ABSTRACT
Objective:To explore the effect of oral contrast agent on the dose distribution and verification pass rate of radiotherapy plan when female patients with pelvic tumor underwent oral contrast agent to assist the delineations for tumors and organ at risk(OAR).Methods:A total of 15 female patients with pelvic tumor were selected.The original computed tomography(CT)images of each patient were the images with oral contrast agent.Based on these images,a 7-field static intensity-modulated radiotherapy plan was designed as plan 1.The intestinal CT values of the original images were modified to simulate the situations without oral contrast agent to obtain new images.The same optimization parameters of plan 1 was used to design a 7-field static intensity-modulated radiotherapy plan as plan 2.The two kinds of plans were normalized to a degree which 95%of volume was covered by 100%dose at the central point of target region.The 9 parameters of dose distribution included the maximum dose(Dmax),and two verification parameters were calculated as statistical method,and then,the effect of contrast agent was assessed.Results:The Dmax values of the target regions of plan 1 and plan 2 were respectively(5457.9±46.41)and(5455.8±46.33).The mean dose(Dmean)values of them were respectively(5185.4±24.39)and(5189.4±22.78).The conformity index(CI)values of them were respectively 1.03±0.03 and(1.03±0.03).The γ(3%/3 mm)pass rates of them were respectively(99.17±0.44)and(98.93±0.81)(P=0.177).The γ(2%/2 mm)pass rates of them were(95.46±1.27)and(94.88±1.87)(P=0.143).The differences of the dose and verification parameters between the designed two plans on the basis of the images with and without oral contrast agent were not statistical significance(P>0.05).Conclusion:Contrast agent does not have statistical effect on the dose distribution and verification pass rate of static intensity-modulated radiotherapy plan for female patients with pelvic tumor.
ABSTRACT
Flood disaster is one of the most serious natural disasters in the world, and it could pose an inestimable impact on the affected people. Based on existing laws, regulations, and emergency manuals in China, extensive literature review, epidemiological and related protection evidence, and expert consultation, this study analyzed different health risk factors of flood disaster and proposed a multi-stage, multi-population, and multi-phase comprehensive protection measures for the public in the perspective of pre-event prevention, in-event intervention and post-event rescue strategy, which could provide a scientific basis for improving the level of public health protection against the flood disaster and corresponding health outcomes.
ABSTRACT
Sulfur mustard (SM) is a bifunctional alkylating agent that can react with multiple biochemical molecules such as DNA, RNA, proteins, and so on, and its alkylation with DNA is one of the major poisoning mechanisms. Presently the pathogenesis of SM included DNA alkylation, poly ADP-ribose polymerase (PARP) activation, oxidative stress, inflammation, activation of immunoregulation and proteolytic enzymes, etc. By now there have been no specific antidotes in clinical treatment, and all the existing drugs are mainly used for symptomatic treatment. The drugs used clinically and currently being under development include free radical scavengers, antioxidant agents, PARP inhibitors, anti-inflammatory drugs and protease inhibitors. This review summarized the advances in pathogenesis of SM and the corresponding protective drugs.
ABSTRACT
<p><b>OBJECTIVE</b>To understand the status of standard medication of antiretroviral therapy and identify its correlationship with preventing mother-to-child transmission of HIV (PMTCT).</p><p><b>METHODS</b>Qualitative and quantitative methods for measuring of standard medication towards antiretroviral therapy of PMTCT were used in a cross-sectional study of 167 pregnant women who had accessed to PMTCT services and 57 physicians providing service from January 2005 to June 2007 in 5 HIV epidemic counties in Yunnan province.</p><p><b>RESULTS</b>A total of 167 mothers were recruited, of which 65.87% (110/167) demonstrated for standard medication. The percentage of rational selection of antivirus-therapy regimen was 88.02% (147/167). HIV positive mothers with rational using medicine during labor covered 81.37% (131/161). 87.42% (146/167) of women demonstrated good compliance. The main correlations with the standard medication level of HIV positive pregnant women and their infants were as follows: diagnose time (OR = 2.617; 95% CI: 1.184 - 5.783), place of delivery (OR = 0.064; 95% CI: 0.007 - 0.607), minorities (OR = 0.344; 95% CI: 0.162 - 0.730), understanding of HIV women for antiretroviral therapy (OR = 6.843; 95% CI: 1.449 - 32.312), and doctors' cognition about the regimen for antiretroviral therapy was not enough; 5 key knowledge points (purpose of PMTCT, the consequence of not requiring standard medication, the effect of knowing regimens, the relationship of CD4 levels and selected regimens, the side effect of the relevant medicine) score rate was 47.72% (136/285).</p><p><b>CONCLUSION</b>The proportions of standard medication in PMTCT antiretroviral therapy were not high. Standard medication might be associated with multiple factors from doctors, patients and society. It is necessary to make some steps to improve standard medication of antiretroviral therapy in PMTCT.</p>