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1.
J Biomed Phys Eng ; 11(1): 1-8, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33564634

ABSTRACT

BACKGROUND: Radiotherapy has become a part of therapeutic process of more than 50 percent of patients suffering from cancer. However, recent studies have shown that radiation therapy might affect the expression of adhesive molecule related genes such as E-cadherin and cause cancer cells to move and migrate. Besides, various studies have reported that the expression of E-cadherin changes differently after radiation treatment. There are several studies which showed the loss of E-cadherin function after radiation; however, this reduction has not been observed in others. OBJECTIVE: This study aims to investigate the effect of different radiation doses of X-ray on changes that might occur in the expression of E-cadherin gene in colorectal cancer cell line HT-29. MATERIAL AND METHODS: In this experimental study, the cells cultured in flasks were irradiated with X- rays in different doses, including 0.1, 2.5, 5, and 10 Gy; then, the expression of E-cadherin gene was measured using real-time PCR. RESULTS: The expression of E-cadherin did not change significantly in post-irradiated HT-29 cell line after different radiation doses of X-ray. CONCLUSION: The results showed that low, medium and high doses of X- radiation did not change the expression of E-cadherin gene in HT-29 cancer cells. However, it has been reported that radiation mostly downregulated the expression of E-cadherin and mediated metastasis formation and invasiveness in different cancer cell lines. Therefore, further studies need to be conducted to investigate the effects of radiation dose on the molecular pathways contributing to regulation of E-cadherin in HT-29 cell line.

3.
J Biomed Phys Eng ; 9(1): 81-88, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30881937

ABSTRACT

BACKGROUND: Osteoporosis is a systemic skeletal disease characterized by low bone mineral density (BMD) and micro-architectural deterioration of bone tissue, leading to bone fragility and increased fracture risk. Since Panoramic image is a feasible and relatively routine imaging technique in dentistry; it could provide an opportunistic chance for screening osteoporosis. In this regard, numerous panoramic derived indices have been developed and suggested for osteoporosis screening. Jaw trabecular pattern is one of the main bone strength factors and trabecular bone pattern assessment is important factor in bone quality analysis. Texture analysis applied to trabecular bone images offers an ability to exploit the information present on conventional radiographs. OBJECTIVE: The purpose of this study was to evaluate the relationship between Jaw trabecular pattern in panoramic image and osteoporosis based on image texture analyzing using local binary pattern. MATERIAL AND METHODS: An experiment is evaluated in this paper based on a real hand-captured database of panoramic radiograph images from osteoporosis and non-osteoporosis person in Namazi Hospital, Shiraz, Iran .An approach is proposed for osteoporosis diagnosis consisting of two steps. First, modified version of local binary patterns is used to extract discriminative features from jaw panoramic radiograph images. Then, classification is done using different classifiers. RESULTS: Comparative results show that the proposed approach provides classification accuracy about 99.6%, which is higher than many state-of-the-art methods. CONCLUSION: High classification accuracy, low computational complexity, multi-resolution and rotation invariant are among advantages of our proposed approach.

4.
J Biomed Phys Eng ; 9(6): 589-590, 2019 Dec.
Article in English | MEDLINE | ID: mdl-32039088
6.
J Biomed Phys Eng ; 8(2): 217-222, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29951449

ABSTRACT

The aim of this report is to present a new two-piece thyroid-neck phantom produced by the concurrent use of epoxy resin and poly(methyl methacrylate) (PMMA: plexiglass) soft tissue equivalent materials. Accordingly, mass attenuation coefficients of the epoxy resin and the plexiglass compounds were obtained from simulation (NIST XCOM 3.1) and measurements (practical dosimetry) and compared to those related to human soft tissue (ICRU 44). The thyroid-neck phantom and thyroid gland dimensions were derived from scientific references and the atlas of human anatomy, respectively. The thyroid phantom was designed by CATIA V5R16 software and produced by the epoxy resin compound by three-dimensional printer. Other organs were designed by ProNest software and made by the plexiglass sheets by CNC laser cutting machine. The mass attenuation coefficients for the epoxy resin (50 keV- 20 MeV) and the plexiglass (0-20 MeV) were comparable to human soft tissue (ICRU 44), all with standard relative deviation beneath 5%. In addition, the SPECT images indicated the similarity between human thyroid tissue and its phantom. In conclusion, this study proves the feasibility and reliability of epoxy resin application in the production of two-piece thyroid-neck phantom. This phantom can be applied in the calibration of gamma camera systems, dosimetry and gamma spectrometry in the nuclear medicine field.

