Objective:To construct the gemcitabine resistant cell lines of human pancreatic cancer cell line (PANC1) and mouse pancreatic cancer cell line (PANC02), and to investigate their biological behavior changes.Methods:Gemcitabine-resistant cell lines PANC1-GR of human pancreatic cancer and PANC02-GR of mouse pancreatic cancer were induced by concentration gradient increment method. Cell count assay (CCK-8), flow cytometry, cell scratch assay and Transwell assay were used to detect the drug resistance, proliferation, cell cycle, migration and invasion of the four groups of cell lines. The drug-resistant cells were also compared with the parent cells.Results:The resistance indices of PANC1-GR and PANC02-GR were 153.3 and 185.4, respectively. The results of CCK-8 showed that with the increase of gemcitabine concentration, the proliferation of resistant cells changed significantly compared with parental cells, the population doubling time of PANC1-GR was significantly shorter than that of PANC1 (1.5±0.1) d vs (2.4±0.2) d ( t=8.00, P<0.001). The proportion of cells in S and G2/M phase increased, and the proportion of cells in G0/G1 phase decreased. The cell scratch and Transwell experiments indicated that the 24h mobility of PANC1-GR and PANC02-GR was higher than that of parent cells (47.6±2.4)% vs (28.7±6.3)% and (53.6±3.2)% vs (30.1±1.4)%, the number of individual field (200 times magnification) penetrating membrane cells was also higher than that of parent cells (269.7±30.9) vs (62.7±10.1) and (172.0±30.8) vs (36.3±4.9), with statistical significance (all P<0.05). Conclusion:Concentration gradient increment method can successfully establish gemcitabine-resistant pancreatic cancer cell lines, which have stronger proliferation, migration and invasiveness, and can be used to study the mechanism of drug resistance in pancreatic cancer.

Objective:To construct the gemcitabine resistant cell lines of human pancreatic cancer cell line (PANC1) and mouse pancreatic cancer cell line (PANC02), and to investigate their biological behavior changes.Methods:Gemcitabine-resistant cell lines PANC1-GR of human pancreatic cancer and PANC02-GR of mouse pancreatic cancer were induced by concentration gradient increment method. Cell count assay (CCK-8), flow cytometry, cell scratch assay and Transwell assay were used to detect the drug resistance, proliferation, cell cycle, migration and invasion of the four groups of cell lines. The drug-resistant cells were also compared with the parent cells.Results:The resistance indices of PANC1-GR and PANC02-GR were 153.3 and 185.4, respectively. The results of CCK-8 showed that with the increase of gemcitabine concentration, the proliferation of resistant cells changed significantly compared with parental cells, the population doubling time of PANC1-GR was significantly shorter than that of PANC1 (1.5±0.1) d vs (2.4±0.2) d ( t=8.00, P<0.001). The proportion of cells in S and G2/M phase increased, and the proportion of cells in G0/G1 phase decreased. The cell scratch and Transwell experiments indicated that the 24h mobility of PANC1-GR and PANC02-GR was higher than that of parent cells (47.6±2.4)% vs (28.7±6.3)% and (53.6±3.2)% vs (30.1±1.4)%, the number of individual field (200 times magnification) penetrating membrane cells was also higher than that of parent cells (269.7±30.9) vs (62.7±10.1) and (172.0±30.8) vs (36.3±4.9), with statistical significance (all P<0.05). Conclusion:Concentration gradient increment method can successfully establish gemcitabine-resistant pancreatic cancer cell lines, which have stronger proliferation, migration and invasiveness, and can be used to study the mechanism of drug resistance in pancreatic cancer.

Objective The CRISPR/Cas9 system was utilized to generate an Apoe knockout mice model to support further investigations of the role of Apoe in lipid metabolism and atherosclerosis.Methods Two single guide RNAs designed for Apoe in C57BL/6J mice were co-injected with Cas9 mRNA into fertilized eggs,followed by transplantation into ICR recipient mice to obtain F0 generation mice.KO mice were identified by polymerase chain reaction(PCR)screening of tail DNA.Apoe mRNA expression in various tissues was assessed by quantitative real-time PCR and lipid indexes were measured in serum samples.Lipid accumulation in the inner lining of aortic vessels was detected by oil red O staining.Results PCR and sequencing confirmed the successful construction of Apoe KO mice(C57BL/6-Apoeem1/Nifdc).Apoe mRNA levels were significantly reduced in the liver,brain,spleen,kidney,and lung tissues of Apoe KO homozygous mice(Apoe-/-),as shown by reverse transcription quantitative real-time PCR.Serum total cholesterol and low-density lipoprotein cholesterol levels were increased in Apoe-/-mice,and high-density lipoprotein cholesterol levels were decreased in male Apoe-/-mice.Extensive lipid plaques were observed in the inner lining of the arteries in Apoe-/-mice compared with WT mice,under normal chow consumption conditions.Conclusions This study successfully established an Apoe KO mice model exhibiting a typical abnormal lipid metabolism phenotype with arterial lipid accumulation,even without a high-fat diet intervention.This work provides background data for the Apoe KO mice resource and a new model for the study of abnormal lipid metabolism.

