988 resultados para Malignant neoplasm
Resumo:
The aim of the current study was to evaluate the expression of vascular endothelial growth factor (VEGF) and the microvascular density in canine soft-tissue sarcomas. Immunohistochemistry for VEGF expression was performed on 20 canine neoplasms by the streptavidin-biotin-peroxidase method using an anti-VEGF mouse monoclonal antibody (ab-119). The Volume fraction of microvessels in the sarcomas was quantified in hematoxylin and eosin-stained tissue sections. At least 10 fields of view (40x magnification) per neoplasm were analyzed by positioning a grid with 100 points and counting the microvessels that fell into the intersection points. This percentage was considered the volume fraction of these microvessels in the tumor section. VEGF expression was detected in 65% of the neoplasms. In 92.3% of the neoplasms, the expression occurred in the peritumor region; in 46.15%, in the intratumor region; and in 38.46%, the expression was present in both regions. The cells responsible for VEGF expression were fibroblasts and macrophages in the peritumor region or in the pseudocapsule and neoplastic cells in the intratumor region. Greater intratumoral VEGF was expressed in hemangiopericytomas (P = 0.04). No difference was present in the volume fraction of tumor microvessels between VEGF-positive and VEGF-negative neoplasms (P = 0.3416) or for the different types of neoplasms (P = 0.5). The results of this study suggest that VEGF participates in the angiogenesis of soft-tissue sat-coma in dogs. Additional research will be necessary to elucidate the contribution of VEGF to the progression of malignancy.
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Background: Dermatomyositis (DM) and polymyositis (PM) are rare systemic autoimmune rheumatic diseases with high fatality rates. There have been few population-based mortality studies of dermatomyositis and polymyositis in the world, and none have been conducted in Brazil. The objective of the present study was to employ multiple-cause of-death methodology in the analysis of trends in mortality related to dermatomyositis and polymyositis in the state of Sao Paulo, Brazil, between 1985 and 2007. Methods: We analyzed mortality data from the Sao Paulo State Data Analysis System, selecting all death certificates on which DM or PM was listed as a cause of death. The variables sex, age and underlying, associated or total mentions of causes of death were studied using mortality rates, proportions and historical trends. Statistical analysis were performed by chi-square and H Kruskal-Wallis tests, variance analysis and linear regression. A p value less than 0.05 was regarded as significant. Results: Over a 23-year period, there were 318 DM-related deaths and 316 PM-related deaths. Overall, DM/PM was designated as an underlying cause in 55.2% and as an associated cause in 44.8%; among 634 total deaths females accounted for 71.5%. During the study period, age-and gender-adjusted DM mortality rates did not change significantly, although PM as an underlying cause and total mentions of PM trended lower (p < 0.05). The mean ages at death were 47.76 +/- 20.81 years for DM and 54.24 +/- 17.94 years for PM (p = 0.0003). For DM/PM, respectively, as underlying causes, the principal associated causes of death were as follows: pneumonia (in 43.8%/33.5%); respiratory failure (in 34.4%/32.3%); interstitial pulmonary diseases and other pulmonary conditions (in 28.9%/17.6%); and septicemia (in 22.8%/15.9%). For DM/PM, respectively, as associated causes, the following were the principal underlying causes of death: respiratory disorders (in 28.3%/26.0%); circulatory disorders (in 17.4%/20.5%); neoplasms (in 16.7%/13.7%); infectious and parasitic diseases (in 11.6%/9.6%); and gastrointestinal disorders (in 8.0%/4.8%). Of the 318 DM-related deaths, 36 involved neoplasms, compared with 20 of the 316 PM-related deaths (p = 0.03). Conclusions: Our study using multiple cause of deaths found that DM/PM were identified as the underlying cause of death in only 55.2% of the deaths, indicating that both diseases were underestimated in the primary mortality statistics. We observed a predominance of deaths in women and in older individuals, as well as a trend toward stability in the mortality rates. We have confirmed that the risk of death is greater when either disease is accompanied by neoplasm, albeit to lesser degree in individuals with PM. The investigation of the underlying and associated causes of death related to DM/PM broaden the knowledge of the natural history of both diseases and could help integrate mortality data for use in the evaluation of control measures for DM/PM.
