To explore whether aberrant methylation in the promoter of p16 gene was associated with development and clinicopathological characteristics of colorectal cancer. Methylation-specific PCR(MSP) was used to detect hypermethylation of p16 gene in tumor tissues obtained from 32 patients with colorectal cancer. The results showed that the hypermethylation of p16 promoter was detected in 40.6% of tumor tissues. p16 hypermethylation in patients with Dukes stages of C and D tumors (63%) was higher than that in the stages of A and B tumors (25%). The highly and intermediately differentiated carcinomas had lower positive rate (30%) than the poorly differentiated carcinoma. Furthermore, the hypermethylation of p16 gene in tumor tissue from patients with the lymph node metastasis was different from that without lymph node metastasis (P

Objective To explore whether hypermethylation in the promoter of p16 gene and protein of p16 were associated with development and clinicopathological characteristics of colorectal cancer. Methods Methylation-specific PCR ( MSP) and immunohistochemistry SP were used to detected hypermethylation of p16 gene and p16 protein in tumor tissues from 32 patients with colorectal cancer. Results The hypermethylation of p16 gene was detected in 40. 6% of tumor tissues. The protein of p16 promoter was detected in 75% of tumor tissues. The hypermethylation of p16 gene was detected in 63% in Dukes stages of C and D tumors. The protein of p16 promoter was detected in 69% of tumor tissues. The hypermethylation of p16 gene was detected in 25% in the stages of A and B tumors. The protein of p16 promoter was detected in 81% of tumor tissues. The hpermethylation of p16 gene was detected in 100% in low differentiated carcinomas. The protein of p16 promoter was detected in 20% , the hypermethylation of p16 gene was detected in 30% , in the high and mediate differentiated carcinomas, the protein of p16 promoter was detected in 85%. Furthermore, the hypermethylation of p16 gene was detected in 63% in the lymph node metastasis and 25% in without lymph node metastasis. The protein of p16 promoter was detected in 65% in rectum and 100% in colon. Conclusions Our study demonstrated that p16 hypermethylation and protein were associated with the development of colorectal cancer and could be used as a putative prognostic indicator for this malignancy.

Objective:To investigate the related factors that affect the timing and prognosis of early tracheostomy in patients with multiple rib fractures.Methods:A retrospective case series study was conducted on medical data of 222 patients with multiple rib fractures who underwent tracheostomy in Affiliated Hospital of Yangzhou University from February 2013 to October 2019，including 160 males and 66 females，with the age of 18 to 85 years ［（49.5 ± 16.3）years］. According to the practice management guidelines for tracheostomy timing and the use of propensity score matching technology，there were 118 patients with tracheostomy within 7 days of tracheal intubation （early group） and 104 patients with tracheostomy after 7 days of tracheal intubation （late group） before matching，and there were 87 patients in early group and 87 patients in late group after matching. Data were compared between groups including the gender，age，underlying disease，injury severity score （ISS），Glasgow coma score （GCS），number of fractured ribs，total number of rib fractures （NTRF），first rib fracture，flail chest，traumatic brain injury，combined injuries （spine，maxillofacial，sternum），acute respiratory distress syndrome （ARDS），volume fraction of pulmonary contusion（VPC），blood lactic acid （within 24 hours of admission），hemothorax，pneumothorax，mechanical ventilation time，duration of tracheostomy，time from tracheal intubation to incision，length of hospital stay，length of stay in ICU，closed thoracic drainage，number of fiberoptic bronchoscopy，multi-drug resistant bacteria infection，ventilator-associated pneumonia，antibiotic use time，duration of sedative and analgesic drugs used and 28-day mortality. The multivariate Logistic regression analysis was used to predict independent risk factors for early tracheostomy. The Pearson method was used to compare the relationship between multiple factors. The receiver operating characteristic （ROC） curve was used to predict indicators that affect the prognosis of patients with early tracheostomy，and calculate the best cut-off value. The Kaplan-Meier single factor and COX multivariate survival were used to analyze the relevant factors affecting the 28-day mortality of patients.Results:（1） In early group，the NTRF，ARDS and VPC were higher than those in late group，and the time from tracheal intubation to incision and 28-day mortality rate were lower than those in late group （ P < 0.05），while the two groups showed no significant differences in the gender，age，underlying diseases and ISS （ P > 0.05）. （2） The multivariate Logistic regression analysis showed that there was statistical significance in NTRF （ OR = 1.775，95% CI 1.439-2.188），ARDS（ OR = 3.740，95% CI 1.441-9.711），VPC （ OR = 1.087，95% CI 1.052-1.124） （ P < 0.05）； the Pearson method analysis showed a significant correlation between VPC and NTRF （ r = 0.369， P < 0.05） and a low degree of correlation between ARDS and VPC （ r = 0.179， P < 0.05），but there was no significant correlation between ARDS and NTRF （ r = 0.132， P > 0.05）. （3） The ROC curve analysis showed that the area under the curve （AUC） of the VPC and NTRF ［AUC = 0.832 （95% CI 0.770-0.893），AUC = 0.804 （95% CI 0.740-0.868）］ were significantly higher than those of the number of rib fractures ［AUC = 0.437（95% CI 0.352-0.523），GCS ［AUC = 0.519 （95% CI 0.432-0.605）］ and ISS ［AUC = 0.484 （95% CI 0.398-0.571）］ （ P < 0.05）. After calculating the Yorden index，the best cut-off value for VPC was 23.9，and the best cut-off value for NTRF was 8.5. （4） The Kaplan-Meier single factor and multivariate COX model survival analysis showed that the 28-day survival ratio of patients with early tracheostomy was significantly better than that of late tracheostomy （ P < 0.05）. Conclusions:The NTRF，ADRS and VPC are independent risk factors for the timing and prognosis of early tracheostomy. There is a significant correlation between VPC and NTRF. The VPC ≥ 23.9% and or NTRF ≥ 8.5 can be used to predict early tracheostomy in patients with multiple rib fractures. Early tracheostomy may benefit the 28-day survival of patients with multiple rib fractures.

Gene editing technology is a genetic operation technology that can modify the DNA sequence at the genomic level. The precision gene editing technology based on CRISPR/Cas9 system is a gene editing technology that is easy to operate and widely used. Unlike the traditional CRISPR/Cas9 system, the precision gene editing technology can perform site-directed mutation of genes without DNA template. This review summarizes the recent development of precision gene editing technology based on CRISPR/Cas9, and prospects the challenges and opportunities of this technology.
Gene Editing ; CRISPR-Cas Systems/genetics* ; Mutation ; Genome