BACKGROUND: P16 inactivation is frequently accompanied by telomerase reverse transcriptase ( TERT ) amplification in human cancer genomes. P16 inactivation by DNA methylation often occurs automatically during immortalization of normal cells by TERT . However, direct evidence remains to be obtained to support the causal effect of epigenetic changes, such as P16 methylation, on cancer development. This study aimed to provide experimental evidence that P16 methylation directly drives cancer development. METHODS: A zinc finger protein-based P16 -specific DNA methyltransferase (P16-Dnmt) vector containing a "Tet-On" switch was used to induce extensive methylation of P16 CpG islands in normal human fibroblast CCD-18Co cells. Battery assays were used to evaluate cell immortalization and transformation throughout their lifespan. Cell subcloning and DNA barcoding were used to track the diversity of cell evolution. RESULTS: Leaking P16-Dnmt expression (without doxycycline-induction) could specifically inactivate P16 expression by DNA methylation. P16 methylation only promoted proliferation and prolonged lifespan but did not induce immortalization of CCD-18Co cells. Notably, cell immortalization, loss of contact inhibition, and anchorage-independent growth were always prevalent in P16-Dnmt&TERT cells, indicating cell transformation. In contrast, almost all TERT cells died in the replicative crisis. Only a few TERT cells recovered from the crisis, in which spontaneous P16 inactivation by DNA methylation occurred. Furthermore, the subclone formation capacity of P16-Dnmt&TERT cells was two-fold that of TERT cells. DNA barcoding analysis showed that the diversity of the P16-Dnmt&TERT cell population was much greater than that of the TERT cell population. CONCLUSION P16 methylation drives TERT -mediated immortalization and transformation of normal human cells that may contribute to cancer development.
Humans ; Telomerase/genetics* ; DNA Methylation/physiology* ; Fibroblasts/cytology* ; Cyclin-Dependent Kinase Inhibitor p16/metabolism* ; Cell Line ; Cell Transformation, Neoplastic/genetics*

Objective:To compare the efficacy of arthroscopic figure-of-eight transtibial tension-reducing technique combined with interference screw fixation versus interface screw fixation alone in the treatment of anterior cruciate ligament (ACL) rupture.Methods:A retrospective cohort study was conducted to analyze the clinical data of 43 patients with ACL rupture admitted to Taihe Hospital between January 2022 and October 2023, including 24 males and 19 females, aged 17-61 years [(38.0±12.6)years]. Based on the tibial fixation method, 20 patients were treated with interference screw fixation alone (interference screw group) and 23 patients with figure-of-eight transtibial tension-reduction technique combined with interference screw fixation (figure-of-eight tension-reduction combined with interference screw group). An Endobutton suspension plate was used in femoral fixation in both groups. The following parameters were compared between the two groups: operative duration and graft diameter; coronal and sagittal tibial tunnel measurements by MRI within 72 hours postoperatively and at the last follow-up; knee range of motion, visual analogue scale (VAS) scores, International Knee Documentation Committee (IKDC) scores, and Lysholm scores preoperatively, at 1 month postoperatively, and at the last follow-up; perioperative complication rates.Results:All the patients were followed up for 11-28 months [(14.1±3.4)months]. There were no significant differences in operative duration or graft diameter between the two groups ( P>0.05). No significant differences were observed in coronal or sagittal tibial tunnel measurements between the two groups within 72 hours postoperatively ( P>0.05). Whereas at the last follow-up, the coronal and sagittal tibial tunnel measurements in the figure-of-eight tension-reduction combined with interference screw group were (11.6±0.7)mm and (11.7±1.1)mm, significantly lower than (13.5±0.6)mm and (13.4±1.9)mm in the interference screw group ( P<0.01). Preoperative knee range of motion, IKDC scores, Lysholm scores, and VAS scores showed no significant differences between the two groups ( P>0.05). At 1 month postoperatively and at the last follow-up, the figure-of-eight tension-reduction combined with interference screw group demonstrated significantly greater knee range of motion [100.0(95.0, 100.0)° and 130.0(120.0, 135.0)°], compared with 72.5(60.0, 95.0)° and 120.0(105.0, 133.3)° in the interference screw group ( P<0.05). VAS scores at 1 month postoperatively and at the last follow-up were 2.0(2.0, 2.0)]points and 1.0(1.0, 1.0)points in the figure-of-eight tension-reduction combined with interference screw group, significantly lower than 3.0(2.3, 4.0)points and 2.0(1.0, 2.0)points in the interference screw group ( P<0.05). IKDC scores at 1 month postoperatively and at the last follow-up were (58.8±5.7)points and (72.4±6.7)points in the figure-of-eight tension-reduction combined with interference screw group, significantly higher than (51.1±5.2)points and (67.4±7.9)points in the interference screw group ( P<0.05). Lysholm scores at 1 month postoperatively and at the last follow-up were (58.9±12.7)points and (89.1±6.0)points in the figure-of-eight tension-reduction combined with interference screw group, significantly higher than (41.2±15.0)points and (78.3±12.3)points in the interference screw group ( P<0.05). No perioperative complications were observed in either group. Conclusion:Compared with interface screw fixation alone, arthroscopic figure-of-eight transtibial tension-reduction technique combined with interference screw fixation for ACL rupture can enhance graft stability, restore knee joint range of motion, alleviate pain, and improve knee function recovery.