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Diffuse infiltrating gliomas are the most common tumors of the central nervous system. Gliomas are classified by the WHO according to their histopathological and clinical characteristics into four classes: grade I (pilocytic astrocytoma), grade II (diffuse astrocytoma), grade III (anaplastic astrocytoma), and grade IV (glioblastoma multiforme). Several genes have already been correlated with astrocytomas, but many others are yet to be uncovered. By analyzing the public SAGE data from 21 patients, comprising low malignant grade astrocytomas and glioblastomas, we found COL6A1 to be differentially expressed, confirming this finding by real time RT-PCR in 66 surgical samples. To the best of our knowledge, COL6A1 has never been described in gliomas. The expression of this gene has significantly different means when normal glia is compared with low-grade astrocytomas (grades I and II) and high-grade astrocytomas (grades III and IV), with a tendency to be greater in higher grade samples, thus rendering it a powerful tumor marker.
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The survey is aimed at critically reviewing information on the UVA-mediated oxidative reactions to cellular components with emphasis on DNA as the result of mostly photosensitized pathways. It appears clearly that UVA radiation is relatively much more efficient than UVB photons in inducing oxidative processes. The main UVA-induced oxidative degradation pathways of DNA are reported and discussed mechanistically. They are mostly rationalized in terms of a major contribution of singlet molecular oxygen ((1)O(2)) and to a lesser extent of hydroxyl radical ((center dot)OH), that in the latter case originates from Fenton-type reactions. This leads to the predominant formation of 8-oxo-7,8-dihydroguanine together with smaller amounts of oxidized pyrimidine bases and DNA strand breaks in UVA-irradiated cells.
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Background: Mutations in TP53 are common events during carcinogenesis. In addition to gene mutations, several reports have focused on TP53 polymorphisms as risk factors for malignant disease. Many studies have highlighted that the status of the TP53 codon 72 polymorphism could influence cancer susceptibility. However, the results have been inconsistent and various methodological features can contribute to departures from Hardy-Weinberg equilibrium, a condition that may influence the disease risk estimates. The most widely accepted method of detecting genotyping error is to confirm genotypes by sequencing and/or via a separate method. Results: We developed two new genotyping methods for TP53 codon 72 polymorphism detection: Denaturing High Performance Liquid Chromatography (DHPLC) and Dot Blot hybridization. These methods were compared with Restriction Fragment Length Polymorphism (RFLP) using two different restriction enzymes. We observed high agreement among all methodologies assayed. Dot-blot hybridization and DHPLC results were more highly concordant with each other than when either of these methods was compared with RFLP. Conclusions: Although variations may occur, our results indicate that DHPLC and Dot Blot hybridization can be used as reliable screening methods for TP53 codon 72 polymorphism detection, especially in molecular epidemiologic studies, where high throughput methodologies are required.
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The development of cancer is a complex, multistage process during which a normal cell undergoes genetic changes that result in phenotypic alterations and in the acquisition of the ability to invade other sites. Inductively coupled plasma optical emission spectroscopy was used to estimate the contents of Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, P, Pb, and Zn in healthy kidney and renal cell carcinoma (RCC), and significant differences were found for all elements. Along with the progression of the malignant disease, a progressive decrease of Cd and K was observed. In fact, for Cd, the concentration in stage T4 was 263.9 times lower than in stage T1, and for K, the concentration in stage T4 was 1.73 times lower than in stage T1. Progressive accumulation was detected for P, Pb, and Zn in stage T4. For P, the concentration in stage T4 was 11.1 times higher than in stage T1; for Pb, the concentration in stage T4 was 232.7 times higher than in T1; and for Zn, the concentration in T4 was 8.452 times higher than in T1. This study highlights the marked differences in the concentrations of selected trace metals in different malignant tumor stages. These findings indicate that some trace metals may play important roles in the pathogenesis of RCC.
