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1.
Food Chem ; 448: 139153, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38569410

RESUMO

Salivary proteins precipitation by interaction with polyphenols is the major mechanism for astringency. However, alternative mechanisms seem involved in the perception of different subqualities of astringency. In this study, adsorption of four astringent agents to in vitro oral models and their sensory properties were assessed. Overall, green tea infusion and tannic acid have shown a higher adsorption potential for models with oral cells and absence of saliva. Alum and grape seed extract presented higher adsorption in models with presence of oral cells and saliva. Multiple factor analysis suggested that adsorption may represent important mechanisms to elicit the astringency of alum. Models including saliva, were closely associated with overall astringency and aggressive subquality. Models with cells and absent saliva were closely associated with greenness, suggesting a taste receptor mechanism involvement in the perception. For the first time a correlation between an oral-cell based assay and astringency sensory perception was shown.

2.
Molecules ; 28(6)2023 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-36985492

RESUMO

Beer is one of the most consumed beverages worldwide with unique organoleptic properties. Bitterness and astringency are well-known key features and, when perceived with high intensity, could lead to beer rejection. Most studies on beer astringency and bitterness use sensory assays and fail to study the molecular events that occur inside the oral cavity responsible for those perceptions. This work focused on deepening this knowledge based on the interaction of salivary proteins (SP) and beer phenolic compounds (PCs) and their effect toward these two sensory attributes. The astringency and bitterness of four different beers were assessed by a sensory panel and were coupled to the study of the SP changes and PC profile characterization of beers. The human SP content was measured before (basal) and after each beer intake using HPLC analysis. The beers' PC content and profile were determined using Folin-Ciocalteu and LC-MS spectrometry, respectively. The results revealed a positive correlation between PCs and astringency and bitterness and a negative correlation between SP changes and these taste modalities. Overall, the results revealed that beers with higher PC content (AAL and IPA) are more astringent and bitter than beers with a lower PC content (HL and SBO). The correlation results suggested that an increase in whole SP content, under stimulation, should decrease astringency and bitterness perception. No correlation was found between the changes in specific families of SP and astringency and bitterness perception.


Assuntos
Adstringentes , Paladar , Humanos , Adstringentes/análise , Cerveja/análise , Percepção Gustatória , Fenóis/análise , Proteínas e Peptídeos Salivares/análise
3.
Talanta ; 256: 124277, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36738622

RESUMO

Zika virus (ZIKV) is a flavivirus transmitted by infected Aedes genus mosquitoes. An infected person may be asymptomatic or present symptoms such as fever, arthralgia, and in pregnancy it may lead to neurological disorders in the fetus, such as microcephaly. Based on the high dissemination potential of ZIVK and its similar antigen composition to other arboviruses, new approaches for selective virus detection are urgently needed. This work reports the development of an electrochemical immunoassay for detection of anti-ZIKV antibodies, using magnetic beads functionalized with recombinant protein derived from the non-structural protein 1 (ΔNS1-ZIKV) and anti-IgG antibodies labeled with horseradish peroxidase (HRP) enzyme. The magneto-immunoassay uses disposable microfluidic devices for detection of anti-ZIKV in serum samples. A linear response was obtained for a wide concentration range from 0.01 to 9.80 × 105 pg mL-1 (r2 = 0.982), with a limit of detection of 0.48 pg mL-1. The proposed immunoassay proved to be highly efficient for the detection of anti-ZIKV antibodies in serum, offering promising perspectives for the development of fast, simple, and affordable point-of-care diagnosis devices for ZIKV.


Assuntos
Culicidae , Infecção por Zika virus , Zika virus , Animais , Humanos , Infecção por Zika virus/diagnóstico , Imunoensaio , Anticorpos Antivirais
4.
J Agric Food Chem ; 71(4): 2070-2081, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36652684