7.
Colorectal Dis ; 20 Suppl 1: 49-51, 2018 05.
Article in English | MEDLINE | ID: mdl-29878676

ABSTRACT

The great challenge for oncologists treating patients who are developing or progressing with metastatic disease is to be able to offer a truly personalized and targeted therapy that can have an early and meaningful effect on the course of the disease. At present the known molecular markers are limited in their frequency and reliability in determining the use of newer chemotherapies. Professor Eng discusses the challenges faced in ensuring timely and effective treatments based on the molecular profile of the tumour and the potential role of real-time analysis of mutational changes in the tumour when progression occurs.


Subject(s)
Gene Expression Regulation, Neoplastic , Neoplasms/genetics , Neoplasms/therapy , Precision Medicine/methods , Antineoplastic Agents/therapeutic use , Biomarkers, Tumor/analysis , DNA Mutational Analysis , Female , Forecasting , Humans , Male , Molecular Targeted Therapy/methods , Neoplasms/pathology , Treatment Outcome
8.
J Biomed Phys Eng ; 8(1): 1-2, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29732335
9.
J Biomed Phys Eng ; 8(1): 141-146, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29732349

ABSTRACT

A large body of evidence now indicates that the amount of mercury released from dental amalgam fillings can be significantly accelerated by exposure to radiofrequency electromagnetic fields (RF-EMFs) such as common mobile phones and magnetic resonance imaging (MRI). Studies performed on the increased microleakage of dental amalgam restorations after exposure to RF-EMFs have further supported these findings. Although the accelerated microleakage induced by RF-EMFs is clinically significant, the entire mechanisms of this phenomenon are not clearly understood. In this paper, we introduce "Triple M" effect, a new evidence-based theory which can explain the accelerated microleakage of dental amalgam fillings after exposure to different sources of electromagnetic radiation. Based on this theory, there are saliva-filled tiny spaces between amalgam and the tooth. Exposure of the oral cavity to RF-EMFs increases the energy of these small amounts of saliva. Due to the small mass of saliva in these tiny spaces, a small amount of energy will be required for heating. Moreover, reflection of the radiofrequency radiation on the inner walls of the tiny spaces causes interference which in turn produces some "hot spots" in these spaces. Finally, formation of gas bubbles in response to increased temperature and very rapid expansion of these bubbles will accelerate the microleakage of amalgam. Experiments that confirm the validity of this theory are discussed.

10.
Br J Dermatol ; 178(3): 715-721, 2018 03.
Article in English | MEDLINE | ID: mdl-29080368

ABSTRACT

BACKGROUND: A core outcomes set (COS) is an agreed minimum set of outcomes that should be measured and reported in all clinical trials for a specific condition. Hidradenitis suppurativa (HS) has no agreed-upon COS. A central aspect in the COS development process is to identify a set of candidate outcome domains from a long list of items. Our long list had been developed from patient interviews, a systematic review of the literature and a healthcare professional survey, and initial votes had been cast in two e-Delphi surveys. In this manuscript, we describe two in-person consensus meetings of Delphi participants designed to ensure an inclusive approach to generation of domains from related items. OBJECTIVES: To consider which items from a long list of candidate items to exclude and which to cluster into outcome domains. METHODS: The study used an international and multistakeholder approach, involving patients, dermatologists, surgeons, the pharmaceutical industry and medical regulators. The study format was a combination of formal presentations, small group work based on nominal group theory and a subsequent online confirmation survey. RESULTS: Forty-one individuals from 13 countries and four continents participated. Nine items were excluded and there was consensus to propose seven domains: disease course, physical signs, HS-specific quality of life, satisfaction, symptoms, pain and global assessments. CONCLUSIONS: The HISTORIC consensus meetings I and II will be followed by further e-Delphi rounds to finalize the core domain set, building on the work of the in-person consensus meetings.


