88 research outputs found

    Study of brake wear particle emissions of a minivan on a chassis dynamometer

    Get PDF
    Car brakes appear to be a significant atmospheric pollutant source, with a contribution to total non-exhaust traffic-related PM10 emissions being estimated at approximately 55% in big cities and urban environments (Bukowiecki et al., 2009). Brake wear particle emissions of a minivan running on a chassis dynamometer were measured using a custom sampling system, positioned close to the braking system, under different initial speeds (30 km/h and 50 km/h), deceleration rates (0.5 m/s2, 1.5 m/s2, 2.5 m/s2), and ambient temperatures (0 °C, 15 °C and 25 °C). Braking from 50 km/h to full stop, results in 40–100% more particles compared to 30 km/h, depending on the deceleration rate. It was also found that only 9–50% of the total particles emitted, are released during the braking phase and therefore the most significant amount is released on the following acceleration phase. High brake pad temperature results in a bimodal distribution with the first peak being at 1 μm and the second falling at the nanometer scale at 200 nm. The ambient temperature appears to have a negligible effect on the particle generation. Document type: Articl

    Dysregulation of MicroRNA-34a Expression in Head and Neck Squamous Cell Carcinoma Promotes Tumor Growth and Tumor Angiogenesis

    Get PDF
    MicroRNAs (miRs) are small non-coding RNAs that play an important role in cancer development where they can act as oncogenes or as tumor-suppressors. miR-34a is a tumor-suppressor that is frequently downregulated in a number of tumor types. However, little is known about the role of miR-34a in head and neck squamous cell carcinoma (HNSCC).miR-34a expression in tumor samples, HNSCC cell lines and endothelial cells was examined by real time PCR. Lipofectamine-2000 was used to transfect miR-34a in HNSCC cell lines and human endothelial cells. Cell-proliferation, migration and clonogenic survival was examined by MTT, Xcelligence system, scratch assay and colony formation assay. miR-34a effect on tumor growth and tumor angiogenesis was examined by in vivo SCID mouse xenograft model. Our results demonstrate that miR-34a is significantly downregulated in HNSCC tumors and cell lines. Ectopic expression of miR-34a in HNSCC cell lines significantly inhibited tumor cell proliferation, colony formation and migration. miR-34a overexpression also markedly downregulated E2F3 and survivin levels. Rescue experiments using microRNA resistant E2F3 isoforms suggest that miR-34a-mediated inhibition of cell proliferation and colony formation is predominantly mediated by E2F3a isoform. In addition, tumor samples from HNSCC patients showed an inverse relationship between miR-34a and survivin as well as miR-34a and E2F3 levels. Overexpression of E2F3a completely rescued survivin expression in miR-34a expressing cells, thereby suggesting that miR-34a may be regulating survivin expression via E2F3a. Ectopic expression of miR-34a also significantly inhibited tumor growth and tumor angiogenesis in a SCID mouse xenograft model. Interestingly, miR-34a inhibited tumor angiogenesis by blocking VEGF production by tumor cells as well as directly inhibiting endothelial cell functions.Taken together, these findings suggest that dysregulation of miR-34a expression is common in HNSCC and modulation of miR34a activity might represent a novel therapeutic strategy for the treatment of HNSCC

    Oral squamous cell cancer: early detection and the role of alcohol and smoking

    Get PDF
    Objective: Oral squamous cell carcinoma has a remarkable incidence worldwide and a fairly onerous prognosis, encouraging further research on factors that might modify disease outcome. Data sources: A web-based search for all types of articles published was initiated using Medline/Pub Med, with the key words such as oral cancer, alcohol consumption, genetic polymorphisms, tobacco smoking and prevention. The search was restricted to articles published in English, with no publication date restriction (last update 2010). Review Methods: In this review article, we approach the factors for a cytologic diagnosis during OSCC development and the markers used in modern diagnostic technologies as well. We also reviewed available studies of the combined effects of alcohol drinking and genetic polymorphisms on alcohol-related cancer risk. Results: The interaction of smoking and alcohol significantly increases the risk for aero-digestive cancers. The interaction between smoking and alcohol consumption seems to be responsible for a significant amount of disease. Conclusion: Published scientific data show promising pathways for the future development of more effective prognosis. There is a clear need for new prognostic indicators, which could be used in diagnostics and, therefore a better selection of the most effective treatment can be achieved

    Short-course hypofractionated radiochemotherapy for unresectable locally advanced cancer of the base of tongue: Palliation only? A case report and short review of the literature

    No full text
    We present a case of unresectable cancer of the base of tongue treated with hypofractionated 3D conformal radiotherapy and concomitant chemotherapy. Based on the excellent tumour response in this radiotherapy regimen and international experience in short course treatments we shortly reviewed, we propose that this therapeutic approach could be considered in a curative setting for patients unsuitable for the a standard long course radiochemotherapy schedule. © 2014. The Korean Society for Radiation Oncology

