Dose assessment and radioactivity of the mineral water resources of Dimeh springs in the Chaharmahal and Bakhtiari Province, Iran

One of the main sources of public exposure from natural radioactivity is radium and radon and its short lived decay products. The aim of this study is focused on determining the concentration of mentioned radionuclides in the mineral water resources in one of the highest altitude regions (Zagros Mountains), the Chaharmahal and Bakhtiari province, in South-West Iran, namely the Dimeh springs. Eighty drinking spring water samples were taken from the Dimeh springs (ten samples for each spring) to determine radium-226 ( 226Ra) and radon-222 (222Rn) concentrations using the emanation method and a liquid scintillation counting method, respectively. The results of this study showed that the effective dose from the consumption of drinking water of Dimeh springs (6.4 μSv/y) is not comparable to the other annual effective dose such as inhalation of radon and its products in cosmic and terrestrial rays published by one of the authors previously. Also, the annual effective dose measured here is much lower than the worldwide mean value 0.45 mSv reported by USCEAR, 2000 and is also low enough and below the proposed limits in other countries and this is the reason why this sources of water may be considered as safe drinking water in the region

Measurement of natural background radiation in Chaharmahal and Bakhtiari province

ساکنین کره زمین همواره تحت تابش پرتوهای زمینه طبیعی شامل پرتوهای کیهانی و پرتوهای زمینی بوده و خواهند بود. این پرتوها سبب بروز عوارض نابهنجار گوناگونی در انسان می شوند. در بیشتر نقاط دنیا و مخصوصا در کشورهای پیشرفته چندین بار اندازه گیری پرتوهای زمینه صورت گرفته است. ایران یکی از معدود کشورهایی است که اطلاعات دقیق و جامعی را در این ارتباط به کمیته بین المللی حفاظت در برابر اشعه (ICRP) ارائه نداده است. اگرچه اندازه گیری ها در برخی از استان ها (مازندران، تهران، اصفهان و غیره) انجام شده است ولی اطلاعات مکتوبی در این زمینه وجود ندارد. اندازه گیری تشعشعات زمینه طبیعی در استان چهارمحال و بختیاری که جزء مناطق کوهستانی و ارتفاع بلند می باشد، ضروری بوده تا بتوان اطلاعات جامعی را در این ارتباط بدست آورد. چرا که به نظر می رسد میزان پرتوهای زمینه در مناطق کوهستانی و با ارتفاع بلندتر، بیشتر می باشد. با استفاده از دزیمتر حساس به پرتوهای هسته ای (گایگر-مولر) و با مراجعه به نقاط مختلف استان در هر نقطه، 8 اندازه گیری انجام شد و میانگین آنها به عنوان پرتودهی آن نقطه محسوب گردید. میانگین آهنگ پرتودهی برابر با (میکرو رونتگن بر ساعت) µR/h 1.4±28.2 و میانگین آهنگ دز جذبی (نانوگری بر ساعت) 49nGy/h و دز معادل موثر سالیانه نیز برابر با (میلی سیورت) 0.49mSv برآورد شده است. این مقادیر از حد میانگین جهانی بیشتر بوده ولی از نقاط با پرتودهی بالای جهان کمتر می باشند. بنابراین احتمال شیوع سرطان ها و ارتباط آنها با پرتوها و هم چنین اثر پرتوها بر روی طول عمر از نکاتی است که باید مورد تحقیق بیشتر قرار گیرد

Targeted Alpha therapy using radiolabeling of monoclonal antibody

کارآیی بهتر رادیوتراپی نیاز به اختصاصی بودن پرتو تابشی و حساسیت بالای سلول های هدف دارد. برای این منظور تابش ذرات آلفا به سلول های سرطان پوست (Melanoma) مورد بررسی قرار گرفت. مونوکلونال آنتی بادی 9.2.27 مخصوص سرطان پوست توسط یک منبع رادیوایزوتوپ آلفا دهنده ²¹³Bi (بیسموت) و یک منبع رادیو ایزوتوپ پوزیترون دهنده 152Tb (تربیوم) نشاندار شده است. دو عامل واسط (Cycelic anhydride diethylene triamine penta acetic acid=cDTPAa) و CHX-A یکی از مشتقات P-isothiocyanatobenzyl) cyclohexyl) DTPA)-دو) یا (P-SCN-Bzlcyclohexyl)-دو) برای نشاندار کردن توسط هردوی رادیوایزوتوپ انتخاب گردید. بازده نشاندار کردن برای ²¹³Bi بترتیب 96 و 92 با cDTPAa حاصل شد و برای رادیوایزوتوپ 152Tb مقادیر 93 برای cDTPAa و 89 برای CHX-A مشاهده گردید. بیشترین مقدار نشاندار نشده (Leaching) حاصل از شستشوی ترکیبات پایداری سرم خون بترتیب 20 و 13 برای ²¹³Bi و 152Tb بدست آمد. بررسی های میل ترکیبی سلول ها (Cell avidity) تفاوت معنی داری بین آنتی بادی های غیر نشاندار و نشاندار را نشان نمی دهد. برای هردو رادیوایزوتوپ بررسی نمودارهای بقاء سلولی مقدار میانگین دز کشنده (D0) مساوی 120 را مشخص می نماید. پایداری بسیار بالای ترکیبات رادیوایزوتوپ های ²¹³Bi و 152Tb همراه با ذرات آلفای گسیلی از آنها نشان می دهد که بکارگیری ذرات آلفا به عنوان یک روش جدید برای درمان سرطان پوست (Melanoma) مناسب می باشد

