Objective To investigate the content stability of polymyxin B sulfate in high concentration solution and its finished infusion,and to provide a scientific basis for clinical administration.Methods Polymyxin B sulfate was dissolved in 0.9%sodium chloride injection and 5%glucose solution to the concentrations of 0.5 mg·mL-1,1 mg·mL-1 and 5 mg·mL-1,respectively.The content of polymyxin B was determined at 0,2,4,6,8,12,16,20 and 24 h by high-performance liquid chromatography under storage conditions of 4℃and 25℃.Results Polymyxin B sulfate was stable in the concentrations of 0.5 mg·mL-1,1 mg·mL-1 and 5 mg·mL-1,respectively,in 0.9%sodium chloride injection or 5%glucose injection.Under the storage conditions of 4℃and 25℃,the content of polymyxin B1 and polymyxin B2 ranged from 97.23%to 101.26%and 97.30%to 102.63%,respectively.Conclusion Polymyxin B sulfate was stable within 24 h dissolved either in 0.9%sodium chloride injection or in 5%glucose injection with the concentrations of 0.5 mg·mL-1,1 mg·mL-1 and 5 mg·mL-1 under the storage condition of 4℃and 25℃.

Traumatic cerebrospinal fluid leakage commonly presents in traumatic brain injury patients, and it may lead to complications such as meningitis, ventriculitis, brain abscess, subdural hematoma or tension pneumocephalus. When misdiagnosed or inappropriately treated, traumatic cerebrospinal fluid leakage may result in severe complications and may be life-threatening. Some traumatic cerebrospinal fluid leakage has concealed manifestations and is prone to misdiagnosis. Due to different sites and mechanisms of trauma and degree of cerebrospinal fluid leak, treatments for traumatic cerebrospinal fluid leakage varies greatly. Hence, the Craniocerebral Trauma Professional Group of Neurosurgery Branch of Chinese Medical Association and the Neurological Injury Professional Group of Trauma Branch of Chinese Medical Association organized relevant experts to formulate the " Chinese expert consensus on the diagnosis and treatment of traumatic cerebrospinal fluid leakage in adults ( version 2023)" based on existing clinical evidence and experience. The consensus consisted of 16 recommendations, covering the leakage diagnosis, localization, treatments, and intracranial infection prevention, so as to standardize the diagnosis and treatment of traumatic cerebrospinal fluid leakage and improve the overall prognosis of the patients.

Objective:To investigate the incidence and treatment of gastric cancer in 16 medical centers in Tianjin from 2020 to 2021.Methods:The retrospective and descriptive study was conducted. The clinical data of 3 122 gastric cancer patients who underwent surgery in 16 medical centers, including Tianjin Medical University Cancer Institute & Hospital, et al, in Tianjin from 2020 to 2021 were collected. There were 2 112 males and 1 010 females, aged (64±11)years. Observation indicators: (1) general data of patients; (2) treatment situations; (3) postoperative complications. Measurement data with normal distribution were represented as Mean± SD, and measurement data with skewed distribution were represented as M(range). Count data were descri-bed as absolute numbers or percentages, and comparison between groups was conducted by the chi-square test. Results:(1) General data of patients. From 2020 to 2021, a total of 3 122 gastric cancer patients received surgeries in 16 medical centers in Tianjin, including 2 112 males and 1 010 females. There were 1 443 cases in 2020, including 976 males and 467 females, aged (63±11) years. There were 1 679 cases in 2021, including 1 136 males and 543 females, aged (65±11) years. Of the 3 122 pati-ents, cases in stage Ⅰ, Ⅱ, Ⅲ, Ⅳ were 696, 667, 1 466, 293, accounting for 22.293%(696/3 122), 21.365%(667/3 122), 46.957%(1 466/3 122), 9.385%(293/3 122), respectively. Cases with early gastric cancer, locally advanced gastric cancer, advanced gastric cancer account for 17.265%(539/3 122), 73.350%(2 290/3 122), 9.385%(293/3 122). There were 2 829 patients without distant metastasis and 293 patients with distant metastasis. For the 2 829 patients without distant metas-tasis, cases in stage T1, T2, T3, T4a, T4b accounted for 19.053%(539/2 829), 12.089%(342/2 829), 20.148%(570/2 829), 41.499%(1 174/2 829), 7.211%(204/2 