Objective : To investigate the effect and mechanism of silencing circFADS2 on ferroptosis in colorectal cancer (CRC) cells . Methods: The human colon adenocarcinoma cell line SW480 was used as the research ob- ject. circFADS2 siRNA interference plasmid (si-circFADS2) and its negative control si-NC , miR-152-3p inhibitor and its negative control inhibitor-NC , miR-152-3p mimics and its negative control mimics NC , SLC7A11 overex- pression plasmid (oe-SLC7A11) and its negative control vector were transfected into SW480 cells . Methylthiazolyl- diphenyl-tetrazolium bromide (MTT) method was used to detect cell proliferation activity; The contents of ferrous ion (Fe2 + ) , malondialdehyde (MDA) and the activities of superoxide dismutase (SOD) and glutathione (GSH) in cells were detected by chemical method . Dichlorodihydrofluorescein diacetate ( DCFH-DA) probe was used to detect the level of reactive oxygen species ( ROS) in cells . Quantitative Real-time polymerase chain reaction (qPCR) was used to detect the expression levels of miR-152-3p and SLC7A11 mRNA in cells . Western blot was used to detect the expression levels of ferroptosis-related proteins such as SLC7A11 and GPX4 in cells . Dual lucif- erase reporter gene experiment was used to verify the sponge adsorption relationship between miR-152-3p and circFADS2 , and the targeted regulation relationship between miR-152-3p and SLC7A11 . Results : Compared with blank group , the proliferation activity of si-circFADS2 group decreased , the levels of Fe2 + , MDA and ROS in- creased , and the levels of SOD and GSH decreased; At the same time , the expression level of miR-152-3p in- creased , and the protein expression levels of SLC7A11 and GPX4 decreased in cells ( all P < 0. 05) . Compared with si-circFADS2 group , the proliferation activity of si-circFADS2 + inhibitor group increased , the levels of Fe2 + , MDA and ROS in cells decreased , and the levels of SOD and GSH increased; At the same time , the expression level of miR-152-3p decreased , and the protein expression levels of SLC7A11 and GPX4 increased (all P < 0. 05) . The results of dual luciferase reporter gene experiment showed that SLC7A11 was a downstream target gene of miR- 152-3p . Conclusion Silencing circFADS2 can induce ferroptosis in CRC cells possibly by targeting the miR-152 - 3p/SLC7A11 signaling axis .

Objective:To explore the value of serum activin A (ACT-A) level in early identification of moderate and severe acute pancreatitis (AP).Methods:A prospective case control study was conducted. A total of 120 patients with AP admitted to department of hepatobiliary surgery of Affiliated Nanhua Hospital of Hengyang Medical College of University of South China between October 2020 and April 2022 were recruited. According to the revised Atlanta classification, all patients were classified into mild AP group and moderate-to-severe AP group. The blood samples within 24 hours of onset were drawn, and the serum ACT-A and C-reactive protein (CRP) levels were detected by enzyme-linked immunosorbent assay (ELISA). The Ranson score and the modified CT severity index (MCTSI) were performed. Pearson correlation method was used to analyze the correlation of various parameters. The receiver operator characteristic curve (ROC curve) was plotted to analyze the predictive value of ACT-A and CRP for moderate-to-severe AP.Results:A total of 120 patients with AP were enrolled, including 83 patients with mild AP and 37 patients with moderate-to-severe AP. Serum ACT-A and CRP levels within 24 hours of onset in the moderate-to-severe AP group were significantly higher than those in the mild AP group [ACT-A (ng/L): 140.4±37.7 vs. 53.9±30.5, lg CRP: 1.42±0.91 vs. 0.77±0.70, both P < 0.01], and the Ranson score and MCTSI score were also significantly higher than those in the mild AP group (Ranson score: 5.3±1.3 vs. 1.8±1.6, MCTSI score: 5.5±1.0 vs. 2.7±1.2, both P < 0.01). Correlation analysis showed that the serum ACT-A level was positively correlated with serum CRP level, Ranson score and MCTSI score ( R2 value was 0.272, 0.841, 0.616, respectively, all P < 0.05). ROC curve analysis showed that the serum ACT-A, CRP and Ranson score had predictive value for moderate-to-severe AP. The area under the ROC curve (AUC) was 0.948 [95% confidence interval (95% CI) was 0.909-0.986], 0.711 (95% CI was 0.606-0.815), 0.946 (95% CI was 0.910-0.982), respectively. When serum ACT-A > 112.6 ng/L, the sensitivity and specificity of predicting moderate-to-severe AP were 78.38% and 96.39%, respectively, which was better than serum CRP with sensitivity and specificity of 72.92% and 66.27%, respectively, and the specificity was better than Ranson score (71.08%). Conclusion:ACT-A can be detected in the early stage of AP, and it is positively correlated with the disease severity, which can early identify moderate-to-severe AP.

Objective To study the radiation-induced mitochondrial damage and energy metabolic alteration in pancreatic exocrine cells,and to explore underlying mechanism.Methods Rat pancreatic exocrine cells (AR42 J) were divided into control group and experimental group irradiated with 6 Gy of X-rays.Mitochondrial membrane potential was detected at 24,48,72 and 96 h,the lactic acid and ATP production were detected at 24 h and 48 h,and reactive oxygen species (ROS) were detected at 24 h after irradiation.The expressions of energy metabolism related factors of HIF-1α,LDHA and PDH were detected by Western blot.The animal experiments were conducted to confirm the changes.According to random number table,eight rats were randomly divided into two groups with 4 rats in each.The irradiated group was exposed to 12 Gy of X-rays,while the control group sham-irradiated.Results Compared with the nonirradiated control group,the mitochondrial membrane potential (△Ψm) of the experimental group was progressively decreased at 24-96 h after irradiation (t =5.438-17.687,P＜0.05).The ATP content in the experimental group decreased at 24 h and 48 h (q=17.300,8.328,P＜0.05),the lactic acid increased (q =21.790,16.250,P＜0.05),and the ROS level increased (t =7.935,P＜0.05).The expressions of HIF-1α and LDHA were significantly increased,but PDH was reduced after radiation.Silencing HIF-1α by siRNA eliminated radiation-induced energy metabolic alteration.These changes were confirmed with animal experiments by locally irradiating rats.Conclusions The expression of HIF-1α is upregulated by irradiation,which leads to the change of energy metabolism as the enhancement of glycolysis pathway and the inhibition of aerobic oxidation of mitochondria in pancreatic exocrine cells.

Objective To investigate the expression of E-cadherin and Snail proteins in rectal cancer and their significance. Methods The expression of Snail and E-cadherin proteins was detected using immunohistochemical SABC method in 101 cases of rectal cancer tissues. Results The positive rate of Snail in rectal cancer was 78.2% (79/101). The negative expression rate of E-cadherin in rectal cancer was 62.4% (63/101). The expression of Snail and E-cadherin were significantly related with the lymph node metastasis and Dukes' stage of rectal cancer (P ＜ 0.05). Conclusion The overexpression of Snail and the decreased expression of E-cadherin might be important biological markers for malignant transformation, invasion and metastasis of rectal carcinoma.

OBJECTIVE:To explore the changes of serum phenytoin levels and its pharmacokinetics in menstrual epilepsy.METHODS:9cases of menstrual epilepsy patients who were treated with phenytoin were collected,whose blood concentra?tions of phenytoin in menstrual period and ovulation period were respectively determined by HPLC,pharmacokinetics study was performed in three of them.RESULTS:The mean serum phenytoin levels in menstrual period and ovulation period were(9.25?2.71)?g/ml and(13.33?3.22)?g/ml,respectively(P