991 resultados para INVASIVE DUCTAL CARCINOMA


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Protoporphyrin IX (PpIX) is a porphyrin derivative that is accumulated in cancerous tissue in consequence of the tumor-specific metabolic alterations. The aim of this study was to evaluate the accumulation of PpIX in mice bearing renal cell carcinoma by spectroscopy analysis. A total of 24 male Balb/c mice, 6 weeks old, were divided into six groups: Normal (without inoculation of tumor cells) and 4, 8, 13, 16, and 20 days after inoculation of tumor cells. The orthotopic tumor model of renal cancer was used. Murine renal cell carcinoma (Renca cells) were inoculated into the subcapsular space of the kidney. Normal and tumor-bearing kidneys in different progression stages were removed and analyzed by ex-vivo spectroscopy and by microscopy, for tumor histometric analysis. Emission spectra were obtained by exciting the samples at 405 nm. Significant differences between normal and tumor-bearing kidneys in autofluorescence shape occurred in the 600-700 nm spectral region. A good correlation was found between emission band intensity at 635 nm and the tumor area.

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Predicting the potential geographical distribution of a species is particularly important for pests with strong invasive abilities. Tetranychus evansi Baker & Pritchard, possibly native to South America, is a spider mite pest of solanaceous crops. This mite is considered an invasive species in Africa and Europe. A CLIMEX model was developed to predict its global distribution. The model results fitted the known records of T. evansi except for some records in dry locations. Dryness as well as excess moisture stresses play important roles in limiting the spread of the mite in the tropics. In North America and Eurasia its potential distribution appears to be essentially limited by cold stress. Detailed potential distribution maps are provided for T. evansi in the Mediterranean Basin and in Japan. These two regions correspond to climatic borders for the species. Mite establishment in these areas can be explained by their relatively mild winters. The Mediterranean region is also the main area where tomato is grown in open fields in Europe and where the pest represents a threat. According to the model, the whole Mediterranean region has the potential to be extensively colonized by the mite. Wide expansion of the mite to new areas in Africa is also predicted. Agricultural issues highlighted by the modelled distribution of the pest are discussed.

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Metalloproteinases, especially metal loprotemase-2 (MMP-2), are known for their role in the degradation of the extracellular matrix. Nevertheless, a thorough understanding of MMP-2 expression in neoplastic lesions of the uterine cervix has yet to be accomplished. This study aimed to analyze the MMP-2 expression in cervical intraepithelial neoplasia III (CIN3) and in cervical squamous cell carcinoma, in tumor cells and adjacent stromal cells. MMP-2 expression was assessed by an immunohistochernical technique. MMP-2 expression was greater in the stromal cells of invasive carcinomas than in CIN3 (p < 0.0001). MMP-2 expression in stromal cells correlates with the clinical stage, gradually increasing as the tumor progresses (p = 0.04). This study corroborates that stromal cells play an important role in tumor invasion and progression, mediated by the progressive enhancement of MMP-2 expression from CIN3 to advanced invasive tumor. The intense MMP-2 expression most probably is associated with poor tumor prognosis.

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Background/purpose: Vitamins C and its derivatives, mainly due to their antioxidant properties, are being used in cosmetic products to protect and to reduce the signs of ageing. However, there are no studies comparing the effects of vitamin C [ascorbic acid (AA)] and its derivatives, magnesium ascorbyl phosphate (MAP) and ascorbyl tetra-isopalmitate (ATIP), when vehiculated in topical formulations, mainly using objective measurements, which are an important tool in clinical efficacy studies. Thus, the objective of this study was to determine the in vitro antioxidant activity of AA and its derivatives, MAP and ATIP, as well as their in vivo efficacy on human skin, when vehiculated in topical formulations. Methods: The study of antioxidant activity in vitro was performed with an aqueous and a lipid system. The in vivo methodology consisted of the application of these formulations on human volunteers` forearm skin and the analysis of the skin conditions after 4-week period daily applications in terms of transepidermal water loss (TEWL), stratum corneum moisture content and viscoelasticity using a Tewameter (R), Corneometer (R) and Cutometer (R), respectively. Results: In vitro experiments demonstrated that in an aqueous system, AA had the best antioxidant potential, and MAP was more effective than ATIP, whereas in the lipid system ATIP was more effective than MAP. In in vivo studies, all formulations enhanced stratum corneum moisture content after a 4-week period daily applications when compared with baseline values; however, only the formulation containing AA caused alterations in TEWL values. The formulations containing MAP caused alterations in the viscoelastic-to-elastic ratio, which suggested its action in the deeper layers of the skin. Conclusion: AA and its derivates presented an in vitro antioxidant activity but AA had the best antioxidant effect. In in vivo efficacy studies, only the formulation containing AA caused alterations in TEWL values and the formulation containing MAP caused alterations in the viscoelastic-to-elastic ratio. This way, vitamin C derivatives did not present the same effects of AA on human skin; however, MAP showed other significant effect-improving skin hydration, which is very important for the normal cutaneous metabolism and also to prevent skin alterations and early ageing.

