Objective To investigate the application value of full-length lower extremity CT scans performed at different noise index(NI)in terms of image quality and radiation dose for robot-assisted total knee arthroplasty(RTKA).Methods Eighty patients who underwent RTKA were selected and randomly divided into four groups based on different NI:NI=8,NI=18,NI=28,and NI=38.Subjective scores were assigned to the full-length lower extremity CT images and the three-dimensional skeletal models generated by volume rendering(VR)post-processing.Objective evaluations were performed using three indicators:dose length product(DLP),volume CT dose index(CTDIvol),and hip-knee-ankle angle(HKA).The application value of full-length lower extremity CT scans in RTKA was analyzed.Results(1)As the NI value increased,the subjective scores of thin-slice images decreased.Images with NI between 8 and 18 met the imaging diagnostic standards,while those with NI higher than 18 were unacceptable.(2)As the NI value increased,all VR skeletal models met the acceptance criteria for RTKA.(3)As the NI value increased,DLP and CTDIvol gradually decreased,with statistically significant differences(P<0.05),However,in the comparison between the NI=28 and NI=38 groups,the difference was not statistically significant(P>0.05).Conclusion Performing full-length lower extremity CT scans with an NI of 28 not only meets the preoperative planning requirements for RTKA but also minimizes the radiation dose.

Objective To investigate the efficacy and safety of transcutaneous electrical acupoint stimulation(TEAS)in reducing the consumption of analgesics after total knee arthroplasty(TKA).Methods Totally 124 patients undergoing unilateral TKA were included and divided into an intervention group and a control group according to random number table method,with 62 cases in each group.Both groups received routine postoperative analgesic protocols,with the intervention group additionally receiving TEAS treatment,30 min per time,twice a day.The additional doses of intravenous patient-controlled analgesia pumps and opioid analgesic consumption in two groups of patients after surgery were analyzed,as well as the adverse events and laboratory test results(WBC,PLT,SCr,BUN,ALT and AST)in both groups.Results The number of additional doses in the intervention group with the patient-controlled analgesia pump and the consumption of opioid analgesic were both lower than those in the control group(P<0.05);the incidence of postoperative nausea symptoms in the intervention group was lower than that in the control group,while other adverse reactions showed no significant difference(P>0.05).There was no significant difference in laboratory test results(WBC,PLT,SCr,BUN,ALT and AST)between the two groups on the day before surgery and on the 1st and 7th days after surgery(P>0.05).Conclusion TEAS can reduce the consumption of analgesics after TKA,decrease some adverse reactions associated with the use of analgesics,and has good safety.

Objective To investigate the application value of full-length lower extremity CT scans performed at different noise index(NI)in terms of image quality and radiation dose for robot-assisted total knee arthroplasty(RTKA).Methods Eighty patients who underwent RTKA were selected and randomly divided into four groups based on different NI:NI=8,NI=18,NI=28,and NI=38.Subjective scores were assigned to the full-length lower extremity CT images and the three-dimensional skeletal models generated by volume rendering(VR)post-processing.Objective evaluations were performed using three indicators:dose length product(DLP),volume CT dose index(CTDIvol),and hip-knee-ankle angle(HKA).The application value of full-length lower extremity CT scans in RTKA was analyzed.Results(1)As the NI value increased,the subjective scores of thin-slice images decreased.Images with NI between 8 and 18 met the imaging diagnostic standards,while those with NI higher than 18 were unacceptable.(2)As the NI value increased,all VR skeletal models met the acceptance criteria for RTKA.(3)As the NI value increased,DLP and CTDIvol gradually decreased,with statistically significant differences(P<0.05),However,in the comparison between the NI=28 and NI=38 groups,the difference was not statistically significant(P>0.05).Conclusion Performing full-length lower extremity CT scans with an NI of 28 not only meets the preoperative planning requirements for RTKA but also minimizes the radiation dose.