829)respectively, cases in stage N0, N1, N2, N3 account for 37.328%(1 056/2 829), 16.331%(462/2 829), 15.836%(448/2 829), 30.505%(863/2 829). For the 293 advanced gastric cancer patients with distant metastasis, 190 cases had peri-toneal metastasis, 47 cases had lymph node metastasis, 27 cases had ovarian metastasis, 37 cases had liver metastasis, 14 cases had other metastasis (some patients had ≥2 distant metastases). (2) Treatment situations. ① For the 539 with early gastric cancer, cases undergoing endoscopic submu-cosal dissection, laparoscopic surgery, open surgery were 22, 150, 86 in 2020, versus 19, 212, 50 in 2021, showing a significant difference between them ( χ2=19.42, P<0.05). For the 498 patients with early gastric cancer who underwent laparoscopic or open surgery, cases undergoing open surgery including total gastrectomy, distal gastrectomy, proximal gastrectomy were 25, 81, 30, and cases undergoing laparoscopic surgery including total gastrectomy, distal gastrectomy, proximal gastrec-tomy were 18, 309, 35, respectively, showing a significant difference between them ( χ2=40.62, P<0.05). For the 2 290 patients with locally advanced gastric cancer, cases undergoing open surgery and laparoscopic surgery were 446 and 617 in 2020, versus 410 and 817 in 2021, showing a significant difference between them ( χ2=17.75, P<0.05). For the 2 290 patients with locally advanced gastric cancer, cases undergoing open surgery including total gastrectomy, distal gastrectomy, proxi-mal gastrectomy were 336, 377, 143, and cases undergoing laparoscopic surgery including total gastrectomy, distal gastrectomy, proximal gastrectomy were 377, 920, 137, respectively, showing a significant difference between them ( χ2=89.64, P<0.05). Of the 293 patients with advanced gastric cancer, 175 cases underwent surgeries due to hemorrhage, stenosis, perforation, 76 cases under-went surgery after chemotherapy, 42 cases underwent surgery directly. ② For 756 cases of 3 122 pati-ents undergoing total gastrectomy, 357 and 4 cases received open digestive tract reconstruction including Roux-en-Y and other anastomosis, versus 380 and 15 cases with laparoscopic digestive tract reconstruction including Roux-en-Y and other anastomosis, showing a significant difference between them ( χ2=5.57, P<0.05). For 1 687 cases undergoing distal gastrectomy, 84, 160, 158, 55 cases received open digestive tract reconstruction including Billroth Ⅰ anastomosis, Billroth Ⅱ + Braun anastomosis, Roux-en-Y anastomosis, uncut Roux-en-Y anastomosis, versus 154, 489, 417, 170 cases with laparoscopic digestive tract reconstruction including Billroth Ⅰ anastomosis, Billroth Ⅱ + Braun anastomosis, Roux-en-Y anastomosis, uncut Roux-en-Y anastomosis, showing a significant difference between them ( χ2=10.90, P<0.05) . Of the 539 patients with early gastric cancer, 65 cases had lymph node metastasis, in which 18 of 306 stage T1a cases had lymph node metastasis and 47 of 233 stage T1b cases had lymph node metastasis. The number of detected lymph nodes for the 2 290 patients with advanced gastric cancer was 31±15, including ≥16 for 2 059 cases and ≥30 for 1 276 cases. Of the 3 122 patients, cases with neoadjuvant therapy, complete response and incomplete response was 128, 13 and 115 in 2020, versus 250, 49 and 201 in 2021, showing a significant difference between them ( χ2=5.51, P<0.05). (3) Postoperative complications. Of the 3 122 patients, 746 cases had postoperative complications, with an incidence of 23.895%(746/3 122). There were 62 patients with grade 3 or more complications. Reoperation was conducted in 34 patients. There were 14 cases of postoperative death. The duration of postoperative hospital stay and hospital expense were (11±5)days and (98 114±46 598)yuan for the 3 122 patients, (26±14)days and (122 066±68 317)yuan for cases with complications, (40±21)days and (196 926±12 747)yuan for cases with grade 3 or more complications. Conclusion:Compared with 2020, cases undergoing laparoscopic surgery and distal gastrectomy for gastric cancer in Tianjin increases in 2021, and the digestive tract reconstruction also differs. The number of patients with neoadjuvant chemotherapy and complete response rate for advanced gastric cancer increases.

