DSpace Coleção: PPGO

Efeito do carvacrol sobre fatores de virulência de cepas de Candida albicans isoladas da mucosa oral: um estudo in vitro

2026-10-07T06:11:11Z

Título: Efeito do carvacrol sobre fatores de virulência de cepas de Candida albicans isoladas da mucosa oral: um estudo in vitro Autor(es): Pequeno, Iasmin Freitas Pimentel Orientador: Rocha, Walicyranison Plinio da Silva Abstract: Oral candidiasis is a fungal infection caused by Candida yeasts, mainly Candida albicans. This infection usually affects the oral mucosa and it is frequently observed in individuals who suffer from immunological impairment. The standard therapeutic approach consists of using conventional antifungal drugs, however, their high levels of toxicity, as well as the emergence of drug resistant strains, request the search for brand new treatment alternatives, in addition to an improved understanding about the impact of such substances on the virulence factors expressed by these pathogens. In this sense, carvacrol, a phenolic monoterpenoid compound, found in oregano essential oils, has stood out for its antifungal and antimicrobial potential. In consideration of that, this investigation aimed to notice the effect of carvacrol on the virulence factors of C. albicans strains isolated from the oral mucosa. The morphogenesis capacity and the lipase activity were the examined virulence aspects. The study involved 13 C. albicans strains collected from the oral mucosa of individuals with oral candidiasis and 1 reference strain (ATCC 90028) which were submitted to every assay under 2 simultaneous conditions: in the presence and in the absence of carvacrol (MIC = 128 μg/mL). The mentioned compound was capable of reducing the germ tube emission in most of the studied strains (from 72,27% ± 14,2% to 13,97% ± 22,2%) and showed efficiency in reducing filamentation (from IM = 2.9 to IM =1,9); as soon as pseudohyphae was the most prevalent morphology in the absence of carvacrol, although, the elongated and spherical cells became most frequent with carvacrol. Afterwards, it was verified that the tested compound could significantly reduce hyphal length on every strain in which remained the hyphal morphology, furthermore it was capable of preventing the formation of filamentous colonies in solid medium, producing uniquely smooth colonies. Finally, carvacrol was efficient inhibiting the lipase activity from each analyzed strain. By highlighting the in vitro influence of carvacrol on the virulence factors of C. albicans, we recommend that this monoterpene should be considered a promising compound added to the formulation of new and efficient antifungal drugs but, obviously, complementary researches aiming its clinical performance are necessary to prove its low toxicity and therapeutic efficacy in human beings. Editor: Universidade Federal da Paraíba Tipo: Dissertação

Estimativa de sexo em brasileiros utilizando mensurações orbitárias em tomografias computadorizadas : abordagens convencional e por aprendizado de máquina

2026-10-02T06:10:03Z

Título: Estimativa de sexo em brasileiros utilizando mensurações orbitárias em tomografias computadorizadas : abordagens convencional e por aprendizado de máquina Autor(es): Oliveira, Yasmin Caldas de Macêdo Abrantes Rodrigues de Orientador: Santiago, Bianca Marques Abstract: Human identification requires resources that match the complexity of the expertise involved. Estimating sex is essential for establishing an individual's biological profile in the process of identifying human remains. However, the use of foreign parameters in Brazilian samples is often ineffective. This study aimed to evaluate the applicability of computed tomography (CT) in measuring the Orbital Index for sex estimation in individuals from the Brazilian population, comparing multiplanar (MPR) and three-dimensional (3D) reconstructions. The sample was obtained by sample calculation (95% confidence, 5% error) and consisted of 386 CT (CBCT and MSCT) scans of patients performed in private clinics, balanced by sex (193 male and 193 female) and distributed proportionally among the five macro-regions of Brazil. Skull or face CT scans with FOV that allowed full visualization of the orbital anatomical points were included; cases with morphofunctional alterations, surgeries, fractures, neoplasms, and individuals with bone immaturity (<18 years) were excluded. Height, width, and IO measurements were performed in MPR and 3D using the free RadiAnt DICOM Viewer 2025.2 software. Intra- and inter-examiner agreement was assessed in 10% of the sample using the Intraclass Correlation Coefficient (ICC), presenting excellent values (ICC > 0.90), with a standardized protocol and triple-blind masking. Descriptive and inferential statistical analyses were performed using Jamovi 2.3 and Python 3.13.5 software. The normality (Kolmogorov-Smirnov, p > 0.05) and homogeneity (Levene, p > 0.05) of the data were confirmed, and parametric tests were then applied. There was a significant difference between MPR and 3D (paired t, p < 0.05), with a mean IO of 110.59 (± 6.112) in MPR and 100.57 (± 6.451) in 3D, indicating an underestimation of 3D in relation to MPR (≈8.84%; ± 5.01%). Men had larger linear orbital dimensions than women in both reconstructions (p < 0.001), but IO dimorphism was confirmed only in 3D (p < 0.001), following this reconstruction for subsequent analyses. The 3D reconstruction revealed a moderate correlation between the right and left orbital indices and a strong correlation between these measurements and the mean orbital index. Linear discriminant analysis (LDA) conducted with the mean index demonstrated low discriminatory capacity, explaining 5% of the variability between sexes and achieving an overall accuracy of 60.6%. The ROC curve confirmed statistically significant but limited discrimination (AUC = 0.637). Machine learning models (Support Vector Machine (SVM), K-Nearest Neighbors (KNN), Decision Tree, Logistic Regression, Multi-Layer Perceptron (MLP), Gradient Boosting, and Random Forest) trained with 3D orbital measurements showed accuracies between 0.603 and 0.679 and AUC between 0.590 and 0.700, indicating moderate and relatively homogeneous performance among the algorithms. In all models, orbital widths—especially the right one—were the most relevant variables, while orbital heights showed minimal contribution. The findings confirm that both linear measurements and orbital indices derived from 3D reconstruction have limited discriminatory capacity for sex estimation, even with the use of advanced multivariate methods. The influence of reconstruction (MPR and 3D) highlights the need for specific morphometric parameters for the Brazilian population, ensuring more accurate interpretations in forensic and clinical applications. The findings show that orbital morphology obtained by computed tomography (MPR and 3D) has limited discriminatory capacity for sex estimation, given the low effect of the measurements, the wide overlap between groups, and the moderate performance of statistical and computational approaches. Thus, the orbital index should not be used either as an aid in multivariate models or as isolated indicators. Editor: Universidade Federal da Paraíba Tipo: Tese