Objective To investigate the efficacy and safety of transcutaneous electrical acupoint stimulation(TEAS)in reducing the consumption of analgesics after total knee arthroplasty(TKA).Methods Totally 124 patients undergoing unilateral TKA were included and divided into an intervention group and a control group according to random number table method,with 62 cases in each group.Both groups received routine postoperative analgesic protocols,with the intervention group additionally receiving TEAS treatment,30 min per time,twice a day.The additional doses of intravenous patient-controlled analgesia pumps and opioid analgesic consumption in two groups of patients after surgery were analyzed,as well as the adverse events and laboratory test results(WBC,PLT,SCr,BUN,ALT and AST)in both groups.Results The number of additional doses in the intervention group with the patient-controlled analgesia pump and the consumption of opioid analgesic were both lower than those in the control group(P<0.05);the incidence of postoperative nausea symptoms in the intervention group was lower than that in the control group,while other adverse reactions showed no significant difference(P>0.05).There was no significant difference in laboratory test results(WBC,PLT,SCr,BUN,ALT and AST)between the two groups on the day before surgery and on the 1st and 7th days after surgery(P>0.05).Conclusion TEAS can reduce the consumption of analgesics after TKA,decrease some adverse reactions associated with the use of analgesics,and has good safety.

Objective:To investigate the value of CT radiomic model based on analysis of primary gastric cancer and the adipose tissue outside the gastric wall beside cancer in differentiating stage T1-2 from stage T3-4 gastric cancer.Methods:This study was a case-control study. Totally 465 patients with gastric cancer treated in Affiliated People′s Hospital of Jiangsu University from December 2011 to December 2019 were retrospectively collected. According to postoperative pathology, they were divided into 2 groups, one with 150 cases of T1-2 tumors and another with 315 cases of T3-4 tumors. The cases were divided into a training set (326 cases) and a test set (139 cases) by stratified sampling method at 7∶3. There were 104 cases of T1-2 stage and 222 cases of T3-4 stage in the training set, 46 cases of T1-2 stage and 93 cases of T3-4 stage in the test set. The axial CT images in the venous phase during one week before surgery were selected to delineate the region of interest (ROI) at the primary lesion and the extramural gastric adipose tissue adjacent to the cancer areas. The radiomic features of the ROIs were extracted by Pyradiomics software. The least absolute shrinkage and selection operator was used to screen features related to T stage to establish the radiomic models of primary gastric cancer and the adipose tissue outside the gastric wall beside cancer. Independent sample t test or χ2 test were used to compare the differences in clinical features between T1-2 and T3-4 patients in the training set, and the features with statistical significance were combined to establish a clinical model. Two radiomic signatures and clinical features were combined to construct a clinical-radiomics model and generate a nomogram. The area under the receiver operating characteristic curve (AUC) was used to evaluate the efficacy of each model in differentiating stage T1-2 from stage T3-4 gastric cancer. The calibration curve was used to evaluate the consistency between the T stage predicted by the nomogram and the actual T stage of gastric cancer. And the decision curve analysis was used to evaluate the clinical net benefit of treatment guided by the nomogram and by the clinical model. Results:There were significant differences in CT-T stage and CT-N stage between T1-2 and T3-4 patients in the training set ( χ2=10.59, 15.92, P=0.014, 0.001) and the clinical model was established. After screening and dimensionality reduction, the 5 features from primary gastric cancer and the 6 features from the adipose tissue outside the gastric wall beside cancer established the radiomic models respectively. In the training set and the test set, the AUC values of the primary gastric cancer radiomic model were 0.864 (95% CI 0.820-0.908) and 0.836 (95% CI 0.762-0.910), and the adipose tissue outside the gastric wall beside cancer radiomic model were 0.782 (95% CI 0.731-0.833) and 0.784 (95% CI 0.702-0.866). The AUC values of the clinical model were 0.761 (95% CI 0.705-0.817) and 0.758 (95% CI 0.671-0.845), and the nomogram were 0.876 (95% CI 0.835-0.917) and 0.851 (95% CI 0.781-0.921). The calibration curve reflected that there was a high consistency between the T stage predicted by the nomogram and the actual T stage in the training set ( χ2=1.70, P=0.989). And the decision curve showed that at the risk threshold 0.01-0.74, a higher clinical net benefit could be obtained by using a nomogram to guide treatment. Conclusions:The CT radiomics features of primary gastric cancer lesions and the adipose tissue outside the gastric wall beside cancer can effectively distinguish T1-2 from T3-4 gastric cancer, and the combination of CT radiomic features and clinical features can further improve the prediction accuracy.

