Locality hypothesis and the speed of light

The locality hypothesis is generally considered necessary for the study of the kinematics of non-inertial systems in special relativity. In this paper we discuss this hypothesis, showing the necessity of an improvement, in order to get a more clear understanding of the various concepts involved, like coordinate velocity and standard velocity of light. Concrete examples are shown, where these concepts are discussed.Comment: 23 page

Diversidade de minhocas e atributos químicos em sistemas de plantio direto e integração lavoura-pecuária do oeste catarinense.

Resumo também apresentado no CONGRESSO DE INICIAÇÃO CIENTÍFICA E PÓS-GRADUAÇÃO, 2., 2012, São Leopoldo. Mostra de iniciação científica da UNISINOS. São Leopoldo: Casa Leiria, 2012. e-book. II CICPG. Disposição dos autores: ORSO, R.; BARTZ, M. L. C.; BROWN, G. G.; KLAUBER FILHO, O.; ROSA, M. G. da; LOCATELLI, M.; ZORTÉA, T.; CASAROTTO, K.; DECÄENS, T.; BARETTA, D

Young Women with Locally Advanced Breast Cancer Who Achieve Breast Conservation after Neoadjuvant Chemotherapy Have a Low Local Recurrence Rate

Women with locally advanced breast cancer (LABC) who are breast conservation (BCT) candidates after neoadjuvant chemotherapy have the best long-term outcome and low local–regional recurrence (LRR) rates. However, young women are thought to have a higher risk of LRR based on historical data. This study sought to evaluate LRR rates in young women who undergo BCT after neoadjuvant chemotherapy. We identified 122 women aged 45 years or younger with American Joint Committee on Cancer (AJCC) Stage II to III breast cancer, excluding T4d, treated with neoadjuvant chemotherapy from 1991 to 2007 from a prospective, Institutional Review Board-approved, single-institution database. Data were analyzed using Fisher eExact test, Wilcoxon tests, and the Kaplan-Meier method. Median follow-up was 6.4 years. Fifty-four (44%) patients had BCT and 68 (56%) mastectomy. Forty-six per cent were estrogen receptor-positivity and 28 per cent overexpressed Her2. Mean pretreatment T size was 5.6 cm in the BCT group and 6.7 cm in the mastectomy group (P = 0.04). LRR rates were no different after BCT compared with mastectomy (13 vs 18%, P = 0.6). Higher posttreatment N stage (P <0.001) and AJCC stage (P = 0.008) were associated with LRR but not pretreatment staging. Disease-free survival was better for patients achieving BCT, with 5-year disease-free survival rates of 82 per cent (95% CI, 69 to 90%) compared with 58 per cent (95% CI, 45 to 69%) for mastectomy (P = 0.03). Young women with LABC who undergo BCT after neoadjuvant chemotherapy appear to have similar LRR rates compared with those with mastectomy. This suggests that neoadjuvant chemotherapy may identify young women for whom BCT may have an acceptable risk of LRR

Internal mammary lymph node recurrence: rare but characteristic metastasis site in breast cancer

<p>Abstract</p> <p>Background</p> <p>To assess the frequency of IMLN recurrence, its associated risk factors with disease-free interval (DFI) and its predicting factors on overall survival time.</p> <p>Methods</p> <p>133 cases of breast cancer IMLN recurrence were identified via the computerized CT reporting system between February 2003 and June 2008, during which chest CT for patients with breast cancer (n = 8867) were performed consecutively at Cancer Hospital, Fudan University, Shanghai, China. Patients' charts were retrieved and patients' characteristics, disease characteristics, and treatments after recurrence were collected for analysis. The frequency was 1.5% (133/8867).</p> <p>Results</p> <p>IMLN recurrence was presented as the first metastatic site in 121 (91%) patients while 88 (66.2%) had other concurrent metastases. Typical chest CT images included swelling of the IMLN at the ipsilateral side with local lump and sternal erosion located mostly between the second and third intercostal space. The median disease-free interval (DFI) of IMLN recurrence was 38 months. The independent factors that could delay the IMLN recurrence were small tumor size (HR 0.5 95%CI: 0.4 - 0.8; <it>p </it>= 0.002), and positive ER/PR disease (HR 0.6, 95% CI: 0.4 - 0.9; <it>p </it>= 0.006). The median survival time after IMLN recurrence was 42 months, with a 5-year survival rate of 30%. Univariate analysis showed four variables significantly influenced the survival time: DFI of IMLN recurrence (p = 0.001), no concurrent distant metastasis (p = 0.024), endocrine therapy for patients with positive ER/PR (p = 0.000), radiotherapy (p = 0.040). The independent factors that reduced the death risk were no concurrent distant metastases (HR: 0.7, 95% CI: 0.4 - 0.9; <it>p </it>= 0.031), endocrine therapy for patients with positive ER/PR status (HR: 0.2, 95% CI: 0.1 - 0.5; <it>p </it>= 0.001) and palliative radiotherapy (HR: 0.3, 95% CI: 0.1- 0.9; <it>p </it>= 0.026).</p> <p>Conclusions</p> <p>The risk of IMLN recurrence is low and there are certain characteristics features on CT images. ER/PR status is both a risk factor for DFI of IMLN recurrence and a prognostic factor for overall survival after IMLN recurrence. Patients with only IMLN recurrence and/or local lesion have a good prognosis.</p

Contraindications of sentinel lymph node biopsy: Áre there any really?

BACKGROUND: One of the most exciting and talked about new surgical techniques in breast cancer surgery is the sentinel lymph node biopsy. It is an alternative procedure to standard axillary lymph node dissection, which makes possible less invasive surgery and side effects for patients with early breast cancer that wouldn't benefit further from axillary lymph node clearance. Sentinel lymph node biopsy helps to accurately evaluate the status of the axilla and the extent of disease, but also determines appropriate adjuvant treatment and long-term follow-up. However, like all surgical procedures, the sentinel lymph node biopsy is not appropriate for each and every patient. METHODS: In this article we review the absolute and relative contraindications of the procedure in respect to clinically positive axilla, neoadjuvant therapy, tumor size, multicentric and multifocal disease, in situ carcinoma, pregnancy, age, body-mass index, allergies to dye and/or radio colloid and prior breast and/or axillary surgery. RESULTS: Certain conditions involving host factors and tumor biologic characteristics may have a negative impact on the success rate and accuracy of the procedure. The overall fraction of patients unsuitable or with multiple risk factors that may compromise the success of the sentinel lymph node biopsy, is very small. Nevertheless, these patients need to be successfully identified, appropriately advised and cautioned, and so do the surgeons that perform the procedure. CONCLUSION: When performed by an experienced multi-disciplinary team, the SLNB is a highly effective and accurate alternative to standard level I and II axillary clearance in the vast majority of patients with early breast cancer

Breast tumour angiogenesis

The central importance of tumour neovascularization has been emphasized by clinical trials using antiangiogenic therapy in breast cancer. This review gives a background to breast tumour neovascularization in in situ and invasive breast cancer, outlines the mechanisms by which this is achieved and discusses the influence of the microenvironment, focusing on hypoxia. The regulation of angiogenesis and the antivascular agents that are used in an antiangiogenic dosing schedule, both novel and conventional, are also summarized