Objective To quantitatively compare the dosimetric differences among 4 volumetric modulated arc therapy(VMAT)plans by analyzing the number of arcs and collimator angle settings,aiming to establish a standardized planning template for hippocampal-sparing prophylactic cranial irradiation(HS-PCI)in clinic and improve both planning quality and clinical efficiency.Methods Twenty HS-PCI patients were enrolled,with 4 VMAT plans(V2c,V2p,V3,and V4)for each patient.The differences in target dose,organs-at-risk dose,and monitor units were compared.Results V4 plan had the highest PTV D98%and V95%,and the differences of PTV D98%in V2c vs V2p,V2c vs V4,and PTV V95%in V2c vs V4 were statistically significant(P<0.05).Meanwhile,V4 plan had the lowest PTV Dmax and Dmin doses.Specifically,statistically significant differences were observed in PTV Dmax in V4 vs V2c,V4 vs V2p,V4 vs V3,as well as PTV Dmin in V2c vs V2p,V2c vs V3,V2c vs V4,V2p vs V4(P<0.05).The PTV Dmean was the highest in V2p plan,with statistically significant differences observed in V2c vs V2p,V2c vs V4,V2p vs V3,and V3 vs V4(P<0.05).The highest PTV D2%dose was observed in V2p plan,and the differences in V2c vs V2p,V2c vs V4,V2p vs V3,V3 vs V4 were statistically significant(P<0.05).The homogeneity index and conformity index were close in 4 plans(P=0.946,P=0.380).V4 plan had the lowest Dmax,Dmean,and Dmin of the hippocampus,with significant differences in hippocampal Dmax in V4 vs V2c,V4 vs V2p,hippocampal Dmean in V4 vs V2c,V4 vs V2p,V3 vs V2c,and hippocampal Dmin in V2c vs V2p/V3/V4,and V4 vs V2p(P<0.05).V3 plan had the lowest Dmax for bilateral lenses,and V4 plan showed the lowest Dmax for lenses with a 3 mm expansion,with significant differences between V2c and V2p/V3/V4(P<0.05).V4 plan had the lowest dose for the right optic nerve,with significant differences in V4 vs V2p,and V4 vs V3(P<0.05).No significant differences were observed for the left optic nerve and optic chiasm.The monitor units in V2p plan was the lowest.Conclusion When differences in organs-at-risk doses and plan quality parameters are insignificant,V2p plan is recommended as it can ensure treatment quality while reducing delivery time.

Objective To quantitatively compare the dosimetric differences among 4 volumetric modulated arc therapy(VMAT)plans by analyzing the number of arcs and collimator angle settings,aiming to establish a standardized planning template for hippocampal-sparing prophylactic cranial irradiation(HS-PCI)in clinic and improve both planning quality and clinical efficiency.Methods Twenty HS-PCI patients were enrolled,with 4 VMAT plans(V2c,V2p,V3,and V4)for each patient.The differences in target dose,organs-at-risk dose,and monitor units were compared.Results V4 plan had the highest PTV D98%and V95%,and the differences of PTV D98%in V2c vs V2p,V2c vs V4,and PTV V95%in V2c vs V4 were statistically significant(P<0.05).Meanwhile,V4 plan had the lowest PTV Dmax and Dmin doses.Specifically,statistically significant differences were observed in PTV Dmax in V4 vs V2c,V4 vs V2p,V4 vs V3,as well as PTV Dmin in V2c vs V2p,V2c vs V3,V2c vs V4,V2p vs V4(P<0.05).The PTV Dmean was the highest in V2p plan,with statistically significant differences observed in V2c vs V2p,V2c vs V4,V2p vs V3,and V3 vs V4(P<0.05).The highest PTV D2%dose was observed in V2p plan,and the differences in V2c vs V2p,V2c vs V4,V2p vs V3,V3 vs V4 were statistically significant(P<0.05).The homogeneity index and conformity index were close in 4 plans(P=0.946,P=0.380).V4 plan had the lowest Dmax,Dmean,and Dmin of the hippocampus,with significant differences in hippocampal Dmax in V4 vs V2c,V4 vs V2p,hippocampal Dmean in V4 vs V2c,V4 vs V2p,V3 vs V2c,and hippocampal Dmin in V2c vs V2p/V3/V4,and V4 vs V2p(P<0.05).V3 plan had the lowest Dmax for bilateral lenses,and V4 plan showed the lowest Dmax for lenses with a 3 mm expansion,with significant differences between V2c and V2p/V3/V4(P<0.05).V4 plan had the lowest dose for the right optic nerve,with significant differences in V4 vs V2p,and V4 vs V3(P<0.05).No significant differences were observed for the left optic nerve and optic chiasm.The monitor units in V2p plan was the lowest.Conclusion When differences in organs-at-risk doses and plan quality parameters are insignificant,V2p plan is recommended as it can ensure treatment quality while reducing delivery time.

