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1.
Angiogenesis ; 26(1): 129-166, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36183032

RESUMO

Cancer cells are embedded within the tissue and interact dynamically with its components during cancer progression. Understanding the contribution of cellular components within the tumor microenvironment is crucial for the success of therapeutic applications. Here, we reveal the presence of perivascular GFAP+/Plp1+ cells within the tumor microenvironment. Using in vivo inducible Cre/loxP mediated systems, we demonstrated that these cells derive from tissue-resident Schwann cells. Genetic ablation of endogenous Schwann cells slowed down tumor growth and angiogenesis. Schwann cell-specific depletion also induced a boost in the immune surveillance by increasing tumor-infiltrating anti-tumor lymphocytes, while reducing immune-suppressor cells. In humans, a retrospective in silico analysis of tumor biopsies revealed that increased expression of Schwann cell-related genes within melanoma was associated with improved survival. Collectively, our study suggests that Schwann cells regulate tumor progression, indicating that manipulation of Schwann cells may provide a valuable tool to improve cancer patients' outcomes.


Assuntos
Neoplasias , Neuroglia , Humanos , Estudos Retrospectivos , Neuroglia/metabolismo , Células de Schwann/metabolismo , Células de Schwann/patologia , Pericitos , Microambiente Tumoral/fisiologia , Neoplasias/patologia
2.
J Surg Oncol ; 126(1): 139-143, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35689573

RESUMO

BACKGROUND AND OBJECTIVES: Previous studies demonstrated an association between OX40+T cell expression with poor prognosis in gastric cancer (GC). The soluble form of OX40 (sOX40) could block the interactions between OX40 on the effector T cell, and it is a ligand (OX40L) in dendritic cells. However, the role of sOX40 as a pretreating biomarker and prognostic predictor remains unclear. This study aimed to evaluate the association of levels of sOX40 and sOX40L with disease progression in GC. METHODS: Between 2017 and 2018, a cross-sectional study was performed on 83 GC patients and 20 healthy controls. RESULTS: Among 83 GC patients (median of 63 years), 32.4% of patients with I/II stages, 42.3% III, and 25.3% in IV stages. Metastatic GC patients had significantly higher levels of soluble OX40 compared with stage III (p = 0.0003) and early stages I and II patients (p = 0.005). There was no significant differences in the sOX40 and sOX40L levels between Lauren's histological subtype (intestinal, diffuse, and mixed). CONCLUSIONS: This study showed that soluble OX40 levels have an essential role in GC progression. OX40 molecules may constitute a predictor for poor prognosis and a potential target for immunotherapy in GC.


Assuntos
Neoplasias Gástricas , Biomarcadores/metabolismo , Estudos Transversais , Humanos , Neoplasias Gástricas/metabolismo , Linfócitos T/metabolismo
3.
J Surg Oncol ; 126(1): 144-149, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35689579

RESUMO

BACKGROUND AND OBJECTIVES: T cells are central in antitumor immunity in gastric cancer (GC). The inducible costimulatory molecule (ICOS) is a T cell receptor that primarily transmits positive signals for T cell activation and is associated with poor prognosis in GC. In contrast, the costimulatory molecule programmed death 1 (PD-1) is an inhibitory receptor related to tumor immune escape. This study aimed to analyze soluble sites and sPD-1 levels in GC. METHODS: This study enrolled 83 GC patients and 20 healthy controls. RESULTS: The median survival time was 23.22 months in the GC patients. Low levels of sPD-1 and sICOS in GC patients compared to the control group (p = 0.003; p < 0.0001, respectively). High sPD-1 levels in stage IV patients compared to I/II and III stages groups (p = 0.008 and p = 0.0004, respectively). GC patients with stages I and II had higher levels of sICOS compared to III and IV stages (p = 0.0005 and p = 0.02, respectively). There were no significant differences in sPD-1 and sICOS levels between Lauren subtypes. CONCLUSION: These results suggest a predominance of inhibitory costimulatory signals in advanced stages of GC, facilitating tumor immune escape, as the opposite occurs in early stages, resulting in an effective antitumor T-cell-mediated immune response.


