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Accumulating evidence suggests that self-renewal and differentiation capabilities reside only in a subpopulation of tumor cells, termed cancer stem cells (CSCs), whereas the remaining tumor cell population lacks the ability to initiate tumor development or support continued tumor growth. In head and neck squamous cell carcinoma (HNSCC), as with other malignancies, CSCs have been increasingly shown to have an integral role in tumor initiation, disease progression, metastasis, and treatment resistance. In this article, the author summarizes the current knowledge of the role of CSCs in HNSCC and discusses the therapeutic implications and future directions of this field.Keywords: CSC, field cancerization, HNSCC, metastasis, tumorigenesis
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BackgroundThe mapping of the malignization mechanism is still incomplete, but oxidative stress is strongly correlated to carcinogenesis. In our research, using fuzzy logic, we aimed to estimate the oxidative stress related-cancerization risk of the oral potentially malignant disorders.MethodsSerum from 16 patients diagnosed (clinical and histopathological) with oral potentially malignant disorders (Dept. of Cranio-Maxillofacial Surgery and Radiology, Iuliu Hațieganu University of Medicine and Pharmacy, Cluj Napoca, Romania) was processed fluorometric for malondialdehyde and proton donors assays (Dept. of Physiology,Iuliu Hațieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania). The values were used as inputs, they were associated linguistic terms using MIN-MAX method and 25 IF-THEN inference rules were generated to estimate the output value, the cancerization risk appreciated on a scale from 1 to 10 - IF malondialdehyde is very high and donors protons are very low THEN the cancer risk is reaching the maximum value (Dept. of Industrial Engineering, Faculty of Managerial and Technological Engineering, University of Oradea, Oradea, Romania) (2012-2014).ResultsWe estimated the cancerization risk of the oral potentially malignant disorders by implementing the multi-criteria decision support system based on serum malondialdehyde and proton donor's values. The risk was estimated as a concrete numerical value on a scale from 1 to 10 depending on the input numerical/linguistic value.ConclusionThe multi-criteria decision support system proposed by us, integrated into a more complex computerized decision support system, could be used as an important aid in oral cancer screening and establish future medical decision in oral potentially malignant disorders.Keywords: Oral potentially malignant disorders, Malondialdehyde, Proton donors, Cancer risk, Fuzzy logic
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زمینه و هدفترکیبات قندی سطح سلول و ماتریکس سلول، دارای نقش با اهمیتی در تنظیم میان کنش های سلول - سلول و سلول - ماتریکس هستند. تغییر قندهای سلولی، یکی از مهم ترین وقایع مولکولی است که در طی فرآیند بدخیمی بافت ها ایجاد می شود. این مطالعه به منظور بررسی هیستوشیمیایی موکوپلی ساکاریدهای سلولی و ارتباط آن با تمایز تومور در کارسینومای مری و معده انجام شد.روش بررسیدر این مطالعه آزمایشگاهی نمونه های بافتی 80 بیمار شامل 40 بیمار با اسکوآموس سل کارسینومای مری (SCC) و 40بیمار با آدنوکارسینومای معده با تمایزهای مختلف تومور، از بخش آسیب شناسی بیمارستان امام رضا (ع) مشهد طی سال 1388 انتخاب گردید. نمونه ها با روش آلسین بلو PH 1 و 5/2 برای شناسایی ترکیبات موکوسی سولفاته و کربوکسیله همراه با شاهد مثبت و منفی رنگ آمیزی و بررسی میکروسکوپی شدند.یافته هاسلول های پوشش طبیعی و کارسینوم مری در تمایزهای مختلف در PH 1 و 5/2 رنگ پذیری منفی داشتند؛ اما سلول های استرومای طبیعی و توموری واکنش مثبت داشتند. سلول های غددی طبیعی و سرطانی معده در PH 1 منفی؛ ولی سلول های غددی طبیعی در PH2.5 مثبت شدند؛ اما سلول های سرطانی در تمایزهای مختلف پاسخ ضعیفی نشان دادند. سلول های استرومای طبیعی و توموری معده در در PH 1 و 5/2 مثبت بودند.نتیجه گیریاین مطالعه نشان داد که احتمالا در فرایند سرطانی شدن، تغییر در عملکرد سلول های پوششی مری از نظر ایجاد ترکیبات موکوسی سولفاته و کربوکسیله پدید نمی آید؛ ولی در سلول های غددی معده تغییراتی به صورت کاهش ترشح ترکیبات موکوسی کربوکسیله ایجاد می گردد.
