Chemotherapy resistance plays a pivotal role in the prognosis and therapeutic failure of patients with colorectal cancer(CRC).Cisplatin(DDP)-resistant cells exhibit an inherent ability to evade the toxic chemotherapeutic drug effects which are characterized by the activation of slow-cycle programs and DNA repair.Among the elements that lead to DDP resistance,O6-methylguanine(O6-MG)-DNA-meth-yltransferase(MGMT),a DNA-repair enzyme,performs a quintessential role.In this study,we clarify the significant involvement of MGMT in conferring DDP resistance in CRC,elucidating the underlying mechanism of the regulatory actions of MGMT.A notable upregulation of MGMT in DDP-resistant cancer cells was found in our study,and MGMT repression amplifies the sensitivity of these cells to DDP treatment in vitro and in vivo.Conversely,in cancer cells,MGMT overexpression abolishes their sensi-tivity to DDP treatment.Mechanistically,the interaction between MGMT and cyclin dependent kinase 1(CDK1)inducing slow-cycling cells is attainted via the promotion of ubiquitination degradation of CDK1.Meanwhile,to achieve nonhomologous end joining,MGMT interacts with XRCC6 to resist chemotherapy drugs.Our transcriptome data from samples of 88 patients with CRC suggest that MGMT expression is co-related with the Wnt signaling pathway activation,and several Wnt inhibitors can repress drug-resistant cells.In summary,our results point out that MGMT is a potential therapeutic target and predictive marker of chemoresistance in CRC.

Objective To investigate the difference of depressive symptoms between adolescents and adults,and to provide possible basis for early detection of adolescent depression.Methods From July 2021 to June 2022,a total of 4 096 patients with"depression"in the psychiatric clinic of the First Affiliated Hospital of Chongqing Medical University were selected as the research objects.They were divided into the adolescent group(n=2 439)and adult group(n=1 657)according to their ages,and the results of self-rating depression scale(SDS)and symptom checklist 90(SCL-90)were collected and analyzed.Results There were significant differences in nationality,residence,native place,family history and degree of depression between the two groups(P<0.05).The adolescent group has more severe depressive symptoms,which were mainly manifes-ted in negative ideas,obsessive-compulsive symptoms,hostile and interpersonal relationship,and psychotic symptoms(P<0.05).The adult group showed more obvious in sleep(P<0.05).Conclusion Early inter-vention should be carried out for adolescents'depressive symptoms such as negative thoughts.

Objective:To evaluate the reliability and validity of the Chinese version of HEMO-FISS-QoL(HF-QoL) questionnaire (HF-QoL-C) in the Chinese population with hemorrhoids.Methods:From November 2021 to November 2022, a self-constructed general information questionnaire, HF-QoL-C, and the 36-item short form health survey (SF-36), Goligher classification, and Giordano severity of hemorrhoid symptom questionnaire (GSQ) were used to conduct a questionnaire survey on 760 hemorrhoid patients in the anorectal department of six hospitals. The data was analyzed for reliability and validity using SPSS 21.0 and AMOS 26.0 software.Results:The Cronbach's α coefficient of HF-QoL-C and its dimension ranged from 0.831 to 0.960, and the split coefficient was 0.832-0.915. Four common factors were extracted through principal component exploratory factor analysis. Confirmatory factor analysis indicated acceptable structural validity( χ2/ df=8.152, RSMEA=0.097, CFI=0.881, IFI=0.881, NFI=0.867). HF-QoL-C was correlated with SF36 and GSQ( r=-0.694, 0.501, both P<0.01). There were differences in the total score and dimensional scores of HF-QoL-C between surgical and drug treated patients, different grades of Goligher classification for hemorrhoidal disease, and different ranges of hemorrhoid prolapse (all P<0.001). No ceiling effect was found in the total score and the scores of each dimension(0.3%-2.0%). There was a floor effect in both psychological function and sexual activity dimensions (16.7%, 35.1%). Conclusion:HF-QoL-C has good reliability and validity, which can be used to measure the quality of life of Chinese hemorrhoid patients.