Objective To investigate the mechanism of metformin for regulating tumor-stromal cell cross-talk in breast cancer.Methods Tumor associated fibroblasts(CAFs)co-cultured with breast cancer cells were treated with metformin,and the changes in expressions of hypoxia-inducible factor-1α(HIF-1α),p-AMPK,stroma-derived factor-1(SDF-1)and interleukin-8(IL-8)in the CAFs were detected using ELISA,RT-qPCR or Western blotting;Transwell assay was used to evaluate the invasiveness of the tumor cells and its changes following treatment with exogenous SDF-1,IL-8 and TGF-β1.The effects of HIF-1α shRNA or overexpression plasmid,AMPK shRNA,and treatment with OG(a proline hydroxylase inhibitor)or 2-OXO(a proline hydroxylase activator)were examined on p-AMPK,HIF-1α,SDF-1 and IL-8 expressions and invasiveness of the CAFs.Results Metformin treatment significantly increased the expression levels of p-AMPK,SDF-1 and IL-8(P<0.05)and decreased HIF-1α expression(P<0.05)without affecting AMPK expression level(P>0.05)in the CAFs.The invasion ability of metformin-treated breast cancer cells was significantly decreased(P<0.05).Exogenous SDF-1 and IL-8,HIF-1α overexpression,and OG-induced upregulation of HIF-1α all significantly attenuated the inhibitory effects of metformin on breast cancer cell invasion(P<0.05)and HIF-1α,SDF-1 and IL-8 expressions in CAFs(P<0.05).Transfection with HIF-1α shRNA or treatment with 2-OXO significantly decreased the invasiveness of breast cancer cells(P<0.05).P-AMPK knockdown significantly suppressed the inhibitory effect of metformin on HIF-1α expression in CAFs and on invasion of breast cancer cells(P<0.05).Treatment with TGF-β1 partially decreased the inhibitory effect of metformin on HIF-1α expression in CAFs and invasiveness of the breast cancer cells(P<0.05).Conclusion Metformin suppresses HIF-1α expression in CAFs to block tumor-stromal cross talk in breast cancer.

Objective To investigate the mechanism of metformin for regulating tumor-stromal cell cross-talk in breast cancer.Methods Tumor associated fibroblasts(CAFs)co-cultured with breast cancer cells were treated with metformin,and the changes in expressions of hypoxia-inducible factor-1α(HIF-1α),p-AMPK,stroma-derived factor-1(SDF-1)and interleukin-8(IL-8)in the CAFs were detected using ELISA,RT-qPCR or Western blotting;Transwell assay was used to evaluate the invasiveness of the tumor cells and its changes following treatment with exogenous SDF-1,IL-8 and TGF-β1.The effects of HIF-1α shRNA or overexpression plasmid,AMPK shRNA,and treatment with OG(a proline hydroxylase inhibitor)or 2-OXO(a proline hydroxylase activator)were examined on p-AMPK,HIF-1α,SDF-1 and IL-8 expressions and invasiveness of the CAFs.Results Metformin treatment significantly increased the expression levels of p-AMPK,SDF-1 and IL-8(P<0.05)and decreased HIF-1α expression(P<0.05)without affecting AMPK expression level(P>0.05)in the CAFs.The invasion ability of metformin-treated breast cancer cells was significantly decreased(P<0.05).Exogenous SDF-1 and IL-8,HIF-1α overexpression,and OG-induced upregulation of HIF-1α all significantly attenuated the inhibitory effects of metformin on breast cancer cell invasion(P<0.05)and HIF-1α,SDF-1 and IL-8 expressions in CAFs(P<0.05).Transfection with HIF-1α shRNA or treatment with 2-OXO significantly decreased the invasiveness of breast cancer cells(P<0.05).P-AMPK knockdown significantly suppressed the inhibitory effect of metformin on HIF-1α expression in CAFs and on invasion of breast cancer cells(P<0.05).Treatment with TGF-β1 partially decreased the inhibitory effect of metformin on HIF-1α expression in CAFs and invasiveness of the breast cancer cells(P<0.05).Conclusion Metformin suppresses HIF-1α expression in CAFs to block tumor-stromal cross talk in breast cancer.

