Objective To observe the phosphorylation of extraceUular signal-regulated kinase (p-ERK1/2) and its nuclear translocation at different time points after the hippocampal neurons were cul-tured in the magnesium-free medium, and discuss the changes of ERK1/2 signal pathway after epileptic injury of hippocampal neurons. Methods Hippocampal neurons from newly-born Wistar rats were cul-tured with NB medium and B-27 for 9 days, and then were transferred to the magnesium-free medium to induce epileptic injury to the hippocampal neurons. The distribution of p-ERK1/2 in the hippocampal neurons before and after the epileptic injury was observed under laser scanning confocal microscope, and the expression of p-ERK1/2 at different time points after culturing the hippocampal neurons in the magne-sium-free medium was detected by Western blot. Results Before the epileptic injury of hippocampal neurons, p-ERK1/2 mainly expressed in the cytoplasm and axoplasm of the neurons. While after the epi-leptic injury, the expression of p-ERK1/2 was detected in the cytoplasm, axoplasm and nucleus of the neurons. The expression of p-ERK1/2 was increased one hour after the epileptic injury, and peaked at hour 3 (p-ERK1:2.2838±0.1 186; p-ERK2:4.1 273±0.0 927). There was significant difference in the expression of p-ERK1/2 between the hippocampal neurons cultured with or without magnesium-free medium (P < 0.05). Conclusion Epileptic injury may induce increased expression of p-ERK1/2 in hippocampal neurons, and the activated ERK1/2 signal pathway may be associated with the epileptic dis-charge in neurons.

OBJECTIVETo explore the factors affecting the operative difficulty of triple-port laparoscopic surgery (TLS) in anterior resection.

METHODSA retrospective case-control study was carried out. Clinical and MRI imaging data of 106 colorectal cancer cases undergoing TLS anterior resection at Department of Colorectal Surgery of Ruijin Hospital between 2013 and 2016 were retrospectively analyzed.

INCLUSION CRITERIA(1) patients receiving TLS anterior resection (Dixon operation); (2) preoperative stageI( to III( malignant tumor;(3) distance of 5-15 cm from inferior margin of tumor to anal verge; and (4) available preoperative rectal MRI.

EXCLUSION CRITERIA(1) patients receiving preoperative adjuvant therapy; (2) patients with low rectal cancer or with local advanced disease; (3) T4b tumor. Rectal MRI was introduced to measure the structure of pelvis. In sagittal view, superior margin of the first sacral vertebrae, superior margin of the third sacral vertebrae, apex of coccyx, and the line of superior margin of pubic symphysis were used to form a pentagon. The 5 lines were marked as N, O, P, Q, R, and the 5 included angles were marked as angle 1, 2, 3, 4, 5. Organs (uterus and prostate) and tumor (transverse diameter, longitudinal diameter, section area, lesion length, distance to circumference cutting edge) were also measured on MRI. The operative time was applied to be the indicator of operative difficulty and patients were divided into 2 groups according to median operative time. Baseline information (age, gender, BMI, distance from inferior margin of tumor to anal verge, operative history, length of tumor), preoperative tumor staging, and MRI measurements (pelvis, tumor, uterus, prostate), etc were compared between two groups. Factors affecting operative difficulty of TLS were analyzed with logistic regression model.

RESULTSOf 106 enrolled patients, 73 were male and 33 female with mean age of (59.8±12.2) years and mean BMI of (22.8±3.3) kg/m; 25 patients had previous abdominal surgery; distance from inferior margin of tumor to anal verge was (7.4±2.0) cm and the tumor diameter was (3.7±1.4) cm; 24, 36 and 46 patients were in stage I(, II( and III( respectively. All operations were completed successfully. The median number of harvested lymph node was 13(11-16); the median length of distal resection margin was 2.5(2.0-3.1) cm; the median operative time was 2.0(1.5-2.6) hours; the median intraoperative blood loss was 50(0-100) ml; the median time to liquid diet was 4(3-5) days; the median hospital stay was 7(6-10) days. Ten cases (9.4%) developed complications within 30 days after surgery. Patients were divided into ≤2 h group and > 2 h group according to median operative time, and both groups had 53 patients. As compared to ≤2 h group, >2 h group had shorter distance from inferior margin of tumor to anal verge [(6.8 ± 1.5) cm vs. (8.0 ± 2.4) cm, t = 3.174, P = 0.004], lower ratio of (R+N)/(O+P)(1.61±0.27 vs. 1.73±0.19, t = 2.494, P = 0.014), larger transverse distance of tumor [(3.45±0.72) cm vs. (3.05±0.89) cm, t = 0.224, P = 0.027]. Multivariate logistic regression analysis showed the distance from inferior margin of tumor to anal verge was the independent factor affecting operative difficulty(OR=0.584, 95%CI:0.429-0.796, P = 0.001).

CONCLUSIONSSurgeons may have less difficulty in performing TLS anterior resection for patients with longer distance from inferior margin of tumor to anal verge. In preoperative assessment of operative difficulty of TLS, comprehensive evaluation should be performed. Distance from inferior margin of tumor to anal verge should be regarded as the main factor, and MRI (R+N)/(O+P) and transverse diameter of tumor should be used as important reference, leading to reasonable choice of cases for TLS and smooth pass of study curve.

Aged ; Anal Canal ; Case-Control Studies ; Female ; Humans ; Laparoscopy ; methods ; Male ; Middle Aged ; Rectal Neoplasms ; diagnostic imaging ; surgery ; Retrospective Studies ; Treatment Outcome