Purpose To evaluate the image quality improvement of deep learning iterative reconstruction(DLIR)on pediatric head CT images of head injury and to evaluate the performance of DLIR and conventional adaptive statistical iterative reconstruction-veo(ASIR-V)of noise and image texture of CT image in children's head trauma.Materials and Methods A total of 80 cases in Beijing Children's Hospital,Capital Medical University from December 7th to 11th 2020 of children's head low-dose CT were retrospectively selected.Scan voltage was 120 kV.Scan current was 150-220 mA.The raw data were reconstructed into 5 mm thick slice and 0.625 mm thin slice brain window and bone window images.50%ASIR-V and high weight DLIR images(DL-H)were reconstructed,respectively.A 4-point system was used to subjectively evaluate the display of sulcus,brain matter and bone.The number of lesions in each group was counted.The CT value and image noise values of gray matter and white matter were measured,and the contrast to noise ratio was calculated,then measured the blur metric index was measured in the same slice.The differences between the two image reconstruction methods were compared.Results Compared to 50%ASIR-V images,DL-H significantly improved the display ability of the sulcus and ventricles,as well as the display ability of the brain parenchyma(W=5.5-22.2,all P<0.05)in both slice thickness.There was no statistically significant difference in the display ability of the sulcus and ventricles between 5 mm 50%ASIR-V and 0.625 mm DL-H images(W=0.9,2.0,P=0.32,0.05,respectively).In terms of bone display ability,all images could achieve a maximum score of 4.0.A total of 35 lesions were found in 80 patients via 5 mm 50%ASIR-V and DL-H images,including 12 hemorrhagic lesions,1 intracranial gas,9 fractures,and 13 soft tissue swelling.In terms of objective evaluation,the noise level of DL-H images was significantly lower than that of 50%ASIR-V images(t=21.4-35.7,all P<0.05),and there was no statistically significant difference in noise and contrast noise ratio between 5 mm 50%ASIR-V and 0.625 mm DL-H images(t=1.7-2.2,all P≥0.05).The blur metric index showed that DL-H was superior to 50%ASIR-V images(t=6.1,10.0,both P<0.05),and there was no statistically significant difference in blur metric index between 0.625 mm DL-H and 5 mm 50%ASIR-V images(t=2.6,P=0.28).Conclusion DLIR can improve the CT image quality and image texture of children's head trauma,0.625 mm DL-H image quality is close to 5 mm 50%ASIR-V image,which can meet the diagnostic requirements,and possible to further reduce the radiation dose.

Objective:To investigate the association of exposure to PM 2.5 and its constituents during pregnancy and fetal growth and to further identify critical windows of exposure for fetal growth. Methods:We included 4 089 mother-child pairs from the Jiangsu Birth Cohort Study between January 2016 and October 2019. Data of general characteristics, clinical information, daily average PM 2.5 exposure, and its constituents during pregnancy were collected. Fetal growth parameters, including head circumference (HC), abdominal circumference (AC), and femur length (FL), were measured by ultrasound after 20 weeks of gestation, and then estimated fetal weight (EFW) was calculated. Generalized linear mixed models were adopted to examine the associations of prenatal exposure to PM 2.5 and its constituents with fetal growth. Distributed lag nonlinear models were used to identify critical exposure windows for each outcome. Results:A 10 μg/m 3 increase in PM 2.5 exposure during pregnancy was associated with a decrease of 0.025 ( β=-0.025, 95% CI: -0.048- -0.001) in HC Z-score, 0.026 ( β=-0.026, 95% CI: -0.049- -0.003) in AC Z-score, and 0.028 ( β=-0.028, 95% CI:-0.052--0.004) in EFW Z-score, along with an increased risk of 8.5% ( RR=1.085, 95% CI: 1.010-1.165) and 13.5% ( RR=1.135, 95% CI: 1.016-1.268) for undergrowth of HC and EFW, respectively. Regarding PM 2.5 constituents, prenatal exposure to black carbon, organic matter, nitrate, sulfate (SO 42-) and ammonium consistently correlated with decreased HC Z-score. SO 42- exposure was also associated with decreased FL Z-scores. In addition, we found that gestational weeks 2-5 were critical windows for HC, weeks 4-13 and 19-40 for AC, weeks 4-13 and 23-37 for FL, and weeks 4-12 and 20-40 for EFW. Conclusions:Our findings demonstrated that exposure to PM 2.5 and its constituents during pregnancy could adversely affect fetal growth and the critical windows for different fetal growth parameters are not completely consistent.