RESUMO

It is well known that repeated exposure to phenolic compounds (PCs) raises astringency perception. However, the link between this increase and the oral cavity's interactions with salivary proteins (SPs) and other oral constituents is unknown. To delve deeper into this connection, a flavonoid-rich green tea extract was tested in a series of exposures to two oral cell-based models using a tongue cell line (HSC3) and a buccal mucosa cell line (TR146). Serial exposures show cumulative PC binding to all oral models at all concentrations of the green tea extract; however, the contribution for the first and second exposures varies. The tongue mucosal pellicle (HSC3-Mu-SP) may contribute more to first-stage astringency (retaining 0.15 ± 0.01 mg mL-1 PCs at the first exposure), whereas the buccal mucosal pellicle (TR146-Mu-SP) retained significantly less (0.08 ± 0.02 mg mL-1). Additionally, increased salivary volume (SV+), which simulates the stimulation of salivary flow brought by a food stimulus, significantly enhances PC binding, particularly for TR146 cells: TR46-Mu-SP_SV+ bound significantly higher total PC concentration (0.17 ± 0.02 mg mL-1) than the model without increased salivary volume TR146-Mu-SP_SV- (0.09 ± 0.03 mg mL-1). This could be associated with a higher contribution of these oral cells for astringency perception during repeated exposures. Furthermore, PCs adsorbed in the first exposure to cell monolayer models (+TR146 and +HSC3) change the profile of PCs bound to these models in the second exposure. Regarding the structure binding activity, PCs with a total higher number of hydroxyl groups were more bound by the models containing SP. Regarding the SP, basic proline-rich proteins (bPRPs) may be involved in the increased perception of astringency upon repeated exposures. The extent of bPRP precipitation by PCs in mucosal pellicle models for both cell lines (HSC3 and TR146) in the second exposure (76 ± 13 and 83 ± 6%, respectively) was significantly higher than in the first one (25 ± 14 and 5 ± 6%, respectively).


Assuntos
Adstringentes , Flavonoides , Aspergillus fumigatus/metabolismo , Adstringentes/química , Azóis , Farmacorresistência Fúngica , Flavonoides/metabolismo , Proteínas Fúngicas/metabolismo , Fenóis/metabolismo , Saliva/química , Proteínas e Peptídeos Salivares/metabolismo , Chá/metabolismo , Boca
5.
J Anim Physiol Anim Nutr (Berl) ; 107(3): 887-896, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-35920193

RESUMO

This study was conducted to determine the metabolizable energy (ME) requirement for quails (Cortunix cortunix cortunix) from 28 to 42 days of age. Four hundred and twenty quails were distributed in a completely randomized design, with 5 treatments (2950, 3000, 3050, 3100 and 3150 kcal of ME/kg of feed), 7 replicates and 12 birds per experimental unit. Performance, relative weights of organs and viscera, carcass characteristics, meat quality, body composition and blood parameters of the birds were evaluated. There was a reduction in feed intake (ADFI) with the use of 3150 kcal ME/kg (p < 0.01), with a quadratic effect on feed efficiency (p < 0.01), estimating the energy requirement in the 3009.4 kcal ME/kg. The breast yield (BY) and the colour b* had an effect (p < 0.01), with better results for 2950 kcal ME/kg, while the meat texture reduced when the birds were fed with 3150 kcal ME/kg. HDL and LDL showed the quadratic effect (p < 0.01) when ME increased to 3111.6 and 3157.4 kcal/kg respectively. Very low density lipoprotein increased linearly (p < 0.01) in birds that received diets with 3000 kcal ME/kg. We conclude that the use of 3009.4 kcal of ME/kg for European quail meets the nutritional needs and provides an improvement in feed efficiency, without affecting the carcass parameters of the birds. Information regarding the nutritional requirements for European quails is still recent; therefore, it is essential to know the adequate levels of metabolizable energy, an important nutritional component for the maximum productive performance of birds.


Assuntos
Dieta , Ingestão de Alimentos , Animais , Dieta/veterinária , Coturnix , Codorniz , Ração Animal/análise , Metabolismo Energético , Fenômenos Fisiológicos da Nutrição Animal , Galinhas
6.
Talanta, v. 256, 124277, jan. 2023
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: bud-4792