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Aim: To evaluate the sexual functioning of breast cancer patients post mastectomy and its association with their quality of life, the personal characteristics of women and their partners, breast reconstruction, cancer staging and adjuvant therapies. Methods: A cross-sectional study was carried out in a University hospital located in the SouthEast of Brazil. A total of 100 women were included in the study. The parameters evaluated were sexual functioning, which was assessed based on the Sexual Quotient Female Version (SQ-F), quality of life (QoL), evaluated by the Medical Outcomes Study 36-item Short Form (SF-36), cancer staging, breast reconstruction, adjuvant therapies and the personal characteristics of patients (age, years of study and years of marriage) and their partners (age, years of study). Results: The majority (40.48%) of women had an unfavorable to regular SQ-F score. A significant positive correlation (p < 0.05) was found between the SQ-F score and years of education (p = 0.03), and the following SF-36 domains: functional capacity (p = 0.03), vitality (p = 0.06), emotional limitations (p = 0.00) and mental health (p = 0.03). A significant negative correlation was found between SQ-F score and the age of the partners (p = 0.03). SQ-F mean value was significantly higher (p = 0.04) among women who underwent breast reconstruction. Conclusions: Women with low educational level, who have older partners, and who did not have a breast reconstruction should receive special attention with respect to their sexuality, and the effects of mastectomy on the sexuality of patients should be assessed. Oncology nurses are best qualified to recognize issues related to sexuality and quality of life, and can offer specific and meaningful support for breast cancer patients. (C) 2010 Elsevier Ltd. All rights reserved.
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FUNDAMENTS: The lethality of squamous cell carcinomas (SCC) of the skin is considered low. SCC in the mouth is usually associated with poor prognosis. Current evidence suggests that mast cells in the normal tissue contribute to the tumorigenesis of SCC, probably by promoting angiogenesis. OBJECTIVE: The aim of this study was to compare the concentration of mast cells in SCC of the mouth and skin and evaluate whether there is a correlation with the degree of differentiation of these tumors. MATERIAL AND METHODS: Thirty cases of SCC of the skin and 34 of the mouth were investigated. Toluidine blue staining was used to identify mast cells in blocks containing the central portion of the neoplasm. RESULTS: A concentration of between 0 and 10 mast cells was found in one single case of SCC of the skin and there were no cases of SCC of the mouth with concentrations of mast cells in the tumor >201. In the majority of cases of SCC of the mouth (47%; n=16), mast cell concentration was between 0 and 10, with a concentration >51 mast cells in 80% of cases of SCC of the skin. All the cases of SCC of the mouth with a concentration of mast cells between 100 and 200 and 80% of those with a concentration of 51-99 were located on the lip. The concentration of mast cells was unrelated to the degree of differentiation of the tumor. CONCLUSION: The concentration of mast cells is lower in SCC of the mouth except when the tumor is located on the lip. This may reflect a lower need for cell activation in the microenvironment to improve vascularization in oral cancer.
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RECK is an anti-tumoral gene whose activity has been associated with its inhibitory effects regulating MMP-2, MMP-9, and MT1-MMP. RECK level decreases as gliobastoma progresses, varying from less invasive grade II gliomas to very invasive human glioblastoma multiforme (GBM). Since RECK expression and glioma invasiveness show an inverse correlation, the aim of the present study is to investigate whether RECK expression would inhibit glioma invasive behavior. We conducted this study to explore forced RECK expression in the highly invasive T98G human GBM cell line. Expression levels as well as protein levels of RECK, MMP-2, MMP-9, and MT1-MMP were assessed by qPCR and immunoblotting in T98G/RECK+ cells. The invasion and migration capacity of RECK+ cells was inhibited in transwell and wound assays. Dramatic cytoskeleton modifications were observed in the T98G/RECK+ cells, when compared to control cells, such as the abundance of stress fibers (contractile actin-myosin II bundles) and alteration of lamellipodia. T98G/RECK+ cells also displayed phosphorylatecl focal adhesion kinase (P-FAK) in mature focal adhesions associated with stress fibers; whereas P-FAK in control cells was mostly associated with immature focal complexes. Interestingly, the RECK protein was predominantly localized at the leading edge of migrating cells, associated with membrane ruffles. Unexpectedly, introduced expression of RECK effectively inhibited the invasive process through rearrangement of actin filaments, promoting a decrease in migratory ability. This work has associated RECK tumor-suppressing activity with the inhibition of motility and invasion in this GBM model, which are two glioma characteristics responsible for the inefficiency of current available treatments. J. Cell. Biochem. 110: 52-61, 2010. (C) 2010 Wiley-Liss. Inc.
