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1.
Dalton Trans ; 53(20): 8563-8575, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38682235

RESUMO

The Oxygen Evolution Reaction (OER) is crucial in various processes such as hydrogen production via water splitting. Several electrocatalysts, including metal oxides, have been evaluated to enhance the reaction efficiency. Zeolitic Imidazolate Framework-67 (ZIF-67) has been employed as a precursor to produce Co3O4, showing high OER activity. Additionally, the formation of composites with carbon-based materials improves the activity of these materials. Thus, this work focuses on synthesizing ZIF-67 and commercial activated carbon (AC) composites, which were used as precursors to obtain Co3O4/C electrocatalysts by calculating ZIF-67/CX (X = 10, 30, and 50, the mass percentage of AC). The obtained materials were thoroughly characterized by employing X-ray powder diffraction (XRD), confirming the cobalt oxide structure with a sphere-like morphology as observed in the TEM images. The presence of oxygen vacancies was confirmed by infrared spectroscopy and EPR measurements. The electrocatalytic performance in the OER was investigated by linear sweep voltammetry (LSV), which revealed an overpotential of 325 mV at 10 mA cm-2 and a Tafel slope value of 65.32 mV dec-1 for Co3O4/C10, superior in activity to several previously reported studies in the literature and electrochemical stability of up to 8 hours. The reduced value of charge transfer resistance, high double-layer capacitance, and the presence of Co3+ ions justify the superior performance of the Co3O4/C10 electrocatalyst.

2.
J Colloid Interface Sci ; 641: 643-652, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36963257

RESUMO

High-entropy materials have received notable attention concern on account of their unique structure, tunable properties, and unprecedented potential applications in many fields. In this work, for the first time a NiCoMnZnMg-containing high-entropy glycerolate (HE-Gly) particles has been synthesized using a scalable solvothermal method. The HE-Gly particles were used as a precursor in design of porous high-entropy oxide (HEO) microparticles. The morphological and structural characterizations demonstrate that the temperature of the annealing process, and the composition of the metal ions in the HE-Gly precursors play important roles in determining porosity, crystallinity, and phase separation in HEOs. In fact, HE-Gly exhibited a porous structure of spinel HEOs with secreted MgO phase after annealing process at 800 °C, while the annealing process at 400 °C led to a low-crystallinity spinel phase without phase segregation. Overall, this work describes HE-Gly as a new precursor for altering the composition, crystallinity, and porosity of HEOs. This strategy is scalable for potential high mass productions, paving a new path toward industrial application of high-entropy materials.

3.
Int J Mol Sci ; 23(19)2022 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-36233023

RESUMO

BACKGROUND: The purpose of this study was to evaluate the status of Epstein-Barr virus (EBV) infection and the expression of programmed cell death ligand-1 (PD-L1) in tumor samples from patients with nasopharyngeal carcinoma (NPC). METHODS: Evaluation of EBV infection was performed through the detection of EBV-encoded small ribonucleic acids (EBER) by in situ hybridization, and PD-L1 expression was performed through immunohistochemistry. RESULTS: In total, 124 samples were evaluated for EBER and 120 for PD-L1 expression. A total of 86.3% of cases were positive for EBER and 55.8% were positive for PD-L1. There was a correlation between EBER positivity and the presence of undifferentiated carcinoma histology (p = 0.007) as well as the absence of tobacco history (p = 0.019). There was a correlation between PD-L1 expression and EBER positivity (p = 0.004). There was no statistically significant difference between overall survival (OS) and EBER (p = 0.290) or PD-L1 (p = 0.801) expression. CONCLUSIONS: This study corresponds to one of the largest cohorts of NPC in a non-endemic region. Phase III studies with checkpoint inhibitors are ongoing and may provide more data about the role of PD-L1 expression in this disease.


