genotype Asian-American (DENV-2-GIII), and the first cases of DENV-2-GII were only described in 2019, in Peru, and in 2021 in Brazil. To gain new information about the circulation of DENV-2-GII in Brazil, we sequenced 237 DENV-2 confirmed cases sampled between March 2021 and March 2023 and revealed that DENV-2-GII is already present in all geographic regions of Brazil. The phylogeographic analysis inferred that DENV-2-GII was introduced at least four times in Brazil, between May 2020 and August 2022, generating multiple clades that spread throughout the country with different success. Despite multiple introductions of DENV-2-GII, analysis of the country-wide laboratory surveillance data showed that the Brazilian dengue epidemic in 2022 was dominated by DENV-1 in most states. We hypothesize that massive circulation of DENV-2-GIII in previous years in Brazil might have created a population immune barrier against symptomatic homotypic reinfections by DENV-2-GII, leading to sustained cryptic circulation in asymptomatic cases and localized outbreaks of this new genotype. In summary, our study stresses the importance of arboviral genomic surveillance to close monitoring and better understanding the potential impact of DENV-2-GII in the coming years.

11.
Medicine (Baltimore) ; 101(45): e31506, 2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36397364

RESUMO

The prevalence of hernias in patient with cirrhosis can reach up to 40%. The pathophysiology of cirrhosis is closely linked to that of the umbilical hernia, but other types are also common in this population. The aim of this study is to evaluate factors that influence in the prognosis after hernia repair in patients with cirrhosis. A historical cohort of 6419 patients submitted to hernia repair was gathered. Clinical, epidemiological data and hernia characteristics were obtained. For patient with cirrhosis, data from exams, surgery and follow-up outcomes were also analyzed. Survival curves were constructed to assess the impact of clinical and surgical variables on survival. 342 of the 6352 herniated patients were cirrhotic. Patient with cirrhosis had a higher prevalence of umbilical hernia (67.5% × 24.2%, P < .001) and a lower prevalence of epigastric (1.8% × 9.0%, P < .001) and lumbar (0% × 0.18%, P = .022). There were no significant differences in relation to inguinal hernia (P = .609). Ascites was present in 70.1% of patient with cirrhosis and its prevalence was different in relation to the type of hernia (P < .001). The survival curve showed higher mortality for emergency surgery, MELD > 14 and ascites (HR 12.6 [3.79-41.65], 4.5 [2.00-10.34], and 6.1 [1.15-20.70], respectively, P < .05). Hernia correction surgery in patient with cirrhosis has a high mortality, especially when performed under urgent conditions associated with more severe clinical conditions of patients, such as the presence of ascites and elevated MELD.


Assuntos
Hérnia Umbilical , Herniorrafia , Humanos , Hérnia Umbilical/cirurgia , Ascite/complicações , Centros de Atenção Terciária , Resultado do Tratamento , Cirrose Hepática/complicações , Cirrose Hepática/epidemiologia , Cirrose Hepática/cirurgia , Medição de Risco , Análise de Sobrevida
12.
Clinics (Sao Paulo) ; 77: 100101, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36122499

RESUMO

INTRODUCTION: The increase in the incidence of pancreatic and biliary cancers has attracted the search for methods of early detection of diseases and biomarkers. The authors propose to analyze new findings on the association between microbiota and Pancreatic Ductal Adenocarcinoma (PDAC) or Cholangiocarcinoma (CCA). METHODS: This systematic review was carried out according to the items of Preferred Reports for Systematic Reviews and Protocol Meta-Analysis (PRISMA-P). This study was registered by the Prospective Register of Systematic Reviews (PROSPERO), identification code CRD42020192748 before the review was carried out. Articles were selected from the PUBMED, EMBASE, and Cochrane databases. RESULTS: Most studies (86.67%) used 16s rRNA as a sequencing method. The main comorbidities found were diabetes mellitus, systemic arterial hypertension, and dyslipidemia. Many studies were limited by the small number of participants, but the biases were mostly low. There was very little concordance about the composition of the microbiome of different sites, for both case and control groups when compared to other studies' results. Bile sample analysis was the one with a greater agreement between studies, as three out of four studies found Escherichia in cases of CCA. CONCLUSION: There was great disagreement in the characterization of both the microbiota of cases and control groups. Studies are still scarce, making it difficult to adequately assess the data in this regard. It was not possible to specify any marker or to associate any genus of microbiota bacteria with PDAC or CCA.