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Pothomorphe umbellata, a native Brazilian plant, is popularly known to be effective in the treatment of skin lesions. This benefit is attributed to 4-nerolidylcatechol (4-NC) a compound extracted from P. umbellata. Since melanomas show prominent resistance to apoptosis and exhibit extreme chemoresistance to multiple forms of therapy, novel compounds addressing induction of cell death are worth investigating. Here, we evaluated effects on cell cycle progression and possible cytotoxic activity of 4-NC in melanoma cell lines as well as human dermal fibroblasts. Inhibitory effects on cell invasion and MMP activity were also investigated. 4-NC showed cytotoxic activity for all melanoma cell lilies tested (IC(50) = 20-40 mu M, 24 h for tumoral cell lines: IC(50) = 50 mu M for fibroblast cell line) associated with its capacity to induce apoptosis. Furthermore, this is the first time that 4-NC is described as an inhibitor of cell invasiveness, due mainly to a G I cell cycle arrest and inhibition of MMP-2 activity in melanoma cell lines. (C) 2008 Elsevier Ltd. All rights reserved.
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Fluoxetine (FIX) is a drug commonly used as antidepressant. However, its effects on tumorigenesis remain controversial. Aiming to evaluate the effects of FIX treatment on early malignant changes, we analyzed serotonin (5-HT) metabolism and recognition, aberrant crypt foci (ACF), proliferative process, microvessels, vascular endothelial growth factor (VEGF), and cyclooxygenase-2 (COX-2) expression in colon tissue. Male Wistar rats received a daily FLX-gavage (30 mg kg(-1)) and, a single dose of 1.2 dimethylhydrazine (DMH; i.p., 125 mg kg(-1)). After 6 weeks of FIX-treatment, our results revealed that FIX and nor-fluoxetine (N-FIX) are present in colon tissue, which was related to significant increase in serotonin (5-HT) levels (P < 0.05) possibly through a blockade in SERT mRNA (serotonin reuptake transporter; P < 0.05) resulting in lower 5-hydroxyindoleacetic acid (5-HIAA) levels (P < 0.01) and, 5-HT2C receptor mRNA expressions. FIX-treatment decreased dysplastic ACF development (P < 0.01) and proliferative process (P < 0.001) in epithelia. We observed a significant decrease in the development of malignant microvessels (P < 0.05), VEGF (P < 0.001), and COX-2 expression (P < 0.01). These findings suggest that FIX may have oncostatic effects on carcinogenic colon tissue, probably due to its modulatory activity on 5-HT metabolism and/or its ability to reduce colonic malignant events. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
Resumo:
The c-myb gene is the cellular homologue of the v-myb oncogenes carried by the avian leukaemia viruses AMV and E26. It encodes a transcription factor (c-Myb), as does each of the viral oncogenes, which recognises the core DNA sequence C/T-A-A-C-G/T-G via a repeated helix-turn-helix-like motif. c-myb is expressed in immature haemopoietic cells, as well as immature cells of the gastro-intestinal epithelium and is down-regulated with differentiation. Enforced expression of activated or even normal forms of Myb can transform haemopoietic cells, most often of the myeloid lineage, in vitro and in vivo. Although many genes have been identified which are likely to be regulated by c-Myb, the critical target genes involved in Myb's transforming activity are not known. Together with data showing increased c-myb expression in colonic tumours, these observations raise the possibility that c-myb may play a role in human malignant disease. (C) 1998 Elsevier Science Ltd. All rights reserved.