    The molecular basis of immuno-radiotherapy

    No full text
    Purpose: Radiotherapy (RT) and immunotherapy are powerful anti-tumor treatment modalities. Experimental research has demonstrated an important interplay between the cytotoxic effects of RT and the immune system. This systematic review provides an overview of the basics of anti-tumor immunity and focuses on the mechanisms underlying the interplay between RT and immune anti-tumor response that set the molecular basis of immuno-RT. Conclusions: An ‘immunity acquired equilibrium’ mimicking tumor dormancy can be achieved post-irradiation treatment, with the balance shifted toward tumor eradication or regrowth when immune cells’ cytotoxic effects or cancer proliferation rate prevail, respectively. RT has both immunosuppressive and immune-enhancing properties. The latter effect is also known as radio-vaccination. Its mechanisms involve up- or down-regulation of membrane molecules, such as PD-L1, HLA-class-I, CD80/86, CD47, and Fas/CD95, that play a vital role in immune checkpoint pathways and increased cytokine expression (e.g. INFα,β,γ, IL1,2, and TNFα) by cancer or immune cells. Moreover, the interactions of radiation with the tumor microenvironment (fibroblasts, tumor-infiltrating lymphocytes, monocytes, and dendritic cells are also an important component of radio-vaccination. Thus, RT may have anti-tumor vaccine properties, whose sequels can be exploited by immunotherapy agents to treat different cancer subtypes effectively. © Copyright © 2022 Taylor & Francis Group LLC

    Successful Treatment of a Locally Recurrent and Metastatic Malignant Phyllodes Tumor with Accelerated Radiotherapy and Nab-Paclitaxel, Cisplatin, and Liposomal Doxorubicin Chemotherapy

    No full text
    Phyllodes tumors are rare breast lesions of fibroepithelial origin. Malignant transformation with metastases is linked with poor prognosis. We present a case of a 62-year-old woman with a recurrent malignant phyllodes tumor of the breast and lung metastases. The patient was originally presented with a borderline phyllodes tumor (7.4 cm) of the left breast, treated with wide local excision. A year later, the patient returned with palpable left breast masses. On PET-CT, increased uptake of 18F-FDG by large breast tumors was evident. A right lung lesion of metastatic origin was also present. A simple left breast mastectomy was performed. Histopathological report described 2 malignant phyllodes tumors (7 cm and 6.5 cm). One month later, during the CT simulation for radiotherapy planning, encysted fluid in the chest wall and 2 additional pulmonary lesions of the right lung were identified, confirming progressive lung metastatic disease. Both the chest wall and the regional lymph node area were irradiated with hypofractionated and accelerated radiotherapy. Biweekly chemotherapy with albumin-bound paclitaxel, cisplatin, and liposomal doxorubicin was also prescribed at the start of radiotherapy for 12 cycles. At the end of chemotherapy, complete regression of lung metastases was achieved, and there was no evidence of local recurrence. Within 2 years of follow-up, the patient is free of disease and treatment-related toxicities. Accelerated hypofractionated radiotherapy is effective in the locoregional control of malignant phyllodes tumors. The combination of cisplatin with nab-paclitaxel and liposomal doxorubicin chemotherapy has acceptable toxicity and is highly effective in eradicating metastatic lesions. © 2021 S. Karger AG, Basel. Copyright: All rights reserved

    Bone density as a marker of response to radiotherapy in bone metastatic lesions: A review of the published data

    No full text
    Metastases to the bone are presenting in a great percentage of patients with cancer, causing a variety of symptoms, affecting the quality of life and survival of patients. A multidisciplinary approach from different health providers is required for treatment, including radiation oncologists, medical oncologists and surgeons. The role of radiotherapy in the management of bone metastases has long been established through multiple randomized trials. The estimation of response to the therapy is subjective and is based on the palliation of the symptoms that the patients report. However, a quantification of the tumor burden and response to the treatment with the use of an objective method to measure those parameters is a clinical expectation in oncology. The change in bone density in affected areas (mainly lytic) after local radiotherapy, representing the cellular changes that have occurred, is a promising marker of response to treatment. © 2016 by the authors; licensee MDPI, Basel, Switzerland

    Anti-Tumor Immunity and Preoperative Radiovaccination: Emerging New Concepts in the Treatment of Breast Cancer

    No full text
    Neoadjuvant chemotherapy (NACT) for certain breast cancer (BC) subtypes confers significant tumor regression rates and a survival benefit for patients with a complete pathologic response. Clinical and preclinical studies have demonstrated that immune-related factors are responsible for better treatment outcomes, and thus, neoadjuvant immunotherapy (IO) has emerged as a means to further improve patient survival rates. Innate immunological “coldness”, however, of specific BC subtypes, especially of the luminal ones, due to their immunosuppressive tumor microenvironment, hinders the efficacy of immune checkpoint inhibitors. Treatment policies aiming to reverse this immunological inertia are, therefore, needed. Moreover, radiotherapy (RT) has been proven to have a significant interplay with the immune system and promote anti-tumor immunity. This “radiovaccination” effect could be exploited in the neoadjuvant setting of BC and significantly enhance the effects of the already established clinical practice. Modern stereotactic irradiation techniques directed to the primary tumor and involved lymph nodes may prove important for the RT-NACT-IO combination. In this review, we provide an overview and critically discuss the biological rationale, clinical experience, and ongoing research underlying the interplay between neoadjuvant chemotherapy, anti-tumor immune response, and the emerging role of RT as a preoperative adjunct with immunological therapeutic implications in BC. © 2023 by the authors
    corecore