RESUMO

Zika virus (ZIKV) is a flavivirus transmitted by infected Aedes genus mosquitoes. An infected person may be asymptomatic or present symptoms such as fever, arthralgia, and in pregnancy it may lead to neurological disorders in the fetus, such as microcephaly. Based on the high dissemination potential of ZIVK and its similar antigen composition to other arboviruses, new approaches for selective virus detection are urgently needed. This work reports the development of an electrochemical immunoassay for detection of anti-ZIKV antibodies, using magnetic beads functionalized with recombinant protein derived from the non-structural protein 1 (ΔNS1-ZIKV) and anti-IgG antibodies labeled with horseradish peroxidase (HRP) enzyme. The magneto-immunoassay uses disposable microfluidic devices for detection of anti-ZIKV in serum samples. A linear response was obtained for a wide concentration range from 0.01 to 9.80 × 105 pg mL−1 (r2 = 0.982), with a limit of detection of 0.48 pg mL−1. The proposed immunoassay proved to be highly efficient for the detection of anti-ZIKV antibodies in serum, offering promising perspectives for the development of fast, simple, and affordable point-of-care diagnosis devices for ZIKV.

7.
Nanomedicine ; 45: 102595, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36031045

RESUMO

The development of safe and effective vaccine formulations against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) represents a hallmark in the history of vaccines. Here we report a COVID-19 subunit vaccine based on a SARS-CoV-2 Spike protein receptor binding domain (RBD) incorporated into nano-multilamellar vesicles (NMV) associated with monophosphoryl lipid A (MPLA). The results based on immunization of C57BL/6 mice demonstrated that recombinant antigen incorporation into NMVs improved antibody and T-cell responses without inducing toxic effects under both in vitro and in vivo conditions. Administration of RBD-NMV-MPLA formulations modulated antigen avidity and IgG subclass responses, whereas MPLA incorporation improved the activation of CD4+/CD8+ T-cell responses. In addition, immunization with the complete vaccine formulation reduced the number of doses required to achieve enhanced serum virus-neutralizing antibody titers. Overall, this study highlights NMV/MPLA technology, displaying the performance improvement of subunit vaccines against SARS-CoV-2, as well as other infectious diseases.


Assuntos
COVID-19 , SARS-CoV-2 , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos , Imunidade , Imunoglobulina G , Lipídeos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Glicoproteína da Espícula de Coronavírus , Vacinas de Subunidades Antigênicas
8.
Front Cell Infect Microbiol ; 12: 787411, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35719329

RESUMO

Reliable serological tests for the detection of SARS-CoV-2 antibodies among infected or vaccinated individuals are important for epidemiological and clinical studies. Low-cost approaches easily adaptable to high throughput screenings, such as Enzyme-Linked Immunosorbent Assays (ELISA) or electrochemiluminescence immunoassay (ECLIA), can be readily validated using different SARS-CoV-2 antigens. A total of 1,119 serum samples collected between March and July of 2020 from health employees and visitors to the University Hospital at the University of São Paulo were screened with the Elecsys® Anti-SARS-CoV-2 immunoassay (Elecsys) (Roche Diagnostics) and three in-house ELISAs that are based on different antigens: the Nucleoprotein (N-ELISA), the Receptor Binding Domain (RBD-ELISA), and a portion of the S1 protein (ΔS1-ELISA). Virus neutralization test (CPE-VNT) was used as the gold standard to validate the serological assays. We observed high sensitivity and specificity values with the Elecsys (96.92% and 98.78%, respectively) and N-ELISA (93.94% and 94.40%, respectively), compared with RBD-ELISA (90.91% sensitivity and 88.80% specificity) and the ΔS1-ELISA (77.27% sensitivity and 76% specificity). The Elecsys® proved to be a reliable SARS-CoV-2 serological test. Similarly, the recombinant SARS-CoV-2 N protein displayed good performance in the ELISA tests. The availability of reliable diagnostic tests is critical for the precise determination of infection rates, particularly in countries with high SARS-CoV-2 infection rates, such as Brazil. Collectively, our results indicate that the development and validation of new serological tests based on recombinant proteins may provide new alternatives for the SARS-CoV-2 diagnostic market.