Assuntos
Neoplasias Gástricas , Antígeno B7-H1/metabolismo , Humanos , Neoplasias Gástricas/patologia
4.
J Surg Oncol ; 126(1): 125-131, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35689589

RESUMO

BACKGROUND AND OBJECTIVES: Gastric cancer (GC) remains responsible for over one million new cases in 2020. Activated platelets express the CD40 ligand (CD40L) and CD62P in the cytoplasmic membrane, and interaction with the vascular endothelium can induce the production of tumor growth factors and metastases. We aimed to characterize the soluble levels of sCD40L and sCD62P in GC patients. METHODS: A cross-sectional study was performed on 83 GC patients and 20 healthy controls. RESULTS: High levels of sCD40L were obtained in GC patients compared to healthy controls (p = 0.003) and in the I/II compared with III and IV stages (p < 0.0001 and p = 0.007, respectively). Low levels of sCD62P in the GC patients compared to healthy controls (p = 0.009). High soluble levels of sCD62P in I/II compared with III and IV stages (p = 0.002 and p = 0.01, respectively). There are no significant differences in the levels of sCD40L and sCD62P were observed between intestinal, diffuse, and mixed types. CONCLUSIONS: We concluded that sCD40L and sCD62P molecules may be predictive biomarkers since the increase in plasma levels was associated with disease progression and metastasis in GC. In addition, the serum sCD40L and sCD62P can potentially be used as an indicator of response to anticancer therapy.


Assuntos
Neoplasias Gástricas , Biomarcadores/metabolismo , Plaquetas/metabolismo , Ligante de CD40 , Carcinogênese , Transformação Celular Neoplásica/metabolismo , Estudos Transversais , Humanos , Ativação Plaquetária , Neoplasias Gástricas/metabolismo
5.
J Surg Oncol ; 126(1): 20-27, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35689578

RESUMO

BACKGROUND: Risk-reducing operations are an important part of the management of hereditary predisposition to cancer. In selected cases, they can considerably reduce the morbidity and mortality associated with cancer in this population. OBJECTIVES: The Brazilian Society of Surgical Oncology (BSSO) developed this guideline to establish national benchmarks for cancer risk-reducing operations. METHODS: The guideline was prepared from May to December 2021 by a multidisciplinary team of experts to discuss the surgical management of cancer predisposition syndromes. Eleven questions were defined and assigned to expert groups that reviewed the literature and drafted preliminary recommendations. Following a review by the coordinators and a second review by all participants, the groups made final adjustments, classified the level of evidence, and voted on the recommendations. RESULTS: For all questions including risk-reducing colectomy, gastrectomy, and thyroidectomy, a major agreement was achieved by the participants, always using accessible alternatives. CONCLUSION: This and its accompanying article represent the first guideline in cancer risk reduction surgery developed by the BSSO and it should serve as an important reference for the management of families with cancer predisposition.


Assuntos
Neoplasias , Oncologia Cirúrgica , Brasil/epidemiologia , Humanos , Glândula Tireoide
6.
Am J Dent ; 34(5): 281-285, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34689453

RESUMO

PURPOSE: To evaluate the bleaching sensitivity and the bleaching effectiveness of in-office bleaching, following a protocol of complete cervical third protection with gingival dam in comparison with a traditional manner of applying gingival dam (used only in the gingival sulcus area). METHODS: 35 participants were selected for this double-blind split-mouth randomized clinical trial. The control group received the gingival barrier in the traditional manner, and in the experimental group the barrier was extended by about 3 mm to include the cervical region. The bleaching agent was applied in two sessions. The risk and intensity of bleaching sensitivity were assessed using two scales. The bleaching effectiveness was evaluated with a digital spectrophotometer with the tip placed in the cervical area. The absolute risk of bleaching sensitivity was compared by the McNemar's test and bleaching effectiveness (ΔEab, ΔE00 and ΔWi) and intensity of bleaching sensitivity was evaluated by Wilcoxon-paired test (α= 0.05). RESULTS: No significant difference at risk (P= 1.0) and intensity of bleaching sensitivity (P> 0.45) was seen between groups. After 30 days, bleaching effectiveness had no statistical difference between the groups (P> 0.09). CLINICAL SIGNIFICANCE: Extending the barrier in the cervical region of teeth did not reduce the risk and intensity of bleaching sensitivity, nor jeopardize the bleaching effectiveness.


Assuntos
Sensibilidade da Dentina , Clareadores Dentários , Clareamento Dental , Sensibilidade da Dentina/prevenção & controle , Humanos , Peróxido de Hidrogênio , Boca , Ensaios Clínicos Controlados Aleatórios como Assunto , Clareamento Dental/efeitos adversos , Clareadores Dentários/efeitos adversos , Resultado do Tratamento
7.
J Surg Oncol ; 121(5): 901-905, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31858621

RESUMO

BACKGROUND AND OBJECTIVES: The prognosis of colorectal cancer (CRC) has improved in the last decades, however, a lower overall survival persists in the elderly. The understanding of immunity changes in the elderly with CRC will allow the emergence of new treatments with higher response rates. 4-1BB and CD40L, an immune checkpoint stimulator, play an important role in T-cell responses and platelets. Our aim was to characterize the soluble levels of CD40L and 4-1BB in CRC elderly patients. METHODS: A cross-sectional study was performed in 41 patients with CRC and 35 healthy elderly controls. Patients with CRC were divided into three groups according to staging: 13 patients with advanced tumor restricted to the organ (stages II); 16 patients with lymph node metastasis (stage III); and 12 patients with distant metastasis (stage IV). RESULTS: There were higher levels of soluble s4-1BB and sCD40L in CRC elderly stage II patients when compared with healthy controls (P = .0009 and P < .0001, respectively), stage III patients (P = .008 and P < .0001, respectively) and stage IV patients (P = .007 and P < .0001, respectively). CONCLUSIONS: We concluded that sCD40L and s4-1BB molecules may be prognostic biomarkers, since the reduction in plasma levels of these molecules was associated with disease progression.


Assuntos
Ligante de CD40/sangue , Neoplasias Colorretais/mortalidade , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/sangue , Idoso , Biomarcadores Tumorais/sangue , Estudos de Casos e Controles , Neoplasias Colorretais/sangue , Neoplasias Colorretais/patologia , Estudos Transversais , Feminino , Humanos , Metástase Linfática , Masculino , Metástase Neoplásica
8.
Microb Pathog ; 78: 29-36, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25450888

RESUMO

Jorge Lobo's disease is a rare mycosis characterized by chronic inflammation, which causes skin lesions in the absence of visceral dissemination. The disease occurs mainly in hot and humid climates and most cases have been registered in the Brazilian Amazon region. This study investigated possible microvascular alterations in skin lesions caused by infection with Lacazia loboi which may interfere with the clinical progression of the disease. Immunohistochemistry was used to evaluate the density of blood and lymphatic vessels, as well as expression of the cell adhesion molecules ICAM-1, VCAM-1 and E-selectin. The results showed a reduced number of blood (62.66 ± 20.30 vessels/mm(2)) and lymphatic vessels (3.55 ± 5.84 vessels/mm(2)) in Jorge Lobo's disease when compared to control skin (169.66 ± 66.38 blood vessels/mm(2) and 8 ± 2.17 lymphatic vessels/mm(2)). There were a larger number of vessels expressing ICAM-1 (27.58 ± 15.32 vessels/mm(2)) and VCAM-1 (7.55 ± 6.2 vessels/mm(2)). No difference was observed in the expression of E-selectin (4.66 ± 11 vessels/mm(2)). Taken together, the results indicate changes in the local microvasculature which may interfere with the development of an efficient cell-mediated immune response and may explain restriction of the fungus to the site of injury.


Assuntos
Células Endoteliais/patologia , Lacazia/fisiologia , Lobomicose/patologia , Microvasos/patologia , Pele/irrigação sanguínea , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/metabolismo , Brasil , Selectina E/genética , Selectina E/metabolismo , Células Endoteliais/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Molécula 1 de Adesão Intercelular/genética , Molécula 1 de Adesão Intercelular/metabolismo , Lobomicose/genética , Lobomicose/metabolismo , Lobomicose/microbiologia , Masculino , Microvasos/metabolismo , Microvasos/microbiologia , Pessoa de Meia-Idade , Pele/metabolismo , Pele/patologia , Molécula 1 de Adesão de Célula Vascular/genética , Molécula 1 de Adesão de Célula Vascular/metabolismo , Adulto Jovem
9.
Bioorg Med Chem ; 23(15): 4397-4404, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-26122772

RESUMO

Cardiotonic steroids (CS), natural compounds with traditional use in cardiology, have been recently suggested to exert potent anticancer effects. However, the repertoire of molecules with Na,K-ATPase activity and anticancer properties is limited. This paper describes the synthesis of 6 new digoxin derivatives substituted (on the C17-butenolide) with γ-benzylidene group and their cytotoxic effect on human fibroblast (WI-26 VA4) and cancer (HeLa and RKO) cell lines as well as their effect on Na,K-ATPase activity and expression. As digoxin, compound BD-4 was almost 100-fold more potent than the other derivatives for cytotoxicity with the three types of cells used and was also the only one able to fully inhibit the Na,K-ATPase of HeLa cells after 24h treatment. No change in the Na,K-ATPase α1 isoform protein expression was detected. On the other hand it was 30-40 fold less potent for direct Na,K-ATPase inhibition, when compared to the most potent derivatives, BD-1 and BD-3, and digoxin. The data presented here demonstrated that the anticancer effect of digoxin derivatives substituted with γ-benzylidene were not related with their inhibition of Na,K-ATPase activity or alteration of its expression, suggesting that this classical molecular mechanism of CS is not involved in the cytotoxic effect of our derivatives.


Assuntos
Antineoplásicos/síntese química , Compostos de Benzilideno/química , Digoxina/análogos & derivados , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Animais , Antineoplásicos/química , Antineoplásicos/toxicidade , Sítios de Ligação , Encéfalo/enzimologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Digoxina/síntese química , Digoxina/toxicidade , Células HeLa , Humanos , Rim/enzimologia , Simulação de Acoplamento Molecular , Estrutura Terciária de Proteína , Ratos , ATPase Trocadora de Sódio-Potássio/metabolismo
10.
Blood Coagul Fibrinolysis ; 34(1): 70-74, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35946469

RESUMO

Venous thromboembolism (VTE) is an important cause of morbidity/mortality in cancer patients, and COMPASS-CAT score must be used to VTE-risk prediction. There is a relationship between cytokines and thrombus formation and/or resolution. This study aimed to investigate the VTE risk and cytokines level in breast cancer patients prior to chemotherapy with doxorubicin (DOXO). Eighty women with breast cancer and indication for DOXO treatment were selected. TNF, IL-1ß, IL-6, and IL-10 were measured after the diagnosis and immediately before DOXO treatment. All 80 patients presented a high risk for VTE when evaluated by COMPASS-CAT model (score ≥7). A positive correlation was observed between IL-10 plasma levels and VTE risk score. Our data showed that higher IL-10 levels before chemotherapy are associated to increased risk of VTE in breast cancer patients. This finding suggests that IL-10 levels and the combination with COMPASS-CAT score could be good markers to predict increased risk of VTE in these patients.


Assuntos
Neoplasias da Mama , Interleucina-10 , Tromboembolia Venosa , Feminino , Humanos , Doxorrubicina/efeitos adversos , Interleucina-10/sangue , Interleucina-10/química , Fatores de Risco , Trombose/etiologia , Tromboembolia Venosa/etiologia , Neoplasias da Mama/complicações , Neoplasias da Mama/tratamento farmacológico
11.
Int J Biol Macromol ; 210: 530-544, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35513094

RESUMO

Among the most lethal forms of cancer, malignant brain tumors persist as one of the greatest challenges faced by oncologists, where nanotechnology-driven theranostics can play a critical role in developing novel polymer-based supramolecular nanoarchitectures with multifunctional and multi-modal characteristics to fight cancer. However, it is virtually a consensus that, besides the complexity of active delivering anticancer drugs by the nanocarriers to the tumor site, the current evaluation methods primarily relying on in vitro assays and in vivo animal models have been accounted for the low translational effectiveness to clinical applications. In this view, the chick chorioallantoic membrane (CAM) assay has been increasingly recognized as one of the best preclinical models to study the effects of anticancer drugs on the tumor microenvironment (TME). Thus, in this study, we designed, characterized, and developed novel hybrid nanostructures encompassing chemically functionalized carboxymethylcellulose (CMC) with mitochondria-targeting pro-apoptotic peptide (KLA) and cell-penetrating moiety (cysteine, CYS) with fluorescent inorganic semiconductor (Ag-In-S, AIS) for simultaneously bioimaging and inducing glioblastoma cancer cell (U-87 MG, GBM) death. The results demonstrated that the CMC-peptide macromolecules produced supramolecular vesicle-like nanostructures with aqueous colloidal stability suitable as nanocarriers for passive and active targeting of cancer tumors. The optical properties and physicochemical features of the nanoconjugates confirmed their suitability as photoluminescent nanoprobes for cell bioimaging and intracellular tracking. Moreover, the results in vitro demonstrated a notable killing activity towards GBM cells of cysteine-bearing CMC conjugates coupled with pro-apoptotic KLA peptides. More importantly, compared to doxorubicin (DOX), a model anticancer drug in chemotherapy that is highly toxic, these innovative nanohybrids nanoconjugates displayed higher lethality against U-87 MG cancer cells. In vivo CAM assays validated these findings where the nanohybrids demonstrated a significant reduction of GBM tumor progression (41% area) and evidenced an antiangiogenic activity. These results pave the way for developing polymer-based hybrid nanoarchitectonics applied as targeted multifunctional theranostics for simultaneous imaging and therapy against glioblastoma while possibly reducing the systemic toxicity and side-effects of conventional anticancer chemotherapeutic agents.


Assuntos
Antineoplásicos , Neoplasias Encefálicas , Glioblastoma , Pontos Quânticos , Animais , Antineoplásicos/química , Neoplasias Encefálicas/tratamento farmacológico , Carboximetilcelulose Sódica/química , Linhagem Celular Tumoral , Cisteína , Doxorrubicina/química , Glioblastoma/tratamento farmacológico , Nanoconjugados/uso terapêutico , Polímeros/uso terapêutico , Pontos Quânticos/química , Nanomedicina Teranóstica , Microambiente Tumoral
12.
Mem Inst Oswaldo Cruz ; 105(2): 132-6, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20428670

RESUMO

In the present paper, we developed a primary culture of Rhodnius prolixus salivary gland and main salivary canal cells. Cells remained viable in culture for 30 days. Three types of cells were indentified in the salivary gland cultures, with binuclear cells being the most abundant. The supernatants of salivary cultures contained mainly 16-24 kDa proteins and presented anticoagulant and apyrase activities. Secretion vesicles were observed budding from the cellular monolayer of the main salivary canal cells. These results indicate that R. prolixus salivary proteins may be produced in vitro and suggest that the main salivary canal may have a possible secretory role.


Assuntos
Rhodnius/citologia , Glândulas Salivares/citologia , Animais , Técnicas de Cultura de Células , Glândulas Salivares/metabolismo , Proteínas e Peptídeos Salivares/metabolismo
13.
Artigo em Inglês | MEDLINE | ID: mdl-32760596

RESUMO

The authors developed a retinoblastoma model using fresh harvested cells from an enucleated eye that were transplanted in chick embryos (chorioallantoic membrane model). The transplanted embryos were treated with escalating doses of Melphalan. This exploratory model was developed with the goal of testing drug sensitivity. Our findings suggest this tumor model could be employed to personalize treatment for patients with retinoblastoma, especially those with bilateral and more refractory disease.

14.
Curr Top Med Chem ; 18(17): 1475-1482, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30345921

RESUMO

BACKGROUND: A series of symmetrical 1,4-disubstituted bis-1,2,3-triazoles was prepared by double copper catalyzed Azide-alkyne Cycloaddition (CuAAC) from aliphatic bis-azides and a tetraethylene glycol bis-azide derivative. The eighteen novel compounds were evaluated in vitro for their cytotoxic activity against two human tumor cell lines: Human breast adenocarcinoma (MDA-MB 231) and ovarian adenocarcinoma (TOV-21G). RESULTS AND CONCLUSION: The results of colorimetric MTT assays showed that compounds 4j and 4q exhibited a better selectivity index and cell viability comparable with the standard drug doxorubicin. These compounds induced apoptosis in both tested cell lines, as assessed by BrdU assay. The results suggest that these structurally simple compounds may be promising prototypes for antitumoral agents.


Assuntos
Alcinos/química , Antineoplásicos Fitogênicos/farmacologia , Azidas/química , Cobre/química , Triazóis/farmacologia , Antineoplásicos Fitogênicos/síntese química , Antineoplásicos Fitogênicos/química , Catálise , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Reação de Cicloadição , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Relação Estrutura-Atividade , Triazóis/síntese química , Triazóis/química , Células Tumorais Cultivadas
15.
Biopreserv Biobank ; 16(4): 258-269, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29957024

RESUMO

AIM: The present study evaluates the effect of different concentrations of antioxidants (catalase - CAT and alpha lipoic acid - ALA) on the follicular activation and morphology, DNA damage, ROS production, and mitochondrial activity in vitrified sheep ovarian tissue. METHODS: This experiment was divided into two steps. First, ovarian fragments were distributed into the following treatments: fresh tissue or control (CTR), incubation (INC), vitrification without antioxidant (VWA), with CAT (10, 20, or 40 IU mL-1) or ALA (25, 50, or 100 µM mL-1). After vitrification/warming, the fragments were additionally incubated for 24 hours and evaluated for morphology and follicular activation, as well as reactive oxygen species (ROS) levels in the culture medium. For the second step, other ovarian fragments were submitted to CTR, VWA, CAT40, and ALA100. After vitrification/warming, the fragments were incubated for 24 hours and evaluated by cell density of ovarian stroma, DNA damage, and mitochondrial and intracellular ROS levels. RESULTS: The percentage of morphologically normal follicles in vitrified ovarian tissue in the presence of ALA in all concentrations did not differ (p > 0.05) from fresh tissue or CTRs. The percentage of activated follicles was higher in ALA100 µM mL-1 than those observed for the treatments INC, CAT (40 IU mL-1), or ALA (25 or 50 µM mL-1). The use of CAT affected (p < 0.05) the density of stromal cells (40 IU mL-1), ROS levels (10 and 20 IU mL-1), as well as DNA damage revealed by ©H2AX (40 IU mL-1). CONCLUSIONS: Although 100 µM/mL of ALA did not alter intracellular ROS, this concentration reduced the levels of ROS in the culture medium, preserved both the follicular morphology, as well as the mitochondrial activity, promoted follicle activation, and protected the follicles from DNA damage.


Assuntos
Catalase/farmacologia , Criopreservação/métodos , Ovário/citologia , Ovário/metabolismo , Ácido Tióctico/farmacologia , Vitrificação , Animais , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/genética , Feminino , Folículo Ovariano/citologia , Folículo Ovariano/efeitos dos fármacos , Folículo Ovariano/metabolismo , Ovário/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Ovinos
16.
Cytotechnology ; 69(4): 699-710, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28321777

RESUMO

Digoxin is a drug widely used to treat heart failure and studies have demonstrated its potential as anticancer agent. In addition, digoxin presents the potential to interact with a series of other compounds used in medicine. The aim of the present study was to evaluate in vitro the cytotoxicity, genotoxicity and mutagenicity of digoxin and its potential to interact with the mutagen Mitomycin C (MMC). The cytotoxicity of digoxin was assessed by employing the MTT method and the comet assay was performed to assess the genotoxicity of this medicine in CHO-K1 and HeLa cell lines. Besides, the cytokinesis-block micronucleus assay was performed to assess the mutagenicity and the antimutagenicity of this drug. The Ames assay was also performed with TA98 and TA100 strains of S. typhimurium. Results showed that digoxin was cytotoxic, genotoxic and mutagenic for HeLa and CHO-K1 cell lines at concentrations many times higher than those observed in human therapeutic conditions. Nevertheless, an antimutagenic effect against the mutagen MMC was observed on both cell lines in concentrations near those used therapeutically in humans. This chemoprotective effect observed is an interesting finding that should be better explored regarding its impact in anticancer chemotherapy.

