ABSTRACT
Objective The in vitro studies of indicators in burn patients with complicated infection have been little studied till now.So this study aims to investigate the change of proliferation of CD64 +neutrophils from the peripheral blood of burn patients in vitro. Methods CD64+neutrophils from peripheral blood of healthy people were isolated and purified, which was followed by stim-ulating its proliferation with inactivated Staphylococcus in vitro.We further analyzed the proliferation index with Modfit 2 analysis soft-ware.86 burn patients were divided into two groups, 44 cases with complicated infection assigned to experimental group, 42 uninfected assigned to controls.We further detect the counts of WBC and the percentage of CD64 +neutrophils, and then analyzed the specificity and sensitivity by using the receiver operating characteristic ( ROC) curves. Results This in vitro study, the average proliferation index of CD64 +cells in experimental wells was significantly higher than controls (6.48 ±0.11 vs 2.63 ±0.02), the difference was statistically significant (P<0.05);the percentage of CD64 +cells in the peripheral blood of patients in experimental group(64.25 ± 13.11%) was significantly higher than patients without infection(16.33 ±2.77%);The sensitivity and specificity of diagnostic meth-od of CD64 +cells for the burn infection were respectively 94.2%and 76.8%, which was superior to the traditional diagnostic meth-od of WBC ( 68.5%, 64.7%) according to ROC curves. Conclusion CD64 + cells in peripheral blood of burn patients complicated by infection increased more significantly and earlier when compared with the traditional diagnostic method, which may be used as a useful diagnostic indicator for burns complicated infection.
ABSTRACT
Objective To investigate the utility of combined test of neutrophil CD64 and C-reactive protein(CRP)for early diag-nosis of burn sepsis.Methods A prospective study was conducted in 76 hospitalized burn patients,including three groups:burn sepsis(n=27),local infection(n=31)and controls without bacterial infection (n=18)based on their diagnosis.Blood samples were collected within 24-48 h after hospital admission for analysis of neutrophil CD64,CRP,white blood cell count (WBC), neutrophils percentage (N)by flow cytometry,and bacterial culture.These parameters were re-evaluated for the patients in sepsis group 7 and 14 days after antibiotic therapy.Results Neutrophil CD64,CRP,WBC and N were significantly higher in sepsis patients than the corresponding values in the patients with local infection or control patients (P < 0.01 ).Neutrophil CD64 and CRP in the patients with local infection were significantly higher than those in the control patients without bacterial infection (P < 0.01).Neutrophil CD64 was positively correlated to CRP.Neutrophil CD64 and CRP decreased 7 days after an-tibiotic therapy,but the difference was not statistically significant compared to the pretreatment levels.Neutrophil CD64 and CRP decreased significantly 14 days after antibiotic therapy compared to the pretreatment levels (P < 0.01),but still higher than the levels in the control group.The receiver operating characteristic (ROC)curve of CD64 + CRP combined test,CD64, CRP,WBC,N for detecting bacterial infection showed an area under curve (AUC)of 0.952,0.923,0.904,0.756 and 0.728,respectively.Conclusions Neutrophil CD64 is useful in early diagnosis of burn sepsis.The expression of neutrophil CD64 does not have significant difference between gram-positive and gram-negative bacterial infections.Combined test of neutrophil CD64 and CRP can improve the efficiency for diagnosis of burn sepsis.
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Objective To explore the relationship of X-ray exposure parameters and false-node rate during image-guidance treatment with CyberKnife spine tracking.Methods Using spine tracking planning on a chest phantom,several combinations of X-ray exposure parameters were used to locate.The false-node ratio and the surface absorbed dose were investigated and the radiation dose was optimized.Results The false-node ratio and surface absorbed radiation dose decreased when the X-ray exposure parameters increased until they saturated.In the range of ≤5.0％ false-node rate,the surface absorbed radiation dose was 0.11,0.26 mGy,and 0.31-0.46 mGy,when the false-node rate was 2.77％,1.07％and 1.0％,respectively.Conclusions In image-guided treatment of CyberKnife,the radiation dose would be optimized,and the patient's radiation dose would be reduced greatly,which is important to protect the patients.
ABSTRACT
Objective To measure and analyze Varian Clinac 21EX accelerator induced radioactivity,and to provide specific recommendations and ways of radiation protection for radiotherapy technicians.Methods To simulate the working environment of radiotherapy technician,and to detect induced radioactivity variation of Varian Clinac 21EX accelerator that induced by 15 MV X-rays under different conditions of beam field area,dose,time,distance and by high energy electron beam (12,16,20 MeV)at the different time.Results The induced radioactivity level was not influenced by different beam field area,and was increased with increasing dose (r =0.930,P ＜ 0.05),decreased with time increase (r =-0.84,P ＜ 0.05),decreased with distance increase(r =-0.975,P ＜ 0.05).The induced radioactivity attenuation levels of the different doses at the same time are different,and have the common characteristic that the induced radioactivity attenuation rate is faster in the initial times.The induced radioactivity levels of high energy electron beams were significantly lower than those of high-energy X-rays.Conclusions During radiotherapy positioning,it is necessary to take measures to protect against the induced radioactivity when high-energy rays with energy greater than 10 MeV will be used.The radiotherapy technician should take the different time and energy interval steps for the different ray type and energy and dose in order to meet the radiation protection principle of optimization.