Assuntos
Carcinoma Ductal Pancreático , Microbiota , Neoplasias Pancreáticas , Carcinoma Ductal Pancreático/patologia , Humanos , Neoplasias Pancreáticas/patologia , RNA Ribossômico 16S/genética , Síndrome , Neoplasias Pancreáticas
13.
Plants (Basel) ; 11(18)2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36145741

RESUMO

Fusarium wilt caused by Fusarium oxysporum f. sp. cubense (Foc) is the most limiting factor in the banana agribusiness worldwide. Therefore, studies regarding pathogen attack mechanisms, and especially host defense responses, in this pathosystem are of utmost importance for genetic breeding programs in the development of Foc-resistant banana cultivars. In this study, analysis at the molecular, histological and histochemical levels of the Musa spp. x Foc interaction was performed. Three Foc isolates representative of race 1 (R1), subtropical race 4 (ST4) and isolate 229A, which is a putative ST4, were inoculated in two Prata-type cultivars (Prata-Anã and BRS Platina) and one cultivar of the Cavendish type (Grand Naine). Of seven genes related to plant-pathogen interactions, five were overexpressed in 'BRS Platina' 12 h after inoculation (HAI) with Foc R1 and ST4 but had reduced or negative expression after inoculation with Foc 229A, according to RT-qPCR analyses. While hyphae, mycelia and spores of the Foc 229A isolate grow towards the central cylinder of the Grand Naine and Prata-Anã cultivars, culminating in the occlusion of the xylem vessels, the BRS Platina cultivar responds with increased presence of cellulose, phenolic compounds and calcium oxalate crystals, reducing colonization within 30 days after inoculation (DAI). In general, these data indicate that the cultivar BRS Platina has potential for use in banana-breeding programs focused on resistance to Foc tropical race 4 (TR4) and in aggregating information on the virulence relationships of the Foc pathogen and the defense responses of banana plants after infection.

14.
Plants (Basel) ; 11(15)2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35956430

RESUMO

Bananas are the main fruits responsible for feeding more than 500 million people in tropical and subtropical countries. Black Sigatoka, caused by the fungus Pseudocercospora fijiensis, is one of the most destructive disease for the crop. This fungus is mainly controlled with the use of fungicides; however, in addition to being harmful to human health, they are associated with a high cost. The development of resistant cultivars through crosses of susceptible commercial cultivars is one of the main focuses of banana breeding programs worldwide. Thus, the objective of the present study was to investigate the interaction between Musa sp. and P. fijiensis through the relative expression of candidate genes involved in the defence response to black Sigatoka in four contrasting genotypes (resistant: Calcutta 4 and Krasan Saichon; susceptible: Grand Naine and Akondro Mainty) using quantitative real-time PCR (RT-qPCR) in addition to histological and histochemical analyses to verify the defence mechanisms activated during the interaction. Differentially expressed genes (DEGs) related to the jasmonic acid and ethylene signalling pathway, GDSL-like lipases and pathogenesis-related proteins (PR-4), were identified. The number and distance between stomata were directly related to the resistance/susceptibility of each genotype. Histochemical tests showed the production of phenolic compounds and callosis as defence mechanisms activated by the resistant genotypes during the interaction process. Scanning electron microscopy (SEM) showed pathogenic structures on the leaf surface in addition to calcium oxalate crystals. The resistant genotype Krasan Saichon stood out in the analyses and has potential for use in breeding programs for resistance to black Sigatoka in banana and plantains.

15.
Estud. psicol. (Natal) ; 27(2): 261-271, mai-ago 2022.
Artigo em Português | LILACS | ID: biblio-1427333

RESUMO

Este artigo tem como objetivo analisar como os jovens rurais vivenciam os valores rurais nos seus relacionamentos afetivo-sexuais no Sertão de Pernambuco. O desenho metodológico foi pautado na pesquisa no cotidiano, por meio da observação participante, e de entrevistas com jovens estudantes de uma escola pública da região. Apesar das mudanças nas áreas rurais, os jovens vivenciam valores camponeses alicerçados no interconhecimento, no valor-família, honra familiar e nas hierarquias intergeracional e de gênero. No cotidiano, criam resistências que objetivam outras possibilidades de existência e de vivências afetivo-sexuais, por meio de deslocamentos, linhas de fugas e recusas parciais desses valores.


This article aims to analyze how rural youth experience rural values in their affective-sexual relationships in the rural area of Pernambuco. The methodological design was based on daily research, through participant observation, and interviews with young students from a public school in the region. Despite changes in rural areas, young people experience peasant values based on inter-knowledge, family value, family honor and intergenerational and gender hierarchies. In everyday life, they create resistance, which aim at other possibilities of existence and affective-sexual experiences, through displacements, lines of escape and partial refusals of these values.