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Detailed analyses of chromosomal damage in hepatocellular carcinoma have confirmed the results of previous studies that identified regions of significant loss. In addition, these studies examined the clinicopathological correlates of this damage, identified new sites for future investigation, and provided evidence of interactions between genes, The insulin-like growth factor II receptor gene is a target for inactivation through chromosomal loss and mutation, with loss also occurring in the cirrhotic liver. The insulin-like growth factor II receptor gene plays a central role in coordinating the competing actions of insulin-like growth factor and transforming growth factor-beta on cell proliferation. Our understanding of the changes in these growth factor pathways helps explain the apparent increase in risk of hepatocellular carcinoma in diabetic patients and the potential use of urinary transforming growth factor-beta in screening tests. Vaccination for hepatitis B in Taiwan has had a significant effect on the incidence of childhood hepatocellular carcinoma. Universal vaccination should result in a major reduction in the incidence of hepatocellular carcinoma worldwide.

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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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Objective: To determine whether mammographic screening has affected the presentation of invasive breast cancer in Western Australia. Design: Population-based reviews of the presentation of all invasive breast cancers diagnosed in Western Australia in 1989 and 1994. Setting: Western Australia (population 1.8 million), Active recruitment of women aged 50-69 years for mammographic screening began in 1989. Main outcome measures: Size and stage of invasive breast cancers at diagnosis. Results: From 1989 to 1994, the age-standardised incidence rose from 109 to 123 per 100 000 woman-years, based on 584 and 750 cases, respectively. The proportion of all invasive breast cancers detected as a result of a mammogram increased from 9.2% in 1989 to 34.5% in 1994. Among the cases where relevant information was recorded, the proportion of impalpable tumours increased from 7.7% in 1989 to 27.6% in 1994, and the average size of palpable tumours fell. There was an unexpected increase in the proportion of tumours that were negative on assays for oestrogen and progesterone receptors. Conclusions: A relatively simple and inexpensive clinical review has boosted confidence that the outlay of public monies required to establish and conduct screening in Australia appears likely to yield the reductions in mortality from breast cancer that would be predicted on the basis of the earlier controlled trials of mammography.

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BACKGROUND. Sentinel lymph node (SLN) mapping and biopsy is emerging as an alternative to axillary lymph node dissection (ALND) in determining the lymph node status of patients with early-stage breast carcinoma. The hypothesis of the technique is that the SLN is the first lymph node in the regional lymphatic basin that drains the primary tumor. Non-SLN (NSLN) metastasis in the axilla is unlikely if the axillary SLN shows no tumor involvement, and, thus, further axillary interference may be avoided. However, the optimal treatment of the axilla in which an SLN metastasis is found requires ongoing evaluation. The objectives of this study were to evaluate the predictors for NSLN metastasis in the presence of a tumor-involved axillary SLN and to examine the treatment implications for patients with early-stage breast carcinoma. METHODS. Between June 1998 and May 2000, 167 patients participated in the pilot study of SLN mapping and biopsy at Westmead Hospital. SLNs were identified successfully and biopsied in 140 axillae. All study patients also underwent ALND. The incidence of NSLN metastasis in the 51 patients with a SLN metastasis was correlated with clinical and pathologic characteristics. RESULTS. Of 51 patients with a positive SLN, 24 patients (47%) had NSLN metastases. The primary tumor size was the only significant predictor for NSLN involvement. NSLN metastasis occurred in 25% of patients (95% confidence interval [95%CI], 10-47%) with a primary tumor size less than or equal to 20 mm and in 67% of patients (95%CI, 46-83%) with a primary tumor size > 20 mm (P = 0.005). The size of the SLN metastasis was not associated significantly with NSLN involvement. Three of 7 patients (43%) with an SLN micrometastasis (< 1 mm) had NSLN involvement compared with 38 of 44 patients (48%) with an SLN macrometastasis (greater than or equal to 1 mm). CONCLUSIONS. The current study did not identify a subgroup of SLN positive patients in whom the incidence of NSLN involvement was low enough to warrant no further axillary interference. At present, a full axillary dissection should be performed in patients with a positive SLN. (C) 2001 American Cancer Society.

