[Short-term complications after transanal total mesorectal excision for mid-low rectal cancer].

Objective: To summarize short-term postoperative complications of transanal total mesorectal excision (taTME) in the treatment of middle-low rectal cancer. Methods: A descriptive case series of cases was constructed. Clinical data of consecutive 83 patients with mid-low rectal cancer who received taTME treatment from November 2016 to April 2021 at Department of General Surgery of Beijing Friendship Hospital, Capital Medical University were collected. Among 83 patients, 58 (69.9%) were males, with a mean age of (61.4±11.8) years; 42 (50.6%) were low rectal cancer, 41 (49.4%) were middle rectal cancer. Short-term postoperative complication was defined as complication occurring within 30 days after operation. The complication was graded according to the Clavien-Dindo classification. At the same time, the morbidity of short-term postoperative complication in the first 40 patients and that in the last 43 patients were compared to understand the differences before and after passing the taTME learning curve. Results: Two patients (2.5%) were converted to laparotomy ; 78 (94.0%) completed anastomosis.While 5 (6.0%) underwent permanent stoma. The total operation time of transabdominal+ transanal procedure was (246.9±85.0) minutes, and the median intraoperative blood loss was 100 (IQR: 100) ml. Seventy-five cases (75 /78, 96.2%) underwent defunctioning stoma, including 74 cases of diverting ileostomy, 1 case of diverting transverse colostomy and 3 cases without stoma. The morbidity of complication within 30 days after operation was 38.6% (32/83), and the morbidity of complication after discharge was 8.4% (7/83). Minor complications accounted for 31.3% (26/83) and major complications accounted for 7.2% (6/83). No patient died within 30 days after operation. The incidence of anastomotic leakage was 15.4% (12/78). Eight patients (9.6%) were hospitalized again due to complications after discharge. The median postoperative hospital stay was 7 (IQR: 3) days. All the patients with minor (I-II) complications received conservative treatment. One patient with grade C anastomotic leakage was transferred to intensive care unit and received a second operation due to sepsis and multiple organ dysfunction. Two patients with paralytic ileus (Clavien-Dindo IIIa) underwent endoscopic ileus catheter placement. There were 3 patients with Clavien-Dindo III or above respiratory complications, including 1 patient with pleural effusion and ultrasound-guided puncture, 2 patients with respiratory failure who were improved and discharged after anti-infection and symptomatic treatment. One patient underwent emergency ureteral stent implantation due to urinary infection (Clavien-Dindo IIIb). The morbidity of postoperative complication in the first 40 cases was 50.0% (20/40), and that in the latter 43 cases decreased significantly (27.9%, 12/43), whose difference was statistically significant (χ(2)=4.270, P=0.039). Conclusions: The procedure of taTME has an acceptable morbidity of short-term postoperative complication in the treatment of mid-low rectal cancer. The accumulation of surgical experience plays an important role in reducing the morbidity of postoperative complication.

[Problems exposed in retrospective study of postoperative complications of rectal cancer and causal analysis].

Rectal cancer is a great threat to the health of the Chinese people. With the continuous improvement of surgical treatment level, complication as an important indicator to measure the safety of surgery has received increasing attention from clinicians both at home and abroad. Although there are many studies on postoperative complications of rectal cancer, the morbidity of complication reported by related studies varies greatly. An important reason occurs in the limitations of retrospective research, such as incomplete medical records, unclear diagnostic criteria for some complications, incomplete follow-up records after discharge, and poor communication mechanisms among MDT members. Starting from a retrospective study on postoperative complications of rectal cancer and finding out the defects and problems in the registration of complications in each center, then clarifying the definition of various postoperative complications, so as to establish a sound and standardized registration system, and carry out prospective research, this path could be a reliable method to obtain relatively accurate postoperative complications of rectal cancer.

[Research progress on early diagnosis and prevention of anastomotic leak after rectal cancer surgery].

Anastomotic leak is a common and serious complication after anterior rectal resection. Despite the continuous advancement of anastomotic instruments and surgical techniques, the incidence of anastomotic leak has not decreased significantly compared with the past. As more studies on the early diagnosis of anastomotic leak are published, postoperative risk factors of anastomotic leak, such as fever, time to first bowel movement, CT, C-reactive protein (CRP) and procalcitonin (PCT), matrix metalloproteinase-9, and other cytokines and biomarkers (IL-6, TNF-α, lactate, pH, urinary neopterin/creatinine ratio), provide a reference for surgeons to assess the risk and increase the possibility of early diagnosis of anastomotic leak. Nevertheless, preventing the occurrence of anastomotic leak is still the ultimate goal. For the prevention of anastomotic leak, intraoperative ICG fluorescence imaging technology provides a simple and safe objective method for surgeons to evaluate anastomotic perfusion. The diversion stoma may reduce the incidence of anastomotic leak. More and more evidence shows that drainage through the anal canal can reduce the incidence of anastomotic leak after rectal cancer, but whether different types of drainage catheters can clearly reduce the incidence of anastomotic leak still needs more evidence. In addition, there has not yet been a unified opinion on the retention time and location of the drainage catheter. At present, the research of anastomotic leak has not adopted a unified definition and the heterogeneity among related studies is still great. We still look forward to more high-quality multi-center large prospective and randomized controlled studies.