Este artículo tiene como objetivo analizar cómo los jóvenes rurales experimentan los valores rurales en sus relaciones afectivo-sexuales en el área rural de Pernambuco. El diseño metodológico se basó en la investigación diaria, a través de la observación participante, y entrevistas con jóvenes estudiantes de una escuela pública de la región. A pesar de los cambios en las zonas rurales, los jóvenes experimentan valores campesinos basados en el interconocimiento, el valor familiar, el honor familiar y las jerarquías intergeneracionales y de género. En la vida cotidiana crean resistencias, que apuntan a otras posibilidades de existencia y vivencias afectivo-sexuales, a través de desplazamientos, líneas de escape y rechazos parciales de estos valores.


Assuntos
Masculino , Feminino , Adulto , População Rural , Cônjuges , Família , Casamento , Entrevista
16.
Clinics (Sao Paulo) ; 77: 100037, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35594623

RESUMO

The objective of this study is to compare the effectiveness of dextrose-prolotherapy with other substances for pain relief in patients with primary knee osteoarthritis. The literature screening was done in January 2021 through Medline (PubMed), EMBASE, and Database of the National Institute of Health based on the following criteria: randomized clinical trials that subjected patients with primary knee osteoarthritis who underwent treatment with dextrose-prolotherapy and other substances for pain relief. Paired reviewers independently identified 3381 articles and included 8 trials that met the eligibility criteria. According to the findings of this review, participants that underwent dextrose-prolotherapy showed improvements between baseline and posterior assessments and when compared to saline injections, but when compared to other substances, the results were not clear. Although dextrose-prolotherapy is a useful treatment method by itself, it is still not possible to clearly affirm that it is superior or inferior to its counterparts. There is an urgent need for further studies to bring more evidence to the field.


Assuntos
Osteoartrite do Joelho , Proloterapia , Glucose/uso terapêutico , Humanos , Injeções Intra-Articulares , Osteoartrite do Joelho/tratamento farmacológico , Dor/tratamento farmacológico , Proloterapia/métodos , Resultado do Tratamento
17.
Microbiol Spectr ; 10(1): e0236621, 2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-35196783

RESUMO

The Amazonas was one of the most heavily affected Brazilian states by the COVID-19 epidemic. Despite a large number of infected people, particularly during the second wave associated with the spread of the Variant of Concern (VOC) Gamma (lineage P.1), SARS-CoV-2 continues to circulate in the Amazonas. To understand how SARS-CoV-2 persisted in a human population with a high immunity barrier, we generated 1,188 SARS-CoV-2 whole-genome sequences from individuals diagnosed in the Amazonas state from 1st January to 6th July 2021, of which 38 were vaccine breakthrough infections. Our study reveals a sharp increase in the relative prevalence of Gamma plus (P.1+) variants, designated Pango Lineages P.1.3 to P.1.6, harboring two types of additional Spike changes: deletions in the N-terminal (NTD) domain (particularly Δ144 or Δ141-144) associated with resistance to anti-NTD neutralizing antibodies or mutations at the S1/S2 junction (N679K or P681H) that probably enhance the binding affinity to the furin cleavage site, as suggested by our molecular dynamics simulations. As lineages P.1.4 (S:N679K) and P.1.6 (S:P681H) expanded (Re > 1) from March to July 2021, the lineage P.1 declined (Re < 1) and the median Ct value of SARS-CoV-2 positive cases in Amazonas significantly decreases. Still, we did not find an increased incidence of P.1+ variants among breakthrough cases of fully vaccinated patients (71%) in comparison to unvaccinated individuals (93%). This evidence supports that the ongoing endemic transmission of SARS-CoV-2 in the Amazonas is driven by the spread of new local Gamma/P.1 sublineages that are more transmissible, although not more efficient to evade vaccine-elicited immunity than the parental VOC. Finally, as SARS-CoV-2 continues to spread in human populations with a declining density of susceptible hosts, the risk of selecting more infectious variants or antibody evasion mutations is expected to increase. IMPORTANCE The continuous evolution of SARS-CoV-2 is an expected phenomenon that will continue to happen due to the high number of cases worldwide. The present study analyzed how a Variant of Concern (VOC) could still circulate in a population hardly affected by two COVID-19 waves and with vaccination in progress. Our results showed that the answer behind that was a new generation of Gamma-like viruses, which emerged locally carrying mutations that made it more transmissible and more capable of spreading, partially evading prior immunity triggered by natural infections or vaccines. With thousands of new cases daily, the current pandemics scenario suggests that SARS-CoV-2 will continue to evolve and efforts to reduce the number of infected subjects, including global equitable access to COVID-19 vaccines, are mandatory. Thus, until the end of pandemics, the SARS-CoV-2 genomic surveillance will be an essential tool to better understand the drivers of the viral evolutionary process.


