Guilherme Fontoura

Mr. Guilherme Fontoura


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 December 2023 in International Journal of Microbiology
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Journal Article
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MMMendes Mendes
Mendes Mendes
GFGuilherme Fontoura
Guilherme Fontoura
LRLiliane dos Santos Rodrigues
Liliane dos Santos Rodrigues
ASAloiso Sampaio Souza
Aloiso Sampaio Souza
JVJesse Pereira Machado Viana
Jesse Pereira Machado Viana
MMmárcia cristina Cristina Gonçalves gonçalves maciel
márcia cristina Cristina Gonçalves gonçalves maciel
Punica granatum Linn has been known for its nutritional and medicinal value since ancient times and is used in the treatment of various pathologies owing to its antibacterial properties. This review reports the results of the most recent studies on the antibacterial effects of P. granatum and its isolated compounds on bacteria of clinical interest. A search in the PubMed, Scopus, Science Direct, and Science Citation Index Expanded (Web of Science) databases was performed, which included articles that evaluated the antibacterial activity of P. granatum extracts and excluded articles that analyzed other microorganisms or nonpathogenic bacteria, as well as theses, dissertations, duplicate articles, and those not fully available. The literature suggests that P. granatum extracts can act on bacteria, such as methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), Streptococcus mutans, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae. In addition, fruit peel was the most commonly used pharmacogen and methanol, ethanol, and water were the most common solvents for the extraction of bioactive compounds. The antibacterial potential of the methanolic extract of pomegranate peel could be attributed to the presence of active compounds, such as 5-hydroxymethylfurfural, punicic acid, gallic acid, and punicalagin. Thus, there is evidence that these plant extracts, having high polyphenol content, can disrupt the bacterial plasma membrane and inhibit the action of proteins related to antimicrobial resistance. P. granatum shows antibacterial activity against Gram-positive and Gram-negative bacteria, with great potential against multidrug-resistant strains. Further research is needed to clarify the mechanism of action related to this biological activity and investigate the isolated substances that may be responsible for the antibacterial effects.

17 May 2021 in Viruses
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RNRaquel Silva Do Nascimento
Raquel Silva Do Nascimento
KBKaren Lorena N. Baia
Karen Lorena N. Baia
SSSamara Borges de Souza
Samara Borges de Souza
GFGuilherme Fontoura
Guilherme Fontoura
PATRICIA NUNESPATRICIA NUNES
PATRICIA NUNES
AOAldemir B. Oliveira-Filho
Aldemir B. Oliveira-Filho
People who use crack-cocaine (PWUCC) have numerous vulnerabilities and pose a challenge to health and social assistance services. The exposure to pathogens and risk situations occur differently according to each individual, region and social group. This study identified the presence, genotypes and factors associated with hepatitis E virus (HEV) exposure among a community-recruited cohort of 437 PWUCC in northern Brazil. Epidemiological information was collected through community-based assessments and interviews. Thereafter, blood and fecal samples were collected and tested for HEV using an immunoenzymatic assay, and the genotype was identified by PCR. Logistic regressions were used to identify the risk factors independently associated with exposure to HEV. In total, 79 (18.1%) PWUCC were exposed to HEV: 73 (16.7%) for IgG and six for IgG + IgM. HEV RNA was detected in six fecal samples and in two blood samples from PWUCC with IgM + IgG. Subtype 3c was identified in all of the samples. The factors associated with exposure to HEV were low monthly income, unstable housing (e.g., homelessness), crack-cocaine use ≥40 months, and the shared use of crack-cocaine equipment. The current study provides unique initial insights into HEV status and risk factors among PWUCC in a remote area in Brazil, with diverse implications for urgently improved diagnosis, prevention, and treatment intervention needs.

1 January 2021 in Revista do Instituto de Medicina Tropical de São Paulo
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LRLiliane dos Santos Rodrigues
Liliane dos Santos Rodrigues
LCLuciana Cavalcante Costa
Luciana Cavalcante Costa
GFGuilherme Fontoura
Guilherme Fontoura
MMmárcia cristina Cristina Gonçalves gonçalves maciel
márcia cristina Cristina Gonçalves gonçalves maciel
Sepsis is the organ dysfunction resulting from an infection associated with an unregulated host inflammatory response, which generates high mortality rates in Brazil. The aim of this stydy was to analyze the trend of early, late and post-neonatal mortality rates due to sepsis in Brazilian regions, from 2009 to 2018. This is an ecological study of time series. The trend of infant mortality from sepsis was analyzed using the International Classification of Diseases (ICD10) according to the place of residence (North, Northeast, Southeast, South and Midwest). Death Certificate data were collected from the Mortality Information System database. The temporal trend was analyzed using the Prais-Winsten estimate, interpreted as increasing, decreasing or stable, through the dependent variable (logarithm of mortality rates) and interdependent variables (years of the historical series). The Stata 14.0 statistical software was used. There were 39,867 infant deaths due to sepsis (78.67% for unspecified bacterial sepsis of the neonate ). Most of the children were male, had mixed ethnicity (black and white) , were born preterm with low birth weight and most mothers were 20-34 years old. There were decreasing trends in mortality rates from 2009 to 2018: early neonatal, in the Southeast (-3.57%), North (-3.33%) and South (-2.91%); late neonatal, in the South (-4.12%), Southeast (-4.53%), North (-4.55%) and Midwest (-6.21%); and post-neonatal, in the Northeast (-1.84%), North (-3.62%), Southeast (-3.83%) and Midwest (-5.81%). The Northeast showed a stable trend in early and late neonatal mortality rates. It was concluded that most regions showed a decreasing trend in mortality rates from sepsis in all age components, despite regional differences.

