Objective:To investigate the relationship between sarcopenia and the long-term prognosis of elderly patients with locally advanced colorectal cancer.Methods:A retrospective analysis was conducted on clinical data from 205 elderly colorectal cancer patients aged 70 years and above who underwent radical resection with TNM staging of stage Ⅱ to Ⅲ at Beijing Hospital between January 2014 and December 2018.The study utilized abdominal CT scans taken within 30 days before surgery to measure the skeletal muscle area(SMA)of the 3rd lumbar vertebrae cross-section.Sarcopenia was defined as a skeletal muscle index(SMI) of ≤52.4 cm 2/m 2 in men and ≤38.5 cm 2/m 2 in women(SMI=SMA/height 2).A comparison was made between the clinical and pathological conditions of patients with and without sarcopenia in the two groups, with an analysis of the impact of sarcopenia on the long-term prognosis of elderly postoperative colorectal cancer patients. Results:Among the 205 patients assessed, 63.4%(130/205)were diagnosed with sarcopenia.The group with sarcopenia had a higher percentage of individuals aged 80 years and older( χ2=6.420, P=0.011)compared to those without sarcopenia.Additionally, this group had a lower proportion of overweight or obese patients( χ2=9.366, P=0.009), fewer patients who underwent adjuvant chemotherapy, and a lower 5-year disease-free survival rate post-surgery( χ2=6.257, 7.347, P=0.012, 0.007).Kaplan-Meier analysis indicated that disease-free survival rate was better in elderly patients with locally advanced colorectal cancer who did not have sarcopenia compared to those with sarcopenia(Log-rank χ2=6.919, P=0.009).Moreover, in elderly patients without sarcopenia, those who received adjuvant chemotherapy had a more favorable disease-free survival outcome than those who did not receive such treatment(Log-rank χ2=4.745, P=0.029).Multifactorial Cox regression analysis showed that TNM stage Ⅲ( HR=1.634, 95% CI: 1.110-2.404, P=0.013)and the presence of sarcopenia( HR=1.509, 95% CI: 1.017-2.238, P=0.041)were significant factors influencing the poor long-term prognosis of elderly patients with locally advanced colorectal cancer. Conclusions:Sarcopenia is associated with aging and body mass index, and has been found to be a significant factor in the long-term prognosis of elderly colorectal cancer patients.Those with sarcopenia tend to have a poorer prognosis, while those without may experience benefits from adjuvant chemotherapy.

Objective:To investigate the characteristics of gene mutations in colorectal cancer(CRC)patients by using next-generation generation sequencing(NGS).Methods:Blood and tissue samples were collected from 90 CRC patients admitted to Beijing Hospital between August 5, 2016 and December 29, 2020.Analysis of driver gene mutations was performed by using a 1021-gene NGS panel.Results:There were 43 tissue samples and 83 blood samples.Also, 36 patients had both tissue and blood samples.The frequency rates of KRAS and BRAF mutations were 51.2%(22/43)and 20.9%(9/43)in tissue samples, and 3 rare concomitant KRAS/ BRAF mutations were detected.The frequency rates of KRAS and BRAF mutations were 26.5%(22/83)and 10.8%(9/83)in blood samples.In patients with tissue and blood samples, the rates of KRAS and BRAF mutations were 52.8%(19/36)and 10.8%(8/36). Conclusions:The rate of KRAS mutations in tissue samples from colorectal cancer patients is similar to rates reported in the literature, but the rate of BRAF mutation and the rate of rare KRAS and BRAF co-mutations are higher than those reported from other countries.

Objective To understand the exposure level of disinfection by-products (DBPs) in drinking water in Xiangyang City and to evaluate the health risks of the population, so as to provide reference for the safety risk control of drinking water. Methods Sampling and laboratory testing were conducted according to national standard methods. The risk assessment model provided by USEPA was used to evaluate the health risks. Results Trichloromethane (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM) and tribromomethane (TBM) were detected in drinking water in Xiangyang City. The contents of halogenated hydrocarbon DBPs in water disinfected with liquid chlorine were higher than those with chlorine dioxide. The contents of three DBPs were higher in wet season than those in dry season except TBM. The content of TCM in pipe network terminal water and secondary water supply disinfected with chlorine dioxide was higher than that in factory water. The carcinogenic risk of DBPs in drinking water disinfected with liquid chlorine was 4.33×10^-5, and the non-carcinogenic risk was 0.114. The carcinogenic risk of DBPs in drinking water disinfected with chlorine dioxide was 1.24×10^-6, and the non-carcinogenic risk was 3.15×10^-3. Conclusion The health risk of DBPs in drinking water in Xiangyang City is acceptable, but TCM produced by liquid chlorine disinfection should be paid more attention. It is recommended that chlorine dioxide disinfection be used to reduce the health risks of halogenated hydrocarbon DBPs.