Assuntos
COVID-19/enzimologia , Furina/metabolismo , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Motivos de Aminoácidos , Brasil/epidemiologia , COVID-19/epidemiologia , COVID-19/transmissão , COVID-19/virologia , Vacinas contra COVID-19/administração & dosagem , Furina/genética , Genômica , Humanos , Mutação , Filogenia , SARS-CoV-2/classificação , SARS-CoV-2/isolamento & purificação , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo
18.
Cell ; 185(3): 467-484.e15, 2022 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-35081335

RESUMO

On 24th November 2021, the sequence of a new SARS-CoV-2 viral isolate Omicron-B.1.1.529 was announced, containing far more mutations in Spike (S) than previously reported variants. Neutralization titers of Omicron by sera from vaccinees and convalescent subjects infected with early pandemic Alpha, Beta, Gamma, or Delta are substantially reduced, or the sera failed to neutralize. Titers against Omicron are boosted by third vaccine doses and are high in both vaccinated individuals and those infected by Delta. Mutations in Omicron knock out or substantially reduce neutralization by most of the large panel of potent monoclonal antibodies and antibodies under commercial development. Omicron S has structural changes from earlier viruses and uses mutations that confer tight binding to ACE2 to unleash evolution driven by immune escape. This leads to a large number of mutations in the ACE2 binding site and rebalances receptor affinity to that of earlier pandemic viruses.

19.
Chem Biol Interact ; 351: 109734, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34742685

RESUMO

Malignant melanoma has a low incidence, but is the most lethal type of skin cancer. Studies have shown that dibenzoylmethanes (DBMs) have interesting biological activities, including antineoplastic properties. These findings led us to investigate whether news DBM derivatives exert antitumor effects against skin cancers. In a previous study, we found that 1,3-diphenyl-2-benzyl-1,3-propanedione (DPBP) has high in vitro antineoplastic activity against murine B16F10 melanoma cells, with an IC50 of 6.25 µg/mL. In the current study, we used transdermal and topical formulations of DPBP to evaluate its activity and molecular mechanism of action in a murine model of melanoma. The compound induces tumor cell death with high selectivity (selectivity index of 41.94) by triggering apoptosis through intrinsic and extrinsic pathways. DPBP treatment reduced tumor volume as well as serum VEGF-A and uric acid levels. Hepatomegaly and nephrotoxicity were not observed at the tested doses. Histopathological analysis of sentinel lymph nodes revealed no evidence of metastases. According to the observed data, the DPBP compound was effective for the topical treatment of melanoma cancer, suggesting that it acts as a chemotherapeutic or chemopreventive agent.


Assuntos
Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Chalconas/uso terapêutico , Melanoma Experimental/tratamento farmacológico , Animais , Antineoplásicos/síntese química , Linhagem Celular Tumoral , Chalconas/síntese química , Masculino , Camundongos Endogâmicos C57BL , Estresse Oxidativo/efeitos dos fármacos
20.
Clinics ; 77: 100101, 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1404303

RESUMO

Abstract Introduction: The increase in the incidence of pancreatic and biliary cancers has attracted the search for methods of early detection of diseases and biomarkers. The authors propose to analyze new findings on the association between microbiota and Pancreatic Ductal Adenocarcinoma (PDAC) or Cholangiocarcinoma (CCA). Methods: This systematic review was carried out according to the items of Preferred Reports for Systematic Reviews and Protocol Meta-Analysis (PRISMA-P). This study was registered by the Prospective Register of Systematic Reviews (PROSPERO), identification code CRD42020192748 before the review was carried out. Articles were selected from the PUBMED, EMBASE, and Cochrane databases. Results: Most studies (86.67%) used 16s rRNA as a sequencing method. The main comorbidities found were diabetes mellitus, systemic arterial hypertension, and dyslipidemia. Many studies were limited by the small number of participants, but the biases were mostly low. There was very little concordance about the composition of the microbiome of different sites, for both case and control groups when compared to other studies' results. Bile sample analysis was the one with a greater agreement between studies, as three out of four studies found Escherichia in cases of CCA. Conclusion: There was great disagreement in the characterization of both the microbiota of cases and control groups. Studies are still scarce, making it difficult to adequately assess the data in this regard. It was not possible to specify any marker or to associate any genus of microbiota bacteria with PDAC or CCA.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA