87 resultados para Tumor-growth


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Snake venoms have been used as antineoplastic substances in several experimental models. We demonstrated in previous studies that Bothrops jararaca venom (BjV) induces inhibition of Ehrlich ascites tumor ( EAT) growth accompanied by an increase of mononuclear (MN) leukocytes in all groups inoculated with EAT and/or venom. The objective of the present study was to characterize the subpopulations of MN leukocytes involved in the inhibition of EAT growth by treatment with BjV. Swiss mice were inoculated with 1.0 x 10(3) EAT cells by the intraperitoneal route and treated with 0.4 mg/kg of BjV by the same route ( Group TV). Treatment was started 24 h after tumor cell inoculation and consisted of five intraperitoneal injections performed at 72 h intervals. After 2, 8 and 14 days, groups of animals were sacrificed and the number of B, TCD4 and TCD8 lymphocytes, macrophages and natural killer cells present in the peritoneal cavity was determined by flow cytometry. The control group consisted of animals inoculated with EAT and treated with 0.1 ml of saline under the same conditions as the experimental group ( Group T). Two additional control groups consisted of animals not inoculated with EAT and treated with saline or venom. Data were analyzed statistically by the Kruskal - Wallis nonparametric test for independent samples. on the 2nd and 8th day we observed a difference between groups T and TV ( group T > group TV) for all cell types, except natural killer cells, that only differed on the 2nd day. However, on the 14th day there was no difference in MN cells among groups. These data suggest that the inhibition of EAT is related to the toxic action of BjV on tumor cells and/or to the proteolytic effect of the venom on the mediators produced by the cells for growth modulation.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Objective and Design: To determine the alpha-2-macroglobulin (alpha2M) levels in mice during acute and chronic inflammatory responses. Materials and Methods: Inflammation was induced by one of the following stimuli: carrageenin, zymosan, lipopolysacharide, thioglycollate, bacilli Calmette Guerin, PPD (in pre-immunized and non-immunized animals) and tumor cells. The concentration of alpha2M was determined in plasma or peritoneal liquid by electroimmunoassay. Results: In all the treatments employed, the plasma levels of alpha2M were higher than in untreated animals. This increase varied from 9%, 24 h after injection up a maximum of 66% 72 h post-injection. When compared to animals injected only with saline, the increases were significant 48 h after treatment with either zymosan or LPS, and 72 h after treatment with either thioglycollate or carrageenin. Treatment with BCG triggers an increase in alpha2M levels after 24 h (18.60%) and 48 h (27.90%). Immunized mice presented higher levels of this protein than non-immunized animals after challenge with PPD. The growth of Ehrlich tumor cells in the peritoneal cavity was directly correlated with the local levels of alpha2M which increased 3.5 fold, 10 days after injection. Conclusions: These results strongly indicate that in mice, the concentration of alpha2M can increase during acute and chronic inflammatory reactions with kinetics dependent on the particular kind of inflammatory agent.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Based on the literature data from HT-29 cell monolayers, we develop a model for its growth, analogous to an epidemic model, mixing local and global interactions. First, we propose and solve a deterministic equation for the progress of these colonies. Thus, we add a stochastic (local) interaction and simulate the evolution of an Eden-like aggregate by using dynamical Monte Carlo methods. The growth curves of both deterministic and stochastic models are in excellent agreement with the experimental observations. The waiting times distributions, generated via our stochastic model, allowed us to analyze the role of mesoscopic events. We obtain log-normal distributions in the initial stages of the growth and Gaussians at long times. We interpret these outcomes in the light of cellular division events: in the early stages, the phenomena are dependent each other in a multiplicative geometric-based process, and they are independent at long times. We conclude that the main ingredients for a good minimalist model of tumor growth, at mesoscopic level, are intrinsic cooperative mechanisms and competitive search for space. © 2013 Elsevier Ltd.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

80.00% 80.00%

Publicador:

Resumo:

This paper is devoted to study the 1D model of invasive avascular tumor growth, which takes into account cell division, death, and motility, proposed by Kolobov and collaborators in 2009. First, we examine the existence and uniqueness of the solution to this model. Second, we studied qualitatively and numerically the traveling wave solutions. Finally, we show some numerical simulations for the cell density and nutrient concentration. © 2013 NSP Natural Sciences Publishing Cor.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

WE previously demonstrated that Bothrops jararaca venom (BjV) has an antitumor effect on Ehrlich ascites tumor (EAT) cells and induces an increase of polymorphonuclear leukocytes in early stages of tumor growth. It has been reported that this venom presents an important inflammatory effect when inoculated in animal models and in human snake-bites, and that cytokine levels have been detected in these cases. To evaluate whether the cytokines can be involved with the suppression of the tumoral growth, we evaluate the cytokine profile in the peritoneal cavity of mice inoculated with EAT cells and treated with BjV. Swiss mice were inoculated with EAT cells by the intraperitoneal route and treated with BjV venom (0.4 mg/kg, intraperitoneally), on the 1st, 4th, 7th, 10th, and 13th day. Mice were evaluated for cytokine levels on the 2nd, 5th, 8th, 11th and 14th day. Analysis was performed using an enzyme-linked immunosorbent assay for interleukin (IL)-1α, IL-2, IL-4, IL-6, IL-10, IL-13, and tumor necrosis factor-α (TNF-α) levels in the peritoneal washing supernatant. Results were analyzed statistically by the Kruskal-Wallis and Dunn's tests at the 5% level of significance. We observed that EAT implantation induces IL-6 production on the 11th and 14th days of tumor growth, IL-10 on the 11th day and TNF-α on the 14th day. The treatment with BjV suppresses production of these cytokines. In addition, IL-13 was produced by animals that were inoculated only with venom on the 11th and 14th days, and by the group inoculated with EAT cells and treated with venom on the 2nd and 14th days. Furthermore, we suggest that the IL-6 detected in the present study is produced by the EAT cells and the suppression of its production could be associated with the antitumor effect of BjV.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Bone tumor incidence in women peaks at age 50-60, coinciding with the menopause. That estrogen (E2) and triiodothyronine (T3) interact in bone metabolism has been well established. However, few data on the action of these hormones are available. Our purpose was to determine the role of E2 and T3 in the expression of bone activity markers, namely alkaline phosphatase (AP) and receptor activator of nuclear factor κB ligand (RANKL). Two osteosarcoma cell lines: MG-63 (which has both estrogen (ER) and thyroid hormone (TR) receptors) and SaOs-29 (ER receptors only) were treated with infraphysiological E2 associated with T3 at infraphysiological, physiological, and supraphysiological concentrations. Real-time RT-PCR was used for expression analysis. Our results show that, in MG-63 cells, infraphysiological E2 associated with supraphysiological T3 increases AP expression and decreases RANKL expression, while infraphysiological E2 associated with either physiological or supraphysiological T3 decreases both AP and RANKL expression. On the other hand, in SaOs-2 cells, the same hormone combinations had no significant effect on the markers' expression. Thus, the analysis of hormone receptors was shown to be crucial for the assessment of tumor potential growth in the face of hormonal changes. Special care should be provided to patients with T3 and E2 hormone receptors that may increase tumor growth. Copyright © 2007 John Wiley & Sons, Ltd.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

The aim of this study is to report the case of a quick growing brown tumour in the jaw after a parathyroidectomy due to the presence of a rare fifth parathyroid gland. The patient had chronic renal disease and the diagnosis was tertiary hyperparathyroidism. Thirty days after the parathyroidectomy, the patient returned with a significant increase in the tumour size. The suspicion of a supernumerary gland was confirmed by parathyroid scintigraphy. The treatment of brown tumour is dependent on the treatment of the hyperparathyroidism. However, curettage should be considered if a large lesion is disturbing mastication. In conclusion, this case should attract the attention of general practitioner dentists, since they may be the first professionals who have contact with the patient with a brown tumour in the jaws. Likewise, this case emphasises the importance of knowing the type of hyperparathyroidism involved to allow for effective treatment planning. © 2011 European Association for Cranio-Maxillo-Facial Surgery.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Introduction. Granular cell tumor is an uncommon neoplasm that can occur in any part of the body, including the orofacial region. The tumor is usually benign, but there are reports of cases in which the tumor shows a locally aggressive behavior, malignancy, and distant metastases. The most widely accepted hypothesis is that granular cell tumor arises from the altered metabolism of Schwann cells. The tumor is typically asymptomatic and appears as a nodule that does not exceed 3 cm. Case presentation. In case 1, a 26-year-old Caucasian man was seen at the Oral Medicine out-patient clinic of the São José dos Campos Dental School, Universidade Estadual Paulista, with a 'small blister on the tongue', which he had noted approximately three years ago. The nodule was located on the dorsum of the tongue, measured about 1.5 cm in diameter, and was not tender to palpation. Treatment consisted of an excisional biopsy performed on the basis of the diagnostic hypothesis of granular cell tumor, which was confirmed by microscopic analysis. In case 2, a 31-year-old Caucasian woman attended the out-patient clinic of the São José dos Campos Dental School, Universidade Estadual Paulista, with a five-year history of a 'painful lump on the tongue'. Intra-oral examination revealed the presence of a nodular lesion measuring approximately 0.8 cm in diameter, which was located deep in the submucosa of the right lateral margin of the tongue. Treatment consisted of an excisional biopsy performed on the basis of the differential diagnosis of neurofibroma and granular cell tumor. Microscopic analysis defined the final diagnosis of granular cell tumor. Conclusions: Granular cell tumor is an uncommon tumor that must be carefully diagnosed and treated correctly. © 2012 Sena Costa et al; licensee BioMed Central Ltd.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

The objective of this work was to evaluate photodynamic therapy (PDT) by using a hematoporphyrin derivative as a photosensitizer and light-emitting diodes (LEDs) as light source in induced mammary tumors of Sprague-Dawley (SD) rats. Twenty SD rats with mammary tumors induced by DMBA were used. Animals were divided into four groups: control (G1), PDT only (G2), surgical removal of tumor (G3), and submitted to PDT immediately after surgical removal of tumor (G4). Tumors were measured over 6 weeks. Lesions and surgical were LEDs lighted up (200 J/cm2 dose). The light distribution in vivo study used two additional animals without mammary tumors. In the control group, the average growth of tumor diameter was approximately 0.40 cm/week. While for PDT group, a growth of less than 0.15 cm/week was observed, suggesting significant delay in tumor growth. Therefore, only partial irradiation of the tumors occurred with a reduction in development, but without elimination. Animals in G4 had no tumor recurrence during the 12 weeks, after chemical induction, when compared with G3 animals that showed 60 % recurrence rate after 12 weeks of chemical induction. PDT used in the experimental model of mammary tumor as a single therapy was effective in reducing tumor development, so the surgery associated with PDT is a safe and efficient destruction of residual tumor, preventing recurrence of the tumor. © 2012 Springer-Verlag London Ltd.