Objective:To explore the changes of levels of coagulation factors at acute phase (within one week) of aneurysmal subarachnoid hemorrhage (aSAH) and their relations with deep venous thrombosis (DVT).Methods:Two hundred and two aSAH patients (aSAH group), admitted to our hospitals from March 2015 to March 2019, were selected in our study, and these patients were divided into a combined DVT subgroup and a uncombined DVT subgroup according to whether they were combined with DVT on the first and third d of onset. One hundred healthy physical examiners whose age and gender matched with those of aSAH group were selected as control group; one, 3, 5, and 7 d after onset, and one d after enrolling of subjects from the control group, thromboelastogram (TEG) was used to detect the R value of TEG (TEG-R) in all subjects. One, two, 3, 4, 5, 6 and 7 d after onset, color Doppler ultrasonography was used to determine whether aSAH patients had DVT.Results:A total of 73 patients (36.14%) were combined with DVT at acute stage of aSAH; 66 were with asymptomatic thrombosis and 7 with symptomatic thrombosis; 59 were with lower extremity intermuscular vein thrombosis and 14 were with intermuscular vein thrombosis. The incidence of DVT (68/73 [93.2%]) peaked on the 1 st-3 rd d of onset. The TEG-R of patients in aSAH group was statistically lower than that of the control group on the 1 st-3 rd d of onset ( P<0.05); the TEG-R of patients in aSAH group on the 1 st-3 rd d of onset was significantly lower than that on 5 th and 7 th d of onset ( P<0.05). The TEG-R of patients in combined DVT subgroup was significantly lower than that of the uncombined DVT subgroup ( P<0.05). Conclusions:Hyperfunction of coagulation factors at acute stage of aSAH is noted within one-3 d of onset; the incidence of DVT is the highest within 3 d of onset, mainly featured as asymptomatic intermuscular venous thrombosis. Whether or not aSAH would combine with DVT is associated with hyperfunction of coagulation factors.

Objective To decrease the p53 gene expression at cellular and animal levels in marmoset using RNA interference technique.Methods The shRNA interference sequences were designed and inserted into the adeno-associated virus vector plasmid after bioinformatics analysis.The plasmids were transfected into African green monkey kidney cos-7 cells.The suppression of p53 mRNA was detected by real-time PCR, and the changes of p53 protein expression were detected by Western bolt.The adeno-associated virus-8 was injected through the hind leg vein.The changes of p53 protein expression in the liver tissue was detected by Western blot and immunohistochemistry.Results We screened two RNA interference effective arget sequences.The expression of p53 mRNA was suppressed ( 82.7 ±8.1 )% and ( 80.7 ± 7.5)%, respectively (P<0.05), and the expression of p53 protein was decreased (77.3 ±11.5)% and (73.7 ± 10.7)%, respectively (P<0.05).The two marmosets after virus infection showed that there were virus distributions in the liver, testes, and neck detected by in vivo fluorescence imaging.The expression of p53 in the marmoset liver was detected by western blot, immunohistochemistry analysis showing no obvious changes.Conclusions In the present study, the decrease of P53 gene expression at cellular level is achieved, however, the liver P53 protein in the marmoset liver is not significantly changes.Further optimization of the way of infection is needed in the future.

Objective To screen the effective silencing targets of P21 gene at the cellular level in rhesus monkey . Methods To detect the expression of P21 gene in COS-7 cells ( derived from the kidney of African green monkey , Cerco-pithecus aethiops).Four small hairpin RNA (shRNA) sequences targeting rhesus monkey P21 gene were designed and in-serted into lentivirus-based gene silencing constructs FUGW-TDT.The vectors were transfected into COS-7 cells respective-ly.The suppression of P21 mRNA was detected by real-time PCR, and the expression of P21 protein was detected by West-ern blot assay .Results Four gene-silencing sequences were screened that lied in 541-561 bp, 542-562 bp, 215-239 bp, and 624-648 bp of the rhesus monkey P21 mRNA.Their silencing rate was (91.82 ±3.21)%, (82.47 ±2.48)%, (81.31 ±2.69 )% and ( 87.35 ±4.59 )%, and the protein expression was ( 11.97 ±0.70 )%, ( 20.22 ±0.65 )%, ( 23.21 ± 0.63)%and (14.42 ±0.86)%, respectively.Conclusions Four effective silencing target sequences are screened at cel-lular level , which can be used in gene silencing research of rhesus monkeys .