Objective To analyze the CT signs of acute blunt or penetrating intestinal injury,and to improve the diagnostic accuracy of multi spiral CT for intestinal injury.Methods The CT and clinical data of 63 patients with intestinal injury confirmed by clinical surgical exploration who underwent emergency CT scan were collected,and the CT findings and surgical findings were comparatively analyzed.Results There were 63 cases of intestinal injury,of which 26 cases were complicated with mesenteric injury.The direct CT signs of intestinal injury included intestinal wall thickening sign and intestinal discontinuity sign,which accounted for 64%(40/63)and 17%(10/63),respectively.The indirect CT signs of intestinal injury included intraperitoneal/retroperitoneal gas sign,intraperitoneal/retroperitoneal effusion sign,intramural air,and portal venous gas,which accounted for 72%(45/63),88%(55/63),7%(5/63)and 5%(3/63),respectively.Conclusion Recognizing the CT signs of intestinal injury,such as intestinal wall thickening sign,intestinal discontinuity sign,intraperitoneal/retroperitoneal gas sign,intraperitoneal/retroperitoneal effusion sign,intramural air,and portal venous gas can help to make the early and correct diagnosis of intestinal injury if combined with clinical practice.

BACKGROUND:The treatment for bacterial biofilms after internal fixation surgery is a very difficult problem in clinic.It is a great significance to establish an animal model of irrigation for treating bacterial biofilms in the early stage after internal fixation surgery. OBJECTIVE:To establish an animal model for treating bacterial biofilms with different drugs through irrigation in early stage after internal fixation surgery. METHODS:Six New Zealand white rabbits were selected.Bilateral femoral surfaces were exposed and drilled holes were made,and bone plates colonized with Pseudomonas aeruginosa(experimental group)and blank bone plates(blank control group)were implanted around the drilled holes on one side,and two drainage tubes were retained and fixed to serve as the"inlet"and"outlet,"respectively.The model was immersed for a certain period of time after simulated perfusion before rinsing.After the simulated irrigation,the plates were soaked for a certain time before washing.At 5 days postoperatively,the rabbits were observed for body temperature,wound condition,bacterial culture of drainage fluid,and crystalline violet staining and scanning electron microscopy of the bone plate. RESULTS AND CONCLUSION:Six rabbits had difficulty in moving the affected limbs after surgery and showed elevated body temperature at 2-4 days after surgery.Local swelling could be touched at some wounds in the experimental group,and the wounds in the blank control group healed well.The results of bacterial culture of drainage fluid showed that Pseudomonas aeruginosa diffused or spread in the experimental group.At 5 days after surgery,the plate in the experimental group became purple shown by crystalline violet staining,and the absorbance value at 570 nm detected by the microplate reader was 2.621±0.088,indicating the presence of bacteria.Scanning electron microscopy at 5 days after surgery showed that a large number of bacterial microcolonies appeared on the surface of the plate in the experimental group,forming a highly inhomogeneous three-dimensional structure similar to the"mushroom-like"and"tower-like"structures,with filamentous water channels connecting the"mushroom-like"structures,which were typical biofilm structures with high densities,while no obvious colonies were seen in the blank control group.Overall,this animal model simulates the state of infected biofilm formation due to early infection after internal fixation and provides an available method of irrigation with different drugs.

Ghrelin is a hormone produced by the stomach that regulates energy metabolism after acting on the central nervous system.Cocaine amphetamine-regulated transcriptional peptide(CART)neurons participate in the regulation of feeding behavior and energy balance.It is known that CART neurons are influenced by hormones to regulate energy homeostasis,but whether ghre-lin exerts its pro-appetite function by influencing CART neurons is unknown.Therefore,this study focuses on the role of VMHCART neurons in the regulation of feeding and relative body weight by ghrelin.Firstly,the whole brain expression of CART was determined by immunofluorescence.Then the effect of intraperitoneal injection of ghrelin on the expression of DMHCART neurons was evalua-ted.Finally,the ghrelin was delivered to DMH and the changes of food intake and relative body weight of mice were measured.CART immunoreactive neurons were detected in medial preoptic nucleus(MPA),arcuate nucleus(ARC),dorsomedial hypothalamic nucleus(DMH),thalamic pa-raventricular nucleus(PVT)and raphe nucleus(ROb).Compared with the control group,periph-eral injection of ghrelin significantly increased the expression of DMHC ART immunoreactive neurons(P=0.037 3).DMH long-term injection of ghrelin resulted in an increase in body weight(P=0.004 0)and feed intake(P=0.023 1).The results provide anatomical evidence for the whole brain distribution of CART,which proves that ghrelin affects feed intake and body weight of mice through CART neurons in DMH,suggesting that specific neuron types and regional specificity are involved in ghrelin regulation of feed intake and energy homeostasis.