Objective:To investigate the cognitive-related networks of patients with different cognitive impairment related to white matter lesions (WMLs), and explore the correlation between the altered functional connectivity and the executive function.Methods:Patients with white matter lesions in Beijing Tiantan Hospital from January 2016 to December 2020 were selected , who were divided into WML-non-dementia vascular cognitive impairment (WML-VCIND) group( n=19)and WML-vascular dementia (VaD) group( n=19). At the same time, 24 normal control group (NC) with no cognitive impairment with age, gender and education level matched were enrolled. The Stroop B, Stroop C, trail making test(TMT-B) and verbal fluency test (VFT) were used to evaluate the executive function of all subjects. The ICA method was used to identity four cognitive-related RSNs: frontoparietal network (FPN), salience network (SN), default network (DMN), and dorsal attention network (DAN). Using SPSS 20.0 software, the functional connectivity (FC) of the regions of interest of the selected RSNs among the three groups were compared by analysis of covariance, and correlation between the altered FCs and executive function scores were explored by Spearman correlation analysis. Results:(1) The FC of the medial prefrontal cortex (MPFC)-left inferior parietal lobe (IPL.L) in the VaD group(0.267±0.320) was significantly lower than that in the NC group (0.520±0.253)( P=0.005). The FC of MPFC-posterior cingulate (PCC) was significantly lower in the VaD group(0.655±0.284) than that in the VCIND group(0.810±0.232) ( P=0.017). The FC of MPFC-left insula and MPFC-left dorsolateral prefrontal cortex (DLPFC.L)was significantly higher in the VaD group(0.411±0.277, 0.545±0.311)than that in the VCIND group(0.239±0.308, 0.353±0.270)( P=0.044, 0.028). The FC of the left superior parietal lobe (SPL.L)-right dorsolateral prefrontal cortex (DLPFC.R) in the VCIND group(0.488±0.157) was significantly higher than that in the NC group(0.301±0.257) ( P=0.010). The FC of MPFC-left insula and MPFC-DLPFC.L was higher in NC group than that in VaD group ( P=0.020, 0.037). (2) The FC of MPFC-PCC was negatively correlated with Stroop C score ( r=-0.279, P=0.036), and TMT-B score ( r=-0.313, P=0.018). The FC of MPFC-IPL.L was negatively correlated with Stroop B score ( r=-0.311, P=0.018), Stroop C score( r=-0.308, P=0.020) and TMT-B score ( r=-0.367, P=0.005), while positively correlated with VFT score ( r=0.357, P=0.006). The FC of SPL.L-DLPFC.R was positively correlated with the Stroop B score ( r=0.305, P=0.021). Conclusion:There are certain differences in the functional connectivity between brain areas within the cognitive related brain networks, and the differences in FC between different brain areas are correlated with executive function scores. The changes of the FC may indicate possibly decline in executive function, which can explain the mechanism of cognitive declines.

Objective:To develop a mesenteric creeping fat index (MCFI) based on CT enterography (CTE) to characterize the degree of creeping fat wrapping around the inflamed gut in Crohn disease (CD), and to assess the relationship between MCFI and the inflammatory intestinal stricture.Methods:From December 2018 to July 2019, the patients with CD who underwent surgery in the First Affiliated Hospital of Sun Yat-Sen University were prospectively collected. The extent of perienteric mesenteric vessels wrapping around the gut was reconstructed to develop MCFI based on CTE images. The intestinal stricture index was obtained by calculating the ratio of the maximal upstream luminal diameter divided by the minimum luminal diameter apparent within the stricturing region. Using region-by-region correlation between CTE and surgical specimen, creeping fat score in intestinal specimen was obtained by assessing the extent of creeping fat wrapping around the resected bowel segment, and HE staining was performed on the bowel specimen corresponding to creeping fat to obtain the pathological inflammatory score. The Spearman correlation analysis was used to evaluate the correlation between MCFI, creeping fat score in intestinal specimen, and inflammatory score, intestinal stricture index. The ROC curve analysis was used to assess the accuracy of MCFI in distinguishing moderate-severe and mild inflammatory bowel walls.Results:Totally 30 CD patients were enrolled. The creeping fat score in intestinal specimen positively correlated with pathological inflammatory score ( r s=0.403, P=0.027) and with intestinal stricture index ( r s=0.642, P<0.001). MCFI positively correlated with creeping fat score in intestinal specimen ( r s=0.840, P<0.001), with pathological inflammatory score ( r s=0.497, P=0.005), and with intestinal stricture index ( r s=0.599, P<0.001). ROC analysis showed that the area under the curve of MCFI for differentiating moderate-severely from mildly inflammatory bowel walls was 0.718 (95%CI 0.522-0.913). Using MCFI≥4 as a cutoff value, the sensitivity and specificity were 81.8% and 47.4%, respectively. Conclusions:There was a correlation between creeping fat and inflammatory intestinal strictures in CD. MCFI can non-invasively depict the degree of creeping fat wrapping around the gut and assess the inflammatory intestinal stricture.