کلید واژگان: اسکوآموس سل کارسینومای مری, آدنوکارسینومای معده, موکوپلی ساکاریدها, تمایز سلولی, آلسین بلوBackground And ObjectiveChange in the cell surface and extracellular matrix glycoconjugates has been reported in many cancers. Moreover, diagnostic and prognostic importance of these substances and also their roles in therapeutic modalities for cancerous patients has been emphasized. This study was designed to explore the histochemical study of cellular mucopolysaccharides in esophageal and gastric carcinoma and its relation to tumor differentiation.Materials And MethodsIn this laboratory study tissue samples of 40 patients with esophageal squamous cell carcinoma and 40 patients with stomach adenocarcinoma in different grades of tumor were selected from pathology department of Emam Reza hospital in Mashhad, Iran. Tissue samples were stained with Alcian Blue (PH 1 and PH 2.5) for Sulfated and Carboxylated mucosubstances respectively, along with positive and negative controls.ResultsNormal esophageal epithelium and carcinoma cells of different grades showed negative reactivity but normal and tumoral stromal cells depicted positive staining in both PHs. In PH 1, normal glandular and carcinoma cells of the stomach were negative but in PH 2 glandular cells were positive though carcinoma cells showed weakly staining. Normal and tumoral gastric stromal cells showed positive staining in PH 1 and PH 2.5.ConclusionIt is highly probable that in the process of cancerization of normal esophageal squamous cells, functional changes, from the perspective of producing Carboxylated and Sulfated mucosubstances, do not occur, whereas some changes in glandular cells of stomach which result in diminishing the production of Carboxylated mucosubstances during cancerization process are observable. -
BackgroundMetallothionein (MT) manifests varying expression levels in carcinomas, and they may be considered as valuable cell cancerization biomarkers for diagnosis of patients with cancers. A meta-analysis was conducted to evaluate comprehensively the MT expression difference in various benign tumors and malignant tumors, which compared the high with low MT expression levels in patients of the available studies. Finally, a total of 13 studies dealing with various tumors were involved for this meta-analysis. The results indicated that lower expression of MT in various benign tumors tissue than that in corresponding malignant tumors with the pooled OR of 0.52 (95 % CI 0.18-1.47, P ＜0.001). In conclusion, MT expression difference is associated with tumor various stages in tumor patients and could be a useful clinical criteria of distinguishing benign tumors and malignant tumors for those patients.Keywords: Metallothionein, Benign tumors, Malignant tumors, Meta, analysis
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Oral lichen planus (OLP) is classified as a potential malignant disorder, and epidermal growth factor (EGF) may play a key role in cancer development. The aim of this study was to compare serum and saliva EGF among patients with OLP and oral squamous cell carcinoma (OSCC). A cross sectional study was performed on 27 patients with OLP (10 reticular and 17 atrophic-erosive forms), 27 patients with OSCC and 27 healthy control group. The study was conducted at the Cancer Department, Clinic of Oral Medicine, Tehran University of Medical Sciences. The serum and saliva EGF were assayed by ELISA method. Statistical analysis of ANOVA was used. The mean serum EGF in OLP and OSCC patients was significantly lower compared to healthy control group (P<0.05), but no significant difference was observed between OLP and OSCC patients. There was no significant difference in mean salivary EGF among groups. As serum EGF levels appear to be statistically similar in OLP and OSCC, it seems that EGF might play a role in the pathogenesis of OLP and its cancerization.Keywords: EGF, Oral lichen planus, Squamous cell carcinoma, Saliva
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Introduction: The use ofmobile communication systems has dramatically increased over the past decade. Although many studies have been performed to determine the effect of radio frequency (RF) but less attention has been paid to the possible biological impact of exposure to extremely low frequency (ELF) components.