Vesicular glutamate transporter 2(VGlut2)is expressed in the PVN of the hypothalamic paraventricular nucleus(PVNVG1ut2)as an excitatory neurotransmitter,which regulates food intake and energy metabolism and plays an important role in maintaining homeostasis.However,it is not clear that the upstream and downstream projection network of PVNVGut2 neurons hinders the anal-ysis of glutamatergic neuron circuit function.Anterograde and retrograde tracer viruses were injec-ted into the PVN of VGlut2 mice by stereotactic brain injection technique to find the input and output nuclei of PVNVGlut2 neurons.Anterograde tracing results showed that PVNVGlut2 neurons pro-jected to the downstream medial amygdala(MeAD)and arcuate nucleus(ARC).Retrograde trac-ing results showed that PVNVGlut2 received input from the prefrontal nucleus(Pr),the reticular tegmental nucleus(RtTg),and the hypoglossal nucleus(12N).In addition,VGlut2 was found to be co-expressed with neuronal nitric oxide synthase(nNOS)neurons in the PVN.The anatomical net-work of PVNVG1ut2 neurons was analyzed by virus tracking tool,which laid the anatomical founda-tion for further study on the functional regulation of PVNVGlut2.

Objective:To investigate the efficacy of 125I seed implantation combined with programmed cell death 1 (PD-1) monoclonal antibody in the treatment of patients with stage Ⅳ non-small cell lung cancer. Methods:A retrospective analysis was performed on 106 patients with stage Ⅳ non-small cell lung cancer treated in Department of Radiology of the Sixth Medical Center of PLA General Hospital from February 2017 to January 2020. All patients were divided into the combination group, radiotherapy group and immunotherapy group according to treatment methods. Besides conventional chemotherapy in all three groups, 125I seed implantation combined with PD-1 monoclonal antibody therapy was given in the combination group, 125I seed implantation therapy was delivered in the radiotherapy, and PD-1 monoclonal antibody therapy was supplemented in the immunotherapy group, respectively. Differences in the general data, maximum tumor diameter, efficacy, progression-free survival (PFS) and safety among the three groups were analyzed. One-way ANOVA was used for comparison between groups, paired sample t-test was used for comparison before and after treatment. Kaplan-Meier method was used to calculate the survival rate, and log-rank test was used to compare the survival curve. Results:After treatment, the maximum tumor diameter in the three groups was decreased, and the data in the combination group was smaller than those in the radiotherapy and immunotherapy groups ( F=4.67, P=0.011). The objective response rate (ORR), disease control rate (DCR) and PFS rate in the combination group were higher than those in the radiotherapy and immunotherapy groups ( χ2=18.93, P<0.001; χ2=11.11, P=0.004; χ2=6.67, P=0.036), and the ORR in the immunoradiotherapy group was higher than that in the radiotherapy group ( χ2=4.23, P=0.040). There was no significant difference in the occurrence of adverse reactions among the three groups ( χ2=1.60, P=0.449). Conclusion:125I seed implantation combined with PD-1 monoclonal antibody may yield high efficacy in patients with stage Ⅳ non-small cell lung cancer, which can alleviate clinical symptoms and improve long-term survival rate with good safety.

Amylin exerts a satiety-limiting effect on food intake by influencing the regulation of en-ergy metabolism in the central nucleus.However,the binding sites of amylin are widely distributed throughout the central nervous system,and it remains unclear whether the locus coeruleus(LC)responds to amylin stimulation.Therefore,this experiment aims to confirm whether amylin exerts its inhibitory effect on food intake through the LC following localized damage to the LC nucleus.The results indicate that amylin,while suppressing appetite,activates c-Fos neurons and tyrosine hydroxylase(TH)within the LC,leading to increased heat production in the interscapular brown adipose tissue(IBAT)of mice.However,after LC damage,the central feeding inhibition mediated by amylin is alleviated,although it is weaker compared to the group with solely LC damage,and the thermogenic capacity of IBAT is reduced.Thus,the study demonstrates that the LC is also one of the sites of action for exogenous amylin and is crucial for maintaining amylin-induced thermo-genesis.These findings expand the understanding of amylin's central actions and ultimately provide potential targets for obesity treatment.

CT simulator has the functions such as original coordination positioning and radiotherapy resetting,and it can provide image and cooridiate information for radiotherapy.Through electronic density calibration,tissue inhomogeneity correction is carried out for supporting dose calculation in treatment planning system.With reference to relevant national standards,international guidelines,clinical functions of CT simulator and the practical experience of the center,a set of acceptance and commissioning testing scheme suitable for big bore CT simulator is presented,aiming to guide and assist the newly opened department in conducting comprehensive,safe and feasible acceptance and commissioning tests.The scheme includes the reference methods and tolerance standards of CT simulator machinery,image quality,radiation dose,radiotherapy related items and safety,so as to ensure the safety and accuracy of CT simulation and survival benefits.

CT simulator has the functions such as original coordination positioning and radiotherapy resetting,and it can provide image and cooridiate information for radiotherapy.Through electronic density calibration,tissue inhomogeneity correction is carried out for supporting dose calculation in treatment planning system.With reference to relevant national standards,international guidelines,clinical functions of CT simulator and the practical experience of the center,a set of acceptance and commissioning testing scheme suitable for big bore CT simulator is presented,aiming to guide and assist the newly opened department in conducting comprehensive,safe and feasible acceptance and commissioning tests.The scheme includes the reference methods and tolerance standards of CT simulator machinery,image quality,radiation dose,radiotherapy related items and safety,so as to ensure the safety and accuracy of CT simulation and survival benefits.