28 March 2021 in Research, Society and Development
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SBSabrina Sousa Barros
Sabrina Sousa Barros
ARAmanda Kelly Ferreira Resende
Amanda Kelly Ferreira Resende
DSDariely de Oliveira Silva
Dariely de Oliveira Silva
MSMarcelo da Silva
Marcelo da Silva
MSMarcos Roberto Nascimento Sousa
Marcos Roberto Nascimento Sousa
ELEvaldo Sales Leal
Evaldo Sales Leal
O câncer do colo do útero, conhecido também como cervical, é considerado um importante problema de saúde que atinge as mulheres em todos os continentes. Diante disso, surgiu a seguinte problemática: quais fatores de risco que contribuem para o desenvolvimento do câncer do colo do útero? Objetiva-se avaliar os fatores de risco que levam ao câncer do colo do útero. A presente pesquisa trata-se de uma revisão integrativa, em que foi realizada mediante as seguintes bases de dados: Biblioteca Virtual em saúde (BVS), LILACS, SCIELO, MEDLINE e BDENF. As palavras chave utilizadas seguiram a descrição dos termos Descritores em Ciências da Saúde (DECS). Foram elas: Fatores, riscos, neoplasias do colo do útero. Para a seleção dos estudos, os critérios de inclusão utilizados foram artigos, de (2014-2019), disponibilizados de forma integral e com livre acesso ao texto e que estivessem adequados ao tema proposto e estudos na língua portuguesa. De acordo com os achados foi possível constatar que os principais fatores envolvidos no desencadeamento do câncer de colo de útero foram: ser tabagistas ou ex-tabagistas, baixa renda, percepção negativa da própria saúde, uso do álcool, baixa escolaridade e renda familiar mensal, precocidade da coitarca, não uso do preservativo, paridade, baixa cobertura do rastreamento, ser solteira e falta de acesso ao serviço de saúde. Os objetivos do estudo foram alcançados de forma satisfatória, à medida que os resultados obtidos mostraram integralmente os fatores envolvidos com o câncer uterino. Um dos desafios encontrados foi a escassez de artigos relacionado ao tema.

26 May 2021 in Advances in Horticultural Science
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SSSuzanna de Sousa Silva
Suzanna de Sousa Silva
PAPatrícia Costa dos Santos Alves
Patrícia Costa dos Santos Alves
DCDenise Fernandes Coutinho Coutinho
Denise Fernandes Coutinho Coutinho
TLTássio Rômulo Silva Araújo Luz
Tássio Rômulo Silva Araújo Luz
GFGuilherme Fontoura
Guilherme Fontoura
MMmárcia cristina Cristina Gonçalves gonçalves maciel
márcia cristina Cristina Gonçalves gonçalves maciel
The study aimed to investigate antimicrobial activity of the hydroalcoholic crude extract from the fruit peel of Punica granatum (Pp) and punicalagin compound (Pg) on phytopathogenic bacterial isolates and its potential use as a sustainable alternative in treatment of vegetable seeds. The antimicrobial activity in vitro was tested by agar well diffusion assay and through viability tests in liquid medium. In vivo treatment with Pp was tested on Eruca vesicaria seeds infected with Xanthomonas campestris pv. campestris. Pp induced the formation of large inhibition zones to the growth of the tested pathogens (35.33 mm – 6.66 mm), with dose-dependent effect. Viability tests confirmed the antimicrobial activity of the Pp on X. campestris pv. campestris and P. carotovorum subsp. carotovorum with minimum inhibitory concentration (MIC) of 125 μg/mL. Punicalagin compound presented MIC of the 31.25 μg/mL. The seed treatment with Pp indicated control of pathogen-induced symptoms in seedlings of the E. vesicaria and positive effect in seed germination, emergence and in stomatal functionality. The results indicate strong potential of the extract from the fruit peel of P. granatum and Punicalagin for formulating botanical pesticides for plant disease control.

23 October 2022 in Revista Colombiana de Ciencias Químico Farmacéuticas
Verified
Journal Article
Open access
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GFGuilherme Fontoura
Guilherme Fontoura
LRLiliane dos Santos Rodrigues
Liliane dos Santos Rodrigues
ARAramys Silva Reis
Aramys Silva Reis
ABAndresa Aparecida Berretta
Andresa Aparecida Berretta
MMmárcia cristina Cristina Gonçalves gonçalves maciel
márcia cristina Cristina Gonçalves gonçalves maciel
Objective: This review aim to report the results of the most recent research and applications of different extracts of P. granatum in the in vivo wound healing process. Methods:For the survey of articles in literature, a search was conducted in the PubMed, Scopus, Science Direct and Science Citation Index Expanded (Web of Science) databases. Results: Punica granatum is a plant native to Iran and adjacent regions widely used worldwide as a food and medicinal source. Its healing property is closely linked to the presence of phenolic compounds, tannins and flavonoids, and its concentration in treatment formulations seems to be determinant for the acceleration of tissue repair, although few data on the standardization and stability of these formulations are available. Studies on experimental models were able to demonstrate the repair potential of P. granatum; however, human studies are still scarce. Conclusions: This contribution summarizes the use of P. granatum extracts in healing different types of lesions, emphasizing its effects on inflammatory, prolif-erative, and remodeling phases.