Objective: To apply level set motion-based elastic registration method to radiotherapy CT image, then to provide technical support for the accurate evaluation of tumor and changing process of patients with endanger organ and its accumulative dose. Methods: Based on Vemuri’s level set motion method, we wrote the algorithm program using Matlab software and applied on two sets of 3D CT images from patients with cervical cancer and NPC for fully automatic elastic registration. Results: Comparing CT images before and after registration, for the cervical cancer patient, the minimum mean square error (MSE) decreased by 55.1%and correlation coefficient (CC) increased by 5.3%. For the NPC patient, MSE decreased by 32.1%and CC increased by 4.6%. Conclusion: From the image difference and evaluation parameters, the efficacy of level set motion-based elastic registration method was preliminarily demonstrated. In order to apply this method to clinical radiotherapy, dit needs to find a more accurate mathematical algorithm further in order to compute human anatomy deformation through image motion.

Objective To explore the relationship between the overlap volume of organ at risk (OAR) and target (Voverlap) and the mean dose to OAR (DmOAR) in intensity-modulated radiotherapy (IMRT).Methods Fifty randomly selected patients undergoing IMRT for nasopharyngeal carcinoma (NPC) and an equal number of patients undergoing radical IMRT for cervical cancer in our hospital were enrolled as subjects.The relationship between Voverlap and DmoAR in IMRT was analyzed.The Matlab software was used to generate function to fit the relationship between Voverlap and DmOAR for different OARs.Results The Voverlap varied among patients with NPC or cervical cancer.The ratio of Voverlap to the volume of OAR (VOAR) was positively correlated with the ratio of DmOAR to the prescribed dose (Dp) (all P=0.01).A function was generated to fit the correlation between Voverlap/VOAR ratio and DmOAR/Dp ratio.Conclusions In IMRT,patients have different Voverlap/VoAR ratios due to varicd target volume,disease stages,OAR filling status,and OAR volume.As criteria for plan verification,a specific DmOAR value for each OAR should be calculated before radiotherapy planning based on the corresponding correlation function and the Voverlap/VoAR ratio with a fixed dose prescription.It can be used to reduce the subjective influence on the optimization of radiotherapy planning.

AIM: To investigate the downstream genes of the transcriptional factor Pax-8 related to cardiopathy. METHODS: The total RNA derived from the heart of Pax-8 KO~(-/-) and Pax-8 KO~(+/-) mice was extracted. Mouse genome DNA microarray containing 31 802 mouse oligonucleotides probes was used to investigate the differential expression between the Pax-8 KO~(-/-) and the Pax-8 KO~(+/-) mice hearts. The candidate genes were confirmed by RT-PCR and real time RT-PCR assay. RESULTS: Microarray results showed that, compared to the Pax-8 KO~(+/-) mice, 25 genes were down-regulated and 17 were up-regulated in the Pax-8 KO~(-/-) mice, concerning metabolize enzymes, cell signal conducting and nuclear transcript factors and so on. Bcl2-like 14 (Bcl2l14) was proved to be up-regulated by RT-PCR. Real time RT-PCR results revealed that Bcl2l14 in the Pax-8 KO~(-/-) mice was 2.07 and 2.23 fold as much as that in the Pax-8 KO~(+/-) and the Pax-8KO~(+/+) mice (P<0.01). CONCLUSION: The Bcl2l14 gene is one of the downstream genes of Pax-8 and probably plays an important role in the mechanism of ventricular septum defect.