Assuntos
Infecções por Vírus Epstein-Barr , Neoplasias Nasofaríngeas , Antígeno B7-H1/metabolismo , Infecções por Vírus Epstein-Barr/complicações , Herpesvirus Humano 4/metabolismo , Humanos , Ligantes , Carcinoma Nasofaríngeo
4.
Nanomaterials (Basel) ; 12(18)2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36144958

RESUMO

The development of efficient electrocatalysts for the oxygen evolution reaction (OER) is of paramount importance in sustainable water-splitting technology for hydrogen production. In this context, this work reports mixed-valence oxide samples of the MnXCo3-XO4 type (0 ≤ X ≤ 1) synthesized for the first time by the proteic sol-gel method using Agar-Agar as a polymerizing agent. The powders were calcined at 1173 K, characterized by FESEM, XRD, RAMAN, UV-Vis, FT-IR, VSM, and XPS analyses, and were investigated as electrocatalysts for the oxygen evolution reaction (OER). Through XRD analysis, it was observed that the pure cubic phase was obtained for all samples. The presence of Co3+, Co2+, Mn2+, Mn3+, and Mn4+ was confirmed by X-ray spectroscopy (XPS). Regarding the magnetic measurements, a paramagnetic behavior at 300 K was observed for all samples. As far as OER is concerned, it was investigated in an alkaline medium, where the best overpotential of 299 mV vs. RHE was observed for the sample (MnCo2O4), which is a lower value than those of noble metal electrocatalysts in the literature, together with a Tafel slope of 52 mV dec-1, and excellent electrochemical stability for 15 h. Therefore, the green synthesis method presented in this work showed great potential for obtaining electrocatalysts used in the oxygen evolution reaction for water splitting.

6.
J Colloid Interface Sci ; 582(Pt A): 124-136, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32823121

RESUMO

Cobalt-based oxides are among the most promising electrocatalysts for oxygen evolution reactions (OER). In this context, this work reports the synthesis of manganese-doped cobaltites using the Zeolitic-Imidazolate Frameworks 67 (ZIF-67) as template. The incorporation of manganese ions into ZIF-67 structure was evaluated in ethanol and methanol, in order to obtain the best synthetic route. Non-doped (ZIF-67C) and Mn-doped cobaltites (Mn/ZIF-67C(E) and Mn/ZIF-67C(M)) were obtained after thermal treatment at 350 °C. Structural and morphological properties were investigated and presence of Mn3+ and Mn4+ was confirmed by X-ray photoelectron spectroscopy (XPS) data and magnetization curves. The electrocatalytic activity in OER was investigated in alkaline medium for manganese cobaltites, and compared to the ZIF-67C. Overpotentials to generate a current of 10 mA cm-2 were 338 mV and 356 mV for Mn/ZIF-67C(E) and Mn/ZIF-67C(M), respectively. These results are superior to those found for similar materials in the literature. The material obtained in methanol (Mn/ZIF-67C(M)) presents lower overpotential, however, shows superior electrocatalytic performance for current density above 100 mA cm-2, therefore being an efficient electrode for commercial electrolysers.

7.
Materials (Basel) ; 13(23)2020 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-33287152

RESUMO

This work reports the effects of microstructural changes due to the secondary phases, in particular sigma (σ), on the mechanical properties and electrochemical behavior of thermally aged duplex stainless steel (DSS). Structural, morphological, mechanical, and electrochemical characterizations were performed. Sigma phase content increased with increasing aging treatment time. It had a net-like shape, as observed by electron backscatter diffractometry (EBSD). Its presence directly damaged mechanical properties. The corrosion assessment included electrochemical impedance spectroscopy (EIS) in 1 M NaCl solution at temperatures of 25, 40, and 65 °C. EIS results demonstrate that an increase in the σ phase content decreased the corrosion resistance (21.1-0.8, 3.5-0.3, and 3.1-0.2 kΩ cm2 at 25, 40, and 60 °C, respectively).