The objective of this study is two folds. One is to design the equipments needed for the measurement of the ELF fields of two types of GSM900 mobile phone. Secondly، use a protocol suitable for an accurate assessment of the ELF fields.
Materials and Methods: First a home-made search coil was provided and calibrated precisely under several experiments. Using Fast Fourier Transform، the power spectrum density of the induced voltage in the search coil was analyzed and the amplitudes of 217 Hz and its harmonics were extracted and then the distribution of magnetic field in the back side of mobile phones was determined.
Results: The values of B-field on the back side of the two kinds of GSM mobile phone were different. They were between 50 to 160 mT in Nokia 3310 and 14 to 30 mT in Nokia 8310. Considering the difference between the amplitudes of frequency components at 217 Hz and its harmonics in the two kinds of mobile phone، a range of magnetic flux density at different times in a five day period was measured.
Discussion and Conclusion: These findings emphasize the need for considering the distribution of low frequency magnetic field from mobile phone when biological effects of magnetic fields are studied. To determine the intensity windowing effect، one must consider the physical characteristics of the fundamental frequency component wave (217 Hz) and its harmonics produced by the mobile phone similar to the one generated under a real situationIntroductionThe use ofmobile communication systems has dramatically increased over the past decade. Although many studies have been performed to determine the effect of radio frequency (RF) but less attention has been paid to the possible biological impact of exposure to extremely low frequency (ELF) components. The objective of this study is two folds. One is to design the equipments needed for the measurement of the ELF fields of two types of GSM900 mobile phone. Secondly، use a protocol suitable for an accurate assessment of the ELF fields.Materials And MethodsFirst a home-made search coil was provided and calibrated precisely under several experiments. Using Fast Fourier Transform، the power spectrum density of the induced voltage in the search coil was analyzed and the amplitudes of 217 Hz and its harmonics were extracted and then the distribution of magnetic field in the back side of mobile phones was determined.ResultsThe values of B-field on the back side of the two kinds of GSM mobile phone were different. They were between 50 to 160 mT in Nokia 3310 and 14 to 30 mT in Nokia 8310. Considering the difference between the amplitudes of frequency components at 217 Hz and its harmonics in the two kinds of mobile phone، a range of magnetic flux density at different times in a five day period was measured. Discussion andConclusionThese findings emphasize the need for considering the distribution of low frequency magnetic field from mobile phone when biological effects of magnetic fields are studied. To determine the intensity windowing effect، one must consider the physical characteristics of the fundamental frequency component wave (217 Hz) and its harmonics produced by the mobile phone similar to the one generated under a real situationKeywords: 217 Hz, Magnetic Fields, Mobile Phones, GSM900 -
Determination of the electric field in insulated cable will lead to an optimum design and a better selection of both conductor size and insulation thickness. A simple numerical method using the Charge Simulation Method (CSM) is used to calculate electric field stresses in high voltage cables. An image charge for each fictitious charge is considered in such a way that the potential of sheath is always kept at zero. The effect of cable sheath is considered and results of the calculation are shown.
