[Report on the application of endoscopic intermuscular dissection for diagnostic resection of early rectal cancer].

Objective: This report presents the initial outcomes of endoscopic intermuscular dissection (EID), a novel technique introduced by our team for the diagnostic resection of early rectal cancer, focusing on the postoperative status of the vertical margins. Methods: On January 26, 2024, a patient with early rectal cancer (cT1-2N0M0) underwent Endoscopic Intermuscular Dissection. The EID procedure consists of six steps: (1) mucosal incision; (2) submucosal dissection; (3) superficial muscular layer incision; (4) intermuscular dissection; (5) complete tumor removal; (6) wound management. Results: The patient was a 70-year-old male with rectal cancer (cT1-2N0M0). The tumor was located on the left anterior wall of the rectum, approximately 9 cm from the anal margin, and measured 20mm in size. The dissection rate was 2.68 mm²/minute, and the total duration of the surgery was 109 minutes. The patient was successfully discharged on the fifth day after surgery. Pathological examination of the post-endoscopic surgery specimen revealed pT1b, with negative vertical margins. Follow-up after more than one month showed good recovery with no complications such as bleeding, perforation, infection, or stricture occurring. Colonoscopy indicated the presence of a granulation tissue suggestive of inflammation. Conclusion: Endoscopic Intermuscular Dissection for the diagnostic resection of early rectal cancer is potentially safe and may achieve negative vertical margins.

[Clinical effects of free latissimus dorsi myocutaneous flap combined with artificial dermis and split-thickness skin graft in the treatment of degloving injury in lower extremity].

Objective: To observe the clinical effects of free latissimus dorsi myocutaneous flap combined with artificial dermis and split-thickness skin graft in the treatment of degloving injury in lower limbs. Methods: A retrospective observational study was conducted. From December 2017 to December 2020, 8 patients with large skin and soft tissue defect caused by degloving injury in lower extremity were admitted to Ningbo No.6 Hospital, including 5 males and 3 females, aged from 39 to 75 years, with wound area of 25 cm×12 cm-61 cm×34 cm. The free latissimus dorsi myocutaneous flap with latissimus dorsi muscle in the width of 12-15 cm and flap area of 20 cm×8 cm-32 cm×8 cm was used to repair the skin and soft tissue defect of bone/tendon exposure site or functional area. The other defect was repaired with bilayer artificial dermis, and the flap donor site was sutured directly. After the artificial dermis was completely vascularized, the split-thickness skin graft from thigh was excised and extended at a ratio of 1∶2 to 1∶4 and then transplanted to repair the residual wound, and the donor site of skin graft was treated by dressing change. The survival of latissimus dorsi myocutaneous flap, artificial dermis, and split-thickness skin graft after operation was observed, the interval time between artificial dermis transplantation and split-thickness skin graft transplantation was recorded, and the healing of donor site was observed. The appearance and function of operative area were followed up. At the last outpatient follow-up, the sensory recovery of flap was evaluated by British Medical Research Council evaluation criteria, the flap function was evaluated by the comprehensive evaluation standard of flap in Operative Hand Surgery, the scar of lower limb skin graft area and thigh skin donor area was evaluated by Vancouver scar scale, and the patient's satisfaction with the curative effects was asked. Results: The latissimus dorsi myocutaneous flap survived in 6 patients, while the distal tip of latissimus dorsi myocutaneous flap was partially necrotic in 2 patient and was repaired by skin grafting after resection at split-thickness skin grafting. The artificial dermis survived in all 8 patients after transplantation. The split-thickness skin graft survived in 7 patients, while partial necrosis of the split-thickness skin graft occurred in one patient and was repaired by skin grafting again. The interval time between artificial dermis transplantation and split-thickness skin graft transplantation was 15-26 (20±5) d. The donor site of latissimus dorsi myocutaneous flap healed with linear scar after operation, and the thigh skin graft donor site healed with scar after operation. The patients were followed up for 6-18 (12.5±2.3) months. The color and elasticity of the flap were similar to those of the surrounding skin tissue, and the lower limb joint activity returned to normal. There was no increase in linear scar at the back donor site or obvious hypertrophic scar at the thigh donor site. At the last outpatient follow-up, the sensation of the flap recovered to grade S2 or S3; 3 cases were excellent, 4 cases were good, and 1 case was fair in flap function; the Vancouver scar scale score of lower limb skin graft area was 4-7 (5.2±0.9), and the Vancouver scar scale score of thigh skin donor area was 1-5 (3.4±0.8). The patients were fairly satisfied with the curative effects. Conclusions: In repairing the large skin and soft tissue defect from degloving injury in lower extremity, to cover the exposed bone/tendon or functional area with latissimus dorsi myocutaneous flap and the residual wound with artificial dermis and extended split-thickness skin graft is accompanied by harvest of small autologous flap and skin graft, good recovery effect of functional area after surgery, and good quality of healing in skin grafted area.

Simvastatin is beneficial to lung cancer progression by inducing METTL3-induced m6A modification on EZH2 mRNA.

OBJECTIVE: To elucidate the molecular mechanism of Simvastatin on inhibiting malignant progression of lung cancer. PATIENTS AND METHODS: Relative levels of METTL3 and EZH2 in lung cancer tissues and adjacent normal ones were detected by quantitative real-time polymerase chain reaction (qRT-PCR). In addition, their levels in lung cancer patients with different pathological stages were determined as well. A549 cells were induced with different doses of Simvastatin for 24 h. Subsequently, relative levels of METTL3 and EZH2 in cells were detected. Proliferative and metastatic abilities in A549 cells were examined by cell counting kit-8 (CCK-8), 5-Ethynyl-2'- deoxyuridine (EdU) and transwell assay, respectively. RIP assay was conducted to detect the presence of m6A modification on EZH2 mRNA and the interaction between IGF2BP2 and EZH2. Relative levels of EZH2 and epithelial-mesenchymal transition (EMT)-associated genes (E-cadherin and N-cadherin), and metastatic abilities were detected in Simvastatin-induced A549 cells transfected with pcDNA-METTL3. RESULTS: METTL3 and EZH2 levels were upregulated in lung cancer tissues, which were higher in advanced stage lung cancer patients. Their levels, as well as cell proliferative and metastatic abilities, were dose-dependently inhibited in Simvastatin-induced A549 cells. METTL3 positively regulated EZH2 level, and m6A modification on its mRNA. Moreover, the interaction between IGF2BP2 and EZH2 could be inhibited by knockdown of METTL3. Simvastatin could abolish the role of METTL3 in regulating relative levels of EZH2 and EMT-associated genes, as well as metastatic abilities in A549 cells. CONCLUSIONS: Simvastatin induces METTL3 down-regulation in lung cancer tissues, which further influences EMT via m6A modification on EZH2 mRNA and thus inhibits the malignant progression of lung cancer.