فهرست مطالب

Journal of Biomedical Physics & Engineering
Volume:3 Issue: 3, May-Jun 2013

  • تاریخ انتشار: 1392/07/08
  • تعداد عناوین: 6
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  • B. J. Allan Page 67
    Background
    The fundamental principles of internal targeted alpha therapy for cancer were established many decades ago.The high linear energy transfer (LET) of alpha radiation to the targeted cancer cellscauses double strand breaks in DNA. At the same time, the short range radiation spares adjacent normal tissues. This targeted approach complements conventional external beam radiotherapy and chemotherapy. Such therapies fail on several fronts, such as lack of control of some primary cancers (e.g.glioblastoma multiforme)and to inhibit the development of lethal metastatic cancer after successful treatment of the primary cancer.
    Objective
    This review charts the developing role of systemic high LET, internal radiation therapy.
    Method
    Targeted alpha therapy is a rapidly advancing experimental therapy that holds promise to deliver high cytotoxicity to targeted cancer cells. Initially thought to be indicated for leukemia and micrometastases, there is now evidence that solid tumors can also be regressed.
    Results
    Alpha therapy may be molecular or physiological in its targeting. Alpha emitting radioisotopes such as Bi-212, Bi-213, At-211 and Ac-225 are used to label monoclonal antibodies or proteins that target specifi c cancer cells. Alternatively, Radium-233 is used for palliative therapy of breast and prostate cancers because of its bone seeking properties.
    Conclusion
    Preclinical studies and clinical trials of alpha therapy are discussed for leukemia, lymphoma, melanoma, glioblastoma multiforme, bone metastases, ovarian cancer, pancreatic cancer and other cancers.
  • M.M. Movahedi, A.R. Mehdizadeh, A. Alipour Page 81
    BCI is one of the most intriguing technologies among other HCI systems, mostly because of its capability of recording brain activities. Spelling BCIs, which help paralyzed people to maintain communication, are one of the striking topics in the field of BCI. In this scientific a spelling BCI system with high transfer rate and accuracy that uses SSVEP signals is proposed.In addition, we suggested that LED light sources can provide proper signals for speller BCIs and they can be used in future.
  • Z. Shankayi, S.M.P. Firoozabadi, Z. Saraf Hassan Page 87
    Propose: Standard electroporation and electrochemotherapy caused the endothe- lial cell permeability and reduction in tumor blood flow. The effects of low voltage and high frequency electroporation on the endothelial cells permeability and viability were expected. Therefore, the propose of present study was to evaluate the effect of electroporation with bleomycin or alone on viability and permeabilization of human Embryo microvascular endothelial (HUVEC) cell line.
    Material And Methods
    The HUVEC cells were exposed to 4000 electric pulsed with 100µs duration, 50-150 v/cm with increment of 10 v/cm in 4, 5 and 6 kHz frequency (33 experimental groups) and then uptake and viability reduction was measured in each group.
    Results
    The results of this study demonstrated that electric pulses alone reduce the cell viability and with bleomycin significantly increases the toxicity to endothelial cells.
    Conclusion
    Our data indicated that low voltage, high frequency ECT is highly cytotoxic for a HUVEC cell offers a possible effect of antivascular actions of this kind of electrochemotherapy.
  • Khosro Rezaee, Javad Haddadnia Page 93
    Background
    Breast cancer is currently one of the leading causes of death among women worldwide. The diagnosis and separation of cancerous tumors in mammographic images require accuracy, experience and time, and it has always posed itself as a major challenge to the radiologists and physicians.
    Objective
    This paper proposes a new algorithm which draws on discrete wavelet transform and adaptive K-means techniques to transmute the medical images implement the tumor estimation and detect breast cancer tumors in mammograms in early stages. It also allows the rapid processing of the input data.
    Methods
    In the first step, after designing a filter, the discrete wavelet transform is applied to the input images and the approximate coefficients of scaling components are constructed. Then, the different parts of image are classified in continuous spectrum. In the next step, by using adaptive K-means algorithm for initializing and smart choice of clusters’ number, the appropriate threshold is selected. Finally, the suspicious cancerous mass is separated by implementing the image processing techniques.
    Results
    We Received 120 mammographic images in LJPEG format, which had been scanned in Gray-Scale with 50 microns size, 3% noise and 20% INU from clinical data taken from two medical databases (mini-MIAS and DDSM). The proposed algorithm detected tumors at an acceptable level with an average accuracy of 92.32% and sensitivity of 90.24%. Also, the Kappa coefficient was approximately 0.85, which proved the suitable reliability of the system performance.
    Conclusion
    The exact positioning of the cancerous tumors allows the radiologist to determine the stage of disease progression and suggest an appropriate treatment in accordance with the tumor growth. The low PPV and high NPV of the system is a warranty of the system and both clinical specialists and patients can trust its output.
  • M. Haghani, S. M. J. Mortazavi, R. Faghihi, S. Mehdizadeh, J. Moradgholi, L. Darvish, E. Fathi, Pour, L. Ansari, M. R. Ghanbar, Pour Page 105
    Background
    Nowadays, extensive technological advancements have made it possible to use nanopaints which show exciting properties. In IR Iran excessive radon levels (up to 3700 Bq m–3) have been reported in homes located in radon prone areas. Over the past decades, concerns have been raised about the risk posed by resi- dential radon exposure.
    Objective
    This study aims at investigating the effect of using nanomaterial con- taining wall paints on radon concentration in homes.
    Methods
    Two wooden model houses were used in this study. Soil samples from Ramsar high background radiation areas were used for simulating the situation of a typical house in radon-prone areas. Conventional water-soluble wall paint was used for painting the walls of the 1st house model; while the 2nd house model was painted with the same wall paint with montmorillonite nanoclay.
    Results
    Three days after sealing the house models, radon level was measured by using a portable radon survey meter. The mean radon level inside the 1st house model (conventional paint) was 515.3 ± 17.8 Bq/m3 while the mean radon concentra- tion in the 2nd house model (nano-painted house model) was 570.8 ± 18.5 Bq/m3. The difference between these means was statistically significant (P<0.001).
    Conclusion
    To the best of our knowledge, this study is the first investigation on the effect of nano-material containing wall paints on indoor radon concentrations. It can be concluded that nano-material-containing wall paints should not be used in houses with wooden walls located in radon prone areas. Although the mechanism of this effect is not clearly known, decreased porosity in nano-paints might be a key factor in increasing the radon concentration in homes.
  • Sar Mortazavi, Mb Shojaei, Fard, M. Haghani, N. Shokrpour, Smj Mortazavi Page 109
    Alzheimer’s disease, the most common type of dementia and a progressive neurode-generative disease, occurs when the nerve cells in the brain die. Although there are medications that can help delay the development of Alzheimer’s disease, there is cur-rently no cure for this disease. Exposure to ionizing and non-ionizing radiation may cause adverse health effects such as cancer. Looking at the other side of the coin, there are reports indicating stimulatory or beneficial effects after exposure to cell phone radiofrequency radiation. Mortazavi et al. have previously reported some ben-eficial cognitive effects such as decreased reaction time after human short-term expo-sure to cell phone radiation or occupational exposure to radar microwave radiation. On the other hand, some recent reports have indicated that RF radiation may have a role in protecting against cognitive impairment in Alzheimer’s disease. Although the majority of these data come from animal studies that cannot be easily extrapolated to humans, it can be concluded that this memory enhancing approach may open new horizons in treatment of cognitive impairment in Alzheimer disease.