45 research outputs found

    Analysis of return distributions in the coherent noise model

    Full text link
    The return distributions of the coherent noise model are studied for the system size independent case. It is shown that, in this case, these distributions are in the shape of q-Gaussians, which are the standard distributions obtained in nonextensive statistical mechanics. Moreover, an exact relation connecting the exponent τ\tau of avalanche size distribution and the q value of appropriate q-Gaussian has been obtained as q=(tau+2)/tau. Making use of this relation one can easily determine the q parameter values of the appropriate q-Gaussians a priori from one of the well-known exponents of the system. Since the coherent noise model has the advantage of producing different tau values by varying a model parameter \sigma, clear numerical evidences on the validity of the proposed relation have been achieved for different cases. Finally, the effect of the system size has also been analysed and an analytical expression has been proposed, which is corroborated by the numerical results.Comment: 14 pages, 3 fig

    Intratumoural chemotherapy with 5-fluorouracil for palliation of bronchial cancer in patients with severe airway obstruction

    No full text
    Patients with tracheal or major airway obstruction owing to inoperable carcinomas are at risk of developing respiratory failure or postobstructive pneumonia. In such cases, there is an urgency to restore the airway. Bronchoscopic interventional procedures for palliation of malignant airway obstruction are becoming more common in clinical practice. However, as current interventional methods may be unavailable or are contraindicated, we have investigated the use of direct intratumoural injection with 5-fluorouracil for tumour regression to open the airway. in this study, 65 patients who presented with greater than 50% obstruction of at least one major airway were treated with 5-fluorouracil injection directly into the endobronchial tumour or area of infiltrated bronchial mucosa through a flexible fiber-optic bronchoscope. The pretreatment luminal opening for this cohort of 65 patients ranged from 0% (totally obstructed) to 40%, with an overall mean luminal opening of 22% (78% occlusion). There was a positive response to intratumoural injection in 56 of 65 patients, and a large reduction in the size of tumours by endoscopic evaluation in the majority of cases. Overall, the mean pretreatment luminal opening of 22.0% was significantly improved to a mean post-treatment luminal opening of 58.5%, an increase in the opening of the airways of 36.5%. The increase in the diameter of the airway lumen was more than 50% for 34 of 65 patients, and 23 showed a 25-50% improvement. The results were of obvious immediate clinical benefit. Statistical analysis of all patient data by a Wilcoxon matched-pairs/sign-ranked test confirmed the significant benefit achieved (P<0.001). The therapy was well tolerated, with no systemic side-effects or any serious complications. The results of this study suggest that in patients with life-threatening airway obstruction, intratumoural injection of anticancer drugs should be regarded as an important new therapeutic approach and an integral part of interventional bronchoscopic management. This study further encourages more general consideration of intratumoural drug injection as a minimally invasive therapeutic method for the treatment of lung cancer and various inoperable cancers

    Intratumoral administration of cisplatin through a bronchoscope followed by irradiation for treatment of inoperable non-small cell obstructive lung cancer

    No full text
    Purpose: Patients presenting-with inoperable non-small cell carcinoma of the lung associated with severe bronchial'obstruction are at a high risk for developing post-obstructive pneumonia or respiratory failure. This often Leads to death in weeks to months. Several studies suggest that initial use of debulking of obstructed airways by Nd-YAG laser photo resection or by cryotherapy lessens morbidity by reducing infections and respiratory insufficiencies. This can shorten hospitalization, improve the quality of life, and prolong survival. It has also been demonstrated that patients first treated for debulking and then by irradiation have better survival than similar patients treated with irradiation atone. Intratumoral (IT) injection of cytotoxic drugs (IT chemotherapy) has also been successfully used to debulk airways. The aim of the present work was to study the effectiveness, safety, and feasibility of initial debulking by IT chemotherapy with cisplatin combined with irradiation with a curative intent in the treatment of obstructive inoperable non-small cell lung cancer

    Prevalence and intra-oral distribution of agenesis of permanent teeth among Eastern Turkish children

    No full text
    Aim The aim of this study was to describe agenesis of permanent teeth, excluding the third molars, in a sample of children in Eastern Turkey

    Intratumoral chemotherapy for lung cancer: re-challenge current targeted therapies