Objective:To investigate the early- and mid-term clinical, functional and radiographic outcomes of patellofemoral arthroplasty (PFA).Methods:A retrospective analysis was conducted in 64 patients (80 knees) who suffered from severe patellofemoral osteoarthritis (PFOA) and underwent PFA from January 2013 to December 2020. These patients were aged 60.50±8.82 (range from 27 to 82) years, including 9 males (12 knees) and 55 females (68 knees). All enrolled individuals presented typical PFOA. Unilateral PFA was performed in 48 cases, bilateral PFA in 16 cases, including one-stage PFA in 9 cases and two-stage PFA in 7 cases. The visual analogue scale (VAS), Hospital for Special Surgery (HSS) knee score and Oxford knee score (OKS) of patients with more than 5 years' follow-up were assessed to evaluate the clinical effects of PFA at the time before surgery, 1 year and 5 years after surgery. In addition, the patellar tilt angle (PTA) and hip-knee-ankle (HKA) angle were measured and analyzed to evaluate the improvement of patellar tracking and progression of tibiofemoral osteoarthritis, based on axial X-ray imaging (skyline view) of knee and the full length standing X-ray imaging of the lower limbs at before surgery and 5 years after surgery. Meanwhile, the complications of all patients that related to the operation were recorded.Results:A total of 64 patients were followed up for 4.31±1.79 (range, 1.5 to 8.2) years. Twenty-five patients (32 knees) who followed up more than 5 years were analyzed. The VAS, HSS and OKS improved from 5.91±0.82, 68.06±6.03 and 21.22±3.46 preoperatively to 0.88±1.01, 90.09±3.30 and 39.06±3.37 at 1 year after surgery, and to 0.41±0.76, 94.53±2.99 and 42.13±3.17 at 5 years after surgery, respectively ( F=89.38, 81.47, 56.73, P<0.001). Additionally, comparing to the preoperative radiological data, the patellar tract was improved with the PTA decreased from 8.21°±3.14° preoperatively to 3.58°±4.48°at 5 years after surgery ( t=4.96, P<0.001). The HKA angle changed from 179.01°±1.43° preoperatively to 178.77°±1.67° at 5 years follow up ( t=1.71, P=0.096). There was no case of prosthesis loosening or wear and no case of obvious progression of tibiofemoral osteoarthritis that needed revision in all patients. Conclusion:Satisfied early- and mid-term clinical outcomes could be achieved by PFA in treating severe PFOA patients. PFA could relieve pain and improve function of knee joint.

Objective To investigate the relationship between the incipient serum C-reactive protein (CRP) and clinicopathologic features in anti-neutrophil cytoplasmic antibody associated vasculitis (AAV).Methods Data of 138 consecutive AAV patients were collected.According to their serum CRP levels,patients were divided into group 1 with normal CRP,group 2 with slightly increased CRP and group 3 with severely increased CRP.Clinical features of AAV and histopathologic features of the kidney injury were compared among groups.Results CRP levels increased in 77.53％ AAV patients on admission.Patients in the group of severely increased CRP had the highest levels of BVAS,serum C3,serum ANCA titer,leukocyte counts and the lowest levels of hemoglobin and albumin among the 3 groups (all P ＜ 0.05).The mortality during the stage of therapy was highest in patients with severely increased CRP (P ＜ 0.05).The focal kidney damage was more obvious in patients with severely increased CRP.There was no significant difference in renal prognosis among patients with different CRP levels.Conclusion The levels of incipient serum C-reactive protein of AAV vary in different patients and are positively correlated with patients' inflammation status as well as the disease activity,but are not correlated with the severity of kidney injury.