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ObjectiveThis study observes the intervention effect of Longmu Piyan prescription on oxidative stress in BALB/c mice with atopic dermatitis （AD） induced by 2，4-dinitrochlorobenzene （DNCB） and explores its mechanism. MethodThe AD model was established using the method of DNCB sensitization on the back skin of BALB/c mice. Forty male BALB/c mice were randomly divided into a blank group， a model group， a vitamin C control group （0.5×10-3 mg·kg-1）， and a Longmu Piyan prescription group （26 g·kg-1）. Except for the blank group， other groups were sensitized with different concentrations of DNCB on the back to induce AD， and the blank group was treated with matrix coating. The gastric administration was started on the seventh day after sensitization with 2% DNCB and on the 24th day after sensitization with 0.2% DNCB continuously for 21 days. The changes in skin lesions of each group were directly observed after the experiment. Enzyme-linked immunosorbent assay （ELISA） was used to detect the levels of interleukin （IL）-4， tumor necrosis factor （TNF）-α， immunoglobulin E （IgE）， and reactive oxygen species （ROS） in the serum of each group. The total antioxidant capacity determination kit-trace method (ABTS method) was used to measure the level of total antioxidant capacity （TAOC） in serum. The Hematoxylin eosin （HE） staining method was used to observe the pathological and morphological changes of the skin lesion site. The immunohistochemical method was used to detect the expression of thymic stromal lymphopoietin （TSLP） in the skin lesion site. Western blot was used to detect the expression of filaggrin （FLG） in the dorsal skin lesions. ResultThe results showed that compared with the blank group， the skin lesion score of the model group mice was significantly increased （P<0.01）， and HE staining showed characteristic pathological changes of AD in the skin lesion site. At the same time， the expression of TSLP in the skin lesion was significantly increased， and that of FLG was reduced （P<0.05）. The levels of TNF-α， IL-4， IgE， and ROS in serum increased， while the activity of TAOC decreased （P<0.01）. Compared with the model group， the Longmu Piyan prescription group showed a significant decrease in skin lesion scores and a significant improvement in skin lesion pathology. At the same time， the expression of TSLP decreased， and the expression of FLG increased in the skin lesions （P<0.05）. In addition， compared with the model group， the serum levels of TNF-α， IL-4， IgE， and ROS also decreased to varying degrees （P<0.05，P<0.01）， and TAOC activity increased in the Longmu Piyan prescription group （P<0.01）. ConclusionThere is a significant correlation among the degree of oxidative stress， the severity of skin lesions in AD， and the levels of inflammatory cytokines. Longmu Piyandu prescription can improve AD-like skin lesions in BALB/c mice by promoting ROS clearance， enhancing TAOC， and inhibiting oxidative stress， thus protecting the skin barrier and reducing inflammation.
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Objective:To understand the epidemiological and clinical characteristics of melioidosis in Haikou City, to rise the people's awareness of melioidosis and to provide basis for prevention and control of the disease.Methods:The clinical data of 254 patients with melioidosis treated in 4 Class A tertiary hospitals in Haikou City from January 2000 to September 2020 were collected, and the epidemiological characteristics, clinical manifestations, infection site, prognosis and drug sensitivity were retrospectively analyzed.Results:Among 254 patients with melioidosis, 226 males (88.98%) and 28 females (11.02%), and the gender ratio was 8.07 ∶ 1.00. Farmers were the main occupation, accounting for 37.80% (96/254). The median age was 53 years old, mainly in 41 - 80 years old, accounting for 83.46% (212/254). Han nationality was the most, accounting for 89.76% (228/254). The onset season was mainly in summer and autumn, and the peak was from August to October (117 cases). Patients were mainly distributed in coastal areas, among which Haikou City (49 cases) was the most, followed by Dongfang City (46 cases), Danzhou City (23 cases) and Wenchang City (21 cases). Totally 196 cases (77.17%) had basic diseases, diabetes was the most common (162 cases). The main symptoms of admission were fever (211 cases), followed by cough (108 cases) and expectoration (88 cases). The infection sites were mainly blood (104 cases, 40.94%), lung (60 cases, 23.62%), liver and spleen (32 cases, 12.60%). Totally 195 patients were treated with sensitive antibiotics, at discharge, 37 cases (18.97%) were cured, 129 cases (66.15%) improved, 18 cases (9.23%) did not heal, 7 cases (3.59%) died and 4 cases (2.05%) were discharged voluntarily. Results of drug sensitivity tests from 2010 to 2020 showed that the sensitivity rates of Burkholderia pseudomallei to imipenem (142 cases), meropenem (16 cases) and ceftazidime (141 cases) were all 100.00%, and the sensitivity rates of doxycycline (25 cases) and compound sulfamethoxazole (142 cases) were 92.00% (23/25) and 99.30% (141/142), respectively. Conclusions:Males, farmers, middle-aged and elderly people and people with diabetes and other basic diseases are the high incidence population of melioidosis in Haikou City. The incidence peak is in summer and autumn. The common clinical manifestations are fever, pulmonary infection, abscess of liver and spleen, etc. In the treatment, Burkholderia pseudomallei is more sensitive to imipenem, meropenem and ceftazidime.