Vitiligo is an acquired depigmented disease, and neurological factors may play an important role in its pathogenesis. Neurogenic inflammatory factors released by sensory nerves that control the skin can directly or indirectly regulate functions of keratinocytes, melanocytes, Langerhans cells, dermal dendritic cells, mast cells, dermal microvascular endothelial cells and immune cells. This review summarizes roles of several relevant neurogenic inflammatory factors in the occurrence and development of vitiligo, including neuropeptide Y, calcitonin gene-related peptide, catecholamines and nerve growth factor, with a view to providing new ideas for clinical treatment of vitiligo.

Objective The CRISPR/Cas9 system was utilized to generate an Apoe knockout mice model to support further investigations of the role of Apoe in lipid metabolism and atherosclerosis.Methods Two single guide RNAs designed for Apoe in C57BL/6J mice were co-injected with Cas9 mRNA into fertilized eggs,followed by transplantation into ICR recipient mice to obtain F0 generation mice.KO mice were identified by polymerase chain reaction(PCR)screening of tail DNA.Apoe mRNA expression in various tissues was assessed by quantitative real-time PCR and lipid indexes were measured in serum samples.Lipid accumulation in the inner lining of aortic vessels was detected by oil red O staining.Results PCR and sequencing confirmed the successful construction of Apoe KO mice(C57BL/6-Apoeem1/Nifdc).Apoe mRNA levels were significantly reduced in the liver,brain,spleen,kidney,and lung tissues of Apoe KO homozygous mice(Apoe-/-),as shown by reverse transcription quantitative real-time PCR.Serum total cholesterol and low-density lipoprotein cholesterol levels were increased in Apoe-/-mice,and high-density lipoprotein cholesterol levels were decreased in male Apoe-/-mice.Extensive lipid plaques were observed in the inner lining of the arteries in Apoe-/-mice compared with WT mice,under normal chow consumption conditions.Conclusions This study successfully established an Apoe KO mice model exhibiting a typical abnormal lipid metabolism phenotype with arterial lipid accumulation,even without a high-fat diet intervention.This work provides background data for the Apoe KO mice resource and a new model for the study of abnormal lipid metabolism.

Objective:To investigate the effects of compound fermented milk on intestinal microbiota, short chain fatty acid (SCFA), intestinal motility and mucosal barrier in mice with constipation.Methods:Twenty-seven C57BL/6JNifdc mice were randomly divided into three groups: control group, model group and intervention group. The model group and the intervention group were given loperamide intragastrically for two weeks. Starting from the second week, the intervention group was treated with compound fermented milk for 7 d. The control group was given normal saline. Food intake, water intake, weight change, fecal moisture content, time of first-time black stool and small intestine propulsion rate were detected. Expression of serotonin C receptor (5-HTR2C), zona occludins-1 (ZO-1) and mucin-2 (MUC-2) at mRNA level in colon was analyzed. Western blot was used to measure the expression of Raf/ERK/MAPK-related proteins. SCFA level in intestinal tract was detected by gas chromatography. Intestinal microbiota diversity was analyzed by high-throughput sequencing.Results:Compared with the control group, the first black stool excretion time was significantly prolonged in the model group ( P<0.01). Moreover, fecal moisture content, small intestine propulsion rate and the expression of 5-HTR2C and ZO-1 at mRNA level in colon were significantly decreased ( P<0.01). Compared with the model group, the first black stool excretion time was significantly shortened ( P<0.05); fecal moisture content, small intestine propelling rate ( P<0.05), the expression of colon 5-HTR2C and ZO-1 at mRNA level ( P<0.05), phosphorylation of Raf/ERK/MAPK pathway in the colon, intestinal SCFA-producing bacteria and intestinal SCFA content were increased in the intervention group. Conclusions:Compound fermented milk had a therapeutic effect on constipation in a mouse model by increasing the abundance of SCFA-producing bacteria and SCFA content, enhancing the phosphorylation of the Raf/ERK/MAPK pathway to up-regulate the expression of 5-HTR2C at mRNA level in the colon, and increasing the expression of ZO-1 at mRNA level in the colon. Intestinal peristalsis and intestinal mucosal barrier function were enhanced, thus improving the symptom of constipation.