    No full text
    Wolfgang Hohenforst-Schmidt,1 Paul Zarogoulidis,2,3 Kaid Darwiche,3 Thomas Vogl,4 Eugene P Goldberg,5 Haidong Huang,6 Michael Simoff,7 Qiang Li,6 Robert Browning,8 J Francis Turner,9 Patrick Le Pivert,10 Dionysios Spyratos,2 Konstantinos Zarogoulidis,2 Seyhan I Celikoglu,11 Firuz Celikoglu,11 Johannes Brachmann11II Medical Clinic, Coburg Hospital, University of Wuerzburg, Coburg, Germany; 2Pulmonary Department-Oncology Unit, G Papanikolaou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece; 3Department of Interventional Pneumology, Ruhrlandklinik, West German Lung Center, University Hospital, University Duisburg-Essen, Essen, Germany; 4Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Frankfurt, Germany; 5Biomaterials Science and Engineering, Department of Materials Science and Engineering, University of Florida, FL, USA; 6Department of Respiratory Diseases, Changhai Hospital/First Affiliated Hospital of the Second Military Medical University, Shanghai, People&#39;s Republic of China; 7Bronchoscopy and Interventional Pulmonology, Pulmonary and Critical Care Medicine, Henry Ford Hospital, Wayne State University, School of Medicine, MI, USA; 8Pulmonary and Critical Care Medicine, Interventional Pulmonology, National Naval Medical Center, Walter Reed Army Medical Center, Bethesda, USA; 9Pulmonary Medicine, University of Nevada School of Medicine, National Supercomputing Center for Energy and the Environment University of Nevada, Las Vegas, USA; 10Interventional Drug Delivery Systems and Strategies (ID2S2), Medical Cryogenics, Jupiter, FL, USA; 11Pulmonary Department, Cerrahpasa Medical Faculty, University of Istanbul, Istanbul, TurkeyAbstract: Strategies to enhance the already established doublet chemotherapy regimen for lung cancer have been investigated for more than 20 years. Initially, the concept was to administer chemotherapy drugs locally to the tumor site for efficient diffusion through passive transport within the tumor. Recent advances have enhanced the diffusion of pharmaceuticals through active transport by using pharmaceuticals designed to target the genome of tumors. In the present study, five patients with non-small cell lung cancer epidermal growth factor receptor (EGFR) negative stage IIIa&ndash;IV International Union Against Cancer 7 (UICC-7), and with Eastern Cooperative Oncology Group (ECOG) 2 scores were administered platinum-based doublet chemotherapy using combined intratumoral-regional and intravenous route of administration. Cisplatin analogues were injected at 0.5%&ndash;1% concentration within the tumor lesion and proven malignant lymph nodes according to pretreatment histological/cytological results and the concentration of systemic infusion was decreased to 70% of a standard protocol. This combined intravenous plus intratumoral-regional chemotherapy is used as a first line therapy on this short series of patients. To the best of our knowledge this is the first report of direct treatment of involved lymph nodes with cisplatin by endobronchial ultrasound drug delivery with a needle without any adverse effects. The initial overall survival and local response are suggestive of a better efficacy compared to established doublet cisplatin&ndash;based systemic chemotherapy in (higher) standard concentrations alone according to the UICC 7 database expected survival. An extensive search of the literature was performed to gather information of previously published literature of intratumoral chemo-drug administration and formulation for this treatment modality. Our study shows a favorable local response, more than a 50% reduction, for a massive tumor mass after administration of five sessions of intratumoral chemotherapy plus two cycles of low-dose intravenous chemotherapy according to our protocol. These encouraging results (even in very sick ECOG 2 patients with central obstructive non-small cell lung cancer having a worse prognosis and quality of life than a non-small cell lung cancer in ECOG 0 of the same tumor node metastasis [TNM]-stage without central obstruction) for a chemotherapy-only protocol that differs from conventional cisplatin-based doublet chemotherapy by the route, target site, and dose paves the way for broader applications of this technique. Finally, future perspectives of this treatment and pharmaceutical design for intratumoral administration are presented.Keywords: cisplatin, lymph nodes, chemotherapy, intratumoral, lung cance
    corecore