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Background: The trend in breast cancer surgery is toward more conservative operative procedures. The new staging technique of sentinel node biopsy facilitates the identification of pathological node-negative patients in whom axillary dissection may be avoided. However, patients with a positive sentinel node biopsy would require a thorough examination of their nodal status. An axillary dissection provides good local control, and accurate staging and prognostic information to inform decisions about adjuvant therapy. In addition, the survival benefit of axillary treatment is still debated. The objectives of the present study were to examine the pattern of lymph node metastases in the axilla, and evaluate the merits of a level III axillary dissection. Methods : Between June 1997 and May 2000, 308 patients underwent a total of 320 level III dissections as part of their treatment for operable invasive breast cancer. The three axillary levels were marked intraoperatively, and the contents in each level were submitted and examined separately. The patterns of axillary lymph node (ALN) metastases were examined, and factors associated with 4 positive nodes, and level III ALN metastases were evaluated by univariate and multivariate analyses. Results: An average of 25 lymph nodes were examined per case (range: 8-54), and using strict anatomical criteria, the mean numbers of ALN found in levels I, II and III were 18 (range: 2-43), 4 (range: 0 19), and 3 ( range: 0-11), respectively. Axillary lymph node involvement was found in 45% of the cases (143/320). Of the 143 cases, 78% (n = 111) had involvement of level I nodes only, and 21% (n = 30) had positive ALN in levels II and, or, III, in addition to level I. Involvement of lymph nodes in level II or III without a level I metastasis was found in two cases only (0.6%). By including level II, in addition to level I, in the dissection, four cases (1%) were converted from one to three positive nodes to 4 positive nodes (P = 0.64). By the inclusion of level III to a level I and II dissection, three cases (1%) were converted from one to three positive nodes to 4 positive nodes (P = 0.74). Involvement of lymph nodes in level III was found in 22 cases (7%), and 51 cases (16%) had 4 positive nodes. Palpability of ALN, pathological tumour size, and lymphovascular invasion (LVI), were significantly associated with level III involvement and 4 positive nodes by univariate and multivariate analyses. The frequencies of level III involvement and 4 positive nodes in patients with palpable ALN were 22% and 42%, respectively. The corresponding frequencies in patients with a clinically negative axilla, and a primary tumour which was >20 mm and LVI positive, were over 14% and 31%, respectively. Conclusion: Level III axillary dissection is appropriate for patients with palpable ALN, and in those with a tumour which is >20 mm and LVI positive, principally to reduce the risk of axillary recurrence. Staging accuracy is achieved with a level II dissection, or even a level I dissection alone based on strict anatomical criteria. Sentinel node biopsy is a promising technique in identifying pathological node-positive patients in whom an axillary clearance provides optimal local control and staging information.

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in the Apis mellifera post-genomic era, RNAi protocols have been used in functional approaches. However, sample manipulation and invasive methods such as injection of double-stranded RNA (dsRNA) can compromise physiology and survival. To circumvent these problems, we developed a non-invasive method for honeybee gene knockdown, using a well-established vitellogenin RNAi system as a model. Second instar larvae received dsRNA for vitellogenin (dsVg-RNA) in their natural diet. For exogenous control, larvae received dsRNA for GFP (dsGFP-RNA). Untreated larvae formed another control group. Around 60% of the treated larvae naturally developed until adult emergence when 0.5 mu g of dsVg-RNA or dsGFP-RNA was offered while no larvae that received 3.0 mu g of dsRNA reached pupal stages. Diet dilution did not affect the removal rates. Viability depends not only on the delivered doses but also on the internal conditions of colonies. The weight of treated and untreated groups showed no statistical differences. This showed that RNAi ingestion did not elicit drastic collateral effects. Approximately 90% of vitellogenin transcripts from 7-day-old workers were silenced compared to controls. A large number of samples are handled in a relatively short time and smaller quantities of RNAi molecules are used compared to invasive methods. These advantages culminate in a versatile and a cost-effective approach. (c) 2008 Elsevier Ltd. All rights reserved.