8.
Thorac Cancer ; 11(10): 2987-2992, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32881389

RESUMO

Epidermal growth factor (EGF) and its receptor (EGFR) play a paramount role in lung carcinogenesis. The polymorphism in the EGF promoter region EGF+61A>G (rs4444903) has been associated with cancer susceptibility, but its role in lung cancer patients treated with tyrosine kinase inhibitors (TKIs) remains unknown. Here, we aimed to evaluate the predictive and prognostic role of EGF+61A>G SNP in lung cancer from Brazilian EGFR-mutated TKI-treated patients. Herein, patients carrying EGFR-sensitizing mutations submitted to TKI treatment (gefitinib/erlotinib) were analyzed (n = 111) for EGF+61A>G genotype by TaqMan genotyping assay. TKI treatment was classified as partial response (PR), stable disease (SD), and disease progression (DP), according to RECIST1.1. Association analysis was assessed by chi-square and Fisher's test (univariate) and multinomial model (multivariate) and survival analysis by Kaplan-Meier method and log-rank test. The EGF+61A>G genotype frequencies observed were: AA = 31.5% (n = 35), AG = 49.6% (n = 55) and GG = 18.9% (n = 21). The allelic frequencies were 56.3% for A, and 43.7% for G and the population was in Hardy-Weinberg equilibrium (P = 0.94). EGF+61A>G codominant model (AA vs. AG vs. GG) was associated with a response to TKIs (P = 0.046), as well as a recessive model (AA vs. AG + GG; P = 0.023). The multinomial regression showed an association between the codominant model (AG) and recessive model (AG + GG) with SD compared with DP (P = 0.01;OR = 0.08; 95% CI = 0.01-0.60 and P = 0.02;OR = 0.12; 95% CI = 0.20-0.72, respectively). No association between genotypes and progression-free or overall survival was observed. In conclusion, the EGF+61 polymorphism (AG and AG + GG) was independently associated with stable disease in lung cancer patients although it was not associated with the overall response rate to first-generation TKIs or patient outcome.


Assuntos
Fator de Crescimento Epidérmico/genética , Predisposição Genética para Doença/genética , Neoplasias Pulmonares/genética , Inibidores de Proteínas Quinases/uso terapêutico , Humanos , Neoplasias Pulmonares/patologia , Pessoa de Meia-Idade , Inibidores de Proteínas Quinases/farmacologia , Estudos Retrospectivos
9.
Dent Mater ; 35(11): e272-e285, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31519351

RESUMO

OBJECTIVES: In this study hybrid nanofibers embedded with niobium pentoxide (Nb2O5) were synthesized, incorporated in self-adhesive resin cement, and their influence on physical-properties was evaluated. METHODS: Poly(D,L-lactide), PDLLA cotton-wool-like nanofibers with and without silica-based sol-gel precursors were formulated and spun into submicron fibers via solution blow spinning, a rapid fiber forming technology. The morphology, chemical composition and thermal properties of the spun fibers were characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS) and Fourier-transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC), respectively. Produced fibers were combined with a self-adhesive resin cement (RelyX U200, 3M ESPE) in four formulations: (1) U200 resin cement (control); (2) U200+1wt.% PDLLA fibers; (3) U200+1wt.% Nb2O5-filled PDLLA composite fibers and (4) U200+1wt.% Nb2O5/SiO2-filled PDLLA inorganic-organic hybrid fibers. Physical properties were assessed in flexure by 3-point bending (n=10), Knoop microhardness (n=5) and degree of conversion (n=3). Data were analyzed with One-way ANOVA and Tukey's HSD (α=5%). RESULTS: Composite fibers formed of PDLLA-Nb2O5 exhibited an average diameter of ∼250nm, and hybrid PDLLA+Nb2O5/SiO2 fibers were slightly larger, ∼300nm in diameter. There were significant differences among formulations for hardness and flexural strength (p<0.05). Degree of conversion of resin cement was not affected for all groups, except for Group 4 (p<0.05). SIGNIFICANCE: Hybrid reinforcement nanofibers are promising as fillers for dental materials. The self-adhesive resin cement with PDLLA+Nb2O5 and PDLLA+Nb2O5/SiO2 presented superior mechanical performance than the control group.