Down-regulation of microRNA-21 inhibits cell proliferation and invasion of high-invasion liver cancer stem cells.

OBJECTIVE: Cancer stem cells (CSCs) play critical roles in tumorigenesis, tumor recurrence and metastasis. This study aims to investigate the effects of small interfere microRNA-21 RNA (miR-21 RNAi) on cell proliferation, invasive ability of high-invasion liver cancer stem cells (H-ILCSCs), HCCLM3 and HL-7702 cells. MATERIALS AND METHODS: pLVX-shRNA2 lentiviral vector system was established, packaged and transfected into H-ILCSCs, HCCLM3 and HL-7702 cells. Cell counting kit-8 (CCK-8) assay was performed to observe cell viabilities of cells. Transwell assay was conducted to evaluate the invasion potential of H-ILCSCs, HCCLM3 and HL-7702 cells. Quantitative PCR (qPCR) assay was used to examine the miR-21 levels in different cell lines. RESULTS: pLVX-anti-miR21 lentiviral vector system was successfully established. miR-21 levels were down-regulated in anti-miR-21 gene steady expression cell lines compared to untreated cells (p<0.05). miR-21 levels were significantly lower in H-ILCSC2-LV-anti-miR-21 group compared to HCCLM3-anti-miR-21 and HL7702-anti-miR-21 (p<0.05). miR-21 inhibition significantly decreased cell proliferation and invasion compared to untreated cells (p<0.05). Cell proliferation and invasive ability of H-ILCSC2-LV-anti-miR-21 group were significantly higher compared to HCCLM3-anti-miR-21 and HL7702-anti-miR-21 (p<0.05). There were even not effects of miR-21 RNAi treatment on the cell proliferation and invasion of HL-7702 cells. CONCLUSIONS: The down-regulation of miR-21 significantly inhibited the cell proliferation and invasion abilities of H-ILCSCs and HCCLM3 cells, and illustrated higher effects on H-ILCSCs.

High-glucose promotes proliferation of human bladder cancer T24 cells by activating Wnt/ß-catenin signaling pathway.

OBJECTIVE: Bladder cancer is the most prevalent genitourinary malignant disorder worldwide. We aimed to observe effects of high-glucose on bladder cancer proliferation and explore the associated mechanisms. MATERIALS AND METHODS: Human bladder cancer cell line, T24, was divided into Blank, Control (Ctrl), 10 mmol/l, 20 mmol/l and 30 mmol/l group. T24 cell proliferation was evaluated by using multiple table tournament (MTT) assay and colony formation analysis, respectively. Quantitative Real-time PCR (qRT-PCR) assay was employed to examine mRNA expression of Wnt-5a and ß-catenin. Meanwhile, Western blot assay was used to evaluate expression of Wnt-5a and ß-catenin protein. The linear regression analysis was utilized to analyze correlation between Wnt-5a/ß-catenin expression and T24 cell proliferation. RESULTS: High-glucose significantly enhanced proliferation of T24 cells compared to that of Blank and Ctrl group (p < 0.05). High-glucose significantly promoted colony formation of T24 cells compared to that of Blank and Ctrl group (p < 0.05). High-glucose significantly up-regulated Wnt-5a mRNA and protein expression compared to that of Blank and Ctrl group (p < 0.01). High-glucose significantly increased ß-catenin mRNA and protein expression compared to that of Blank and Ctrl group (p < 0.01). Effects of high-glucose on T24 cell proliferation were increased following with the enhanced glucose concentration. Wnt/ß-catenin signaling pathway molecules were correlated with colony formation of T24 cells (p < 0.05). CONCLUSIONS: High-glucose promoted the proliferation of T24 cells by activating the Wnt/ß-catenin signaling pathway. This study would provide the novel targets for bladder cancer therapy.

Replication-dependent mutagenesis by 5-bromodeoxyuridine: identification of base change and sequence effects on mutability.