AIM: To investigate the effect of selective silencing of SLC7a8 on uptaking L-dopa in renal tubular epithelial cells of rat (NRK-52E). METHODS: The three siRNAs targeting SLC7a8 (siRNA-1, siRNA-2, siRNA-3) were designed and synthesized. A siRNA with nonspecific coding sequence (siRNA-con) was used for control. All siRNAs were transfected into NRK-52E cells. The siRNA-con transfected group, blank control group and gene-specific silencing SLC7a8 group were set up. The efficiency of transfection was estimated by flow cytometry. The efficiency of RNA interference was detected and screened by RT-PCR preliminarily, and was followed by Western blotting at protein level. The concentrations of L-dopa uptake into the NRK-52E cells were detected by ultraviolet spectrophotometry at different time points (6, 12, 24, 36, 48, 60, 72 and 120 min). RESULTS: The transfection efficiency was 94% detected by flow cytometry. The initial screening of RT-PCR showed that the efficiencies of RNA interference of siRNA-1 and siRNA-3 were higher, and siRNA-3 was the highest at protein level determined by Western blotting. No distinctive change was found between siRNA-con treated NRK-52E and blank control cells. The L-dopa uptake at different time points (6, 12, 24, 36, 48, 60, 72 and 120min) in siRNA-interference group was lower than that in siRNA-con transfected group and blank control group. No significant difference of L-dopa uptake between siRNA-con group and blank control group was observed. CONCLUSION: RNA interference technology selectively down-regulates SLC7a8 expression in rat renal tubular epithelial cells. The L-dopa uptake is also decreased after specifically silencing the slc7a8 expression.

Objective To explore the dose of template-assisted ¹⁹²Ir source hypofractionated stereotactic brachytherapy (SABT) for peripheral lung cancer. Methods We retrospectively analyzed the dose parameters of GTV and OARs of 28 peripheral lung cancer patients treated with template-assisted ¹⁹²Ir-source hypofractionated SABT, and compared the dose parameters between SABT with virtual SBRT. Results The D_mean and V₁₅₀ for the GTV in the SABT plan were significantly higher than those in the SBRT plan (all P < 0.01). For OARs, all dosimetric parameters in the SABT plan were significantly lower than those in the SBRT plan (all P < 0.01), except for the D_1000cm³ and D_1500cm³ for the lung (P > 0.05). Conclusion Template-assisted ¹⁹²Ir source hypofractionated SABT ensures high dose in the gross tumor volume and reduces the dose in organs at risk in the treatment of peripheral lung cancer.

Objective: To preliminarily evaluate the safety of the coplanar template-assisted ¹⁹²Ir hypofractionated stereotactic ablative brachytherapy (SABT) in patients with locally advanced non-small cell lung cancer (LA-NSCLC), and assess the effect of template-assisted technology upon the accuracy of SABT by comparing the consistency of dosimetric parameters between preoperative and operative plans. Methods: Fifteen patients histologically confirmed with LA-NSCLC (stage Ⅱ_B-Ⅲ_A) were recruited and received the template-assisted SABT delivered in a risk-adapted fractionation (30 Gy/1F). Preoperative planning, template-assisted needle implantation, operative planning and implementation were performed in all patients. Dosimetric results of preoperative and operative plans were statistically compared by assessing the dosimetric parameters of gross tumor volume (HI, CI, D₉₀, V₁₀₀ and V₁₅₀) and organ at risk(V₅, V₂₀ and mean dose of bilateral lung, D_2cc of spinal cord. The incidence of perioperative complications of SABT was recorded. The safety and feasibility of SABT were evaluated. Results: Slight changes were noted in terms of target dose and irradiated dose to the lung between preoperative and operative plans without statistical significance (both P>0.05). No severe adverse events, such as severe pneumothorax, hemothorax and hemoptysis were observed. Conclusions Application of the template-assisted SABT can enhance the accuracy of implantation, maintain the consistency of the dosimetric parameters between the preoperative and operative plans and guarantee the clinical efficacy.

