Background and Purpose:Previous studies have investigated the prognostic significance of skeletal muscle and adipose tissue composition and distribution in colorectal cancer patients,yet most have not differentiated between rectal and colon cancer patient cohorts.This study aimed to explore the relationship between body composition and long-term prognosis,and to develop a postoperative predictive model.Methods:Clinical data of rectal cancer patients who underwent surgical treatment at Qingdao University Affiliated Hospital from January 2018 to December 2021 were retrospectively collected.Inclusion criteria:①Age＞18 years;② Preoperative colonoscopy and pathological diagnosis of colorectal cancer;③ Complete surgical resection;④Abdominal computed tomography(CT)scan 1 month before surgery.Exclusion criteria:① Clinical data is missing;② Multiple metastases of tumors;③ Tumor T stage 0 or carcinoma in situ;④ Severe artifacts lead to poor quality CT imaging,making it difficult to distinguish between fat and muscle;⑤ Inability to obtain follow-up results.This study has been approved by the Medical Ethics Committee of the Affiliated Hospital of Qingdao University(approval number:QYFYWZLL30313),and informed consent has been waived in the ethical approval process.The skeletal muscle index(SMI)and subcutaneous adipose tissue index(SATI)were calculated by dividing the areas of skeletal muscle and subcutaneous fat observed on CT scans by the square of the patient's height.Univariate and multivariate COX regression analyses were conducted to identify risk factors influencing recurrence-free survival(RFS)and overall survival(OS)in rectal cancer patients.Based on the results of the multivariate analysis,a nomogram prediction model was developed,its predictive power and accuracy were assessed using the receiver operating characteristic(ROC)curve,calibration plots and decision curve analysis(DCA),and internal validation was conducted.Results:A total of 696 patients were included in this study,with 96(13.8%)patients experiencing postoperative recurrence and 89(12.8%)patients dying.Multivariate COX regression analysis showed that SMI,SATI,tumor T stage and N stage were independent factors affecting the postoperative RFS and OS of patients.Nomogram prediction models for RFS and OS in rectal cancer patients were constructed based on the above independent predictors.The area under ROC curve(AUC)for 3-,4-and 5-year RFS was 0.862,0.846 and 0.824,respectively;the AUC for 3-,4-and 5-year OS was 0.886,0.898 and 0.875,respectively.The models were evaluated using calibration curves and decision curves,and internal validation was performed,which showed that the prediction accuracy of the models was good.Conclusion:CT body composition is an independent predictor of RFS and OS in rectal cancer patients,and the nomogram model developed based on these factors demonstrates good predictive value for patient prognosis.