Objective:To explore abnormal microstructural changes of white matter in patients with white matter lesions(WML) using diffusion tensor imaging(DTI), and to determine the association of such abnormalities of DTI parameters with executive function.Methods:Totally 34 patients with WML were recruited from the department of Neurology, Beijing Tiantan Hospital, Capital Medical University from March 2012 to May 2019.All patients with WML were scored with Hamilton depression scale (HAMD) and Hamilton anxiety scale (HAMA), and assessed with Montreal cognitive assessment (MoCA) and clinical dementia rating(CDR). They were divided into WML-cognitive normal group, WML-vascular cognitive impairment-non dementia group and WML-Dementia group.The Stroop color and word test (SCWT), trail making test-A (TMTA), digit symbol test and verbal fluency test were carried out to evaluate executive function.In addition, the healthy elderly without WML lesions were selected as the control group after they were examined by MRI, and all brains of the subjects went through DTI with Siemens 3.0 T MR.The data were collected and analyzed by voxel based analysis (VBA). The anisotropy and mean diffusion coefficient of DTI in the region of interest (ROI) and other regions in the brain were studied in the four groups, and their correlation with scores of executive function in WML patients was analyzed.Results:(1)In these executive function test, there were significant differences between the patients with cognitive impairment (WML-VAD group, WML-VCIND group) and normal cognition group(WML-CN group, NC group), such as SCWT(B)(65.54±6.24 vs 43.67±0.95, 76.75±2.13 vs 43.67±0. 95, 65.54±6.24 vs 43.66±1.81, 76.75±2.13 vs 43.66±1.81), SCWT(C)(88.58±6.76 vs 61.63±1.31, 96.37±1.47 vs 61 63±1.31, 88.58±6.76 vs 66.31±8.19, 96.37±1.47 vs 66.31±8.19), TMTA(40.47±2.76 vs 30.92±0.47, 44.24±1.43 vs 30.92±0.47, 44.24±1.43 vs 31.99±2.07, 40.47±2.76 vs 31.99±2.07), TMTB(88.66±6.55 vs 80.34±0.61, 96.70±1.72 vs 80.34±0.61, 88.66±6.55 vs 83.10±5.91, 96.70±1.72 vs 83. 10±5.91), Digit Symbol Test(39.25±5.63 vs 47.00±2.55, 31.27±3.93 vs 47.00±2.5, 39.25±5.63 vs 48.86±4.34, 31.27±3.93 vs 48.86±4.34) and Verbal Fluency Test(8.94±1.00 vs 11.71±0.47, 6.64±0.81 vs 11.71±0.47, 8.94±1.00 vs 10.86±0.69, 6.64±0.81 vs 10.86±0.69) scores ( P<0.05); In the patients with cognitive impairment, there were significant differences between WML-VAD group and WML-VCIND group, such as SCWT(B), SCWT(C), TMTA, TMTB, digit symbol test and verbal fluency test scores ( P<0.05); There were significant differences between WML-CN patients and NC group in the scores of SCWT (C), verbal fluency test( P<0.05). (2)FA values in the genu of corpus callosum and the inferior longitudinal fasciculus were negatively correlated with the time of SCWT (B), SCWT (C) and the TMTA( r=-0.436--0.471), but positively correlated with the scores of digit symbol test and verbal fluency test( r=0.428-0.573). MD values in the genu of corpus callosum, the superior/inferior longitudinal fasciculus and the inferior fronto-occipital fasciculus were positively correlated with the time of SCWT (B), SCWT (C) and TMTA( r=0.432~0.609), but negatively correlated with the scores of digit symbol test and verbal fluency test( r=-0.424--0.630, all P<0.003125 after emendation). Conclusion:The executive function of patients with WML-Dementia decreases significantly.The more serious the damage of white matter microstructure, the more serious the damage of executive of function.