Objective The aim of this study was to explore the effectiveness of self-made oral humidity detection device to assist in evaluating the degree of parotid gland damage in radiotherapy for nasopharyngeal carcinoma,so as to guide doctors to change the radiotherapy plan in time,reduce the radiation dose to parotid gland,and reduce the incidence of xerostomia after radiotherapy.Methods A retrospective analysis was conducted on the relationship between oral humidity and parotid gland dose of radiotherapy in 60 patients with nasopharyngeal carcinoma using oral detection devices in the Department of Oncology of Southwest Medical University Affiliated Hospital from January 1,2022 to December 31,2022.According to the method of changing the radiotherapy plan,patients were divided into experimental group(n=30)and control group(n=30).The patients in the experimental group used a self-made oral humidity detection device to detect oral humidity,when 30 patients with oral relative humidity below 65%underwent CT simulation positioning and changed the radiotherapy plan to reduce the dose of parotid gland;The control group patients collected oral humidity but did not interfere in the radiotherapy plan,and only underwent CT positioning during the mid-term radiotherapy.The average oral humidity,parotid gland,and target area dose parameters of patients were analyzed after radiotherapy.The follow-up questionnaire was conducted to evaluate the life quality of patients in terms of dry mouth,decreased taste,difficulty opening mouth,and dental caries in two groups.Results The average oral humidity(t=2.938,P<0.05),the Dmean of average dose of bilateral parotid glands(tleft=-2.076,tright=-2.094,P<0.05),the D50 for dose of 50%volume of bilateral parotid glands(tleft=-2.123,tright=-2.230,P<0.05),and the volume percentage V30 of bilateral parotid gland dose(tleft=-2.505,tright=-2.491,P<0.05)in patients were significantly re-duced in the experimental group compared to the control group,while there was no statistically significant differences in target area do-simetric parameters(P>0.05).The dry mouth and taste loss in the experimental group were lower than those of the control group(P<0.05),and the difficulty in opening the mouth and caries scores were lower than those of the control group,but the difference was not statistically significant(P>0.05).Conclusion The oral humidity detection device can detect the oral humidity of radiotherapy pa-tients in time,objectively evaluate the impact of radiation on patient's parotid gland,guide doctors to change the radiotherapy treatment plan in a timely manner,minimize the degree of parotid gland damage,and improve their quality of life in nasopharyngeal carcinoma radiotherapy patients.At the same time,the device is easy to operate,time-consuming,and non-invasive,which improves the effec-tiveness and safety of radiotherapy technology and is worth promoting this device.

Objective To analyze the effect of needle arrangement on the lung dose in interstitial brachytherapy for lung cancer. Methods For 15 patients undergoing interstitial brachytherapy for lung cancer, a virtual radiotherapy plan in which needle arrangement was not restricted by the ribs was designed and compared with the original plan. For the two plans, V5, V20, V30, and mean lung dose(MLD)of the whole lung were determined when the prescribed doses were 10,30, 60, and 120 Gy, respectively. The data were analyzed by Wilcoxon signed-rank test. Results The lung V5,V20, V30, and MLD were significantly smaller in the virtual plan than in the actual plan(all P<0.05). Conclusions Irregular needle arrangement prevents a further reduction in the lung dose in interstitial brachytherapy for lung cancer. In the implantation surgery, therefore, the needles should be arranged as regularly as possible.