Assuntos
COVID-19 , Anticorpos Antivirais , Brasil/epidemiologia , COVID-19/diagnóstico , Técnicas de Laboratório Clínico/métodos , Hospitais , Humanos , Estudos Retrospectivos , SARS-CoV-2 , Sensibilidade e Especificidade
9.
Food Chem ; 367: 130607, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34388630

RESUMO

This work reports the study of the interaction of human salivary proteins (SP) with phenolic compounds that migrate from cork stoppers to wine. This study yields valuable data to understand the influence that these compounds may have on the sensory perception of wine from an astringency perspective. For that, three cork fractions containing the phenolic compounds that migrate in greater amounts from cork to model wine solutions were selected. Fraction M1 contains gallic acid, protocatechuic acid, vanillin and protocatechuic aldehyde; fraction M2 comprises essentially gallic acid and ellagic acid, as well as castalagin and dehydrocastalagin; and fraction M3 contains the two isomeric ellagitannins castalagin and vescalagin. The reactivity of each fraction towards SP was M3 > M2 > M1. Within M3 fraction, castalagin showed a higher ability to precipitate SP (mainly aPRPs, statherin and P-B peptide) comparatively to vescalagin. In M1 fraction, caffeic and sinapic acids were the compounds with the highest interaction with SP, mainly cystatins. In addition, there also seems to be a matrix effect (presence of other compounds) that could be affecting these interactions.


Assuntos
Vinho , Adstringentes , Humanos , Fenóis , Proteínas e Peptídeos Salivares , Vinho/análise
10.
Food Chem ; 375: 131642, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34838404

RESUMO

Astringency is a tactile sensation of puckering, tightening and dryness in the oral cavity, commonly induced by polyphenols. In this study, the interaction of two phenolic compound mixtures, one rich in gallotannins and the other in flavonols, with two oral models (tongue (HSC3) or buccal mucosa (TR146) was evaluated. Results provided evidence that gallotannins and flavonols seem to bind in a different way to the different oral constituents and models used. Gallotannins seems to bind more to the tongue than to the buccal mucosa cell line, but this difference is overcome by the presence of salivary proteins. Conversely, for the flavonol mixture, the presence of salivary proteins seems to restrain the interaction with oral cell lines. Structure-binding activity relationships were evidenced within each mixture: for gallotannins, interactions seem to increase along with the galloylation degree while for flavonol it was observed that increasing numbers of glucose residues decreased the binding activity.


Assuntos
Adstringentes , Proteínas e Peptídeos Salivares , Flavonóis , Boca , Fenóis
11.
Front Immunol ; 13: 956326, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36726986

RESUMO

Increased risk of intestinal dysfunction has been reported in patients after Clostridioides difficile infection (CDI). Enteric glial cells (EGCs), a component of the enteric nervous system (ENS), contribute to gut homeostasis. Previous studies showed that adenosine receptors, A2A and A2B, modulate inflammation during CDI. However, it is unknown how these receptors can modulate the EGC response to the C. difficile toxins (TcdA and TcdB). We investigated the effects of these toxins on the expression of adenosine receptors in EGCs and the role of these receptors on toxin-induced EGC death. Rat EGCs line were incubated with TcdA or TcdB alone or in combination with adenosine analogues 1h prior to toxins challenge. After incubation, EGCs were collected to evaluate gene expression (adenosine receptors and proinflammatory markers) and cell death. In vivo, WT, A2A, and A2B KO mice were infected with C. difficile, euthanized on day 3 post-infection, and cecum tissue was processed. TcdA and TcdB increased A2A and A3 transcripts, as well as decreased A2B. A2A agonist, but not A2A antagonist, decreased apoptosis induced by TcdA and TcdB in EGCs. A2B blocker, but not A2B agonist, diminished apoptosis in EGCs challenged with both toxins. A3 agonist, but not A3 blocker, reduced apoptosis in EGCs challenged with TcdA and TcdB. Inhibition of protein kinase A (PKA) and CREB, both involved in the main signaling pathway driven by activation of adenosine receptors, decreased EGC apoptosis induced by both toxins. A2A agonist and A2B antagonist decreased S100B upregulation induced by C. difficile toxins in EGCs. In vivo, infected A2B KO mice, but not A2A, exhibited a decrease in cell death, including EGCs and enteric neuron loss, compared to infected WT mice, reduced intestinal damage and decreased IL-6 and S100B levels in cecum. Our findings indicate that upregulation of A2A and A3 and downregulation of A2B in EGCs and downregulation of A2B in intestinal tissues elicit a protective response against C. difficile toxins. Adenosine receptors appear to play a regulatory role in EGCs death and proinflammatory response induced by TcdA and TcdB, and thus may be potential targets of intervention to prevent post-CDI intestinal dysmotility.