Assuntos
Colagem Dentária , Nanofibras , Cimentos Dentários , Teste de Materiais , Nióbio , Óxidos , Cimentos de Resina , Dióxido de Silício , Propriedades de Superfície
10.
PLoS One ; 14(4): e0214722, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30958836

RESUMO

PURPOSE: To estimate the effect size of a serious game for cardiopulmonary resuscitation (CPR) training in comparison with a video-based on-line course in terms of learning outcomes among medical students before simulation-based CPR using a manikin. METHODS: Participants were 45 first-year medical students randomly assigned to CPR self-training using either a video-based Apple Keynote presentation (n = 22) or a serious game developed in a 3D learning environment (n = 23) for up to 20 min. Each participant was evaluated on a written, multiple-choice test (theoretical test) and then on a scenario of cardiac arrest (practical test) before and after exposure to the self-learning methods. The primary endpoint was change in theoretical and practical baseline scores during simulated CPR. This study was conducted in 2017. RESULTS: Both groups improved scores after exposure. The video group had superior performance in both the theoretical test (7.56±0.21 vs 6.51±0.21 for the game group; p = 0.001) and the practical test (9.67±0.21 vs 8.40±0.21 for the game group; p < 0.001). However, students showed a preference for using games, as suggested by the longer time they remained interested in the method (18.57±0.66 min for the game group vs 7.41±0.43 for the video group; p < 0.001). CONCLUSIONS: The self-training modality using a serious game, after a short period of exposure, resulted in inferior students' performance in both theoretical and practical CPR tests compared to the video-based self-training modality. However, students showed a clear preference for using games rather than videos as a form of self-training.


Assuntos
Reanimação Cardiopulmonar/educação , Educação a Distância , Avaliação Educacional , Feminino , Parada Cardíaca/terapia , Humanos , Masculino , Manequins , Estudantes de Medicina , Jogos de Vídeo , Gravação em Vídeo , Adulto Jovem
11.
Melanoma Res ; 29(5): 474-482, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30839356

RESUMO

Alterations in nuclear size and shape are commonly observed in cancers, and its objective evaluation may provide valuable clinical information about the outcome of the disease. Here, we applied the nuclear morphometric analysis in tissues in hematoxylin and eosin-digitized slides of nevi and melanoma, to objectively contribute to the prognostic evaluation of these tumors. To this, we analyzed the nuclear morphometry of 34 melanomas classified according to the TNM stage. Eight cases of melanocytic nevi were used as non-neoplastic tissues to set the non-neoplastic parameters of nuclear morphology. Our samples were set as G1 (control, nevi), G2 (T1T2N0M0), G3 (T3T4N0M0), G4 (T1T2N1M1), and G5 (T3T4N1M1). Image-Pro Plus 6.0 software was used to acquire measurements related to nuclear size (variable: Area) and shape (variables: Aspect, AreaBox, Roundness, and RadiusRatio, which were used to generate the Nuclear Irregularity Index). From these primary variables, a set of secondary variables were generated. All the seven primary and secondary variables related to the nuclear area were different among groups (Pillai's trace P<0.001), whereas Nuclear Irregularity Index, which is the variable related to nuclear shape, did not differ among groups. The secondary variable 'Average Area of Large Nuclei' was able to differ all pairwise comparisons, including thin nonmetastatic from thin metastatic tumors. In conclusion, the objective quantification of nuclear area in hematoxylin and eosin slides may provide objective information about the risk stratification of these tumors and has the potential to be used as an additional method in clinical decision making.


Assuntos
Biomarcadores Tumorais/metabolismo , Melanoma/diagnóstico , Melanoma/metabolismo , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/metabolismo , Núcleo Celular/metabolismo , DNA de Neoplasias , Tomada de Decisões , Feminino , Humanos , Masculino , Metástase Neoplásica , Estadiamento de Neoplasias , Nevo Pigmentado/metabolismo , Prognóstico , Estudos Retrospectivos , Medição de Risco
12.
J Colloid Interface Sci ; 540: 59-65, 2019 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-30622059