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The human papillomaviruses (HPVs) are associated with several human epithelial diseases. These diseases are confined to cutaneous and mucosal epithelia and comprise papillomas (warts) and benign or malignant neoplasms. Globally, infection by HPVs presents a considerable health problem given that at any one time approximately 10% of the population may have warts of one form or another. Of more serious concern is the prevalence of HPV-associated cervical carcinoma. It is estimated that 500,000 new cases of cervical neoplasia are diagnosed per year (primarily squamous carcinomas). Thus, HPV-associated cancer represents one of the most common cancers afflicting women and is one of the three most common causes of cancer death among women globally.(15) Although some genotypes of human papillomaviruses are clearly associated with the development of cancer (in particular, HPVs 16 and 18) these viruses share significant structural and functional similarity to the nononcogenic genotypes, and one of the puzzles of HPV biology is why essentially similar viruses vary so widely in their oncogenic potential.
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Hepatitis C infection is associated with the development of hepatocellular carcinoma, and progress has been made in a number of areas. Transgenic mice lines expressing the hepatitis C core protein develop hepatic steatosis, adenomas, and hepatocellular carcinomas, with no significant hepatitis or fibrosis. This implies that hepatitis C can lead directly to malignant transformation, A new lesion, irregular regeneration, has been described in chronic hepatitis C infection and is associated with a 15-fold increase in the relative risk of developing hepatocellular carcinoma. A minority of patients with hepatitis C-related hepatocellular carcinoma have intense lymphocytic infiltration of the cancer, a feature associated with a better prognosis, Several studies have confirmed the association between large cell dysplasia and hepatocellular carcinoma, However, large cell dysplasia may not be a premalignant lesion and instead may be a marker for premalignant alterations elsewhere in the liver. Oral contraceptives previously have been linked to an increased risk of hepatocellular carcinoma. A large multicenter European case-control study has shown minimal increased risk of hepatocellular carcinoma with use of steroidal contraception. Tamoxifen had shown promise in the management of advanced hepatocellular carcinoma. However, a randomized placebo-controlled study of 477 patients with hepatocellular carcinoma found no benefit from tamoxifen, In a preliminary study, however, octreotide has shown improved survival and quality of life in patients with advanced hepatocellular carcinoma, Finally, interferon treatment continues to be linked to a reduced risk of hepatocellular carcinoma in patients with hepatitis C, These studies generally are not randomized, and a randomized prospective study is required to address this issue. (C) 1999 Lippincott Williams & Wilkins, Inc.
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In a case-control study in three Australian states that included 794 women with epithelial ovarian cancer and 853 community controls for whom we had adequate contraceptive and reproductive histories, Re examined the effects of oral contraceptive use after controlling for estimated number of ovulatory cycles. Other covariates included in the multiple logistic regression analysis were parity, smoking, and history of pelvic surgery. The protective effect of duration of oral contraceptive use appeared to be multiplicative, with a 7% decrease in relative risk per year [95% confidence interval (CI) = 4-9%], persisting beyond 15 years of exposure. Use for up to 1 year may have a greater effect than predicted (odds ratio = 0.57; 95% CI = 0.40-0.82), whereas use before the first pregnancy may be additionally beneficial (odds ratio = 0.95; 95% CI = 0.87-1.03, adjusted for overall duration of use). Better control for ovulatory life might attenuate these estimates somewhat. There was little evidence of waning protection with time since last exposure or of extra benefit with early commencement of oral contraceptive use. We found no convincing evidence of effect modification in any factor examined or differences in effect among the three main histologic cancer types or between borderline and malignant tumors. Oral contraceptives may act by both suppressing ovulation and altering the tumor-promoting milieu.