Avaliação de colutório contendo sistema de liberação controlada de flúor: estudo clínico Randomizado

2026-10-01T06:10:42Z

Título: Avaliação de colutório contendo sistema de liberação controlada de flúor: estudo clínico Randomizado Autor(es): Moura, Helene Soares Orientador: Sampaio, Fábio Correia Abstract: Objective: To evaluate in vivo the effect of mouthwash with controlled-release system (CRS) for the delivery of fluoride (F) on the retention of F in dental biofilm and saliva. Material and methods: The mouthwashes used in the study were: Placebo (without F); A (225 ppm, all free sodium fluoride); B (225 ppm, 50% free sodium fluoride + 50% CRS-sodium fluoride); C (225 ppm all CRS-sodium fluoride). A randomized, triple-blind crossover clinical trial study was performed with twenty- one residents of a city without water fluoridation programe. After weekly use of mouthwashes, samples of biofilm and saliva were collected 1h and 12h after the last rinse for biofilm and, 0 to 60 minutes and 12 hours for saliva. The concentrations of F in saliva and biofilm were analyzed by specific electrode through diffusion technique facilitated by hexamethyldisiloxane (HMDS). Data were analyzed by repeated measures ANOVA followed by the Bonferroni test (p<0.05). Area under the curve (AUC) was calculated for saliva data. Results: For AUC0-60min the values were: A (162.2) > B (138.3) > C (129.6) > Placebo (4.80). In biofilm, mouthwash B presented highest value of F concentration (ug/kg) for 1h (4.886) and A (5.038) for 12h. Conclusion: It can be concluded that the CRS for delivery of fluoride tested in this study provides a different pattern of fluoride delivery compared to free fluoride formulations and may present a beneficial effect since it has the potential for increasing substantivity of F in the oral cavity. Clinical relevance: Mouthwashes with controlled fluoride release systems can be a good post-brushing product to increase the levels of fluoride in the oral cavity. Editor: Universidade Federal da Paraíba Tipo: Dissertação

Atividade antifúngica do 2-benzil-5-metilbenzo[d]xazol frente a candida spp.

2026-08-11T06:12:26Z

Título: Atividade antifúngica do 2-benzil-5-metilbenzo[d]xazol frente a candida spp. Autor(es): Souza, Lara Danúbia Galvão de Orientador: Guerra, Felipe Queiroga Sarmento Abstract: Over the past three decades, there has been a significant increase in the incidence of fungal infections caused by Candida species. Among these, oral candidiasis stands out as the most common oral fungal infection, primarily triggered by Candida albicans. Vulnerable groups include cancer patients, immunosuppressed individuals, and denture users. However, current treatments are associated with adverse effects and increasing pathogen resistance, making it urgent to search for new, more effective, and safer pharmacological compounds for treating these infections. This study aimed to evaluate the antifungal potential of 2-benzyl-5-methylbenzo[d]oxazole (Compound 1), a benzoxazole derivative, against Candida species. The antifungal activity was determined using the broth microdilution technique to establish the minimum inhibitory concentration (MIC). Subsequently, agar plates containing SDA were used to determine the minimum fungicidal concentration (MFC). Additionally, the compound's effects on biofilm formation were assessed, focusing on both the adhesion phase and mature biofilm. Tests with sorbitol and ergosterol were conducted to investigate the action of Compound 1 on the fungal cell wall and membrane, respectively. An in silico analysis of pharmacokinetic and toxicological properties was performed using ADMET, Molinspiration, and Passonline software. The MIC values varied across species: MIC of 16 µg/mL for C. krusei, MIC of 32 µg/mL for C. albicans and C. parapsilosis, and MIC of 64 µg/mL for C. glabrata. The MFC/MIC ratio < 4 indicated fungicidal activity, and the probable mode of action involves the plasma membrane, as an increase in MIC was observed in the presence of exogenous ergosterol. A 64% reduction in pre- formed biofilm and 84% inhibition of biofilm in the adhesion phase were observed, both at a concentration of 320 µg/mL (p < 0.0001). In in silico tests, 2-benzyl-5- methylbenzo[d]oxazole exhibited good theoretical bioavailability after oral administration, good solubility, stability, and absorption, along with moderate theoretical toxicity. Based on these findings, 2-benzyl-5-methylbenzo[d]oxazole demonstrated promising pharmacological activity. These results may serve as an important starting point for developing new antifungal drug candidates, although further studies are required to evaluate its cytotoxicity. Editor: Universidade Federal da Paraíba Tipo: Dissertação