RESUMO

The development of low-cost transition metal electrocatalysts for the oxygen evolution reaction (OER) has been the focus of intense research. Herein, we report for the first time the synthesis of one dimensional (1D) hollow MFe2O4 (M = Cu, Co and Ni) fibers by the Solution Blow Spinning (SBS) technique and their performance towards OER in alkaline medium. The formation mechanism of the hollow structure and the influence of the fibrillar morphology on the performance of electrocatalysts were discussed. Electrocatalytic performance to generate 10 mA cm-2 with low overpotential followed the sequence: CuFe2O4 > CoFe2O4 > NiFe2O4. The improved OER performance of hollow CuFe2O4 fibers is due to a superior number of active sites exposed to surface reactions, confirmed by a remarkable electrochemically active surface area (ECSA) of 225 cm2. Solution blow spun hollow ferrite fibers showed better electrocatalytic activity towards OER than 1D, 2D and 3D ferrite-based nanostructures reported in the literature.

13.
J. Bras. Patol. Med. Lab. (Online) ; 54(6): 372-378, Nov.-Dec. 2018. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-975869

RESUMO

ABSTRACT Introduction: The involvement of the immune system in the process of neoplasms has been increasingly studied due to its potential in antitumor therapy. Objectives: To evaluate the expression of heat shock protein 27 (Hsp27) in tissue samples from invasive ductal carcinomas with and without the presence of axillary sentinel lymph node metastasis, as well as to study the relationship of cell proliferation rate (Ki-76) and apoptosis (caspase 3) compared with samples of fibrocystic change in breast tissue. Methods: Cross-sectional study with tissue samples collected at the Hospital São Lucas, between September 2001 and October 2009, divided into three groups: 1. fibrocystic breast change (control group); 2. invasive ductal carcinoma of the breast with presence of lymph node metastasis; and 3. absence of lymph node metastasis. Results: Increased Hsp27 expression was observed in the group of non-metastasis carcinomas when compared to the other groups. There was difference in Ki-67 protein expression and in the ratio between cell proliferation and apoptosis among the carcinoma groups compared to the control group. However, there was no significant difference between the carcinoma groups or between the expressions of caspase 3 in the three groups, when compared to each other. Conclusion: Quantitative analysis of Hsp27 demonstrated increased protein expression in primary neoplasm tissues and in lymph nodes in carcinomas without axillary sentinel lymph node metastasis. Although the methodology and the number of cases do not allow concluding that this behavior in metastatic disease is a constant finding, this justifies the need to evaluate this finding in future studies.


RESUMO Introdução: O envolvimento do sistema imunológico no processo de neoplasias vem sendo cada vez mais estudado devido ao seu potencial em terapia antitumorais. Objetivos: Avaliar a expressão de heat shock protein 27 (Hsp27) em amostras teciduais de carcinomas ductais invasores com e sem presença de metástase em linfonodo sentinela axilar, bem como estudar a relação da taxa de proliferação celular (Ki-76) e apoptose (caspase 3) em comparação com amostras de alteração fibrocística no tecido mamário. Métodos: Estudo transversal com amostras de tecidos coletados no Hospital São Lucas, entre setembro de 2001 e outubro de 2009, divididas em três grupos: 1. alteração fibrocística da mama (grupo-controle); 2. carcinoma ductal invasor de mama com presença de metástase linfonodal; e 3. sem presença de metástase linfonodal. Resultados: Observou-se expressão aumentada da Hsp27 no grupo de carcinomas sem metástase, quando comparado com os demais grupos. Houve diferença na expressão da proteína Ki-67 e na razão entre proliferação celular e apoptose entre os grupos com carcinoma quando comparados com o grupo-controle. Contudo, não houve diferença significativa entre os grupos com carcinoma ou entre a expressão de caspase 3 nos três grupos, quando comparados entre si. Conclusão: A análise quantitativa da Hsp27 demonstrou maior expressão da proteína nos tecidos da neoplasia primária e nos linfonodos em carcinomas sem metástase em linfonodo sentinela axilar. Embora a metodologia e o número de casos não permitam concluir que esse comportamento na doença metastática seja um achado constante, justifica-se a necessidade de avaliar esse achado em estudos futuros.