Background and Purpose:Previous studies have investigated the prognostic significance of skeletal muscle and adipose tissue composition and distribution in colorectal cancer patients,yet most have not differentiated between rectal and colon cancer patient cohorts.This study aimed to explore the relationship between body composition and long-term prognosis,and to develop a postoperative predictive model.Methods:Clinical data of rectal cancer patients who underwent surgical treatment at Qingdao University Affiliated Hospital from January 2018 to December 2021 were retrospectively collected.Inclusion criteria:①Age＞18 years;② Preoperative colonoscopy and pathological diagnosis of colorectal cancer;③ Complete surgical resection;④Abdominal computed tomography(CT)scan 1 month before surgery.Exclusion criteria:① Clinical data is missing;② Multiple metastases of tumors;③ Tumor T stage 0 or carcinoma in situ;④ Severe artifacts lead to poor quality CT imaging,making it difficult to distinguish between fat and muscle;⑤ Inability to obtain follow-up results.This study has been approved by the Medical Ethics Committee of the Affiliated Hospital of Qingdao University(approval number:QYFYWZLL30313),and informed consent has been waived in the ethical approval process.The skeletal muscle index(SMI)and subcutaneous adipose tissue index(SATI)were calculated by dividing the areas of skeletal muscle and subcutaneous fat observed on CT scans by the square of the patient's height.Univariate and multivariate COX regression analyses were conducted to identify risk factors influencing recurrence-free survival(RFS)and overall survival(OS)in rectal cancer patients.Based on the results of the multivariate analysis,a nomogram prediction model was developed,its predictive power and accuracy were assessed using the receiver operating characteristic(ROC)curve,calibration plots and decision curve analysis(DCA),and internal validation was conducted.Results:A total of 696 patients were included in this study,with 96(13.8%)patients experiencing postoperative recurrence and 89(12.8%)patients dying.Multivariate COX regression analysis showed that SMI,SATI,tumor T stage and N stage were independent factors affecting the postoperative RFS and OS of patients.Nomogram prediction models for RFS and OS in rectal cancer patients were constructed based on the above independent predictors.The area under ROC curve(AUC)for 3-,4-and 5-year RFS was 0.862,0.846 and 0.824,respectively;the AUC for 3-,4-and 5-year OS was 0.886,0.898 and 0.875,respectively.The models were evaluated using calibration curves and decision curves,and internal validation was performed,which showed that the prediction accuracy of the models was good.Conclusion:CT body composition is an independent predictor of RFS and OS in rectal cancer patients,and the nomogram model developed based on these factors demonstrates good predictive value for patient prognosis.

Objective The CRISPR/Cas9 system was utilized to generate an Apoe knockout mice model to support further investigations of the role of Apoe in lipid metabolism and atherosclerosis.Methods Two single guide RNAs designed for Apoe in C57BL/6J mice were co-injected with Cas9 mRNA into fertilized eggs,followed by transplantation into ICR recipient mice to obtain F0 generation mice.KO mice were identified by polymerase chain reaction(PCR)screening of tail DNA.Apoe mRNA expression in various tissues was assessed by quantitative real-time PCR and lipid indexes were measured in serum samples.Lipid accumulation in the inner lining of aortic vessels was detected by oil red O staining.Results PCR and sequencing confirmed the successful construction of Apoe KO mice(C57BL/6-Apoeem1/Nifdc).Apoe mRNA levels were significantly reduced in the liver,brain,spleen,kidney,and lung tissues of Apoe KO homozygous mice(Apoe-/-),as shown by reverse transcription quantitative real-time PCR.Serum total cholesterol and low-density lipoprotein cholesterol levels were increased in Apoe-/-mice,and high-density lipoprotein cholesterol levels were decreased in male Apoe-/-mice.Extensive lipid plaques were observed in the inner lining of the arteries in Apoe-/-mice compared with WT mice,under normal chow consumption conditions.Conclusions This study successfully established an Apoe KO mice model exhibiting a typical abnormal lipid metabolism phenotype with arterial lipid accumulation,even without a high-fat diet intervention.This work provides background data for the Apoe KO mice resource and a new model for the study of abnormal lipid metabolism.

Objective We generated ob mice(C57BL/6N-Lepem1/Nifdc)with Lep gene knockout(ob/ob)using the CRISPR/Cas9 system,to establish a suitable animal model for preclinical drug evaluation for clinical diseases such as diabetes.Methods According to the principle of CRISPR/Cas9 target design,single guide RNA targeting the mouse Lep gene was designed for transcription in vitro,and microinjected with Cas9 mRNA into mouse zygotes.Mouse tail DNA was extracted and detected by polymerase chain reaction and sequencing,followed by mating of positive and wild-type mice.Blood biochemistry and liver pathology were assessed in homozygous ob mice.Results Eight positive mice were identified and a stable mouse strain was selected for further breeding.Serum triglycerides,total cholesterol,and alanine aminotransferase levels were significantly higher in homozygous ob mice than in wild-type mice,and liver pathology showed inflammatory infiltration and lipid vacuolar transformations.Conclusions We successfully established a Lep gene knockout mouse model,which will provide an important addition to the national rodent experimental animal database and an animal model for preclinical drug evaluation.