Objective : In the present study，the changes of left atrial matrix characteristics and the effect of cathe- ter ablation on cardiac function in elderly patients with persistent atrial fibrillation were observed．Furthermore，the application of two catheter ablation methods including circular pulmonary vein isolation combined with left atrial ma- trix modification or left atrial posterior wall isolation were compared by researchers in order to explore effectiveness and safety of the two methods in elderly persistent atrial fibrillation patients． Methods : A total of 86 elderly pa- tients with persistent atrial fibrillation were selected and divided into two groups using randomization principle ; the pulmonary vein isolation combined with left atrial matrix modified catheter ablation method was named matrix modi- fied group (43 cases) ; the pulmonary vein isolation combined with left atrial posterior wall isolation catheter abla- tion method was named posterior wall isolation group (43 cases) ．During ablation left atrial electro matrix mapping were analyzed by multipole catheter for all patients．After ablation all patients were follow-up in 12 months by car- diac color doppler ultrasound examination，ECG and Holter．The incidence of arrhythmia ，serious adverse event and complications were compared between two groups． Successful rate of single ablation and blank period recur- rence after ablation were observed in 12 months follow-up time. Results : Through electrogram mapping of left atri- um low-voltage areas or scar areas were founded in 72 cases among the 86 cases after ablation，After a 12-month follow-up，the incidence of arrhythmia in the blank period between the two groups was 41．9% ( matrix modified group) and 23. 3% (posterior wall isolation group) ，independently，P＜0. 01，successful rates of single ablation in the two groups were 83. 7% (matrix modified group) ，60. 5% (posterior wall isolation group) ，independently， P ＜0. 01 ．No adverse event occurred in the two groups．After AF ablation LVEF increased，LVEDD and LVAD significantly decreased in all of the cases．There was no significant difference between the two groups in patients ’ characters ablation time and complications rate． Conclusion Circular pulmonary vein isolation combined with left atrial matrix modification is as safe as left atrial posterior wall isolation，and it is a simplified，personalized，and more effective ablation strategy in elderly patients with persistent atrial fibrillation.

Objective:To investigate clinical efficacy of narrow-band ultraviolet B (NB-UVB) irradiation around vitiliginous lesions in the treatment of refractory vitiligo.Methods:A total of 126 patients with refractory vitiligo were retrospectively collected from Department of Dermatology, the First Affiliated Hospital of Nanjing Medical University from June 2019 to November 2020. The patients were treated with NB-UVB irradiation around vitiliginous lesions after partial covering (perilesional irradiation group) , or conventional NB-UVB irradiation (conventional irradiation group) , twice a week for 3 consecutive months. After the treatment, the efficacy was evaluated. By using the propensity score method, the lesions in the 2 groups were matched at a ratio of 1∶1. Univariate and multivariate logistic regression analyses and stratified analysis were used to analyze the clinical efficacy of NB-UVB irradiation around vitiliginous lesions in the treatment of refractory vitiligo.Results:Totally, there were 420 skin lesions in the perilesional irradiation group and 257 in the conventional irradiation group, and 190 lesions were enrolled into each group by propensity-score matching. Before and after the matching, the response rates were both significantly higher in the perilesional irradiation group (71.9%, 67.9%, respectively) than in the conventional irradiation group (31.9%, 30.0%, respectively, both P < 0.05) . After the propensity-score matching, both univariate and multivariate logistic regression analyses showed significant differences in the efficacy between the perilesional irradiation group and conventional irradiation group ( OR = 4.9, 95% CI: 3.2, 7.6, P < 0.001; OR = 12.0, 95% CI: 6.5, 22.3, P < 0.001, respectively) . Vitiliginous lesions were classified according to hair types and irradiation methods: before the matching, there were 187 vitiliginous lesions with white hairs treated with the conventional irradiation and 246 treated with the perilesional irradiation, and there were 70 vitiliginous lesions with black hairs treated with the conventional irradiation and 174 treated with the perilesional irradiation; after the matching, 140 vitiliginous lesions with white hairs and 50 with black hairs were enrolled into each radiation group. Stratified analysis showed that the response rates of vitiliginous lesions with white hairs were significantly higher in the perilesional irradiation group (77.6%, 72.8%, respectively) than in the conventional irradiation group before and after the matching (19.3%, 20.7%, respectively, both P < 0.01) ; for the vitiliginous lesions with black hairs, there was no significant difference in the response rate between the 2 groups ( P = 0.908) . Conclusion:The efficacy of NB-UVB irradiation around vitiliginous lesions is superior to the conventional irradiation in the treatment of refractory vitiligo, especially vitiliginous lesions with white hairs.

There published 186 papers in Chinese Journal of Trauma in 2019. The yearly monographic topic was concentrated in spine and spinal cord injuries, involving 54 papers covering basic, clinical and rehabilitative studies. The columns mainly included Forum for Academician, Consensus and Guidelines, Trauma Center Construction, Special Monograph for 70^th Anniversary of the Founding of People's Republic of China, Spine and Spinal Cord Injuries, Posttraumatic Bone Infection, Trauma Nursing and Basically Scientific Research. The authors introduce the key contents so as to help readers deepen their understanding of the publication and academic orientation of the Chinese Journal of Trauma.

There published papers in Chinese Journal of Trauma in 2018.The yearly monographic topic is concentrated in sports injury.The author reviews the main research progress of papers from following aspects:Forum for Academician,Expert Consensus,Innovation and Contention,Military Medicine,Monographic Topic,Trauma Nursing,Basically Scientific Research so as to facilitate the readers' understanding of the journal.