Synthesis and application of new gadolinium-porphyrins as potential MR imaging contrast agents for cancer detection in nude mice

Two new potential magnetic resonance imaging contrast agents, Gd-hematoporphyrin (Gd-H) and Gd-tetra-carboranylmethoxyphenyl-porphyrin (Gd-TCP), were synthesized and applied to nude mice with human melanoma (MM-138) xenografts. These agents showed a high relaxivity because of their greater potential to coordinate water molecules. The reduction of T1 relaxation times of 16 and 21% was observed in human melanoma tumors grafted in the nude mice 24 h after injection of Gd-TCP andGd-H, respectively. The percent of injected Gd, that localized to the tumor and measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES), was approximately 21% for Gd- TCP and 28% for Gd-H. A higher concentration of Gd was achieved compared with control indicating selective delivery of Gd-porphyrins to the melanoma xenografts. The data indicate that Gd-TCP can be used as a dual probe for diagnosis in MR imaging and for therapy in boron neutron capture therapy (BNCT)

Radiation cancer risk from doses to newborn infants hospitalized in neonatal intensive care units in children hospitals of Isfahan province

Background: This study aimed to invesgate dose area product (DAP), effecve dose, and radiaon risk in newborn infants hospitalized in neonatal intensive care units in Isfahan and Kashan. Materials and Methods: During a period of six months, DAP for chest X-ray examinaons for newborn infants hospitalized in NICUs of five special hospitals including Behesh (in Kashan), Al-Zahra, Imam Hossein, Amin and Goldis (in Isfahan) were measured using DAP meter. Then, using the dose area product (DAP) and conversion coefficients, the effecve dose was calculated. Radiaon risk per single exposure was esmated by applying 2.8 × 10-2 and 13 × 10-2 factors per Sievert. Also, to esmate the radiaon risk in the exposed populaon, the collecve effecve dose and the menoned factors were used. Results: The mean DAP, the effecve dose, the radiaon risk per single exposure, and the radiaon risk in the exposed populaon were found to be 15.37 ± (1.19), 45.52 ± (3.28), [1.27-5.91] × 10-6, and [0.0045-0.021], respecvely. Conclusion: Findings indicate that the effecve dose and therefore radiaon risk in NICUs for newborn infants is higher than that of other studied cies in Iran. Consequently, it is necessary to aCempt to reduce radiaon dose while maintaining the image quality. In addion, theorecal and praccal training programs are needed to increase the knowledge and skills of radiologic technologists on the concept of As Low As Reasonably Achievable (ALARA) and possible radiaon cancer risks

In vitro study of relationship between signal intensity and gadolinium-DTPA concentration at high magnetic field strength

Although gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) has been used as a contrast material in MRI, it is known that the contrast enhancement effect is not uniform for high concentrations of Gd-DTPA. In order to evaluate the proper pulse sequences for dynamic MRI in aqueous solutions of Gd-DTPA, blood samples and melanoma cells, the signal intensity for several concentrations of Gd-DTPA were measured under inversion recovery (T1weighted) at high magnetic field strength (7.0 Tesla). For aqueous solutions of Gd-DTPA, signal intensity correlated linearly with the concentration of Gd-DTPA between 0 mmol/L and 4 mmol/L Using blood and melanoma cells, signal intensity correlated non-linearly with the concentration of Gd-DTPA between 0 mmol/L and 1.5 mmol/L. For concentrations of more than 4 mmol/L in aqueous solutions of Gd-DTPA, 1 mmol/L in blood and 1.5 mmol/L in melanoma, signal intensity decreased with increased Gd-DTPA concentration

In vivo studies of Gd-DTPA-monoclonal antibody and gd-porphyrins: potential magnetic resonance imaging contrast agents for melanoma.