Objective:To investigate a surgical method and clinical outcomes of a fascia pedicled island flap with dorsal branch of proper palmar digital nerve in reconstruction of defects of digital pulp.Methods:Seventy-five patients who had digital pulp defects and treated at Department of Orthopaedics, Xinjiang Production and Construction Corps Alar Hospital, Shaw Hospital Affiliated Zhejiang University School of Medicine, from December 2019 to December 2022, were retrospectively analysed. The patients were 40 males and 35 females aged 25-61 years with an average age of 42 years. The defects of digital pulp involved in 23 thumbs, 15 per group of index fingers, middle fingers and ring fingers, and 7 little fingers. The digital pulp defects were 0.8 cm×0.9 cm to 1.5 cm×2.1 cm in size, and the sizes of flap were 1.0 cm×1.2 cm to 1.8 cm×2.4 cm. Donor sites were covered by medium-thickness skin grafts and pressurised bandage was applied. Clinical outcomes of the surgery were monitored through the postoperative follow-ups at outpatient clinic, WeChat and telephone reviews.Results:Postoperative follow-up ranged 9 to 15 months, with an average of 12 months. The donor sites and skin grafts all achieved stage-I healing. Seventy-three flaps completely survived after surgery. However, 2 flaps had partial necrosis, which healed after dressing changes, 4 flaps encountered flap bruising and swelling, which were rectified by removal of high-tension sutures, and 7 flaps had tension blisters, which had disappeared in 2 weeks. At the final follow-up, the appearance and texture of the flaps were graded as excellent for 54 flaps and good for 21 flaps, all without pale, cyanotic or dark in colour. Forty-nine flaps showed normal elasticity or with slight atrophy, 24 with mild atrophy, 2 with moderate atrophy and none with obvious or severe atrophy. Mobility of the affected digits was rated as excellent for 57 digits (average 42.3°), good for 12 (average 26.7°) and fair in 6 digits (average 16.3°). TPD of flap surfaces ranged 6 to 11 mm, with an average of 8.1 mm. Digital function were evaluated according to the Evaluation Trial Standards of Upper Limb Partial Functional of Hand Surgery of Chinese Medical Association, with 48 digits in excellent (average 11.2 points), 22 in good (average 8.1 points) and 5 in fair (average 5.4 points) and with a combined excellence and good rates of 93.33%. All flap donor sites were in normal function. For patient satisfaction: 53 patients were well satisfied, 21 were fairly satisfied and 1 was dissatisfied.Conclusion:Application of the island flap with dorsal branch of proper palmar digital nerve with fascio-pedicled in reconstruction of the defect of digital pulp has a high survival rate, simple surgical operation, good satisfactory outcome, with the digital artery being remained intact.

Strabismus, a common ocular condition, arises from an imbalance in the extraocular muscle force and deviation of the visual axis due to various factors. Concomitant strabismus is the predominant form of exotropia, with its pathogenesis believed to be associated with hereditary factors, abnormal eye accommodation function, and anomalies in binocular anatomy. Surgical intervention is often necessary for aligning the visual axes of both eyes and facilitating the recovery and establishment of stereoscopic vision. Despite this, the etiology of concomitant exotropia remains incompletely understood. This review consolidates recent research on aberrant molecular expression and pathological morphological changes within extraocular muscles affected by concomitant exotropia, offering insights into disease causation at molecular and pathological levels to underpin future preventive measures and clinical interventions. The discussion encompasses histological changes observed under electron microscopy as well as the impact of heavy chain protein, satellite cells, cadherin, growth factors on extraocular muscle protein expression.

