Mohammadreza Baiatiani, M Fatemeh Seif, Mohammad Javad Tahmasebi, Mansur Ansari, Amir Sohrabi, Fakhri Sadat Hosseini,
Volume 11, Issue 4 (12-2008)
Abstract
Background: Radiotherapy is one of the cancer treatment methods. Prescribed dose for each fraction is considered based on radiosensitivity of tumoral and normal tissues. Viral agents are the effiectiv factors on tissue sensitivity. This research aimed to determine the effect of ionizing radiation of Cobal 60 on radiosensitivity of Hela cells infected with Measles virus. Methods and Materials: In this study, the radiosensitivity of Hela cells is investigated experimentally and qualitively. The cells have been cultivated in two groups (experimental and blank) and plating efficiency has been obtained. Then 100λ measles virus with serial dilution method was used to induce infection in different ratio for experimental group. After cell growth and passage, the two groups were irradiated with 2Gy gamma radiation of cobalt 60. Results: Results respectively indicated cell death increases up to 5-7%, 15-20% and 50-65%, after 2Gy irradiation by Co 60 for contaminating to Measles in low, moderate and high concentrations. Conclusion: Radiosensitivity of tumoral cells increases when they are infected by viral agent. The result in radiotherapy of cancers showed, in prescribing dose fraction non cancer disease should be considered.
Mohammad Shayestehpour, Mohammad Kazem Shahkarami, Abbas Shafyi, Mohammad Taqavian, Razieh Kamali Jamil, Fatemeh Esna-Ashari, Ashraf Mohammadi, Reza Shahbazi,
Volume 15, Issue 4 (9-2012)
Abstract
Background: Noticing the sensitivity of measles virus to temperature and light, maintaining its stability is highly important in live vaccines. The aim of the study is to evaluate the stability of measles vaccine produced by AIK-C strain. Materials and Methods: In this experimental study, three lyophilized vaccine vials were incubated at 37˚C for one week and their stability was evaluated via accelerated test. In addition, reconstituted vaccines were incubated at 4˚C, 25˚C, and 37˚C for 0, 4, 8, 12, 16 hours after reconstitution and their remaining infectious virus titer was measured using CCID50 method. Half-life of the reconstituted measles vaccine was evaluated according to linear regression analysis. Results: When the reconstituted vaccine was incubated at 4˚C, 25˚C, and 37˚C, the titer loss per hour was equal to 0.05, 0.1 and 0.2 Log10 CCID50, respectively. Also, the half-life of this vaccine at these temperatures was 5.31, 2.26, and 1.36 hours, respectively. Conclusion: The loss of potency for measles vaccine produced by AIK-C strain is 0.33 Log after storage at 37°C for one week, while the reported amounts for commercial vaccines such as Mevilin-L, Attenuvax, Edmonston-Zagreb, and Rimevax are 0.7, 0.7, 1 and 0.78, respectively. Lyophilized and reconstituted vaccine containing AIK-C strain is more stable in comparison with Edmonston B, Schwartz, Biken-CAM, and Leningrad strains. The stability of the reconstituted AIK-C strain vaccine is similar to Moraten strain at 37˚C.