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Objective:To develope an automatic volumetric modulated arc therapy (VMAT) planning for rectal cancer based on a dose-prediction model for organs at risk(OARs) and an iterative optimization algorithm for objective parameter optimization.Methods:Totally 165 VMAT plans of rectal cancer patients treated in Peking University Cancer Hospital & Institute from June 2018 to January 2021 were selected to establish automatic VMAT planning. Among them, 145 cases were used for training the deep-learning model and 20 for evaluating the feasibility of the model by comparing the automatic planning with manual plans. The deep learning model was used to predict the essential dose-volume histogram (DVH) index as initial objective parameters(IOPs) and the iterative optimization algorithm can automatically modify the objective parameters according to the result of protocol-based automatic iterative optimization(PBAIO). With the predicted IOPs, the automatic planning model based on the iterative optimization algorithm was achieved using a program mable interface.Results:The IOPs of OARs of 20 cases were effectively predicted using the deep learning model, with no significantly statistical difference in the conformity index(CI) for planning target volume(PTV)and planning gross tumor volume(PGTV)between automatic and manual plans( P>0.05). The homogeneity index (HI) of PGTV in automatic and manual plans was 0.06 and 0.05, respectively( t=-6.92, P< 0.05). Compared with manual plans, the automatic plans significantly decreased the V30 for urinary bladder by 2.7% and decreased the V20 for femoral head sand auxiliary structure(avoidance)by 8.37% and 15.95%, respectively ( t=5.65, 11.24, P< 0.05). Meanwhile, the average doses to bladder, femoral heads, and avoidance decreased by 1.91, 4.01, and 3.88 Gy, respectively( t=9.29, 2.80, 10.23, P< 0.05) using the automatic plans. The time of automatic VMAT planning was (71.49±25.48)min in 20 cases. Conclusions:The proposed automatic planning based on dose prediction and an iterative optimization algorithm is feasible and has great potential for sparing OARs and improving the utilization rate of clinical resources.
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Objective:To assess the three-dimensional dose distribution in radiotherapy plans using the structural similarity index(SSIM), compare the performance of SSIM with commonly used quality assessment indices, and develop a SSIM-based quality assessment method of multiple prescribed doses.Methods:The SSIM was introduced to providea quality score of various voxels by comparing actual and ideal three-dimensional dose data and combining the spatial location information of the voxels. Then the average value in a region of interest (ROI) was calculated as the quality score of the region. Fifty-three cases of cervical cancer were selected to analyze the correlation of the SSIM with the uniformity index (HI), conformity index (CI) of the dose distribution in various ROIs and to explore the capability of the SSIM to reflect the uniformity and conformity of dose distribution.Two types of quality defects were individually introduced into two of 53 radiotherapy plans. Then the two plans were compared with normal plans to characterize the response of the SSIM.Results:There was no correlation between HI and SSIM in positive lymph nodes(PGTVnd) due to the decrease in the HI sensitivity, while there was a significant negative correlation between them in regions where PGTVnd was removed from the planning target volume(PTV, R=-0.86, P<0.01). Meanwhile, there was a significant positive correlation between CI and SSIM in PGTVnd ( R=0.83, P<0.01). Therefore, the SSIM can be used to identify the artificial design defects in plans by determining abnormal dose gradients. Conclusions:Apart from reducing the defects of previous assessment parameters, the SSIM has the capability to assess the quality of radiotherapy plans by combining the uniformity and conformity of dose distribution and can provide accurate feedback on the spatial locations of quality defects.
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Neutrophils are the most abundant leukocytes in the peripheral blood and play an important role in the immune response. However, there is growing evidence indicating that in addition to the immune response, neutrophils also have a crucial role in tumor development, especially in the process of invasion and metastasis. According to current research, depending on their phenotype, neu-trophils appear to be either anti-metastasis (N1) or pro-metastasis (N2). However, the role of tumor-associated neutrophils (TANs) in the metastasis of tumors is relatively complex and lacks a systematic introduction. This review mainly introduces TANs and focuses on the mechanism of TANs in promoting tumor invasion and metastasis. Finally, the possibility of TANs as an anti-tumor treatment strate-gy is discussed.