Objective To conduct microbiological monitoring before the operation of the purified water treatment system in a newly-built endoscopy center,comprehensively analyze the causes for the standard-exceeding results of microbial detection of final rinse water,propose solutions,and provide reference for handling similar events in the future.Methods Microbial detection data of the final rinse water in the newly-built digestive endoscopy center of a tertiary first-class general hospital in Beijing from April to July 2024 were monitored.The potential causes for standard-exceeding results of microbial detection of final rinse water were analyzed from the perspectives of equip-ment maintenance and management of the purified water treatment system as well as the improvement of cleaning and disinfection methods for the purified water supply pipeline in the endoscopy center,targeted improvement mea-sures were proposed accordingly.Results The microbial monitoring result of final rinse water in the newly-built di-gestive endoscopy center built in April 2024 was 1 400 CFU/100 mL,with the main bacterial type being Cupriavi-duspauculus.After five rounds of improvement measures and rechecks,microbial monitoring result of the final rinse water in the newly-built endoscopy center was 0 CFU/100 mL,with a qualification rate of 100％.Analysis suggested that the main causes for the standard-exceeding results of microbial detection of final rinse water were due to the damage of the reverse osmosis membrane,lack of cleaning for the pure water storage tank before use,and non-standard cleaning and disinfection process for the pure water supply pipeline,after targeted improvement,the problem was solved.Conclusion Medical institutions should continuously conduct periodic monitoring on water used for endoscope,regularly perform cleaning and disinfection of the purified water treatment system,standardize cleaning and disinfection procedures,ensure medical quality and patient safety.

Objective:This study evaluated the efficacy of the PST technique: Preservation of the left colic artery (P), suture reinforcement (S), and transanal tube (T) combined with selective fecal diversion via end ileostomy, in preventing anastomotic leakage following laparoscopic anterior resection (LAR) for mid-to-low rectal cancer.Methods:We retrospectively collected data for this descriptive case series from patients who underwent laparoscopic LAR with complete or partial application of the PST technique, some of whom received prophylactic ileostomy, at the Department of Colorectal Surgery, Zhongshan Hospital Affiliated to Fudan University, and its Xiamen Branch between July, 2022 and December, 2024. "Partial PST" was defined as the implementation of PS (Preservation of the left colic artery + suture reinforcement), PT (Preservation of the left colic artery + transanal tube), ST (suture reinforcement + transanal tube), or a single T procedure (Transanal tube). The primary outcome measures were the proportion of patients who received the PST technique and terminal ileostomy, as well as the incidence of anastomotic leaks.Results:Among 198 patients, 145 received complete PST. Fifty-three patients underwent partial PST (PT) because anastomotic reinforcement was not feasible due to an excessively low anastomosis or obesity. All patients achieved R0 resection. Postoperative pathology showed that 108 patients (54.5%) were at T3-T4 stage, and 81 patients (40.9%) had poorly differentiated adenocarcinoma or mucinous adenocarcinoma. A total of 19.7% (39/198) of patients developed grade II or higher postoperative complications, including 11 cases (5.6%) of surgical site infection and 7 cases (3.5%) of urinary retention. Five patients were rehospitalized within 30 days after surgery, among whom 2 had intestinal obstruction, and 3 developed grade C anastomotic leaks that required reoperation for salvage enterostomy. The overall incidence of anastomotic leakage was 3.0% (6/198). Fifty-three patients (26.8%) received protective ileostomy, with an anastomotic leak incidence of 1.9% (1/53). Methylene blue leakage occurred in 20 patients (10.1%), all of whom received prophylactic ileostomy and had no anastomotic leakage postoperatively. Among 61 patients who received neoadjuvant chemoradiotherapy before surgery, 28 underwent prophylactic ileostomy, and none developed anastomotic leaks after surgery.Conclusions:Routine application of the PST technique during laparoscopic low anterior resection, along with prophylactic enterostomy for ultra-high-risk populations, can effectively control the incidence of anastomotic leakage.

Objective To conduct microbiological monitoring before the operation of the purified water treatment system in a newly-built endoscopy center,comprehensively analyze the causes for the standard-exceeding results of microbial detection of final rinse water,propose solutions,and provide reference for handling similar events in the future.Methods Microbial detection data of the final rinse water in the newly-built digestive endoscopy center of a tertiary first-class general hospital in Beijing from April to July 2024 were monitored.The potential causes for standard-exceeding results of microbial detection of final rinse water were analyzed from the perspectives of equip-ment maintenance and management of the purified water treatment system as well as the improvement of cleaning and disinfection methods for the purified water supply pipeline in the endoscopy center,targeted improvement mea-sures were proposed accordingly.Results The microbial monitoring result of final rinse water in the newly-built di-gestive endoscopy center built in April 2024 was 1 400 CFU/100 mL,with the main bacterial type being Cupriavi-duspauculus.After five rounds of improvement measures and rechecks,microbial monitoring result of the final rinse water in the newly-built endoscopy center was 0 CFU/100 mL,with a qualification rate of 100％.Analysis suggested that the main causes for the standard-exceeding results of microbial detection of final rinse water were due to the damage of the reverse osmosis membrane,lack of cleaning for the pure water storage tank before use,and non-standard cleaning and disinfection process for the pure water supply pipeline,after targeted improvement,the problem was solved.Conclusion Medical institutions should continuously conduct periodic monitoring on water used for endoscope,regularly perform cleaning and disinfection of the purified water treatment system,standardize cleaning and disinfection procedures,ensure medical quality and patient safety.