Objective:To analyze the characteristic of nerve tracts in different stages of cognitive impairment caused by white matter hypertensities, applying diffusion tensor imaging-peak width of skeletonized mean diffusivity as evaluation indicator.Methods:Demographic characteristics and vascular risk factors of all subjects were recorded.Screened out 50 subjects without WMH and whose MoCA scale was more than or equal 26 points as normal control group.Then, we assessed 85 patients with WMH using the MoCA scale and clinical dementia assessment. Of 85 patients, 45 cases were divided into the normal cognition group, 23 cases were assigned into non-dementia vascular cognitive impairment group, and 17 cases into the vascular dementia group.The diffusion tensor imaging-peak width of skeletonized mean diffusivity marking method was used to compare the integrity of white matter fibers in WMH patients with varying degrees of cognitive impairment and normal control group.Results:The difference of PSMD among the four groups was statistically significant(CN group: 3.558±0.157, VCIND group: 4.128±0.222, VaD group: 5.469±0.000, NC group: 2.612±0.105, F=42.479, P<0.05). PSMD in WMH groups were higher than that in NC group (all P<0.05). There was no significant difference between WMH-VCIND group and WMH-CN group ( P=0.067). The PSMD of WMH-VAD group was higher than that of WMH-CN group and WMH-VCIND group (both P<0.05). Conclusion:PSMD can accurately detect white matter fiber damage caused by WMH.The degree of WMH combined cognitive decline was not completely consistent with the degree of PSMD increase.Compared with the cases with normal WMH cognition, PSMD was not significantly increased when WMH was combined with VCIND, while PSMD was significantly increased when WMH was combined with VaD.DTI-PSMD value as imaging marker can provide objective basis for clinical diagnosis of WMH-VaD.

Objective:To investigate the effects of naturally occurring mild hypothermia and artificial mild hypothermia on the expression of high mobility group box 1(HMGB1) in lung tissues of septic mice.Methods:One hundred and twenty BALB/C mice (SPF level) were randomly numbered.Twelve mice with integer multiples of 10 were used as the normal control (NC) group, and the remaining 108 mice were chosen as the septic group.The septic mouse model was established by intra abdominal injection of lipopolysaccharide (LPS) 10 mg/kg.The NC group was given the same dose of normal saline.Anal temperature of the septic mice were measured 1 hour after the model was established successfully, and then were divided into naturally occurring mild hypothermia group and non-mild hypothermia group according to T≤36℃ and T>36℃.In the naturally occurring mild hypothermia group, the mice with T<34℃ were eliminated, and the remaining septic mice were randomly divided into the naturally occurring mild hypothermia(NOMH) observation group and the keep normothermia (KN) group.NOMH group was not given preheating intervention, while KN group was placed in an incubator to maintain the anal temperature between 36.0℃ and 37.5℃.Septic mice in the non-mild hypothermia group were randomly divided into the nonhypothermia (NH) observation group and the artificial mild hypothermia (ATMH) group.The NH group was not treated with hypothermia, while the ATMH group was treated with physical hypothermia, so that the anal temperature of the mice were maintained at 34℃-36℃.Four mice in each group were randomly selected at 6 and 12 hours after modeling, and the concentrations of tumor necrosis factor-α(TNF-α), interleukin-6(IL-6) and HMGB1 in serum were detected by enzyme-linked immunosorbent assay(ELISA). At 12 hours, the survival rate of each group of mice was observed.Then 4 mice of each group were sacrificed and lung tissues were taken.The pathological changes of lung tissues were observed by hematoxylin-eosin (HE) staining, and the expression of HMGB1 in lung tissues was observed by immunohistochemical staining.Real time fluorescence quantitative PCR and Western blot were used to detect the relative expression of HMGB1 at mRNA and protein levels.Results:(1)Twelve hours after modeling, the survival number of NOMH group, ATMH group, KN group and NH group were 36(40), 6(11), 27(40), 4(11), respectively, and there were differences between the four groups (χ 2=32.286, P=0.002). Compared with the other three groups of septic mice, the survival rate was highest in the NOMH group (compared with ATMH group: χ 2=5.222, P=0.022; compared with the KN group: χ 2=6.050, P=0.013; and the NH group: χ 2=11.672, P=0.001), but the differences between the other two groups were not statistically significant (all P>0.05). (2)Compared with the NC group, the concentrations of serum TNF-α, IL-6 and HMGB1 of septic mice in each group were significantly increased at 6 h and 12 h (all P<0.05). Compared with NOMH group, the concentrations of TNF-α, IL-6 and HMGB1 in ATMH group, KN group and NH group were significantly increased at 6 h and 12 h(all P<0.05), and the concentrations of TNF-α, IL-6 and HMGB1 in NH group were the highest at all time points (all P<0.05). The concentrations of TNF-α at 12 h decreased compared with 6 h (all P<0.05), while the concentrations of IL-6 and HMGB1 at 12 h increased compared with 6 h (all P<0.05). (3)HE staining showed that the lung tissue damage were minimal in NOMH group, followed by ATMH group.