Subject(s)
Hidradenitis Suppurativa/therapy , Clinical Trials as Topic , Consensus , Consensus Development Conferences as Topic , Delphi Technique , Global Health , Humans , Treatment Outcome
11.
Br Dent J ; 223(10): 746, 2017 11 24.
Article in English | MEDLINE | ID: mdl-29171513
12.
J Biomed Phys Eng ; 7(3): 191-204, 2017 Sep.
Article in English | MEDLINE | ID: mdl-29082211

ABSTRACT

BACKGROUND: A new treatment approach for most patients who have undergone early stage non-small-cell lung carcinoma (NSCLC) is wedge resection plus permanent implant brachytherapy. However, the specification of dose to medium at low energies especially in heterogeneous lung is unclear yet. OBJECTIVE: The present study aims to modify source strength for different configurations of 125I and 103Pd seeds used in lung permanent implant brachytherapy. METHODS: Different arrays of 125I and 103Pd seeds were simulated by MCNPX code in protocol-based water vs. actual 3D lung environments. Absorbed dose was, then, scored in both mediums. Dose differences between both environments were calculated and source strength was modified for the prescription point. In addition, lung-to-water absorbed dose ratio was obtained and presented by precise equations. RESULTS: Due to significant differences in prescription dose, source strength was modified 16%-19% and 37%-43% for different configurations of 125I and 103Pd seeds, respectively. In addition, depth-dependent dose differences were observed between the actual lung and protocol-based water mediums (dose difference as a function of depth). CONCLUSION: Modification of source strength is essential for different arrangements of 125I and 103Pd seeds in lung implantation. Modified source strength and presented equations are recommended to be considered in future studies based on lung brachytherapy.

13.
J Biomed Phys Eng ; 6(3): 123-126, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27853719
15.
Lasers Med Sci ; 31(2): 221-7, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26694488

ABSTRACT

Surface plasmon resonance effect of gold nanostructures makes them good candidates for photothermal therapy (PTT) application. Herein, gold-ferrite nanocomposite (GFNC) was synthesized and characterized as a photothermal agent in PTT. The aim of this study was to investigate the effect of GFNC upon laser irradiation on treatment of cancer in mice bearing melanoma cancer. Thirty mice received 1.5 × 10(6) B16/F10 cells subcutaneously. After 1 week, the mice bearing solid tumor were divided into four groups: control group (without any treatment), laser group (received laser irradiation without GFNC injection), GFNC group (only received intratumorally GFNC), and GFNC + laser group (received intratumorally GFNC upon laser irradiation). In GFNC + laser group, 200 µL of fluid, 1.3 × 10(-7) mol L(-1) gold nanoparticles, was injected intratumorally and immediately the site of tumor was exposed to continuous wave diode laser beam (808 nm, 1.6 W cm(-2)) for 15 min. All mice but four were euthanized 24 h after treatment to compare the necrotic surface area histologically by using measuring graticule. Statistical analyses revealed significant differences in necrosis extent for GFNC + laser group, compared to other groups. Four subjects (control group and GFNC + laser group, two mice each) were kept for longitudinal study. Histological analyses and tumor volume measurements of the four subjects indicated that tumor in GFNC + laser group was controlled appropriately. It was concluded that combining an 808-nm laser at a power density of 1.6 W cm(-2) with GFNC has a destruction effect in melanoma cancer cells in an animal model.


Subject(s)
Ferric Compounds/chemistry , Gold/chemistry , Infrared Rays/therapeutic use , Laser Therapy/methods , Melanoma, Experimental/therapy , Nanocomposites/chemistry , Nanocomposites/therapeutic use , Animals , Cell Line, Tumor , Combined Modality Therapy , Disease Models, Animal , Male , Melanoma, Experimental/drug therapy , Melanoma, Experimental/pathology , Mice , Nanoparticles/chemistry
16.
J Biomed Phys Eng ; 5(3): 91-4, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26396964
17.
J Biomed Phys Eng ; 5(3): 151-4, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26396971