کلید واژگان: Three phase cable, field distribution, charge simulation method -
BackgroundSquamous Cell Carcinoma (SCC) is the second most common malignancy of the respiratory tract. Recently, researchers believe that thioredoxin system is effective in the cancerization of some tissues. Thus, this study has been conducted with the aim of measuring of thioredoxin reductase (TrxR) enzyme activity and tissue distribution in the pathologic specimens of patients with laryngeal SCC.Materials And MethodsThis study was performed on 40 pathologic blocks (20 healthy and 20 tumoral) from 20 patients with laryngeal SCC who were candidates for laryngectomy surgery. The TrxR enzyme activity was measured by the commercial kit. Also, the tissue distribution of TrxR was determined by immunohistochemical staining and the percentage of staining cells (SC%) and staining intensity were calculated. Data were analyzed by using SPSS13 and significant level was set at P≤0.05.ResultsThe average the TrxR enzyme activity in the healthy and tumoral tissues was 0.004±0.003µM/min/ml and 0.006±0.003µM/min/ml, respectively (ranged 0.0009 to 0.0104 vs. 0.001 to 0.011 ). However, there was no relationship between the TrxR enzyme activity in the tumoral and healthy tissues (P=0.084). The total score of IHC staining in the healthy tissue was 4.45±1.09 whereas the total of these scores in the tumoral tissue 6.25±0.63. The both scores of SC% and staining intensity in the tumoral tissue was significantly higher than the healthy tissue (PConclusionBased on the results, although the TrxR enzyme activity has not the significant differences in tumoral tissue compare to healthy tissue, but the tissue distribution in tumoral tissue was higher than healthy tissue.Keywords: Laryngeal, Squamous Cell Carcinoma, Thioredoxin Reductase Enzyme
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Background And AimOral lichen planus (OLP) is a chronic, autoimmune, inflammatory disease. The progression of OLP to oral squamous cell carcinoma (OSCC) has generated a longstanding controversy about the details of this malignant transformation potential. This study aimed to do a systematic review on the molecular markers related to the malignant transformation of OLP.MethodsWe searched the databases PubMed, Google Scholar, Science Direct, Scopus, Cochrane and Thomson Reuters Web of Science (1990-2015) with the MeSH key words of: (oral lichenoid reaction, oral lichenoid lesion, oral lichenoid eruption, oral lichen planus lichen planus, lichenoid) AND (malignant transformation, premalignant character, cancerization, pre-neoplasm, squamous cell carcinoma). The reviewers screened the identified publications in three steps according to title, abstract and full text, extracted all the investigated markers in screened articles and finally classified the markers according to the frequency. Extracted data were saved in Excel software.ResultsOut of 570 articles, 66 were finally enrolled in the study. The most frequent evaluated markers were p53, cyclooxygenase-2 (COX-2), Ki67, B-cell lymphoma-2 (Bcl-2), Bax, p21, and caspase-3.ConclusionThe present study concluded that there were some documented evidences for association between malignant transformation of OLP and seven molecular markers (p53, COX-2, Ki67, Bcl-2, Bax, p21, and caspase-3).Keywords: Biomarkers, Tumor, Gene Expression, Oral Lichen Planus