Objective:To investigate the clinical efficacy of gastrojejunal bypass surgery combined with radical gastrectomy following conversion therapy for gastric cancer with outlet obstruction.Methods:The retrospective and descriptive study was conducted. The clinicopatho-logical data of 10 initially unresectable gastric cancer patients with outlet obstruction who were admitted to Ruijin Hospital of Shanghai Jiao Tong University School of Medicine from October 2019 to July 2020 were collected. There were 8 males and 2 females, aged from 41 to 59 years, with a median age of 53 years. Patients underwent 'sandwich therapy' of gastrojejunal bypass surgery combined with gastrectomy following conversion therapy. Observation indicators: (1) gastrojejunal bypass surgery and postoperative situations; (2) conversion therapy and complications; (3) radical gastrectomy and postoperative situations; (4) follow-up. Follow-up using outpatient examinations or telephone interview was conducted to detect postoperative complications, progress-free survival, tumor recurrence and metastasis up to March 2019. Measurement data with normal distribution were represented as Mean± SD, and measurement data with skewed distribution were represented as M(range). Count data were described as absolute numbers. Results:(1) Gastrojejunal bypass surgery and postoperative situations: 10 patients received modified gastrojejunal bypass surgery combined with No.4sb lymph node dissection, without intraoperative serious complications, conversion to laparotomy or death. The operation time, volume of intraoperative blood loss, time to postoperative first flatus, time to liquid diet intake were 73 minutes(range, 60-87 minutes), 33 mL(range,20-110 mL), 3 days(range, 2-6 days), 4 days(range, 4-9 days). One patient had post-operative Clavien-Dindo grade Ⅱ complication of anastomotic bleeding, and was improved after transfusion of blood products. (2) Conversion therapy and complications: of 10 patients, 9 cases received 4 cycles of FLOT regimen. One of the 9 cases was suspended chemotherapy due to Clavien-Dindo grade Ⅱ anastomotic edema after 2 cycles of FLOT regimen. Of 10 patients, there were 6 cases with partial response and 4 cases with stable disease. Of 6 patients with partial response, 4 cases with preoperative cT4b stage were down stage to T4a stage, showing the relationship of tumor with transverse mesentery and pancreatic capsule clearer than the first exploration, 2 cases with preoperative lymph nodes fusion had shrank obviously. Of 4 patients with stable disease, 3 cases were negative for lymph nodes shranking, and the rest 1 case with tumor peritoneal metastasis diagnosed by initial laparoscopy can not be evaluated by imaging examination after chemotherapy. Two of 10 patients had Clavien-Dindo grade I complication of elevated blood glucose during the chemotherapy, which were improved after insulin therapy. (3) Radical gastrectomy and post-operative situations: 10 patients underwent radical resection after conversion therapy. Of 4 cases with stable disease, 3 cases with preoperative lymph nodes fusion showed obvious space between lymph nodes and surrounding tissues at resurgical exploration and received radical resection, 1 case with peritoneal metastasis showed abdominal wall nodelus and omental tuberosity as fibrous scars at resurgical exploration and received radical resection. The operation time, volume of intra-operative blood loss, time to postoperative first flatus, time to initial liquid diet intake, duration of total hospital stay, duration of postoperative hospital stay of 10 patients were 148 minutes(range, 95-195 minutes), 108 mL(range, 100-180 mL), 3 days(range, 2-7 days), 4 days(range, 3-9 days), 11 days(range, 10-21 days), 8 days(range, 7-16 days). Two of 10 patients had perioperative complications. Results of pathological examination of 10 patients showed the number of dissected lymph nodes as 25±6. There were 1 case of stage T1, 5 cases of stage T3, 4 cases of stage T4a. There were 1 case of stage N0, 2 cases of stage N1, 3 cases of stage N2, 4 cases of stage N3. There were 3 cases of tumor regression grade 1a, 1 case of grade 1b, 4 cases of grade 2, 2 cases of grade 3. (4) Follow-up: 10 patients were followed up for 3.9-13.0 months, with a median follow-up time of 6.0 months. The median progression-free survival time of 10 patients was 6.0 months. During the follow-up, 1 case underwent postoperative Clavien-Dindo grade Ⅱ complication of delayed gastric emptying and was improved after symptomatic treatment.Conclusion:The gastrojejunal bypass surgery combined with gastrectomy following conversion therapy for gastric cancer with outlet obstruction is safe and effective.