ABSTRACT

BACKGROUND: Nowadays, mothers are continuously exposed to different sources of electromagnetic fields before and even during pregnancy.  It has recently been shown that exposure to mobile phone radiation during pregnancy may lead to adverse effects on the brain development in offspring and cause hyperactivity. Researchers have shown that behavioral problems in laboratory animals which have a similar appearance to ADHD are caused by intrauterine exposure to mobile phones. OBJECTIVE: The purpose of this study was to investigate whether the maternal exposure to different sources of electromagnetic fields affect on the rate and severity of speech problems in their offspring. METHODS: In this study, mothers of 35 healthy 3-5 year old children (control group) and 77 children and diagnosed with speech problems who had been referred to a speech treatment center in Shiraz, Iran were interviewed. These mothers were asked whether they had exposure to different sources of electromagnetic fields such as mobile phones, mobile base stations, Wi-Fi, cordless phones, laptops and power lines. RESULTS: We found a significant association between either the call time (P=0.002) or history of mobile phone use (months used) and speech problems in the offspring (P=0.003). However, other exposures had no effect on the occurrence of speech problems. To the best of our knowledge, this is the first study to investigate a possible association between maternal exposure to electromagnetic field and speech problems in the offspring. Although a major limitation in our study is the relatively small sample size, this study indicates that the maternal exposure to common sources of electromagnetic fields such as mobile phones can affect the occurrence of speech problems in the offspring.

18.
J Biomed Phys Eng ; 5(1): 1-2, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25973405
19.
Colloids Surf B Biointerfaces ; 129: 15-20, 2015 May 01.
Article in English | MEDLINE | ID: mdl-25819361

ABSTRACT

Application of superparamagnetic iron oxide nanoparticles (NPs) as a negative contrast agent in magnetic resonance imaging (MRI) has been of widespread interest. These particles can enhance contrast of images by altering the relaxation times of the water protons. In this study, dextrin-coated zinc substituted cobalt-ferrite (Zn0.5Co0.5Fe2O4) NPs were synthesized by a co-precipitation method, and the morphology, size, structure and magnetic properties of the NPs were investigated. These NPs had superparamagnetic behavior with an average size of 3.9 (±0.9, n=200)nm measured by transmission electron microscopy. Measurements on the relaxivities (r2 and r2(*)) of the NPs were performed in vitro by agarose phantom. In addition, after subcutaneous injection of the NPs into C540 cell line in C-57 inbred mice, the relaxivities were measured in vivo by a 1.5T MRI system. These NPs could effectively increase the image contrast in both T2-and T2(*)-weighted samples.


Subject(s)
Cobalt/chemistry , Contrast Media/pharmacokinetics , Dextrins/chemistry , Ferric Compounds/chemistry , Magnetic Resonance Imaging/methods , Neoplasms, Experimental/pathology , Phantoms, Imaging , Zinc/chemistry , Animals , Female , In Vitro Techniques , Mice , Mice, Inbred C57BL , Microscopy, Electron, Transmission , Neoplasms, Experimental/metabolism , Particle Size , Protons , Tissue Distribution , Tumor Cells, Cultured , Xenograft Model Antitumor Assays
20.
J Biomed Phys Eng ; 4(1): 1-8, 2014 Mar.
Article in English | MEDLINE | ID: mdl-25505762

ABSTRACT

BACKGROUND: Numerical study of angulation effects of renal arteries on blood flow has been of great interest for many researchers. Objective : This paper aims at numerically determining the angulation effects of stenosed renal arteries on blood flow velocity and renal mass flow. METHOD: An anatomically realistic model of abdominal aorta and renal arteries is reconstructed from CT-scan images and used to conduct numerical simulation of pulsatile non-Newtonian blood flow incorporating fluid-structure interaction. The renal arteries in the realistic model have left and right branch angles of 53˚ and 45˚, respectively. Atrapezium shape stenosis is considered in the entrance of right renal artery. Two other branch angles, i.e. 90 and 135˚, are also considered for right renal artery to study the angulation effects. RESULTS: Comparison between models with right renal branch angles of 45˚, 90˚ and 135˚ reveals that high curvature of streamlines in the entrance of the renal artery with the angle of 135˚ causes the flow velocity and renal mass flow to be less than those of 45˚and 90˚. CONCLUSION: It is concluded that large renal branch angles cause the arteries to be unable to deliver blood in the requisite amounts to kidney. Kidney responds to counteract low blood flow by activating the renin-angiotension system which leads to severe hypertension.

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