New tumor-specific contrast agents for clinical imaging and therapy for cancer are required. To this end Gd-H (Gd-hematoporphyrin), Gd-TCP (Gd-tetra-carboranylmethoxyphenyl-porphyrin), Gd-DTPA-WM53, and Gd-DTPA-9.2.27 were synthesized and administered by systemic injection to nude mice with human melanoma (MM-138) xenografts. The biodistribution T1 relaxation times and magnetic resonance (MR) image signal enhancement of the contrast agents are presented for the first time and compared for each group of five mice. A change (20%) in T1 relaxation times of water in human melanoma tumor xenografts was revealed 24 hours after injection of the labeled immunoconjugate Gd-DTPA-9.2.27. The percent of injected antibody or gadolinium that localized to the tumor was measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) to be approximately 35%. A higher concentration of gadolinium was achieved compared with nonspecific compounds, indicating selective delivery of Gd-DTPA-9.2.27 to the melanoma xenografts. Porphyrin-based contrast agents (Gd-H and Gd-TCP) also showed significant uptake in melanomas. The uptake of Gd-TCP by the tumor was sufficient to deliver boron atoms into the tumor, making possible dual use for both MR imaging (MRI) and boron neutron capture therapy (BNCT). The linear relationship found between the paramagnetic contribution to the relaxation rates and contrast agent concentration allows quantitative studies of paramagnetic contrast agent uptake

In vitro studies of gadolinium-DTPA conjugated with monoclonal antibodies as cancer-specific magnetic resonance imaging contrast agents.

The monoclonal antibodies, 9.2.27 against human melanoma cell lines and WM53 against leukemia cell lines, were conjugated with cyclic anhydride gadolinium-diethylenetriaminepenta-acetic acid (Gd-cDTPAa) and used as tumor-specific contrast agents in magnetic resonance imaging (MRI). The data indicate that Gd-DTPA-9.2.27 in solution decreased the T1 relaxation of water protons at 7.0 Tesla (300 MHz) in direct proportion to the gadolinium concentration, and this effect was greater than in Gd-DTPA solutions. These conjugates show high specificity for melanoma and leukemia cell lines. T1 relaxation time at 7.0 Tesla, measured for the melanoma cell line (MM-138) and leukemia cell line (HL-60) after incubation at 37 degrees C for 4 hr, were significantly decreased (approximately 25%) relative to controls. The gadolinium concentration in cells and washing solutions was measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES). A linear relationship was observed between T1 relaxation rates and gadolinium concentrations obtained by ICP-AES. The ICP-AES results showed no gadolinium uptake in the non-targeted HT-29 colorectal cancer cells

Gold nanoparticle and mean inactivation dose of human intestinal colon cancer HT-29 cells

Background: Mean inactivation dose is a useful radiobiological parameter for the comparison of human cell survival curves. Objectives: Given the importance and accuracy of these parameters, in the present study, the radio sensitivity enhancement of colon cancer (HT-29) cells in the presence of gold nanoparticles (GNPs) were studied using the mean inactivation dose (MID). Materials and Methods: Naked-GNPs with 50 nm diameters were incubated with HT-29 cells. The cytotoxicity and uptake of these particles on HT-29 cells were assessed. After determining the optimum GNPs concentration, the cells were incubated with gold nanoparticle for 24 hours. The change in the MID value as well as the radio sensitization enhancement under irradiation with 9 MV X-ray beams in the presence of GNPs were evaluated by multiple (3-(4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium)MTS assay. Results: Cell survival in the presence of GNPs was more than 90% and the maximum uptake of GNPs was observed at 60 μM of gold nanoparticles. In contrast, in the presence of GNPs combined with radiation, cell survival and MID value significantly decreased, so that the radio sensitization enhancement was 1.4. Conclusions: Due to the significant reduction in the mean inactivation dose of colon cancer cells in the presence of gold nanoparticles, it seems that GNPs are suitable options to achieve a new approach in order to improve radiotherapy efficiency without increasing the prescribed radiation dose

Evaluation of the radiosensitizing potency of bromelain for radiation therapy of 4T1 breast cancer cells

Breast cancer (BC) remains the leading cause of death in women worldwide, despite the improvements of cancer screening and treatment methods. Recently, development of novel anticancer drugs for the improved prevention and treatment of BC is in the center of research. The anticancer effects of bromelain, as enzyme extract derived from the pineapples, contains chemicals that interfere with the growth of tumor cells. The aim of this study was to evaluate the effect of radiosensitizing of bromelain in 4T1 BC cells. This investigation utilized the 3-(4,5-dimethylthiazol-2-yl)-2,5-dimethyltetrazolium bromide assay to characterize the cytotoxicity of bromelain. Colony formation method was used to establish the truth of the capability of bromelain to make sensitive to radiation therapy. Flowcytometry performed to define the contribution the apoptosis effect to bromelain mediated radiosensitization of 4T1 cells. Bromelain reduced growth and proliferation of 4T1 cell as a concentration-dependence manner significantly. The survival of 4T1 cancer cells was decreased after combined treatment in a number and size-dependent manner with regard to the control group (P < 0.05). Combination of bromelain with radiation does not influence 4T1 cell apoptosis. The results suggested that bromelain can inhibit the growth and proliferation and reduce survival of 4T1 BC cells and might be used as a candidate radiosensitizer in BC patien