Objective:This study evaluated the efficacy of the PST technique: Preservation of the left colic artery (P), suture reinforcement (S), and transanal tube (T) combined with selective fecal diversion via end ileostomy, in preventing anastomotic leakage following laparoscopic anterior resection (LAR) for mid-to-low rectal cancer.Methods:We retrospectively collected data for this descriptive case series from patients who underwent laparoscopic LAR with complete or partial application of the PST technique, some of whom received prophylactic ileostomy, at the Department of Colorectal Surgery, Zhongshan Hospital Affiliated to Fudan University, and its Xiamen Branch between July, 2022 and December, 2024. "Partial PST" was defined as the implementation of PS (Preservation of the left colic artery + suture reinforcement), PT (Preservation of the left colic artery + transanal tube), ST (suture reinforcement + transanal tube), or a single T procedure (Transanal tube). The primary outcome measures were the proportion of patients who received the PST technique and terminal ileostomy, as well as the incidence of anastomotic leaks.Results:Among 198 patients, 145 received complete PST. Fifty-three patients underwent partial PST (PT) because anastomotic reinforcement was not feasible due to an excessively low anastomosis or obesity. All patients achieved R0 resection. Postoperative pathology showed that 108 patients (54.5%) were at T3-T4 stage, and 81 patients (40.9%) had poorly differentiated adenocarcinoma or mucinous adenocarcinoma. A total of 19.7% (39/198) of patients developed grade II or higher postoperative complications, including 11 cases (5.6%) of surgical site infection and 7 cases (3.5%) of urinary retention. Five patients were rehospitalized within 30 days after surgery, among whom 2 had intestinal obstruction, and 3 developed grade C anastomotic leaks that required reoperation for salvage enterostomy. The overall incidence of anastomotic leakage was 3.0% (6/198). Fifty-three patients (26.8%) received protective ileostomy, with an anastomotic leak incidence of 1.9% (1/53). Methylene blue leakage occurred in 20 patients (10.1%), all of whom received prophylactic ileostomy and had no anastomotic leakage postoperatively. Among 61 patients who received neoadjuvant chemoradiotherapy before surgery, 28 underwent prophylactic ileostomy, and none developed anastomotic leaks after surgery.Conclusions:Routine application of the PST technique during laparoscopic low anterior resection, along with prophylactic enterostomy for ultra-high-risk populations, can effectively control the incidence of anastomotic leakage.