Objective The CRISPR/Cas9 system was utilized to generate an Apoe knockout mice model to support further investigations of the role of Apoe in lipid metabolism and atherosclerosis.Methods Two single guide RNAs designed for Apoe in C57BL/6J mice were co-injected with Cas9 mRNA into fertilized eggs,followed by transplantation into ICR recipient mice to obtain F0 generation mice.KO mice were identified by polymerase chain reaction(PCR)screening of tail DNA.Apoe mRNA expression in various tissues was assessed by quantitative real-time PCR and lipid indexes were measured in serum samples.Lipid accumulation in the inner lining of aortic vessels was detected by oil red O staining.Results PCR and sequencing confirmed the successful construction of Apoe KO mice(C57BL/6-Apoeem1/Nifdc).Apoe mRNA levels were significantly reduced in the liver,brain,spleen,kidney,and lung tissues of Apoe KO homozygous mice(Apoe-/-),as shown by reverse transcription quantitative real-time PCR.Serum total cholesterol and low-density lipoprotein cholesterol levels were increased in Apoe-/-mice,and high-density lipoprotein cholesterol levels were decreased in male Apoe-/-mice.Extensive lipid plaques were observed in the inner lining of the arteries in Apoe-/-mice compared with WT mice,under normal chow consumption conditions.Conclusions This study successfully established an Apoe KO mice model exhibiting a typical abnormal lipid metabolism phenotype with arterial lipid accumulation,even without a high-fat diet intervention.This work provides background data for the Apoe KO mice resource and a new model for the study of abnormal lipid metabolism.

Objective We generated ob mice(C57BL/6N-Lepem1/Nifdc)with Lep gene knockout(ob/ob)using the CRISPR/Cas9 system,to establish a suitable animal model for preclinical drug evaluation for clinical diseases such as diabetes.Methods According to the principle of CRISPR/Cas9 target design,single guide RNA targeting the mouse Lep gene was designed for transcription in vitro,and microinjected with Cas9 mRNA into mouse zygotes.Mouse tail DNA was extracted and detected by polymerase chain reaction and sequencing,followed by mating of positive and wild-type mice.Blood biochemistry and liver pathology were assessed in homozygous ob mice.Results Eight positive mice were identified and a stable mouse strain was selected for further breeding.Serum triglycerides,total cholesterol,and alanine aminotransferase levels were significantly higher in homozygous ob mice than in wild-type mice,and liver pathology showed inflammatory infiltration and lipid vacuolar transformations.Conclusions We successfully established a Lep gene knockout mouse model,which will provide an important addition to the national rodent experimental animal database and an animal model for preclinical drug evaluation.

Objective:To repair the secondary mandibular angle caused by madibular osteotomy by using digital technology and to make quantitative comparative evaluation.Methods:Thirty-nine patients with secondary mandibular angle with unsmooth mandibular margin or bilateral asymmetry after mandibular osteotomy in Southern Theater General Hospital from 1996 to 2017 were included. The three-dimensional model of skull was established by CT skull scan and Mimics 13.0 software. The computer aided design was used to carry out the secondary surgical repair according to the design line, and the mandibular angle was quantitatively measured and evaluated before and after the revision operation. The mandibular angles before, after design and after restoration were measured on the reconstructed images, and the bilateral symmetry and the consistency between the design result and the final result were compared by Paired- t sample test. P< 0.05 indicates statistical difference. Results:All the 39 patients completed the operation successfully, and 1 case developed hematoma 15 days after operation, which was drained and bandaged by oral dressing. Two weeks after operation, the hematoma was resolved. No infection, nerve injury and accidental fracture of mental process were found in all patients. During the 6-month follow-up, the mandibular angle of 39 patients improved from 118.12°±18.08° on the left side and 114.60°±16.01° on the right side to 121.28°±6.96° on the left side and 121.32°±5.88° on the right side. There was significant difference between the left and right sides before operation ( t=1.744, P=0.045), but there was no significant difference between the two sides about 6 months after operation( t=-0.074, P=0.529). The angle of mandibular angle after design was compared with the actual outcomes of patients 6 months after operation and there was no significant difference( t=-0.527, P=0.601). All the patients were satisfied with the improvement of the secondary mandibular angle and facial shape. Conclusions:The application of digital technique to repair the secondary mandibular angle after mandibular osteotomy not only avoids the injury of inferior alveolar neurovascular bundle and mental nerve, but also effectively improves the facial shape of the patients.