Objective:To evaluate the feasibility, safety and efficacy of robotic-assisted lateral lymph node dissection for mid-low advanced rectal cancer.Methods:A retrospective cohort study was performed. Inclusion criteria: (1) age between 18 and 80 years old; (2) rectal adenocarcinoma diagnosed by pathology; (3) without distant metastasis by preoperative CT or MRI; (4) patients underwent robotic-assisted total mesorectal resection (TME). Exclusion criteria: (1) conversion to open surgery; (2) multiple primary tumors; (3) patients underwent combined multiple organ resection. According to the above criteria, 137 patients undergoing robotic-assisted mid-low rectal cancer resection in the First Affiliated Hospital of Xi′an Jiaotong University from December 2016 to April 2019 were enrolled. Ninety-seven cases underwent robotic-assisted total mesorectal excision (TME group) and 40 underwent robotic-assisted total mesorectal resection with lateral lymph node dissection (LLND) (TME+LLND group, pelvic LLND was performed with neurovascular guidance to retain pelvic autonomic nerves in the order of the left side the first and then the right side). The propensity score matching of 1:1 was performed with R software, based on age, sex, BMI, ASA classification, distance from tumor to the anal verge, preoperative chemoradiotherapy history, preoperative abdominal surgery history, the size of tumors and TNM stage. The operative indicators, postoperative recovery, pathology and postoperative complications within 30 days were compared between the two groups.Results:A total of 72 cases were successfully matched (36 in each group), and there were no statistically significant differences in baseline data between the two groups (all P>0.05). The operation time of TME+LLND group was significantly longer than that of TME group [275.0 (180-405) minutes vs. 220.0 (140-320) minutes, Z=-3.680, P<0.001], while there were no statistically significant differences in blood loss during operation, time to postoperative first flatus, postoperative hospital stay, total hospital cost, tumor differentiation, and distal resection length of margin (all P>0.05). Circumferential resection margin was all negative in both groups. The number of harvested lymph modes in the TME+LLND groups was higher than that in the TME group [26 (18-37) vs. 14 (9-36), Z=-6.407, P<0.001]. In addition, there were no statistically significant differences in postoperative morbidity and Clavien-Dindo classification of complication within 30 days between the two groups (both P>0.05). Conclusions:Although robotic lateral lymph node dissection requires longer operation time, it is a feasible, safe and effective procedure.