This paper discusses the definition , classification, selection, monitoring and evaluation of animal biosafety isolation device .Evaluation order of animal biosafety isolation device follows animal survival needs -biosafety needs-animal welfare requirements .

Objective In order to establish a rhesus monkey model of p53 gene silencing, firstly we screened and determined the effective silencing targets of p53 gene at the cellular level in rhesus monkey.Methods The expression of p53 gene was detected in COS-7 cells ( derived from the kidney of the African Green Monkey, Cercopithecus aethiops).Three small hairpin RNA ( shRNA) sequences targeting rhesus monkey p53 gene were designed, analysed by bioinformatics, and inserted into lentivirus-based gene silencing constructs FUGW-TDT.The plasmids of p53-RNAi and control vector were transfected into the COS-7 cells, respectively.The suppression of p53 mRNA was detected by real-time PCR, and the changes of p53 protein expression were detected by Western blot assay.Results p53 gene expression was detected in COS-7 cells.Bioinformatics analysis showed that three gene-silencing sequences were screened which lied in the open reading frame ( ORF) region and targeted 238 -258bp, 681 -701bp, 169 -189bp of the rhesus monkey p53 mRNA.At 48 hrs after transfection of the three silencing constructs, p53 mRNA was suppressed by(87.17 ±4.03)%, ( 72.62 ±4.11)% and(76.22 ±0.98 )%, and p53 protein was suppressed by ( 84.44 ±2.18 )%, ( 71.04 ±1.18)% and ( 74.17 ±0.95 )%, respectively. Conclusions We obtained three effective target sequences showing high efficiency in p53silencing, which can be used in further studies on gene silencing in rhesus monkey.

Objective To compare the efficiency of intra-articular injection of tranexamic acid (TXA) and autolo-gous transfusion drain on the blood loss after total knee arthroplasty (TKA). Methods A total of 124 patients (124 knees) with varus knee osteoarthritis, who were performed TKA,were retrospectively analyzed. Patients included 24 males and 100 females. The mean age was(65.03±6.84)years. Due to the blood loss control method, patients were divided into two groups including TXA application group (test group, n=49) and autologous transfusion drain group (control group, n=75). The data of blood routine examination, blood loss and blood transfusion after TKA were analyzed. Results The blood transfusion rates were 10.20%(5/49) in test group and 17.33%(13/75) in control group 7 days after TKA surgery. There was no signifi-cant difference between two groups (P>0.05). There were significant differences in red blood cell (RBC), hemoglobin (Hb) and haematocrit (HCT) between groups and effects of interaction in the two groups (P＜0.01). There were significantly higher values of RBC, Hb and HCT at 1, 3 and 7 days after surgery in test group than those of control group (P＜0.05).The total blood loss 1 and 3 days after TKA was significantly lower in test group than that of control group (P＜0.05). There was no sig-nificant difference in the blood loss 7 days after surgery between two groups (P>0.05). Conclusion The single dose intra-articular injection of tranexamic acid is a safe and effective procedure for hemostasis after TKA.

Objective To evaluate the femur biomechanical changes of finite analysis with different femoral stem ex-tension implants in total knee arthroplasty (TKA). Methods The full-length femoral CT scan was performed in selected healthy volunteers. The femoral digital model was established with Mimics 10.0 and Geomagic Studio 10.0 software. The models of femoral prosthesis and stem extension implant were created by laser scanner. According to the common three hip loading modes (1 586 N, 1 690 N and 2 132 N), the maximum principal stress (MPS), the maximum principal elastic deforma-tion (MPES) and MPES distribution changes were recorded and analyzed by three-dimensional finite element analysis with ANSYS Workbench13.0 software. Results The MPS values before TKA were 98.54, 147.36 and 143.51 MPa respectively when values of femoral head loading were 1 586 N, 1 690 N and 2 132 N. With the increase in the length of the femoral pros-thesis extension rod, the MPS and MPES showed a decreasing trend. There was a positive correlation between free femur ra-tio (FFR) and MPES (P<0.05). The MPES distribution was gradually concentrated at the top point of femur stem extension implant with the increase in the length of the femoral prosthesis extension rod. Conclusion The values of MPS and MPES were gradually decreased with the increase in the length of the femoral stem extension implant. There was a positive linear correlation between FFR and MPES. The stress concentration was focused obviously at the top end of femoral stem extension implant with its length more than 120 mm.