Assuntos
Toxinas Bacterianas , Clostridioides difficile , Infecções por Clostridium , Ratos , Camundongos , Animais , Toxinas Bacterianas/metabolismo , Clostridioides difficile/fisiologia , Proteínas de Bactérias/genética , Infecções por Clostridium/metabolismo , Apoptose , Neuroglia/metabolismo , Receptores Purinérgicos P1/metabolismo
12.
Soft Matter ; 17(48): 10926-10934, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34811564

RESUMO

The formation of hydrogels by photosensitized oxidation and crosslinking of histidine-derived polymers is demonstrated for the first time. The photooxidation of pendant His mediated by singlet oxygen was used to promote covalent coupling by its dimerization. As a proof-of-concept, two systems were studied: (i) chondroitin sulfate (CS) functionalized with His, and (ii) an elastin-like peptide (ELP) containing His produced by recombinant techniques. Both materials were crosslinked by irradiation at 425 nm in the presence of Zn-porphyrin derivatives yielding His-based hydrogels. The molecular structure and physicochemical properties of ELP-His and other 5 ELPs with photooxidizable amino acids were studied in silica by computer simulation. A correlation between the protein conformation and its elastic properties is discussed. CS-His hydrogels demonstrate larger storage moduli than ELPs with other amino acids. The obtained results show the potential use of photooxidation to create a new type of His-based hydrogels.


Assuntos
Histidina , Hidrogéis , Simulação por Computador , Elastina , Oxigênio , Oxigênio Singlete
13.
Food Res Int ; 147: 110538, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34399515

RESUMO

The aim of this study was to analyze the residue powders of Malpighia emarginata L., Psidium guajava L., Genipa americana L. and Spondias tuberosa L. regarding their total phenolic compounds contents, antioxidant activity (ABTS, DPPH and FRAP), soluble sugars, carotenoids, organic acids by HPLC-DAD/RID and individual phenolic compounds by the UPLC-QDa-MS system. The genipap residue had a high content of soluble sugars (422.72 ± 19.15 mg.g-1 DW), with a higher content of sucrose (170.83 ± 10.89 mg.g-1 DW). Nystose was found in the residues of guava (6.59 ± 0.56 mg.g-1 DW) and umbu (65.61 ± 2.31 mg.g-1 DW). The residues of acerola and umbu showed contents of ß-carotene of 5.84 ± 0.01 mg.g-1 DW and 0.10 ± 0.05 mg.g-1 DW, respectively while high concentration (1116.00 ± 2.00 mg.100 g-1 DW) of tartaric acid was found in acerola residue and quinic acid (6340 ± 104.00 mg.100 g-1 DW) in umbu residue. Acetone (80%) and ultrasonic extraction were the best conditions for the residues of acerola, guava and genipap, however, for the umbu residue, extraction with shaker showed better results. The acerola and umbu residues showed higher yields of total phenolics, the values being 378.69-444.05 mg GAE.100 g-1 DW and 326.14-404.36 mg GAE.100 g-1 DW, respectively, as well as antioxidant activity. Naringenin was the individual phenolic compound with the highest concentration in the residue of acerola and genipap, vanillin in guava and rutin in umbu. Thus, residues powders from acerola, guava, genipap and umbu constitute potential sources of bioactive compounds, which could be used in the food, pharmaceutical and cosmetic industries.


Assuntos
Anacardiaceae , Psidium , Antioxidantes , Frutas , Extratos Vegetais , Rutina , Ultrassom
14.
Nanomedicine ; 37: 102445, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34303841

RESUMO

Chikungunya virus (CHIKV) is responsible for a self-limited illness that can evolve into long-lasting painful joint inflammation. In this study, we report a novel experimental CHIKV vaccine formulation of lipid nanoparticles loaded with a recombinant protein derived from the E2 structural protein. This antigen fragment, designated ∆E2.1, maintained the antigenicity of the native viral protein and was specifically recognized by antibodies induced in CHIKV-infected patients. The antigen has been formulated into nanoparticles consisting of nano-multilamellar vesicles (NMVs) combined with the adjuvant monophosphoryl lipid A (MPLA). The vaccine formulation demonstrated a depot effect, leading to controlled antigen release, and induced strong antibody responses significantly higher than in mice immunized with the purified protein combined with the adjuvant. More relevantly, E2-specific antibodies raised in mice immunized with ∆E2.1-loaded NMV-MPLA neutralized CHIKV under in vitro conditions. Taken together, the results demonstrated that the new nanoparticle-based vaccine formulation represents a promising approach for the development of effective anti-CHIKV vaccines.