18.
Acta Trop ; 98(1): 34-42, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16533494

RESUMO

Mice chronically infected with Schistosoma mansoni develop one of two anatomical forms of hepatic lesions: severe, periportal (pipestem) fibrosis or milder, isolated granulomas. The pathogenesis of periportal fibrosis is poorly understood. In this work we compared mice with either periportal fibrosis or isolated granulomas to identify specific markers of severe pathology. BALB/c or Swiss Webster mice were infected with 30 cercarie, once or six times, and liver biopsies were performed to classify the animals into two pathological groups 16 weeks later. Sixty percent of the animals sacrificed at 20 or 24 weeks had periportal fibrosis, 15-20% had isolated granulomas and the remainder had indeterminate pathology. There was no correlation between frequency of infections or egg burden (eggs/gliver) at 20 and 24 weeks post-infection and the development of periportal fibrosis. Livers with periportal fibrosis at 20 or 24 weeks of infection were characterized by larger areas of fibrotic tissue and greater vascularization compared to livers of mice with isolated granulomas. Plastic casts of the portal vein system showed marked changes in vascular structure in mice with periportal fibrosis, including collateral vessels sprouting from the main portal branches, amputation of the more delicate peripheral ramifications, and distortions of the medium and small branches. Vascular changes were not observed in mice with isolated granulomas. These results suggest that the interaction between schistosome eggs and portal vascular changes is of paramount importance in the development of pipestem fibrosis.


Assuntos
Cirrose Hepática/patologia , Cirrose Hepática/parasitologia , Esquistossomose mansoni/complicações , Animais , Doença Crônica , Cirrose Hepática/etiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C
19.
Vet Microbiol ; 115(1-3): 117-27, 2006 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-16431041

RESUMO

Definition of virulent Streptococcus suis strains is controversial. One successful approach for identification of virulent European strains is differentiation of capsular serotypes (or the corresponding cps types) and subsequent detection of virulence-associated factors, namely the extracellular factor (EF, epf), the muramidase-released protein (MRP, mrp) and the hemolysin suilysin (SLY, sly). In this work we present a novel multiplex PCR (MP-PCR) and an mrp variant PCR for identification and characterization of virulent S. suis strains. These new methods were used to identify association of disease with particular profiles of virulence-associated genes. The MP-PCR allowed identification of S. suis through detection of the housekeeping gene gdh, differentiation of four cps types (1, 2, 7 and 9), and detection of epf, mrp, sly and arcA (arginine deiminase from S. suis). Furthermore, this study describes the first PCR assay for differentiation of at least six mrp variants. Expression of the corresponding size variants of MRP was shown for four of the six mrp variants, but was undetectable for the two larger mrp variants in the particular strains investigated. The results of this study suggest that cps7 strains are associated with pneumonia and that variation of mrp is very pronounced among these strains. Gene profiles of invasive, pneumonia and carrier S. suis isolates by combination of PCR assays allowed differentiation of 24 different genotypes among cps1, 2, 7 and 9 strains. Forty-five percent of the invasive S. suis diseases investigated in this study were caused by only two of these genotypes, namely cps2/mrp+/epf+/sly+ and cps9/mrp(*)/epf-/sly+. Thus, this study demonstrates for the first time a uniform profile of the particular virulence-associated genes for the vast majority of the investigated invasive cps9 strains.


Assuntos
Proteínas de Bactérias/biossíntese , Infecções Estreptocócicas/veterinária , Streptococcus suis/classificação , Streptococcus suis/patogenicidade , Doenças dos Suínos/microbiologia , Fatores de Virulência/genética , Animais , Antígenos de Bactérias/biossíntese , Antígenos de Bactérias/genética , Cápsulas Bacterianas , Proteínas de Bactérias/genética , Sequência de Bases , DNA Bacteriano/análise , Eletroforese em Gel de Poliacrilamida/veterinária , Perfilação da Expressão Gênica/veterinária , Genótipo , Immunoblotting/veterinária , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/veterinária , Infecções Estreptocócicas/microbiologia , Streptococcus suis/genética , Streptococcus suis/isolamento & purificação , Suínos , Virulência
20.
Stud Health Technol Inform ; 217: 1003-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26294601

RESUMO

This study aimed to report on the design and development of a low cost Reverse Walker through a participative development cycle with people undergoing rehabilitation. The creation and fundamentals of the concept are described, as well as the development of prototypes and their provision to subjects with mobility problems. The Reverse Walker benefits the user by promoting a more upright posture and favoring the development of postural balance. Enhancing the mobility of people with disabilities may benefit their independence, social participation and quality of life.


Assuntos
Pessoas com Deficiência/reabilitação , Desenho de Equipamento/economia , Tecnologia Assistiva/economia , Andadores/economia , Idoso , Criança , Redução de Custos , Feminino , Humanos , Masculino , Equilíbrio Postural , Estudo de Prova de Conceito
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