Objective:To evaluate the feasibility, safety and efficacy of robotic-assisted lateral lymph node dissection for mid-low advanced rectal cancer.Methods:A retrospective cohort study was performed. Inclusion criteria: (1) age between 18 and 80 years old; (2) rectal adenocarcinoma diagnosed by pathology; (3) without distant metastasis by preoperative CT or MRI; (4) patients underwent robotic-assisted total mesorectal resection (TME). Exclusion criteria: (1) conversion to open surgery; (2) multiple primary tumors; (3) patients underwent combined multiple organ resection. According to the above criteria, 137 patients undergoing robotic-assisted mid-low rectal cancer resection in the First Affiliated Hospital of Xi′an Jiaotong University from December 2016 to April 2019 were enrolled. Ninety-seven cases underwent robotic-assisted total mesorectal excision (TME group) and 40 underwent robotic-assisted total mesorectal resection with lateral lymph node dissection (LLND) (TME+LLND group, pelvic LLND was performed with neurovascular guidance to retain pelvic autonomic nerves in the order of the left side the first and then the right side). The propensity score matching of 1:1 was performed with R software, based on age, sex, BMI, ASA classification, distance from tumor to the anal verge, preoperative chemoradiotherapy history, preoperative abdominal surgery history, the size of tumors and TNM stage. The operative indicators, postoperative recovery, pathology and postoperative complications within 30 days were compared between the two groups.Results:A total of 72 cases were successfully matched (36 in each group), and there were no statistically significant differences in baseline data between the two groups (all P>0.05). The operation time of TME+LLND group was significantly longer than that of TME group [275.0 (180-405) minutes vs. 220.0 (140-320) minutes, Z=-3.680, P<0.001], while there were no statistically significant differences in blood loss during operation, time to postoperative first flatus, postoperative hospital stay, total hospital cost, tumor differentiation, and distal resection length of margin (all P>0.05). Circumferential resection margin was all negative in both groups. The number of harvested lymph modes in the TME+LLND groups was higher than that in the TME group [26 (18-37) vs. 14 (9-36), Z=-6.407, P<0.001]. In addition, there were no statistically significant differences in postoperative morbidity and Clavien-Dindo classification of complication within 30 days between the two groups (both P>0.05). Conclusions:Although robotic lateral lymph node dissection requires longer operation time, it is a feasible, safe and effective procedure.

Objective To prepare a wound dressing using nitrocellulose as a membrane and optimize its formulation. Methods Partial analysis was performed on commercial available products. The wound dressings were prepared by using nitrocellulose as a film-forming material, benzyl alcohol as a bacteriostatic agent, castor oil as a plasticizer, isopropyl palmitate as a skin emollient, camphor as a fragrance, and isopropyl alcohol, ethyl acetate and butyl acetate as volatile solvent. The tensile strength, breakpoint elongation percentage, breathability and waterproof performance were tested and evaluated. Results The film-forming performance of the prepared liquid wound dressing was good. The final use amount of nitrocellulose was determined to be 6%. The use amount of plasticizer castor oil was determined to be 4%. Conclusion The prepared liquid wound dressing has good film-forming property, good mechanical property, good waterproof and certain breathability.

Objective: To evaluate combined robotic and endoscopic surgery in the third space for gastric submucosal tumors(SMTs). Methods: Combined surgery in 4 patients were compared with 19 patients who underwent laparoscopic wedge resection between Aug 2017 and Feb 2018. Results: R₀ resection was achieved in all combined surgery patients. The operation time was longer (112±29 )min vs. (93±11 ) min (t=2.338, P<0.05), but less blood loss, (11±6)ml vs.(59±6)ml (t=15.102, P<0.01). In combined surgery group, there was a larger tumor over resected tissue percentage, 65.4%±28.2% vs.22.8%±19.6% ( t=3.680, P<0.05). Combined surgery group patients were with earlier first breaking wind (3±1.4) d vs.(4.1±0.9) d (t=2.026, P>0.05), and shorter hospital stay (6.5±1.3) d vs.( 8.5±0.6) d (t=4.902, P<0.01), but a little higher hospitalization costs(57 651±10 097)rmb vs.(42 620±5 086)rmb (t=4.508, P<0.01). There were no major postoperative complications occurred in neither groups, nor tumor recurrences after 3-month follow-up. Conclusion Combined robotic and endoscopic surgery in the third space for submucosal gastric tumors is a novel operation with short operation time, less blood loss and good result.