فهرست مطالب masoome karimi

Transfusion-associated graft-versus-host disease is a complication being mortal in 90% of cases. Today, Co-60 devices are utilized for the suppression of the lymphocytes to prevent this complication. Due to problems such as radioactive source age, problems in source replacement, and protection risks, we sought to replace a linear accelerator for this purpose and carefully determinate the X-ray dose and other settings.
First, the venous blood of the right-handed people with blood group O was exposed to different radiation doses of Linac and diluted. The proliferative responses of the exposed cells were examined by MTT assay and TB in comparison with controls after 48h. The average percentage of cell survival at each delivered dose and the required dose of radiation for the inhibition of lymphocyte proliferation were checked and the optimal dose of radiation was obtained as 25 Gy in a special radiation condition.
The results indicated that the irradiation with 25 Gy at 3.5 Gy/min in the internal mid-plan by compact 6MV for 30*30-field size at an 8 cm-distance of the samples to the source and 1370-monitor unit could completely suppress the lymphocytes. Under the same condition and 1096-monitor unit for total 20 Gy, we did not find optimal results.
In this research, we found that a linear accelerator in a specific exposure condition is a suitable alternative for Cobalt-60 sources and the above-mentioned condition of irradiation can be used to overcome the GVHD concern.

The aim of this study was to investigate psychometric properties of General Health Questionnaire of the students. In this study, 500 students of medical universities in Tehran were selected in a relative sampling. Participants responded to the General Health Questionnaire 12 items form and interviewed by trained interviewers with the Composite International Diagnostic Interview Form (CIDI). Exploratory factor analysis through principle component analysis showed the two-factor structure of this questionnaire. This questionnaire was made of two components, of which the first factor explained the greatest amount of variance. The best cut-off point of GHQ-12 questionnaire was 9, and the sensitivity, specificity, and overall classification error for the best cut-off point were81.5%, 77.1%, and 17.8%, respectively. The cut-off point with maximum sensitivity index (95.5%) was five and the maximum specificity score (95.8%) was 15. Construct validity by examining correlations between the subscales of the questionnaire together with the total score was calculated, which were strongly significantly correlated. Cronbach's alpha coefficient was 0.92 and the split-half and Spearman-Brown reliability was 0.91. The best cut-off point for this questionnaire was 9 for two-stage studies and 15 for one-stage studies. Obtained construct validity and reliability coefficients indicate that this questionnaire is suitable for screening psychopathology in university students.