Assuntos
Febre de Chikungunya/imunologia , Vírus Chikungunya/imunologia , Lipossomos/imunologia , Proteínas do Envelope Viral/genética , Animais , Anticorpos Neutralizantes/biossíntese , Anticorpos Neutralizantes/efeitos dos fármacos , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/biossíntese , Anticorpos Antivirais/efeitos dos fármacos , Anticorpos Antivirais/imunologia , Febre de Chikungunya/terapia , Febre de Chikungunya/virologia , Vírus Chikungunya/patogenicidade , Humanos , Lipossomos/química , Lipossomos/farmacologia , Camundongos , Nanopartículas/química , Proteínas do Envelope Viral/farmacologia , Vacinas Virais/imunologia
15.
Nanomedicine ; 32: 102334, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33188909

RESUMO

Self-assembling proteins may be generated after the addition of short specific amino acid sequences at both the N- and C-terminal ends. To date, this approach has not been evaluated regarding the impact of self-assembled proteins on the induction of immune responses. In the present study, we report the application of this experimental approach to the immunogenicity of protein antigens by measuring the antibody responses in mice immunized with nanoparticles made with a recombinant form of Zika virus nonstructural protein 1 (∆NS1). The results clearly indicated that ∆NS1-derived nanoparticles (NP-∆NS1) are assembled into a 3-dimensional structure with a high degree of multimerization. While ∆NS1 proved to be a weak immunogen, immunization with NP-∆NS1 enhanced subunit vaccines' immunogenicity with improved longevity in vaccinated mice. Thus, immunization with self-assembled antigens (nanovaccines) represents a new and promising strategy to enhance NS1-specific antibodies' induction based on purified recombinant proteins.


Assuntos
Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , Nanopartículas/química , Proteínas não Estruturais Virais/imunologia , Vacinas Virais/imunologia , Zika virus/imunologia , Animais , Epitopos/imunologia , Feminino , Imunização , Imunoglobulina G/metabolismo , Camundongos Endogâmicos C57BL
16.
J Agric Food Chem ; 68(47): 13824-13832, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33170702

RESUMO

Procyanidins are widely associated with astringency perception and promptly interact/precipitate salivary proteins (SPs). In this work, the SP profile of 17 volunteers was monitored for 1 year, focusing on the SP families most related to astringency [aPRPs (acidic proline-rich proteins), bPRPs (basic proline-rich proteins), gPRPs (glycosylated proline-rich proteins), cystatins, P-B peptide, and statherin]. Although the total SP content remained constant, bPRPs showed high variability. Saliva from 5 volunteers was selected, each individual's saliva presenting a prominence in one of the referred SP families; each was used to interact with grape seed procyanidin oligomeric fraction. Independent of the prominences, a total depletion in statherin and P-B peptide was observed. These subjects performed a sensory assay and the limit of detection for astringency was determined. Overall, the specificity of SP toward procyanidins seemed to be more important in the interactions than the total SP content. The highest reactivity toward SPs was observed for epicatechin gallate, procyanidin dimers B7, B2g, and trimer C1.


Assuntos
Biflavonoides , Proantocianidinas , Catequina , Humanos , Saliva , Proteínas e Peptídeos Salivares
17.
Front Med Technol ; 2: 558984, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-35047876