14.
Purinergic Signal ; 13(3): 279-292, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28397110

RESUMO

Esophageal cancer is an aggressive tumor and is the sixth leading cause of cancer death worldwide. ATP is well known to regulate cancer progression in a variety of models by different mechanisms, including P2X7R activation. This study aimed to evaluate the role of P2X7R in esophageal squamous cell carcinoma (ESCC) proliferation. Our results show that treatment with high ATP concentrations induced a decrease in cell number, cell viability, number of polyclonal colonies, and reduced migration of ESCC. The treatment with the selective P2X7R antagonist A740003 or siRNA for P2X7 reverted this effect in the KYSE450 cell line. In addition, results showed that P2X7R is highly expressed, at mRNA and protein levels, in KYSE450 lineage. Additionally, KYSE450, KYSE30, and OE21 cells express P2X3R, P2X4R, P2X5R, P2X6R, and P2X7R genes. P2X1R is expressed by KYSE30 and KYSE450, and only KYSE450 expresses the P2X2R gene. Furthermore, esophageal cancer cell line KYSE450 presented higher expression of E-NTPDases 1 and 2 and of Ecto-5'-NT/CD73 when compared to normal cells. This cell line also exhibits ATPase, ADPase, and AMPase activity, although in different levels, and the co-treatment of apyrase was able to revert the antiproliferative effects of ATP. Moreover, results showed high immunostaining for P2X7R in biopsies of patients with esophageal carcinoma, indicating the involvement of this receptor in the growth of this type of cancer. The results suggest that P2X7R may be a potential pharmacological target to treat ESCC and can lead us to further investigate the effect of this receptor in cancer cell progression.


Assuntos
Proliferação de Células/genética , Sobrevivência Celular/genética , RNA Interferente Pequeno/genética , Receptores Purinérgicos P2X7/metabolismo , Trifosfato de Adenosina/metabolismo , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Linhagem Celular Tumoral , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas do Esôfago , Humanos
15.
Eur J Immunol ; 47(4): 646-657, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28294319

RESUMO

Drug-induced liver injury (DILI) is a major cause of acute liver failure (ALF), where hepatocyte necrotic products trigger liver inflammation, release of CXC chemokine receptor 2 (CXCR2) ligands (IL-8) and other neutrophil chemotactic molecules. Liver infiltration by neutrophils is a major cause of the life-threatening tissue damage that ensues. A GRPR (gastrin-releasing peptide receptor) antagonist impairs IL-8-induced neutrophil chemotaxis in vitro. We investigated its potential to reduce acetaminophen-induced ALF, neutrophil migration, and mechanisms underlying this phenomenon. We found that acetaminophen-overdosed mice treated with GRPR antagonist had reduced DILI and neutrophil infiltration in the liver. Intravital imaging and cell tracking analysis revealed reduced neutrophil mobility within the liver. Surprisingly, GRPR antagonist inhibited CXCL2-induced migration in vivo, decreasing neutrophil activation through CD11b and CD62L modulation. Additionally, this compound decreased CXCL8-driven neutrophil chemotaxis in vitro independently of CXCR2 internalization, induced activation of MAPKs (p38 and ERK1/2) and downregulation of neutrophil adhesion molecules CD11b and CD66b. In silico analysis revealed direct binding of GRPR antagonist and CXCL8 to the same binding spot in CXCR2. These findings indicate a new potential use for GRPR antagonist for treatment of DILI through a mechanism involving adhesion molecule modulation and possible direct binding to CXCR2.


Assuntos
Bombesina/análogos & derivados , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Neutrófilos/imunologia , Fragmentos de Peptídeos/farmacologia , Receptores da Bombesina/antagonistas & inibidores , Receptores de Interleucina-8B/metabolismo , Animais , Bombesina/farmacologia , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Doença Hepática Induzida por Substâncias e Drogas/imunologia , Quimiotaxia/efeitos dos fármacos , Humanos , Interleucina-8/metabolismo , Camundongos , Camundongos Endogâmicos , Ativação de Neutrófilo/efeitos dos fármacos , Ligação Proteica , Transdução de Sinais/efeitos dos fármacos
17.
Melanoma Res ; 26(3): 261-6, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26795273