The molecular mechanism of reversion induced by 5-bromodeoxyuridine (BrdU) replication-dependent mutagenesis in mammalian cells was studied. Murine cells with single mutant copies of the E. coli gpt gene integrated chromosomally as part of a shuttle vector were mutagenized with BrdU, and GPT+ revertants were selected. Thirteen mutant cell lines (each of which had a gpt gene that varied from the wild-type gene by a different GC----AT base transition in the coding region) were mutagenized, and only four were found to be effectively reverted. All revertant gpt genes that were analyzed had reverted via AT----GC base transition at the original site of mutation, thus demonstrating that replication-dependent mutagenesis by BrdU causes AT----GC transitions. The nine cell lines that were nonrevertible by BrdU replication-dependent mutagenesis could be mutated by this protocol to ouabain resistance as effectively as the four revertible lines, indicating that the nonrevertible lines were susceptible to such mutagenesis. Thus, differences among the cell lines in frequencies of HATr revertants generated by BrdU replication-dependent mutagenesis could not be attributed to differences in general susceptibility of the lines to the mutagenic protocol. The revertible and nonrevertible lines could not be separated according to the position of the original GC----AT transition in the gpt coding region. However, there was evidence that the DNA base sequence flanking the site of mutation affected the susceptibility of that site to BrdU replication-dependent mutagenesis. For example, six of the cell lines tested had gpt genes in which the mutant T residue was immediately adjacent on its 3' side to an A residue, and all six were found to be nonrevertible by BrdU replication-dependent mutagenesis. Furthermore, a target AT base pair flanked by GC base pairs in opposite orientation and either immediately adjacent to or one base removed from the target site on both the 5' and 3' sides appeared to have an increased susceptibility to BrdU replication-dependent mutagenesis.

[Susceptibility and R plasmids conjugation tests for 44 strains of gram negative bacilli in a burn unit].

44 strains of 9 species Gram negative bacilli were isolated and identified in a burn unit, among them 25 strains were from patients and 19 from ward environment. All strains were tested for susceptibility to antibiotics and R plasmids. Using both agar dilution and disc diffusion methods to test susceptibility to 12 kinds of antibiotics, namely, Streptomycin Chloramphenicol, Tetracycline, Ampicillin, Kanamycin, Gentamycin, Nalidixic acid, Amikacin Rifampin, Carbenicillin, Cefazolin and Polymyxin, we found that all 44 strains were susceptible to Rifampin and Polymyxin. To the other 10 kinds of antibiotics, the susceptibilities varied. 40 strains of bacteria (91%) were resistant to 3 kinds or more of antibiotics, i.e, multiple resistant bacteria, 2 strains resistant to 2 kinds of antibiotics (4.6%), and 2 strains susceptible to all 12 kinds of antibiotics (4.6%). The multiple resistant strains consisted of 9 strains (22.5%) of R plasmid-harboured bacteria, Pseudomonas aeruginosa 2 strains, Citrobacter 4 strains, Proteins 1 strain, Enterobacter aerogenes 1 strain and Escherichia coli 1 strain. All the R plasmids carried the marks of resistance to chloramphenicol, tetracycline, ampicillin, kanamycin, gentamycin, streptomycin, and carbenicillin, but no one carried marks of resistance to Cefazolin and Amikacin indicating that drug-resistance of the last two antibiotics might not be mediated by R plasmids. Two strains of Citrobacter freundii isolated from 2 patients and showing susceptibility to all antibiotics were induced to be Rifampin-resistance (Rif) strains without changing their original biological characters. They both could receive the R plasmids of the multiple resistance strains one from patient and the other from ward environment.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular analysis of ethyl methanesulfonate-induced reversion of a chromosomally integrated mutant shuttle vector gene in mammalian cells.

The molecular mechanisms of ethyl methanesulfonate-induced reversion in mammalian cells were studied by using as a target a gpt gene that was integrated chromosomally as part of a shuttle vector. Murine cells containing mutant gpt genes with single base changes were mutagenized with ethyl methanesulfonate, and revertant colonies were isolated. Ethyl methanesulfonate failed to increase the frequency of revertants for cell lines with mutant gpt genes carrying GC----AT transitions or AT----TA transversions, whereas it increased the frequency 50-fold to greater than 800-fold for cell lines with mutant gpt genes carrying AT----GC transitions and for one cell line with a GC----CG transversion. The gpt genes of 15 independent revertants derived from the ethyl methanesulfonate-revertible cell lines were recovered and sequenced. All revertants derived from cell lines with AT----GC transitions had mutated back to the wild-type gpt sequence via GC----AT transitions at their original sites of mutation. Five of six revertants derived from the cell line carrying a gpt gene with a GC----CG transversion had mutated via GC----AT transition at the site of the original mutation or at the adjacent base in the same triplet; these changes generated non-wild-type DNA sequences that code for non-wild-type amino acids that are apparently compatible with xanthine-guanine phosphoribosyltransferase activity. The sixth revertant had mutated via CG----GC transversion back to the wild-type sequence. The results of this study define certain amino acid substitutions in the xanthine-guanine phosphoribosyltransferase polypeptide that are compatible with enzyme activity. These results also establish mutagen-induced reversion analysis as a sensitive and specific assay for mutagenesis in mammalian cells.