Objective:To evaluate the relationship between hippocampal miR-3065-5p and insulin-like growth factor-1/phosphatidylinositol 3-kinase/protein kinase B(IGF-1/PI3K/Akt)signaling pathway in a mouse model of perioperative neurocognitive disorder (PND).Methods:Eighty clean-grade healthy male C75BL/6 mice, aged 12-14 weeks, weighing 20-30 g, were divided them into 4 groups ( n=20 each) using the random number table method: control group (C group), PND group, miR-3065-5p agonist group (Ag group) and miR-3065-5p agonist negative control group (Ag-NC group). PND model was prepared by internal fixation of tibial fracture under anesthesia with 1.5% isoflurane. Two days before developing the model, miR-3065-5p agomir 2 μl was injected into the lateral ventricle in Ag group, miR-3065-5p agomir negative control 2 μl was injected into the lateral ventricle in Ag-NC group. Morris water maze test and open field test were performed at 7 days after surgery. The mice were sacrificed after the end of test, and hippocampal tissues were obtained for determination of the expression of miR-3065-5p, IGF-1 mRNA and Bcl-2 mRNA (by quantitative real-time polymerase chain reaction) and expression of IGF-1, phosphorylated Akt (p-Akt), phosphorylated glycogen synthase kinase-3β (p-GSK3β) and Bcl-2 (by Western blot). Results:There was no significant difference in each parameter in the open field test among the four groups ( P>0.05). Compared with group C, the postoperative escape latency was significantly prolonged, the percentage of time of stay at the target quadrant was decreased, the number of crossing the original platform was reduced, the expression of miR-3065-5p was up-regulated, and the expression of IGF-1 mRNA, Bcl-2 mRNA, IGF-1, p-Akt, p-GSK3β and Bcl-2 was down-regulated in the other three groups ( P<0.05). Compared with PND group and Ag-NC group, the postoperative escape latency was significantly prolonged, the percentage of time of stay at the target quadrant was decreased, the number of crossing the original platform was reduced, the expression of miR-3065-5p was up-regulated, and the expression of IGF-1 mRNA, Bcl-2 mRNA, IGF-1, p-Akt, p-GSK3β and Bcl-2 was down-regulated in Ag group ( P<0.05). Conclusions:Up-regulation of miR-3065-5p can inhibit the activation of IGF-1/PI3K/Akt signaling pathway, which might be one of the mechanisms of PND developed in mice.

Objective:To investigate the effects of mild hypothermia on microglia polarization and janus kinase 2/signal transduction and transcriptional activation factor 3 (JAK2/STAT3) signaling pathway during cerebral ischemia-reperfusion (I/R) in rats.Methods:Forty-five clean-grade healthy male Sprague-Dawley rats, aged 8 weeks, weighing 260-280 g, were divided into 3 groups ( n=15 each) by the random number table method: sham operation group (S group), cerebral I/R group (I/R) and mild hypothermia group (H group). In I/R group and H group, cerebral I/R was induced by middle cerebral artery occlusion using a nylon thread in anesthetized animals, the nylon thread was removed to restore the perfusion after 2 h of occlusion, and the rectal temperature was maintained at 36-37 ℃ during the period. Group H was wiped with 75% alcohol for 3 h starting from the time point immediately after reperfusion, and the rectal temperature was maintained at 32-33℃. Modified neurological severity score (mNSS) was evaluated at 24 h of reperfusion. Animals were then sacrificed for determination of the cerebral infarct size (using TTC staining), expression of M1 marker inducible nitric oxide synthase (iNOS), M2 marker arginase 1(Arg-1), phosphorylated JAK2(p-JAK2)and phosphorylated STAT3(p-STAT3)(by Western blot), expression of iNOS mRNA and Arg-1 mRNA (by quantitative polymerase chain reaction), and contents of interleukin-6 (IL-6) and IL-10 (by enzyme-linked immunosorbent assay). Results:Compared with group S, mNSS and cerebral infarct size were significantly increased, the expression of iNOS, Arg-1 protein and mRNA in cerebral ischemic penumbral zone was up-regulated, and the p-JAK2/JAK2 ratio, p-STAT3/STAT3 ratio, and contents of IL-6 and IL-10 were increased in the other two groups ( P<0.05). Compared with I/R group, mNSS and cerebral infarct size were significantly decreased, the expression of iNOS protein and mRNA in cerebral ischemic penumbral zone was down-regulated, the expression of Arg-1 and mRNA was up-regulated, and the p-JAK2/JAK2 ratio, p-STAT3/STAT3 ratio and IL-6 content were decreased, and the IL-10 content was increased in group H ( P<0.05). Conclusions:Mild hypothermia can promote the polarization shift of microglia from M1 to M2 phenotype during cerebral I/R and inhibit the central inflammatory responses, and the mechanism may be related to inhibition of JAK2/STAT3 signaling pathway in rats.