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Objective To investigate the influence of respiratory motion on target dose distribution in three-dimensional conformal radiation therapy(3DCRT) and intensity modulated radiation therapy(IM-RT). Methods A 2D air vented ionization chamber array MatriXX system,a platform which can mimic the clip motion of lung tumor, and a home-made solid water(RW3) phantom were used to measure the 2D dose distribution of static and moving targets irradiated by 3DCRT and IMRT beams using multiple gantry an-gles. The period of the moving platform was set to 3.5 s and the amplitude was ± 1 cm. Then the differences of dose distribution between the static phantom and moving phantom were compared and analyzed with the MatriXX system software. Results Compared with the static phantom in 3DCRT, the penumbra of dose distribution of the periodic moving phantom along the moving directions was increased by 6-9 mm, the high dose area was shrinked by about 5 ram,and the low dose area was extended by 5 mm,but the area of 50% i-sodose and the dose center area changed very little. When a single segment beam of IMRT was delivered and measured and the maximum dose of measuring plane was normalized to 100% ,the average difference of dose distribution between the static and dynamic phantoms was ±27% (from -56.4% to 56.1%) ;When all of the segment beams of IMRT were dehvered and the integrated dose distribution was measured ,the dose differ-ences were less than ±3% ,and the maximum difference of dose distribution was about ±15% which mainly appeared at the field margin and were similar to 3DCRT. Conclusions The dose distribution of most cen-ter areas of the periodic moving target using multi-fraction 3DCRT/IMRT beams is similar to that of the static target, while the high dose area of the former is shrinked and the low dose area is extended.
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Objective To find the best sample collecting and template making methods. Methods The multiplex PCR results of three sample collecting methods and eight template making methods in malaria diagnosis were compared. Results Conserved blood sample collecting, and Na 3PO 4 template making were sensitive and simple. Conclusion Conserved blood of sample collecting and Na 3PO 4 in template making are the best methods in multiplex PCR diagnosis of malaria, and are worthy of wide use.
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Objective To study the exposure dose-effectiveness of ? irradiation on killing the plasmodium in the mice RBC,for the further exploration on the method that could kill the plasmodium in RBC without affecting the activity and function of normal RBC. Methods After infection with Plamodium yoelii (P.y),blood was collected from mice and exposed to ? irradiation (radiated group). An unirradiated group served as control. In the irradiated group,P.y infected blood was divided into three aliquots,each aliquot was irradiated one time by ? radiation using Gammacell 1000 Elite blood radiation apparatus. The dosage of each aliquot was 25,35 and 45Gy. After irradiation,the blood samples were stored at 4℃. Then mice were inoculated with these irradiated blood stored for 1,3 or 5 days after irradiation,or with unirradiated blood. Two days later,the blood samples were taken from inoculated mice and were examined under microscope and plasmodium infection rates were calculated. Results The mice in the control group had parasitemia much earlier than those in irradiated group (1—2 days),and the plasmodium infection rate in the control group was significantly higher than that in the irradiated group(3.7% vs 0.07%). With increasing dosage of irradiation,the survived plasmodium in blood decreased,and survival of mice increased(8—12 days). After 45 Gy irradiation and 5 day storage at 4℃,there were no plasmodium found in the red blood cell of inoculated mice. In the control group,blood testing result was positive,and all the mice died.Conclusion Plasmodium in mice RBC can be killed effectively when blood is exposed to 45Gy irradiation and stored at 4℃ for 5 days.
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Objective] To explore the humoral and cellular immune responses in mice to eukaryotic expression recombinant plasmid encoding histidine rich protein 2 (HRP\|Ⅱ) of Plasmodium falciparum. [Methods] The start and stop codes were introduced into HRP\|Ⅱ gene fragment, the reading frame and the position of start and stop codes in HRP\|Ⅱ were identified by sequencing. HRP\|Ⅱ fragment containing the start and stop codes was cloned into pcDNA3 1(\|) to form pcDNA3 1(\|)/HRP\|Ⅱ. The BALB/c mice were immunized i.m. with the plasmids for 3 times in 3 weeks intervals. Two weeks after the last immunization, the sera and splenocytes were collected to investigate anti\|HRP\|Ⅱ antibodies by ELISA and the splenocytes proliferation response to HRP\|Ⅱ. [Results] Sequence data show that the reading frame and the position of start and stop codes are correct. Restriction enzyme digestion indicated that the HRP\|Ⅱ gene fragment containing start and stop codes was successfully cloned into pcDNA3 1(\|). Mice raised significant anti\|HRP\|Ⅱ antibodies after pcDNA3 1(\|)/HRP\|Ⅱ immunization, and the splenocytes proliferated prominently when stimulated with HRP\|Ⅱ protein. [Conclusion] Eukaryotic expression recombinant plasmid \{encoding\} HRP\|Ⅱ gene can induce significantly humoral and cellular immune response in mice. HRP\|Ⅱ gene may be a good candidate for P.falciparum blood\|stage multiple DNA vaccine.