(4)Immunohistochemical staining showed that the expression of HMGB1 protein was in order of NOMH group, ATMH group, KN group and NH group; (5)The relative expressions of HMGB1 protein in lung tissues of septic mice in NOMH group, ATMH group, KN group, and NH group was 0.280±0.013, 0.320±0.016, 0.340±0.018, and 0.380±0.014, respectively, and the relative expression level of HMGB1 mRNA was 4.86±0.22, 6.02±0.18, 6.26±0.20, and 7.98±0.28, respectively, compared with NC group (HMGB1 protein content was 0.240±0.013, and the relative expression level of HMGB1 mRNA was 2.21±0.12) significantly increased (all P<0.05). Cmpared with NOMH group, the relative expression levels of HMGB1 protein and HMGB1 mRNA in the lung tissues of the ATMH group, KN group and NH group were significantly increased(all P<0.05), with the highest expression level in the NH group(all P<0.05). Conclusion:Mild hypothermia may reduce lung tissue damage by down-regulating the expression of HMGB1 in lung tissues of septic mice, and the improvement of spontaneous mild hypothermia was more significant.

Objective: To establish a real-time PCR (RT-PCR) assay for detecting mRNA expression of killer cell immunoglobulin-like receptor (KIR) 2DS1 gene( KIR2DS1 ) on the surface of natural killer (NK) cells, and evaluate its performance. Methods: A total of 57 recipient-donor pairs of allogeneic hematopoietic stem cell transplantation (Allo-HSCT) were enrolled in this study. The specific primers and probe of KIR2DS1 gene were designed for Taqman-MGB fluorescence quantitative PCR detection system. The performance parameters of the detecting system, such as coincidence rate, repeatability, sensitivity, scope of application of the instrument and reproducibility of operation technicians were evaluated and validated. Results: The KIR-SSO Genotyping Test was used as the gold standard. The results of 35 samples showed the accuracies of self-built method were all 100% for both of positive and negative KIR2DS1 . Three samples with high, median and low value of Ct values were used to verify the repeatability. The coefficients of variation of intra-assay and inter-assay were ranged from 0.09% to 0.46% and 0.71% to 1.13% respectively. The sensitivity of the established method was up to 10 2 copies/μL at least. The coefficients of variation of the three samples with sensitivity of 10 2 copies/μL were 5.37%, 2.71% and 5.51% in five repeated tests respectively. The regression analysis for the samples measured by ABI-7500 and LC-480 fluorescence quantitative PCR instrument showed regression equation was Y=0.973 6X+0.118 3 (R 2 =0.961 9, R 2 ＞0.95). The reproducibility of 10 samples with positive KIR2DS1 operated by two technicians showed that the biases were all less than ±5%. Conclusion A TaqMan-MGB real-time PCR assay for detection of mRNA expression of KIR2DS1 gene was established successfully with fine performance.

Objective: To investigate the mechanism of chemokine-like factor superfamily member (CMTM) 5 on the proliferation of multiple myeloma cells. Methods: RT-qPCR method was used to detect the expression and correlation of CMTM5, caspase3 and caspase9 in U266 after decitabine demethylation treatment; U266 transfected with pcDNA3.1 plasmid overexpressed CMTM5, then cell proliferation activity was detected by CCK-8 assay. Results: Compared with the control group, the low-dose demethylation treatment increased mRNA expression of CMTM5, caspase3, and caspase9 in U266, and showed a time-dependent (P<0.01). The up-trend of CMTM5, caspase3, and caspase9 in the high-demethylation drug treatment group was more significant and also showed time-dependent (P<0.001); There was a significant positive correlation between CMTM5 and caspase3 (r=0.937) and caspase9 (r=0.945) in each group (P<0.001). After transfection of U266 with the pcDNA3.1-CMTM5 plasmid, overexpression of CMTM5 inhibited the cell proliferation activity compared with the control and pcDNA3.1-vector group. Conclusion Decitabine has a reductive effect on the low level of CMTM5 in U266 cells, and its recovery level is significantly positively correlated with caspase 3 and caspase9. Re-expression of CMTM5 inhibits the proliferative activity of U266.