Objective:To compare the efficacy of arthroscopic figure-of-eight transtibial tension-reducing technique combined with interference screw fixation versus interface screw fixation alone in the treatment of anterior cruciate ligament (ACL) rupture.Methods:A retrospective cohort study was conducted to analyze the clinical data of 43 patients with ACL rupture admitted to Taihe Hospital between January 2022 and October 2023, including 24 males and 19 females, aged 17-61 years [(38.0±12.6)years]. Based on the tibial fixation method, 20 patients were treated with interference screw fixation alone (interference screw group) and 23 patients with figure-of-eight transtibial tension-reduction technique combined with interference screw fixation (figure-of-eight tension-reduction combined with interference screw group). An Endobutton suspension plate was used in femoral fixation in both groups. The following parameters were compared between the two groups: operative duration and graft diameter; coronal and sagittal tibial tunnel measurements by MRI within 72 hours postoperatively and at the last follow-up; knee range of motion, visual analogue scale (VAS) scores, International Knee Documentation Committee (IKDC) scores, and Lysholm scores preoperatively, at 1 month postoperatively, and at the last follow-up; perioperative complication rates.Results:All the patients were followed up for 11-28 months [(14.1±3.4)months]. There were no significant differences in operative duration or graft diameter between the two groups ( P>0.05). No significant differences were observed in coronal or sagittal tibial tunnel measurements between the two groups within 72 hours postoperatively ( P>0.05). Whereas at the last follow-up, the coronal and sagittal tibial tunnel measurements in the figure-of-eight tension-reduction combined with interference screw group were (11.6±0.7)mm and (11.7±1.1)mm, significantly lower than (13.5±0.6)mm and (13.4±1.9)mm in the interference screw group ( P<0.01). Preoperative knee range of motion, IKDC scores, Lysholm scores, and VAS scores showed no significant differences between the two groups ( P>0.05). At 1 month postoperatively and at the last follow-up, the figure-of-eight tension-reduction combined with interference screw group demonstrated significantly greater knee range of motion [100.0(95.0, 100.0)° and 130.0(120.0, 135.0)°], compared with 72.5(60.0, 95.0)° and 120.0(105.0, 133.3)° in the interference screw group ( P<0.05). VAS scores at 1 month postoperatively and at the last follow-up were 2.0(2.0, 2.0)]points and 1.0(1.0, 1.0)points in the figure-of-eight tension-reduction combined with interference screw group, significantly lower than 3.0(2.3, 4.0)points and 2.0(1.0, 2.0)points in the interference screw group ( P<0.05). IKDC scores at 1 month postoperatively and at the last follow-up were (58.8±5.7)points and (72.4±6.7)points in the figure-of-eight tension-reduction combined with interference screw group, significantly higher than (51.1±5.2)points and (67.4±7.9)points in the interference screw group ( P<0.05). Lysholm scores at 1 month postoperatively and at the last follow-up were (58.9±12.7)points and (89.1±6.0)points in the figure-of-eight tension-reduction combined with interference screw group, significantly higher than (41.2±15.0)points and (78.3±12.3)points in the interference screw group ( P<0.05). No perioperative complications were observed in either group. Conclusion:Compared with interface screw fixation alone, arthroscopic figure-of-eight transtibial tension-reduction technique combined with interference screw fixation for ACL rupture can enhance graft stability, restore knee joint range of motion, alleviate pain, and improve knee function recovery.

Objective:To investigate a surgical method and clinical outcomes of a fascia pedicled island flap with dorsal branch of proper palmar digital nerve in reconstruction of defects of digital pulp.Methods:Seventy-five patients who had digital pulp defects and treated at Department of Orthopaedics, Xinjiang Production and Construction Corps Alar Hospital, Shaw Hospital Affiliated Zhejiang University School of Medicine, from December 2019 to December 2022, were retrospectively analysed. The patients were 40 males and 35 females aged 25-61 years with an average age of 42 years. The defects of digital pulp involved in 23 thumbs, 15 per group of index fingers, middle fingers and ring fingers, and 7 little fingers. The digital pulp defects were 0.8 cm×0.9 cm to 1.5 cm×2.1 cm in size, and the sizes of flap were 1.0 cm×1.2 cm to 1.8 cm×2.4 cm. Donor sites were covered by medium-thickness skin grafts and pressurised bandage was applied. Clinical outcomes of the surgery were monitored through the postoperative follow-ups at outpatient clinic, WeChat and telephone reviews.Results:Postoperative follow-up ranged 9 to 15 months, with an average of 12 months. The donor sites and skin grafts all achieved stage-I healing. Seventy-three flaps completely survived after surgery. However, 2 flaps had partial necrosis, which healed after dressing changes, 4 flaps encountered flap bruising and swelling, which were rectified by removal of high-tension sutures, and 7 flaps had tension blisters, which had disappeared in 2 weeks. At the final follow-up, the appearance and texture of the flaps were graded as excellent for 54 flaps and good for 21 flaps, all without pale, cyanotic or dark in colour. Forty-nine flaps showed normal elasticity or with slight atrophy, 24 with mild atrophy, 2 with moderate atrophy and none with obvious or severe atrophy. Mobility of the affected digits was rated as excellent for 57 digits (average 42.3°), good for 12 (average 26.7°) and fair in 6 digits (average 16.3°). TPD of flap surfaces ranged 6 to 11 mm, with an average of 8.1 mm. Digital function were evaluated according to the Evaluation Trial Standards of Upper Limb Partial Functional of Hand Surgery of Chinese Medical Association, with 48 digits in excellent (average 11.2 points), 22 in good (average 8.1 points) and 5 in fair (average 5.4 points) and with a combined excellence and good rates of 93.33%. All flap donor sites were in normal function. For patient satisfaction: 53 patients were well satisfied, 21 were fairly satisfied and 1 was dissatisfied.Conclusion:Application of the island flap with dorsal branch of proper palmar digital nerve with fascio-pedicled in reconstruction of the defect of digital pulp has a high survival rate, simple surgical operation, good satisfactory outcome, with the digital artery being remained intact.