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زمینه و هدفپرتودرمانی یکی از روش های اصلی درمان و کنترل تومورها است. امروزه سیستم های تلفیقی پرتودرمانی و تصویربرداری MRI توسعه یافته اند. میدان های مغناطیسی ناشی از این سیستم ها می تواند بر توزیع دوز در بافت هدف تاثیر بگذارد. لذا، هدف از این مطالعه، بررسی آثار میدان های مغناطیسی بر توزیع دوز پرتوها در درمان است.روش بررسیاین مطالعه مروری با کلید واژه های« radiation therapy and »magnetic field ،« photon therapy and magnetic field»، «electron therapy and magnetic field» و «proton therapy and magnetic field» در پایگاه های google scholar وpub med به بررسی مقالات محققین مختلف، دسته بندی و جمع بندی نتایج آن ها پرداخته است.یافته هامیدان های مغناطیسی، قادر به تغییر مسیر حرکت ذرات باردار هستند و اگر عمود بر مسیر دسته پرتوهای ذره ای باردار و فوتونی اعمال شوند، ذرات باردار اولیه و همچنین، الکترون های ثانویه و پوزیترون ها را در فوتون درمانی وادار به چرخش می نمایند و یک دوز پیک تولید می کنند. میدان های مغناطیسی طولی نیز باعث کاهش نیم سایه و انحراف جانبی الکترون ها می شوند.نتیجه گیریمیدان های مغناطیسی، باعث تغییر توزیع دوز پرتوها در پرتودرمانی می شوند و نیاز به اصلاح طرح درمان در صورت استفاده از سیستم های پرتودرمانی مبتنی بر MRI وجود دارد. همچنین، با اعمال میدان مغناطیسی عرضی و تنظیم شدت و مکان اعمال آن، می توان محل وقوع افزایش و کاهش دوز را به ترتیب روی حجم تومور و بافت نرمال تنظیم کرد.کلید واژگان: توزیع دوز, سیستم های تلفیقی پرتودرمانی, MRI, میدان مغناطیسیBackground And ObjectiveRadiotherapy in one of the main methods of tumor treatment and control. Today, the integrated radiation therapy-MRI systems have been developed. The magnetic fields of imaging systems can have effects on dose distribution in target volume. Therefore, the aim of this study was to investigate the effect of magnetic fields on dose distribution in radiation therapy.Materials And MethodsThis is a review article which was done through searching the google scholar and PubMed data bases by expressions: radiation therapy and magnetic field photon therapy and magnetic field, electron therapy and magnetic field, proton therapy and magnetic field. Related research papers were sorted and their results were summarized.ResultsMagnetic fields can change the path of charged particles in the medium can enforce the primary charged particles, secondary electrons and positrons to experience a spiral path, if applied perpendicular to beam axes which leads to produce a peak dose. Longitudinal magnetic field decreases the penumbra and lateral deflection of electrons.ConclusionMagnetic fields influence the dose distribution in radiotherapy and modification of treatment plan is essential when applying integrated MRI-radiation therapy systems. Also, applying an intensity controlled transverse magnetic field can be an inexpensive approach to adjusting the maximum dose of charged particles in tumor volume while protecting normal tissues.Keywords: Dose distributions, Integrated MRI- radiation therapy systems, Magnetic field
نکته:
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از آنجا که گزینه «جستجوی دقیق» غیرفعال است همه کلمات به تنهایی جستجو و سپس با الگوهای استاندارد، رتبه‌ای بر حسب کلمات مورد نظر شما به هر نتیجه اختصاص داده شده‌است.
- نتایج بر اساس میزان ارتباط مرتب شده‌اند و انتظار می‌رود نتایج اولیه به موضوع مورد نظر شما بیشتر نزدیک باشند. تغییر ترتیب نمایش به تاریخ در جستجوی چندکلمه چندان کاربردی نیست!
- جستجوی عادی ابزار ساده‌ای است تا با درج هر کلمه یا عبارت، مرتبط ترین مطلب به شما نمایش داده‌شود. اگر هر شرطی برای جستجوی خود در نظر دارید لازم است از جستجوی پیشرفته استفاده کنید. برای نمونه اگر به دنبال نوشته‌های نویسنده خاصی هستید، یا می‌خواهید کلمات فقط در عنوان مطلب جستجو شود یا دوره زمانی خاصی مدنظر شماست حتما از جستجوی پیشرفته استفاده کنید تا نتایج مطلوب را ببینید.
* با توجه به بالا بودن تعداد نتایج یافت‌شده، آمار تفکیکی نمایش داده نمی‌شود. بهتراست برای بهینه‌کردن نتایج، شرایط جستجو را تغییر دهید یا از فیلترهای زیر استفاده کنید.
* ممکن است برخی از فیلترهای زیر دربردارنده هیچ نتیجه‌ای نباشند.
* ممکن است برخی از فیلترهای زیر دربردارنده هیچ نتیجه‌ای نباشند.
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