RESUMO

This small exploratory study was designed to test the hypothesis that thin melanoma lesions contain nuclei of two similar phenotypes, in different proportions. In lesions likely to progress to metastatic disease, one of these phenotypes predominates. Histopathological sections from 18 cases of thin melanomas which did not progress to metastasis, and from 10 cases which did progress were imaged and digitized at high resolution, with a total of 2084 and 1148 nuclei, respectively, recorded. Five karyometric features were used to discriminate between nuclei from indolent and from potentially metastatic lesions. For each case, the percentage of nuclei classified by the discriminant function as having come from a potentially metastatic lesion was determined and termed as case classification criterion. Standard histopathological criteria, such as ulceration and high mitotic index, indicated in this material the need for intensive therapy for only one of the 10 participants, as compared with 7/10 identified correctly by the karyometric measure. Using a case classification criterion threshold of 40%, the overall accuracy was 86% in the test set. The proportion of nuclei of an aggressive phenotype may lend itself as an effective prognostic clue for thin melanoma lesions. The algorithm developed in this training set appears to identify those patients at high risk for metastatic disease, and demonstrates a basis for a further study to assess the utility of prognostic clues for thin melanomas.


Assuntos
Melanoma/complicações , Neoplasias Cutâneas/complicações , Feminino , Humanos , Masculino , Melanoma/patologia , Pessoa de Meia-Idade , Metástase Neoplásica , Estudos Retrospectivos , Risco , Neoplasias Cutâneas/patologia
18.
PLoS One ; 8(7): e65833, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23935818

RESUMO

The purpose of this study was to develop and validate a multimedia software application for mobile platforms to assist in the teaching and learning process of design and construction of a skin flap. Traditional training in surgery is based on learning by doing. Initially, the use of cadavers and animal models appeared to be a valid alternative for training. However, many conflicts with these training models prompted progression to synthetic and virtual reality models. Fifty volunteer fifth- and sixth-year medical students completed a pretest and were randomly allocated into two groups of 25 students each. The control group was exposed for 5 minutes to a standard text-based print article, while the test group used multimedia software describing how to fashion a rhomboid flap. Each group then performed a cutaneous flap on a training bench model while being evaluated by three blinded BSPS (Brazilian Society of Plastic Surgery) board-certified surgeons using the OSATS (Objective Structured Assessment of Technical Skill) protocol and answered a post-test. The text-based group was then tested again using the software. The computer-assisted learning (CAL) group had superior performance as confirmed by checklist scores (p<0.002), overall global assessment (p = 0.017) and post-test results (p<0.001). All participants ranked the multimedia method as the best study tool. CAL learners exhibited better subjective and objective performance when fashioning rhomboid flaps as compared to those taught with standard print material. These findings indicate that students preferred to learn using the multimedia method.


Assuntos
Instrução por Computador , Procedimentos Cirúrgicos Dermatológicos/educação , Educação Médica , Software , Estudantes de Medicina , Retalhos Cirúrgicos , Animais , Brasil , Lista de Checagem , Avaliação Educacional , Feminino , Humanos , Masculino , Distribuição Aleatória , Reprodutibilidade dos Testes
19.
J Oral Pathol Med ; 42(3): 235-42, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23157441

RESUMO

BACKGROUND: This study aimed to analyze the oral lesions of chronic paracoccidioidomycosis concerning their histomorphometric, immunohistochemical, and clinical features in a standardized sample. METHODS: Fifty biopsy specimens of oral lesions of chronic paracoccidioidomycosis were submitted to hematoxylin and eosin (H&E), Grocott-Gomori and immunohistochemical staining. Data regarding disease duration and size and number of oral lesions, as well as erythrocytes, leukocytes, lymphocytes, hematocrit, hemoglobin, and erythrocyte sedimentation rate, were collected from medical charts. Granuloma density and number and diameter of buds and fungal cells, and IL-2, TNF-alpha and IFN-gamma expression, as well as clinical and hematological features, were quantified and correlated. RESULTS: Bud diameter was significantly greater in intermediate density granulomas compared to higher density granulomas. The other variables (number of buds, number and diameter of fungi, expression of IL-2, TNF-alpha and IFN-gamma, and clinical and hematological features) did not significantly change with the density of granulomas. There was a positive correlation between bud number and fungal cell number (r = 0.834), bud diameter and fungal cell diameter (r = 0.496), erythrocytes and number of fungi (r = 0.420), erythrocytes and bud number (r = 0.408), and leukocytes and bud number (r = 0.396). Negative correlation occurred between number and diameter of fungi (r = -0.419), bud diameter and granuloma density (r = -0.367), TNF-alpha expression and number of fungi (r = -0.372), and TNF-alpha expression and bud number (r = -0.300). CONCLUSION: The histological, immunological, and clinical features of oral lesions evaluated did not differ significantly between patients in our sample of chronic paracoccidioidomycosis. TNF-alpha levels were inversely correlated with intensity of infection.