RESUMO

Dengue virus represents the main arbovirus affecting humans, but there are no effective drugs or available worldwide licensed vaccine formulations capable of conferring full protection against the infection. Experimental studies and results generated after the release of the licensed anti-DENV vaccine demonstrated that induction of high-titer neutralizing antibodies does not represent the sole protection correlate and that, indeed, T cell-based immune responses plays a relevant role in the establishment of an immune protective state. In this context, this study aimed to further demonstrate protective features of immune responses elicited in immunocompetent C57BL/6 mice immunized with three plasmids encoding DENV2 nonstructural proteins (NS1, NS3, and NS5), which were subsequently challenged with a DENV2 strain naturally capable of inducing lethal encephalitis in immunocompetent mouse strains. The animals were immunized intramuscularly with the DNA vaccine mix and complete protection was observed among vaccinated mice. Vaccine induced protection correlated with the cytokine profiles expressed by spleen cells and brain-infiltrating mononuclear cells. The results confirm the pivotal role of cellular immune responses targeting nonstructural DENV proteins and validate the experimental model based on a DENV2 strain capable of infecting and killing immunocompetent mice as a tool for the evaluation of protective immunity induced by anti-DENV vaccines.

18.
Front Med Technol ; 2: 604160, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-35047887

RESUMO

Zika virus (ZIKV) is a globally-distributed flavivirus transmitted to humans by Aedes mosquitoes, usually causing mild symptoms that may evolve to severe conditions, including neurological alterations, such as neonatal microcephaly and Guillain-Barré syndrome. Due to the absence of specific and effective preventive methods, we designed a new subunit vaccine based on a DNA vector (pgDNS1-ZIKV) encoding the non-structural protein 1 (NS1) genetically fused to the Herpes Simplex Virus (HSV) glycoprotein D (gD) protein. Recombinant plasmids were replicated in Escherichia coli and the expression of the target protein was confirmed in transfected HEK293 cells. C57BL/6 and AB6 (IFNAR1-/-) mice were i.m. immunized by electroporation in order to evaluate pgDNS1-ZIKV immunogenicity. After two doses, high NS1-specific IgG antibody titers were measured in serum samples collected from pgDNS1-ZIKV-immunized mice. The NS1-specific antibodies were capable to bind the native protein expressed in infected mammalian cells. Immunization with pgDNS1-ZIKV increased both humoral and cellular immune responses regarding mice immunized with a ZIKV NS1 encoding vaccine. Immunization with pgDNS1-ZIKV reduced viremia and morbidity scores leading to enhanced survival of immunodeficient AB6 mice challenged with a lethal virus load. These results give support to the use of ZIKV NS1 as a target antigen and further demonstrate the relevant adjuvant effects of HSV-1 gD.

20.
Quad. psicol. (Bellaterra, Internet) ; 22(3): e1640-e1640, 2020.
Artigo em Português | IBECS | ID: ibc-200529

RESUMO

Partimos do pressuposto que o rigor científico da pesquisa qualitativa é dar visibilidade às decisões teórico-metodológicas e considerar as implicações éticas decorrentes. Nesta direção, adotamos a perspectiva das práticas discursivas e produção de sentidos, uma das vertentes da psicologia social de base construcionista. Para tanto, expomos detalhadamente os procedimentos de produção e análise realizados em uma dissertação sobre atuação de psicólogas no campo do HIV/aids. Defendemos a explicitação de todos os passos, ajustes, refinamentos, incorporações e procedimentos adotados. O rigor da produção de conhecimento que defendemos está baseado não na busca de rigidez, mas nos alcances da maleabilidade, que à primeira vista é contraditório, mas ao juntar-se à visibilidade, assenta na boa qualidade da pesquisa. Além disso, ressaltamos que uma postura ética não se limita ao cumprimento de Resoluções de Ética


We infer that scientific rigor of qualitative research is to give visibility to theoretical and methodological decisions and to consider ethical implications arising from the knowledge production process. We adopt the perspective of discursive practices and production of meanings, one of the aspects of social psychology with constructionist basis. For this purpose, we set out in detail the production and analysis procedures carried out in a dissertation on the role of psychologists in the field of HIV/AIDS. We defend the explanation of all steps, adjustments, refinements, incorporations and procedures adopted. The rigor of the knowledge production we defend is based not on the search for rigidity, but on the reach of malleability, which at first sight is contradictory, but when added to the visibility, it is based on the good quality of the research. In addition, we emphasize that an ethical posture is not limited to compliance with Ethical Resolutions


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Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Pesquisa Qualitativa , Psicologia Social/métodos , Psicologia Social/estatística & dados numéricos , Inquéritos e Questionários
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