Objective:To repair the secondary mandibular angle caused by madibular osteotomy by using digital technology and to make quantitative comparative evaluation.Methods:Thirty-nine patients with secondary mandibular angle with unsmooth mandibular margin or bilateral asymmetry after mandibular osteotomy in Southern Theater General Hospital from 1996 to 2017 were included. The three-dimensional model of skull was established by CT skull scan and Mimics 13.0 software. The computer aided design was used to carry out the secondary surgical repair according to the design line, and the mandibular angle was quantitatively measured and evaluated before and after the revision operation. The mandibular angles before, after design and after restoration were measured on the reconstructed images, and the bilateral symmetry and the consistency between the design result and the final result were compared by Paired- t sample test. P< 0.05 indicates statistical difference. Results:All the 39 patients completed the operation successfully, and 1 case developed hematoma 15 days after operation, which was drained and bandaged by oral dressing. Two weeks after operation, the hematoma was resolved. No infection, nerve injury and accidental fracture of mental process were found in all patients. During the 6-month follow-up, the mandibular angle of 39 patients improved from 118.12°±18.08° on the left side and 114.60°±16.01° on the right side to 121.28°±6.96° on the left side and 121.32°±5.88° on the right side. There was significant difference between the left and right sides before operation ( t=1.744, P=0.045), but there was no significant difference between the two sides about 6 months after operation( t=-0.074, P=0.529). The angle of mandibular angle after design was compared with the actual outcomes of patients 6 months after operation and there was no significant difference( t=-0.527, P=0.601). All the patients were satisfied with the improvement of the secondary mandibular angle and facial shape. Conclusions:The application of digital technique to repair the secondary mandibular angle after mandibular osteotomy not only avoids the injury of inferior alveolar neurovascular bundle and mental nerve, but also effectively improves the facial shape of the patients.

Objective To investigate the effect of FK506 on the in vitro ostengenic potential of rat bone marrow-derived mesenchymal stem cells(MSCs)and the dose-response effect of FK506(5-5000 nmol/ L)on the ostengenic potential of MSCs in vitro.Methods MSCs derived from primary culture were sub- cultured for 16 days under four conditions:(1)?-MEM containing L-ascorbicacid-2-phosphate(AsAP)and?-glycemphosphate(?-GP)(basic culture medium)as a control;(2) AsAP and?-GP(basic culture medi- um) plus dexamethasone;(3)AsAP and?-GP(basic culture medium)plus FK506,(4)AsAP and?-GP (basic culture medium)plus FK506 and dexamethasone.Osteogenie potential was determined by testing os- teoblastic morphology,cell proliferation,alkaline phosphatase(APase)activity,bone nodule formation and the expression of osteocalcin mRNA.Results FK506 promoted the proliferation of MSCs,induced mineral- izing bone-like nodule formation,and increased APase activity and the expression of osteocalcin mRNA.The data also showed that the efficacy of FK506 was greater when used in combination with dexamethasone.Opti- mal ostengenesis was achieved with?-MEM containing 0.25mmol/L AsAP,10mmol/L?-GP,10nmol/L dexa- methasone and 50nmol/L FK506.Conclusion FK506 has powerful ostengenic ablility.It can be consid- ered as an osteogenic agent to repair bone defects.