Assuntos
Doenças da Boca/microbiologia , Paracoccidioidomicose/patologia , Adulto , Idoso , Biópsia , Sedimentação Sanguínea , Doença Crônica , Contagem de Colônia Microbiana , Eritrócitos/patologia , Feminino , Granuloma/microbiologia , Hematócrito , Hemoglobinas/análise , Humanos , Hifas/citologia , Imuno-Histoquímica , Interferon gama/análise , Interleucina-2/análise , Leucócitos/patologia , Linfócitos/patologia , Masculino , Pessoa de Meia-Idade , Doenças da Boca/sangue , Paracoccidioides/citologia , Paracoccidioidomicose/sangue , Fator de Necrose Tumoral alfa/análise
20.
J Oral Pathol Med ; 41(9): 702-12, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22417074

RESUMO

BACKGROUND: The aim of this study was to compare clodronate and zoledronic acid regarding their influence on the repair of surgical wounds in maxillae (soft tissue wound and tooth extraction) and their relation to osteonecrosis. MATERIAL AND METHODS: Thirty-four Wistar rats were allocated into three groups according to the treatment received: (i) 12 animals treated with zoledronic acid, (ii) 12 animals treated with clodronate and (iii) 10 animals that were given saline solution. All animals were subjected to tooth extractions and surgically induced soft tissue injury. Histological analysis of the wound sites was performed by means of hematoxylin-eosin (H&E) staining and immunohistochemical staining for receptor activator of nuclear factor-kB ligand (RANKL), osteoprotegerin (OPG), von Willebrand factor, and caspase-3. RESULTS: The zoledronic acid group showed higher incidence of non-vital bone than did the clodronate group at the tooth extraction site. At the soft tissue wound site, there were no significant differences in non-vital bone between the test groups. RANKL, OPG, von Willebrand factor, and caspase-3 did not show significant differences between the groups for both sites of surgical procedures. CONCLUSION: Both of the bisphosphonates zoledronic acid and clodronate are capable of inducing maxillary osteonecrosis. Immunohistochemical analysis suggests that the involvement of soft tissues as the initiator of osteonecrosis development is less probable than has been pointed out.


Assuntos
Conservadores da Densidade Óssea/farmacologia , Ácido Clodrônico/farmacologia , Difosfonatos/farmacologia , Imidazóis/farmacologia , Maxila/cirurgia , Animais , Carga Bacteriana , Caspase 3/análise , Tecido Conjuntivo/efeitos dos fármacos , Tecido Conjuntivo/patologia , Epitélio/efeitos dos fármacos , Epitélio/patologia , Feminino , Maxila/efeitos dos fármacos , Maxila/microbiologia , Maxila/patologia , Doenças Maxilares/induzido quimicamente , Doenças Maxilares/patologia , Mucosa Bucal/efeitos dos fármacos , Mucosa Bucal/lesões , Osteonecrose/induzido quimicamente , Osteonecrose/patologia , Osteoprotegerina/análise , Ligante RANK/análise , Ratos , Ratos Wistar , Extração Dentária , Alvéolo Dental/efeitos dos fármacos , Alvéolo Dental/microbiologia , Alvéolo Dental/patologia , Cicatrização/efeitos dos fármacos , Ácido Zoledrônico , Fator de von Willebrand/análise
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